Science.gov

Sample records for absolute concentration determination

  1. Absolute determination of local tropospheric OH concentrations

    NASA Technical Reports Server (NTRS)

    Armerding, Wolfgang; Comes, Franz-Josef

    1994-01-01

    Long path absorption (LPA) according to Lambert Beer's law is a method to determine absolute concentrations of trace gases such as tropospheric OH. We have developed a LPA instrument which is based on a rapid tuning of the light source which is a frequency doubled dye laser. The laser is tuned across two or three OH absorption features around 308 nm with a scanning speed of 0.07 cm(exp -1)/microsecond and a repetition rate of 1.3 kHz. This high scanning speed greatly reduces the fluctuation of the light intensity caused by the atmosphere. To obtain the required high sensitivity the laser output power is additionally made constant and stabilized by an electro-optical modulator. The present sensitivity is of the order of a few times 10(exp 5) OH per cm(exp 3) for an acquisition time of a minute and an absorption path length of only 1200 meters so that a folding of the optical path in a multireflection cell was possible leading to a lateral dimension of the cell of a few meters. This allows local measurements to be made. Tropospheric measurements have been carried out in 1991 resulting in the determination of OH diurnal variation at specific days in late summer. Comparison with model calculations have been made. Interferences are mainly due to SO2 absorption. The problem of OH self generation in the multireflection cell is of minor extent. This could be shown by using different experimental methods. The minimum-maximum signal to noise ratio is about 8 x 10(exp -4) for a single scan. Due to the small size of the absorption cell the realization of an open air laboratory is possible in which by use of an additional UV light source or by additional fluxes of trace gases the chemistry can be changed under controlled conditions allowing kinetic studies of tropospheric photochemistry to be made in open air.

  2. Method for determining the absolute number concentration of nanoparticles from electrospray sources.

    PubMed

    Li, Mingdong; Guha, Suvajyoti; Zangmeister, Rebecca; Tarlov, Michael J; Zachariah, Michael R

    2011-12-20

    We have developed a simple, fast, and accurate method to measure the absolute number concentration of nanoparticles in solution. The method combines electrospray differential mobility analysis (ES-DMA) with a statistical analysis of droplet-induced oligomer formation. A key feature of the method is that it allows determination of the absolute number concentration of particles by knowing only the droplet size generated from a particular ES source, thereby eliminating the need for sample-specific calibration standards or detailed analysis of transport losses. The approach was validated by comparing the total number concentration of monodispersed Au nanoparticles determined by ES-DMA with UV/vis measurements. We also show that this approach is valid for protein molecules by quantifying the absolute number concentration of Rituxan monoclonal antibody in solution. The methodology is applicable for quantification of any electrospray process coupled to an analytical tool that can distinguish monomers from higher order oligomers. The only requirement is that the droplet size distribution be evaluated. For users only interested in implementation of the theory, we provide a section that summarizes the relevant formulas. This method eliminates the need for sample-specific calibration standards or detailed analysis of transport losses.

  3. Determining the Absolute Concentration of Nanoparticles without Calibration Factor by Visualizing the Dynamic Processes of Interfacial Adsorption.

    PubMed

    Wo, Xiang; Li, Zhimin; Jiang, Yingyan; Li, Minghe; Su, Yu-Wen; Wang, Wei; Tao, Nongjian

    2016-02-16

    Previous approaches of determining the molar concentration of nanoparticles often relied on the calibration factors extracted from standard samples or required prior knowledge regarding the geometry, optical, or chemical properties. In the present work, we proposed an absolute quantification method that determined the molar concentration of nano-objects without any calibration factor or prior knowledge. It was realized by monitoring the dynamic adsorption processes of individual nanoparticles with a high-speed surface plasmon resonance microscopy. In this case, diffusing nano-objects stochastically collided onto an adsorption interface and stayed there ("hit-n-stay" scenario), resulting in a semi-infinite diffusion system. The dynamic processes were analyzed with a theoretical model consisting of Fick's laws of diffusion and random-walk assumption. The quantification of molar concentration was achieved on the basis of an analytical expression, which involved only physical constants and experimental parameters. By using spherical polystyrene nanoparticles as a model, the present approach provided a molar concentration with excellent accuracy. PMID:26781326

  4. Absolute concentration measurements inside a jet plume using video digitization

    NASA Astrophysics Data System (ADS)

    Vauquelin, O.

    An experimental system based on digitized video image analysis is used to measure the local value of the concentration inside a plume. Experiments are carried out in a wind-tunnel for a smoke-seeded turbulent jet plume illuminated with a laser beam. Each test is filmed, subsequently video images are digitized and analysed in order to determine the smoke absolute concentration corresponding to each pixel gray level. This non-intrusive measurement technique is first calibrated and different laws connecting gray level to concentration are established. As a first application, concentration measurements are made inside a turbulent jet plume and compared with measurements conducted using a classic gas analysis method. We finally present and discuss the possibilities offered for the measurements of absolute concentration fluctuations.

  5. Under proper control, oxidation of proteins with known chemical structure provides an accurate and absolute method for the determination of their molar concentration.

    PubMed

    Guermant, C; Azarkan, M; Smolders, N; Baeyens-Volant, D; Nijs, M; Paul, C; Brygier, J; Vincentelli, J; Looze, Y

    2000-01-01

    Oxidation at 120 degrees C of inorganic and organic (including amino acids, di- and tripeptides) model compounds by K(2)Cr(2)O(7) in the presence of H(2)SO(4) (mass fraction: 0.572), Ag(2)SO(4) (catalyst), and HgSO(4) results in the quantitative conversion of their C-atoms into CO(2) within 24 h or less. Under these stressed, well-defined conditions, the S-atoms present in cysteine and cystine residues are oxidized into SO(3) while, interestingly, the oxidation states of all the other (including the N-) atoms normally present in a protein do remain quite unchanged. When the chemical structure of a given protein is available, the total number of electrons the protein is able to transfer to K(2)Cr(2)O(7) and thereof, the total number of moles of Cr(3+) ions which the protein is able to generate upon oxidation can be accurately calculated. In such cases, unknown protein molar concentrations can thus be determined through straightforward spectrophotometric measurements of Cr(3+) concentrations. The values of molar absorption coefficients for several well-characterized proteins have been redetermined on this basis and observed to be in excellent agreement with the most precise values reported in the literature, which fully assesses the validity of the method. When applied to highly purified proteins of known chemical structure (more generally of known atomic composition), this method is absolute and accurate (+/-1%). Furthermore, it is well adapted to series measurements since available commercial kits for chemical oxygen demand (COD) measurements can readily be adapted to work under the experimental conditions recommended here for the protein assay. PMID:10610688

  6. MAGSAT: Vector magnetometer absolute sensor alignment determination

    NASA Technical Reports Server (NTRS)

    Acuna, M. H.

    1981-01-01

    A procedure is described for accurately determining the absolute alignment of the magnetic axes of a triaxial magnetometer sensor with respect to an external, fixed, reference coordinate system. The method does not require that the magnetic field vector orientation, as generated by a triaxial calibration coil system, be known to better than a few degrees from its true position, and minimizes the number of positions through which a sensor assembly must be rotated to obtain a solution. Computer simulations show that accuracies of better than 0.4 seconds of arc can be achieved under typical test conditions associated with existing magnetic test facilities. The basic approach is similar in nature to that presented by McPherron and Snare (1978) except that only three sensor positions are required and the system of equations to be solved is considerably simplified. Applications of the method to the case of the MAGSAT Vector Magnetometer are presented and the problems encountered discussed.

  7. Behavior of Multiclass Pesticide Residue Concentrations during the Transformation from Rose Petals to Rose Absolute.

    PubMed

    Tascone, Oriane; Fillâtre, Yoann; Roy, Céline; Meierhenrich, Uwe J

    2015-05-27

    This study investigates the concentrations of 54 multiclass pesticides during the transformation processes from rose petal to concrete and absolute using roses spiked with pesticides as a model. The concentrations of the pesticides were followed during the process of transforming the spiked rose flowers from an organic field into concrete and then into absolute. The rose flowers, the concrete, and the absolute, as well as their transformation intermediates, were analyzed for pesticide content using gas chromatography/tandem mass spectrometry. We observed that all the pesticides were extracted and concentrated in the absolute, with the exception of three molecules: fenthion, fenamiphos, and phorate. Typical pesticides were found to be concentrated by a factor of 100-300 from the rose flowers to the rose absolute. The observed effect of pesticide enrichment was also studied in roses and their extracts from four classically phytosanitary treated fields. Seventeen pesticides were detected in at least one of the extracts. Like the case for the spiked samples in our model, the pesticides present in the rose flowers from Turkey were concentrated in the absolute. Two pesticides, methidathion and chlorpyrifos, were quantified in the rose flowers at approximately 0.01 and 0.01-0.05 mg kg(-1), respectively, depending on the treated field. The concentrations determined for the corresponding rose absolutes were 4.7 mg kg(-1) for methidathion and 0.65-27.25 mg kg(-1) for chlorpyrifos.

  8. Behavior of Multiclass Pesticide Residue Concentrations during the Transformation from Rose Petals to Rose Absolute.

    PubMed

    Tascone, Oriane; Fillâtre, Yoann; Roy, Céline; Meierhenrich, Uwe J

    2015-05-27

    This study investigates the concentrations of 54 multiclass pesticides during the transformation processes from rose petal to concrete and absolute using roses spiked with pesticides as a model. The concentrations of the pesticides were followed during the process of transforming the spiked rose flowers from an organic field into concrete and then into absolute. The rose flowers, the concrete, and the absolute, as well as their transformation intermediates, were analyzed for pesticide content using gas chromatography/tandem mass spectrometry. We observed that all the pesticides were extracted and concentrated in the absolute, with the exception of three molecules: fenthion, fenamiphos, and phorate. Typical pesticides were found to be concentrated by a factor of 100-300 from the rose flowers to the rose absolute. The observed effect of pesticide enrichment was also studied in roses and their extracts from four classically phytosanitary treated fields. Seventeen pesticides were detected in at least one of the extracts. Like the case for the spiked samples in our model, the pesticides present in the rose flowers from Turkey were concentrated in the absolute. Two pesticides, methidathion and chlorpyrifos, were quantified in the rose flowers at approximately 0.01 and 0.01-0.05 mg kg(-1), respectively, depending on the treated field. The concentrations determined for the corresponding rose absolutes were 4.7 mg kg(-1) for methidathion and 0.65-27.25 mg kg(-1) for chlorpyrifos. PMID:25942486

  9. The Multispecimen Method for Absolute Paleointensity Determination

    NASA Astrophysics Data System (ADS)

    Dekkers, M. J.; de Groot, L. V.; Monster, M.

    2015-12-01

    Paleointensity methods have seen a large improvement in the 21th century. This included optimizing classic Thellier-style protocols along with establishing stringent sets of quality criteria, developing microwave excitation as an alternative to thermal treatment, selecting sample material that contains the most suitable remanence carriers (i.e. single domain magnetic particles), calibrating non-heating paleointensity methods, and the introduction of the multispecimen paleointensity (MSP) protocol. An MSP experiment is carried out at one specific temperature selected to avoid thermochemical alteration; a series of specimens is heated and cooled in various applied furnace fields oriented parallel to the specimen's NRM. The furnace field value at which no change in NRM occurs is the paleofield. While the rationale of the MSP approach is surprisingly straightforward, some of the original claims (Dekkers and Böhnel, 2006) are by now shown to be untenable. This pertains to the claimed domain state independence in the original MSP method, although the Fabian and Leonhardt (2010) extended protocol largely corrects for domain state effects. Here we describe the optimal workflow for MSP experiments derived from our collection of historic flows from four volcanic edifices: Mt. Etna, Hawaii, the Canary Islands, and the Azores. By comparing the experimental outcome derived from historic flows with known paleointensities we found that technically acceptable experiments may yield overestimates, correct determinations, as well as underestimates of the paleofield. The so-called "ARM test" (de Groot et al., 2012) can distinguish between those three options. Based on TRM and ARM being analogues, this test compares ARM acquisition curves of sister samples before and after heating to the MSP experiment temperature. Simulated paleointensity experiments following this workflow consistently deliver the correct answer (Monster et al., submitted).

  10. Non-invasive quantification of brain glycogen absolute concentration

    PubMed Central

    van Heeswijk, Ruud B.; Xin, Lijing; Laus, Sabrina; Frenkel, Hanne; Lei, Hongxia; Gruetter, Rolf

    2009-01-01

    The only currently available method to measure brain glycogen in vivo is 13C NMR spectroscopy. Incorporation of 13C-labeled glucose (Glc) is necessary to allow glycogen measurement, but might be affected by turnover changes. Our aim was to measure glycogen absolute concentration in the rat brain by eliminating label turnover as variable. The approach is based on establishing an increased, constant 13C isotopic enrichment (IE). 13C-Glc infusion is then performed at the IE of brain glycogen. As glycogen IE cannot be assessed in vivo, we validated that it can be inferred from that of N-acetyl-aspartate IE in vivo: After [1-13C]-Glc ingestion, glycogen IE was 2.2 ± 0.1 fold that of N-acetyl-aspartate (n = 11, R2 = 0.77). After subsequent Glc infusion, glycogen IE equaled brain Glc IE (n = 6, paired t-test, p = 0.37), implying isotopic steady-state achievement and complete turnover of the glycogen molecule. Glycogen concentration measured in vivo by 13C NMR (mean ± SD: 5.8 ± 0.7 μmol/g) was in excellent agreement with that in vitro (6.4 ± 0.6 μmol/g, n = 5). When insulin was administered, the stability of glycogen concentration was analogous to previous biochemical measurements implying that glycogen turnover is activated by insulin. We conclude that the entire glycogen molecule is turned over and that insulin activates glycogen turnover. PMID:19013831

  11. Multifrequency continuous wave terahertz spectroscopy for absolute thickness determination

    SciTech Connect

    Scheller, Maik; Baaske, Kai; Koch, Martin

    2010-04-12

    We present a tunable multifrequency continuous wave terahertz spectrometer based on two laser diodes, photoconductive antennas, and a coherent detection scheme. The system is employed to determine the absolute thickness of samples utilizing a proposed synthetic difference frequency method to circumvent the 2pi uncertainty known from conventional photomixing systems while preserving a high spatial resolution.

  12. Non-Invasive Method of Determining Absolute Intracranial Pressure

    NASA Technical Reports Server (NTRS)

    Yost, William T. (Inventor); Cantrell, John H., Jr. (Inventor); Hargens, Alan E. (Inventor)

    2004-01-01

    A method is presented for determining absolute intracranial pressure (ICP) in a patient. Skull expansion is monitored while changes in ICP are induced. The patient's blood pressure is measured when skull expansion is approximately zero. The measured blood pressure is indicative of a reference ICP value. Subsequently, the method causes a known change in ICP and measured the change in skull expansion associated therewith. The absolute ICP is a function of the reference ICP value, the known change in ICP and its associated change in skull expansion; and a measured change in skull expansion.

  13. Determination of absolute internal conversion coefficients using the SAGE spectrometer

    NASA Astrophysics Data System (ADS)

    Sorri, J.; Greenlees, P. T.; Papadakis, P.; Konki, J.; Cox, D. M.; Auranen, K.; Partanen, J.; Sandzelius, M.; Pakarinen, J.; Rahkila, P.; Uusitalo, J.; Herzberg, R.-D.; Smallcombe, J.; Davies, P. J.; Barton, C. J.; Jenkins, D. G.

    2016-03-01

    A non-reference based method to determine internal conversion coefficients using the SAGE spectrometer is carried out for transitions in the nuclei of 154Sm, 152Sm and 166Yb. The Normalised-Peak-to-Gamma method is in general an efficient tool to extract internal conversion coefficients. However, in many cases the required well-known reference transitions are not available. The data analysis steps required to determine absolute internal conversion coefficients with the SAGE spectrometer are presented. In addition, several background suppression methods are introduced and an example of how ancillary detectors can be used to select specific reaction products is given. The results obtained for ground-state band E2 transitions show that the absolute internal conversion coefficients can be extracted using the methods described with a reasonable accuracy. In some cases of less intense transitions only an upper limit for the internal conversion coefficient could be given.

  14. Engine performance and the determination of absolute ceiling

    NASA Technical Reports Server (NTRS)

    Diehl, Walter S

    1924-01-01

    This report contains a brief study of the variation of engine power with temperature and pressure. The variation of propeller efficiency in standard atmosphere is obtained from the general efficiency curve which is developed in NACA report no. 168. The variation of both power available and power required are then determined and curves plotted, so that the absolute ceiling may be read directly from any known sea-level value of the ratio of power available to power required.

  15. ICP-MS for multiplex absolute determinations of proteins.

    PubMed

    Sanz-Medel, Alfredo

    2010-11-01

    In the last few years MS-based proteomics has been turning quantitative because only the quantity of existing proteins or changes of their abundance in a studied sample reflect the actual status and the extent of possible changes in a given biological system. So far, however, only relative quantifications are common place. Recently, the ideal analytical features of ICP-MS that allow robust, accurate and precise absolute determinations of heteroelements (present in proteins and their peptides) have opened the door to its use, as a complementary ion source of MALDI- and/or ESI-(MS), in achieving the "absolute" quantification of a protein. Unfortunately, so far such "heteroatom-tagged proteomics" applications deal with only single-heteroatom measurements. Thus, the outstanding capability of ICP-MS for multi-element (-isotope) simultaneous determinations is somewhat wasted. On the other hand, multiplexed determinations of proteins (e.g. in common or new multiplexed formats) today constitute a pressing need in medical science (e.g. to determine accurately many biomarkers at a time). This is a clear trend in analytical science where ICP-MS could eventually play an important role. Therefore, reported approaches to multiplex protein determinations using ICP-MS, with liquid sample nebulisation and with laser direct sampling from a solid, are discussed here. Apart from such multiplex bioassays for absolute protein determinations, efforts to simultaneously quantitate enzyme activities are also discussed. It appears that the time is ripe to combine the multi-isotopic character of ICP-MS with well-known multi-analyte separation techniques (e.g. HPLC or multiplex immunoassays) to tackle the challenge of analysing abundances and activities of several proteins and enzymes, respectively, in a single assay. Many attractive opportunities for creative work and interdisciplinary developments for analytical atomic spectroscopists seem to lie ahead related to multiplexed quantitative

  16. Microfabricated Collector-Generator Electrode Sensor for Measuring Absolute pH and Oxygen Concentrations.

    PubMed

    Dengler, Adam K; Wightman, R Mark; McCarty, Gregory S

    2015-10-20

    Fast-scan cyclic voltammetry (FSCV) has attracted attention for studying in vivo neurotransmission due to its subsecond temporal resolution, selectivity, and sensitivity. Traditional FSCV measurements use background subtraction to isolate changes in the local electrochemical environment, providing detailed information on fluctuations in the concentration of electroactive species. This background subtraction removes information about constant or slowly changing concentrations. However, determination of background concentrations is still important for understanding functioning brain tissue. For example, neural activity is known to consume oxygen and produce carbon dioxide which affects local levels of oxygen and pH. Here, we present a microfabricated microelectrode array which uses FSCV to detect the absolute levels of oxygen and pH in vitro. The sensor is a collector-generator electrode array with carbon microelectrodes spaced 5 μm apart. In this work, a periodic potential step is applied at the generator producing transient local changes in the electrochemical environment. The collector electrode continuously performs FSCV enabling these induced changes in concentration to be recorded with the sensitivity and selectivity of FSCV. A negative potential step applied at the generator produces a transient local pH shift at the collector. The generator-induced pH signal is detected using FSCV at the collector and correlated to absolute solution pH by postcalibration of the anodic peak position. In addition, in oxygenated solutions a negative potential step at the generator produces hydrogen peroxide by reducing oxygen. Hydrogen peroxide is detected with FSCV at the collector electrode, and the magnitude of the oxidative peak is proportional to absolute oxygen concentrations. Oxygen interference on the pH signal is minimal and can be accounted for with a postcalibration.

  17. Using Absolute Humidity and Radiochemical Analyses of Water Vapor Samples to Correct Underestimated Atmospheric Tritium Concentrations

    SciTech Connect

    Eberhart, C.F.

    1999-06-01

    Los Alamos National Laboratory (LANL) emits a wide variety of radioactive air contaminants. An extensive ambient air monitoring network, known as AIRNET, is operated on-site and in surrounding communities to estimate radioactive doses to the public. As part of this monitoring network, water vapor is sampled continuously at more than 50 sites. These water vapor samples are collected every two weeks by absorbing the water vapor in the sampled air with silica gel and then radiochemically analyzing the water for tritium. The data have consistently indicated that LANL emissions cause a small, but measurable impact on local concentrations of tritium. In early 1998, while trying to independently verify the presumed 100% water vapor collection efficiency, the author found that this efficiency was normally lower and reached a minimum of 10 to 20% in the middle of summer. This inefficient collection was discovered by comparing absolute humidity (g/m{sup 3}) calculated from relative humidity and temperature to the amount of water vapor collected by the silica gel per cubic meter of air sampled. Subsequent experiments confirmed that the elevated temperature inside the louvered housing was high enough to reduce the capacity of the silica gel by more than half. In addition, their experiments also demonstrated that, even under optimal conditions, there is not enough silica gel present in the sampling canister to absorb all of the moisture during the higher humidity periods. However, there is a solution to this problem. Ambient tritium concentrations have been recalculated by using the absolute humidity values and the tritium analyses. These recalculated tritium concentrations were two to three times higher than previously reported. Future tritium concentrations will also be determined in the same manner. Finally, the water vapor collection process will be changed by relocating the sampling canister outside the housing to increase collection efficiency and, therefore

  18. Determination of Absolute Zero Using a Computer-Based Laboratory

    ERIC Educational Resources Information Center

    Amrani, D.

    2007-01-01

    We present a simple computer-based laboratory experiment for evaluating absolute zero in degrees Celsius, which can be performed in college and undergraduate physical sciences laboratory courses. With a computer, absolute zero apparatus can help demonstrators or students to observe the relationship between temperature and pressure and use…

  19. In situ measurement of leaf chlorophyll concentration: analysis of the optical/absolute relationship.

    PubMed

    Parry, Christopher; Blonquist, J Mark; Bugbee, Bruce

    2014-11-01

    In situ optical meters are widely used to estimate leaf chlorophyll concentration, but non-uniform chlorophyll distribution causes optical measurements to vary widely among species for the same chlorophyll concentration. Over 30 studies have sought to quantify the in situ/in vitro (optical/absolute) relationship, but neither chlorophyll extraction nor measurement techniques for in vitro analysis have been consistent among studies. Here we: (1) review standard procedures for measurement of chlorophyll; (2) estimate the error associated with non-standard procedures; and (3) implement the most accurate methods to provide equations for conversion of optical to absolute chlorophyll for 22 species grown in multiple environments. Tests of five Minolta (model SPAD-502) and 25 Opti-Sciences (model CCM-200) meters, manufactured from 1992 to 2013, indicate that differences among replicate models are less than 5%. We thus developed equations for converting between units from these meter types. There was no significant effect of environment on the optical/absolute chlorophyll relationship. We derive the theoretical relationship between optical transmission ratios and absolute chlorophyll concentration and show how non-uniform distribution among species causes a variable, non-linear response. These results link in situ optical measurements with in vitro chlorophyll concentration and provide insight to strategies for radiation capture among diverse species.

  20. Absolute tracer dye concentration using airborne laser-induced water Raman backscatter

    NASA Technical Reports Server (NTRS)

    Hoge, F. E.; Swift, R. N.

    1981-01-01

    The use of simultaneous airborne-laser-induced dye fluorescence and water Raman backscatter to measure the absolute concentration of an ocean-dispersed tracer dye is discussed. Theoretical considerations of the calculation of dye concentration by the numerical comparison of airborne laser-induced fluorescence spectra with laboratory spectra for known dye concentrations using the 3400/cm OH-stretch water Raman scatter as a calibration signal are presented which show that minimum errors are obtained and no data concerning water mass transmission properties are required when the laser wavelength is chosen to yield a Raman signal near the dye emission band. Results of field experiments conducted with an airborne conical scan lidar over a site in New York Bight into which rhodamine dye had been injected in a study of oil spill dispersion are then indicated which resulted in a contour map of dye concentrations, with a minimum detectable dye concentration of approximately 2 ppb by weight.

  1. Using absolute gravimeter data to determine vertical gravity gradients

    USGS Publications Warehouse

    Robertson, D.S.

    2001-01-01

    The position versus time data from a free-fall absolute gravimeter can be used to estimate the vertical gravity gradient in addition to the gravity value itself. Hipkin has reported success in estimating the vertical gradient value using a data set of unusually good quality. This paper explores techniques that may be applicable to a broader class of data that may be contaminated with "system response" errors of larger magnitude than were evident in the data used by Hipkin. This system response function is usually modelled as a sum of exponentially decaying sinusoidal components. The technique employed here involves combining the x0, v0 and g parameters from all the drops made during a site occupation into a single least-squares solution, and including the value of the vertical gradient and the coefficients of system response function in the same solution. The resulting non-linear equations must be solved iteratively and convergence presents some difficulties. Sparse matrix techniques are used to make the least-squares problem computationally tractable.

  2. Noninvasive imaging of absolute PpIX concentration distribution in nonmelanoma skin tumors at pre-PDT

    NASA Astrophysics Data System (ADS)

    Sunar, Ulas; Rohrbach, Daniel; Morgan, Janet; Zeitouni, Natalie

    2013-03-01

    Photodynamic Therapy (PDT) has proven to be an effective treatment option for nonmelanoma skin cancers. The ability to quantify the concentration of drug in the treated area is crucial for effective treatment planning as well as predicting outcomes. We utilized spatial frequency domain imaging for quantifying the accurate concentration of protoporphyrin IX (PpIX) in phantoms and in vivo. We correct fluorescence against the effects of native tissue absorption and scattering parameters. First we quantified the absorption and scattering of the tissue non-invasively. Then, we corrected raw fluorescence signal by compensating for optical properties to get the absolute drug concentration. After phantom experiments, we used basal cell carcinoma (BCC) model in Gli mice to determine optical properties and drug concentration in vivo at pre-PDT.

  3. Accurate determination of absolute carrier-envelope phase dependence using photo-ionization.

    PubMed

    Sayler, A M; Arbeiter, M; Fasold, S; Adolph, D; Möller, M; Hoff, D; Rathje, T; Fetić, B; Milošević, D B; Fennel, T; Paulus, G G

    2015-07-01

    The carrier-envelope phase (CEP) dependence of few-cycle above-threshold ionization (ATI) of Xe is calibrated for use as a reference measurement for determining and controlling the absolute CEP in other interactions. This is achieved by referencing the CEP-dependent ATI measurements of Xe to measurements of atomic H, which are in turn referenced to ab initio calculations for atomic H. This allows for the accurate determination of the absolute CEP dependence of Xe ATI, which enables relatively easy determination of the offset between the relative CEP measured and/or controlled by typical devices and the absolute CEP in the interaction. PMID:26125386

  4. Determination of the Absolute Stereochemistry of Secondary Alcohols: An Advanced Organic Chemistry Experiment for Undergraduate Students.

    ERIC Educational Resources Information Center

    Bandaranayake, Wickramasinghe M.

    1980-01-01

    Describes experiments which can be completed in five four-hour laboratory sessions, including two synthesis (alpha-phenylbutyric and alpha-phenylbutyric acid anhydride) and determining the absolute stereochemistry of secondary alcohols using the synthetic products. (JN)

  5. A Simple Watt Balance for the Absolute Determination of Mass

    ERIC Educational Resources Information Center

    Quinn, Terry; Quinn, Lucas; Davis, Richard

    2013-01-01

    A watt balance is an electromechanical device that allows a mass to be determined in terms of measurable electrical and mechanical quantities, themselves traceable to the fundamental constants of physics. International plans are well advanced to redefine the unit of mass, the kilogram, in terms of a fixed numerical value for the Planck constant. A…

  6. Crystallization of an achiral cyclohexanone ethylene ketal in enantiomorphs and determination of the absolute structure.

    PubMed

    Graus, Sara; Tejedor, Rosa M; Uriel, Santiago; Serrano, José Luis; Alkorta, Ibon; Elguero, José

    2010-06-16

    The achiral 4-methoxy-4-(p-methoxyphenyl)-cyclohexanone ethylene ketal (1) resolves spontaneously. The crystal structure is solved in chiral spatial group P2(1). Because compound 1 is composed of only light atoms (C, H, O) it is not possible to determine its absolute structure configuration. An efficient procedure for the absolute structure configuration determination of flexible molecules containing only light atoms is proposed, based on the combination of X-ray diffraction, solid-state VCD, and DFT calculations.

  7. On determining absolute entropy without quantum theory or the third law of thermodynamics

    NASA Astrophysics Data System (ADS)

    Steane, Andrew M.

    2016-04-01

    We employ classical thermodynamics to gain information about absolute entropy, without recourse to statistical methods, quantum mechanics or the third law of thermodynamics. The Gibbs–Duhem equation yields various simple methods to determine the absolute entropy of a fluid. We also study the entropy of an ideal gas and the ionization of a plasma in thermal equilibrium. A single measurement of the degree of ionization can be used to determine an unknown constant in the entropy equation, and thus determine the absolute entropy of a gas. It follows from all these examples that the value of entropy at absolute zero temperature does not need to be assigned by postulate, but can be deduced empirically.

  8. Gravimetric determination of phospholipid concentration.

    PubMed

    Tejera-Garcia, Roberto; Connell, Lisa; Shaw, Walter A; Kinnunen, Paavo K J

    2012-09-01

    Accurate determination of lipid concentrations is an obligatory routine in a research laboratory engaged in studies using this class of biomaterials. For phospholipids, this is frequently accomplished using the phosphate assay (Bartlett, G.R. Phosphorus Assay in Column Chromatography. J. Biol. Chem. 234, 466-468, 1959). Given the purity of the currently commercially available synthetic and isolated natural lipids, we have observed that determination of the dry weight of lipid stock solutions provides the fastest, most accurate, and generic method to assay their concentrations. The protocol described here takes advantage of the high resolution and accuracy obtained by modern weighing technology. We assayed by this technique the concentrations of a number of phosphatidylcholine samples, with different degrees of acyl chain saturation and length, and in different organic solvents. The results were compared with those from Bartlett assay, (31)P NMR, and Langmuir compression isotherms. The data obtained show that the gravimetric assay yields lipid concentrations with a resolution similar or better than obtained by the other techniques.

  9. Determination of absolute quantum efficiency of X-ray nano phosphors by thin film photovoltaic cells.

    PubMed

    Davidson, R Andrew; Sugiyama, Chad; Guo, Ting

    2014-10-21

    The absolute optical power at 611 nm emitting from Eu doped Gd2O3 nano phosphors upon X-ray excitation from a microfocus X-ray source operated at 100 kV was measured with thin film photovoltaic cells (TFPCs), whose optical response was calibrated using an He-Ne laser at 632 nm. The same TFPCs were also used to determine the absorbed X-ray power by the nano phosphors. These measurements provided a convenient and inexpensive way to determine the absolute quantum efficiency of nano phosphors, normally a difficult task. The measured absolute X-ray-to-optical fluorescence efficiency of the nano phosphors annealed at 1100 °C was 3.2%. This is the first time such efficiency for Eu/Gd2O3 nano phosphors is determined, and the measured efficiency is a fraction of the theoretically predicted maximum efficiency of 10% reported in the literature.

  10. Principles and procedures for determining absolute differential electron-molecule (atom) scattering cross sections

    NASA Technical Reports Server (NTRS)

    Nickel, J. C.; Zetner, P. W.; Shen, G.; Trajmar, S.

    1989-01-01

    Procedures and calibration techniques for measuring the absolute elastic and inelastic differential cross sections (DCS) for electron impact on molecular (atomic) species are described and illustrated by examples. The elastic DCS for the molecule under study is first determined by calibration against helium using the relative flow technique. The second step involves the production of energy-loss spectra for the instrument response function, the unfolding of overlapping inelastic structures and the normalization of inelastic intensities to the elastic cross sections. It is concluded that this method of determining absolute differential electron-molecule (atom) scattering cross sections is generally applicable and provides reliable results.

  11. Spectrofluorimetric determination of aluminum ions via complexation with luteolin in absolute ethanol.

    PubMed

    Sun, Jinyu; Wu, You; Xiao, Dan; Lin, Xia; Li, Hui

    2014-08-01

    An optimized and validated spectrofluorimetric method has been developed for the rapid determination of aluminum in absolute ethanol. The method is based on the chelation of aluminum and luteolin which results in a complex exhibiting an intense emission signal. The characterization of Al-luteolin complex was studied using ultraviolet-visible spectrometry, infrared spectrometry, fluorescence and mass spectrometry. The complex stoichiometry ratio of aluminum:luteolin was 1:2. The fluorescence of the complex was monitored at an emission wavelength of 545 nm with excitation at 518 nm. The linear concentration range was 6.5 × 10(-7) to 4.0 × 10(-5)  M with a correlation coefficient of r = 0.998. The detection limit was 5.0 × 10(-7)  M. The method was appropriately validated and yielded relative standard deviations of < 2.3% (n = 5), which was considered acceptable. The method was successfully applied in the determination of aluminum in river water, skin care products and pharmaceutical samples.

  12. Simultaneous absolute determination of particle size and effective density of submicron colloids by disc centrifuge photosedimentometry.

    PubMed

    Kamiti, Mungai; Boldridge, David; Ndoping, Linda M; Remsen, Edward E

    2012-12-18

    Disc centrifuge photosedimentometry (DCP) with fluids of different densities is used to simultaneously determine the particle size and effective density of spherical silica particles. Incorporation of a calibrated infrared pyrometer into a DCP instrument is shown to enhance the measurement capability of the DCP technique by correcting for the temperature dependence of the spin fluid's density and viscosity. Advantages of absolute DCP determinations for size and density analysis relative to standardized DCP measurements include the elimination of instrument standardization with a particle of known density and measurements or estimation of the effective particle density. The reliability of diameter determinations provided by absolute DCP was confirmed using silica particles with nominal diameters ranging from 250 to 700 nm by comparison of these analyses with a diameter determination by transmission electron microscopy for silica particle size standards. Effective densities determined by absolute DCP for the silica particles ranged from 2.02 to 2.34 g/cm(3). These findings indicate that the silica particles have little or no porosity. The reported characterization of colloidal silica using absolute DCP suggests applicability of the technique to a variety of particle types including colloidal materials other than silica, core-shell particles, compositionally heterogeneous mixtures of nanoparticles, and irregularly shaped, structured colloids. PMID:23157599

  13. Fast, Computer Supported Experimental Determination of Absolute Zero Temperature at School

    ERIC Educational Resources Information Center

    Bogacz, Bogdan F.; Pedziwiatr, Antoni T.

    2014-01-01

    A simple and fast experimental method of determining absolute zero temperature is presented. Air gas thermometer coupled with pressure sensor and data acquisition system COACH is applied in a wide range of temperature. By constructing a pressure vs temperature plot for air under constant volume it is possible to obtain--by extrapolation to zero…

  14. Mosher Amides: Determining the Absolute Stereochemistry of Optically-Active Amines

    ERIC Educational Resources Information Center

    Allen, Damian A.; Tomaso, Anthony E., Jr.; Priest, Owen P.; Hindson, David F.; Hurlburt, Jamie L.

    2008-01-01

    The use of chiral reagents for the derivatization of optically-active amines and alcohols for the purpose of determining their enantiomeric purity or absolute configuration is a tool used by many chemists. Among the techniques used, Mosher's amide and Mosher's ester analyses are among the most reliable and one of the most often used. Despite this,…

  15. Metrological activity determination of 133Ba by sum-peak absolute method

    NASA Astrophysics Data System (ADS)

    da Silva, R. L.; de Almeida, M. C. M.; Delgado, J. U.; Poledna, R.; Santos, A.; de Veras, E. V.; Rangel, J.; Trindade, O. L.

    2016-07-01

    The National Laboratory for Metrology of Ionizing Radiation provides gamma sources of radionuclide and standardized in activity with reduced uncertainties. Relative methods require standards to determine the sample activity while the absolute methods, as sum-peak, not. The activity is obtained directly with good accuracy and low uncertainties. 133Ba is used in research laboratories and on calibration of detectors for analysis in different work areas. Classical absolute methods don't calibrate 133Ba due to its complex decay scheme. The sum-peak method using gamma spectrometry with germanium detector standardizes 133Ba samples. Uncertainties lower than 1% to activity results were obtained.

  16. A facile method to determine the absolute structure of achiral molecules: supramolecular-tilt structures.

    PubMed

    Tejedor, Rosa María; Uriel, Santiago; Graus, Sara; Sierra, Teresa; Serrano, José Luis; Claramunt, Rosa M; López, Concepción; Pérez-Torralba, Marta; Alkorta, Ibon; Elguero, José

    2013-05-01

    Achiral compounds 4-methoxy-4-(p-methoxyphenyl)cyclohexanoneethylene ketal (2), 4-hydroxy-4-(p-methoxy phenyl)cyclohexanoneethylene ketal (3), and 3,5-dimethyl-4-nitropyrazole (4) crystallized in chiral structures and the samples showed an enantiomeric excess. We have determined the absolute structures of these compounds by using X-ray diffraction with copper radiation at low temperatures. Moreover, we have also established the prevalent absolute structures in these samples, by comparing their calculated and solid-state vibrational circular dichroism (VCD) spectra. The consistency of this method was confirmed by using (R,R)-2,8-diiodo-4,10-dimethyl-6 H,12H-5,11-methano-dibenzo[b,f][1,5]diazocine, Tröger's base, (R,R)-1, as a chiral compound of known absolute configuration.

  17. Determination of absolute configuration using heavy atom based co-crystallization method: Halogen atom effects

    NASA Astrophysics Data System (ADS)

    Wang, Jian-Rong; Fan, Xiaowu; Ding, Qiaoce; Mei, Xuefeng

    2016-09-01

    Heavy atom (chloride, bromide, and iodide) based co-crystals for determination of absolute configuration (AC) for chiral molecules were synthesized and evaluated. Co-crystals of cholestanol and L-ascorbic acid were analysed and the effects and potential benefits of varying the heavy atom are discussed. Changing the halogen atoms (chloride, bromide, or iodide) affects the co-crystal formation, X-ray absorption, and anomalous dispersion, and hence the ability to determine AC.

  18. Isolation and determination of absolute configurations of insect-produced methyl-branched hydrocarbons.

    PubMed

    Bello, Jan E; McElfresh, J Steven; Millar, Jocelyn G

    2015-01-27

    Although the effects of stereochemistry have been studied extensively for volatile insect pheromones, little is known about the effects of chirality in the nonvolatile methyl-branched hydrocarbons (MBCHs) used by many insects as contact pheromones. MBCHs generally contain one or more chiral centers and so two or more stereoisomeric forms are possible for each structure. However, it is not known whether insects biosynthesize these molecules in high stereoisomeric purity, nor is it known whether insects can distinguish the different stereoisomeric forms of MBCHs. This knowledge gap is due in part to the lack of methods for isolating individual MBCHs from the complex cuticular hydrocarbon (CHC) blends of insects, as well as the difficulty in determining the absolute configurations of the isolated MBCHs. To address these deficiencies, we report a straightforward method for the isolation of individual cuticular hydrocarbons from the complex CHC blend. The method was used to isolate 36 pure MBCHs from 20 species in nine insect orders. The absolute stereochemistries of the purified MBCHs then were determined by digital polarimetry. The absolute configurations of all of the isolated MBCHs were determined to be (R) by comparison with a library of synthesized, enantiomerically pure standards, suggesting that the biosynthetic pathways used to construct MBCHs are highly conserved within the Insecta. The development of a straightforward method for isolation of specific CHCs will enable determination of their functional roles by providing pure compounds for bioassays.

  19. Isolation and determination of absolute configurations of insect-produced methyl-branched hydrocarbons

    PubMed Central

    Bello, Jan E.; McElfresh, J. Steven; Millar, Jocelyn G.

    2015-01-01

    Although the effects of stereochemistry have been studied extensively for volatile insect pheromones, little is known about the effects of chirality in the nonvolatile methyl-branched hydrocarbons (MBCHs) used by many insects as contact pheromones. MBCHs generally contain one or more chiral centers and so two or more stereoisomeric forms are possible for each structure. However, it is not known whether insects biosynthesize these molecules in high stereoisomeric purity, nor is it known whether insects can distinguish the different stereoisomeric forms of MBCHs. This knowledge gap is due in part to the lack of methods for isolating individual MBCHs from the complex cuticular hydrocarbon (CHC) blends of insects, as well as the difficulty in determining the absolute configurations of the isolated MBCHs. To address these deficiencies, we report a straightforward method for the isolation of individual cuticular hydrocarbons from the complex CHC blend. The method was used to isolate 36 pure MBCHs from 20 species in nine insect orders. The absolute stereochemistries of the purified MBCHs then were determined by digital polarimetry. The absolute configurations of all of the isolated MBCHs were determined to be (R) by comparison with a library of synthesized, enantiomerically pure standards, suggesting that the biosynthetic pathways used to construct MBCHs are highly conserved within the Insecta. The development of a straightforward method for isolation of specific CHCs will enable determination of their functional roles by providing pure compounds for bioassays. PMID:25583471

  20. Improved statistical determination of absolute neutrino masses via radiative emission of neutrino pairs from atoms

    NASA Astrophysics Data System (ADS)

    Zhang, Jue; Zhou, Shun

    2016-06-01

    The atomic transition from an excited state |e ⟩ to the ground state |g ⟩ by emitting a neutrino pair and a photon, i.e., |e ⟩→|g ⟩+|γ ⟩+|νi⟩+|ν¯j⟩ with i , j =1 , 2, 3, has been proposed by Yoshimura and his collaborators as an alternative way to determine the absolute scale m0 of neutrino masses. More recently, a statistical analysis of the fine structure of the photon spectrum from this atomic process has been performed [N. Song et al. Phys. Rev. D 93, 013020 (2016)] to quantitatively examine the experimental requirements for a realistic determination of absolute neutrino masses. In this paper, we show how to improve the statistical analysis and demonstrate that the previously required detection time can be reduced by one order of magnitude for the case of a 3 σ determination of m0˜0.01 eV with an accuracy better than 10%. Such an improvement is very encouraging for further investigations on measuring absolute neutrino masses through atomic processes.

  1. Chiral isothiocyanates - An approach to determination of the absolute configuration using circular dichroism measurement

    NASA Astrophysics Data System (ADS)

    Michalski, Oskar; Cież, Dariusz

    2013-04-01

    Chiral alkyl 2-isothiocyanates have been obtained from enantiopure, aliphatic amines. ECD measurements allowed us to correlate an absolute configuration at C-2 with a sign of the Cotton effect (CE) observed for n-π* transition at the longer-wavelength range of the spectrum. Chirooptical data calculated for all enantiomers were consistent with the measured CE values and indicated that the weak absorption band at 240 nm could give an important information concerning the stereochemistry of simple, chiral isothiocyanates. Optically active esters of 2-isothiocyanatocarboxylic acids, prepared from α-amino acids, showed two absorption bands located over 195 nm. The more intensive band near 200 nm and the weak absorption located at 250 nm were related to n-π* transitions in NCS group. TD DFT calculations carried out for methyl esters of 2-isothiocyanatocarboxylic acids showed the correlation between signs of CE determined for both absorption bands, and the absolute configuration on C-2.

  2. Determination of the Absolute Configurations of Chiral Drugs Using Chiroptical Spectroscopy.

    PubMed

    Polavarapu, Prasad L

    2016-01-01

    Chiroptical spectroscopy has emerged as a promising tool for the determination of absolute configurations and predominant conformations of chiral molecules in academic laboratories. This promise has led to the adaption of chiroptical spectroscopic methods as valuable tools in chiral drug discovery research programs of the pharmaceutical industry. Most major pharmaceutical companies have invested in in-house chiroptical spectroscopy applications and reported successful outcomes. In the context of continuously increasing applications of chiroptical spectroscopy for chiral molecular structure determination, a review of recent developments and applications for chiral drugs is presented in this manuscript. PMID:27529201

  3. System for determining biofuel concentration

    DOEpatents

    Huff, Shean P.; Janke, Christopher James; Kass, Michael D.; Lewis, Sr, Samuel Arthur; Pawel, Steven J; Theiss, Timothy J.

    2016-09-13

    A measurement device or system configured to measure the content of biofuels within a fuel blend. By measuring a state of a responsive material within a fuel blend, a biofuel content of the fuel blend may be measured. For example, the solubility of a responsive material to biofuel content within a fuel blend, may affect a property of the responsive material, such as shape, dimensional size, or electrical impedance, which may be measured and used as a basis for determining biofuel content.

  4. Improved method for measuring absolute O2(a1Δg) concentration by O2(a1Δg-->X3Σg-) IR radiation

    NASA Astrophysics Data System (ADS)

    Deng, Liezheng; Shi, Wenbo; Yang, Heping; Sha, Guohe; Zhang, Cunhao

    2004-11-01

    We describe an improved technique for measuring the absolute O2(a1Δ) concentration via the quantitative determination of IR radiation from O2(a1Δg→X3Σg-) transition. An exact geometrical optical model was first established, in which the influence of reflection and refraction on the radiation characteristics of a luminous volume source was given full consideration, making possible the accurate calculation of the coupling efficiency between the volume source and a receiving area. Then, an IR radiation receiving apparatus (IRRRA) was constructed and its responsivity (mV/W) to the power of IR radiation calibrated by a tungsten standard lamp. An optical detection system was, in turn, built according to the optical model with fine alignment between the IRRRA and an optical cell. We then demonstrate the procedure to obtain the absolute concentration of O2(a1Δ) flowing through the optical cell from a jet singlet oxygen generator from the signal of the IRRRA, the optical cell volume, and the coupling efficiency between the cell and the IRRRA. Moreover, to verify the accuracy of this method, the absolute O2(a1Δ) concentration was compared to that measured by an established isothermal calorimetry method. Based on the comparison of the O2(a1Δ) concentrations determined by the two methods, the Einstein A-coefficient was estimated as (2.70±0.84)×10-4 s-1, which agrees with Badger's value of 2.58×10-4, Špalek's of 2.24×10-4, Newman's of 2.19×10-4, and Miller's of 2.3×10-4 within the uncertainty of the experimental techniques. The method advanced in this article is worthwhile for the measurement of absolute O2(a1Δ) concentration in a chemical oxygen iodine laser or a singlet oxygen generator. It can also provide a general technique for the measurement of absolute concentrations of long-lifetime luminous species other than O2(a1Δ).

  5. In situ TDLAS measurement of absolute acetylene concentration profiles in a non-premixed laminar counter-flow flame

    NASA Astrophysics Data System (ADS)

    Wagner, S.; Klein, M.; Kathrotia, T.; Riedel, U.; Kissel, T.; Dreizler, A.; Ebert, V.

    2012-06-01

    Acetylene (C2H2), as an important precursor for chemiluminescence species, is a key to understand, simulate and model the chemiluminescence and the related reaction paths. Hence we developed a high resolution spectrometer based on direct Tunable Diode Laser Absorption Spectroscopy (TDLAS) allowing the first quantitative, calibration-free and spatially resolved in situ C2H2 measurement in an atmospheric non-premixed counter-flow flame supported on a Tsuji burner. A fiber-coupled distributed feedback diode laser near 1535 nm was used to measure several absolute C2H2 concentration profiles (peak concentrations up to 9700 ppm) in a laminar non-premixed CH4/air flame ( T up to 1950 K) supported on a modified Tsuji counter-flow burner with N2 purge slots to minimize end flames. We achieve a fractional optical resolution of up to 5×10-5 OD (1 σ) in the flame, resulting in temperature-dependent acetylene detection limits for the P17e line at 6513 cm-1 of up to 2.1 ppmṡm. Absolute C2H2 concentration profiles were obtained by translating the burner through the laser beam using a DC motor with 100 μm step widths. Intercomparisons of the experimental C2H2 profiles with simulations using our new hydrocarbon oxidation mechanisms show excellent agreement in position, shape and in the absolute C2H2 values.

  6. Absolute determination of radiation bursts and of proportional counters space charge effect through the influence method

    NASA Astrophysics Data System (ADS)

    Rios, I. J.; Mayer, R. E.

    2016-11-01

    When proportional counters are employed in charge integration mode to determine the magnitude of a radiation pulse, so intense that individual detection events take place in a time too short to produce individual output pulses, mostly in pulsed neutron sources, the strong build-up of positive space charge reduces the electric multiplication factor of the proportional detector. Under such conditions the ensuing measurement underestimates the amount of radiation that interacted with the detector. If the geometric characteristics, the filling gas pressure and the voltage applied to that detector are known, it becomes possible to apply an analytical correction method to the measurement. In this article we present a method that allows to determine the absolute value of the detected radiation burst without the need to know the characteristics of the employed detectors. It is necessary to employ more than one detector, taking advantage of the Influence Method. The "Influence Method" is conceived for the absolute determination of a nuclear particle flux in the absence of known detector efficiency and without the need to register coincidences of any kind. This method exploits the influence of the presence of one detector in the count rate of another detector, when they are placed one behind the other and define statistical estimators for the absolute number of incident particles and for the efficiency (Rios and Mayer, 2015 [1,2]). Its practical implementation in the measurement of a moderated neutron flux arising from an isotopic neutron source was exemplified in (Rios and Mayer, 2016 [3]) and the extension for multiple detectors in (Rios and Mayer 2016 [4]).

  7. Time dependent corrections to absolute gravity determinations in the establishment of modern gravity control

    NASA Astrophysics Data System (ADS)

    Dykowski, Przemyslaw; Krynski, Jan

    2015-04-01

    The establishment of modern gravity control with the use of exclusively absolute method of gravity determination has significant advantages as compared to the one established mostly with relative gravity measurements (e.g. accuracy, time efficiency). The newly modernized gravity control in Poland consists of 28 fundamental stations (laboratory) and 168 base stations (PBOG14 - located in the field). Gravity at the fundamental stations was surveyed with the FG5-230 gravimeter of the Warsaw University of Technology, and at the base stations - with the A10-020 gravimeter of the Institute of Geodesy and Cartography, Warsaw. This work concerns absolute gravity determinations at the base stations. Although free of common relative measurement errors (e.g. instrumental drift) and effects of network adjustment, absolute gravity determinations for the establishment of gravity control require advanced corrections due to time dependent factors, i.e. tidal and ocean loading corrections, atmospheric corrections and hydrological corrections that were not taken into account when establishing the previous gravity control in Poland. Currently available services and software allow to determine high accuracy and high temporal resolution corrections for atmospheric (based on digital weather models, e.g. ECMWF) and hydrological (based on hydrological models, e.g. GLDAS/Noah) gravitational and loading effects. These corrections are mostly used for processing observations with Superconducting Gravimeters in the Global Geodynamics Project. For the area of Poland the atmospheric correction based on weather models can differ from standard atmospheric correction by even ±2 µGal. The hydrological model shows the annual variability of ±8 µGal. In addition the standard tidal correction may differ from the one obtained from the local tidal model (based on tidal observations). Such difference at Borowa Gora Observatory reaches the level of ±1.5 µGal. Overall the sum of atmospheric and

  8. The Br+HO 2 reaction revisited: Absolute determination of the rate constant at 298 K

    NASA Astrophysics Data System (ADS)

    Laverdet, G.; Le Bras, G.; Mellouki, A.; Poulet, G.

    1990-09-01

    The absolute determination of the rate constant for the reaction Br+HO 2→HBr+O 2 has been done at 298 K using the discharge-flor EPR method. The value k1 = (1.5±0.2) × 10 -12 cm 3 molecule -1 s -1 was obtained. Previous indirect measurements of k1 from a discharge-flow, LIF/mass spectrometric study of the Br/H 2CO/O 2 system have been reinterpreted, leading to values for k1 ranging from 1.0 × 10 -12 to 2.2 × 10 -12 cm 3 molecule -1 s -1 at 298 K. These results are discussed and compared with other literature values.

  9. Determination of absolute interferometric phase using the beam-amplitude ratio technique

    SciTech Connect

    Bickel, D.L.; Hensley, W.H.

    1996-03-01

    Determination of the absolute phase difference (i.e., not modulo 2{pi}) is a key problem in interferometric synthetic aperture radar (IFSAR) for topographic mapping. One way of solving this problem requires use of a technique different from the basic interferometry to resolve a `coarse` angle measurement that lies within the IFSAR ambiguity angle. The method investigated in this paper involves taking advantage of the difference in the amplitude ratio versus elevation angle that occurs when the elevation beams of the two IFSAR antennas are pointed in slightly different directions. The performance of the technique is a function of the angular separation of the two beams, the elevation beamwidth, and the symmetry of the two beam-amplitude patterns. The performance required of the technique is set by the ambiguity angle of the interferometer. This paper presents an analysis of the beam-amplitude ratio technique and shows experimental results.

  10. Determination of the absolute chirality of tellurium using resonant diffraction with circularly polarized x-rays

    NASA Astrophysics Data System (ADS)

    Tanaka, Y.; Collins, S. P.; Lovesey, S. W.; Matsumami, M.; Moriwaki, T.; Shin, S.

    2010-03-01

    Many proteins, sugars and pharmaceuticals crystallize into two forms that are mirror images of each other (enantiomers) like our right and left hands. Tellurium is one enantiomer having a space group pair, P3121 (right-handed screw) and P3221 (left-handed screw). X-ray diffraction with dispersion correction terms has been playing an important role in determining the handedness of enantiomers for a long time. However, this approach is not applicable for an elemental crystal such as tellurium or selenium. We have demonstrated that positive and negative circularly polarized x-rays at the resonant energy of tellurium can be used to absolutely distinguish right from left tellurium. This method is applicable to chiral motifs that occur in biomolecules, liquid crystals, ferroelectrics and antiferroelectrics, multiferroics, etc.

  11. Using star tracks to determine the absolute pointing of the Fluorescence Detector telescopes of the Pierre Auger Observatory

    SciTech Connect

    De Donato, Cinzia; Sanchez, Federico; Santander, Marcos; Natl.Tech.U., San Rafael; Camin, Daniel; Garcia, Beatriz; Grassi, Valerio; /Milan U. /INFN, Milan

    2005-05-01

    To accurately reconstruct a shower axis from the Fluorescence Detector data it is essential to establish with high precision the absolute pointing of the telescopes. To d that they calculate the absolute pointing of a telescope using sky background data acquired during regular data taking periods. The method is based on the knowledge of bright star's coordinates that provide a reliable and stable coordinate system. it can be used to check the absolute telescope's pointing and its long-term stability during the whole life of the project, estimated in 20 years. They have analyzed background data taken from January to October 2004 to determine the absolute pointing of the 12 telescopes installed both in Los Leones and Coihueco. The method is based on the determination of the mean-time of the variance signal left by a star traversing a PMT's photocathode which is compared with the mean-time obtained by simulating the track of that star on the same pixel.

  12. Rapid analytical determination of glutaraldehyde concentrations

    NASA Technical Reports Server (NTRS)

    Frigerio, N. A.; Shaw, M. H.

    1971-01-01

    Technique utilizes the iodimetric procedure which adds unknown excess of bisulfite to glutaraldehyde /GA/ then titrates unreacted bisulfite with standard iodine isotope to determine GA concentrations. Technique may interest microscopists, food researchers, biochemical or medical laboratories, and drug manufacturers.

  13. Absolute lymphocyte count is not a suitable alternative to CD4 count for determining initiation of antiretroviral therapy in fiji.

    PubMed

    Balak, Dashika A; Bissell, Karen; Roseveare, Christine; Ram, Sharan; Devi, Rachel R; Graham, Stephen M

    2014-01-01

    Introduction. An absolute lymphocyte count is commonly used as an alternative to a CD4 count to determine initiation of antiretroviral therapy for HIV-infected individuals in Fiji when a CD4 count is unavailable. Methods. We conducted a retrospective analysis of laboratory results of HIV-infected individuals registered at all HIV clinics in Fiji. Results. Paired absolute lymphocyte and CD4 counts were available for 101 HIV-infected individuals, and 96% had a CD4 count of ≤500 cells/mm(3). Correlation between the counts in individuals was poor (Spearman rank correlation r = 0.5). No absolute lymphocyte count could be determined in this population as a suitable surrogate for a CD4 count of either 350 cells/mm(3) or 500 cells/mm(3). The currently used absolute lymphocyte count of ≤2300 cells/μL had a positive predictive value of 87% but a negative predictive value of only 17% for a CD4 of ≤350 cells/mm(3) and if used as a surrogate for a CD4 of ≤500 cells/mm(3) it would result in all HIV-infected individuals receiving ART including those not yet eligible. Weight, CD4 count, and absolute lymphocyte count increased significantly at 3 months following ART initiation. Conclusions. Our findings do not support the use of absolute lymphocyte count to determine antiretroviral therapy initiation in Fiji.

  14. Quantification of silane molecules on oxidized silicon: are there options for a traceable and absolute determination?

    PubMed

    Dietrich, P M; Streeck, C; Glamsch, S; Ehlert, C; Lippitz, A; Nutsch, A; Kulak, N; Beckhoff, B; Unger, W E S

    2015-10-01

    Organosilanes are used routinely to functionalize various support materials for further modifications. Nevertheless, reliable quantitative information about surface functional group densities after layer formation is rarely available. Here, we present the analysis of thin organic nanolayers made from nitrogen containing silane molecules on naturally oxidized silicon wafers with reference-free total reflection X-ray fluorescence (TXRF) and X-ray photoelectron spectroscopy (XPS). An areic density of 2-4 silane molecules per nm(2) was calculated from the layer's nitrogen mass deposition per area unit obtained by reference-free TXRF. Complementary energy and angle-resolved XPS (ER/AR-XPS) in the Si 2p core-level region was used to analyze the outermost surface region of the organic (silane layer)-inorganic (silicon wafer) interface. Different coexisting silicon species as silicon, native silicon oxide, and silane were identified and quantified. As a result of the presented proof-of-concept, absolute and traceable values for the areic density of silanes containing nitrogen as intrinsic marker are obtained by calibration of the XPS methods with reference-free TXRF. Furthermore, ER/AR-XPS is shown to facilitate the determination of areic densities in (mono)layers made from silanes having no heteroatomic marker other than silicon. After calibration with reference-free TXRF, these areic densities of silane molecules can be determined when using the XPS component intensity of the silane's silicon atom.

  15. Absolute determination of the gelling point of gelatin under quasi-thermodynamic equilibrium.

    PubMed

    Bellini, Franco; Alberini, Ivana; Ferreyra, María G; Rintoul, Ignacio

    2015-05-01

    Thermodynamic studies on phase transformation of biopolymers in solution are useful to understand their nature and to evaluate their technological potentials. Thermodynamic studies should be conducted avoiding time-related phenomena. This condition is not easily achieved in hydrophilic biopolymers. In this contribution, the simultaneous effects of pH, salt concentration, and cooling rate (Cr) on the folding from random coil to triple helical collagen-like structures of gelatin were systematically studied. The phase transformation temperature at the absolute invariant condition of Cr = 0 °C/min (T(T)Cr=0) ) is introduced as a conceptual parameter to study phase transformations in biopolymers under quasi-thermodynamic equilibrium and avoiding interferences coming from time-related phenomena. Experimental phase diagrams obtained at different Cr are presented. The T(T)(Cr=0) compared with pH and TT(Cr=0) compared with [NaCl] diagram allowed to explore the transformation process at Cr = 0 °C/min. The results were explained by electrostatic interactions between the biopolymers and its solvation milieu.

  16. Absolute determination of the gelling point of gelatin under quasi-thermodynamic equilibrium.

    PubMed

    Bellini, Franco; Alberini, Ivana; Ferreyra, María G; Rintoul, Ignacio

    2015-05-01

    Thermodynamic studies on phase transformation of biopolymers in solution are useful to understand their nature and to evaluate their technological potentials. Thermodynamic studies should be conducted avoiding time-related phenomena. This condition is not easily achieved in hydrophilic biopolymers. In this contribution, the simultaneous effects of pH, salt concentration, and cooling rate (Cr) on the folding from random coil to triple helical collagen-like structures of gelatin were systematically studied. The phase transformation temperature at the absolute invariant condition of Cr = 0 °C/min (T(T)Cr=0) ) is introduced as a conceptual parameter to study phase transformations in biopolymers under quasi-thermodynamic equilibrium and avoiding interferences coming from time-related phenomena. Experimental phase diagrams obtained at different Cr are presented. The T(T)(Cr=0) compared with pH and TT(Cr=0) compared with [NaCl] diagram allowed to explore the transformation process at Cr = 0 °C/min. The results were explained by electrostatic interactions between the biopolymers and its solvation milieu. PMID:25832543

  17. Non-destructive method for determining neutron exposure and constituent concentrations of a body

    DOEpatents

    Gold, Raymond; McElroy, William N.

    1986-01-01

    A non-destructive method for determination of neutron exposure and constituent concentrations in an object, such as reactor pressure vessel, is based on the observation of characteristic gamma-rays emitted by activation products in the object by using a unique continuous gamma-ray spectrometer. The spectrometer views the object through appropriate collimators to determine the absolute emission rate of these characteristic gamma-rays, thereby ascertaining the absolute activity of given activation products in the object. These data can then be used to deduce the spatial and angular dependence of neutron exposure or the spatial constituent concentration at regions of interest within the object.

  18. An absolute dose determination of helical tomotherapy accelerator, TomoTherapy High-Art II

    SciTech Connect

    Bailat, Claude J.; Buchillier, Thierry; Pachoud, Marc; Moeckli, Raphaeel; Bochud, Francois O.

    2009-09-15

    Purpose: A helical tomotherapy accelerator presents a dosimetric challenge because, to this day, there is no internationally accepted protocol for the determination of the absolute dose. Because of this reality, we investigated the different alternatives for characterizing and measuring the absolute dose of such an accelerator. We tested several dosimetric techniques with various metrological traceabilities as well as using a number of phantoms in static and helical modes. Methods: Firstly, the relationship between the reading of ionization chambers and the absorbed dose is dependent on the beam quality value of the photon beam. For high energy photons, the beam quality is specified by the tissue phantom ratio (TPR{sub 20,10}) and it is therefore necessary to know the TPR{sub 20,10} to calculate the dose delivered by a given accelerator. This parameter is obtained through the ratio of the absorbed dose at 20 and 10 cm depths in water and was measured in the particular conditions of the tomotherapy accelerator. Afterward, measurements were performed using the ionization chamber (model A1SL) delivered as a reference instrument by the vendor. This chamber is traceable in absorbed dose to water in a Co-60 beam to a water calorimeter of the American metrology institute (NIST). Similarly, in Switzerland, each radiotherapy department is directly traceable to the Swiss metrology institute (METAS) in absorbed dose to water based on a water calorimeter. For our research, this traceability was obtained by using an ionization chamber traceable to METAS (model NE 2611A), which is the secondary standard of our institute. Furthermore, in order to have another fully independent measurement method, we determined the dose using alanine dosimeters provided by and traceable to the British metrology institute (NPL); they are calibrated in absorbed dose to water using a graphite calorimeter. And finally, we wanted to take into account the type of chamber routinely used in clinical

  19. Synthesis of enantiopure phthalides including 3-butylphthalide, a fragrance component of celery oil, and determination of their absolute configurations.

    PubMed

    Kosaka, Masashi; Sekiguchi, Satoshi; Naito, Junpei; Uemura, Makoto; Kuwahara, Shunsuke; Watanabe, Masataka; Harada, Nobuyuki; Hiroi, Kunio

    2005-05-01

    Enantiopure phthalides 2 and 5-8 were synthesized via enantioresolution of the corresponding alcohols with a chiral auxiliary of camphorsultam dichlorophthalic acid, (1S,2R,4R)-(-)-CSDP acid 3, followed by solvolysis with KOH in MeOH and the catalytic oxidation of chiral glycols with iridium complex 28. The absolute configurations of phthalides 2 and 5-8 were determined by applying the (1)H-NMR anisotropy method of MalphaNP acid (4), 2-methoxy-2-(1-naphthyl)propionic acid, to the chiral synthetic precursory alcohols. In the case of 3-phenylphthalide (R)-(-)-7, the absolute configuration determined by the (1)H-NMR anisotropy method using MalphaNP acid 4 agreed with that by the X-ray crystallographic method. By applying these methods, 3-butylphthalide (S)-(-)-2, a fragrance component of essential oil of celery, has been synthesized in an enantiopure form, and its absolute configuration was unambiguously determined.

  20. Systematic determination of absolute absorption cross-section of individual carbon nanotubes

    PubMed Central

    Liu, Kaihui; Hong, Xiaoping; Choi, Sangkook; Jin, Chenhao; Capaz, Rodrigo B.; Kim, Jihoon; Wang, Wenlong; Bai, Xuedong; Louie, Steven G.; Wang, Enge; Wang, Feng

    2014-01-01

    Optical absorption is the most fundamental optical property characterizing light–matter interactions in materials and can be most readily compared with theoretical predictions. However, determination of optical absorption cross-section of individual nanostructures is experimentally challenging due to the small extinction signal using conventional transmission measurements. Recently, dramatic increase of optical contrast from individual carbon nanotubes has been successfully achieved with a polarization-based homodyne microscope, where the scattered light wave from the nanostructure interferes with the optimized reference signal (the reflected/transmitted light). Here we demonstrate high-sensitivity absorption spectroscopy for individual single-walled carbon nanotubes by combining the polarization-based homodyne technique with broadband supercontinuum excitation in transmission configuration. To our knowledge, this is the first time that high-throughput and quantitative determination of nanotube absorption cross-section over broad spectral range at the single-tube level was performed for more than 50 individual chirality-defined single-walled nanotubes. Our data reveal chirality-dependent behaviors of exciton resonances in carbon nanotubes, where the exciton oscillator strength exhibits a universal scaling law with the nanotube diameter and the transition order. The exciton linewidth (characterizing the exciton lifetime) varies strongly in different nanotubes, and on average it increases linearly with the transition energy. In addition, we establish an empirical formula by extrapolating our data to predict the absorption cross-section spectrum for any given nanotube. The quantitative information of absorption cross-section in a broad spectral range and all nanotube species not only provides new insight into the unique photophysics in one-dimensional carbon nanotubes, but also enables absolute determination of optical quantum efficiencies in important

  1. Systematic determination of absolute absorption cross-section of individual carbon nanotubes.

    PubMed

    Liu, Kaihui; Hong, Xiaoping; Choi, Sangkook; Jin, Chenhao; Capaz, Rodrigo B; Kim, Jihoon; Wang, Wenlong; Bai, Xuedong; Louie, Steven G; Wang, Enge; Wang, Feng

    2014-05-27

    Optical absorption is the most fundamental optical property characterizing light-matter interactions in materials and can be most readily compared with theoretical predictions. However, determination of optical absorption cross-section of individual nanostructures is experimentally challenging due to the small extinction signal using conventional transmission measurements. Recently, dramatic increase of optical contrast from individual carbon nanotubes has been successfully achieved with a polarization-based homodyne microscope, where the scattered light wave from the nanostructure interferes with the optimized reference signal (the reflected/transmitted light). Here we demonstrate high-sensitivity absorption spectroscopy for individual single-walled carbon nanotubes by combining the polarization-based homodyne technique with broadband supercontinuum excitation in transmission configuration. To our knowledge, this is the first time that high-throughput and quantitative determination of nanotube absorption cross-section over broad spectral range at the single-tube level was performed for more than 50 individual chirality-defined single-walled nanotubes. Our data reveal chirality-dependent behaviors of exciton resonances in carbon nanotubes, where the exciton oscillator strength exhibits a universal scaling law with the nanotube diameter and the transition order. The exciton linewidth (characterizing the exciton lifetime) varies strongly in different nanotubes, and on average it increases linearly with the transition energy. In addition, we establish an empirical formula by extrapolating our data to predict the absorption cross-section spectrum for any given nanotube. The quantitative information of absorption cross-section in a broad spectral range and all nanotube species not only provides new insight into the unique photophysics in one-dimensional carbon nanotubes, but also enables absolute determination of optical quantum efficiencies in important

  2. Absolute densities, masses, and radii of the WASP-47 system determined dynamically

    NASA Astrophysics Data System (ADS)

    Almenara, J. M.; Díaz, R. F.; Bonfils, X.; Udry, S.

    2016-10-01

    We present a self-consistent modelling of the available light curve and radial velocity data of WASP-47 that takes into account the gravitational interactions between all known bodies in the system. The joint analysis of light curve and radial velocity data in a multi-planetary system allows deriving absolute densities, radii, and masses without the use of theoretical stellar models. For WASP-47 the precision is limited by the reduced dynamical information that is due to the short time span of the K2 light curve. We achieve a precision of around 22% for the radii of the star and the transiting planets, between 40% and 60% for their masses, and between 1.5% and 38% for their densities. All values agree with previously reported measurements. When theoretical stellar models are included, the system parameters are determined with a precision that exceeds that achieved by previous studies, thanks to the self-consistent modelling of light curve and radial velocity data.

  3. An absolute instrument for determination of the speed of sound in water.

    PubMed

    Li, Zhiwei; Zhu, Junchao; Li, Tao; Zhang, Baofeng

    2016-05-01

    An apparatus for the absolute determination of the sound speed in water based on the time-of-flight technique is described. The time measurement is realized by hardware circuits and the distance measurement by a double-beam plane-mirror interferometer. A highly accurate time chip, with a resolution of approximately 90 ps, is employed for time measurements. The acoustic path length is adjustable and can be measured directly. Two transducers are used for transmitting and receiving ultrasonic signals without reflection. The transducers are immersed in a thermostatic vessel that maintains bath temperature with high stability. The speed of sound in pure water was measured at ambient pressure and at the temperatures 308 K, 303 K, 298 K, and 293 K. The achieved measurement uncertainties are 2 mK for temperature and 0.045 m/s for speed of sound. The results are compared to data from the literature, equation of state models, and measurements by two commercial sensors in the same experiment, showing excellent agreement among them. PMID:27250470

  4. Infrared mapping of ultrasound fields generated by medical transducers: Feasibility of determining absolute intensity levels

    PubMed Central

    Khokhlova, Vera A.; Shmeleva, Svetlana M.; Gavrilov, Leonid R.; Martin, Eleanor; Sadhoo, Neelaksh; Shaw, Adam

    2013-01-01

    Considerable progress has been achieved in the use of infrared (IR) techniques for qualitative mapping of acoustic fields of high intensity focused ultrasound (HIFU) transducers. The authors have previously developed and demonstrated a method based on IR camera measurement of the temperature rise induced in an absorber less than 2 mm thick by ultrasonic bursts of less than 1 s duration. The goal of this paper was to make the method more quantitative and estimate the absolute intensity distributions by determining an overall calibration factor for the absorber and camera system. The implemented approach involved correlating the temperature rise measured in an absorber using an IR camera with the pressure distribution measured in water using a hydrophone. The measurements were conducted for two HIFU transducers and a flat physiotherapy transducer of 1 MHz frequency. Corresponding correction factors between the free field intensity and temperature were obtained and allowed the conversion of temperature images to intensity distributions. The system described here was able to map in good detail focused and unfocused ultrasound fields with sub-millimeter structure and with local time average intensity from below 0.1 W/cm2 to at least 50 W/cm2. Significantly higher intensities could be measured simply by reducing the duty cycle. PMID:23927199

  5. Easy Absolute Values? Absolutely

    ERIC Educational Resources Information Center

    Taylor, Sharon E.; Mittag, Kathleen Cage

    2015-01-01

    The authors teach a problem-solving course for preservice middle-grades education majors that includes concepts dealing with absolute-value computations, equations, and inequalities. Many of these students like mathematics and plan to teach it, so they are adept at symbolic manipulations. Getting them to think differently about a concept that they…

  6. Dietary determinants of plasma homocysteine concentrations.

    PubMed

    Verhoef, Petra; de Groot, Lisette C P G M

    2005-05-01

    Severe hyperhomocysteinemia is typically caused by rare enzymatic defects or by renal failure. In contrast, mild to moderate hyperhomocysteinemia chiefly results from suboptimal status of nutritional factors involved in homocysteine metabolism. Low dietary intake of folate is the most important nutritional cause of elevated homocysteine (tHcy) concentrations. Folic acid is more effective than dietary folate in lowering tHcy concentrations, and a daily dose of 400 mug of folic acid is the minimum daily dose associated with the maximum tHcy-lowering effect ( approximately 20-25% reduction). Mean fasting tHcy concentrations have dropped substantially in populations with mandatory folic acid fortification, and other B-vitamins, such as vitamin B (12), are important determinants of tHcy levels in this setting. Vitamins B (2) and B (6) have little influence on fasting tHcy concentrations, although the former may be relevant in individuals with the MTHFR 677 TT-genotype, and the latter may improve tHcy catabolism in elderly individuals. Betaine and choline can lower fasting tHcy concentrations to a similar extent as folic acid, particularly in the setting of a high intake of methionine. Consumption of tea and coffee increase tHcy concentrations by up to 20%. A high-protein meal also increases tHcy, but these changes are transient, and levels return to normal after an overnight fast. Serine and cystine also influence the methionine-induced postprandial rise in tHcy concentrations. In conclusion, alteration in dietary intake or use of folic acid supplements can substantially lower tHcy concentrations. However, it is not known whether lowering tHcy levels can reduce the risk of cardiovascular disease or cognitive decline or prevent pregnancy complications or osteoporosis. PMID:16047264

  7. Simple iodine reference at 1064 nm for absolute laser frequency determination in space applications.

    PubMed

    Kokuyama, Wataru; Numata, Kenji; Camp, Jordan

    2010-11-10

    Using an iodine cell with fixed gas pressure, we built a simple frequency reference at 1064 nm with 10 MHz absolute accuracy and used it to demonstrate deterministic phase locking between two single-frequency lasers. The reference was designed to be as simple as possible, and it does not use a cooler or frequency modulator. This system should be useful, especially for space interferometric missions such as the Laser Interferometer Space Antenna.

  8. Resolution of 1- and 2-naphthylmethoxyacetic acids, NMR reagents for absolute configuration determination, by use of L-phenylalaninol.

    PubMed

    Arita, Shoko; Yabuuchi, Tetsuya; Kusumi, Takenori

    2003-08-01

    Racemic 1- and 2-naphthylmethoxyacetic acids (1NMA and 2NMA), the chiral anisotropic reagents used for absolute configuration determination of chiral secondary alcohols and primary amines, were conveniently resolved to enantiomers (>99% ee) by condensation with L-phenylalaninol (2-amino-3-phenylpropanol), chromatographic separation of the diastereomers, and hydrolysis. This method enables large-scale preparation of enantiomeric 1NMA and 2NMA. PMID:12840826

  9. Determination of the Absolute Number of Cytokine mRNA Molecules within Individual Activated Human T Cells

    NASA Technical Reports Server (NTRS)

    Karr, Laurel J.; Marshall, Gwen; Hockett, Richard D.; Bucy, R. Pat; Curreri, Peter A. (Technical Monitor)

    2002-01-01

    A primary function of activated T cells is the expression and subsequent secretion of cytokines, which orchestrate the differentiation of other lymphocytes, modulate antigen presenting cell activity, and alter vascular endothelium to mediate an immune response. Since many features of immune regulation probably result from modest alterations of endogenous rates of multiple interacting processes, quantitative analysis of the frequency and specific activity of individual T cells is critically important. Using a coordinated set of quantitative methods, the absolute number of molecules of several key cytokine mRNA species in individual T cells has been determined. The frequency of human blood T cells activated in vitro by mitogens and recall protein antigens was determined by intracellular cytokine protein staining, in situ hybridization for cytokine mRNA, and by limiting dilution analysis for cytokine mRNA+ cells. The absolute number of mRNA molecules was simultaneously determined in both homogenates of the entire population of cells and in individual cells obtained by limiting dilution, using a quantitative, competitive RT-PCR assay. The absolute numbers of mRNA molecules in a population of cells divided by the frequency of individual positive cells, yielded essentially the same number of mRNA molecules per cell as direct analysis of individual cells by limiting dilution analysis. Mean numbers of mRNA per positive cell from both mitogen and antigen activated T cells, using these stimulation conditions, were 6000 for IL-2, 6300 for IFN-gamma, and 1600 for IL-4.

  10. Studies Culminating in the Total Synthesis and Determination of the Absolute Configuration of (-)-Saudin

    PubMed Central

    Boeckman, Robert K.; del Rosario Ferreira, Maria Rico; Mitchell, Lorna H.; Shao, Pengcheng; Neeb, Michael J.; Fang, Yue

    2011-01-01

    A full account of studies that culminated in the total synthesis of both antipodes and the assignment of its absolute configuration of Saudin, a hypoglycemic natural product. Two approaches are described, the first proceeding though bicyclic lactone intermediates and related second monocyclic esters. The former was obtained via asymmetric Diels-Alder cycloaddition and the latter by an asymmetric annulation protocol. Both approaches employ a Lewis acid promoted Claisen rearrangement, with the successful approach taking advantage of bidentate chelation to control the facial selectivity of the key Claisen rearrangement PMID:22523435

  11. Determining Concentration of Nanoparticles from Ellipsometry

    NASA Technical Reports Server (NTRS)

    Venkatasubbarao, Srivatsa; Kempen, Lothar U.; Chipman, Russell

    2008-01-01

    various concentrations of gold nanoparticles having an assumed radius. The modeled data indicates distinct spectral features for both the real and the imaginary part of the dielectric function. An ellipsometric measurement would determine this distinct feature and thus can be used to measure nanoparticle concentration. By "ellipsometric responses" is meant the intensities of light measured in various polarization states as functions of the angle of incidence and the polarization states of the incident light. These calculated ellipsometric responses are used as calibration curves: Data from subsequent ellipsometric measurements on real specimens are compared with the calibration curves. The concentration of the nanoparticles on a specimen is assumed to be that of the calibration curve that most closely matches the data pertaining to that specimen.

  12. Absolute measurement of cerebral optical coefficients, hemoglobin concentration and oxygen saturation in old and young adults with near-infrared spectroscopy

    Technology Transfer Automated Retrieval System (TEKTRAN)

    We present near-infrared spectroscopy measurement of absolute cerebral hemoglobin concentration and saturation in a large sample of 36 healthy elderly (mean age, 85 ± 6 years) and 19 young adults (mean age, 28 ± 4 years). Non-invasive measurements were obtained on the forehead using a commercially a...

  13. Monte Carlo calculations for absolute dosimetry to determine machine outputs for proton therapy fields

    PubMed Central

    Paganetti, Harald

    2008-01-01

    The prescribed dose in radiation therapy has to be converted into machine monitor units for patient treatment. This is done routinely for each spread-out Bragg peak (SOBP) field either by calibration measurements, by using analytical algorithms or by relying on empirical data. At the Northeast Proton Therapy Center, a monitor unit corresponds to a fixed amount of charge collected in a segmented transmission ionization chamber inside the treatment head. The goal of this work was to use a detailed Monte Carlo model of the treatment head to calculate the dose delivered to the patient as a function of ionization chamber reading, i.e. to yield absolute dose in patients in terms of machine monitor units. The results show excellent agreement with measurements. For 50 SOBP fields considered in this study, the mean absolute difference between the experimental and the calculated value is 1.5%, where ~50% of the fields agree within 1%. This is within the uncertainties of the data. The Monte Carlo method has advantages over analytical algorithms because it takes into account scattered and secondary radiation, does not rely on empirical parameters, and provides a tool to study the influence of parts of the treatment head on the ionization chamber reading. Compared to experimental methods the Monte Carlo method has the advantage of being able to verify the dose in the patient geometry. PMID:16723767

  14. The realization of the dipole (γ, γ) method and its application to determine the absolute optical oscillator strengths of helium

    NASA Astrophysics Data System (ADS)

    Xu, Long-Quan; Liu, Ya-Wei; Kang, Xu; Ni, Dong-Dong; Yang, Ke; Hiraoka, Nozomu; Tsuei, Ku-Ding; Zhu, Lin-Fan

    2015-12-01

    The dipole (γ, γ) method, which is the inelastic x-ray scattering operated at a negligibly small momentum transfer, is proposed and realized to determine the absolute optical oscillator strengths of the vanlence-shell excitations of atoms and molecules. Compared with the conventionally used photoabsorption method, this new method is free from the line saturation effect, which can seriously limit the accuracies of the measured photoabsorption cross sections for discrete transitions with narrow natural linewidths. Furthermore, the Bethe-Born conversion factor of the dipole (γ, γ) method varies much more slowly with the excitation energy than does that of the dipole (e, e) method. Absolute optical oscillator strengths for the excitations of 1s2 → 1 snp(n = 3 - 7) of atomic helium have been determined using the high-resolution dipole (γ, γ) method, and the excellent agreement of the present measurements with both those measured by the dipole (e, e) method and the previous theoretical calculations indicates that the dipole (γ, γ) method is a powerful tool to measure the absolute optical oscillator strengths of the valence-shell excitations of atoms and molecules.

  15. The realization of the dipole (γ, γ) method and its application to determine the absolute optical oscillator strengths of helium.

    PubMed

    Xu, Long-Quan; Liu, Ya-Wei; Kang, Xu; Ni, Dong-Dong; Yang, Ke; Hiraoka, Nozomu; Tsuei, Ku-Ding; Zhu, Lin-Fan

    2015-01-01

    The dipole (γ, γ) method, which is the inelastic x-ray scattering operated at a negligibly small momentum transfer, is proposed and realized to determine the absolute optical oscillator strengths of the vanlence-shell excitations of atoms and molecules. Compared with the conventionally used photoabsorption method, this new method is free from the line saturation effect, which can seriously limit the accuracies of the measured photoabsorption cross sections for discrete transitions with narrow natural linewidths. Furthermore, the Bethe-Born conversion factor of the dipole (γ, γ) method varies much more slowly with the excitation energy than does that of the dipole (e, e) method. Absolute optical oscillator strengths for the excitations of 1s(2) → 1 snp(n = 3-7) of atomic helium have been determined using the high-resolution dipole (γ, γ) method, and the excellent agreement of the present measurements with both those measured by the dipole (e, e) method and the previous theoretical calculations indicates that the dipole (γ, γ) method is a powerful tool to measure the absolute optical oscillator strengths of the valence-shell excitations of atoms and molecules.

  16. The realization of the dipole (γ, γ) method and its application to determine the absolute optical oscillator strengths of helium

    PubMed Central

    Xu, Long-Quan; Liu, Ya-Wei; Kang, Xu; Ni, Dong-Dong; Yang, Ke; Hiraoka, Nozomu; Tsuei, Ku-Ding; Zhu, Lin-Fan

    2015-01-01

    The dipole (γ, γ) method, which is the inelastic x-ray scattering operated at a negligibly small momentum transfer, is proposed and realized to determine the absolute optical oscillator strengths of the vanlence-shell excitations of atoms and molecules. Compared with the conventionally used photoabsorption method, this new method is free from the line saturation effect, which can seriously limit the accuracies of the measured photoabsorption cross sections for discrete transitions with narrow natural linewidths. Furthermore, the Bethe-Born conversion factor of the dipole (γ, γ) method varies much more slowly with the excitation energy than does that of the dipole (e, e) method. Absolute optical oscillator strengths for the excitations of 1s2 → 1 snp(n = 3 − 7) of atomic helium have been determined using the high-resolution dipole (γ, γ) method, and the excellent agreement of the present measurements with both those measured by the dipole (e, e) method and the previous theoretical calculations indicates that the dipole (γ, γ) method is a powerful tool to measure the absolute optical oscillator strengths of the valence-shell excitations of atoms and molecules. PMID:26678298

  17. The realization of the dipole (γ, γ) method and its application to determine the absolute optical oscillator strengths of helium.

    PubMed

    Xu, Long-Quan; Liu, Ya-Wei; Kang, Xu; Ni, Dong-Dong; Yang, Ke; Hiraoka, Nozomu; Tsuei, Ku-Ding; Zhu, Lin-Fan

    2015-01-01

    The dipole (γ, γ) method, which is the inelastic x-ray scattering operated at a negligibly small momentum transfer, is proposed and realized to determine the absolute optical oscillator strengths of the vanlence-shell excitations of atoms and molecules. Compared with the conventionally used photoabsorption method, this new method is free from the line saturation effect, which can seriously limit the accuracies of the measured photoabsorption cross sections for discrete transitions with narrow natural linewidths. Furthermore, the Bethe-Born conversion factor of the dipole (γ, γ) method varies much more slowly with the excitation energy than does that of the dipole (e, e) method. Absolute optical oscillator strengths for the excitations of 1s(2) → 1 snp(n = 3-7) of atomic helium have been determined using the high-resolution dipole (γ, γ) method, and the excellent agreement of the present measurements with both those measured by the dipole (e, e) method and the previous theoretical calculations indicates that the dipole (γ, γ) method is a powerful tool to measure the absolute optical oscillator strengths of the valence-shell excitations of atoms and molecules. PMID:26678298

  18. Absolute OH concentration profiles measurements in high pressure counterflow flames by coupling LIF, PLIF, and absorption techniques

    NASA Astrophysics Data System (ADS)

    Matynia, A.; Idir, M.; Molet, J.; Roche, C.; de Persis, S.; Pillier, L.

    2012-08-01

    A high-pressure combustion chamber enclosing counterflow burners was set-up at ICARE-CNRS laboratory. It allows the stabilization of flat twin premixed flames at atmospheric and high pressure. In this study, lean and stoichiometric methane/air counterflow premixed flames were studied at various pressures (0.1 MPa to 0.7 MPa). Relative OH concentration profiles were measured by Laser Induced Fluorescence. Great care was attached to the determination of the fluorescence signal by taking into account the line broadening and deexcitation by quenching which both arise at high pressure. Subsequently, OH profiles were calibrated in concentration by laser absorption technique associated with planar laser induced fluorescence. Results are successfully compared with literature. The good quality of the results attests of the experimental set-up ability to allow the study of flame structure at high pressure.

  19. Determination of Natural In Vivo Noble-Gas Concentrations in Human Blood

    PubMed Central

    Tomonaga, Yama; Brennwald, Matthias S.; Livingstone, David M.; Tomonaga, Geneviève; Kipfer, Rolf

    2014-01-01

    Although the naturally occurring atmospheric noble gases He, Ne, Ar, Kr, and Xe possess great potential as tracers for studying gas exchange in living beings, no direct analytical technique exists for simultaneously determining the absolute concentrations of these noble gases in body fluids in vivo. In this study, using human blood as an example, the absolute concentrations of all stable atmospheric noble gases were measured simultaneously by combining and adapting two analytical methods recently developed for geochemical research purposes. The partition coefficients determined between blood and air, and between blood plasma and red blood cells, agree with values from the literature. While the noble-gas concentrations in the plasma agree rather well with the expected solubility equilibrium concentrations for air-saturated water, the red blood cells are characterized by a distinct supersaturation pattern, in which the gas excess increases in proportion to the atomic mass of the noble-gas species, indicating adsorption on to the red blood cells. This study shows that the absolute concentrations of noble gases in body fluids can be easily measured using geochemical techniques that rely only on standard materials and equipment, and for which the underlying concepts are already well established in the field of noble-gas geochemistry. PMID:24811123

  20. Absolute polarity determination of teeth cementum by phase sensitive second harmonic generation microscopy.

    PubMed

    Aboulfadl, Hanane; Hulliger, Jürg

    2015-10-01

    The absolute sign of local polarity in relation to the biological growth direction has been investigated for teeth cementum using phase sensitive second harmonic generation microscopy (PS-SHGM) and a crystal of 2-cyclooctylamino-5-nitropyridine (COANP) as a nonlinear optic (NLO) reference material. A second harmonic generation (SHG) response was found in two directions of cementum: radial (acellular extrinsic fibers that are oriented more or less perpendicular to the root surface) and circumferential (cellular intrinsic fibers that are oriented more or less parallel to the surface). A mono-polar state was demonstrated for acellular extrinsic cementum. However, along the different parts of cementum in circumferential direction, two corresponding domains were observed featuring an opposite sign of polarity indicative for a bi-polar microscopic state of cellular intrinsic cementum. The phase information showed that the orientation of radial collagen fibrils of cementum is regularly organized with the donor (D) groups pointing to the surface. Circumferential collagen molecules feature orientational disorder and are oriented up and down in random manner showing acceptor or donor groups at the surface of cementum. Considering that the cementum continues to grow in thickness throughout life, we can conclude that the cementum is growing circumferentially in two opposite directions and radially in one direction. A Markov chain type model for polarity formation in the direction of growth predicts D-groups preferably appearing at the fiber front.

  1. Absolute polarity determination of teeth cementum by phase sensitive second harmonic generation microscopy.

    PubMed

    Aboulfadl, Hanane; Hulliger, Jürg

    2015-10-01

    The absolute sign of local polarity in relation to the biological growth direction has been investigated for teeth cementum using phase sensitive second harmonic generation microscopy (PS-SHGM) and a crystal of 2-cyclooctylamino-5-nitropyridine (COANP) as a nonlinear optic (NLO) reference material. A second harmonic generation (SHG) response was found in two directions of cementum: radial (acellular extrinsic fibers that are oriented more or less perpendicular to the root surface) and circumferential (cellular intrinsic fibers that are oriented more or less parallel to the surface). A mono-polar state was demonstrated for acellular extrinsic cementum. However, along the different parts of cementum in circumferential direction, two corresponding domains were observed featuring an opposite sign of polarity indicative for a bi-polar microscopic state of cellular intrinsic cementum. The phase information showed that the orientation of radial collagen fibrils of cementum is regularly organized with the donor (D) groups pointing to the surface. Circumferential collagen molecules feature orientational disorder and are oriented up and down in random manner showing acceptor or donor groups at the surface of cementum. Considering that the cementum continues to grow in thickness throughout life, we can conclude that the cementum is growing circumferentially in two opposite directions and radially in one direction. A Markov chain type model for polarity formation in the direction of growth predicts D-groups preferably appearing at the fiber front. PMID:26297858

  2. Spectroscopic determination of electrical conductivity in an MHD duct from absolute intensity measurements

    NASA Technical Reports Server (NTRS)

    Wang, S. Y.; Smith, J. M.

    1977-01-01

    Measurements of the electrical conductivity in the NASA Lewis cesium seeded, H2-O2 MHD duct made by applying a voltage across the channel from one end electrode to the other, measuring the current, and using the inner electrodes as probes to monitor the voltage distribution along the channel were found to be in good agreement with theory except at low combustion pressures and/or high ratios of seed/oxygen mass flows. To corroborate these measurements and to analyze the possibility of nonuniform seed injection as a cause of the above deviations, a spectroscopic investigation of the plasma conductivity was undertaken. Radial profiles of emission coefficient were obtained from measured transverse profiles of the absolute integrated intensity by Abel inversion. Radial profiles of electrical conductivity were then obtained under two different assumptions. In the first the Cs seed fraction is assumed uniform and equal to the measured flow rate at the time when the temperature and conductivity were obtained. In the second method the local temperature and pressure are taken to be those given by a one-dimensional channel calculation including heat transfer and friction. The results of the two methods are compared to the previously measured conductivity.

  3. Spectroscopic determination of electrical conductivity in an MHD duct from absolute intensity measurements

    NASA Technical Reports Server (NTRS)

    Wang, S. Y.; Smith, M.

    1977-01-01

    Measurements of the electrical conductivity in the NASA Lewis cesium seeded, H2-O2 MHD duct have been previously reported. In order to corroborate the above measurements and to analyze the possibility of nonuniform seed injection as a cause of the deviations, a spectroscopic investigation of the plasma conductivity has been undertaken. Transverse profiles of the absolute integrated intensity were measured from the optically thin lines of CSI-.5664 microns and .5636 microns. Radial profiles of emission coefficient were obtained from the measured transverse profiles of intensity by Abel inversion. Radial profiles of electrical conductivity were then obtained under two different assumptions. In the first, the Cs seed fraction is assumed uniform and equal to the measured flow rate at the time when the temperature and conductivity were obtained. In the second method, the local temperature and pressure are taken to be those given by a one-dimensional channel calculation including heat transfer and friction. In this case profiles of conductivity and seed fractions are obtained. The results of the two methods are compared to the previously measured conductivity.

  4. Biological evaluation and determination of the absolute configuration of chloromonilicin, a strong antimicrobial metabolite isolated from Alternaria sonchi.

    PubMed

    Cimmino, Alessio; Pescitelli, Gennaro; Berestetskiy, Alexander; Dalinova, Anna; Krivorotov, Denis; Tuzi, Angela; Evidente, Antonio

    2016-01-01

    Chloromonilicin was isolated for the first time from Alternaria sonchi, a mycoherbicide proposed for the control of the noxious weed Sonchus arvensis. The already known alternethanoxins A and B and the three recently isolated phytotoxic polycyclic ethanones named alternethanoxins C-E were also isolated from the same source. Chloromonilicin was identified by spectroscopic data (essentially one-dimensional NMR, 2-dimensional NMR and high-resolution ESI-MS) and its structure was confirmed by single X-ray analysis, which also allowed the assignment of the absolute configuration. This latter was independently confirmed by electronic CD calculations. When chloromonilicin was tested for its antimicrobial activity, it was active at concentrations 0.5-1 μg per disc against four bacterial species and a yeast fungus. The compound inhibited conidial germination of four plant pathogens at concentration of 1-10 μg ml(-1). No phytotoxic activity of this antibiotic by leaf-disc puncture bioassay was detected.

  5. 30 CFR 33.32 - Determination of dust concentration.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 30 Mineral Resources 1 2012-07-01 2012-07-01 false Determination of dust concentration. 33.32... MINES Test Requirements § 33.32 Determination of dust concentration. (a) Concentrations of airborne dust... microscopic technique shall be employed in determining concentrations of dust in terms of millions...

  6. 30 CFR 33.32 - Determination of dust concentration.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 30 Mineral Resources 1 2013-07-01 2013-07-01 false Determination of dust concentration. 33.32... MINES Test Requirements § 33.32 Determination of dust concentration. (a) Concentrations of airborne dust... microscopic technique shall be employed in determining concentrations of dust in terms of millions...

  7. 30 CFR 33.32 - Determination of dust concentration.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 30 Mineral Resources 1 2014-07-01 2014-07-01 false Determination of dust concentration. 33.32... MINES Test Requirements § 33.32 Determination of dust concentration. (a) Concentrations of airborne dust... microscopic technique shall be employed in determining concentrations of dust in terms of millions...

  8. Determination of carrier concentration and compensation microprofiles in GaAs

    NASA Technical Reports Server (NTRS)

    Jastrzebski, L.; Lagowski, J.; Walukiewicz, W.; Gatos, H. C.

    1980-01-01

    Simultaneous microprofiling of semiconductor free carrier, donor, and acceptor concentrations was achieved for the first time from the absolute value of the free carrier absorption coefficient and its wavelength dependence determined by IR absorption in a scanning mode. Employing Ge- and Si-doped melt-grown GaAs, striking differences were found between the variations of electron concentration and those of ionized impurity concentrations. These results showed clearly that the electronic characteristics of this material are controlled by amphoteric doping and deviations from stoichiometry rather than by impurity segregation.

  9. Pyridine Hemochromagen Assay for Determining the Concentration of Heme in Purified Protein Solutions

    PubMed Central

    Barr, Ian; Guo, Feng

    2016-01-01

    Heme is a common cofactor in proteins, found in hemoglobin, myoglobin, cytochrome P450, DGCR8, and nitric oxide synthase, among others. This protocol describes a method for quantifying heme that works best in purified protein samples. This protocol might be used to, for example, determine whether a given heme-binding protein is fully occupied by heme, thus allowing correlation of heme content with activity. This requires the absolute heme concentration and an accurate protein concentration. Another use is to determine the extinction coefficients of a heme-bound protein. This assay is fast, easy, and reproducible if done correctly. PMID:27390766

  10. Atom-chip based quantum gravimetry for the precise determination of absolute local gravity

    NASA Astrophysics Data System (ADS)

    Abend, S.

    2015-12-01

    We present a novel technique for the precise measurement of absolute local gravity based on cold atom interferometry. Atom interferometry utilizes the interference of matter waves interrogated by laser light to read out inertial forces. Today's generation of these devices typically operate with test mass samples, that consists of ensembles of laser cooled atoms. Their performance is limited by the velocity spread and finite-size of the test masses that impose systematic uncertainties at the level of a few μGal. Rather than laser cooled atoms we employ quantum degenerate ensembles, so called Bose-Einstein condensates, as ultra-sensitive probes for gravity. These sources offer unique properties in temperature as well as in ensemble size that will allow to overcome the current limitations with the next generation of sensors. Furthermore, atom-chip technologies offer the possibility to generate Bose-Einstein condensates in a fast and reliable way. We show a lab-based prototype that uses the atom-chip itself to retro-reflect the interrogation laser and thus serving as inertial reference inside the vacuum. With this setup it is possible to demonstrate all necessary steps to measure gravity, including the preparation of the source, spanning an interferometer as well as the detection of the output signal, within an area of 1 cm3 right below the atom-chip and to analyze relevant systematic effects. In the framework of the center of excellence geoQ a next generation device is under construction at the Institut für Quantenoptik, that will allow for in-field measurements. This device will feature a state-of-the-art atom-chip source with a high-flux of ultra-cold atoms at a repetition rate of 1-2 Hz. In cooperation with the Müller group at the Institut für Erdmessung the sensor will be characterized in the laboratory first, to be ultimately employed in campaigns to measure the Fennoscandian uplift at the level of 1 μGal. The presented work is part of the center of

  11. Precision laser surveying instrument using atmospheric turbulence compensation by determining the absolute displacement between two laser beam components

    DOEpatents

    Veligdan, James T.

    1993-01-01

    Atmospheric effects on sighting measurements are compensated for by adjusting any sighting measurements using a correction factor that does not depend on atmospheric state conditions such as temperature, pressure, density or turbulence. The correction factor is accurately determined using a precisely measured physical separation between two color components of a light beam (or beams) that has been generated using either a two-color laser or two lasers that project different colored beams. The physical separation is precisely measured by fixing the position of a short beam pulse and measuring the physical separation between the two fixed-in-position components of the beam. This precisely measured physical separation is then used in a relationship that includes the indexes of refraction for each of the two colors of the laser beam in the atmosphere through which the beam is projected, thereby to determine the absolute displacement of one wavelength component of the laser beam from a straight line of sight for that projected component of the beam. This absolute displacement is useful to correct optical measurements, such as those developed in surveying measurements that are made in a test area that includes the same dispersion effects of the atmosphere on the optical measurements. The means and method of the invention are suitable for use with either single-ended systems or a double-ended systems.

  12. Synthesis of enantiopure 2-aryl-2-methoxypropionic acids and determination of their absolute configurations by X-ray crystallography.

    PubMed

    Sekiguchi, Satoshi; Naito, Junpei; Taji, Hiromi; Kasai, Yusuke; Sugio, Akinori; Kuwahara, Shunsuke; Watanabe, Masataka; Harada, Nobuyuki

    2008-03-01

    Racemic 2-aryl-2-methoxypropionic acids were enantioresolved by the use of (S)-(-)-phenylalaninol 4. For instance, racemic 2-methoxy-2-phenylpropionic acid (+/-)-7 was condensed with phenylalaninol (S)-(-)-4 yielding a diastereomeric mixture of amides, which was easily separated by HPLC on silica gel affording the first-eluted amide (-)-13a and the second-eluted amide (+)-13b: alpha = 3.19, Rs = 3.49. The absolute configuration of amide (-)-13a was determined to be (R;S) by X-ray crystallography by reference to the S configuration of the phenylalaninol moiety. Amide (R;S)-(-)-13a was converted to oxazoline (R;S)-(-)-14a, from which enantiopure 2-methoxy-2-phenylpropionic acid (R)-(-)-7 was recovered. Other 2-aryl-2-methoxypropionic acids, (R)-(-)-8, (R)-(-)-9, (R)-(+)-10, (R)-(-)-11, and (R)-(-)-12, were similarly prepared in enantiopure forms with the use of phenylalaninol (S)-(-)-4, and their absolute configurations were clearly determined by X-ray crystallography or by chemical correlation. PMID:17559106

  13. Determining the importance of model calibration for forecasting absolute/relative changes in streamflow from LULC and climate changes

    USGS Publications Warehouse

    Niraula, Rewati; Meixner, Thomas; Norman, Laura M.

    2015-01-01

    Land use/land cover (LULC) and climate changes are important drivers of change in streamflow. Assessing the impact of LULC and climate changes on streamflow is typically done with a calibrated and validated watershed model. However, there is a debate on the degree of calibration required. The objective of this study was to quantify the variation in estimated relative and absolute changes in streamflow associated with LULC and climate changes with different calibration approaches. The Soil and Water Assessment Tool (SWAT) was applied in an uncalibrated (UC), single outlet calibrated (OC), and spatially-calibrated (SC) mode to compare the relative and absolute changes in streamflow at 14 gaging stations within the Santa Cruz River Watershed in southern Arizona, USA. For this purpose, the effect of 3 LULC, 3 precipitation (P), and 3 temperature (T) scenarios were tested individually. For the validation period, Percent Bias (PBIAS) values were >100% with the UC model for all gages, the values were between 0% and 100% with the OC model and within 20% with the SC model. Changes in streamflow predicted with the UC and OC models were compared with those of the SC model. This approach implicitly assumes that the SC model is “ideal”. Results indicated that the magnitude of both absolute and relative changes in streamflow due to LULC predicted with the UC and OC results were different than those of the SC model. The magnitude of absolute changes predicted with the UC and SC models due to climate change (both P and T) were also significantly different, but were not different for OC and SC models. Results clearly indicated that relative changes due to climate change predicted with the UC and OC were not significantly different than that predicted with the SC models. This result suggests that it is important to calibrate the model spatially to analyze the effect of LULC change but not as important for analyzing the relative change in streamflow due to climate change. This

  14. Absolute ages from crater statistics: Using radiometric ages of Martian samples for determining the Martian cratering chronology

    NASA Technical Reports Server (NTRS)

    Neukum, G.

    1988-01-01

    In the absence of dates derived from rock samples, impact crater frequencies are commonly used to date Martian surface units. All models for absolute dating rely on the lunar cratering chronology and on the validity of its extrapolation to Martian conditions. Starting from somewhat different lunar chronologies, rather different Martian cratering chronologies are found in the literature. Currently favored models are compared. The differences at old ages are significant, the differences at younger ages are considerable and give absolute ages for the same crater frequencies as different as a factor of 3. The total uncertainty could be much higher, though, since the ratio of lunar to Martian cratering rate which is of basic importance in the models is believed to be known no better than within a factor of 2. Thus, it is of crucial importance for understanding the the evolution of Mars and determining the sequence of events to establish an unambiguous Martian cratering chronology from crater statistics in combination with clean radiometric ages of returned Martian samples. For the dating goal, rocks should be as pristine as possible from a geologically simple area with a one-stage emplacement history of the local formation. A minimum of at least one highland site for old ages, two intermediate-aged sites, and one very young site is needed.

  15. Absolute determination of photoluminescence quantum efficiency using an integrating sphere setup

    SciTech Connect

    Leyre, S.; Coutino-Gonzalez, E.; Hofkens, J.; Joos, J. J.; Poelman, D.; Smet, P. F.; Ryckaert, J.; Meuret, Y.; Durinck, G.; Hanselaer, P.

    2014-12-15

    An integrating sphere-based setup to obtain a quick and reliable determination of the internal quantum efficiency of strongly scattering luminescent materials is presented. In literature, two distinct but similar measurement procedures are frequently mentioned: a “two measurement” and a “three measurement” approach. Both methods are evaluated by applying the rigorous integrating sphere theory. It was found that both measurement procedures are valid. Additionally, the two methods are compared with respect to the uncertainty budget of the obtained values of the quantum efficiency. An inter-laboratory validation using the two distinct procedures was performed. The conclusions from the theoretical study were confirmed by the experimental data.

  16. Absolute np and pp Cross Section Determinations Aimed At Improving The Standard For Cross Section Measurements

    SciTech Connect

    Laptev, A. B.; Haight, R. C.; Tovesson, F.; Arndt, R. A.; Briscoe, W. J.; Paris, M. W.; Strakovsky, I. I.; Workman, R. L.

    2011-06-01

    Purpose of present research is a keeping improvement of the standard for cross section measurements of neutron-induced reactions. The cross sections for np and pp scattering below 1 GeV are determined based on partial-wave analyses (PWAs) of nucleon-nucleon scattering data. These cross sections are compared with the most recent ENDF/B-VII.0 and JENDL-4.0 data files, and the Nijmegen PWA. Also a comparison of evaluated data with recent experimental data was made to check a quality of evaluation. Excellent agreement was found between the new experimental data and our PWA predictions.

  17. Absolute np and pp cross section determinations aimed at improving the standard for cross section measurements

    SciTech Connect

    Laptev, Alexander B; Haight, Robert C; Tovesson, Fredrik; Arndt, Richard A; Briscoe, William J; Paris, Mark W; Strakovsky, Igor I; Workman, Ron L

    2010-01-01

    Purpose of present research is a keeping improvement of the standard for cross section measurements of neutron-induced reactions. The cross sections for np and pp scattering below 1000 MeV are determined based on partial-wave analyses (PW As) of nucleon-nucleon scattering data. These cross sections are compared with the most recent ENDF/B-V11.0 and JENDL-4.0 data files, and the Nijmegen PWA. Also a comparison of evaluated data with recent experimental data was made to check a quality of evaluation. Excellent agreement was found between the new experimental data and our PWA predictions.

  18. Novelty is not enough: laser-evoked potentials are determined by stimulus saliency, not absolute novelty.

    PubMed

    Ronga, I; Valentini, E; Mouraux, A; Iannetti, G D

    2013-02-01

    Event-related potentials (ERPs) elicited by transient nociceptive stimuli in humans are largely sensitive to bottom-up novelty induced, for example, by changes in stimulus attributes (e.g., modality or spatial location) within a stream of repeated stimuli. Here we aimed 1) to test the contribution of a selective change of the intensity of a repeated stimulus in determining the magnitude of nociceptive ERPs, and 2) to dissect the effect of this change of intensity in terms of "novelty" and "saliency" (an increase of stimulus intensity is more salient than a decrease of stimulus intensity). Nociceptive ERPs were elicited by trains of three consecutive laser stimuli (S1-S2-S3) delivered to the hand dorsum at a constant 1-s interstimulus interval. Three, equally spaced intensities were used: low (L), medium (M), and high (H). While the intensities of S1 and S2 were always identical (L, M, or H), the intensity of S3 was either identical (e.g., HHH) or different (e.g., MMH) from the intensity of S1 and S2. Introducing a selective change in stimulus intensity elicited significantly larger N1 and N2 waves of the S3-ERP but only when the change consisted in an increase in stimulus intensity. This observation indicates that nociceptive ERPs do not simply reflect processes involved in the detection of novelty but, instead, are mainly determined by stimulus saliency. PMID:23136349

  19. Absolute Bragg wavelength and dispersion determination in dispersive incoherent OFDR interrogators

    NASA Astrophysics Data System (ADS)

    Clement, J.; Torregrosa, G.; Hervás, J.; Fernández-Pousa, C. R.

    2016-05-01

    We report on an incoherent OFDR interrogator of FBG arrays based on the concept of dispersive wavelength to time delay mapping. The system is specifically designed to show stability to environmental thermal variations by the incorporation of a composite dispersive delay and weak broadband reflectors for delay and dispersion monitoring. Dispersion is imparted by the combination of a fiber coil and an athermally-packaged chirped fiber Bragg grating for dispersion compensation. Using differential measurements over a single acquisition trace, the values of Bragg wavelengths and dispersion are determined from the delays experienced by the FBGs and by additional reference wavelengths reflected in the broadband reflectors. The results show maximum deviations of 20 pm and 0.2 ps/nm with respect to OSA measurements of Bragg wavelengths and nominal dispersion values, respectively.

  20. Absolute concentrations of highly vibrationally excited OH(υ = 9 + 8) in the mesopause region derived from the TIMED/SABER instrument

    NASA Astrophysics Data System (ADS)

    Mast, Jeffrey; Mlynczak, Martin G.; Hunt, Linda A.; Marshall, B. Thomas; Mertens, Christoper J.; Russell, James M.; Thompson, R. Earl; Gordley, Larry L.

    2013-02-01

    Abstract <span class="hlt">Absolute</span> <span class="hlt">concentrations</span> (cm-3) of highly vibrationally excited hydroxyl (OH) are derived from measurements of the volume emission rate of the υ = 9 + 8 states of the OH radical made by the SABER instrument on the TIMED satellite. SABER has exceptionally sensitive measurement precision that corresponds to an ability to detect changes in volume emission rate on the order of ~5 excited OH molecules per cm3. Peak zonal annual mean <span class="hlt">concentrations</span> observed by SABER exceed 1000 cm-3 at night and 225 cm-3 during the day. Measurements since 2002 show an apparent altitude-dependent variation of the night OH(υ = 9 + 8) <span class="hlt">concentrations</span> with the 11 year solar cycle, with <span class="hlt">concentrations</span> decreasing below ~ 95 km from 2002 to 2008. These observations provide a global database for evaluating photochemical model computations of OH abundance, reaction kinetics, and rates and mechanisms responsible for maintaining vibrationally excited OH in the mesopause region.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_3");'>3</a></li> <li><a href="#" onclick='return showDiv("page_4");'>4</a></li> <li class="active"><span>5</span></li> <li><a href="#" onclick='return showDiv("page_6");'>6</a></li> <li><a href="#" onclick='return showDiv("page_7");'>7</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_5 --> <div id="page_6" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_4");'>4</a></li> <li><a href="#" onclick='return showDiv("page_5");'>5</a></li> <li class="active"><span>6</span></li> <li><a href="#" onclick='return showDiv("page_7");'>7</a></li> <li><a href="#" onclick='return showDiv("page_8");'>8</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="101"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2012JBO....17h1406H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2012JBO....17h1406H"><span id="translatedtitle"><span class="hlt">Absolute</span> measurement of cerebral optical coefficients, hemoglobin <span class="hlt">concentration</span> and oxygen saturation in old and young adults with near-infrared spectroscopy</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Hallacoglu, Bertan; Sassaroli, Angelo; Wysocki, Michael; Guerrero-Berroa, Elizabeth; Schnaider Beeri, Michal; Haroutunian, Vahram; Shaul, Merav; Rosenberg, Irwin H.; Troen, Aron M.; Fantini, Sergio</p> <p>2012-08-01</p> <p>We present near-infrared spectroscopy measurement of <span class="hlt">absolute</span> cerebral hemoglobin <span class="hlt">concentration</span> and saturation in a large sample of 36 healthy elderly (mean age, 85±6 years) and 19 young adults (mean age, 28±4 years). Non-invasive measurements were obtained on the forehead using a commercially available multi-distance frequency-domain system and analyzed using a diffusion theory model for a semi-infinite, homogeneous medium with semi-infinite boundary conditions. Our study included repeat measurements, taken five months apart, on 16 elderly volunteers that demonstrate intra-subject reproducibility of the <span class="hlt">absolute</span> measurements with cross-correlation coefficients of 0.9 for absorption coefficient (μa), oxy-hemoglobin <span class="hlt">concentration</span> ([HbO2]), and total hemoglobin <span class="hlt">concentration</span> ([HbT]), 0.7 for deoxy-hemoglobin <span class="hlt">concentration</span> ([Hb]), 0.8 for hemoglobin oxygen saturation (StO2), and 0.7 for reduced scattering coefficient (). We found significant differences between the two age groups. Compared to young subjects, elderly subjects had lower cerebral [HbO2], [Hb], [HbT], and StO2 by 10±4 μM, 4±3 μM, 14±5 μM, and 6%±5%, respectively. Our results demonstrate the reliability and robustness of multi-distance near-infrared spectroscopy measurements based on a homogeneous model in the human forehead on a large sample of human subjects. <span class="hlt">Absolute</span>, non-invasive optical measurements on the brain, such as those presented here, can significantly advance the development of NIRS technology as a tool for monitoring resting/basal cerebral perfusion, hemodynamics, oxygenation, and metabolism.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/26521445','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/26521445"><span id="translatedtitle">[HPLC enantioseparation, <span class="hlt">absolute</span> configuration <span class="hlt">determination</span> and anti-HIV-1 activity of (±)-F18 enantiomers].</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Zhang, Lei-lei; Xue, Hai; Li, Li; Lu, Xiao-fan; Chen, Zhi-wei; Lu, Gang</p> <p>2015-06-01</p> <p>Racemic (±)-F18 (10-chloromethyl-11-demethyl-12-oxo-calanolide A), an analog of nature product (+)-calanolide A, is a new anti-HIV-1 nonnucleoside reverse transcript inhibitor (NNRTI). A successful enantioseparation of (±)-F18 offering (R)-F18 and (S)-F18 was achieved by a chiral stationary phase prepared HPLC. Their <span class="hlt">absolute</span> configurations were <span class="hlt">determined</span> by measurement of their electronic circular dichroisms combined with modem quantum-chemical calculations. Further investigation revealed that (R)-F18 and (S)-F18 shared a similar anti-HIV activities, however, (R)-F18 was more potent than (S)-F18 against wild-type virus, K101E mutation and P225H mutation pseudoviruses. PMID:26521445</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/1024379','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/1024379"><span id="translatedtitle">The recent <span class="hlt">absolute</span> total np and pp cross section <span class="hlt">determinations</span>: quality of data description and prediction of experimental observables</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Laptev, Alexander B; Haight, Robert C; Arndt, Richard A; Briscoe, William J; Paris, Mark W; Strakovsky, Igor I; Workman, Ron L</p> <p>2010-01-01</p> <p>The <span class="hlt">absolute</span> total cross sections for np and pp scattering below 1000 MeV are <span class="hlt">determined</span> based on partial-wave analyses (PWAs) of nucleon-nucleon scattering data. These cross sections are compared with the most recent ENDF/B-VII.0 and JENDL-3.3 data files, and the Nijmegen PWA. Systematic deviations from the ENDF/B-VII.0 and JENDL-3.3 evaluations are found to exist in the low-energy region. Comparison of the np evaluation with the result of most recent np total and differential cross section measurements will be discussed. Results of those measurements were not used in the evaluation database. A comparison was done to check a quality of evaluation and its capabilities to predict experimental observables. Excellent agreement was found between the new experimental data and our PWA predictions.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/26536162','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/26536162"><span id="translatedtitle">Using DNA origami nanostructures to <span class="hlt">determine</span> <span class="hlt">absolute</span> cross sections for UV photon-induced DNA strand breakage.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Vogel, Stefanie; Rackwitz, Jenny; Schürman, Robin; Prinz, Julia; Milosavljević, Aleksandar R; Réfrégiers, Matthieu; Giuliani, Alexandre; Bald, Ilko</p> <p>2015-11-19</p> <p>We have characterized ultraviolet (UV) photon-induced DNA strand break processes by <span class="hlt">determination</span> of <span class="hlt">absolute</span> cross sections for photoabsorption and for sequence-specific DNA single strand breakage induced by photons in an energy range from 6.50 to 8.94 eV. These represent the lowest-energy photons able to induce DNA strand breaks. Oligonucleotide targets are immobilized on a UV transparent substrate in controlled quantities through attachment to DNA origami templates. Photon-induced dissociation of single DNA strands is visualized and quantified using atomic force microscopy. The obtained quantum yields for strand breakage vary between 0.06 and 0.5, indicating highly efficient DNA strand breakage by UV photons, which is clearly dependent on the photon energy. Above the ionization threshold strand breakage becomes clearly the dominant form of DNA radiation damage, which is then also dependent on the nucleotide sequence.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4185095','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4185095"><span id="translatedtitle">Procoagulant and platelet-derived microvesicle <span class="hlt">absolute</span> counts <span class="hlt">determined</span> by flow cytometry correlates with a measurement of their functional capacity</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Ayers, Lisa; Harrison, Paul; Kohler, Malcolm; Ferry, Berne</p> <p>2014-01-01</p> <p>Background Flow cytometry is the most commonly used technology to measure microvesicles (MVs). Despite reported limitations of this technique, MV levels obtained using conventional flow cytometry have yielded many clinically relevant findings, such as associations with disease severity and ability to predict clinical outcomes. This study aims to <span class="hlt">determine</span> if MV enumeration by flow cytometry correlates with a measurement of their functional capacity, as this may explain how flow cytometry generates clinically relevant results. Methods One hundred samples from healthy individuals and patients with obstructive sleep apnoea were analysed by conventional flow cytometry (FACSCalibur) and by three functional MV assays: Zymuphen MP-activity in which data were given as phosphatidylserine equivalent, STA® Phospholipid Procoag Assay expressed as clotting time and Endogenous Thrombin Potential (ETP) reflecting in vitro thrombin generation. Correlations were <span class="hlt">determined</span> by Spearman correlation. Results <span class="hlt">Absolute</span> counts of lactadherin+ procoagulant MVs generated by flow cytometry weakly correlated with the results obtained from the Zymuphen MP-activity (r=0.5370, p<0.0001); correlated with ETP (r=0.7444, p<0.0001); negatively correlated with STA® Phospholipid Procoag Assay clotting time (−0.7872, p<0.0001), reflecting a positive correlation between clotting activity and flow cytometry. Levels of Annexin V+ procoagulant and platelet-derived MVs were also associated with functional assays. <span class="hlt">Absolute</span> counts of MVs derived from other cell types were not correlated with the functional results. Conclusions Quantitative results of procoagulant and platelet-derived MVs from conventional flow cytometry are associated with the functional capability of the MVs, as defined by three functional MV assays. Flow cytometry is a valuable technique for the quantification of MVs from different cellular origins; however, a combination of several analytical techniques may give the most comprehensive</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=19760034386&hterms=water+dissociation+constant&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D60%26Ntt%3Dwater%2Bdissociation%2Bconstant','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=19760034386&hterms=water+dissociation+constant&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D60%26Ntt%3Dwater%2Bdissociation%2Bconstant"><span id="translatedtitle"><span class="hlt">Absolute</span> rate constant <span class="hlt">determinations</span> for the deactivation of O/1D/ by time resolved decay of O/1D/ yields O/3P/ emission</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Davidson, J. A.; Sadowski, C. M.; Schiff, H. I.; Howard, C. J.; Schmeltekopf, A. L.; Jennings, D. A.; Streit, G. E.</p> <p>1976-01-01</p> <p><span class="hlt">Absolute</span> rate constants for the deactivation of O(1D) atoms by some atmospheric gases have been <span class="hlt">determined</span> by observing the time-resolved emission of O(1D) at 630 nm. O(1D) atoms were produced by the dissociation of ozone via repetitive laser pulses at 266 nm. <span class="hlt">Absolute</span> rate constants for the relaxation of O(1D) at 298 K are reported for N2, O2, CO2, O3, H2, D2, CH4, HCl, NH3, H2O, N2O, and Ne. The results obtained are compared with previous relative and <span class="hlt">absolute</span> measurements reported in the literature.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/765951','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/765951"><span id="translatedtitle">Toxicity Data to <span class="hlt">Determine</span> Refrigerant <span class="hlt">Concentration</span> Limits</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Calm, James M.</p> <p>2000-09-30</p> <p>This report reviews toxicity data, identifies sources for them, and presents resulting exposure limits for refrigerants for consideration by qualified parties in developing safety guides, standards, codes, and regulations. It outlines a method to calculate an acute toxicity exposure limit (ATEL) and from it a recommended refrigerant <span class="hlt">concentration</span> limit (RCL) for emergency exposures. The report focuses on acute toxicity with particular attention to lethality, cardiac sensitization, anesthetic and central nervous system effects, and other escape-impairing effects. It addresses R-11, R-12, R-22, R-23, R-113, R-114, R-116, R-123, R-124, R-125, R-134, R-134a, R-E134, R-141b, R-142b, R-143a, R-152a, R-218, R-227ea, R-236fa, R-245ca, R-245fa, R-290, R-500, R-502, R-600a, R-717, and R-744. It summarizes additional data for R-14, R-115, R-170 (ethane), R-C318, R-600 (n-butane), and R-1270 (propylene) to enable calculation of limits for blends incorporating them. The report summarizes the data a nd related safety information, including classifications and flammability data. It also presents a series of tables with proposed ATEL and RCL <span class="hlt">concentrations</span>-in dimensionless form and the latter also in both metric (SI) and inch-pound (IP) units of measure-for both the cited refrigerants and 66 zerotropic and azeotropic blends. They include common refrigerants, such as R-404A, R-407C, R-410A, and R-507A, as well as others in commercial or developmental status. Appendices provide profiles for the cited single-compound refrigerants and for R-500 and R-502 as well as narrative toxicity summaries for common refrigerants. The report includes an extensive set of references.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.gpo.gov/fdsys/pkg/CFR-2010-title30-vol1/pdf/CFR-2010-title30-vol1-sec33-32.pdf','CFR'); return false;" href="https://www.gpo.gov/fdsys/pkg/CFR-2010-title30-vol1/pdf/CFR-2010-title30-vol1-sec33-32.pdf"><span id="translatedtitle">30 CFR 33.32 - <span class="hlt">Determination</span> of dust <span class="hlt">concentration</span>.</span></a></p> <p><a target="_blank" href="http://www.gpo.gov/fdsys/browse/collectionCfr.action?selectedYearFrom=2010&page.go=Go">Code of Federal Regulations, 2010 CFR</a></p> <p></p> <p>2010-07-01</p> <p>..., EVALUATION, AND APPROVAL OF MINING PRODUCTS DUST COLLECTORS FOR USE IN CONNECTION WITH ROCK DRILLING IN COAL MINES Test Requirements § 33.32 <span class="hlt">Determination</span> of dust <span class="hlt">concentration</span>. (a) <span class="hlt">Concentrations</span> of airborne dust... 30 Mineral Resources 1 2010-07-01 2010-07-01 false <span class="hlt">Determination</span> of dust <span class="hlt">concentration</span>....</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2012QuRes..78..442P','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2012QuRes..78..442P"><span id="translatedtitle"><span class="hlt">Absolute</span> geomagnetic intensity <span class="hlt">determinations</span> on Formative potsherds (1400-700 BC) from the Oaxaca Valley, Southwestern Mexico</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Pétronille, Marie; Goguitchaichvili, Avto; Morales, Juan; Carvallo, Claire; Hueda-Tanabe, Yuki</p> <p>2012-11-01</p> <p>New Thellier-Coe archeointensity <span class="hlt">determinations</span> have been measured on 15 potsherds from the Oaxaca Valley belonging to three of the four Formative Periods (Pre-Classical) of Mesoamerica, spanning 1400-700 BC. Seven of these are considered to be reliable and indicate a geomagnetic field strength of about 30 μT. This value is some 75% of the present geomagnetic field strength but is in agreement with the <span class="hlt">absolute</span> intensities predicted from global models for this time and location, and consistent with coeval published <span class="hlt">determinations</span>. These data thus provide significant evidence for the geomagnetic field strength in an area and for a time that was previously poorly constrained, thus providing an important contribution towards establishing a local master curve for the last 3500 yr. When established, such a curve would be a useful dating tool and also enable establishing for field strength correlations with climatic events and civilization evolutions in a region that is particularly strong in archeological and geological features. Such potential is examined for aridity events, although such observations can only be considered tentative at this stage.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014SPIE.9268E..0VC','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014SPIE.9268E..0VC"><span id="translatedtitle">Mapping the microvascular and the associated <span class="hlt">absolute</span> values of oxy-hemoglobin <span class="hlt">concentration</span> through turbid media via local off-set diffuse optical imaging</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Chen, Chen; Klämpfl, Florian; Stelzle, Florian; Schmidt, Michael</p> <p>2014-11-01</p> <p>An imging resolution of micron-scale has not yet been discovered by diffuse optical imaging (DOI), while a superficial response was eliminated. In this work, we report on a new approach of DOI with a local off-set alignment to subvert the common boundary conditions of the modified Beer-Lambert Law (MBLL). It can resolve a superficial target in micron scale under a turbid media. To validate both major breakthroughs, this system was used to recover a subsurface microvascular mimicking structure under an skin equivalent phantom. This microvascular was included with oxy-hemoglobin solution in variant <span class="hlt">concentrations</span> to distiguish the <span class="hlt">absolute</span> values of CtRHb and CtHbO2 . Experimental results confirmed the feasibility of recovering the target vascular of 50 µm in diameter, and graded the values of the <span class="hlt">concentrations</span> of oxy-hemoglobin from 10 g/L to 50 g/L <span class="hlt">absolutely</span>. Ultimately, this approach could evolve into a non-invasive imaging system to map the microvascular pattern and the associated oximetry under a human skin in-vivo.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2010AIPC.1277..187V','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2010AIPC.1277..187V"><span id="translatedtitle"><span class="hlt">Determination</span> of Parameters of PV <span class="hlt">Concentrating</span> System With Heliostat</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Vardanyan, R.; Norsoyan, A.; Dallakyan, V.</p> <p>2010-10-01</p> <p>The structure of PV <span class="hlt">concentrating</span> system with heliostat is analyzed. The mathematical model of system consisting of PV <span class="hlt">concentrating</span> module and heliostat is developed. With the use of developed mathematical model the optimal parameters of the system are <span class="hlt">determined</span>. The results of this work can be used during the design of PV <span class="hlt">concentrating</span> systems with heliostats.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/985344','DOE-PATENT-XML'); return false;" href="http://www.osti.gov/scitech/servlets/purl/985344"><span id="translatedtitle">Method of trivalent chromium <span class="hlt">concentration</span> <span class="hlt">determination</span> by atomic spectrometry</span></a></p> <p><a target="_blank" href="http://www.osti.gov/doepatents">DOEpatents</a></p> <p>Reheulishvili, Aleksandre N.; Tsibakhashvili, Neli Ya.</p> <p>2006-12-12</p> <p>A method is disclosed for <span class="hlt">determining</span> the <span class="hlt">concentration</span> of trivalent chromium Cr(III) in a sample. The addition of perchloric acid has been found to increase the atomic chromium spectrometric signal due to Cr(III), while leaving the signal due to hexavalent chromium Cr(VI) unchanged. This enables <span class="hlt">determination</span> of the Cr(III) <span class="hlt">concentration</span> without pre-<span class="hlt">concentration</span> or pre-separation from chromium of other valences. The Cr(III) <span class="hlt">concentration</span> may be measured using atomic absorption spectrometry, atomic emission spectrometry or atomic fluorescence spectrometry.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://pubs.er.usgs.gov/publication/70011564','USGSPUBS'); return false;" href="http://pubs.er.usgs.gov/publication/70011564"><span id="translatedtitle">Atomic-absorption <span class="hlt">determination</span> of rhodium in chromite <span class="hlt">concentrates</span></span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Schnepfe, M.M.; Grimaldi, F.S.</p> <p>1969-01-01</p> <p>Rhodium is <span class="hlt">determined</span> in chromite <span class="hlt">concentrates</span> by atomic absorption after <span class="hlt">concentration</span> either by co-precipitation with tellurium formed by the reduction of tellurite with tin(II) chloride or by fire assay into a gold bead. Interelement interferences in the atomic-absorption <span class="hlt">determination</span> are removed by buffering the solutions with lanthanum sulphate (lanthanum <span class="hlt">concentration</span> 1%). Substantial amounts of Ag, Al, Au, Bi, Ca, Cd, Co, Cr, Cu, Fe, Ho, Hg, K, La, Mg, Mn, Mo, Na, Ni, Pb, Te, Ti, V, Y, Zn and platinum metals can be tolerated. A lower limit of approximately 0.07 ppm Rh can be <span class="hlt">determined</span> in a 3-g sample. ?? 1969.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/21168556','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/21168556"><span id="translatedtitle">Automatic twin vessel recrystallizer. Effective purification of acetaminophen by successive automatic recrystallization and <span class="hlt">absolute</span> <span class="hlt">determination</span> of purity by DSC.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Nara, Osamu</p> <p>2011-01-24</p> <p>I describe an interchangeable twin vessel (J, N) automatic glass recrystallizer that eliminates the time-consuming recovery and recycling of crystals for repeated recrystallization. The sample goes in the dissolution vessel J containing a magnetic stir-bar K; J is clamped to the upper joint H of recrystallizer body D. Empty crystallization vessel N is clamped to the lower joint M. Pure solvent is delivered to the dissolution vessel and the crystallization vessel via the head of the condenser A. Crystallization vessel is heated (P). The dissolution reservoir is stirred and heated by the solvent vapor (F). Continuous outflow of filtrate E out of J keeps N at a stable boiling temperature. This results in efficient dissolution, evaporation and separation of pure crystals Q. Pure solvent in the dissolution reservoir is recovered by suction. Empty dissolution and crystallization vessels are detached. Stirrer magnet is transferred to the crystallization vessel and the role of the vessels are then reversed. Evacuating mother liquor out of the upper twin vessel, the apparatus unit is ready for the next automatic recrystallization by refilling twin vessels with pure solvent. We show successive automatic recrystallization of acetaminophen from diethyl ether obtaining acetaminophen of higher melting temperatures than USP and JP reference standards by 8× automatic recrystallization, 96% yield at each stage. Also, I demonstrate a novel approach to the <span class="hlt">determination</span> of <span class="hlt">absolute</span> purity by combining the successive automatic recrystallization with differential scanning calorimetry (DSC) measurement requiring no reference standards. This involves the measurement of the criterial melting temperature T(0) corresponding to the 100% pure material and quantitative ΔT in DSC based on the van't Hoff law of melting point depression. The purity of six commercial acetaminophen samples and reference standards and an eight times recrystallized product evaluated were 98.8 mol%, 97.9 mol%, 99</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2004IJTSM.124...49H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2004IJTSM.124...49H"><span id="translatedtitle"><span class="hlt">Determination</span> of Glucose <span class="hlt">Concentration</span> in Yeast Culture Medium</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Hara, Seiichi; Kishimoto, Tomokazu; Muraji, Masafumi; Tsujimoto, Hiroaki; Azuma, Masayuki; Ooshima, Hiroshi</p> <p></p> <p>The present paper describes a sensor for measuring the glucose <span class="hlt">concentration</span> of yeast culture medium. The sensor <span class="hlt">determines</span> glucose <span class="hlt">concentration</span> by measuring the yield of hydrogen peroxide produced by glucose oxidase, which is monitored as luminescence using photomultiplier. The present sensor is able to measure low glucose <span class="hlt">concentration</span> in media in which yeast cells keep respiration state. We herein describe the system and the characteristics of the glucose sensor.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2009JPhD...42o5208I','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2009JPhD...42o5208I"><span id="translatedtitle">A novel method to <span class="hlt">determine</span> the electron temperature and density from the <span class="hlt">absolute</span> intensity of line and continuum emission: application to atmospheric microwave induced Ar plasmas</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Iordanova, E.; Palomares, J. M.; Gamero, A.; Sola, A.; van der Mullen, J. J. A. M.</p> <p>2009-08-01</p> <p>An <span class="hlt">absolute</span> intensity measurement (AIM) technique is presented that combines the <span class="hlt">absolute</span> measurements of the line and the continuum emitted by strongly ionizing argon plasmas. AIM is an iterative combination of the <span class="hlt">absolute</span> line intensity-collisional radiative model (ALI-CRM) and the <span class="hlt">absolute</span> continuum intensity (ACI) method. The basis of ALI-CRM is that the excitation temperature T13 <span class="hlt">determined</span> by the method of ALI is transformed into the electron temperature Te using a CRM. This gives Te as a weak function of electron density ne. The ACI method is based on the <span class="hlt">absolute</span> value of the continuum radiation and <span class="hlt">determines</span> the electron density in a way that depends on Te. The iterative combination gives ne and Te. As a case study the AIM method is applied to plasmas created by torche à injection axiale (TIA) at atmospheric pressure and fixed frequency at 2.45 GHz. The standard operating settings are a gas flow of 1 slm and a power of 800 W; the measurements have been performed at a position of 1 mm above the nozzle. With AIM we found an electron temperature of 1.2 eV and electron density values around 1021 m-3. There is not much dependence of these values on the plasma control parameters (power and gas flow). From the error analysis we can conclude that the <span class="hlt">determination</span> of Te is within 7% and thus rather accurate but comparison with other studies shows strong deviations. The ne <span class="hlt">determination</span> comes with an error of 40% but is in reasonable agreement with other experimental results.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016APS..MAR.G1327P','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016APS..MAR.G1327P"><span id="translatedtitle"><span class="hlt">Absolute</span> Summ</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Phillips, Alfred, Jr.</p> <p></p> <p>Summ means the entirety of the multiverse. It seems clear, from the inflation theories of A. Guth and others, that the creation of many universes is plausible. We argue that <span class="hlt">Absolute</span> cosmological ideas, not unlike those of I. Newton, may be consistent with dynamic multiverse creations. As suggested in W. Heisenberg's uncertainty principle, and with the Anthropic Principle defended by S. Hawking, et al., human consciousness, buttressed by findings of neuroscience, may have to be considered in our models. Predictability, as A. Einstein realized with Invariants and General Relativity, may be required for new ideas to be part of physics. We present here a two postulate model geared to an <span class="hlt">Absolute</span> Summ. The seedbed of this work is part of Akhnaton's philosophy (see S. Freud, Moses and Monotheism). Most important, however, is that the structure of human consciousness, manifest in Kenya's Rift Valley 200,000 years ago as Homo sapiens, who were the culmination of the six million year co-creation process of Hominins and Nature in Africa, allows us to do the physics that we do. .</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2000OptSp..89..756K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2000OptSp..89..756K"><span id="translatedtitle"><span class="hlt">Determination</span> of Optical Constants of Latex in <span class="hlt">Concentrated</span> Suspensions</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Khaĭrullina, A. Ya.; Oleĭnik, T. V.; Buĭ, L. M.</p> <p>2000-11-01</p> <p>The possibility of taking into account <span class="hlt">concentration</span> effects in the <span class="hlt">determination</span> of optical constants of latex in the visible and near IR regions of the spectrum is demonstrated, and the limits of applicability of the methods proposed for this purpose are <span class="hlt">determined</span>. The limiting <span class="hlt">concentration</span> of particles in suspensions for which these effects should be taken into account depend on the particle size. Using latex as an example, ways of increasing the accuracy of reconstruction of optical constants of weakly absorbing particles of micron and submicron size are shown. Similar <span class="hlt">concentration</span> effects can take place in the study of blood substituents, proteins, and other weakly absorbing particles in weakly absorbing media.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://cfpub.epa.gov/si/si_public_record_report.cfm?dirEntryId=308156&keyword=Progression&actType=&TIMSType=+&TIMSSubTypeID=&DEID=&epaNumber=&ntisID=&archiveStatus=Both&ombCat=Any&dateBeginCreated=&dateEndCreated=&dateBeginPublishedPresented=&dateEndPublishedPresented=&dateBeginUpdated=&dateEndUpdated=&dateBeginCompleted=&dateEndCompleted=&personID=&role=Any&journalID=&publisherID=&sortBy=revisionDate&count=50&CFID=78943025&CFTOKEN=80906802','EPA-EIMS'); return false;" href="http://cfpub.epa.gov/si/si_public_record_report.cfm?dirEntryId=308156&keyword=Progression&actType=&TIMSType=+&TIMSSubTypeID=&DEID=&epaNumber=&ntisID=&archiveStatus=Both&ombCat=Any&dateBeginCreated=&dateEndCreated=&dateBeginPublishedPresented=&dateEndPublishedPresented=&dateBeginUpdated=&dateEndUpdated=&dateBeginCompleted=&dateEndCompleted=&personID=&role=Any&journalID=&publisherID=&sortBy=revisionDate&count=50&CFID=78943025&CFTOKEN=80906802"><span id="translatedtitle">Characterizing <span class="hlt">Determinants</span> of Risk: <span class="hlt">Concentration</span>, Duration, and Timing of Exposure</span></a></p> <p><a target="_blank" href="http://oaspub.epa.gov/eims/query.page">EPA Science Inventory</a></p> <p></p> <p></p> <p>An ongoing challenge in human health risk assessment is to <span class="hlt">determine</span> the best approach for characterizing the risk from real-world exposures. Three major <span class="hlt">determinants</span> characterize exposure: <span class="hlt">concentration</span> (how much), duration (the frequency and how long), and critical timing (whe...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015ChPhB..24k4204Y','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015ChPhB..24k4204Y"><span id="translatedtitle">Quantitative measurements of one-dimensional OH <span class="hlt">absolute</span> <span class="hlt">concentration</span> profiles in a methane/air flat flame by bi-directional laser-induced fluorescence</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Yu, Xin; Yang, Zhen; Peng, Jiang-Bo; Zhang, Lei; Ma, Yu-Fei; Yang, Chao-Bo; Li, Xiao-Hui; Sun, Rui</p> <p>2015-11-01</p> <p>The one-dimensional (1D) spatial distributions of OH <span class="hlt">absolute</span> <span class="hlt">concentration</span> in methane/air laminar premixed flat flame under different equivalence ratios at atmospheric pressure are investigated by using bi-directional laser-induced fluorescence (LIF) detection scheme combined with the direct absorption spectroscopy. The effective peak absorption cross section and the average temperature at a height of 2 mm above the burner are obtained by exciting absorption on the Q1(8) rotational line in the A2Σ+ (ʋ‧ = 0) ← X2Π (ʋ″ = 0) at 309.240 nm. The measured values are 1.86×10-15 cm2 and 1719 K, respectively. Spatial filtering and frequency filtering methods of reducing noise are used to deal with the experimental data, and the smoothing effects are also compared using the two methods. The spatial distribution regularities of OH <span class="hlt">concentration</span> are obtained with the equivalence ratios ranging from 0.8 to 1.3. The spatial resolution of the measured result is 84 μm. Finally, a comparison is made between the experimental result of this paper and other relevant study results. Project supported by the National Key Scientific Instrument and Equipment Development Projects of China (Grant No. 2012YQ040164), the National Natural Science Foundation of China (Grant Nos. 61275127 and 91441130), the China Postdoctoral Science Foundation (Grant No. 2014M560262), and the Postdoctoral Fellowship in Heilongjiang Province, China (Grant No. LBH-Z14074).</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_4");'>4</a></li> <li><a href="#" onclick='return showDiv("page_5");'>5</a></li> <li class="active"><span>6</span></li> <li><a href="#" onclick='return showDiv("page_7");'>7</a></li> <li><a href="#" onclick='return showDiv("page_8");'>8</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_6 --> <div id="page_7" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_5");'>5</a></li> <li><a href="#" onclick='return showDiv("page_6");'>6</a></li> <li class="active"><span>7</span></li> <li><a href="#" onclick='return showDiv("page_8");'>8</a></li> <li><a href="#" onclick='return showDiv("page_9");'>9</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="121"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/26244379','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/26244379"><span id="translatedtitle">Resolution and <span class="hlt">Determination</span> of the <span class="hlt">Absolute</span> Configuration of a Twisted Bis-Lactam Analogue of Tröger's Base: A Comparative Spectroscopic and Computational Study.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Rúnarsson, Ögmundur Vidar; Benkhäuser, Christian; Christensen, Niels Johan; Ruiz, Josep Artacho; Ascic, Erhad; Harmata, Michael; Snieckus, Victor; Rissanen, Kari; Fristrup, Peter; Lützen, Arne; Wärnmark, Kenneth</p> <p>2015-08-21</p> <p>The first reported twisted bis-lactam, a racemic Tröger's base (TB) analogue (2), was resolved into its enantiomers on a chiral stationary phase HPLC column. The <span class="hlt">absolute</span> configuration of (+)-2 was <span class="hlt">determined</span> to be (R,R)-2 by comparing experimental and calculated vibrational circular dichroism (VCD) and electronic circular dichroism (ECD) spectra. The <span class="hlt">absolute</span> configuration of (-)-2 was <span class="hlt">determined</span> by comparing experimental and calculated electronic circular dichroism (ECD) spectra. The corresponding theoretical spectra were calculated using the lowest energy conformation of (R,R)-2 and (S,S)-2 at the B3LYP/6-31G(d,p) level of theory. The <span class="hlt">absolute</span> configuration of (+)-2 was also <span class="hlt">determined</span> to (R,R)-2 by anomalous X-ray diffraction (AXRD) in a chiral space group P212121 using Cu-irradiation resulting in a very low Flack parameter of -0.06(3), despite the heaviest element being an oxygen atom, thus unambiguously confirming the results from the spectroscopic studies. We conclude that, for the Tröger's base (TB) analogue (2), we may rank the reliability of the individual methods for AC <span class="hlt">determination</span> as AXRD ≫ VCD > ECD, while the synergy of all three methods provides very strong confidence in the assigned ACs of (+)-(R,R)-2 and (-)-(S,S)-2. PMID:26244379</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/6340999','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/6340999"><span id="translatedtitle">An analyzer for the <span class="hlt">determination</span> of protein <span class="hlt">concentration</span> in corn</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Nazarov, V.M.; Ostrovnaya, T.M.; Pavlov, S.S.; Sysoev, V.P. )</p> <p>1992-01-01</p> <p>A neutron capture gamma-ray analyzer has been constructed for rapid <span class="hlt">determination</span> of protein <span class="hlt">concentration</span> in corn. In contrast to the well-known methods of protein <span class="hlt">determination</span> (e.g., chemical method of Kjeldahl, infrared method), the present method uses large volume samples and does not require special sample preparation, thereby achieving a measurement time reduction by several times. The neutron capture gamma-ray analysis is based on the <span class="hlt">determination</span> of nitrogen because the protein <span class="hlt">concentration</span> is directly proportional to the nitrogen <span class="hlt">concentration</span> with different proportionality constant for different types of corn. Fast neutrons from a [sup 252]Cf neutron source are moderated by the corn itself to thermal energies. The measurement chamber is a sphere with double walls. The spherical annulus is filled with a biological shield. The sample is placed inside the inner sphere, and the neutron source is placed at the center of the sample sphere.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013SPIE.8723E..17P','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013SPIE.8723E..17P"><span id="translatedtitle"><span class="hlt">Determination</span> of soil ionic <span class="hlt">concentration</span> using impedance spectroscopy</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Pandey, Gunjan; Kumar, Ratnesh; Weber, Robert J.</p> <p>2013-05-01</p> <p>This paper presents a novel approach to estimate the soil ionic <span class="hlt">concentration</span> by way of multi-frequency impedance measurements and using the quasi-static dielectric mixing models to infer the various ionic <span class="hlt">concentrations</span>. In our approach, the permittivity of the soil dielectric mixture is measured using impedance spectroscopy and the results are used as input parameters to dielectric mixing models, combined with the debye-type dielectric relaxation models. We observe that the dielectric mixing models work well for low RF (radio-frequency) range and help in <span class="hlt">determining</span> the individual ionic <span class="hlt">concentration</span> in a multi-component soil mixture. Using the fact that the permittivity of a dielectric mixture is proportional to its impedance, we validated our approach by making multi-frequency impedance measurements of a soil mixture at different <span class="hlt">concentrations</span> of various components. The method provides a good estimate of individual components such as air, water and ions like nitrates. While the paper is written with the perspective of soil constituent <span class="hlt">concentration</span> <span class="hlt">determination</span>, the underlying principle of <span class="hlt">determining</span> individual component <span class="hlt">concentration</span> using multi-frequency impedance measurement is applicable more generally in areas such as characterizing biological systems like pathogens, quality control of pharmaceuticals etc.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/25707319','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/25707319"><span id="translatedtitle"><span class="hlt">Determination</span> of <span class="hlt">concentration</span> and activity of immobilized enzymes.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Singh, Priyanka; Morris, Holly; Tivanski, Alexei V; Kohen, Amnon</p> <p>2015-09-01</p> <p>Methods that directly measure the <span class="hlt">concentration</span> of surface-immobilized biomolecules are scarce. More commonly, the <span class="hlt">concentration</span> of the soluble molecule is measured before and after immobilization, and the bound <span class="hlt">concentration</span> is assessed by elimination, assuming that all bound molecules are active. An assay was developed for measuring the active site <span class="hlt">concentration</span>, activity, and thereby the catalytic turnover rate (kcat) of an immobilized dihydrofolate reductase as a model system. The new method yielded a similar first-order rate constant, kcat, to that of the same enzyme in solution. The findings indicate that the activity of the immobilized enzyme, when separated from the surface by the DNA spacers, has not been altered. In addition, a new immobilization method that leads to solution-like activity of the enzyme on the surface is described. The approaches developed here for immobilization and for <span class="hlt">determining</span> the <span class="hlt">concentration</span> of an immobilized enzyme are general and can be extended to other enzymes, receptors, and antibodies.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016JIMTW..37..473M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016JIMTW..37..473M"><span id="translatedtitle">Real-Time <span class="hlt">Determination</span> of <span class="hlt">Absolute</span> Frequency in Continuous-Wave Terahertz Radiation with a Photocarrier Terahertz Frequency Comb Induced by an Unstabilized Femtosecond Laser</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Minamikawa, Takeo; Hayashi, Kenta; Mizuguchi, Tatsuya; Hsieh, Yi-Da; Abdelsalam, Dahi Ghareab; Mizutani, Yasuhiro; Yamamoto, Hirotsugu; Iwata, Tetsuo; Yasui, Takeshi</p> <p>2016-05-01</p> <p>A practical method for the <span class="hlt">absolute</span> frequency measurement of continuous-wave terahertz (CW-THz) radiation uses a photocarrier terahertz frequency comb (PC-THz comb) because of its ability to realize real-time, precise measurement without the need for cryogenic cooling. However, the requirement for precise stabilization of the repetition frequency ( f rep) and/or use of dual femtosecond lasers hinders its practical use. In this article, based on the fact that an equal interval between PC-THz comb modes is always maintained regardless of the fluctuation in f rep, the PC-THz comb induced by an unstabilized laser was used to <span class="hlt">determine</span> the <span class="hlt">absolute</span> frequency f THz of CW-THz radiation. Using an f rep-free-running PC-THz comb, the f THz of the frequency-fixed or frequency-fluctuated active frequency multiplier chain CW-THz source was <span class="hlt">determined</span> at a measurement rate of 10 Hz with a relative accuracy of 8.2 × 10-13 and a relative precision of 8.8 × 10-12 to a rubidium frequency standard. Furthermore, f THz was correctly <span class="hlt">determined</span> even when fluctuating over a range of 20 GHz. The proposed method enables the use of any commercial femtosecond laser for the <span class="hlt">absolute</span> frequency measurement of CW-THz radiation.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/23952055','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/23952055"><span id="translatedtitle">Environmental <span class="hlt">determinants</span> of polychlorinated biphenyl <span class="hlt">concentrations</span> in residential carpet dust.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>DellaValle, Curt T; Wheeler, David C; Deziel, Nicole C; De Roos, Anneclaire J; Cerhan, James R; Cozen, Wendy; Severson, Richard K; Flory, Abigail R; Locke, Sarah J; Colt, Joanne S; Hartge, Patricia; Ward, Mary H</p> <p>2013-09-17</p> <p>Polychlorinated biphenyls (PCBs), banned in the United Sates in the late 1970s, are still found in indoor and outdoor environments. Little is known about the <span class="hlt">determinants</span> of PCB levels in homes. We measured <span class="hlt">concentrations</span> of five PCB congeners (105, 138, 153, 170, and 180) in carpet dust collected between 1998 and 2000 from 1187 homes in four sites: Detroit, Iowa, Los Angeles, and Seattle. Home characteristics, occupational history, and demographic information were obtained by interview. We used a geographic information system to geocode addresses and <span class="hlt">determine</span> distances to the nearest major road, freight route, and railroad; percentage of developed land; number of industrial facilities within 2 km of residences; and population density. Ordinal logistic regression was used to estimate the associations between the covariates of interest and the odds of PCB detection in each site separately. Total PCB levels [all congeners < maximum practical quantitation limit (MPQL) vs at least one congener ≥ MPQL to < median <span class="hlt">concentration</span> vs at least one congener > median <span class="hlt">concentration</span>] were positively associated with either percentage of developed land [odds ratio (OR) range 1.01-1.04 for each percentage increase] or population density (OR 1.08 for every 1000/mi(2)) in each site. The number of industrial facilities within 2 km of a home was associated with PCB <span class="hlt">concentrations</span>; however, facility type and direction of the association varied by site. Our findings suggest that outdoor sources of PCBs may be significant <span class="hlt">determinants</span> of indoor <span class="hlt">concentrations</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4076890','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4076890"><span id="translatedtitle">Environmental <span class="hlt">determinants</span> of polychlorinated biphenyl <span class="hlt">concentrations</span> in residential carpet dust</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>DellaValle, Curt T.; Wheeler, David C.; Deziel, Nicole C.; De Roos, Anneclaire J.; Cerhan, James R.; Cozen, Wendy; Severson, Richard K.; Flory, Abigail R.; Locke, Sarah J.; Colt, Joanne S.; Hartge, Patricia; Ward, Mary H.</p> <p>2014-01-01</p> <p>Polychlorinated biphenyls (PCBs), banned in the United Sates in the late 1970s, are still found in indoor and outdoor environments. Little is known about the <span class="hlt">determinants</span> of PCB levels in homes. We measured <span class="hlt">concentrations</span> of 5 PCB congeners (105, 138, 153, 170, 180) in carpet dust collected between 1998–2000 from 1,187 homes in four sites: Detroit, Iowa, Los Angeles, and Seattle. Home characteristics, occupational history, and demographic information were obtained by interview. We used a geographic information system to geocode addresses and <span class="hlt">determine</span> distances to the nearest major road, freight route, and railroad, percentage of developed land, number of industrial facilities within 2 km of residences, and population density. Ordinal logistic regression was used to estimate the associations between the covariates of interest and the odds of PCB detection in each site separately. Total PCBs levels (all congeners < maximum practical quantitation limit [MPQL] vs. at least one congener ≥ MPQL to < median <span class="hlt">concentration</span> vs. at least one congener >median <span class="hlt">concentration</span>) were positively associated with either percentage of developed land (ORrange: 1.01-1.04 for each percentage increase) or population density (OR: 1.08 for every 1,000/mi2) in each site. The number of industrial facilities within 2 km of a home was associated with PCB <span class="hlt">concentrations</span>; however, facility type and the direction of the association varied by site. Our findings suggest that outdoor sources of PCBs may be significant <span class="hlt">determinants</span> of indoor <span class="hlt">concentrations</span>. PMID:23952055</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.gpo.gov/fdsys/pkg/CFR-2011-title30-vol1/pdf/CFR-2011-title30-vol1-sec33-32.pdf','CFR2011'); return false;" href="https://www.gpo.gov/fdsys/pkg/CFR-2011-title30-vol1/pdf/CFR-2011-title30-vol1-sec33-32.pdf"><span id="translatedtitle">30 CFR 33.32 - <span class="hlt">Determination</span> of dust <span class="hlt">concentration</span>.</span></a></p> <p><a target="_blank" href="http://www.gpo.gov/fdsys/browse/collectionCfr.action?selectedYearFrom=2011&page.go=Go">Code of Federal Regulations, 2011 CFR</a></p> <p></p> <p>2011-07-01</p> <p>... 30 Mineral Resources 1 2011-07-01 2011-07-01 false <span class="hlt">Determination</span> of dust <span class="hlt">concentration</span>. 33.32 Section 33.32 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR TESTING, EVALUATION, AND APPROVAL OF MINING PRODUCTS DUST COLLECTORS FOR USE IN CONNECTION WITH ROCK DRILLING IN...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/7887470','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/7887470"><span id="translatedtitle">An improved method for <span class="hlt">absolute</span> quantification of mRNA using multiplex polymerase chain reaction: <span class="hlt">determination</span> of renin and angiotensinogen mRNA levels in various tissues.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Dostal, D E; Rothblum, K N; Baker, K M</p> <p>1994-12-01</p> <p>We have developed a multiplex, competitive, reverse-transcriptase polymerase chain reaction (RT-PCR) method which measures <span class="hlt">absolute</span> levels of renin, angiotensinogen, and the housekeeping transcript elongation factor-1 alpha (EF-1 alpha) mRNA. Sample RNA was simultaneously titrated with serial dilutions of renin, angiotensinogen, and EF-1 alpha competitor RNAs which flanked the endogenous <span class="hlt">concentrations</span> of target transcripts. The samples were coreverse transcribed in the presence of random primers and resulting first-strand cDNA was coamplified for 10-15 cycles with [32P]-dCTP and primers for renin angiotensinogen, after which EF-1 alpha primers were added. Amplified DNA was separated by electrophoresis on polyacrylamide gel and radioactivity in the bands was quantified by direct radioanalytical scanning. Three conditions were necessary to obtain <span class="hlt">absolute</span> quantification of renin and angiotensinogen mRNA levels: (a) exogenous competitor RNA was used to control for tube-to-tube variability in the efficiencies of reverse transcription and amplification; (b) Sample RNA was titrated with flanking <span class="hlt">concentrations</span> of competitor RNA to correct for intraassay differences in the efficiency of amplification due to <span class="hlt">concentration</span> differences between competitor and target templates; and (c) a housekeeping transcript EF-1 alpha was used to control for tube-to-tube differences in RNA loading and/or degradation. We show that the multiplex RT-PCR method is precise and accurate over approximately three logs of transcript <span class="hlt">concentration</span> and sensitive to less than 5 and 0.5 fg for renin and angiotensinogen mRNA, respectively. This method will be useful for <span class="hlt">absolute</span> quantification of target mRNAs, especially when the amount of sample RNA is limited or unknown and/or the gene expression is low. PMID:7887470</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=19930027131&hterms=self+determination+theory&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D50%26Ntt%3Dself%2Bdetermination%2Btheory','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=19930027131&hterms=self+determination+theory&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D50%26Ntt%3Dself%2Bdetermination%2Btheory"><span id="translatedtitle"><span class="hlt">Determination</span> of monomer <span class="hlt">concentrations</span> in crystallizing lysozyme solutions</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Wilson, L. J.; Pusey, Marc L.</p> <p>1992-01-01</p> <p>We have developed a non-optical technique for the study of aggregation in lysozyme and other protein solutions. By monitoring the rate at which lysozyme traverses a semipermeable membrane it was possible to quantitate the degree of aggregation in supersaturated solutions. Using this technique, we have measured the <span class="hlt">concentration</span> of monomers and larger aggregates in under- and oversaturated lysozyme solutions, and in the presence of crystals, at pH 4.0 and 3 percent NaCl (0.1M NaAc). Comparison of these <span class="hlt">concentration</span> profiles with (110) face growth rate data supports the theory that tetragonal lysozyme crystals grow by addition of preformed aggregates and not by monomer addition. The data suggest that a considerable population of aggregates larger than dimers are present at lysozyme <span class="hlt">concentrations</span> above 22 mg/ml. <span class="hlt">Determination</span> of dimer <span class="hlt">concentrations</span>, and equilibrium constants for subsequent aggregation levels, are currently underway.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3091859','PMC'); return false;" href="http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3091859"><span id="translatedtitle">Multispectral Imaging for <span class="hlt">Determination</span> of Astaxanthin <span class="hlt">Concentration</span> in Salmonids</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Dissing, Bjørn S.; Nielsen, Michael E.; Ersbøll, Bjarne K.; Frosch, Stina</p> <p>2011-01-01</p> <p>Multispectral imaging has been evaluated for characterization of the <span class="hlt">concentration</span> of a specific cartenoid pigment; astaxanthin. 59 fillets of rainbow trout, Oncorhynchus mykiss, were filleted and imaged using a rapid multispectral imaging device for quantitative analysis. The multispectral imaging device captures reflection properties in 19 distinct wavelength bands, prior to <span class="hlt">determination</span> of the true <span class="hlt">concentration</span> of astaxanthin. The samples ranged from 0.20 to 4.34 g per g fish. A PLSR model was calibrated to predict astaxanthin <span class="hlt">concentration</span> from novel images, and showed good results with a RMSEP of 0.27. For comparison a similar model were built for normal color images, which yielded a RMSEP of 0.45. The acquisition speed of the multispectral imaging system and the accuracy of the PLSR model obtained suggest this method as a promising technique for rapid in-line estimation of astaxanthin <span class="hlt">concentration</span> in rainbow trout fillets. PMID:21573000</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/22415704','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/22415704"><span id="translatedtitle">Accurate and <span class="hlt">absolute</span> diffusion measurements of Rhodamine 6G in low-<span class="hlt">concentration</span> aqueous solutions by the PGSE-WATERGATE sequence</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Majer, G.; Zick, K.</p> <p>2015-04-28</p> <p>A pulsed field gradient spin-echo nuclear magnetic resonance (NMR) sequence with solvent suppression (PGSE-WATERGATE) was applied to accurately measure the diffusion coefficients of Rhodamine 6G (Rh6G) in low-<span class="hlt">concentration</span> aqueous solutions. Three samples with Rh6G <span class="hlt">concentrations</span> of C{sub Rh6G} = 1, 4.5, and 25 μM were investigated. The precise <span class="hlt">determination</span> of the diffusion coefficients in this low-<span class="hlt">concentration</span> range was made possible by using a cryogenically cooled NMR probe and by the effective solvent suppression of the PGSE-WATERGATE sequence. The present results bridge the gap between diffusion data measured by fluorescence correlation spectroscopy in the single molecule limit and diffusivities obtained by pulsed field gradient NMR (PFG-NMR) without solvent suppression at higher <span class="hlt">concentrations</span>. To further extend the <span class="hlt">concentration</span> range, the diffusion coefficient of Rh6G was also measured on a sample with C{sub Rh6G} = 410 μM by PFG-NMR. The overall <span class="hlt">concentration</span> dependence of the Rh6G diffusion at 25 °C is discussed in terms of dimerization of the Rh6G molecules. The <span class="hlt">concentration</span>-dependent monomer/dimer proportion is deduced from the diffusion data.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/323766','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/323766"><span id="translatedtitle"><span class="hlt">Determining</span> controls on element <span class="hlt">concentrations</span> in cement kiln dust leachate</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Duchesne, J.; Reardon, E.J.</p> <p>1998-12-31</p> <p>Cement kiln dust is a waste residue composed chiefly of oxidized, anhydrous, micron-sized particles generated as a by-product of the manufacture of Portland cement. When cement kiln dust is brought into contact with water, high <span class="hlt">concentrations</span> of potassium, sulfate and caustic alkalinity are leached. Other constitutents are leached to a lesser extent. The objective of this study was to <span class="hlt">determine</span> whether the <span class="hlt">concentration</span> of a given chemical constituent in kiln dust leachate is controlled by the precipitation of a secondary mineral phase or whether its <span class="hlt">concentration</span> depends on its initial availability to the leachate solution and its subsequent diffusive flux from hydrating particles with time. Differentiating between these two distinctive styles of leaching behavior is necessary to predict the chemical composition of kiln dust leachate under dynamic flow conditions in disposal environments. Evidence of solubility control was found for Si, Ca, Mg, Al, Zn, Ti, Sr, and Ba. The <span class="hlt">concentrations</span> of Na, Cl, K, Mo, Cr and Se, however, were found to have no solubility control. Because of the observed lack of solubility control and the particularly high <span class="hlt">concentrations</span> of Cr and Mo in kiln dust leachate, The authors tested two additives to reduce their <span class="hlt">concentrations</span>: (1) aluminum oxide to promote the precipitation of calcium aluminosulfates and the proxying of chromate and molybdate for sulfate in their structures; and (2) iron metal to promote the reduction of chromate and molybdate to lower valent and less soluble forms. Neither treatment had any effect on the <span class="hlt">concentration</span> levels of Cr and Mo in solution.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/27231970','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/27231970"><span id="translatedtitle">A Nonempirical Approach for Direct <span class="hlt">Determination</span> of the <span class="hlt">Absolute</span> Configuration of 1,2-Diols and Amino Alcohols Using Mg(II)bisporphyrin.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Ikbal, Sk Asif; Dhamija, Avinash; Brahma, Sanfaori; Rath, Sankar Prasad</p> <p>2016-07-01</p> <p>We report here a simple, facile, and direct nonempirical protocol for <span class="hlt">determining</span> the <span class="hlt">absolute</span> stereochemistry of a variety of chiral 1,2-diols and amino alcohols at room temperature with no chemical derivatization using Mg(II)bisporphyrin as a host. Addition of excess substrates resulted in the formation of a 1:2 host-guest complex in which two substrates bind in an unusual endo-endo fashion because of interligand H-bonding within the bisporphyrin cavity leading to the formation of a unidirectional screw in the bisporphyrin moiety that allowed us an accurate <span class="hlt">absolute</span> stereochemical <span class="hlt">determination</span> of the chiral substrate via exciton-coupled circular dichroism (ECCD). The sign of the CD couplet has also been found to be inverted when the stereogenic center is moved by one C atom simply from the bound to an unbound functionality and thus able to discriminate between them successfully. Strong complexation of the alcoholic oxygen with Mg(II)bisporphyrin rigidifies the host-guest complex, which eventually enhances its ability to stereochemically differentiate the asymmetric center. The ECCD sign of a large number of substrates has followed consistent and predictable trends; thus, the system is widely applicable. Moreover, computational calculations clearly support the experimental observations along with the <span class="hlt">absolute</span> stereochemistry of the chiral substrate. PMID:27231970</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013PSST...22c5009R','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013PSST...22c5009R"><span id="translatedtitle">Line-ratio <span class="hlt">determination</span> of atomic oxygen and N_2(A\\,{}^3\\Sigma_u^+) metastable <span class="hlt">absolute</span> densities in an RF nitrogen late afterglow</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Ricard, André; Oh, Soo-ghee; Guerra, Vasco</p> <p>2013-06-01</p> <p>Optical emission spectroscopy line-ratio methods are developed in order to estimate the <span class="hlt">absolute</span> densities of nitrogen and oxygen atoms and metastable N2(A) molecules in the nitrogen late afterglow of an RF discharge, operating at p = 8 Torr, Q = 1 slm and P = 100 W, in what constitutes an extension of the typical domain of application of these methods. [N] is obtained from the first positive (1+) emission with calibration by NO titration, [O] from the ratio of the NOβ to 1+ bands, and [N2(A)] from the ratios of (i) the NOγ and NOβ bands, (ii) the second positive (2+) and NOβ bands and (iii) the 1+ and 2+ bands. In addition to the <span class="hlt">determination</span> of the N, O and N2(A) <span class="hlt">absolute</span> densities, the present investigation gives an indication on the order of magnitude of the rate coefficient of the very important reaction N2(X, v ⩾ 13) + O → NO + N at room temperature.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/25056998','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/25056998"><span id="translatedtitle"><span class="hlt">Determination</span> of the <span class="hlt">absolute</span> configuration of perylene quinone-derived mycotoxins by measurement and calculation of electronic circular dichroism spectra and specific rotations.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Podlech, Joachim; Fleck, Stefanie C; Metzler, Manfred; Bürck, Jochen; Ulrich, Anne S</p> <p>2014-09-01</p> <p>Altertoxins I-III, alterlosins I and II, alteichin (alterperylenol), stemphyltoxins I-IV, stemphyperylenol, stemphytriol, 7-epi-8-hydroxyaltertoxin I, and 6-epi-stemphytriol are mycotoxins derived from perylene quinone, for which the <span class="hlt">absolute</span> configuration was not known. Electronic circular dichroism (ECD) spectra were calculated for these compounds and compared with measured spectra of altertoxins I-III, alteichin, and stemphyltoxin III and with reported Cotton effects. Specific rotations were calculated and compared with reported specific rotations. The <span class="hlt">absolute</span> configuration of all the toxins, except for stemphyltoxin IV, could thus be <span class="hlt">determined</span>. The validity of the assignment was high whenever reported ECD data were available for comparison, and the validity was lower when the assignment was based only on the comparison of calculated and reported specific rotations. ECD spectra are intrinsically different for toxins with a biphenyl substructure and for toxins derived from dihydroanthracene.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/229666','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/229666"><span id="translatedtitle"><span class="hlt">Determination</span> of waterborne {sup 222}Rn <span class="hlt">concentrations</span> using AC canisters</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Mancini, C.; Giannelli, G.</p> <p>1995-09-01</p> <p>A method for measuring {sup 222}Rn <span class="hlt">concentration</span> in water using charcoal canisters is presented. {sup 222}Rn is transferred within a few minutes from water contained in a 0.720 L bottle to a charcoal canister using a portable degassing unit. In the laboratory, gamma counting is performed at least 10 h after sampling to <span class="hlt">determine</span> waterborne {sup 222}Rn <span class="hlt">concentration</span>. The results obtained with charcoal canisters are compared to measurements made with Marinelli beakers calibrated in a comparison with liquid scintillation counting. The efficiency of transferring dissolved {sup 222}Rn in water to activated charcoal is 99% based on measurements made using Marinelli beakers. The lower limit of detection at the 95% confidence level is approximately 1 kBq m{sup -3} for a 15 min gamma count. the system was used to measure radon <span class="hlt">concentration</span> in mineral groundwater near Rome. 7 refs., 1 fig., 1 tab.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015EPJWC..9308003T','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015EPJWC..9308003T"><span id="translatedtitle"><span class="hlt">Determination</span> of Trace <span class="hlt">Concentration</span> in TMD Detectors using PGAA</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Tomandl, I.; Viererbl, L.; Kudějová, P.; Lahodová, Z.; Klupák, V.; Fikrle, M.</p> <p>2015-05-01</p> <p>Transmutation detectors could be alternative to the traditional activation detector method for neutron fluence dosimetry at power nuclear reactors. This new method require an isotopically highly-sensitive, non-destructive in sense of compactness as well as isotopic content, precise and standardly used analytical method for trace <span class="hlt">concentration</span> <span class="hlt">determination</span>. The capability of Prompt Gamma-ray Activation Analysis (PGAA) for <span class="hlt">determination</span> of trace <span class="hlt">concentrations</span> of transmuted stable nuclides in the metallic foils of Ni, Au, Cu and Nb, which were irradiated for 21 days in the reactor core at the LVR-15 research reactor in Řež, is reported. The PGAA measurements of these activation foils were performed at the PGAA facility at Forschungs-Neutronenquelle Heinz Maier-Leibnitz (FRMII) in Garching.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1990SPIE.1269...88M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1990SPIE.1269...88M"><span id="translatedtitle"><span class="hlt">Determination</span> of nitrous oxide <span class="hlt">concentrations</span> by spectroscopic method</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Mirzoeva, Larissa A.; Kiseleva, Margarete S.; Sinelnikova, Galina E.</p> <p>1990-08-01</p> <p>In the proposed paper an empirical method has been developed for <span class="hlt">determination</span> of nitrous oxide <span class="hlt">concentration</span> using the absorption band 2'), in proximity of), 3.87J4m, free from overlapping with absorption bands from other atmospheric gases. The transmission spectra of the atmospheric air are recorded with unresolved rotation-vibration structure. The method is inexpensive, simple and efficient It may be used for <span class="hlt">determination</span> of enviromental pollution in homogeneous media (laboratory or production plant conditions, ground layer of atmosphere) and of unhomogeneous composistion mixtures when studying the contents of nitrous oxide along slope paths in troposphere and stratosphere.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/22149199','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/22149199"><span id="translatedtitle">Polychlorinated biphenyls in Spanish adults: <span class="hlt">Determinants</span> of serum <span class="hlt">concentrations</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Agudo, Antonio; Goni, Fernando; Etxeandia, Arsenio; Vives, Asuncion; Millan, Esmeralda; Lopez, Raul; Amiano, Pilar; Ardanaz, Eva; Barricarte, Aurelio; Dolores Chirlaque, M.; Dorronsoro, Miren; Jakszyn, Paula; Larranaga, Nerea; Martinez, Carmen; Navarro, Carmen; Rodriguez, Laudina; and others</p> <p>2009-07-15</p> <p>Background: Polychlorinated biphenyls (PCBs) are persistent compounds that may pose an environmental hazard to humans, food being the main source of exposure for the general population. Objective: To measure the serum <span class="hlt">concentrations</span> of the main PCBs in subjects from the general population in Spain, and to assess potential <span class="hlt">determinants</span> of such <span class="hlt">concentrations</span>. Methods: Serum was obtained from blood samples of 953 subjects aged 35-64 years, residents in five Spanish regions (three from the North and two from the South), randomly selected from the EPIC-Spain cohort. Blood collection took place during 1992-1996 and four PCB congeners (118, 138, 153 and 180) were <span class="hlt">determined</span> by means of gas chromatography with electron-capture detection (GC-ECD). Results: The <span class="hlt">concentration</span> of total PCBs was 459 ng/g lipids (or 3.1 {mu}g/l); the corresponding figures for PCB 153 were 186 ng/g lipids and 1.25 {mu}g/l. Men had higher values than women, PCB levels increased with age, and serum <span class="hlt">concentration</span> of PCBs was higher in northern regions. Body mass index (BMI) was inversely related to PCB <span class="hlt">concentrations</span>, and fish intake was the dietary factor showing the greatest association with serum PCBs. The pattern described was similar for each congener separately. Conclusions: We found <span class="hlt">concentrations</span> similar to those reported in European countries where blood collection was carried during the same period. Regional differences within Spain are not fully explained by anthropometric or dietary factors. The inverse association with BMI suggests that in the mid-1990s there was still ongoing or recent exposure to PCBs in Spain.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_5");'>5</a></li> <li><a href="#" onclick='return showDiv("page_6");'>6</a></li> <li class="active"><span>7</span></li> <li><a href="#" onclick='return showDiv("page_8");'>8</a></li> <li><a href="#" onclick='return showDiv("page_9");'>9</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_7 --> <div id="page_8" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_6");'>6</a></li> <li><a href="#" onclick='return showDiv("page_7");'>7</a></li> <li class="active"><span>8</span></li> <li><a href="#" onclick='return showDiv("page_9");'>9</a></li> <li><a href="#" onclick='return showDiv("page_10");'>10</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="141"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1995NIMPA.355..195W','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1995NIMPA.355..195W"><span id="translatedtitle"><span class="hlt">Determination</span> of the <span class="hlt">concentration</span> of SF 6 in an accelerator gas mixture by measuring the velocity of sound</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Wilburn, W. S.; Gould, C. R.; Haase, D. G.; Hoffenberg, R. S.; Mioduszewski, S.; Roberson, N. R.</p> <p>1995-02-01</p> <p>A simple and reliable method for <span class="hlt">determining</span> the <span class="hlt">concentration</span> of SF 6 in an accelerator gas mixture with N 2 and CO 2 is described. The technique makes use of the low velocity of sound in SF 6 (approximately {1}/{3} that of air). The sound velocity of the mixture is <span class="hlt">determined</span> by measuring the spacing of acoustic resonances in a tube filled with the gas. Data from standard gas mixtures containing 0-10% SF 6 are presented, showing that the technique is accurate to approximately 0.5% <span class="hlt">absolute</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/25513886','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/25513886"><span id="translatedtitle">Evaluation of nanoparticle-ligand distributions to <span class="hlt">determine</span> nanoparticle <span class="hlt">concentration</span>.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Uddayasankar, Uvaraj; Shergill, Ravi T; Krull, Ulrich J</p> <p>2015-01-20</p> <p>The <span class="hlt">concentration</span> of nanoparticles in solution is an important, yet challenging, parameter to quantify. In this work, a facile strategy for the <span class="hlt">determination</span> of nanoparticle <span class="hlt">concentration</span> is presented. The method relies on the quantitative analysis of the inherent distribution of nanoparticle-ligand conjugates that are generated when nanoparticles are functionalized with ligands. Validation of the method was accomplished by applying it to gold nanoparticles and semiconductor nanoparticles (CdSe/ZnS; core/shell). Poly(ethylene glycol) based ligands, with functional groups that quantitatively react with the nanoparticles, were incubated with the nanoparticles at varying equivalences. Agarose gel electrophoresis was subsequently used to separate and quantify the nanoparticle-ligand conjugates of varying valences. The distribution in the nanoparticle-ligand conjugates agreed well with that predicted by the Poisson model. A protocol was then developed, where a series of only eight different ligand amounts could provide an estimate of the nanoparticle <span class="hlt">concentration</span> that spans 3 orders of magnitude (1 μM to 1 mM). For the gold nanoparticles and semiconductor nanoparticles, the measured <span class="hlt">concentrations</span> were found to deviate by only 7% and 2%, respectively, from those <span class="hlt">determined</span> by UV-vis spectroscopy. The precision of the assay was evaluated, resulting in a coefficient of variation of 5-7%. Finally, the protocol was used to <span class="hlt">determine</span> the extinction coefficient of alloyed semiconductor nanoparticles (CdSxSe1-x/ZnS), for which a reliable estimate is currently unavailable, of three different emission wavelengths (525, 575, and 630 nm). The extinction coefficient of the nanoparticles of all emission wavelengths was similar and was found to be 2.1 × 10(5) M(-1)cm(-1).</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/16979649','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/16979649"><span id="translatedtitle">Optical factors <span class="hlt">determined</span> by the T-matrix method in turbidity measurement of <span class="hlt">absolute</span> coagulation rate constants.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Xu, Shenghua; Liu, Jie; Sun, Zhiwei</p> <p>2006-12-01</p> <p>Turbidity measurement for the <span class="hlt">absolute</span> coagulation rate constants of suspensions has been extensively adopted because of its simplicity and easy implementation. A key factor in deriving the rate constant from experimental data is how to theoretically evaluate the so-called optical factor involved in calculating the extinction cross section of doublets formed during aggregation. In a previous paper, we have shown that compared with other theoretical approaches, the T-matrix method provides a robust solution to this problem and is effective in extending the applicability range of the turbidity methodology, as well as increasing measurement accuracy. This paper will provide a more comprehensive discussion of the physical insight for using the T-matrix method in turbidity measurement and associated technical details. In particular, the importance of ensuring the correct value for the refractive indices for colloidal particles and the surrounding medium used in the calculation is addressed, because the indices generally vary with the wavelength of the incident light. The comparison of calculated results with experiments shows that the T-matrix method can correctly calculate optical factors even for large particles, whereas other existing theories cannot. In addition, the data of the optical factor calculated by the T-matrix method for a range of particle radii and incident light wavelengths are listed.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/27331118','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/27331118"><span id="translatedtitle"><span class="hlt">Absolute</span> nutrient <span class="hlt">concentration</span> measurements in cell culture media: (1)H q-NMR spectra and data to compare the efficiency of pH-controlled protein precipitation versus CPMG or post-processing filtering approaches.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Goldoni, Luca; Beringhelli, Tiziana; Rocchia, Walter; Realini, Natalia; Piomelli, Daniele</p> <p>2016-09-01</p> <p>The NMR spectra and data reported in this article refer to the research article titled "A simple and accurate protocol for <span class="hlt">absolute</span> polar metabolite quantification in cell cultures using q-NMR" [1]. We provide the (1)H q-NMR spectra of cell culture media (DMEM) after removal of serum proteins, which show the different efficiency of various precipitating solvents, the solvent/DMEM ratios, and pH of the solution. We compare the data of the <span class="hlt">absolute</span> nutrient <span class="hlt">concentrations</span>, measured by PULCON external standard method, before and after precipitation of serum proteins and those obtained using CPMG (Carr-Purcell-Meiboom-Gill) sequence or applying post-processing filtering algorithms to remove, from the (1)H q-NMR spectra, the proteins signal contribution. For each of these approaches, the percent error in the <span class="hlt">absolute</span> value of every measurement for all the nutrients is also plotted as accuracy assessment. PMID:27331118</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/25099190','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/25099190"><span id="translatedtitle">Nanoparticle counting: towards accurate <span class="hlt">determination</span> of the molar <span class="hlt">concentration</span>.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Shang, Jing; Gao, Xiaohu</p> <p>2014-11-01</p> <p>Innovations in nanotechnology have brought tremendous opportunities for the advancement of many research frontiers, ranging from electronics, photonics, energy, to medicine. To maximize the benefits of nano-scaled materials in different devices and systems, precise control of their <span class="hlt">concentration</span> is a prerequisite. While <span class="hlt">concentrations</span> of nanoparticles have been provided in other forms (e.g., mass), accurate <span class="hlt">determination</span> of molar <span class="hlt">concentration</span>, arguably the most useful one for chemical reactions and applications, has been a major challenge (especially for nanoparticles smaller than 30 nm). Towards this significant yet chronic problem, a variety of strategies are currently under development. Most of these strategies are applicable to a specialized group of nanoparticles due to their restrictions on the composition and size range of nanoparticles. As research and uses of nanomaterials are being explored in an unprecedented speed, it is necessary to develop universal strategies that are easy to use and are compatible with nanoparticles of different sizes, compositions, and shapes. This review outlines the theories and applications of current strategies to measure nanoparticle molar <span class="hlt">concentration</span>, discusses the advantages and limitations of these methods, and provides insights into future directions.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/17897803','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/17897803"><span id="translatedtitle">ET-AAS <span class="hlt">determination</span> of aluminium in dialysis <span class="hlt">concentrates</span> after continuous flow solvent extraction.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Komárek, J; Cervenka, R; Růzicka, T; Kubán, V</p> <p>2007-11-01</p> <p>Conditions of a continuous flow extraction (CFE) of aluminium acetylacetonate in acetylacetone and aluminium 8-hydroxyquinolinate into methylisobutylketone (lengths of reaction and extraction coils, flow rates of aqueous and organic phases and their flow rate ratio, pH of aqueous phase, lengths of coils for transport of aqueous and organic phases and effect of salts) were studied. The analytical signal of the aluminium chelates present in the organic phase was measured at 309.3 nm using atomic absorption spectrometry with electrothermal atomization (ET-AAS) at the flow rate ratio F aq/F org=3 for aqueous and organic phases. The five points calibration curves were linear (R2 0.9973 and 0.9987) up to 21 microgl(-1) Al with the limits of detection of 0.3 microgl(-1) and the recovery 100+/-2% and precision of 3% at 2-10-fold dilution of the dialysis <span class="hlt">concentrates</span>. The acetylacetonate method was applied to the <span class="hlt">determination</span> of aluminium in real dialysis <span class="hlt">concentrates</span>. Aluminium in <span class="hlt">concentrations</span> 5-6 microgl(-1) (R.S.D.s 5-10% in real samples) were found and the results were in the very good agreement with those obtained by an ET-AAS using preconcentration of Al(III) on a Spheron-Salicyl chelating sorbent (<span class="hlt">absolute</span> and relative differences were under 0.4 microgl(-1) and 8.2%, respectively). PMID:17897803</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=5064742','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=5064742"><span id="translatedtitle"><span class="hlt">Absolute</span> bioavailability of evacetrapib in healthy subjects <span class="hlt">determined</span> by simultaneous administration of oral evacetrapib and intravenous [13C8]‐evacetrapib as a tracer</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Aburub, Aktham; Ward, Chris; Hinds, Chris; Czeskis, Boris; Ruterbories, Kenneth; Suico, Jeffrey G.; Royalty, Jane; Ortega, Demetrio; Pack, Brian W.; Begum, Syeda L.; Annes, William F.; Lin, Qun; Small, David S.</p> <p>2015-01-01</p> <p>This open‐label, single‐period study in healthy subjects estimated evacetrapib <span class="hlt">absolute</span> bioavailability following simultaneous administration of a 130‐mg evacetrapib oral dose and 4‐h intravenous (IV) infusion of 175 µg [13C8]‐evacetrapib as a tracer. Plasma samples collected through 168 h were analyzed for evacetrapib and [13C8]‐evacetrapib using high‐performance liquid chromatography/tandem mass spectrometry. Pharmacokinetic parameter estimates following oral and IV doses, including area under the concentration‐time curve (AUC) from zero to infinity (AUC[0‐∞]) and to the last measureable <span class="hlt">concentration</span> (AUC[0‐tlast]), were calculated. Bioavailability was calculated as the ratio of least‐squares geometric mean of dose‐normalized AUC (oral : IV) and corresponding 90% confidence interval (CI). Bioavailability of evacetrapib was 44.8% (90% CI: 42.2–47.6%) for AUC(0‐∞) and 44.3% (90% CI: 41.8–46.9%) for AUC(0‐tlast). Evacetrapib was well tolerated with no reports of clinically significant safety assessment findings. This is among the first studies to estimate <span class="hlt">absolute</span> bioavailability using simultaneous administration of an unlabeled oral dose with a 13C‐labeled IV microdose tracer at about 1/1000th the oral dose, with measurement in the pg/mL range. This approach is beneficial for poorly soluble drugs, does not require additional toxicology studies, does not change oral dose pharmacokinetics, and ultimately gives researchers another tool to evaluate <span class="hlt">absolute</span> bioavailability. PMID:26639670</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://pubs.er.usgs.gov/publication/70013244','USGSPUBS'); return false;" href="http://pubs.er.usgs.gov/publication/70013244"><span id="translatedtitle">Synchrotron radiation <span class="hlt">determination</span> of elemental <span class="hlt">concentrations</span> in coal</span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Chen, J.R.; Martys, N.; Chao, E.C.T.; Minkin, J.A.; Thompson, C.L.; Hanson, A.L.; Kraner, H.W.; Jones, K.W.; Gordon, B.M.; Mills, R.E.</p> <p>1984-01-01</p> <p>The variations with depth of the elemental <span class="hlt">concentrations</span> in vitrinites in a series of vitrites have been <span class="hlt">determined</span> using radiation from the Cornell high energy synchrotron source. All of the vitrites were selected from a single drill core sample of coal from the Emery coalfield, Utah. The results are compared with similar <span class="hlt">determinations</span> using the Heidelberg proton microprobe. The advantages and disadvantages of the two techniques are discussed. Results are reported for S, Ca, Ti, Fe, Zn, Br, and Sr. For example, it is found that Fe increases from top to bottom of the coal bed in contrast to S, which decreases from top to bottom of the bed. Other features of the two data sets are also described. ?? 1984.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/27653489','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/27653489"><span id="translatedtitle">Electrophysiological <span class="hlt">Determination</span> of Submembrane Na(+) <span class="hlt">Concentration</span> in Cardiac Myocytes.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Hegyi, Bence; Bányász, Tamás; Shannon, Thomas R; Chen-Izu, Ye; Izu, Leighton T</p> <p>2016-09-20</p> <p>In the heart, Na(+) is a key modulator of the action potential, Ca(2+) homeostasis, energetics, and contractility. Because Na(+) currents and cotransport fluxes depend on the Na(+) <span class="hlt">concentration</span> in the submembrane region, it is necessary to accurately estimate the submembrane Na(+) <span class="hlt">concentration</span> ([Na(+)]sm). Current methods using Na(+)-sensitive fluorescent indicators or Na(+) -sensitive electrodes cannot measure [Na(+)]sm. However, electrophysiology methods are ideal for measuring [Na(+)]sm. In this article, we develop patch-clamp protocols and experimental conditions to <span class="hlt">determine</span> the upper bound of [Na(+)]sm at the peak of action potential and its lower bound at the resting state. During the cardiac cycle, the value of [Na(+)]sm is constrained within these bounds. We conducted experiments in rabbit ventricular myocytes at body temperature and found that 1) at a low pacing frequency of 0.5 Hz, the upper and lower bounds converge at 9 mM, constraining the [Na(+)]sm value to ∼9 mM; 2) at 2 Hz pacing frequency, [Na(+)]sm is bounded between 9 mM at resting state and 11.5 mM; and 3) the cells can maintain [Na(+)]sm to the above values, despite changes in the pipette Na(+) <span class="hlt">concentration</span>, showing autoregulation of Na(+) in beating cardiomyocytes. PMID:27653489</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4582785','PMC'); return false;" href="http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4582785"><span id="translatedtitle"><span class="hlt">Determinants</span> of 25-Hydroxyvitamin D <span class="hlt">Concentrations</span> in Infants and Toddlers</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Michel, Hilary; Olabopo, Flora; Wang, Li; Nucci, Anita; Greenspan, Susan L; Rajakumar, Kumaravel</p> <p>2015-01-01</p> <p>Background Resurgence of rickets and recognition of excessive prevalence of hypovitaminosis D among all age groups in the western hemisphere have refocused attention on vitamin D nutrition. Objective To examine the prevalence of hypovitaminosis D [25-hydroxyvitamin D [25(OH)D] <30ng/mL] and characterize the <span class="hlt">determinants</span> of 25(OH)D <span class="hlt">concentrations</span> in 8- to 24-month-old healthy infants and toddlers living in Pittsburgh, Pennsylvania. Methods Serum 25(OH)D <span class="hlt">concentrations</span> were measured and dietary intake of vitamin D, mode of feeding, summertime sun exposure characteristics, and skin color (sun-reactive skin type and melanin index) were assessed. Results A total of 111 healthy 8- to 24-month-old children (mean age [±SD] 14.4 [±3.5] months; male, 51%; black, 67%) were studied. Serum 25(OH)D <span class="hlt">concentration</span> was <30 ng/mL in 16% (n=18) of the children. Median (interquartile) 25(OH)D <span class="hlt">concentration</span> was lower in children who were ≥ 13 months vs. <13 months of age [35 (31, 40.5) vs. 40 (35.8, 44.3) ng/mL, p=0.013]; with sun-reactive skin type IV and V vs. I, II, and III [36 (31, 41) vs. 44 (36.5, 48.5) ng/mL, p=0.001]; and examined during fall/winter vs. spring/summer [35.5 (32.5, 38.5) vs. 39 (32.5, 44) ng/mL, p=0.05]. Age and skin type were significant independent predictors of 25(OH)D. Conclusions <span class="hlt">Concentrations</span> of 25(OH)D tend to be lower in infants and toddlers during fall/winter, and in children who are older (≥13 months vs. <13 months of age) and have darker skin tone. Benefits of enhancement of 25(OH)D <span class="hlt">concentrations</span> during fall/winter and in children with higher sun-reactive skin type need further exploration. PMID:26417213</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/26210115','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/26210115"><span id="translatedtitle">Towards <span class="hlt">determination</span> of <span class="hlt">absolute</span> molar mass of cellulose polymer by size exclusion chromatography with mulitple angle laser light scattering detection.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Pawcenis, Dominika; Thomas, Jacob L; Łojewski, Tomasz; Milczarek, Jakub M; Łojewska, Joanna</p> <p>2015-08-28</p> <p>The study focuses on <span class="hlt">determination</span> of a set of crucial parameters for molar mass calculation of cellulose from the results of size exclusion chromatography coupled with multiple angle laser light scattering (MALLS) and differential refractive index (DRI) detectors. In the present work, cellulose has been derivatised to obtain cellulose tricarbanilate (CTC) soluble in tetrahydrofuran (THF). The parameters of Rayleigh scattering in the MALLS detector: refractive index increment (dn/dc) and second virial coefficient (A2) of CTC in THF were <span class="hlt">determined</span> for laser wavelength 658nm. In order to avoid errors resulting from cellulose derivatisation by-products present in the CTC solution, the so called "on-line" method of measuring dn/dc and A2 was applied. Based on the A2 <span class="hlt">determination</span>, its influence on cellulose molar mass calculations and cellulose molecular dimensions were critically assessed. The latter includes evaluation of artificially aged cellulose towards conceivable branching by conformation plot analysis.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/26210115','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/26210115"><span id="translatedtitle">Towards <span class="hlt">determination</span> of <span class="hlt">absolute</span> molar mass of cellulose polymer by size exclusion chromatography with mulitple angle laser light scattering detection.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Pawcenis, Dominika; Thomas, Jacob L; Łojewski, Tomasz; Milczarek, Jakub M; Łojewska, Joanna</p> <p>2015-08-28</p> <p>The study focuses on <span class="hlt">determination</span> of a set of crucial parameters for molar mass calculation of cellulose from the results of size exclusion chromatography coupled with multiple angle laser light scattering (MALLS) and differential refractive index (DRI) detectors. In the present work, cellulose has been derivatised to obtain cellulose tricarbanilate (CTC) soluble in tetrahydrofuran (THF). The parameters of Rayleigh scattering in the MALLS detector: refractive index increment (dn/dc) and second virial coefficient (A2) of CTC in THF were <span class="hlt">determined</span> for laser wavelength 658nm. In order to avoid errors resulting from cellulose derivatisation by-products present in the CTC solution, the so called "on-line" method of measuring dn/dc and A2 was applied. Based on the A2 <span class="hlt">determination</span>, its influence on cellulose molar mass calculations and cellulose molecular dimensions were critically assessed. The latter includes evaluation of artificially aged cellulose towards conceivable branching by conformation plot analysis. PMID:26210115</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/23665766','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/23665766"><span id="translatedtitle"><span class="hlt">Absolute</span> <span class="hlt">determination</span> of power density in the VVER-1000 mock-up on the LR-0 research reactor.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Košt'ál, Michal; Švadlenková, Marie; Milčák, Ján</p> <p>2013-08-01</p> <p>The work presents a detailed comparison of calculated and experimentally <span class="hlt">determined</span> net peak areas of selected fission products gamma lines. The fission products were induced during a 2.5 h irradiation on the power level of 9.5 W in selected fuel pins of the VVER-1000 Mock-Up. The calculations were done with deterministic and stochastic (Monte Carlo) methods. The effects of different nuclear data libraries used for calculations are discussed as well. The Net Peak Area (NPA) may be used for the <span class="hlt">determination</span> of fission density across the mock-up. This fission density is practically identical to power density.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016PEPI..258...51H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016PEPI..258...51H"><span id="translatedtitle">A whole rock <span class="hlt">absolute</span> paleointensity <span class="hlt">determination</span> of dacites from the Duffer Formation (ca. 3.467 Ga) of the Pilbara Craton, Australia: An impossible task?</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Herrero-Bervera, Emilio; Krasa, David; Van Kranendonk, Martin J.</p> <p>2016-09-01</p> <p>We have conducted a whole-rock type magnetic and <span class="hlt">absolute</span> paleointensity <span class="hlt">determination</span> of the red dacite of the Duffer Formation from the Pilbara Craton, Australia. The age of the dated rock unit is 3467 ± 5 Ma (95% confidence). Vector analyses results of the step-wise alternating field demagnetization (NRM up to 100 mT) and thermal demagnetization (from NRM up to 650 °C) yield three components of magnetization. Curie point <span class="hlt">determinations</span> indicate three characteristic temperatures, one at 150-200 °C, a second one at ∼450 °C and a third one at ∼580 °C. Magnetic grain-size experiments were performed on small specimens with a variable field translation balance (VFTB). The coercivity of remanence (Hcr) suggests that the NRM is carried by low-coercivity grains that are associated with a magnetite fraction as is shown by the high-temperature component with blocking temperatures above 450 °C and up to at least 580 °C. The ratios of the hysteresis parameters plotted as a modified Day diagram show that most grain sizes are scattered within the Single Domain (SD) and the Superparamagnetic and Single Domain SP-SD domain ranges. In addition to the rock magnetic experiments we have performed <span class="hlt">absolute</span> paleointensity experiments on the samples using the modified Thellier-Coe double heating method to <span class="hlt">determine</span> the paleointensities. Partial-TRM (p-TRM) checks were performed systematically to document magnetomineralogical changes during heating. The temperature was incremented by steps of 50 °C between room temperature and 590 °C. The paleointensity <span class="hlt">determinations</span> were obtained from the slope of Arai diagrams. Our paleointensity results indicate that the paleofield obtained was ∼6.4 ± 0.68 (N = 11) micro-Teslas with a Virtual Dipole Moment (VDM) of 1.51 ± 0.81 × 1022 Am2, from a medium-to high-temperature component ranging from 300 to 590 °C that has been interpreted to be the oldest magnetization yet recorded in paleomagnetic studies of the Duffer Formation. The</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/17155736','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/17155736"><span id="translatedtitle">Measurement of the B-->pi l nu branching fraction and <span class="hlt">determination</span> of <span class="hlt">absolute</span> value of V(ub) with tagged B mesons.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Aubert, B; Barate, R; Bona, M; Boutigny, D; Couderc, F; Karyotakis, Y; Lees, J P; Poireau, V; Tisserand, V; Zghiche, A; Grauges, E; Palano, A; Chen, J C; Qi, N D; Rong, G; Wang, P; Zhu, Y S; Eigen, G; Ofte, I; Stugu, B; Abrams, G S; Battaglia, M; Brown, D N; Button-Shafer, J; Cahn, R N; Charles, E; Gill, M S; Groysman, Y; Jacobsen, R G; Kadyk, J A; Kerth, L T; Kolomensky, Yu G; Kukartsev, G; Lynch, G; Mir, L M; Orimoto, T J; Pripstein, M; Roe, N A; Ronan, M T; Wenzel, W A; del Amo Sanchez, P; Barrett, M; Ford, K E; Harrison, T J; Hart, A J; Hawkes, C M; Morgan, S E; Watson, A T; Held, T; Koch, H; Lewandowski, B; Pelizaeus, M; Peters, K; Schroeder, T; Steinke, M; Boyd, J T; Burke, J P; Cottingham, W N; Walker, D; Cuhadar-Donszelmann, T; Fulsom, B G; Hearty, C; Knecht, N S; Mattison, T S; McKenna, J A; Khan, A; Kyberd, P; Saleem, M; Sherwood, D J; Teodorescu, L; Blinov, V E; Bukin, A D; Druzhinin, V P; Golubev, V B; Onuchin, A P; Serednyakov, S I; Skovpen, Yu I; Solodov, E P; Todyshev, K Yu; Best, D S; Bondioli, M; Bruinsma, M; Chao, M; Curry, S; Eschrich, I; Kirkby, D; Lankford, A J; Lund, P; Mandelkern, M; Mommsen, R K; Roethel, W; Stoker, D P; Abachi, S; Buchanan, C; Foulkes, S D; Gary, J W; Long, O; Shen, B C; Wang, K; Zhang, L; Hadavand, H K; Hill, E J; Paar, H P; Rahatlou, S; Sharma, V; Berryhill, J W; Campagnari, C; Cunha, A; Dahmes, B; Hong, T M; Kovalskyi, D; Richman, J D; Beck, T W; Eisner, A M; Flacco, C J; Heusch, C A; Kroseberg, J; Lockman, W S; Nesom, G; Schalk, T; Schumm, B A; Seiden, A; Spradlin, P; Williams, D C; Wilson, M G; Albert, J; Chen, E; Dvoretskii, A; Fang, F; Hitlin, D G; Narsky, I; Piatenko, T; Porter, F C; Ryd, A; Samuel, A; Mancinelli, G; Meadows, B T; Mishra, K; Sokoloff, M D; Blanc, F; Bloom, P C; Chen, S; Ford, W T; Hirschauer, J F; Kreisel, A; Nagel, M; Nauenberg, U; Olivas, A; Ruddick, W O; Smith, J G; Ulmer, K A; Wagner, S R; Zhang, J; Chen, A; Eckhart, E A; Soffer, A; Toki, W H; Wilson, R J; Winklmeier, F; Zeng, Q; Altenburg, D D; Feltresi, E; Hauke, A; Jasper, H; Petzold, A; Spaan, B; Brandt, T; Klose, V; Lacker, H M; Mader, W F; Nogowski, R; Schubert, J; Schubert, K R; Schwierz, R; Sundermann, J E; Volk, A; Bernard, D; Bonneaud, G R; Grenier, P; Latour, E; Thiebaux, Ch; Verderi, M; Clark, P J; Gradl, W; Muheim, F; Playfer, S; Robertson, A I; Xie, Y; Andreotti, M; Bettoni, D; Bozzi, C; Calabrese, R; Cibinetto, G; Luppi, E; Negrini, M; Petrella, A; Piemontese, L; Prencipe, E; Anulli, F; Baldini-Ferroli, R; Calcaterra, A; de Sangro, R; Finocchiaro, G; Pacetti, S; Patteri, P; Peruzzi, I M; Piccolo, M; Rama, M; Zallo, A; Buzzo, A; Capra, R; Contri, R; Lo Vetere, M; Macri, M M; Monge, M R; Passaggio, S; Patrignani, C; Robutti, E; Santroni, A; Tosi, S; Brandenburg, G; Chaisanguanthum, K S; Morii, M; Wu, J; Dubitzky, R S; Marks, J; Schenk, S; Uwer, U; Bard, D J; Bhimji, W; Bowerman, D A; Dauncey, P D; Egede, U; Flack, R L; Nash, J A; Nikolich, M B; Panduro Vazquez, W; Behera, P K; Chai, X; Charles, M J; Mallik, U; Meyer, N T; Ziegler, V; Cochran, J; Crawley, H B; Dong, L; Eyges, V; Meyer, W T; Prell, S; Rosenberg, E I; Rubin, A E; Gritsan, A V; Denig, A G; Fritsch, M; Schott, G; Arnaud, N; Davier, M; Grosdidier, G; Höcker, A; Le Diberder, F; Lepeltier, V; Lutz, A M; Oyanguren, A; Pruvot, S; Rodier, S; Roudeau, P; Schune, M H; Stocchi, A; Wang, W F; Wormser, G; Cheng, C H; Lange, D J; Wright, D M; Chavez, C A; Forster, I J; Fry, J R; Gabathuler, E; Gamet, R; George, K A; Hutchcroft, D E; Payne, D J; Schofield, K C; Touramanis, C; Bevan, A J; Di Lodovico, F; Menges, W; Sacco, R; Cowan, G; Flaecher, H U; Hopkins, D A; Jackson, P S; McMahon, T R; Ricciardi, S; Salvatore, F; Wren, A C; Brown, D N; Davis, C L; Allison, J; Barlow, N R; Barlow, R J; Chia, Y M; Edgar, C L; Lafferty, G D; Naisbit, M T; Williams, J C; Yi, J I; Chen, C; Hulsbergen, W D; Jawahery, A; Lae, C K; Roberts, D A; Simi, G; Blaylock, G; Dallapiccola, C; Hertzbach, S S; Li, X; Moore, T B; Saremi, S; Staengle, H; Cowan, R; Sciolla, G; Sekula, S J; Spitznagel, M; Taylor, F; Yamamoto, R K; Kim, H; McLachlin, S E; Patel, P M; Robertson, S H; Lazzaro, A; Lombardo, V; Palombo, F; Bauer, J M; Cremaldi, L; Eschenburg, V; Godang, R; Kroeger, R; Sanders, D A; Summers, D J; Zhao, H W; Brunet, S; Côté, D; Simard, M; Taras, P; Viaud, F B; Nicholson, H; Cavallo, N; De Nardo, G; Fabozzi, F; Gatto, C; Lista, L; Monorchio, D; Paolucci, P; Piccolo, D; Sciacca, C; Baak, M; Raven, G; Snoek, H L; Jessop, C P; Losecco, J M; Allmendinger, T; Benelli, G; Gan, K K; Honscheid, K; Hufnagel, D; Jackson, P D; Kagan, H; Kass, R; Rahimi, A M; Ter-Antonyan, R; Wong, Q K; Blount, N L; Brau, J; Frey, R; Igonkina, O; Lu, M; Rahmat, R; Sinev, N B; Strom, D; Strube, J; Torrence, E; Gaz, A; Margoni, M; Morandin, M; Pompili, A; Posocco, M; Rotondo, M; Simonetto, F; Stroili, R; Voci, C; Benayoun, M; Chauveau, J; Briand, H; David, P; Del Buono, L; de la Vaissière, Ch; Hamon, O; Hartfiel, B L; John, M J J; Leruste, Ph; Malclès, J; Ocariz, J; Roos, L; Therin, G; Gladney, L; Panetta, J; Biasini, M; Covarelli, R; Angelini, C; Batignani, G; Bettarini, S; Bucci, F; Calderini, G; Carpinelli, M; Cenci, R; Forti, F; Giorgi, M A; Lusiani, A; Marchiori, G; Mazur, M A; Morganti, M; Neri, N; Paoloni, E; Rizzo, G; Walsh, J J; Haire, M; Judd, D; Wagoner, D E; Biesiada, J; Danielson, N; Elmer, P; Lau, Y P; Lu, C; Olsen, J; Smith, A J S; Telnov, A V; Bellini, F; Cavoto, G; D'Orazio, A; del Re, D; Di Marco, E; Faccini, R; Ferrarotto, F; Ferroni, F; Gaspero, M; Li Gioi, L; Mazzoni, M A; Morganti, S; Piredda, G; Polci, F; Safai Tehrani, F; Voena, C; Ebert, M; Schröder, H; Waldi, R; Adye, T; De Groot, N; Franek, B; Olaiya, E O; Wilson, F F; Aleksan, R; Emery, S; Gaidot, A; Ganzhur, S F; Hamel de Monchenault, G; Kozanecki, W; Legendre, M; Vasseur, G; Yèche, Ch; Zito, M; Chen, X R; Liu, H; Park, W; Purohit, M V; Wilson, J R; Allen, M T; Aston, D; Bartoldus, R; Bechtle, P; Berger, N; Claus, R; Coleman, J P; Convery, M R; Cristinziani, M; Dingfelder, J C; Dorfan, J; Dubois-Felsmann, G P; Dujmic, D; Dunwoodie, W; Field, R C; Glanzman, T; Gowdy, S J; Graham, M T; Halyo, V; Hast, C; Hryn'ova, T; Innes, W R; Kelsey, M H; Kim, P; Leith, D W G S; Li, S; Luitz, S; Luth, V; Lynch, H L; MacFarlane, D B; Marsiske, H; Messner, R; Muller, D R; O'Grady, C P; Ozcan, V E; Perazzo, A; Perl, M; Pulliam, T; Ratcliff, B N; Roodman, A; Salnikov, A A; Schindler, R H; Schwiening, J; Snyder, A; Stelzer, J; Su, D; Sullivan, M K; Suzuki, K; Swain, S K; Thompson, J M; Va'vra, J; van Bakel, N; Weaver, M; Weinstein, A J R; Wisniewski, W J; Wittgen, M; Wright, D H; Yarritu, A K; Yi, K; Young, C C; Burchat, P R; Edwards, A J; Majewski, S A; Petersen, B A; Roat, C; Wilden, L; Ahmed, S; Alam, M S; Bula, R; Ernst, J A; Jain, V; Pan, B; Saeed, M A; Wappler, F R; Zain, S B; Bugg, W; Krishnamurthy, M; Spanier, S M; Eckmann, R; Ritchie, J L; Satpathy, A; Schilling, C J; Schwitters, R F; Izen, J M; Lou, X C; Ye, S; Bianchi, F; Gallo, F; Gamba, D; Bomben, M; Bosisio, L; Cartaro, C; Cossutti, F; Della Ricca, G; Dittongo, S; Lanceri, L; Vitale, L; Azzolini, V; Martinez-Vidal, F; Banerjee, Sw; Bhuyan, B; Brown, C M; Fortin, D; Hamano, K; Kowalewski, R; Nugent, I M; Roney, J M; Sobie, R J; Back, J J; Harrison, P F; Latham, T E; Mohanty, G B; Pappagallo, M; Band, H R; Chen, X; Cheng, B; Dasu, S; Datta, M; Flood, K T; Hollar, J J; Kutter, P E; Mellado, B; Mihalyi, A; Pan, Y; Pierini, M; Prepost, R; Wu, S L; Yu, Z; Neal, H</p> <p>2006-11-24</p> <p>We report a measurement of the B-->pi l nu branching fraction based on 211 fb(-1) of data collected with the BABAR detector. We use samples of B0 and B+ mesons tagged by a second B meson reconstructed in a semileptonic or hadronic decay and combine the results assuming isospin symmetry to obtain B(B(0)-->pi- l+ nu) = (1.33+/-0.17stat+/-0.11syst) x 10(-4). We <span class="hlt">determine</span> the magnitude of the Cabibbo-Kobayashi-Maskawa matrix element <span class="hlt">absolute</span> value V(ub) by combining the partial branching fractions measured in ranges of the momentum transfer squared and theoretical calculations of the form factor. Using a recent lattice QCD calculation, we find <span class="hlt">absolute</span> value V(ub) = (4.5+/-0.5stat+/-0.3syst(+0.7) -0.5FF x 10(-3), where the last error is due to the normalization of the form factor. PMID:17155736</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016PEPI..257..158G','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016PEPI..257..158G"><span id="translatedtitle"><span class="hlt">Absolute</span> paleointensity <span class="hlt">determinations</span> by using of conventional double-heating and multispecimen approaches on a Pliocene lava flow sequence from the Lesser Caucasus</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Goguitchaichvili, Avto; Caccavari, Ana; Calvo-Rathert, Manuel; Morales, Juan; Solano, Miguel Cervantes; Vashakidze, Goga; Huaiyu, He; Vegas, Néstor</p> <p>2016-08-01</p> <p>We report 28 successful Thellier type <span class="hlt">absolute</span> geomagnetic paleointensity <span class="hlt">determinations</span> from a Pleistocene lava sequence composed of 39 successive flows in the Djavakheti Highland (Lesser Caucasus, Georgia). Additionally, multispecimen technique provided the estimation of geomagnetic field strength for 12 independent cooling units. Paleointensity studies were performed using both Thellier type double heating and multispecimen techniques. Samples selection was mainly based on uni-vectorial remanent magnetization, thermal stability and domain size of the samples. Flow-mean Thellier paleointensity values range from 16.3 ± 5.2 to 71.0 ± 0.3 μT, while intensities obtained using multispecimen approach vary from17.2 ± 2.3 to 69.3 ± 7.9 μT. One of the flows is located near a possible discontinuity in the sequence and yields a rather low Thellier <span class="hlt">absolute</span> intensity (16.3 ± 5.2) suggesting a transitional regime and the onset of the Matuyama-Olduvai polarity transition, which does not appear on the directional record. Multispecimen paleointensities from the same flow, however, yield higher, close to present day values which makes untenable the hypothesis of occurrence of transitional field. Thus the whole sequence was emplaced in a short time between the Olduvai chron and 1.73 ± 0.03 Ma, as suggested by available radiometric and paleomagnetic data (Caccavari et al., 2014).</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/24566373','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/24566373"><span id="translatedtitle"><span class="hlt">Determination</span> of critical assembly <span class="hlt">absolute</span> power using post-irradiation activation measurement of week-lived fission products.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Košťál, Michal; Švadlenková, Marie; Milčák, Ján; Rypar, Vojtěch; Koleška, Michal</p> <p>2014-07-01</p> <p>The work presents a detailed comparison of calculated and experimentally <span class="hlt">determined</span> net peak areas of longer-living fission products after 100 h irradiation on a reactor with power of ~630 W and several days cooling. Specifically the nuclides studied are (140)Ba, (103)Ru, (131)I, (141)Ce, (95)Zr. The good agreement between the calculated and measured net peak areas, which is better than in <span class="hlt">determination</span> using short lived (92)Sr, is reported. The experiment was conducted on the VVER-1000 mock-up installed on the LR-0 reactor. The Monte Carlo approach has been used for calculations. The influence of different data libraries on results of calculation is discussed as well.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2004PSST...13..375L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2004PSST...13..375L"><span id="translatedtitle"><span class="hlt">Determination</span> of gas temperature and C2 <span class="hlt">absolute</span> density in Ar/H2/CH4 microwave discharges used for nanocrystalline diamond deposition from the C2 Mulliken system</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Lombardi, G.; Bénédic, F.; Mohasseb, F.; Hassouni, K.; Gicquel, A.</p> <p>2004-08-01</p> <p>The spectroscopic characterization of Ar/H2/CH4 discharges suitable for the synthesis of nanocrystalline diamond using the microwave plasma assisted chemical vapour deposition process is reported. The experiments are realized in a moderate-pressure bell jar reactor, where discharges are ignited using a microwave cavity coupling system. The <span class="hlt">concentration</span> of CH4 is maintained at 1% and the coupled set of hydrogen <span class="hlt">concentration</span>/microwave power (MWP) ranges from 2%/500 W to 7%/800 W at a pressure of 200 mbar. Emission spectroscopy and broadband absorption spectroscopy studies are carried out on the \\C_{2}(D\\,^{1\\!}\\Sigma_u^{+}\\mbox{--}X\\,^{1\\!}\\Sigma_g^{+}) Mulliken system and the C2(d 3Pgrg-a 3Pgru) Swan system in order to <span class="hlt">determine</span> the gas temperature and the C2 <span class="hlt">absolute</span> density within the plasma. For this purpose, and since the Swan system is quite well-known, much importance is devoted to the achievement of a detailed simulation of the Mulliken system, which allows the <span class="hlt">determination</span> of both the rotational temperature and the density of the \\smash{X\\,^{1\\!}\\Sigma_g^{+}} ground state, as well as the rotational temperature of the \\smash{D\\,^{1\\!}\\Sigma_u^{+}} state, from experimental data. All the experimental values are compared to those predicted by a thermochemical model developed to describe Ar/H2/CH4 microwave discharges under quasi-homogeneous plasma assumption. This comparison shows a reasonable agreement between the values measured from the C2 Mulliken system, those measured from the C2 Swan system and that calculated from plasma modelling, especially at low hydrogen <span class="hlt">concentration</span>/MWP. These consistent results show that the use of the Mulliken system leads to fairly good estimates of the gas temperature and of the C2 <span class="hlt">absolute</span> density. The relatively high gas temperatures found for the conditions investigated, typically between 3000 K and 4000 K, are attributed to the low thermal conductivity of argon that may limit thermal losses to the</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016isms.confEFB07H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016isms.confEFB07H"><span id="translatedtitle"><span class="hlt">Determining</span> <span class="hlt">Concentrations</span> and Temperatures in Semiconductor Manufacturing Plasmas via Submillimeter Absorption Spectroscopy</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Helal, Yaser H.; Neese, Christopher F.; De Lucia, Frank C.; Ewing, Paul R.; Agarwal, Ankur; Craver, Barry; Stout, Phillip J.; Armacost, Michael D.</p> <p>2016-06-01</p> <p>Plasmas used in the manufacturing processes of semiconductors are similar in pressure and temperature to plasmas used in studying the spectroscopy of astrophysical species. Likewise, the developed technology in submillimeter absorption spectroscopy can be used for the study of industrial plasmas and for monitoring manufacturing processes. An advantage of submillimeter absorption spectroscopy is that it can be used to <span class="hlt">determine</span> <span class="hlt">absolute</span> <span class="hlt">concentrations</span> and temperatures of plasma species without the need for intrusive probes. A continuous wave, 500 - 750 GHz absorption spectrometer was developed for the purpose of being used as a remote sensor of gas and plasma species. An important part of this work was the optical design to match the geometry of existing plasma reactors in the manufacturing industry. A software fitting routine was developed to simultaneously fit for the background and absorption signal, solving for <span class="hlt">concentration</span>, rotational temperature, and translational temperature. Examples of measurements made on inductively coupled plasmas will be demonstrated. We would like to thank the Texas Analog Center of Excellence/Semiconductor Research Corporation (TxACE/SRC) and Applied Materials for their support of this work.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/26132165','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/26132165"><span id="translatedtitle">Using a Novel <span class="hlt">Absolute</span> Ontogenetic Age <span class="hlt">Determination</span> Technique to Calculate the Timing of Tooth Eruption in the Saber-Toothed Cat, Smilodon fatalis.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Wysocki, M Aleksander; Feranec, Robert S; Tseng, Zhijie Jack; Bjornsson, Christopher S</p> <p>2015-01-01</p> <p>Despite the superb fossil record of the saber-toothed cat, Smilodon fatalis, ontogenetic age <span class="hlt">determination</span> for this and other ancient species remains a challenge. The present study utilizes a new technique, a combination of data from stable oxygen isotope analyses and micro-computed tomography, to establish the eruption rate for the permanent upper canines in Smilodon fatalis. The results imply an eruption rate of 6.0 millimeters per month, which is similar to a previously published average enamel growth rate of the S. fatalis upper canines (5.8 millimeters per month). Utilizing the upper canine growth rate, the upper canine eruption rate, and a previously published tooth replacement sequence, this study calculates <span class="hlt">absolute</span> ontogenetic age ranges of tooth development and eruption in S. fatalis. The timing of tooth eruption is compared between S. fatalis and several extant conical-toothed felids, such as the African lion (Panthera leo). Results suggest that the permanent dentition of S. fatalis, except for the upper canines, was fully erupted by 14 to 22 months, and that the upper canines finished erupting at about 34 to 41 months. Based on these developmental age calculations, S. fatalis individuals less than 4 to 7 months of age were not typically preserved at Rancho La Brea. On the whole, S. fatalis appears to have had delayed dental development compared to dental development in similar-sized extant felids. This technique for <span class="hlt">absolute</span> ontogenetic age <span class="hlt">determination</span> can be replicated in other ancient species, including non-saber-toothed taxa, as long as the timing of growth initiation and growth rate can be <span class="hlt">determined</span> for a specific feature, such as a tooth, and that growth period overlaps with the development of the other features under investigation.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_6");'>6</a></li> <li><a href="#" onclick='return showDiv("page_7");'>7</a></li> <li class="active"><span>8</span></li> <li><a href="#" onclick='return showDiv("page_9");'>9</a></li> <li><a href="#" onclick='return showDiv("page_10");'>10</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_8 --> <div id="page_9" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_7");'>7</a></li> <li><a href="#" onclick='return showDiv("page_8");'>8</a></li> <li class="active"><span>9</span></li> <li><a href="#" onclick='return showDiv("page_10");'>10</a></li> <li><a href="#" onclick='return showDiv("page_11");'>11</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="161"> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4489498','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4489498"><span id="translatedtitle">Using a Novel <span class="hlt">Absolute</span> Ontogenetic Age <span class="hlt">Determination</span> Technique to Calculate the Timing of Tooth Eruption in the Saber-Toothed Cat, Smilodon fatalis</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Wysocki, M. Aleksander; Feranec, Robert S.; Tseng, Zhijie Jack; Bjornsson, Christopher S.</p> <p>2015-01-01</p> <p>Despite the superb fossil record of the saber-toothed cat, Smilodon fatalis, ontogenetic age <span class="hlt">determination</span> for this and other ancient species remains a challenge. The present study utilizes a new technique, a combination of data from stable oxygen isotope analyses and micro-computed tomography, to establish the eruption rate for the permanent upper canines in Smilodon fatalis. The results imply an eruption rate of 6.0 millimeters per month, which is similar to a previously published average enamel growth rate of the S. fatalis upper canines (5.8 millimeters per month). Utilizing the upper canine growth rate, the upper canine eruption rate, and a previously published tooth replacement sequence, this study calculates <span class="hlt">absolute</span> ontogenetic age ranges of tooth development and eruption in S. fatalis. The timing of tooth eruption is compared between S. fatalis and several extant conical-toothed felids, such as the African lion (Panthera leo). Results suggest that the permanent dentition of S. fatalis, except for the upper canines, was fully erupted by 14 to 22 months, and that the upper canines finished erupting at about 34 to 41 months. Based on these developmental age calculations, S. fatalis individuals less than 4 to 7 months of age were not typically preserved at Rancho La Brea. On the whole, S. fatalis appears to have had delayed dental development compared to dental development in similar-sized extant felids. This technique for <span class="hlt">absolute</span> ontogenetic age <span class="hlt">determination</span> can be replicated in other ancient species, including non-saber-toothed taxa, as long as the timing of growth initiation and growth rate can be <span class="hlt">determined</span> for a specific feature, such as a tooth, and that growth period overlaps with the development of the other features under investigation. PMID:26132165</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://eric.ed.gov/?q=stallings&id=EJ1000865','ERIC'); return false;" href="http://eric.ed.gov/?q=stallings&id=EJ1000865"><span id="translatedtitle">Teaching <span class="hlt">Absolute</span> Value Meaningfully</span></a></p> <p><a target="_blank" href="http://www.eric.ed.gov/ERICWebPortal/search/extended.jsp?_pageLabel=advanced">ERIC Educational Resources Information Center</a></p> <p>Wade, Angela</p> <p>2012-01-01</p> <p>What is the meaning of <span class="hlt">absolute</span> value? And why do teachers teach students how to solve <span class="hlt">absolute</span> value equations? <span class="hlt">Absolute</span> value is a concept introduced in first-year algebra and then reinforced in later courses. Various authors have suggested instructional methods for teaching <span class="hlt">absolute</span> value to high school students (Wei 2005; Stallings-Roberts…</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/19384056','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/19384056"><span id="translatedtitle">The <span class="hlt">determination</span> of <span class="hlt">absolute</span> intensity of 234mPa's 1001 keV gamma emission using Monte Carlo simulation.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Begy, Robert-Csaba; Cosma, Constantin; Timar, Alida; Fulea, Dan</p> <p>2009-05-01</p> <p>The 1001 keV gamma line of (234m)Pa became important in gamma spectrometric measurements of samples with (238)U content with the advent of development of HpGe detectors of great dimension and high efficiency. In this study the emission probability of the 1001 keV (Y(gamma)) peak of (234m)Pa, was <span class="hlt">determined</span> by gamma-ray spectrometric measurements performed on glass with Uranium content using Monte Carlo simulation code for efficiency calibration. This method of calculation was not applied for the values quoted in literature so far, at least to our knowledge. The measurements gave an average of 0.836 +/- 0.022%, a value that is in very good agreement to some of the recent results previously presented.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/19384056','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/19384056"><span id="translatedtitle">The <span class="hlt">determination</span> of <span class="hlt">absolute</span> intensity of 234mPa's 1001 keV gamma emission using Monte Carlo simulation.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Begy, Robert-Csaba; Cosma, Constantin; Timar, Alida; Fulea, Dan</p> <p>2009-05-01</p> <p>The 1001 keV gamma line of (234m)Pa became important in gamma spectrometric measurements of samples with (238)U content with the advent of development of HpGe detectors of great dimension and high efficiency. In this study the emission probability of the 1001 keV (Y(gamma)) peak of (234m)Pa, was <span class="hlt">determined</span> by gamma-ray spectrometric measurements performed on glass with Uranium content using Monte Carlo simulation code for efficiency calibration. This method of calculation was not applied for the values quoted in literature so far, at least to our knowledge. The measurements gave an average of 0.836 +/- 0.022%, a value that is in very good agreement to some of the recent results previously presented. PMID:19384056</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/22034529','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/22034529"><span id="translatedtitle">MODELING MULTI-WAVELENGTH STELLAR ASTROMETRY. III. <span class="hlt">DETERMINATION</span> OF THE <span class="hlt">ABSOLUTE</span> MASSES OF EXOPLANETS AND THEIR HOST STARS</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Coughlin, J. L.; Lopez-Morales, Mercedes</p> <p>2012-05-10</p> <p>Astrometric measurements of stellar systems are becoming significantly more precise and common, with many ground- and space-based instruments and missions approaching 1 {mu}as precision. We examine the multi-wavelength astrometric orbits of exoplanetary systems via both analytical formulae and numerical modeling. Exoplanets have a combination of reflected and thermally emitted light that causes the photocenter of the system to shift increasingly farther away from the host star with increasing wavelength. We find that, if observed at long enough wavelengths, the planet can dominate the astrometric motion of the system, and thus it is possible to directly measure the orbits of both the planet and star, and thus directly <span class="hlt">determine</span> the physical masses of the star and planet, using multi-wavelength astrometry. In general, this technique works best for, though is certainly not limited to, systems that have large, high-mass stars and large, low-mass planets, which is a unique parameter space not covered by other exoplanet characterization techniques. Exoplanets that happen to transit their host star present unique cases where the physical radii of the planet and star can be directly <span class="hlt">determined</span> via astrometry alone. Planetary albedos and day-night contrast ratios may also be probed via this technique due to the unique signature they impart on the observed astrometric orbits. We develop a tool to examine the prospects for near-term detection of this effect, and give examples of some exoplanets that appear to be good targets for detection in the K to N infrared observing bands, if the required precision can be achieved.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4052308','PMC'); return false;" href="http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4052308"><span id="translatedtitle">Synthesis of (3S,3′S)- and meso-Stereoisomers of Alloxanthin and <span class="hlt">Determination</span> of <span class="hlt">Absolute</span> Configuration of Alloxanthin Isolated from Aquatic Animals</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Yamano, Yumiko; Maoka, Takashi; Wada, Akimori</p> <p>2014-01-01</p> <p>In order to <span class="hlt">determine</span> the <span class="hlt">absolute</span> configuration of naturally occurring alloxanthin, a HPLC analytical method for three stereoisomers 1a–c was established by using a chiral column. Two authentic samples, (3S,3′S)- and meso-stereoisomers 1b and 1c, were chemically synthesized according to the method previously developed for (3R,3′R)-alloxanthin (1a). Application of this method to various alloxanthin specimens of aquatic animals demonstrated that those isolated from shellfishes, tunicates, and crucian carp are identical with (3R,3′R)-stereoisomer 1a, and unexpectedly those from lake shrimp, catfish, biwa goby, and biwa trout are mixtures of three stereoisomers of 1a–c. PMID:24862182</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2007AJ....133.2684T','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2007AJ....133.2684T"><span id="translatedtitle">Astrometric-Spectroscopic <span class="hlt">Determination</span> of the <span class="hlt">Absolute</span> Masses of the HgMn Binary Star φ Herculis</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Torres, Guillermo</p> <p>2007-06-01</p> <p>The mercury-manganese star φ Her is a well-known spectroscopic binary that has been the subject of a recent study by Zavala and coworkers in which they resolved the companion using long-baseline interferometry. The total mass of the binary is now fairly well established, but the combination of spectroscopy with astrometry has not resulted in individual masses consistent with the spectral types of the components. The motion of the center of light of φ Her was clearly detected by the Hipparcos satellite. Here we make use of the Hipparcos intermediate data (``abscissa residuals'') and show that by combining them in an optimal fashion with the interferometry the individual masses can be obtained reliably using only astrometry. We reexamine and then incorporate existing radial velocity measurements into the orbital solution, obtaining improved masses of 3.05+/-0.24 and 1.614+/-0.066 Msolar that are consistent with the theoretical mass-luminosity relation from recent stellar evolution models. These mass <span class="hlt">determinations</span> provide important information for the understanding of the nature of this peculiar class of stars.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3605228','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3605228"><span id="translatedtitle"><span class="hlt">Determinants</span> of plasma <span class="hlt">concentrations</span> of perfluoroalkyl substances in pregnant Norwegian women</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Whitworth, KW; Ydersbond, TA; Haug, LS; Haugen, M; Knutsen, HK; Thomsen, C; Meltzer, HM; Becher, G; Sabaredzovic, A; Hoppin, JA; Eggesbø, M; Longnecker, MP</p> <p>2013-01-01</p> <p> was associated with plasma PFOS, PFOA, PFHxS, and PFNA <span class="hlt">concentration</span> increases of 7.2%, 3.3%, 5.8% and 9.8%, respectively, resulting in small, although non-trivial <span class="hlt">absolute</span> changes in PFAS <span class="hlt">concentrations</span>. Conclusion The history of previous pregnancies and breastfeeding were the most important <span class="hlt">determinants</span> of PFASs in this sample of pregnant women. PMID:23419425</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=19720059878&hterms=rights+author&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D80%26Ntt%3Drights%2Bauthor','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=19720059878&hterms=rights+author&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D80%26Ntt%3Drights%2Bauthor"><span id="translatedtitle">Singular perturbation of <span class="hlt">absolute</span> stability.</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Siljak, D. D.</p> <p>1972-01-01</p> <p>It was previously shown (author, 1969) that the regions of <span class="hlt">absolute</span> stability in the parameter space can be <span class="hlt">determined</span> when the parameters appear on the right-hand side of the system equations, i.e., the regular case. Here, the effect on <span class="hlt">absolute</span> stability of a small parameter attached to higher derivatives in the equations (the singular case) is studied. The Lur'e-Postnikov class of nonlinear systems is considered.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=1999PEPI..115...53G&link_type=ABSTRACT','NASAADS'); return false;" href="http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=1999PEPI..115...53G&link_type=ABSTRACT"><span id="translatedtitle">An attempt to <span class="hlt">determine</span> the <span class="hlt">absolute</span> geomagnetic field intensity in Southwestern Iceland during the Gauss-Matuyama reversal</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Goguitchaichvili, Avto; Prévot, Michel; Thompson, John; Roberts, Neil</p> <p>1999-08-01</p> <p>We have measured the variation in the intensity of the geomagnetic field during the Gauss-Matuyama (N4-R3) polarity reversal by application of the Thelliers' method to specimens of lava flows from Hvalfjördur district in Western Iceland (Reynivallahals Mts.). Eleven lava flows all show very similar directions corresponding to an equatorial VGP (Plat=2.9°N, Plong=81.9°E, A95=4.2, K=119). Twenty-nine specimens from nine of the flows were pre-selected for palaeointensity <span class="hlt">determination</span> on the basis that specimens from the same drill cores showed a single component of magnetisation upon thermal or AF demagnetisation, and possessed low magnetic viscosity and reversible susceptibility curves upon heating at 600-650°C. Observation that the directional data obtained in the course of the palaeointensity experiments occasionally showed substantial non-linearity indicates that a significant chemical remanent magnetization (CRM) can be acquired in the direction of the laboratory field during heating at T. For each double heating step we calculated the ratio of CRM( T) to the magnitude of the natural remanent magnetization (NRM( T)) in the direction of characteristic remanence (obtained independently from another specimen from the same core). When this ratio exceeded 15%, the paleointensity data was rejected. In addition, specimens for which the quality factor was less than 5 were rejected. Twelve reliable palaeointensity values were obtained from specimens representing five lava flows. The results confirm that the palaeointensity was substantially reduced during the N4-R3 reversal. The range of mean palaeointensity values obtained for the five flows is 8.8 to 20.5 and the overall mean is 14.8±4.6 μT. This corresponds to an equivalent VDM of 3.81±1.19 (10 22 A m 2). A comparison of all Thellier palaeointensity data from the R3 magnetozone in the Rayinivallahals Mts. area reveals a progressive although irregular increase in the palaeointensity between the Gauss</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/15007221','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/15007221"><span id="translatedtitle">Fluorescence lifetime measurements of boronate derivatives to <span class="hlt">determine</span> glucose <span class="hlt">concentration</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Gable, J H</p> <p>2000-06-01</p> <p>)-anthracene (MAMA), and N-benzyl-N-methyl-N-methyl anthracene (AB-B). Fluorescence lifetime measurements confirmed the two species of AB, with and without PET. Fluorescence lifetimes were approximately 11 nsec without PET and 3 nsec with PET. The degree of the interaction between the N and the B atoms was also <span class="hlt">determined</span> by fluorescence lifetime measurements. Electron transfer rates of AB were measured to be on the order of 10{sup 8} sec{sup -1}. Analysis of AB as a glucose sensor shows it has the potential for measuring glucose <span class="hlt">concentrations</span> in solution with less than 5% error. Two novel glucose sensing molecules, Chloro-oxazone boronate (COB) and Napthyl-imide boronate (NIB), were synthesized. Both molecules have a N{yields}B dative bond similar to AB, but with longer wavelength fluorophores. COB and NIB were found to be unacceptable for use as glucose sensor molecules due to the small changes in average fluorescence lifetime.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://medlineplus.gov/ency/article/003649.htm','NIH-MEDLINEPLUS'); return false;" href="https://medlineplus.gov/ency/article/003649.htm"><span id="translatedtitle">Eosinophil count - <span class="hlt">absolute</span></span></a></p> <p><a target="_blank" href="http://medlineplus.gov/">MedlinePlus</a></p> <p></p> <p></p> <p>Eosinophils; <span class="hlt">Absolute</span> eosinophil count ... the white blood cell count to give the <span class="hlt">absolute</span> eosinophil count. ... than 500 cells per microliter (cells/mcL). Normal value ranges may vary slightly among different laboratories. Talk ...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/632533','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/632533"><span id="translatedtitle"><span class="hlt">Determination</span> of methyl radical <span class="hlt">concentrations</span> in a methane/air flame by infrared cavity ringdown laser absorption spectroscopy</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Scherer, J.J.; Aniolek, K.W.; Cernansky, N.P.; Rakestraw, D.J.</p> <p>1997-10-01</p> <p>Infrared cavity ringdown laser absorption spectroscopy (IR-CRLAS) is employed to <span class="hlt">determine</span> <span class="hlt">absolute</span> methyl radical <span class="hlt">concentrations</span> in a 37.5 Torr laminar methane/air flame. IR-CRLAS rovibrational absorption spectra of the {nu}{sub 3} fundamental band system near 3200thinspcm{sup {minus}1} are combined with N{sub 2}-CARS temperature measurements to obtain methyl radical <span class="hlt">concentrations</span> as a function of height above the burner surface. These data are compared with flame chemistry simulations under both stoichiometric and rich flame conditions. Issues regarding the applicability of IR-CRLAS for combustion studies are discussed, including the uncertainties present for the specific case of methyl radical. These IR-CRLAS measurements indicate the ability to monitor reactants, intermediates, and products within a narrow spectral window, and, to our knowledge, constitute the first infrared detection of a polyatomic radical in a flame. {copyright} {ital 1997 American Institute of Physics.}</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/21471260','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/21471260"><span id="translatedtitle">MODELING MULTI-WAVELENGTH STELLAR ASTROMETRY. II. <span class="hlt">DETERMINING</span> <span class="hlt">ABSOLUTE</span> INCLINATIONS, GRAVITY-DARKENING COEFFICIENTS, AND SPOT PARAMETERS OF SINGLE STARS WITH SIM LITE</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Coughlin, Jeffrey L.; Harrison, Thomas E.; Gelino, Dawn M.</p> <p>2010-11-10</p> <p>We present a novel technique to <span class="hlt">determine</span> the <span class="hlt">absolute</span> inclination of single stars using multi-wavelength submilliarcsecond astrometry. The technique exploits the effect of gravity darkening, which causes a wavelength-dependent astrometric displacement parallel to a star's projected rotation axis. We find that this effect is clearly detectable using SIM Lite for various giant stars and rapid rotators, and present detailed models for multiple systems using the REFLUX code. We also explore the multi-wavelength astrometric reflex motion induced by spots on single stars. We find that it should be possible to <span class="hlt">determine</span> spot size, relative temperature, and some positional information for both giant and nearby main-sequence stars utilizing multi-wavelength SIM Lite data. These data will be extremely useful in stellar and exoplanet astrophysics, as well as supporting the primary SIM Lite mission through proper multi-wavelength calibration of the giant star astrometric reference frame, and reduction of noise introduced by starspots when searching for extrasolar planets.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015Ge%26Ae..55..763Y','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015Ge%26Ae..55..763Y"><span id="translatedtitle">Influence of GPS/GLONASS differential code biases on the <span class="hlt">determination</span> accuracy of the <span class="hlt">absolute</span> total electron content in the ionosphere</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Yasyukevich, Yu. V.; Mylnikova, A. A.; Kunitsyn, V. E.; Padokhin, A. M.</p> <p>2015-11-01</p> <p>Systematic error arises when the total electron content (TEC) is estimated with the simultaneous use of phase and code GPS/GLONASS measurements. This is related to the different signal propagation times at L1 and L2 frequencies in the radio frequency path of the transmitting and receiving equipment, the so-called differential code biases. A differential code bias of 1 ns results in an error of ~2.9 TECU when TEC is <span class="hlt">determined</span>. Differential code bias variations on a long time interval, which were obtained at the CODE laboratory, were analyzed. It has been found that the systematic variation in these biases and considerable seasonal variations apparently caused by the environmental state (temperature and humidity), which sometimes reach 20 TECU (in TEC units), are observed for several stations. The algorithm for <span class="hlt">determining</span> differential code biases at an individual station and the results of correction for <span class="hlt">absolute</span> slant TEC are also presented. Presented results show algorithm effectiveness for various geographical regions and solar activity.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2009SJRUE...3...97S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2009SJRUE...3...97S"><span id="translatedtitle"><span class="hlt">Determination</span> of Solid Particle <span class="hlt">Concentration</span> at coal Transshipment site</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Siliņš, K.; Žandeckis, A.; Valtere, S.</p> <p>2009-01-01</p> <p>Coal handling and grinding processes are associated with significant particulate matter emissions into the atmosphere. This problem is particularly urgent when a coal-processing company is located in or nearby a densely populated city. To quantitatively evaluate <span class="hlt">concentrations</span> generated into the atmosphere according to the standardized methodology, it is necessary to make extensive measurements using an automatic real-time, infrared dust and aerosol monitor. Before the experiments, the impact of particulate matter on human health and the environment was explored, six solid particle <span class="hlt">concentration</span> detection methods and best available techniques for particulate matter emission prevention was described. During this study field measurements were carried out at on the territory of a coal transshipment company. Using the solid particle <span class="hlt">concentration</span> detection system Dust Detective kit, <span class="hlt">concentration</span> monitoring of total particulate matter (TSP), PM10 and PM2.5 was carried out. The equipment was located 6 m above ground and 120 m away from the emission source - coal crushing and handling site. TSP monitoring was carried out during four diurnal, PM10 - during 17 diunral and PM2.5 - during 12 days. After comparison of results with <span class="hlt">concentration</span> values set in normative documents of Latvia and EU, it was found out that average 17 diurnal day <span class="hlt">concentration</span> values of PM10 exceeded normative values for nine times. PM2.5 daily average <span class="hlt">concentrations</span> of 12 days exceeded for four times exceeded the value of 25 μg/m3, which is mentioned in Directive 2008/50/EC of EU. After analysis of wind behaviour impact on the <span class="hlt">concentration</span> values it is now understood that if wind comes from the dust emission source to the measurement system, the increase in wind speed increases particle <span class="hlt">concentration</span> as all particles in the air and those raised from coal piles are driven towards the equipment. If wind comes from the opposite direction, the decrease of wind velocity results in an increase of</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ars.usda.gov/research/publications/publication/?seqNo115=332153','TEKTRAN'); return false;" href="http://www.ars.usda.gov/research/publications/publication/?seqNo115=332153"><span id="translatedtitle">The role of endophyte in <span class="hlt">determining</span> swainsonine <span class="hlt">concentrations</span></span></a></p> <p><a target="_blank" href="http://www.ars.usda.gov/services/TekTran.htm">Technology Transfer Automated Retrieval System (TEKTRAN)</a></p> <p></p> <p></p> <p>Locoweeds contain the toxic indolizidine alkaloid swainsonine, which is produced by the endophytic fungi Undifilum species. Previously we reported that swainsonine <span class="hlt">concentrations</span> differ between populations of Oxytropis sericea. We hypothesized that the genotype of the plant, endophyte, or an inter...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/16801447','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/16801447"><span id="translatedtitle">Prospective <span class="hlt">determination</span> of plasma imipenem <span class="hlt">concentrations</span> in critically ill children.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Giannoni, Eric; Moreillon, Philippe; Cotting, Jacques; Moessinger, Adrien; Bille, Jacques; Décosterd, Laurent; Zanetti, Giorgio; Majcherczyk, Paul; Bugnon, Denis</p> <p>2006-07-01</p> <p>Plasma imipenem <span class="hlt">concentrations</span> were measured in 19 critically ill children (median age, 0.8 year; range, 0.02 to 12.9 years). Wide interindividual variations (2 to 4x at peak and >10x at trough <span class="hlt">concentrations</span>) resulted in unpredictable plasma levels in several children. To avoid subtherapeutic drug levels, we recommend treatment with at least 100 mg/kg of body weight/day of imipenem-cilastatin for critically ill children requiring such therapy.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1994SPIE.2135..147B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1994SPIE.2135..147B"><span id="translatedtitle">Investigations concerning the <span class="hlt">determination</span> of NADH <span class="hlt">concentrations</span> using optical biopsy</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Beuthan, Juergen; Bocher, Thomas; Minet, Olaf; Roggan, Andre; Schmitt, Isabella; Weber, A.; Mueller, Gerhard J.</p> <p>1994-05-01</p> <p>The intrinsic NADH autofluorescence intensity of biological tissue depends on the local, cellular <span class="hlt">concentration</span> of this coenzyme. It plays a dominant role in the Krebs-Cycle and therefore serves as indicator for the vitality of the observed cells. Due to individually and locally varying boundary conditions and optical tissue properties, which are scattering coefficients, absorption coefficients and g-factors the fluorescence signal needs to be rescaled. One possible rescaling method is the theoretical derived Photon Migration Theory. Our new rescaling method is partly based on measurements and partly theoretical derived. By using the 4 information channels: LIF time-resolved signal, biochemical <span class="hlt">concentration</span> measurements, Monte Carlo simulations with optical parameters and microscopic investigations we demonstrate that simultaneous detection of the fluorescence and the backscattering signal can easily and accurately provide rescaled, quantitative values for the NADH <span class="hlt">concentrations</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/15500482','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/15500482"><span id="translatedtitle"><span class="hlt">Determination</span> of threshold <span class="hlt">concentrations</span> of allergens and evaluation of two different histamine <span class="hlt">concentrations</span> in canine intradermal testing.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Hensel, Patrick; Austel, Michaela; Medleau, Linda; Zhao, Ying; Vidyashankar, Anand</p> <p>2004-10-01</p> <p>The purpose of this study was to <span class="hlt">determine</span> the optimal histamine <span class="hlt">concentration</span> and allergen threshold <span class="hlt">concentrations</span> for canine intradermal testing. Thirty healthy dogs were tested using two different <span class="hlt">concentrations</span> of histamine and four different <span class="hlt">concentrations</span> of each allergen. The optimal histamine <span class="hlt">concentration</span> was <span class="hlt">determined</span> to be 1:10 000 w/v. The threshold <span class="hlt">concentration</span> was at least 1750 PNU/mL for all tested grasses, weeds, trees, moulds and insects, except for fleas which was as least 1:500 w/v. For Dermatophagoides pteronyssinus, the optimal threshold <span class="hlt">concentration</span> was 250 PNU/mL, whereas for Dermatophagoides farinae and Tyrophagus putrescentiae, it was 100 PNU/mL. Threshold <span class="hlt">concentration</span> for all epidermals except human dander was at least 1250 PNU/mL. The optimal threshold <span class="hlt">concentration</span> for human dander was 300 PNU/mL. Our results suggest that the currently used 1:100 000 w/v <span class="hlt">concentration</span> of histamine and the 1000 PNU/mL <span class="hlt">concentration</span> for most grasses, weeds, trees, moulds, epidermals and insects may not be appropriate for canine intradermal testing.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_7");'>7</a></li> <li><a href="#" onclick='return showDiv("page_8");'>8</a></li> <li class="active"><span>9</span></li> <li><a href="#" onclick='return showDiv("page_10");'>10</a></li> <li><a href="#" onclick='return showDiv("page_11");'>11</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_9 --> <div id="page_10" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_8");'>8</a></li> <li><a href="#" onclick='return showDiv("page_9");'>9</a></li> <li class="active"><span>10</span></li> <li><a href="#" onclick='return showDiv("page_11");'>11</a></li> <li><a href="#" onclick='return showDiv("page_12");'>12</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="181"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://eric.ed.gov/?q=laser+AND+technology&pg=5&id=EJ516927','ERIC'); return false;" href="http://eric.ed.gov/?q=laser+AND+technology&pg=5&id=EJ516927"><span id="translatedtitle">Laser Light: Using Laser Refractometry to <span class="hlt">Determine</span> <span class="hlt">Concentration</span>.</span></a></p> <p><a target="_blank" href="http://www.eric.ed.gov/ERICWebPortal/search/extended.jsp?_pageLabel=advanced">ERIC Educational Resources Information Center</a></p> <p>Gauger, Robert</p> <p>1995-01-01</p> <p>Laser refractometry is a science-technology-based activity that requires students to manipulate a variety of equipment, tools, materials, and critical-thinking skills. Students use a laser to measure the percent of glucose in a solution by calibrating the system, taking measurements, and computing the <span class="hlt">concentration</span>. (MKR)</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2010AMTD....3.3675S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2010AMTD....3.3675S"><span id="translatedtitle"><span class="hlt">Absolute</span> accuracy and sensitivity analysis of OP-FTIR retrievals of CO2, CH4 and CO over <span class="hlt">concentrations</span> representative of ''clean air'' and ''polluted plumes''</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Smith, T. E. L.; Wooster, M. J.; Tattaris, M.; Griffith, D. W. T.</p> <p>2010-08-01</p> <p>When compared to established point-sampling methods, Open-Path Fourier Transform Infrared (OP-FTIR) spectroscopy can provide path-integrated <span class="hlt">concentrations</span> of multiple gases simultaneously, in situ and near-continuously. <span class="hlt">Concentrations</span> can be retrieved from the measured IR spectra using a forward model coupled to a non-linear least squares fitting procedure, without requiring ''background'' spectral measurements unaffected by the gases of interest. However, few studies have investigated the accuracy of such retrievals for CO2, CH4 and CO, particularly across a broad <span class="hlt">concentration</span> range covering ambient to highly polluted air (e.g. from biomass burning or industrial plumes). Here we perform such an assessment using data collected by a field-portable FTIR spectrometer. The FTIR was positioned to view a fixed IR source placed at the other end of an IR-transparent cell filled with the gases of interest, whose target <span class="hlt">concentrations</span> were varied by up to two orders of magnitude. Retrievals made using the forward model are complicated by absorption line pressure broadening, the effects of temperature on absorption band shape and by convolution of the gas absorption lines and the instrument line shape (ILS). Despite this, with optimal forward model parameterisation (i.e. the wavenumber range used in the retrieval, gas temperature, pressure and ILS), <span class="hlt">concentration</span> retrievals for all gases were able to be made to within 5% of the true value. Sensitivity to the aforementioned model inputs was also investigated. CO retrievals were shown to be most sensitive to the ILS (a function of the assumed instrument FOV), which is due to the narrow nature of CO absorption lines and their consequent sensitivity to convolution with the ILS. Conversely, CO2 retrievals were most sensitive to assumed atmospheric parameters, particularly temperature. The analysis suggests that trace gas <span class="hlt">concentration</span> retrieval errors can remain well below 10%, even with the uncertainties in atmospheric pressure</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19670000129','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19670000129"><span id="translatedtitle">Ion exchange <span class="hlt">determines</span> iodine-131 <span class="hlt">concentration</span> in aqueous samples</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Fairman, W. D.; Sedlet, J.</p> <p>1967-01-01</p> <p>Inorganic radioiodide in aqueous media is analyzed by separating the radioactive iodine-131 as the iodide ion on a silver chloride column. The activity in the final precipitate may be <span class="hlt">determined</span> by beta or gamma counting.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2011AMT.....4...97S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2011AMT.....4...97S"><span id="translatedtitle"><span class="hlt">Absolute</span> accuracy and sensitivity analysis of OP-FTIR retrievals of CO2, CH4 and CO over <span class="hlt">concentrations</span> representative of "clean air" and "polluted plumes"</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Smith, T. E. L.; Wooster, M. J.; Tattaris, M.; Griffith, D. W. T.</p> <p>2011-01-01</p> <p>When compared to established point-sampling methods, Open-Path Fourier Transform Infrared (OP-FTIR) spectroscopy can provide path-integrated <span class="hlt">concentrations</span> of multiple gases simultaneously, in situ and near-continuously. The trace gas pathlength amounts can be retrieved from the measured IR spectra using a forward model coupled to a non-linear least squares fitting procedure, without requiring "background" spectral measurements unaffected by the gases of interest. However, few studies have investigated the accuracy of such retrievals for CO2, CH4 and CO, particularly across broad <span class="hlt">concentration</span> ranges covering those characteristic of ambient to highly polluted air (e.g. from biomass burning or industrial plumes). Here we perform such an assessment using data collected by a field-portable FTIR spectrometer. The FTIR was positioned to view a fixed IR source placed at the other end of an IR-transparent cell filled with the gases of interest, whose target <span class="hlt">concentrations</span> were varied by more than two orders of magnitude. Retrievals made using the model are complicated by absorption line pressure broadening, the effects of temperature on absorption band shape, and by convolution of the gas absorption lines and the instrument line shape (ILS). Despite this, with careful model parameterisation (i.e. the optimum wavenumber range, ILS, and assumed gas temperature and pressure for the retrieval), <span class="hlt">concentrations</span> for all target gases were able to be retrieved to within 5%. Sensitivity to the aforementioned model inputs was also investigated. CO retrievals were shown to be most sensitive to the ILS (a function of the assumed instrument field-of-view), which is due to the narrow nature of CO absorption lines and their consequent sensitivity to convolution with the ILS. Conversely, CO2 retrievals were most sensitive to assumed atmospheric parameters, particularly gas temperature. Our findings provide confidence that FTIR-derived trace gas retrievals of CO2, CH4 and CO based on</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/21141836','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/21141836"><span id="translatedtitle">Direct gravimetric <span class="hlt">determination</span> of aerosol mass <span class="hlt">concentration</span> in central antarctica.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Annibaldi, Anna; Truzzi, Cristina; Illuminati, Silvia; Scarponi, Giuseppe</p> <p>2011-01-01</p> <p>In Antarctica, experimental difficulties due to extreme conditions have meant that aerosol mass has rarely been measured directly by gravimetry, and only in coastal areas where <span class="hlt">concentrations</span> were in the range of 1-7 μg m(-3). The present work reports on a careful differential weighing methodology carried out for the first time on the plateau of central Antarctica (Dome C, East Antarctica). To solve problems of accurate aerosol mass measurements, a climatic room was used for conditioning and weighing filters. Measurements were carried out in long stages of several hours of readings with automatic recording of temperature/humidity and mass. This experimental scheme allowed us to sample from all the measurements (up to 2000) carried out before and after exposure, those which were recorded under the most stable humidity conditions and, even more importantly, as close to each other as possible. The automatic reading of the mass allowed us in any case to obtain hundreds of measurements from which to calculate average values with uncertainties sufficiently low to meet the requirements of the differential weighing procedure (±0.2 mg in filter weighing, between ±7% and ±16% both in aerosol mass and <span class="hlt">concentration</span> measurements). The results show that the average summer aerosol mass <span class="hlt">concentration</span> (aerodynamic size ≤10 μm) in central Antarctica is about 0.1 μg m(-3), i.e., about 1/10 of that of coastal Antarctic areas. The <span class="hlt">concentration</span> increases by about 4-5 times at a site very close to the station.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/21141836','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/21141836"><span id="translatedtitle">Direct gravimetric <span class="hlt">determination</span> of aerosol mass <span class="hlt">concentration</span> in central antarctica.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Annibaldi, Anna; Truzzi, Cristina; Illuminati, Silvia; Scarponi, Giuseppe</p> <p>2011-01-01</p> <p>In Antarctica, experimental difficulties due to extreme conditions have meant that aerosol mass has rarely been measured directly by gravimetry, and only in coastal areas where <span class="hlt">concentrations</span> were in the range of 1-7 μg m(-3). The present work reports on a careful differential weighing methodology carried out for the first time on the plateau of central Antarctica (Dome C, East Antarctica). To solve problems of accurate aerosol mass measurements, a climatic room was used for conditioning and weighing filters. Measurements were carried out in long stages of several hours of readings with automatic recording of temperature/humidity and mass. This experimental scheme allowed us to sample from all the measurements (up to 2000) carried out before and after exposure, those which were recorded under the most stable humidity conditions and, even more importantly, as close to each other as possible. The automatic reading of the mass allowed us in any case to obtain hundreds of measurements from which to calculate average values with uncertainties sufficiently low to meet the requirements of the differential weighing procedure (±0.2 mg in filter weighing, between ±7% and ±16% both in aerosol mass and <span class="hlt">concentration</span> measurements). The results show that the average summer aerosol mass <span class="hlt">concentration</span> (aerodynamic size ≤10 μm) in central Antarctica is about 0.1 μg m(-3), i.e., about 1/10 of that of coastal Antarctic areas. The <span class="hlt">concentration</span> increases by about 4-5 times at a site very close to the station. PMID:21141836</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2012SPIE.8207E..0JY','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2012SPIE.8207E..0JY"><span id="translatedtitle"><span class="hlt">Determination</span> of optimal glycerol <span class="hlt">concentration</span> for optical tissue clearing</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Youn, Eungjun; Son, Taeyoon; Kim, Han-Sung; Jung, Byungjo</p> <p>2012-02-01</p> <p>The laser scattering in tissue is significant in diagnostic and therapeutic purposes of laser. Many studies have been conducted to minimize laser scattering in tissue and therefore, to maximize the clinical efficacy by enhancing photon density. Optical clearing agents (OCAs) have been employed for optical tissue clearing (OTC). This study was aimed to investigate the optimal <span class="hlt">concentration</span> of an OCA, glycerol, in topical application,, so that it can be utilized for clinical diagnosis and therapy in dermatology. Glycerol was topically applied to avoid possible edema caused by dermal injection. The effect of OTC was quantitatively evaluated as a function of the <span class="hlt">concentration</span> of glycerol with various methods. Optical methods such as optical coherence tomography (OCT) and an integrating sphere were used to assess the enhancement of light penetration depth and refractive index matching. In addition, a non-optical method, ultrasound scanner, was utilized to evaluate quantitatively collagen dissociation. The results revealed that 70 % glycerol was the optimal <span class="hlt">concentration</span> of OTC for topical application. This study may provide a guideline regarding to the use of glycerol for optimal diagnostic and therapeutic effects in dermatology.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/93163','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/93163"><span id="translatedtitle"><span class="hlt">Determination</span> of flue gas alkali <span class="hlt">concentrations</span> in fluidized-bed coal combustion by excimer-laser-induced fragmentation fluorescence</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Hartinger, K.T.; Monkhouse, P.B.; Wolfrum, J.; Baumann, H.; Bonn, B.</p> <p>1994-12-31</p> <p>Gas-phase sodium <span class="hlt">concentrations</span> were measured for the first time in situ in the flue gas of a fluidized-bed reactor by the excimer-laser-induced fragmentation fluorescence (ELIF) technique. This method involves using ArF-excimer laser light at 193 nm to simultaneously photodissociate the alkali compounds of interest and excite electronically the alkali atoms formed. The resulting fluorescence from Na (3{sup 2}P) atoms can he readily detected at 589 nm. Measured signals were converted to <span class="hlt">absolute</span> <span class="hlt">concentrations</span> using a calibration system that monitors alkali compounds under known conditions of temperature, pressure, and composition and rising the same optical setup as at the reactor. Several different coals were investigated under a specific set of reactor conditions at total pressures close to 1 bar. Sodium <span class="hlt">concentrations</span> ranging from the sub-ppb region to 20 ppb were obtained, and a detection limit for sodium of 0.1 ppb under the present conditions was estimated. Over the course of the reactor program, contrasting <span class="hlt">concentration</span> histories were observed for the two lignites and the hard coal investigated. In particular, significantly higher sodium <span class="hlt">concentrations</span> were found for the hard coal, consistent with both the higher chlorine and sodium contents <span class="hlt">determined</span> in the corresponding coal analysis.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/1042637','DOE-PATENT-XML'); return false;" href="http://www.osti.gov/scitech/servlets/purl/1042637"><span id="translatedtitle"><span class="hlt">Absolute</span> nuclear material assay</span></a></p> <p><a target="_blank" href="http://www.osti.gov/doepatents">DOEpatents</a></p> <p>Prasad, Manoj K.; Snyderman, Neal J.; Rowland, Mark S.</p> <p>2012-05-15</p> <p>A method of <span class="hlt">absolute</span> nuclear material assay of an unknown source comprising counting neutrons from the unknown source and providing an <span class="hlt">absolute</span> nuclear material assay utilizing a model to optimally compare to the measured count distributions. In one embodiment, the step of providing an <span class="hlt">absolute</span> nuclear material assay comprises utilizing a random sampling of analytically computed fission chain distributions to generate a continuous time-evolving sequence of event-counts by spreading the fission chain distribution in time.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/993087','DOE-PATENT-XML'); return false;" href="http://www.osti.gov/scitech/servlets/purl/993087"><span id="translatedtitle"><span class="hlt">Absolute</span> nuclear material assay</span></a></p> <p><a target="_blank" href="http://www.osti.gov/doepatents">DOEpatents</a></p> <p>Prasad, Manoj K.; Snyderman, Neal J.; Rowland, Mark S.</p> <p>2010-07-13</p> <p>A method of <span class="hlt">absolute</span> nuclear material assay of an unknown source comprising counting neutrons from the unknown source and providing an <span class="hlt">absolute</span> nuclear material assay utilizing a model to optimally compare to the measured count distributions. In one embodiment, the step of providing an <span class="hlt">absolute</span> nuclear material assay comprises utilizing a random sampling of analytically computed fission chain distributions to generate a continuous time-evolving sequence of event-counts by spreading the fission chain distribution in time.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015AIPC.1679d0005G','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015AIPC.1679d0005G"><span id="translatedtitle">Energy yield <span class="hlt">determination</span> of <span class="hlt">concentrator</span> solar cells using laboratory measurements</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Geisz, John F.; García, Iván; McMahon, William E.; Steiner, Myles A.; Ochoa, Mario; France, Ryan M.; Habte, Aron; Friedman, Daniel J.</p> <p>2015-09-01</p> <p>The annual energy conversion efficiency is calculated for a four junction inverted metamorphic solar cell that has been completely characterized in the laboratory at room temperature using measurements fit to a comprehensive optoelectronic model of the multijunction solar cells. A simple model of the temperature dependence is used predict the performance of the solar cell under varying temperature and spectra characteristic of Golden, CO for an entire year. The annual energy conversion efficiency is calculated by integrating the predicted cell performance over the entire year. The effects of geometric <span class="hlt">concentration</span>, CPV system thermal characteristics, and luminescent coupling are highlighted.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/567742','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/567742"><span id="translatedtitle">Use of passive sampling devices to <span class="hlt">determine</span> soil contaminant <span class="hlt">concentrations</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Johnson, K.A. |; Hooper, M.J.; Weisskopf, C.P.</p> <p>1996-12-31</p> <p>The effective remediation of contaminated sites requires accurate identification of chemical distributions. A rapid sampling method using passive sampling devices (PSDs) can provide a thorough site assessment. We have been pursuing their application in terrestrial systems and have found that they increase the ease and speed of analysis, decrease solvent usage and overall cost, and minimize the transport of contaminated soils. Time and cost savings allow a higher sampling frequency than is generally the case using traditional methods. PSDs have been used in the field in soils of varying physical properties and have been successful in estimating soil <span class="hlt">concentrations</span> ranging from 1 {mu}g/kg (parts per billion) to greater than 200 mg/kg (parts per million). They were also helpful in identifying hot spots within the sites. Passive sampling devices show extreme promise as an analytical tool to rapidly characterize contaminant distributions in soil. There are substantial time and cost savings in laboratory personnel and supplies. By selectively excluding common interferences that require sample cleanup, PSDs can be retrieved from the field and processed rapidly (one technician can process approximately 90 PSDs in an 8-h work day). The results of our studies indicate that PSDs can be used to accurately estimate soil contaminant <span class="hlt">concentrations</span> and provide lower detection limits. Further, time and cost savings will allow a more thorough and detailed characterization of contaminant distributions. 13 refs., 4 figs., 2 tabs.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2008AIPC..992....9R','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2008AIPC..992....9R"><span id="translatedtitle">Stratospheric NO2 <span class="hlt">Concentration</span> <span class="hlt">Determined</span> by DOAS Using Compact Spectrographs</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Raponi, Marcelo M.; Wolfram, Elian; Rinaldi, Horacio; Rosales, Alejandro; Quel, Eduardo J.; Tocho, Jorge O.</p> <p>2008-04-01</p> <p>In this work we present the results for stratospheric NO2-total column <span class="hlt">concentration</span> retrieved by DOAS (Differential Optical Absorption Spectroscopy) performed with compact spectrographs. The behavior for three different spectrographs (MonoSpec 27, Jarrell-Ash; HR4000, Ocean Optics and Mechelle 900, Multichannel Instruments) are analyzed making one intercomparison in the facilities of the LIDAR Division of CEILAP (CITEFA—CONICET), in Villa Martelli, Argentina (34.5° S, 58.5° W, 20 m amsl). The three instruments have a similar resolution (approximately 0.1 nm) but operate with different optical configurations and have optical sensors of different characteristics; two of them have cooling capability and the other one (HR4000) operates at room temperature. The NO2 <span class="hlt">concentration</span> was obtained from spectral results at twilight using solar noon spectra as reference. In all cases zenithal diffuse irradiance was used. The NO2 absorption cross section given by S. Voigt and J. P. Burrows (University of Bremen—Institute of Environmental Physics) corresponding to 223 °K and 100 mbar is used. Results are compared with public data corresponding to ground-based device or to instruments mounted in satellites. These atmospheric soundings are of extreme importance to understand the roll that plays the stratospheric NO2 in the associated phenomena of destruction and formation of ozone in the low stratosphere at middle latitudes.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2008AGUFM.B31F0363G','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2008AGUFM.B31F0363G"><span id="translatedtitle">Comparison of Methods to <span class="hlt">Determine</span> Algal <span class="hlt">Concentrations</span> in Freshwater Lakes</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Georgian, S. E.; Halfman, J. D.</p> <p>2008-12-01</p> <p>Algal populations are extremely important to the ecological health of freshwater lake systems. As lakes become eutrophic (highly productive) through nutrient loading, sediment accumulation rates increase, bottom waters become anoxic in the mid-to late summer, the opacity of the water column decreases, and significantly decreases the lake's potential as a drinking water source and places respiratory stress on aquatic animals. One indicator of eutrophication is increasing algal <span class="hlt">concentrations</span> over annual time frames. Algal <span class="hlt">concentrations</span> can be measured by the <span class="hlt">concentration</span> of chlorophyll a, or less directly by fluorescence, secchi disk depth, and turbidity by backscattering and total suspended solids. Here, we present a comparison of these methods using data collected on Honeoye, Canandaigua, Keuka, Seneca, Cayuga, Owasco, Skaneateles, and Otisco, the largest Finger Lakes of western and central New York State during the 2008 field season. A total of 124 samples were collected from at least two mid-lake, deep-water sites in each lake monthly through the 2008 field season (May-Oct); Seneca Lake was sampled weekly at four sites and Cayuga Lake every two weeks at six sites. Secchi depths, CTD profiles and surface water samples were collected at each site. Chlorophyll a was measured by spectrophotometer in the lab after filtration at 0.45 um and digestion of the residue in acetone. Water samples were also filtered through pre-weighed glass-fiber filters for total suspended solids <span class="hlt">concentrations</span>. A SBE-25 SeaLogger CTD collected profiles of turbidity and fluorescence with WetLabs ECO FL-NTU. Surface CTD values were used in the comparison. The strongest linear correlations were detected between chlorophyll-a and fluorescence (r2 = 0.65), and total suspended solids and turbidity (r2 = 0.63). Weaker correlations were detected between secchi depths and chlorophyll-a (r2 = 0.42), and secchi depths and turbidity (r2 = 0.46). The weakest correlations were detected between secchi</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/27518826','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/27518826"><span id="translatedtitle">Optical Resolution, <span class="hlt">Determination</span> of <span class="hlt">Absolute</span> Configuration, and Photoracemization of cis-RuL2(CN)2 (L = 2,2'-Bipyridine and Its Analogues).</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Aihara, Yusuke; Sato, Kyohei; Shinozaki, Kazuteru</p> <p>2016-09-01</p> <p>We synthesized neutral Ru(II) complexes cis-Ru(bpy)2(CN)2 (bpy = 2,2'-bipyridine), cis-Ru(dmb)2(CN)2 (dmb = 4,4'-dimethyl-2,2'-bipyridine), cis-Ru(dbb)2(CN)2 (dbb = 4,4'-di-tert-butyl-2,2'-bipyridine), and cis-Ru(phen)2(CN)2 (phen = 1,10-phenanthroline) and optically resolved them into respective enantiomers using high-performance liquid chromatography with a chiral column. The <span class="hlt">absolute</span> configuration of enantiomer of cis-Ru(dbb)2(CN)2 was <span class="hlt">determined</span> by an X-ray crystallography. Upon photoirradiation, the entire enantiomers of the complexes underwent the racemization with considerably slow rates (k = 1 × 10(-6) to 1 × 10(-5) s(-1)) and small quantum yields (ϕ = 1 × 10(-6) to 1 × 10(-5)). The photoracemization was concluded to proceed via a five-coordinate pyramidal intermediate with the base plane composed of Ru, bidentate polypyridine, and two cyanides and the axial ligand of monodentate polypyridine. We derived the equations for photoracemization rate and quantum yield by a kinetics analysis of the photoracemization reaction that depended on polypyridine ligand, solvent, temperature, wavelength and intensity of irradiation light, and emission lifetime. From the temperature-dependent photoracemization reaction, the energy gap between (3)MLCT (metal-to-ligand charge transfer) and (3)d-d* states was estimated as ΔE = 4000-5000 cm(-1), and the energy of invisible (3)d-d* state was estimated to be ca. 20 500 cm(-1), which was in good agreement with that of [Ru(bpy)3](2+). PMID:27518826</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/7034596','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/7034596"><span id="translatedtitle">[<span class="hlt">Determination</span> of the serum <span class="hlt">concentration</span> of lipoproptein x (author's transl)].</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Poittevin, M; Legrand, A; Chappuis, P; Paolaggi, F; Peynet, J; Rousselet, F</p> <p>1981-01-01</p> <p>Lipoprotein X (LPX) is a cholestase marker. The authors wish to set forth a simple and quick method for the quantity <span class="hlt">determination</span> of this abnormal--a method which could be combined with other biochemical tests permitting the demonstration and monitoring of a cholestatic syndrome. The phospholipid composition of lipoprotein X is thought to be constant; therefore, the proposed method of quantity <span class="hlt">determination</span> consists in an enzymatic quantity <span class="hlt">determination</span> of phospholipids, performed on the lipoprotein, isolated from the normal serum lipoproteins by means of a simple operative protocol: elimination of the LDL and VLDL by means of immuno-precipitation, followed by separation of the HDL by means of the action of phosphotungstate. In addition to its quantitative characteristic, the proposed method has been shown to be more selective than the traditional demonstration which uses electrophoresis on agar. This electrophoretic research can in effect, show itself to be negative if practised on biological samples which are rich in biliary acids or free fatty acids; conversely, the operative protocol described permits the demonstration of the quantification of lipoprotein X.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.gpo.gov/fdsys/pkg/CFR-2012-title40-vol17/pdf/CFR-2012-title40-vol17-sec80-1238.pdf','CFR2012'); return false;" href="https://www.gpo.gov/fdsys/pkg/CFR-2012-title40-vol17/pdf/CFR-2012-title40-vol17-sec80-1238.pdf"><span id="translatedtitle">40 CFR 80.1238 - How is a refinery's or importer's average benzene <span class="hlt">concentration</span> <span class="hlt">determined</span>?</span></a></p> <p><a target="_blank" href="http://www.gpo.gov/fdsys/browse/collectionCfr.action?selectedYearFrom=2012&page.go=Go">Code of Federal Regulations, 2012 CFR</a></p> <p></p> <p>2012-07-01</p> <p>... average benzene <span class="hlt">concentration</span> <span class="hlt">determined</span>? 80.1238 Section 80.1238 Protection of Environment ENVIRONMENTAL... Benzene Gasoline Benzene Requirements § 80.1238 How is a refinery's or importer's average benzene <span class="hlt">concentration</span> <span class="hlt">determined</span>? (a) The average benzene <span class="hlt">concentration</span> of gasoline produced at a refinery or...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.gpo.gov/fdsys/pkg/CFR-2011-title40-vol16/pdf/CFR-2011-title40-vol16-sec80-1238.pdf','CFR2011'); return false;" href="https://www.gpo.gov/fdsys/pkg/CFR-2011-title40-vol16/pdf/CFR-2011-title40-vol16-sec80-1238.pdf"><span id="translatedtitle">40 CFR 80.1238 - How is a refinery's or importer's average benzene <span class="hlt">concentration</span> <span class="hlt">determined</span>?</span></a></p> <p><a target="_blank" href="http://www.gpo.gov/fdsys/browse/collectionCfr.action?selectedYearFrom=2011&page.go=Go">Code of Federal Regulations, 2011 CFR</a></p> <p></p> <p>2011-07-01</p> <p>... average benzene <span class="hlt">concentration</span> <span class="hlt">determined</span>? 80.1238 Section 80.1238 Protection of Environment ENVIRONMENTAL... Benzene Gasoline Benzene Requirements § 80.1238 How is a refinery's or importer's average benzene <span class="hlt">concentration</span> <span class="hlt">determined</span>? (a) The average benzene <span class="hlt">concentration</span> of gasoline produced at a refinery or...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.gpo.gov/fdsys/pkg/CFR-2010-title40-vol16/pdf/CFR-2010-title40-vol16-sec80-1238.pdf','CFR'); return false;" href="https://www.gpo.gov/fdsys/pkg/CFR-2010-title40-vol16/pdf/CFR-2010-title40-vol16-sec80-1238.pdf"><span id="translatedtitle">40 CFR 80.1238 - How is a refinery's or importer's average benzene <span class="hlt">concentration</span> <span class="hlt">determined</span>?</span></a></p> <p><a target="_blank" href="http://www.gpo.gov/fdsys/browse/collectionCfr.action?selectedYearFrom=2010&page.go=Go">Code of Federal Regulations, 2010 CFR</a></p> <p></p> <p>2010-07-01</p> <p>... average benzene <span class="hlt">concentration</span> <span class="hlt">determined</span>? 80.1238 Section 80.1238 Protection of Environment ENVIRONMENTAL... Benzene Gasoline Benzene Requirements § 80.1238 How is a refinery's or importer's average benzene <span class="hlt">concentration</span> <span class="hlt">determined</span>? (a) The average benzene <span class="hlt">concentration</span> of gasoline produced at a refinery or...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.gpo.gov/fdsys/pkg/CFR-2013-title40-vol17/pdf/CFR-2013-title40-vol17-sec80-1238.pdf','CFR2013'); return false;" href="https://www.gpo.gov/fdsys/pkg/CFR-2013-title40-vol17/pdf/CFR-2013-title40-vol17-sec80-1238.pdf"><span id="translatedtitle">40 CFR 80.1238 - How is a refinery's or importer's average benzene <span class="hlt">concentration</span> <span class="hlt">determined</span>?</span></a></p> <p><a target="_blank" href="http://www.gpo.gov/fdsys/browse/collectionCfr.action?selectedYearFrom=2013&page.go=Go">Code of Federal Regulations, 2013 CFR</a></p> <p></p> <p>2013-07-01</p> <p>... average benzene <span class="hlt">concentration</span> <span class="hlt">determined</span>? 80.1238 Section 80.1238 Protection of Environment ENVIRONMENTAL... Benzene Gasoline Benzene Requirements § 80.1238 How is a refinery's or importer's average benzene <span class="hlt">concentration</span> <span class="hlt">determined</span>? (a) The average benzene <span class="hlt">concentration</span> of gasoline produced at a refinery or...</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_8");'>8</a></li> <li><a href="#" onclick='return showDiv("page_9");'>9</a></li> <li class="active"><span>10</span></li> <li><a href="#" onclick='return showDiv("page_11");'>11</a></li> <li><a href="#" onclick='return showDiv("page_12");'>12</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_10 --> <div id="page_11" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_9");'>9</a></li> <li><a href="#" onclick='return showDiv("page_10");'>10</a></li> <li class="active"><span>11</span></li> <li><a href="#" onclick='return showDiv("page_12");'>12</a></li> <li><a href="#" onclick='return showDiv("page_13");'>13</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="201"> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.gpo.gov/fdsys/pkg/CFR-2014-title40-vol17/pdf/CFR-2014-title40-vol17-sec80-1238.pdf','CFR2014'); return false;" href="https://www.gpo.gov/fdsys/pkg/CFR-2014-title40-vol17/pdf/CFR-2014-title40-vol17-sec80-1238.pdf"><span id="translatedtitle">40 CFR 80.1238 - How is a refinery's or importer's average benzene <span class="hlt">concentration</span> <span class="hlt">determined</span>?</span></a></p> <p><a target="_blank" href="http://www.gpo.gov/fdsys/browse/collectionCfr.action?selectedYearFrom=2014&page.go=Go">Code of Federal Regulations, 2014 CFR</a></p> <p></p> <p>2014-07-01</p> <p>... average benzene <span class="hlt">concentration</span> <span class="hlt">determined</span>? 80.1238 Section 80.1238 Protection of Environment ENVIRONMENTAL... Benzene Gasoline Benzene Requirements § 80.1238 How is a refinery's or importer's average benzene <span class="hlt">concentration</span> <span class="hlt">determined</span>? (a) The average benzene <span class="hlt">concentration</span> of gasoline produced at a refinery or...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/24328707','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/24328707"><span id="translatedtitle"><span class="hlt">Absolute</span> <span class="hlt">determination</span> of single-stranded and self-complementary adeno-associated viral vector genome titers by droplet digital PCR.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Lock, Martin; Alvira, Mauricio R; Chen, Shu-Jen; Wilson, James M</p> <p>2014-04-01</p> <p>Accurate titration of adeno-associated viral (AAV) vector genome copies is critical for ensuring correct and reproducible dosing in both preclinical and clinical settings. Quantitative PCR (qPCR) is the current method of choice for titrating AAV genomes because of the simplicity, accuracy, and robustness of the assay. However, issues with qPCR-based <span class="hlt">determination</span> of self-complementary AAV vector genome titers, due to primer-probe exclusion through genome self-annealing or through packaging of prematurely terminated defective interfering (DI) genomes, have been reported. Alternative qPCR, gel-based, or Southern blotting titering methods have been designed to overcome these issues but may represent a backward step from standard qPCR methods in terms of simplicity, robustness, and precision. Droplet digital PCR (ddPCR) is a new PCR technique that directly quantifies DNA copies with an unparalleled degree of precision and without the need for a standard curve or for a high degree of amplification efficiency; all properties that lend themselves to the accurate quantification of both single-stranded and self-complementary AAV genomes. Here we compare a ddPCR-based AAV genome titer assay with a standard and an optimized qPCR assay for the titration of both single-stranded and self-complementary AAV genomes. We demonstrate <span class="hlt">absolute</span> quantification of single-stranded AAV vector genomes by ddPCR with up to 4-fold increases in titer over a standard qPCR titration but with equivalent readout to an optimized qPCR assay. In the case of self-complementary vectors, ddPCR titers were on average 5-, 1.9-, and 2.3-fold higher than those <span class="hlt">determined</span> by standard qPCR, optimized qPCR, and agarose gel assays, respectively. Droplet digital PCR-based genome titering was superior to qPCR in terms of both intra- and interassay precision and is more resistant to PCR inhibitors, a desirable feature for in-process monitoring of early-stage vector production and for vector genome biodistribution</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/5689288','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/5689288"><span id="translatedtitle">The behaviour of trypsin towards alpha-N-methyl-alpha-N-toluene-p-sulfonyl-L-lysine beta-naphthyl ester. A new method for <span class="hlt">determining</span> the <span class="hlt">absolute</span> molarity of solutions of trypsin.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Elmore, D T; Smyth, J J</p> <p>1968-03-01</p> <p>1. alpha-N-Methyl-alpha-N-toluene-p-sulphonyl-l-lysine beta-naphthyl ester (MTLNE) was synthesized as its hydrobromide and shown to be slowly hydrolysed by bovine pancreatic trypsin. The acylation step, however, is so much faster than deacylation of the acyl-enzyme that spectrophotometric measurement of the ;burst' of beta-naphthol provides a convenient method for <span class="hlt">determining</span> the <span class="hlt">absolute</span> molarity of trypsin solutions. 2. By using the same stock solution of trypsin, application of this method at pH4.0 and pH7.0 as well as that of Bender et al. (1966) at pH3.7 gave concordant results. 3. Provided that [S](0)>[E](0), the size of the ;burst' is independent of substrate <span class="hlt">concentration</span>. 4. In the trypsin-catalysed hydrolysis of alpha-N-toluene-p-sulphonyl-l-arginine methyl ester, MTLNE functions as a powerful non-competitive inhibitor. 5. There is no detectable reaction between MTLNE and either bovine pancreatic alpha-chymotrypsin at pH4.0 or bovine thrombin at pH6.0.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/23180110','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/23180110"><span id="translatedtitle">A method for <span class="hlt">determining</span> weights for excess relative risk and excess <span class="hlt">absolute</span> risk when applied in the calculation of lifetime risk of cancer from radiation exposure.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Walsh, Linda; Schneider, Uwe</p> <p>2013-03-01</p> <p>Radiation-related risks of cancer can be transported from one population to another population at risk, for the purpose of calculating lifetime risks from radiation exposure. Transfer via excess relative risks (ERR) or excess <span class="hlt">absolute</span> risks (EAR) or a mixture of both (i.e., from the life span study (LSS) of Japanese atomic bomb survivors) has been done in the past based on qualitative weighting. Consequently, the values of the weights applied and the method of application of the weights (i.e., as additive or geometric weighted means) have varied both between reports produced at different times by the same regulatory body and also between reports produced at similar times by different regulatory bodies. Since the gender and age patterns are often markedly different between EAR and ERR models, it is useful to have an evidence-based method for <span class="hlt">determining</span> the relative goodness of fit of such models to the data. This paper identifies a method, using Akaike model weights, which could aid expert judgment and be applied to help to achieve consistency of approach and quantitative evidence-based results in future health risk assessments. The results of applying this method to recent LSS cancer incidence models are that the relative EAR weighting by cancer solid cancer site, on a scale of 0-1, is zero for breast and colon, 0.02 for all solid, 0.03 for lung, 0.08 for liver, 0.15 for thyroid, 0.18 for bladder and 0.93 for stomach. The EAR weighting for female breast cancer increases from 0 to 0.3, if a generally observed change in the trend between female age-specific breast cancer incidence rates and attained age, associated with menopause, is accounted for in the EAR model. Application of this method to preferred models from a study of multi-model inference from many models fitted to the LSS leukemia mortality data, results in an EAR weighting of 0. From these results it can be seen that lifetime risk transfer is most highly weighted by EAR only for stomach cancer. However</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/21611867','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/21611867"><span id="translatedtitle"><span class="hlt">Absolute</span> neutrino mass measurements</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Wolf, Joachim</p> <p>2011-10-06</p> <p>The neutrino mass plays an important role in particle physics, astrophysics and cosmology. In recent years the detection of neutrino flavour oscillations proved that neutrinos carry mass. However, oscillation experiments are only sensitive to the mass-squared difference of the mass eigenvalues. In contrast to cosmological observations and neutrino-less double beta decay (0v2{beta}) searches, single {beta}-decay experiments provide a direct, model-independent way to <span class="hlt">determine</span> the <span class="hlt">absolute</span> neutrino mass by measuring the energy spectrum of decay electrons at the endpoint region with high accuracy.Currently the best kinematic upper limits on the neutrino mass of 2.2eV have been set by two experiments in Mainz and Troitsk, using tritium as beta emitter. The next generation tritium {beta}-experiment KATRIN is currently under construction in Karlsruhe/Germany by an international collaboration. KATRIN intends to improve the sensitivity by one order of magnitude to 0.2eV. The investigation of a second isotope ({sup 137}Rh) is being pursued by the international MARE collaboration using micro-calorimeters to measure the beta spectrum. The technology needed to reach 0.2eV sensitivity is still in the R and D phase. This paper reviews the present status of neutrino-mass measurements with cosmological data, 0v2{beta} decay and single {beta}-decay.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/27581485','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/27581485"><span id="translatedtitle">Transient <span class="hlt">absolute</span> robustness in stochastic biochemical networks.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Enciso, German A</p> <p>2016-08-01</p> <p><span class="hlt">Absolute</span> robustness allows biochemical networks to sustain a consistent steady-state output in the face of protein <span class="hlt">concentration</span> variability from cell to cell. This property is structural and can be <span class="hlt">determined</span> from the topology of the network alone regardless of rate parameters. An important question regarding these systems is the effect of discrete biochemical noise in the dynamical behaviour. In this paper, a variable freezing technique is developed to show that under mild hypotheses the corresponding stochastic system has a transiently robust behaviour. Specifically, after finite time the distribution of the output approximates a Poisson distribution, centred around the deterministic mean. The approximation becomes increasingly accurate, and it holds for increasingly long finite times, as the total protein <span class="hlt">concentrations</span> grow to infinity. In particular, the stochastic system retains a transient, <span class="hlt">absolutely</span> robust behaviour corresponding to the deterministic case. This result contrasts with the long-term dynamics of the stochastic system, which eventually must undergo an extinction event that eliminates robustness and is completely different from the deterministic dynamics. The transiently robust behaviour may be sufficient to carry out many forms of robust signal transduction and cellular decision-making in cellular organisms. PMID:27581485</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/5714411','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/5714411"><span id="translatedtitle">Process for <span class="hlt">determining</span> the <span class="hlt">concentration</span> of benzodiazepines in a body fluid</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Braestrup, C.; Squires, R.F.</p> <p>1981-07-28</p> <p>A process for <span class="hlt">determining</span> the <span class="hlt">concentration</span> of benzodiazepines in a body liquid comprising the steps of contacting freeze-dried brain tissue with tritium labelled flunitrazepam to bond labelled flunitrazepam to receptor sites of the brain tissue, <span class="hlt">determining</span> the <span class="hlt">concentration</span> of labelled flunitrazepam of the brain tissue, incubating the brain tissue containing labelled flunitrazepam with a sample of body liquid containing benzodiazepine, the <span class="hlt">concentration</span> of which is to be <span class="hlt">determined</span>, to induce displacement of labelled flunitrazepam from said brain tissue, <span class="hlt">determining</span> the <span class="hlt">concentration</span> of labelled flunitrazepam bonded to the brain tissue after establishing equilibrium conditions and <span class="hlt">determining</span> the <span class="hlt">concentration</span> of benzodiazepine in the body liquid based on the change of <span class="hlt">concentration</span> of labelled flunitrazepam induced by benzodiazepine contained in the sample.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/840055','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/840055"><span id="translatedtitle">Diagnostic Application of <span class="hlt">Absolute</span> Neutron Activation Analysis in Hematology</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Zamboni, C.B.; Oliveira, L.C.; Dalaqua, L. Jr.</p> <p>2004-10-03</p> <p>The <span class="hlt">Absolute</span> Neutron Activation Analysis (ANAA) technique was used to <span class="hlt">determine</span> element <span class="hlt">concentrations</span> of Cl and Na in blood of healthy group (male and female blood donators), select from Blood Banks at Sao Paulo city, to provide information which can help in diagnosis of patients. This study permitted to perform a discussion about the advantages and limitations of using this nuclear methodology in hematological examinations.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/23586876','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/23586876"><span id="translatedtitle"><span class="hlt">Absolute</span> biological needs.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>McLeod, Stephen</p> <p>2014-07-01</p> <p><span class="hlt">Absolute</span> needs (as against instrumental needs) are independent of the ends, goals and purposes of personal agents. Against the view that the only needs are instrumental needs, David Wiggins and Garrett Thomson have defended <span class="hlt">absolute</span> needs on the grounds that the verb 'need' has instrumental and <span class="hlt">absolute</span> senses. While remaining neutral about it, this article does not adopt that approach. Instead, it suggests that there are <span class="hlt">absolute</span> biological needs. The <span class="hlt">absolute</span> nature of these needs is defended by appeal to: their objectivity (as against mind-dependence); the universality of the phenomenon of needing across the plant and animal kingdoms; the impossibility that biological needs depend wholly upon the exercise of the abilities characteristic of personal agency; the contention that the possession of biological needs is prior to the possession of the abilities characteristic of personal agency. Finally, three philosophical usages of 'normative' are distinguished. On two of these, to describe a phenomenon or claim as 'normative' is to describe it as value-dependent. A description of a phenomenon or claim as 'normative' in the third sense does not entail such value-dependency, though it leaves open the possibility that value depends upon the phenomenon or upon the truth of the claim. It is argued that while survival needs (or claims about them) may well be normative in this third sense, they are normative in neither of the first two. Thus, the idea of <span class="hlt">absolute</span> need is not inherently normative in either of the first two senses. PMID:23586876</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/23586876','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/23586876"><span id="translatedtitle"><span class="hlt">Absolute</span> biological needs.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>McLeod, Stephen</p> <p>2014-07-01</p> <p><span class="hlt">Absolute</span> needs (as against instrumental needs) are independent of the ends, goals and purposes of personal agents. Against the view that the only needs are instrumental needs, David Wiggins and Garrett Thomson have defended <span class="hlt">absolute</span> needs on the grounds that the verb 'need' has instrumental and <span class="hlt">absolute</span> senses. While remaining neutral about it, this article does not adopt that approach. Instead, it suggests that there are <span class="hlt">absolute</span> biological needs. The <span class="hlt">absolute</span> nature of these needs is defended by appeal to: their objectivity (as against mind-dependence); the universality of the phenomenon of needing across the plant and animal kingdoms; the impossibility that biological needs depend wholly upon the exercise of the abilities characteristic of personal agency; the contention that the possession of biological needs is prior to the possession of the abilities characteristic of personal agency. Finally, three philosophical usages of 'normative' are distinguished. On two of these, to describe a phenomenon or claim as 'normative' is to describe it as value-dependent. A description of a phenomenon or claim as 'normative' in the third sense does not entail such value-dependency, though it leaves open the possibility that value depends upon the phenomenon or upon the truth of the claim. It is argued that while survival needs (or claims about them) may well be normative in this third sense, they are normative in neither of the first two. Thus, the idea of <span class="hlt">absolute</span> need is not inherently normative in either of the first two senses.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/12719564','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/12719564"><span id="translatedtitle"><span class="hlt">Determination</span> of infectious retrovirus <span class="hlt">concentration</span> from colony-forming assay with quantitative analysis.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Kwon, Young Jik; Hung, Gene; Anderson, W French; Peng, Ching-An; Yu, Hong</p> <p>2003-05-01</p> <p>The colony formation assay is the most commonly used titration method for defining the <span class="hlt">concentration</span> of replication-incompetent murine leukemia virus-derived retroviral vectors. However, titer varies with target cell type and number, transduction time, and <span class="hlt">concentration</span> of polycation (e.g., Polybrene). Moreover, because most of the viruses cannot encounter target cells due to Brownian motion, their short half-lives, and the requirement for target cell division for activity, the actual infectious retrovirus <span class="hlt">concentration</span> in the collected supernatant is higher than the viral titer. Here we correlate the physical viral particle <span class="hlt">concentration</span> with the infectious virus <span class="hlt">concentration</span> and colony formation titer with the help of a mathematical model. Ecotropic murine leukemia retrovirus supernatant, collected from the GP+E86/LNCX retroviral vector producer cell line, was <span class="hlt">concentrated</span> by centrifugation and further purified by a sucrose density gradient. The physical <span class="hlt">concentration</span> of purified viral vectors was <span class="hlt">determined</span> by direct particle counting with an electron microscope. The <span class="hlt">concentrations</span> of fresh and <span class="hlt">concentrated</span> supernatant were <span class="hlt">determined</span> by a quantitative reverse transcriptase activity assay. Titration of all supernatants by neomycin-resistant colony formation assay was also performed. There were 767 +/- 517 physical viral particles per infectious CFU in the crude viral supernatant. However, the infectious viral <span class="hlt">concentration</span> <span class="hlt">determined</span> by mathematical simulation was 143 viral particles per infectious unit, which is more consistent with the <span class="hlt">concentration</span> <span class="hlt">determined</span> by particle counting in purified viral solution. Our results suggest that the mathematical model can be used to extract a more accurate and reliable <span class="hlt">concentration</span> of infectious retrovirus.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/20376389','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/20376389"><span id="translatedtitle">An acoustic based, laser induced breakdown method for <span class="hlt">determining</span> the sizes and <span class="hlt">concentrations</span> of nanoparticles.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Jin, Hyun; Kim, Ji-Woong; Son, Ji-A; Choi, Joong-Gill</p> <p>2010-01-01</p> <p>An acoustic, laser induced breakdown (LIBD) method has been developed for <span class="hlt">determining</span> the sizes and <span class="hlt">concentrations</span> of nano-sized colloids. The size distributions from a mixture of aquatic nanoparticles are <span class="hlt">determined</span> by measuring amplitudes of plasma shockwave that are fitted to multi-curve Gaussian distributions displayed in separate peaks with positions corresponding to particle sizes and areas being proportional to <span class="hlt">concentrations</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/24454572','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/24454572"><span id="translatedtitle">Synthesis and <span class="hlt">determination</span> of the <span class="hlt">absolute</span> configuration of (-)-(5R,6Z)-dendrolasin-5-acetate from the nudibranch Hypselodoris jacksoni.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Mudianta, I Wayan; Challinor, Victoria L; Winters, Anne E; Cheney, Karen L; De Voss, James J; Garson, Mary J</p> <p>2013-12-23</p> <p>A small sample of (-)-(5R,6Z)-dendrolasin-5-acetate, which was fully characterized by 2D NMR studies, was isolated from the nudibranch Hypselodoris jacksoni, along with the sesquiterpenes (+)-agassizin, (-)-furodysinin, (-)-euryfuran, (-)-dehydroherbadysidolide and (+)-pallescensone. A synthetic sample ([α]D -8.7) of the new metabolite was prepared by [1,2]-Wittig rearrangement of a geranylfuryl ether followed by acetylation of purified alcohol isomers. The <span class="hlt">absolute</span> configuration at C-5 was established as R by the analysis of MPA ester derivatives of (Z)-5-hydroxydendrolasin obtained by preparative enantioselective HPLC. PMID:24454572</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/14510606','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/14510606"><span id="translatedtitle">Biotransformation of citronellal by Solanum aviculare suspension cultures: preparation of p-menthane-3,8-diols and <span class="hlt">determination</span> of their <span class="hlt">absolute</span> configurations.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Vanek, Tomás; Novotný, Michal; Podlipná, Radka; Saman, David; Valterová, Irena</p> <p>2003-09-01</p> <p>Citronellal was transformed by Solanum aviculare suspension cultures to menthane-3,8-diols. cis-Menthane-3,8-diol dominated over the trans-isomer (39% and 15%, respectively). <span class="hlt">Absolute</span> configurations of menthane-3,8-diols were assigned by critical analysis of 1H and 19F NMR spectra of prepared esters with 2-methoxy-2-phenyl-3,3,3-trifluoropropanoic acid. Citronellol and isopulegol were other products of the transformation (23% and 17%, respectively). The reaction course was identical for both citronellal enantiomers. PMID:14510606</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/14510606','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/14510606"><span id="translatedtitle">Biotransformation of citronellal by Solanum aviculare suspension cultures: preparation of p-menthane-3,8-diols and <span class="hlt">determination</span> of their <span class="hlt">absolute</span> configurations.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Vanek, Tomás; Novotný, Michal; Podlipná, Radka; Saman, David; Valterová, Irena</p> <p>2003-09-01</p> <p>Citronellal was transformed by Solanum aviculare suspension cultures to menthane-3,8-diols. cis-Menthane-3,8-diol dominated over the trans-isomer (39% and 15%, respectively). <span class="hlt">Absolute</span> configurations of menthane-3,8-diols were assigned by critical analysis of 1H and 19F NMR spectra of prepared esters with 2-methoxy-2-phenyl-3,3,3-trifluoropropanoic acid. Citronellol and isopulegol were other products of the transformation (23% and 17%, respectively). The reaction course was identical for both citronellal enantiomers.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=19880033615&hterms=VALUE+ABSOLUTE&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D40%26Ntt%3DVALUE%2BABSOLUTE','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=19880033615&hterms=VALUE+ABSOLUTE&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D40%26Ntt%3DVALUE%2BABSOLUTE"><span id="translatedtitle"><span class="hlt">Absolute</span> instability of the Gaussian wake profile</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Hultgren, Lennart S.; Aggarwal, Arun K.</p> <p>1987-01-01</p> <p>Linear parallel-flow stability theory has been used to investigate the effect of viscosity on the local <span class="hlt">absolute</span> instability of a family of wake profiles with a Gaussian velocity distribution. The type of local instability, i.e., convective or <span class="hlt">absolute</span>, is <span class="hlt">determined</span> by the location of a branch-point singularity with zero group velocity of the complex dispersion relation for the instability waves. The effects of viscosity were found to be weak for values of the wake Reynolds number, based on the center-line velocity defect and the wake half-width, larger than about 400. <span class="hlt">Absolute</span> instability occurs only for sufficiently large values of the center-line wake defect. The critical value of this parameter increases with decreasing wake Reynolds number, thereby indicating a shrinking region of <span class="hlt">absolute</span> instability with decreasing wake Reynolds number. If backflow is not allowed, <span class="hlt">absolute</span> instability does not occur for wake Reynolds numbers smaller than about 38.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016Ocgy...56..363C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016Ocgy...56..363C"><span id="translatedtitle"><span class="hlt">Determination</span> of threshold <span class="hlt">concentrations</span> of metals in indicator algae of coastal waters in the northwest Sea of Japan</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Chernova, E. N.; Kozhenkova, S. I.</p> <p>2016-05-01</p> <p>Background <span class="hlt">concentrations</span> of Fe, Mn, Cu, Zn, Pb, Cd, and Ni were calculated for thalli of abundant algae of Fucus, Silvetia, Sargassum, Cystoseira spp. from the northwest Sea of Japan during 1987-2008. As the upper threshold levels of metal background <span class="hlt">concentrations</span>, the median values plus double medians of <span class="hlt">absolute</span> deviations from the medians were used (Me + 2MAD). The lower threshold level of the background <span class="hlt">concentration</span> equal to the physiological need for an element is the median of 15% minimum values in the sampling minus the double median of <span class="hlt">absolute</span> deviations from the median (Me15-2MAD15). The range of Me15 ± 2MAD15 is considered the natural background range of <span class="hlt">concentrations</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/1231575-absolute-path-command','SCIGOV-ESTSC'); return false;" href="http://www.osti.gov/scitech/biblio/1231575-absolute-path-command"><span id="translatedtitle">The <span class="hlt">absolute</span> path command</span></a></p> <p><a target="_blank" href=""></a></p> <p></p> <p>2012-05-11</p> <p>The ap command traveres all symlinks in a given file, directory, or executable name to identify the final <span class="hlt">absolute</span> path. It can print just the final path, each intermediate link along with the symlink chan, and the permissions and ownership of each directory component in the final path. It has functionality similar to "which", except that it shows the final path instead of the first path. It is also similar to "pwd", but it canmore » provide the <span class="hlt">absolute</span> path to a relative directory from the current working directory.« less</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/1231575','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/1231575"><span id="translatedtitle">The <span class="hlt">absolute</span> path command</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Moody, A.</p> <p>2012-05-11</p> <p>The ap command traveres all symlinks in a given file, directory, or executable name to identify the final <span class="hlt">absolute</span> path. It can print just the final path, each intermediate link along with the symlink chan, and the permissions and ownership of each directory component in the final path. It has functionality similar to "which", except that it shows the final path instead of the first path. It is also similar to "pwd", but it can provide the <span class="hlt">absolute</span> path to a relative directory from the current working directory.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1995SPIE.2461..347M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1995SPIE.2461..347M"><span id="translatedtitle"><span class="hlt">Determination</span> of the <span class="hlt">concentration</span> of a Bryonia Dioica tincture by Raman spectroscopy</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Milea, Irimie; Culea, E.; Iliescu, T.; Milea, Janetta</p> <p>1995-03-01</p> <p>It was established a method based on Raman spectroscopy in order to control the content and <span class="hlt">concentration</span> of homeopathic dilutions. Dilutions of a tincture of Bryonia Dioica in ethanol were prepared and investigated by Raman spectroscopy. The Raman line at 881 cm-1 was found to depend linearly versus the <span class="hlt">concentration</span> of Bryonia Dioica. This permits to obtain a calibration curve that may be used to <span class="hlt">determine</span> the <span class="hlt">concentration</span> of Bryonia Dioica in ethanol. The method may be extended to <span class="hlt">determine</span> the <span class="hlt">concentration</span> of various homeopathic dilutions.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_9");'>9</a></li> <li><a href="#" onclick='return showDiv("page_10");'>10</a></li> <li class="active"><span>11</span></li> <li><a href="#" onclick='return showDiv("page_12");'>12</a></li> <li><a href="#" onclick='return showDiv("page_13");'>13</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_11 --> <div id="page_12" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_10");'>10</a></li> <li><a href="#" onclick='return showDiv("page_11");'>11</a></li> <li class="active"><span>12</span></li> <li><a href="#" onclick='return showDiv("page_13");'>13</a></li> <li><a href="#" onclick='return showDiv("page_14");'>14</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="221"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/871356','DOE-PATENT-XML'); return false;" href="http://www.osti.gov/scitech/servlets/purl/871356"><span id="translatedtitle">Method for <span class="hlt">determining</span> the <span class="hlt">concentration</span> of atomic species in gases and solids</span></a></p> <p><a target="_blank" href="http://www.osti.gov/doepatents">DOEpatents</a></p> <p>Loge, Gary W.</p> <p>1998-01-01</p> <p>Method for <span class="hlt">determining</span> the <span class="hlt">concentration</span> of atomic species in gases and solids. Measurement of at least two emission intensities from a species in a sample that is excited by incident laser radiation. Which generates a plasma therein after a sufficient time period has elapsed and during a second time period, permits an instantaneous temperature to be established within the sample. The <span class="hlt">concentration</span> of the atomic species to be <span class="hlt">determined</span> is then derived from the known emission intensity of a predetermined <span class="hlt">concentration</span> of that species in the sample at the measured temperature, a quantity which is measured prior to the <span class="hlt">determination</span> of the unknown <span class="hlt">concentration</span>, and the actual measured emission from the unknown species, or by this latter emission and the emission intensity of a species having known <span class="hlt">concentration</span> within the sample such as nitrogen for gaseous air samples.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/570483','DOE-PATENT-XML'); return false;" href="http://www.osti.gov/scitech/biblio/570483"><span id="translatedtitle">Method for <span class="hlt">determining</span> the <span class="hlt">concentration</span> of atomic species in gases and solids</span></a></p> <p><a target="_blank" href="http://www.osti.gov/doepatents">DOEpatents</a></p> <p>Loge, G.W.</p> <p>1998-02-03</p> <p>Method is described for <span class="hlt">determining</span> the <span class="hlt">concentration</span> of atomic species in gases and solids. The method involves measurement of at least two emission intensities from a species in a sample that is excited by incident laser radiation. This generates a plasma therein after a sufficient time period has elapsed and during a second time period, permits an instantaneous temperature to be established within the sample. The <span class="hlt">concentration</span> of the atomic species to be <span class="hlt">determined</span> is then derived from the known emission intensity of a predetermined <span class="hlt">concentration</span> of that species in the sample at the measured temperature, a quantity which is measured prior to the <span class="hlt">determination</span> of the unknown <span class="hlt">concentration</span>, and the actual measured emission from the unknown species, or by this latter emission and the emission intensity of a species having known <span class="hlt">concentration</span> within the sample such as nitrogen for gaseous air samples. 4 figs.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/872693','DOE-PATENT-XML'); return false;" href="http://www.osti.gov/scitech/servlets/purl/872693"><span id="translatedtitle">Method for <span class="hlt">determining</span> the <span class="hlt">concentration</span> of atomic species in gases and solids</span></a></p> <p><a target="_blank" href="http://www.osti.gov/doepatents">DOEpatents</a></p> <p>Loge, Gary W.</p> <p>1999-01-01</p> <p>Method for <span class="hlt">determining</span> the <span class="hlt">concentration</span> of atomic species in gases and solids. Measurement of at least two emission intensities from a species in a plasma containing the species after a sufficient time period has elapsed after the generation of the plasma and during a second time period, permits an instantaneous temperature to be established within the sample. The <span class="hlt">concentration</span> of the atomic species to be <span class="hlt">determined</span> is then derived from the known emission intensity of a predetermined <span class="hlt">concentration</span> of that species in the sample at the measured temperature, a quantity which is measured prior to the <span class="hlt">determination</span> of the unknown <span class="hlt">concentration</span>, and the actual measured emission from the unknown species, or by this latter emission and the emission intensity of a species having known <span class="hlt">concentration</span> within the sample.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/20338428','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/20338428"><span id="translatedtitle"><span class="hlt">Determination</span> of water quality variables, endotoxin <span class="hlt">concentration</span>, and Enterobacteriaceae <span class="hlt">concentration</span> and identification in southern High Plains dairy lagoons.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Purdy, C W; Clark, R N; Straus, D C</p> <p>2010-04-01</p> <p>The objectives of this study were to <span class="hlt">determine</span> the <span class="hlt">concentration</span> of endotoxin, <span class="hlt">determine</span> 20 water quality variables, and identify and enumerate fungal and bacterial pathogens from United States southern High Plains dairy lagoons and control lakes during summer and winter. Water samples were collected in triplicate from the north, south, east, and west quadrants of each body of water. The mean (+/- SEM) winter dairy lagoon endotoxin <span class="hlt">concentration</span> was significantly higher (9,678+/-1,834 ng/mL) than the summer <span class="hlt">concentration</span> (3,220+/-810 ng/mL). The mean endotoxin <span class="hlt">concentration</span> of the 2 control lakes (summer: 58.1+/-8.8 ng/mL; winter: 38.6+/-4.2 ng/mL) was significantly less than that of the dairy lagoons. Two hundred-one Salmonella enterica spp. isolates were identified, 7 serovars were recovered from the dairy lagoons, and 259 Salmonella ssp. were identified from 5 other dairy locations (milk barn, ditch effluent, settling basin, feed alley pad flush, and center pivots). Twenty-eight Salmonella spp. were identified from center pivot water. Escherichia coli O157:H7 pathogens were isolated from other dairy locations but not from lagoons. Neither Salmonella spp. nor E. coli O157:H7 were identified from control lakes. Enterobacteriaceae opportunistic pathogens were isolated from both dairies and control lakes. Important mesophilic and thermophilic catabolic (to manure biosolids) fungal isolates were identified from dairy effluent locations, but no thermophilic fungal isolates were cultured from the control lakes. Adequate curing of green forage following center pivot irrigation is important to kill lagoon water enteric pathogens, even though the lagoon water is mixed with fresh water. Recirculating lagoon water to flush the feed alley pad, where cows stand while eating, to remove manure and using lagoon water to abate dairy dust in loafing pens and unimproved dairy roads is inconsistent with good environmental practice management.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014OptMa..36..932K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014OptMa..36..932K"><span id="translatedtitle"><span class="hlt">Determination</span> of refractive index and <span class="hlt">concentration</span> of iodine solutions using opals</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Kępińska, Mirosława; Starczewska, Anna; Szala, Janusz</p> <p>2014-03-01</p> <p>The <span class="hlt">determination</span> of refractive index of iodine-ethanol solutions using SiO2 opals has been presented. For the first time <span class="hlt">concentration</span> of solution iodine in ethanol has been <span class="hlt">determined</span> by applying a simple method of using opal and de Feijter's relation. Basing on wavelength of diffraction peaks the appropriate formula describing <span class="hlt">concentration</span> of iodine ethanol solution has been evolved. The uncertainty of the <span class="hlt">determined</span> <span class="hlt">concentration</span> has been established, too. The coefficient dnc/dC = 0.0201(4) (% w/w-1) of the linear dependence between refractive index and the <span class="hlt">concentration</span> of iodine solution has been <span class="hlt">determined</span>. The procedure of calibration of the used opal sensor is described. The opal sensor is not distracted by the measurement and can be used repeatedly.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.gpo.gov/fdsys/pkg/CFR-2011-title40-vol31/pdf/CFR-2011-title40-vol31-sec761-358.pdf','CFR2011'); return false;" href="https://www.gpo.gov/fdsys/pkg/CFR-2011-title40-vol31/pdf/CFR-2011-title40-vol31-sec761-358.pdf"><span id="translatedtitle">40 CFR 761.358 - <span class="hlt">Determining</span> the PCB <span class="hlt">concentration</span> of samples of waste.</span></a></p> <p><a target="_blank" href="http://www.gpo.gov/fdsys/browse/collectionCfr.action?selectedYearFrom=2011&page.go=Go">Code of Federal Regulations, 2011 CFR</a></p> <p></p> <p>2011-07-01</p> <p>... 40 Protection of Environment 31 2011-07-01 2011-07-01 false <span class="hlt">Determining</span> the PCB <span class="hlt">concentration</span> of samples of waste. 761.358 Section 761.358 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY... <span class="hlt">concentration</span> of samples of waste. Use either Method 3500B/3540C or Method 3500B/3550B from EPA's SW-846,...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.gpo.gov/fdsys/pkg/CFR-2010-title40-vol30/pdf/CFR-2010-title40-vol30-sec761-358.pdf','CFR'); return false;" href="https://www.gpo.gov/fdsys/pkg/CFR-2010-title40-vol30/pdf/CFR-2010-title40-vol30-sec761-358.pdf"><span id="translatedtitle">40 CFR 761.358 - <span class="hlt">Determining</span> the PCB <span class="hlt">concentration</span> of samples of waste.</span></a></p> <p><a target="_blank" href="http://www.gpo.gov/fdsys/browse/collectionCfr.action?selectedYearFrom=2010&page.go=Go">Code of Federal Regulations, 2010 CFR</a></p> <p></p> <p>2010-07-01</p> <p>... 40 Protection of Environment 30 2010-07-01 2010-07-01 false <span class="hlt">Determining</span> the PCB <span class="hlt">concentration</span> of samples of waste. 761.358 Section 761.358 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY... <span class="hlt">concentration</span> of samples of waste. Use either Method 3500B/3540C or Method 3500B/3550B from EPA's SW-846,...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.gpo.gov/fdsys/pkg/CFR-2012-title40-vol32/pdf/CFR-2012-title40-vol32-sec761-358.pdf','CFR2012'); return false;" href="https://www.gpo.gov/fdsys/pkg/CFR-2012-title40-vol32/pdf/CFR-2012-title40-vol32-sec761-358.pdf"><span id="translatedtitle">40 CFR 761.358 - <span class="hlt">Determining</span> the PCB <span class="hlt">concentration</span> of samples of waste.</span></a></p> <p><a target="_blank" href="http://www.gpo.gov/fdsys/browse/collectionCfr.action?selectedYearFrom=2012&page.go=Go">Code of Federal Regulations, 2012 CFR</a></p> <p></p> <p>2012-07-01</p> <p>... 40 Protection of Environment 32 2012-07-01 2012-07-01 false <span class="hlt">Determining</span> the PCB <span class="hlt">concentration</span> of samples of waste. 761.358 Section 761.358 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY... <span class="hlt">concentration</span> of samples of waste. Use either Method 3500B/3540C or Method 3500B/3550B from EPA's SW-846,...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.gpo.gov/fdsys/pkg/CFR-2014-title40-vol31/pdf/CFR-2014-title40-vol31-sec761-358.pdf','CFR2014'); return false;" href="https://www.gpo.gov/fdsys/pkg/CFR-2014-title40-vol31/pdf/CFR-2014-title40-vol31-sec761-358.pdf"><span id="translatedtitle">40 CFR 761.358 - <span class="hlt">Determining</span> the PCB <span class="hlt">concentration</span> of samples of waste.</span></a></p> <p><a target="_blank" href="http://www.gpo.gov/fdsys/browse/collectionCfr.action?selectedYearFrom=2014&page.go=Go">Code of Federal Regulations, 2014 CFR</a></p> <p></p> <p>2014-07-01</p> <p>... 40 Protection of Environment 31 2014-07-01 2014-07-01 false <span class="hlt">Determining</span> the PCB <span class="hlt">concentration</span> of samples of waste. 761.358 Section 761.358 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY... <span class="hlt">concentration</span> of samples of waste. Use either Method 3500B/3540C or Method 3500B/3550B from EPA's SW-846,...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.gpo.gov/fdsys/pkg/CFR-2013-title40-vol32/pdf/CFR-2013-title40-vol32-sec761-358.pdf','CFR2013'); return false;" href="https://www.gpo.gov/fdsys/pkg/CFR-2013-title40-vol32/pdf/CFR-2013-title40-vol32-sec761-358.pdf"><span id="translatedtitle">40 CFR 761.358 - <span class="hlt">Determining</span> the PCB <span class="hlt">concentration</span> of samples of waste.</span></a></p> <p><a target="_blank" href="http://www.gpo.gov/fdsys/browse/collectionCfr.action?selectedYearFrom=2013&page.go=Go">Code of Federal Regulations, 2013 CFR</a></p> <p></p> <p>2013-07-01</p> <p>... 40 Protection of Environment 32 2013-07-01 2013-07-01 false <span class="hlt">Determining</span> the PCB <span class="hlt">concentration</span> of samples of waste. 761.358 Section 761.358 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY... <span class="hlt">concentration</span> of samples of waste. Use either Method 3500B/3540C or Method 3500B/3550B from EPA's SW-846,...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://cfpub.epa.gov/si/si_public_record_report.cfm?dirEntryId=218658&keyword=vacuum&actType=&TIMSType=+&TIMSSubTypeID=&DEID=&epaNumber=&ntisID=&archiveStatus=Both&ombCat=Any&dateBeginCreated=&dateEndCreated=&dateBeginPublishedPresented=&dateEndPublishedPresented=&dateBeginUpdated=&dateEndUpdated=&dateBeginCompleted=&dateEndCompleted=&personID=&role=Any&journalID=&publisherID=&sortBy=revisionDate&count=50&CFID=68457073&CFTOKEN=94309464','EPA-EIMS'); return false;" href="http://cfpub.epa.gov/si/si_public_record_report.cfm?dirEntryId=218658&keyword=vacuum&actType=&TIMSType=+&TIMSSubTypeID=&DEID=&epaNumber=&ntisID=&archiveStatus=Both&ombCat=Any&dateBeginCreated=&dateEndCreated=&dateBeginPublishedPresented=&dateEndPublishedPresented=&dateBeginUpdated=&dateEndUpdated=&dateBeginCompleted=&dateEndCompleted=&personID=&role=Any&journalID=&publisherID=&sortBy=revisionDate&count=50&CFID=68457073&CFTOKEN=94309464"><span id="translatedtitle">Continuous <span class="hlt">Determination</span> of High-Vapor Phase <span class="hlt">Concentrations</span> of Tetrachloroethylene Using On-Line Mass Spectrometry</span></a></p> <p><a target="_blank" href="http://oaspub.epa.gov/eims/query.page">EPA Science Inventory</a></p> <p></p> <p></p> <p>A method was developed to <span class="hlt">determine</span> the vapor <span class="hlt">concentration</span> of tetrachloroethylene (PCE) at and below its equilibrium vapor phase <span class="hlt">concentration</span>, 168,000 μg/L (25°C). Vapor samples were drawn by vacuum into a six-port sampling valve and injected through a jet separator into an io...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://cfpub.epa.gov/si/si_public_record_report.cfm?dirEntryId=80504&keyword=Research+AND+education+AND+method+AND+Research&actType=&TIMSType=+&TIMSSubTypeID=&DEID=&epaNumber=&ntisID=&archiveStatus=Both&ombCat=Any&dateBeginCreated=&dateEndCreated=&dateBeginPublishedPresented=&dateEndPublishedPresented=&dateBeginUpdated=&dateEndUpdated=&dateBeginCompleted=&dateEndCompleted=&personID=&role=Any&journalID=&publisherID=&sortBy=revisionDate&count=50&CFID=77560687&CFTOKEN=83010897','EPA-EIMS'); return false;" href="http://cfpub.epa.gov/si/si_public_record_report.cfm?dirEntryId=80504&keyword=Research+AND+education+AND+method+AND+Research&actType=&TIMSType=+&TIMSSubTypeID=&DEID=&epaNumber=&ntisID=&archiveStatus=Both&ombCat=Any&dateBeginCreated=&dateEndCreated=&dateBeginPublishedPresented=&dateEndPublishedPresented=&dateBeginUpdated=&dateEndUpdated=&dateBeginCompleted=&dateEndCompleted=&personID=&role=Any&journalID=&publisherID=&sortBy=revisionDate&count=50&CFID=77560687&CFTOKEN=83010897"><span id="translatedtitle">BUBBLE STRIPPING TO <span class="hlt">DETERMINE</span> HYDROGEN <span class="hlt">CONCENTRATIONS</span> IN GROUND WATER: A PRACTICAL APPLICATION OF HENRY'S LAW</span></a></p> <p><a target="_blank" href="http://oaspub.epa.gov/eims/query.page">EPA Science Inventory</a></p> <p></p> <p></p> <p>The Bubble Stripping Method is a chemical testing method that operates on the principle of Henry's Law. It is useful for <span class="hlt">determining</span> <span class="hlt">concentrations</span> of hydrogen in well water, and it is capable of detecting <span class="hlt">concentrations</span> on the order of nanomoles per liter. The method provides ...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://eric.ed.gov/?q=Photosynthesis&pg=3&id=EJ963135','ERIC'); return false;" href="http://eric.ed.gov/?q=Photosynthesis&pg=3&id=EJ963135"><span id="translatedtitle"><span class="hlt">Determining</span> How Atmospheric Carbon Dioxide <span class="hlt">Concentrations</span> Have Changed during the History of the Earth</span></a></p> <p><a target="_blank" href="http://www.eric.ed.gov/ERICWebPortal/search/extended.jsp?_pageLabel=advanced">ERIC Educational Resources Information Center</a></p> <p>Badger, Marcus P. S.; Pancost, Richard D.; Harrison, Timothy G.</p> <p>2011-01-01</p> <p>The reconstruction of ancient atmospheric carbon dioxide <span class="hlt">concentrations</span> is essential to understanding the history of the Earth and life. It is also an important guide to identifying the sensitivity of the Earth system to this greenhouse gas and, therefore, constraining its future impact on climate. However, <span class="hlt">determining</span> the <span class="hlt">concentration</span> of…</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ars.usda.gov/research/publications/publication/?seqNo115=205759','TEKTRAN'); return false;" href="http://www.ars.usda.gov/research/publications/publication/?seqNo115=205759"><span id="translatedtitle"><span class="hlt">Determination</span> of folate <span class="hlt">concentrations</span> in diverse potato germplasm using a trienzyme extraction and microbiological assay</span></a></p> <p><a target="_blank" href="http://www.ars.usda.gov/services/TekTran.htm">Technology Transfer Automated Retrieval System (TEKTRAN)</a></p> <p></p> <p></p> <p>We <span class="hlt">determined</span> total folate <span class="hlt">concentrations</span> of potato tubers from 67 cultivars, advanced breeding lines, or wild species. Folates were extracted by a tri-enzyme treatment and analyzed by using a Lactobacillus rhamnosus microbiological assay. Folate <span class="hlt">concentrations</span> varied from 521 ± 96 to 1373 ± 230 ng/...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/18403847','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/18403847"><span id="translatedtitle">Application of laser-induced photoacoustic spectroscopy for <span class="hlt">determination</span> of plutonium <span class="hlt">concentration</span> in nuclear waste solutions.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Surugaya, Naoki; Sato, Soichi; Jitsukata, Syu; Watahiki, Masaru</p> <p>2008-04-01</p> <p>Laser-induced photoacoustic spectroscopy was used in a quantitative analysis of Pu in HNO3 medium. Plutonium was quantitatively oxidized to Pu(VI) using Ce(IV). The photoacoustic measurement of Pu(VI) with maximum absorption at 830.5 nm was subsequently performed to <span class="hlt">determine</span> the <span class="hlt">concentration</span>. The photoacoustic signal was linearly proportional to the Pu(VI) ion <span class="hlt">concentration</span>. The detection limit of Pu(VI) was estimated to be 0.5 microg mL(-1) (3sigma) in 3 M HNO3. By the proposed method, Pu <span class="hlt">concentration</span> was successfully <span class="hlt">determined</span> in a nuclear waste solution for use in nuclear materials management.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19670000245','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19670000245"><span id="translatedtitle">Automated urinalysis technique <span class="hlt">determines</span> <span class="hlt">concentration</span> of creatine and creatinine by colorimetry</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Rho, J. H.</p> <p>1967-01-01</p> <p>Continuous urinalysis technique is useful in the study of muscle wastage in primates. Creatinine <span class="hlt">concentration</span> in urine is <span class="hlt">determined</span> in an aliquot mixture by a color reaction. Creatine is <span class="hlt">determined</span> in a second aliquot by converting it to creatinine and measuring the difference in color intensity between the two aliquots.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/16106389','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/16106389"><span id="translatedtitle">Antifungal activity of tuberose <span class="hlt">absolute</span> and some of its constituents.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Nidiry, Eugene Sebastian J; Babu, C S Bujji</p> <p>2005-05-01</p> <p>The antifungal activity of the <span class="hlt">absolute</span> of tuberose (Polianthes tuberosa ) and some of its constituents were evaluated against the mycelial growth of Colletotrichum gloeosporioides on potato-dextrose-agar medium. Tuberose <span class="hlt">absolute</span> showed only mild activity at a <span class="hlt">concentration</span> of 500 mg/L. However, three constituents present in the <span class="hlt">absolute</span>, namely geraniol, indole and methyl anthranilate exhibited significant activity showing total inhibition of the mycelial growth at this <span class="hlt">concentration</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015JMoSt1098...76C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015JMoSt1098...76C"><span id="translatedtitle">Correlations among experimental and theoretical NMR data to <span class="hlt">determine</span> the <span class="hlt">absolute</span> stereochemistry of darcyribeirine, a pentacyclic indole alkaloid isolated from Rauvolfia grandiflora</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Cancelieri, Náuvia Maria; Ferreira, Thiago Resende; Vieira, Ivo José Curcino; Braz-Filho, Raimundo; Piló-Veloso, Dorila; Alcântara, Antônio Flávio de Carvalho</p> <p>2015-10-01</p> <p>Darcyribeirine (1) is a pentacyclic indole alkaloid isolated from Rauvolfia grandiflora. Stereochemistry of 1 was previously proposed based on 1D (coupling constant data) and 2D (NOESY correlations) NMR techniques, having been established a configuration 3R, 15S, and 20R (isomer 1a). Stereoisomers of 1 (i.e., 1a-1h) can be grouped into four sets of enantiomers. Carbon chemical shifts and hydrogen coupling constants were calculated using BLYP/6-31G* theory level for the eight isomers of 1. Calculated NMR data of 1a-1h were correlated with the corresponding experimental data of 1. The best correlations between theoretical and experimental carbon chemical shift data were obtained for the set of enantiomers 1e/1f to structures in the gaseous phase and considering solvent effects (using PCM and explicit models). Similar results were obtained when the same procedure was performed to correlations between theoretical and experimental coupling constant data. Finally, optical rotation calculations indicate 1e as its <span class="hlt">absolute</span> stereochemistry. Orbital population analysis indicates that the hydrogen bonding between N-H of 1e and DMSO is due to contributions of its frontier unoccupied molecular orbitals, mainly LUMO+1, LUMO+2, and LUMO+3.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/15020127','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/15020127"><span id="translatedtitle"><span class="hlt">Determination</span> of Delta m(d) and <span class="hlt">absolute</span> calibration of flavor taggers for the Delta m(s) analysis, in fully reconstructed decays at the CDF experiment</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Gomez, Jonatan Piedra</p> <p>2005-04-21</p> <p>The new trigger processor, the Silicon Vertex Tracking (SVT), has dramatically improved the B physics capabilities of the upgraded CDF II Detector; for the first time in a hadron collider, the SVT has enabled the access to non-lepton-triggered B meson decays. Within the new available range of decay modes, the B$0\\atop{s}$ → D$-\\atop{s}$π<sup>+</sup> signature is of paramount importance in the measurement of the Δm<sub>s</sub> mixing frequency. The analysis reported here is a step towards the measurement of this frequency; two where our goals: carrying out the <span class="hlt">absolute</span> calibration of the opposite side flavor taggers, used in the Δm<sub>s</sub> measurement; and measuring the B$0\\atop{d}$ mixing frequency in a B → Dπ sample, establishing the feasibility of the mixing measurement in this sample whose decay-length is strongly biased by the selective SVT trigger. We analyze a total integrated luminosity of 355 pb<sup>-1</sup> collected with the CDF II Detector. By triggering on muons, using the conventional di-muon trigger; or displaced tracks, using the SVT trigger, we gather a sample rich in bottom and charm mesons.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2005JPhB...38.2613M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2005JPhB...38.2613M"><span id="translatedtitle"><span class="hlt">Absolute</span> cross sections and branching ratios for the radiative decay of doubly excited helium <span class="hlt">determined</span> by photon-induced fluorescence spectroscopy</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Mickat, S.; Schartner, K.-H.; Kammer, Sv; Schill, R.; Werner, L.; Klumpp, S.; Ehresmann, A.; Schmoranzer, H.; Sukhorukov, V. L.</p> <p>2005-08-01</p> <p>The decay of doubly excited helium states below the N = 2 threshold, cascading radiatively over three steps, were investigated using the photon-induced fluorescence spectroscopy (PIFS) at BESSY II. <span class="hlt">Absolute</span> cross sections as the product of the resonance excitation cross section of the doubly excited states and their fluorescence rate to decay into the singly excited 1sms(1S) and 1smd(1D) states were measured. The experiments showed that the (sp,2n+)(1P) states decay predominantly into the 1sns(1S) states, whereas the (pd,2n)(1P) states prefer to decay into the 1snd(1D) states. For the (sp,2n-)(1P) states with n = 4, 5 and 6 we observed a broad and complex decay pattern. In addition the angular distribution of the fluorescence radiation was measured. The results are in good agreement with theoretical predictions. Furthermore, the weakening of the LS coupling scheme and the mixing between singlet and triplet states in helium was confirmed by observation of the 1s6d(3D0,1,2) → 1s2p(3P0,1,2) transition on a doubly excited singlet state.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_10");'>10</a></li> <li><a href="#" onclick='return showDiv("page_11");'>11</a></li> <li class="active"><span>12</span></li> <li><a href="#" onclick='return showDiv("page_13");'>13</a></li> <li><a href="#" onclick='return showDiv("page_14");'>14</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_12 --> <div id="page_13" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_11");'>11</a></li> <li><a href="#" onclick='return showDiv("page_12");'>12</a></li> <li class="active"><span>13</span></li> <li><a href="#" onclick='return showDiv("page_14");'>14</a></li> <li><a href="#" onclick='return showDiv("page_15");'>15</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="241"> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/22215308','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/22215308"><span id="translatedtitle">The influence of walking with an orthosis on bone mineral density by <span class="hlt">determination</span> of the <span class="hlt">absolute</span> values of the loads applied on the limb.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Karimi, Mohammad Taghi</p> <p>2012-03-01</p> <p>Spinal cord injury is damage to the spinal cord that results in loss of mobility and sensation below the level of injury. Most patients use various types of orthoses to stand and walk. It has been claimed that walking and standing with orthosis reduces bone osteoporosis, improves joint range of motion and decreases muscle spasm. Unfortunately, there are discrepancies regarding the clinical effects of walking and standing on bone mineral density. The aim of this research was to find the <span class="hlt">absolute</span> values of the loads transmitted by body and orthosis in walking with use of an orthosis. 5 normal subjects were recruited to stand and walk with a new design of reciprocal gait orthosis. The loads transmitted through the orthosis and anatomy was measured by use of strain gauge and motion analysis systems. It has been shown that the loads applied on the anatomy were significantly more than that transmitted through the orthosis. Moreover, the patterns of the forces and moments of the orthosis and body completely differed from each other. As the most part of the loads applied on the complex transmitted by anatomy in walking with an orthosis, walking with orthosis can influence bone mineral density.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/25668425','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/25668425"><span id="translatedtitle">Using nonequilibrium capillary electrophoresis of equilibrium mixtures (NECEEM) for simultaneous <span class="hlt">determination</span> of <span class="hlt">concentration</span> and equilibrium constant.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Kanoatov, Mirzo; Galievsky, Victor A; Krylova, Svetlana M; Cherney, Leonid T; Jankowski, Hanna K; Krylov, Sergey N</p> <p>2015-03-01</p> <p>Nonequilibrium capillary electrophoresis of equilibrium mixtures (NECEEM) is a versatile tool for studying affinity binding. Here we describe a NECEEM-based approach for simultaneous <span class="hlt">determination</span> of both the equilibrium constant, K(d), and the unknown <span class="hlt">concentration</span> of a binder that we call a target, T. In essence, NECEEM is used to measure the unbound equilibrium fraction, R, for the binder with a known <span class="hlt">concentration</span> that we call a ligand, L. The first set of experiments is performed at varying <span class="hlt">concentrations</span> of T, prepared by serial dilution of the stock solution, but at a constant <span class="hlt">concentration</span> of L, which is as low as its reliable quantitation allows. The value of R is plotted as a function of the dilution coefficient, and dilution corresponding to R = 0.5 is <span class="hlt">determined</span>. This dilution of T is used in the second set of experiments in which the <span class="hlt">concentration</span> of T is fixed but the <span class="hlt">concentration</span> of L is varied. The experimental dependence of R on the <span class="hlt">concentration</span> of L is fitted with a function describing their theoretical dependence. Both K(d) and the <span class="hlt">concentration</span> of T are used as fitting parameters, and their sought values are <span class="hlt">determined</span> as the ones that generate the best fit. We have fully validated this approach in silico by using computer-simulated NECEEM electropherograms and then applied it to experimental <span class="hlt">determination</span> of the unknown <span class="hlt">concentration</span> of MutS protein and K(d) of its interactions with a DNA aptamer. The general approach described here is applicable not only to NECEEM but also to any other method that can <span class="hlt">determine</span> a fraction of unbound molecules at equilibrium.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1982asme.conf...19B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1982asme.conf...19B"><span id="translatedtitle">Development of a consensus standard for <span class="hlt">determining</span> thermal performance of high-<span class="hlt">concentration</span>-ratio solar collectors</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Blackmon, J. B.; Linskens, M. C.; Reed, K. A.</p> <p>1982-12-01</p> <p>Consensus standard test method, for <span class="hlt">determining</span> the thermal performance of <span class="hlt">concentrating</span> solar collectors is described. The method applies to outdoor testing of one or two axis <span class="hlt">concentrating</span> collectors with heat fluids for use in thermal systems and whose design is such that the effects of diffuse sky irradiance is negligible. The procedures <span class="hlt">determine</span> the optical response of the collector for various angles of incidence of solar radiation, and the thermal performance of the collector at various operating temperatures for the condition of maximum optical response. The method requires quasi steady state conditions, measurement of enviromental parameters, and <span class="hlt">determination</span> of the fluidmass flow rate specific heat product and temperature difference of the heat transfer fluid between the inlet and outlet of the collector. These quantities <span class="hlt">determine</span> the rate of heat gain for the solar irradiance condition encountered. Thermal performance is <span class="hlt">determined</span> as the rate of heat gain of the collector relative to the solar power incident on the plane of the collector aperture.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016GPC...143..152B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016GPC...143..152B"><span id="translatedtitle">What <span class="hlt">determines</span> the calcium <span class="hlt">concentration</span> of speleothem-forming drip waters?</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Baker, Andy; Flemons, Ingrid; Andersen, Martin S.; Coleborn, Katie; Treble, Pauline C.</p> <p>2016-08-01</p> <p>Cave drip water calcium ion <span class="hlt">concentration</span> is a primary <span class="hlt">determinant</span> of speleothem deposition and growth rate. The factors that <span class="hlt">determine</span> drip water calcium ion <span class="hlt">concentrations</span> are the soil and vadose zone CO2 <span class="hlt">concentrations</span>, and the hydrogeochemical evolution of the water from soil to cave. Here, we use a systematic literature review of cave drip water calcium <span class="hlt">concentrations</span>, combined with PHREEQC equilibrium modelling, to investigate the global relationship between calcium <span class="hlt">concentration</span> and surface climate. Our results are discussed in the context of understanding the climatic and environmental controls on drip water calcium <span class="hlt">concentration</span>, speleothem growth rates and proxies of past climate and environmental change. We use an empirical, global soil CO2 <span class="hlt">concentration</span>-temperature relationship to derive PHREEQC modelled cave drip water calcium <span class="hlt">concentrations</span>. The global mean modelled drip water calcium <span class="hlt">concentration</span> is close to that observed, but it over-predicts at high and low temperatures, and significantly under-predicts at temperate conditions. We hypothesise that closed system hydrochemical evolution due to water saturation is an important control on carbonate dissolution at colder temperatures. Under warmer conditions, for example temperate climates with a dry and hot or warm summer, seasonally-limited water availability can lead to: < 100% soil cover; water-limitations on microbial and root respiration; wildfire; and prior calcite precipitation, all of which limit drip water calcium <span class="hlt">concentrations</span>. In temperate climates with no dry season, higher CO2 <span class="hlt">concentrations</span> than modelled from soil values are necessary to explain the observed drip water calcium values, which we propose is from an additional source of CO2 from microbial activity and root respiration in the vadose zone during open system hydrochemical evolution.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016OptSp.120..546K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016OptSp.120..546K"><span id="translatedtitle"><span class="hlt">Determination</span> of free iodine <span class="hlt">concentration</span> in an X-ray contrast agent</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Kljubin, V. V.; Kljubina, K. A.; Makovetskaya, K. N.</p> <p>2016-04-01</p> <p>Based on the analysis of the absorption spectra of solutions of iodine in ethanol, we propose a simple and sensitive (at a level of 1 μg/g) method for <span class="hlt">determination</span> of the <span class="hlt">concentration</span> of free (not bound to polymer) iodine in substances synthesized from ether oils and iodine. The method uses absorption of molecular iodine in the UV region. Iodine dissolved in alcohols has a rather large absorption cross section in the UV region. These absorption bands can be used to detect very small quantities of iodine. It is shown that, for iodine <span class="hlt">concentrations</span> in the 1-50 μg/g range, the intensity of absorption band at a wavelength of 359 nm depends linearly on the iodine <span class="hlt">concentration</span>, which allows one to use this band to <span class="hlt">determine</span> the <span class="hlt">concentration</span> of iodine not bound with the polymer in the X-ray contrast material.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015APS..DMP.C1002T','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015APS..DMP.C1002T"><span id="translatedtitle">Non-Adiabatic Mechanism for Photosynthetic Energy Transfer and All-Optical <span class="hlt">Determination</span> of <span class="hlt">Concentration</span> using Femtosecond Lasers</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Tiwari, Vivek</p> <p>2015-05-01</p> <p>Understanding the fundamental physics of light-harvesting in both, natural and artificial systems is key for the development of efficient light-harvesting technologies. My thesis addresses the following topics, i.) the mechanism underlying the remarkably efficient electronic energy transfer in natural light harvesting antennas, ii.) a femtosecond time-resolved photonumeric technique to quantitatively characterize transient chemical species. This talk will <span class="hlt">concentrate</span> on the first project, while briefly touching the key ideas of the second project. Light harvesting antennas use a set of closely spaced pigment molecules held in a controlled relative geometry by a protein. It is shown that in certain antenna proteins the excited state electronic energy gaps between the pigments are resonant with a quantum of pigment vibrational energy. With such a vibrational-electronic resonance, anti-correlated motions between the pigments lead to a strong coupling between the electronic and nuclear motions, that is, breakdown of the Born-Oppenheimer approximation, over a wide range of pigment vibrational motions. It is shown that the 2D spectroscopic signatures of the resulting unavoidable nested non-adiabatic energy funnel on the excited states of photosynthetic antennas are consistent with all the reported 2D signatures of long-lived coherent oscillations, including the ones that are not explained by prior models of excited state electronic energy transfer. Extensions that account for both resonant and near-resonant pigment vibrations suggest that photosynthetic energy transfer presents a novel design in which electronic energy transfer proceeds non-adiabatically through clusters of vibrations with frequencies distributed around electronic energy gaps. I will also briefly talk about our experiments demonstrating quantitative time-resolved measurement of <span class="hlt">absolute</span> number of excited state molecules. Based on these measurements, an all-optical technique that simultaneously <span class="hlt">determines</span></p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2003AtmEn..37.2317R','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2003AtmEn..37.2317R"><span id="translatedtitle">Validation of Ogawa passive samplers for the <span class="hlt">determination</span> of gaseous ammonia <span class="hlt">concentrations</span> in agricultural settings</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Roadman, M. J.; Scudlark, J. R.; Meisinger, J. J.; Ullman, W. J.</p> <p></p> <p>The Ogawa passive sampler (Ogawa USA, Pompano Beach, Florida) is a useful tool for monitoring atmospheric ammonia (NH 3(g)) <span class="hlt">concentrations</span> and assessing the effects of agricultural waste management practices on NH 3(g) emissions. The Ogawa sampler, with filter-discs impregnated with citric acid, was used to trap and <span class="hlt">determine</span> NH 3(g) <span class="hlt">concentrations</span> in a variety of agricultural settings. A wide range of NH 3(g) <span class="hlt">concentrations</span> can be monitored by varying the sampler exposure time, provided that no more than ˜10 μg of NH 3-N are adsorbed on the acid-coated filters. <span class="hlt">Concentrations</span> less than 1 μg NH 3-N m -3 can be detected using long deployments (⩽14 days), while <span class="hlt">concentrations</span> as great as 10 mg NH 3-N m -3 may be <span class="hlt">determined</span> in very short (e.g. 5 min) deployments. Reproducibility ranged from 5% to 10% over the range of <span class="hlt">concentrations</span> studied and passive <span class="hlt">determinations</span> of NH 3(g) were similar to those <span class="hlt">determined</span> using dilute-acid gas scrubbers. Background levels of NH 3(g) at a non-agricultural site in southern Delaware were typically <1 μg NH 3-N m -3. The air entering a chicken house was 10 μg NH 3-N m -3, reflecting the background levels in agricultural settings in this region. Within the house, <span class="hlt">concentrations</span> ⩽8.5 mg NH 3-N m -3 were observed, reflecting the high rates of NH 3(g) emission from chicken excreta. Using measured NH 3(g) <span class="hlt">concentrations</span> and poultry house ventilation rates, we estimate that each broiler grown to production size over 6 weeks contributes approximately 19±3 g of NH 3-N to the atmosphere, a value consistent with other published results.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://pubs.er.usgs.gov/publication/70011493','USGSPUBS'); return false;" href="http://pubs.er.usgs.gov/publication/70011493"><span id="translatedtitle">Emission spectrographic <span class="hlt">determination</span> of barium in sea water using a cation exchange <span class="hlt">concentration</span> procedure</span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Szabo, B. J.; Joensuu, O.</p> <p>1967-01-01</p> <p>A <span class="hlt">concentration</span> technique employing Dowex 50W cation exchange resin is described for the <span class="hlt">determination</span> of barium in sea water. The separated barium is precipitated as fluoride together with calcium and strontium and measured by emission spectrographic analysis. The vertical distribution of barium in sea water has been measured in the Caribbean Sea and the Atlantic Ocean. The barium content varied between 7 and 23 ??g. per liter; in two profiles, the lowest <span class="hlt">concentrations</span> were at a depth of about 1000 meters.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/983026','DOE-PATENT-XML'); return false;" href="http://www.osti.gov/scitech/servlets/purl/983026"><span id="translatedtitle">Simultaneous and rapid <span class="hlt">determination</span> of multiple component <span class="hlt">concentrations</span> in a Kraft liquor process stream</span></a></p> <p><a target="_blank" href="http://www.osti.gov/doepatents">DOEpatents</a></p> <p>Li, Jian; Chai, Xin Sheng; Zhu, Junyoung</p> <p>2008-06-24</p> <p>The present invention is a rapid method of <span class="hlt">determining</span> the <span class="hlt">concentration</span> of the major components in a chemical stream. The present invention is also a simple, low cost, device of <span class="hlt">determining</span> the in-situ <span class="hlt">concentration</span> of the major components in a chemical stream. In particular, the present invention provides a useful method for simultaneously <span class="hlt">determining</span> the <span class="hlt">concentrations</span> of sodium hydroxide, sodium sulfide and sodium carbonate in aqueous kraft pulping liquors through use of an attenuated total reflectance (ATR) tunnel flow cell or optical probe capable of producing a ultraviolet absorbency spectrum over a wavelength of 190 to 300 nm. In addition, the present invention eliminates the need for manual sampling and dilution previously required to generate analyzable samples. The inventive method can be used in Kraft pulping operations to control white liquor causticizing efficiency, sulfate reduction efficiency in green liquor, oxidation efficiency for oxidized white liquor and the active and effective alkali charge to kraft pulping operations.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016JChPh.144d4709S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016JChPh.144d4709S"><span id="translatedtitle"><span class="hlt">Determination</span> of the critical micelle <span class="hlt">concentration</span> in simulations of surfactant systems</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Santos, Andrew P.; Panagiotopoulos, Athanassios Z.</p> <p>2016-01-01</p> <p>Alternative methods for <span class="hlt">determining</span> the critical micelle <span class="hlt">concentration</span> (cmc) are investigated using canonical and grand canonical Monte Carlo simulations of a lattice surfactant model. A common measure of the cmc is the "free" (unassociated) surfactant <span class="hlt">concentration</span> in the presence of micellar aggregates. Many prior simulations of micellizing systems have observed a decrease in the free surfactant <span class="hlt">concentration</span> with overall surfactant loading for both ionic and nonionic surfactants, contrary to theoretical expectations from mass-action models of aggregation. In the present study, we investigate a simple lattice nonionic surfactant model in implicit solvent, for which highly reproducible simulations are possible in both the canonical (NVT) and grand canonical (μVT) ensembles. We confirm the previously observed decrease of free surfactant <span class="hlt">concentration</span> at higher overall loadings and propose an algorithm for the precise calculation of the excluded volume and effective <span class="hlt">concentration</span> of unassociated surfactant molecules in the accessible volume of the solution. We find that the cmc can be obtained by correcting the free surfactant <span class="hlt">concentration</span> for volume exclusion effects resulting from the presence of micellar aggregates. We also develop an improved method for <span class="hlt">determination</span> of the cmc based on the maximum in curvature for the osmotic pressure curve <span class="hlt">determined</span> from μVT simulations. Excellent agreement in cmc and other micellar properties between NVT and μVT simulations of different system sizes is observed. The methodological developments in this work are broadly applicable to simulations of aggregating systems using any type of surfactant model (atomistic/coarse grained) or solvent description (explicit/implicit).</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/921934','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/921934"><span id="translatedtitle"><span class="hlt">ABSOLUTE</span> POLARIMETRY AT RHIC.</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>OKADA; BRAVAR, A.; BUNCE, G.; GILL, R.; HUANG, H.; MAKDISI, Y.; NASS, A.; WOOD, J.; ZELENSKI, Z.; ET AL.</p> <p>2007-09-10</p> <p>Precise and <span class="hlt">absolute</span> beam polarization measurements are critical for the RHIC spin physics program. Because all experimental spin-dependent results are normalized by beam polarization, the normalization uncertainty contributes directly to final physics uncertainties. We aimed to perform the beam polarization measurement to an accuracy Of {Delta}P{sub beam}/P{sub beam} < 5%. The <span class="hlt">absolute</span> polarimeter consists of Polarized Atomic Hydrogen Gas Jet Target and left-right pairs of silicon strip detectors and was installed in the RHIC-ring in 2004. This system features proton-proton elastic scattering in the Coulomb nuclear interference (CNI) region. Precise measurements of the analyzing power A{sub N} of this process has allowed us to achieve {Delta}P{sub beam}/P{sub beam} = 4.2% in 2005 for the first long spin-physics run. In this report, we describe the entire set up and performance of the system. The procedure of beam polarization measurement and analysis results from 2004-2005 are described. Physics topics of AN in the CNI region (four-momentum transfer squared 0.001 < -t < 0.032 (GeV/c){sup 2}) are also discussed. We point out the current issues and expected optimum accuracy in 2006 and the future.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/371207','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/371207"><span id="translatedtitle">Molecular iodine <span class="hlt">absolute</span> frequencies. Final report</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Sansonetti, C.J.</p> <p>1990-06-25</p> <p>Fifty specified lines of {sup 127}I{sub 2} were studied by Doppler-free frequency modulation spectroscopy. For each line the classification of the molecular transition was <span class="hlt">determined</span>, hyperfine components were identified, and one well-resolved component was selected for precise <span class="hlt">determination</span> of its <span class="hlt">absolute</span> frequency. In 3 cases, a nearby alternate line was selected for measurement because no well-resolved component was found for the specified line. <span class="hlt">Absolute</span> frequency <span class="hlt">determinations</span> were made with an estimated uncertainty of 1.1 MHz by locking a dye laser to the selected hyperfine component and measuring its wave number with a high-precision Fabry-Perot wavemeter. For each line results of the <span class="hlt">absolute</span> measurement, the line classification, and a Doppler-free spectrum are given.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/22227958','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/22227958"><span id="translatedtitle">Using the HEMOCLOT direct thrombin inhibitor assay to <span class="hlt">determine</span> plasma <span class="hlt">concentrations</span> of dabigatran.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Stangier, Joachim; Feuring, Martin</p> <p>2012-03-01</p> <p>The objective of the present study was to assess the suitability of an accurate, sensitive, standardized, chronometric blood coagulation test to <span class="hlt">determine</span> the anticoagulation activity of dabigatran and to quantify <span class="hlt">concentrations</span> of dabigatran in plasma. Dabigatran was spiked at increasing <span class="hlt">concentrations</span> in pooled citrated normal human plasma to measure diluted thrombin time with the HEMOCLOT THROMBIN INHIBITOR assay. Calibration curve linearity, inter-assay and intra-assay precision, and assay accuracy were investigated. Dabigatran stability in plasma and the feasibility of lyophilized dabigatran standards for assay calibration were assessed. Data are presented as back-calculated plasma <span class="hlt">concentrations</span> of dabigatran using regression analysis. Dabigatran's calibration curve for thrombin clotting time was linear over the <span class="hlt">concentration</span> range 0-4000  nmol/l (0-1886  ng/ml). The R was 0.99. Total assay imprecision for dabigatran was 4.7-12.0% coefficient of variation, with 1.2-3.1% for intra-run imprecision, 4.0-10.0% for inter-run precision and 0.3-8.3% for between-day imprecision. Assay accuracy was <span class="hlt">determined</span> at three dabigatran <span class="hlt">concentrations</span>; deviation from sample target <span class="hlt">concentrations</span> ranged from -20.7% (100  nmol/l; 47.15  ng/ml) to 5.6% (1500  nmol/l; 707.3  ng/ml). Assay robustness was <span class="hlt">determined</span> by analysing identical dabigatran samples in two independent laboratories. The mean bias of dabigatran coagulation times between laboratories was 6.6%. The HEMOCLOT Thrombin Inhibitors assay is suitable for <span class="hlt">determining</span> the anticoagulant activity and calculating plasma <span class="hlt">concentrations</span> of dabigatran using simple and widely available chronometric coagulation devices. The use of this rapid, established, standardized and calibrated assay should provide accurate and consistent results when assessing the anticoagulant activity of dabigatran. PMID:22227958</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/903188','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/903188"><span id="translatedtitle">Raman Spectroscopy <span class="hlt">Determination</span> of Hole <span class="hlt">Concentration</span> in p-Type GaSb</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Maslar JE, Hurst WS, Wang CA</p> <p>2007-04-05</p> <p>Room temperature p-type GaSb bulk coupled mode spectra were measured as a function of hole <span class="hlt">concentration</span>. These spectra were obtained using an optical system based on 752.55 nm excitation in order to obtain more sensitivity to bulk GaSb coupled mode scattering than possible with visible wavelength excitation-based systems. A relatively simple spectral model for the electronic contribution to the dielectric function was evaluated for <span class="hlt">determination</span> of hole <span class="hlt">concentration</span> from the bulk coupled mode spectra. Optically-derived values for hole <span class="hlt">concentration</span> were <span class="hlt">determined</span> by minimizing the sum of the residuals squared between an experimental and simulated spectrum as a function of total hole <span class="hlt">concentration</span> and a plasmon damping parameter. Hole <span class="hlt">concentrations</span> obtained from the Raman spectroscopic measurements deviated from the values <span class="hlt">determined</span> from single field Hall effect measurements that were corrected to account for two band conduction by {approx}20% to {approx}65%. These deviations were attributed to the limitations of the spectral model employed and uncertainties in GaSb materials properties.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20040110742','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20040110742"><span id="translatedtitle"><span class="hlt">Absolute</span> Equilibrium Entropy</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Shebalin, John V.</p> <p>1997-01-01</p> <p>The entropy associated with <span class="hlt">absolute</span> equilibrium ensemble theories of ideal, homogeneous, fluid and magneto-fluid turbulence is discussed and the three-dimensional fluid case is examined in detail. A sigma-function is defined, whose minimum value with respect to global parameters is the entropy. A comparison is made between the use of global functions sigma and phase functions H (associated with the development of various H-theorems of ideal turbulence). It is shown that the two approaches are complimentary though conceptually different: H-theorems show that an isolated system tends to equilibrium while sigma-functions allow the demonstration that entropy never decreases when two previously isolated systems are combined. This provides a more complete picture of entropy in the statistical mechanics of ideal fluids.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://eric.ed.gov/?q=hollow&pg=7&id=EJ386281','ERIC'); return false;" href="http://eric.ed.gov/?q=hollow&pg=7&id=EJ386281"><span id="translatedtitle">The <span class="hlt">Determination</span> of the <span class="hlt">Concentrations</span> of Sugar Solutions by Laser Refractometry.</span></a></p> <p><a target="_blank" href="http://www.eric.ed.gov/ERICWebPortal/search/extended.jsp?_pageLabel=advanced">ERIC Educational Resources Information Center</a></p> <p>Hughes, Elvin, Jr.; And Others</p> <p>1988-01-01</p> <p>Presents an easily performed experiment to <span class="hlt">determine</span> sucrose <span class="hlt">concentrations</span> using a laser and a hollow glass prism. The experiment is suggested for high school, freshman college, and instrumental analysis classes. Notes an Erlenmeyer flask can be used instead of a prism. (MVL)</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://eric.ed.gov/?q=titrations&id=EJ1073052','ERIC'); return false;" href="http://eric.ed.gov/?q=titrations&id=EJ1073052"><span id="translatedtitle">Using Conductivity Measurements to <span class="hlt">Determine</span> the Identities and <span class="hlt">Concentrations</span> of Unknown Acids: An Inquiry Laboratory Experiment</span></a></p> <p><a target="_blank" href="http://www.eric.ed.gov/ERICWebPortal/search/extended.jsp?_pageLabel=advanced">ERIC Educational Resources Information Center</a></p> <p>Smith, K. Christopher; Garza, Ariana</p> <p>2015-01-01</p> <p>This paper describes a student designed experiment using titrations involving conductivity measurements to identify unknown acids as being either HCl or H[subscript 2]SO[subscript 4], and to <span class="hlt">determine</span> the <span class="hlt">concentrations</span> of the acids, thereby improving the utility of standard acid-base titrations. Using an inquiry context, students gain experience…</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=2650928','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=2650928"><span id="translatedtitle">High <span class="hlt">Concentrations</span> of Manganese in Mueller-Hinton Agar Increase MICs of Tigecycline <span class="hlt">Determined</span> by Etest▿</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Fernández-Mazarrasa, Carlos; Mazarrasa, Olav; Calvo, Jorge; del Arco, Asunción; Martínez-Martínez, Luis</p> <p>2009-01-01</p> <p>MICs of tigecycline <span class="hlt">determined</span> by Etest were 4 to 12 times (three ATCC strains) and 2 to 8 times (50 clinical isolates) higher in Mueller-Hinton agar from Merck than in Mueller-Hinton agar from either Oxoid or Difco. This was related to a much higher <span class="hlt">concentration</span> of manganese in the medium from Merck. PMID:19144806</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://pubs.er.usgs.gov/publication/70010573','USGSPUBS'); return false;" href="http://pubs.er.usgs.gov/publication/70010573"><span id="translatedtitle"><span class="hlt">Concentration</span> method for the spectrochemical <span class="hlt">determination</span> of seventeen minor elements in natural water</span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Silvey, W.D.; Brennan, R.</p> <p>1962-01-01</p> <p>A method for the quantitative spectrochemical <span class="hlt">determination</span> of microgram amounts of 17 minor elements in water is given. The chelating reagents 8-quinolinol, tannic acid, and thionalide are utilized to <span class="hlt">concentrate</span> traces (1 to 500 ??g.) of aluminum, cobalt, chromium, copper, iron, gallium, germanium, manganese, nickel, titanium, vanadium, bismuth, lead, molybdenum, cadmium, zinc, and beryllium. Indium is added as a buffer, and palladium is used as an internal standard. The ashed oxides of these 17 metals are subsequently subjected to direct current arcing conditions during spectrum analysis. The method can be used to analyze waters with dissolved solids ranging from less than 100 to more than 100,000 p.p.m. There is no limiting <span class="hlt">concentration</span> range for the <span class="hlt">determination</span> of the heavy metals since any volume of sample can be used that will contain a heavy metal <span class="hlt">concentration</span> within the analytical range of the method. Both the chemical and spectrographic procedures are described, and precision and accuracy data are given.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/16674734','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/16674734"><span id="translatedtitle">Evaluation of three different histamine <span class="hlt">concentrations</span> in intradermal testing of normal cats and attempted <span class="hlt">determination</span> of 'irritant' threshold <span class="hlt">concentrations</span> for 48 allergens.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Austel, Michaela; Hensel, Patrick; Jackson, Dawn; Vidyashankar, Anand; Zhao, Ying; Medleau, Linda</p> <p>2006-06-01</p> <p>The purpose of this study was to <span class="hlt">determine</span> the optimal histamine <span class="hlt">concentration</span> and 'irritant' allergen threshold <span class="hlt">concentrations</span> in intradermal testing (IDT) in normal cats. Thirty healthy cats were tested with three different histamine <span class="hlt">concentrations</span> and four different <span class="hlt">concentrations</span> of each allergen. The optimal histamine <span class="hlt">concentration</span> was <span class="hlt">determined</span> to be 1: 50,000 w/v (0.05 mg mL(-1)). Using this histamine <span class="hlt">concentration</span>, the 'irritant' threshold <span class="hlt">concentration</span> for most allergens was above the highest <span class="hlt">concentrations</span> tested (4,000 PNU mL(-1) for 41 allergens and 700 PNU mL(-1) for human dander). The 'irritant' threshold <span class="hlt">concentration</span> for flea antigen was <span class="hlt">determined</span> to be 1:750 w/v. More than 10% of the tested cats showed positive reactions to Dermatophagoides farinae, Dermatophagoides pteronyssinus, housefly, mosquito and moth at every allergen <span class="hlt">concentration</span>, which suggests that the 'irritant' threshold <span class="hlt">concentration</span> for these allergens is below 1,000 PNU mL(-1), the lowest allergen <span class="hlt">concentration</span> tested. Our results confirm previous studies in indicating that allergen and histamine <span class="hlt">concentrations</span> used in feline IDT may need to be revised.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_11");'>11</a></li> <li><a href="#" onclick='return showDiv("page_12");'>12</a></li> <li class="active"><span>13</span></li> <li><a href="#" onclick='return showDiv("page_14");'>14</a></li> <li><a href="#" onclick='return showDiv("page_15");'>15</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_13 --> <div id="page_14" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_12");'>12</a></li> <li><a href="#" onclick='return showDiv("page_13");'>13</a></li> <li class="active"><span>14</span></li> <li><a href="#" onclick='return showDiv("page_15");'>15</a></li> <li><a href="#" onclick='return showDiv("page_16");'>16</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="261"> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3586831','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3586831"><span id="translatedtitle"><span class="hlt">Determination</span> of Methanol <span class="hlt">Concentrations</span> in Traditional Herbal Waters of Different Brands in Iran</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Mousavi, Seyed Reza; Namaei-Ghassemi, Mohssen; Layegh, Massomeh; AfzalAghaee, Monavar; vafaee, Manssoreh; Zare, Gholamali; Moghiman, Toktam; Mood, Mahdi Balali</p> <p>2011-01-01</p> <p>Objective(s) Herbal waters are extensively used in most parts of including . Visiting a patient with total blindness due to daily ingestion of around 200 ml of herbal water (Plant forty water) per day for six months was the rational for methanol <span class="hlt">determination</span> in all herbal waters available in markets. Materials and Methods A total of two hundred and nineteen bottles of herbal waters were randomly bought from market. Methanol <span class="hlt">concentration</span> was <span class="hlt">determined</span> by gas chromatography, using a Flame Ionized Detector. Benzene (1000 mg/l) was applied as the internal standard. Collected data was analyzed by SPSS software (version 11.5), using appropriate descriptive statistical tests. Results Forty six different herbal waters from three main producing factories (A, B and C) were tested. Highest methanol <span class="hlt">concentration</span> was measured in dill water of A (1208±202.74 mg/l), <span class="hlt">concentrated</span> rose water of A (1017.41±59.68 mg/l) and <span class="hlt">concentrated</span> rose water of B (978.52±92.81 mg/l). Lowest methanol <span class="hlt">concentration</span> was <span class="hlt">determined</span> in Trachyspermum copticum water of B (18.93±1.04 mg/l), cinnamon and ginger water of B (29.64±10.88 mg/l) and rice skin water of A (41.33±7.85 mg/l). Mean methanol <span class="hlt">concentrations</span> of herbal waters including ginger, cinnamon, dill, peppermint, alfalfa, and plant forty from A, B and C were 374.69, 209.81 and 280.12 mg/l, respectively (P< 0.001). Conclusion Methanol <span class="hlt">concentration</span> in all herbal waters, especially rose water of the three producers was very high that may induce toxicity in people taking these products regularly for a long time. PMID:23493100</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016AIPC.1722c0008K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016AIPC.1722c0008K"><span id="translatedtitle"><span class="hlt">Determination</span> of indoor radon <span class="hlt">concentrations</span> at the elementary schools of Fatih district in Istanbul</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Kurt, A.; Yalcin, L. Sahin; Oktem, Y.; Akkus, B.; Bozkurt, E.; Hafizoglu, N.; Ozturk, F. C.; Aytan, O.; Ertoprak, A.</p> <p>2016-03-01</p> <p>Radon is an odorless, tasteless, colorless noble radioactive gas which is produced within the radioactive decay chain of Uranium. The Radon forms in rocks, diffuses into soil and then escapes into atmosphere. When human exposure to high <span class="hlt">concentration</span> of radon gas from inside, risk of developing lung cancer is increased. There are many methods to <span class="hlt">determine</span> 222Rn <span class="hlt">concentration</span> in the air. In this study, radon <span class="hlt">concentration</span> of confined air spaces were measured by using LR-115 solid state nuclear track detectors. 509 LR-115 nuclear trace detectors were placed to 25 schools in Fatih District and they effective dose values were calculated. The results of measurements showed that the radon <span class="hlt">concentration</span> varies between 40-395 Bq/m3. This results compared with Turkey's limits (400 Bq/m3) are low, conversely higher compared with WHO's limits (100 Bq/m3).</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/1043643','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/1043643"><span id="translatedtitle"><span class="hlt">Absolute</span> <span class="hlt">determination</span> of charge-coupled device quantum detection efficiency using Si K-edge x-ray absorption fine structure</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Dunn, J; Steel, A B</p> <p>2012-05-06</p> <p>We report a method to <span class="hlt">determine</span> the quantum detection efficiency and the absorbing layers on a front-illuminated charge-coupled device (CCD). The CCD under study, as part of a crystal spectrometer, measures intense continuum x-ray emission from a picosecond laser-produced plasma and spectrally resolves the Si K-edge x-ray absorption fine structure features due to the electrode gate structure of the device. The CCD response across the Si K-edge shows a large discontinuity as well as a number of oscillations that are identified individually and uniquely from Si, SiO{sub 2}, and Si{sub 3}N{sub 4} layers. From the spectral analysis of the structure and K-edge discontinuity, the active layer thickness and the different absorbing layers thickness can be <span class="hlt">determined</span> precisely. A precise CCD detection model from 0.2-10 keV can be deduced from this highly sensitive technique.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/26351013','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/26351013"><span id="translatedtitle">Comparison of various hours living fission products for <span class="hlt">absolute</span> power density <span class="hlt">determination</span> in VVER-1000 mock up in LR-0 reactor.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Košťál, Michal; Švadlenková, Marie; Koleška, Michal; Rypar, Vojtěch; Milčák, Ján</p> <p>2015-11-01</p> <p>Measuring power level of zero power reactor is a quite difficult task. Due to the absence of measurable cooling media heating, it is necessary to employ a different method. The gamma-ray spectroscopy of fission products induced within reactor operation is one of possible ways of power <span class="hlt">determination</span>. The method is based on the proportionality between fission product buildup and released power. The (92)Sr fission product was previously preferred as nuclide for LR-0 power <span class="hlt">determination</span> for short-time irradiation experiments. This work aims to find more appropriate candidates, because the (92)Sr, however suitable, has a short half-life, which limits the maximal measurable amount of fuel pins within a single irradiation batch. The comparison of various isotopes is realized for (92)Sr, (97)Zr, (135)I, (91)Sr, and (88)Kr. The comparison between calculated and experimentally <span class="hlt">determined</span> (C/E-1 values) net peak areas is assessed for these fission products. Experimental results show that studied fission products, except (88)Kr, are in comparable agreement with (92)Sr results. Since (91)Sr has notably higher half-life than (92)Sr, (91)Sr seems to be more appropriate marker in experiments with a large number of measured fuel pins.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/23257955','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/23257955"><span id="translatedtitle">A simple liquid chromatography-tandem mass spectrometry method for <span class="hlt">determination</span> of plasma fentanyl <span class="hlt">concentration</span> in rats and patients with cancer pain.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Hisada, Tatsuya; Katoh, Miki; Hitoshi, Kotaro; Kondo, Yuya; Fujioka, Miho; Toyama, Yukio; Ieda, Hideaki; Gocho, Saori; Nadai, Masayuki</p> <p>2013-01-01</p> <p>A fentanyl patch is widely used for the treatment of cancer pain. Its few adverse effects include constipation and drowsiness. The absorption volume of transdermally applied fentanyl may differ according to its site of application and variability in patch adhesion. Since fentanyl is predominantly metabolized by the drug-metabolizing enzyme cytochrome P450 (CYP) 3A4 in the liver, its <span class="hlt">concentration</span> may vary in cases of physiologically reduced CYP3A4 activity in the liver (liver disease and aging) or on co-administration of drugs. The clinical significance of measuring plasma <span class="hlt">concentration</span> of fentanyl is high, but conventional methods require complicated processes such as solid-phase extraction and liquid-liquid extraction before the sample is injected into an HPLC system. In this study, a simple liquid chromatography-tandem mass spectrometry (LC-MS/MS) method was developed for <span class="hlt">determining</span> plasma fentanyl <span class="hlt">concentrations</span> by deproteinization with acetonitrile. A recovery test was conducted using an <span class="hlt">absolute</span> calibration curve to confirm the method's linearity and inter- and intra-day reproducibility. The required plasma volume for detection was reduced from 1 mL in the conventional method to 20 µL in the present study, and a good calibration curve was obtained in the <span class="hlt">concentration</span> range from 0.05 to 5 ng/mL. These findings suggest that the method for sample preparation and quantification developed in this study are appropriate for measuring fentanyl <span class="hlt">concentration</span> in human plasma in clinical settings.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014EGUGA..16.7648T','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014EGUGA..16.7648T"><span id="translatedtitle">New directional results and <span class="hlt">determination</span> of <span class="hlt">absolute</span> archaeointensity using both the classical Thellier and the multi-specimen procedures for two kilns excavated at Osterietta, Italy</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Tema, Evdokia; Camps, Pierre; Ferrara, Enzo</p> <p>2014-05-01</p> <p>A detailed rock-magnetic and archaeomagnetic study has been carried out on two rescue excavation kilns discovered during the works to expand a highway at the location of Osterietta, in Northen Italy. Systematic archaeomagnetic sampling was carried out collecting 15 samples from the first kiln (OSA) and 8 samples from the second kiln (OSB), all of them oriented in situ with a magnetic compass and an inclinometer. Magnetic mineralogy measurements have been carried out in order to <span class="hlt">determine</span> the main magnetic carrier of the samples and to check their thermal stability. Standard thermal demagnetization procedures have been used to <span class="hlt">determine</span> the archaeomagnetic direction registered by the bricks during their last firing. Demagnetization results show a very stable characteristic remanent magnetization (ChRM). We averaged the directions for each kiln separately and calculated the statistical parameters assuming a Fisherian distribution. The archaeointensity of both kilns has also been recovered with both the classical Thellier-Thellier method and the multi-specimen procedure (MSP-DSC). During the Thellier experiments, regular partial thermoremanent magnetization checks have been performed and the effect of the anisotropy of the thermoremanent magnetization (TRM) and cooling rate upon TRM intensity acquisition have been investigated in all samples. The multi-specimen procedure was performed with a very fast-heating oven developed at Montpellier (France). The intensity results obtained from both methods have been compared and the full geomagnetic field vector <span class="hlt">determined</span> for each kiln has been used for archaeomagnetic dating. The obtained results show that the kilns were almost contemporaneous and their last use occurred in the 1750-1850 AD time interval.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/20102208','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/20102208"><span id="translatedtitle"><span class="hlt">Determination</span> of bisphenol A in U.S. infant formulas: updated methods and <span class="hlt">concentrations</span>.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Ackerman, Luke K; Noonan, Gregory O; Heiserman, Wendy M; Roach, John A; Limm, William; Begley, Timothy H</p> <p>2010-02-24</p> <p>An updated survey of U.S. infant formula was conducted to <span class="hlt">determine</span> the <span class="hlt">concentrations</span> of bisphenol A (BPA). The purpose was to accurately assess BPA <span class="hlt">concentrations</span> across the infant formula market, accounting for lot variability, and <span class="hlt">determine</span> if geographic location or can age influences BPA <span class="hlt">concentrations</span>. A method was developed to measure BPA in formula utilizing isotope dilution, solid-phase extraction, and liquid chromatography-tandem mass spectrometry (HPLC-MS/MS). The method was tested and found to be reproducible (10% relative standard deviation), reliable (47 +/- 1% recovery), and sensitive (0.15 ng g(-1) method detection limit). Over 160 analyses were conducted using 104 formula containers representing 36 products. Samples from U.S. east and west coast markets demonstrated no significant difference, and <span class="hlt">concentrations</span> in older cans were not higher. BPA <span class="hlt">concentrations</span> in liquid formula (0.48-11 ng g(-1)) were consistent with previous studies, and BPA was detected in only 1 of 14 powder formula products analyzed.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=2567591','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=2567591"><span id="translatedtitle"><span class="hlt">Determining</span> median urinary iodine <span class="hlt">concentration</span> that indicates adequate iodine intake at population level.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Delange, François; de Benoist, Bruno; Burgi, Hans</p> <p>2002-01-01</p> <p>OBJECTIVE: Urinary iodine <span class="hlt">concentration</span> is the prime indicator of nutritional iodine status and is used to evaluate population-based iodine supplementation. In 1994, WHO, UNICEF and ICCIDD recommended median urinary iodine <span class="hlt">concentrations</span> for populations of 100- 200 micro g/l, assuming the 100 micro g/l threshold would limit <span class="hlt">concentrations</span> <50 micro g/l to </=20% of people. Some scientists felt this proportion was unacceptably high and wanted to increase the threshold above 100 micro g/l. The study was carried out to <span class="hlt">determine</span> the frequency distribution of urinary iodine in iodine-replete populations (schoolchildren and adults) and the proportion of <span class="hlt">concentrations</span> <50 micro g/l. METHOD: A questionnaire on frequency distribution of urinary iodine in iodine-replete populations was circulated to 29 scientific groups. FINDINGS: Nineteen groups reported data from 48 populations with median urinary iodine <span class="hlt">concentrations</span> >100 micro g/l. The total population was 55 892, including 35 661 (64%) schoolchildren. Median urinary iodine <span class="hlt">concentrations</span> were 111-540 (median 201) micro g/l for all populations, 100-199 micro g/l in 23 (48%) populations and >/=200 micro g/l in 25 (52%). The frequencies of values <50 micro g/l were 0-20.8 (mean 4.8%) overall and 7.2% and 2.5% in populations with medians of 100-199 micro g/l and >200 micro g/l, respectively. The frequency reached 20% only in two places where iodine had been supplemented for <2 years. CONCLUSION: The frequency of urinary iodine <span class="hlt">concentrations</span> <50 micro g/l in populations with median urinary iodine <span class="hlt">concentrations</span> >/=100 micro g/l has been overestimated. The threshold of 100 micro g/l does not need to be increased. In populations, median urinary iodine <span class="hlt">concentrations</span> of 100-200 micro g/l indicate adequate iodine intake and optimal iodine nutrition. PMID:12219154</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19880002971','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19880002971"><span id="translatedtitle">A simplified CARS measurement system for rapid <span class="hlt">determination</span> of temperature and oxygen <span class="hlt">concentration</span></span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Fujii, Shoichi</p> <p>1987-01-01</p> <p>A new spectroscopic concept for the rapid <span class="hlt">determination</span> of temperature and oxygen <span class="hlt">concentration</span> by CARS (Coherent Anti-Stokes Raman Spectroscopy) was described. The ratio of two spectral regions in the broadband Q-branch spectrum was detected by photomultipliers in a monochromator, which ratio depends on temperature and species <span class="hlt">concentration</span>. The comparison of the measured data with theory was made using a flat flame burner and an electric furnace, with reasonable results. Various optical techniques for alignment were introduced including a highly efficient, stable dye oscillator. The combination of the spectroscopic concept and the optical techniques will make the CARS measurement system rapid in data processing and simple in optical parts.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://pubs.er.usgs.gov/publication/70021421','USGSPUBS'); return false;" href="http://pubs.er.usgs.gov/publication/70021421"><span id="translatedtitle">Use of behavioral endpoints to <span class="hlt">determine</span> protective <span class="hlt">concentrations</span> of the insecticide fonofos for bluegill (Lepomis macrochirus)</span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Fairchild, J.F.; Little, E.E.</p> <p>1999-01-01</p> <p>This research compared the results of laboratory and mesocosm studies to <span class="hlt">determine</span> the effectiveness of using behavioral measures of sublethal exposure to define environmental <span class="hlt">concentration</span> ranges that are protective of free-ranging populations of bluegill (Lepomis macrochirus) exposed to the organophophate insecticide fonofos. Thirty-day laboratory chronic studies were conducted to <span class="hlt">determine</span> the relative sensitivity of standard (e.g. survival and growth) and non-standard behavioral (e.g. swimming capacity, feeding efficiency, and aggression) endpoints in predicting <span class="hlt">concentrations</span> of fonofos protective of bluegill growth and survival. The lowest observable effect <span class="hlt">concentration</span> (LOECs) for the standard measures of survival and growth was 5.6 ??g/L. Two behavioral endpoints were of similar sensitivity to the standard measures: swimming capacity, LOEC of 5.6 ??g/L; and prey strike frequency, LOEC of 5.6 ??g/L. However, aggressive interactions were ten-fold more sensitive than swimming or feeding behavior with a LOEC occurring at 0.6 ??g/L. Lab results were compared to an aquatic mesocosm study which exposed adult and juvenile bluegill to a 9.41 ??g/L <span class="hlt">concentration</span> of fonofos. The dissipation half-life of fonofos was 5 days in 0.1 hectare aquatic mesocosms. Significant mortality among caged bluegill occurred within 4 days of exposure at 9.41 ??g/L. However, the 9.41 ??g/L <span class="hlt">concentration</span> of fonofos had no statistically significant effects on survival, growth, reproduction, or total biomass of free-ranging populations of bluegill. We conclude from these studies that laboratory data can accurately estimate <span class="hlt">concentrations</span> that are lethal in the field and that the use of behavioral endpoints can provide ecologically relevant, yet conservative estimates of <span class="hlt">concentrations</span> that are protective of field populations.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=19880047730&hterms=equilibrium+constant&qs=N%3D0%26Ntk%3DAll%26Ntx%3Dmode%2Bmatchall%26Ntt%3Dequilibrium%2Bconstant','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=19880047730&hterms=equilibrium+constant&qs=N%3D0%26Ntk%3DAll%26Ntx%3Dmode%2Bmatchall%26Ntt%3Dequilibrium%2Bconstant"><span id="translatedtitle">The equilibrium constant for N2O5 = NO2 + NO3 - <span class="hlt">Absolute</span> <span class="hlt">determination</span> by direct measurement from 243 to 397 K</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Cantrell, C. A.; Davidson, J. A.; Mcdaniel, A. H.; Shetter, R. E.; Calvert, J. G.</p> <p>1988-01-01</p> <p>Direct <span class="hlt">determinations</span> of the equilibrium constant for the reaction N2O5 = NO2 + NO3 were carried out by measuring NO2, NO3, and N2O5 using long-path visible and infrared absorption spectroscopy as a function of temperature from 243 to 397 K. The first-order decay rate constant of N2O5 was experimentally measured as a function of temperature. These results are in turn used to derive a value for the rate coefficient for the NO-forming channel in the reaction of NO3 with NO2. The implications of the results for atmospheric chemistry, the thermodynamics of NO3, and for laboratory kinetics studies are discussed.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/12024304','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/12024304"><span id="translatedtitle">A comparison of coulometric titration and potentiometric <span class="hlt">determination</span> of chloride <span class="hlt">concentration</span> in rumen fluid.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Cebra, Christopher K.; Tornquist, Susan J.; Vap, Lomda M.; Dodson, Linda A.</p> <p>2001-01-01</p> <p>The <span class="hlt">concentration</span> of chloride ions in rumen fluid is a useful measure of obstructive gastrointestinal disease in ruminants and camelids. However, rumen fluid is very different from other biological fluids in its bacterial populations, consistency, and <span class="hlt">concentrations</span> of various anions. Two methods of <span class="hlt">determining</span> the chloride <span class="hlt">concentration</span> in biological fluids were compared using centrifuged and filtered rumen fluid containing different amounts of sodium chloride. Although coulometric titration and potentiometric electrode analysis yielded results that had a strong linear relationship, the results of potentiometry were consistently and significantly higher, by about 20 mEq/L. This difference was investigated further by analyzing a series of fluids containing different <span class="hlt">concentrations</span> of sodium acetate. Acetate was detected as chloride (0.21 chloride molecules per acetate molecule) by potentiometry but not by coulometric titration. Therefore, the acetate <span class="hlt">concentration</span> of rumen fluid was the most likely cause of the discrepancy between tests in the original trial. In conclusion, the coulometric procedure may be more accurate than the potentiometric procedure for measuring rumen chloride when the <span class="hlt">concentrations</span> of possible confounding ions are unknown.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2012EPJWC..2403005S&link_type=ABSTRACT','NASAADS'); return false;" href="http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2012EPJWC..2403005S&link_type=ABSTRACT"><span id="translatedtitle"><span class="hlt">Determination</span> of uranium <span class="hlt">concentration</span> in ground water samples of Northern Greece</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Samaropoulos, I.; Efstathiou, M.; Pashalidis, I.; Ioannidou, A.</p> <p>2012-04-01</p> <p>The activity <span class="hlt">concentration</span> of 238U and 234U has been <span class="hlt">determined</span> in groundwater samples of hot springs and deep wells from the region of Northern Greece. The analysis was performed by alpha spectroscopy after pre-<span class="hlt">concentration</span> and separation of uranium by cation exchange (Chelex 100 resin) and finally its electro-deposition on stainless steel discs. The uranium <span class="hlt">concentration</span> in deep wells and springs varies strongly between 0.15 and 7.66 μg l-1. Generally the springs present higher uranium <span class="hlt">concentration</span> than the deep wells, except of the Apol-lonia spring, which has shown the lowest value of 0.15 mg l-1. 238U and 234U activity <span class="hlt">concentration</span> ranged between 1.8-95.3 mBq l-1 and 1.7-160.1 mBq l-1, respectively. The obtained isotopic ratio 234U/238U varies between 0.95 and 1.74 which means that the two isotopes are not in radioactive equilibrium. The highest 234U/238U activity ratio values correspond to the Langada springs, indicating most probably old-type waters. On the other hand, ground waters from wells with relatively low uranium activity <span class="hlt">concentration</span> and low 234U/238U isotopic ratios, point to the presence of younger waters with a stronger contribution of a local recharge component to the groundwater.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/20860866','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/20860866"><span id="translatedtitle">Accurate <span class="hlt">absolute</span> reference frequencies from 1511 to 1545 nm of the {nu}{sub 1}+{nu}{sub 3} band of {sup 12}C{sub 2}H{sub 2} <span class="hlt">determined</span> with laser frequency comb interval measurements</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Madej, Alan A.; Alcock, A. John; Czajkowski, Andrzej; Bernard, John E.; Chepurov, Sergei</p> <p>2006-10-15</p> <p><span class="hlt">Absolute</span> frequency measurements, with uncertainties as low as 2 kHz (1x10{sup -11}), are presented for the {nu}{sub 1}+{nu}{sub 3} band of {sup 12}C{sub 2}H{sub 2} at 1.5 {mu}m (194-198 THz). The measurements were made using cavity-enhanced, diode-laser-based saturation spectroscopy. With one laser system stabilized to the P(16) line of {sup 13}C{sub 2}H{sub 2} and a system stabilized to the line in {sup 12}C{sub 2}H{sub 2} whose frequency was to be <span class="hlt">determined</span>, a Cr:YAG laser-based frequency comb was employed to measure the frequency intervals. The systematic uncertainty is notably reduced relative to that of previous studies, and the region of measured lines has been extended. Improved molecular constants are obtained.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/20768752','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/20768752"><span id="translatedtitle">Accurate <span class="hlt">absolute</span> frequencies of the {nu}{sub 1}+{nu}{sub 3} band of {sup 13}C{sub 2}H{sub 2} <span class="hlt">determined</span> using an infrared mode-locked Cr:YAG laser frequency comb</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Madej, Alan A.; Bernard, John E.; John Alcock, A.; Czajkowski, Andrzej; Chepurov, Sergei</p> <p>2006-04-15</p> <p><span class="hlt">Absolute</span> frequency measurements, with up to 1x10{sup -11} level accuracies, are presented for 60 lines of the P and R branches for the {nu}{sub 1}+{nu}{sub 3} band of {sup 13}C{sub 2}H{sub 2} at 1.5 {mu}m (194 THz). The measurements were made using cavity-enhanced, diode-laser-based saturation spectroscopy. With one laser system stabilized to the P(16) line and a second laser system stabilized to the line whose frequency was to be <span class="hlt">determined</span>, a Cr:YAG frequency comb was employed to accurately measure the tetrahertz level frequency intervals. The results are compared with recent work from other groups and indicate that these lines would form a basis for a high-quality atlas of reference frequencies for this region of the spectrum.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/21024675','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/21024675"><span id="translatedtitle"><span class="hlt">Determination</span> of neutral carbon <span class="hlt">concentration</span> in electron cyclotron resonance generated plasma discharges</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Ene, A. B.; Lindner, P.; Stirn, R.; Schumacher, U.</p> <p>2007-12-15</p> <p>Carbon containing plasmas play an important role not only in plasma technology but also in thermonuclear fusion research. In order to understand and control the processes taking place in the plasma, the knowledge of the carbon ground state density is of major importance. It can be <span class="hlt">determined</span> by absorption and emission spectroscopy. Detailed measurements were performed in the past to <span class="hlt">determine</span> the silicon ground state density by means of spectroscopy of the self-absorbed spectral lines of the silicon ground state multiplet at 251 nm. The same procedure was applied for the <span class="hlt">determination</span> of the carbon <span class="hlt">concentration</span>, for which the carbon multiplet at 165 nm was analyzed and compared to a simulated spectrum. The ground state density was <span class="hlt">determined</span> by two independent methods.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014Ocgy...54..660K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014Ocgy...54..660K"><span id="translatedtitle"><span class="hlt">Determination</span> of the <span class="hlt">concentration</span> of mineral particles and suspended organic substance based on their spectral absorption</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Konovalov, B. V.; Kravchishina, M. D.; Belyaev, N. A.; Novigatsky, A. N.</p> <p>2014-09-01</p> <p>A method to <span class="hlt">determine</span> the <span class="hlt">concentrations</span> of the particulate mineral matter ( C PMM) and the particulate organic matter ( C POM) is suggested. The values of C PMM and C POM are calculated from the measurements of the spectral coefficients of the light absorption a POM(440) and a PMM(750) using empirical equations. The latter have been obtained by comparing the <span class="hlt">concentrations</span> of the suspended solids measured by means of the gravimetric method with the spectral values of the optical density of the suspended matter settled on membrane filters. The data used are typical of the coastal waters of inland and marginal seas and the open ocean and cover the range of three and two orders of magnitude for the <span class="hlt">concentrations</span> of C PMM and C POM, respectively.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/14687641','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/14687641"><span id="translatedtitle"><span class="hlt">Determination</span> of thorium <span class="hlt">concentrations</span> and activity ratios in silicate rocks by alpha spectrometry.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>dos Santos, R N; Marques, L S; Nicolai, S H A; Ribeiro, F B</p> <p>2004-01-01</p> <p>A detailed radiochemical procedure for alpha spectrometry measurements of thorium <span class="hlt">concentrations</span> and of 230Th/232Th activity ratios in silicates is presented. The Th behaviour, during each step of the chemical process, was investigated by using a 234Th tracer, which is a gamma-ray emitter. The described chemical processing provides relatively high thorium yields, which varied between 56% and 88%, in the analysis of GB-1 (granite) and BB-1 (basalt) Brazilian geological standards. Also, the application of the established radiochemical method allowed a <span class="hlt">determination</span> of both Th <span class="hlt">concentrations</span> and activity ratios with high reproducibility, on the order of 2%. The estimation of the <span class="hlt">concentration</span> result accuracy is also about 2%, which was calculated by using published data obtained from neutron activation analysis as reference values.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/11228997','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/11228997"><span id="translatedtitle">Uncertainties in risk assessment for the <span class="hlt">determination</span> of drinking water pollutant <span class="hlt">concentrations</span>: Cryptosporidium case study.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Fewtrell, L; Macgill, S M; Kay, D; Casemore, D</p> <p>2001-02-01</p> <p>There is a growing acknowledgement of the need to recognise uncertainties in the estimation of waterborne risks. In this paper, the strength of the science available to characterise Cryptosporidium risks in drinking water is investigated, in particular the <span class="hlt">determination</span> of oocyst <span class="hlt">concentrations</span> at various points in the chain of water supply. A recently developed scientific quality audit framework is used as a tool to guide this investigation. The framework systematically reveals the relatively greater strength of the science for the "upstream" elements (estimation of <span class="hlt">concentrations</span> in environmental reservoirs) than for the "downstream" elements (<span class="hlt">concentrations</span> in distribution). It is the downstream elements that have greater bearing on human health and public policy issues. It is noted that the adoption of new monitoring Regulations is likely to prompt action to strengthen knowledge of these downstream elements in the future.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/26123605','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/26123605"><span id="translatedtitle"><span class="hlt">Determination</span> of tritium <span class="hlt">concentrations</span> in humans before the development of a nuclear power plant in Turkey.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Dizman, Serdar; Yilmaz, Adnan; Keser, Recep</p> <p>2015-01-01</p> <p>The most widely used method to <span class="hlt">determine</span> the level of tritium in humans is testing urine. Tritium <span class="hlt">concentrations</span> in urine samples of 100 persons aged 18-66 years selected randomly from a pilot region in Turkey were analysed. The average activity <span class="hlt">concentration</span> of urine samples was 4.66 ± 1.94 Bq L(-1) and the maximum activity <span class="hlt">concentration</span> was 27.91 Bq L(-1). The minimum detectable activity was 2.38 Bq L(-1). The annual effective dose from tritium was also evaluated on the basis of the measurement results and reference values recommended by the International Commission on Radiological Protection. The effective doses for males and females were 4.56 and 3.54 nSv, respectively. These results were lower than the permissible annual effective dose for members of the public. PMID:26123605</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_12");'>12</a></li> <li><a href="#" onclick='return showDiv("page_13");'>13</a></li> <li class="active"><span>14</span></li> <li><a href="#" onclick='return showDiv("page_15");'>15</a></li> <li><a href="#" onclick='return showDiv("page_16");'>16</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_14 --> <div id="page_15" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_13");'>13</a></li> <li><a href="#" onclick='return showDiv("page_14");'>14</a></li> <li class="active"><span>15</span></li> <li><a href="#" onclick='return showDiv("page_16");'>16</a></li> <li><a href="#" onclick='return showDiv("page_17");'>17</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="281"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/870028','DOE-PATENT-XML'); return false;" href="http://www.osti.gov/scitech/servlets/purl/870028"><span id="translatedtitle">Apparatus for the field <span class="hlt">determination</span> of <span class="hlt">concentration</span> of radioactive constituents in a medium</span></a></p> <p><a target="_blank" href="http://www.osti.gov/doepatents">DOEpatents</a></p> <p>Perkins, Richard W.; Schilk, Alan J.; Warner, Ray A.; Wogman, Ned A.</p> <p>1995-01-01</p> <p>The instant invention is an apparatus for <span class="hlt">determining</span> the <span class="hlt">concentration</span> of radioactive constituents in a test sample; such as surface soils, via rapid real-time analyses, and direct readout on location utilizing a probe made up of multiple layers of detection material used in combination with an analyzer and real-time readout unit. This is accomplished by comparing the signal received from the probe, which can discriminate between types of radiation and energies with stored patterns that are based upon experimental results. This comparison can be used in the calibration of a readout display that reads out in real-time the <span class="hlt">concentrations</span> of constituents per given volume. For example, the <span class="hlt">concentration</span> of constituents such as Cs-137, Sr-90, U-238 in the soil, and noble gas radionuclides such as Kr-85 in the atmosphere, can be measured in real-time, on location, without the need for laboratory analysis of samples.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/100975','DOE-PATENT-XML'); return false;" href="http://www.osti.gov/scitech/biblio/100975"><span id="translatedtitle">Apparatus for the field <span class="hlt">determination</span> of <span class="hlt">concentration</span> of radioactive constituents in a medium</span></a></p> <p><a target="_blank" href="http://www.osti.gov/doepatents">DOEpatents</a></p> <p>Perkins, R.W.; Schilk, A.J.; Warner, R.A.; Wogman, N.A.</p> <p>1995-08-15</p> <p>The instant invention is an apparatus for <span class="hlt">determining</span> the <span class="hlt">concentration</span> of radioactive constituents in a test sample; such as surface soils, via rapid real-time analyses, and direct readout on location utilizing a probe made up of multiple layers of detection material used in combination with an analyzer and real-time readout unit. This is accomplished by comparing the signal received from the probe, which can discriminate between types of radiation and energies with stored patterns that are based upon experimental results. This comparison can be used in the calibration of a readout display that reads out in real-time the <span class="hlt">concentrations</span> of constituents per given volume. For example, the <span class="hlt">concentration</span> of constituents such as Cs-137, Sr-90, U-238 in the soil, and noble gas radionuclides such as Kr-85 in the atmosphere, can be measured in real-time, on location, without the need for laboratory analysis of samples. 14 figs.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/3160598','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/3160598"><span id="translatedtitle">Dehydroepiandrosterone sulphate loading test and <span class="hlt">determination</span> of plasma oestetrol <span class="hlt">concentration</span> in late pregnancy.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Schollberg, K; Seiler, E; Wagner, S</p> <p>1985-04-01</p> <p>Intravenous application of dehydroepiandrosterone sulphate (DHEA-S) was performed in 6 women with normal progress of pregnancy, 3 pregnant women with multiple pregnancy and 4 pregnants with intrauterine death of the foetus (32nd to 38th week). The oestetrol <span class="hlt">concentrations</span> in blood serum were estimated during 5 h after the injection. In most cases an increase could be observed, but this was inhomogenous. The oestetrol <span class="hlt">concentration</span> even rises in cases of intrauterine death of the foetus. In 7 cases of uncomplicated pregnancies the DHEA-S loading test was done within 2 to 6 h before delivery. The oestetrol <span class="hlt">concentration</span> in the cord serum of the newborns was not higher than in controls without DHEA-S application, whereas oestradiol in maternal serum showed the expected rise. We conclude that the <span class="hlt">determination</span> of oestetrol after DHEA-S loading can not be used for the judgement of the foetal situation. PMID:3160598</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/663400','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/663400"><span id="translatedtitle">Position for <span class="hlt">determining</span> gas-phase volatile organic compound <span class="hlt">concentrations</span> in transuranic waste containers. Revision 2</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Connolly, M.J.; Liekhus, K.J.; Djordjevic, S.M.; Loehr, C.A.; Spangler, L.R.</p> <p>1998-06-01</p> <p>In the conditional no-migration <span class="hlt">determination</span> (NMD) for the test phase of the Waste Isolation Pilot Plant (WIPP), the US Environmental Protection Agency (EPA) imposed certain conditions on the US Department of Energy (DOE) regarding gas phase volatile organic compound (VOC) <span class="hlt">concentrations</span> in the void space of transuranic (TRU) waste containers. Specifically, the EPA required the DOE to ensure that each waste container has no layer of confinement that contains flammable mixtures of gases or mixtures of gases that could become flammable when mixed with air. The EPA also required that sampling of the headspace of waste containers outside inner layers of confinement be representative of the entire void space of the container. The EPA stated that all layers of confinement in a container would have to be sampled until DOE can demonstrate to the EPA that sampling of all layers is either unnecessary or can be safely reduced. A test program was conducted at the Idaho National Engineering and Environmental Laboratory (INEEL) to demonstrate that the gas phase VOC <span class="hlt">concentration</span> in the void space of each layer of confinement in vented drums can be estimated from measured drum headspace using a theoretical transport model and that sampling of each layer of confinement is unnecessary. This report summarizes the studies performed in the INEEL test program and extends them for the purpose of developing a methodology for <span class="hlt">determining</span> gas phase VOC <span class="hlt">concentrations</span> in both vented and unvented TRU waste containers. The methodology specifies conditions under which waste drum headspace gases can be said to be representative of drum gases as a whole and describes a method for predicting drum <span class="hlt">concentrations</span> in situations where the headspace <span class="hlt">concentration</span> is not representative. The methodology addresses the approach for <span class="hlt">determining</span> the drum VOC gas content for two purposes: operational period drum handling and operational period no-migration calculations.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/118375','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/118375"><span id="translatedtitle">Position for <span class="hlt">determining</span> gas phase volatile organic compound <span class="hlt">concentrations</span> in transuranic waste containers. Revision 1</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Connolly, M.J.; Liekhus, K.J.; Djordjevic, S.M.; Loehr, C.A.; Spangler, L.R.</p> <p>1995-08-01</p> <p>In the conditional no-migration <span class="hlt">determination</span> (NMD) for the test phase of the Waste Isolation Pilot Plant (WIPP), the US Environmental Protection Agency (EPA) imposed certain conditions on the US Department of Energy (DOE) regarding gas phase volatile organic compound (VOC) <span class="hlt">concentrations</span> in the void space of transuranic (TRU) waste containers. Specifically, the EPA required the DOE to ensure that each waste container has no layer of confinement that contains flammable mixtures of gases or mixtures of gases that could become flammable when mixed with air. The EPA also required that sampling of the headspace of waste containers outside inner layers of confinement be representative of the entire void space of the container. The EPA stated that all layers of confinement in a container would have to be sampled until DOE can demonstrate to the EPA that sampling of all layers is either unnecessary or can be safely reduced. A test program was conducted at the Idaho National Engineering Laboratory (INEL) to demonstrate that the gas phase VOC <span class="hlt">concentration</span> in the void space of each layer of confinement in vented drums can be estimated from measured drum headspace using a theoretical transport model and that sampling of each layer of confinement is unnecessary. This report summarizes the studies performed in the INEL test program and extends them for the purpose of developing a methodology for <span class="hlt">determining</span> gas phase VOC <span class="hlt">concentrations</span> in both vented and unvented TRU waste containers. The methodology specifies conditions under which waste drum headspace gases can be said to be representative of drum gases as a whole and describes a method for predicting drum <span class="hlt">concentrations</span> in situations where the headspace <span class="hlt">concentration</span> is not representative. The methodology addresses the approach for <span class="hlt">determining</span> the drum VOC gas content for two purposes: operational period drum handling and operational period no-migration calculations.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016SPIE.9917E..17L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016SPIE.9917E..17L"><span id="translatedtitle"><span class="hlt">Determination</span> of type and <span class="hlt">concentration</span> of DNA nitrogenous bases by Raman spectroscopy using artificial neural networks</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Laptinskiy, Kirill A.; Burikov, Sergey A.; Sarmanova, Olga E.; Dolenko, Sergey A.; Dolenko, Tatiana A.</p> <p>2016-04-01</p> <p>In this article the results of solution of two-parametrical inverse problems of laser Raman spectroscopy of identification and <span class="hlt">determination</span> of <span class="hlt">concentration</span> of DNA nitrogenous bases in two-component solutions are presented. Elaboration of methods of control of reactions with DNA strands in remote real-time mode is necessary for solution of one of the basic problems of creation of biocomputers - increase of reliability of molecular DNA-computations. The comparative analysis of two used methods of solution of stated problems has demonstrated convincing advantages of technique of artificial neural networks. Use of artificial neural networks allowed to reach the accuracy of <span class="hlt">determination</span> of <span class="hlt">concentration</span> of each base in two-component solutions 0.2-0.3 g/l.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/2930407','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/2930407"><span id="translatedtitle"><span class="hlt">Determination</span> of chicken and turkey plasma and serum protein <span class="hlt">concentrations</span> by refractometry and the biuret method.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Andreasen, C B; Latimer, K S; Kircher, I M; Brown, J</p> <p>1989-01-01</p> <p>Plasma and serum protein <span class="hlt">concentrations</span> were <span class="hlt">determined</span> in chickens and turkeys by refractometry (with human and veterinary refractometers) and by the biuret method. Chicken and turkey serum protein values were significantly lower than respective plasma protein values according to both methods. Refractometer readings for both plasma and serum correlated closely with the results of the biuret test (r2 = 0.72 to 0.97). These findings indicate that plasma and serum protein values may be <span class="hlt">determined</span> accurately in chickens and turkeys with a handheld refractometer.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/11231318','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/11231318"><span id="translatedtitle">In vivo confocal Raman microspectroscopy of the skin: noninvasive <span class="hlt">determination</span> of molecular <span class="hlt">concentration</span> profiles.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Caspers, P J; Lucassen, G W; Carter, E A; Bruining, H A; Puppels, G J</p> <p>2001-03-01</p> <p>Confocal Raman spectroscopy is introduced as a noninvasive in vivo optical method to measure molecular <span class="hlt">concentration</span> profiles in the skin. It is shown how it can be applied to <span class="hlt">determine</span> the water <span class="hlt">concentration</span> in the stratum corneum as a function of distance to the skin surface, with a depth resolution of 5 microm. The resulting in vivo <span class="hlt">concentration</span> profiles are in qualitative and quantitative agreement with published data, obtained by in vitro X-ray microanalysis of skin samples. Semi-quantitative <span class="hlt">concentration</span> profiles were <span class="hlt">determined</span> for the major constituents of natural moisturizing factor (serine, glycine, pyrrolidone-5-carboxylic acid, arginine, ornithine, citrulline, alanine, histidine, urocanic acid) and for the sweat constituents lactate and urea. A detailed description is given of the signal analysis methodology that enables the extraction of this information from the skin Raman spectra. No other noninvasive in vivo method exists that enables an analysis of skin molecular composition as a function of distance to the skin surface with similar detail and spatial resolution. Therefore, it may be expected that in vivo confocal Raman spectroscopy will find many applications in basic and applied dermatologic research. PMID:11231318</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/17595204','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/17595204"><span id="translatedtitle"><span class="hlt">Determination</span> of uranium, thorium and potassium activity <span class="hlt">concentrations</span> in soil cores in Araba valley, Jordan.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Abusini, M; Al-Ayasreh, K; Al-Jundi, J</p> <p>2008-01-01</p> <p>Soil samples were collected from six different locations in Araba valley, situated between Aqaba port and Dead sea. The samples have been analysed by using gamma-ray spectrometry. From the measured gamma-ray spectra, activity <span class="hlt">concentrations</span> are <span class="hlt">determined</span> for (238)U, (232)Th and (40)K. The mean activity <span class="hlt">concentration</span> for (238)U, (232)Th and (40)K was found to be in the range 19 +/- 1.4 to 38.7 +/- 3, 14.3 +/- 0.8 to 35 +/- 3.2 and 94 +/- 18.9 to 762 +/- 47.4 Bq kg(-1), respectively. These results indicate that the mean <span class="hlt">concentrations</span> of (238)U, (232)Th and (40)K in the populated Araba valley are lower than those in other populated areas. On the other hand, the <span class="hlt">concentrations</span> of the major oxides (Al(2)O(3), SiO(2), K(2)O, CaO and Fe(2)O(3)) in the samples were <span class="hlt">determined</span> using wavelength dispersive X-ray fluorescence. High potassium and iron content in some samples might be attributed to the active faults, which refer to the Dead sea transform fault.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19990110469','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19990110469"><span id="translatedtitle">A Photometric Technique for <span class="hlt">Determining</span> Fluid <span class="hlt">Concentration</span> using Consumer-Grade Hardware</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Leslie, F.; Ramachandran, N.</p> <p>1999-01-01</p> <p>In support of a separate study to produce an exponential <span class="hlt">concentration</span> gradient in a magnetic fluid, a noninvasive technique for <span class="hlt">determining</span>, species <span class="hlt">concentration</span> from off-the-shelf hardware has been developed. The approach uses a backlighted fluid test cell photographed with a commercial digital camcorder. Because the light extinction coefficient is wavelength dependent, tests were conducted to <span class="hlt">determine</span> the best filter color to use, although some guidance was also provided using an absorption spectrophotometer. With the appropriate filter in place, the provide attenuation of the light passing, through the test cell was captured by the camcorder. The digital image was analyzed for intensity using, software from Scion Image Corp. downloaded from the Internet. The analysis provides a two-dimensional array of <span class="hlt">concentration</span> with an average error of 0.0095 ml/ml. This technique is superior to invasive techniques, which require extraction of a sample that disturbs the <span class="hlt">concentration</span> distribution in the test cell. Refinements of this technique using a true monochromatic laser light Source are also discussed.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4018806','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4018806"><span id="translatedtitle"><span class="hlt">Determining</span> Source Strength of Semivolatile Organic Compounds using Measured <span class="hlt">Concentrations</span> in Indoor Dust</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Shin, Hyeong-Moo; McKone, Thomas E.; Nishioka, Marcia G.; Fallin, M. Daniele; Croen, Lisa A.; Hertz-Picciotto, Irva; Newschaffer, Craig J.; Bennett, Deborah H.</p> <p>2014-01-01</p> <p>Consumer products and building materials emit a number of semivolatile organic compounds (SVOCs) in the indoor environment. Because indoor SVOCs accumulate in dust, we explore the use of dust to <span class="hlt">determine</span> source strength and report here on analysis of dust samples collected in 30 U.S. homes for six phthalates, four personal care product ingredients, and five flame retardants. We then use a fugacity-based indoor mass-balance model to estimate the whole house emission rates of SVOCs that would account for the measured dust <span class="hlt">concentrations</span>. Di-2-ethylhexyl phthalate (DEHP) and di-iso-nonyl phthalate (DiNP) were the most abundant compounds in these dust samples. On the other hand, the estimated emission rate of diethyl phthalate (DEP) is the largest among phthalates, although its dust <span class="hlt">concentration</span> is over two orders of magnitude smaller than DEHP and DiNP. The magnitude of the estimated emission rate that corresponds to the measured dust <span class="hlt">concentration</span> is found to be inversely correlated with the vapor pressure of the compound, indicating that dust <span class="hlt">concentrations</span> alone cannot be used to <span class="hlt">determine</span> which compounds have the greatest emission rates. The combined dust-assay modeling approach shows promise for estimating indoor emission rates for SVOCs. PMID:24118221</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/26000023','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/26000023"><span id="translatedtitle"><span class="hlt">Determination</span> of heavy metals <span class="hlt">concentration</span> in traditional herbs commonly consumed in the United Arab Emirates.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Dghaim, Rania; Al Khatib, Safa; Rasool, Husna; Ali Khan, Munawwar</p> <p>2015-01-01</p> <p>Herbs are extensively consumed in the United Arab Emirates for their flavoring and medicinal properties. This study aimed at <span class="hlt">determining</span> the <span class="hlt">concentration</span> of heavy metals in selected traditional herbs consumed in the United Arab Emirates (UAE). A total of 81 samples of seven herbs, parsley (Petroselinum crispum), basil (Ocimum basilicum), sage (Salvia officinalis), oregano (Origanum vulgare), mint (Mentha spicata), thyme (Thymus vulgaris), and chamomile (Matricaria chamomilla), were purchased from the local market in Dubai and analyzed for their cadmium, lead, copper, iron, and zinc contents. Microwave-assisted digestion was applied for the dissolution of the samples and heavy metals <span class="hlt">concentration</span> was <span class="hlt">determined</span> using Atomic Absorption Spectrometry (AAS). Metals were found to be present in varied <span class="hlt">concentrations</span> in the herb samples. The <span class="hlt">concentration</span> ranges were found as follows: less than 0.1-1.11 mg·kg(-1) for cadmium, less than 1.0-23.52 mg·kg(-1) for lead, 1.44-156.24 mg·kg(-1) for copper, 12.65-146.67 mg·kg(-1) for zinc, and 81.25-1101.22 mg·kg(-1) for iron. The findings of the study suggest that most of the analyzed herbs contained unsafe levels of heavy metals that exceeded the World Health Organization (WHO) permissible limits (PL). PMID:26000023</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4426653','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4426653"><span id="translatedtitle"><span class="hlt">Determination</span> of Heavy Metals <span class="hlt">Concentration</span> in Traditional Herbs Commonly Consumed in the United Arab Emirates</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Dghaim, Rania; Al Khatib, Safa; Rasool, Husna; Ali Khan, Munawwar</p> <p>2015-01-01</p> <p>Herbs are extensively consumed in the United Arab Emirates for their flavoring and medicinal properties. This study aimed at <span class="hlt">determining</span> the <span class="hlt">concentration</span> of heavy metals in selected traditional herbs consumed in the United Arab Emirates (UAE). A total of 81 samples of seven herbs, parsley (Petroselinum crispum), basil (Ocimum basilicum), sage (Salvia officinalis), oregano (Origanum vulgare), mint (Mentha spicata), thyme (Thymus vulgaris), and chamomile (Matricaria chamomilla), were purchased from the local market in Dubai and analyzed for their cadmium, lead, copper, iron, and zinc contents. Microwave-assisted digestion was applied for the dissolution of the samples and heavy metals <span class="hlt">concentration</span> was <span class="hlt">determined</span> using Atomic Absorption Spectrometry (AAS). Metals were found to be present in varied <span class="hlt">concentrations</span> in the herb samples. The <span class="hlt">concentration</span> ranges were found as follows: less than 0.1–1.11 mg·kg−1 for cadmium, less than 1.0–23.52 mg·kg−1 for lead, 1.44–156.24 mg·kg−1 for copper, 12.65–146.67 mg·kg−1 for zinc, and 81.25–1101.22 mg·kg−1 for iron. The findings of the study suggest that most of the analyzed herbs contained unsafe levels of heavy metals that exceeded the World Health Organization (WHO) permissible limits (PL). PMID:26000023</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/26000023','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/26000023"><span id="translatedtitle"><span class="hlt">Determination</span> of heavy metals <span class="hlt">concentration</span> in traditional herbs commonly consumed in the United Arab Emirates.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Dghaim, Rania; Al Khatib, Safa; Rasool, Husna; Ali Khan, Munawwar</p> <p>2015-01-01</p> <p>Herbs are extensively consumed in the United Arab Emirates for their flavoring and medicinal properties. This study aimed at <span class="hlt">determining</span> the <span class="hlt">concentration</span> of heavy metals in selected traditional herbs consumed in the United Arab Emirates (UAE). A total of 81 samples of seven herbs, parsley (Petroselinum crispum), basil (Ocimum basilicum), sage (Salvia officinalis), oregano (Origanum vulgare), mint (Mentha spicata), thyme (Thymus vulgaris), and chamomile (Matricaria chamomilla), were purchased from the local market in Dubai and analyzed for their cadmium, lead, copper, iron, and zinc contents. Microwave-assisted digestion was applied for the dissolution of the samples and heavy metals <span class="hlt">concentration</span> was <span class="hlt">determined</span> using Atomic Absorption Spectrometry (AAS). Metals were found to be present in varied <span class="hlt">concentrations</span> in the herb samples. The <span class="hlt">concentration</span> ranges were found as follows: less than 0.1-1.11 mg·kg(-1) for cadmium, less than 1.0-23.52 mg·kg(-1) for lead, 1.44-156.24 mg·kg(-1) for copper, 12.65-146.67 mg·kg(-1) for zinc, and 81.25-1101.22 mg·kg(-1) for iron. The findings of the study suggest that most of the analyzed herbs contained unsafe levels of heavy metals that exceeded the World Health Organization (WHO) permissible limits (PL).</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://pubs.er.usgs.gov/publication/70156718','USGSPUBS'); return false;" href="http://pubs.er.usgs.gov/publication/70156718"><span id="translatedtitle">Evaluation of analytical techniques to <span class="hlt">determine</span> AQUI-S(R) 20E (eugenol) <span class="hlt">concentrations</span> in water</span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Meinertz, Jeffery R.; Hess, Karina R.</p> <p>2013-01-01</p> <p>There is a critical need in U.S. public aquaculture and fishery management programs for an immediate-release sedative, i.e. a compound that can be safely and effectively used to sedate fish and subsequently, allow for their immediate release. AQUI-S® 20E (10% active ingredient, eugenol; any use of trade, firm, or product names is for descriptive purposes only and does not imply endorsement by the U.S. Government) is being pursued for U.S. approval as an immediate-release sedative. As part of the approval process, data describing animal safety and efficacy are needed. Essential to conducting studies that generate those data, is a method to accurately and precisely <span class="hlt">determine</span> AQUI-S® 20E <span class="hlt">concentrations</span> in exposure baths. Spectrophotometric and solid phase extraction (SPE)–high pressure liquid chromatography (LC) methods were developed and evaluated as methods to <span class="hlt">determine</span> AQUI-S® 20E (eugenol) <span class="hlt">concentrations</span> in water, methods that could be applied to any situation where eugenol was being evaluated as a fish sedative. The spectrophotometric method was accurate and precise (accuracy, > 87%; precision, < 0.70 %CV) when <span class="hlt">determining</span> eugenol <span class="hlt">concentrations</span> in solutions of 50 to 1000 mg/L AQUI-S® 20E made with LC grade water and water with varying pH and hardness. The spectrophotometric method's accuracy was negatively affected when analyzing water containing fish feed. The SPE–LC method was also accurate and precise (accuracy > 86%; precision < 8.9 %CV) when <span class="hlt">determining</span> eugenol <span class="hlt">concentrations</span> in solutions of 50 to 1000 mg/L AQUI-S® 20E made with LC grade water and water with varying pH and hardness. The SPE–LC method was influenced to a lesser degree by the presence of fish feed indicating greater specificity for eugenol.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://pubs.er.usgs.gov/publication/70104742','USGSPUBS'); return false;" href="http://pubs.er.usgs.gov/publication/70104742"><span id="translatedtitle">Evaluation of analytical techniques to <span class="hlt">determine</span> AQUI-S® 20E (eugenol) <span class="hlt">concentrations</span> in water</span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Meinertz, Jeffery R.; Hess, Karina R.</p> <p>2014-01-01</p> <p>There is a critical need in U.S. public aquaculture and fishery management programs for an immediate-release sedative, i.e. a compound that can be safely and effectively used to sedate fish and subsequently, allow for their immediate release. AQUI-S® 20E (10% active ingredient, eugenol; any use of trade, firm, or product names is for descriptive purposes only and does not imply endorsement by the U.S. Government) is being pursued for U.S. approval as an immediate-release sedative. As part of the approval process, data describing animal safety and efficacy are needed. Essential to conducting studies that generate those data, is a method to accurately and precisely <span class="hlt">determine</span> AQUI-S® 20E <span class="hlt">concentrations</span> in exposure baths. Spectrophotometric and solid phase extraction (SPE)–high pressure liquid chromatography (LC) methods were developed and evaluated as methods to <span class="hlt">determine</span> AQUI-S® 20E (eugenol) <span class="hlt">concentrations</span> in water, methods that could be applied to any situation where eugenol was being evaluated as a fish sedative. The spectrophotometric method was accurate and precise (accuracy, > 87%; precision, 86%; precision < 8.9 %CV) when <span class="hlt">determining</span> eugenol <span class="hlt">concentrations</span> in solutions of 50 to 1000 mg/L AQUI-S® 20E made with LC grade water and water with varying pH and hardness. The SPE–LC method was influenced to a lesser degree by the presence of fish feed indicating greater specificity for eugenol.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://pubs.er.usgs.gov/publication/70024844','USGSPUBS'); return false;" href="http://pubs.er.usgs.gov/publication/70024844"><span id="translatedtitle">Assessment of relative accuracy in the <span class="hlt">determination</span> of organic matter <span class="hlt">concentrations</span> in aquatic systems</span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Aiken, G.; Kaplan, L.A.; Weishaar, J.</p> <p>2002-01-01</p> <p>Accurate <span class="hlt">determinations</span> of total (TOC), dissolved (DOC) and particulate (POC) organic carbon <span class="hlt">concentrations</span> are critical for understanding the geochemical, environmental, and ecological roles of aquatic organic matter. Of particular significance for the drinking water industry, TOC measurements are the basis for compliance with US EPA regulations. The results of an interlaboratory comparison designed to identify problems associated with the <span class="hlt">determination</span> of organic matter <span class="hlt">concentrations</span> in drinking water supplies are presented. The study involved 31 laboratories and a variety of commercially available analytical instruments. All participating laboratories performed well on samples of potassium hydrogen phthalate (KHP), a compound commonly used as a standard in carbon analysis. However, problems associated with the oxidation of difficult to oxidize compounds, such as dodecylbenzene sulfonic acid and caffeine, were noted. Humic substances posed fewer problems for analysts. Particulate organic matter (POM) in the form of polystyrene beads, freeze-dried bacteria and pulverized leaf material were the most difficult for all analysts, with a wide range of performances reported. The POM results indicate that the methods surveyed in this study are inappropriate for the accurate <span class="hlt">determination</span> of POC and TOC <span class="hlt">concentration</span>. Finally, several analysts had difficulty in efficiently separating inorganic carbon from KHP solutions, thereby biasing DOC results.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/22472108','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/22472108"><span id="translatedtitle"><span class="hlt">Determination</span> of a brass alloy <span class="hlt">concentration</span> composition using calibration-free laser-induced breakdown spectroscopy</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Achouri, M.; Baba-Hamed, T.; Beldjilali, S. A. Belasri, A.</p> <p>2015-09-15</p> <p>Laser-induced breakdown spectroscopy (LIBS) is a technique that can provide qualitative and quantitative measurements of the characteristics of irradiated metals. In the present work, we have calculated the parameters of the plasma produced from a brass alloy sample under the action of a pulsed Nd: YAG laser operating at 1064 nm. The emission lines of copper atoms (Cu I), zinc atoms (Zn I), and lead atoms (Pb I), which are elements of a brass alloy composition, were used to investigate the parameters of the brass plasma. The spectral profiles of Cu, Zn, and Pb lines have been used to extract the electron temperature and density of the brass alloy plasma. The characteristics of Cu, Zn, and Pb were <span class="hlt">determined</span> quantatively by the calibration-free LIBS (CF-LIBS) method considering for accurate analysis that the laser-induced ablated plasma is optically thin in local thermodynamic equilibrium conditions and the plasma ablation is stoichiometric. The Boltzmann plot method was used to evaluate the plasma temperature, and the Stark broadened profiles were used to <span class="hlt">determine</span> the electron density. An algorithm based on the experimentally measured values of the intensity of spectral lines and the basic laws of plasma physics was developed for the <span class="hlt">determination</span> of Cu, Zn, and Pb <span class="hlt">concentrations</span> in the brass sample. The <span class="hlt">concentrations</span> C{sub CF-LIBS} calculated by CF-LIBS and the certified <span class="hlt">concentrations</span> C{sub certified} were very close.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/27420153','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/27420153"><span id="translatedtitle">Sodium chloride <span class="hlt">concentration</span> <span class="hlt">determines</span> exoelectrogens in anode biofilms occurring from mangrove-grown brackish sediment.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Miyahara, Morio; Kouzuma, Atsushi; Watanabe, Kazuya</p> <p>2016-10-01</p> <p>Single-chamber microbial fuel cells (MFCs) were inoculated with mangrove-grown brackish sediment (MBS) and continuously supplied with an acetate medium containing different <span class="hlt">concentrations</span> of NaCl (0-1.8M). Different from MFCs inoculated with paddy-field soil (high power outputs were observed between 0.05 and 0.1M), power outputs from MBS-MFCs were high at NaCl <span class="hlt">concentrations</span> from 0 to 0.6M. Amplicon-sequence analyses of anode biofilms suggest that different exoelectrogens occurred from MBS depending on NaCl <span class="hlt">concentrations</span>; Geobacter occurred abundantly below 0.1M, whereas Desulfuromonas was abundant from 0.3M to 0.6M. These results suggest that NaCl <span class="hlt">concentration</span> is the major <span class="hlt">determinant</span> of exoelectrogens that occur in anode biofilms from MBS. It is also suggested that MBS is a potent source of microbes for MFCs to be operated in a wide range of NaCl <span class="hlt">concentrations</span>. PMID:27420153</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/16002129','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/16002129"><span id="translatedtitle">Sperm <span class="hlt">concentration</span> <span class="hlt">determination</span> between hemacytometric and CASA systems: why they can be different.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Kuster, Chris</p> <p>2005-08-01</p> <p><span class="hlt">Determination</span> of sperm <span class="hlt">concentration</span> is a critical component of semen analysis. Traditionally, the hemacytometer has been the standard for calibrating other technologies used to estimate sperm <span class="hlt">concentration</span>, including photometry, Coulter counters, flow cytometry, and computer-automated semen analysis (CASA). Disposable capillary-loaded slides are commonly used in conjunction with most CASA systems currently in use. Questions have been raised regarding differences in sperm <span class="hlt">concentration</span> measurements between CASA systems (using 20 microm disposable slides) and hemacytometry. This review explains that these differences are largely due to the Segre-Silberberg (SS) effect, which occurs during Poiseuille flow in thin, capillary-loaded slides. The SS effect can lead to errors in estimation of particle <span class="hlt">concentration</span>, as demonstrated with latex beads and suspensions of human or porcine spermatozoa. The SS effect does not appear to have time to develop in the hemacytometer, which at 100 microm is considerably deeper than most disposable slides. Thus, hemacytometry, when properly performed, remains the gold standard for estimation of sperm <span class="hlt">concentration</span>. When using thin (20 microm) slides with CASA systems, recognition of the appropriate compensation factor to adjust for the SS effect is critical for accuracy. PMID:16002129</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_13");'>13</a></li> <li><a href="#" onclick='return showDiv("page_14");'>14</a></li> <li class="active"><span>15</span></li> <li><a href="#" onclick='return showDiv("page_16");'>16</a></li> <li><a href="#" onclick='return showDiv("page_17");'>17</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_15 --> <div id="page_16" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_14");'>14</a></li> <li><a href="#" onclick='return showDiv("page_15");'>15</a></li> <li class="active"><span>16</span></li> <li><a href="#" onclick='return showDiv("page_17");'>17</a></li> <li><a href="#" onclick='return showDiv("page_18");'>18</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="301"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015AGUFMAE31C0449D','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015AGUFMAE31C0449D"><span id="translatedtitle"><span class="hlt">Determination</span> of <span class="hlt">concentration</span> of charged particles in various regions of thunderstorms</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Detwiler, A. G.; Mo, Q.</p> <p>2015-12-01</p> <p>During the Severe Thunderstorm Precipitation and Electrification Study in 2000, data on hydrometeor sizes and charges were obtained in thunderstorms using an optical array probe modified by the New Mexico Institute of Mining and Technology and mounted on the South Dakota School of Mines and Technology armored T-28 research aircraft. Analysis yielded quantitative observations of hydrometeor size and charge data in selected regions of storms with relatively low <span class="hlt">concentrations</span> of charged particles. In most regions hydrometeor <span class="hlt">concentrations</span> were so high that there were multiple charged particles in the probe sample volume at the same time and quantitative charge analysis was not possible. While it is impossible to reliably <span class="hlt">determine</span> individual particle charges in these high <span class="hlt">concentration</span> regions, we can use Poisson statistics to estimate the total number <span class="hlt">concentration</span> of charged particles based on the fraction of records with just one particle in them. We compare these number <span class="hlt">concentrations</span> for different thunderstorm regions, including updrafts, flanking cells, core precipitation regions, and trailing stratiform regions, at approximately the -10 C level, in several thunderstorms. We will discuss the implications of these results for understanding charge-separation processes in thunderstorms.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015AtmEn.112....1L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015AtmEn.112....1L"><span id="translatedtitle"><span class="hlt">Determinants</span> of spikes in ultrafine particle <span class="hlt">concentration</span> whilst commuting by bus</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Lim, Shanon; Dirks, Kim N.; Salmond, Jennifer A.; Xie, Shanju</p> <p>2015-07-01</p> <p>This paper examines <span class="hlt">concentration</span> of ultrafine particles (UFPs) based on data collected using high-resolution UFP monitors whilst travelling by bus during rush hour along three different urban routes in Auckland, New Zealand. The factors influencing in-bus UFP <span class="hlt">concentration</span> were assessed using a combination of spatial, statistical and GIS analysis techniques to <span class="hlt">determine</span> both spatial and temporal variability. Results from 68 bus trips showed that <span class="hlt">concentrations</span> varied more within a route than between on a given day, despite differences in urban morphology, land use and traffic densities between routes. A number of trips were characterised by periods of very rapid increases in UFPs (<span class="hlt">concentration</span> 'spikes'), followed by slow declines. Trips which recorded at least one spike (an increase of greater than 10,000 pt/cm3) resulted in significantly higher mean <span class="hlt">concentrations</span>. Spikes in UFPs were significantly more likely to occur when travelling at low speeds and when passengers were alighting and boarding at bus stops close to traffic light intersections.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/1031412','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/1031412"><span id="translatedtitle">Emission Controls Versus Meteorological Conditions in <span class="hlt">Determining</span> Aerosol <span class="hlt">Concentrations</span> in Beijing during the 2008 Olympic Games</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Gao, Yi; Liu, Xiaohong; Zhao, Chun; Zhang, Meigen</p> <p>2011-12-12</p> <p>A series of emission control measures were undertaken in Beijing and the adjacent provinces in China during the 2008 Beijing Olympic Games on August 8th-24th, 2008. This provides a unique opportunity for investigating the effectiveness of emission controls on air pollution in Beijing. We conducted a series of numerical experiments over East Asia for the period of July to September 2008 using a coupled meteorology-chemistry model (WRF-Chem). Model can generally reproduce the observed variation of aerosol <span class="hlt">concentrations</span>. Consistent with observations, modeled <span class="hlt">concentrations</span> of aerosol species (sulfate, nitrate, ammonium, black carbon, organic carbon, total particulate matter) in Beijing were decreased by 30-50% during the Olympic period compared to the other periods in July and August in 2008 and the same period in 2007. Model results indicate that emission controls were effective in reducing the aerosol <span class="hlt">concentrations</span> by comparing simulations with and without emission controls. However, our analysis suggests that meteorological conditions (e.g., wind direction and precipitation) are at least as important as emission controls in producing the low aerosol <span class="hlt">concentrations</span> appearing during the Olympic period. Transport from the regions surrounding Beijing <span class="hlt">determines</span> the temporal variation of aerosol <span class="hlt">concentrations</span> in Beijing. Based on the budget analysis, we suggest that emission control strategy should focus on the regional scale instead of the local scale to improve the air quality over Beijing.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013OptEn..52e3602H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013OptEn..52e3602H"><span id="translatedtitle">Fluorescence-based <span class="hlt">determination</span> of the copper <span class="hlt">concentration</span> in drinking water</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Hötzer, Benjamin; Scheu, Timo; Jung, Gregor; Castritius, Stefan</p> <p>2013-05-01</p> <p>Copper is a heavy metal, which is used in heat and electrical conductors and in a multitude of alloys in the technical context. Moreover, it is a trace element that is essential for the life of organisms but can cause toxic effects in elevated <span class="hlt">concentrations</span>. Maximum limits in water and beverages exist. Here, the decrease of the fluorescence lifetime of green fluorescent protein (GFP) by Förster resonance energy transfer is used to measure the copper ion <span class="hlt">concentration</span> in drinking water. Therefore, a system is developed that is based on a GFP sample in a predefined <span class="hlt">concentration</span>. The GFP mutant can be excited with blue light. For binding of copper ions, a His-tag is included in the GFP. After measuring the fluorescence lifetime of pure GFP, the copper <span class="hlt">determination</span> of the sample is performed by lifetime measurement. Therefore, the lifetime can be assigned to the copper <span class="hlt">concentration</span> of the GFP-doped drinking water sample. In summary, a method for the quantification of copper ions based on changes of the fluorescence lifetime of GFP is developed, and the measurement of the copper <span class="hlt">concentration</span> in water samples is performed.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4243524','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4243524"><span id="translatedtitle"><span class="hlt">Determinants</span> of personal, indoor and outdoor VOC <span class="hlt">concentrations</span>: An analysis of the RIOPA data</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Su, Feng-Chiao; Mukherjee, Bhramar; Batterman, Stuart</p> <p>2014-01-01</p> <p>Community and environmental exposure to volatile organic compounds (VOCs) has been associated with a number of emission sources and activities, e.g., environmental tobacco smoke and pumping gasoline. Such factors have been identified from mostly small studies with relatively limited information regarding influences on VOC levels. This study uses data from the Relationship of Indoor Outdoor and Personal Air (RIOPA) study to investigate environmental, individual and social <span class="hlt">determinants</span> of VOC <span class="hlt">concentrations</span>. RIOPA included outdoor, indoor and personal measurements of 18 VOCs from 310 non-smoking households and adults in three cities and two seasons, and collected a wide range of information pertaining to participants, family members, households, and neighborhoods. Exposure <span class="hlt">determinants</span> were identified using stepwise regressions and linear mixed-effect models. Most VOC exposure (66 to 78% of the total exposure, depending on VOC) occurred indoors, and outdoor VOC sources accounted for 5 (d-limonene) to 81% (carbon tetrachloride) of the total exposure. Personal exposure and indoor measurements had similar <span class="hlt">determinants</span>, which depended on the VOC. Gasoline-related VOCs (e.g., benzene, methyl tertiary butyl ether) were associated with city, residences with attached garages, self-pumping of gas, wind speed, and house air exchange rate (AER). Odorant and cleaning-related VOCs (e.g., 1,4-dichlorobenzene and chloroform) also were associated with city and AER, and with house size and family members showering. Dry-cleaning and industry-related VOCs (e.g., tetrachloroethylene and trichloroethylene) were associated with city, residence water supply type, and dry-cleaner visits. These and other relationships were significant, explained from 10 to 40% of the variation, and are consistent with known emission sources and the literature. Outdoor <span class="hlt">concentrations</span> had only two common <span class="hlt">determinants</span>: city and wind speed. Overall, personal exposure was dominated by the home setting, although a</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/27073847','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/27073847"><span id="translatedtitle"><span class="hlt">Determinants</span> of C-reactive protein <span class="hlt">concentrations</span> in pregnant women with type 1 diabetes.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Gutaj, Paweł; Krzyżanowska, Patrycja; Brązert, Jacek; Wender-Ożegowska, Ewa</p> <p>2016-04-13</p> <p>INTRODUCTION    Increased C-reactive protein (CRP) <span class="hlt">concentrations</span> during pregnancy are associated with several perinatal complications. OBJECTIVES    The aim of the study was to assess serum CRP <span class="hlt">concentrations</span> and identify its <span class="hlt">determinants</span> in pregnant women with type 1 diabetes. PATIENTS AND METHODS    CRP <span class="hlt">concentrations</span> were <span class="hlt">determined</span> using a high-sensitivity assay (hs-CRP) in the first trimester (I, week <12 of gestation), in mid-pregnancy (II, weeks 20 to 24 of gestation), and in the late third trimester (III, weeks 34 to 39 of gestation) in a group of 73 patients with type 1 diabetes. RESULTS    There was a significant increase in CRP <span class="hlt">concentrations</span> between the first trimester and mid‑pregnancy (median [interquartile range], 2.5 mg/l [1.3-4.5 mg/l] and 5.6 mg/l [2.5-11.6 mg/l]; P = 0.0001), which then stabilized with no further change between mid-pregnancy and the late third trimester (5.7 mg/l [2.5-9.6 mg/l]). CRP <span class="hlt">concentrations</span> in all 3 trimesters were positively correlated with the waist‑to-hip ratio (I, P <0.0001; II, P = 0.0004; III, P = 0.0369) and body mass index (I, P = 0.015; II, P = 0.0025; III, P = 0.0048), measured in the first trimester. CRP <span class="hlt">concentrations</span> during pregnancy were positively correlated with a measure of insulin resistance, namely, the estimated glucose disposal rate, assessed in the first trimester (I, P = 0.01; II, P = 0.0165; III, P = 0.0062). There was a positive correlation between the levels of hs-CRP and total cholesterol (P = 0.001), low-density lipoprotein cholesterol (P = 0.013), and triglycerides (P = 0.0014) in the first trimester. There was no significant correlation between CRP and hemoglobin A1c, daily insulin requirement/kg, high-density lipoprotein cholesterol levels, maternal age, and diabetes duration. CONCLUSIONS    Adiposity, abnormal body fat distribution, and insulin resistance are the major <span class="hlt">determinants</span> of CRP <span class="hlt">concentrations</span> in pregnant women with type 1 diabetes. Our results confirm the</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/1176532','DOE-PATENT-XML'); return false;" href="http://www.osti.gov/scitech/servlets/purl/1176532"><span id="translatedtitle"><span class="hlt">Absolute</span> cavity pyrgeometer</span></a></p> <p><a target="_blank" href="http://www.osti.gov/doepatents">DOEpatents</a></p> <p>Reda, Ibrahim</p> <p>2013-10-29</p> <p>Implementations of the present disclosure involve an apparatus and method to measure the long-wave irradiance of the atmosphere or long-wave source. The apparatus may involve a thermopile, a <span class="hlt">concentrator</span> and temperature controller. The incoming long-wave irradiance may be reflected from the <span class="hlt">concentrator</span> to a thermopile receiver located at the bottom of the <span class="hlt">concentrator</span> to receive the reflected long-wave irradiance. In addition, the thermopile may be thermally connected to a temperature controller to control the device temperature. Through use of the apparatus, the long-wave irradiance of the atmosphere may be calculated from several measurements provided by the apparatus. In addition, the apparatus may provide an international standard of pyrgeometers' calibration that is traceable back to the International System of Units (SI) rather than to a blackbody atmospheric simulator.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19860006746','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19860006746"><span id="translatedtitle">Optical and probe <span class="hlt">determination</span> of soot <span class="hlt">concentrations</span> in a model gas turbine combustor</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Eckerle, W. A.; Rosfjord, T. J.</p> <p>1986-01-01</p> <p>An experimental program was conducted to track the variation in soot loading in a generic gas turbine combustor. The burner is a 12.7-cm dia cylindrical device consisting of six sheet-metal louvers. <span class="hlt">Determination</span> of soot loading along the burner length is achieved by measurement at the exit of the combustor and then at upstream stations by sequential removal of liner louvers to shorten burner length. Alteration of the flow field approaching and within the shortened burners is minimized by bypassing flow in order to maintain a constant linear pressure drop. The burner exhaust flow is sampled at the burner centerline to <span class="hlt">determine</span> soot mass <span class="hlt">concentration</span> and smoke number. Characteristic particle size and number density, transmissivity of the exhaust flow, and local radiation from luminous soot particles in the exhaust are <span class="hlt">determined</span> by optical techniques. Four test fuels are burned at three fuel-air ratios to <span class="hlt">determine</span> fuel chemical property and flow temperature influences. Particulate <span class="hlt">concentration</span> data indicate a strong oxidation mechanism in the combustor secondary zone, though the oxidation is significantly affected by flow temperature. Soot production is directly related to fuel smoke point.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/155781','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/155781"><span id="translatedtitle">Position for <span class="hlt">determining</span> gas phase volatile organic compound <span class="hlt">concentrations</span> in transuranic waste containers</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Connolly, M.J.; Liekhus, K.J.; Djordjevic, S.M.; Loehr, C.A. Spangler, L.R.</p> <p>1995-12-01</p> <p>In the conditional no-migration <span class="hlt">determination</span> (NMD) for the test phase of the Waste isolation Pilot Plant (WIPP), the US Environmental Protection Agency (EPA) imposed certain conditions on the US Department of Energy (DOE) regarding gas phase volatile organic compound (VOC) <span class="hlt">concentrations</span> in the void space of transuranic (TRU) waste containers. The EPA required the DOE to ensure that each waste container has no layer of confinement that contains flammable mixtures of gases or mixtures of gases that could become flammable when mixed with air. The EPA also required that sampling of the headspace of waste containers outside inner layers of confinement be representative of the entire void space of the container. The EPA stated that all layers of confinement in a container would have to be sampled until DOE can demonstrate to the EPA that sampling of all layers is unnecessary. A test program was conducted to demonstrate that the gas phase VOC <span class="hlt">concentration</span> in the void space of each layer of confinement in vented drums can be estimated from measured drum headspace using a theoretical transport model and that sampling of each layer of confinement is unnecessary. This report summarizes the studies performed in the INEL test program and extends them for the purpose of developing a methodology for <span class="hlt">determining</span> gas phase VOC <span class="hlt">concentrations</span> in both vented and unvented TRU waste containers. The methodology specifies conditions under which waste drum headspace gases can be said to be representative of drum gases as a whole and describes a method for predicting drum <span class="hlt">concentrations</span> in situations where the headspace <span class="hlt">concentration</span> is not representative.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/532965','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/532965"><span id="translatedtitle">Ground-water sampling and time-series evaluation techniques to <span class="hlt">determine</span> vertical <span class="hlt">concentration</span> distributions</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Cosler, D.J.</p> <p>1997-09-01</p> <p>Data analysis methodologies are developed for using time-series measurements of effluent <span class="hlt">concentrations</span> during continuous sampling to <span class="hlt">determine</span> the vertical shape and location of a horizontally uniform contaminant plume and to estimate physical/chemical aquifer parameters such as vertical anisotropy, effective porosity, and retardation factor. Temporal water-quality variations during constant-flow sampling are calculated in the form of <span class="hlt">concentration</span> type curves for a wide variety of plume shapes and positions and are shown to be directly related to the geometry and growth rate of the three-dimensional capture volume of the well. An analytical type-curve solution is derived for discrete-interval sampling in homogeneous and isotropic/anisotropic aquifers containing plumes with complex vertical shapes that are described by the superposition of multiple Gaussian distributions. Results from two-dimensional, axisymmetric simulations of ground-water flow and particle transport demonstrate the sensitivity of <span class="hlt">concentration</span> type curves to sandpack hydraulic conductivity, screen length, well diameter, flow through the well screen during discrete-interval sampling, aquifer anisotropy and heterogeneities, pumping rate, effective porosity, and chemical retardation. Two applications of the <span class="hlt">concentration</span> type-curve method for <span class="hlt">determining</span> plume and aquifer characteristics are presented. The first illustrates the use of discrete-interval sampling to evaluate the vertical shape and location of a hypothetical plume in a homogeneous, isotropic aquifer. In the second, extraction-well effluent data collected during a field experiment were used to evaluate the vertical <span class="hlt">concentration</span> distribution in a sulfate plume and estimate the vertical anisotropy ratio of the aquifer. The results demonstrate the importance of developing consistency in purge and sample volumes to minimize artificial measurement variability in monitoring programs.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/18960389','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/18960389"><span id="translatedtitle">Photometric and spectrochemical <span class="hlt">determination</span> of gold in iron pyrites, copper and lead <span class="hlt">concentrates</span>.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Jordanov, N; Mareva, S; Krasnobaeva, N; Nedyalkova, N</p> <p>1968-09-01</p> <p>A photometric and a spectrochemical method have been developed for <span class="hlt">determining</span> gold in iron pyrites, copper and lead <span class="hlt">concentrates</span>. In both, the sample is dissolved and gold is extracted from 1M hydrochloric add solution with a mixture of ethyl methyl ketone and chloroform (1:1). Gold was <span class="hlt">determined</span> photometrically with N,N'-tetramethyl-o-tolidine. Conditions have been found for satisfactorily sensitive and reproducible spectral <span class="hlt">determination</span> of gold. For this purpose the effect of various collectors and buffers on the evaporation curves of gold has been studied, as well as excitation conditions, form of the electrodes, optimum slit-width, and photographic variables. The sensitivity and precision of both methods have been evaluated. PMID:18960389</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/18960389','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/18960389"><span id="translatedtitle">Photometric and spectrochemical <span class="hlt">determination</span> of gold in iron pyrites, copper and lead <span class="hlt">concentrates</span>.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Jordanov, N; Mareva, S; Krasnobaeva, N; Nedyalkova, N</p> <p>1968-09-01</p> <p>A photometric and a spectrochemical method have been developed for <span class="hlt">determining</span> gold in iron pyrites, copper and lead <span class="hlt">concentrates</span>. In both, the sample is dissolved and gold is extracted from 1M hydrochloric add solution with a mixture of ethyl methyl ketone and chloroform (1:1). Gold was <span class="hlt">determined</span> photometrically with N,N'-tetramethyl-o-tolidine. Conditions have been found for satisfactorily sensitive and reproducible spectral <span class="hlt">determination</span> of gold. For this purpose the effect of various collectors and buffers on the evaporation curves of gold has been studied, as well as excitation conditions, form of the electrodes, optimum slit-width, and photographic variables. The sensitivity and precision of both methods have been evaluated.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://eric.ed.gov/?q=serial+AND+position+AND+effect&id=EJ735377','ERIC'); return false;" href="http://eric.ed.gov/?q=serial+AND+position+AND+effect&id=EJ735377"><span id="translatedtitle"><span class="hlt">Absolute</span> Identification by Relative Judgment</span></a></p> <p><a target="_blank" href="http://www.eric.ed.gov/ERICWebPortal/search/extended.jsp?_pageLabel=advanced">ERIC Educational Resources Information Center</a></p> <p>Stewart, Neil; Brown, Gordon D. A.; Chater, Nick</p> <p>2005-01-01</p> <p>In unidimensional <span class="hlt">absolute</span> identification tasks, participants identify stimuli that vary along a single dimension. Performance is surprisingly poor compared with discrimination of the same stimuli. Existing models assume that identification is achieved using long-term representations of <span class="hlt">absolute</span> magnitudes. The authors propose an alternative…</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://eric.ed.gov/?q=VALUE+AND+ABSOLUTE&id=EJ765743','ERIC'); return false;" href="http://eric.ed.gov/?q=VALUE+AND+ABSOLUTE&id=EJ765743"><span id="translatedtitle">Be Resolute about <span class="hlt">Absolute</span> Value</span></a></p> <p><a target="_blank" href="http://www.eric.ed.gov/ERICWebPortal/search/extended.jsp?_pageLabel=advanced">ERIC Educational Resources Information Center</a></p> <p>Kidd, Margaret L.</p> <p>2007-01-01</p> <p>This article explores how conceptualization of <span class="hlt">absolute</span> value can start long before it is introduced. The manner in which <span class="hlt">absolute</span> value is introduced to students in middle school has far-reaching consequences for their future mathematical understanding. It begins to lay the foundation for students' understanding of algebra, which can change…</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/7850990','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/7850990"><span id="translatedtitle"><span class="hlt">Determinants</span> of serum 1,25-dihydroxyvitamin D <span class="hlt">concentration</span> in healthy premenopausal subjects.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Ho, S C; Mac Donald, D; Chan, C; Fan, Y K; Chan, S S; Swaminathan, R</p> <p>1994-10-14</p> <p><span class="hlt">Concentrations</span> of serum phosphate and parathyroid hormone (PTH) are well known regulators of the production of 1,25-dihydroxyvitamin D (1,25-(OH)2D) and acidosis is known to affect the serum <span class="hlt">concentration</span> of 1,25-(OH)2D. However, the factors that play a role in the regulation of serum 1,25-(OH)2D <span class="hlt">concentration</span> in healthy subjects have not been fully evaluated. The associations of ionised calcium, pH, serum <span class="hlt">concentration</span> of phosphate, PTH, 25-hydroxyvitamin D (25-OHD) and serum 1,25-(OH)2D were examined in 296 healthy premenopausal women (age range 17-40 years). Calculation of partial correlation coefficients showed that serum 1,25-(OH)2D was significantly correlated with phosphate (r = -0.148, P < 0.01), pH (r = 0.221, P < 0.001) and PTH (r = 0.136. P < 0.01). Ionised calcium was not related to serum 1,25-(OH)2D. When the results were stratified according to quartiles based on serum 1,25-(OH)2D <span class="hlt">concentration</span>, significant trends (by analysis of variance) were seen in phosphate, pH, age, albumin and 25-OHD. Stepwise multiple regression analysis showed that phosphate and pH were the major contributors of serum 1,25-(OH)2D levels. There was a small contribution from PTH and 25-OHD. The results suggest that in young healthy premenopausal women plasma phosphate and pH may be important <span class="hlt">determinants</span> of serum 1,25-(OH)2D <span class="hlt">concentration</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/27343863','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/27343863"><span id="translatedtitle">Bias in <span class="hlt">determining</span> aluminum <span class="hlt">concentrations</span>: Comparison of digestion methods and implications on Al management.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>He, Y Thomas; Ziemkiewicz, Paul F</p> <p>2016-09-01</p> <p>Aluminum is an important aquatic contaminant due to its ubiquity, toxicity and low regulatory discharge limits. Aluminum is mobilized in mining related, acidic drainage and is commonly a regulated pollutant. However, while aquatic toxicity studies and toxicity criteria are based on dissolved aluminum(Ald), discharge levels are, for statutory reasons, based on total recoverable aluminum (Alt). The rationale for using total recoverable aluminum recognizes the potential for the release of exchangeable, toxic cations or dissolution of metastable metal flocs in the event the discharge enters an acidic receiving stream. The digestion methods used in <span class="hlt">determining</span> total recoverable metals are not meant to dissolve aluminosilicate clay particles but we found that they do, resulting in positively biased total recoverable aluminum values. This study explored the interaction between total suspended solids (TSS) and total recoverable aluminum using three digestion methods to evaluate which method introduced the least bias. Using field collected water and sediment samples from two coal mine drainage sites in Central West Virginia, three total recoverable digestion methods (USEPA Method 200.7, M1; USGS In-Bottle method, M2; and a Modified In-Bottle method, M3) were used to <span class="hlt">determine</span> total recoverable aluminum across a range of total suspended solids <span class="hlt">concentrations</span>. Baseline simulation experiments were conducted at pH 2.5, 3.5, 4.5 and 5.5 at different total suspended solids <span class="hlt">concentrations</span>. Results indicated that dissolved aluminum did not respond to increasing total suspended solids <span class="hlt">concentrations</span> while <span class="hlt">determined</span> total recoverable aluminum increased with total suspended solids, indicating varying degrees of clay dissolution and, thus bias in the total recoverable aluminum <span class="hlt">concentration</span>. While all three digestion methods overestimated total recoverable aluminum, at the same total suspended solids <span class="hlt">concentration</span>, total recoverable aluminum extracted by USEPA Method 200.7 (M1) was</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/21513406','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/21513406"><span id="translatedtitle">Using Photon Activation Analysis To <span class="hlt">Determine</span> <span class="hlt">Concentrations</span> Of Unknown Components In Reference Materials</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Green, Jaromy; Sun, Zaijing; Wells, Doug; Maschner, Herb</p> <p>2011-06-01</p> <p>Using certified multi-element reference materials for instrumental analyses one frequently is confronted with the embarrassing fact that the <span class="hlt">concentration</span> of some desired elements are not given in the respective certificate, nonetheless are detectable, e.g. by photon activation analysis (PAA). However, these elements might be <span class="hlt">determinable</span> with sufficient quality of the results using scaling parameters and the well-known quantities of a reference element within the reference material itself. Scaling parameters include: activation threshold energy, Giant Dipole Resonance (GDR) peak and endpoint energy of the bremsstrahlung continuum; integrated photo-nuclear cross sections for the isotopes of the reference element; bremsstrahlung continuum integral; target thickness; photon flux density. Photo-nuclear cross sections from the unreferenced elements must be known, too. With these quantities, the integral was obtained for both the known and unknown elements resulting in an inference of the <span class="hlt">concentration</span> of the unreported element based upon the reported value, thus also the <span class="hlt">concentration</span> of the unreferenced element in the reference material. A similar method to <span class="hlt">determine</span> elements using the basic nuclear and experimental data has been developed for thermal neutron activation analysis some time ago (k{sub 0} Method).</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/26872214','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/26872214"><span id="translatedtitle"><span class="hlt">Concentration</span> Sensing by the Moving Nucleus in Cell Fate <span class="hlt">Determination</span>: A Computational Analysis.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Aggarwal, Varun; Dickinson, Richard B; Lele, Tanmay P</p> <p>2016-01-01</p> <p>During development of the vertebrate neuroepithelium, the nucleus in neural progenitor cells (NPCs) moves from the apex toward the base and returns to the apex (called interkinetic nuclear migration) at which point the cell divides. The fate of the resulting daughter cells is thought to depend on the sampling by the moving nucleus of a spatial <span class="hlt">concentration</span> profile of the cytoplasmic Notch intracellular domain (NICD). However, the nucleus executes complex stochastic motions including random waiting and back and forth motions, which can expose the nucleus to randomly varying levels of cytoplasmic NICD. How nuclear position can <span class="hlt">determine</span> daughter cell fate despite the stochastic nature of nuclear migration is not clear. Here we derived a mathematical model for reaction, diffusion, and nuclear accumulation of NICD in NPCs during interkinetic nuclear migration (INM). Using experimentally measured trajectory-dependent probabilities of nuclear turning, nuclear waiting times and average nuclear speeds in NPCs in the developing zebrafish retina, we performed stochastic simulations to compute the nuclear trajectory-dependent probabilities of NPC differentiation. Comparison with experimentally measured nuclear NICD <span class="hlt">concentrations</span> and trajectory-dependent probabilities of differentiation allowed estimation of the NICD cytoplasmic gradient. Spatially polarized production of NICD, rapid NICD cytoplasmic consumption and the time-averaging effect of nuclear import/export kinetics are sufficient to explain the experimentally observed differentiation probabilities. Our computational studies lend quantitative support to the feasibility of the nuclear <span class="hlt">concentration</span>-sensing mechanism for NPC fate <span class="hlt">determination</span> in zebrafish retina.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/24163953','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/24163953"><span id="translatedtitle">The <span class="hlt">determination</span> of water quality and metal <span class="hlt">concentrations</span> of Ampang Hilir Lake, Selangor, Peninsular Malaysia.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Said, Khaled S A; Shuhaimi-Othman, M; Ahmad, A K</p> <p>2012-05-01</p> <p>A study of water quality parameters (temperature, conductivity, total dissolved solid, dissolved oxygen, pH and water hardness) in Ampang Hilir Lake was conducted in January, April, July and October 2010. The water quality parameters were tested and recorded at different sampling stations chosen randomly using Hydrolab Data Sonde 4 and Surveyor 4 a water quality multi probe (USA). Six metals which were cadmium, chromium, lead, nickel, zinc and copper were <span class="hlt">determined</span> in five different compartments of the lake namely water, total suspended solids, plankton, sediment and fish. The metals <span class="hlt">concentration</span> were <span class="hlt">determined</span> by Inductively Coupled Plasma Mass Spectrometer (ICP-MS), Perkin Elmer Elan, model 9000.The water quality parameters were compared with National Water Quality Standard (NWQS Malaysia) while metal <span class="hlt">concentrations</span> were compared with Malaysian and international standards. The study shows that water quality parameters are of class 2. This condition is suitable for recreational activities where body contact is allowed and suitable for sensitive fishing activities. Furthermore, metal <span class="hlt">concentrations</span> were found to be lower than the international standards, therefore toxic effects for these metals would be rarely observed and the adverse effects to aquatic organisms would not frequently occur. PMID:24163953</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/26035119','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/26035119"><span id="translatedtitle">New ¹H NMR-Based Technique To <span class="hlt">Determine</span> Epoxide <span class="hlt">Concentrations</span> in Oxidized Oil.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Xia, Wei; Budge, Suzanne M; Lumsden, Michael D</p> <p>2015-06-24</p> <p>A new method to <span class="hlt">determine</span> epoxide <span class="hlt">concentrations</span> in oxidized oils was developed and validated using (1)H NMR. Epoxides derived from lipid oxidation gave signals between 2.90 and 3.24 ppm, well separated from the signals of other lipid oxidation products. To calibrate, soybean oils with a range of epoxide <span class="hlt">concentrations</span> were synthesized and analyzed using (1)H NMR by taking the sn-1,3 glycerol protons (4.18, 4.33 ppm) as internal references. The (1)H NMR signals were compared to the epoxide content <span class="hlt">determined</span> by titration with hydrogen bromide (HBr)-acetic acid solution. As expected, the signal response increased with <span class="hlt">concentration</span> linearly (R(2) = 99.96%), and validation of the method gave results comparable to those of the HBr method. A study of the oxidative stability of soybean oil was performed by applying this method to monitor epoxides during thermal lipid oxidation. The epoxide content increased over time and showed a different trend compared to peroxide value (PV). A phenomenological model was suggested to model epoxides derived from lipid oxidation. PMID:26035119</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_14");'>14</a></li> <li><a href="#" onclick='return showDiv("page_15");'>15</a></li> <li class="active"><span>16</span></li> <li><a href="#" onclick='return showDiv("page_17");'>17</a></li> <li><a href="#" onclick='return showDiv("page_18");'>18</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_16 --> <div id="page_17" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_15");'>15</a></li> <li><a href="#" onclick='return showDiv("page_16");'>16</a></li> <li class="active"><span>17</span></li> <li><a href="#" onclick='return showDiv("page_18");'>18</a></li> <li><a href="#" onclick='return showDiv("page_19");'>19</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="321"> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4970144','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4970144"><span id="translatedtitle">Quantitative <span class="hlt">Determination</span> of Fusarium proliferatum <span class="hlt">Concentration</span> in Intact Garlic Cloves Using Near-Infrared Spectroscopy</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Tamburini, Elena; Mamolini, Elisabetta; De Bastiani, Morena; Marchetti, Maria Gabriella</p> <p>2016-01-01</p> <p>Fusarium proliferatum is considered to be a pathogen of many economically important plants, including garlic. The objective of this research was to apply near-infrared spectroscopy (NIRS) to rapidly <span class="hlt">determine</span> fungal <span class="hlt">concentration</span> in intact garlic cloves, avoiding the laborious and time-consuming procedures of traditional assays. Preventive detection of infection before seeding is of great interest for farmers, because it could avoid serious losses of yield during harvesting and storage. Spectra were collected on 95 garlic cloves, divided in five classes of infection (from 1-healthy to 5-very highly infected) in the range of fungal <span class="hlt">concentration</span> 0.34–7231.15 ppb. Calibration and cross validation models were developed with partial least squares regression (PLSR) on pretreated spectra (standard normal variate, SNV, and derivatives), providing good accuracy in prediction, with a coefficient of <span class="hlt">determination</span> (R2) of 0.829 and 0.774, respectively, a standard error of calibration (SEC) of 615.17 ppb, and a standard error of cross validation (SECV) of 717.41 ppb. The calibration model was then used to predict fungal <span class="hlt">concentration</span> in unknown samples, peeled and unpeeled. The results showed that NIRS could be used as a reliable tool to directly detect and quantify F. proliferatum infection in peeled intact garlic cloves, but the presence of the external peel strongly affected the prediction reliability. PMID:27428978</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://pubs.usgs.gov/of/1997/0043/report.pdf','USGSPUBS'); return false;" href="https://pubs.usgs.gov/of/1997/0043/report.pdf"><span id="translatedtitle"><span class="hlt">Determining</span> <span class="hlt">concentrations</span> of 2-bromoallyl alcohol and dibromopropene in ground water using quantitative methods</span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Panshin, Sandra Y.</p> <p>1997-01-01</p> <p>A method for <span class="hlt">determining</span> levels of 2-bromoallyl alcohol and 2,3-dibromopropene from ground-water samples using liquid/liquid extraction followed by gas chromatography/mass spectrometry is described. Analytes were extracted from the water using three aliquots of dichloromethane. The aliquots were combined and reduced in volume by rotary evaporation followed by evaporation using a nitrogen stream. The extracts were analyzed by capillary-column gas chromatography/mass spectrometry in the full-scan mode. Estimated method detection limits were 30 nanograms per liter for 2-bromoallyl alcohol and 10 nanograms per liter for 2,3-dibromopropene. Recoveries were <span class="hlt">determined</span> by spiking three matrices at two <span class="hlt">concentration</span> levels (0.540 and 5.40 micrograms per liter for 2-bromoallyl alcohol; and 0.534 and 5.34micro-grams per liter for dibromopropene). For seven replicates of each matrix at the high <span class="hlt">concentration</span> level, the mean percent recoveries ranged from 43.9 to 64.9 percent for 2-bromoallyl alcohol, and from 87.5 to 99.3 percent for dibromopropene. At the low <span class="hlt">concentration</span> level, the mean percent recoveries ranged from 43.8 to 95.2 percent for 2-bromoallyl alcohol, and from 71.3 to 84.9 percent for dibromopropene.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/26872214','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/26872214"><span id="translatedtitle"><span class="hlt">Concentration</span> Sensing by the Moving Nucleus in Cell Fate <span class="hlt">Determination</span>: A Computational Analysis.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Aggarwal, Varun; Dickinson, Richard B; Lele, Tanmay P</p> <p>2016-01-01</p> <p>During development of the vertebrate neuroepithelium, the nucleus in neural progenitor cells (NPCs) moves from the apex toward the base and returns to the apex (called interkinetic nuclear migration) at which point the cell divides. The fate of the resulting daughter cells is thought to depend on the sampling by the moving nucleus of a spatial <span class="hlt">concentration</span> profile of the cytoplasmic Notch intracellular domain (NICD). However, the nucleus executes complex stochastic motions including random waiting and back and forth motions, which can expose the nucleus to randomly varying levels of cytoplasmic NICD. How nuclear position can <span class="hlt">determine</span> daughter cell fate despite the stochastic nature of nuclear migration is not clear. Here we derived a mathematical model for reaction, diffusion, and nuclear accumulation of NICD in NPCs during interkinetic nuclear migration (INM). Using experimentally measured trajectory-dependent probabilities of nuclear turning, nuclear waiting times and average nuclear speeds in NPCs in the developing zebrafish retina, we performed stochastic simulations to compute the nuclear trajectory-dependent probabilities of NPC differentiation. Comparison with experimentally measured nuclear NICD <span class="hlt">concentrations</span> and trajectory-dependent probabilities of differentiation allowed estimation of the NICD cytoplasmic gradient. Spatially polarized production of NICD, rapid NICD cytoplasmic consumption and the time-averaging effect of nuclear import/export kinetics are sufficient to explain the experimentally observed differentiation probabilities. Our computational studies lend quantitative support to the feasibility of the nuclear <span class="hlt">concentration</span>-sensing mechanism for NPC fate <span class="hlt">determination</span> in zebrafish retina. PMID:26872214</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/390156','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/390156"><span id="translatedtitle">Use of SPMDs to <span class="hlt">determine</span> average water <span class="hlt">concentration</span> of polycyclic aromatic hydrocarbons in urban stormwater runoff</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>DeVita, W.; Crunkilton, R.</p> <p>1995-12-31</p> <p>Semipermeable polymeric membrane devices (SPMDS) were deployed for 30 day periods to monitor polycyclic aromatic hydrocarbons (PAHs) in an urban stream which receives much of its flow from urban runoff. SPMDs are capable of effectively sampling several liters of water per day for some PAHs. Unlike conventional methods, SPMDs sample only those non-polar organic contaminants which are truly dissolved and available for bioconcentration. Also, SPMDs may <span class="hlt">concentrate</span> contaminants from episodic events such as stormwater discharge. The State of Wisconsin has established surface water quality criteria based upon human lifetime cancer risk of 23 ppt for benzo(a)pyrene and 23 ppt as the sum of nine other potentially carcinogenic PAHs. Bulk water samples analyzed by conventional methodology were routinely well above this criteria, but contained particulate bound PAHs as well as PAHs bound by dissolved organic carbon (DOC) which are not available for bioconcentration. Average water <span class="hlt">concentrations</span> of dissolved PAHs <span class="hlt">determined</span> using SPMDs were also above this criteria. Variables used for <span class="hlt">determining</span> water <span class="hlt">concentration</span> included sampling rate at the exposure temperature, length of exposure and estimation of biofouling of SPMD surface.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/27428978','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/27428978"><span id="translatedtitle">Quantitative <span class="hlt">Determination</span> of Fusarium proliferatum <span class="hlt">Concentration</span> in Intact Garlic Cloves Using Near-Infrared Spectroscopy.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Tamburini, Elena; Mamolini, Elisabetta; De Bastiani, Morena; Marchetti, Maria Gabriella</p> <p>2016-01-01</p> <p>Fusarium proliferatum is considered to be a pathogen of many economically important plants, including garlic. The objective of this research was to apply near-infrared spectroscopy (NIRS) to rapidly <span class="hlt">determine</span> fungal <span class="hlt">concentration</span> in intact garlic cloves, avoiding the laborious and time-consuming procedures of traditional assays. Preventive detection of infection before seeding is of great interest for farmers, because it could avoid serious losses of yield during harvesting and storage. Spectra were collected on 95 garlic cloves, divided in five classes of infection (from 1-healthy to 5-very highly infected) in the range of fungal <span class="hlt">concentration</span> 0.34-7231.15 ppb. Calibration and cross validation models were developed with partial least squares regression (PLSR) on pretreated spectra (standard normal variate, SNV, and derivatives), providing good accuracy in prediction, with a coefficient of <span class="hlt">determination</span> (R²) of 0.829 and 0.774, respectively, a standard error of calibration (SEC) of 615.17 ppb, and a standard error of cross validation (SECV) of 717.41 ppb. The calibration model was then used to predict fungal <span class="hlt">concentration</span> in unknown samples, peeled and unpeeled. The results showed that NIRS could be used as a reliable tool to directly detect and quantify F. proliferatum infection in peeled intact garlic cloves, but the presence of the external peel strongly affected the prediction reliability. PMID:27428978</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://eric.ed.gov/?q=forks&pg=2&id=EJ860239','ERIC'); return false;" href="http://eric.ed.gov/?q=forks&pg=2&id=EJ860239"><span id="translatedtitle"><span class="hlt">Determining</span> <span class="hlt">Absolute</span> Zero Using a Tuning Fork</span></a></p> <p><a target="_blank" href="http://www.eric.ed.gov/ERICWebPortal/search/extended.jsp?_pageLabel=advanced">ERIC Educational Resources Information Center</a></p> <p>Goldader, Jeffrey D.</p> <p>2008-01-01</p> <p>The Celsius and Kelvin temperature scales, we tell our students, are related. We explain that a change in temperature of 1 degree C corresponds to a change of 1 Kelvin and that atoms and molecules have zero kinetic energy at zero Kelvin, -273 degrees C. In this paper, we will show how students can derive the relationship between the Celsius and…</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://eric.ed.gov/?q=charles+AND+law&pg=3&id=EJ450639','ERIC'); return false;" href="http://eric.ed.gov/?q=charles+AND+law&pg=3&id=EJ450639"><span id="translatedtitle"><span class="hlt">Determining</span> <span class="hlt">Absolute</span> Zero in the Kitchen Sink.</span></a></p> <p><a target="_blank" href="http://www.eric.ed.gov/ERICWebPortal/search/extended.jsp?_pageLabel=advanced">ERIC Educational Resources Information Center</a></p> <p>Otani, Robert; Siegel, Peter</p> <p>1991-01-01</p> <p>Presents an experiment to demonstrate Charles's Law of Ideal Gases by creating a constant-pressure thermometer from materials that can be found in the kitchen. Discusses the underlying mathematical relationships and a step-by-step description of the experiment. (MDH)</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/11757479','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/11757479"><span id="translatedtitle">[Prenatal evaluation of fetal lung maturity by <span class="hlt">determination</span> of phosphatidylglycerol (PG) <span class="hlt">concentration</span> in amniotic fluid].</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Krasomski, G; Sałacińska, B; Broniarczyk, D; Swiatkowska, E</p> <p>2001-09-01</p> <p>Phosphatidylglycerol (PG) is considered to be the most important phospholipid of lung surfactant, responsible for its biological activity. The aim of the study was to investigate the predictive value of phosphatidylglycerol (PG) <span class="hlt">concentration</span> in amniotic fluid in prediction of neonatal lung maturity. The study was carried out on 180 pregnant women, chosen by random selection, hospitalized in Polish Mother's Health Centre Hospital in the period from 15.06.1994 to 31.12.1995. 223 samples of amniotic fluid were tested--phosphatidylglycerol (PG) <span class="hlt">concentration</span> was assayed by immunological test Amnio Stat FLM. In the study value PG < or = 0.2 microgram/ml was found in 110 (49.3%) samples of amniotic fluid, PG = 0.5 microgram/ml in 57 (25.6%) and PG > or = 2.0 micrograms/ml in 56 (25.1%). In our research predictive value of PG in relation to clinical lung maturity of neonates was verified. It turned out that PG <span class="hlt">concentration</span> in amniotic fluid < or = 0.2 microgram/ml indicates a possibility of RDS occurring in neonates born before 72 hours of performed <span class="hlt">determination</span>. <span class="hlt">Concentration</span> PG in amniotic fluid PG > or = 2.0 micrograms/ml corresponds to complete clinical lung maturity of neonates with predictive value 98%. PMID:11757479</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016PhRvB..94b4421S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016PhRvB..94b4421S"><span id="translatedtitle"><span class="hlt">Determination</span> of nitrogen spin <span class="hlt">concentration</span> in diamond using double electron-electron resonance</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Stepanov, Viktor; Takahashi, Susumu</p> <p>2016-07-01</p> <p>Diamond has been extensively investigated recently due to a wide range of potential applications of nitrogen-vacancy (NV) defect centers existing in a diamond lattice. The applications include magnetometry and quantum information technologies, and long decoherence time (T2) of NV centers is critical for those applications. Although it has been known that T2 highly depends on the <span class="hlt">concentration</span> of paramagnetic impurities in diamond, precise measurement of the impurity <span class="hlt">concentration</span> remains challenging. In the present work we show a method to <span class="hlt">determine</span> a wide range of the nitrogen <span class="hlt">concentration</span> (n ) in diamond using a wide-band high-frequency electron spin resonance and double electron-electron resonance spectrometer. Moreover, we investigate T2 of the nitrogen impurities and show the relationship between T2 and n . The method developed here is applicable for various spin systems in solid and implementable in nanoscale magnetic resonance spectroscopy with NV centers to characterize the <span class="hlt">concentration</span> of the paramagnetic spins within a microscopic volume.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/6812756','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/6812756"><span id="translatedtitle">Lethal body <span class="hlt">concentrations</span> and accumulation patterns <span class="hlt">determine</span> time-dependent toxicity of cadmium in soil arthropods</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Crommentuijn, T.; Doodeman, C.J.A.M.; Doornekamp, A.; Pol, J.J.C. van der; Bedaux, J.J.M.; Gestel, C.A.M. van )</p> <p>1994-11-01</p> <p>Time-dependent toxicity in bioassays is usually explained in terms of uptake and elimination kinetics of the toxicant. By comparing different species with essentially different accumulation kinetics, a firm test of this concept may be made. This article compares the sensitivity of six soil arthropods, the collembolans Orchesella cincta and Tomocerus minor, the oribatid mite Platynothrus peltifer, the isopods Porcellio scaber and Oniscus asellus, and the diplopod Cylindroiulus britannicus, when exposed to cadmium in the food. Survival was <span class="hlt">determined</span> at various time intervals; accumulation of cadmium in the animals was measured at one time interval. Kinetic-based toxicity models were fitted to the data, and estimates were obtained for lethal body <span class="hlt">concentration</span>, uptake rate constant, elimination rate constant, and ultimate LC50. Two different accumulation patterns could be discerned; these were correlated with time-survival relationships. One, species that have the possibility to eliminate cadmium will reach an equilibrium for the internal <span class="hlt">concentration</span> and also an ultimate LC50. Two, species that are unable to eliminate cadmium but store it in the body will have an ultimate LC50 equal to zero. For these species the time in which the lethal body <span class="hlt">concentration</span> is reached is more important. Taxonomically related species appeared to have comparable accumulation patterns, but lethal body <span class="hlt">concentrations</span> differed. It is concluded that knowledge of the accumulation pattern is indispensable for the evaluation of species' sensitivities to toxicants.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/23088631','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/23088631"><span id="translatedtitle">Precise <span class="hlt">determination</span> of the <span class="hlt">absolute</span> isotopic abundance ratio and the atomic weight of chlorine in three international reference materials by the positive thermal ionization mass spectrometer-Cs2Cl+-graphite method.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Wei, Hai-Zhen; Jiang, Shao-Yong; Xiao, Ying-Kai; Wang, Jun; Lu, Hai; Wu, Bin; Wu, He-Pin; Li, Qing; Luo, Chong-Guang</p> <p>2012-12-01</p> <p>Because the variation in chlorine isotopic abundances of naturally occurring chlorine bearing substances is significant, the IUPAC Inorganic Chemistry Division, Commission on Isotopic Abundances and Atomic Weights (CIAAW-IUPAC) decided that the uncertainty of atomic weight of chlorine (A(r)(Cl)) should be increased so that the implied range was related to terrestrial variability in 1999 (Coplen, T. B. Atomic weights of the elements 1999 (IUPAC Technical Report), Pure Appl. Chem.2001, 73(4), 667-683; and then, it emphasized that the standard atomic weights of ten elements including chlorine were not constants of nature but depend upon the physical, chemical, and nuclear history of the materials in 2009 (Wieser, M. E.; Coplen, T. B. Pure Appl. Chem.2011, 83(2), 359-396). According to the agreement by CIAAW that an atomic weight could be defined for one specified sample of terrestrial origin (Wieser, M. E.; Coplen, T. B. Pure Appl. Chem.2011, 83(2), 359-396), the <span class="hlt">absolute</span> isotope ratios and atomic weight of chlorine in standard reference materials (NIST 975, NIST 975a, ISL 354) were accurately <span class="hlt">determined</span> using the high-precision positive thermal ionization mass spectrometer (PTIMS)-Cs(2)Cl(+)-graphite method. After eliminating the weighing error caused from evaporation by designing a special weighing container and accurately <span class="hlt">determining</span> the chlorine contents in two highly enriched Na(37)Cl and Na(35)Cl salts by the current constant coulometric titration, one series of gravimetric synthetic mixtures prepared from two highly enriched Na(37)Cl and Na(35)Cl salts was used to calibrate two thermal ionization mass spectrometers in two individual laboratories. The correction factors (i.e., K(37/35) = R(37/35meas)/R(37/35calc)) were obtained from five cycles of iterative calculations on the basis of calculated and <span class="hlt">determined</span> R((37)Cl/(35)Cl) values in gravimetric synthetic mixtures. The <span class="hlt">absolute</span> R((37)Cl/(35)Cl) ratios for NIST SRM 975, NIST 975a, and ISL 354 by the precise</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/20381692','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/20381692"><span id="translatedtitle">Flow injection method for the <span class="hlt">determination</span> of silver <span class="hlt">concentration</span> in drinking water for spacecrafts.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Bruzzoniti, Maria Concetta; Kobylinska, Dorota Korte; Franko, Mladen; Sarzanini, Corrado</p> <p>2010-04-14</p> <p>A flow injection method has been developed for <span class="hlt">determination</span> of silver. The method is based on a reduction reaction with sodium borohydride which leads to the formation of a colloidal species which is monitored at a wavelength of 390 nm. The reaction variables flow rate, sodium borohydride <span class="hlt">concentration</span> and pH, which affect sensitivity, were investigated and their effects were established using a two-levels, three-factor experimental design. Further optimization of manifold variables (reaction coil and injection volume) allowed us to <span class="hlt">determine</span> silver in the range 0.050-5.0 mg L(-1) with a minimum detectable <span class="hlt">concentration</span> of 0.050 mg L(-1). Silver is added, as biocide, to drinking water for spacecrafts. The chemical species of silver, present in this kind of sample, were characterized by a procedure based on the selective retention of Ag(+) onto a 2.2.2. cryptand based substrate followed by <span class="hlt">determination</span> of the non-bound and bound (after elution) Ag(+) by the FIA method. The method optimized was applied to a drinking water sample provided for the launch with the Automated Transfer Vehicle (ATV) module Jule Verne to the International Space Station (March 9, 2008).</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/25712620','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/25712620"><span id="translatedtitle">Dosimetry <span class="hlt">determines</span> the initial OH radical <span class="hlt">concentration</span> in fast photochemical oxidation of proteins (FPOP).</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Niu, Ben; Zhang, Hao; Giblin, Daryl; Rempel, Don L; Gross, Michael L</p> <p>2015-05-01</p> <p>Fast photochemical oxidation of proteins (FPOP) employs laser photolysis of hydrogen peroxide to give OH radicals that label amino acid side-chains of proteins on the microsecond time scale. A method for quantitation of hydroxyl radicals after laser photolysis is of importance to FPOP because it establishes a means to adjust the yield of •OH, offers the opportunity of tunable modifications, and provides a basis for kinetic measurements. The initial <span class="hlt">concentration</span> of OH radicals has yet to be measured experimentally. We report here an approach using isotope dilution gas chromatography/mass spectrometry (GC/MS) to <span class="hlt">determine</span> quantitatively the initial •OH <span class="hlt">concentration</span> (we found ~0.95 mM from 15 mM H2O2) from laser photolysis and to investigate the quenching efficiencies for various •OH scavengers.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/20632615','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/20632615"><span id="translatedtitle"><span class="hlt">Determination</span> of elemental <span class="hlt">concentrations</span> of iron gall ink components by PIXE</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Budnar, Milos; Simcic, Jure; Ursic, Mitja; Rupnik, Zdravko; Kolar, Jana; Strlic, Matija</p> <p>2003-08-26</p> <p>The harmful effects of the iron gall ink on the supporting media (i.e. paper, parchment) are known for a long time. High contents of the catalytic ions and acids present in the ink can cause corrosion of the support and even its irreversible damage. Several historical documents from National and University Library (NUL) are being studied. The samples were measured nondestructively by the in-air PIXE for <span class="hlt">determination</span> of the iron gall elemental composition. The measured <span class="hlt">concentrations</span> prove that the analyzed inks contain a variety of different transition metals, which may influence the ink's corrosive character. For already measured documents dating from 14th to 19th century the ink and paper elemental <span class="hlt">concentrations</span> and their ratios to iron were studied by the statistical methods.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/15491651','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/15491651"><span id="translatedtitle"><span class="hlt">Determination</span> of soluble aluminium <span class="hlt">concentration</span> in alkaline humic water using atomic absorption spectrophotometry.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Nguyen, K L; Lewis, D M; Jolly, M; Robinson, J</p> <p>2004-11-01</p> <p>The steps of the standard method to <span class="hlt">determine</span> soluble aluminium <span class="hlt">concentration</span> are filtering, followed by acidifying, then analysing with the atomic absorption spectrophotometer (AAS). When applied to alkaline humic water, acidification gives rise to the formation of humic acid as a brown particulate matter. Of the total soluble aluminium in the original water, 49-61% forms complexes with the particulate humic acid upon acidification. Although the AAS is capable of detecting the binding aluminium, the particulate nature of humic acid easily induces inaccurate readings as a result of the non-uniform distribution of the particulate matter. A more precise analysis of soluble aluminium <span class="hlt">concentration</span> of alkaline humic water is shown to be achievable in basicified solutions instead. Basicified solutions keep humic acid in the soluble form; hence maintain the homogeneity of the sample.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015APS..DNP.EA120A','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015APS..DNP.EA120A"><span id="translatedtitle"><span class="hlt">Determination</span> of <span class="hlt">Concentrations</span> of Radioactive Nuclides in Soil Samples using Gamma Ray Spectroscopy</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Adil, Arsalan; Weaver, Joshua</p> <p>2015-10-01</p> <p>A hyper-pure Germanium detector system was used to <span class="hlt">determine</span> the contents and <span class="hlt">concentrations</span> of various nuclides in soil samples collected from different parts of the United States. These include areas in close proximity to nuclear power plants, areas susceptible to nuclear fallout from weapons testing from the pre Comprehensive Nuclear Test Ban Treaty (CTBT) period, and areas vulnerable to fallout from Fukushima from the west coast. The <span class="hlt">concentrations</span> of naturally occurring nuclides in the 238U, 232Th, and 40K decay chains as well as that of synthetic isotopes of 137Cs and 60Co were measured with the aid of Genie-2000 and Radware (gf3m). An efficiency curve was obtained by designing a simulation and compared with standard sources. The research, now in its next stage, aims to do the same in samples from Karachi (Pakistan) which is home to three nuclear power plant projects but has no available baseline radioactivity measurements. University of Richmond.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://cfpub.epa.gov/si/si_public_record_report.cfm?dirEntryId=213575&keyword=wps&actType=&TIMSType=+&TIMSSubTypeID=&DEID=&epaNumber=&ntisID=&archiveStatus=Both&ombCat=Any&dateBeginCreated=&dateEndCreated=&dateBeginPublishedPresented=&dateEndPublishedPresented=&dateBeginUpdated=&dateEndUpdated=&dateBeginCompleted=&dateEndCompleted=&personID=&role=Any&journalID=&publisherID=&sortBy=revisionDate&count=50&CFID=80727729&CFTOKEN=34194884','EPA-EIMS'); return false;" href="http://cfpub.epa.gov/si/si_public_record_report.cfm?dirEntryId=213575&keyword=wps&actType=&TIMSType=+&TIMSSubTypeID=&DEID=&epaNumber=&ntisID=&archiveStatus=Both&ombCat=Any&dateBeginCreated=&dateEndCreated=&dateBeginPublishedPresented=&dateEndPublishedPresented=&dateBeginUpdated=&dateEndUpdated=&dateBeginCompleted=&dateEndCompleted=&personID=&role=Any&journalID=&publisherID=&sortBy=revisionDate&count=50&CFID=80727729&CFTOKEN=34194884"><span id="translatedtitle">Improved Strategies and Optimization of Calibration Models for Real-time PCR <span class="hlt">Absolute</span> Quantification</span></a></p> <p><a target="_blank" href="http://oaspub.epa.gov/eims/query.page">EPA Science Inventory</a></p> <p></p> <p></p> <p>Real-time PCR <span class="hlt">absolute</span> quantification applications rely on the use of standard curves to make estimates of DNA target <span class="hlt">concentrations</span> in unknown samples. Traditional <span class="hlt">absolute</span> quantification approaches dictate that a standard curve must accompany each experimental run. However, t...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=1739996','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=1739996"><span id="translatedtitle"><span class="hlt">Determinants</span> of bone and blood lead <span class="hlt">concentrations</span> in the early postpartum period</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Brown, M. J.; Hu, H.; Gonzales-Cossio, T.; Peterson, K.; Sanin, L.; Kageyama, M. d.; Palazuelos, E.; Aro, A.; Schnaas, L.; Hernandez-Avila, M.</p> <p>2000-01-01</p> <p>OBJECTIVE—This study investigated <span class="hlt">determinants</span> of bone and blood lead <span class="hlt">concentrations</span> in 430 lactating Mexican women during the early postpartum period and the contribution of bone lead to blood lead.
METHODS—Maternal venous lead was measured at delivery and postpartum, and bone lead <span class="hlt">concentrations</span>, measured with in vivo K-x ray fluorescence, were measured post partum. Data on environmental exposure, demographic characteristics, and maternal factors related to exposure to lead were collected by questionnaire. Linear regression was used to examine the relations between bone and blood lead, demographics, and environmental exposure variables.
RESULTS—Mean (SD) blood, tibial, and patellar lead <span class="hlt">concentrations</span> were 9.5 (4.5) µg/dl, 10.2 (10.1) µg Pb/g bone mineral, and 15.2 (15.1) µg Pb/g bone mineral respectively. These values are considerably higher than values for women in the United States. Older age, the cumulative use of lead glazed pottery, and higher proportion of life spent in Mexico City were powerful predictors of higher bone lead <span class="hlt">concentrations</span>. Use of lead glazed ceramics to cook food in the past week and increased patellar lead <span class="hlt">concentrations</span> were significant predictors of increased blood lead. Patellar lead <span class="hlt">concentrations</span> explained one third of the variance accounted for by the final blood lead model. Women in the 90th percentile for patella lead had an untransformed predicted mean blood lead <span class="hlt">concentration</span> 3.6 µg/dl higher than those in the 10th percentile.
CONCLUSIONS—This study identified the use of lead glazed ceramics as a major source of cumulative exposure to lead, as reflected by bone lead <span class="hlt">concentrations</span>, as well as current exposure, reflected by blood lead, in Mexico. A higher proportion of life spent in Mexico City, a proxy for exposure to leaded gasoline emissions, was identified as the other major source of cumulative lead exposure. The influence of bone lead on blood lead coupled with the long half life of lead in bone has</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/23417055','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/23417055"><span id="translatedtitle"><span class="hlt">Determination</span> of radon and radium <span class="hlt">concentrations</span> in drinking water samples around the city of Kutahya.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Sahin, Latife; Cetinkaya, Hakan; Murat Saç, Müslim; Içhedef, Mutlu</p> <p>2013-08-01</p> <p>The <span class="hlt">concentration</span> of radium and radon has been <span class="hlt">determined</span> in drinking water samples collected from various locations of Kutahya city, Turkey. The water samples are taken from public water sources and tap water, with the collector chamber method used to measure the radon and radium <span class="hlt">concentration</span>. The radon <span class="hlt">concentration</span> ranges between 0.1 and 48.6±1.7 Bq l(-1), while the radium <span class="hlt">concentration</span> varies from a minimum detectable activity of <0.02-0.7±0.2 Bq l(-1) in Kutahya city. In addition to the radon and radium levels, parameters such as pH, conductivity and temperature of the water, humidity, pressure, elevation and the coordinates of the sampling points have also been measured and recorded. The annual effective dose from radon and radium due to typical water usage has been calculated. The resulting contribution to the annual effective dose due to radon ingestion varies between 0.3 and 124.2 μSv y(-1); the contribution to the annual effective dose due to radium ingestion varies between 0 and 143.3 μSv y(-1); the dose contribution to the stomach due to radon ingestion varies between 0.03 and 14.9 μSv y(-1). The dose contribution due to radon inhalation ranges between 0.3 and 122.5 μSv y(-1), assuming a typical transfer of radon in water to the air. For the overwhelming majority of the Kutahya population, it is <span class="hlt">determined</span> that the average radiation exposure from drinking water is less than 73.6 µSv y(-1).</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/12708691','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/12708691"><span id="translatedtitle">Evaluation of an acid ammonium oxalate extraction to <span class="hlt">determine</span> fluoride resident <span class="hlt">concentrations</span> in soils.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Bégin, Louis; Fortin, Josée</p> <p>2003-01-01</p> <p>Fluoride depositions near aluminum smelters and other fluoride-emitting plants can lead to fluoride accumulation in soils, which constitutes a risk for ground water contamination. This study was conducted to investigate the capacity of a 0.2 M acid ammonium oxalate solution to selectively and quantitatively extract fluoride accumulated in soils. The recovery of fluoride added to three soils was evaluated following 7- to 28-d incubations. Oxalate extraction was also compared with a total fluoride extraction method, using oxalate-extractable fluoride (Fox) and total fluoride (Ftot) accumulation profiles derived from column percolation experiments. To <span class="hlt">determine</span> low-level fluoride <span class="hlt">concentrations</span> without interference from high Al and Fe <span class="hlt">concentrations</span>, an adapted ion chromatography method was used. Following soil incubations, oxalate extracted 42 to 86% of added fluoride. Recovery varied between soils and, in one soil, increased with added fluoride <span class="hlt">concentration</span>. Recovery was unaffected by incubation time. Maximum recovery was obtained in a soil high in amorphous Fe and Al, low in clay, and free of carbonate. Lower recoveries were obtained in soils with higher clay or carbonate contents. Only 4 to 8% of Ftot was extracted in untreated samples using Fox, which suggests a high selectivity of this method for added fluoride. In percolation experiments, the use of Fox reduced considerably the background noise associated with Ftot for the evaluation of fluoride accumulation profiles. Because of its high selectivity and despite incomplete fluoride recovery, the use of Fox to <span class="hlt">determine</span> fluoride resident <span class="hlt">concentrations</span> in soils may improve environmental monitoring of fluoride accumulation and movement in contaminated soils.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_15");'>15</a></li> <li><a href="#" onclick='return showDiv("page_16");'>16</a></li> <li class="active"><span>17</span></li> <li><a href="#" onclick='return showDiv("page_18");'>18</a></li> <li><a href="#" onclick='return showDiv("page_19");'>19</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_17 --> <div id="page_18" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_16");'>16</a></li> <li><a href="#" onclick='return showDiv("page_17");'>17</a></li> <li class="active"><span>18</span></li> <li><a href="#" onclick='return showDiv("page_19");'>19</a></li> <li><a href="#" onclick='return showDiv("page_20");'>20</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="341"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://pubs.er.usgs.gov/publication/70021784','USGSPUBS'); return false;" href="http://pubs.er.usgs.gov/publication/70021784"><span id="translatedtitle">New method for the direct <span class="hlt">determination</span> of dissolved Fe(III) <span class="hlt">concentration</span> in acid mine waters</span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>To, T.B.; Nordstrom, D.K.; Cunningham, K.M.; Ball, J.W.; McCleskey, R.B.</p> <p>1999-01-01</p> <p>A new method for direct <span class="hlt">determination</span> of dissolved Fe(III) in acid mine water has been developed. In most present methods, Fe(III) is <span class="hlt">determined</span> by computing the difference between total dissolved Fe and dissolved Fe(II). For acid mine waters, frequently Fe(II) >> Fe(III); thus, accuracy and precision are considerably improved by <span class="hlt">determining</span> Fe(III) <span class="hlt">concentration</span> directly. The new method utilizes two selective ligands to stabilize Fe(III) and Fe(II), thereby preventing changes in Fe reduction-oxidation distribution. Complexed Fe(II) is cleanly removed using a silica-based, reversed-phase adsorbent, yielding excellent isolation of the Fe(III) complex. Iron(III) <span class="hlt">concentration</span> is measured colorimetrically or by graphite furnace atomic absorption spectrometry (GFAAS). The method requires inexpensive commercial reagents and simple procedures that can be used in the field. Calcium(II), Ni(II), Pb(II), AI(III), Zn(II), and Cd(II) cause insignificant colorimetric interferences for most acid mine waters. Waters containing >20 mg of Cu/L could cause a colorimetric interference and should be measured by GFAAS. Cobalt(II) and Cr(III) interfere if their molar ratios to Fe(III) exceed 24 and 5, respectively. Iron(II) interferes when its <span class="hlt">concentration</span> exceeds the capacity of the complexing ligand (14 mg/L). Because of the GFAAS elemental specificity, only Fe(II) is a potential interferent in the GFAAS technique. The method detection limit is 2 ??g/L (40 nM) using GFAAS and 20 ??g/L (0.4 ??M) by colorimetry.A new method for direct <span class="hlt">determination</span> of dissolved Fe(III) in acid mine water has been developed. In most present methods, Fe(III) is <span class="hlt">determined</span> by computing the difference between total dissolved Fe and dissolved Fe(II). For acid mine waters, frequently Fe(II)???Fe(III); thus, accuracy and precision are considerably improved by <span class="hlt">determining</span> Fe(III) <span class="hlt">concentration</span> directly. The new method utilizes two selective ligands to stabilize Fe(III) and Fe(II), thereby preventing changes</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/27193003','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/27193003"><span id="translatedtitle">Practical Considerations for <span class="hlt">Determination</span> of Glass Transition Temperature of a Maximally Freeze <span class="hlt">Concentrated</span> Solution.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Pansare, Swapnil K; Patel, Sajal Manubhai</p> <p>2016-08-01</p> <p>Glass transition temperature is a unique thermal characteristic of amorphous systems and is associated with changes in physical properties such as heat capacity, viscosity, electrical resistance, and molecular mobility. Glass transition temperature for amorphous solids is referred as (T g), whereas for maximally freeze <span class="hlt">concentrated</span> solution, the notation is (T g'). This article is focused on the factors affecting <span class="hlt">determination</span> of T g' for application to lyophilization process design and frozen storage stability. Also, this review provides a perspective on use of various types of solutes in protein formulation and their effect on T g'. Although various analytical techniques are used for <span class="hlt">determination</span> of T g' based on the changes in physical properties associated with glass transition, the differential scanning calorimetry (DSC) is the most commonly used technique. In this article, an overview of DSC technique is provided along with brief discussion on the alternate analytical techniques for T g' <span class="hlt">determination</span>. Additionally, challenges associated with T g' <span class="hlt">determination</span>, using DSC for protein formulations, are discussed. The purpose of this review is to provide a practical industry perspective on <span class="hlt">determination</span> of T g' for protein formulations as it relates to design and development of lyophilization process and/or for frozen storage; however, a comprehensive review of glass transition temperature (T g, T g'), in general, is outside the scope of this work. PMID:27193003</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2005JPhD...38.2696D','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2005JPhD...38.2696D"><span id="translatedtitle">Non-invasive in vivo <span class="hlt">determination</span> of the carotenoids beta-carotene and lycopene <span class="hlt">concentrations</span> in the human skin using the Raman spectroscopic method</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Darvin, M. E.; Gersonde, I.; Meinke, M.; Sterry, W.; Lademann, J.</p> <p>2005-08-01</p> <p>Resonance Raman spectroscopy was used as a fast and non-invasive optical method of measuring the <span class="hlt">absolute</span> <span class="hlt">concentrations</span> of beta-carotene and lycopene in living human skin. Beta-carotene and lycopene have different absorption values at 488 and 514.5 nm and, consequently, the Raman lines for beta-carotene and lycopene have different scattering efficiencies at 488 and 514.5 nm excitations. These differences were used for the <span class="hlt">determination</span> of the <span class="hlt">concentrations</span> of beta-carotene and lycopene. Using multiline Ar+ laser excitation, clearly distinguishable carotenoid Raman spectra can be obtained which are superimposed on a large fluorescence background. The Raman signals are characterized by two prominent Stokes lines at 1160 and 1525 cm-1, which have nearly identical relative intensities. Both substances were detected simultaneously. The Raman spectra are obtained rapidly, i.e. within about 10 s, and the required laser light exposure level is well within safety standards. The disturbance of the measurements by non-homogeneous skin pigmentation was avoided by using a relatively large measuring area of 35 mm2. It was shown that beta-carotene and lycopene distribution in human skin strongly depends upon the skin region studied and drastically changed inter-individually. Skin beta-carotene and lycopene <span class="hlt">concentrations</span> are lower in smokers than in non-smokers and higher in the vegetarian group.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=20000064542&hterms=alexander+bruce&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D10%26Ntt%3Dalexander%2Bbruce','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=20000064542&hterms=alexander+bruce&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D10%26Ntt%3Dalexander%2Bbruce"><span id="translatedtitle">Issues in <span class="hlt">Absolute</span> Spectral Radiometric Calibration: Intercomparison of Eight Sources</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Goetz, Alexander F. H.; Kindel, Bruce; Pilewskie, Peter</p> <p>1998-01-01</p> <p>The application of atmospheric models to AVIRIS and other spectral imaging data to derive surface reflectance requires that the sensor output be calibrated to <span class="hlt">absolute</span> radiance. Uncertainties in <span class="hlt">absolute</span> calibration are to be expected, and claims of 92% accuracy have been published. Measurements of accurate surface albedos and cloud absorption to be used in radiative balance calculations depend critically on knowing the <span class="hlt">absolute</span> spectral-radiometric response of the sensor. The Earth Observing System project is implementing a rigorous program of <span class="hlt">absolute</span> radiometric calibration for all optical sensors. Since a number of imaging instruments that provide output in terms of <span class="hlt">absolute</span> radiance are calibrated at different sites, it is important to <span class="hlt">determine</span> the errors that can be expected among calibration sites. Another question exists about the errors in the <span class="hlt">absolute</span> knowledge of the exoatmospheric spectral solar irradiance.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/22686054','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/22686054"><span id="translatedtitle">[Isolation, extractive <span class="hlt">concentration</span>, and <span class="hlt">determination</span> of caffeine in the studies of blood plasma].</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Korenman, Ia I; Shormanov, V K; Mokshina, N Ia; Krivosheeva, O A; Golubitskiĭ, G B</p> <p>2012-01-01</p> <p>The optimal conditions for the isolation of caffeine from human blood by means of acetone extraction are described with special reference to the peculiarities of extraction from aqueous solutions. The possibility of <span class="hlt">concentration</span> and purification of caffeine from blood plasma using acetone and aceton-chlorophorm mixture (2:8) as the solvents is illustrated. In addition, purification by silica-gel thin layer chromatography is discussed. Thin layer chromatography, UV-spectrophotometry, and high performance liquid chromatography are considered as potential methods for the identification and quantitative <span class="hlt">determination</span> of caffeine.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=284512','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=284512"><span id="translatedtitle"><span class="hlt">Determination</span> of pefloxacin <span class="hlt">concentration</span> in mesenteric lymph nodes by high-performance chromatography.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Munera, M I; Cuesta, F; Abadia, A; Vasquez, J; Restrepo, M</p> <p>1994-01-01</p> <p>Ten patients who had undergone laparotomies for different abdominal pathological conditions were studied to <span class="hlt">determine</span> the levels of pefloxacin in mesenteric lymph nodes. Each patient was given 400 mg of oral pefloxacin every 12 h for the 3 days prior to surgery. Drug levels in tissue were <span class="hlt">determined</span> by high-pressure liquid chromatography (reverse phase); the mean +/- standard deviation was 17.1 +/- 11.9 micrograms/g, with a range of 2.12 to 36.6 micrograms/g. This indicates an adequate pefloxacin <span class="hlt">concentration</span> in lymph nodes and makes the drug a good option for the treatment of conditions in which lymph nodes act as an infection-promoting and/or relapse-favoring factor. PMID:8203867</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=19850052423&hterms=Actinide+elements&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D70%26Ntt%3D%2528Actinide%2Belements%2529','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=19850052423&hterms=Actinide+elements&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D70%26Ntt%3D%2528Actinide%2Belements%2529"><span id="translatedtitle">Ion probe <span class="hlt">determinations</span> of the rare earth <span class="hlt">concentrations</span> of individual meteoritic phosphate grains</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Crozaz, G.; Zinner, E.</p> <p>1985-01-01</p> <p>A new ion probe method for quantitative measurements of the <span class="hlt">concentrations</span> of all the REE down to the ppm level in 5-20 micron spots is presented. The first application of the method is the <span class="hlt">determination</span> of REE abundances in meteoritic phosphates. Results are shown to be in good agreement with previous INAA and ion probe <span class="hlt">determinations</span>. The merrillites in the St. Severin amphoterite are richer in REE than the apatites (the enrichment factors, for various REE, range from 2.3 to 14.2) in contradiction with the results of Ebihara and Honda (1983). Provided good standards for other mineral phases are found or implanted marker ion techniques are used, the method should find a wide range of applications for the study of both terrestrial and extraterrestrial crystals at the microscopic level.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/16260147','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/16260147"><span id="translatedtitle">Validation of ELISA for the <span class="hlt">determination</span> of anti-ricin immunoglobulin G <span class="hlt">concentration</span> in mouse sera.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Lindsey, Changhong Y; Pace-Templeton, Judith G; Millard, Charles B; Wannemacher, Robert W; Hewetson, John F</p> <p>2006-03-01</p> <p>An enzyme-linked immunosorbent assay (ELISA) for the <span class="hlt">determination</span> of anti-ricin immunoglobulin G (IgG) <span class="hlt">concentration</span> in mouse sera was systematically validated. The results obtained throughout the validation process strongly demonstrated that the ELISA was reliable, reproducible, and suitable for its intended use. The assay had a high level of precision within and between runs, was specific for the anti-ricin IgG, and showed no interference with a number of different serum matrices. The assay exhibited excellent accuracy, linearity, and stability. The mean recovery of four test samples with different known <span class="hlt">concentrations</span> was 100.9+/-11.3%, 102.7+/-10.8%, 99.0+/-7.2%, and 95.9+/-11.3%, respectively (n=10). The mean recovery of the observed anti-ricin IgG <span class="hlt">concentration</span> of three quality control samples run on 73 plates to their nominal <span class="hlt">concentrations</span> was 100.1+/-7.3%, 100.2+/-5.8%, and 103.7+/-8.1%; and the coefficient of variation (CV) was 7.3%, 5.8%, and 7.8%, respectively. The back-calculated anti-ricin IgG <span class="hlt">concentration</span>, %CV, and relative error of seven standards from the calibration curves run in the entire validation study were analyzed (n=7 x 73). The results indicated that the four-parameter logistic (4PL) equation, y=(a-d)/(1+(x/c)b)+d, provided an accurate representation of a sigmoidal relationship between the measured response and the logarithm of observed <span class="hlt">concentration</span> of anti-ricin IgG in mouse sera for this ELISA. The lower limit of quantification and upper limit of quantification of the calibration curve were 3.3 ng/ml and 82.8 ng/ml, respectively. The measurable range of the assay would cover all possible anti-ricin IgG <span class="hlt">concentrations</span> in mouse sera stimulated with a ricin vaccine candidate, when the test sera are measured at a 1:800 starting dilution followed by four additional fourfold serial dilutions.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/17438918','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/17438918"><span id="translatedtitle">Correlation between linezolid zone diameter and minimum inhibitory <span class="hlt">concentration</span> values <span class="hlt">determined</span> by regression analysis.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Dimitriu, G; Poiata, Antonia; Tuchiluş, Cristina; Buiuc, D</p> <p>2006-01-01</p> <p>Linezolid is a new synthetic antibiotic belonging to the oxazolidinone class, available for the therapy of gram-positive infections, caused by methicillin-resistant staphylococci, vancomycin-resistant enterococci and penicillin-resistant pneumococci. The aim of the study was to <span class="hlt">determine</span> the in vitro activity of linezolid against staphylococci strains and also to <span class="hlt">determine</span> the relationship between the minimum inhibitory <span class="hlt">concentration</span> (MIC) and inhibition zone diameter by calculating the regression analysis. We tested one hundred S. aureus isolates, obtained from healthy persons (naso-pharyngeal swabs) during 2005 year. The antibiotic susceptibility of strains was <span class="hlt">determined</span> by disk diffusion standardized method and by agar dilution method using a multipoint inoculator. The relationship between the diameter of the inhibition zone produced by a linezolid disc impregnated with a fixed amount (30 eg) was <span class="hlt">determined</span> by regression performed with the least squares method, considering the log2 of the minimum inhibitory <span class="hlt">concentrations</span> (MICs) as the independent variable and the zone diameter as the dependent variable. The MIC values expressed in logarithmic form are plotted against inhibition zone diameter (arithmetic scale) of the same strain. The activity of linezolid against staphylococci was very good, with MIC 90 of 1 mg/l. All strains were fully sensitive. The regression line for linezolid passes through a continuous series of points that all are approximately located on the a straight line. For each of the MIC values the differences result no greater than 23 mm in diameter sizes were registered. Regression equation was y= -0.188x + 8.048. In conclusion, the regression line analysis calculated for linezolid, demonstrates a significant correlation between MIC values and the inhibition zone diameters obtained by a 30 mg disc.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/26350448','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/26350448"><span id="translatedtitle"><span class="hlt">Determinants</span> of Anemia and Hemoglobin <span class="hlt">Concentration</span> in Haitian School-Aged Children.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Iannotti, Lora L; Delnatus, Jacques R; Odom, Audrey R; Eaton, Jacob C; Griggs, Jennifer J; Brown, Sarah; Wolff, Patricia B</p> <p>2015-11-01</p> <p>Anemia diminishes oxygen transport in the body, resulting in potentially irreversible growth and developmental consequences for children. Limited evidence for <span class="hlt">determinants</span> of anemia exists for school-aged children. We conducted a cluster randomized controlled trial in Haiti from 2012 to 2013 to test the efficacy of a fortified school snack. Children (N = 1,047) aged 3-13 years were followed longitudinally at three time points for hemoglobin (Hb) <span class="hlt">concentrations</span>, anthropometry, and bioelectrical impedance measures. Dietary intakes, infectious disease morbidities, and socioeconomic and demographic factors were collected at baseline and endline. Longitudinal regression modeling with generalized least squares and logit models with random effects identified anemia risk factors beyond the intervention effect. At baseline, 70.6% of children were anemic and 2.6% were severely anemic. Stunting increased the odds of developing anemia (adjusted odds ratio [OR]: 1.48, 95% confidence interval [CI]: 1.05-2.08) and severe anemia (adjusted OR: 2.47, 95% CI: 1.30-4.71). Parent-reported vitamin A supplementation and deworming were positively associated with Hb <span class="hlt">concentrations</span>, whereas fever and poultry ownership showed a negative relationship with Hb <span class="hlt">concentration</span> and increased odds of severe anemia, respectively. Further research should explore the full spectrum of anemia etiologies in school children, including genetic causes.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/21342811','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/21342811"><span id="translatedtitle">Methods for <span class="hlt">determining</span> agent <span class="hlt">concentration</span> profiles in agarose gel during convection-enhanced delivery.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Sindhwani, Nikhil; Ivanchenko, Oleksandr; Lueshen, Eric; Prem, Komal; Linninger, Andreas A</p> <p>2011-03-01</p> <p>Convection-enhanced delivery (CED) is a promising technique to deliver large molecular weight drugs to the human brain for treatment of Parkinson's, Alzheimer's, or brain tumors. Researchers have used agarose gels to study mechanisms of agent transport in soft tissues like brain due to its similar mechanical and transport properties. However, inexpensive quantitative techniques to precisely measure achieved agent distribution in agarose gel phantoms during CED are missing. Such precise measurements of <span class="hlt">concentration</span> distribution are needed to optimize drug delivery. An optical experimental method to accurately quantify agent <span class="hlt">concentration</span> in agarose is presented. A novel geometry correction algorithm is used to <span class="hlt">determine</span> real <span class="hlt">concentrations</span> from observable light intensities captured by a digital camera. We demonstrate the technique in dye infusion experiments that provide cylindrical and spherical distributions when infusing with porous membrane and conventional single-port catheters, respectively. This optical method incorporates important parameters, such as optimum camera exposure, captured camera intensity calibration, and use of collimated light source for maximum precision. We compare experimental results with numerical solutions to the convection diffusion equation. The solutions of convection-diffusion equations in the cylindrical and spherical domains were found to match the experimental data obtained by geometry correction algorithm.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/26350448','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/26350448"><span id="translatedtitle"><span class="hlt">Determinants</span> of Anemia and Hemoglobin <span class="hlt">Concentration</span> in Haitian School-Aged Children.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Iannotti, Lora L; Delnatus, Jacques R; Odom, Audrey R; Eaton, Jacob C; Griggs, Jennifer J; Brown, Sarah; Wolff, Patricia B</p> <p>2015-11-01</p> <p>Anemia diminishes oxygen transport in the body, resulting in potentially irreversible growth and developmental consequences for children. Limited evidence for <span class="hlt">determinants</span> of anemia exists for school-aged children. We conducted a cluster randomized controlled trial in Haiti from 2012 to 2013 to test the efficacy of a fortified school snack. Children (N = 1,047) aged 3-13 years were followed longitudinally at three time points for hemoglobin (Hb) <span class="hlt">concentrations</span>, anthropometry, and bioelectrical impedance measures. Dietary intakes, infectious disease morbidities, and socioeconomic and demographic factors were collected at baseline and endline. Longitudinal regression modeling with generalized least squares and logit models with random effects identified anemia risk factors beyond the intervention effect. At baseline, 70.6% of children were anemic and 2.6% were severely anemic. Stunting increased the odds of developing anemia (adjusted odds ratio [OR]: 1.48, 95% confidence interval [CI]: 1.05-2.08) and severe anemia (adjusted OR: 2.47, 95% CI: 1.30-4.71). Parent-reported vitamin A supplementation and deworming were positively associated with Hb <span class="hlt">concentrations</span>, whereas fever and poultry ownership showed a negative relationship with Hb <span class="hlt">concentration</span> and increased odds of severe anemia, respectively. Further research should explore the full spectrum of anemia etiologies in school children, including genetic causes. PMID:26350448</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3642945','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3642945"><span id="translatedtitle"><span class="hlt">Determination</span> of Blood Glucose <span class="hlt">Concentration</span> by Using Wavelet Transform and Neural Networks</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Ashok, Vajravelu; Kumar, Nirmal</p> <p>2013-01-01</p> <p>Background: Early and non-invasive <span class="hlt">determination</span> of blood glucose level is of great importance. We aimed to present a new technique to accurately infer the blood glucose <span class="hlt">concentration</span> in peripheral blood flow using non-invasive optical monitoring system. Methods: The data for the research were obtained from 900 individuals. Of them, 750 people had diabetes mellitus (DM). The system was designed using a helium neon laser source of 632.8 nm wavelength with 5mW power, photo detectors and digital storage oscilloscope. The laser beam was directed through a single optical fiber to the index finger and the scattered beams were collected by the photo detectors placed circumferentially to the transmitting fiber. The received signals were filtered using band pass filter and finally sent to a digital storage oscilloscope. These signals were then decomposed into approximation and detail coefficients using modified Haar Wavelet Transform. Back propagation neural and radial basis functions were employed for the prediction of blood glucose <span class="hlt">concentration</span>. Results: The data of 450 patients were randomly used for training, 225 for testing and the rest for validation. The data showed that outputs from radial basis function were nearer to the clinical value. Significant variations could be seen from signals obtained from patients with DM and those without DM. Conclusion: The proposed non-invasive optical glucose monitoring system is able to predict the glucose <span class="hlt">concentration</span> by proving that there is a definite variation in hematological distribution between patients with DM and those without DM. PMID:23645958</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4998580','PMC'); return false;" href="http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4998580"><span id="translatedtitle">Chemical Structure and <span class="hlt">Concentration</span> of Intratumor Catabolites <span class="hlt">Determine</span> Efficacy of Antibody Drug Conjugates</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Yu, Shang-Fan; Ma, Yong; Xu, Keyang; Dragovich, Peter S.; Pillow, Thomas H.; Liu, Luna; Del Rosario, Geoffrey; He, Jintang; Pei, Zhonghua; Sadowsky, Jack D.; Erickson, Hans K.; Hop, Cornelis E. C. A.; Khojasteh, S. Cyrus</p> <p>2016-01-01</p> <p>Despite recent technological advances in quantifying antibody drug conjugate (ADC) species, such as total antibody, conjugated antibody, conjugated drug, and payload drug in circulation, the correlation of their exposures with the efficacy of ADC outcomes in vivo remains challenging. Here, the chemical structures and <span class="hlt">concentrations</span> of intratumor catabolites were investigated to better understand the drivers of ADC in vivo efficacy. Anti-CD22 disulfide-linked pyrrolobenzodiazepine (PBD-dimer) conjugates containing methyl- and cyclobutyl-substituted disulfide linkers exhibited strong efficacy in a WSU-DLCL2 xenograft mouse model, whereas an ADC derived from a cyclopropyl linker was inactive. Total ADC antibody <span class="hlt">concentrations</span> and drug-to-antibody ratios (DAR) in circulation were similar between the cyclobutyl-containing ADC and the cyclopropyl-containing ADC; however, the former afforded the release of the PBD-dimer payload in the tumor, but the latter only generated a nonimmolating thiol-containing catabolite that did not bind to DNA. These results suggest that intratumor catabolite analysis rather than systemic pharmacokinetic analysis may be used to better explain and predict ADC in vivo efficacy. These are good examples to demonstrate that the chemical nature and <span class="hlt">concentration</span> of intratumor catabolites depend on the linker type used for drug conjugation, and the potency of the released drug moiety ultimately <span class="hlt">determines</span> the ADC in vivo efficacy. PMID:27417182</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/26485531','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/26485531"><span id="translatedtitle">General, Label-Free Method for <span class="hlt">Determining</span> K(d) and Ligand <span class="hlt">Concentration</span> Simultaneously.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Jalali-Yazdi, Farzad; Takahashi, Terry T; Roberts, Richard W</p> <p>2015-12-01</p> <p>Some of the most commonly used affinity reagents (e.g., antibodies) are often developed and used in conditions where their input <span class="hlt">concentrations</span> ([L]0) and affinities (K(d)) are not known. Here, we have developed a general approach to <span class="hlt">determine</span> both [L]0 and K(d) values simultaneously for affinity reagents (small molecules, proteins, and antibodies). To do this, we perform quantitative equilibrium exclusion immunoassays with two different <span class="hlt">concentrations</span> of target and fit the data simultaneously to <span class="hlt">determine</span> K(d) and [L]0. The results give accurate and reproducible measures of both values compared to established methods. By performing detailed error analysis, we demonstrate that our fitting gives unique solutions and indicates where K(d) and [L]0 measures are reliable. Furthermore, we found that a divalent model of antibody binding gives accurate K(d) and [L]0 values in both the forward (antibody immobilized) and the reverse (target immobilized) assays-addressing the long-term problem of obtaining quantitative data from reverse assays.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2011JPhCS.276a2144S&link_type=ABSTRACT','NASAADS'); return false;" href="http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2011JPhCS.276a2144S&link_type=ABSTRACT"><span id="translatedtitle">A Rapid Method for <span class="hlt">Determining</span> the <span class="hlt">Concentration</span> of Recombinant Protein Secreted from Pichia pastoris</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Sun, L. W.; Zhao, Y.; Niu, L. P.; Jiang, R.; Song, Y.; Feng, H.; feng, K.; Qi, C.</p> <p>2011-02-01</p> <p>Pichia secretive expression system is one of powerful eukaryotic expression systems in genetic engineering, which is especially suitable for industrial utilization. Because of the low <span class="hlt">concentration</span> of the target protein in initial experiment, the methods and conditions for expression of the target protein should be optimized according to the protein yield repetitively. It is necessary to set up a rapid, simple and convenient analysis method for protein expression levels instead of the generally used method such as ultrafiltration, purification, dialysis, lyophilization and so on. In this paper, acetone precipitation method was chosen to <span class="hlt">concentrate</span> the recombinant protein firstly after comparing with four different protein precipitation methods systematically, and then the protein was analyzed by SDS-Polyacrylamide Gel Electrophoresis. The recombinant protein was <span class="hlt">determined</span> with the feature of protein band by the Automated Image Capture and 1-D Analysis Software directly. With this method, the optimized expression conditions of basic fibroblast growth factor secreted from pichia were obtained, which is as the same as using traditional methods. Hence, a convenient tool to <span class="hlt">determine</span> the optimized conditions for the expression of recombinant proteins in Pichia was established.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/919420','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/919420"><span id="translatedtitle">Acute hypoproteinemic fluid overload: its <span class="hlt">determinants</span>, distribution, and treatment with <span class="hlt">concentrated</span> albumin and diuretics.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Pappova, E; Bachmeier, W; Crevoisier, J L; Kollar, J; Kollar, M; Tobler, P; Zahler, H W; Zaugg, D; Lundsgaard-Hansen, P</p> <p>1977-01-01</p> <p>We simulated the use of massive volumes of crystalloid fluids as a treatment of acute plasma loss in a standardized experimental model and studied the factors <span class="hlt">determining</span> the retention or excretion of the resulting acute hypoproteinemic fluid overload, its distribution within the body, and its treatment with <span class="hlt">concentrated</span> albumin and diuretics. In accordance with the classic Starling concept, the serum protein level, i.e. the serum colloid osmotic pressure, <span class="hlt">determined</span> the excretion/retention ratio of a given water and sodium load. Of the total fluid retention, fat and muscle each accommodated 25%, whereas the skin, which contributes only 7% to the total body weight, accounted for 37% and increased its volume by roughly one third. <span class="hlt">Concentrated</span> albumin promoted fluid excretion in direct proportion to the achieved increment of the serum protein level and abolished the edema of fat, muscle and skin. Furosemide was virtually ineffective. The implications of these results for the 'adult respiratory distress syndrome' and disturbed wound healing are discussed and related to the concept of a critical threshold of the serum protein level. PMID:919420</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/22476786','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/22476786"><span id="translatedtitle"><span class="hlt">Determination</span> of perfluorinated alkyl acid <span class="hlt">concentrations</span> in biological standard reference materials.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Reiner, Jessica L; O'Connell, Steven G; Butt, Craig M; Mabury, Scott A; Small, Jeff M; De Silva, Amila O; Muir, Derek C G; Delinsky, Amy D; Strynar, Mark J; Lindstrom, Andrew B; Reagen, William K; Malinsky, Michelle; Schäfer, Sandra; Kwadijk, Christiaan J A F; Schantz, Michele M; Keller, Jennifer M</p> <p>2012-11-01</p> <p>Standard reference materials (SRMs) are homogeneous, well-characterized materials used to validate measurements and improve the quality of analytical data. The National Institute of Standards and Technology (NIST) has a wide range of SRMs that have mass fraction values assigned for legacy pollutants. These SRMs can also serve as test materials for method development, method validation, and measurement for contaminants of emerging concern. Because inter-laboratory comparison studies have revealed substantial variability of measurements of perfluoroalkyl acids (PFAAs), future analytical measurements will benefit from <span class="hlt">determination</span> of consensus values for PFAAs in SRMs to provide a means to demonstrate method-specific performance. To that end, NIST, in collaboration with other groups, has been measuring <span class="hlt">concentrations</span> of PFAAs in a variety of SRMs. Here we report levels of PFAAs and perfluorooctane sulfonamide (PFOSA) <span class="hlt">determined</span> in four biological SRMs: fish tissue (SRM 1946 Lake Superior Fish Tissue, SRM 1947 Lake Michigan Fish Tissue), bovine liver (SRM 1577c), and mussel tissue (SRM 2974a). We also report <span class="hlt">concentrations</span> for three in-house quality-control materials: beluga whale liver, pygmy sperm whale liver, and white-sided dolphin liver. Measurements in SRMs show an array of PFAAs, with perfluorooctane sulfonate (PFOS) being the most frequently detected. Reference and information values are reported for PFAAs measured in these biological SRMs. PMID:22476786</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015SPIE.9640E..0OS','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015SPIE.9640E..0OS"><span id="translatedtitle">Mixing layer height measurements <span class="hlt">determines</span> influence of meteorology on air pollutant <span class="hlt">concentrations</span> in urban area</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Schäfer, Klaus; Blumenstock, Thomas; Bonn, Boris; Gerwig, Holger; Hase, Frank; Münkel, Christoph; Nothard, Rainer; von Schneidemesser, Erika</p> <p>2015-10-01</p> <p>Mixing layer height (MLH) is a key parameter to <span class="hlt">determine</span> the influence of meteorological parameters upon air pollutants such as trace gas species and particulate <span class="hlt">concentrations</span> near the surface. Meteorology, and MLH as a key parameter, affect the budget of emission source strengths, deposition, and accumulation. However, greater possibilities for the application of MLH data have been identified in recent years. Here, the results of measurements in Berlin in 2014 are shown and discussed. The <span class="hlt">concentrations</span> of NO, NO2, O3, CO, PM1, PM2.5, PM10 and about 70 volatile organic compounds (anthropogenic and biogenic of origin) as well as particle size distributions and contributions of SOA and soot species to PM were measured at the urban background station of the Berlin air quality network (BLUME) in Nansenstr./Framstr., Berlin-Neukölln. A Vaisala ceilometer CL51, which is a commercial mini-lidar system, was applied at that site to detect the layers of the lower atmosphere in real time. Special software for these ceilometers with MATLAB provided routine retrievals of MLH from vertical profiles of laser backscatter data. Five portable Bruker EM27/SUN FTIR spectrometers were set up around Berlin to detect column averaged abundances of CO2 and CH4 by solar absorption spectrometry. Correlation analyses were used to show the coupling of temporal variations of trace gas compounds and PM with MLH. Significant influences of MLH upon NO, NO2, PM10, PM2.5, PM1 and toluene (marker for traffic emissions) <span class="hlt">concentrations</span> as well as particle number <span class="hlt">concentrations</span> in the size modes 70 - 100 nm, 100 - 200 nm and 200 - 500 nm on the basis of averaged diurnal courses were found. Further, MLH was taken as important auxiliary information about the development of the boundary layer during each day of observations, which was required for the proper estimation of CO2 and CH4 source strengths from Berlin on the basis of atmospheric column density measurements.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/26802341','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/26802341"><span id="translatedtitle">An assay for <span class="hlt">determining</span> minimal <span class="hlt">concentrations</span> of antibiotics that drive horizontal transfer of resistance.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Jutkina, Jekaterina; Rutgersson, Carolin; Flach, Carl-Fredrik; Larsson, D G Joakim</p> <p>2016-04-01</p> <p>Ability to understand the factors driving horizontal transfer of antibiotic resistance from unknown, harmless bacteria to pathogens is crucial in order to tackle the growing resistance problem. However, current methods to measure effects of stressors on horizontal gene transfer have limitations and often fall short, as the estimated endpoints can be a mix of both the number of transfer events and clonal growth of transconjugants. Our aim was therefore to achieve a proper strategy for assessing the minimal <span class="hlt">concentration</span> of a stressor (exemplified by tetracycline) that drives horizontal transfer of antibiotic resistance from a complex community to a model pathogen. Conditions were optimized to improve a culture-based approach using the bacterial community of treated sewage effluent as donor, and fluorescent, traceable Escherichia coli as recipient. Reduced level of background resistance, differentiation of isolates as well as decreased risk for measuring effects of selection were achieved through the use of chromogenic medium, optimization of conjugation time as well as applying a different antibiotic for isolation of transconjugants than the one tested for its ability to drive transfer. Using this assay, we showed that a very low <span class="hlt">concentration</span> of tetracycline, 10μg/L i.e. 150 times below the minimal inhibitory <span class="hlt">concentration</span> of the recipient, promoted horizontal transfer of multiple antibiotic-resistance <span class="hlt">determinants</span>. Higher <span class="hlt">concentrations</span> favoured selection of a tetracycline-resistance phenotype along with a decline in the number of detectable transfer events. The described method can be used to evaluate different environmental conditions and factors that trigger horizontal dissemination of mobile resistance elements, eventually resulting in the formation of drug-resistant pathogens.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_16");'>16</a></li> <li><a href="#" onclick='return showDiv("page_17");'>17</a></li> <li class="active"><span>18</span></li> <li><a href="#" onclick='return showDiv("page_19");'>19</a></li> <li><a href="#" onclick='return showDiv("page_20");'>20</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_18 --> <div id="page_19" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_17");'>17</a></li> <li><a href="#" onclick='return showDiv("page_18");'>18</a></li> <li class="active"><span>19</span></li> <li><a href="#" onclick='return showDiv("page_20");'>20</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="361"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015APS..APR.S5004S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015APS..APR.S5004S"><span id="translatedtitle">Redetermining CEBAF's <span class="hlt">Absolute</span> Energy</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Su, Tong; Jlab Marathon Collaboration</p> <p>2015-04-01</p> <p>With the upgrade of the Jefferson Lab accelerator (CEBAF) from 6 GeV max energy to 12 GeV, all the dipole magnets in the machine were refurbished. Most of them were switched from open c-shaped to closed h-shaped by adding extra iron. With these upgraded magnets, the energy calibration of the accelerator needed to be redetermined. We will show how an extra external dipole, which is run in series with those in the machine, helps us cross check the current in the magnets as well as precisely map out the integral field for any machine setting. Using knowledge of the relative performance of the dipoles as well as the bend angle into the Hall, has allowed us to already <span class="hlt">determine</span> a 4th pass 7 GeV beam to better than 7 MeV. In the future, we will use g-2 spin precession as a second independent energy <span class="hlt">determination</span>. This work is supported by Kent State University, NSF Grant PHY-1405814, and DOE Contract DE-AC05-06OR23177 (JLab).</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=19910047599&hterms=H2O2&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D10%26Ntt%3DH2O2','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=19910047599&hterms=H2O2&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D10%26Ntt%3DH2O2"><span id="translatedtitle"><span class="hlt">Absolute</span> linestrengths in the H2O2 nu6 band</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>May, Randy D.</p> <p>1991-01-01</p> <p><span class="hlt">Absolute</span> linestrengths at 295 K have been measured for selected lines in the nu6 band of H2O2 using a tunable diode-laser spectrometer. H2O2 <span class="hlt">concentrations</span> in a flowing gas mixture were <span class="hlt">determined</span> by ultraviolet (uv) absorption at 254 nm using a collinear infrared (ir) and uv optical arrangement. The measured linestrengths are approx. 60 percent larger than previously reported values when absorption by hot bands in H2O2 is taken into account.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/15865194','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/15865194"><span id="translatedtitle">Evaluation of capillary electrophoresis for <span class="hlt">determining</span> the <span class="hlt">concentration</span> of dissolved silica in geothermal brines.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Santoyo, E; García, R; Aparicio, A; Verma, Surendra P; Verma, M P</p> <p>2005-04-15</p> <p>The <span class="hlt">determination</span> of silica <span class="hlt">concentrations</span> in geothermal brines is widely recognized as a difficult analytical task due to its complex chemical polymerization kinetics that occurs during sample collection and chemical analysis. Capillary electrophoresis (CE) has been evaluated as a new reliable analytical method to measure silica (as silicates) in geothermal brines. Synthetic and geothermal brine samples were used to evaluate CE methodology. A capillary electrophoresis instrument, Quanta 4000 (Waters-Millipore) coupled with a Waters 820 workstation was used to carry out the experimental work. The separation of silicates was completed in approximately 5.5 min using a conventional fused-silica capillary (75 microm i.d. x 375 microm o.d. x 60 cm total length). A hydrostatic injection (10 cm for 20 s at 25 degrees C) was employed for introducing the samples. The carrier electrolyte consisted of 10 mM sodium chromate, 3 mM tetradecyltrimethyl-ammonium hydroxide (TTAOH), 2 mM sodium carbonate, and 1 mM sodium hydroxide, adjusted to a pH 11.0 +/- 0.1. Silicates were <span class="hlt">determined</span> using an indirect UV detection at a wavelength of 254 nm with a mercury lamp and with a negative power supply (-15 kV). A good reproducibility in the migration times (%R.S.D. approximately 1.6%) based on six non-consecutive injections of synthetic brine solutions was obtained. A linear response between silica <span class="hlt">concentration</span> and corrected peak area was observed. Ordinary (OLR) and weighted (WLR) linear regression models were used for calculating silica <span class="hlt">concentrations</span> in all samples using the corresponding fitted calibration curves. The analytical results of CE were finally compared with the most probable values of synthetic reference standards of silica using the Student's t-test. No significant differences were found between them at P = 0.01. Similarly, the atomic absorption spectrometry (AAS) results were also compared with the most probable <span class="hlt">concentrations</span> of the same reference standards, finding</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1999HydJ....7..236Y','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1999HydJ....7..236Y"><span id="translatedtitle"><span class="hlt">Determining</span> <span class="hlt">concentration</span> fields of tracer plumes for layered porous media in flow-tank experiments</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Yu, Zhongbo; Schwartz, Franklin W.</p> <p></p> <p>In the laboratory, computer-assisted image analysis provides an accurate and efficient way to monitor tracer experiments. This paper describes the <span class="hlt">determination</span> of detailed temporal <span class="hlt">concentration</span> distributions of tracers in a flow-tank experiment by analyzing photographs of plumes of Rhodamine dye through the glass wall of the tank. The methodology developed for this purpose consists of four steps: (1) digitally scanning black and white negatives obtained from photographs of the flow-tank experiment; (2) calibrating and normalizing each digitized image to a standard optical-density scale by <span class="hlt">determining</span> the relation between the optical density and pixel value for each image; (3) constructing standard curves relating the <span class="hlt">concentration</span> in an optical density from five experimental runs with predetermined <span class="hlt">concentrations</span> (2-97mg/L) and (4) converting the optical density to <span class="hlt">concentration</span>. The spatial distribution of <span class="hlt">concentration</span> for two photographs was <span class="hlt">determined</span> by applying these calibration and conversion procedures to all pixels of the digitized images. This approach provides an efficient way to study patterns of plume evolution and transport mechanisms. Résumé Au laboratoire, l'analyse d'images assistée par ordinateur est un moyen précis et efficace pour suivre certaines expériences de traçage. Ce papier présente comment sont déterminées dans le détail les distributions temporelles de la <span class="hlt">concentration</span> en traceur au cours d'une expérience d'écoulement en réservoir au moyen de l'analyse de photographies de panaches de rhodamine à travers la paroi de verre du réservoir. La méthodologie développée dans cette expérience suit quatre étapes: (1) digitalisation par balayage des négatifs noir et blanc des prises de vue de l'expérience d'écoulement en réservoir (2) calibration et normalisation de chaque image digitalisée par rapport à une échelle étalon de densité optique en déterminant la relation entre la densité optique et la valeur des pixels</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016SPIE.9694E..0DK','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016SPIE.9694E..0DK"><span id="translatedtitle"><span class="hlt">Determination</span> of the low <span class="hlt">concentration</span> correction in the macroscopic singlet oxygen model for PDT</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Kim, Michele M.; Penjweini, Rozhin; Finlay, Jarod C.; Zhu, Timothy C.</p> <p>2016-03-01</p> <p>The macroscopic singlet oxygen model has been used for singlet oxygen explicit dosimetry in photodynamic therapy (PDT). The photophysical parameters for commonly used sensitizers, HPPH and BPD, have been investigated in pre-clinical studies using mouse models. So far, studies have involved optimizing fitting algorithms to obtain the some of the photophysical parameters (ξ, σ, g) and the threshold singlet oxygen dose ([1O2]rx,sh), while other parameters such as the low <span class="hlt">concentration</span> correction, δ, has been kept as a constant. In this study, using photobleaching measurements of mice in vivo, the value of δ was also optimized and fit to better describe experimental data. Furthermore, the value of the specific photobleaching ratio (σ) was also fine-tuned using the photobleaching results. Based on literature values of δ, σ for photosensitizers can be uniquely <span class="hlt">determined</span> using the additional photobleaching measurements. This routine will further improve the macroscopic model of singlet oxygen production for use in explicit dosimetry.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://pubs.er.usgs.gov/publication/70006789','USGSPUBS'); return false;" href="http://pubs.er.usgs.gov/publication/70006789"><span id="translatedtitle">Rapid method for <span class="hlt">determining</span> <span class="hlt">concentrations</span> of Bayer 73 in water during lampricide treatments</span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Dawson, V.K.; Harman, P.D.; Schultz, D.P.; Allen, J.L.</p> <p>1978-01-01</p> <p>Two simple, rapid, sensitive methods were developed for <span class="hlt">determining</span> the <span class="hlt">concentration</span> of the lampricide 2',5-dichloro-4'-nitrosalicylanilide (Bayer 73) in stream water. Bayer 73 was extracted from acidified water samples with chloroform and then hydrolyzed to 2-chloro-4-nitroaniline (CNA) with either acid or base. The CNA was diazotized with sodium nitrite, and an azo dye was formed with either N-( 1-naphthyl) ethylenediamine dihydrochloride (after acid hydrolysis) or 1-naphthol (after base hydrolysis). There was no interference from the lampricide 3-trifluoromethyl-4-nitrophenol (TFM) in either method. Standard curves were prepared with untreated water to compensate for interfering substances that occurred naturally in some streams. The methods were sensitive to about 0.005 mg/L (ppm). Time required for analysis of a sample ranged from 25 min to 1 h.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/12911150','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/12911150"><span id="translatedtitle">Uncertainty estimation in chemical measurements: carbon dioxide <span class="hlt">determination</span> at atmospheric <span class="hlt">concentration</span>.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Amico Di Meane, Elena; Sega, Michela</p> <p>2003-01-01</p> <p>The present work deals with the evaluation of measurement uncertainty in the <span class="hlt">determination</span> of carbon dioxide (CO2) <span class="hlt">concentration</span> in atmosphere, given the high relevance of this greenhouse gas that influences earth climate. In order to carry out CO2 measurements, non dispersive infrared (NDIR) analysers are usually employed as they are stable and scarcely affected by interferences from other air components or pollutants. Typical uncertainty sources are the resolution of the analyser, its time drift and the contributions due to instrument calibration, which is required in order to produce traceable measurement results. The calibration uncertainty takes into account the uncertainty of the composition of the calibration gas mixtures, the instrument repeatability and the possible or residual lack of fit of the adopted mathematical model.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/10185825','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/10185825"><span id="translatedtitle"><span class="hlt">Determination</span> of the <span class="hlt">concentration</span> and isotopic composition of uranium in environmental air filters</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Russ, G.P. III; Bazan, J.M.</p> <p>1994-08-26</p> <p>For many years, Lawrence Livermore National Laboratory has collected monthly air-particulate filter samples from a variety of environmental monitoring stations on and off site. Historically the <span class="hlt">concentration</span> and isotopic composition of uranium collected on these filters was <span class="hlt">determined</span> by isotope dilution using a {sup 233}U spike and thermal ionization mass spectrometry (TIMS). For samples containing as little as 10 nanograms of uranium, ICP-MS is now used to make these measurements to the required level of precision, about 5% in the measured 235/238 and 233/238. Unless particular care is taken to control bias in the mass filter, variable mass bias limits accuracy to a few percent. Measurements of the minor isotopes 236 (if present) and 234 are also possible and provide useful information for identifying the source of the uranium. The advantage of ICP-MS is in rapid analysis, {approximately}12 minutes of instrument time per sample.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/5978735','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/5978735"><span id="translatedtitle">Radiometric method for <span class="hlt">determining</span> <span class="hlt">concentration</span> of naturally occurring isotopes and device therefor</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Yakubovich, S.L.; Gerling, V.E.; Golubnichy, V.V.; Kotsen, M.E.; Stepanov, J.N.</p> <p>1984-10-09</p> <p>The proposed method essentially consists in that a sample of a substance is placed between two scintillators in immediate contact therewith whereupon said sample is hermetically sealed. Arranged in close proximity to each scintillator is a photomultiplier tube recording ionizing ..cap alpha..- and b-radiation. A selector is utilized to select pulses corresponding to ..cap alpha..- and b-particles, and delayed coincidence circuits of a recording element separate and record b-..cap alpha.. and ..cap alpha..-..cap alpha.. cascade pairs of delayed coincidences of RaC, ThC, and AcA radionuclides. Flows are measured twice at a predetermined time interval to account for emanation build-up tendency and <span class="hlt">concentration</span> of isotopes of radium is <span class="hlt">determined</span> from a formula.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20080023613','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20080023613"><span id="translatedtitle">Method and system for fiber optic <span class="hlt">determination</span> of gas <span class="hlt">concentrations</span> in liquid receptacles</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Nguyen, Quang-Viet (Inventor)</p> <p>2008-01-01</p> <p>A system for <span class="hlt">determining</span> gas compositions includes a probe, inserted into a source of gaseous material, the probe having a gas permeable sensor tip and being capable of sending and receiving light to and from the gaseous material, a sensor body, connected to the probe, situated outside of the source and a fiber bundle, connected to the sensor body and communicating light to and from the probe. The system also includes a laser source, connected to one portion of the fiber bundle and providing laser light to the fiber bundle and the probe a Raman spectrograph, connected to another portion of the fiber bundle, receiving light from the probe and filtering the received light into specific channels and a data processing unit, receiving and analyzing the received light in the specific channels and outputting <span class="hlt">concentration</span> of specific gas species in the gaseous material based on the analyzed received light.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016MeScT..27k7002R','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016MeScT..27k7002R"><span id="translatedtitle"><span class="hlt">Absolute</span> and relative emissions analysis in practical combustion systems—effect of water vapor condensation</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Richter, J. P.; Mollendorf, J. C.; DesJardin, P. E.</p> <p>2016-11-01</p> <p>Accurate knowledge of the <span class="hlt">absolute</span> combustion gas composition is necessary in the automotive, aircraft, processing, heating and air conditioning industries where emissions reduction is a major concern. Those industries use a variety of sensor technologies. Many of these sensors are used to analyze the gas by pumping a sample through a system of tubes to reach a remote sensor location. An inherent characteristic with this type of sampling strategy is that the mixture state changes as the sample is drawn towards the sensor. Specifically, temperature and humidity changes can be significant, resulting in a very different gas mixture at the sensor interface compared with the in situ location (water vapor dilution effect). Consequently, the gas <span class="hlt">concentrations</span> obtained from remotely sampled gas analyzers can be significantly different than in situ values. In this study, inherent errors associated with sampled combustion gas <span class="hlt">concentration</span> measurements are explored, and a correction methodology is presented to <span class="hlt">determine</span> the <span class="hlt">absolute</span> gas composition from remotely measured gas species <span class="hlt">concentrations</span>. For in situ (wet) measurements a heated zirconium dioxide (ZrO2) oxygen sensor (Bosch LSU 4.9) is used to measure the <span class="hlt">absolute</span> oxygen <span class="hlt">concentration</span>. This is used to correct the remotely sampled (dry) measurements taken with an electrochemical sensor within the remote analyzer (Testo 330-2LL). In this study, such a correction is experimentally validated for a specified <span class="hlt">concentration</span> of carbon monoxide (5020 ppmv).</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/26091617','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/26091617"><span id="translatedtitle">Interferences of resveratrol with fura-2-derived fluorescence in intracellular free-Ca(2+) <span class="hlt">concentration</span> <span class="hlt">determinations</span>.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Santofimia-Castaño, Patricia; Salido, Gines M; Gonzalez, Antonio</p> <p>2016-08-01</p> <p>Resveratrol (3,4',5-trihydroxy-trans-stilbene) is an antioxidant widely employed in cell physiology studies. It has been reported that it interferes with fura-2-derived fluorescence, making the employment of this dye nonviable. In this work, the interference of resveratrol with fura-2 <span class="hlt">determinations</span> of intracellular free-Ca(2+) <span class="hlt">concentration</span> ([Ca(2+)]c) was examined. Solutions containing different <span class="hlt">concentrations</span> of resveratrol, with or without fura-2, in the presence or in the absence of Ca(2+), were analyzed by spectrofluorimetry. AR42J tumor cells were employed to study the influence of resveratrol on fura-2 fluorescence in living cells, by single cell fluorimetry. Resveratrol impaired the detection of fura-2-fluorescence emission (510 nm) at the 340, 360 and 380 nm excitation wavelengths. Resveratrol emitted fluorescence at 510 nm when lighted at all three excitation wavelengths. In addition, resveratrol emitted fluorescence at 380 nm when excited at 340 nm. Our observations suggest that the employment of the ratiometric properties of fura-2 to follow changes in [Ca(2+)]c in the presence of resveratrol is not viable. However, we think that the 380 nm excitation light could be employed. Results could be expressed as F0/F380, where F0 is the resting fluorescence and F380 is the value of fluoresce at a certain time point. We could follow changes in [Ca(2+)]c evoked by CCK-8, and we also detected Ca(2+) mobilization by 100 µM resveratrol in AR42J cells. This investigation presents evidence demonstrating that resveratrol interferes with fura-2 fluorescence spectra. Nevertheless, a chance still exists if the 380 nm excitation wavelength is employed in the middle or low micromolar <span class="hlt">concentrations</span> of resveratrol.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/2760817','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/2760817"><span id="translatedtitle">Relationship between <span class="hlt">concentration</span> and anticonvulsant effect of phenytoin against electroshock-induced seizures in rats: comparison of sampling sites for <span class="hlt">concentration</span> <span class="hlt">determinations</span>.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Ramzan, I; Levy, G</p> <p>1989-06-01</p> <p>The purpose of this investigation was to <span class="hlt">determine</span> the optimum sampling site for phenytoin <span class="hlt">concentration</span> measurements in the context of pharmacodynamic studies of the anticonvulsant effect of phenytoin. <span class="hlt">Determination</span> of drug <span class="hlt">concentrations</span> in the serum, serum water, brain, and cerebrospinal fluid (CSF) of rats as a function of time after iv injection of a 6-mg/kg dose revealed a significant disequilibrium between brain and serum water for 15 min and between CSF and serum water for 5 min after injection. The <span class="hlt">concentrations</span> of phenytoin in serum water 1 min after injection of 3 mg/kg (0.371 +/- 0.054 microgram/mL) and 45 min after injection of 8 mg/kg (0.399 +/- 0.049 microgram/mL) were not significantly different, but drug <span class="hlt">concentrations</span> in the CSF and brain were appreciably higher after the latter dose. There was no protection against electroshock-induced seizures 1 min after the 3-mg/kg dose, but there was complete protection 45 min after the 8-mg/kg dose. At 15 min after drug injection, phenytoin <span class="hlt">concentrations</span> in CSF and serum water were essentially identical over a wide <span class="hlt">concentration</span> range. Fifty female Lewis rats weighing approximately 225 g, that consistently exhibited maximal electroshock-induced seizures in three preliminary trials on separate days, received 1, 2, 4, 6, or 8 mg/kg of phenytoin by iv injection. Electroshock was applied 15 min later, the percentage of animals protected from seizure by each dose was <span class="hlt">determined</span>, and drug <span class="hlt">concentrations</span> in serum, serum water, brain, and CSF were measured by gas chromatography. The relationship between anticonvulsant activity and drug <span class="hlt">concentration</span> could be described by a Hill-type equation.(ABSTRACT TRUNCATED AT 250 WORDS)</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/19148607','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/19148607"><span id="translatedtitle"><span class="hlt">Determination</span> of collagen content, <span class="hlt">concentration</span>, and sub-types in kidney tissue.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Samuel, Chrishan S</p> <p>2009-01-01</p> <p>Fibrosis and sclerosis are widely recognized as hallmarks of progressive renal disease and are caused by the excessive accumulation of connective tissue, mostly collagen. The detection of collagen content, <span class="hlt">concentration</span> (collagen content/dry weight tissue), and sub-types from kidney tissues is therefore an important part of <span class="hlt">determining</span> the extent of renal fibrosis in ageing and diseased states. This chapter describes a colorimetric-based hydroxyproline assay used to estimate total collagen content and <span class="hlt">concentration</span>. Based on the method of Bergman and Loxley (8), this spectrophotometric technique estimates total collagen by measuring the hydroxyproline content of tissue. The assay relies on the fact that the collagen triple helix is one of the few proteins that contain the amino acid hydroxyproline. The second part of this chapter describes the use of sodium dodecyl sulfate (SDS) polyacrylamide gel electrophoresis (PAGE) to isolate, detect and quantify changes in the soluble and insoluble interstitial collagen sub-types. This technique complements the hydroxyproline assay by providing a means of identifying which interstitial collagens are altered in renal disease.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/27476381','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/27476381"><span id="translatedtitle">Transient Method for <span class="hlt">Determining</span> Indoor Chemical <span class="hlt">Concentrations</span> Based on SPME: Model Development and Calibration.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Cao, Jianping; Xiong, Jianyin; Wang, Lixin; Xu, Ying; Zhang, Yinping</p> <p>2016-09-01</p> <p>Solid-phase microextraction (SPME) is regarded as a nonexhaustive sampling technique with a smaller extraction volume and a shorter extraction time than traditional sampling techniques and is hence widely used. The SPME sampling process is affected by the convection or diffusion effect along the coating surface, but this factor has seldom been studied. This paper derives an analytical model to characterize SPME sampling for semivolatile organic compounds (SVOCs) as well as for volatile organic compounds (VOCs) by considering the surface mass transfer process. Using this model, the chemical <span class="hlt">concentrations</span> in a sample matrix can be conveniently calculated. In addition, the model can be used to <span class="hlt">determine</span> the characteristic parameters (partition coefficient and diffusion coefficient) for typical SPME chemical samplings (SPME calibration). Experiments using SPME samplings of two typical SVOCs, dibutyl phthalate (DBP) in sealed chamber and di(2-ethylhexyl) phthalate (DEHP) in ventilated chamber, were performed to measure the two characteristic parameters. The experimental results demonstrated the effectiveness of the model and calibration method. Experimental data from the literature (VOCs sampled by SPME) were used to further validate the model. This study should prove useful for relatively rapid quantification of <span class="hlt">concentrations</span> of different chemicals in various circumstances with SPME. PMID:27476381</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/25982547','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/25982547"><span id="translatedtitle">Pollutant threshold <span class="hlt">concentration</span> <span class="hlt">determination</span> in marine ecosystems using an ecological interaction endpoint.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Wang, Changyou; Liang, Shengkang; Guo, Wenting; Yu, Hua; Xing, Wenhui</p> <p>2015-09-01</p> <p>The threshold <span class="hlt">concentrations</span> of pollutants are <span class="hlt">determined</span> by extrapolating single-species effect data to community-level effects. This assumes the most sensitive endpoint of the life cycle of individuals and the species sensitivity distribution from single-species toxic effect tests, thus, ignoring the ecological interactions. The uncertainties due to this extrapolation can be partially overcome using the equilibrium point of a customized ecosystem. This method incorporates ecological interactions and integrates the effects on growth, survival, and ingestion into a single effect measure, the equilibrium point excursion in the customized ecosystem, in order to describe the toxic effects on plankton. A case study showed that the threshold <span class="hlt">concentration</span> of copper calculated with the endpoint of the equilibrium point was 10 μg L(-1), which is significantly different from the threshold calculated with a single-species endpoint. The endpoint calculated using this method provides a more relevant measure of the ecological impact than any single individual-level endpoint. PMID:25982547</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/25369723','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/25369723"><span id="translatedtitle"><span class="hlt">Determinants</span> of health <span class="hlt">concentration</span> selection among University of Southern California MSW students.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Mitchell, Keyon R; Joosten, Dawn Marie</p> <p>2014-11-01</p> <p>By 2020, health care social workers are projected to make up 25 percent of the entire number of professional social workers in the United States. At the University of Southern California, the number of graduate students selecting the health social work <span class="hlt">concentration</span> has increased exponentially over the last five years. Although there are no published findings to indicate that other schools of social work are experiencing a similar trend, the Bureau of Labor Statistics has reported that, nationally, the number of social workers employed in health care has increased and is projected to continue increasing over the next decade. The purpose of this study was to identify decision-making <span class="hlt">determinants</span> of MSW students pursuing a specific vocational interest in health care settings. The study used a questionnaire to gather quantitative and qualitative data from a population of MSW students. The findings suggest that graduate students select the health <span class="hlt">concentration</span> based on self-knowledge (abilities and interests) and vocational knowledge (job demands and labor market). This article concludes with a discussion of the implications of these findings for health social work curriculums, practice, research, policy, and the integral role social workers play in health care reform in the present and will play in the future.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://pubs.er.usgs.gov/publication/70006539','USGSPUBS'); return false;" href="http://pubs.er.usgs.gov/publication/70006539"><span id="translatedtitle">Liquid chromatographic method for <span class="hlt">determining</span> the <span class="hlt">concentration</span> of bisazir in water</span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Scholefield, Ronald J.; Slaght, Karen S.; Allen, John L.</p> <p>1997-01-01</p> <p>Barrier dams, traps, and lampricides are the techniques currently used by the Great Lakes Fishery Commission to control sea lampreys (Petromyzon marinus) in the Great Lakes. To augment these control techniques, a sterile-male-release research program was initiated at the Lake Huron Biological Station. Male sea lampreys were sterilized by intraperitoneal injection of the chemical sterilant P,P-bis(1-aziridinyl)-N-methylphosphinothioic amide (bisazir). An analytical method was needed to quantitate the <span class="hlt">concentration</span> of bisazir in water and to routinely verify that bisazir (>25 μg/L) does not persist in the treated effluent discharged from the sterilization facility to Lake Huron. A rapid, accurate, and sensitive liquid chromatographic (LC) method was developed for <span class="hlt">determining</span> bisazir in water. Bisazir was dissolved in Lake Huron water; extracted and <span class="hlt">concentrated</span> on a C18 solid-phase extraction column; eluted with methanol; and quantitated by reversed-phase LC using a C18 column, a mobile phase of 70% water and 30% methanol (v/v), and UV detection (205 nm). Bisazir retention time was 7-8 min; total run time was about 20 min. Method detection limit for bisazir dissolved in Lake Huron water was about 15 μg/L. Recovery from Lake Huron water fortified with bisazir at 100 μg/L was 94% (95% confidence interval, 90.2-98.2%).</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016SPIE.9705E..0GA','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016SPIE.9705E..0GA"><span id="translatedtitle">Advances towards reliable identification and <span class="hlt">concentration</span> <span class="hlt">determination</span> of rare cells in peripheral blood</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Alemany Server, R.; Martens, D.; Jans, K.; Bienstman, P.; Hill, D.</p> <p>2016-03-01</p> <p>Through further development, integration and validation of micro-nano-bio and biophotonics systems FP7 CanDo is developing an instrument that will permit highly reproducible and reliable identification and <span class="hlt">concentration</span> <span class="hlt">determination</span> of rare cells in peripheral blood for two key societal challenges, early and low cost anti-cancer drug efficacy <span class="hlt">determination</span> and cancer diagnosis/monitoring. A cellular link between the primary malignant tumour and the peripheral metastases, responsible for 90% of cancerrelated deaths, has been established in the form of circulating tumour cells (CTCs) in peripheral blood. Furthermore, the relatively short survival time of CTCs in peripheral blood means that their detection is indicative of tumour progression thereby providing in addition to a prognostic value an evaluation of therapeutic efficacy and early recognition of tumour progression in theranostics. In cancer patients however blood <span class="hlt">concentrations</span> are very low (=1 CTC/1E9 cells) and current detection strategies are too insensitive, limiting use to prognosis of only those with advanced metastatic cancer. Similarly, problems occur in therapeutics with anti-cancer drug development leading to lengthy and costly trials often preventing access to market. The novel cell separation/Raman analysis technologies plus nucleic acid based molecular characterization of the CanDo platform will provide an accurate CTC count with high throughput and high yield meeting both key societal challenges. Being beyond the state of art it will lead to substantial share gains not just in the high end markets of drug discovery and cancer diagnostics but due to modular technologies also in others. Here we present preliminary DNA hybridization sensing results.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/22020391','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/22020391"><span id="translatedtitle">Methane emission from naturally ventilated livestock buildings can be <span class="hlt">determined</span> from gas <span class="hlt">concentration</span> measurements.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Bjerg, Bjarne; Zhang, Guoqiang; Madsen, Jørgen; Rom, Hans B</p> <p>2012-10-01</p> <p><span class="hlt">Determination</span> of emission of contaminant gases as ammonia, methane, or laughing gas from natural ventilated livestock buildings with large opening is a challenge due to the large variations in gas <span class="hlt">concentration</span> and air velocity in the openings. The close relation between calculated animal heat production and the carbon dioxide production from the animals have in several cases been utilized for estimation of the ventilation air exchange rate for the estimation of ammonia and greenhouse gas emissions. Using this method, the problem of the complicated air velocity and <span class="hlt">concentration</span> distribution in the openings is avoided; however, there are still some important issues remained unanswered: (1) the precision of the estimations, (2) the requirement for the length of measuring periods, and (3) the required measuring point number and location. The purpose of this work was to investigate how estimated average gas emission and the precision of the estimation are influenced by different calculation procedures, measuring period length, measure point locations, measure point numbers, and criteria for excluding measuring data. The analyses were based on existing data from a 6-day measuring period in a naturally ventilated, 150 milking cow building. The results showed that the methane emission can be <span class="hlt">determined</span> with much higher precision than ammonia or laughing gas emissions, and, for methane, relatively precise estimations can be based on measure periods as short as 3 h. This result makes it feasible to investigate the influence of feed composition on methane emission in a relative large number of operating cattle buildings and consequently it can support a development towards reduced greenhouse gas emission from cattle production. PMID:22020391</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_17");'>17</a></li> <li><a href="#" onclick='return showDiv("page_18");'>18</a></li> <li class="active"><span>19</span></li> <li><a href="#" onclick='return showDiv("page_20");'>20</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_19 --> <div id="page_20" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_18");'>18</a></li> <li><a href="#" onclick='return showDiv("page_19");'>19</a></li> <li class="active"><span>20</span></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="381"> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/23265466','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/23265466"><span id="translatedtitle">Development of novel potentiometric sensors for <span class="hlt">determination</span> of tartrazine dye <span class="hlt">concentration</span> in foodstuff products.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Abu Shawish, Hazem M; Ghalwa, Nasser Abu; Saadeh, Salman M; El Harazeen, Heba</p> <p>2013-05-01</p> <p>Tartrazine dye Na(3)TZ in foodstuff products was <span class="hlt">determined</span> by a new modified carbon paste electrode, encoded sensor A, and a coated silver wire electrode, encoded sensor B, based on tartrazine TZ- cetryltrimethyl ammoniumbromide CTAB as a chemical modifier TZ-CTA. The electrodes exhibit the following characteristics listed respectively: a Nernstian slope of 17.9±0.5 and 19.4±0.2 mV/decade for tartrazine ion over a wide <span class="hlt">concentration</span> range from 4.3×10(-7) to 1.0×10(-2) and 1.1×10(-7) to 1.0×10(-2) M. The lower detection limits: 3.2×10(-7) and 5.5×10(-8) M. Short response time (5-8 s) over the pH range 3.8-7.7 and 4.2-8.1. The proposed sensors display significantly high selectivity for TZ ion over a wide variety of sugars, some anions, common organic, inorganic compounds and additives. The developed electrodes were applied to the potentiometric <span class="hlt">determination</span> of tartrazine ion in different kinds of foodstuffs: solid jelly (strawberry and custard) powder samples and soft drink (orange) samples with satisfactory results.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2011Nanot..22x5105C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2011Nanot..22x5105C"><span id="translatedtitle">Human haptoglobin phenotypes and <span class="hlt">concentration</span> <span class="hlt">determination</span> by nanogold-enhanced electrochemical impedance spectroscopy</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Cheng, Tsai-Mu; Lee, Tzu-Cheng; Tseng, Shin-Hua; Chu, Hsueh-Liang; Pan, Ju-Pin; Chang, Chia-Ching</p> <p>2011-06-01</p> <p>Haptoglobin (Hp) is an acute phase protein that binds free hemoglobin (Hb), preventing Hb-induced oxidative damage in the vascular system. There are three phenotypes in human Hp, whose heterogeneous polymorphic structures and varying <span class="hlt">concentrations</span> in plasma have been attributed to the cause of diseases and outcome of clinical treatments. Different phenotypes of Hp may be composed of the same subunits but different copy numbers, rendering their <span class="hlt">determination</span> difficult by a single procedure. In this study, we have developed a simple, fast, reliable and sensitive method, using label-free nanogold-modified bioprobes coupled with self-development electrochemical impedance spectroscopy (EIS). By this method, probe surface charge transfer resistance is detected. The relative charge transfer resistance ratios for Hp 1-1, Hp 2-1 and Hp 2-2 were characterized. We were able to <span class="hlt">determine</span> protein size difference within 3 nm, and the linear region of the calibration curve for Hp levels in the range of 90 pg ml - 1 and 90 µg ml - 1 (~1 fM to 1 pM). We surmise that similar approaches can be used to investigate protein polymorphism and altered protein-protein interaction associated with diseases.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/26259834','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/26259834"><span id="translatedtitle"><span class="hlt">Determination</span> of iron in drinking water after its flotation <span class="hlt">concentration</span> by two new dithiocarbamate collectors.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Pavlovska, Gorica; Stafilov, Trajče; Čundeva, Katarina</p> <p>2015-01-01</p> <p>Two new methods for the <span class="hlt">determination</span> of iron by atomic absorption spectrometry (AAS) are proposed for drinking water. The <span class="hlt">determination</span> was made after flotation <span class="hlt">concentration</span> of Fe by using of two new flotation collectors: lead(II) heptyldithiocarbamate, Pb(HpDTC)2 and cobalt(III) heptyldithiocarbamate Co(HpDTC)3. All important parameters for the two proposed procedures were optimised (pH, mass of Pb, mass of Co, amount of HpDTC(-), type of surfactant, induction time, etc.). Flotation recovery (R) of Fe was very high (from 94.4 to 104.4%) for the two proposed procedures. The detection limit of the methods was 2.17 μg L(-1) for Pb(HpDTC)2 and 2.39 μg L(-1) for Co(HpDTC)3, respectively. The proposed methods have been applied for the analysis of five samples of drinking water. The acquired AAS results for Fe by both new methods were compared with those obtained by inductively coupled plasma-atomic emission spectrometry (AES-ICP). It is shown that they are in good agreement. The results are also confirmed by the method of standard additions.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016PCE....94....2A','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016PCE....94....2A"><span id="translatedtitle"><span class="hlt">Determination</span> of background <span class="hlt">concentrations</span> of hydrochemical parameters and water quality assessment in the Akhuryan River Basin (Armenia)</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Arpine, Hovhannisyan; Gayane, Shahnazaryan</p> <p>2016-08-01</p> <p>The <span class="hlt">determination</span> of background values of hydrochemical parameters, to distinguish between natural <span class="hlt">concentration</span> and anthropogenically-influenced <span class="hlt">concentrations</span>, is highly relevant. In presented study, to estimate the background values of hydrochemical parameters in Akhuryan River Basin, log-normal probability functions on the hydrochemical parameters <span class="hlt">concentrations</span> was applied. The study is carried out on the basis of hydrochemical data of surface water quality monitoring for the period of 2010-2013. This study highlights the usefulness of application of site-specific background <span class="hlt">concentrations</span> for the evaluation, interpretation of surface water quality and for <span class="hlt">determination</span> of pollution sources.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/25691399','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/25691399"><span id="translatedtitle">On Using Model Populations to <span class="hlt">Determine</span> Mechanical Properties of Skeletal Muscle. Application to <span class="hlt">Concentric</span> Contraction Simulation.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Sierra, M; Miana-Mena, F J; Calvo, B; Muñoz, M J; Rodríguez, J F; Grasa, J</p> <p>2015-10-01</p> <p>In the field of computational biomechanics, the experimental evaluation of the material properties is crucial for the development of computational models that closely reproduce real organ systems. When simulations of muscle tissue are concerned, stress/strain relations for both passive and active behavior are required. These experimental relations usually exhibit certain variability. In this study, a set of material parameters involved in a 3D skeletal muscle model are <span class="hlt">determined</span> by using a system biology approach in which the parameters are randomly varied leading to a population of models. Using a set of experimental results from an animal model, a subset of the entire population of models was selected. This reduced population predicted the mechanical response within the window of experimental observations. Hence, a range of model parameters, instead of a single set of them, was <span class="hlt">determined</span>. Rat Tibialis Anterior muscle was selected for this study. Muscles ([Formula: see text]) were activated through the sciatic nerve and during contraction the tissue pulled a weight fixed to the distal tendon (<span class="hlt">concentric</span> contraction). Three different weights 1, 2 and 3 N were used and the time course of muscle stretch was analyzed obtaining values of (mean [Formula: see text] standard deviation): [Formula: see text], [Formula: see text] and [Formula: see text] respectively. A paired two-sided sign rank test showed significant differences between the muscle response for the three weights ([Formula: see text]). This study shows that the Monte Carlo method could be used for <span class="hlt">determine</span> muscle characteristic parameters considering the variability of the experimental population.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/7023362','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/7023362"><span id="translatedtitle"><span class="hlt">Absolute</span> flux scale for radioastronomy</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Ivanov, V.P.; Stankevich, K.S.</p> <p>1986-07-01</p> <p>The authors propose and provide support for a new <span class="hlt">absolute</span> flux scale for radio astronomy, which is not encumbered with the inadequacies of the previous scales. In constructing it the method of relative spectra was used (a powerful tool for choosing reference spectra). A review is given of previous flux scales. The authors compare the AIS scale with the scale they propose. Both scales are based on <span class="hlt">absolute</span> measurements by the ''artificial moon'' method, and they are practically coincident in the range from 0.96 to 6 GHz. At frequencies above 6 GHz, 0.96 GHz, the AIS scale is overestimated because of incorrect extrapolation of the spectra of the primary and secondary standards. The major results which have emerged from this review of <span class="hlt">absolute</span> scales in radio astronomy are summarized.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/19621754','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/19621754"><span id="translatedtitle">[Effect of ligand <span class="hlt">concentration</span> on the precision of <span class="hlt">determining</span> the parameters of ligand-receptor interaction by serial dilution methods].</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Bobrovnik, S A</p> <p>2004-01-01</p> <p>Earlier we suggested the method of serial dilution, which allows one to <span class="hlt">determine</span> the parameters of ligand-receptor interaction even if the reactants are in a mixture and their <span class="hlt">concentrations</span> are unknown. The method is especially useful if the liability of studied receptor does not allow its separation from corresponding ligand. The important prerequisite of the method's precision is that the <span class="hlt">concentration</span> of the ligand should be sufficiently high comparing to the <span class="hlt">concentration</span> of the receptor. In the present paper it was demonstrated that the method allows one to obtain sufficiently good precision even in the case when the <span class="hlt">concentration</span> of the ligand is only one tenth of the receptor <span class="hlt">concentration</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=19750063653&hterms=VALUE+ABSOLUTE&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D80%26Ntt%3DVALUE%2BABSOLUTE','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=19750063653&hterms=VALUE+ABSOLUTE&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D80%26Ntt%3DVALUE%2BABSOLUTE"><span id="translatedtitle"><span class="hlt">Absolute</span> radiometry and the solar constant</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Willson, R. C.</p> <p>1974-01-01</p> <p>A series of active cavity radiometers (ACRs) are described which have been developed as standard detectors for the accurate measurement of irradiance in <span class="hlt">absolute</span> units. It is noted that the ACR is an electrical substitution calorimeter, is designed for automatic remote operation in any environment, and can make irradiance measurements in the range from low-level IR fluxes up to 30 solar constants with small <span class="hlt">absolute</span> uncertainty. The instrument operates in a differential mode by chopping the radiant flux to be measured at a slow rate, and irradiance is <span class="hlt">determined</span> from two electrical power measurements together with the instrumental constant. Results are reported for measurements of the solar constant with two types of ACRs. The more accurate measurement yielded a value of 136.6 plus or minus 0.7 mW/sq cm (1.958 plus or minus 0.010 cal/sq cm per min).</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/22218280','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/22218280"><span id="translatedtitle"><span class="hlt">Absolute</span> and relative dosimetry for ELIMED</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Cirrone, G. A. P.; Schillaci, F.; Scuderi, V.; Cuttone, G.; Candiano, G.; Musumarra, A.; Pisciotta, P.; Romano, F.; Carpinelli, M.; Presti, D. Lo; Raffaele, L.; Tramontana, A.; Cirio, R.; Sacchi, R.; Monaco, V.; Marchetto, F.; Giordanengo, S.</p> <p>2013-07-26</p> <p>The definition of detectors, methods and procedures for the <span class="hlt">absolute</span> and relative dosimetry of laser-driven proton beams is a crucial step toward the clinical use of this new kind of beams. Hence, one of the ELIMED task, will be the definition of procedures aiming to obtain an <span class="hlt">absolute</span> dose measure at the end of the transport beamline with an accuracy as close as possible to the one required for clinical applications (i.e. of the order of 5% or less). Relative dosimetry procedures must be established, as well: they are necessary in order to <span class="hlt">determine</span> and verify the beam dose distributions and to monitor the beam fluence and the energetic spectra during irradiations. Radiochromic films, CR39, Faraday Cup, Secondary Emission Monitor (SEM) and transmission ionization chamber will be considered, designed and studied in order to perform a fully dosimetric characterization of the ELIMED proton beam.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015SPIE.9319E..1NP','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015SPIE.9319E..1NP"><span id="translatedtitle">Utilizing an open-microcavity optoacoustic sensor for spectroscopic <span class="hlt">determination</span> of methemoglobin <span class="hlt">concentration</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Peterson, Ralph W.; Kadugodinandareddy, Kavya; Karunakaran, Vinitha; Whitney, Casey; Ling, Jian; Ye, Jing Yong</p> <p>2015-03-01</p> <p>We present a simple, non-destructive photoacoustic spectroscopy method utilizing a unique open-microcavity optoacoustic sensor to measure the <span class="hlt">concentration</span> ratio of Methemoglobin (MetHb) in an optically scattering medium. Elevated levels of MetHb, present for example in the blood disorder Methemeglobinemia, cannot be detected by conventional pulse oximetry, and may result in inaccurate arterial oxygen saturation measurements. Samples with different ratios of Oxygenated Hemoglobin (HbO2), Deoxygenated Hemoglobin (HHb), and MetHb were obtained and mixed with nanoscale latex beads to present an optical scattering effect. Polymer encapsulated hemoglobin (PEH) samples were also studied. A sample chamber containing 20 μL of each sample was positioned directly underneath our patented optoacoustic sensor. Unlike a piezoelectric transducer, our optoacoustic sensor allows an excitation laser beam from an OPO laser to pass through and be absorbed by the sample to produce a photoacoustic signal. The cavity layer of the optoacoustic sensor is exposed directly to the resulting ultrasound signal, which causes an intensity modulation of a HeNe laser that is used to monitor the resonance condition of the sensor. A probe laser beam is total internally reflected off of the sensor and detected with a fiber-coupled APD detector. Three wavelengths are chosen for our excitation laser based on the absorption peaks and isobestic points of HHb, HbO2, and MetHb. Using established values of the molar extinction coefficients of HbO2, HHb, and MetHb a set of three simultaneous equations can be solved to accurately <span class="hlt">determine</span> the <span class="hlt">concentration</span> ratio of MetHb.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=1388767','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=1388767"><span id="translatedtitle">Use of Solid-Phase Extraction To <span class="hlt">Determine</span> Ergosterol <span class="hlt">Concentrations</span> in Plant Tissue Colonized by Fungi</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Gessner, M. O.; Schmitt, A. L.</p> <p>1996-01-01</p> <p>At present, the ergosterol and acetate-to-ergosterol techniques are generally considered to be the methods of choice to quantify fungal biomass, growth rate, and productivity under natural conditions. Both methods rely on the accurate isolation and quantification of ergosterol, a major membrane component of eumycotic fungi. Taking advantage of the solid-phase extraction (SPE) technique, we present a novel method to <span class="hlt">determine</span> the ergosterol <span class="hlt">concentration</span> in lipid extracts derived from plant tissues and dead organic matter colonized by fungi. In this method, a primary alkaline extract is acidified and passed through a reversed-phase (C(inf18)) SPE column. The column is then washed with an alkaline methanol-water solution to eliminate interfering substances and increase pH and is thoroughly dried in air. Ergosterol is eluted with alkaline isopropanol. This eluting solvent was chosen to produce a strongly basic pH of the final extract and thus confer stability on the ergosterol molecule before high-performance liquid chromatography analysis. The recovery of ergosterol from plant tissues and the O(infhf) horizon of a woodland soil ranged from 85 to 98%, and the overall extraction efficiency was similar to that obtained by a conventional procedure involving liquid-liquid extraction. Potential pitfalls of ergosterol analysis by SPE include (i) insufficient acidification before sample loading on the extraction column, resulting in a poor affinity of ergosterol for the sorbent; (ii) incomplete drying of the sorbent bed before the elution step; and (iii) chemical breakdown of ergosterol after elution, which was found to be related to a low pH of the final extract and a high <span class="hlt">concentration</span> of matrix compounds. When these pitfalls are avoided, SPE is an attractive alternative to existing methods of ergosterol analysis of environmental samples. PMID:16535229</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/23870107','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/23870107"><span id="translatedtitle"><span class="hlt">Determination</span> of bile salt critical micellization <span class="hlt">concentration</span> on the road to drug discovery.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Natalini, Benedetto; Sardella, Roccaldo; Gioiello, Antimo; Ianni, Federica; Di Michele, Alessandro; Marinozzi, Maura</p> <p>2014-01-01</p> <p>With the discovery of the bile acid (BA)-activated nuclear and membrane receptors, the role of BAs as signalling molecules in important paracrine and endocrine networks has been fully documented in the last decade. Besides regulating their own synthesis and transport, BAs have been demonstrated being involved in triggering the adaptive response to cholestasis and other insults to liver. More to the point, their recognized ability to control the general energy-related metabolism and inflammation processes has contributed to justify the renewed interest towards this class of amphiphilic steroidal compounds. All these evidences feed a continuing interest in the BA research aimed at designing and synthesizing new side chain- and body-modified derivatives endowed with improved biological and physico-chemical profiles, as well as with proper ADMET behaviour. In this context, the micellar aggregation of BAs, and the respective critical micellization <span class="hlt">concentration</span> (CMC) value (<span class="hlt">determined</span> on the BA sodium salt, BS), is considered a key parameter that needs to be <span class="hlt">determined</span> in the preliminary phase of compound characterization, being implicated in cytotoxicity issues. An extraordinary variety of different analytical techniques and methods have been proposed along the years with the aim of better identifying the start of the self-aggregation process of BS monomers. The unicity of the physico-chemical nature of such class of compounds can be invoked to explain this unusual interest. Accordingly, a number of both invasive and non-invasive approaches have been developed along with a limited number of indirect chromatographic-based estimation strategies. Worth to be mentioned among the non-invasive <span class="hlt">determination</span> methods are those based on potentiometry, freezing point depression, surface tension, nuclear magnetic resonance, viscosimetry, turbidimetry, microcalorimetry, refractometry, conductimetry, spectrophotometry, cholesterol solubilization, and monoglucuronide solubilization</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/23870107','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/23870107"><span id="translatedtitle"><span class="hlt">Determination</span> of bile salt critical micellization <span class="hlt">concentration</span> on the road to drug discovery.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Natalini, Benedetto; Sardella, Roccaldo; Gioiello, Antimo; Ianni, Federica; Di Michele, Alessandro; Marinozzi, Maura</p> <p>2014-01-01</p> <p>With the discovery of the bile acid (BA)-activated nuclear and membrane receptors, the role of BAs as signalling molecules in important paracrine and endocrine networks has been fully documented in the last decade. Besides regulating their own synthesis and transport, BAs have been demonstrated being involved in triggering the adaptive response to cholestasis and other insults to liver. More to the point, their recognized ability to control the general energy-related metabolism and inflammation processes has contributed to justify the renewed interest towards this class of amphiphilic steroidal compounds. All these evidences feed a continuing interest in the BA research aimed at designing and synthesizing new side chain- and body-modified derivatives endowed with improved biological and physico-chemical profiles, as well as with proper ADMET behaviour. In this context, the micellar aggregation of BAs, and the respective critical micellization <span class="hlt">concentration</span> (CMC) value (<span class="hlt">determined</span> on the BA sodium salt, BS), is considered a key parameter that needs to be <span class="hlt">determined</span> in the preliminary phase of compound characterization, being implicated in cytotoxicity issues. An extraordinary variety of different analytical techniques and methods have been proposed along the years with the aim of better identifying the start of the self-aggregation process of BS monomers. The unicity of the physico-chemical nature of such class of compounds can be invoked to explain this unusual interest. Accordingly, a number of both invasive and non-invasive approaches have been developed along with a limited number of indirect chromatographic-based estimation strategies. Worth to be mentioned among the non-invasive <span class="hlt">determination</span> methods are those based on potentiometry, freezing point depression, surface tension, nuclear magnetic resonance, viscosimetry, turbidimetry, microcalorimetry, refractometry, conductimetry, spectrophotometry, cholesterol solubilization, and monoglucuronide solubilization</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4909359','PMC'); return false;" href="http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4909359"><span id="translatedtitle"><span class="hlt">Determining</span> the Volume of Additive Solution and Residual Plasma in Whole Blood Filtered and Buffy Coat Processed Red Cell <span class="hlt">Concentrates</span></span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Jordan, Andrew; Acker, Jason P.</p> <p>2016-01-01</p> <p>Summary Background Residual plasma in transfused red cell <span class="hlt">concentrates</span> (RCCs) has been associated with adverse transfusion outcomes. Despite this, there is no consensus on the standard procedure for measuring residual plasma volume. Methods The volumes of residual plasma and additive solution were measured in RCCs processed using two separation methods: whole blood filtration (WBF) and buffy coat (BC)/RCC filtration. The <span class="hlt">concentration</span> of mannitol and albumin in RCC components was measured using colorimetric assays. Mannitol <span class="hlt">concentration</span> was used to calculate additive solution volume. Residual plasma volume was calculated using two methods. Results Calculated RCC supernatant volumes were much lower in BC-processed components compared to WBF-processed components (BC = 97 ± 6 ml, WBF = 109 ± 4 ml; p < 0.05). Calculated additive solution volumes were greater in WBF- than in BC-processed components (BC = 81 ± 4 ml, WBF = 105 ± 2 ml; p < 0.05). <span class="hlt">Absolute</span> residual plasma volume varied significantly based on the calculation method used. Conclusion Disparity between plasma volume calculation methods was observed. Efforts should be made to standardize residual plasma volume measurement methods in order to accurately assess the impact of residual plasma on transfusion outcomes. PMID:27330533</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/18574165','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/18574165"><span id="translatedtitle">The <span class="hlt">determination</span> of carbon dioxide <span class="hlt">concentration</span> using atmospheric pressure ionization mass spectrometry/isotopic dilution and errors in <span class="hlt">concentration</span> measurements caused by dryers.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>DeLacy, Brendan G; Bandy, Alan R</p> <p>2008-01-01</p> <p>An atmospheric pressure ionization mass spectrometry/isotopically labeled standard (APIMS/ILS) method has been developed for the <span class="hlt">determination</span> of carbon dioxide (CO(2)) <span class="hlt">concentration</span>. Descriptions of the instrumental components, the ionization chemistry, and the statistics associated with the analytical method are provided. This method represents an alternative to the nondispersive infrared (NDIR) technique, which is currently used in the atmospheric community to <span class="hlt">determine</span> atmospheric CO(2) <span class="hlt">concentrations</span>. The APIMS/ILS and NDIR methods exhibit a decreased sensitivity for CO(2) in the presence of water vapor. Therefore, dryers such as a nafion dryer are used to remove water before detection. The APIMS/ILS method measures mixing ratios and demonstrates linearity and range in the presence or absence of a dryer. The NDIR technique, on the other hand, measures molar <span class="hlt">concentrations</span>. The second half of this paper describes errors in molar <span class="hlt">concentration</span> measurements that are caused by drying. An equation describing the errors was derived from the ideal gas law, the conservation of mass, and Dalton's Law. The purpose of this derivation was to quantify errors in the NDIR technique that are caused by drying. Laboratory experiments were conducted to verify the errors created solely by the dryer in CO(2) <span class="hlt">concentration</span> measurements post-dryer. The laboratory experiments verified the theoretically predicted errors in the derived equations. There are numerous references in the literature that describe the use of a dryer in conjunction with the NDIR technique. However, these references do not address the errors that are caused by drying.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/18574165','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/18574165"><span id="translatedtitle">The <span class="hlt">determination</span> of carbon dioxide <span class="hlt">concentration</span> using atmospheric pressure ionization mass spectrometry/isotopic dilution and errors in <span class="hlt">concentration</span> measurements caused by dryers.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>DeLacy, Brendan G; Bandy, Alan R</p> <p>2008-01-01</p> <p>An atmospheric pressure ionization mass spectrometry/isotopically labeled standard (APIMS/ILS) method has been developed for the <span class="hlt">determination</span> of carbon dioxide (CO(2)) <span class="hlt">concentration</span>. Descriptions of the instrumental components, the ionization chemistry, and the statistics associated with the analytical method are provided. This method represents an alternative to the nondispersive infrared (NDIR) technique, which is currently used in the atmospheric community to <span class="hlt">determine</span> atmospheric CO(2) <span class="hlt">concentrations</span>. The APIMS/ILS and NDIR methods exhibit a decreased sensitivity for CO(2) in the presence of water vapor. Therefore, dryers such as a nafion dryer are used to remove water before detection. The APIMS/ILS method measures mixing ratios and demonstrates linearity and range in the presence or absence of a dryer. The NDIR technique, on the other hand, measures molar <span class="hlt">concentrations</span>. The second half of this paper describes errors in molar <span class="hlt">concentration</span> measurements that are caused by drying. An equation describing the errors was derived from the ideal gas law, the conservation of mass, and Dalton's Law. The purpose of this derivation was to quantify errors in the NDIR technique that are caused by drying. Laboratory experiments were conducted to verify the errors created solely by the dryer in CO(2) <span class="hlt">concentration</span> measurements post-dryer. The laboratory experiments verified the theoretically predicted errors in the derived equations. There are numerous references in the literature that describe the use of a dryer in conjunction with the NDIR technique. However, these references do not address the errors that are caused by drying. PMID:18574165</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/975437','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/975437"><span id="translatedtitle"><span class="hlt">Absolute</span> photoionization cross-section of the methyl radical.</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Taatjes, C. A.; Osborn, D. L.; Selby, T.; Meloni, G.; Fan, H.; Pratt, S. T.; Chemical Sciences and Engineering Division; SNL</p> <p>2008-01-01</p> <p>The <span class="hlt">absolute</span> photoionization cross-section of the methyl radical has been measured using two completely independent methods. The CH{sub 3} photoionization cross-section was <span class="hlt">determined</span> relative to that of acetone and methyl vinyl ketone at photon energies of 10.2 and 11.0 eV by using a pulsed laser-photolysis/time-resolved synchrotron photoionization mass spectrometry method. The time-resolved depletion of the acetone or methyl vinyl ketone precursor and the production of methyl radicals following 193 nm photolysis are monitored simultaneously by using time-resolved synchrotron photoionization mass spectrometry. Comparison of the initial methyl signal with the decrease in precursor signal, in combination with previously measured <span class="hlt">absolute</span> photoionization cross-sections of the precursors, yields the <span class="hlt">absolute</span> photoionization cross-section of the methyl radical; {sigma}{sub CH}(10.2 eV) = (5.7 {+-} 0.9) x 10{sup -18} cm{sup 2} and {sigma}{sub CH{sub 3}}(11.0 eV) = (6.0 {+-} 2.0) x 10{sup -18} cm{sup 2}. The photoionization cross-section for vinyl radical <span class="hlt">determined</span> by photolysis of methyl vinyl ketone is in good agreement with previous measurements. The methyl radical photoionization cross-section was also independently measured relative to that of the iodine atom by comparison of ionization signals from CH{sub 3} and I fragments following 266 nm photolysis of methyl iodide in a molecular-beam ion-imaging apparatus. These measurements gave a cross-section of (5.4 {+-} 2.0) x 10{sup -18} cm{sup 2} at 10.460 eV, (5.5 {+-} 2.0) x 10{sup -18} cm{sup 2} at 10.466 eV, and (4.9 {+-} 2.0) x 10{sup -18} cm{sup 2} at 10.471 eV. The measurements allow relative photoionization efficiency spectra of methyl radical to be placed on an <span class="hlt">absolute</span> scale and will facilitate quantitative measurements of methyl <span class="hlt">concentrations</span> by photoionization mass spectrometry.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/27154679','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/27154679"><span id="translatedtitle"><span class="hlt">Determination</span> of boron <span class="hlt">concentration</span> in oilfield water with a microfluidic ion exchange resin instrument.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Floquet, Cedric F A; Sieben, Vincent J; MacKay, Bruce A; Mostowfi, Farshid</p> <p>2016-07-01</p> <p>We developed and validated a microfluidic instrument for interference-free <span class="hlt">determination</span> of boron in produced water. The instrument uses a boron-specific chelating resin to separate the analyte from its complex matrix. Ten produced water samples were analyzed with the instrument and the results were successfully validated against ICP-MS measurements. Removing interference effects enables precise boron measurement for wastewater even with high total dissolved solid (TDS) levels. 1,4-Piperazinediethanesulfonic acid conditions the resin and maintains the optimum pH for boron adsorption from the sample. Boron is then eluted from the resin using a 10% sulfuric acid solution and its <span class="hlt">concentration</span> measured with the colorimetric carminic acid assay in 95% sulfuric acid. The use of a microfluidic mixer greatly enhances the sensitivity and kinetics of the carminic acid assay, by factors of 2 and 7.5, respectively, when compared against the same assay performed manually. A maximum sensitivity of 2.5mg(-1)L, a precision of 4.2% over the 0-40.0mgL(-1) measuring range, a 0.3mgL(-1) limit of detection, and a sampling rate of up to four samples per hour were achieved. Automation and microfluidics reduce the operator workload and fluid manipulation errors, translating into safer and higher-quality measurements in the field. PMID:27154679</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016Nanot..27K5503A','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016Nanot..27K5503A"><span id="translatedtitle">Colorimetric <span class="hlt">determination</span> of Timolol <span class="hlt">concentration</span> based on localized surface plasmon resonance of silver nanoparticles</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Amirjani, Amirmostafa; Bagheri, Mozhgan; Heydari, Mojgan; Hesaraki, Saeed</p> <p>2016-09-01</p> <p>In this work, a rapid and simple colorimetric method based on the surface plasmon resonance of silver nanoparticles (AgNPs) was developed for the detection of the drug Timolol. The method used is based on the interaction of Timolol with the surface of the as-synthesized AgNPs, which promotes aggregation of the nanoparticles. This aggregation exploits the surface plasmon resonance through the electric dipole-dipole interaction and coupling among the agglomerated particles, hence bringing forth distinctive changes in the spectra as well as the color of colloidal silver. UV-vis spectrophotometery was used to monitor the changes of the localized surface plasmon resonance of AgNPs at wavelengths of 400 and 550 nm. The developed colorimetric sensor has a wide dynamic range of 1.0 × 10-7 M-1.0 × 10-3 M for detection of Timolol with a low detection limit of 1.2 × 10-6 M. The proposed method was successfully applied for the <span class="hlt">determination</span> of Timolol <span class="hlt">concentration</span> in ophthalmic eye-drop solution with a response time lower than 40 s.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2016Nanot..27K5503A&link_type=ABSTRACT','NASAADS'); return false;" href="http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2016Nanot..27K5503A&link_type=ABSTRACT"><span id="translatedtitle">Colorimetric <span class="hlt">determination</span> of Timolol <span class="hlt">concentration</span> based on localized surface plasmon resonance of silver nanoparticles</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Amirjani, Amirmostafa; Bagheri, Mozhgan; Heydari, Mojgan; Hesaraki, Saeed</p> <p>2016-09-01</p> <p>In this work, a rapid and simple colorimetric method based on the surface plasmon resonance of silver nanoparticles (AgNPs) was developed for the detection of the drug Timolol. The method used is based on the interaction of Timolol with the surface of the as‑synthesized AgNPs, which promotes aggregation of the nanoparticles. This aggregation exploits the surface plasmon resonance through the electric dipole–dipole interaction and coupling among the agglomerated particles, hence bringing forth distinctive changes in the spectra as well as the color of colloidal silver. UV‑vis spectrophotometery was used to monitor the changes of the localized surface plasmon resonance of AgNPs at wavelengths of 400 and 550 nm. The developed colorimetric sensor has a wide dynamic range of 1.0 × 10‑7 M–1.0 × 10‑3 M for detection of Timolol with a low detection limit of 1.2 × 10‑6 M. The proposed method was successfully applied for the <span class="hlt">determination</span> of Timolol <span class="hlt">concentration</span> in ophthalmic eye‑drop solution with a response time lower than 40 s.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_18");'>18</a></li> <li><a href="#" onclick='return showDiv("page_19");'>19</a></li> <li class="active"><span>20</span></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_20 --> <div id="page_21" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_19");'>19</a></li> <li><a href="#" onclick='return showDiv("page_20");'>20</a></li> <li class="active"><span>21</span></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li><a href="#" onclick='return showDiv("page_23");'>23</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="401"> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/27504595','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/27504595"><span id="translatedtitle">Colorimetric <span class="hlt">determination</span> of Timolol <span class="hlt">concentration</span> based on localized surface plasmon resonance of silver nanoparticles.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Amirjani, Amirmostafa; Bagheri, Mozhgan; Heydari, Mojgan; Hesaraki, Saeed</p> <p>2016-09-16</p> <p>In this work, a rapid and simple colorimetric method based on the surface plasmon resonance of silver nanoparticles (AgNPs) was developed for the detection of the drug Timolol. The method used is based on the interaction of Timolol with the surface of the as-synthesized AgNPs, which promotes aggregation of the nanoparticles. This aggregation exploits the surface plasmon resonance through the electric dipole-dipole interaction and coupling among the agglomerated particles, hence bringing forth distinctive changes in the spectra as well as the color of colloidal silver. UV-vis spectrophotometery was used to monitor the changes of the localized surface plasmon resonance of AgNPs at wavelengths of 400 and 550 nm. The developed colorimetric sensor has a wide dynamic range of 1.0 × 10(-7) M-1.0 × 10(-3) M for detection of Timolol with a low detection limit of 1.2 × 10(-6) M. The proposed method was successfully applied for the <span class="hlt">determination</span> of Timolol <span class="hlt">concentration</span> in ophthalmic eye-drop solution with a response time lower than 40 s.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/7098497','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/7098497"><span id="translatedtitle"><span class="hlt">Determination</span> of hepatic uridine 5'-diphosphoglucuronic acid <span class="hlt">concentration</span> by conjugation with diethylstilbestrol.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Watkins, J B; Klaassen, C D</p> <p>1982-03-01</p> <p>A sensitive and reliable assay for uridine 5'-diphosphoglucuronic acid (UDPGA) was developed that involved conjugation of diethylstilbestrol (DES) in vitro. This conjugation reaction is solely dependent upon UDPGA <span class="hlt">concentration</span>. The assay uses 0.13 M Tris-HCl, pH 7.4, 6.7 mM MgCl2, 0.05% Brig 58, 0.25 mg guinea pig liver microsomal protein, 0.13 mM 3H-DES (0.2 microCi/ml), and 200 microliters of boiled 10% liver homogenate in a total volume of 0.5 ml. After a 60-min incubation at 37 degrees C, unconjugated DES is extracted into 5 ml of chloroform and the residual metabolized 3H-DES in the aqueous phase is <span class="hlt">determined</span> by liquid scintillation spectrometry. After addition of beta-glucuronidase to the aqueous phase, about 90% of the radioactivity could be extracted into chloroform, demonstrating the DES-glucuronic acid is the primary metabolite. Thus, this method easily permits quantitation of UDPGA in rat liver in the 1-10 nmol range.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1999JChEd..76...93H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1999JChEd..76...93H"><span id="translatedtitle"><span class="hlt">Determination</span> of the Critical Micelle <span class="hlt">Concentration</span> of Cationic Surfactants: An Undergraduate Experiment</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Huang, Xirong; Yang, Jinghe; Zhang, Wenjuan; Zhang, Zhenyu; An, Zesheng</p> <p>1999-01-01</p> <p>A novel method based on the catalytic effect of micelles exerted by cetyltrimethylammonium bromide (CTAB) and cetylpyridinium bromide (CPB), respectively, on the indicator reaction between H2O2 and bromopyrogallol red (BPR), a triphenylmethane dye, was developed for undergraduates to <span class="hlt">determine</span> the critical micelle <span class="hlt">concentration</span> (cmc) of CTAB and CPB. The indicator reaction was monitored by a fixed-time kinetic-spectrophotometric technique. Under the experimental conditions the cmc values of CTAB and CPB were (4.8 ± 0.3) x 10-4 mol/L and (4.5 ± 0.3) x 10-4mol/L, which were close to the literature values of 9.2 x 10-4 mol/L and 9.0 x 10-4 mol/L, respectively. Detailed discussion on the selection of experimental conditions was made to minimize the effect of electrolytes on the cmc's of surfactants and to maintain the high accuracy of the experimental data. As an undergraduate physicochemical laboratory experiment the present method had several attractive features. The procedure is simple and easy to perform, does not require special equipment, and does not need expensive or toxic reagents. In addition, it is a versatile method that can be applied to a wide variety of both anionic and cationic surfactants.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/18329861','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/18329861"><span id="translatedtitle">Pharmaceutical gel analysis by NIR spectroscopy. <span class="hlt">Determination</span> of the active principle and low <span class="hlt">concentration</span> of preservatives.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Blanco, M; Alcalá, M; Bautista, M</p> <p>2008-04-23</p> <p>Near infrared spectroscopy has proved highly suitable for the analysis of pharmaceutical formulations. However, its limited sensitivity can severely restrict its scope of application. In this work, we <span class="hlt">determine</span> the active principle and two preservatives in a pharmaceutical preparation available as a hydrogel. The matrix of the pharmaceutical preparation exhibits strong absorption in the NIR spectral region; also, the two preservatives (parabens) are very similar in chemical and spectral terms, and present at low <span class="hlt">concentrations</span> in the pharmaceutical. These complications make it rather difficult to accurately quantify the active principle and the preservatives, which can only be accomplished by using an effective design in order to prepare the samples to be included in the calibration set and select the optimum spectral range for measuring each analyte. The evaporation of solvents during the measurement process produces increasing errors related with sample's air exposition; the introductions of new samples with a wider range of the volatile components correct this effect. An ANOVA of the predictions obtained with the new models shows that correct the error due to evaporation. The proposed method was validated for the analytical control of the studied preparation.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/27504595','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/27504595"><span id="translatedtitle">Colorimetric <span class="hlt">determination</span> of Timolol <span class="hlt">concentration</span> based on localized surface plasmon resonance of silver nanoparticles.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Amirjani, Amirmostafa; Bagheri, Mozhgan; Heydari, Mojgan; Hesaraki, Saeed</p> <p>2016-09-16</p> <p>In this work, a rapid and simple colorimetric method based on the surface plasmon resonance of silver nanoparticles (AgNPs) was developed for the detection of the drug Timolol. The method used is based on the interaction of Timolol with the surface of the as-synthesized AgNPs, which promotes aggregation of the nanoparticles. This aggregation exploits the surface plasmon resonance through the electric dipole-dipole interaction and coupling among the agglomerated particles, hence bringing forth distinctive changes in the spectra as well as the color of colloidal silver. UV-vis spectrophotometery was used to monitor the changes of the localized surface plasmon resonance of AgNPs at wavelengths of 400 and 550 nm. The developed colorimetric sensor has a wide dynamic range of 1.0 × 10(-7) M-1.0 × 10(-3) M for detection of Timolol with a low detection limit of 1.2 × 10(-6) M. The proposed method was successfully applied for the <span class="hlt">determination</span> of Timolol <span class="hlt">concentration</span> in ophthalmic eye-drop solution with a response time lower than 40 s. PMID:27504595</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19970041484','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19970041484"><span id="translatedtitle">Research to Support the <span class="hlt">Determination</span> of Spacecraft Maximum Acceptable <span class="hlt">Concentrations</span> of Potential Atmospheric Contaminants</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Orr, John L.</p> <p>1997-01-01</p> <p>In many ways, the typical approach to the handling of bibliographic material for generating review articles and similar manuscripts has changed little since the use of xerographic reproduction has become widespread. The basic approach is to collect reprints of the relevant material and place it in folders or stacks based on its dominant content. As the amount of information available increases with the passage of time, the viability of this mechanical approach to bibliographic management decreases. The personal computer revolution has changed the way we deal with many familiar tasks. For example, word processing on personal computers has supplanted the typewriter for many applications. Similarly, spreadsheets have not only replaced many routine uses of calculators but have also made possible new applications because the cost of calculation is extremely low. Objective The objective of this research was to use personal computer bibliographic software technology to support the <span class="hlt">determination</span> of spacecraft maximum acceptable <span class="hlt">concentration</span> (SMAC) values. Specific Aims The specific aims were to produce draft SMAC documents for hydrogen sulfide and tetrachloroethylene taking maximum advantage of the bibliographic software.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/7152949','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/7152949"><span id="translatedtitle">Activated charcoal filter counting for radioiodine effluent <span class="hlt">concentration</span> <span class="hlt">determination</span> in protein iodinations.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Button, T M; Hamilton, R G</p> <p>1982-12-01</p> <p>Regulatory agencies have recently placed emphasis upon quantification of 125I released to the environment during protein iodinations at radioiodination facilities. This necessitates air sampling in order to <span class="hlt">determine</span> the <span class="hlt">concentration</span> of 125I in the effluent. Air sample trapping mechanisms generally employed are activated charcoal filters. Difficulty arises in quantifying the activity of 125I trapped because of the attenuation of the 125I decay photons by the charcoal. Evaluation of the activity incident upon commercially available filters using a scintillation detector and large detector source separation is considered here. It is demonstrated that the activity in the filter may be treated as an exponential distribution within an attentuating matrix. This treatment essentially adds a constant correction factor to the counting efficiency of a given geometry for a filter-affluent flow rate combination. Finally, it is shown that an approximation assuming a uniform distribution of activity produces a large error in correction factor to the counting efficiency for the filters examined. PMID:7152949</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://eric.ed.gov/?q=Absolutism&pg=3&id=EJ265369','ERIC'); return false;" href="http://eric.ed.gov/?q=Absolutism&pg=3&id=EJ265369"><span id="translatedtitle">Relativistic <span class="hlt">Absolutism</span> in Moral Education.</span></a></p> <p><a target="_blank" href="http://www.eric.ed.gov/ERICWebPortal/search/extended.jsp?_pageLabel=advanced">ERIC Educational Resources Information Center</a></p> <p>Vogt, W. Paul</p> <p>1982-01-01</p> <p>Discusses Emile Durkheim's "Moral Education: A Study in the Theory and Application of the Sociology of Education," which holds that morally healthy societies may vary in culture and organization but must possess <span class="hlt">absolute</span> rules of moral behavior. Compares this moral theory with current theory and practice of American educators. (MJL)</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=19720027445&hterms=Phosphorus&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D60%26Ntt%3DPhosphorus','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=19720027445&hterms=Phosphorus&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D60%26Ntt%3DPhosphorus"><span id="translatedtitle"><span class="hlt">Absolute</span> transition probabilities of phosphorus.</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Miller, M. H.; Roig, R. A.; Bengtson, R. D.</p> <p>1971-01-01</p> <p>Use of a gas-driven shock tube to measure the <span class="hlt">absolute</span> strengths of 21 P I lines and 126 P II lines (from 3300 to 6900 A). Accuracy for prominent, isolated neutral and ionic lines is estimated to be 28 to 40% and 18 to 30%, respectively. The data and the corresponding theoretical predictions are examined for conformity with the sum rules.-</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://pubs.er.usgs.gov/publication/70017408','USGSPUBS'); return false;" href="http://pubs.er.usgs.gov/publication/70017408"><span id="translatedtitle">Use of dissolved H2 <span class="hlt">concentrations</span> to <span class="hlt">determine</span> distribution of microbially catalyzed redox reactions in anoxic groundwater</span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Lovley, D.R.; Chapelle, F.H.; Woodward, J.C.</p> <p>1994-01-01</p> <p>The potential for using <span class="hlt">concentrations</span> of dissolved H2 to <span class="hlt">determine</span> the distribution of redox processes in anoxic groundwaters was evaluated. In pristine aquifers in which standard geochemical measurements indicated that Fe-(III) reduction, sulfate reduction, or methanogenesis was the terminal electron accepting process (TEAP), the H2 <span class="hlt">concentrations</span> were similar to the H2 <span class="hlt">concentrations</span> that have previously been reported for aquatic sediments with the same TEAPs. In two aquifers contaminated with petroleum products, it was impossible with standard geochemical analyses to <span class="hlt">determine</span> which TEAPs predominated in specific locations. However, the TEAPs predicted from measurements of dissolved H2 were the same as those <span class="hlt">determined</span> directly through measurements of microbial processes in incubated aquifer material. These results suggest that H2 <span class="hlt">concentrations</span> may be a useful tool for analyzing the redox chemistry of nonequilibrium groundwaters.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016AtmEn.136...16F','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016AtmEn.136...16F"><span id="translatedtitle">Technical note: An improved approach to <span class="hlt">determining</span> background aerosol <span class="hlt">concentrations</span> with PILS sampling on aircraft</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Fukami, Christine S.; Sullivan, Amy P.; Ryan Fulgham, S.; Murschell, Trey; Borch, Thomas; Smith, James N.; Farmer, Delphine K.</p> <p>2016-07-01</p> <p>Particle-into-Liquid Samplers (PILS) have become a standard aerosol collection technique, and are widely used in both ground and aircraft measurements in conjunction with off-line ion chromatography (IC) measurements. Accurate and precise background samples are essential to account for gas-phase components not efficiently removed and any interference in the instrument lines, collection vials or off-line analysis procedures. For aircraft sampling with PILS, backgrounds are typically taken with in-line filters to remove particles prior to sample collection once or twice per flight with more numerous backgrounds taken on the ground. Here, we use data collected during the Front Range Air Pollution and Photochemistry Éxperiment (FRAPPÉ) to demonstrate that not only are multiple background filter samples are essential to attain a representative background, but that the chemical background signals do not follow the Gaussian statistics typically assumed. Instead, the background signals for all chemical components analyzed from 137 background samples (taken from ∼78 total sampling hours over 18 flights) follow a log-normal distribution, meaning that the typical approaches of averaging background samples and/or assuming a Gaussian distribution cause an over-estimation of background samples - and thus an underestimation of sample <span class="hlt">concentrations</span>. Our approach of deriving backgrounds from the peak of the log-normal distribution results in detection limits of 0.25, 0.32, 3.9, 0.17, 0.75 and 0.57 μg m-3 for sub-micron aerosol nitrate (NO3-), nitrite (NO2-), ammonium (NH4+), sulfate (SO42-), potassium (K+) and calcium (Ca2+), respectively. The difference in backgrounds calculated from assuming a Gaussian distribution versus a log-normal distribution were most extreme for NH4+, resulting in a background that was 1.58× that <span class="hlt">determined</span> from fitting a log-normal distribution.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2004AGUSM.V51B..10B&link_type=ABSTRACT','NASAADS'); return false;" href="http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2004AGUSM.V51B..10B&link_type=ABSTRACT"><span id="translatedtitle">Selenium Preconcentration in Geological Materials for <span class="hlt">Determination</span> at sub-μ g\\ g-1 <span class="hlt">Concentration</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Bedard, L. P.</p> <p>2004-05-01</p> <p>Selenium is important because it is a path finder element in economic geology. It has similar geochemical properties as sulfur, but slightly less mobile and less volatile in sulfides. Although its environmental cycle is better understood, its geological cycle is almost unknown. In geological samples, Se <span class="hlt">concentration</span> ranges 0,02-1 μ g\\ g-1. Se has many spectral interefences in ICP-MS, rendering difficult to <span class="hlt">determine</span>. INAA detection limit for geological samples is about 10 μ g\\ g-1. The analytical difficulties are one of the main reason why the geological cycle of Se is so poorly known. The preconcentration of Se with Thiol Cotton Fiber (TCF) followed by atomic absorption (AA) has been modified to be used with INAA. The modified technique involves sample dissolution (HF-HNO3) and evaporation to dryness at low temperature (55-60 oC) to keep Se in solution. Se is converted to SeIV by adding 5-6 mol l-1 HCl and heating covered in a boiling bath (95-100oC). Sample is diluted with deionized water to obtain 0,3 - 1 mol l-1 HCl and then collected on TCF. TCF is put in a polyethylene vial for irradiation in the SLOWPOKE II reactor for 10 seconds at a neutron flux of 1015 m-2 s-1. The 162 KeV peak of 77Se (half-life 17,36 sec) is read for 20 seconds after a decay of 7 seconds. Results for certified reference materials show the TCF preconcentration technique followed by INAA provides results comparable with AA with a detection limit of approximately 0,05 μ g\\ g-1. Moreover INAA provides many advantages such as eliminating the desorption step and is less time consuming than AA.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/394032','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/394032"><span id="translatedtitle"><span class="hlt">Determination</span> of radionuclide <span class="hlt">concentrations</span> in ground level air using the ASS-500 high volume sampler</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Frenzel, E.; Arnold, D.; Wershofen, H.</p> <p>1996-06-01</p> <p>A method for <span class="hlt">determination</span> of radionuclide <span class="hlt">concentrations</span> in air aerosol samples collected by the high volume aerosol sampler ASS-500 was elaborated. The aerosol sampling station ASS-500 is a Stand alone, all-weather proofed instrument. It is designed for representative sampling of airborne radionuclides from ground level air at a height of about 1.5 m above ground level. The ASS-500 station enables continuous air monitoring both normal and emergency Situations. The collection of aerosols on the Petrianov FPP-15-1.5 type filter out of an air volume of about 100,000 m{sup 3} (sampling period 1 wk) or of about 250,000 m{sup 3} (sampling period 3 wk) admits accurate spectrometric low level measurements of natural and artificial radionuclides. The achieved detection limit is 0.5 {mu}Bq m{sup -3} and 0.2 {mu}Bq m{sup -3} for {sup 137}Cs, respectively. A new developed air flow Meter system allows to enhance the collected air volume to about 150,000 m{sup 3} per week and lowers the detection limit to <0.4 {mu}Bq m{sup -3} for {sup 137}Cs for weekly collected aerosol samples. In Poland the CLOR uses 9 Stations ASS-500 at different sites as atmospheric radioactivity control system. On the basis of spectrometric measurements of natural and artificial radionuclides in the collected aerosol samples at the different sites, CLOR establishes a weekly report about the radiological situation at Poland for responsible authorities. The very low achievable detection limit of the Station ASS-500 due 10 the high air flow fate and the long possible sampling period were the key argument for other government radiation protection authorities in Europe to introduce the Station ASS-500 into their low level radionuclide atmospheric monitoring programs (Austria, Belarus, France, Germany, Iceland, Spain, Switzerland, Ukraine).</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/23598194','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/23598194"><span id="translatedtitle">Precise <span class="hlt">determination</span> of U isotopic compositions in low <span class="hlt">concentration</span> carbonate samples by MC-ICP-MS.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Wang, Ruo-Mei; You, Chen-Feng</p> <p>2013-03-30</p> <p>We developed a fast and simple analytical procedure for precise <span class="hlt">determination</span> of U isotopic compositions in low <span class="hlt">concentration</span> natural samples. The main advantage of the new method is that it requires only 12ng U and can obtain all U isotopic ratios without using spike. Five carbonate reference materials (JCp-1, RKM-4, RKM-5, GBW04412 and GBW04413) and 3 international standards with different matrices (IAPSO, IRMM-3184 and CRM-U010) were analyzed for ((234)U/(238)U) and (238)U/(235)U ratios by MC-ICPMS. Using our method, the results for these standards are in close agreement with the certified values, 1.144 ± 0.004, 0.966 ± 0.004 and 0.990 ± 0.003 for ((234)U/(238)U) and 137.72 ± 0.13, 137.64 ± 0.15 and 98.63 ± 0.04 for (238)U/(235)U, in IAPSO, IRMM-3184 and CRM-U010, respectively. The long-term reproducibility of ((234)U/(238)U) and (238)U/(235)U is 0.970 ± 0.002 and 137.56 ± 0.09; 1.144 ± 0.004 and 137.72 ± 0.13, respectively, for in-house U solution and IAPSO. The new ((234)U/(238)U) results for carbonates show much better precision than previous studies and also reflect their age variability. The obtained (238)U/(235)U ratios, representing the first measurements in these carbonate specimens, are rather constant. The method described here requires only 12 ng of U for analysis and can be completed in 5.2 min. The approach provides a fast method to measure ((234)U/(238)U) and (238)U/(235)U ratios in sample matrices commonly encountered in studies of chemical weathering, oceanography and paleoclimatology. PMID:23598194</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/25641710','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/25641710"><span id="translatedtitle">Factors that <span class="hlt">determine</span> stability of highly <span class="hlt">concentrated</span> chemically defined production media.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>McCoy, Rebecca E; Costa, Nicole A; Morris, Arvia E</p> <p>2015-01-01</p> <p>High cell density perfusion processes for the production of therapeutic antibodies require large volumes of media to meet cellular stoichiometric and energy demands. The use of media <span class="hlt">concentrates</span> provides a way to reduce the cost of manufacturing. Reducing the number and size of liquid media batches reduces the media footprint in the manufacturing plant and cuts costs associated with single-use systems for preparation and storage of liquid media. <span class="hlt">Concentrates</span> that can be stored at room temperature also reduce costs by eliminating the need for refrigerated storage. To meet these economic and operational objectives, we developed a complete <span class="hlt">concentrated</span> medium system consisting of a 5X medium <span class="hlt">concentrate</span> that can be used in conjunction with a <span class="hlt">concentrated</span> supplement of cystine, tyrosine, and folic acid. The effects of pyruvate, bicarbonate, and glutamine on the stability of the 5X <span class="hlt">concentrates</span> were studied. Pyruvate and bicarbonate were found to have profound impacts on media stability, including media coloration, precipitate formation and ability to support cell culture. Bicarbonate was found to have detrimental effects in 5X <span class="hlt">concentrated</span> media, resulting in precipitation of pyruvate-free media and accelerated glutamine degradation. Pyruvate prevented precipitation in bicarbonate-containing <span class="hlt">concentrates</span>. Moreover, the presence of pyruvate in bicarbonate-free, glutamine-free 5X <span class="hlt">concentrates</span> resulted in the substantial preservation of the functional activity of the medium for 1 month at room temperature. PMID:25641710</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/21821811','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/21821811"><span id="translatedtitle">Technical note: Effect of <span class="hlt">determining</span> baseline plasma urea nitrogen <span class="hlt">concentrations</span> on subsequent posttreatment plasma urea nitrogen <span class="hlt">concentrations</span> in 20- to 50-kilogram pigs.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Waguespack, A M; Powell, S; Roux, M L; Frugé, E D; Bidner, T D; Payne, R L; Southern, L L</p> <p>2011-12-01</p> <p>Plasma urea N (PUN) has been used as an indicator of AA requirements and efficiency of AA utilization in swine. However, PUN <span class="hlt">concentrations</span> vary among a population of pigs, even a population with a close range of BW and fed the same diet. Thus, pretreatment or baseline PUN <span class="hlt">concentrations</span> are used as a covariate to reduce variation of posttreatment PUN. However, this procedure increases experimental costs and stress to the pigs. Data from 14 experiments (26 to 28 d in duration) conducted using PUN as a response variable were compiled into 1 data set. Each experiment had 4 to 6 treatments. The purpose of this technical report was to summarize the effect of <span class="hlt">determining</span> pretreatment baseline PUN <span class="hlt">concentrations</span> on subsequent posttreatment PUN <span class="hlt">concentrations</span> in 20- to 50-kg pigs. In all experiments, pigs were fed corn- and soybean meal-based diets and low-CP diets with various AA additions; pigs were assigned to dietary treatments in a randomized complete block design with a minimum of 4 replicates of 3 to 5 pigs each. Before the start of each experiment, all pigs were fed a common diet for a minimum of 3 d. Blood samples were collected from each pig before allotment to dietary treatments (d 0) and at the end of each experiment. The baseline (d 0) PUN was analyzed as a covariate for posttreatment PUN. Data from each experiment were analyzed without and with baseline PUN in the statistical model. In all experiments combined, there were 768 possible treatment comparisons. The covariate baseline PUN was statistically significant (P < 0.10) in 9 of 14 experiments. However, only 8 treatment differences changed statistical significance as a result of analyzing the data with baseline PUN as a covariate. These 8 treatment differences were in 3 experiments. These results indicate that it is not always necessary to <span class="hlt">determine</span> baseline PUN <span class="hlt">concentrations</span> when feeding diets with large differences in AA content.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2016PhRvA..94a3808D&link_type=ABSTRACT','NASAADS'); return false;" href="http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2016PhRvA..94a3808D&link_type=ABSTRACT"><span id="translatedtitle">Optomechanics for <span class="hlt">absolute</span> rotation detection</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Davuluri, Sankar</p> <p>2016-07-01</p> <p>In this article, we present an application of optomechanical cavity for the <span class="hlt">absolute</span> rotation detection. The optomechanical cavity is arranged in a Michelson interferometer in such a way that the classical centrifugal force due to rotation changes the length of the optomechanical cavity. The change in the cavity length induces a shift in the frequency of the cavity mode. The phase shift corresponding to the frequency shift in the cavity mode is measured at the interferometer output to estimate the angular velocity of <span class="hlt">absolute</span> rotation. We derived an analytic expression to estimate the minimum detectable rotation rate in our scheme for a given optomechanical cavity. Temperature dependence of the rotation detection sensitivity is studied.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/11262641','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/11262641"><span id="translatedtitle">Moral <span class="hlt">absolutism</span> and ectopic pregnancy.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Kaczor, C</p> <p>2001-02-01</p> <p>If one accepts a version of <span class="hlt">absolutism</span> that excludes the intentional killing of any innocent human person from conception to natural death, ectopic pregnancy poses vexing difficulties. Given that the embryonic life almost certainly will die anyway, how can one retain one's moral principle and yet adequately respond to a situation that gravely threatens the life of the mother and her future fertility? The four options of treatment most often discussed in the literature are non-intervention, salpingectomy (removal of tube with embryo), salpingostomy (removal of embryo alone), and use of methotrexate (MXT). In this essay, I review these four options and introduce a fifth (the milking technique). In order to assess these options in terms of the <span class="hlt">absolutism</span> mentioned, it will also be necessary to discuss various accounts of the intention/foresight distinction. I conclude that salpingectomy, salpingostomy, and the milking technique are compatible with absolutist presuppositions, but not the use of methotrexate.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/11262641','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/11262641"><span id="translatedtitle">Moral <span class="hlt">absolutism</span> and ectopic pregnancy.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Kaczor, C</p> <p>2001-02-01</p> <p>If one accepts a version of <span class="hlt">absolutism</span> that excludes the intentional killing of any innocent human person from conception to natural death, ectopic pregnancy poses vexing difficulties. Given that the embryonic life almost certainly will die anyway, how can one retain one's moral principle and yet adequately respond to a situation that gravely threatens the life of the mother and her future fertility? The four options of treatment most often discussed in the literature are non-intervention, salpingectomy (removal of tube with embryo), salpingostomy (removal of embryo alone), and use of methotrexate (MXT). In this essay, I review these four options and introduce a fifth (the milking technique). In order to assess these options in terms of the <span class="hlt">absolutism</span> mentioned, it will also be necessary to discuss various accounts of the intention/foresight distinction. I conclude that salpingectomy, salpingostomy, and the milking technique are compatible with absolutist presuppositions, but not the use of methotrexate. PMID:11262641</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=20100014902&hterms=asp&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D50%26Ntt%3Dasp','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=20100014902&hterms=asp&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D50%26Ntt%3Dasp"><span id="translatedtitle">The <span class="hlt">Absolute</span> Spectrum Polarimeter (ASP)</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Kogut, A. J.</p> <p>2010-01-01</p> <p>The <span class="hlt">Absolute</span> Spectrum Polarimeter (ASP) is an Explorer-class mission to map the <span class="hlt">absolute</span> intensity and linear polarization of the cosmic microwave background and diffuse astrophysical foregrounds over the full sky from 30 GHz to 5 THz. The principal science goal is the detection and characterization of linear polarization from an inflationary epoch in the early universe, with tensor-to-scalar ratio r much greater than 1O(raised to the power of { -3}) and Compton distortion y < 10 (raised to the power of{-6}). We describe the ASP instrument and mission architecture needed to detect the signature of an inflationary epoch in the early universe using only 4 semiconductor bolometers.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_19");'>19</a></li> <li><a href="#" onclick='return showDiv("page_20");'>20</a></li> <li class="active"><span>21</span></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li><a href="#" onclick='return showDiv("page_23");'>23</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_21 --> <div id="page_22" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_20");'>20</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li class="active"><span>22</span></li> <li><a href="#" onclick='return showDiv("page_23");'>23</a></li> <li><a href="#" onclick='return showDiv("page_24");'>24</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="421"> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/15831074','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/15831074"><span id="translatedtitle">Classification images predict <span class="hlt">absolute</span> efficiency.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Murray, Richard F; Bennett, Patrick J; Sekuler, Allison B</p> <p>2005-02-24</p> <p>How well do classification images characterize human observers' strategies in perceptual tasks? We show mathematically that from the classification image of a noisy linear observer, it is possible to recover the observer's <span class="hlt">absolute</span> efficiency. If we could similarly predict human observers' performance from their classification images, this would suggest that the linear model that underlies use of the classification image method is adequate over the small range of stimuli typically encountered in a classification image experiment, and that a classification image captures most important aspects of human observers' performance over this range. In a contrast discrimination task and in a shape discrimination task, we found that observers' <span class="hlt">absolute</span> efficiencies were generally well predicted by their classification images, although consistently slightly (approximately 13%) higher than predicted. We consider whether a number of plausible nonlinearities can account for the slight under prediction, and of these we find that only a form of phase uncertainty can account for the discrepancy.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/1175308','DOE-PATENT-XML'); return false;" href="http://www.osti.gov/scitech/servlets/purl/1175308"><span id="translatedtitle"><span class="hlt">Absolute</span> calibration of optical flats</span></a></p> <p><a target="_blank" href="http://www.osti.gov/doepatents">DOEpatents</a></p> <p>Sommargren, Gary E.</p> <p>2005-04-05</p> <p>The invention uses the phase shifting diffraction interferometer (PSDI) to provide a true point-by-point measurement of <span class="hlt">absolute</span> flatness over the surface of optical flats. Beams exiting the fiber optics in a PSDI have perfect spherical wavefronts. The measurement beam is reflected from the optical flat and passed through an auxiliary optic to then be combined with the reference beam on a CCD. The combined beams include phase errors due to both the optic under test and the auxiliary optic. Standard phase extraction algorithms are used to calculate this combined phase error. The optical flat is then removed from the system and the measurement fiber is moved to recombine the two beams. The newly combined beams include only the phase errors due to the auxiliary optic. When the second phase measurement is subtracted from the first phase measurement, the <span class="hlt">absolute</span> phase error of the optical flat is obtained.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2012AGUFM.G11B0924M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2012AGUFM.G11B0924M"><span id="translatedtitle"><span class="hlt">Absolute</span> Antenna Calibration at the US National Geodetic Survey</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Mader, G. L.; Bilich, A. L.</p> <p>2012-12-01</p> <p>Geodetic GNSS applications routinely demand millimeter precision and extremely high levels of accuracy. To achieve these accuracies, measurement and instrument biases at the centimeter to millimeter level must be understood. One of these biases is the antenna phase center, the apparent point of signal reception for a GNSS antenna. It has been well established that phase center patterns differ between antenna models and manufacturers; additional research suggests that the addition of a radome or the choice of antenna mount can significantly alter those a priori phase center patterns. For the more demanding GNSS positioning applications and especially in cases of mixed-antenna networks, it is all the more important to know antenna phase center variations as a function of both elevation and azimuth in the antenna reference frame and incorporate these models into analysis software. <span class="hlt">Determination</span> of antenna phase center behavior is known as "antenna calibration". Since 1994, NGS has computed relative antenna calibrations for more than 350 antennas. In recent years, the geodetic community has moved to <span class="hlt">absolute</span> calibrations - the IGS adopted <span class="hlt">absolute</span> antenna phase center calibrations in 2006 for use in their orbit and clock products, and NGS's CORS group began using <span class="hlt">absolute</span> antenna calibration upon the release of the new CORS coordinates in IGS08 epoch 2005.00 and NAD 83(2011,MA11,PA11) epoch 2010.00. Although NGS relative calibrations can be and have been converted to <span class="hlt">absolute</span>, it is considered best practice to independently measure phase center characteristics in an <span class="hlt">absolute</span> sense. Consequently, NGS has developed and operates an <span class="hlt">absolute</span> calibration system. These <span class="hlt">absolute</span> antenna calibrations accommodate the demand for greater accuracy and for 2-dimensional (elevation and azimuth) parameterization. NGS will continue to provide calibration values via the NGS web site www.ngs.noaa.gov/ANTCAL, and will publish calibrations in the ANTEX format as well as the legacy ANTINFO</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.gpo.gov/fdsys/pkg/CFR-2011-title40-vol15/pdf/CFR-2011-title40-vol15-part65-subpartD-app1.pdf','CFR2011'); return false;" href="https://www.gpo.gov/fdsys/pkg/CFR-2011-title40-vol15/pdf/CFR-2011-title40-vol15-part65-subpartD-app1.pdf"><span id="translatedtitle">40 CFR Table 1 to Subpart D of... - <span class="hlt">Concentration</span> for Group <span class="hlt">Determination</span></span></a></p> <p><a target="_blank" href="http://www.gpo.gov/fdsys/browse/collectionCfr.action?selectedYearFrom=2011&page.go=Go">Code of Federal Regulations, 2011 CFR</a></p> <p></p> <p>2011-07-01</p> <p>... subject to subpart G of 40 CFR part 63, the owner or operator may measure HAP or TOC <span class="hlt">concentration</span> with... 40 CFR part 63, subpart G sources. Process vents subject to only 40 CFR part 60, subparts RRR or NNN... 40 Protection of Environment 15 2011-07-01 2011-07-01 false <span class="hlt">Concentration</span> for Group...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.gpo.gov/fdsys/pkg/CFR-2013-title40-vol16/pdf/CFR-2013-title40-vol16-part65-subpartD-app1.pdf','CFR2013'); return false;" href="https://www.gpo.gov/fdsys/pkg/CFR-2013-title40-vol16/pdf/CFR-2013-title40-vol16-part65-subpartD-app1.pdf"><span id="translatedtitle">40 CFR Table 1 to Subpart D of... - <span class="hlt">Concentration</span> for Group <span class="hlt">Determination</span></span></a></p> <p><a target="_blank" href="http://www.gpo.gov/fdsys/browse/collectionCfr.action?selectedYearFrom=2013&page.go=Go">Code of Federal Regulations, 2013 CFR</a></p> <p></p> <p>2013-07-01</p> <p>... subject to subpart G of 40 CFR part 63, the owner or operator may measure HAP or TOC <span class="hlt">concentration</span> with... 40 CFR part 63, subpart G sources. Process vents subject to only 40 CFR part 60, subparts RRR or NNN... 40 Protection of Environment 16 2013-07-01 2013-07-01 false <span class="hlt">Concentration</span> for Group...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.gpo.gov/fdsys/pkg/CFR-2012-title40-vol16/pdf/CFR-2012-title40-vol16-part65-subpartD-app1.pdf','CFR2012'); return false;" href="https://www.gpo.gov/fdsys/pkg/CFR-2012-title40-vol16/pdf/CFR-2012-title40-vol16-part65-subpartD-app1.pdf"><span id="translatedtitle">40 CFR Table 1 to Subpart D of... - <span class="hlt">Concentration</span> for Group <span class="hlt">Determination</span></span></a></p> <p><a target="_blank" href="http://www.gpo.gov/fdsys/browse/collectionCfr.action?selectedYearFrom=2012&page.go=Go">Code of Federal Regulations, 2012 CFR</a></p> <p></p> <p>2012-07-01</p> <p>... subject to subpart G of 40 CFR part 63, the owner or operator may measure HAP or TOC <span class="hlt">concentration</span> with... 40 CFR part 63, subpart G sources. Process vents subject to only 40 CFR part 60, subparts RRR or NNN... 40 Protection of Environment 16 2012-07-01 2012-07-01 false <span class="hlt">Concentration</span> for Group...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.gpo.gov/fdsys/pkg/CFR-2014-title40-vol16/pdf/CFR-2014-title40-vol16-part65-subpartD-app1.pdf','CFR2014'); return false;" href="https://www.gpo.gov/fdsys/pkg/CFR-2014-title40-vol16/pdf/CFR-2014-title40-vol16-part65-subpartD-app1.pdf"><span id="translatedtitle">40 CFR Table 1 to Subpart D of... - <span class="hlt">Concentration</span> for Group <span class="hlt">Determination</span></span></a></p> <p><a target="_blank" href="http://www.gpo.gov/fdsys/browse/collectionCfr.action?selectedYearFrom=2014&page.go=Go">Code of Federal Regulations, 2014 CFR</a></p> <p></p> <p>2014-07-01</p> <p>... subject to subpart G of 40 CFR part 63, the owner or operator may measure HAP or TOC <span class="hlt">concentration</span> with... 40 CFR part 63, subpart G sources. Process vents subject to only 40 CFR part 60, subparts RRR or NNN... 40 Protection of Environment 16 2014-07-01 2014-07-01 false <span class="hlt">Concentration</span> for Group...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.gpo.gov/fdsys/pkg/CFR-2013-title40-vol21/pdf/CFR-2013-title40-vol21-sec92-130.pdf','CFR2013'); return false;" href="https://www.gpo.gov/fdsys/pkg/CFR-2013-title40-vol21/pdf/CFR-2013-title40-vol21-sec92-130.pdf"><span id="translatedtitle">40 CFR 92.130 - <span class="hlt">Determination</span> of steady-state <span class="hlt">concentrations</span>.</span></a></p> <p><a target="_blank" href="http://www.gpo.gov/fdsys/browse/collectionCfr.action?selectedYearFrom=2013&page.go=Go">Code of Federal Regulations, 2013 CFR</a></p> <p></p> <p>2013-07-01</p> <p>... values shall be used instead of a steady-state or integrated <span class="hlt">concentration</span>: (1) The highest value of the... same units as the steady-state <span class="hlt">concentration</span>; this value is h. (iii) Bisect the peak height by drawing... the line described in paragraph (b)(2)(iv) of this section intersects the baseline; this value is...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.gpo.gov/fdsys/pkg/CFR-2011-title40-vol20/pdf/CFR-2011-title40-vol20-sec92-130.pdf','CFR2011'); return false;" href="https://www.gpo.gov/fdsys/pkg/CFR-2011-title40-vol20/pdf/CFR-2011-title40-vol20-sec92-130.pdf"><span id="translatedtitle">40 CFR 92.130 - <span class="hlt">Determination</span> of steady-state <span class="hlt">concentrations</span>.</span></a></p> <p><a target="_blank" href="http://www.gpo.gov/fdsys/browse/collectionCfr.action?selectedYearFrom=2011&page.go=Go">Code of Federal Regulations, 2011 CFR</a></p> <p></p> <p>2011-07-01</p> <p>... values shall be used instead of a steady-state or integrated <span class="hlt">concentration</span>: (1) The highest value of the... same units as the steady-state <span class="hlt">concentration</span>; this value is h. (iii) Bisect the peak height by drawing... the line described in paragraph (b)(2)(iv) of this section intersects the baseline; this value is...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.gpo.gov/fdsys/pkg/CFR-2010-title40-vol20/pdf/CFR-2010-title40-vol20-sec92-130.pdf','CFR'); return false;" href="https://www.gpo.gov/fdsys/pkg/CFR-2010-title40-vol20/pdf/CFR-2010-title40-vol20-sec92-130.pdf"><span id="translatedtitle">40 CFR 92.130 - <span class="hlt">Determination</span> of steady-state <span class="hlt">concentrations</span>.</span></a></p> <p><a target="_blank" href="http://www.gpo.gov/fdsys/browse/collectionCfr.action?selectedYearFrom=2010&page.go=Go">Code of Federal Regulations, 2010 CFR</a></p> <p></p> <p>2010-07-01</p> <p>... values shall be used instead of a steady-state or integrated <span class="hlt">concentration</span>: (1) The highest value of the... same units as the steady-state <span class="hlt">concentration</span>; this value is h. (iii) Bisect the peak height by drawing... the line described in paragraph (b)(2)(iv) of this section intersects the baseline; this value is...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.gpo.gov/fdsys/pkg/CFR-2014-title40-vol20/pdf/CFR-2014-title40-vol20-sec92-130.pdf','CFR2014'); return false;" href="https://www.gpo.gov/fdsys/pkg/CFR-2014-title40-vol20/pdf/CFR-2014-title40-vol20-sec92-130.pdf"><span id="translatedtitle">40 CFR 92.130 - <span class="hlt">Determination</span> of steady-state <span class="hlt">concentrations</span>.</span></a></p> <p><a target="_blank" href="http://www.gpo.gov/fdsys/browse/collectionCfr.action?selectedYearFrom=2014&page.go=Go">Code of Federal Regulations, 2014 CFR</a></p> <p></p> <p>2014-07-01</p> <p>... values shall be used instead of a steady-state or integrated <span class="hlt">concentration</span>: (1) The highest value of the... same units as the steady-state <span class="hlt">concentration</span>; this value is h. (iii) Bisect the peak height by drawing... the line described in paragraph (b)(2)(iv) of this section intersects the baseline; this value is...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.gpo.gov/fdsys/pkg/CFR-2012-title40-vol21/pdf/CFR-2012-title40-vol21-sec92-130.pdf','CFR2012'); return false;" href="https://www.gpo.gov/fdsys/pkg/CFR-2012-title40-vol21/pdf/CFR-2012-title40-vol21-sec92-130.pdf"><span id="translatedtitle">40 CFR 92.130 - <span class="hlt">Determination</span> of steady-state <span class="hlt">concentrations</span>.</span></a></p> <p><a target="_blank" href="http://www.gpo.gov/fdsys/browse/collectionCfr.action?selectedYearFrom=2012&page.go=Go">Code of Federal Regulations, 2012 CFR</a></p> <p></p> <p>2012-07-01</p> <p>... values shall be used instead of a steady-state or integrated <span class="hlt">concentration</span>: (1) The highest value of the... same units as the steady-state <span class="hlt">concentration</span>; this value is h. (iii) Bisect the peak height by drawing... the line described in paragraph (b)(2)(iv) of this section intersects the baseline; this value is...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ars.usda.gov/research/publications/publication/?seqNo115=257998','TEKTRAN'); return false;" href="http://www.ars.usda.gov/research/publications/publication/?seqNo115=257998"><span id="translatedtitle">Are dietary choline and betaine intakes <span class="hlt">determinants</span> of total homocysteine <span class="hlt">concentration</span>?</span></a></p> <p><a target="_blank" href="http://www.ars.usda.gov/services/TekTran.htm">Technology Transfer Automated Retrieval System (TEKTRAN)</a></p> <p></p> <p></p> <p>Elevated homocysteine <span class="hlt">concentrations</span> are associated with an increased risk of cardiovascular disease and a decline in cognitive function. Intakes of choline and betaine, as methyl donors, may affect homocysteine <span class="hlt">concentrations</span>. The objective was to examine whether choline and betaine intakes, assess...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014PhRvE..89c3017S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014PhRvE..89c3017S"><span id="translatedtitle"><span class="hlt">Concentration</span> dependence of nanochannel impedance and the <span class="hlt">determination</span> of surface charge</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Schiffbauer, Jarrod; Liel, Uri; Yossifon, Gilad</p> <p>2014-03-01</p> <p>In this paper, we demonstrate the variation of nanochannel impedance with bulk (reservoir) electrolyte <span class="hlt">concentration</span>. The impedance of a nanochannel is shown to correspond to a characteristic deformed semicircular arc. The degree of deformation decreases with increasing <span class="hlt">concentration</span>, and at a sufficiently low <span class="hlt">concentration</span> the complex impedance saturates, becoming essentially independent of the reservoir <span class="hlt">concentration</span>. This behavior is indicative of a surface-conduction dominant regime. Here we demonstrate that this effect extends beyond dc conductance and affects the ac response of the system as well, including both phase relationship and magnitude. The nanochannel resistance, obtained from low-voltage ac measurements, is then used to extract the nanochannel surface charge density. This is found to increase in magnitude with increasing electrolyte <span class="hlt">concentration</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2009WRR....45.6423G','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2009WRR....45.6423G"><span id="translatedtitle">An advanced passive diffusion sampler for the <span class="hlt">determination</span> of dissolved gas <span class="hlt">concentrations</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Gardner, P.; Solomon, D. K.</p> <p>2009-06-01</p> <p>We have designed and tested a passive headspace sampler for the collection of noble gases that allows for the precise calculation of dissolved gas <span class="hlt">concentrations</span> from measured gas mixing ratios. Gas permeable silicon tubing allows for gas exchange between the headspace in the sampler volume and the dissolved gases in the adjacent water. After reaching equilibrium, the aqueous-phase <span class="hlt">concentration</span> is related to the headspace <span class="hlt">concentration</span> by Henry's law. Gas exchange between the water and headspace can be shut off in situ, preserving the total dissolved gas pressure upon retrieval. Gas samples are then sealed in an all metal container, retaining even highly mobile helium. Dissolved noble gas <span class="hlt">concentrations</span> measured in these diffusion samplers are in good agreement with traditional copper tube aqueous-phase samples. These significantly reduce the laboratory labor in extracting the gases from a water sample and provide a simple and robust method for collecting dissolved gas <span class="hlt">concentrations</span> in a variety of aqueous environments.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/22280009','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/22280009"><span id="translatedtitle"><span class="hlt">Determination</span> of the geographic origin of rice by chemometrics with strontium and lead isotope ratios and multielement <span class="hlt">concentrations</span>.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Ariyama, Kaoru; Shinozaki, Miyuki; Kawasaki, Akira</p> <p>2012-02-22</p> <p>The objective of this study was to develop a technique for <span class="hlt">determining</span> the country of origin of rice in the Japanese market. The rice samples included a total of 350 products grown in Japan (n = 200), the United States (n = 50), China (n = 50), and Thailand (n = 50). In this study, (87)Sr/(86)Sr and Pb isotope ((204)Pb, (206)Pb, (207)Pb, and (208)Pb) ratios and multielement <span class="hlt">concentrations</span> (Al, Fe, Co, Ni, Cu, Rb, Sr, and Ba) were <span class="hlt">determined</span> by high-resolution inductively coupled plasma mass spectrometry. By combining three chemometric techniques based on different principles and <span class="hlt">determination</span> criteria, the countries of origin of rice were <span class="hlt">determined</span>. The predictions made by 10-fold cross-validation were around 97% accurate. The presented method demonstrated the effectiveness of <span class="hlt">determining</span> the geographic origin of an agricultural product by combining several chemometric techniques using heavy element isotope ratios and multielement <span class="hlt">concentrations</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19820024977','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19820024977"><span id="translatedtitle"><span class="hlt">Determination</span> of optimum sunlight <span class="hlt">concentration</span> level in space for 3-4 cascade solar cells</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Curtis, H. B.</p> <p>1982-01-01</p> <p>The optimum range of <span class="hlt">concentration</span> in space for III-V cascade cells has been calculated using a realistic solar cell diode equation. Temperature was varied with <span class="hlt">concentration</span> using several models and ranged from 55 deg at one sun to between 80 deg and 200 deg C at 100 suns. A variety of series resistance and internal resistances were used. Coefficients of the diffusion and recombination terms are strongly temperature dependent. The study indicates that the maximum efficiency of 30 percent occurs in the 50 to 100 X sun <span class="hlt">concentration</span> range provided series resistance is below 0.015 ohm sq cm and cell temperature is about 80 C at 100 suns.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19830007543','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19830007543"><span id="translatedtitle"><span class="hlt">Determination</span> of optimum sunlight <span class="hlt">concentration</span> level in space for 3-5 cascade solar cells</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Curtis, H. B.</p> <p>1982-01-01</p> <p>The optimum range of <span class="hlt">concentration</span> levels in space for III-V cascade cells was calculated using a realistic solar cell diode equation. Temperature was varied with <span class="hlt">concentration</span> using several models and ranged from 55 C at 1 sun to between 80 and 200 C at 100 suns. A variety of series resistance and internal resistances were used. Coefficients of the diffusion and recombination terms are strongly temperature dependent. The study indicates that the maximum efficiency of 30 percent occurs in the 50 to 100 sun <span class="hlt">concentration</span> range provided series resistance is below 0.015 ohm-sq cm and cell temperature is about 80 C at 100 suns.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/1123230','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/1123230"><span id="translatedtitle"><span class="hlt">Determination</span> of Uranium Metal <span class="hlt">Concentration</span> in Irradiated Fuel Storage Basin Sludge Using Selective Dissolution</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Delegard, Calvin H.; Sinkov, Sergey I.; Chenault, Jeffrey W.; Schmidt, Andrew J.; Welsh, Terri L.; Pool, Karl N.</p> <p>2014-03-01</p> <p>Uranium metal corroding in water-saturated sludges now held in the US Department of Energy Hanford Site K West irradiated fuel storage basin can create hazardous hydrogen atmospheres during handling, immobilization, or subsequent transport and storage. Knowledge of uranium metal <span class="hlt">concentration</span> in sludge thus is essential to safe sludge management and process design, requiring an expeditious routine analytical method to detect uranium metal <span class="hlt">concentrations</span> as low as 0.03 wt% in sludge even in the presence of 30 wt% or higher total uranium <span class="hlt">concentrations</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=20070032798&hterms=radiometric+calibration&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D20%26Ntt%3Dradiometric%2Bcalibration','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=20070032798&hterms=radiometric+calibration&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D20%26Ntt%3Dradiometric%2Bcalibration"><span id="translatedtitle"><span class="hlt">Absolute</span> Radiometric Calibration of EUNIS-06</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Thomas, R. J.; Rabin, D. M.; Kent, B. J.; Paustian, W.</p> <p>2007-01-01</p> <p>The Extreme-Ultraviolet Normal-Incidence Spectrometer (EUNIS) is a soundingrocket payload that obtains imaged high-resolution spectra of individual solar features, providing information about the Sun's corona and upper transition region. Shortly after its successful initial flight last year, a complete end-to-end calibration was carried out to <span class="hlt">determine</span> the instrument's <span class="hlt">absolute</span> radiometric response over its Longwave bandpass of 300 - 370A. The measurements were done at the Rutherford-Appleton Laboratory (RAL) in England, using the same vacuum facility and EUV radiation source used in the pre-flight calibrations of both SOHO/CDS and Hinode/EIS, as well as in three post-flight calibrations of our SERTS sounding rocket payload, the precursor to EUNIS. The unique radiation source provided by the Physikalisch-Technische Bundesanstalt (PTB) had been calibrated to an <span class="hlt">absolute</span> accuracy of 7% (l-sigma) at 12 wavelengths covering our bandpass directly against the Berlin electron storage ring BESSY, which is itself a primary radiometric source standard. Scans of the EUNIS aperture were made to <span class="hlt">determine</span> the instrument's <span class="hlt">absolute</span> spectral sensitivity to +- 25%, considering all sources of error, and demonstrate that EUNIS-06 was the most sensitive solar E W spectrometer yet flown. The results will be matched against prior calibrations which relied on combining measurements of individual optical components, and on comparisons with theoretically predicted 'insensitive' line ratios. Coordinated observations were made during the EUNIS-06 flight by SOHO/CDS and EIT that will allow re-calibrations of those instruments as well. In addition, future EUNIS flights will provide similar calibration updates for TRACE, Hinode/EIS, and STEREO/SECCHI/EUVI.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_20");'>20</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li class="active"><span>22</span></li> <li><a href="#" onclick='return showDiv("page_23");'>23</a></li> <li><a href="#" onclick='return showDiv("page_24");'>24</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_22 --> <div id="page_23" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li class="active"><span>23</span></li> <li><a href="#" onclick='return showDiv("page_24");'>24</a></li> <li><a href="#" onclick='return showDiv("page_25");'>25</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="441"> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/8313598','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/8313598"><span id="translatedtitle">Effects of specimen turbidity and glycerol <span class="hlt">concentration</span> on nine enzymatic methods for triglyceride <span class="hlt">determination</span>.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Sampson, M; Ruddel, M; Elin, R J</p> <p>1994-02-01</p> <p>We compared the effects of specimen turbidity and glycerol <span class="hlt">concentration</span> on nine enzymatic methods for triglyceride measurement. We assayed 51 specimens with triglyceride <span class="hlt">concentrations</span> of 0.85-8.21 mmol/L (75-727 mg/dL) and turbidity at 420 nm equivalent to > or = 0.1 mmol/L (8.8 mg/dL) triglyceride (measured as part of our comparison method). The data were analyzed by multiple regression, which gave coefficients for the effects of glycerol <span class="hlt">concentration</span> and the change in turbidity during the reaction. The effects of specimen turbidity and glycerol <span class="hlt">concentration</span> were method-dependent and ranged from 6.20% to -15.67% of the measured result. The magnitude of the turbidity effect (in assays with a significant turbidity interference) was similar to that for glycerol (in assays with a significant glycerol interference). A triglyceride assay with a bichromatic measurement was less subject to interference from turbidity.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://cfpub.epa.gov/si/si_public_record_report.cfm?dirEntryId=105101&keyword=biopsy&actType=&TIMSType=+&TIMSSubTypeID=&DEID=&epaNumber=&ntisID=&archiveStatus=Both&ombCat=Any&dateBeginCreated=&dateEndCreated=&dateBeginPublishedPresented=&dateEndPublishedPresented=&dateBeginUpdated=&dateEndUpdated=&dateBeginCompleted=&dateEndCompleted=&personID=&role=Any&journalID=&publisherID=&sortBy=revisionDate&count=50&CFID=65141553&CFTOKEN=56151301','EPA-EIMS'); return false;" href="http://cfpub.epa.gov/si/si_public_record_report.cfm?dirEntryId=105101&keyword=biopsy&actType=&TIMSType=+&TIMSSubTypeID=&DEID=&epaNumber=&ntisID=&archiveStatus=Both&ombCat=Any&dateBeginCreated=&dateEndCreated=&dateBeginPublishedPresented=&dateEndPublishedPresented=&dateBeginUpdated=&dateEndUpdated=&dateBeginCompleted=&dateEndCompleted=&personID=&role=Any&journalID=&publisherID=&sortBy=revisionDate&count=50&CFID=65141553&CFTOKEN=56151301"><span id="translatedtitle">A BIOPSY PROCEDURE FOR <span class="hlt">DETERMINING</span> FILET AND PREDICTING WHOLE-FISH MERCURY <span class="hlt">CONCENTRATION</span></span></a></p> <p><a target="_blank" href="http://oaspub.epa.gov/eims/query.page">EPA Science Inventory</a></p> <p></p> <p></p> <p>Although mercury contamination of fish is a widespread phenomenon, its regional evaluation is hindered by the reluctance of permitting agencies to grant collection permits, securing adequate freezer space, and processing whole, large fish or filets. We evaluated Hg <span class="hlt">concentration</span>...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://pubs.er.usgs.gov/publication/70169863','USGSPUBS'); return false;" href="http://pubs.er.usgs.gov/publication/70169863"><span id="translatedtitle"><span class="hlt">Determining</span> the 95% limit of detection for waterborne pathogen analyses from primary <span class="hlt">concentration</span> to qPCR</span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Stokdyk, Joel P.; Firnstahl, Aaron; Spencer, Susan K.; Burch, Tucker R; Borchardt, Mark A.</p> <p>2016-01-01</p> <p>The limit of detection (LOD) for qPCR-based analyses is not consistently defined or <span class="hlt">determined</span> in studies on waterborne pathogens. Moreover, the LODs reported often reflect the qPCR assay alone rather than the entire sample process. Our objective was to develop an approach to <span class="hlt">determine</span> the 95% LOD (lowest <span class="hlt">concentration</span> at which 95% of positive samples are detected) for the entire process of waterborne pathogen detection. We began by spiking the lowest <span class="hlt">concentration</span> that was consistently positive at the qPCR step (based on its standard curve) into each procedural step working backwards (i.e., extraction, secondary <span class="hlt">concentration</span>, primary <span class="hlt">concentration</span>), which established a <span class="hlt">concentration</span> that was detectable following losses of the pathogen from processing. Using the fraction of positive replicates (n = 10) at this <span class="hlt">concentration</span>, we selected and analyzed a second, and then third, <span class="hlt">concentration</span>. If the fraction of positive replicates equaled 1 or 0 for two <span class="hlt">concentrations</span>, we selected another. We calculated the LOD using probit analysis. To demonstrate our approach we <span class="hlt">determined</span> the 95% LOD for Salmonella enterica serovar Typhimurium, adenovirus 41, and vaccine-derived poliovirus Sabin 3, which were 11, 12, and 6 genomic copies (gc) per reaction (rxn), respectively (equivalent to 1.3, 1.5, and 4.0 gc L−1 assuming the 1500 L tap-water sample volume prescribed in EPA Method 1615). This approach limited the number of analyses required and was amenable to testing multiple genetic targets simultaneously (i.e., spiking a single sample with multiple microorganisms). An LOD <span class="hlt">determined</span> this way can facilitate study design, guide the number of required technical replicates, aid method evaluation, and inform data interpretation.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015SPIE.9619E..0MR','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015SPIE.9619E..0MR"><span id="translatedtitle"><span class="hlt">Determination</span> of glucose <span class="hlt">concentration</span> based on pulsed laser induced photoacoustic technique and least square fitting algorithm</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Ren, Zhong; Liu, Guodong; Huang, Zhen</p> <p>2015-08-01</p> <p>In this paper, a noninvasive glucose <span class="hlt">concentration</span> monitoring setup based on the photoacoustic technique was established. In this setup, a 532nm pumped Q switched Nd: YAG tunable pulsed laser with repetition rate of 20Hz was used as the photoacoustic excitation light source, and a ultrasonic transducer with central response frequency of 9.55MHz was used as the detector of the photoacoustic signal of glucose. As the preliminary exploration of the blood glucose <span class="hlt">concentration</span>, a series of in vitro photoacoustic monitoring of glucose aqueous solutions by using the established photoacoustic setup were performed. The photoacoustic peak-to-peak values of different <span class="hlt">concentrations</span> of glucose aqueous solutions induced by the pulsed laser with output wavelength of 1300nm to 2300nm in interval of 10nm were obtained with the average times of 512. The differential spectral and the first order derivative spectral method were used to get the characteristic wavelengths. For the characteristic wavelengths of glucose, the least square fitting algorithm was used to establish the relationship between the glucose <span class="hlt">concentrations</span> and photoacoustic peak-to-peak values. The characteristic wavelengths and the predicted <span class="hlt">concentrations</span> of glucose solution were obtained. Experimental results demonstrated that the prediction effect of characteristic wavelengths of 1410nm and 1510nm were better than others, and this photoacoustic setup and analysis method had a certain potential value in the monitoring of the blood glucose <span class="hlt">concentration</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/23622475','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/23622475"><span id="translatedtitle"><span class="hlt">Concentrations</span> of drugs <span class="hlt">determined</span> in blood samples collected from suspected drugged drivers in England and Wales.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Burch, Hilary J; Clarke, Elizabeth J; Hubbard, Alison M; Scott-Ham, Michael</p> <p>2013-05-01</p> <p>This communication reports the blood <span class="hlt">concentrations</span> of alcohol and drugs from 376 cases of alleged driving under the influence of drugs analysed at the Forensic Science Service Chorley and London laboratories between February 2010 and March 2011. The samples were analysed for alcohol, amphetamine, benzodiazepines, cocaine, MDMA, opiates, γ-hydroxybutyrate (GHB), ketamine, methadone and methylmethcathinone (the 4-isomer of which is known as mephedrone). The results were interpreted with respect to the number and type of drugs of abuse detected and the <span class="hlt">concentrations</span> measured. Alcohol was quantified in 113 cases (30%), and of these a level in excess of the prescribed UK limit for driving of 80 mg% was present in 90 cases. In 80 cases, only the <span class="hlt">concentration</span> of alcohol was measured, the <span class="hlt">concentrations</span> of both drugs and alcohol were measured in 33 cases. In the remaining 263 cases, only the <span class="hlt">concentrations</span> of relevant drugs of abuse were measured. The most common drug of abuse quantified was cocaine which was detected in 92 cases, either as the active drug or as its major metabolite benzoylecgonine, followed by diazepam which was quantified in 76 cases. <span class="hlt">Concentrations</span> of some new drugs, and drugs rarely reported in driving under the influence cases are also presented.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/8727517','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/8727517"><span id="translatedtitle"><span class="hlt">Determination</span> of cadmium-metallothioneins in zebra mussels exposed to subchronic <span class="hlt">concentrations</span> of Cd2+.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Tessier, C; Blais, J S</p> <p>1996-04-01</p> <p>Metallothioneins have been detected and investigated in zebra mussels (Dreissena polymorpha) using high-performance liquid chromatography (size exclusion) coupled with microatomization-AAS or inductively coupled plasma mass spectrometry. The mussels were exposed to 0.2, 2, and 20 micrograms/liter Cd2+ (as CdCl2) for 1 month under controlled temperature and dietary conditions. Elevated (relative to control) <span class="hlt">concentrations</span> of tissue Cd2+ were detected in all specimens exposed to 2 micrograms Cd/liter and more than 50% of the specimens exposed to 0.2 micrograms Cd/liter, demonstrating that Dreissena cannot regulate Cd2+ at trace exposure <span class="hlt">concentrations</span>. In most specimens, at least 85% of the measured Cd2+ was bound to metallothioneins. After reduction and exposure to excess Cd2+, the metallothionein fraction of all extracts adsorbed similar quantities of Cd2+, indicating that the physiological <span class="hlt">concentration</span> of metallothionein in the exposed specimens remained similar to the basal <span class="hlt">concentration</span> in the control specimens. Thus, a short-term exposure to environmentally relevant <span class="hlt">concentrations</span> of Cd2+ did not produce a genetic induction of metallothionein biosynthesis as generally observed in specimens exposed to higher <span class="hlt">concentrations</span> of d10 metals.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/27090731','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/27090731"><span id="translatedtitle">Influence of Analyte <span class="hlt">Concentration</span> on Stability Constant Values <span class="hlt">Determined</span> by Capillary Electrophoresis.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Sursyakova, Viktoria V; Burmakina, Galina V; Rubaylo, Anatoly I</p> <p>2016-08-01</p> <p>The influence of analyte <span class="hlt">concentration</span> when compared with the <span class="hlt">concentration</span> of a charged ligand in background electrolyte (BGE) on the measured values of electrophoretic mobilities and stability constants (association, binding or formation constants) is studied using capillary electrophoresis (CE) and a dynamic mathematical simulator of CE. The study is performed using labile complexes (with fast kinetics) of iron (III) and 5-sulfosalicylate ions (ISC) as an example. It is shown that because the ligand <span class="hlt">concentration</span> in the analyte zone is not equal to that in BGE, considerable changes in the migration times and electrophoretic mobilities are observed, resulting in systematic errors in the stability constant values. Of crucial significance is the slope of the dependence of the electrophoretic mobility decrease on the ligand equilibrium <span class="hlt">concentration</span>. Without prior information on this dependence to accurately evaluate the stability constants for similar systems, the total ligand <span class="hlt">concentration</span> must be at least >50-100 times higher than the total <span class="hlt">concentration</span> of analyte. Experimental ISC peak fronting and the difference between the direction of the experimental pH dependence of the electrophoretic mobility decrease and the mathematical simulation allow assuming the presence of capillary wall interaction. PMID:27090731</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/26432028','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/26432028"><span id="translatedtitle">Host-parasite relationships as <span class="hlt">determinants</span> of heavy metal <span class="hlt">concentrations</span> in perch (Perca fluviatilis) and its intestinal parasite infection.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Brázová, Tímea; Hanzelová, Vladimíra; Miklisová, Dana; Šalamún, Peter; Vidal-Martínez, Víctor M</p> <p>2015-12-01</p> <p>The <span class="hlt">concentrations</span> of As, Cd, Cr, Cu, Hg, Mn, Ni, Pb, and Zn and their bioconcentration factors (BCFs) were <span class="hlt">determined</span> in two intestinal parasites, an acanthocephalan, Acanthocephalus lucii, a tapeworm, Proteocephalus percae, present in the same host, the European perch (Perca fluviatilis, L.), in the heavily polluted Ružín reservoir in eastern Slovakia. The bioaccumulation of heavy metals in the fish organs and parasites was studied for acanthocephalan and tapeworm monoinfections or mixed infections by the two parasites and for the size of their parasitic infrapopulations. Bioconcentration factors (c[parasite]/c[muscle tissue]) showed that the <span class="hlt">concentrations</span> of As, Ni, Pb and Zn were higher in mixed infections than in monoinfections. Negative correlations between heavy metal <span class="hlt">concentrations</span> in perch organs and the parasites were found. For example, higher <span class="hlt">concentrations</span> of Ni and Zn in both parasite species corresponded with lower metal <span class="hlt">concentrations</span> in perch and hard roe. Likewise, significant negative relationships between metal <span class="hlt">concentrations</span> in fish organs and number of parasites were noticed with lower levels of Pb in fish harbouring higher numbers of tapeworms. Similarly, in both parasite species the <span class="hlt">concentrations</span> of some essential elements (Cr, Mn) were lower at high infection intensities compared to low intensities. Our study revealed that the differential <span class="hlt">concentration</span> of heavy metals in perch organs was affected by the type of infection (mono- or mixed-infection), and needs to be considered in field ecotoxicological and parasitological studies as a potentially important factor influencing the pollutant <span class="hlt">concentrations</span> in fish.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/26432028','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/26432028"><span id="translatedtitle">Host-parasite relationships as <span class="hlt">determinants</span> of heavy metal <span class="hlt">concentrations</span> in perch (Perca fluviatilis) and its intestinal parasite infection.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Brázová, Tímea; Hanzelová, Vladimíra; Miklisová, Dana; Šalamún, Peter; Vidal-Martínez, Víctor M</p> <p>2015-12-01</p> <p>The <span class="hlt">concentrations</span> of As, Cd, Cr, Cu, Hg, Mn, Ni, Pb, and Zn and their bioconcentration factors (BCFs) were <span class="hlt">determined</span> in two intestinal parasites, an acanthocephalan, Acanthocephalus lucii, a tapeworm, Proteocephalus percae, present in the same host, the European perch (Perca fluviatilis, L.), in the heavily polluted Ružín reservoir in eastern Slovakia. The bioaccumulation of heavy metals in the fish organs and parasites was studied for acanthocephalan and tapeworm monoinfections or mixed infections by the two parasites and for the size of their parasitic infrapopulations. Bioconcentration factors (c[parasite]/c[muscle tissue]) showed that the <span class="hlt">concentrations</span> of As, Ni, Pb and Zn were higher in mixed infections than in monoinfections. Negative correlations between heavy metal <span class="hlt">concentrations</span> in perch organs and the parasites were found. For example, higher <span class="hlt">concentrations</span> of Ni and Zn in both parasite species corresponded with lower metal <span class="hlt">concentrations</span> in perch and hard roe. Likewise, significant negative relationships between metal <span class="hlt">concentrations</span> in fish organs and number of parasites were noticed with lower levels of Pb in fish harbouring higher numbers of tapeworms. Similarly, in both parasite species the <span class="hlt">concentrations</span> of some essential elements (Cr, Mn) were lower at high infection intensities compared to low intensities. Our study revealed that the differential <span class="hlt">concentration</span> of heavy metals in perch organs was affected by the type of infection (mono- or mixed-infection), and needs to be considered in field ecotoxicological and parasitological studies as a potentially important factor influencing the pollutant <span class="hlt">concentrations</span> in fish. PMID:26432028</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=2231632','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=2231632"><span id="translatedtitle"><span class="hlt">Determinants</span> of Allergen <span class="hlt">Concentrations</span> in Apartments of Asthmatic Children Living in Public Housing</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Levy, Jonathan I.; Rogers, Christine A.; Burge, Harriet A.; Spengler, John D.</p> <p>2007-01-01</p> <p>There is growing evidence linking poor housing conditions and respiratory diseases, including asthma. The association between housing conditions and asthma in the inner city has been attributed in part to cockroach and mouse infestation and the resulting allergen exposures. Multiple social and behavioral factors can influence environmental exposures and health conditions, necessitating a thorough examination of such factors. As part of the Healthy Public Housing Initiative, we evaluated the association between physical and household characteristics and pest-related allergen levels in three public housing developments in Boston, MA. We detected cockroach allergens (Bla g 1 and Bla g 2) in bedroom air, bed, and especially high <span class="hlt">concentrations</span> in kitchen samples. In multivariate Tobit regressions controlling for development and season, clutter and lack of cleanliness in the apartment were associated with a tenfold increase in Bla g 1 <span class="hlt">concentration</span> in the air, a sevenfold increase in Bla g 1 and an eightfold increase in Bla g 2 <span class="hlt">concentrations</span> in the bed, and an 11-fold increase in Bla g 2 in the kitchen (p<0.05 for all). Holes in the wall/ceiling were associated with a six- to 11-fold increase in kitchen cockroach allergen <span class="hlt">concentrations</span> (p<0.05). Occupancy in an apartment unit of 2 years or more was also associated with increased cockroach allergen <span class="hlt">concentrations</span>. In contrast, there were low <span class="hlt">concentrations</span> of mouse urinary protein in this population. In conclusion, these results suggest that interventions in these homes should focus on reducing cockroach allergen <span class="hlt">concentrations</span> and that building-wide interventions should be supplemented with targeted efforts focused on high-risk units. PMID:17216349</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://pubs.er.usgs.gov/publication/70020169','USGSPUBS'); return false;" href="http://pubs.er.usgs.gov/publication/70020169"><span id="translatedtitle">Metal exposures to native populations of the caddisfly Hydropsyche (Trichoptera: Hydropsychidae) <span class="hlt">determined</span> from cytosolic and whole body metal <span class="hlt">concentrations</span></span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Cain, D.J.; Luoma, S.N.</p> <p>1998-01-01</p> <p>Metal <span class="hlt">concentrations</span> of the soluble fraction of the cytoplasm (cytosol) and the whole body were <span class="hlt">determined</span> in the caddisfly Hydropsyche spp. (Trichoptera). Metal accumulation in the cytosol and the whole body were compared in samples collected along 380 kms of a contamination gradient in the Clark Fork river in four consecutive years (1992-1995), and from a contaminated tributary (Flint Creek). Samples from the contaminated sites were compared to an uncontaminated tributary (Blackfoot River). Relations between cytosolic metal <span class="hlt">concentration</span> and cytosolic protein (used as a general biomarker of protein metabolism) also were examined in 1994 and 1995. Relative to whole body <span class="hlt">concentrations</span>, cytosolic metal <span class="hlt">concentrations</span> varied among metals and years. Spatial patterns in whole body and cytosolic Cd, Cu and Pb <span class="hlt">concentrations</span> were qualitatively similar each year, and these <span class="hlt">concentrations</span> generally corresponded to contamination levels measured in bed sediments. The proportions of metals recovered in the cytosol of ranged from 12 to 64% for Cd and Cu and from 2 to 38% for Pb. Zinc in the whole body also was consistent with contamination levels, but cytosolic Zn <span class="hlt">concentrations</span> increased only at the highest whole body Zn <span class="hlt">concentrations</span>. As a result, the proportion of Zn recovered in the cytosol ranged from 16 to 63% and tended to be inversely related to whole body Zn <span class="hlt">concentrations</span>. The proportions of cytosolic metals varied significantly among years and, as a result, interannual differences in metal <span class="hlt">concentrations</span> were greater in the cytosol than in the whole body. The results demonstrated that Hydropsyche in the river were chronically exposed to biologically available metals. Some features of this exposure were not evident from whole body <span class="hlt">concentrations</span>. In general, protein levels did not correspond to cytosolic metal <span class="hlt">concentrations</span>. A variety of environmental factors could interact with metal exposures to produce complex responses in protein metabolism. Systematic study</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/24969531','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/24969531"><span id="translatedtitle">Why to compare <span class="hlt">absolute</span> numbers of mitochondria.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Schmitt, Sabine; Schulz, Sabine; Schropp, Eva-Maria; Eberhagen, Carola; Simmons, Alisha; Beisker, Wolfgang; Aichler, Michaela; Zischka, Hans</p> <p>2014-11-01</p> <p>Prompted by pronounced structural differences between rat liver and rat hepatocellular carcinoma mitochondria, we suspected these mitochondrial populations to differ massively in their molecular composition. Aiming to reveal these mitochondrial differences, we came across the issue on how to normalize such comparisons and decided to focus on the <span class="hlt">absolute</span> number of mitochondria. To this end, fluorescently stained mitochondria were quantified by flow cytometry. For rat liver mitochondria, this approach resulted in mitochondrial protein contents comparable to earlier reports using alternative methods. We <span class="hlt">determined</span> similar protein contents for rat liver, heart and kidney mitochondria. In contrast, however, lower protein contents were <span class="hlt">determined</span> for rat brain mitochondria and for mitochondria from the rat hepatocellular carcinoma cell line McA 7777. This result challenges mitochondrial comparisons that rely on equal protein amounts as a typical normalization method. Exemplarily, we therefore compared the activity and susceptibility toward inhibition of complex II of rat liver and hepatocellular carcinoma mitochondria and obtained significant discrepancies by either normalizing to protein amount or to <span class="hlt">absolute</span> mitochondrial number. Importantly, the latter normalization, in contrast to the former, demonstrated a lower complex II activity and higher susceptibility toward inhibition in hepatocellular carcinoma mitochondria compared to liver mitochondria. These findings demonstrate that solely normalizing to protein amount may obscure essential molecular differences between mitochondrial populations.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/27173565','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/27173565"><span id="translatedtitle">Quantitative <span class="hlt">determination</span> of aflatoxin B1 <span class="hlt">concentration</span> in acetonitrile by chemometric methods using terahertz spectroscopy.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Ge, Hongyi; Jiang, Yuying; Lian, Feiyu; Zhang, Yuan; Xia, Shanhong</p> <p>2016-10-15</p> <p>Aflatoxins contaminate and colonize agricultural products, such as grain, and thereby potentially cause human liver carcinoma. Detection via conventional methods has proven to be time-consuming and complex. In this paper, the terahertz (THz) spectra of aflatoxin B1 in acetonitrile solutions with <span class="hlt">concentration</span> ranges of 1-50μg/ml and 1-50μg/l are obtained and analyzed for the frequency range of 0.4-1.6THz. Linear and nonlinear regression models are constructed to relate the absorption spectra and the <span class="hlt">concentrations</span> of 160 samples using the partial least squares (PLS), principal component regression (PCR), support vector machine (SVM), and PCA-SVM methods. Our results indicate that PLS and PCR models are more accurate for the <span class="hlt">concentration</span> range of 1-50μg/ml, whereas SVM and PCA-SVM are more accurate for the <span class="hlt">concentration</span> range of 1-50μg/l. Furthermore, ten unknown <span class="hlt">concentration</span> samples extracted from mildewed maize are analyzed quantitatively using these methods. PMID:27173565</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/20982781','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/20982781"><span id="translatedtitle">The <span class="hlt">determinants</span> of hydrogen <span class="hlt">concentrations</span> in hydrogenated amorphous silicon films prepared using a triode deposition system</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Shimizu, Satoshi; Matsuda, Akihisa; Kondo, Michio</p> <p>2007-03-15</p> <p>It is important to reduce the hydrogen <span class="hlt">concentration</span>, in particular, the Si-H{sub 2} bond <span class="hlt">concentration</span>, in a hydrogenated amorphous silicon film to improve its light-soaking stability. In a previous study, we found that a triode configuration plasma enhanced chemical vapor deposition method provides high quality and a very low hydrogen <span class="hlt">concentration</span> film; however, the origin of the hydrogen reduction has been unknown. In this article, we investigate the essential factor causing the very low hydrogen <span class="hlt">concentrations</span> observed in the triode system. In several experiments, we observed strong influences of deposition precursors on the resulting hydrogen <span class="hlt">concentrations</span>. We propose that due to a steric hindrance, the hydrogen elimination process during film growth is disturbed when higher silane radicals stick to a growth surface. In a triode system, corresponding with the separation of the film growth surface from the precursor generation region, the contribution of higher silane radicals to film growth is suppressed due to their short diffusion length and frequent collisions with silane molecules.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/23595410','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/23595410"><span id="translatedtitle"><span class="hlt">Determination</span> of radon <span class="hlt">concentration</span> levels in well water in Konya, Turkey.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Erdogan, M; Eren, N; Demirel, S; Zedef, V</p> <p>2013-10-01</p> <p>Radon ((222)Rn) measurements were undertaken in 16 samples of well water representing different depths and different types of aquifers found at the city centre of Konya, Central Turkey. The radon activity <span class="hlt">concentrations</span> of the well water samples collected in the spring and summer seasons of 2012 were measured by using the radon gas analyser (AlphaGUARD PQ 2000PRO). The radon <span class="hlt">concentrations</span> for spring and summer seasons are 2.29 ± 0.17 to 27.25 ± 1.07 and 1.44 ± 0.18 to 27.45 ± 1.25 Bq l(-1), respectively. The results at hand revealed that the radon <span class="hlt">concentration</span> levels of the waters strictly depend on the seasons and are slightly variable with depth. Eleven of the 16 well water samples had radon <span class="hlt">concentration</span> levels below the safe limit of 11.11 Bq l(-1) recommended by the United States Environmental Protection Agency. However, all measured radon <span class="hlt">concentration</span> levels are well below the 100 Bq l(-1) safe limit declared by the World Health Organisation. The doses resulting from the consumption of these waters were calculated. The calculated minimum and maximum effective doses are 0.29 and 5.49 µSv a(-1), respectively. PMID:23595410</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/17514980','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/17514980"><span id="translatedtitle">[CAIS correction for blood matrix effect on <span class="hlt">determination</span> of lead <span class="hlt">concentration</span> and isotope ratio by ICP-MS].</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Zeng, Jing; Wang, Xiao-yan; Liu, Hu-sheng; Dun, Zhe; Zhai, Lei; Wang, Jing-yu</p> <p>2007-02-01</p> <p>The research studied the influence of matrix effect on the <span class="hlt">determination</span> of lead <span class="hlt">concentration</span> and isotope ratio through simulating blood matrix, and its correction by common analyte internal standardization (CAIS) method. The experiment results showed that CAIS method was suitable for the multi-element-matrix. The relative errors between the <span class="hlt">determined</span> and the true <span class="hlt">concentration</span> values are 20% (without correction), 8% (by conventional internal reference correction) and 2% (by CAIS correction), respectively. Otherwise, the influence of matrix effect and its correction for isotope ratio <span class="hlt">determination</span> are not that obvious. Similarity of the mass number and properties between internal reference and analyte elements seems not important for CAIS correction, since very close correction results were obtained by using Tl and Dy as internal reference elements. Besides, correction results are not affected by different matrix dilution. Reliability and practicality of CAIS were proved by bovine blood standard material <span class="hlt">determination</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4269781','PMC'); return false;" href="http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4269781"><span id="translatedtitle">Tetracycline <span class="hlt">Determines</span> the Conformation of Its Aptamer at Physiological Magnesium <span class="hlt">Concentrations</span></span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Reuss, Andreas J.; Vogel, Marc; Weigand, Julia E.; Suess, Beatrix; Wachtveitl, Josef</p> <p>2014-01-01</p> <p>Synthetic riboswitches are versatile tools for the study and manipulation of biological systems. Yet, the underlying mechanisms governing its structural properties and regulation under physiological conditions are poorly studied. We performed spectroscopic and calorimetric experiments to explore the folding kinetics and thermodynamics of the tetracycline-binding aptamer, which can be employed as synthetic riboswitch, in the range of physiological magnesium <span class="hlt">concentrations</span>. The dissociation constant of the ligand-aptamer complex was found to strongly depend on the magnesium <span class="hlt">concentration</span>. At physiological magnesium <span class="hlt">concentrations</span>, tetracycline induces a significant conformational shift from a compact, but heterogeneous intermediate state toward the completely formed set of tertiary interactions defining the regulation-competent structure. Thus, the switching functionality of the tetracycline-binding aptamer appears to include both a conformational rearrangement toward the regulation-competent structure and its thermodynamic stabilization. PMID:25517161</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015SPIE.9668E..5WA','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015SPIE.9668E..5WA"><span id="translatedtitle"><span class="hlt">Determination</span> of effect factor for effective parameter on saccharification of lignocellulosic material by <span class="hlt">concentrated</span> acid</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Aghili, Sina; Nodeh, Ali Arasteh</p> <p>2015-12-01</p> <p>Tamarisk usage as a new group of lignocelluloses material to produce fermentable sugars in bio ethanol process was studied. The overall aim of this work was to establish the optimum condition for acid hydrolysis of this new material and a mathematical model predicting glucose release as a function of operation variable. Sulfuric acid <span class="hlt">concentration</span> in the range of 20 to 60%(w/w), process temperature between 60 to 95oC, hydrolysis time from 120 to 240 min and solid content 5,10,15%(w/w) were used as hydrolysis conditions. HPLC was used to analysis of the product. This analysis indicated that glucose was the main fermentable sugar and was increase with time, temperature and solid content and acid <span class="hlt">concentration</span> was a parabola influence in glucose production. The process was modeled by a quadratic equation. Curve study and model were found that 42% acid <span class="hlt">concentration</span>, 15 % solid content and 90oC were optimum condition.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3672909','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3672909"><span id="translatedtitle"><span class="hlt">Determinants</span> and Within-Person Variability of Urinary Cadmium <span class="hlt">Concentrations</span> among Women in Northern California</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Gunier, Robert B.; Horn-Ross, Pamela L.; Canchola, Alison J.; Duffy, Christine N.; Reynolds, Peggy; Hertz, Andrew; Garcia, Erika</p> <p>2013-01-01</p> <p>Background: Cadmium (Cd) is a toxic metal associated with increased morbidity and mortality. Urinary Cd (U-Cd) <span class="hlt">concentration</span> is considered a biomarker of long-term exposure. Objectives: Our objectives were to evaluate the within-person correlation among repeat samples and to identify predictors of U-Cd <span class="hlt">concentrations</span>. Methods: U-Cd <span class="hlt">concentrations</span> (micrograms per liter) were measured in 24-hr urine samples collected from 296 women enrolled in the California Teachers Study in 2000 and a second 24-hr sample collected 3–9 months later from 141 of the participants. Lifestyle and sociodemographic characteristics were obtained via questionnaires. The Total Diet Study database was used to quantify dietary cadmium intake based on a food frequency questionnaire. We estimated environmental cadmium emissions near participants’ residences using a geographic information system. Results: The geometric mean U-Cd <span class="hlt">concentration</span> was 0.27 µg/L and the range was 0.1–3.6 µg/L. The intraclass correlation among repeat samples from an individual was 0.50. The use of a single 24-hr urine specimen to characterize Cd exposure in a case–control study would result in an observed odds ratio of 1.4 for a true odds ratio of 2.0. U-Cd <span class="hlt">concentration</span> increased with creatinine, age, and lifetime pack-years of smoking among ever smokers or lifetime intensity-years of passive smoking among nonsmokers, whereas it decreased with greater alcohol consumption and number of previous pregnancies. These factors explained 42–44% of the variability in U-Cd <span class="hlt">concentrations</span>. Conclusion: U-Cd levels varied with several individual characteristics, and a single measurement of U-Cd in a 24-hr sample did not accurately reflect medium- to long-term body burden. PMID:23552363</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19790013324','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19790013324"><span id="translatedtitle">The AFGL <span class="hlt">absolute</span> gravity program</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Hammond, J. A.; Iliff, R. L.</p> <p>1978-01-01</p> <p>A brief discussion of the AFGL's (Air Force Geophysics Laboratory) program in <span class="hlt">absolute</span> gravity is presented. Support of outside work and in-house studies relating to gravity instrumentation are discussed. A description of the current transportable system is included and the latest results are presented. These results show good agreement with measurements at the AFGL site by an Italian system. The accuracy obtained by the transportable apparatus is better than 0.1 microns sq sec 10 microgal and agreement with previous measurements is within the combined uncertainties of the measurements.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li class="active"><span>23</span></li> <li><a href="#" onclick='return showDiv("page_24");'>24</a></li> <li><a href="#" onclick='return showDiv("page_25");'>25</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_23 --> <div id="page_24" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li><a href="#" onclick='return showDiv("page_23");'>23</a></li> <li class="active"><span>24</span></li> <li><a href="#" onclick='return showDiv("page_25");'>25</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="461"> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=1287535','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=1287535"><span id="translatedtitle">Familial Aggregation of <span class="hlt">Absolute</span> Pitch</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Baharloo, Siamak; Service, Susan K.; Risch, Neil; Gitschier, Jane; Freimer, Nelson B.</p> <p>2000-01-01</p> <p><span class="hlt">Absolute</span> pitch (AP) is a behavioral trait that is defined as the ability to identify the pitch of tones in the absence of a reference pitch. AP is an ideal phenotype for investigation of gene and environment interactions in the development of complex human behaviors. Individuals who score exceptionally well on formalized auditory tests of pitch perception are designated as “AP-1.” As described in this report, auditory testing of siblings of AP-1 probands and of a control sample indicates that AP-1 aggregates in families. The implications of this finding for the mapping of loci for AP-1 predisposition are discussed. PMID:10924408</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/416372','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/416372"><span id="translatedtitle"><span class="hlt">Determination</span> of optimal sulfate <span class="hlt">concentration</span> for methane production from volatile fatty acids</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Demafelis, R.B.; Tomita, Osamu; Kajiuchi, Toshio</p> <p>1996-12-31</p> <p>The effect of sulfate on methane production from individual volatile fatty acids were investigated using batch cultures. Optimum sulfate <span class="hlt">concentrations</span> were found to be at 220mg/l for propionate digestion and 55mg/l for butyrate and valerate digestions. Methane productions were significantly increased at these conditions compared to cultures containing no sulfates. Hydrogen sulfide levels, at optimum sulfate <span class="hlt">concentration</span> were relatively low up to 0.7 % in the gas phase. Sulfate reducing bacteria (SRB) predominates the bacterial population while Methanosaeta concilii outnumbered Methanospirillium hungatei. 7 refs., 3 figs.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2001SPIE.4434..260B&link_type=ABSTRACT','NASAADS'); return false;" href="http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2001SPIE.4434..260B&link_type=ABSTRACT"><span id="translatedtitle">Development of a novel noninvasive sensor for <span class="hlt">determination</span> of blood glucose <span class="hlt">concentration</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Boeckle, Stefan; Rovati, Luigi; Ansari, Rafat R.</p> <p>2001-10-01</p> <p>Optical methods represent the most promising techniques to perform non-invasive glucose detection. Glucose <span class="hlt">concentration</span> in the aqueous humor closely mimics glucose levels in the blood and therefore non-invasive optical measurement of glucose can be performed by an optical beam crossing the eye anterior chamber. We propose a polarimetric method that exploits the Brewster-reflection of circularly polarized light on the lens of the eye. After reflection, the resulting linearly polarized light is subject to rotation by the glucose in the aqueous humor and thus carries the <span class="hlt">concentration</span> information. A preliminary experimental setup, using glucose samples in a beaker, was realized and investigated.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3954740','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3954740"><span id="translatedtitle"><span class="hlt">Determinants</span> of urinary bisphenol A <span class="hlt">concentrations</span> in Mexican/Mexican-American pregnant women</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Quirós-Alcalá, Lesliam; Eskenazi, Brenda; Bradman, Asa; Ye, Xiaoyun; Calafat, Antonia M.; Harley, Kim</p> <p>2013-01-01</p> <p>Prenatal exposure to bisphenol A (BPA) may be associated with adverse health effects in the developing fetus; however, little is known about predictors of BPA exposure during pregnancy. We examined BPA exposure in 491 pregnant women from the Center for the Health Assessment of Mothers and Children of Salinas (CHAMACOS) cohort and explored the role of living in the United States on significant dietary predictors of BPA exposure. Women provided urine samples up to two times during pregnancy (n=866 total samples). We computed the intraclass correlation coefficient (ICC) to evaluate variability in <span class="hlt">concentrations</span> between collections and used generalized estimating equation (GEE) models to assess predictors of exposure. Geometric mean (GSD) BPA <span class="hlt">concentrations</span> were 0.9 (2.8) µg/L and 1.0 (2.6) µg/L at the first and second prenatal visit, respectively. We observed greater within- than between-woman variability in urinary BPA <span class="hlt">concentrations</span> (ICC=0.22). GEE models suggest that women who lived in the United States their entire life had 38% (CI:−0.1, 89.3) higher urinary BPA <span class="hlt">concentrations</span> compared with other immigrant women. Additionally, women who consumed ≥3 sodas per day or hamburgers three times a week or more had 58% (CI:18.0, 112.1) and 20% (CI: −0.2, 45.2) higher urinary BPA <span class="hlt">concentrations</span>, respectively, compared with women who consumed no sodas or hamburgers. A higher percentage of women who lived their entire life in the United States reported increased consumption of sodas and hamburgers compared with other immigrant women. Independent of other factors, BPA urinary <span class="hlt">concentrations</span> were slightly higher when the sample was collected later in the day. As in previous studies, high within-woman variability in urinary BPA <span class="hlt">concentrations</span> confirms that several samples are needed to properly characterize exposure during pregnancy. Results also suggest that some factors could be modified to minimize exposures during pregnancy in our study participants (e.g., reducing</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2011SPIE.8027E..05S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2011SPIE.8027E..05S"><span id="translatedtitle">A quantitative study for <span class="hlt">determination</span> of sugar <span class="hlt">concentration</span> using attenuated total reflectance terahertz (ATR-THz) spectroscopy</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Suhandy, Diding; Suzuki, Tetsuhito; Ogawa, Yuichi; Kondo, Naoshi; Ishihara, Takeshi; Takemoto, Yuichiro</p> <p>2011-06-01</p> <p>The objective of our research was to use ATR-THz spectroscopy together with chemometric for quantitative study in food analysis. Glucose, fructose and sucrose are main component of sugar both in fresh and processed fruits. The use of spectroscopic-based method for sugar <span class="hlt">determination</span> is well reported especially using visible, near infrared (NIR) and middle infrared (MIR) spectroscopy. However, the use of terahertz spectroscopy for sugar <span class="hlt">determination</span> in fruits has not yet been reported. In this work, a quantitative study for sugars <span class="hlt">determination</span> using attenuated total reflectance terahertz (ATR-THz) spectroscopy was conducted. Each samples of glucose, fructose and sucrose solution with different <span class="hlt">concentrations</span> were prepared respectively and their absorbance spectra between wavenumber 20 and 450 cm-1 (between 0.6 THz and 13.5 THz) were acquired using a terahertz-based Fourier Transform spectrometer (FARIS-1S, JASCO Co., Japan). This spectrometer was equipped with a high pressure of mercury lamp as light source and a pyroelectric sensor made from deuterated L-alanine triglycine sulfate (DLTGS) as detector. Each spectrum was acquired using 16 cm-1 of resolution and 200 scans for averaging. The spectra of water and sugar solutions were compared and discussed. The results showed that increasing sugar <span class="hlt">concentration</span> caused decreasing absorbance. The correlation between sugar <span class="hlt">concentration</span> and its spectra was investigated using multivariate analysis. Calibration models for glucose, fructose and sucrose <span class="hlt">determination</span> were developed using partial least squares (PLS) regression. The calibration model was evaluated using some parameters such as coefficient of <span class="hlt">determination</span> (R2), standard error of calibration (SEC), standard error of prediction (SEP), bias between actual and predicted sugar <span class="hlt">concentration</span> value and ratio prediction to deviation (RPD) parameter. The cross validation method was used to validate each calibration model. It is showed that the use of ATR</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/2952408','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/2952408"><span id="translatedtitle">Prevalence of morning hyperglycaemia: <span class="hlt">determinants</span> of fasting blood glucose <span class="hlt">concentrations</span> in insulin-treated diabetics.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Francis, A J; Home, P D; Walford, S; Alberti, K G; Mann, N; Reeves, W G</p> <p>1985-03-01</p> <p>A rise in blood glucose <span class="hlt">concentration</span> at the end of the night, and consequent morning hyperglycaemia, are well recognized events in some diabetic patients. In 94 patients on twice daily insulin injections we have examined the prevalence and extent of morning hyperglycaemia, and its relation to control, insulin therapy, and insulin antibody levels. Blood glucose reached the highest level of the day before or after breakfast in 83% of patients, and in 50% this value was 2 mmol/l greater than any other time of day. Patients with higher fasting <span class="hlt">concentrations</span> did not have worse blood glucose control over the rest of the day. No correlation was found between fasting blood glucose <span class="hlt">concentrations</span> and the evening dose of intermediate acting insulin or the level of insulin antibodies. No consistent change in fasting blood glucose <span class="hlt">concentrations</span> occurred with changes in antibody levels in patients switched between pork and beef insulin. Morning hyperglycaemia was as common with both insulin species. Pre- and post-breakfast hyperglycaemia is common and significant in insulin-treated diabetic patients. It is not directly related to diabetic control at other times of the day, and is independent of insulin species and insulin antibody levels.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=2212745','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=2212745"><span id="translatedtitle"><span class="hlt">Determination</span> of the Critical <span class="hlt">Concentration</span> of Neutrophils Required to Block Bacterial Growth in Tissues</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Li, Yongmei; Karlin, Arthur; Loike, John D.; Silverstein, Samuel C.</p> <p>2004-01-01</p> <p>We showed previously that the competition between bacterial killing by neutrophils and bacterial growth in stirred serum-containing suspensions could be modeled as the competition between a first-order reaction (bacterial growth) and a second-order reaction (bacterial killing by neutrophils). The model provided a useful parameter, the critical neutrophil <span class="hlt">concentration</span> (CNC), below which bacterial <span class="hlt">concentration</span> increased and above which it decreased, independent of the initial bacterial <span class="hlt">concentration</span>. We report here that this model applies to neutrophil killing of bacteria in three-dimensional fibrin matrices and in rabbit dermis. We measured killing of 103–108 colony forming units/ml Staphylococcus epidermidis by 105–108 human neutrophils/ml in fibrin gels. The CNC was ∼4 × 106 neutrophils/ml gel in the presence of normal serum and ∼1.6 × 107 neutrophils/ml gel in the presence of C5-deficient serum. Application of our model to published data of others on killing of ∼5 × 107 to 2 × 108 E. coli/ml rabbit dermis yielded CNCs from ∼4 × 106 to ∼8 × 106 neutrophils/ml dermis. Thus, in disparate tissues and tissuelike environments, our model fits the kinetics of bacterial killing and gives similar lower limits (CNCs) to the neutrophil <span class="hlt">concentration</span> required to control bacterial growth. PMID:15353554</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/9550566','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/9550566"><span id="translatedtitle">Variability and <span class="hlt">determinants</span> of total homocysteine <span class="hlt">concentrations</span> in plasma in an elderly population.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Clarke, R; Woodhouse, P; Ulvik, A; Frost, C; Sherliker, P; Refsum, H; Ueland, P M; Khaw, K T</p> <p>1998-01-01</p> <p>The variability of plasma total homocysteine (tHcy) was examined in 96 individuals over a 1-yr period. Blood tHcy <span class="hlt">concentrations</span> varied from 7.1 micromol/L in the bottom quintile to 14.5 micromol/L in the top quintile. The mean tHcy was 10.4 micromol/L, the between-person SD was 2.5 micromol/L, and the within-person SD was 0.93 micromol/L. There was little seasonal variation, and the reliability coefficient was 0.88. Mean tHcy <span class="hlt">concentrations</span> were inversely related to mean plasma folate (r = -0.36) and vitamin B12 (r = -0.35) <span class="hlt">concentrations</span>. Median tHcy <span class="hlt">concentrations</span> were approximately 1 micromol/L higher in men than in women and in older (70 to 74 years) than in younger (65 to 69 years) individuals and higher in those with the TT and CT genotypes for the methylenetetrahydrofolate reductase polymorphism than in those with the CC genotype (10.7 and 10.6 vs 9.6 micromol/L). Epidemiological studies based on single tHcy measurements may underestimate the magnitude of any risk associations with disease by 10-15%. PMID:9550566</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://eric.ed.gov/?q=%22calibration+curve%22&pg=3&id=EJ820861','ERIC'); return false;" href="http://eric.ed.gov/?q=%22calibration+curve%22&pg=3&id=EJ820861"><span id="translatedtitle">New Analytical Method for the <span class="hlt">Determination</span> of Detergent <span class="hlt">Concentration</span> in Water by Fabric Dyeing</span></a></p> <p><a target="_blank" href="http://www.eric.ed.gov/ERICWebPortal/search/extended.jsp?_pageLabel=advanced">ERIC Educational Resources Information Center</a></p> <p>Seng, Set; Kita, Masakazu; Sugihara, Reiko</p> <p>2007-01-01</p> <p>The use of harmful organic solvents in classrooms has become a critical issue of concern in the field of chemistry education. This article describes a classroom activity at a high school in which an acrylic fabric was used as the extraction medium in the analysis of the detergent <span class="hlt">concentration</span> in water instead of organic solvents. Dyes were used…</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/9550566','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/9550566"><span id="translatedtitle">Variability and <span class="hlt">determinants</span> of total homocysteine <span class="hlt">concentrations</span> in plasma in an elderly population.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Clarke, R; Woodhouse, P; Ulvik, A; Frost, C; Sherliker, P; Refsum, H; Ueland, P M; Khaw, K T</p> <p>1998-01-01</p> <p>The variability of plasma total homocysteine (tHcy) was examined in 96 individuals over a 1-yr period. Blood tHcy <span class="hlt">concentrations</span> varied from 7.1 micromol/L in the bottom quintile to 14.5 micromol/L in the top quintile. The mean tHcy was 10.4 micromol/L, the between-person SD was 2.5 micromol/L, and the within-person SD was 0.93 micromol/L. There was little seasonal variation, and the reliability coefficient was 0.88. Mean tHcy <span class="hlt">concentrations</span> were inversely related to mean plasma folate (r = -0.36) and vitamin B12 (r = -0.35) <span class="hlt">concentrations</span>. Median tHcy <span class="hlt">concentrations</span> were approximately 1 micromol/L higher in men than in women and in older (70 to 74 years) than in younger (65 to 69 years) individuals and higher in those with the TT and CT genotypes for the methylenetetrahydrofolate reductase polymorphism than in those with the CC genotype (10.7 and 10.6 vs 9.6 micromol/L). Epidemiological studies based on single tHcy measurements may underestimate the magnitude of any risk associations with disease by 10-15%.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.gpo.gov/fdsys/pkg/CFR-2013-title40-vol12/pdf/CFR-2013-title40-vol12-sec63-1426.pdf','CFR2013'); return false;" href="https://www.gpo.gov/fdsys/pkg/CFR-2013-title40-vol12/pdf/CFR-2013-title40-vol12-sec63-1426.pdf"><span id="translatedtitle">40 CFR 63.1426 - Process vent requirements for <span class="hlt">determining</span> organic HAP <span class="hlt">concentration</span>, control efficiency, and...</span></a></p> <p><a target="_blank" href="http://www.gpo.gov/fdsys/browse/collectionCfr.action?selectedYearFrom=2013&page.go=Go">Code of Federal Regulations, 2013 CFR</a></p> <p></p> <p>2013-07-01</p> <p>..., liquid-to-vapor ratio, scrubbing liquid flow rate and <span class="hlt">concentration</span>, temperature, and the reaction... CFR part 270 and complies with the requirements for hazardous waste burned in boilers and industrial furnaces in 40 CFR part 266, subpart H; or (ii) Has certified compliance with the interim...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.gpo.gov/fdsys/pkg/CFR-2010-title40-vol15/pdf/CFR-2010-title40-vol15-part65-subpartD-app1.pdf','CFR'); return false;" href="https://www.gpo.gov/fdsys/pkg/CFR-2010-title40-vol15/pdf/CFR-2010-title40-vol15-part65-subpartD-app1.pdf"><span id="translatedtitle">40 CFR Table 1 to Subpart D of... - <span class="hlt">Concentration</span> for Group <span class="hlt">Determination</span></span></a></p> <p><a target="_blank" href="http://www.gpo.gov/fdsys/browse/collectionCfr.action?selectedYearFrom=2010&page.go=Go">Code of Federal Regulations, 2010 CFR</a></p> <p></p> <p>2010-07-01</p> <p>... 40 CFR part 63, subpart G sources. Process vents subject to only 40 CFR part 60, subparts RRR or NNN... process vent provisions of subpart DDD are not consolidated under this subpart. 2 For process vents subject to subpart G of 40 CFR part 63, the owner or operator may measure HAP or TOC <span class="hlt">concentration</span>...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://eric.ed.gov/?q=Herfindahl+AND+Index&id=EJ465340','ERIC'); return false;" href="http://eric.ed.gov/?q=Herfindahl+AND+Index&id=EJ465340"><span id="translatedtitle">On the <span class="hlt">Determination</span> of the Critical Level of Market <span class="hlt">Concentration</span> in Education.</span></a></p> <p><a target="_blank" href="http://www.eric.ed.gov/ERICWebPortal/search/extended.jsp?_pageLabel=advanced">ERIC Educational Resources Information Center</a></p> <p>Borland, Melvin V.; Howsen, Roy M.</p> <p>1993-01-01</p> <p>Attempts to estimate a critical level of market <span class="hlt">concentration</span> within the educational sector for Kentucky. The critical Herfindahl was estimated at 0.50. Counties experiencing a Herfindahl index at or above this number can expect, on average, a 1.6 percentage point decrease (or a 3% reduction) in student achievement scores. (MLH)</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/26094801','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/26094801"><span id="translatedtitle"><span class="hlt">Concentration</span> and <span class="hlt">determinants</span> of molds and allergens in indoor air and house dust of French dwellings.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Dallongeville, Arnaud; Le Cann, Pierre; Zmirou-Navier, Denis; Chevrier, Cécile; Costet, Nathalie; Annesi-Maesano, Isabella; Blanchard, Olivier</p> <p>2015-12-01</p> <p>Molds and allergens are common indoor biocontaminants. The aims of this study were to assess the <span class="hlt">concentrations</span> of common molds in indoor air and floor dust and the <span class="hlt">concentrations</span> of house dust mite, cat and dog allergens in mattress dust in French dwellings, and to assess predictors of these <span class="hlt">concentrations</span>. A sample of 150 houses in Brittany (western France) was investigated. Airborne Cladosporium and Penicillium were detected in more than 90% of the dwellings, Aspergillus in 46% and Alternaria in only 6% of the housings. Regarding floor dust samples, Cladosporium and Penicillium were detected in 92 and 80% of the housings respectively, Aspergillus in 49% and Alternaria in 14%. House dust mite allergens Der p1 and Der f1 were detected in 90% and 77% of the mattress dust samples respectively and Can f1 and Fel d1 in 37% and 89% of the homes. Airborne and dustborne mold <span class="hlt">concentrations</span>, although not statistically correlated (except for Aspergillus) shared most of their predictors. Multivariate linear models for mold levels, explaining up to 62% of the variability, showed an influence of the season, of the age of the dwelling, of aeration habits, presence of pets, smoking, signals of dampness, temperature and relative humidity. Allergens in the dust of the mattress were strongly related to the presence of pets and cleaning practices of bedsheets, these factors accounting for 60% of the variability. This study highlights ubiquitous contamination by molds and underlines complex interaction between outdoor and indoor sources and factors. PMID:26094801</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/20628720','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/20628720"><span id="translatedtitle">[Evaluation of folate substitution in women with epilepsy. <span class="hlt">Determination</span> of erythrocyte folic acid <span class="hlt">concentrations</span>].</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Bauer, J; Bös, M; Rück, J; Stoffel-Wagner, B</p> <p>2011-04-01</p> <p>Insufficient maternal folate <span class="hlt">concentrations</span> appear to be a fetal risk factor for neural tube defects (NTD). Erythrocyte folate <span class="hlt">concentrations</span> are widely accepted as an indicator of tissue folate storage. We retrospectively evaluated erythrocyte folate <span class="hlt">concentrations</span> to examine if a recommended daily dosage of 5 mg folic acid is sufficient to balance the impact of antiepileptic drugs (AED) on folate metabolism in women with epilepsy. Data of 48 women (mean age 30.3 years) with idiopathic epilepsy with generalized seizures (n=12) or symptomatic epilepsy with focal seizures (n=36) were available, 43 women submitted to further analysis and 30 women received AED monotherapy. Duration of folic acid supplementation varied between 0.5 and 12 months. The daily dosage of folic acid ranged from 0.4 to 15 mg and 32 women received 5 mg/day. Erythrocyte folate <span class="hlt">concentrations</span> ranged from 282 to 1596 ng/ml (mean 780 ng/ml). In 29 out of the 32 women (90.6%) on 5 mg folic acid per day, red cell folate was ≥400 ng/ml. In previous studies the risk for NTD was estimated to be 0.8‰ if red cell folate was ≥400 ng/ml. Our results suggest that 5 mg/day folic acid as preconception supplementation in women with epilepsy is effective to balance the impact of AEDs on folate metabolism in women with epilepsy.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=20140005478&hterms=fingerprint&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D30%26Ntt%3Dfingerprint','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=20140005478&hterms=fingerprint&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D30%26Ntt%3Dfingerprint"><span id="translatedtitle">Achieving Climate Change <span class="hlt">Absolute</span> Accuracy in Orbit</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Wielicki, Bruce A.; Young, D. F.; Mlynczak, M. G.; Thome, K. J; Leroy, S.; Corliss, J.; Anderson, J. G.; Ao, C. O.; Bantges, R.; Best, F.; Bowman, K.; Brindley, H.; Butler, J. J.; Collins, W.; Dykema, J. A.; Doelling, D. R.; Feldman, D. R.; Fox, N.; Huang, X.; Holz, R.; Huang, Y.; Jennings, D.; Jin, Z.; Johnson, D. G.; Jucks, K.; Kato, S.; Kratz, D. P.; Liu, X.; Lukashin, C.; Mannucci, A. J.; Phojanamongkolkij, N.; Roithmayr, C. M.; Sandford, S.; Taylor, P. C.; Xiong, X.</p> <p>2013-01-01</p> <p>The Climate <span class="hlt">Absolute</span> Radiance and Refractivity Observatory (CLARREO) mission will provide a calibration laboratory in orbit for the purpose of accurately measuring and attributing climate change. CLARREO measurements establish new climate change benchmarks with high <span class="hlt">absolute</span> radiometric accuracy and high statistical confidence across a wide range of essential climate variables. CLARREO's inherently high <span class="hlt">absolute</span> accuracy will be verified and traceable on orbit to Système Internationale (SI) units. The benchmarks established by CLARREO will be critical for assessing changes in the Earth system and climate model predictive capabilities for decades into the future as society works to meet the challenge of optimizing strategies for mitigating and adapting to climate change. The CLARREO benchmarks are derived from measurements of the Earth's thermal infrared spectrum (5-50 micron), the spectrum of solar radiation reflected by the Earth and its atmosphere (320-2300 nm), and radio occultation refractivity from which accurate temperature profiles are derived. The mission has the ability to provide new spectral fingerprints of climate change, as well as to provide the first orbiting radiometer with accuracy sufficient to serve as the reference transfer standard for other space sensors, in essence serving as a "NIST [National Institute of Standards and Technology] in orbit." CLARREO will greatly improve the accuracy and relevance of a wide range of space-borne instruments for decadal climate change. Finally, CLARREO has developed new metrics and methods for <span class="hlt">determining</span> the accuracy requirements of climate observations for a wide range of climate variables and uncertainty sources. These methods should be useful for improving our understanding of observing requirements for most climate change observations.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2012RScI...83jD519K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2012RScI...83jD519K"><span id="translatedtitle">Method to obtain <span class="hlt">absolute</span> impurity density profiles combining charge exchange and beam emission spectroscopy without <span class="hlt">absolute</span> intensity calibrationa)</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Kappatou, A.; Jaspers, R. J. E.; Delabie, E.; Marchuk, O.; Biel, W.; Jakobs, M. A.</p> <p>2012-10-01</p> <p>Investigation of impurity transport properties in tokamak plasmas is essential and a diagnostic that can provide information on the impurity content is required. Combining charge exchange recombination spectroscopy (CXRS) and beam emission spectroscopy (BES), <span class="hlt">absolute</span> radial profiles of impurity densities can be obtained from the CXRS and BES intensities, electron density and CXRS and BES emission rates, without requiring any <span class="hlt">absolute</span> calibration of the spectra. The technique is demonstrated here with <span class="hlt">absolute</span> impurity density radial profiles obtained in TEXTOR plasmas, using a high efficiency charge exchange spectrometer with high etendue, that measures the CXRS and BES spectra along the same lines-of-sight, offering an additional advantage for the <span class="hlt">determination</span> of <span class="hlt">absolute</span> impurity densities.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4208148','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4208148"><span id="translatedtitle">Temperature Compensation in <span class="hlt">Determining</span> of Remazol Black B <span class="hlt">Concentrations</span> Using Plastic Optical Fiber Based Sensor</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Chong, Su Sin; Aziz, A.R. Abdul; Harun, Sulaiman W.; Arof, Hamzah</p> <p>2014-01-01</p> <p>In this study, the construction and test of tapered plastic optical fiber (POF) sensors, based on an intensity modulation approach are described. Tapered fiber sensors with different diameters of 0.65 mm, 0.45 mm, and 0.35 mm, were used to measure various <span class="hlt">concentrations</span> of Remazol black B (RBB) dye aqueous solutions at room temperature. The <span class="hlt">concentrations</span> of the RBB solutions were varied from 0 ppm to 70 ppm. In addition, the effect of varying the temperature of the RBB solution was also investigated. In this case, the output of the sensor was measured at four different temperatures of 27 °C, 30 °C, 35 °C, and 40 °C, while its <span class="hlt">concentration</span> was fixed at 50 ppm and 100 ppm. The experimental results show that the tapered POF with d = 0.45 mm achieves the best performance with a reasonably good sensitivity of 61 × 10−4 and a linearity of more than 99%. It also maintains a sufficient and stable signal when heat was applied to the solution with a linearity of more than 97%. Since the transmitted intensity is dependent on both the <span class="hlt">concentration</span> and temperature of the analyte, multiple linear regression analysis was performed to combine the two independent variables into a single equation. The resulting equation was then validated experimentally and the best agreement between the calculated and experimental results was achieved by the sensor with d = 0.45 mm, where the minimum discrepancy is less than 5%. The authors conclude that POF-based sensors are suitable for RBB dye <span class="hlt">concentration</span> sensing and, with refinement in fabrication, better results could be achieved. Their low fabrication cost, simple configuration, accuracy, and high sensitivity would attract many potential applications in chemical and biological sensing. PMID:25166498</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/25166498','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/25166498"><span id="translatedtitle">Temperature compensation in <span class="hlt">determining</span> of Remazol black B <span class="hlt">concentrations</span> using plastic optical fiber based sensor.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Chong, Su Sin; Aziz, A R Abdul; Harun, Sulaiman W; Arof, Hamzah</p> <p>2014-08-27</p> <p>In this study, the construction and test of tapered plastic optical fiber (POF) sensors, based on an intensity modulation approach are described. Tapered fiber sensors with different diameters of 0.65 mm, 0.45 mm, and 0.35 mm, were used to measure various <span class="hlt">concentrations</span> of Remazol black B (RBB) dye aqueous solutions at room temperature. The <span class="hlt">concentrations</span> of the RBB solutions were varied from 0 ppm to 70 ppm. In addition, the effect of varying the temperature of the RBB solution was also investigated. In this case, the output of the sensor was measured at four different temperatures of 27 °C, 30 °C, 35 °C, and 40 °C, while its <span class="hlt">concentration</span> was fixed at 50 ppm and 100 ppm. The experimental results show that the tapered POF with d = 0.45 mm achieves the best performance with a reasonably good sensitivity of 61 × 10(-4) and a linearity of more than 99%. It also maintains a sufficient and stable signal when heat was applied to the solution with a linearity of more than 97%. Since the transmitted intensity is dependent on both the <span class="hlt">concentration</span> and temperature of the analyte, multiple linear regression analysis was performed to combine the two independent variables into a single equation. The resulting equation was then validated experimentally and the best agreement between the calculated and experimental results was achieved by the sensor with d = 0.45 mm, where the minimum discrepancy is less than 5%. The authors conclude that POF-based sensors are suitable for RBB dye <span class="hlt">concentration</span> sensing and, with refinement in fabrication, better results could be achieved. Their low fabrication cost, simple configuration, accuracy, and high sensitivity would attract many potential applications in chemical and biological sensing.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/16303275','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/16303275"><span id="translatedtitle">Method development for the enantiomeric purity <span class="hlt">determination</span> of low <span class="hlt">concentrations</span> of adrenaline in local anaesthetic solutions by capillary electrophoresis.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Sänger-van de Griend, Cari E; Ek, Anders G; Widahl-Näsman, Monica E; Andersson, E K Margareta</p> <p>2006-04-11</p> <p>L-adrenaline is often included in local anaesthetic (LA) solutions for injection to improve the quality of the anaesthetic block. The <span class="hlt">concentration</span> of the LA is between 2.5 and 20 mg/ml and the <span class="hlt">concentration</span> of adrenaline is typically < or = 0.1% of the LA <span class="hlt">concentration</span>. In order to follow the racemization into d-adrenaline, not only is chiral separation needed but also sufficient resolution from the LA and other components of the injection solution. Furthermore, very high sensitivity is needed in order to be able to <span class="hlt">determine</span> the d-enantiomer at very low <span class="hlt">concentrations</span>, i.e. down to about 0.1 microg/ml. The development of a chiral capillary electrophoresis method that is able to <span class="hlt">determine</span> the racemization of adrenaline is described, together with a limited validation. Samples are injected without pretreatment and analysed with a capillary electrophoresis buffer containing 40 mM heptakis(2,6-di-O-methyl)-beta-cyclodextrin, 0.10 M phosphoric acid and 0.05 M triethanolamine. The amounts of d-adrenaline found in the LA products tested were typically < 3% of the l-adrenaline <span class="hlt">concentration</span> and < 0.003% of the LA <span class="hlt">concentration</span>.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li><a href="#" onclick='return showDiv("page_23");'>23</a></li> <li class="active"><span>24</span></li> <li><a href="#" onclick='return showDiv("page_25");'>25</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_24 --> <div id="page_25" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li><a href="#" onclick='return showDiv("page_23");'>23</a></li> <li><a href="#" onclick='return showDiv("page_24");'>24</a></li> <li class="active"><span>25</span></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="481"> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.gpo.gov/fdsys/pkg/CFR-2012-title40-vol14/pdf/CFR-2012-title40-vol14-sec63-7943.pdf','CFR2012'); return false;" href="https://www.gpo.gov/fdsys/pkg/CFR-2012-title40-vol14/pdf/CFR-2012-title40-vol14-sec63-7943.pdf"><span id="translatedtitle">40 CFR 63.7943 - How do I <span class="hlt">determine</span> the average VOHAP <span class="hlt">concentration</span> of my remediation material?</span></a></p> <p><a target="_blank" href="http://www.gpo.gov/fdsys/browse/collectionCfr.action?selectedYearFrom=2012&page.go=Go">Code of Federal Regulations, 2012 CFR</a></p> <p></p> <p>2012-07-01</p> <p>... results from a <span class="hlt">determination</span> of VOHAP <span class="hlt">concentration</span> using direct measurement by Method 305 in 40 CFR part... in 40 CFR part 60, appendix A. (2) Analysis. Each collected sample must be prepared and analyzed... according to Method 301 in 40 CFR part 63, appendix A as the basis for knowledge of the material....</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.gpo.gov/fdsys/pkg/CFR-2014-title40-vol14/pdf/CFR-2014-title40-vol14-sec63-7943.pdf','CFR2014'); return false;" href="https://www.gpo.gov/fdsys/pkg/CFR-2014-title40-vol14/pdf/CFR-2014-title40-vol14-sec63-7943.pdf"><span id="translatedtitle">40 CFR 63.7943 - How do I <span class="hlt">determine</span> the average VOHAP <span class="hlt">concentration</span> of my remediation material?</span></a></p> <p><a target="_blank" href="http://www.gpo.gov/fdsys/browse/collectionCfr.action?selectedYearFrom=2014&page.go=Go">Code of Federal Regulations, 2014 CFR</a></p> <p></p> <p>2014-07-01</p> <p>... results from a <span class="hlt">determination</span> of VOHAP <span class="hlt">concentration</span> using direct measurement by Method 305 in 40 CFR part... in 40 CFR part 60, appendix A. (2) Analysis. Each collected sample must be prepared and analyzed... according to Method 301 in 40 CFR part 63, appendix A as the basis for knowledge of the material....</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.gpo.gov/fdsys/pkg/CFR-2010-title40-vol21/pdf/CFR-2010-title40-vol21-part122-appC.pdf','CFR'); return false;" href="https://www.gpo.gov/fdsys/pkg/CFR-2010-title40-vol21/pdf/CFR-2010-title40-vol21-part122-appC.pdf"><span id="translatedtitle">40 CFR Appendix C to Part 122 - Criteria for <span class="hlt">Determining</span> a <span class="hlt">Concentrated</span> Aquatic Animal Production Facility (§ 122.24)</span></a></p> <p><a target="_blank" href="http://www.gpo.gov/fdsys/browse/collectionCfr.action?selectedYearFrom=2010&page.go=Go">Code of Federal Regulations, 2010 CFR</a></p> <p></p> <p>2010-07-01</p> <p>... 40 Protection of Environment 21 2010-07-01 2010-07-01 false Criteria for <span class="hlt">Determining</span> a <span class="hlt">Concentrated</span> Aquatic Animal Production Facility (§ 122.24) C Appendix C to Part 122 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) WATER PROGRAMS EPA ADMINISTERED PERMIT PROGRAMS: THE NATIONAL POLLUTANT DISCHARGE ELIMINATION SYSTEM...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/323761','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/323761"><span id="translatedtitle">Using solid-phase microextraction to <span class="hlt">determine</span> partition coefficients to humic acids and bioavailable <span class="hlt">concentrations</span> of hydrophobic chemicals</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Ramos, E.U.; Meijer, S.N.; Vaes, W.H.J.; Verhaar, H.J.M.; Hermens, J.L.M.</p> <p>1998-11-01</p> <p>In the current study, the suitability of negligible depletion solid-phase microextraction (nd-SPME) to <span class="hlt">determine</span> free fractions of chemicals in aquatic environments was explored. The potential interferences of the dissolved matrix (i.e., humic acids) with the SPME measurements were tested. Results show that nd-SPME measures only the freely dissolved fraction and that the measurements are not disturbed by the humic acids. In addition, nd-SPME was used to <span class="hlt">determine</span> partition coefficients between dissolved organic carbon and water for four hydrophobic chemicals. Obtained values are in excellent agreement with previously reported data. Finally, the bioaccumulation of hexachlorobenzene and PCB 77 to Daphnia magna was <span class="hlt">determined</span> in the presence and absence of humic acids. The bioconcentration factors (BCF) were calculated based on total as well as on free <span class="hlt">concentration</span>. Lower BCF values are obtained in the presence of humic acids using total <span class="hlt">concentrations</span>, whereas equal BCFs are found using free <span class="hlt">concentrations</span> measured with nd-SPME. Therefore, the authors can conclude that negligible depletion SPME is a good technique to <span class="hlt">determine</span> bioavailable <span class="hlt">concentrations</span> of hydrophobic chemicals in aquatic environments.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://cfpub.epa.gov/si/si_public_record_report.cfm?dirEntryId=307815&keyword=competition&actType=&TIMSType=+&TIMSSubTypeID=&DEID=&epaNumber=&ntisID=&archiveStatus=Both&ombCat=Any&dateBeginCreated=&dateEndCreated=&dateBeginPublishedPresented=&dateEndPublishedPresented=&dateBeginUpdated=&dateEndUpdated=&dateBeginCompleted=&dateEndCompleted=&personID=&role=Any&journalID=&publisherID=&sortBy=revisionDate&count=50&CFID=78815043&CFTOKEN=99318230','EPA-EIMS'); return false;" href="http://cfpub.epa.gov/si/si_public_record_report.cfm?dirEntryId=307815&keyword=competition&actType=&TIMSType=+&TIMSSubTypeID=&DEID=&epaNumber=&ntisID=&archiveStatus=Both&ombCat=Any&dateBeginCreated=&dateEndCreated=&dateBeginPublishedPresented=&dateEndPublishedPresented=&dateBeginUpdated=&dateEndUpdated=&dateBeginCompleted=&dateEndCompleted=&personID=&role=Any&journalID=&publisherID=&sortBy=revisionDate&count=50&CFID=78815043&CFTOKEN=99318230"><span id="translatedtitle">The Gellyfish: an in-situ equilibrium-based sampler for <span class="hlt">determining</span> multiple free metal ion <span class="hlt">concentrations</span> in marine ecosystems</span></a></p> <p><a target="_blank" href="http://oaspub.epa.gov/eims/query.page">EPA Science Inventory</a></p> <p></p> <p></p> <p>Free metal ions are usually the most bioavailable and toxic metal species to aquatic organisms, but they are difficult to measure because of their extremely low <span class="hlt">concentrations</span> in the marine environment. Many of the current methods for <span class="hlt">determining</span> free metal ions are complicated a...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://cfpub.epa.gov/si/si_public_record_report.cfm?dirEntryId=126427&keyword=occupational+AND+health+AND+Technology&actType=&TIMSType=+&TIMSSubTypeID=&DEID=&epaNumber=&ntisID=&archiveStatus=Both&ombCat=Any&dateBeginCreated=&dateEndCreated=&dateBeginPublishedPresented=&dateEndPublishedPresented=&dateBeginUpdated=&dateEndUpdated=&dateBeginCompleted=&dateEndCompleted=&personID=&role=Any&journalID=&publisherID=&sortBy=revisionDate&count=50&CFID=80600204&CFTOKEN=27642328','EPA-EIMS'); return false;" href="http://cfpub.epa.gov/si/si_public_record_report.cfm?dirEntryId=126427&keyword=occupational+AND+health+AND+Technology&actType=&TIMSType=+&TIMSSubTypeID=&DEID=&epaNumber=&ntisID=&archiveStatus=Both&ombCat=Any&dateBeginCreated=&dateEndCreated=&dateBeginPublishedPresented=&dateEndPublishedPresented=&dateBeginUpdated=&dateEndUpdated=&dateBeginCompleted=&dateEndCompleted=&personID=&role=Any&journalID=&publisherID=&sortBy=revisionDate&count=50&CFID=80600204&CFTOKEN=27642328"><span id="translatedtitle">EVALUATION OF THREE CLEANING METHODS FOR REMOVING ASBESTOS FROM CARPET. <span class="hlt">DETERMINATION</span> OF AIRBORNE ASBESTOS <span class="hlt">CONCENTRATIONS</span> ASSOCIATED WITH EACH METHOD</span></a></p> <p><a target="_blank" href="http://oaspub.epa.gov/eims/query.page">EPA Science Inventory</a></p> <p></p> <p></p> <p>This study was conducted to compare the effectiveness of three cleaning methods to remove asbestos from contaminated carpet and to <span class="hlt">determine</span> the airborne asbestos <span class="hlt">concentrations</span> associated with the use of each method. The carpet on which the methods were tested was naturally cont...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.gpo.gov/fdsys/pkg/CFR-2013-title40-vol14/pdf/CFR-2013-title40-vol14-sec63-7943.pdf','CFR2013'); return false;" href="https://www.gpo.gov/fdsys/pkg/CFR-2013-title40-vol14/pdf/CFR-2013-title40-vol14-sec63-7943.pdf"><span id="translatedtitle">40 CFR 63.7943 - How do I <span class="hlt">determine</span> the average VOHAP <span class="hlt">concentration</span> of my remediation material?</span></a></p> <p><a target="_blank" href="http://www.gpo.gov/fdsys/browse/collectionCfr.action?selectedYearFrom=2013&page.go=Go">Code of Federal Regulations, 2013 CFR</a></p> <p></p> <p>2013-07-01</p> <p>... in 40 CFR part 60, appendix A. (2) Analysis. Each collected sample must be prepared and analyzed... according to Method 301 in 40 CFR part 63, appendix A as the basis for knowledge of the material. This... results from a <span class="hlt">determination</span> of VOHAP <span class="hlt">concentration</span> using direct measurement by Method 305 in 40 CFR...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://eric.ed.gov/?q=triclosan&id=EJ1050711','ERIC'); return false;" href="http://eric.ed.gov/?q=triclosan&id=EJ1050711"><span id="translatedtitle">Spectroscopic <span class="hlt">Determination</span> of Triclosan <span class="hlt">Concentration</span> in a Series of Antibacterial Soaps: A First-Year Undergraduate Laboratory Experiment</span></a></p> <p><a target="_blank" href="http://www.eric.ed.gov/ERICWebPortal/search/extended.jsp?_pageLabel=advanced">ERIC Educational Resources Information Center</a></p> <p>Wyllie, Graeme R. A.</p> <p>2015-01-01</p> <p>The antibacterial chemical triclosan is a common component in personal care products but recently the subject of many reports concerning environmental toxicity and health impacts. Although triclosan <span class="hlt">concentration</span> in a soap can be <span class="hlt">determined</span> simply via high-performance liquid chromatography, this is a technique not routinely available in the…</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19720024184','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19720024184"><span id="translatedtitle"><span class="hlt">Absolute</span> calibration of ultraviolet filter photometry</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Bless, R. C.; Fairchild, T.; Code, A. D.</p> <p>1972-01-01</p> <p>The essential features of the calibration procedure can be divided into three parts. First, the shape of the bandpass of each photometer was <span class="hlt">determined</span> by measuring the transmissions of the individual optical components and also by measuring the response of the photometer as a whole. Secondly, each photometer was placed in the essentially-collimated synchrotron radiation bundle maintained at a constant intensity level, and the output signal was <span class="hlt">determined</span> from about 100 points on the objective. Finally, two or three points on the objective were illuminated by synchrotron radiation at several different intensity levels covering the dynamic range of the photometers. The output signals were placed on an <span class="hlt">absolute</span> basis by the electron counting technique described earlier.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/12884933','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/12884933"><span id="translatedtitle">The use of Fourier-transform infrared spectroscopy for the quantitative <span class="hlt">determination</span> of glucose <span class="hlt">concentration</span> in whole blood.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Shen, Y C; Davies, A G; Linfleld, E H; Elsey, T S; Taday, P F; Arnone, D D</p> <p>2003-07-01</p> <p>Fourier-transform infrared transmission spectroscopy has been used for the <span class="hlt">determination</span> of glucose <span class="hlt">concentration</span> in whole blood samples from 28 patients. A 4-vector partial least-squares calibration model, using the spectral range 950-1200 cm(-1), yielded a standard-error-of-prediction of 0.59 mM for an independent test set. For blood samples from a single patient, we found that the glucose <span class="hlt">concentration</span> was proportional to the difference between the values of the second derivative spectrum at 1082 cm(-1) and 1093 cm(-1). This indicates that spectroscopy at these two specific wavenumbers alone could be used to <span class="hlt">determine</span> the glucose <span class="hlt">concentration</span> in blood plasma samples from a single patient, with a prediction error of 0.95 mM. PMID:12884933</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/75840','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/75840"><span id="translatedtitle">Indirect <span class="hlt">determination</span> of Mn-BOPP <span class="hlt">concentrations</span> using neutron activation analysis</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Combs, M.J.; Oveissi, C.; Mulder, R.U.; Berr, S.</p> <p>1994-12-31</p> <p>ONe aspect of neutron capture therapy (NCT) is the <span class="hlt">determination</span> of boron levels in tissues as a function of time. The objective of this work was the development of a simple instrumental neutron activation analysis method for the indirect <span class="hlt">determination</span> of boron. One compound studied for use in NCT was Mn-BOPP because Mn 55 will neutron activate to Mn 56 which could serve as an indicator of boron levels. In addition, it can be used as a magnetic resonance imaging agent.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/511699','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/511699"><span id="translatedtitle">Method for estimating <span class="hlt">absolute</span> lung volumes at constant inflation pressure.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Hills, B A; Barrow, R E</p> <p>1979-10-01</p> <p>A method has been devised for measuring functional residual capacity in the intact killed animal or <span class="hlt">absolute</span> lung volumes in any excised lung preparation without changing the inflation pressure. This is achieved by titrating the <span class="hlt">absolute</span> pressure of a chamber in which the preparation is compressed until a known volume of air has entered the lungs. This technique was used to estimate the volumes of five intact rabbit lungs and five rigid containers of known dimensions by means of Boyle's law. Results were found to agree to within +/- 1% with values <span class="hlt">determined</span> by alternative methods. In the discussion the advantage of <span class="hlt">determining</span> <span class="hlt">absolute</span> lung volumes at almost any stage in a study of lung mechanics without the <span class="hlt">determination</span> itself changing inflation pressure and, hence, lung volume is emphasized. PMID:511699</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/24144617','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/24144617"><span id="translatedtitle">Accurate <span class="hlt">determination</span> of ⁴¹Ca <span class="hlt">concentrations</span> in spent resins from the nuclear industry by accelerator mass spectrometry.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Nottoli, Emmanuelle; Bourlès, Didier; Bienvenu, Philippe; Labet, Alexandre; Arnold, Maurice; Bertaux, Maité</p> <p>2013-12-01</p> <p>The radiological characterisation of nuclear waste is essential for managing storage sites. <span class="hlt">Determining</span> the <span class="hlt">concentration</span> of Long-Lived RadioNuclides (LLRN) is fundamental for their long-term management. This paper focuses on the measurement of low (41)Ca <span class="hlt">concentrations</span> in ions exchange resins used for primary fluid purification in Pressurised Water Reactors (PWR). (41)Ca <span class="hlt">concentrations</span> were successfully measured by Accelerator Mass Spectrometry (AMS) after the acid digestion of resin samples, followed by radioactive decontamination and isobaric suppression through successive hydroxide, carbonate, nitrate and final CaF2 precipitations. Measured (41)Ca <span class="hlt">concentrations</span> ranged from 0.02 to 0.03 ng/g, i.e. from 0.06 to 0.09 Bq/g. The (41)Ca/(60)Co activity ratios obtained were remarkably reproducible and in good agreement with the current ratio used for resins management. PMID:24144617</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20000000444','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20000000444"><span id="translatedtitle">Micron Accurate <span class="hlt">Absolute</span> Ranging System: Range Extension</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Smalley, Larry L.; Smith, Kely L.</p> <p>1999-01-01</p> <p>The purpose of this research is to investigate Fresnel diffraction as a means of obtaining <span class="hlt">absolute</span> distance measurements with micron or greater accuracy. It is believed that such a system would prove useful to the Next Generation Space Telescope (NGST) as a non-intrusive, non-contact measuring system for use with secondary <span class="hlt">concentrator</span> station-keeping systems. The present research attempts to validate past experiments and develop ways to apply the phenomena of Fresnel diffraction to micron accurate measurement. This report discusses past research on the phenomena, and the basis of the use Fresnel diffraction distance metrology. The apparatus used in the recent investigations, experimental procedures used, preliminary results are discussed in detail. Continued research and equipment requirements on the extension of the effective range of the Fresnel diffraction systems is also described.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3582809','PMC'); return false;" href="http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3582809"><span id="translatedtitle">Seasonal <span class="hlt">concentrations</span> and <span class="hlt">determinants</span> of indoor particulate matter in a low-income community in Dhaka, Bangladesh</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Gurley, Emily S.; Salje, Henrik; Homaira, Nusrat; Ram, Pavani K.; Haque, Rashidul; Petri, William A.; Bresee, Joseph; Moss, William J.; Luby, Stephen P.; Breysse, Patrick; Azziz-Baumgartner, Eduardo</p> <p>2013-01-01</p> <p>Indoor exposure to particulate matter (PM) increases the risk of acute lower respiratory tract infections, which are the leading cause of death in young children in Bangladesh. Few studies, however, have measured children’s exposures to indoor PM over time. The World Health Organization recommends that daily indoor <span class="hlt">concentrations</span> of PM less than 2.5 μm in diameter (PM2.5) not exceed 25 μg/m3. This study aimed to describe the seasonal variation and <span class="hlt">determinants</span> of <span class="hlt">concentrations</span> of indoor PM2.5 in a low-income community in urban Dhaka, Bangladesh. PM2.5 was measured in homes monthly during May 2009 to April 2010. We calculated the time-weighted average, 90th percentile PM2.5 <span class="hlt">concentrations</span> and the daily hours PM2.5 exceeded 100 μg/m3. Linear regression models were used to estimate the associations between fuel use, ventilation, indoor smoking, and season to each metric describing indoor PM2.5 <span class="hlt">concentrations</span>. Time-weighted average PM2.5 <span class="hlt">concentrations</span> were 190 μg/m3 (95% CI 170 – 210). Sixteen percent of 258 households primarily used biomass fuels for cooking and PM2.5 <span class="hlt">concentrations</span> in these homes had average <span class="hlt">concentrations</span> 75 μg/m3 (95% CI 56 – 124) greater than other homes. PM2.5 <span class="hlt">concentrations</span> were also associated with burning both biomass and kerosene, indoor smoking, and ventilation, and were more than twice as high during winter than during other seasons. Young children in this community are exposed to indoor PM2.5 <span class="hlt">concentrations</span> 7 times greater than those recommended by World Health Organization guidelines. Interventions to reduce biomass burning could result in a daily reduction of 75 μg/m3 (40%) in time-weighted average PM2.5 <span class="hlt">concentrations</span>. PMID:23127494</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/1225464','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/1225464"><span id="translatedtitle">Energy Yield <span class="hlt">Determination</span> of <span class="hlt">Concentrator</span> Solar Cells using Laboratory Measurements: Preprint</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Geisz, John F.; Garcia, Ivan; McMahon, William E.; Steiner, Myles A.; Ochoa, Mario; France, Ryan M.; Habte, Aron; Friedman, Daniel J.</p> <p>2015-09-14</p> <p>The annual energy conversion efficiency is calculated for a four junction inverted metamorphic solar cell that has been completely characterized in the laboratory at room temperature using measurements fit to a comprehensive optoelectronic model of the multijunction solar cells. A simple model of the temperature dependence is used to predict the performance of the solar cell under varying temperature and spectra characteristic of Golden, CO for an entire year. The annual energy conversion efficiency is calculated by integrating the predicted cell performance over the entire year. The effects of geometric <span class="hlt">concentration</span>, CPV system thermal characteristics, and luminescent coupling are highlighted. temperature and spectra characteristic of Golden, CO for an entire year. The annual energy conversion efficiency is calculated by integrating the predicted cell performance over the entire year. The effects of geometric <span class="hlt">concentration</span>, CPV system thermal characteristics, and luminescent coupling are highlighted.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=19920054019&hterms=Chlorophyll&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D70%26Ntt%3DChlorophyll','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=19920054019&hterms=Chlorophyll&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D70%26Ntt%3DChlorophyll"><span id="translatedtitle"><span class="hlt">Determination</span> of phytoplankton chlorophyll <span class="hlt">concentrations</span> in the Chesapeake Bay with aircraft remote sensing</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Harding, Lawrence W., Jr.; Itsweire, Eric C.; Esaias, Wayne E.</p> <p>1992-01-01</p> <p>Remote sensing measurements of the distribution of phytoplankton chlorophyll <span class="hlt">concentrations</span> in Chesapeake Bay during 1989 are described. It is shown that remote sensing from light aircraft can complement and extend measurements made from traditional platforms and provide data of improved temporal and spatial resolution, leading to a better understanding of phytoplankton dynamics in the estuary. The developments of the winter-spring diatom bloom in the polyhaline to mesohaline regions of the estuary and of the late-spring and summer dinoflagellate blooms in oligohaline and mesohaline regions are traced. The study presents the local chlorophyll algorithm developed using the NASA Ocean Data Acquisition System data and in situ chlorophyll data, interpolated maps of chlorophyll <span class="hlt">concentration</span> generated by applying the algorithm to aircraft radiance data, ancillary in situ data on nutrients, turbidity, streamflow, and light availability, and an interpretation of phytoplankton dynamics in terms of the chlorophyll distribution in Chesapeake Bay during 1989.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/22038668','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/22038668"><span id="translatedtitle"><span class="hlt">Determining</span> <span class="hlt">concentration</span> depth profiles in fluorinated networks by means of electric force microscopy</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Miccio, Luis A.; Schwartz, Gustavo A.</p> <p>2011-08-14</p> <p>By means of electric force microscopy, composition depth profiles were measured with nanometric resolution for a series of fluorinated networks. By mapping the dielectric permittivity along a line going from the surface to the bulk, we were able to experimentally access to the fluorine <span class="hlt">concentration</span> profile. Obtained data show composition gradient lengths ranging from 30 nm to 80 nm in the near surface area for samples containing from 0.5 to 5 wt. % F, respectively. In contrast, no gradients of <span class="hlt">concentration</span> were detected in bulk. This method has several advantages over other techniques because it allows profiling directly on a sectional cut of the sample. By combining the obtained results with x-ray photoelectron spectroscopy measurements, we were also able to quantify F/C ratio as a function of depth with nanoscale resolution.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=19830006461&hterms=solar+concentration&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D30%26Ntt%3Dsolar%2Bconcentration','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=19830006461&hterms=solar+concentration&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D30%26Ntt%3Dsolar%2Bconcentration"><span id="translatedtitle"><span class="hlt">Determination</span> of optimum sunlight <span class="hlt">concentration</span> level in space for 3-5 cascade solar cells</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Curtis, H. B.</p> <p>1982-01-01</p> <p>Current-voltage curves were calculated for each cell in a cascade structure using a solar cell diode equation and superposition. Terms for the light generated current, diffusion current, space charge recombination current and series and shunt resistance are included. Individual current voltage curves are added in series with ohmic resistance losses for the cell interconnects to obtain the cascade cell performance. Temperature was varied with <span class="hlt">concentration</span>, using several models, and ranged from 55 C at one Sun to between 80 and 200 C at 100 Suns. A variety of series resistance and internal resistances were used. Coefficients of the diffusion and recombination terms are strongly temperature dependent. The study indicates that maximum efficiency (30%) occurs in the 50 to 100X Sun <span class="hlt">concentration</span> range, provided series resistance is below 0.015 ohm-sq cm and cell temperature is 80 C at 100 Suns.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1986AtmEn..20..979C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1986AtmEn..20..979C"><span id="translatedtitle">A new technique for collection, <span class="hlt">concentration</span> and <span class="hlt">determination</span> of gaseous tropospheric formaldehyde</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Cofer, Wesley R.; Edahl, Robert A.</p> <p></p> <p>This article describes an improved technique for making in situ measurements of gaseous tropospheric formaldehyde (CH 2O). The new technique is based on nebulization/reflux principles that have proved very effective in quantitatively scrubbing water soluble trace gases (e.g. CH 2O) into aqueous mediums, which are subsequently analyzed. Atmospheric formaldehyde extractions and analyses have been performed with the nebulization/reflux <span class="hlt">concentrator</span> using an acidified dinitrophenylhydrazine solution that indicate that quantitative analysis of CH 2O at global background levels (˜ 0.1 ppbv) is feasible with 20-min extractions. Analysis of CH 2O, once <span class="hlt">concentrated</span>, is accomplished using high performance liquid chromatography (HPLC) with ultraviolet photometric detection. The CH 2O-hydrazone derivative, produced by the reaction of 2,4-dinitrophenylhydrazine in H 2SO 4 acidified aqueous solution, is detected as CH 2O.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li><a href="#" onclick='return showDiv("page_23");'>23</a></li> <li><a href="#" onclick='return showDiv("page_24");'>24</a></li> <li class="active"><span>25</span></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_25 --> <center> <div class="footer-extlink text-muted"><small>Some links on this page may take you to non-federal websites. 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