Science.gov

Sample records for additional laboratory studies

  1. Applicability of the DPPH assay for evaluating the antioxidant capacity of food additives - inter-laboratory evaluation study -.

    PubMed

    Shimamura, Tomoko; Sumikura, Yoshihiro; Yamazaki, Takeshi; Tada, Atsuko; Kashiwagi, Takehiro; Ishikawa, Hiroya; Matsui, Toshiro; Sugimoto, Naoki; Akiyama, Hiroshi; Ukeda, Hiroyuki

    2014-01-01

    An inter-laboratory evaluation study was conducted in order to evaluate the antioxidant capacity of food additives by using a 1,1-diphenyl-2-picrylhydrazyl (DPPH) assay. Four antioxidants used as existing food additives (i.e., tea extract, grape seed extract, enju extract, and d-α-tocopherol) and 6-hydroxy-2,5,7,8-tetramethylchroman-2-carboxylic acid (Trolox) were used as analytical samples, and 14 laboratories participated in this study. The repeatability relative standard deviation (RSD(r)) of the IC50 of Trolox, four antioxidants, and the Trolox equivalent antioxidant capacity (TEAC) were 1.8-2.2%, 2.2-2.9%, and 2.1-2.5%, respectively. Thus, the proposed DPPH assay showed good performance within the same laboratory. The reproducibility relative standard deviation (RSD(R)) of IC50 of Trolox, four antioxidants, and TEAC were 4.0-7.9%, 6.0-11%, and 3.7-9.3%, respectively. The RSD(R)/RSD(r) values of TEAC were lower than, or nearly equal to, those of IC50 of the four antioxidants, suggesting that the use of TEAC was effective for reducing the variance among the laboratories. These results showed that the proposed DPPH assay could be used as a standard method to evaluate the antioxidant capacity of food additives.

  2. A laboratory study of the perceived benefit of additional noise attenuation by houses

    NASA Technical Reports Server (NTRS)

    Flindell, I. H.

    1983-01-01

    Two Experiments were conducted to investigate the perceived benefit of additional house attenuation against aircraft flyover noise. First, subjects made annoyance judgments in a simulated living room while an operative window with real and dummy storm windows was manipulated in full view of those subjects. Second, subjects made annoyance judgments in an anechoic audiometric test chamber of frequency shaped noise signals having spectra closely matched to those of the aircraft flyover noises reproduced in the first experiment. These stimuli represented the aircraft flyover noises in levels and spectra but without the situational and visual cues present in the simulated living room. Perceptual constancy theory implies that annoyance tends to remain constant despite reductions in noise level caused by additional attenuation of which the subjects are fully aware. This theory was supported when account was taken for a reported annoyance overestimation for certain spectra and for a simulated condition cue overreaction.

  3. Laboratory tests of sludge-control additives

    SciTech Connect

    Tatnall, R.E.

    1996-07-01

    Laboratory {open_quotes}jar{close_quotes} tests compared eleven different fuel oil and diesel fuel sludge-control additives. Factors studied included (1) ability to disperse and prevent buildup of sludge deposits on surfaces, (2) ability to protect steel from corrosion, (3) ability to inhibit growth and proliferation of bacteria, and (4) ability to disperse water. Results varied greatly, and it was found that many commercial products do not do what they claim. It is concluded that fuel retailers should not believe manufacturers` claims for their additive products, but rather should test such products themselves to be sure that the benefits of treatment are real. A simplified form of the procedure used here is proposed as one way for dealers to do such testing.

  4. Tethered gravity laboratories study

    NASA Technical Reports Server (NTRS)

    Lucchetti, F.

    1989-01-01

    Variable Gravity Laboratory studies are discussed. The following subject areas are covered: (1) conceptual design and engineering analysis; (2) control strategies (fast crawling maneuvers, main perturbations and their effect upon the acceleration level); and (3) technology requirements.

  5. Tethered gravity laboratories study

    NASA Technical Reports Server (NTRS)

    Lucchetti, F.

    1990-01-01

    The scope of the study is to investigate ways of controlling the microgravity environment of the International Space Station by means of a tethered system. Four main study tasks were performed. First, researchers analyzed the utilization of the tether systems to improve the lowest possible steady gravity level on the Space Station and the tether capability to actively control the center of gravity position in order to compensate for activities that would upset the mass distribution of the Station. The purpose of the second task was to evaluate the whole of the experiments performable in a variable gravity environment and the related beneficial residual accelerations, both for pure and applied research in the fields of fluid, materials, and life science, so as to assess the relevance of a variable g-level laboratory. The third task involves the Tethered Variable Gravity Laboratory. The use of the facility that would crawl along a deployed tether and expose experiments to varying intensities of reduced gravity is discussed. Last, a study performed on the Attitude Tether Stabilizer concept is discussed. The stabilization effect of ballast masses tethered to the Space Station was investigated as a means of assisting the attitude control system of the Station.

  6. Effect of cattle slurry pre-treatment by separation and addition of nitrification inhibitors on gaseous emissions and N dynamics: a laboratory study.

    PubMed

    Pereira, José; Fangueiro, David; Chadwick, David R; Misselbrook, Tom H; Coutinho, João; Trindade, Henrique

    2010-04-01

    The application of untreated or treated animal manure to soils can result in increased N and C gaseous emissions contributing to ecosystem change and global warming. In the present study, dairy cattle slurry (liquid manure) was subjected first to pre-treatment by separation using a screw press to obtain a liquid (LF) and a solid fraction (SF). Then, the different fractions and the whole slurry (WS) were combined with two nitrification inhibitors (NI), dicyandiamide (DCD) or 3,4-dimethylpyrazole phosphate (DMPP), were applied to soil to assess the effect of slurry treatment by separation and NI addition on soil N dynamics and CH4, CO2, NH3, NO and N2O emissions. The WS and the two slurry fractions, combined or not with DCD or DMPP, were applied to soil at an equivalent field dosage of 120 kg total N ha(-1). Controls including a soil only, soil-DCD and soil-DMPP treatments were also included. The mixtures were incubated for 93-d at 20 degrees C. Results obtained show that NI inhibited nitrification between 16 and 30-d in WS and LF, with DMPP having a longer effect over time compared to DCD. There was no significant effect of NI on nitrification for the SF treatment. Nitrification inhibitors did not significantly affect (P>0.05) the CH4, CO2 and N2O emissions, but significantly decreased (P<0.05) NO emissions. Furthermore, the two NIs had a similar effect on gaseous emissions. Throughout the entire experiment, the greatest amount of NO was released from the LF treatment (without NI), while the greatest amount of N2O was released from the SF treatment. Slurry separation had no impact on N emissions, while the combination of this process with one of the two NI led to a small reduction in total N emissions.

  7. Tethered gravity laboratories study

    NASA Technical Reports Server (NTRS)

    Lucchetti, F.

    1989-01-01

    The following subject areas are covered: (1) thermal control issues; (2) attitude control sybsystem; (3) configuration constraints; (4) payload; (5) acceleration requirements on Variable Gravity Laboratory (VGL); and (6) VGL configuration highlights.

  8. Oak Ridge National Laboratory's Preparations for Additional Protocol Implementation

    SciTech Connect

    McCowan, Janie; Cain, Ronald A

    2009-01-01

    The United States Additional Protocol (AP) with the International Atomic Energy Agency (IAEA) entered into force (EIF) January 6, 2009. In anticipation of the EIF, the Department of Energy (DOE) National Nuclear Security Administration Office of International Regimes and Agreements (NA-243) began the initial DOE AP data call on November 3, 2008. This paper describes the Oak Ridge National Laboratory's (ORNL's) preparation, organization, and development efforts to successfully implement the AP and complete the AP data call. ORNL had 35 days to identify declarable activities and finalize the declaration line items (DLIs) for submission to NA-243. To be able to respond within the required time frame, many preparation activities at ORNL were necessary, such as determining the AP coordinator (APC) and team roles; conducting site awareness training; creating the ORNL Standards-Based Management System (SBMS) procedure Reporting of Nuclear Fuel Cycle Activities; training personnel; and defining site implementation software tools. Identifying, updating, compiling, reviewing, and submitting the DLIs to NA-243 were all critical activities for successfully implementing the AP and completing the AP data call at ORNL.

  9. Laboratory study of TLEs

    NASA Astrophysics Data System (ADS)

    Kochkin, P.; Van Deursen, A.; Ebert, U.

    2014-12-01

    Sprites are high-altitude kilometre-scale electrical discharges that happen above thundercloud. Pilot systems are pre-breakdown phenomena that usually attributed to stepped leader development. In Eindhoven University of Technology we investigate meter-scale laboratory discharges looking for similarities with natural lightning and its related phenomena. Negative lightning possesses step-like propagation behaviour which is associated with space leader formation in front of its main leader. Meter-scale laboratory sparks also develop via formation of a space stem that transforms into a pilot system and finally develops into a space leader in longer gaps. With ns-fast photography we investigated the pilot system formation and found striking similarities with high-altitude sprites. But sprites are different in size, environment and polarity. Laboratory pilot barely reaches 70 cm and develops in STP air, while high-altitude sprites reaches ionosphere stretching for dozens of kilometres. Also sprites are assumed to be of opposite to the pilot polarity. Besides that, the pilots are directly involved in x-ray generation in long laboratory sparks. The detailed pilot system development process will be shown, in particular focusing on similarities with natural sprites. Basic properties of the x-ray emission will be presented and discussed.

  10. Tethered gravity laboratories study

    NASA Technical Reports Server (NTRS)

    Lucchetti, F.

    1989-01-01

    The use is studied of tether systems to improve the lowest possible steady gravity level on the Space Station. Particular emphasis is placed by the microgravity community on the achievement of high quality microgravity conditions. The tether capability is explored for active control of the center of gravity and the analysis of possible tethered configurations.

  11. Microscale Immune Studies Laboratory.

    SciTech Connect

    Poschet, Jens Fredrich; Carroll-Portillo, Amanda; Wu, Meiye; Manginell, Ronald Paul; Herr, Amy Elizabeth; Martino, Anthony A.; Perroud, Thomas D.; Branda, Catherine; Srivastava, Nimisha; Sinclair, Michael B.; Moorman, Matthew Wallace; Apblett, Christopher Alan; Sale, Kenneth L.; James, Conrad D.; Carles, Elizabeth L.; Lidke, Diane S.; Van Benthem, Mark Hilary; Rebeil, Roberto; Kaiser, Julie; Seaman, William; Rempe, Susan; Brozik, Susan Marie; Jones, Howland D. T.; Gemperline, Paul; Throckmorton, Daniel J.; Misra, Milind; Murton, Jaclyn K.; Carson, Bryan D.; Zhang, Zhaoduo; Plimpton, Steven James; Renzi, Ronald F.; Lane, Todd W.; Ndiaye-Dulac, Elsa; Singh, Anup K.; Haaland, David Michael; Faulon, Jean-Loup Michel; Davis, Ryan W.; Ricken, James Bryce; Branda, Steven S.; Patel, Kamlesh D.; Joo, Jaewook; Kubiak, Glenn D.; Brennan, James S.; Martin, Shawn Bryan; Brasier, Allan

    2009-01-01

    The overarching goal is to develop novel technologies to elucidate molecular mechanisms of the innate immune response in host cells to pathogens such as bacteria and viruses including the mechanisms used by pathogens to subvert/suppress/obfuscate the immune response to cause their harmful effects. Innate immunity is our first line of defense against a pathogenic bacteria or virus. A comprehensive 'system-level' understanding of innate immunity pathways such as toll-like receptor (TLR) pathways is the key to deciphering mechanisms of pathogenesis and can lead to improvements in early diagnosis or developing improved therapeutics. Current methods for studying signaling focus on measurements of a limited number of components in a pathway and hence, fail to provide a systems-level understanding. We have developed a systems biology approach to decipher TLR4 pathways in macrophage cell lines in response to exposure to pathogenic bacteria and their lipopolysaccharide (LPS). Our approach integrates biological reagents, a microfluidic cell handling and analysis platform, high-resolution imaging and computational modeling to provide spatially- and temporally-resolved measurement of TLR-network components. The Integrated microfluidic platform is capable of imaging single cells to obtain dynamic translocation data as well as high-throughput acquisition of quantitative protein expression and phosphorylation information of selected cell populations. The platform consists of multiple modules such as single-cell array, cell sorter, and phosphoflow chip to provide confocal imaging, cell sorting, flow cytomtery and phosphorylation assays. The single-cell array module contains fluidic constrictions designed to trap and hold single host cells. Up to 100 single cells can be trapped and monitored for hours, enabling detailed statistically-significant measurements. The module was used to analyze translocation behavior of transcription factor NF-kB in macrophages upon activation by E

  12. Additional technician tasks and turnaround time in the clinical Stat laboratory

    PubMed Central

    Salinas, Maria; López-Garrigós, Maite; Flores, Emilio; Leiva-Salinas, Maria; Lillo, Rosa; Leiva-Salinas, Carlos

    2016-01-01

    Introduction Many additional tasks in the Stat laboratory (SL) increase the workload. It is necessary to control them because they can affect the service provided by the laboratory. Our aim is to calculate these tasks, study their evolution over a 10 year period, and compare turnaround times (TAT) in summer period to the rest of the year. Materials and methods Additional tasks were classified as “additional test request” and “additional sample”. We collected those incidences from the laboratory information system (LIS), and calculated their evolution over time. We also calculated the monthly TAT for troponin for Emergency department (ED) patients, as the difference between the verification and LIS registration time. A median time of 30 minutes was our indicator target. TAT results and tests workload in summer were compared to the rest of the year. Results Over a 10-year period, the technologists in the SL performed 51,385 additional tasks, a median of 475 per month. The workload was significantly higher during the summer (45,496 tests) than the rest of the year (44,555 tests) (P = 0.019). The troponin TAT did not show this variation between summer and the rest of the year, complying always with our 30 minutes indicator target. Conclusion The technicians accomplished a significant number of additional tasks, and the workload kept increasing over the period of 10 years. That did not affect the TAT results. PMID:27346970

  13. Additive synthesis with DIASS-M4C on Argonne National Laboratory`s IBM POWERparallel System (SP)

    SciTech Connect

    Kaper, H.; Ralley, D.; Restrepo, J.; Tiepei, S.

    1995-12-31

    DIASS-M4C, a digital additive instrument was implemented on the Argonne National Laboratory`s IBM POWER parallel System (SP). This paper discusses the need for a massively parallel supercomputer and shows how the code was parallelized. The resulting sounds and the degree of control the user can have justify the effort and the use of such a large computer.

  14. Laboratory Governance: Issues for the Study Group on Regional Laboratories.

    ERIC Educational Resources Information Center

    Schultz, Thomas; Dominic, Joseph

    Background information and an analysis of issues involved in the governance of new regional educational laboratories are presented. The new laboratories are to be established through a 1984 competition administered by the National Institute of Education (NIE). The analysis is designed to assist the Study Group on Regional Laboratories to advise…

  15. Laboratory studies of volcanic jets.

    USGS Publications Warehouse

    Kieffer, S.W.; Sturtevant, B.

    1984-01-01

    Laboratory experiments to study the fluid dynamics of violent volcanic eruptions employed pure gases erupted from small reservoirs. The gases used were Freon 12 and Freon 22, both of high molecular weight and high density, to model heavy, particulate- laden volcanic gases; nitrogen, a moderate molecular weight and density gas with well known thermodynamic properties; and He, a low molecular weight and density gas used as an analogue of steam, the dominant gas of most volcanic eruptions.-W.H.B.

  16. Additional Sawmill Electrical Energy Study.

    SciTech Connect

    Carroll, Hatch & Associates.

    1987-02-01

    This study was undertaken to investigate the potential for reducing use of electrical energy at lumber dry kilns by reducing fan speeds part way through the lumber drying process. It included three tasks: to quantify energy savings at a typical mill through field tests; to investigate the level of electric energy use at a representative sample of other mills and thereby to estimate the transferability of the conservation to the region; and to prepare a guidebook to present the technology to mill operators, and to allow them to estimate the economic value of adopting the technique at their facilities. This document reports on the first two tasks.

  17. Wentworth Institute Mechanical Engineering Laboratory Manual. Laboratory Study Guide.

    ERIC Educational Resources Information Center

    Avakian, Harry; And Others

    This publication is a laboratory study guide designed for mechanical engineering students. All of the experiments (with the exception of experiment No. 1) contained in the Mechanical Engineering Laboratory Manual have been included in this guide. Brief theoretical backgrounds, examples and their solutions, charts, graphs, illustrations, and…

  18. Veterinary Laboratory Services Study - 1976.

    DTIC Science & Technology

    1976-09-01

    courses for veterinary laboratory officers and all of the diagnostic service being provided such as rabies , toxoplasmosis , melioidosis, and...2) The request for special diagnostic procedures such as toxoplasmosis , trichinosis, or for other clinical chemistry procedures is occasionally

  19. Laboratory studies of volcanic jets

    NASA Astrophysics Data System (ADS)

    Kieffer, Susan Werner; Sturtevant, Bradford

    1984-09-01

    The study of the fluid dynamics of violent volcanic eruptions by laboratory experiment is described, and the important fluid-dynamic processes that can be examined in laboratory models are discussed in detail. In preliminary experiments, pure gases are erupted from small reservoirs. The gases used are Freon 12 and Freon 22, two gases of high molecular weight and high density that are good analogs of heavy and particulate-laden volcanic gases; nitrogen, a moderate molecular weight, moderate density gas for which the thermodynamic properties are well known; and helium, a low molecular weight, lowdensity gas that is used as a basis for comparison with the behavior of the heavier gases and as an analog of steam, the gas that dominates many volcanic eruptions. Transient jets erupt from the reservoir into the laboratory upon rupture of a thin diaphragm at the exit of a convergent nozzle. The gas accelerates from rest in the reservoir to high velocity in the jet. Reservoir pressures and geometries are such that the fluid velocity in the jets is initially supersonic and later decays to subsonic. The measured reservoir pressure decreases as the fluid expands through repetitively reflecting rarefaction waves, but for the conditions of these experiments, a simple steady-discharge model is sufficient to explain the pressure decay and to predict the duration of the flow. Density variations in the flow field have been visualized with schlieren and shadowgraph photography. The observed structure of the jet is correlated with the measured pressure history. The starting vortex generated when the diaphragm ruptures becomes the head of the jet. Though the exit velocity is sonic, the flow head in the helium jet decelerates to about one-third of sonic velocity in the first few nozzle diameters, the nitrogen head decelerates to about three-fourths of sonic velocity, while Freon maintains nearly sonic velocity. The impulsive acceleration of reservoir fluid into the surrounding atmosphere

  20. Non-additive increases in sediment stability are generated by macroinvertebrate species interactions in laboratory streams.

    PubMed

    Albertson, Lindsey K; Cardinale, Bradley J; Sklar, Leonard S

    2014-01-01

    Previous studies have shown that biological structures such as plant roots can have large impacts on landscape morphodynamics, and that physical models that do not incorporate biology can generate qualitatively incorrect predictions of sediment transport. However, work to date has focused almost entirely on the impacts of single, usually dominant, species. Here we ask whether multiple, coexisting species of hydropsychid caddisfly larvae have different impacts on sediment mobility compared to single-species systems due to competitive interactions and niche differences. We manipulated the presence of two common species of net-spinning caddisfly (Ceratopsyche oslari, Arctopsyche californica) in laboratory mesocosms and measured how their silk filtration nets influence the critical shear stress required to initiate sediment grain motion when they were in monoculture versus polyculture. We found that critical shear stress increases non-additively in polycultures where species were allowed to interact. Critical shear stress was 26% higher in multi-species assemblages compared to the average single-species monoculture, and 21% greater than levels of stability achieved by the species having the largest impact on sediment motion in monoculture. Supplementary behavioral experiments suggest the non-additive increase in critical shear stress may have occurred as competition among species led to shifts in the spatial distribution of the two populations and complementary habitat use. To explore the implications of these results for field conditions, we used results from the laboratory study to parameterize a common model of sediment transport. We then used this model to estimate potential bed movement in a natural stream for which we had measurements of channel geometry, grain size, and daily discharge. Although this extrapolation is speculative, it illustrates that multi-species impacts could be sufficiently large to reduce bedload sediment flux over annual time scales in

  1. Non-Additive Increases in Sediment Stability Are Generated by Macroinvertebrate Species Interactions in Laboratory Streams

    PubMed Central

    Albertson, Lindsey K.; Cardinale, Bradley J.; Sklar, Leonard S.

    2014-01-01

    Previous studies have shown that biological structures such as plant roots can have large impacts on landscape morphodynamics, and that physical models that do not incorporate biology can generate qualitatively incorrect predictions of sediment transport. However, work to date has focused almost entirely on the impacts of single, usually dominant, species. Here we ask whether multiple, coexisting species of hydropsychid caddisfly larvae have different impacts on sediment mobility compared to single-species systems due to competitive interactions and niche differences. We manipulated the presence of two common species of net-spinning caddisfly (Ceratopsyche oslari, Arctopsyche californica) in laboratory mesocosms and measured how their silk filtration nets influence the critical shear stress required to initiate sediment grain motion when they were in monoculture versus polyculture. We found that critical shear stress increases non-additively in polycultures where species were allowed to interact. Critical shear stress was 26% higher in multi-species assemblages compared to the average single-species monoculture, and 21% greater than levels of stability achieved by the species having the largest impact on sediment motion in monoculture. Supplementary behavioral experiments suggest the non-additive increase in critical shear stress may have occurred as competition among species led to shifts in the spatial distribution of the two populations and complementary habitat use. To explore the implications of these results for field conditions, we used results from the laboratory study to parameterize a common model of sediment transport. We then used this model to estimate potential bed movement in a natural stream for which we had measurements of channel geometry, grain size, and daily discharge. Although this extrapolation is speculative, it illustrates that multi-species impacts could be sufficiently large to reduce bedload sediment flux over annual time scales in

  2. Laboratory studies in ultraviolet solar physics

    NASA Technical Reports Server (NTRS)

    Parkinson, W. H.; Kohl, J. L.; Gardner, L. D.; Raymond, J. C.; Smith, P. L.

    1991-01-01

    The research activity comprised the measurement of basic atomic processes and parameters which relate directly to the interpretation of solar ultraviolet observations and to the development of comprehensive models of the component structures of the solar atmosphere. The research was specifically directed towards providing the relevant atomic data needed to perform and to improve solar diagnostic techniques which probe active and quiet portions of the solar chromosphere, the transition zone, the inner corona, and the solar wind acceleration regions of the extended corona. The accuracy with which the physical conditions in these structures can be determined depends directly on the accuracy and completeness of the atomic and molecular data. These laboratory data are used to support the analysis programs of past and current solar observations (e.g., the Orbiting solar Observatories, the Solar Maximum Mission, the Skylab Apollo Telescope Mount, and the Naval Research Laboratory's rocket-borne High Resolution Telescope and Spectrograph). In addition, we attempted to anticipate the needs of future space-borne solar studies such as from the joint ESA/NASA Solar and Heliospheric Observatory (SOHO) spacecraft. Our laboratory activities stressed two categories of study: (1) the measurement of absolute rate coefficients for dielectronic recombination and electron impact excitation; and (2) the measurement of atomic transition probabilities for solar density diagnostics. A brief summary of the research activity is provided.

  3. Laboratory Study of Till Rheology

    NASA Astrophysics Data System (ADS)

    Rathbun, A. P.; Marone, C. J.; Anandakrishnan, S.; Alley, R. B.

    2005-12-01

    Recent studies show that small-amplitude stress changes can trigger ice sheet motion and subglacial seismicity. Deformation in the subglacial region plays a key role in determining slip behavior, including creep, transient slip, stick-slip motion, and seismicity. However, progress in understanding these phenomena is limited by uncertainty in the rheology and frictional properties of glacial till. We report on detailed laboratory experiments to measure the creep and frictional constitutive properties of till sampled from the Matanuska Glacier, Alaska and Caesar Till from the Scioto Lobe of the Laurentide Ice Sheet, sampled in central Ohio. Experiments were conducted in a servo-controlled, double direct shear apparatus with air dried samples at a normal stresses ranging from 50 kPa to 5 MPa. Till was sheared in a three-block arrangement in which two layers are sandwiched between a central forcing block and two stationary blocks. We studied the effect of saturation, initial deformation fabric, stress history, and the boundary conditions of loading. The nominal frictional contact area is 100 cm2 and remains constant during shear. The layer thickness is 1 cm prior to shear. All blocks are grooved perpendicular to the shear direction to ensure that deformation occurs within the layer. The Matanuska till has grains ranging from 6.3 mm to finer than .063 mm with a mean of 2.67 mm whereas the Caesar till has a smaller mean grain size of 0.60 mm, but lacks silt and clay sized particles. We conducted both constant strain rate and constant stress tests. Constant shear stress experiments were employed to study frictional creep. In these tests, stress steps were conducted at 2 % and 5 % steps of the shear strength with strain rate calculated at 20 and 40 minute intervals after the stress steps. Strain rate was calculated by taking a linear fit of strain versus time over two minutes. The stress exponent, n was then calculated from the equation dɛ/dt = bτn. Where ɛ is strain,

  4. Field and laboratory determination of a poly(vinyl/vinylidene chloride) additive in brick mortar.

    PubMed

    Law, S L; Newman, J H; Ptak, F L

    1990-02-01

    A polymerized vinyl/vinylidene chloride additive, used in brick mortar during the 60s and 70s, is detected at the building site by the field method, which employs a commercially available chloride test strip. The field test results can then be verified by the laboratory methods. In one method, total chlorine in the mortar is determined by an oxygen-bomb method and the additive chloride is determined by difference after water-soluble chlorides have been determined on a separate sample. In the second method, the polymerized additive is extracted directly from the mortar with tetrahydrofuran (THF). The difference in weight before and after extraction of the additive gives the weight of additive in the mortar. Evaporation of the THF from the extract leaves a thin film of the polymer, which gives an infrared "fingerprint" spectrum characteristic of the additive polymer.

  5. Additive manufacturing capabilities applied to inertial confinement confusion at Los Alamos National Laboratory

    SciTech Connect

    Cardenas, Tana; Schmidt, Derek William; Peterson, Dominic S.

    2016-08-01

    We describe the use at Los Alamos National Laboratory of additive manufacturing (AM) for a variety of jigs and coating, assembly, and radiography fixtures. Additive manufacturing has also been used to produce shipping containers of complex design that would be too costly to have fabricated using traditional techniques. The current goal for AM use in target fabrication is to increase target accuracy and rigidity. This has been realized by implementing AM into target stalk fabrication, allowing increased complexity to address target strength and the addition of features for alignment at facilities. As a result, we will describe the fabrication of these components and our plans to utilize AM in the future.

  6. Laboratory and Field Evaluation of Fluid-Loss Additive Systems Used in the Williston Basin

    SciTech Connect

    Woo, G.T.; Cramer, D.D.

    1984-05-01

    Many formations in the Williston Basin are naturally fractured limestones and dolomites. Naturally fractured reservoirs are typically the most difficult to maintain control of fracturing fluid leakoff. Treatments in the Mission Canyon, Midale and Ratcliffe formations of the Madison Group have had high fracturing fluid leakoffs. Polymer/inert solids mixtures, 100 mesh sand, silica flour and oil-soluble resins have been used in an attempt to control fluid loss. These additives have not consistently solved the problem of excessive fluid loss, and frequent screenouts, gel-outs or pressure-outs have resulted. A laboratory simulation of naturally fractured reservoir leakoff was employed to evaluate the efficiency of ten fluid loss additive systems. Tapered-slot fluid loss tests and proppant pack damage tests were performed using each additive system. Five fluid loss additive systems were identified which performed well in both tests. This paper also summarizes the results of a field evaluation of nine of the original ten fluid loss additive systems used in 70 wells in the Madison Group. Two fluid loss additive systems, a mixture of silica flour and 100 mesh sand, and a mixture of oil-soluble resin (nominal 250 mesh) and 100 mesh sand, performed well in the laboratory tests and had a high success rate in the field.

  7. Additive manufacturing capabilities applied to inertial confinement confusion at Los Alamos National Laboratory

    DOE PAGES

    Cardenas, Tana; Schmidt, Derek William; Peterson, Dominic S.

    2016-08-01

    We describe the use at Los Alamos National Laboratory of additive manufacturing (AM) for a variety of jigs and coating, assembly, and radiography fixtures. Additive manufacturing has also been used to produce shipping containers of complex design that would be too costly to have fabricated using traditional techniques. The current goal for AM use in target fabrication is to increase target accuracy and rigidity. This has been realized by implementing AM into target stalk fabrication, allowing increased complexity to address target strength and the addition of features for alignment at facilities. As a result, we will describe the fabrication ofmore » these components and our plans to utilize AM in the future.« less

  8. Laboratory Studies Of Circumstellar Carbonaceous Grain Formation

    NASA Astrophysics Data System (ADS)

    Contreras, Cesar; Sciamma-O'Brien, Ella; Salama, Farid

    2014-06-01

    The study of the formation processes of dust is essential to understand the budget of extraterrestrial organic molecules. Although dust with all its components plays an important role in the evolution of interstellar (IS) chemistry and in the formation of organic molecules, little is known on the formation processes of carbonaceous dust. We report the progress that was recently achieved in this domain using NASA Ames’ COSmIC facility (Contreras & Salama 2013, ApJS, 208, 6). PAHs are important chemical building blocks of IS dust. They are detected in IDPs and in meteoritic samples. Additionally, observational, laboratory, and theoretical studies have shown that PAHs are an important, ubiquitous component of the ISM. The formation of PAHs from smaller molecules has not been extensively studied. Therefore, we have performed laboratory experiments to study the dynamic processes of carbon grain formation, starting from the smallest hydrocarbon molecules into the formation of larger PAH and further into nanograins. Studies of IS dust analogs formed from a variety of PAH and hydrocarbon precursors as well as species that include the atoms O, N, and S, have recently been performed in our laboratory using the COSmIC facility to provide conditions that simulate IS and circumstellar environments. The species formed in the COSmiC chamber through a pulsed discharge nozzle plasma source are detected and characterized with a cavity ringdown spectrometer coupled to a time-of-flight mass spectrometer, thus providing both spectroscopic and ion mass information in-situ. Analysis of solid soot particles was also conducted using scanning electron microscopy at the UCSC/NASA Ames’ MACS facility. The SEM analysis of the deposition of soot from methane and acetylene precursors seeded in argon plasmas provide examples on the types of nanoparticles and micrograins that are produced in these gas mixtures under our experimental conditions. From these measurements, we derive information on

  9. Laboratory Studies of DIB Carriers

    NASA Technical Reports Server (NTRS)

    Allamandola, L. J.

    1995-01-01

    Spectroscopic studies of the following potential diffuse interstellar band (DIB) carriers are reviewed: unspecified organics, carbon chains, polycyclic aromatic hydrocarbons (PAHs), fullerenes and derivatives, as well as porphyrins and related material. An assessment of each is given, along with suggestions for further experimental studies needed to fully test each candidate. Of the experimental techniques in common use matrix isolation spectroscopy with neon matrices is the most appropriate for the DIBs. The low vapor pressure and high reactivity of these materials preclude gas phase studies on many of these species. At this point, given the type and quality of published data available, carbon chains and PARs are the most promising candidates for a number of the DIBs.

  10. Simulated Laboratory/Field Study of Evolution.

    ERIC Educational Resources Information Center

    Dubowsky, Nathan; Hartman, Elliott M., Jr.

    1986-01-01

    Immediately following a lecture discussion on early hominid characteristics and behavior, students participate in a laboratory study of bipedal locomotion based on an analysis of footprints. The development and use of this simulation are described. (JN)

  11. LABORATORY SCALE STEAM INJECTION TREATABILITY STUDIES

    EPA Science Inventory

    Laboratory scale steam injection treatability studies were first developed at The University of California-Berkeley. A comparable testing facility has been developed at USEPA's Robert S. Kerr Environmental Research Center. Experience has already shown that many volatile organic...

  12. Laboratory studies of interplanetary dust

    NASA Technical Reports Server (NTRS)

    Walker, R. M.

    1986-01-01

    Interplanetary dust particles (IDPs) are a form of primitive extraterrestrial material. In spite of the formidable experimental problems in working with particles that are too small to be seen with the naked eye, it has proven possible to obtain considerable information concerning their properties and possible origins. Dust particles collected in the stratosphere were reviewed. These particles are the best available samples of interplanetary dust and were studied using a variety of analytical techniques.

  13. Photographic laboratory studies of explosions.

    NASA Technical Reports Server (NTRS)

    Kamel, M. M.; Oppenheim, A. K.

    1973-01-01

    Description of a series of cinematographic studies of explosions made with a high-speed rotating-mirror streak camera which uses a high-frequency stroboscopic ruby laser as the light source. The results obtained mainly concern explosions initiated by focused laser irradiation from a pulsed neodymium laser in a detonating gas consisting essentially of an equimolar mixture of acetylene and oxygen at an initial pressure of 100 torr at room temperature. Among the most significant observations were observations of a spherical blast wave preceded by a Chapman-Jouguet detonation which is stabilized immediately after initiation, the merging of a spherical flame with a shock front of the blast wave in which the flame is propagating, the division of a spherical detonation front into a shock wave and flame, and the generation of shock waves by a network of spherical flames.

  14. 42 CFR 493.645 - Additional fee(s) applicable to approved State laboratory programs and laboratories issued a...

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ..., DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) STANDARDS AND CERTIFICATION LABORATORY REQUIREMENTS... based on the actual resources and time necessary to perform the followup visits. HHS revokes the... assesses that laboratory a fee to cover the cost of these activities. Costs are based on the...

  15. Additives

    NASA Technical Reports Server (NTRS)

    Smalheer, C. V.

    1973-01-01

    The chemistry of lubricant additives is discussed to show what the additives are chemically and what functions they perform in the lubrication of various kinds of equipment. Current theories regarding the mode of action of lubricant additives are presented. The additive groups discussed include the following: (1) detergents and dispersants, (2) corrosion inhibitors, (3) antioxidants, (4) viscosity index improvers, (5) pour point depressants, and (6) antifouling agents.

  16. Bodies in flowing plasmas - Laboratory studies

    NASA Technical Reports Server (NTRS)

    Stone, N. H.; Samir, U.

    1981-01-01

    A brief review of early rudimentary laboratory studies of bodies in flowing, rarefied plasmas is presented (e.g., Birkeland, 1908), along with a discussion of more recent parametric studies conducted in steady plasma wind tunnels, which includes the study by Hall et al. (1964), in which a strong ion density enhancement in the center of the ion void created downstream from the body was observed. Good agreement was found between the experimental results and theoretical calculations which omit ion thermal motion. Examples in which in situ data on the interaction between satellites and the ionospheric plasma have been elucidated by the laboratory results are presented, and include evidence for a midwake axial ion peak, and ion current density in the near-wake region. The application of the ionospheric laboratory to basic space plasma physics is discussed, and its application to some types of solar system plasma phenomena is illustrated.

  17. Effectiveness of fluid loss additives in laboratory dynamic fluid loss experiments

    SciTech Connect

    Charles, D.D.; Xie, X.

    1995-12-31

    A commercially available HTHP (high temperature, high pressure) dynamic filtration unit and a widely available HTHP rheometer was used to study dynamic fluid-loss behavior of uncrosslinked hydroxypropyl guar hydraulic fracturing fluid containing varying concentrations of silica flour, starch, and diesel. New dimensionless groups were defined for the dynamic fluid-loss problem. These groups were used first to effectively correlate previously reported laboratory data and later were employed to analyze the ensuing experimental data. Results demonstrate that low and high permeability cores require different mechanisms for fluid-loss control and that, compared to silica flour, starch may lose its effectiveness at higher concentrations.

  18. Additional EIPC Study Analysis. Final Report

    SciTech Connect

    Hadley, Stanton W; Gotham, Douglas J.; Luciani, Ralph L.

    2014-12-01

    Between 2010 and 2012 the Eastern Interconnection Planning Collaborative (EIPC) conducted a major long-term resource and transmission study of the Eastern Interconnection (EI). With guidance from a Stakeholder Steering Committee (SSC) that included representatives from the Eastern Interconnection States Planning Council (EISPC) among others, the project was conducted in two phases. Phase 1 involved a long-term capacity expansion analysis that involved creation of eight major futures plus 72 sensitivities. Three scenarios were selected for more extensive transmission- focused evaluation in Phase 2. Five power flow analyses, nine production cost model runs (including six sensitivities), and three capital cost estimations were developed during this second phase. The results from Phase 1 and 2 provided a wealth of data that could be examined further to address energy-related questions. A list of 14 topics was developed for further analysis. This paper brings together the earlier interim reports of the first 13 topics plus one additional topic into a single final report.

  19. Electrostatic Levitation for Studies of Additive Manufactured Materials

    NASA Technical Reports Server (NTRS)

    SanSoucie, Michael P.; Rogers, Jan R.; Tramel, Terri

    2014-01-01

    The electrostatic levitation (ESL) laboratory at NASA's Marshall Space Flight Center is a unique facility for investigators studying high temperature materials. The laboratory boasts two levitators in which samples can be levitated, heated, melted, undercooled, and resolidified. Electrostatic levitation minimizes gravitational effects and allows materials to be studied without contact with a container or instrumentation. The lab also has a high temperature emissivity measurement system, which provides normal spectral and normal total emissivity measurements at use temperature. The ESL lab has been instrumental in many pioneering materials investigations of thermophysical properties, e.g., creep measurements, solidification, triggered nucleation, and emissivity at high temperatures. Research in the ESL lab has already led to the development of advanced high temperature materials for aerospace applications, coatings for rocket nozzles, improved medical and industrial optics, metallic glasses, ablatives for reentry vehicles, and materials with memory. Modeling of additive manufacturing materials processing is necessary for the study of their resulting materials properties. In addition, the modeling of the selective laser melting processes and its materials property predictions are also underway. Unfortunately, there is very little data for the properties of these materials, especially of the materials in the liquid state. Some method to measure thermophysical properties of additive manufacturing materials is necessary. The ESL lab is ideal for these studies. The lab can provide surface tension and viscosity of molten materials, density measurements, emissivity measurements, and even creep strength measurements. The ESL lab can also determine melting temperature, surface temperatures, and phase transition temperatures of additive manufactured materials. This presentation will provide background on the ESL lab and its capabilities, provide an approach to using the ESL

  20. Human Laboratory Studies on Cannabinoids and Psychosis.

    PubMed

    Sherif, Mohamed; Radhakrishnan, Rajiv; D'Souza, Deepak Cyril; Ranganathan, Mohini

    2016-04-01

    Some of the most compelling evidence supporting an association between cannabinoid agonists and psychosis comes from controlled laboratory studies in humans. Randomized, double-blind, placebo-controlled, crossover laboratory studies demonstrate that cannabinoid agonists, including phytocannabinoids and synthetic cannabinoids, produce a wide range of positive, negative, and cognitive symptoms and psychophysiologic deficits in healthy human subjects that resemble the phenomenology of schizophrenia. These effects are time locked to drug administration, are dose related, and are transient and rarely necessitate intervention. The magnitude of effects is similar to the effects of ketamine but qualitatively distinct from other psychotomimetic drugs, including ketamine, amphetamine, and salvinorin A. Cannabinoid agonists have also been shown to transiently exacerbate symptoms in individuals with schizophrenia in laboratory studies. Patients with schizophrenia are more vulnerable than healthy control subjects to the acute behavioral and cognitive effects of cannabinoid agonists and experience transient exacerbation of symptoms despite treatment with antipsychotic medications. Furthermore, laboratory studies have failed to demonstrate any "beneficial" effects of cannabinoid agonists in individuals with schizophrenia-challenging the cannabis self-medication hypothesis. Emerging evidence suggests that polymorphisms of several genes related to dopamine metabolism (e.g., COMT, DAT1, and AKT1) may moderate the effects of cannabinoid agonists in laboratory studies. Cannabinoid agonists induce dopamine release, although the magnitude of release does not appear to be commensurate to the magnitude and spectrum of their acute psychotomimetic effects. Interactions between the endocannabinoid, gamma-aminobutyric acid, and glutamate systems and their individual and interactive effects on neural oscillations provide a plausible mechanism underlying the psychotomimetic effects of

  1. Addition of a Project-Based Component to a Conventional Expository Physical Chemistry Laboratory

    ERIC Educational Resources Information Center

    Tsaparlis, Georgios; Gorezi, Marianna

    2007-01-01

    Students should enjoy their laboratory classes and for this purpose a project-based activity is added to a conventional physical chemistry laboratory. Students were given project work instead of conventional experiment and then they had to make progress in the project according to instructions and then carry out experiments related to the project.

  2. Laboratory studies of crystal growth in magma

    NASA Astrophysics Data System (ADS)

    Hammer, J. E.; Welsch, B. T.; First, E.; Shea, T.

    2012-12-01

    The proportions, compositions, and interrelationships among crystalline phases and glasses in volcanic rocks cryptically record pre-eruptive intensive conditions, the timing of changes in crystallization environment, and the devolatilization history of eruptive ascent. These parameters are recognized as important monitoring tools at active volcanoes and interpreting geologic events at prehistoric and remote eruptions, thus motivating our attempts to understand the information preserved in crystals through an experimental appoach. We are performing laboratory experiments in mafic, felsic, and intermediate composition magmas to study the mechanisms of crystal growth in thermochemical environments relevant to volcanic environments. We target features common to natural crystals in igneous rocks for our experimental studies of rapid crystal growth phenomena: (1) Surface curvature. Do curved interfaces and spongy cores represent evidence of dissolution (i.e., are they corrosion features), or do they record the transition from dendritic to polyhedral morphology? (2) Trapped melt inclusions. Do trapped liquids represent bulk (i.e., far-field) liquids, boundary layer liquids, or something intermediate, depending on individual species diffusivity? What sequence of crystal growth rates leads to preservation of sealed melt inclusions? (3) Subgrain boundaries. Natural phenocrysts commonly exhibit tabular subgrain regions distinguished by small angle lattice misorientations or "dislocation lamellae" and undulatory extinction. Might these crystal defects be produced as dendrites undergo ripening? (4) Clusters. Contacting clusters of polymineralic crystals are the building blocks of cumulates, and are ubiquitous features of mafic volcanic rocks. Are plagioclase and clinopyroxene aligned crystallographically, suggesting an epitaxial (surface energy) relationship? (5) Log-normal size distribution. What synthetic cooling histories produce "natural" distributions of crystal sizes, and

  3. Laboratory studies of radionuclide migration in tuff

    SciTech Connect

    Rundberg, R.S.; Mitchell, A.J.; Ott, M.A.; Thompson, J.L.; Triay, I.R.

    1989-10-01

    The movement of selected radionuclides has been observed in crushed tuff, intact tuff, and fractured tuff columns. Retardation factors and dispersivities were determined from the elution profiles. Retardation factors have been compared with those predicted on the basis of batch sorption studies. This comparison forms a basis for either validating distribution coefficients or providing evidence of speciation, including colloid formation. Dispersivities measured as a function of velocity provide a means of determining the effect of sorption kinetics or mass transfer on radionuclide migration. Dispersion is also being studied in the context of scaling symmetry to develop a basis for extrapolating from the laboratory scale to the field. 21 refs., 6 figs., 2 tabs.

  4. The work of the European Union Reference Laboratory for Food Additives (EURL) and its support for the authorisation process of feed additives in the European Union: a review

    PubMed Central

    von Holst, Christoph; Robouch, Piotr; Bellorini, Stefano; de la Huebra, María José González; Ezerskis, Zigmas

    2016-01-01

    ABSTRACT This paper describes the operation of the European Union Reference Laboratory for Feed Additives (EURL) and its role in the authorisation procedure of feed additives in the European Union. Feed additives are authorised according to Regulation (EC) No. 1831/2003, which introduced a completely revised authorisation procedure and also established the EURL. The regulations authorising feed additives contain conditions of use such as legal limits of the feed additives, which require the availability of a suitable method of analysis for official control purposes under real world conditions. It is the task of the EURL to evaluate the suitability of analytical methods as proposed by the industry for this purpose. Moreover, the paper shows that one of the major challenges is the huge variety of the methodology applied in feed additive analysis, thus requiring expertise in quite different analytical areas. In order to cope with this challenge, the EURL is supported by a network of national reference laboratories (NRLs) and only the merged knowledge of all NRLs allows for a scientifically sound assessment of the analytical methods. PMID:26540604

  5. Laboratory Studies of Interstellar PAH Analogs

    NASA Technical Reports Server (NTRS)

    Salama, Farid; DeVincenzi, Donald (Technical Monitor)

    2000-01-01

    Polycyclic aromatic hydrocarbons (PAHs) are now considered to be an important and ubiquitous component of the organic material in space. PAHs are found in a large variety of extraterrestrial materials such as interplanetary dust particles (IDPs) and meteoritic materials. PAHs are also good candidates to account for the infrared emission bands (UIRs) and the diffuse interstellar optical absorption bands (DIBs) detected in various regions of the interstellar medium. The recent observations made with the Infrared Space Observatory (ISO) have confirmed the ubiquitous nature of the UIR bands and their carriers. PAHs are though to form through chemical reactions in the outflow from carbon-rich stars in a process similar to soot formation. Once injected in the interstellar medium, PAHs are further processed by the interstellar radiation field, interstellar shocks and energetic particles. A major, dedicated, laboratory effort has been undertaken over the past years to measure the physical and chemical characteristics of these complex molecules and their ions under experimental conditions that mimic the interstellar conditions. These measurements require collision-free conditions where the molecules and ions are cold and chemically isolated. The spectroscopy of PAHs under controlled conditions represents an essential diagnostic tool to study the evolution of extraterrestrial PAHs. The Astrochemistry Laboratory program will be discussed through its multiple aspects: objectives, approach and techniques adopted, adaptability to the nature of the problem(s), results and implications for astronomy as well as for molecular spectroscopy. A review of the data generated through laboratory simulations of space environments and the role these data have played in our current understanding of the properties of interstellar PAHs will be presented. The discussion will also introduce the newest generation of laboratory experiments that are currently being developed in order to provide a

  6. Structure Property Studies for Additively Manufactured Parts

    SciTech Connect

    Milenski, Helen M; Schmalzer, Andrew Michael; Kelly, Daniel

    2015-08-17

    Since the invention of modern Additive Manufacturing (AM) processes engineers and designers have worked hard to capitalize on the unique building capabilities that AM allows. By being able to customize the interior fill of parts it is now possible to design components with a controlled density and customized internal structure. The creation of new polymers and polymer composites allow for even greater control over the mechanical properties of AM parts. One of the key reasons to explore AM, is to bring about a new paradigm in part design, where materials can be strategically optimized in a way that conventional subtractive methods cannot achieve. The two processes investigated in my research were the Fused Deposition Modeling (FDM) process and the Direct Ink Write (DIW) process. The objectives of the research were to determine the impact of in-fill density and morphology on the mechanical properties of FDM parts, and to determine if DIW printed samples could be produced where the filament diameter was varied while the overall density remained constant.

  7. Flue gas conditioning for improved particle collection in electrostatic precipitators. First topical report, Results of laboratory screening of additives

    SciTech Connect

    Durham, M.D.

    1993-04-16

    Several tasks have been completed in a program to evaluate additives to improve fine particle collection in electrostatic precipitators. Screening tests and laboratory evaluations of additives are summarized in this report. Over 20 additives were evaluated; four were found to improve flyash precipitation rates. The Insitec particle analyzer was also evaluated; test results show that the analyzer will provide accurate sizing and counting information for particles in the size range of {le} 10 {mu}m dia.

  8. Effect of a laboratory surfactant on compatibility of type IV dental stones with addition-cured silicone impression materials.

    PubMed

    Tredwin, Christopher Jeremy; Nesbit, Michael; Butta, Rajeev; Moles, David R

    2008-06-01

    This study compared the effect of a surfactant on surface detail reproduction between combinations of addition-cured silicone impression materials and type IV stones. Six hundred impressions were made of a ruled test block using; Examix-NDS, Doric-Es Flo-Light, Panasil Contact Plus, Extrude Wash and President Plus Jet. Half of the impressions were treated with a surfactant (Aurofilm). Impressions were poured with type IV dental stones; Silky Rock, Fuji Rock, Suprastone and Vel-Mix and the 20 mu line was scored. A laboratory surfactant (Aurofilm) significantly reduced (P<0.01) compatibility with; (i) Examix-NDS and Suprastone, (ii) Examix-NDS and Velmix, (iii) Extrude Wash and Fuji Rock.

  9. Laboratory models for studying ectopic pregnancy

    PubMed Central

    Brown, Jeremy K; Horne, Andrew W

    2011-01-01

    Purpose of Review Understanding of the aetiology of tubal ectopic pregnancy (tEP) remains incomplete. We aim to summarize the latest advances in laboratory models of tEP that we believe will, ultimately, contribute to improving the diagnosis and management of the condition. Recent Findings Progress in proteome pre-fractionation and multidimensional protein identification technology has proved particularly effective in identifying novel biomarkers of tEP. These, and related global proteomic and genomic approaches, have as yet to be fully exploited in this context but do have substantial potential to inform future hypothesis driven studies. The majority of data generated since 2009 to explain the aetiology of tEP continues to derive from descriptive human ex-vivo studies. In-vitro models of Fallopian tube ciliary and smooth muscle function have improved to a limited degree, on the back of continuing advances in imaging and data acquisition. We believe that the recent development of a primary human Fallopian tube epithelium culture system represents the most significant recent advance in laboratory models for studying ectopic pregnancy. There remain no good animal models of tEP. Summary The establishment of a viable animal model of tEP remains the key obstacle to a complete understanding the aetiology of the condition. PMID:21666470

  10. DNA binding studies of tartrazine food additive.

    PubMed

    Kashanian, Soheila; Zeidali, Sahar Heidary

    2011-07-01

    The interaction of native calf thymus DNA with tartrazine in 10 mM Tris-HCl aqueous solution at neutral pH 7.4 was investigated. Tartrazine is a nitrous derivative and may cause allergic reactions, with a potential of toxicological risk. Also, tartrazine induces oxidative stress and DNA damage. Its DNA binding properties were studied by UV-vis and circular dichroism spectra, competitive binding with Hoechst 33258, and viscosity measurements. Tartrazine molecules bind to DNA via groove mode as illustrated by hyperchromism in the UV absorption band of tartrazine, decrease in Hoechst-DNA solution fluorescence, unchanged viscosity of DNA, and conformational changes such as conversion from B-like to C-like in the circular dichroism spectra of DNA. The binding constants (K(b)) of DNA with tartrazine were calculated at different temperatures. Enthalpy and entropy changes were calculated to be +37 and +213 kJ mol(-1), respectively, according to the Van't Hoff equation, which indicated that the reaction is predominantly entropically driven. Also, tartrazine does not cleave plasmid DNA. Tartrazine interacts with calf thymus DNA via a groove interaction mode with an intrinsic binding constant of 3.75 × 10(4) M(-1).

  11. IMPACTS OF DRILLING ADDITIVES ON DATA OBTAINED FROM HYDROGEOLOGIC CHARACTERIZATION WELLS AT LOS ALAMOS NATIONAL LABORATORY

    EPA Science Inventory

    Personnel at the EPA Ground Water and Ecosystems Restoration Division (GWERD) were requested by EPA Region 6 to evaluate the impacts of well drilling practices at the Los Alamos National Laboratory (LANL). The focus of this review involved analysis of the impacts of bentonite- a...

  12. Zero-gravity cloud physics laboratory: Experiment program definition and preliminary laboratory concept studies

    NASA Technical Reports Server (NTRS)

    Eaton, L. R.; Greco, E. V.

    1973-01-01

    The experiment program definition and preliminary laboratory concept studies on the zero G cloud physics laboratory are reported. This program involves the definition and development of an atmospheric cloud physics laboratory and the selection and delineations of a set of candidate experiments that must utilize the unique environment of zero gravity or near zero gravity.

  13. Atmospheric cloud physics laboratory project study

    NASA Technical Reports Server (NTRS)

    Schultz, W. E.; Stephen, L. A.; Usher, L. H.

    1976-01-01

    Engineering studies were performed for the Zero-G Cloud Physics Experiment liquid cooling and air pressure control systems. A total of four concepts for the liquid cooling system was evaluated, two of which were found to closely approach the systems requirements. Thermal insulation requirements, system hardware, and control sensor locations were established. The reservoir sizes and initial temperatures were defined as well as system power requirements. In the study of the pressure control system, fluid analyses by the Atmospheric Cloud Physics Laboratory were performed to determine flow characteristics of various orifice sizes, vacuum pump adequacy, and control systems performance. System parameters predicted in these analyses as a function of time include the following for various orifice sizes: (1) chamber and vacuum pump mass flow rates, (2) the number of valve openings or closures, (3) the maximum cloud chamber pressure deviation from the allowable, and (4) cloud chamber and accumulator pressure.

  14. How toxic is coal ash? A laboratory toxicity case study

    SciTech Connect

    Sherrard, Rick M.; Carriker, Neil; Greeley, Jr., Mark Stephen

    2014-12-08

    Under a consent agreement among the Environmental Protection Agency (EPA) and proponents both for and against stricter regulation, EPA is to issue a new coal ash disposal rule by the end of 2014. Laboratory toxicity investigations often yield conservative estimates of toxicity because many standard test species are more sensitive than resident species, thus could provide information useful to the rule-making. However, few laboratory studies of coal ash toxicity are available; most studies reported in the literature are based solely on field investigations. In this paper, we describe a broad range of toxicity studies conducted for the Tennessee Valley Authority (TVA) Kingston ash spill, results of which help provide additional perspective on the toxicity of coal ash.

  15. How toxic is coal ash? A laboratory toxicity case study

    DOE PAGES

    Sherrard, Rick M.; Carriker, Neil; Greeley, Jr., Mark Stephen

    2014-12-08

    Under a consent agreement among the Environmental Protection Agency (EPA) and proponents both for and against stricter regulation, EPA is to issue a new coal ash disposal rule by the end of 2014. Laboratory toxicity investigations often yield conservative estimates of toxicity because many standard test species are more sensitive than resident species, thus could provide information useful to the rule-making. However, few laboratory studies of coal ash toxicity are available; most studies reported in the literature are based solely on field investigations. In this paper, we describe a broad range of toxicity studies conducted for the Tennessee Valley Authoritymore » (TVA) Kingston ash spill, results of which help provide additional perspective on the toxicity of coal ash.« less

  16. Effects of biochar addition on greenhouse gas emissions and microbial responses in a short-term laboratory experiment.

    PubMed

    Yoo, Gayoung; Kang, Hojeong

    2012-01-01

    Biochar application to soil has drawn much attention as a strategy to sequester atmospheric carbon in soil ecosystems. The applicability of this strategy as a climate change mitigation option is limited by our understanding of the mechanisms responsible for the observed changes in greenhouse gas emissions from soils, microbial responses, and soil fertility changes. We conducted an 8-wk laboratory incubation using soils from PASTURE (silt loam) and RICE PADDY (silt loam) sites with and without two types of biochar (biochar from swine manure [CHAR-M] and from barley stover [CHAR-B]). Responses to addition of the different biochars varied with the soil source. Addition of CHAR-B did not change CO and CH evolution from the PASTURE or the RICE PADDY soils, but there was a decrease in NO emissions from the PASTURE soil. The effects of CHAR-M addition on greenhouse gas emissions were different for the soils. The most substantial change was an increase in NO emissions from the RICE PADDY soil. This result was attributed to a combination of abundant denitrifiers in this soil and increased net nitrogen mineralization. Soil phosphatase and N-acetylglucosaminidase activity in the CHAR-B-treated soils was enhanced compared with the controls for both soils. Fungal biomass was higher in the CHAR-B-treated RICE PADDY soil. From our results, we suggest CHAR-B to be an appropriate amendment for the PASTURE and RICE PADDY soils because it provides increased nitrogen availability and microbial activity with no net increase in greenhouse gas emissions. Application of CHAR-M to RICE PADDY soils could result in excess nitrogen availability, which may increase NO emissions and possible NO leaching problems. Thus, this study confirms that the ability of environmentally sound biochar additions to sequester carbon in soils depends on the characteristics of the receiving soil as well as the nature of the biochar.

  17. Laboratory study of mini-magnetosphere

    NASA Astrophysics Data System (ADS)

    Shaikhislamov, Ildar; Zakharov, Yuri; Posukh, Vitaly; Melekhov, Aleksandr; Antonov, Vladimir; Boyarintsev, Eduard; Ponomarenko, Arnold

    Laboratory study of mini-magnetosphere Magnetosphere at ion kinetic scales, or mini-magnetosphere, which is observed above lunar magnetic anomalies or might be discovered around magnetized asteroids in future missions, possesses unusual features as predicted by numerical simulations. However, there are practically no data on the subject from space observations and the data which is available is far too incomplete. In the present work we describe results of laboratory experiment on interaction of plasma flow with magnetic dipole with parameters such that ion inertia length is smaller than a size of observed magnetosphere. A detailed structure of non-coplanar or out-of-plane component of magnetic field has been obtained in meridian plane. Independence of this component on dipole moment reversal, as was reported in previous works (Shaikhislamov et al 2013, 2014), has been verified. In the tail distinct lobes and central current sheet have been observed. It was found that lobe regions adjacent to boundary layer are dominated by non-coplanar component of magnetic field. Tail-ward oriented electric current in plasma associated with that component appears to be equal to ion current in the frontal part of magnetosphere and in the tail current sheet implying that electrons are stationary in those regions while ions flow by. Obtained data strongly support the proposed model of mini-magnetosphere based on two-fluid effects as described by the Hall term and suggest that spacecraft crossing the tail of magnetized asteroid might observe, instead of simple reversion of tail-ward field, a complex 3-D rotation of magnetic field vector. Acknowledgements This work was supported by SB RAS Research Program grant II.8.1.4, Russian Fund for Basic Research grant 12-02-00367, OFN RAS Research Program 15 and Presidium RAS Research Program 22. References Shaikhislamov, I. F., Antonov, V. M., Zakharov, Yu. P., Boyarintsev, E. L., Melekhov, A. V., Posukh, V. G. and Ponomarenko, A. G. Mini

  18. The Mathematics Laboratory in Engineering Studies.

    ERIC Educational Resources Information Center

    Quesada, Jose Fco. Carballido

    1986-01-01

    Discusses the need for mathematics laboratories to supplement classroom instruction in mathematics for engineering students. Provides a description of such a laboratory, including a listing of equipment and materials that are recommended. Describes the uses for personal computers and suggests various problems that could be explored in the…

  19. Weapons and Materials Research Directorate (WMRD) Laboratory Demonstration Study

    DTIC Science & Technology

    2015-02-01

    Weapons and Materials Research Directorate (WMRD) Laboratory Demonstration Study by Nora M Eldredge ARL-SR-0311 February 2015...Weapons and Materials Research Directorate (WMRD) Laboratory Demonstration Study Nora M Eldredge Weapons and Materials Research Directorate, ARL...September 2014 4. TITLE AND SUBTITLE Weapons and Materials Research Directorate (WMRD) Laboratory Demonstration Study 5a. CONTRACT NUMBER 5b

  20. Mass spectrometry contamination from Tinuvin 770, a common additive in laboratory plastics.

    PubMed

    Schauer, Kevin L; Broccardo, Carolyn J; Webb, Kimberly M; Covey, Paul A; Prenni, Jessica E

    2013-07-01

    The superior sensitivity of current mass spectrometers makes them prone to contamination issues, which can have deleterious effects on sample analysis. Here, bis(2,2,6,6-tetramethyl-4-piperidyl) sebacate (marketed under the name Tinuvin 770) is identified as a major contaminant in applications using liquid chromatography coupled with mass spectrometry (LC-MS). Tinuvin 770 is often added to laboratory and medical plastics as a UV stabilizer. One particular lot of microcentrifuge tubes was found to have an excess of this compound that would leach into samples and drastically interfere with LC-MS data acquisition. Further analysis found that Tinuvin 770 readily leached into polar and nonpolar solvents from the contaminated tube lot. Efforts to remove Tinuvin 770 from contaminated samples were unsuccessful. A prescreening method using MALDI-TOF MS is presented to prevent system contamination and sample loss.

  1. Rocket and Laboratory Studies in Astronomy

    NASA Technical Reports Server (NTRS)

    Feldman, Paul D.

    2001-01-01

    This is the final report for NASA Grant NAG5-5122 and covers the period from March 1, 1997 to February 28, 2001. This grant was a continuation of a program in rocket and laboratory studies in ultraviolet astronomy that was supported by NASA grant NAG5-619. As of March 1, 2001, this program is continuing under grant NAG5-5315. During the period of the grant, annual status reports have been submitted detailing the scientific achievements and current objectives of each report period. These will not be repeated here. Among the highlights of the program are four successful rocket launches including participation in the campaign to study comet Hale-Bopp in April 1997. We have continued our emphasis on long-slit spectroscopy of extended sources in the shorter wavelength far-ultraviolet, necessitating the development of evacuated telescope/spectrograph payloads. Finally, we also note the use of our ultraviolet calibration facilities in support of other sounding rocket investigators and for other space missions such as the Far Ultraviolet Spectroscopic Explorer. We include a list of the sounding rocket launches performed under NASA sponsorship during this period, a list of Ph.D. degrees awarded to students who worked in this program, and a summary bibliography of publications between 1997 and 2001.

  2. Laboratory Studies in Support of Planetary Science

    NASA Astrophysics Data System (ADS)

    Dalton, James B.; Castillo, J.; Hodyss, R.; Spilker, T.; Brown, L.; Orton, G.; Gudipati, M.; Mastrapa, R.; Atreya, S.; Nimmo, F.; Blankenship, D.; Durham, B.; Khurana, K.; others

    2009-09-01

    Scientific understanding in several fields within Planetary Science could enter a period of rapid progress and discovery once certain laboratory investigations are performed to provide valuable constraints on fundamental properties of radiation and matter, the physics and chemistry of atmospheric, surface and subsurface compounds, and dynamic interactions within the Solar System. Much theoretical work at present is based upon rough estimates of basic parameters that could be measured under carefully controlled laboratory conditions. Due to the exotic nature of many planetary environments, these investigations are unique, challenging, and generally expensive for the individual researchers. Traditionally, funding for laboratory work has lagged behind that of missions; at present, there is sufficient mission data already recorded to justify a sustained investment in laboratory activities over the coming decade that would result in an exponential return in scientific progress. Specific laboratory investigations are needed to provide fundamental physical, chemical, and biological parameters for theoretical models and observational interpretations that will drive the entire field of Planetary Science forward, particularly with regard to atmospheric dynamics, chemistry, and composition; celestial dynamics, surface chemistry and composition, planetary formation, geology, and geophysics; plasmas and magnetospheres; and applications of astrobiology and astrophysics for Solar System bodies. A series of topical white papers addressing each of these are being submitted to the Planetary Science Decadal Survey and highlighting the areas most in need of supporting laboratory work.

  3. A Study of Mathematics Needed for Dental Laboratory Technology, Medical Laboratory Technology, and Respiratory Therapy.

    ERIC Educational Resources Information Center

    Roberts, Keith J.

    A study was conducted to determine what mathematics skills were needed for Dental Laboratory Technology, Medical Laboratory Technology, and Respiratory Therapy. Data obtained from studies, course outlines, textbooks, and reports were used to construct a 79-item mathematics skill questionnaire. This questionnaire was administered to employers,…

  4. Infrared laboratory studies of synthetic planetary atmospheres

    NASA Technical Reports Server (NTRS)

    Williams, D.

    1972-01-01

    The initial stages of the research were involved with a test of Burch's law of multiplicative transmittance for mixed absorbing gases when their lines are broadened by H2 and He, which are constituents of the atmospheres of the major planets. The broadening of individual lines in the CO fundamental by various gases was investigated. Line strength and half-width for individual CO lines were studied as a function of temperature. Measurements of total band absorptance as a function of absorber thickness and total effective pressure were made at various temperatures for bands of CO and N2O. Attempts were made to develop a phenomenological theory of line broadening that would account for the phenomena observed for the CO fundamental and those reported for more highly polar gases. Laboratory measurements of nitric acid vapor absorptance were compared with balloon measurements in arriving at an estimate of the quantity of nitric acid vapor present in the earth's atmosphere in the region of the ozone layer.

  5. A laboratory study of floating lenticular anticyclones

    NASA Astrophysics Data System (ADS)

    Le Gal, Patrice; de La Rosa, Hector; Cros, Anne; Cruz-Gomez, Raúl; Le Bars, Michael

    2014-11-01

    Oceanic vortices play an important role in the redistribution of heat, salt and momentum in the oceans. Among these vortices, floating lenses or rings are often met in the meanders of warm currents. For instance the North Brazil Current rings are among the most intense and large anticyclonic vortices on Earth. In order to better describe these vortices, we propose here a laboratory study of these floating anticyclonic lenses. A blob of fresh water is slowly injected near the surface of a rotating layer of homogeneous salted water. Because of the opposite effects of rotation that tends to generate columnar structures and density stratification that spreads light water on the surface, the vortices take a finite size three dimensionnal typical shape. Visualization and PIV measurements of the shape, aspect ratios and vorticity profiles are compared to analytical predictions that use first a simple solid body rotation model and then a more realistic isolated Gaussian vorticity field inside the anticyclones. This work was carried out within the framework of a bilateral cooperation between CNRS (France) and CONACYT (Mexico).

  6. Viscosity, electrical conductivity, and cesium volatility of ORNL (Oak Ridge National Laboratory) vitrified soils with limestone and sodium additives

    SciTech Connect

    Shade, J.W.; Piepel, G.F.

    1990-05-01

    Engineering- and pilot-scale tests of the in situ vitrification (ISV) process have been conducted for Oak Ridge National Laboratory (ORNL) to successfully demonstrate the feasibility of applying ISV to seepage trenches and pits at ORNL. These sites contain soil that overlies crushed limestone fill; therefore, the ISV process is applied to a soil-limestone mixture. Previous testing indicated that while a good retention level of {sup 137}Cs and {sup 90}Sr was achieved in the melt, it would be desirable to improve {sup 137}Cs retention to 99.99% if possible to minimize activity in the off-gas system. Previous testing was limited to one soil-limestone composition. Both Cs volatility and ISV power requirements are in part dependent on melt temperature and viscosity, which depend on melt composition. The study described in this report determined the effect of varying soil and limestone compositions, as well as the addition of a sodium flux, on melt viscosity, electrical conductivity, and Cs volatility. 10 refs., 15 figs., 9 tabs.

  7. Rocket and Laboratory Studies in Astronomy

    NASA Technical Reports Server (NTRS)

    Feldman, Paul D.; McCandliss, Stephan R.

    2004-01-01

    This report covers the period from March 1, 2001 to August 31, 2004. This grant was the continuation of NASA grant NAG5-5122 and supported the Johns Hopkins sounding rocket program that had its roots in the 1960s. The emphasis of this program has been the development of instrumentation for far-ultraviolet astronomy, the training of graduate students in all aspects of a space mission, and the application of these techniques to timely scientific problems. During this period we completed the fabrication of our new long-slit dual-order spectrograph (LIDOS), and successfully flew it on a Black Brant sounding rocket on December 16, 2003 (36.208 UG). The targets were the bright star gamma-Cassiopeiae and its surrounding reflection nebulae, IC 59 and IC 63. We also continued the analysis of the data from our previous flight to study the reflection nebula IC 405 (36.198 UG), which revealed a far-ultraviolet nebular scatter to stellar flux ratio that, contrary to expectations, rises steeply toward the blue. Verifying this result required extensive post-flight analysis and calibration of the Faint Object Telescope FOT) payload, which entailed measuring the telescope mirror reflectivities, the absolute efficiency of the spectrograph, and the telescope point spread function, using a new vacuum collimator developed as part of former graduate student Eric Burgh's Ph.D. dissertation. This work, being done with graduate student Kevin France, has been completed and a paper describing the results has been accepted for publication by the Astrophysical Journal. We have also continued a number of laboratory calibration studies and design efforts.

  8. 222-S LABORATORY FUME HOOD TESTING STUDY

    SciTech Connect

    RUELAS, B.H.

    2007-03-26

    The 222-S Laboratory contains 155 active fume hoods that are used to support analytical work with radioactive and/or toxic materials. The performance of a fume hood was brought into question after employees detected odors in the work area while mixing chemicals within the subject fume hood. Following the event, testing of the fume hood was conducted to assess the performance of the fume hood. Based on observations from the testing, it was deemed appropriate to conduct performance evaluations of other fume hoods within the laboratory.

  9. Gene Polymorphism Studies in a Teaching Laboratory

    ERIC Educational Resources Information Center

    Shultz, Jeffry

    2009-01-01

    I present a laboratory procedure for illustrating transcription, post-transcriptional modification, gene conservation, and comparative genetics for use in undergraduate biology education. Students are individually assigned genes in a targeted biochemical pathway, for which they design and test polymerase chain reaction (PCR) primers. In this…

  10. Laboratory Experiments and Instrument Intercomparison Studies of Carbonaceous Aerosol Particles

    SciTech Connect

    Davidovits, Paul

    2015-10-20

    Aerosols containing black carbon (and some specific types of organic particulate matter) directly absorb incoming light, heating the atmosphere. In addition, all aerosol particles backscatter solar light, leading to a net-cooling effect. Indirect effects involve hydrophilic aerosols, which serve as cloud condensation nuclei (CCN) that affect cloud cover and cloud stability, impacting both atmospheric radiation balance and precipitation patterns. At night, all clouds produce local warming, but overall clouds exert a net-cooling effect on the Earth. The effect of aerosol radiative forcing on climate may be as large as that of the greenhouse gases, but predominantly opposite in sign and much more uncertain. The uncertainties in the representation of aerosol interactions in climate models makes it problematic to use model projections to guide energy policy. The objective of our program is to reduce the uncertainties in the aerosol radiative forcing in the two areas highlighted in the ASR Science and Program Plan. That is, (1) addressing the direct effect by correlating particle chemistry and morphology with particle optical properties (i.e. absorption, scattering, extinction), and (2) addressing the indirect effect by correlating particle hygroscopicity and CCN activity with particle size, chemistry, and morphology. In this connection we are systematically studying particle formation, oxidation, and the effects of particle coating. The work is specifically focused on carbonaceous particles where the uncertainties in the climate relevant properties are the highest. The ongoing work consists of laboratory experiments and related instrument inter-comparison studies both coordinated with field and modeling studies, with the aim of providing reliable data to represent aerosol processes in climate models. The work is performed in the aerosol laboratory at Boston College. At the center of our laboratory setup are two main sources for the production of aerosol particles: (a

  11. The DoD Laboratory Utilization Study

    DTIC Science & Technology

    1975-04-28

    0 04) t C &4 0j w.0 m~i 0 4) 4) in - 4-. ~ I I-. u~ *1 0 1 0 0 S. 4 0 - V; 0)0 0. 4) ’U U C)I~ U : ’U’U ’ EUQ en 0 "U I0 0U 0 U - 0 u-0 00 a .4 0 10...COVERED 6 The DoD Laboratory’ Utilization" td in],tet C)John L./A.Uen., Rodney E nhmDonald B W’chols / 9. PERFORMING, ’NRGANIZATION NAME AND ADDRESS 10

  12. Gene Polymorphism Studies in a Teaching Laboratory

    NASA Astrophysics Data System (ADS)

    Shultz, Jeffry

    2009-02-01

    I present a laboratory procedure for illustrating transcription, post-transcriptional modification, gene conservation, and comparative genetics for use in undergraduate biology education. Students are individually assigned genes in a targeted biochemical pathway, for which they design and test polymerase chain reaction (PCR) primers. In this example, students used genes annotated for the steroid biosynthesis pathway in soybean. The authoritative Kyoto encyclopedia of genes and genomes (KEGG) interactive database and other online resources were used to design primers based first on soybean expressed sequence tags (ESTs), then on ESTs from an alternate organism if soybean sequence was unavailable. Students designed a total of 50 gene-based primer pairs (37 soybean, 13 alternative) and tested these for polymorphism state and similarity between two soybean and two pea lines. Student assessment was based on acquisition of laboratory skills and successful project completion. This simple procedure illustrates conservation of genes and is not limited to soybean or pea. Cost per student estimates are included, along with a detailed protocol and flow diagram of the procedure.

  13. Airborne and laboratory studies of interstellar PAHs

    NASA Technical Reports Server (NTRS)

    Allamandola, L. J.; Sandford, S. A.; Hudgins, D. M.; Witteborn, Fred C.

    1995-01-01

    A brief history of the observations which have led to the hypothesis that polycyclic aromatic hydrocarbons (PAH's) are the carriers of the widespread interstellar emission features near 3050, 1615, '1300' and 890 cm(exp -1) (3.29, 6.2, '7.7', and 11.2 mu m) is presented. The central role of airborne spectroscopy is stressed. The principal reason for the assignment to PAH's was the resemblance of the interstellar emission spectrum to the laboratory absorption spectra of PAH's and PAH-like materials. Since precious little information was available on the properties of PAH's in the forms that are thought to exist under interstellar conditions -isolated and ionized in the emission zones, with the smallest PAH's being dehydrogenated- there was a need for a spectral data base on PAH's taken in these states. Here, the relevant infrared spectroscopic properties of PAH's will be reviewed. These laboratory spectra show that relative band intensities are severely altered and that band frequencies shift. It is shown that these new data alleviate several of the spectroscopic criticisms previously leveled at the hypothesis.

  14. Automated microbial metabolism laboratory. [design of advanced labeled release experiment based on single addition of soil and multiple sequential additions of media into test chambers

    NASA Technical Reports Server (NTRS)

    1974-01-01

    The design and rationale of an advanced labeled release experiment based on single addition of soil and multiple sequential additions of media into each of four test chambers are outlined. The feasibility for multiple addition tests was established and various details of the methodology were studied. The four chamber battery of tests include: (1) determination of the effect of various atmospheric gases and selection of that gas which produces an optimum response; (2) determination of the effect of incubation temperature and selection of the optimum temperature for performing Martian biochemical tests; (3) sterile soil is dosed with a battery of C-14 labeled substrates and subjected to experimental temperature range; and (4) determination of the possible inhibitory effects of water on Martian organisms is performed initially by dosing with 0.01 ml and 0.5 ml of medium, respectively. A series of specifically labeled substrates are then added to obtain patterns in metabolic 14CO2 (C-14)O2 evolution.

  15. ACCURACY OF LABORATORY REPORTING IN EPAS WET INTERLABORATORY VARIABILITY STUDY

    EPA Science Inventory

    In 1999 and 2000, EPA conducted an interlaboratory variability study of whole effluent toxicity (WET) test methods. This study provided an excellent opportunity to evaluate the accuracy with which laboratories analyzed and reported WET test data. Twenty-eight laboratories reporte...

  16. A qualitative case study of instructional support for web-based simulated laboratory exercises in online college chemistry laboratory courses

    NASA Astrophysics Data System (ADS)

    Schulman, Kathleen M.

    This study fills a gap in the research literature regarding the types of instructional support provided by instructors in online introductory chemistry laboratory courses that employ chemistry simulations as laboratory exercises. It also provides information regarding students' perceptions of the effectiveness of that instructional support. A multiple case study methodology was used to carry out the research. Two online introductory chemistry courses were studied at two community colleges. Data for this study was collected using phone interviews with faculty and student participants, surveys completed by students, and direct observation of the instructional designs of instructional support in the online Blackboard web sites and the chemistry simulations used by the participating institutions. The results indicated that the instructors provided multiple types of instructional support that correlated with forms of effective instructional support identified in the research literature, such as timely detailed feedback, detailed instructions for the laboratory experiments, and consistency in the instructional design of lecture and laboratory course materials, including the chemistry lab simulation environment. The students in one of these courses identified the following as the most effective types of instructional support provided: the instructor's feedback, opportunities to apply chemistry knowledge in the chemistry lab exercises, detailed procedures for the simulated laboratory exercises, the organization of the course Blackboard sites and the chemistry lab simulation web sites, and the textbook homework web sites. Students also identified components of instructional support they felt were missing. These included a desire for more interaction with the instructor, more support for the simulated laboratory exercises from the instructor and the developer of the chemistry simulations, and faster help with questions about the laboratory exercises or experimental

  17. Laboratory endurance testing of a 25/75 sunflower oil-diesel fuel blend treated with fuel additives

    SciTech Connect

    Ziejewski, M.; Kaufman, K.R.; Tupa, R.C.

    1984-01-01

    The engine performance and durability effects of a barium smoke suppressant additive, Lubrizol 565, and an ashless polymeric additive, Lubrizol 552, in a 25-75 blend (v/v) of alkali refined sunflower oil with diesel fuel were investigated. The study was performed on a direct injected, turbocharged, and intercooled diesel engine. These additives were tested in an attempt to reduce carbon buildup problems observed while using an untreated 25-75 blend of sunflower oil and diesel fuel.

  18. Study on thermal effects & sulfurized additives, in lubricating greases

    NASA Astrophysics Data System (ADS)

    Shah, Ami Atul

    Lithium Base grease constitutes about 50% of market. The greases are developed to be able to work in multiple working conditions and have longer working life. Greases with extreme pressure additives and anti-wear additives have been developed as a solution to many of the applications. These developed greases are tested under ASTM D2266 testing conditions to meet the requirements. The actual working conditions, although, differ than the real testing conditions. The loading, speed and temperature conditions can be more harsh, or fluctuating in nature. The cyclic nature of the parameters cannot be directly related to the test performance. For this purpose studies on the performance under spectrum loading, variable speed and fluctuating temperature must be performed. This study includes tests to understand the effect of thermal variation on some of the most commonly used grease additives that perform well under ASTM D2266 testing conditions. The studied additives include most widely used industrial extreme pressure additive MoS2. Performance of ZDDP which is trying to replace MoS2 in its industrial applications has also been studied. The tests cover study of extreme pressure, anti-wear and friction modifier additives to get a general idea on the effects of thermal variation in three areas. Sulphur is the most common extreme pressure additive. Sulphur based MoS 2 is extensively used grease additive. Study to understand the tribological performance of this additive through wear testing and SEM/EDX studies has been done. This performance is also studied for other metallic sulfides like WS2 and sulphur based organic compound. The aim is to study the importance of the type of bond that sulphur shares in its additive's structure on its performance. The MoS2 film formation is found to be on the basis of the FeS formation on the substrate and protection through sacrificial monolayer deposition of the MoS2 sheared structure. The free Mo then tends to oxidise. An attempt to

  19. Lessons Learned at the Idaho National Laboratory for the Entry into Force of the U.S. Additional Protocol

    SciTech Connect

    Jeffrey C. Joe; Shauna A. Hoiland

    2009-07-01

    For a number of years, the Idaho National Laboratory (INL) has been preparing for the entry into force of the U.S. Additional Protocol (AP). These preparations included attending training, participating in tabletop exercises, preparing draft declarations, developing INL-specific guidance documents, preparing for and hosting a mock complementary access visit, and preparing declarations for official submittal. All of these activities, the training materials, and software developed by other U.S. DOE national laboratories (PNNL, ORNL, LANL, and BNL) were very helpful in preparing for the entry into force of the AP. As with any endeavor of this size and complexity, however, there are always instances where even the best preparations and advanced planning do not anticipate every challenge. As the DOE's lead nuclear energy research and development facility, the INL faced many unique challenges. The majority of research conducted at the INL is nuclear fuel cycle related, most of which is not protected by the National Security Exclusion. This paper describes the lessons learned from the INL’s experience of preparing for the entry into force of the AP, specifically how translating and implementing general principles into actual activities proved to be one of many challenges, and provides general suggestions on how to respond effectively and efficiently to routine annual data calls and other AP requests.

  20. Laboratory Studies Of Astrophysically-interesting Phosphorus-bearing Molecules

    NASA Astrophysics Data System (ADS)

    Ziurys, Lucy M.; Halfen, D. T.; Sun, M.; Clouthier, D. J.

    2009-05-01

    Over the past year, there has been a renewed interest in the presence of phosphorus-containing molecules in the interstellar medium. Recent observations have increased the number of known interstellar phosphorus-bearing species from two (PN, CP) to six with the identification of HCP, CCP, and PH3 in the carbon-rich circumstellar shell of IRC+10216 and PO in the oxygen-rich envelope of VY Canis Majoris. More species of this type may be present in the ISM, but laboratory rest frequencies, necessary for such detections, are not generally known for many potential molecules. To fill in this gap, we have been conducting measurements of the pure rotational spectra of phosphorus-containing molecules of astrophysical interest, using both millimeter/submm direct absorption and Fourier transform microwave (FTMW) spectroscopy. We have developed a new phosphorus source for this purpose. These methods cover the frequency ranges 65-850 GHz and 4-40 GHz, respectively. Our recent study of the CCP radical (X2Πr) using both of these techniques has resulted in its identification in IRC+10216. Rotational spectra of other molecules such as PCN, HPS, and CH3PH2 have been recorded. We will report on these species and additional new laboratory developments

  1. Heterogeneous processes: Laboratory, field, and modeling studies

    NASA Technical Reports Server (NTRS)

    Poole, Lamont R.; Kurylo, Michael J.; Jones, Rod L.; Wahner, Andreas; Calvert, Jack G.; Leu, M.-T.; Fried, A.; Molina, Mario J.; Hampson, Robert F.; Pitts, M. C.

    1991-01-01

    The efficiencies of chemical families such as ClO(x) and NO(x) for altering the total abundance and distribution of stratospheric ozone are controlled by a partitioning between reactive (active) and nonreactive (reservoir) compounds within each family. Gas phase thermodynamics, photochemistry, and kinetics would dictate, for example, that only about 1 percent of the chlorine resident in the lower stratosphere would be in the form of active Cl or ClO, the remainder existing in the reservoir compounds HCl and ClONO2. The consistency of this picture was recently challenged by the recognition that important chemical transformations take place on polar regions: the Airborne Antarctic Ozone Experiment (AAOE) and the Airborne Arctic Stratospheric Expedition (AASA). Following the discovery of the Antarctic ozone hole, Solomon et al. suggested that the heterogeneous chemical reaction: ClONO2(g)+HCl(s) yields Cl2(g)+HNO3(s) could play a key role in converting chlorine from inactive forms into a species (Cl2) that would rapidly dissociate in sunlight to liberate atomic chlorine and initiate ozone depletion. The symbols (s) and (g) denote solid phase, or adsorbed onto a solid surface, and gas phase, respectively, and represent the approach by which such a reaction is modeled rather than the microscopic details of the reaction. The reaction was expected to be most important at altitudes where PSC's were most prevalent (10 to 25 km), thereby extending the altitude range over which chlorine compounds can efficiently destroy ozone from the 35 to 45 km region (where concentrations of active chlorine are usually highest) to lower altitudes where the ozone concentration is at its peak. This chapter will briefly review the current state of knowledge of heterogeneous processes in the stratosphere, emphasizing those results obtained since the World Meteorological Organization (WMO) conference. Sections are included on laboratory investigations of heterogeneous reactions, the

  2. A Science Librarian in the Laboratory: A Case Study

    ERIC Educational Resources Information Center

    Tomaszewski, Robert

    2011-01-01

    A science librarian in the laboratory can become a "point of access" for database instruction and provide a learning opportunity for students to develop their information literacy skills. A case study describes how a librarian in an organic chemistry laboratory helps the class run smoothly and identifies the science librarian as an ally and a…

  3. Laboratory studies of ocean mixing by microorganisms

    NASA Astrophysics Data System (ADS)

    Martinez-Ortiz, Monica; Dabiri, John O.

    2011-11-01

    Ocean mixing plays a major role in nutrient and energy transport and is an important input to climate models. Recent studies suggest that the contribution of fluid transport by swimming microorganisms to ocean mixing may be of the same order of magnitude as winds and tides. An experimental setup has been designed in order to study the mixing efficiency of vertical migration of plankton. To this end, a stratified water column is created to model the ocean's density gradient. The vertical migration of Artemia Salina (brine shrimp) within the water column is controlled via luminescent signals on the top and bottom of the column. By fluorescently labelling portions of the water column, the stirring of the density gradient by the animals is visualized and quantified. Preliminary results show that the vertical movement of these organisms produces enhanced mixing relative to control cases in which only buoyancy forces and diffusion are present.

  4. Laboratory studies of refractory metal oxide smokes

    NASA Technical Reports Server (NTRS)

    Nuth, Joseph A.; Nelson, R. N.; Donn, Bertram

    1989-01-01

    Studies of the properties of refractory metal oxide smokes condensed from a gas containing various combinations of SiH4, Fe(CO)5, Al(CH3)3, TiCl4, O2 and N2O in a hydrogen carrier stream at 500 K greater than T greater than 1500 K were performed. Ultraviolet, visible and infrared spectra of pure, amorphous SiO(x), FeO(x), AlO(x) and TiO(x) smokes are discussed, as well as the spectra of various co-condensed amorphous oxides, such as FE(x)SiO(y) or Fe(x)AlO(y). Preliminary studies of the changes induced in the infrared spectra of iron-containing oxide smokes by vacuum thermal annealing suggest that such materials become increasingly opaque in the near infrared with increased processing: hydration may have the opposite effect. More work on the processing of these materials is required to confirm such a trend: this work is currently in progress. Preliminary studies of the ultraviolet spectra of amorphous Si2O3 and MgSiO(x) smokes revealed no interesting features in the region from 200 to 300 nm. Studies of the ultraviolet spectra of both amorphous, hydrated and annealed SiO(x), TiO(x), AlO(x) and FeO(x) smokes are currently in progress. Finally, data on the oxygen isotopic composition of the smokes produced in the experiments are presented, which indicate that the oxygen becomes isotopically fractionated during grain condensation. Oxygen in the grains is as much as 3 percent per amu lighter than the oxygen in the original gas stream. The authors are currently conducting experiments to understand the mechanism by which fractionation occurs.

  5. Laboratory study of avalanches in magnetized plasmas.

    PubMed

    Van Compernolle, B; Morales, G J; Maggs, J E; Sydora, R D

    2015-03-01

    It is demonstrated that a novel heating configuration applied to a large and cold magnetized plasma allows the study of avalanche phenomena under controlled conditions. Intermittent collapses of the plasma pressure profile, associated with unstable drift-Alfvén waves, exhibit a two-slope power-law spectrum with exponents near -1 at lower frequencies and in the range of -2 to -4 at higher frequencies. A detailed mapping of the spatiotemporal evolution of a single avalanche event is presented.

  6. Current status of laboratory sorption studies

    SciTech Connect

    Vine, E.N.; Wolfsberg, K.; Bayhurst, B.P.; Daniels, W.R.; DeVilliers, S.J.; Erdal, B.R.; Lawrence, F.O.

    1980-01-01

    LASL batch sorption methodology was used to obtain data on granite, argillite, and tuff samples. Effects of solution-to-solid ratio, isotope concentration, atmosphere, and mineralogy were investigated for the elements strontium, cesium, barium, cerium, europium, technetium, uranium, plutonium, and americium. A circulating system was used in making sorption measurements for comparison with conventional batch techniques. The mineralogy of several tuff, granite, and argillite samples was studied and compared with sorption ratios. A significant correlation between sorption of strontium, cesium, and barium and major rock phases was observed.

  7. Laboratory studies of water column separation

    NASA Astrophysics Data System (ADS)

    Autrique, R.; Rodal, E.

    2013-12-01

    Results of experimental studies of water column separation following an upstream valve closure are presented. Different geometrical arrangements with transparent PVC pipes are installed immediately downstream of the closing valve, namely, horizontal pipes, vertical pipes flowing down, and humpback profile pipes, the last two being used in order to obtain full pipe section vapor cavities. Maximum over pressures at water column rejoining, and maximum cavity lengths and duration, are compared with theoretical values and with previous experiments with horizontal pipes. Good agreement is found between theory and experiments, and interesting visual material is obtained.

  8. Laboratory Scale Antifoam Studies for the STTPB Process

    SciTech Connect

    Baich, M.A.

    2001-02-13

    Three candidate antifoam/defoam agents were tested on a laboratory scale with simulated KTPB slurry using the proposed STTPB process precipitation, concentration, and washing steps. Conclusions are if air entrainment in the slurry is carefully avoided, little or no foam will be generated during normal operations during precipitation, concentration, and washing of the precipitate. Three candidate antifoam/defoam agents were tested on a laboratory scale with simulated KTPB slurry using the proposed STTPB process precipitation, concentration and washing steps. In all cases little or no foam formed during normal operations of precipitation, concentration and washing. Foam was produced by purposely-introducing gas sub-surface into the slurry. Once produced, the IIT B52 antifoam was effective in defoaming the slurry. In separate foam column tests, all antifoam/defoam agents were effective in mitigating foam formation and in defoaming a foamed 10 wt % insoluble solids slurry. Based on the results in this report as well as foam column studies at IIT, it is recommended that IIT B52 antifoam at the 1000 ppmV level be used in subsequent STTPB work where foaming is a concern. This study indicates that the addition of antifoam agent hinders the recovery of NaTPB during washing. Washing precipitate with no antifoam agent added had the highest level of NaTPB recovery, but had the shortest overall washing time ({approximately}19 hours) compared to 26-28 hours for antifoam runs. The solubilities of the three candidate antifoam/defoam agents were measured in a 4.7 M sodium salt solution. The Surfynol DF-110D defoamer was essentially insoluble while the two IIT antifoamers; Particle Modifier (PM) and B52 were soluble to at least the 2000 ppmV level.

  9. Laboratory Information Management System (LIMS): A case study

    NASA Technical Reports Server (NTRS)

    Crandall, Karen S.; Auping, Judith V.; Megargle, Robert G.

    1987-01-01

    In the late 70's, a refurbishment of the analytical laboratories serving the Materials Division at NASA Lewis Research Center was undertaken. As part of the modernization efforts, a Laboratory Information Management System (LIMS) was to be included. Preliminary studies indicated a custom-designed system as the best choice in order to satisfy all of the requirements. A scaled down version of the original design has been in operation since 1984. The LIMS, a combination of computer hardware, provides the chemical characterization laboratory with an information data base, a report generator, a user interface, and networking capabilities. This paper is an account of the processes involved in designing and implementing that LIMS.

  10. Laboratory endurance testing of a 25/75 sunflower oil-diesel fuel blend treated with fuel additives

    SciTech Connect

    Ziejewski, M.; Kaufman, K.R.; Tupa, R.C.

    1984-02-01

    The engine performance and durability effects of a barium smoke suppressant additive, Lubrizol 565, and an ashless polymeric additive, Lubrizol 552, in a 25-75 blend (v/v) of alkali refined sunflower oil with diesel fuel were investigated. The study was performed on a direct injected, turbocharged, and intercooled diesel engine. These additives were tested in an attempt to reduce carbon buildup problems observed while using an untreated 25-75 blend of sunflower oil and diesel fuel. Compared to the engine tests on the untreated 25-75 mixture, the barium smoke suppressant additive proved effective in cleaning the inside of injection nozzles (no needle sticking, no carbon build-up inside the orifices), reducing diesel exhaust smoke, and increasing engine power output. However, there was increased residue accumulation in the combustion chamber and on the exterior of the injection nozzle tips. The ashless dispersant additive also improved nozzle cleanliness but did not demonstrate any effect on engine power or cause excessive carbon buildup on the nozzle tips, top of the pistons, and cylinder head. The Lubrizol 552 dispersant looks very promising as an additive for vegetable oil diesel fuel blends for controlling excessive carbon and lacquer deposits.

  11. Analytical evaluation of laboratories wishing to perform environmental characterization studies

    SciTech Connect

    Lauenstein, G.G.; Cantillo, A.Y.

    1997-07-01

    Laboratories competing to analyze bivalve mollusks under contract to the National Oceanic and Atmospheric Administration`s Mussel Watch Project were required to undergo analytical tests of their ability to quantify environmental contaminants as part of the contract evaluation process. During the 1989 selection process laboratories that appeared to qualify on the basis of their written proposals were provided a gravimetrically prepared solution with unknown quantities of an undefined number of organic contaminants that are regularly quantified for the Mussel Watch Project. In 1994, competing laboratories were once again tested but this time using matrix materials for the quantification of both trace elements and organic contaminants. Three laboratory groups participated in the exercises. For the 1989 gravimetrically prepared solutions, all participating laboratories were able to identify the contaminants present and in all but two cases were able to report values to within {+-}25% of the known values. In 1994, all laboratories were within the acceptance criteria for the quantification of trace elements in the homogenate sample. Analytical laboratory testing is an important first step to ensure that environmental characterization studies are successful.

  12. Clinical evaluation of hypnotic drugs: contributions from sleep laboratory studies.

    PubMed

    Kales, A; Scharf, M B; Soldatos, C R; Bixler, E O

    1979-07-01

    The most thorough and clinically relevant approach to hypnotic drug evaluation is one that balances the strengths and weaknesses of clinical trials and sleep laboratory evaluations. Advantages of clinical trials include the ability to evaluate large numbers of subjects and specific target groups and to thoroughly assess and quantify a drug's side effects, whereas sleep laboratory studies are very limited in all of these areas. Sleep laboratory studies however provide a rigorous, precise, and comprehensive profile of a drug's activity since there is more control over experimental variables and measurements are objective as well as continuous throughout the night. These benefits offset the shortcomings of clinical trials, which include a lack of objective measurements, less control over experimental variables, failure to evaluate a drug's effectiveness with continued use, and inattention to drug interaction and withdrawal effect. Several basic principles derived from sleep laboratory findings have been incorporated into both the clinical trials and sleep laboratory evaluations recommended in the new FDA Guidelines for the Clinical Evaluation of Hypnotic Drugs. These principles include provision for adequate baseline and withdrawal periods, use of multiple consecutive drug nights to assess a drug's effectiveness with continued use, and inclusion of an adequate washout period when a cross-over design is used. The guidelines do not emphasize either clinical trials or sleep laboratory studies at the expense of each other, but rather stress their complementary utilization.

  13. Change in argonne national laboratory: a case study.

    PubMed

    Mozley, A

    1971-10-01

    Despite traditional opposition to change within an institution and the known reluctance of an "old guard" to accept new managerial policies and techniques, the reactions suggested in this study go well beyond the level of a basic resistance to change. The response, indeed, drawn from a random sampling of Laboratory scientific and engineering personnel, comes close to what Philip Handler has recently described as a run on the scientific bank in a period of depression (1, p. 146). It appears that Argonne's apprehension stems less from the financial cuts that have reduced staff and diminished programs by an annual 10 percent across the last 3 fiscal years than from the administrative and conceptual changes that have stamped the institution since 1966. Administratively, the advent of the AUA has not forged a sense of collaborative effort implicit in the founding negotiations or contributed noticeably to increasing standards of excellence at Argonne. The AUA has, in fact, yet to exercise the constructive powers vested in them by the contract of reviewing and formulating long-term policy on the research and reactor side. Additionally, the University of Chicago, once the single operator, appears to have forfeited some of the trust and understanding that characterized the Laboratory's attitude to it in former years. In a period of complex and sensitive management the present directorate at Argonne is seriously dissociated from a responsible spectrum of opinion within the Laboratory. The crux of discontent among the creative scientific and engineering community appears to lie in a developed sense of being overadministered. In contrast to earlier periods, Argonne's professional staff feels a critical need for a voice in the formulation of Laboratory programs and policy. The Argonne senate could supply this mechanism. Slow to rally, their present concern springs from a firm conviction that the Laboratory is "withering on the vine." By contrast, the Laboratory director Powers

  14. Laboratory and field evaluation of a combined fluid-loss-control additive and gel breaker for fracturing fluids

    SciTech Connect

    Cantu, L.A.; Boyd, P.A. )

    1990-08-01

    More than 200% increase in fracture conductivity and permeability was obtained when a new degradable fluid-loss-control additive was used in place of silica flour (SF) in 40-lbm crosslinked hydroxypropyl-guar (HPG) fracturing-fluid systems. The new additive, and organic acid particulate (OAP), slowly degraded into water-soluble monomeric units at temperatures {ge}150{degrees}F after fracture stimulation experiments. The high-acid-content degradation product then acted as an excellent HPG gel breaker and effectively cleaned the proppant packs. As a fluid-loss-control additive, the measured wall-building coefficients were as good as, or better than, those of SF in crosslinked-gel, linear-gel, and N{sub 2}-foam systems. This paper summarizes a 2-year study of the evaluation and application of this new product in fracturing-fluid systems.

  15. Extremely low frequency fields and cancer: laboratory studies

    SciTech Connect

    Anderson, Larry E. )

    1998-10-01

    There is now convincing evidence from a large number of laboratories, that exposure to extremely low frequency (ELF) magnetic and electric fields produces biological responses in animals. However, no animal studies clearly demonstrate deleterious effects of ELF fields, although several are suggestive of potential health impacts. A major current emphasis in laboratory research is to determine whether or not the reported epidemiological studies that suggest an association between EMF exposure and risk of cancer are supported in studies using animal models. Several approaches are outlined in the experimental approach to this question. With specific reference to the radiofrequencies (RF) associated with wireless technology, even less research has been carried out than with ELF. Particularly, in regard to research on carcinogenesis and RF exposure in animals, little is known This section addresses laboratory studies in animals exposed to extremely low-power-frequency EMF, the relevance of which, to RF, is unknown. However, the approaches used with ELF may be useful in guiding laboratory research on the issue of RF exposure and cancer. From the perspective of laboratory animal studies, this paper will discuss studies investigating the potential relationship between ELF magnetic and/or electric field exposure and the risk of cancer.

  16. Benchmark Study of Industrial Needs for Additive Manufacturing in Finland

    NASA Astrophysics Data System (ADS)

    Lindqvist, Markku; Piili, Heidi; Salminen, Antti

    Additive manufacturing (AM) is a modern way to produce parts for industrial use. Even though the technical knowledge and research of AM processes are strong in Finland, there are only few industrial applications. Aim of this study is to collect practical knowledge of companies who are interested in industrial use of AM, especially in South-Eastern Finland. Goal of this study is also to investigate demands and requirements of applications for industrial use of AM in this area of Finland. It was concluded, that two of the reasons prohibiting wider industrial use of AM in Finland, are wrong expectations against this technology as well as lack of basic knowledge of possibilities of the technology. Especially, it was noticed that strong 3D-hype is even causing misunderstandings. Nevertheless, the high-level industrial know-how in the area, built around Finnish lumber industry is a strong foundation for the additive manufacturing technology.

  17. Field and laboratory procedures used in a soil chronosequence study

    USGS Publications Warehouse

    Singer, Michael J.; Janitzky, Peter

    1986-01-01

    In 1978, the late Denis Marchand initiated a research project entitled "Soil Correlation and Dating at the U.S. Geological Survey" to determine the usefulness of soils in solving geologic problems. Marchand proposed to establish soil chronosequences that could be dated independently of soil development by using radiometric and other numeric dating methods. In addition, by comparing dated chronosequences in different environments, rates of soil development could be studied and compared among varying climates and mineralogical conditions. The project was fundamental in documenting the value of soils in studies of mapping, correlating, and dating late Cenozoic deposits and in studying soil genesis. All published reports by members of the project are included in the bibliography.The project demanded that methods be adapted or developed to ensure comparability over a wide variation in soil types. Emphasis was placed on obtaining professional expertise and on establishing consistent techniques, especially for the field, laboratory, and data-compilation methods. Since 1978, twelve chronosequences have been sampled and analyzed by members of this project, and methods have been established and used consistently for analysis of the samples.The goals of this report are to:Document the methods used for the study on soil chronosequences,Present the results of tests that were run for precision, accuracy, and effectiveness, andDiscuss our modifications to standard procedures.Many of the methods presented herein are standard and have been reported elsewhere. However, we assume less prior analytical knowledge in our descriptions; thus, the manual should be easy to follow for the inexperienced analyst. Each chapter presents one or more references of the basic principle, an equipment and reagents list, and the detailed procedure. In some chapters this is followed by additional remarks or example calculations.The flow diagram in figure 1 outlines the step-by-step procedures used to

  18. Meteoric water - basalt interactions: a field and laboratory study

    SciTech Connect

    Gislason, S.R.

    1985-01-01

    The goal of this study is to define and interpret the composition of the meteoric waters in N.E. Iceland in their cycle through the hydrosphere and the upper part of the crust, and to calibrate the natural process by dissolution experiments done in the laboratory. The composition of rain, snow, spring and geothermal waters from the rift zone of N.E. Iceland can be explained by sea-spray addition (1/10000), dissolution of basalts and buffering by alteration minerals. Rates, stoichiometry and activation energy of dissolution, pH vs. time and activity-activity paths were determined by dissolving basaltic rocks under simulated natural conditions at 25 to 60/sup 0/C. Dissolution follows a linear rate law, with basaltic glass dissolving 10 times faster than the crystalline basalt. Rates are independent of pH from 7 to 10. The average activation energy for dissolution of basaltic glass is 31.8 kJ/mol (+/-3). For individual elements leached from crystalline basalt it ranges from 35 to 15 kJ/mol. This indicates that under the experimental conditions reactions on the surfaces of the solids are the rate determining step in the dissolution mechanism. Considerable differences (2 to 4 log units) exist in the calculated oxygen fugacities obtained from different redox species in the geothermal fluids. This is primarily caused by the nonequilibrium state of the sulfur redox pair.

  19. The Essential Role for Laboratory Studies in Atmospheric Chemistry.

    PubMed

    Burkholder, James B; Abbatt, Jonathan P D; Barnes, Ian; Roberts, James M; Melamed, Megan L; Ammann, Markus; Bertram, Allan K; Cappa, Christopher D; Carlton, Annmarie G; Carpenter, Lucy J; Crowley, John N; Dubowski, Yael; George, Christian; Heard, Dwayne E; Herrmann, Hartmut; Keutsch, Frank N; Kroll, Jesse H; McNeill, V Faye; Ng, Nga Lee; Nizkorodov, Sergey A; Orlando, John J; Percival, Carl J; Picquet-Varrault, Bénédicte; Rudich, Yinon; Seakins, Paul W; Surratt, Jason D; Tanimoto, Hiroshi; Thornton, Joel A; Tong, Zhu; Tyndall, Geoffrey S; Wahner, Andreas; Weschler, Charles J; Wilson, Kevin R; Ziemann, Paul J

    2017-03-07

    Laboratory studies of atmospheric chemistry characterize the nature of atmospherically relevant processes down to the molecular level, providing fundamental information used to assess how human activities drive environmental phenomena such as climate change, urban air pollution, ecosystem health, indoor air quality, and stratospheric ozone depletion. Laboratory studies have a central role in addressing the incomplete fundamental knowledge of atmospheric chemistry. This article highlights the evolving science needs for this community and emphasizes how our knowledge is far from complete, hindering our ability to predict the future state of our atmosphere and to respond to emerging global environmental change issues. Laboratory studies provide rich opportunities to expand our understanding of the atmosphere via collaborative research with the modeling and field measurement communities, and with neighboring disciplines.

  20. A Laboratory Analogue for the Study of Peer Sexual Harassment

    ERIC Educational Resources Information Center

    Mitchell, Damon; Hirschman, Richard; Angelone, D. J.; Lilly, Roy S.

    2004-01-01

    The purpose of this study was to develop a laboratory analogue for the study of peer sexual harassment, and to examine person and situational factors associated with male on female peer sexual harassment. One hundred twenty-two male participants were given the opportunity to tell jokes to a female confederate from a joke list that included…

  1. The Study of Deceptive and Antisocial Behavior in the Laboratory.

    ERIC Educational Resources Information Center

    Brodsky, Stanley L.; Jacobsen, Linda S.

    Research on crime and delinquents is generally studying norm-violating behavior outside of its social context. Building on Hartshorne and May's use of situational tests, the authors sought to study the major contributing variables to norm-violating behavior in a laboratory setting. Two groups of subjects were used: (1) 116 male college students;…

  2. Tracer Studies In A Laboratory Beach Subjected To Waves

    EPA Science Inventory

    This work investigated the washout of dissolved nutrients from beaches due to waves by conducting tracer studies in a laboratory beach facility. The effects of waves were studied in the case where the beach was subjected to the tide, and that in which no tidal action was present...

  3. Recommended Protocol for Round Robin Studies in Additive Manufacturing.

    PubMed

    Moylan, Shawn; Brown, Christopher U; Slotwinski, John

    2016-03-01

    One way to improve confidence and encourage proliferation of additive manufacturing (AM) technologies and parts is by generating more high quality data describing the performance of AM processes and parts. Many in the AM community see round robin studies as a way to generate large data sets while distributing the cost among the participants, thereby reducing the cost to individual users. The National Institute of Standards and Technology (NIST) has conducted and participated in several of these AM round robin studies. While the results of these studies are interesting and informative, many of the lessons learned in conducting these studies concern the logistics and methods of the study and unique issues presented by AM. Existing standards for conducting interlaboratory studies of measurement methods, along with NIST's experience, form the basis for recommended protocols for conducting AM round robin studies. The role of round robin studies in AM qualification, some of the limitations of round robin studies, and the potential benefit of less formal collaborative experiments where multiple factors, AM machine being only one, are varied simultaneously are also discussed.

  4. Recommended Protocol for Round Robin Studies in Additive Manufacturing

    PubMed Central

    Moylan, Shawn; Brown, Christopher U.; Slotwinski, John

    2016-01-01

    One way to improve confidence and encourage proliferation of additive manufacturing (AM) technologies and parts is by generating more high quality data describing the performance of AM processes and parts. Many in the AM community see round robin studies as a way to generate large data sets while distributing the cost among the participants, thereby reducing the cost to individual users. The National Institute of Standards and Technology (NIST) has conducted and participated in several of these AM round robin studies. While the results of these studies are interesting and informative, many of the lessons learned in conducting these studies concern the logistics and methods of the study and unique issues presented by AM. Existing standards for conducting interlaboratory studies of measurement methods, along with NIST’s experience, form the basis for recommended protocols for conducting AM round robin studies. The role of round robin studies in AM qualification, some of the limitations of round robin studies, and the potential benefit of less formal collaborative experiments where multiple factors, AM machine being only one, are varied simultaneously are also discussed. PMID:27274602

  5. Genotoxicity studies of the food additive ester gum.

    PubMed

    Mukherjee, A; Agarwal, K; Chakrabarti, J

    1992-07-01

    Ester gum (EG) is used in citrus oil-based beverage flavourings as a weighting or colouring agent. In the present study, concentrations of 50, 100 and 150 mg/kg body weight were administered orally to male Swiss albino mice, and sister chromatid exchange and chromosomal aberration were used as the cytogenetic endpoints to determine the genotoxic and clastogenic potential of the food additive. Although EG was weakly clastogenic and could induce a marginal increase in sister chromatid exchange frequencies, it was not a potential health hazard at the doses tested.

  6. Making intelligent systems team players: Additional case studies

    NASA Technical Reports Server (NTRS)

    Malin, Jane T.; Schreckenghost, Debra L.; Rhoads, Ron W.

    1993-01-01

    Observations from a case study of intelligent systems are reported as part of a multi-year interdisciplinary effort to provide guidance and assistance for designers of intelligent systems and their user interfaces. A series of studies were conducted to investigate issues in designing intelligent fault management systems in aerospace applications for effective human-computer interaction. The results of the initial study are documented in two NASA technical memoranda: TM 104738 Making Intelligent Systems Team Players: Case Studies and Design Issues, Volumes 1 and 2; and TM 104751, Making Intelligent Systems Team Players: Overview for Designers. The objective of this additional study was to broaden the investigation of human-computer interaction design issues beyond the focus on monitoring and fault detection in the initial study. The results of this second study are documented which is intended as a supplement to the original design guidance documents. These results should be of interest to designers of intelligent systems for use in real-time operations, and to researchers in the areas of human-computer interaction and artificial intelligence.

  7. Additive Manufacturing Materials Study for Gaseous Radiation Detection

    SciTech Connect

    Steer, C.A.; Durose, A.; Boakes, J.

    2015-07-01

    Additive manufacturing (AM) techniques may lead to improvements in many areas of radiation detector construction; notably the rapid manufacturing time allows for a reduced time between prototype iterations. The additive nature of the technique results in a granular microstructure which may be permeable to ingress by atmospheric gases and make it unsuitable for gaseous radiation detector development. In this study we consider the application of AM to the construction of enclosures and frames for wire-based gaseous radiation tracking detectors. We have focussed on oxygen impurity ingress as a measure of the permeability of the enclosure, and the gas charging and discharging curves of several simplistic enclosure shapes are reported. A prototype wire-frame is also presented to examine structural strength and positional accuracy of an AM produced frame. We lastly discuss the implications of this study for AM based radiation detection technology as a diagnostic tool for incident response scenarios, such as the interrogation of a suspect radiation-emitting package. (authors)

  8. RAMSEYS DRAFT WILDERNESS STUDY AREA AND ADDITION, VIRGINIA.

    USGS Publications Warehouse

    Lesure, Frank G.; Mory, Peter C.

    1984-01-01

    Mineral-resource surveys of the Ramseys Draft Wilderness Study Area and adjoining roadless area addition in George Washington National Forest in the western valley and ridge province, Augusta and Highland Counties, Virginia, were done. The surveys outlined three small areas containing anomalous amounts of copper, lead, and zinc related to stratabound red-bed copper mineralization, but these occurrences are not large and are not considered as having mineral-resource potential. The area contains abundant sandstone suitable for construction materials and shale suitable for making brick, tile, and other low-grade ceramic products, but these commodities occur in abundance outside the wilderness study area. Structural conditions are probably favorable for the accumulation of natural gas, but exploratory drilling has not been done sufficiently near the area to evaluate the gas potential.

  9. Developing Medicare Competitive Bidding: A Study of Clinical Laboratories

    PubMed Central

    Hoerger, Thomas J.; Meadow, Ann

    1997-01-01

    Competitive bidding to derive Medicare fees promises several advantages over administered fee systems. The authors show how incentives for cost savings, quality, and access can be incorporated into bidding schemes, and they report on a study of the clinical laboratory industry conducted in preparation for a bidding demonstration. The laboratory industry is marked by variable concentration across geographic markets and, among firms themselves, by social and economic heterogeneity. The authors conclude that these conditions can be accommodated by available bidding design options and by careful selection of bidding markets. PMID:10180003

  10. Los Alamos National Laboratory W76 Pit Tube Lifetime Study

    SciTech Connect

    Abeln, Terri G.

    2012-04-25

    A metallurgical study was requested as part of the Los Alamos National Laboratory (LANL) W76-1 life-extension program (LEP) involving a lifetime analysis of type 304 stainless steel pit tubes subject to repeat bending loads during assembly and disassembly operations at BWXT/Pantex. This initial test phase was completed during the calendar years of 2004-2006 and the report not issued until additional recommended tests could be performed. These tests have not been funded to this date and therefore this report is considered final. Tubes were reportedly fabricated according to Rocky Flats specification P14548 - Seamless Type 304 VIM/VAR Stainless Steel Tubing. Tube diameter was specified as 0.125 inches and wall thickness as 0.028 inches. A heat treat condition is not specified and the hardness range specification can be characteristic of both 1/8 and 1/4 hard conditions. Properties of all tubes tested were within specification. Metallographic analysis could not conclusively determine a specified limit to number of bends allowable. A statistical analysis suggests a range of 5-7 bends with a 99.95% confidence limit. See the 'Statistical Analysis' section of this report. The initial phase of this study involved two separate sets of test specimens. The first group was part of an investigation originating in the ESA-GTS [now Gas Transfer Systems (W-7) Group]. After the bend cycle test parameters were chosen (all three required bends subjected to the same amount of bend cycles) and the tubes bent, the investigation was transferred to Terri Abeln (Metallurgical Science and Engineering) for analysis. Subsequently, another limited quantity of tubes became available for testing and were cycled with the same bending fixture, but with different test parameters determined by T. Abeln.

  11. Rock fragment movement in shallow rill flow - A laboratory study

    NASA Astrophysics Data System (ADS)

    Becker, Kerstin; Wirtz, Stefan; Seeger, Manuel; Gronz, Oliver; Remke, Alexander; Iserloh, Thomas; Brings, Christine; Casper, Markus; Ries, Johannes B.

    2014-05-01

    Studies concerning rill erosion mainly deal with the erosion and transport of fine material. The transport of rock fragments is examined mostly for mountain rivers. But there are important differences between the conditions and processes in rivers and in rills: (1) In most cases, the river cuts into a coarse substrate, where fine material is sparse, whereas rill erosion occurs on arable land. So the main part of the substrate is fine material and only single rock fragments influence the processes. (2) In rivers, the water depth is relatively high. There are a lot of studies about hydraulic parameters in such flows, but there is almost nothing known about hydraulic conditions in surface runoff events of a few centimeters. Additionally, little information exists about the rock fragment movement as a part of rill erosion processes on arable land. This knowledge should be increased because rock fragments cause non-stationary water turbulences in rills, which enhance the erosive force of flowing water. Field experiments can only show the fact that a certain rock fragment has moved: The starting point and the final position can be estimated. But the moving path and especially the initiation of the movement is not detectable under field conditions. Hence, we developed a laboratory setup to analyze the movement of rock fragments depending on rock fragment properties (size, form), slope gradient, flow velocity and surface roughness. By observing the rock fragments with cameras from two different angles we are able (1) to measure the rotation angles of a rock fragment during the experiment and (2) to deduce different rock fragment movement patterns. On this poster we want to present the experimental setup, developed within the scope of a master thesis, and the results of these experiments.

  12. Hiero-Dermato-Glyphics: Laboratory Study of the Skin

    ERIC Educational Resources Information Center

    Roark, Oakley F.

    1977-01-01

    Explains several laboratory exercises using the skin, including the mapping of receptors, counting of sweat glands, computation of total skin area, comparison of various animal skins, measurement of the palm triradius angle, and study of epidermal ridges (dermatoglyphics) in males and females. (CS)

  13. Alternatives to Pyrotechnic Distress Signals; Laboratory and Field Studies

    DTIC Science & Technology

    2015-03-01

    London, CT 06320 Alternatives to Pyrotechnic Distress Signals; Laboratory and Field Studies iii UNCLAS//Public | CG-926 RDC | M. J. Lewandowski...1 Chelsea Street New London, CT 06320 10. Work Unit No. (TRAIS) 11. Contract or Grant No. 12. Sponsoring Organization Name and Address...various wind speeds (WS). ...................................... 22  Figure 15. Signal generator signal head

  14. Field Research Studying Whales in an Undergraduate Animal Behavior Laboratory

    ERIC Educational Resources Information Center

    MacLaren, R. David; Schulte, Dianna; Kennedy, Jen

    2012-01-01

    This work describes a new field research laboratory in an undergraduate animal behavior course involving the study of whale behavior, ecology and conservation in partnership with a non-profit research organization--the Blue Ocean Society for Marine Conservation (BOS). The project involves two weeks of training and five weekend trips on whale watch…

  15. Study of Scientists and Engineers in DoD Laboratories

    DTIC Science & Technology

    1982-09-01

    shortages, since such sho..ages are very closely linked to the future economic picture, a subject of much spec- ulation and unpredictability. The study panel...also took advantage of personal experience from the laboratory community, including interviews with knowledge- able people at the director...supervisor and non-supervisory S&E level, as well as person - nel experts and people from headquarters. Finally, the study group reviewed other studies that had

  16. Co-addition of manure increases the dissipation rates of tylosin A and the numbers of resistance genes in laboratory incubation experiments.

    PubMed

    Li, Qian; Wang, Yan; Zou, Yong-De; Liao, Xin-Di; Liang, Juan-Boo; Xin, Wen; Wu, Yin-Bao

    2015-09-15

    The behavior of veterinary antibiotics in the soil is commonly studied using the following methods to add antibiotics to the soil: (A) adding manure collected from animals fed a diet that includes antibiotics; (B) adding antibiotic-free animal manure spiked with antibiotics; and (C) the direct addition of antibiotics. However, most studies have only used methods (B) and (C) in their research, and few studies have simultaneously compared the different antibiotic addition methods. This study used tylosin A (TYLA) as a model antibiotic to compare the effects of these three commonly used antibiotic addition methods on the dissipation rates of TYLA and the numbers of resistance genes in laboratory incubation experiments. The results showed that the three treatment methods produced similar TYLA degradation trends; however, there were significant differences (P<0.05) in the TYLA degradation half-life (t1/2) among the three methods. The half-life of TYLA degradation in treatments A, B and C was 2.44 ± 0.04, 1.21 ± 0.03 and 5.13 ± 0.11 days, respectively. The presence of manure resulted in a higher electrical conductivity (EC), higher relative abundance of Citrobacter amalonaticus, higher macrolide resistant gene (ermB, ermF and ermT) count and lower ecological toxicity in the soil, which could partially explain the higher TYLA degradation rate in the treatments containing manure. The higher degradation rate of TYLA in treatment B when compared to treatment A could be due to the lower concentrations of tylosin B (TYLB) and tylosin D (TYLD). The main route for veterinary antibiotics to enter the soil is via the manure of animals that have been administered antibiotics. Therefore, the more appropriate method to study the degradation and ecotoxicity of antibiotic residues in the soil is by using manure from animals fed/administered the particular antibiotic rather than by adding the antibiotic directly to the soil.

  17. Laboratory studies of weakly bound adducts of atmospheric interest

    SciTech Connect

    Wine, P.H.; Nicovich, J.M.; Stickel, R.E.; Hynes, A.J.

    1995-12-31

    It is now well-established that weakly bound adducts, i.e., species whose life-times toward unimolecular decomposition are only fractions of a second under atmospheric conditions, play an important role in tropospheric sulfur chemistry. In this presentation, recent results from our laboratory concerning the existence and atmospheric fates of two such weakly bound species, (CH{sub 3}){sub 2}S-OH and (CH{sub 3}){sub 2}S-Cl, will be discussed. In addition, evidence for the formation of weakly bound adducts in reactions of chlorine atoms with methyl halides will be presented.

  18. Laboratory study supporting the interpretation of Solar Dynamics Observatory data

    DOE PAGES

    Trabert, E.; Beiersdorfer, P.

    2015-01-29

    High-resolution extreme ultraviolet spectra of ions in an electron beam ion trap are investigated as a laboratory complement of the moderate-resolution observation bands of the AIA experiment on board the Solar Dynamics Observatory (SDO) spacecraft. Here, the latter observations depend on dominant iron lines of various charge states which in combination yield temperature information on the solar plasma. Our measurements suggest additions to the spectral models that are used in the SDO data interpretation. In the process, we also note a fair number of inconsistencies among the wavelength reference data bases.

  19. Site study plan for routine laboratory rock mechanics, Deaf Smith County Site, Texas: Revision 1

    SciTech Connect

    Not Available

    1987-12-01

    This Site Study Plan for Routine Laboratory Rock Mechanics describes routine laboratory testing to be conducted on rock samples collected as part of the characterization of the Deaf Smith County site, Texas. This study plan describes the early laboratory testing. Additional testing may be required and the type and scope of testing will be dependent upon the results of the early testing. This study provides for measurements of index, hydrological, mechanical, and chemical properties with tests which are standardized and used widely in geotechnical investigations. Another Site Study Plan for Nonroutine Laboratory Rock Mechanics describes laboratory testing of samples from the site to determine mechanical, thermomechanical, and thermal properties by less widely used methods, many of which have been developed specifically for characterization of the site. Data from laboratory tests will be used for characterization of rock strata, design of shafts and underground facilities, and modeling of repository behavior in support of resolution of both preclosure and postclosure issues. A tentative testing schedule and milestone log are given. A quality assurance program will be utilized to assure that activities affecting quality are performed correctly and that appropriate documentation is maintained. 18 refs., 8 figs., 3 tabs.

  20. [Ethical problems in utilization of specimens after laboratory examinations for clinical studies].

    PubMed

    Murakami, Masami

    2011-03-01

    Ethical Committee in Japanese Society of Laboratory Medicine published "Opinions of Japanese Society of Laboratory Medicine about utilization of specimens after laboratory examinations for laboratory work, education and clinical studies" in 2002. Ministry of Health, Labour and Welfare in Japan established "Ethical Guidelines for Clinical Studies" in 2003, and amended the document in 2008. According to the guidelines, Ethical Committee in Japanese Society of Laboratory Medicine revised the "Opinions of Japanese Society of Laboratory Medicine about utilization of specimens after laboratory examinations for laboratory work, education and clinical studies" in 2010. Ethical problems in utilization of specimens after laboratory examinations for clinical studies are discussed.

  1. Maintaining plethodontid salamanders in the laboratory for regeneration studies.

    PubMed

    Arenas, Claudia Marcela; Gómez-Molina, Andrea; Delgado, Jean Paul

    2015-01-01

    Limb regeneration studies have been extensively carried out in species of Ambystomatidae and Salamandridae families. So far limited research has been conducted in species belonging to the Plethodontidae family, where some of the species differs from other salamander families due to their direct development, thus absence of a larval life. Here, we describe a protocol to maintain the plethodontid salamanders of genus Bolitoglossa species under laboratory conditions to perform regeneration studies.

  2. Laboratory Studies of Simple Dust Analogs in Astrophysical Environments

    NASA Astrophysics Data System (ADS)

    Brucato, John R.; Nuth, Joseph A., III

    2010-02-01

    Laboratory techniques seek to understand and to place limits upon chemical and physical processes that occur in space. Dust can be modified by long-term exposure to high-energy cosmic rays, thus rendering crystalline material amorphous.It can be heated to high temperatures, thus making amorphous material crystalline. Dust may be coated by organic molecules, changing its spectral properties, or may act as a catalyst in the synthesis of both simple and complex molecules. We describe experimental studies to understand such processes and report studies that focus on the properties of simple oxide grains. We give an overview of the synthesis and characterization techniques most often utilized to study the properties of solids in the laboratory and have concentrated on those techniques that have been most useful for the interpretation of astrophysical data. We also discuss silicate catalysis as an important mechanism that may drive the formation of complex molecular compounds relevant for prebiotic chemistry.

  3. Experimental Study of Additives on Viscosity biodiesel at Low Temperature

    NASA Astrophysics Data System (ADS)

    Fajar, Berkah; Sukarno

    2015-09-01

    An experimental investigation was performed to find out the viscosity of additive and biodiesel fuel mixture in the temperature range from 283 K to 318 K. Solutions to reduce the viscosity of biodiesel is to add the biodiesel with some additive. The viscosity was measured using a Brookfield Rheometer DV-II. The additives were the generic additive (Diethyl Ether/DDE) and the commercial additive Viscoplex 10-330 CFI. Each biodiesel blends had a concentration of the mixture: 0.0; 0.25; 0.5; 0.75; 1.0; and 1.25% vol. Temperature of biodiesel was controlled from 40°C to 0°C. The viscosity of biodiesel and additive mixture at a constant temperature can be approximated by a polynomial equation and at a constant concentration by exponential equation. The optimum mixture is at 0.75% for diethyl ether and 0.5% for viscoplex.

  4. Additive Manufacturing in Production: A Study Case Applying Technical Requirements

    NASA Astrophysics Data System (ADS)

    Ituarte, Iñigo Flores; Coatanea, Eric; Salmi, Mika; Tuomi, Jukka; Partanen, Jouni

    Additive manufacturing (AM) is expanding the manufacturing capabilities. However, quality of AM produced parts is dependent on a number of machine, geometry and process parameters. The variability of these parameters affects the manufacturing drastically and therefore standardized processes and harmonized methodologies need to be developed to characterize the technology for end use applications and enable the technology for manufacturing. This research proposes a composite methodology integrating Taguchi Design of Experiments, multi-objective optimization and statistical process control, to optimize the manufacturing process and fulfil multiple requirements imposed to an arbitrary geometry. The proposed methodology aims to characterize AM technology depending upon manufacturing process variables as well as to perform a comparative assessment of three AM technologies (Selective Laser Sintering, Laser Stereolithography and Polyjet). Results indicate that only one machine, laser-based Stereolithography, was feasible to fulfil simultaneously macro and micro level geometrical requirements but mechanical properties were not at required level. Future research will study a single AM system at the time to characterize AM machine technical capabilities and stimulate pre-normative initiatives of the technology for end use applications.

  5. Optical properties of particles in planetary atmospheres - Laboratory studies

    NASA Technical Reports Server (NTRS)

    Williams, D.

    1974-01-01

    The laboratory techniques employed for the determination of optical constants are discussed briefly. The values obtained for the real n and imaginary k parts of the refractive indices of water, ice, and liquid ammonia are presented graphically. Work currently in progress on solid ammonia and on sulphuric acid is discussed. Other approaches to studies of the properties of aerosols in planetary atmospheres are presented briefly.

  6. A rapid automated procedure for laboratory and shipboard spectrophotometric measurements of seawater alkalinity: continuously monitored single-step acid additions

    NASA Astrophysics Data System (ADS)

    Liu, X.; Byrne, R. H.; Lindemuth, M.; Easley, R. A.; Patsavas, M. C.

    2012-12-01

    An automated system for shipboard and laboratory alkalinity measurements is presented. The simple system, which consists of a Dosimat titrator to deliver acid volumetrically and a USB 4000 spectrophotometer to monitor the titration progress, provides fast, precise and accurate measurements of total alkalinity for oceanographic research. The analytical method is based on single-point HCl titrations of seawater samples of a known volume; bromol cresol purple is used as an indicator to determine the final pH. Field data from an Arctic cruise demonstrates accuracy and precision around 1 micro mol/kg and a sample processing rate of 6 min per sample.

  7. Laboratory studies of heterogeneous processes relevant to Mars

    NASA Astrophysics Data System (ADS)

    Gough, Raina V.

    Heterogeneous (gas-surface) processes may play an important role in both the atmospheric and surface chemistry of Mars. Atmospheric species may be affected by the chemistry and physical properties of the planetary surface and the surface material may be affected by the components and properties of the atmosphere. In this thesis, several laboratory studies are described which experimentally investigate two types of atmosphere-surface systems likely to exist on Mars. First, experiments were performed to better understand the spatial and temporal variability of atmospheric methane (CH4) on Mars. Reported CH4 plumes in the atmosphere of Mars are difficult to explain using known chemical or physical processes. The observations imply a strong, present-day source and also a rapid yet unknown CH4 sink. We have investigated the potential role of mineral dust in CH4 variability. First, using a Knudsen cell capable of simulating Martian temperature and pressure conditions, we have studied the adsorption of CH4 to a Martian mineral analog as a function of temperature. An uptake coefficient was determined and then applied to the Martian surface-atmosphere system. Our results suggest that adsorption to soil grains could possibly affect the CH4 mixing ratio on a seasonal time scale especially at mid-latitude regions. Additionally, chemical oxidation of CH4 by oxidants thought to exist in the Martian regolith was studied. The Viking mission in the 1970's found Martian soil was able to oxidize complex organic compounds to CO 2. The identity of the oxidant is unknown, but has been proposed to be either hydrogen peroxide or perchlorate salts. We used a gas chromatograph to determine if simulated Mars soil containing these oxidants was able to oxidize CH4 to CO2. However, no CH4 was oxidized within the detection limit of the instrument and only an upper limit reaction coefficient could be reported. Even these upper limit values suggest CH 4 could not be removed from the Martian

  8. Variability in baseline laboratory measurements of the Brazilian Longitudinal Study of Adult Health (ELSA-Brasil).

    PubMed

    Ladwig, R; Vigo, A; Fedeli, L M G; Chambless, L E; Bensenor, I; Schmidt, M I; Vidigal, P G; Castilhos, C D; Duncan, B B

    2016-08-01

    Multi-center epidemiological studies must ascertain that their measurements are accurate and reliable. For laboratory measurements, reliability can be assessed through investigation of reproducibility of measurements in the same individual. In this paper, we present results from the quality control analysis of the baseline laboratory measurements from the ELSA-Brasil study. The study enrolled 15,105 civil servants at 6 research centers in 3 regions of Brazil between 2008-2010, with multiple biochemical analytes being measured at a central laboratory. Quality control was ascertained through standard laboratory evaluation of intra- and inter-assay variability and test-retest analysis in a subset of randomly chosen participants. An additional sample of urine or blood was collected from these participants, and these samples were handled in the same manner as the original ones, locally and at the central laboratory. Reliability was assessed with the intraclass correlation coefficient (ICC), estimated through a random effects model. Coefficients of variation (CV) and Bland-Altman plots were additionally used to assess measurement variability. Laboratory intra and inter-assay CVs varied from 0.86% to 7.77%. From test-retest analyses, the ICCs were high for the majority of the analytes. Notably lower ICCs were observed for serum sodium (ICC=0.50; 95%CI=0.31-0.65) and serum potassium (ICC=0.73; 95%CI=0.60-0.83), due to the small biological range of these analytes. The CVs ranged from 1 to 14%. The Bland-Altman plots confirmed these results. The quality control analyses showed that the collection, processing and measurement protocols utilized in the ELSA-Brasil produced reliable biochemical measurements.

  9. Variability in baseline laboratory measurements of the Brazilian Longitudinal Study of Adult Health (ELSA-Brasil)

    PubMed Central

    Ladwig, R.; Vigo, A.; Fedeli, L.M.G.; Chambless, L.E.; Bensenor, I.; Schmidt, M.I.; Vidigal, P.G.; Castilhos, C.D.; Duncan, B.B.

    2016-01-01

    Multi-center epidemiological studies must ascertain that their measurements are accurate and reliable. For laboratory measurements, reliability can be assessed through investigation of reproducibility of measurements in the same individual. In this paper, we present results from the quality control analysis of the baseline laboratory measurements from the ELSA-Brasil study. The study enrolled 15,105 civil servants at 6 research centers in 3 regions of Brazil between 2008–2010, with multiple biochemical analytes being measured at a central laboratory. Quality control was ascertained through standard laboratory evaluation of intra- and inter-assay variability and test-retest analysis in a subset of randomly chosen participants. An additional sample of urine or blood was collected from these participants, and these samples were handled in the same manner as the original ones, locally and at the central laboratory. Reliability was assessed with the intraclass correlation coefficient (ICC), estimated through a random effects model. Coefficients of variation (CV) and Bland-Altman plots were additionally used to assess measurement variability. Laboratory intra and inter-assay CVs varied from 0.86% to 7.77%. From test-retest analyses, the ICCs were high for the majority of the analytes. Notably lower ICCs were observed for serum sodium (ICC=0.50; 95%CI=0.31–0.65) and serum potassium (ICC=0.73; 95%CI=0.60–0.83), due to the small biological range of these analytes. The CVs ranged from 1 to 14%. The Bland-Altman plots confirmed these results. The quality control analyses showed that the collection, processing and measurement protocols utilized in the ELSA-Brasil produced reliable biochemical measurements. PMID:27533768

  10. A review of the work of the EU Reference Laboratory supporting the authorisation process of feed additives in the EU. [corrected].

    PubMed

    von Holst, Christoph; Robouch, Piotr; Bellorini, Stefano; González de la Huebra, María José; Ezerskis, Zigmas

    2016-01-01

    This paper describes the operation of the European Union Reference Laboratory for Feed Additives (EURL) and its role in the authorisation procedure of feed additives in the European Union. Feed additives are authorised according to Regulation (EC) No. 1831/2003, which introduced a completely revised authorisation procedure and also established the EURL. The regulations authorising feed additives contain conditions of use such as legal limits of the feed additives, which require the availability of a suitable method of analysis for official control purposes under real world conditions. It is the task of the EURL to evaluate the suitability of analytical methods as proposed by the industry for this purpose. Moreover, the paper shows that one of the major challenges is the huge variety of the methodology applied in feed additive analysis, thus requiring expertise in quite different analytical areas. In order to cope with this challenge, the EURL is supported by a network of national reference laboratories (NRLs) and only the merged knowledge of all NRLs allows for a scientifically sound assessment of the analytical methods.

  11. Evaluation of Non-Laboratory and Laboratory Prediction Models for Current and Future Diabetes Mellitus: A Cross-Sectional and Retrospective Cohort Study

    PubMed Central

    Hahn, Seokyung; Moon, Min Kyong; Park, Kyong Soo; Cho, Young Min

    2016-01-01

    Background Various diabetes risk scores composed of non-laboratory parameters have been developed, but only a few studies performed cross-validation of these scores and a comparison with laboratory parameters. We evaluated the performance of diabetes risk scores composed of non-laboratory parameters, including a recently published Korean risk score (KRS), and compared them with laboratory parameters. Methods The data of 26,675 individuals who visited the Seoul National University Hospital Healthcare System Gangnam Center for a health screening program were reviewed for cross-sectional validation. The data of 3,029 individuals with a mean of 6.2 years of follow-up were reviewed for longitudinal validation. The KRS and 16 other risk scores were evaluated and compared with a laboratory prediction model developed by logistic regression analysis. Results For the screening of undiagnosed diabetes, the KRS exhibited a sensitivity of 81%, a specificity of 58%, and an area under the receiver operating characteristic curve (AROC) of 0.754. Other scores showed AROCs that ranged from 0.697 to 0.782. For the prediction of future diabetes, the KRS exhibited a sensitivity of 74%, a specificity of 54%, and an AROC of 0.696. Other scores had AROCs ranging from 0.630 to 0.721. The laboratory prediction model composed of fasting plasma glucose and hemoglobin A1c levels showed a significantly higher AROC (0.838, P < 0.001) than the KRS. The addition of the KRS to the laboratory prediction model increased the AROC (0.849, P = 0.016) without a significant improvement in the risk classification (net reclassification index: 4.6%, P = 0.264). Conclusions The non-laboratory risk scores, including KRS, are useful to estimate the risk of undiagnosed diabetes but are inferior to the laboratory parameters for predicting future diabetes. PMID:27214034

  12. Laboratories for the 21st Century: Case Studies; National Renewable Energy Laboratory, Science and Technology Facility, Golden, Colorado

    SciTech Connect

    Not Available

    2007-03-01

    This publication is one in series of case studies for "Laboratories for the 21st Century," a joint program of the U.S. Environmental Protection Agency and the U.S. Department of Energy Federal Energy Management Program. It is intended for those who plan to design and construct public and private-sector laboratory buildings. This case study describes the Science and Technology Facility, a new laboratory at NREL that incorporated energy-efficient and sustainable design features including underfloor air distribution in offices, daylighting, and process cooling.

  13. Studies Of Proton Emitting Nuclei At Legnaro National Laboratories

    NASA Astrophysics Data System (ADS)

    Soramel, F.; Guglielmetti, A.; Bonetti, R.; Gernetti, M.; Stroe, L.; Mazzocco, M.; Signorini, C.; Ivasçu, M.; Petrache, C. M.

    2003-09-01

    Since few years at the Legnaro National Laboratories we have recently started a program to study exotic decays at the proton drip-line with particular attention to proton radioactivity in the rare earth region. In fact pemitting nuclei with 54 < Z < 64 are expected to be quite deformed in their ground state and their study is an important input for the theoretical models that describe this kind of decay. Our studies have brought, as first result, the discovery of the decay by pemission of 117La where to p-decaying levels have been found. Our experimental program continued with the study of the decay of 126Pm. For this nucleus we can only conclude that our low statistics data show no evidence of p emission.

  14. New prospects for the study of leprosy in the laboratory

    PubMed Central

    Rees, R. J. W.

    1969-01-01

    Although Mycobacterium leprae was identified earlier than Myco. tuberculosis, it has still not been cultured in vitro and only in 1960 was an infection obtained in laboratory animals. However, important advances have been made in the field of experimental leprosy in the last decade due to the development of new techniques and models for studying Myco. leprae in vivo, thus overcoming the limitations imposed by a non-cultivable mycobacterium. Quantitative techniques using Myco. lepraemurium provided the first model for developing an indirect method for distinguishing dead (non-infectious) from living (infectious) bacilli, based on morphological differences in organisms stained by the Ziehl—Neelsen method. However, the most important advances resulted from the limited and localized growth of Myco. leprae when inoculated into the foot pads of mice and, later, the more substantial and generalized multiplication of Myco. leprae in immunologically deficient mice (thymectomized and irradiated with a dose of 900 r). Moreover, in the immunologically deficient animals, the infection eventually resulted in a disease replicating that of lepromatous type leprosy in man, including the involvement of peripheral nerves. The results from these studies and the future prospects for the study of leprosy in the laboratory are reviewed in this article. ImagesFIG. 5FIG. 6FIG. 4FIG. 7 PMID:4898388

  15. Laboratory studies of oil spill bioremediation; toward understanding field behavior

    SciTech Connect

    Prince, R.C.; Hinton, S.M.; Elmendorf, D.L.; Lute, J.R.; Grossman, M.J.; Robbins, W.K.; Hsu, Chang S.; Richard, B.E.; Haith, C.E.; Senius, J.D.; Minak-Bernero, V.; Chianelli, R.R.; Bragg, J.R.; Douglas, G.S.

    1993-12-31

    Oil spill remediation aims to enhance the natural process of microbial hydrocarbon biodegradation. The microbial foundations have been studied throughout this century, but the focus of most of this work has been on the degradation of well defined compounds by well defined microbial species. This paper addresses laboratory studies on crude oil biodegradation by microbial consortia obtained from oiled beaches in Prince William Sound, Alaska following the spill from the Exxon Valdez. It demonstrates that oil degradation is indeed likely to be nitrogen-limited in Prince William Sound, the different molecular classes in crude oil that are subjected to biodegradation, the identification of conserved species in the oil that can be used for assessing biodegradation and bioremediation in the field, the effectiveness of fertilizers in stimulating sub-surface biodegradation, the role of the olephilic fertilizer Inipol EAP22, and the identification of the oil-degrading microorganisms in Prince William Sound. Together, these laboratory studies provided guidance and important insights into the microbial phenomena underlying the successful bioremediation of the oiled shorelines.

  16. [External quality assessment in clinical biochemistry laboratories: pilot study in 11 laboratories of Lomé (Togo)].

    PubMed

    Kouassi, Kafui; Fétéké, Lochina; Assignon, Selom; Dorkenoo, Ameyo; Napo-Koura, Gado

    2015-01-01

    This study aims to evaluate the performance of a few biochemistry analysis and make recommendations to the place of the stakeholders. It is a cross-sectional study conducted between the October 1(st), 2012 and the July 31, 2013 bearing on the results of 5 common examinations of clinical biochemistry, provided by 11 laboratories volunteers opening in the public and private sectors. These laboratories have analysed during the 3 cycles, 2 levels (medium and high) of serum concentration of urea, glucose, creatinine and serum aminotransferases. The performance of laboratories have been determined from the acceptable limits corresponding to the limits of total errors, defined by the French Society of Clinical Biology (SFBC). A system of internal quality control is implemented by all laboratories and 45% of them participated in international programs of external quality assessment (EQA). The rate of acceptable results for the entire study was of 69%. There was a significant difference (p<0.002) between the performance of the group of laboratories engaged in a quality approach and the group with default implementation of the quality approach. Also a significant difference was observed between the laboratories of the central level and those of the peripheral level of our health system (p<0.047). The performance of the results provided by the laboratories remains relatively unsatisfactory. It is important that the Ministry of Health put in place a national program of EQA with mandatory participation.

  17. Behavioral Toxicological Studies of Pesticides in Laboratory Rats,

    DTIC Science & Technology

    Behavior, *Toxicology, *Pesticides, *Rats, Symposia, Laboratory tests, Toxicity, Insecticides, Exposure( General ), Dosage, Perception, Motor reactions, Learning, Military psychology , Military medicine

  18. Simulation studies of plasma lens experiments at Daresbury laboratory

    NASA Astrophysics Data System (ADS)

    Hanahoe, K.; Mete, O.; Xia, G.; Angal-Kalinin, D.; Jones, J.; Smith, J.

    2016-03-01

    Experiments are planned to study plasma lensing using the VELA and CLARA Front End accelerators at Daresbury Laboratory. This paper presents results of 2-dimensional particle-in-cell simulations of the proposed experiments. The variation in focusing strength and emittance growth with beam and plasma parameters are studied in the overdense (plasma density much greater than bunch density) regime for the VELA beam. The effect of spherical and longitudinal aberrations on the beam emittance was estimated through numerical and theoretical studies. Simulation results show that a focusing strength equivalent to a magnetic field gradient of 10 T m-1 can be achieved using VELA, and a gradient of 247 T m-1 can be achieved using CLARA Front End.

  19. Laboratory plant study on the melting process of asbestos waste

    SciTech Connect

    Sakai, Shinichi; Terazono, Atsushi; Takatsuki, Hiroshi; Tsunemi, Takeshi

    1996-12-31

    The melting process was studied as a method of changing asbestos into non-hazardous waste and recovering it as a reusable resource. In an initial effort, the thermal behaviors of asbestos waste in terms of physical and chemical structure have been studied. Then, 10 kg/h-scale laboratory plant experiments were carried out. By X-ray diffraction analysis, the thermal behaviors of sprayed-on asbestos waste revealed that chrysotile asbestos waste change in crystal structure at around 800 C, and becomes melted slag, mainly composed of magnesium silicate, at around 1,500 C. Laboratory plant experiments on the melting process of sprayed-on asbestos have shown that melted slag can be obtained. X-ray diffraction analysis of the melted slag revealed crystal structure change, and SEM analysis showed the slag to have a non-fibrous form. And more, TEM analysis proved the very high treatment efficiency of the process, that is, reduction of the asbestos content to 1/10{sup 6} as a weight basis. These analytical results indicate the effectiveness of the melting process for asbestos waste treatment.

  20. Laboratory combustion tube studies. Part II. Report SUPRI TR-10

    SciTech Connect

    Brigham, W.E.; Fassihi, M.R.; Satman, A.; Williams, R.L.; Pettit, P.; Grim, J.; Ramey, H.J. Jr.

    1981-03-01

    To promote a better understanding of the problems and mechanisms involved in dry in-situ combustion of crude oils in porous media, continuing laboratory studies are carried out at SUPRI. The report about the first two experiments was submitted earlier to the Department of Energy. This report describes the results of the last three tube runs. Three laboratory combustion tube studies were made with unconsolidated core material, and Lombardi Zone crude oil from the San Ardo field, California. After preparation, the material was packed into the combustion tube. Conditions employed during the steady burning phase of each run were about constant. Injection pressure for all of them was 100 Psig (6.8 Atm.). Burning front velocities ranged from 7.22 cm/hr (5.68 ft/day) to 12.96 cm/hr (10.2 ft/day) while the stream front velocities ranged from 10.4 cm/hr to 13.48 cm/hr. The air flux was between 88.33 SCF/hr-ft/sup 2/ and 122.7SCF/hr-ft/sup 2/. Observed fuel ration ranged from 162.54 SCF/lb to 169.33 SCF/lb of fuel burned. The detailed analysis of these experiments accompanied with their field application will be presented later.

  1. Laboratory study of biological retention for urban stormwater management.

    PubMed

    Davis, A P; Shokouhian, M; Sharma, H; Minami, C

    2001-01-01

    Urban stormwater runoff contains a broad range of pollutants that are transported to natural water systems. A practice known as biological retention (bioretention) has been suggested to manage stormwater runoff from small, developed areas. Bioretention facilities consist of porous soil, a topping layer of hardwood mulch, and a variety of different plant species. A detailed study of the characteristics and performance of bioretention systems for the removal of several heavy metals (copper, lead, and zinc) and nutrients (phosphorus, total Kjeldahl nitrogen [TKN], ammonium, and nitrate) from a synthetic urban stormwater runoff was completed using batch and column adsorption studies along with pilot-scale laboratory systems. The roles of the soil, mulch, and plants in the removal of heavy metals and nutrients were evaluated to estimate the treatment capacity of laboratory bioretention systems. Reductions in concentrations of all metals were excellent (> 90%) with specific metal removals of 15 to 145 mg/m2 per event. Moderate reductions of TKN, ammonium, and phosphorus levels were found (60 to 80%). Little nitrate was removed, and nitrate production was noted in several cases. The importance of the mulch layer in metal removal was identified. Overall results support the use of bioretention as a stormwater best management practice and indicate the need for further research and development.

  2. Additive empirical parametrization and microscopic study of deuteron breakup

    NASA Astrophysics Data System (ADS)

    Avrigeanu, M.; Avrigeanu, V.

    2017-02-01

    Comparative assessment of the total breakup proton-emission cross sections measured for 56 MeV deuteron interaction with target nuclei from 12C to 209Bi, with an empirical parametrization and recently calculated microscopic neutron-removal cross sections was done at the same time with similar data measured at 15, 25.5, 70, and 80 MeV. Comparable mass dependencies of the elastic-breakup (EB) cross sections provided by the empirical parametrization and the microscopic results have been also found at the deuteron energy of 56 MeV, while the assessment of absolute-values variance up to a factor of two was not possible because of the lack of EB measurements at energies higher than 25.5 MeV. While the similarities represent an additional validation of the microscopic calculations, the cross-section difference should be considered within the objectives of further measurements.

  3. Laboratory-Based Studies of Eating among Children and Adolescents

    PubMed Central

    Tanofsky-Kraff, Marian; Haynos, Ann F.; Kotler, Lisa A.; Yanovski, Susan Z.; Yanovski, Jack A.

    2008-01-01

    The prevalence of pediatric overweight has increased dramatically over the past three decades, likely due to changes in food intake as well as physical activity. Therefore, information examining eating patterns among children and adolescents is needed to illuminate which aspects of eating behavior require modification to prevent and treat pediatric overweight. Because child self-report and parent-report of children's eating habits are often inconsistent and limited by recall and other biases, laboratory-based studies in which food intake is observed and monitored have increased in number. Such studies offer objective and controlled methods of measuring and describing eating behaviors. However, to our knowledge, no publication exists that consolidates, reviews, and provides critical commentary on the literature to date in pediatric samples. In this paper, we review the literature of studies utilizing laboratory methods to examine eating behavior in samples ranging from birth through adolescence. Our review includes all relevant articles retrieved from the PubMed, Medline and PsychInfo search engines. Specifically, we examine meal-feeding studies conducted during the various developmental stages (infancy, preschool, middle childhood, and adolescence), with a focus on methodology. Included in our review are feeding studies related to dietary regulation, exposure and preference, as well as paradigms examining disordered eating patterns and their relationship to body composition. We have structured this review so that both consistent and inconsistent findings are presented by age group, and innovative methods of assessment are discussed in more detail. Following each section, we summarize findings and draw potential conclusions from the available data. We then discuss clinical implications of the research data and suggest directions for the next generation of studies of feeding behavior in children. PMID:19030122

  4. A laboratory study of arched magnetic flux rope eruptions*

    NASA Astrophysics Data System (ADS)

    Tripathi, S.; Gekelman, W. N.

    2010-12-01

    Arched magnetic flux ropes (AMFRs) are arch-shaped twisted magnetic-structures that confine plasma and carry electrical current. Coronal loops and solar prominences are the main examples of AMFRs in the solar atmosphere. Solar AMFRs appear stable for long duration (several Alfven transit times) and then suddenly erupt due to occurrence of instabilities (e.g., kink instability). Solar AMFR eruptions have been frequently observed to evolve into more energetic events such as solar flares and coronal mass ejections. A laboratory plasma experiment has been constructed to simulate such eruptions in an ambient magnetized plasma. The laboratory AMFR (n ~ 1019 m-3 , Te ~ 10 eV, B ~ 1 kG, L ~ 0.5 m) is produced using an annular LaB6 cathode and an annular anode mounted on two movable shafts in a vacuum chamber (1.0 m diameter, 4.5 m long). Each AMFR electrode has an electromagnet to produce a vacuum magnetic field along the curved axis of the AMFR. The vacuum chamber has an additional plasma source and electromagnets to produce the ambient magnetized plasma (n ~ 1018 m-3, Te ~ 4 eV, B ~ 25 G). Two laser beams (1064 nm, ~0.5 J/pulse) strike movable carbon targets placed behind the orifices of the electrodes to generate controlled plasma flows from the AMFR footpoints that drives the eruption. The experiment operates with a 0.5 Hz repetition rate and is highly reproducible. Thus, time evolution of the AMFR is recorded in three-dimensions with high spatio-temporal resolutions using movable diagnostic probes. Initial results on the dramatic eruption of an arched magnetic flux rope will be presented that demonstrate outward expansion of the AMFR, release of the AMFR plasma to the background, and excitation of magnetosonic waves in the ambient plasma. Reference: S. K. P. Tripathi and W. Gekelman, Phys. Rev. Lett. 105, 075005 *Work supported by US DOE and NSF Fast camera image of a laboratory AMFR. Laser generated flows can be seen emanating from the both footpoints of the AMFR.

  5. Laboratory Studies of Organic Compounds With Reflectance Spectroscopy

    NASA Astrophysics Data System (ADS)

    Curchin, J. M.; Clark, R. N.; Hoefen, T. M.

    2007-12-01

    In order to properly interpret reflectance spectra of any solar system surface from the earth to the Oort cloud, laboratory spectra of candidate materials for comparative analysis are needed. Although the common cosmochemical species (H2O, CO2, CO, NH3, and CH4) are well represented in the spectroscopic literature, comparatively little reflectance work has been done on organics from room to cryogenic temperatures at visible to near infrared wavelengths. Reflectance spectra not only enhance weak or unseen transmission features, they are also more analogous to spectra obtained by spacecraft that are imaging such bodies as giant planet moons, kuiper belt objects, centaurs, comets and asteroids, as well as remote sensing of the earth. The USGS Spectroscopy Laboratory is measuring reflectance spectra of organic compounds from room to cryogenic temperatures over the spectral range of 0.35 to 15.5 microns. This region encompasses the fundamental absorptions and many overtones and combinations of C, H, O, and N molecular bonds. Because most organic compounds belong to families whose members have similar structure and composition, individual species identification within a narrow wavelength range may be ambiguous. By measuring spectral reflectance of the pure laboratory samples from the visible through the near and mid-infrared, absorption bands unique to each can be observed, cataloged, and compared to planetary reflectance data. We present here spectra of organic compounds belonging to five families: the alkanes, alkenes, alkynes, aromatics, and cyanides. Common to all of these are the deep C-H stretch fundamental absorptions, which shift shortward from 3.35+ microns in alkanes to 3.25+ microns in aromatics, to 3.2+ microns in alkenes, and down to 3.0+ microns in alkynes. Mid-IR absorptions due to C-H bending deformations at 6.8+ and 7.2+ microns are also identified. In the near infrared these stretching and bending fundamentals yield a diagnostic set of combination

  6. NMR relaxometry study of plaster mortar with polymer additives

    SciTech Connect

    Jumate, E.; Manea, D.; Moldovan, D.; Fechete, R.

    2013-11-13

    The cement mixed with water forms a plastic paste or slurry which stiffness in time and finally hardens into a resistant stone. The addition of sand aggregates, polymers (Walocel) and/or calcium carbonate will modify dramatically the final mortar mechanic and thermal properties. The hydration processes can be observed using the 1D NMR measurements of transverse T{sub 2} relaxation times distributions analysed by a Laplace inversion algorithm. These distributions were obtained for mortar pasta measured at 2 hours after preparation then at 3, 7 and 28 days after preparation. Multiple components are identified in the T{sub 2} distributions. These can be associated with the proton bounded chemical or physical to the mortar minerals characterized by a short T{sub 2} relaxation time and to water protons in pores with three different pore sizes as observed from SEM images. The evaporation process is faster in the first hours after preparation, while the mortar hydration (bonding of water molecules to mortar minerals) can be still observed after days or months from preparation. Finally, the mechanic resistance was correlated with the transverse T{sub 2} relaxation rates corresponding to the bound water.

  7. Laboratory Study of Angular Momentum Transport in Astrophysical Accretion Disks

    NASA Astrophysics Data System (ADS)

    Ji, Hantao

    2014-10-01

    Studying astrophysical processes in the lab becomes increasingly possible and exciting, as one of Stirling's favorite subjects throughout his scientific career. In this talk, I will describe experimental efforts to study mechanisms of rapid angular momentum transport required to occur in accretion disks to explain a wide range of phenomena from star formation, energetic activity of cataclysmic variables, to powering quasars, the most luminous steady sources in the Universe. By carefully isolating effects due to artificial boundaries, which are inherent to terrestrial experiments, certain astrophysical questions regarding hydrodynamic and magnetohydrodynamic stabilities are being addressed in the laboratory. Inspirations from Stirling as well as scientific exchanges with him will be mentioned during this talk as part of my scientific journey on this subject.

  8. Laboratory studies of actinide partitioning relevant to 244Pu chronometry

    NASA Technical Reports Server (NTRS)

    Benjamin, T.; Heuser, W. R.; Burnett, D. S.

    1978-01-01

    Actinide partitioning and light lanthanide fractionation have been studied to gain an understanding of Pu chemistry under meteoritic and lunar conditions. The goal of the study was to identify conditions and samples from which chronological information can be retrieved. The laboratory investigations involved particle track radiography of the crystal/liquid partitioning of Th, U and Pu among diopsidic clinopyroxene, whitlockite and liquid. It is found that trivalent Pu plays an important role in partitioning for lunar and most meteoritic conditions. The use of Pu/Nd for relative age assessments is supported to some extent by the investigations; samples with unfractionated U, Th and Nd abundances (relative to average solar system values) may be suitable for Pu chronometry.

  9. Laboratory Studies of Ice Nucleation on Volcanic Ash

    NASA Astrophysics Data System (ADS)

    Tolbert, M. A.; Schill, G. P.; Genareau, K. D.

    2014-12-01

    Ice nucleation on volcanic ash controls both ash aggregation and cloud glaciation, which affect human respiratory health, atmospheric transport, and global climate. We have performed laboratory studies of the depositional and immersion freezing efficiency of three distinct samples of volcanic ash using Raman Microscopy coupled to an environmental cell. Ash from the Fuego (Basaltic Ash, Guatemala), Soufriere Hills (Andesetic Ash, Montserrat), and Taupo (Rhyolitic Ash, New Zealand) volcanoes were chosen to represent different geographical locations and silica content. All ash samples were quantitatively analyzed for both percent crystallinity and mineralogy using X-ray diffraction. We find that all three samples of volcanic ash are excellent depositional ice nuclei, nucleating ice at ice saturation ratios of 1.05 ± 0.1. For immersion freezing, however, only the Taupo ash exhibited efficient heterogeneous ice nucleation activity. Similar to recent studies on mineral dust, we suggest that the mineralogy of volcanic ash may dictate its ice nucleation activity in the immersion mode.

  10. Anterior chamber lenses. Part II: A laboratory study.

    PubMed

    Apple, D J; Hansen, S O; Richards, S C; Ellis, G W; Kavka-Van Norman, D; Tetz, M R; Pfeffer, B R; Park, R B; Crandall, A S; Olson, R J

    1987-03-01

    An analysis of 606 surgically removed anterior chamber intraocular lens (IOL) specimens revealed that 351 or 58% of these were small-diameter, round loop, closed-loop styles. Because of the extremely high percentage of IOLs with this design received in our laboratory and the correlation of clinical histories with our histopathologic findings, we have concluded that such IOLs do not provide the safety and efficacy achieved by other anterior chamber lens designs. The finely polished, one-piece, all-PMMA styles fared well in our study. Although these one-piece styles comprise well over 50% of the American market share of anterior chamber IOLs, they comprise only 14% of all anterior chamber IOLs accessioned in our laboratory, compared to 58% for closed-loop designs. We believe that implantation of anterior chamber lenses with small-diameter, round, closed loops is no longer warranted. Patients in whom these IOLs have already been implanted should be carefully followed. It is our opinion that the FDA should recall or closely monitor all IOLs of this design and that implantation of closed-loop lenses should be discontinued in the United States. Furthermore, we believe that an IOL deemed to be not medically sound or worthy of implantation in the United States should not be marketed or donated outside of this country.

  11. Laboratory study of carbonaceous dust and molecules of astrochemical interest

    NASA Astrophysics Data System (ADS)

    Cataldo, F.; Garcia-Hernandez, D. A.; Manchado, A.; Kwok, S.

    2016-07-01

    In this paper are reviewed some research works dedicated to the study of carbonaceous dust and molecules of astrochemical interest. First of all it is discussed the carbon arc through which it is possible to produce carbon soot and fullerenes under helium but also many other different products just changing the arcing conditions. For example, when the carbon arc is struck in an hydrocarbon solvent it is possible to produce and trap polyynes in the solvent. Monocyanopolyynes and dicyanopolyynes can be produced as well by selecting the appropriate conditions. Amorphous carbon soot or partially graphitized carbon black can be produced with the carbon arc. Fullerenes were found in space thanks to the reference infrared spectra and the absorption cross sections which were determined in laboratory. Fullerenes are readily reactive with hydrogen yielding fulleranes the hydrogenated fullerenes. Furthermore fullerenes react with PAHs and with iron carbonyl yielding adducts. All these fullerene derivatives were synthesized and their reference spectra recorded in laboratory. It was proposed that petroleum fractions can be used as model substrates in the explanation of the carriers of the AIB (Aromatic Infrared Bands) observed in protoplanetary and planetary nebulae and the UIE (Unidentified Infrared Bands) found in the interstellar medium.

  12. Design of laboratory experiments to study radiation-driven implosions

    NASA Astrophysics Data System (ADS)

    Keiter, P. A.; Trantham, M.; Malamud, G.; Klein, S. R.; Davis, J.; VanDervort, R.; Shvarts, D.; Drake, R. P.; Stone, J. M.; Fraenkel, M.; Frank, Y.; Raicher, E.

    2017-03-01

    The interstellar medium is heterogeneous with dense clouds amid an ambient medium. Radiation from young OB stars asymmetrically irradiate the dense clouds. Bertoldi (1989) developed analytic formulae to describe possible outcomes of these clouds when irradiated by hot, young stars. One of the critical parameters that determines the cloud's fate is the number of photon mean free paths in the cloud. For the extreme cases where the cloud size is either much greater than or much less than one mean free path, the radiation transport should be well understood. However, as one transitions between these limits, the radiation transport is much more complex and is a challenge to solve with many of the current radiation transport models implemented in codes. We present the design of laboratory experiments that use a thermal source of x-rays to asymmetrically irradiate a low-density plastic foam sphere. The experiment will vary the density and hence the number of mean free paths of the sphere to study the radiation transport in different regimes. We have developed dimensionless parameters to relate the laboratory experiment to the astrophysical system and we show that we can perform the experiment in the same transport regime.

  13. Laboratory Studies of Vibrational Relaxation: Important Insights for Mesospheric OH

    NASA Astrophysics Data System (ADS)

    Kalogerakis, Konstantinos S.; Matsiev, Daniel

    2016-04-01

    The hydroxyl radical has a key role in the chemistry and energetics of the Earth's middle atmosphere. A detailed knowledge of the rate constants and relevant pathways for OH(high v) vibrational relaxation by atomic and molecular oxygen and their temperature dependence is absolutely critical for understanding mesospheric OH and extracting reliable chemical heating rates from atmospheric observations. We have developed laser-based experimental approaches to study the complex collisional energy transfer processes involving the OH radical and other relevant atmospheric species. Previous work in our laboratory indicated that the total removal rate constant for OH(v = 9) + O at room temperature is more than one order of magnitude larger than that for removal by O2. Thus, O atoms are expected to significantly influence the intensity and vibrational distribution extracted from the Meinel OH(v) emissions. We will report our most recent laboratory experiments that corroborate the aforementioned result for OH(v = 9) + O and provide important new insights on the mechanistic pathways involved. We will also highlight relevant atmospheric implications, including warranted revisions of current mesospheric OH models. Research supported by SRI International Internal R&D and NSF Aeronomy grant AGS-1441896. Previously supported by NASA Geospace Science grant NNX12AD09G.

  14. Feasibility study of medical isotope production at Sandia National Laboratories

    SciTech Connect

    Massey, C.D.; Miller, D.L.; Carson, S.D.

    1995-12-01

    In late 1994, Sandia National Laboratories in Albuquerque, New Mexico, (SNL/NM), was instructed by the Department of Energy (DOE) Isotope Production and Distribution Program (IPDP) to examine the feasibility of producing medically useful radioisotopes using the Annular Core Research Reactor (ACRR) and the Hot Cell Facility (HCF). Los Alamos National Laboratory (LANL) would be expected to supply the targets to be irradiated in the ACRR. The intent of DOE would be to provide a capability to satisfy the North American health care system demand for {sup 99}Mo, the parent of {sup 99m}Tc, in the event of an interruption in the current Canadian supply. {sup 99m}Tc is used in 70 to 80% of all nuclear medicine procedures in the US. The goal of the SNL/NM study effort is to determine the physical plant capability, infrastructure, and staffing necessary to meet the North American need for {sup 99}Mo and to identify and examine all issues with potential for environmental impact.

  15. Ribotyping as an additional molecular marker for studying Neisseria meningitidis serogroup B epidemic strains.

    PubMed Central

    Tondella, M L; Sacchi, C T; Neves, B C

    1994-01-01

    The molecular method of ribotyping was used as an additional epidemiological marker to study the epidemic strains of Neisseria meningitidis serogroup B, referred to as the ET-5 complex, responsible for the epidemic which occurred in greater São Paulo, Brazil. Ribotyping analysis of these strains showed only a single rRNA gene restriction pattern (Rb1), obtained with ClaI restriction enzyme. This method, as well as multilocus enzyme electrophoresis, provided useful information about the clonal characteristics of the N. meningitidis serogroup B strains isolated during this epidemic. The N. meningitidis serogroup B isolates obtained from epidemics which occurred in Norway, Chile, and Cuba also demonstrated the same pattern (Rb1). Ribotyping was a procedure which could be applied to a large number of isolates and was felt to be appropriate for routine use in laboratories, especially because of the convenience of using nonradioactive probes. Images PMID:7852566

  16. Pre-operative laboratory testing: A prospective study on comparison and cost analysis

    PubMed Central

    Keshavan, Venkatesh H; Swamy, Chidananda MN

    2016-01-01

    Background and Aims: Pre-operative investigations are performed before any surgical intervention under anaesthesia. Many are considered as routine. However, there are no clear guidelines regarding these in India. We aim to look at the relevance of the laboratory investigations ordered routinely and their cost implications compared with the National Institute of Clinical Excellence (NICE) guidelines. Methods: This prospective study was carried out at a tertiary care hospital. A total of 163 patients scheduled for elective surgical procedures were included in this study. Neither the surgeons nor anaesthesiologists involved in the case were aware of the study. The laboratory investigations of the patients who underwent surgery were noted. All values were categorised as normal or abnormal and they were assessed as indicated or unindicated based on NICE guidelines. Results: One hundred and sixty-three patients were subjected to a total of 984 tests. Forty three patients (26%) were subjected to tests as per NICE guidelines. Of the 984 tests, 515 tests were unindicated (52%). Out of the 515 unindicated tests, 7 (1.3%) were abnormal. None of these seven tests required any intervention or change of anaesthetic plan. The most common unindicated tests done were cardiac echocardiography and chest X-ray (92.5% and 93% respectively). The additional cost incurred towards unindicated tests was 63% of the total cost for the tests. Conclusion: Pre-operative laboratory investigations add to cost significantly. Patient premorbid conditions and surgical grade should guide the clinician to request for the relevant laboratory tests. PMID:27942058

  17. An Undergraduate Laboratory Exercise to Study Weber’s Law

    PubMed Central

    Holden, Jameson K.; Francisco, Eric M.; Zhang, Zheng; Baric, Cristina; Tommerdahl, Mark

    2011-01-01

    Weber’s Law describes the relationship between actual and perceived differences in stimulus intensity. To observe the relationship described in this law, we developed an exercise for undergraduate students, as experiential learning is an integral part of scientific education. We describe the experimental methods used for determining the subject’s discriminative capacity at multiple vibrotactile amplitudes. A novel four-point stimulator (designed and fabricated at the University of North Carolina) was used for the study. Features of the device, such as automated skin detection, make it feasible to perform this laboratory exercise in a reasonable lab period. At the conclusion of the lab exercise, students will thoroughly understand the principle of Weber’s Law as well as fundamental quantitative sensory testing concepts. This introduction to sensory testing will provide a suitable foundation for the undergraduate neuroscience student to investigate other aspects of sensory information processing in subsequent lab exercises. PMID:23493843

  18. Laboratory Studies on Silicates Relevant for the Physics of TNOs

    NASA Astrophysics Data System (ADS)

    Brucato, John Robert; Strazzulla, Giovanni; Baratta, Giuseppe; Mennella, Vito; Colangeli, Luigi

    2003-06-01

    Silicates are one of the principal components present in Solar System objects. Silicates evolve in space modifying their physical properties according to the astronomical environments they go through. To characterise the nature of TNOs in the framework of the formation and evolution of the Solar System, experiments on structural transitions of silicates have been performed in the laboratory to simulate some of the processing suffered by the dust. The infrared spectral properties of possible silicate candidates thought to be present in TNOs have been studied. The results of thermal annealing of amorphous silicates and amorphisation of crystalline forsterite (pure-Mg olivine) by ion irradiation are presented. The observable properties of TNOs surfaces are inferred.

  19. Study of CSR Effects in the Jefferson Laboratory FEL Driver

    SciTech Connect

    Hall, C. C.; Biedron, S.; Burleson, Theodore A.; Milton, Stephen V.; Morin, Auralee L.; Benson, Stephen V.; Douglas, David R.; Evtushenko, Pavel E.; Hannon, Fay E.; Li, Rui; Tennant, Christopher D.; Zhang, Shukui; Carlsten, Bruce E.; Lewellen, John W.

    2013-08-01

    In a recent experiment conducted on the Jefferson Laboratory IR FEL driver the effects of Coherent Synchrotron Radiation (CSR) on beam quality were studied. The primary goal of this work was to explore CSR output and effect on the beam with variation of the bunch compression in the IR chicane. This experiment also provides a valuable opportunity to benchmark existing CSR models in a system that may not be fully represented by a 1-D CSR model. Here we present results from this experiment and compare to initial simulations of CSR in the magnetic compression chicane of the machine. Finally, we touch upon the possibility for CSR induced microbunching gain in the magnetic compression chicane, and show that parameters in the machine are such that it should be thoroughly damped.

  20. NASA ER-2: Flying Laboratory for Earth Science Studies

    NASA Technical Reports Server (NTRS)

    Navarro, Robert

    2007-01-01

    This viewgraph presentation gives an overview of the NASA ER-2 aircraft. The contents include: 1) ER-2 Specifications; 2) ER-2 Basic Configuration; 3) ER-2 Payload Areas: Nose Area; 4) ER-2 Payload Areas: SuperPod Fore and Aftbody; 5) ER-2 Payload Areas: SuperPod Midbody; 6) ER-2 Payload Areas: Q-Bay; 7) ER-2 Payload Areas: Q-Bay Hatch Designs; 8) ER-2 Payload Areas: External Pods; 9) ER-2 Electrical/Control Interface; 10) ER-2 Typical Flight Profile; 11) Tropical Composition, Cloud and Climate Coupling TC-4; 12) TC-4 Timeline; 13) TC4 Area of Interest; 14) ER-2 TC4 Payload; 15) A/C ready for fuel; 16) ER-2 Pilot being suited; 17) ER-2 Taxing; 18) ER-2 Pilot post flight debrief; and 19) NASA ER-2: Flying Laboratory for Earth Science Studies and Remote Sensing.

  1. Additional EIPC Study Analysis: Interim Report on High Priority Topics

    SciTech Connect

    Hadley, Stanton W

    2013-11-01

    Between 2010 and 2012 the Eastern Interconnection Planning Collaborative (EIPC) conducted a major long-term resource and transmission study of the Eastern Interconnection (EI). With guidance from a Stakeholder Steering Committee (SSC) that included representatives from the Eastern Interconnection States Planning Council (EISPC) among others, the project was conducted in two phases. Phase 1 involved a long-term capacity expansion analysis that involved creation of eight major futures plus 72 sensitivities. Three scenarios were selected for more extensive transmission- focused evaluation in Phase 2. Five power flow analyses, nine production cost model runs (including six sensitivities), and three capital cost estimations were developed during this second phase. The results from Phase 1 and 2 provided a wealth of data that could be examined further to address energy-related questions. A list of 13 topics was developed for further analysis; this paper discusses the first five.

  2. Additional studies for the spectrophotometric measurement of iodine in water

    NASA Technical Reports Server (NTRS)

    1972-01-01

    Previous work in iodine spectroscopy is briefly reviewed. Continued studies of the direct spectrophotometric determination of aqueous iodine complexed with potassium iodide show that free iodine is optimally determined at the isosbestic point for these solutions. The effects on iodine determinations of turbidity and chemical substances (in trace amounts) is discussed and illustrated. At the levels tested, iodine measurements are not significantly altered by such substances. A preliminary design for an on-line, automated iodine monitor with eventual capability of operating also as a controller was analyzed and developed in detail with respect single beam colorimeter operating at two wavelengths (using a rotating filter wheel). A flow-through sample cell allows the instrument to operate continuously, except for momentary stop flow when measurements are made. The timed automatic cycling of the system may be interrupted whenever desired, for manual operation. An analog output signal permits controlling an iodine generator.

  3. Partnering at the National Laboratories: Catalysis as a Case Study

    SciTech Connect

    JACKSON,NANCY B.

    1999-09-14

    The role of the national laboratories, particularly the defense program laboratories, since the end of the cold war, has been a topic of continuing debate. The relationship of national laboratories to industry spurred debate which ranged from designating the labs as instrumental to maintaining U.S. economic competitiveness to concern over the perception of corporate welfare to questions regarding the industrial globalization and the possibility of U.S. taxpayer dollars supporting foreign entities. Less debated, but equally important, has been the national laboratories' potential competition with academia for federal research dollars and discussions detailing the role of each in the national research enterprise.

  4. Food additives and Hymenolepis nana infection: an experimental study.

    PubMed

    El-Nouby, Kholoud A; Hamouda, Hala E; Abd El Azeem, Mona A; El-Ebiary, Ahmad A

    2009-12-01

    The effect of sodium benzoate (SB) on the pathogenesis of Hymenolepis nana (H. nana) and its neurological manifestations was studied in the present work. One hundred and thirty five mice were classified into three groups. GI: received SB alone. GII: received SB before & after infection with H. nana and GIII: infected with H. nana. All groups were subjected to parasitological, histopathological, immunohistochemical and biochemical assays. The results revealed a significant decrease in IL-4 serum level with a significant increase in gamma amino butyric acid (GABA) and decrease in zinc brain levels in GI, while GII showed non significant increase in IL-4 level that resulted in a highly significant increase in the mean number of cysticercoids and adult worms with delayed expulsion as compared to GIII. This was reflected on histopathological and immunohistochemical changes in the brain. Also, there was a highly significant increase in GABA and decrease in zinc brain levels in GII to the degree that induced behavioral changes. This emphasizes the possible synergistic effect of SB on the neurological manifestations of H. nana and could, in part, explain the increased incidence of behavioral changes in children exposed to high doses of SB and unfortunately have H. nana infection.

  5. Impact of the addition of chicken litter on mercury speciation and emissions from coal combustion in a laboratory-scale fluidized bed combustor

    SciTech Connect

    Songgeng Li; Shuang Deng; Andy Wu; Wei-ping Pan

    2008-07-15

    Co-combustion of chicken litter with coal was performed in a laboratory-scale fluidized bed combustor to investigate the effect of chicken litter addition on the partitioning behavior of mercury. Gaseous total and elemental mercury concentrations in the flue gas were measured online, and ash was analyzed for particle-bound mercury along with other elemental and surface properties. The mercury mass balance was between 85 and 105%. The experimental results show that co-combustion of chicken litter decreases the amount of elemental and total mercury in the gas phase. Mercury content in fly ash increases with an increasing chicken litter share. 22 refs., 6 figs., 5 tabs.

  6. The Role of Heterogeneous Chemistry of Volatile ORganic Compounds: A Modeling and Laboratory Study

    SciTech Connect

    Gregory R. Carmichael; Vicki H. Grassian

    2007-03-01

    Overview The outputs of this research have been reported annually via the RIMS system. This report serves as an update and final report. The focus of our DOE BES funded project is on the importance of heterogeneous reactions in the troposphere. The primary objectives of our study were to: (i) Evaluate the extent to which heterogeneous chemistry affects the photochemical oxidant cycle, particularly, sources and sinks of tropospheric ozone; and (ii) Conduct laboratory studies on heterogeneous reactions involving NOy, O3 and VOCs on aerosol surfaces. These objectives were pursued through a multidisciplinary approach that combines modeling and laboratory components as discussed in more detail below. In addition, in response to the reconfiguring of the Atmospheric Science Program to focus on aerosol radiative forcing of climate, we also began to investigate the radiative properties of atmospheric aerosol.

  7. ELF electric and magnetic fields: Pacific Northwest Laboratory studies

    NASA Astrophysics Data System (ADS)

    Anderson, L. E.

    1992-06-01

    Studies were conducted at Battelle, Pacific Northwest Laboratory, to examine extremely-low-frequency (ELF) electromagnetic fields for possible biological effects in animals. Three areas of investigation are reported here: (1) studies on the nervous system, including behavior and neuroendocrine function; (2) experiments on cancer development in animals; and (3) measurements of currents and electric fields induced in animal models by exposure to external magnetic fields. In behavioral experiments, rats were shown to be responsive to ELF electric field exposure. Furthermore, experimental data indicate that short-term memory may be affected in albino rats exposed to combined ELF and static magnetic fields. Neuroendocrine studies were conducted to demonstrate an apparent stress-related response in rats exposed to 60-Hz electric fields. Nighttime pineal melatonin levels were shown to be significantly depressed in animals exposed to either electric or magnetic fields. A number of animal tumor models are currently under investigation to examine possible relationships between ELF exposure and carcinogenesis. Finally, theoretical and experimental measurements were performed which form the basis for animals and human exposure comparisons.

  8. Dynamic axle and wheel loads identification: laboratory studies

    NASA Astrophysics Data System (ADS)

    Zhu, X. Q.; Law, S. S.

    2003-12-01

    Two methods have been reported by Zhu and Law to identify moving loads on the top of a bridge deck. One is based on the exact solution (ESM) and the other is based on the finite element formulation (FEM). Simulation studies on the effect of different influencing factors have been reported previously. This paper comparatively studies the performances of these two methods with experimental measurements obtained from a bridge/vehicle system in the laboratory. The strains of the bridge deck are measured when a model car moves across the bridge deck along different paths. The moving loads on the bridge deck are identified from the measured strains using these two methods, and the responses are reconstructed from the identified loads for comparison with the measured responses to verify the performances of these methods. Studies on the identification accuracy due to the effect of the number of vibration mode used, the number of measuring points and eccentricities of travelling paths are performed. Results show that the ESM could identify the moving loads individually or as axle loads when they are travelling at an eccentricity with the sensors located close to the travelling path of the forces. And the accuracy of the FEM is dependent on the amount of measured information used in the identification.

  9. ELF electric and magnetic fields: Pacific Northwest Laboratory studies

    SciTech Connect

    Anderson, L.E.

    1992-06-01

    Studies have been conducted at Battelle, Pacific Northwest Laboratory, to examine extremely-low-frequency (ELF) electromagnetic fields for possible biological effects in animals. Three areas of investigation are reported here: (1) studies on the nervous system, including behavior and neuroendocrine function, (2) experiments on cancer development in animals, and (3) measurements of currents and electric fields induced in animal models by exposure to external magnetic fields. In behavioral experiments, rats have been shown to be responsive to ELF electric field exposure. Furthermore, experimental data indicate that short-term memory may be affected in albino rats exposed to combined ELF and static magnetic fields. Neuroendocrine studies have been conducted to demonstrate an apparent stress-related response in rats exposed to 60-Hz electric fields. Nighttime pineal melatonin levels have been shown to be significantly depressed in animals exposed to either electric or magnetic fields. A number of animal tumor models are currently under investigation to examine possible relationships between ELF exposure and carcinogenesis. Finally, theoretical and experimental measurements have been performed which form the basis for animals and human exposure comparisons.

  10. Recent laboratory studies of loudness and annoyance to sonic booms

    NASA Astrophysics Data System (ADS)

    Leatherwood, Jack D.; Sullivan, Brenda M.

    NASA Langley Research Center is supporting NASA High-Speed Research Program efforts to develop an updated technology base for future high-speed civil transport aircraft. Part of this effort involves (a) quantification of loudness and annoyance benefits due to sonic boom shaping and (b) determination of boom exposures acceptable to the public. Langley is conducting a series of laboratory studies to investigate in detail the subjective reactions to a wide range of shaped sonic boom signatures and to examine several metrics as estimators of sonic boom subjective effects. Results from several of these studies, as well as results obtained by other investigators, demonstrated that substantial reductions in the loudness of sonic booms can be achieved by careful shaping of the boom signatures. Recent Langley studies extended this work to include: (a) quantification of subjective effects due to booms heard indoors, (b) determination of subjective reactions due to ground-reflected booms, and (c) determination of subjective reactions to simulator reproductions of booms recently at White Sands Missile Range.

  11. Molecular Carbon in the Galaxy: Laboratory and Observational Studies

    NASA Technical Reports Server (NTRS)

    Saykally, Richard James

    2003-01-01

    In a collaboration with the Mats Larsson group from Stockholm, we carried out a new measurement of the rate of dissociative recombination of H(sup *, sub j), using a new pulsed supersonic beam source of rotationally cold H(sup *, sub j). This source was first designed and characterized in our lab by IR cavity ringdown spectroscopy, determining a rotationaYtranslationa1 temperature of 20-60K, depending on conditions. This new source was then taken to Stockholm for the recombination rate studies at the CRYRING storage ring. The recombination rate constant measured against temperature yields values consistent with the most recent calculations, whereas previous experimental measurements varied over a range of 10(exp 4) and were poor agreement with theory. This is a crucial achievement for understanding the ion chemistry of diffuse clouds. Moreover, this result in combination with recent observations implies a greatly enhanced (factor of 40) cosmic ray ionization rate in a diffuse cloud (zeta Persei) relative to previous studies. The implications of this are discussed in our recent Nature paper. An enhanced cosmic-ray flux towards zeta Persei inferred from a laboratory study of the H(sup *, sub j)-e(sup -) recombination rate.

  12. Laboratory study of selected personal inhalable aerosol samplers.

    PubMed

    Görner, Peter; Simon, Xavier; Wrobel, Richard; Kauffer, Edmond; Witschger, Olivier

    2010-03-01

    Assessment of inhalable dust exposure requires reliable sampling methods in order to measure airborne inhalable particles' concentrations. Many inhalable aerosol samplers can be used but their performances widely vary and remain unknown in some cases. The sampling performance of inhalable samplers is strongly dependent on particle size and ambient air velocity. Five inhalable aerosol samplers have been studied in two laboratory wind tunnels using polydisperse glass-beads' test aerosol. Samplers tested were IOM sampler (UK), two versions of CIP 10-I sampler, v1 and v2 (F), 37-mm closed face cassette sampler (USA), 37-mm cassette fitted up with an ACCU-CAP insert (USA), and Button sampler (USA). Particle size-dependent sampling efficiencies were measured in a horizontal wind tunnel under a 1 m s(-1) wind velocity and in a vertical tunnel under calm air, using a specific method with Coulter(R) counter particle size number distribution determinations. Compared with CEN-ISO-ACGIH sampling criteria for inhalable dust, the experimental results show fairly high sampling efficiency for the IOM and CIP 10-I v2 samplers and slightly lower efficiencies for the Button and CIP 10-I v1 samplers. The closed face cassette (4-mm orifice) produced the poorest performances of all the tested samplers. This can be improved by using the ACCU-CAP internal capsule, which prevents inner wall losses inside the cassette. Significant differences between moving air and calm air sampling efficiency were observed for all the studied samplers.

  13. Laboratory study of forced rotating shallow water turbulence

    NASA Astrophysics Data System (ADS)

    Espa, Stefania; Di Nitto, Gabriella; Cenedese, Antonio

    2011-12-01

    During the last three decades several authors have studied the appearance of multiple zonal jets in planetary atmospheres and in the Earths oceans. The appearance of zonal jets has been recovered in numerical simulations (Yoden & Yamada, 1993), laboratory experiments (Afanasyev & Wells, 2005; Espa et al., 2008, 2010) and in field measurements of the atmosphere of giant planets (Galperin et al., 2001). Recent studies have revealed the presence of zonation also in the Earths oceans, in fact zonal jets have been found in the outputs of Oceanic General Circulation Models-GCMs (Nakano & Hasumi, 2005) and from the analysis of satellite altimetry observations (Maximenko et al., 2005). In previous works (Espa et al., 2008, 2010) we have investigated the impact of the variation of the rotation rate and of the fluid depth on jets organization in decaying and forced regimes. In this work we show results from experiments performed in a bigger domain in which the fluid is forced continuously. The experimental set-up consists of a rotating tank (1m in diameter) where the initial distribution of vorticity has been generated via the Lorentz force in an electromagnetic cell. The latitudinal variation of the Coriolis parameter has been simulated by the parabolic profile assumed by the free surface of the rotating fluid. Flow measurements have been performed using an image analysis technique. Experiments have been performed changing the tank rotation rate and the fluid thickness. We have investigated the flow in terms of zonal and radial flow pattern, flow variability and jet scales.

  14. Software Engineering Laboratory Ada performance study: Results and implications

    NASA Technical Reports Server (NTRS)

    Booth, Eric W.; Stark, Michael E.

    1992-01-01

    The SEL is an organization sponsored by NASA/GSFC to investigate the effectiveness of software engineering technologies applied to the development of applications software. The SEL was created in 1977 and has three organizational members: NASA/GSFC, Systems Development Branch; The University of Maryland, Computer Sciences Department; and Computer Sciences Corporation, Systems Development Operation. The goals of the SEL are as follows: (1) to understand the software development process in the GSFC environments; (2) to measure the effect of various methodologies, tools, and models on this process; and (3) to identify and then to apply successful development practices. The activities, findings, and recommendations of the SEL are recorded in the Software Engineering Laboratory Series, a continuing series of reports that include the Ada Performance Study Report. This paper describes the background of Ada in the Flight Dynamics Division (FDD), the objectives and scope of the Ada Performance Study, the measurement approach used, the performance tests performed, the major test results, and the implications for future FDD Ada development efforts.

  15. Toxicogenomics concepts and applications to study hepatic effects of food additives and chemicals

    SciTech Connect

    Stierum, Rob . E-mail: stierum@voeding.tno.nl; Heijne, Wilbert; Kienhuis, Anne; Ommen, Ben van; Groten, John

    2005-09-01

    Transcriptomics, proteomics and metabolomics are genomics technologies with great potential in toxicological sciences. Toxicogenomics involves the integration of conventional toxicological examinations with gene, protein or metabolite expression profiles. An overview together with selected examples of the possibilities of genomics in toxicology is given. The expectations raised by toxicogenomics are earlier and more sensitive detection of toxicity. Furthermore, toxicogenomics will provide a better understanding of the mechanism of toxicity and may facilitate the prediction of toxicity of unknown compounds. Mechanism-based markers of toxicity can be discovered and improved interspecies and in vitro-in vivo extrapolations will drive model developments in toxicology. Toxicological assessment of chemical mixtures will benefit from the new molecular biological tools. In our laboratory, toxicogenomics is predominantly applied for elucidation of mechanisms of action and discovery of novel pathway-supported mechanism-based markers of liver toxicity. In addition, we aim to integrate transcriptome, proteome and metabolome data, supported by bioinformatics to develop a systems biology approach for toxicology. Transcriptomics and proteomics studies on bromobenzene-mediated hepatotoxicity in the rat are discussed. Finally, an example is shown in which gene expression profiling together with conventional biochemistry led to the discovery of novel markers for the hepatic effects of the food additives butylated hydroxytoluene, curcumin, propyl gallate and thiabendazole.

  16. Studying collisions in the general physics laboratory with quadrature light emitting diode sensors

    NASA Astrophysics Data System (ADS)

    DeYoung, P. A.; Mulder, B.

    2002-12-01

    We have developed the means to measure position rapidly and precisely as a function of time in the general physics laboratory. These measurements are of sufficient quality that velocities and accelerations can be calculated from the position data using numerical derivatives. The precision of the measurements is such that any disagreement between theoretical expectations and experimental measurements is less than a few percent. Measurements of the system under study can be made as rapidly as every 200 μs, which is faster than the typical time scales over which the system changes. Measuring rapidly also allows one to investigate additional phenomena not previously accessible and to see features of the physics previously unobserved. The measurement system is based on commercially available sensors, computer hardware, and computer software (LABVIEW™). Many general physics laboratories based on this system have been developed but only an investigation of Newton's second law will be described here.

  17. The Study of a Cobalt Complex--A Laboratory Project.

    ERIC Educational Resources Information Center

    Loehlin, James H.; And Others

    1982-01-01

    Describes an 8-week project involving the synthesis of cobalt compounds. Once synthesized, compounds are qualitatively and quantitatively analyzed. Background information, laboratory procedures, and results/discussion are provided for three project experiments. (Author/JN)

  18. Rearing and Maintaining Midge Cultures (Chironomus tentans) for Laboratory Studies.

    ERIC Educational Resources Information Center

    Hein, John; Mahadeva, Madhu N.

    1992-01-01

    The life history of the Chironomus tentans can be observed in easily established and maintained laboratory cultures. Projects for the classroom include observing hydration of an egg mass; embryonic development, hatching and larval feeding; larval activity; and mating activity. (MDH)

  19. Analytical study of the Atmospheric Cloud Physics Laboratory (ACPL) experiments

    NASA Technical Reports Server (NTRS)

    Davis, M. H.

    1977-01-01

    The design specifications of the research laboratory as a Spacelab facility are discussed along with the types of planned experiments. These include cloud formation, freezing and scavenging, and electrical phenomena. A summary of the program conferences is included.

  20. A Laboratory Study of X-to-Frequency Converters.

    ERIC Educational Resources Information Center

    Kartalopoulos, Stamatios V.

    1979-01-01

    Describes a laboratory demonstration that can be used to convert an analog quantity into frequency, which can then be converted into a binary measure using either an oscilloscope or a frequency counter. (MA)

  1. 21 CFR 58.185 - Reporting of nonclinical laboratory study results.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 1 2014-04-01 2014-04-01 false Reporting of nonclinical laboratory study results. 58.185 Section 58.185 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES GENERAL GOOD LABORATORY PRACTICE FOR NONCLINICAL LABORATORY STUDIES Records and Reports §...

  2. 21 CFR 58.130 - Conduct of a nonclinical laboratory study.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 1 2012-04-01 2012-04-01 false Conduct of a nonclinical laboratory study. 58.130 Section 58.130 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES GENERAL GOOD LABORATORY PRACTICE FOR NONCLINICAL LABORATORY STUDIES Protocol for and Conduct of...

  3. 21 CFR 58.185 - Reporting of nonclinical laboratory study results.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 1 2011-04-01 2011-04-01 false Reporting of nonclinical laboratory study results. 58.185 Section 58.185 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES GENERAL GOOD LABORATORY PRACTICE FOR NONCLINICAL LABORATORY STUDIES Records and Reports §...

  4. 21 CFR 58.185 - Reporting of nonclinical laboratory study results.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 1 2010-04-01 2010-04-01 false Reporting of nonclinical laboratory study results. 58.185 Section 58.185 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES GENERAL GOOD LABORATORY PRACTICE FOR NONCLINICAL LABORATORY STUDIES Records and Reports §...

  5. 21 CFR 58.130 - Conduct of a nonclinical laboratory study.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... GENERAL GOOD LABORATORY PRACTICE FOR NONCLINICAL LABORATORY STUDIES Protocol for and Conduct of a... date of collection. This information shall be located on the specimen container or shall accompany...

  6. Changes in water, carbon, and nitrogen fluxes with the addition of biochar to soils: lessons learned from laboratory and greenhouse experiments

    NASA Astrophysics Data System (ADS)

    Barnes, R. T.; Gallagher, M. E.; Masiello, C. A.; Liu, Z.; Dugan, B.; Rudgers, J. A.

    2011-12-01

    The addition of biochar to agricultural soils has the potential to provide a number of ecosystem services, ranging from carbon (C) sequestration to increased soil fertility and crop production. It is estimated that 0.5 to 0.9 Pg of C yr-1 can be sequestered through the addition of biochar to soils, significantly increasing the charcoal flux to the biosphere over natural inputs from fire (0.05 to 0.20 Pg C yr-1). There remain large uncertainties about biochar mobility within the environment, making it a challenge to assess the ecosystem residence time of biochar. We conducted laboratory and greenhouse experiments to understand how soil amendment with laboratory-produced biochar changes water, C, and nitrogen (N) fluxes from soils. We used column experiments to assess how biochar amendment to three types of soils (sand, organic, clay-rich) affected hydraulic conductivity and dissolved organic carbon (DOC) and total dissolved nitrogen (TDN) fluxes. Results varied with soil type; biochar significantly decreased the hydraulic conductivity of the sand and organic soils by a factor of 10.6 and 2.7, respectively. While not statistically significant, biochar addition increased the hydraulic conductivity of the clay-rich soil by 50% on average. The addition of biochar significantly increased the DOC fluxes from the C-poor sand and clay soils while it significantly decreased the DOC flux from the organic-rich soil. In contrast, TDN fluxes decreased with biochar additions from all soil types, though the results were not statistically significant from the clay-rich soil. These laboratory experiments suggest that changes in the hydraulic conductivity of soil due to biochar amendments could play a significant role in understanding how biochar additions to agricultural fields will change watershed C and N dynamics. We additionally conducted a 28-day greenhouse experiment with sorghum plants using a three-way factorial treatment (water availability x biochar x mycorrhizae) to

  7. Laboratory studies of aeolian sediment transport processes on planetary surfaces

    NASA Astrophysics Data System (ADS)

    Rasmussen, Keld R.; Valance, Alexandre; Merrison, Jonathan

    2015-09-01

    We review selected experimental saltation studies performed in laboratory wind tunnels and collision experiments performed in (splash-) laboratory facilities that allow detailed observations between impinging particles on a stationary bed. We also discuss progress in understanding aeolian transport in nonterrestrial environments. Saltation studies in terrestrial wind tunnels can be divided into two groups. The first group comprises studies using a short test bed, typically 1-4 m long, and focuses on the transitional behavior near the upwind roughness discontinuity where saltation starts. The other group focuses on studies using long test beds - typically 6 m or more - where the saturated saltation takes place under equilibrium conditions between wind flow and the underlying rough bed. Splash studies using upscaled model experiments allow collision simulations with large spherical particles to be recorded with a high speed video camera. The findings indicate that the number of ejected particles per impact scales linearly with the impact velocity of the saltating particles. Studies of saturated saltation in several facilities using predominantly Particle Tracking Velocimetry or Laser Doppler Velocimetry indicate that the velocity of the (few) particles having high trajectories increases with increasing friction velocity. However, the speed of the majority of particles that do not reach much higher than Bagnold's focal point is virtually independent of Shields parameter - at least for low or intermediate u*-values. In this case mass flux depends on friction velocity squared and not cubed as originally suggested by Bagnold. Over short beds particle velocity shows stronger dependence on friction velocity and profiles of particle velocity deviate from those obtained over long beds. Measurements using horizontally segmented traps give average saltation jump-lengths near 60-70 mm and appear to be only weakly dependent on friction velocity, which is in agreement with some

  8. Laboratory study of the underground sound generated by debris flows

    NASA Astrophysics Data System (ADS)

    Huang, Ching-Jer; Shieh, Chieng-Lun; Yin, Hsiao-Yuan

    2004-03-01

    This experimental study investigates the underground sound generated by different kinds of rock motions that occur in debris flows. The experiments were divided into two parts. The first part consisted of measuring the main characteristics of the underground sound caused by friction of a rock rubbed against a bed of gravel and of that caused by a free-falling rock hitting a similar bed of gravel. In the second part a hydrophone was installed at the bottom of a laboratory channel to measure the underground sound of debris flows in that channel. The sound signals were analyzed using both the fast Fourier transform and the Gabor transform to represent the signals in both the frequency and time-frequency domains. The measurement results reveal that the frequency of the sound generated by the rock-gravel bed friction is relatively low, being mostly between 20 and 80 Hz. In contrast, the frequency range of the collision sound is relatively higher, between 10 and 500 Hz. Finally, the frequency of the underground sound caused by the debris flows in the flume is in the range of 20-300 Hz.

  9. A laboratory study on groundwater quality and mass movement occurrence

    NASA Astrophysics Data System (ADS)

    Fan, Jen-Chen; Liu, Che-Hsin; Yang, Chih-Hsiang; Huang, Hsiao-Yu

    2009-06-01

    In this study, soil samples collected from the sides of two streams with high debris flow potential at Shenmu and Fengchiou village in Nantou County, Taiwan, were used for seepage tank tests in the laboratory. While the tests were being conducted, observations were made to investigate the relationships among displacement of the slope, quality of the seepage water and occurrence of mass movement. The results showed that according to the change rate, displacement could be divided into two stages, namely, the initial failure displacement stage and primary failure displacement stage. While the displacement of the slope was in primary failure displacement stages, the probability of slope failure became much higher. Before general slope failure, electrical conductivity (EC) and sulfate ion (SO4 2-) concentration of the seepage water increased significantly. The time when EC of the seepage water started to increase rapidly was much earlier than that when displacement of the slope started to increase significantly. Therefore, from the hazard mitigation view, there will be a longer time for response if EC of the seepage water was monitored.

  10. Methanogenic Hydrocarbon Degradation: Evidence from Field and Laboratory Studies.

    PubMed

    Jiménez, Núria; Richnow, Hans H; Vogt, Carsten; Treude, Tina; Krüger, Martin

    2016-01-01

    Microbial transformation of hydrocarbons to methane is an environmentally relevant process taking place in a wide variety of electron acceptor-depleted habitats, from oil reservoirs and coal deposits to contaminated groundwater and deep sediments. Methanogenic hydrocarbon degradation is considered to be a major process in reservoir degradation and one of the main processes responsible for the formation of heavy oil deposits and oil sands. In the absence of external electron acceptors such as oxygen, nitrate, sulfate or Fe(III), fermentation and methanogenesis become the dominant microbial metabolisms. The major end product under these conditions is methane, and the only electron acceptor necessary to sustain the intermediate steps in this process is CO2, which is itself a net product of the overall reaction. We are summarizing the state of the art and recent advances in methanogenic hydrocarbon degradation research. Both the key microbial groups involved as well as metabolic pathways are described, and we discuss the novel insights into methanogenic hydrocarbon-degrading populations studied in laboratory as well as environmental systems enabled by novel cultivation-based and molecular approaches. Their possible implications on energy resources, bioremediation of contaminated sites, deep-biosphere research, and consequences for atmospheric composition and ultimately climate change are also addressed.

  11. Asymmetry of wind waves studied in a laboratory tank

    NASA Astrophysics Data System (ADS)

    Leykin, I. A.; Donelan, M. A.; Mellen, R. H.; McLaughlin, D. J.

    Asymmetry of wind waves was studied in laboratory tank tinder varied wind and fetch conditions using both bispectral analysis of wave records and third-order statistics of the surface elevation. It is found skewness S (the normalized third-order moment of surface elevation describing the horizontal asymmetry waves) varies only slightly with the inverse wave u*/Cm (where u* is the air friction velocity and Cm is phase speed of the dominant waves). At the same time asymmetry A, which is determined from the Hilbert transform of the wave record and characterizes the skewness of the rate of change of surface elevation, increase consistently in magnitude with the ratio u*/Cm. This suggests that nonlinear distortion of the wave profile determined by the degree of wind forcing and is a sensitive indicator of wind-wave interaction processes. It is shown that the asymmetric profile of waves can described within the frameworks of the nonlinear nonspectral concept (Plate, 1972; Lake and Yuen, 197 according to which the wind-wave field can be represented as a coherent bound-wave system consisting mainly of dominant component w. and its harmonics propagating with the same speed C. , as observed by Ramamonjiaris and Coantic (1976). The phase shift between o). harmonics is found and shown to increase with the asymmetry of the waves.

  12. Asymmetry of wind waves studied in a laboratory tank

    NASA Astrophysics Data System (ADS)

    Ileykin, L. A.; Donelan, M. A.; Mellen, R. H.; McLaughlin, D. J.

    1995-03-01

    Asymmetry of wind waves was studied in laboratory tank tinder varied wind and fetch conditions using both bispectral analysis of wave records and third-order statistics of the surface elevation. It is found skewness S (the normalized third-order moment of surface elevation describing the horizontal asymmetry waves) varies only slightly with the inverse wave u*/Cm (where u* is the air friction velocity and Cm is phase speed of the dominant waves). At the same time asymmetry A, which is determined from the Hilbert transform of the wave record and characterizes the skewness of the rate of change of surface elevation, increase consistently in magnitude with the ratio u*/Cm. This suggests that nonlinear distortion of the wave profile determined by the degree of wind forcing and is a sensitive indicator of wind-wave interaction processes. It is shown that the asymmetric profile of waves can described within the frameworks of the nonlinear nonspectral concept (Plate, 1972; Lake and Yuen, 197 according to which the wind-wave field can be represented as a coherent bound-wave system consisting mainly of dominant component w. and its harmonics propagating with the same speed C. , as observed by Ramamonjiaris and Coantic (1976). The phase shift between o). harmonics is found and shown to increase with the asymmetry of the waves.

  13. Napping: A public health issue. From epidemiological to laboratory studies.

    PubMed

    Faraut, Brice; Andrillon, Thomas; Vecchierini, Marie-Françoise; Leger, Damien

    2016-09-13

    Sleep specialists have proposed measures to counteract the negative short- and long-term consequences of sleep debt, and some have suggested the nap as a potential and powerful "public health tool". Here, we address this countermeasure aspect of napping viewed as an action against sleep deprivation rather than an action associated with poor health. We review the physiological functions that have been associated positively with napping in both public health and clinical settings (sleep-related accidents, work and school, and cardiovascular risk) and in laboratory-based studies with potential public health issues (cognitive performance, stress, immune function and pain sensitivity). We also discuss the circumstances in which napping-depending on several factors, including nap duration, frequency, and age-could be a potential public health tool and a countermeasure for sleep loss in terms of reducing accidents and cardiovascular events and improving sleep-restriction-sensitive working performance. However, the impact of napping and the nature of the sleep stage(s) involved still need to be evaluated, especially from the perspective of coping strategies in populations with chronic sleep debt, such as night and shift workers.

  14. ER-2: Flying Laboratory for Earth Science Studies

    NASA Technical Reports Server (NTRS)

    Navarro, Robert

    2007-01-01

    The National Aeronautics and Space Administration (NASA) Dryden Flight Research Center (DFRC), (Edwards, California, USA) has two Lockheed Martin Corporation (Bethesda, Maryland) Earth Research-2 (ER-2) aircraft that serve as high-altitude and long-range flying laboratories. The ER-2 has been utilized to conduct scientific studies of stratospheric and tropospheric chemistry, land-use mapping, disaster assessment, preliminary testing and calibration and validation of satellite sensors. The ER-2 aircraft provides experimenters with a wide array of payload accommodation areas with suitable environment control with required electrical and mechanical interfaces. Missions may be flown out of DFRC or from remote bases worldwide. The NASA ER-2 is utilized by a variety of customers, including U.S. Government agencies, civilian organizations, universities, and state governments. The combination of the ER-2 s range, endurance, altitude, payload power, payload volume and payload weight capabilities complemented by a trained maintenance and operations team provides an excellent and unique platform system to the science community.

  15. Field and Laboratory Studies of Atmospheric Organic Aerosol

    NASA Astrophysics Data System (ADS)

    Coggon, Matthew Mitchell

    This thesis is the culmination of field and laboratory studies aimed at assessing processes that affect the composition and distribution of atmospheric organic aerosol. An emphasis is placed on measurements conducted using compact and high-resolution Aerodyne Aerosol Mass Spectrometers (AMS). The first three chapters summarize results from aircraft campaigns designed to evaluate anthropogenic and biogenic impacts on marine aerosol and clouds off the coast of California. Subsequent chapters describe laboratory studies intended to evaluate gas and particle-phase mechanisms of organic aerosol oxidation. The 2013 Nucleation in California Experiment (NiCE) was a campaign designed to study environments impacted by nucleated and/or freshly formed aerosol particles. Terrestrial biogenic aerosol with > 85% organic mass was observed to reside in the free troposphere above marine stratocumulus. This biogenic organic aerosol (BOA) originated from the Northwestern United States and was transported to the marine atmosphere during periodic cloud-clearing events. Spectra recorded by a cloud condensation nuclei counter demonstrated that BOA is CCN active. BOA enhancements at latitudes north of San Francisco, CA coincided with enhanced cloud water concentrations of organic species such as acetate and formate. Airborne measurements conducted during the 2011 Eastern Pacific Emitted Aerosol Cloud Experiment (E-PEACE) were aimed at evaluating the contribution of ship emissions to the properties of marine aerosol and clouds off the coast of central California. In one study, analysis of organic aerosol mass spectra during periods of enhanced shipping activity yielded unique tracers indicative of cloud-processed ship emissions (m/z 42 and 99). The variation of their organic fraction (f42 and f 99) was found to coincide with periods of heavy (f 42 > 0.15; f99 > 0.04), moderate (0.05 < f42 < 0.15; 0.01 < f99 < 0.04), and negligible (f42 < 0.05; f99 < 0.01) ship influence. Application of

  16. Laboratory standardizatin in an international study: the Kaunas--Rotterdam intervention study (KRIS).

    PubMed

    Boerma, G J; Toleikis, A; Mather, A; Bartels, C T; Margeviciene, L; Glasunov, I S; Leijnse, B

    1978-07-01

    Laboratory results obtained in different laboratories over lengthy periods of time usually are difficult to compare. In cooperative long-term studies where such results must be pooled, thorough standardization of methods is vital. We describe a program in which comparable plasma cholesterol and glucose analyses have been obtained, by simple methods. In the Netherlands and the Soviet Union in close collaboration with the Center for Disease Control, Atlanta, Ga., U.S.A. The two laboratories produced glucose values (direct o-toluidine reaction) within 2% of the target reference values and cholesterol results (direct Liebermann-Burchard reaction) with a consistent 6-8% positive bias over the reference method values. Intralaboratory precision was subject to preset acceptance limits. The use of common control materials, exchange of patient samples, and on-site comparison of all details of laboratory procedures are vital tools in standardization efforts. A laboratory protocol that included quality requirements and rejection criteria was developed and proved to be indispensable. The experience gained should be useful in standardizing inter-laboratory results in similar studies.

  17. NGSI student activities in open source information analysis in support of the training program of the U.S. DOE laboratories for the entry into force of the additional protocol

    SciTech Connect

    Sandoval, M Analisa; Uribe, Eva C; Sandoval, Marisa N; Boyer, Brian D; Stevens, Rebecca S

    2009-01-01

    In 2008 a joint team from Los Alamos National Laboratory (LANL) and Brookhaven National Laboratory (BNL) consisting of specialists in training of IAEA inspectors in the use of complementary access activities formulated a training program to prepare the U.S. Doe laboratories for the entry into force of the Additional Protocol. As a major part of the support of the activity, LANL summer interns provided open source information analysis to the LANL-BNL mock inspection team. They were a part of the Next Generation Safeguards Initiative's (NGSI) summer intern program aimed at producing the next generation of safeguards specialists. This paper describes how they used open source information to 'backstop' the LANL-BNL team's effort to construct meaningful Additional Protocol Complementary Access training scenarios for each of the three DOE laboratories, Lawrence Livermore National Laboratory, Idaho National Laboratory, and Oak Ridge National Laboratory.

  18. Summary of Previous Chamber or Controlled Anthrax Studies and Recommendations for Possible Additional Studies

    SciTech Connect

    Piepel, Gregory F.; Amidan, Brett G.; Morrow, Jayne B.

    2010-12-29

    This report and an associated Excel file(a) summarizes the investigations and results of previous chamber and controlled studies(b) to characterize the performance of methods for collecting, storing and/or transporting, extracting, and analyzing samples from surfaces contaminated by Bacillus anthracis (BA) or related simulants. This report and the Excel are the joint work of the Pacific Northwest National Laboratory (PNNL) and the National Institute of Standards and Technology (NIST) for the Department of Homeland Security, Science and Technology Directorate. The report was originally released as PNNL-SA-69338, Rev. 0 in November 2009 with limited distribution, but was subsequently cleared for release with unlimited distribution in this Rev. 1. Only minor changes were made to Rev. 0 to yield Rev. 1. A more substantial update (including summarizing data from other studies and more condensed summary tables of data) is underway

  19. Knowledge Retention for Computer Simulations: A study comparing virtual and hands-on laboratories

    NASA Astrophysics Data System (ADS)

    Croom, John R., III

    The use of virtual laboratories has the potential to change physics education. These low-cost, interactive computer activities interest students, allow for easy setup, and give educators a way to teach laboratory based online classes. This study investigated whether virtual laboratories could replace traditional hands-on laboratories and whether students could retain the same long-term knowledge in virtual laboratories as compared to hands-on laboratories. This study is a quantitative quasi-experiment that used a multiple posttest design to determine if students using virtual laboratories would retain the same knowledge as students who performed hands-on laboratories after 9 weeks. The study was composed of 336 students from 14 school districts. Students had their performances on the laboratories and their retention of the laboratories compared to a series of factors that might have affected their retention using a pretest and two posttests, which were compared using a t test. The results showed no significant difference in short-term learning between the hands-on laboratory groups and virtual laboratory groups. There was, however, a significant difference (p = .005) between the groups in long-term retention; students in the hands-on laboratory groups retained more information than those in the virtual laboratory groups. These results suggest that long-term learning is enhanced when a laboratory contains a hands-on component. Finally, the results showed that both groups of students felt their particular laboratory style was superior to the alternative method. The findings of this study can be used to improve the integration of virtual laboratories into science curriculum.

  20. Laboratory-lysimeter studies of dry FGD wastes from tests of the Coolside technology

    SciTech Connect

    Taulbee, D.N.; Schram, W.H.; Thomas, G.A.; Rathbone, R.F.; Robl, T.L.

    1996-12-31

    Twenty two laboratory lysimeters were monitored for 12 months in an effort to characterize the leaching behavior of dry flue-gas desulfurization wastes generated during tests of the Coolside duct-injection Technology. Included were samples from Ohio Edison`s 1990 demonstration runs conducted at its Edgewater power plant and materials derived from runs conducted in CONSOL`s Coolside pilot plant. The primary objective of the study was to generate predictive information on leaching behavior of Coolside wastes. In addition, the test matrix was designed to examine the impact of various parameters including (1)lysimeter packing density, (2) use of a constant vs rain simulation method of water addition, (3) variation in the extent of prehydration of the wastes prior to loading, and (4) exposure to elevated levels of CO{sub 2} during the study. The relationships between these latter parameters and leachate characteristics are discussed.

  1. Pinon Pine Tree Study, Los Alamos National Laboratory: Source document

    SciTech Connect

    P. R. Fresquez; J. D. Huchton; M. A. Mullen; L. Naranjo, Jr.

    2000-01-01

    One of the dominant tree species growing within and around Los Alamos National Laboratory (LANL), Los Alamos, NM, lands is the pinon pine (Pinus edulis) tree. Pinon pine is used for firewood, fence posts, and building materials and is a source of nuts for food--the seeds are consumed by a wide variety of animals and are also gathered by people in the area and eaten raw or roasted. This study investigated the (1) concentration of {sup 3}H, {sup 137}Cs, {sup 90}Sr, {sup tot}U, {sup 238}Pu, {sup 239,240}Pu, and {sup 241}Am in soils (0- to 12-in. [31 cm] depth underneath the tree), pinon pine shoots (PPS), and pinon pine nuts (PPN) collected from LANL lands and regional background (BG) locations, (2) concentrations of radionuclides in PPN collected in 1977 to present data, (3) committed effective dose equivalent (CEDE) from the ingestion of nuts, and (4) soil to PPS to PPN concentration ratios (CRs). Most radionuclides, with the exception of {sup 3}H in soils, were not significantly higher (p < 0.10) in soils, PPS, and PPN collected from LANL as compared to BG locations, and concentrations of most radionuclides in PPN from LANL have decreased over time. The maximum net CEDE (the CEDE plus two sigma minus BG) at the most conservative ingestion rate (10 lb [4.5 kg]) was 0.0018 mrem (0.018 {micro}Sv). Soil-to-nut CRs for most radionuclides were within the range of default values in the literature for common fruits and vegetables.

  2. Soil erosion-runoff relationships: insights from laboratory studies

    NASA Astrophysics Data System (ADS)

    Mamedov, Amrakh; Warrington, David; Levy, Guy

    2016-04-01

    Understanding the processes and mechanisms affecting runoff generation and subsequent soil erosion in semi-arid regions is essential for the development of improved soil and water conservation management practices. Using a drip type laboratory rain simulator, we studied runoff and soil erosion, and the relationships between them, in 60 semi-arid region soils varying in their intrinsic properties (e.g., texture, organic matter) under differing extrinsic conditions (e.g., rain properties, and conditions prevailing in the field soil). Both runoff and soil erosion were significantly affected by the intrinsic soil and rain properties, and soil conditions within agricultural fields or watersheds. The relationship between soil erosion and runoff was stronger when the rain kinetic energy was higher rather than lower, and could be expressed either as a linear or exponential function. Linear functions applied to certain limited cases associated with conditions that enhanced soil structure stability, (e.g., slow wetting, amending with soil stabilizers, minimum tillage in clay soils, and short duration exposure to rain). Exponential functions applied to most of the cases under conditions that tended to harm soil stability (e.g., fast wetting of soils, a wide range of antecedent soil water contents and rain kinetic energies, conventional tillage, following biosolid applications, irrigation with water of poor quality, consecutive rain simulations). The established relationships between runoff and soil erosion contributed to a better understanding of the mechanisms governing overland flow and soil loss, and could assist in (i) further development of soil erosion models and research techniques, and (ii) the design of more suitable management practices for soil and water conservation.

  3. Recent Results from a Laboratory Study of Charging Mechanisms in a Dusty Plasma

    NASA Technical Reports Server (NTRS)

    Venturini, Catherine C.; Spann, James F., Jr.; Comfort, Richard H.

    1998-01-01

    A laboratory investigation has been developed to experimentally study the interaction of micron sized particles with plasmas and electromagnetic radiation. The intent is to investigate under what conditions particles of various compositions and sizes become charged, or discharged, while exposed to an electron beam and UV radiation. This investigation uses a unique laboratory technique known as electrodynamic suspension of particles. Here, a single charged micron size particle is suspended in a quadrupole trap and then subjected to a controlled environment. In this paper, we will discuss recent results from this experiment in which different materials including polystyrene and aluminum oxide, and sizes ranging from 10 microns to 1 micron have been used to determine charge to mass ratios and then subjected to an electron beam and /or UV radiation. In each instance, the particle's charge as well as beam current flux and radiation intensity flux is measured. These results will be compared with initial results using salt crystals. It was found that a negatively charged salt crystal exposed for 30 minutes to a 500 eV electron beam with primary electron beam current of -3.06 x 10(exp -5) picoamps yielded a secondary electron current of 3.23 x 10(exp -5) picoamps. Additionally, the particle was observed to be steadily losing charge over this time interval. By studying the microphysics of one particle, a better understanding of theoretical models and other laboratory results associated with particle charging mechanisms can be achieved.

  4. Laboratory study of effects of sonic boom shaping on subjective loudness and acceptability

    NASA Technical Reports Server (NTRS)

    Leatherwood, Jack D.; Sullivan, Brenda M.

    1992-01-01

    A laboratory study was conducted to determine the effects of sonic boom signature shaping on subjective loudness and acceptability. The study utilized the sonic boom simulator at the Langley Research Center. A wide range of symmetrical, front-shock-minimized signature shapes were investigated together with a limited number of asymmetrical signatures. Subjective loudness judgments were obtained from 60 test subjects by using an 11-point numerical category scale. Acceptability judgments were obtained using the method of constant stimuli. Results were used to assess the relative predictive ability of several noise metrics, determine the loudness benefits of detailed boom shaping, and derive laboratory sonic boom acceptability criteria. These results indicated that the A-weighted sound exposure level, the Stevens Mark 7 Perceived Level, and the Zwicker Loudness Level metrics all performed well. Significant reductions in loudness were obtained by increasing front-shock rise time and/or decreasing front-shock overpressure of the front-shock minimized signatures. In addition, the asymmetrical signatures were rated to be slightly quieter than the symmetrical front-shock-minimized signatures of equal A-weighted sound exposure level. However, this result was based on a limited number of asymmetric signatures. The comparison of laboratory acceptability results with acceptability data obtained in more realistic situations also indicated good agreement.

  5. Microbial Evolution at High Pressure: Deep Sea and Laboratory Studies

    NASA Astrophysics Data System (ADS)

    Bartlett, D. H.

    2011-12-01

    Elevated hydrostatic pressures are present in deep-sea and deep-Earth environments where this physical parameter has influenced the evolution and characteristics of life. Piezophilic (high-pressure-adapted) microbes have been isolated from diverse deep-sea settings, and would appear likely to occur in deep-subsurface habitats as well. In order to discern the factors enabling life at high pressure my research group has explored these adaptations at various levels, most recently including molecular analyses of deep-sea trench communities, and through the selective evolution of the model microbe Escherichia coli in the laboratory to progressively higher pressures. Much of the field work has focused on the microbes present in the deeper portions of the Puerto Rico Trench (PRT)and in the Peru-Chile Trench (PCT), from 6-8.5 km below the sea surface (~60-85 megapascals pressure). Culture-independent phylogenetic data on the Bacteria and Archaea present on particles or free-living, along with data on the microeukarya present was complemented with genomic analyses and the isolation and characterization of microbes in culture. Metagenomic analyses of the PRT revealed increased genome sizes and an overrepresentation at depth of sulfatases for the breakdown of sulfated polysaccharides and specific categories of transporters, including those associated with the transport of diverse cations or carboxylate ions, or associated with heavy metal resistance. Single-cell genomic studies revealed several linneages which recruited to the PRT metagenome far better than existing marine microbial genome sequences. analyses. Novel high pressure culture approaches have yielded new piezophiles including species preferring very low nutrient levels, those living off of hydrocarbons, and those adapted to various electron donor/electron acceptor combinations. In order to more specifically focus on functions enabling life at increased pressure selective evolution experiments were performed with

  6. A Study of the Effectiveness of the Instructional Systems Laboratory.

    ERIC Educational Resources Information Center

    Philipson, Will D.; Chan-Tam, Pik Wai

    A survey examined perception and use of the services of the Instructional Systems Laboratory (ISL) by the faculty of the University of Minnesota's College of Education. The questionnaire, mailed to all College of Education faculty members, emphasized faculty perception of instructional systems in the following areas: (1) instructional commitment:…

  7. Do Laboratory Tests Predict Everyday Memory? A Neuropsychological Study.

    ERIC Educational Resources Information Center

    Sunderland, Alan; And Others

    1983-01-01

    The relationship between memory performance in everyday life and performance on laboratory tests was investigated with normal-memory and previously severely head-injured subjects. Correlation of the two test types was found in normal-memory and long-term head-injured, but not with the recently-injured. Highest correlations were with prose recall…

  8. Tethered variable gravity laboratory study: Low gravity process identification report

    NASA Technical Reports Server (NTRS)

    Briccarello, M.

    1989-01-01

    Experiments are described performable in the variable gravity environment, and the related compatible/beneficial residual accelerations, both for pure and applied research in the fields of Fluid Mechanics (static and dynamic), Materials Sciences (Crystal Growth, Metal and Alloy Solidification, Glasses, etc.), and Life Sciences, so as to assess the relevance of a variable G-level laboratory.

  9. Waste management study: Process development at Lawrence Livermore National Laboratory

    SciTech Connect

    Not Available

    1984-12-01

    This report presents the results of an evaluation of the present Toxic Waste Control Operations at the Lawrence Livermore National Laboratory, evaluates the technologies most applicable to the treatment of toxic and hazardous wastes and presents conceptual designs of processes for the installation of a new decontamination and waste treatment facility (DWTF) for future treatment of these wastes.

  10. The Study of Biobehavioral Rhythms in a Psychology Laboratory Course.

    ERIC Educational Resources Information Center

    Rowland, David L.; Wesselhoft, Theresa

    1998-01-01

    Reports on a laboratory experiment where students measured their heart rate, blood pressure, mood, alertness, and cognitive performance. Measures showed significant circadian heart rhythm variations. They were strongly correlated and peaked at different times. Discusses the implications of this and students' reactions to the experiment. (MJP)

  11. An Undergraduate Laboratory Exercise for Studying Kinetics of Batch Crystallization

    ERIC Educational Resources Information Center

    Louhi­-Kultanen, Marjatta; Han, Bing; Nurkka, Annikka; Hatakka, Henry

    2015-01-01

    The present work describes an undergraduate laboratory exercise for improving understanding of fundamental phenomena in cooling crystallization. The exercise of nucleation and crystal growth kinetics supports learning of theories and models presented in lectures and calculation exercises. The teaching methodology incorporates precepts the…

  12. Chronic cyanide exposure: a clinical, radioisotope, and laboratory study.

    PubMed Central

    El Ghawabi, S H; Gaafar, M A; El-Saharti, A A; Ahmed, S H; Malash, K K; Fares, R

    1975-01-01

    The effect of chronic cyanide exposure in the electroplating sections of three factories employing 36 workers was studied and compared with a control group. The concentration of cyanides to which the workers were exposed was measured. The regression line showing the relationship between thiocyanates in urine and the concentration of cyanides in the air was plotted. Increased percentages of haemoglobin and lymphocyte count were present in all exposed workers, in addition to punctate basophilia in 28 workers. Cyanmethaemoglobin was found to be characteristic. Apart from other complaints, two men with psychosis similar to one case reported in therapeutic thiocyanate intoxication were found. Twenty of the workers had thyroid enlargements to a variable degree and consistency, in two of whom it resembled lymphadenoid goitre. Thyroid 131I uptakes at 4 and 24 hours were significantly higher than in the controls, while 131PBI was unchanged. The reason for this iodine deficiency-like action is discussed. PMID:1156569

  13. Laboratory studies of imitation/field studies of tradition: towards a synthesis in animal social learning.

    PubMed

    Galef, Bennett G

    2015-03-01

    Here I discuss: (1) historical precedents that have resulted in comparative psychologists accepting the two-action method as the "gold standard" in laboratory investigations of imitation learning, (2) evidence suggesting that the two-action procedure may not be adequate to answer questions concerning the role of imitation in the development of traditional behaviors of animals living in natural habitat, and (3) an alternative approach to the laboratory study of imitation that might increase the relevance of laboratory studies of imitation to the work of behavioral ecologists/primatologists interested in animal traditions and their relationship to human cumulative culture. This article is part of a Special Issue entitled: Tribute to Tom Zentall.

  14. SENIORLAB: a prospective observational study investigating laboratory parameters and their reference intervals in the elderly

    PubMed Central

    Risch, Martin; Nydegger, Urs; Risch, Lorenz

    2017-01-01

    Abstract Background: In clinical practice, laboratory results are often important for making diagnostic, therapeutic, and prognostic decisions. Interpreting individual results relies on accurate reference intervals and decision limits. Despite the considerable amount of resources in clinical medicine spent on elderly patients, accurate reference intervals for the elderly are rarely available. The SENIORLAB study set out to determine reference intervals in the elderly by investigating a large variety of laboratory parameters in clinical chemistry, hematology, and immunology. Methods/design: The SENIORLAB study is an observational, prospective cohort study. Subjectively healthy residents of Switzerland aged 60 years and older were included for baseline examination (n = 1467), where anthropometric measurements were taken, medical history was reviewed, and a fasting blood sample was drawn under optimal preanalytical conditions. More than 110 laboratory parameters were measured, and a biobank was set up. The study participants are followed up every 3 to 5 years for quality of life, morbidity, and mortality. The primary aim is to evaluate different laboratory parameters at age-related reference intervals. The secondary aims of this study include the following: identify associations between different parameters, identify diagnostic characteristics to diagnose different circumstances, identify the prevalence of occult disease in subjectively healthy individuals, and identify the prognostic factors for the investigated outcomes, including mortality. Discussion: To obtain better grounds to justify clinical decisions, specific reference intervals for laboratory parameters of the elderly are needed. Reference intervals are obtained from healthy individuals. A major obstacle when obtaining reference intervals in the elderly is the definition of health in seniors because individuals without any medical condition and any medication are rare in older adulthood. Reference

  15. Study of the atmospheric chemistry of radon progeny in laboratory and real indoor atmospheres

    SciTech Connect

    Hopke, P.K.

    1990-01-01

    The chemical and physical behavior of the {sup 218}Po atom immediately following its formation by the alpha decay of radon must be understood if the exposure to radon progeny is to be fully assessed. Two areas of radon progeny behavior will be studied; laboratory studies and studies in actual indoor environments. Laboratory studies include: Measure the neutralization rate of {sup 218}Po{sup +}{sub x} in O{sub 2} at low radon concentrations. Determine the formation rates of {center dot}OH, {center dot}O, or other oxidative radicals formed by the radiolysis of air following radon decay. Examine the formation of particles by the radiolytic oxidation of substances and measure the rate of ion-induced nucleation in the sulfuric acid-water vapor system with and without NH{sub 3} additions using a thermal diffusion cloud chamber. Exposure studies include: Initiate measurements of the activity size distribution in actual homes with occupants present; Initiate a prospective study of the utility of measurement of deposited {sup 210}Pb embedded in glass surfaces as a measure of the long-term, integrated exposure of the population to radon, and acquire the components and begin to develop the methodology to determine the hygroscopicity of the indoor aerosol.

  16. Analysis of degradation in UHMWPE a comparative study among the various commercial and laboratory grades UHMWPE

    NASA Astrophysics Data System (ADS)

    Azam, A. M.; Ali, A.; Khan, H.; Yasin, T.; Mehmood, M. S.

    2016-08-01

    Oxidative degradation of the ultra-high molecular weight polyethylene (UHMWPE) limits the life of implants. This degradation can be monitored to estimate the service life of UHMWPE following the standard protocols as defined by American Standards for Testing Materials (ASTM). In this work, a comparative study has been carried on two commercially available UHMWPE grades i.e. GUR 1020 and GUR 1050 and one laboratory grade UHMWPE which was purchased from Sigma Aldrich. These powder samples were pressed while using hot press with controlled heating and cooling setup in open air under 200 bar of external pressure. These sheets were then subjected to accelerated aging in an oven at 80 °C for three weeks. The degradation of the UHMWPE was monitored by ATR-FTIR techniquefor three weeks. The oxidation index (OI) measurement showed that the commercial grade UHMWPE i.e. GUR-1020 and GUR-1050 degrade more as compared to laboratory grade UHMWPE. The values of OI after three weeks of accelerating aging were found 0.18, 0.14, and 0.09 for GUR-1020, GUR-1050, and Sigma Aldrich, respectively. In addition to this, it was found that commercial grades of UHMWPE suffer more structural alterations as compared to laboratory grade one. We hope that these results will be of particular and fundamental importance for the researchers and orthopaedic industry.

  17. How compliant are technicians with universal safety measures in medical laboratories in Croatia? – A pilot study

    PubMed Central

    Dukic, Kristina; Zoric, Matea; Pozaic, Petra; Starcic, Jelena; Culjak, Marija; Saracevic, Andrea; Miler, Marijana

    2015-01-01

    Introduction This pilot study aimed to investigate the use of personal protective equipment (PPE) and compliance to the code of conduct (rules defined in institutional, governmental and professional guidelines) among laboratory technicians in Croatian medical laboratories. In addition, we explored the differences in compliance between participants of different age groups, laboratory ownership and accreditation status. Materials and methods An anonymous and voluntary survey with 15 questions was conducted among Croatian medical laboratory technicians (N = 217). The questions were divided into two groups: demographic characteristics and the use of PPE. The questions of the second part were graded according to the Likert scale (1-4) and an overall score, shown as median and range (min-max), was calculated for each participant. Differences between the overall scores were tested for each group of participants. Results The majority of participants always wear protective clothes at work, 38.7% of them always wear gloves in daily routine, more than 30.0% consume food and almost half of them drink beverages at workplace. A significantly lower overall score was found for participants working in public compared to private laboratories (36 (16-40) vs. 40 (31-40), P < 0.001). There were no statistically significant differences in overall scores for participants of different age groups (P = 0.456) and laboratory accreditation status (P = 0.081). Conclusion A considerable percentage of laboratory technicians in Croatian medical laboratories do not comply with safety measures. Lack of compliance is observed in all personnel regardless laboratory accreditation and participants’ age. However, those working in private laboratories adhere more to the code of conduct. PMID:26526817

  18. Characterization of the protease activity of detergents: laboratory practicals for studying the protease profile and activity of various commercial detergents.

    PubMed

    Valls, Cristina; Pujadas, Gerard; Garcia-Vallve, Santi; Mulero, Miquel

    2011-07-01

    Detergent enzymes account for about 30% of the total worldwide production of enzymes and are one of the largest and most successful applications of modern industrial biotechnology. Proteases can improve the wash performance of household, industrial, and institutional laundry detergents used to remove protein-based stains such as blood, grass, body fluids, and food soils. This article describes two easy and cheap laboratory exercises to study the presence, profile, and basic enzymology of detergent proteases. These laboratory practicals are based on the determination of the detergent protease activity of various commercial detergents using the N-succinyl-L-alanyl-L-alanyl-L-prolyl-L-phenylalanine p-nitroanilide method and the bovine serum albumin degradation capacity. Students are also required to elucidate the enzymatic subtype of detergent proteases by studying the inhibitory potential of several types of protease inhibitors revealed by the same experimental methodology. Additionally, the results of the exercises can be used to provide additional insights on elementary enzymology by studying the influence of several important parameters on protease activity such as temperature (in this article) and the influence of pH and effects of surfactants and oxidizers (proposed). Students also develop laboratory skills, problem-solving capacities, and the ability to write a laboratory report. The exercises are mainly designed for an advanced undergraduate project in the biochemistry and biotechnology sciences. Globally, these laboratory practicals show students the biotechnological applications of proteases in the detergent industry and also reinforce important enzymology concepts.

  19. Industrywide studies report: a walk through survey of Ross Laboratories (Division of Abbott Laboratories), Columbus, Ohio. [Ethylene oxide

    SciTech Connect

    Greife, A.; Steenland, K.

    1985-10-02

    A walk-through survey was conducted at Ross Laboratories, a Division of Abbott Laboratories, Columbus, Ohio in August, 1985. The purpose of the survey was to determine the feasibility of including the facility in a NIOSH industry wide mortality/industrial hygiene survey of ethylene oxide. The facility produced infant formula and infant related products, including nipples. The company had a full time nurse on the first and second shifts. A physician was available on a contract basis. New employees were given preemployment physicals. Employees received annual physicals until 1982 after which they became optional. The physicals did not include any components relating to ethylene-oxide exposure. The authors conclude that the personnel records are not adequate to identify a cohort of exposed individuals at the facility. The facility will not be included in the NIOSH study.

  20. Laboratory study of fault healing in Carrara marble

    NASA Astrophysics Data System (ADS)

    Lacey, Helen; Evans, Brian; Mok, Ulrich

    2016-04-01

    High-pressure fluids on a fault plane can trigger fault movement, but precipitation from these fluids can also lead to cementation, which may alter fault plane strength and permeability and may reduce the probability of reactivation. Chemically reactive rocks such as carbonates present us with the opportunity to study this healing in more detail. This work reports upon the influence of precipitation upon the strength and frictional response of the fault plane in Carrara marble. Hold-slide experiments were undertaken on cores with pre-cut faults in the presence of either water or argon at identical conditions; T = 450oC, Pc = 130MPa, Pp = 45MPa, hold time = 7200 s. When water was present, cementation occurred along the fault plane. When the fault plane was fully cemented, the sample was up to 16MPa stronger compared to those in experiments undertaken with argon as the pore fluid. In addition, the fully cemented faults produced a much more ductile response during slip. It is likely that in the presence of argon, the frictional strength depended on the asperities on the fault surface, i.e., fault roughness. In the presence of water, fault strengthening was accompanied by a major change in the fault topology. Apparently, slip along the cemented calcite grain contacts occurred in a much more ductile manner.

  1. [Tuberculosis Laboratory Surveillance Network (TuLSA) study group. The first step for national tuberculosis laboratory surveillance: Ankara, 2011].

    PubMed

    Sezen, Figen; Albayrak, Nurhan; Özkara, Şeref; Karagöz, Alper; Alp, Alpaslan; Duyar Ağca, Filiz; İnan Süer, Asiye; Müderris, Tuba; Ceyhan, İsmail; Durmaz, Rıza; Ertek, Mustafa

    2015-04-01

    The most effective method for monitoring country-level drug resistance frequency and to implement the necessary control measures is the establishment of a laboratory-based surveillance system. The aim of this study was to summarize the follow up trend of the drug-resistant tuberculosis (TB) cases, determine the load of resistance and evaluate the capacities of laboratories depending on laboratory quality assurance system for the installation work of National Tuberculosis Laboratory Surveillance Network (TuLSA) which has started in Ankara in 2011. TuLSA studies was carried out under the coordination of National Tuberculosis Reference Laboratory (NRL) with the participation of TB laboratories and dispensaries. Specimens of TB patients, reported from health institutions, were followed in TB laboratories, and the epidemiological information was collected from the dispensaries. One isolate per patient with the drug susceptibility test (DST) results were sent to NRL from TB laboratories and in NRL the isolates were rechecked with the genotypical (MTBDRplus, Hain Lifescience, Germany) and phenotypical (MGIT 960, BD, USA) DST methods. Molecular epidemiological analysis were also performed by spoligotyping and MIRU/VNTR. Second-line DST was applied to the isolates resistant to rifampin. A total of 1276 patients were reported between January 1st to December 31th 2011, and 335 cases were defined as "pulmonary TB from Ankara province". The mean age of those patients was 43.4 ± 20 years, and 67.5% were male. Three hundred seventeen (94.6%) patients were identified as new cases. The average sample number obtained from pulmonary TB cases was 3.26 ± 2.88, and 229 (68.3%) of them was culture positive. DST was applied to all culture positive isolates; 90.4% (207/229) of cases were susceptible to the five drugs tested (ethambutol, isoniazid, pyrazinamide, rifampicin, streptomycin). Eight (3.5%) of the isolates were multidrug-resistant (MDR-TB), while no extensively drug

  2. Evaluation of bioaccumulation using in vivo laboratory and field studies.

    PubMed

    Weisbrod, Annie V; Woodburn, Kent B; Koelmans, Albert A; Parkerton, Thomas F; McElroy, Anne E; Borgå, Katrine

    2009-10-01

    A primary consideration in the evaluation of chemicals is the potential for substances to be absorbed and retained in an organism's tissues (i.e., bioaccumulated) at concentrations sufficient to pose health concerns. Substances that exhibit properties that enable biomagnification in the food chain (i.e., amplification of tissue concentrations at successive trophic levels) are of particular concern due to the elevated long-term exposures these substances pose to higher trophic organisms, including humans. Historically, biomarkers of in vivo chemical exposure (e.g., eggshell thinning, bill deformities) retrospectively led to the identification of such compounds, which were later categorized as persistent organic pollutants. Today, multiple bioaccumulation metrics are available to quantitatively assess the bioaccumulation potential of new and existing chemicals and identify substances that, upon or before environmental release, may be characterized as persistent organic pollutants. This paper reviews the various in vivo measurement approaches that can be used to assess the bioaccumulation of chemicals in aquatic or terrestrial species using laboratory-exposed, field-deployed, or collected organisms. Important issues associated with laboratory measurements of bioaccumulation include appropriate test species selection, test chemical dosing methods, exposure duration, and chemical and statistical analyses. Measuring bioaccumulation at a particular field site requires consideration of which test species to use and whether to examine natural populations or to use field-deployed populations. Both laboratory and field methods also require reliable determination of chemical concentrations in exposure media of interest (i.e., water, sediment, food or prey, etc.), accumulated body residues, or both. The advantages and disadvantages of various laboratory and field bioaccumulation metrics for assessing biomagnification potential in aquatic or terrestrial food chains are discussed

  3. Holographic study of a vibrating bell: An undergraduate laboratory experiment

    NASA Astrophysics Data System (ADS)

    Menou, Kristen; Audit, Benjamin; Boutillon, Xavier; Vach, Holger

    1998-05-01

    An experiment combining holography and musical acoustics is described. Structures of vibration modes of a bell are visualized by time-average holography under either acoustical or mechanical excitation. The vibration amplitude as measured by an accelerometer shows very good quantitative agreement with that determined from our holograms by fringe counting. An effect of degenerate level separation is shown in the mechanical case. It is argued that this experiment is not only very inexpensive for a physics laboratory already equipped for holography, but that it also strongly stimulates students to deepen their insight into a variety of different topics in applied physics.

  4. Laboratory studies of fines movement in gravel packs

    SciTech Connect

    Jennings, A.R. Jr.

    1996-12-31

    Most high permeability, high deliverability, unconsolidated and loosely consolidated sandstone formations require gravel packing as part of the completion procedure. The gravel packs are designed to allow the soft formations to produce sand-free at economic production rates. Techniques and procedures used for gravel size selection are typically based on criteria which have been used by the industry for over 20 years. Simple laboratory flow tests using clean gravel columns and fines from a variety of formations, however, indicate existing gravel-size selection guidelines are too conservative. Although the gravels selected are very efficient in preventing formation fines from entering the pack, the buildup of silt and fines at the gravel/formation interface can cause quick degradation of the effective permeability through the pack. Improvements in gravel pack life can be obtained by using gravel with higher initial permeability, either by increasing the average size of the gravels used (i.e. larger sand grains) or through the use of more spherical particles (synthetic gravel). The laboratory tests reported in this paper suggest that both alternatives can be considered in gravel pack operations. It is a further premise of this paper that sufficient improvements have been made in gravel pack procedures in recent years to allow effective placement of the higher permeability gravels proposed.

  5. Laboratory studies of fines movement in gravel packs

    SciTech Connect

    Jennings, A.R. Jr.

    1997-12-01

    Most high-permeability, high-deliverability, unconsolidated, and loosely consolidated sandstone formations require gravel packing as part of the completion procedure. The gravel packs are designed to allow the soft formations to produce sand-free at economical production rates. Techniques and procedures used for gravel-size selection are typically based on criteria that have been used by the industry for more than 20 years. Simple laboratory flow tests using clean gravel columns and fines from a variety of formations, however, indicate that existing gravel-size-selection guidelines are too conservative. Although the gravels selected are very efficient in preventing formation fines from entering the pack, the buildup of silt and fines at the gravel/formation interface can cause quick degradation of the effective permeability through the pack. Improvements in gravel-pack life can be obtained by using gravel with higher initial permeability, either by increasing the average size of the gravels used (i.e., larger sand grains) or through the use of more spherical particles (synthetic gravel). The laboratory tests reported in this paper suggest that both alternatives can be considered in gravel-pack operations. It is a further premise of this paper that sufficient improvements have been made in gravel-pack procedures in recent years to allow effective placement of the proposed higher-permeability gravels.

  6. Determination of the Composition and Quantity of Phthalate Ester Additives in PVC Children's Toys. Greenpeace Research Laboratories Technical Note 06/97.

    ERIC Educational Resources Information Center

    Stringer, Ruth; Labounskaia, Irina; Santillo, David; Johnston, Paul; Siddorn, John; Stephenson, Angela

    Polyvinyl chloride (vinyl or PVC) is widely used in toys and other children's products. This study, conducted by Greenpeace, examined the composition and quantity of phthalate ester additives in children's PVC toys, used to give the toys added flexibility. Drawn from 17 countries, a total of 71 toys designed to be chewed by babies and young…

  7. Study of wood plastic composite in the presence of nitrogen containing additives

    NASA Astrophysics Data System (ADS)

    Ali, K. M. Idriss; Khan, Mubarak A.; Husain, M. M.

    1994-10-01

    Effect of nitrogen-containing additives in the study of wood plastic composites of MMA with simul and mango wood of Bangladesh has been investigated. Nine different additives were used and the additives containing carboamide group induce the highest tensile strength to the composite.

  8. A laboratory study of spray generation in high winds

    NASA Astrophysics Data System (ADS)

    Ortiz-Suslow, D. G.; Haus, B. K.; Mehta, S.; Laxague, N. J. M.

    2016-05-01

    Characterizing the vertical distribution of large spray particles (i.e., spume) in high wind conditions is necessary for better understanding of the development of the atmospheric boundary layer in extreme conditions. To this end a laboratory experiment was designed to observe the droplet concentration in the air above actively breaking waves. The experiments were carried out in hurricane force conditions (U 10 equivalent wind speed of 36 to 54 m/s) and using both fresh water and salt water. While small differences between fresh and salt water were observed in profiles of radius-integrated spray volume fraction, the profiles tend to converge as the wind forcing increases. This supports the assumption that the physical mechanism for spume production is not sensitive to salinity and its corresponding link to the bubble size distribution.

  9. Diamonds in space: a brief history and recent laboratory studies

    NASA Astrophysics Data System (ADS)

    Chang, Huan-Cheng

    2016-07-01

    Stardust grains exist in outer space. However, due to their low abundance, structural heterogeneities, and lack of distinct spectroscopic features, unambiguous identification of their chemical composition has been a challenge. Diamond is a notable exception because it is composed of carbon and has several unique physicochemical properties that make the identification possible. Here, we provide a brief review on how diamonds were discovered in space based on the remarkable spectral matching between laboratory spectra and astronomical observations of the infrared emission at 3.43 and 3.53 µm, followed by a discussion of fluorescent nanodiamond as a possible carrier for extended red emission at 600 — 800 nm. Recent evidence to support the latter suggestion is provided.

  10. Renewable Energy Laboratory Development for Biofuels Advanced Combustion Studies

    SciTech Connect

    Soloiu, Valentin A.

    2012-03-31

    The research advanced fundamental science and applied engineering for increasing the efficiency of internal combustion engines and meeting emissions regulations with biofuels. The project developed a laboratory with new experiments and allowed investigation of new fuels and their combustion and emissions. This project supports a sustainable domestic biofuels and automotive industry creating economic opportunities across the nation, reducing the dependence on foreign oil, and enhancing U.S. energy security. The one year period of research developed fundamental knowledge and applied technology in advanced combustion, emissions and biofuels formulation to increase vehicle's efficiency. Biofuels combustion was investigated in a Compression Ignition Direct Injection (DI) to develop idling strategies with biofuels and an Indirect Diesel Injection (IDI) intended for auxiliary power unit.

  11. Study of polyelectrolytes for Los Alamos National Laboratory. Final report

    SciTech Connect

    Labonne, N.

    1994-11-01

    To assess the safety of a potential radioactive waste repository, analysis of the fluid solution containing low levels of activity need to be performed. In some cases, the radioactivity would be so weak (3--30 pCi/L) that the solution must be concentrated for measurement. For this purpose, Los Alamos National Laboratory scientists are synthesizing some water soluble polyelectrolytes, which, because they are strong complexing agents for inorganic cations, can concentrate the radioelements in solution. To assist in characterization of these polyelectrolytes, the author has performed experiments to determine physico-chemical constants, such as pKa values and stability constants. The complexation constants between both polyelectrolytes and europium were determined by two methods: solvent extraction and ion exchange. Results are presented.

  12. Feasibility study of an orbiting laboratory for testing CSI technology

    NASA Technical Reports Server (NTRS)

    Bicos, Andrew S.; Loboda, Gregory G.

    1993-01-01

    A concept for an orbiting laboratory for testing Controls-Structures Integration (CSI) technology is described. The CSI-Star concept reflects a lower cost, higher risk approach. The concept supports demonstration and validation testing for critical CSI technologies at a cost of $20M to $26M with a 1-year reliability of approximately 0.9. The Ball Aerospace QuickStar bus is the carrier for the CSI test article. QuickStar is launched as a secondary payload on the McDonnell Douglas Delta 2. The QuickStar/Delta 2 approach is flight proven. The CSI test article is a 20 foot, 1 Hz, truss beam which is deployed from the QuickStar bus. The test article is well instrumented for quality system identification. The laboratory provides three layers of active control consisting of global vibration suppression along the truss beam, vibration isolation between the beam and instrument platforms, and vibration compensation through the use of gimbaled platforms which point lasers relative to optical sensor targets. The configuration simulates the dynamics of multi-instrument science platforms such as those of the Earth Observation System (EOS) while maintaining strong ties to astrophysics missions such as the Optical Interferometer. Uplink/downlink services and a reprogrammable computer provide flexibility for long-term investigations by members of the CSI community (NASA, DoD, academia, and industry). CSI-Star fills the gap between short-term experiments, which have been conducted primarily on the Shuttle, and future science missions which require the technology. The on-orbit maturity of CSI technology must be established to obtain acceptance by project managers and to promote injection of the technology into future science missions.

  13. Feasibility study of an orbiting laboratory for testing CSI technology

    NASA Astrophysics Data System (ADS)

    Bicos, Andrew S.; Loboda, Gregory G.

    1993-08-01

    A concept for an orbiting laboratory for testing Controls-Structures Integration (CSI) technology is described. The CSI-Star concept reflects a lower cost, higher risk approach. The concept supports demonstration and validation testing for critical CSI technologies at a cost of $20M to $26M with a 1-year reliability of approximately 0.9. The Ball Aerospace QuickStar bus is the carrier for the CSI test article. QuickStar is launched as a secondary payload on the McDonnell Douglas Delta 2. The QuickStar/Delta 2 approach is flight proven. The CSI test article is a 20 foot, 1 Hz, truss beam which is deployed from the QuickStar bus. The test article is well instrumented for quality system identification. The laboratory provides three layers of active control consisting of global vibration suppression along the truss beam, vibration isolation between the beam and instrument platforms, and vibration compensation through the use of gimbaled platforms which point lasers relative to optical sensor targets. The configuration simulates the dynamics of multi-instrument science platforms such as those of the Earth Observation System (EOS) while maintaining strong ties to astrophysics missions such as the Optical Interferometer. Uplink/downlink services and a reprogrammable computer provide flexibility for long-term investigations by members of the CSI community (NASA, DoD, academia, and industry). CSI-Star fills the gap between short-term experiments, which have been conducted primarily on the Shuttle, and future science missions which require the technology. The on-orbit maturity of CSI technology must be established to obtain acceptance by project managers and to promote injection of the technology into future science missions.

  14. A Comparison of Science Laboratory Classrooms in Asia, Australia, South Pacific and USA: An International Study.

    ERIC Educational Resources Information Center

    Giddings, Geoffrey; Waldrip, Bruce G.

    This study attempted to compare the science laboratory learning environments of secondary schools across both developed and developing countries (Australia, Brunei, Cook Islands, Fiji, Papua New Guinea, Singapore, Solomon Islands, Tonga, Tuvalu, United States, Vanuatu, and Western Samoa). The study used a version of the Science Laboratory Learning…

  15. An Exploratory Study of Objective Attainment in the Divergent Physics Laboratory.

    ERIC Educational Resources Information Center

    Lerch, Robert Donald

    Students enrolled in the introductory physics laboratory at New Mexico State University participated in this study. A stated set of objectives, developed by Dr. John M. Fowler of the Commission on College Physics, was used in the laboratory. This study attempted to measure student achievement based on the use of these objectives as opposed to the…

  16. Seven Principles of Instructional Content Design for a Remote Laboratory: A Case Study on ERRL

    ERIC Educational Resources Information Center

    Cagiltay, N. E.; Aydin, E.; Aydin, C. C.; Kara, A.; Alexandru, M.

    2011-01-01

    This paper discusses the results of a study of the requirements for developing a remote radio frequency (RF) laboratory for electrical engineering students. It investigates students' preferred usage of the technical content of a state-of-the-art RF laboratory. The results of this study are compared to previous findings, which dealt with other user…

  17. Observations related to tetrahydrofuran and methane hydrates for laboratory studies of hydrate-bearing sediments

    USGS Publications Warehouse

    Lee, J.Y.; Yun, T.S.; Santamarina, J.C.; Ruppel, C.

    2007-01-01

    The interaction among water molecules, guest gas molecules, salts, and mineral particles determines the nucleation and growth behavior of gas hydrates in natural sediments. Hydrate of tetrahydrofuran (THF) has long been used for laboratory studies of gas hydrate-bearing sediments to provide close control on hydrate concentrations and to overcome the long formation history of methane hydrate from aqueous phase methane in sediments. Yet differences in the polarizability of THF (polar molecule) compared to methane (nonpolar molecule) raise questions about the suitability of THF as a proxy for methane in the study of hydrate-bearing sediments. From existing data and simple macroscale experiments, we show that despite its polar nature, THF's large molecular size results in low permittivity, prevents it from dissolving precipitated salts, and hinders the solvation of ions on dry mineral surfaces. In addition, the interfacial tension between water and THF hydrate is similar to that between water and methane hydrate. The processes that researchers choose for forming hydrate in sediments in laboratory settings (e.g., from gas, liquid, or ice) and the pore-scale distribution of the hydrate that is produced by each of these processes likely have a more pronounced effect on the measured macroscale properties of hydrate-bearing sediments than do differences between THF and methane hydrates themselves.

  18. A survey and evaluation of human genetic traits used in classroom laboratory studies.

    PubMed

    Barnes, P; Mertens, T R

    1976-01-01

    Twenty-six selected introductory biology and genetics laboratory manuals were examined and were found to include 57 human "inherited" traits as examples for classroom study. Forty-three of these 57 traits are included in McKusick's catalog of human inherited characteristics, Mendelian Inheritance in Man. Of these 43 traits, 26 are annotated with an asterisk, indicating that their modes of inheritance are well documented, while 17 traits are not so annotated, suggesting uncertain mechanisms of inheritance. Fourteen of the 57 traits are not found in McKusick's catalog, implying that they may not be inherited traits at all or that their modes of inheritance may be polygenic. Current literature also suggest that certain traits included in the McKusick catalog may, in fact, not have a genetic basis. Notable examples of such questionable traits are handedness, hand clasping, and tongue rolling. Clearly, a need exists for reliable morphological and easily detected biochemical human genetic traits for use in classroom instruction. Authors preparing instructional manuals for introductory biology and genetics laboratory studies should carefully select the traits with which they illustrate human inheritance. A first requisite for selection of such characteristics must be conclusive evidence that the trait does, indeed, have an established genetic basis. Additional criteria for selection of such traits are also discussed.

  19. Tracer Studies In Laboratory Beach Simulating Tidal Influences

    EPA Science Inventory

    Bioremediation of oil spills on tidally influenced beaches commonly involves the addition of a nutrient solution to the contaminated region of the beach at low tide to stimulate the growth of indigenous oil-degrading bacteria. Maximizing the residentce time of nutrients in the be...

  20. How do laboratory technicians perceive their role in the tuberculosis diagnostic process? A cross-sectional study among laboratory technicians in health centers of Central Java Province, Indonesia

    PubMed Central

    Widjanarko, Bagoes; Widyastari, Dyah Anantalia; Martini, Martini; Ginandjar, Praba

    2016-01-01

    Purpose Detection of acid-fast bacilli in respiratory specimens serves as an initial pulmonary tuberculosis (TB) diagnosis. Laboratories are the essential and fundamental part of all health systems. This study aimed to describe how laboratory technicians perceived their own self and work. This included perceived self-efficacy, perceived role, perceived equipment availability, perceived procedures, perceived reward and job, and perceived benefit of health education, as well as level of knowledge and attitudes related to work performance of laboratory technicians. Methods This was a cross-sectional quantitative study involving 120 laboratory technicians conducted in Central Java. Interviews and observation were conducted to measure performance and work-related variables. Results Among 120 laboratory technicians, 43.3% showed fairly good performance. They complied with 50%–75% of all procedures, including sputum collection, laboratory tools utilization, sputum smearing, staining, smear examination, grading of results, and universal precaution practice. Perceived role, perceived self-efficacy, and knowledge of laboratory procedures were significantly correlated to performance, besides education and years of working as a laboratory technician. Perceived equipment availability was also significantly correlated to performance after the education variable was controlled. Conclusion Most of the laboratory technicians believed that they have an important role in TB patients’ treatment and should display proper self-efficacy in performing laboratory activities. The result may serve as a basic consideration to develop a policy for enhancing motivation of laboratory technicians in order to improve the TB control program. PMID:27660502

  1. Laboratory Studies of Ammonia Ices Relevant to the Jovian Atmosphere

    NASA Astrophysics Data System (ADS)

    Meharchand, R. T.; Boulter, J. E.; Baer, C. E.; Kalogerakis, K. S.

    2004-12-01

    Ammonia ice condensation and cloud formation microphysics are topics of relevance for understanding the atmospheres of the giant planets. Ammonia ices are also considered important components of the icy satellites found in the outer solar system, and are thought to play an important role in their geological activity. Although observational evidence and thermochemical models suggest ammonia clouds in the Jovian atmosphere should be ubiquitous, less than only 1% of Jupiter's atmosphere appears covered by spectrally identifiable ammonia clouds, with a clear preference in turbulent regions.1,2 The paradox of the rather scarce spectroscopic signatures of ammonia clouds and their appearance in turbulent regions suggests that the nascent ammonia clouds may undergo processing that modifies their spectroscopic properties. No relevant laboratory experimental results are available to resolve this problem. Two possible sources of processing that have been suggested in the literature include photochemical solid-state modification (''tanning'') and coating of ammonia particles by other substances present in the stratospheric haze.2,3 We are performing laboratory investigations with the objective to provide information on the photophysical and chemical processes that control the optical properties of the Jovian ammonia clouds. In the experiments, thin ice films of ammonia are coated with organic molecules, such as saturated and aromatic hydrocarbons, and characterized by infrared spectroscopy. Preliminary results indicate suppression of the ammonia absorption feature at 2.7 μ m by a thin layer of hydrocarbons. The implications for the spectral signatures of ammonia clouds in the atmospheres of Jupiter and Saturn will be discussed. Funding from the NSF Planetary Astronomy Program under grant AST-0206270 is gratefully acknowledged. The participation of Rhiannon Meharchand and Christina Baer was made possible by the NSF Research Experiences for Undergraduates Program under grant

  2. Voice measures of workload in the advanced flight deck: Additional studies

    NASA Technical Reports Server (NTRS)

    Schneider, Sid J.; Alpert, Murray

    1989-01-01

    These studies investigated acoustical analysis of the voice as a measure of workload in individual operators. In the first study, voice samples were recorded from a single operator during high, medium, and low workload conditions. Mean amplitude, frequency, syllable duration, and emphasis all tended to increase as workload increased. In the second study, NASA test pilots performed a laboratory task, and used a flight simulator under differing work conditions. For two of the pilots, high workload in the simulator brought about greater amplitude, peak duration, and stress. In both the laboratory and simulator tasks, high workload tended to be associated with more statistically significant drop-offs in the acoustical measures than were lower workload levels. There was a great deal of intra-subject variability in the acoustical measures. The results suggested that in individual operators, increased workload might be revealed by high initial amplitude and frequency, followed by rapid drop-offs over time.

  3. Laboratory Studies of Turbulence Associated with Localized Current Layers

    NASA Astrophysics Data System (ADS)

    Vincena, Stephen

    2006-04-01

    Localized current layers are a natural consequence of the interaction of the solar wind with the earth's magnetic field. In particular, field-aligned currents dynamically link the active magnetotail to the auroral ionosphere. Within these currents there may develop small-scale phenomena such as density-gradient or shear-driven instabilities, or electron solitary structures and micro-turbulence which may profoundly influence the larger-scale dynamics of the system. The Basic Plasma Science Facility (BaPSF) at UCLA offers a unique opportunity to model magneto/heliospheric phenomena, including current sheets. We present measurements from laboratory experiments of an electron current sheet which is several ion-gyroradii thick by up to ten Alfv'en wavelengths along the field(1cm by 20m). The current sheet leads to a depletion of the background plasma, forming a field-aligned density depression. Drift-Alfv'en waves are spontaneously excited and drive cross-field particle transport which relaxes the density gradient and modulates the current flow. We will also present initial results of small-scale electric field spikes within the current sheet using specially fabricated dipole probes with separation on the order of the Debye length---here 13 microns. These measurements are motivated by the observation of electron solitary structures throughout the magnetosphere.

  4. Synchrotron and laboratory studies utilizing a new powder diffraction technique

    SciTech Connect

    Knapp, G.S.; Beno, M.A.; Jennings, G.; Engbretson, M.; Ramanathan, M.

    1992-10-01

    We have developed a new type of powder diffractometer that is much more efficient than existing methods. The diffractometer has the potential of both high count rates and very high resolution when used at a synchrotron source. The laboratory based instrument has an order of magnitude improvement in count rate over existing methods. The method uses a focusing diffracted beam monochromator in combination with a multichannel detector. The incident x-rays fall on a flat plate or capillary sample and are intercepted by a bent focusing monochromator which has the focus of the bend at the sample surface. The powder diffraction lines emerging from the bent crystal monochromator are detected by a linear or 2-dimensional detector. This allows us to eliminate the background from fluorescence or other scattering and to take data over a range of 3[degrees] to 4[degrees] instead of one angle at a time thereby providing a large improvement over conventional diffractometers. Results are presented for fluorapatite Fe[sub 2]O[sub 3], and a high-TC superconductor.

  5. Synchrotron and laboratory studies utilizing a new powder diffraction technique

    SciTech Connect

    Knapp, G.S.; Beno, M.A.; Jennings, G.; Engbretson, M.; Ramanathan, M.

    1992-10-01

    We have developed a new type of powder diffractometer that is much more efficient than existing methods. The diffractometer has the potential of both high count rates and very high resolution when used at a synchrotron source. The laboratory based instrument has an order of magnitude improvement in count rate over existing methods. The method uses a focusing diffracted beam monochromator in combination with a multichannel detector. The incident x-rays fall on a flat plate or capillary sample and are intercepted by a bent focusing monochromator which has the focus of the bend at the sample surface. The powder diffraction lines emerging from the bent crystal monochromator are detected by a linear or 2-dimensional detector. This allows us to eliminate the background from fluorescence or other scattering and to take data over a range of 3{degrees} to 4{degrees} instead of one angle at a time thereby providing a large improvement over conventional diffractometers. Results are presented for fluorapatite Fe{sub 2}O{sub 3}, and a high-TC superconductor.

  6. Laboratory studies on antimycin A as a fish toxicant

    USGS Publications Warehouse

    Berger, Bernard L.; Lennon, Robert E.; Hogan, James W.

    1969-01-01

    Liquid and sand formulations of antimycin A were tested in laboratory waters of various temperature, hardness, pH, and turbidity against 31 species of fresh-water fish of various sizes and life stages. Each formulation of toxicant was lethal under all water conditions to fish eggs, fry, fingerlings, and adult fish. Trouts are the most sensitive and catfishes the least sensitive. Of the 31 species, 24 succumb to 5 p.p.b. or less of the toxicant; only certain catfishes survive 25 p.p.b, The order of toxicity to various species of fish suggests that antimycin has possibilities for selective or partial control of certain unwanted fish. Although toxic to fish under ice, antimycin is more active in warm water than in cold. It is slightly more active in soft water than in hard; it is more active and persists far longer in water at pH 5 to 8 than at pH 9 or 10. It is active on fish in either clear and turbid waters, and it can be detoxified by potassium permanganate, The results contributed to registration of antimycin A in Fintrol-5 formulation as a fish toxicant.

  7. Laboratory studies of molecular growth in the Titan ionosphere.

    PubMed

    Thissen, Roland; Vuitton, Veronique; Lavvas, Panayotis; Lemaire, Joel; Dehon, Christophe; Dutuit, Odile; Smith, Mark A; Turchini, Stefano; Catone, Daniele; Yelle, Roger V; Pernot, Pascal; Somogyi, Arpad; Coreno, Marcello

    2009-10-22

    Experimental simulations of the initial steps of the ion-molecule reactions occurring in the ionosphere of Titan were performed at the synchrotron source Elettra in Italy. The measurements consisted of irradiating gas mixtures with a monochromatic photon beam, from the methane ionization threshold at 12.6 eV, up to and beyond the molecular nitrogen dissociative ionization threshold at 24.3 eV. Three gas mixtures of increasing complexity were used: N(2)/CH(4) (0.96/0.04), N(2)/CH(4)/C(2)H(2) (0.96/0.04/0.001), and N(2)/CH(4)/C(2)H(2)/C(2)H(4) (0.96/0.04/0.001/0.001). The resulting ions were detected with a high-resolution (1 T) FT-ICR mass spectrometer as a function of time and VUV photon energy. In order to interpret the experimental results, a Titan ionospheric model was adapted to the laboratory conditions. This model had previously allowed the identification of the ions detected in the Titan upper atmosphere by the ion neutral mass spectrometer (INMS) onboard the Cassini spacecraft. Comparison between observed and modeled ion densities validates the kinetic model (reactions, rate constants, product branching ratios) for the primary steps of molecular growth. It also reveals differences that we attribute to an intense surface chemistry. This result implies that heterogeneous chemistry on aerosols might efficiently produce HCN and NH(3) in the Titan upper atmosphere.

  8. In vivo effects of bisphenol A in laboratory rodent studies

    USGS Publications Warehouse

    Richter, Catherine A.; Birnbaum, Linda S.; Farabollini, Francesca; Newbold, Retha R.; Rubin, Beverly S.; Talsness, Chris E.; Vandenbergh, John G.; Walser-Kuntz, Debby R.; vom Saal, Frederick S.

    2007-01-01

    Concern is mounting regarding the human health and environmental effects of bisphenol A (BPA), a high-production-volume chemical used in synthesis of plastics. We have reviewed the growing literature on effects of low doses of BPA, below 50 mg/(kg day), in laboratory exposures with mammalian model organisms. Many, but not all, effects of BPA are similar to effects seen in response to the model estrogens diethylstilbestrol and ethinylestradiol. For most effects, the potency of BPA is approximately 10–1000-fold less than that of diethylstilbestrol or ethinylestradiol. Based on our review of the literature, a consensus was reached regarding our level of confidence that particular outcomes occur in response to low dose BPA exposure. We are confident that adult exposure to BPA affects the male reproductive tract, and that long lasting, organizational effects in response to developmental exposure to BPA occur in the brain, the male reproductive system, and metabolic processes. We consider it likely, but requiring further confirmation, that adult exposure to BPA affects the brain, the female reproductive system, and the immune system, and that developmental effects occur in the female reproductive system.

  9. Laboratory Studies of Cometary Materials - Continuity Between Asteroid and Comet

    NASA Technical Reports Server (NTRS)

    Messenger, Scott; Walker, Robert M.

    2015-01-01

    Laboratory analysis of cometary samples have been enabled by collection of cometary dust in the stratosphere by high altitude aircraft and by the direct sampling of the comet Wild-2 coma by the NASA Stardust spacecraft. Cometary materials are composed of a complex assemblage of highly primitive, unprocessed interstellar and primordial solar system materials as well as a variety of high temperature phases that must have condensed in the inner regions of the protoplanetary disk. These findings support and contradict conclusions of comet properties based solely on astronomical observations. These sample return missions have instead shown that there is a continuity of properties between comets and asteroids, where both types of materials show evidence for primitive and processed materials. Furthermore, these findings underscore the importance and value of direct sample return. There will be great value in comparing the findings of the Stardust cometary coma sample return mission with those of future asteroid surface sample returns OSIRIS-REx and Hayabusa II as well as future comet nucleus sample returns.

  10. Laboratory, Field, and Modeling Studies of Aerobic Cometabolism of CAHs by Butane-Utilizing Microorganisms

    NASA Astrophysics Data System (ADS)

    Mathias, M.; Semprini, L.; Dolan, M. E.; McCarty, P. L.; Hopkins, G. D.

    2002-12-01

    The ability of butane-utilizing microorganisms to aerobically cometabolize a mixture of chlorinated aliphatic hydrocarbons (CAHs) in laboratory microcosms and in an in-situ field demonstration was modeled using parameter values measured in laboratory experiments. The butane grown culture was inoculated into soil and groundwater microcosms and exposed to butane with several repeated additions of 1,1,1-trichloroethane (TCA), 1,1-dichloroethylene (1,1-DCE), and 1,1-dichloroethane (1,1-DCA) at aqueous concentrations of 200 μg/L, 100 μg/L, and 200 μg/L, respectively. The utilization of butane and the transformation of the CAH mixture in the batch microcosms were simulated using differential equations accounting for Michaelis-Menten kinetics with cell growth and decay, substrate utilization, transformation product toxicity, and substrate inhibition of CAH transformation. Both competitive inhibition kinetics and mixed inhibition kinetics, determined in prior laboratory studies, were included in the model construct. The equations were solved simultaneously using fourth-order Runge-Kutta numerical integration. The batch microcosm experimental results were simulated well with parameter values determined independently in culture kinetic studies, with some minor adjustments. Having adequately defined the parameter values from laboratory studies, the biotransformation model was combined with 1-D advective-dispersive transport to simulate the results of in-situ bioremediation tests conducted at the Moffett Field Test Facility in CA. The butane-utilizing culture was injected into a 7 m subsurface test site and exposed to alternating pulses of oxygen and butane, along with TCA (150 μg/L), 1,1-DCE (50 μg/L) and 1,1-DCA (150 μg/L). The model simulated well the transient transformation of the CAHs in response to different butane and oxygen pulse cycles and injection concentrations. Model simulations correlated well with field results and indicated that better remediation

  11. Laboratory and Field Studies of Fracture Flow and Its Extension in Underground Settings

    NASA Astrophysics Data System (ADS)

    Wang, J. S.; Hudson, J. A.

    2012-12-01

    Basic studies of fracture flow, such as the cubic law, were widely cited for over four decades and used in understanding processes in fractured media. We evaluate the fracture flow law implications and its extensions. The understanding of fluid flow through fractured rocks is important for progress in the many existing and proposed engineering projects dedicated to the support of mankind. Moreover, the characterization of this understanding is crucial during the use of the supporting computer modeling—which is becoming evermore ambitious and ubiquitous. The calculations and resultant outputs need to be validated, both in order to ensure appropriate engineering decisions and because there is increasing emphasis on the use of the Earth's resources, their sustainability and more accountability of engineers' decisions. Within this context, there remain many unknowns: how do we establish the geometrical and hydro-geological properties of fractures in a specific rock mass?; how do we establish the link between the hydro-geological fracture properties and other variables such as the in situ stress state?; and how do we validate the results at the full scale? Concurrently with the laboratory and numerical studies of fracture flows, we have made progresses in developing underground research laboratories (URLs) in both hard and soft rocks, in housing large halls for particle detections at great depths, and in testing the energy and resource recovery capacities and the waste disposal potentials through borehole complexes. In addition to existing worldwide networks for radioactive wastes, we initiate comparisons of different underground laboratories and facilities, including also physics laboratories and borehole complexes. The 2011-2012 findings of a Commission for the International Society for Rock Mechanics on URL Networking are summarized. Side drifts of roadway tunnels, dedicated facilities with tunneling and shafting to reach desired depths, and levels in active and

  12. A SURVEY OF LABORATORY AND STATISTICAL ISSUES RELATED TO FARMWORKER EXPOSURE STUDIES

    EPA Science Inventory

    Developing internally valid, and perhaps generalizable, farmworker exposure studies is a complex process that involves many statistical and laboratory considerations. Statistics are an integral component of each study beginning with the design stage and continuing to the final da...

  13. High-Energy-Density, Laboratory-Astrophysics Studies of Jets and Bow Shocks

    SciTech Connect

    Foster, J M; Wilde, B H; Rosen, P A; Perry, T S; Khokhlov, A M; Coker, R F; Frank, A; Keiter, P A; Blue, B E; Drake, R P; Knauer, J P; Williams, R R

    2005-01-24

    Large-scale directional outflows of supersonic plasma, also known as ''jets'', are ubiquitous phenomena in astrophysics [1]. The interaction of such jets with surrounding matter often results in spectacular bow shocks, and intense radiation from radio to gamma-ray wavelengths. The traditional approach to understanding such phenomena is through theoretical analysis and numerical simulations. However, such numerical simulations have limited resolution, often assume axial symmetry, do not include all relevant physical processes, and fail to scale correctly in Reynolds number and perhaps other key dimensionless parameters. Additionally, they are frequently not tested by comparison with laboratory experiments. Recent advances in high-energy-density physics using large inertial-confinement-fusion devices now allow controlled laboratory experiments on macroscopic volumes of plasma of direct relevance relevant to astrophysics [2]. In this Letter we report the first results of experiments designed to study the evolution of supersonic plasma jets and the bow shocks they drive into a surrounding medium. Our experiments reveal both regular and highly complex flow patterns in the bow shock, thus opening a new window--complementary to computer simulations--into understanding the nature of three-dimensional astrophysical jets.

  14. Core outcome measures for opioid abuse liability laboratory assessment studies in humans: IMMPACT recommendations

    PubMed Central

    Comer, Sandra D.; Zacny, James P.; Dworkin, Robert H.; Turk, Dennis C.; Bigelow, George E.; Foltin, Richard W.; Jasinski, Donald R.; Sellers, Edward M.; Adams, Edgar H.; Balster, Robert; Burke, Laurie B.; Cerny, Igor; Colucci, Robert D.; Cone, Edward; Cowan, Penney; Farrar, John T.; Haddox, J. David; Haythornthwaite, Jennifer A.; Hertz, Sharon; Jay, Gary W.; Johanson, Chris-Ellyn; Junor, Roderick; Katz, Nathaniel P.; Klein, Michael; Kopecky, Ernest A.; Leiderman, Deborah B.; McDermott, Michael P.; O’Brien, Charles; O’Connor, Alec B.; Palmer, Pamela P.; Raja, Srinivasa N.; Rappaport, Bob A.; Rauschkolb, Christine; Rowbotham, Michael C.; Sampaio, Cristina; Setnik, Beatrice; Sokolowska, Marta; Stauffer, Joseph W.; Walsh, Sharon L.

    2012-01-01

    A critical component in development of opioid analgesics is assessment of their abuse liability (AL). Standardization of approaches and measures used in assessing AL has the potential to facilitate comparisons across studies, research laboratories, and drugs. The goal of this report is to provide consensus recommendations regarding core outcome measures for assessing abuse potential of opioid medications in humans in a controlled laboratory setting. Although many of the recommended measures are appropriate for assessing the AL of medications from other drug classes, the focus here is on opioid medications because they present unique risks from both physiological (e.g., respiratory depression, physical dependence) and public health (e.g., individuals in pain) perspectives. A brief historical perspective on AL testing is provided and then those measures that can be considered primary and secondary outcomes and possible additional outcomes in AL assessment are discussed. These outcome measures include: (1) subjective effects (some of which comprise the primary outcome measures, including drug liking); (2) physiological responses; (3) drug self-administration behavior; and (4) cognitive and psychomotor performance. Prior to presenting recommendations for standardized approaches and measures to be used in AL assessments, the appropriateness of using these measures in clinical trials with patients in pain is discussed. PMID:22998781

  15. Laboratories for the 21st Century: Case Studies: Donald Bren Hall, Santa Barbara, California

    SciTech Connect

    Nancy Carlisle: NREL

    2004-03-23

    This publication is one of a series of case studies of energy-efficient modern laboratories; it was prepared for "Laboratories for the 21st Century," a joint program of the Environmental Protection Agency and the U.S. DOE Federal Energy Management Program

  16. A Feasibility Study for Mobile Marketing and Distribution Occupational Laboratories in North Dakota.

    ERIC Educational Resources Information Center

    Kohns, Donald P.

    A study determined the feasibility of a mobile laboratory for marketing and distribution in North Dakota. It attempted to answer four questions: (1) What types of staffing, equipment, curriculum, and delivery systems are presently being utilized in mobile laboratories throughout the nation? (2) What significant information obtained from mobile…

  17. Seeking More Effective Outcomes from Science Laboratory Experiences (Grades 7-14): Six Companion Studies.

    ERIC Educational Resources Information Center

    Sutman, Frank X.; And Others

    The series of three sets of companion studies reported in this presentation addresses the need for seeking more effective outcomes from science laboratory experiences, which is indicated by conflicting outcomes of earlier reported research related to laboratory instruction at two different academic levels--grades 7-12 and beginning college. Four…

  18. Performance testing of radiobioassay laboratories: In vitro measurements, fecal study report

    SciTech Connect

    MacLellan, J.A.

    1988-09-01

    This study evaluated nine radiobioassay laboratories; performances in analyzing fecal samples to determine the samples' levels of radioactivity. A total of 135 artificial fecal samples were sent to nine laboratories. Each laboratory received five samples spiked with 9. 58 pCi of /sup 239/Pu, five samples spiked with 1.13 pCi /sup 239/Pu, and five unspiked blank samples. Four of the laboratories returned data for all samples; four reported they were unable to complete the analyses; one analyzed six samples (three blanks and three of the lower activity samples). Results reported by the laboratories were analyzed by statistical methods specified in the draft standard for relative bias, relative precision, and minimum detectable activity (MDA). The calculated relative biases of all laboratories were well within the criteria of the standard (/minus/0.25 to +0.5). Biases for three laboratories were about 5% and the two others were within +-20%. Relative precision statistics for all participating laboratories were lower than the acceptance criteria of the standard (40%). Relative precision was less than 15% for one laboratory; for two others, it was less than 10%; and for the remaining two, it was less than 5% of the acceptance criteria. For the MDA criterion, four of the five laboratories passed. For all four of the passing laboratories, the entire 90% confidence interval was less than the specified acceptable minimum detectable amount (acceptable MDA) of 1 pCi. for the fifth laboratory, the MDA was 80% above the acceptable MDA specified in the draft standard. 16 refs., 3 figs., 3 tabs.

  19. Inter-laboratory study to improve the quality of the analysis of nutrients in rainwater chemistry

    NASA Astrophysics Data System (ADS)

    Karthikeyan, Sathrugnan; Balasubramanian, Rajasekhar; He, Jun

    This paper describes the results of an inter-laboratory study conducted for the analysis of nutrients (nitrate, ammonium, phosphate, total nitrogen (TN), and total phosphorus (TP)) in natural rainwater. For this purpose, rainwater samples were collected and aggregated in Singapore and homogenized. These samples were immediately filtered through 0.45 μm membrane filters and autoclaved for 15 min at 80 °C in order to stabilize the nutrients. The homogeneity and the stability of nutrients were rigorously tested for a period of three months initially. Upon ensuring the homogeneity and stability, the samples were distributed to 15 different laboratories from various countries around the world (Australia, Brazil, India, Mauritius, Singapore, Slovenia, Spain, Taiwan, and USA). Almost all laboratories have reported the analytical results for nitrate whereas only 8 of the 15 laboratories reported results for other nutrients such as ammonium, phosphate, TN, and TP. The discrepancy was mainly due to the presence of these nutrients in low concentration levels (particularly ammonium ion and phosphate). Not all the laboratories were equipped with analytical capabilities to conduct the analysis of nutrients in low concentration levels. Further, the uncertainty associated with the analysis of TN and TP restricted the number of laboratories that could report their analytical data on nutrients. All 14 laboratories reported nitrate-nitrogen results which were in good agreement with each other (0.68 ± 0.07 mg l -1). Similarly, the results of TN and TP were also comparable among at least 8 laboratories. This inter-laboratory study on the analysis of nutrients in natural rainwater, conducted for the first time, provided an opportunity to the participating laboratories to assess and improve their laboratory performance, thereby, improving the quality of their analytical data.

  20. Laboratory infrared studies of molecules of atmospheric and astrophysical interest

    NASA Technical Reports Server (NTRS)

    Rao, N. N.

    1982-01-01

    Nineteen reprints on the molecular species are compiled. Much of the work was done by using the Doppler-limited resolution provided by diode lasers. The diode laser was used as a source to a grating spectrometer which has been used earlier for high resolution studies. This technique provided many advantages. Wherever possible, the studies have been directed to intensity determinations of infrared bands.

  1. Scientometric Study of Doctoral Theses of the Physical Research Laboratory

    NASA Astrophysics Data System (ADS)

    Anilkumar, N.

    2010-10-01

    This paper presents the results of a study of bibliographies compiled from theses submitted in the period 2001-2005. The bibliographies have been studied to find out how research carried out at PRL is being used by the doctoral students. Resources are categorized by type of resource — book, journal article, proceedings, doctoral thesis, etc., to understand the usage of content procured by the library. The period of the study, 2001-2005, has been chosen because technology is changing so fast and so are the formats of scholarly communications. For the sake of convenience, only the "e-journals period" is considered for the sample.

  2. Software Engineering Laboratory (SEL) Ada performance study report

    NASA Technical Reports Server (NTRS)

    Booth, Eric W.; Stark, Michael E.

    1991-01-01

    The goals of the Ada Performance Study are described. The methods used are explained. Guidelines for future Ada development efforts are given. The goals and scope of the study are detailed, and the background of Ada development in the Flight Dynamics Division (FDD) is presented. The organization and overall purpose of each test are discussed. The purpose, methods, and results of each test and analyses of these results are given. Guidelines for future development efforts based on the analysis of results from this study are provided. The approach used on the performance tests is discussed.

  3. Zero-gravity cloud physics laboratory: Candidate experiments definition and preliminary concept studies

    NASA Technical Reports Server (NTRS)

    Eaton, L. R.; Greco, R. V.; Hollinden, A. B.

    1973-01-01

    The candidate definition studies on the zero-g cloud physics laboratory are covered. This laboratory will be an independent self-contained shuttle sortie payload. Several critical technology areas have been identified and studied to assure proper consideration in terms of engineering requirements for the final design. Areas include chambers, gas and particle generators, environmental controls, motion controls, change controls, observational techniques, and composition controls. This unique laboratory will allow studies to be performed without mechanical, aerodynamics, electrical, or other type techniques to support the object under study. This report also covers the candidate experiment definitions, chambers and experiment classes, laboratory concepts and plans, special supporting studies, early flight opportunities and payload planning data for overall shuttle payload requirements assessments.

  4. Laboratory Studies in UV and EUV Solar Physics

    NASA Technical Reports Server (NTRS)

    Wagner, William J. (Technical Monitor); Kohl, John L.

    2005-01-01

    A new 5 GHZ Electron Cyclotron Resonance (ECR) ion source for SAO's Ion Beam Experiment was designed, built and tested. Absolute cross sections were measured for electron impact excitation (EIE) in C(2+) (2s2p (3)P(sup o) - 2p(sup 2) (3)P), and empirical EIE rate coefficients were derived. The absolute cross section for EIE in Si(2+) (3s3p (3)P(sup o) - 3s3p (1)P(sup o)) was measured, and our experimental values for absolute cross sections for EIE in C(3+) (2s (2)S - 2p (2)P(sup o)) were reanalyzed and compared to values obtained by other experimental methods and by theory. In addition, a paper was published. The development and testing of the new ion source, the Si(2+) EIE measurements, and the reevaluation of the cross sections for C(3+) resulted from the Ph.D. research of Paul H. Janzen who completed the degree requirements for the Harvard University Department of Physics in 2002. John Kohl served as the Ph.D.Thesis Advisor. Because of delays in bringing the new ion source on line, the measurements of EIE in C(2+) (2s2p (3)P(sup o) - (2)p(sup 2) (3)P) were not completed until 2004. Preparations for measurements of EIE in C(2+) (1s(sup 2) (1)S - 2s2p (1)P(sup o)) are currently underway.

  5. Laboratory studies of the 1984 influenza epidemic on the Witwatersrand.

    PubMed

    Schoub, B D; Johnson, S; McAnerney, J M; Martin, E; dos Santos, I L

    1986-12-20

    A particularly severe outbreak of influenza occurred on the Witwatersrand from May to August 1984, caused sequentially by influenza A (H3N2), B/influenza and influenza A (H1N1) viruses. Although the precise extent of the infection was impossible to determine, valuable anecdotal information was provided by a network of sentinel sampling stations in private practices, clinics and hospitals, representing a cross-section of population groups on the Witwatersrand. This active surveillance programme was invaluable in providing some 85% of all the specimens, the remainder being routine clinical specimens; in addition, isolation was approximately twice as efficient for the actively acquired specimens than for the routine ones. The epidemic affected all individuals approximately equally, regardless of age, race or socio-economic status. Infection with H1N1 virus tended to predominate in the younger age group, 78% of isolates being from subjects under 30 years of age, whereas 71% of H3N2 isolates came from subjects over 30 years of age. The B/influenza isolates tended to be more evenly dispersed. Novel strains of B/influenza and H1N1 viruses were introduced into the country and possibly contributed to the greater than usual severity of the epidemic. An active surveillance programme is essential to monitor the extent of influenza virus activity and to alert virologists to the introduction of new strains, although at present forecasting of future influenza epidemics is not possible with any significant degree of reliability.

  6. Inertial-fusion-reactor studies at Lawrence Livermore National Laboratory

    SciTech Connect

    Monsler, M.J.; Meier, W.R.

    1982-08-01

    We present results of our reactor studies for inertial-fusion energy production. Design studies of liquid-metal wall chambers have led to reactors that are remarkably simple in design, and that promise long life and low cost. Variants of the same basic design, called HYLIFE, can be used for electricity production, as a fissile-fuel factory, a dedicated tritium breeder, or hybrids of each.

  7. 7 CFR 1710.253 - Engineering and cost studies-addition of generation capacity.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 7 Agriculture 11 2010-01-01 2010-01-01 false Engineering and cost studies-addition of generation... TO ELECTRIC LOANS AND GUARANTEES Construction Work Plans and Related Studies § 1710.253 Engineering... engineering and cost studies as specified by RUS. The studies shall cover a period from the beginning of...

  8. 7 CFR 1710.253 - Engineering and cost studies-addition of generation capacity.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 7 Agriculture 11 2011-01-01 2011-01-01 false Engineering and cost studies-addition of generation... TO ELECTRIC LOANS AND GUARANTEES Construction Work Plans and Related Studies § 1710.253 Engineering... engineering and cost studies as specified by RUS. The studies shall cover a period from the beginning of...

  9. 7 CFR 1710.253 - Engineering and cost studies-addition of generation capacity.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 7 Agriculture 11 2013-01-01 2013-01-01 false Engineering and cost studies-addition of generation... TO ELECTRIC LOANS AND GUARANTEES Construction Work Plans and Related Studies § 1710.253 Engineering... engineering and cost studies as specified by RUS. The studies shall cover a period from the beginning of...

  10. 7 CFR 1710.253 - Engineering and cost studies-addition of generation capacity.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 7 Agriculture 11 2014-01-01 2014-01-01 false Engineering and cost studies-addition of generation... TO ELECTRIC LOANS AND GUARANTEES Construction Work Plans and Related Studies § 1710.253 Engineering... engineering and cost studies as specified by RUS. The studies shall cover a period from the beginning of...

  11. 7 CFR 1710.253 - Engineering and cost studies-addition of generation capacity.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 7 Agriculture 11 2012-01-01 2012-01-01 false Engineering and cost studies-addition of generation... TO ELECTRIC LOANS AND GUARANTEES Construction Work Plans and Related Studies § 1710.253 Engineering... engineering and cost studies as specified by RUS. The studies shall cover a period from the beginning of...

  12. Part-whole bias in intertemporal choice: An empirical study of additive assumption

    NASA Astrophysics Data System (ADS)

    Lu, Yang; Wu, Dongmei; Zhuang, Xintian

    2016-12-01

    Additive assumption means the overall value of multiple-dated outcomes is based on a simple aggregation of the values of each individual outcome. This assumption is generally accepted in the field of intertemporal choices. However, recent studies show additive assumption is questionable. In this paper, we experimentally tested the additive property of multiple-dated monetary rewards. Our results show: (1) additive assumption does not hold regardless of gain or loss; (2) the sum of subjective values of individual rewards is consistently larger than the valuation placed on the same rewards as a whole. This finding suggests that part-whole bias exists in the context of valuation of intertemporal monetary rewards.

  13. [LABORATORY AND EXPERIMENTAL STUDY OF THE COMPLEX PROBIOTIC PREPARATION "BIFILACT-BILS" IN CAPSULATED FORM].

    PubMed

    Neschislyaev, V A; Stolbova, M G; Mokin, P A; Orlova, E V; Ershov, A E

    2016-01-01

    The composition and technology of complex probiotic in hard gelatin capsules was developed in Perm Branch "Biomed" of "Microgen" State Company. The preparation contains three production strains: Lactobacillus plantarum 8P-A3, L. acidophilus K3W24 and Bifidobacterium bifidum 1. Laboratory and experimental (preclinical) study of the probiotic included investigation of the antagonistic activity, "acute" and "chronic" toxicity, the effect of the preparation on histology and hematology of laboratory animals. The result of these studies suggested of the probiotic had high inhibitory activity against pathogenic microflora when compared with probiotic monopreparations and had no toxic effects on laboratory animals.

  14. Electric air filtration: theory, laboratory studies, hardware development, and field evaluations

    SciTech Connect

    Bergman, W.; Biermann, A.; Kuhl, W.; Lum, B.; Bogdanoff, A.; Hebard, H.; Hall, M.; Banks, D.; Mazumder, M.; Johnson, J.

    1983-09-01

    We summarize the results of a seven-year research project for the US Department of Energy (DOE) to develop electric air filters that extend the service life of high-efficiency particulate air (HEPA) filters used in the nuclear industry. This project was unique to Lawrence Livermore National Laboratory (LLNL), and it entailed comprehensive theory, laboratory studies, and hardware development. We present our work in three major areas: (1) theory of and instrumentation for filter test methods, (2) theoretical and laboratory studies of electric air filters, and (3) development and evaluation of eight experimental electric air filters.

  15. Global Inter-Laboratory Fecal Source Identification Methods Comparison Study

    EPA Science Inventory

    Source tracking is key to identifying sources of fecal contamination for remediation as well as risk assessment. Previous intra- and inter-lab studies have investigated the performance of human and cow-associated source tracking markers, as well as library-dependent fecal source ...

  16. Laboratory of plasma studies. Papers on high power particle beams

    SciTech Connect

    Not Available

    1990-01-01

    This book contains paper on Exploding metal film active anode sources experiments on the Lion extractor Ion Diode; Long conductor time plasma opening switch experiments; and Focusing studies of an applied B{sub r} extraction diode on the Lion accelerator.

  17. A Study of Language Laboratory Teaching in German.

    ERIC Educational Resources Information Center

    Jiven, L. M.

    This report contains experiment results obtained from a comparative study of two groups of seventh grade students learning German in Sweden. The main objectives of the investigation, which lasted one school year, are: (1) to investigate possible achievement differences in German between similar groups of students when one group is instructed…

  18. Laboratories for the 21st Century: Case Studies, Molecular Foundry, Berkeley, California

    SciTech Connect

    Not Available

    2010-11-01

    This case study provides information on the Molecular Foundry, which incorporates Labs21 principles in its design and construction. The design includes many of the strategies researched at Lawrence Berkeley Laboratory for energy efficient cleanroom and data centers.

  19. [Providing studies quality for pesticides risk evaluation in their use according to proper laboratory practice rules].

    PubMed

    Rakitskiy, V N; Bereznyak, I V

    2016-01-01

    The article covers experience of proper laboratory practice in hygienic studies examining air and workers' skin for assessment of exposure levels of pesticides in natural conditions of agricultural production.

  20. ENHANCED BIOREMEDIATION UTILIZING HYDROGEN PEROXIDE AS A SUPPLEMENTAL SOURCE OF OXYGEN: A LABORATORY AND FIELD STUDY

    EPA Science Inventory

    Laboratory and field scale studies were conducted to investigate the feasibility of using hydrogen peroxide as a supplemental source of oxygen for bioremediation of an aviation gasoline fuel spill. Field samples of aviation gasoline contaminated aquifer material were artificially...

  1. Cancer prevention by tea: Evidence from laboratory studies.

    PubMed

    Yang, Chung S; Wang, Hong; Li, Guang Xun; Yang, Zhihong; Guan, Fei; Jin, Huanyu

    2011-08-01

    The cancer preventive activities of tea (Camellia sinensis Theaceae) have been studied extensively. Inhibition of tumorigenesis by green tea extracts and tea polyphenols has been demonstrated in different animal models, including those for cancers of the skin, lung, oral cavity, esophagus, stomach, small intestine, colon, bladder, liver, pancreas, prostate, and mammary glands. Many studies in cell lines have demonstrated the modulation of signal transduction and metabolic pathways by (-)-epigallocatechin-3-gallate (EGCG), the most abundant and active polyphenol in green tea. These molecular events can result in cellular changes, such as enhancement of apoptosis, suppression of cell proliferation, and inhibition of angiogenesis. Nevertheless, the molecular mechanisms of inhibition of carcinogenesis in animals and humans remain to be further investigated. Future research directions in this area are discussed.

  2. Air Force Geophysics Laboratory Management Information System Study.

    DTIC Science & Technology

    1985-11-01

    management information system (MIS) at AFGL. The study summarizes current management and administrative practices at AFGL. Requirements have been identified for automating several currently manual functions to compile accurate and timely information to better manage and plan AFGL programs. This document describes the functions and relative priorities of five MIS subsystems and provides suggestions for implementation solutions. Creation of a detailed Development Plan is recommended as the follow-on task.

  3. Country leadership and policy are critical factors for implementing laboratory accreditation in developing countries: a study on Uganda.

    PubMed

    Opio, Alex; Wafula, Winnie; Amone, Jackson; Kajumbula, Henry; Nkengasong, John N

    2010-09-01

    Accreditation of laboratories is one means to promote quality laboratory services, underscoring the need to document factors that facilitate laboratory accreditation. A desk review and key informant's interviews were conducted to determine the roles of country leadership and policies in laboratory accreditation. Overall, the review revealed that Uganda has enabling factors for laboratory accreditation, putting the country in a state of accreditation-readiness and including strong leadership that provides stewardship and availability of a national health laboratory policy with an explicit statement on laboratory accreditation. A National Laboratory Technical and Policy Committee coordinated the development of the policy. Laboratory training schools provide leadership in training laboratory professionals, while the Association of Medical Laboratory Technologists provides professional leadership. Although there is no national accreditation system, some laboratories are participating in international laboratory accreditation. Key informants expressed strong support for and observed that laboratory accreditation is beneficial and can be implemented in Uganda. Lessons from this study can benefit countries planning to implement laboratory accreditation. Countries that have not developed national laboratory policies and strategic plans should do so to guide the strengthening of laboratory systems and services as a part of health systems strengthening, which would be a springboard for laboratory accreditation.

  4. Oviposition behaviour of Phlebotomus argentipes - A laboratory-based study

    PubMed Central

    Kumar, Vijay; Rama, Aarti; Kesari, Shreekant; Bhunia, Gouri Sankar; Dinesh, Diwakar Singh; Das, Pradeep

    2013-01-01

    The breeding habitat of sandflies is a little studied and poorly understood phenomenon. More importantly, oviposition behaviour is a largely neglected aspect of sandfly biology and this knowledge gap further undermines our understanding of the biology of sandflies. Pheromones released by the eggs play an important role in identifying good sites for oviposition by female insects. Several recent studies have examined the oviposition pheromone. The present study provides a preliminary report on the oviposition behaviour of Phlebotomus argentipes, the only vector of kala-azar (or visceral leishmaniasis) on the Indian sub-continent. Sandflies prefer to oviposit their eggs on surfaces that contain organic substances, especially substances with an odour of decaying animal products and the remains of conspecific eggs. The results presented here suggest that the odour released by the organic substances of old sandfly colony remains that contain dead flies, old unhatched eggs, larval food containing vertebrate faeces, frass and other organic matter serves as an attractant for the ovipositing females of P. argentipes and hence greatly increases the number of oviposited eggs compared to eggs deposited in controlled oviposition pots. This result will be helpful in maintaining an efficient colony of P. argentipes and may be a promising tool for monitoring and controlling the target insect as part of a synergistic approach. PMID:24141963

  5. Laboratory study of nitrate photolysis in Antarctic snow. II. Isotopic effects and wavelength dependence

    SciTech Connect

    Berhanu, Tesfaye A.; Erbland, Joseph; Savarino, Joël; Meusinger, Carl; Johnson, Matthew S.; Jost, Rémy; Bhattacharya, S. K.

    2014-06-28

    Atmospheric nitrate is preserved in Antarctic snow firn and ice. However, at low snow accumulation sites, post-depositional processes induced by sunlight obscure its interpretation. The goal of these studies (see also Paper I by Meusinger et al. [“Laboratory study of nitrate photolysis in Antarctic snow. I. Observed quantum yield, domain of photolysis, and secondary chemistry,” J. Chem. Phys. 140, 244305 (2014)]) is to characterize nitrate photochemistry and improve the interpretation of the nitrate ice core record. Naturally occurring stable isotopes in nitrate ({sup 15}N, {sup 17}O, and {sup 18}O) provide additional information concerning post-depositional processes. Here, we present results from studies of the wavelength-dependent isotope effects from photolysis of nitrate in a matrix of natural snow. Snow from Dome C, Antarctica was irradiated in selected wavelength regions using a Xe UV lamp and filters. The irradiated snow was sampled and analyzed for nitrate concentration and isotopic composition (δ{sup 15}N, δ{sup 18}O, and Δ{sup 17}O). From these measurements an average photolytic isotopic fractionation of {sup 15}ε = (−15 ± 1.2)‰ was found for broadband Xe lamp photolysis. These results are due in part to excitation of the intense absorption band of nitrate around 200 nm in addition to the weaker band centered at 305 nm followed by photodissociation. An experiment with a filter blocking wavelengths shorter than 320 nm, approximating the actinic flux spectrum at Dome C, yielded a photolytic isotopic fractionation of {sup 15}ε = (−47.9 ± 6.8)‰, in good agreement with fractionations determined by previous studies for the East Antarctic Plateau which range from −40 to −74.3‰. We describe a new semi-empirical zero point energy shift model used to derive the absorption cross sections of {sup 14}NO{sub 3}{sup −} and {sup 15}NO{sub 3}{sup −} in snow at a chosen temperature. The nitrogen isotopic fractionations obtained by applying

  6. Going GLP: Conducting Toxicology Studies in Compliance with Good Laboratory Practices.

    PubMed

    Carroll, Erica Eggers

    2016-01-01

    Good laboratory practice standards are US federal regulations enacted as part of the Federal Insecticide, Fungicide, and Rodenticide Act (40 CFR Part 160), the Toxic Substance Control Act (40 CFR Part 792), and the Good Laboratory Practice for Nonclinical Laboratory Studies (21 CFR Part 58) to support protection of public health in the areas of pesticides, chemicals, and drug investigations in response to allegations of inaccurate data acquisition. Essentially, good laboratory practices (GLPs) are a system of management controls for nonclinical research studies involving animals to ensure the uniformity, consistency, reliability, reproducibility, quality, and integrity of data collected as part of chemical (including pharmaceuticals) tests, from in vitro through acute to chronic toxicity tests. The GLPs were established in the United States in 1978 as a result of the Industrial Bio-Test Laboratory scandal which led to congressional hearings and actions to prevent fraudulent data reporting and collection. Although the establishment of infrastructure for GLPs compliance is labor-intensive and time-consuming, achievement and maintenance of GLP compliance ensures the accuracy of the data collected from each study, which is critical for defending results, advancing science, and protecting human and animal health. This article describes how and why those in the US Army Medical Department responsible for protecting the public health of US Army and other military personnel made the policy decision to have its toxicology laboratory achieve complete compliance with GLP standards, the first such among US Army laboratories. The challenges faced and how they were overcome are detailed.

  7. Extraction of Carbon Dioxide from Seawater by an Electrochemical Acidification Cell. Part 2 - Laboratory Scaling Studies

    DTIC Science & Technology

    2011-04-11

    Acidification Cell Part II—Laboratory Scaling Studies HeatHer D. Willauer Navy Technology Center for Safety and Survivability Chemistry Division Felice...an Electrochemical Acidification Cell Part II—Laboratory Scaling Studies Heather D. Willauer, Felice DiMascio,* Dennis R. Hardy, M. Kathleen Lewis...Unclassified Unclassified Unclassified UL 18 Heather D. Willauer (202) 767-2673 Electrochemical acidification cell Seawater pH Carbon dioxide An

  8. Isentropic Compression Studies at the Los Alamos National High Magnetic Field Laboratory

    DTIC Science & Technology

    2011-06-01

    actinide samples in extremes of high magnetic field (to 300 Tesla) [1, 2]. A simple modification to the single-turn magnet has converted it to a fast...Isentropic Compression Studies At The Los Alamos National High Magnetic Field Laboratory 5a. CONTRACT NUMBER 5b. GRANT NUMBER 5c. PROGRAM ELEMENT ...Laboratory (NHMFL) at Los Alamos was originally designed to study actinide samples in extremes of high magnetic field (to 300 Tesla) [1, 2]. A simple

  9. A Laboratory Study Investigating the Feasibility of Applying Calcite-Type Coatings to Segregated Ballast Tanks

    DTIC Science & Technology

    1981-08-01

    A LABORATORY STUDY INVESTIGATIING THE FEASIBILITY OF APPLYING CALCITE -TYPE COATINGS TO SEGREGATED BALLAST TANKS AUGUST, 1981 Prepared by: Ocean City...Laboratory Study Investigating The Feasibility of Applying Calcite -Type Coatings to Segregated Ballast Tanks 5a. CONTRACT NUMBER 5b. GRANT NUMBER 5c...Executive Summary List of Figures I. Conclusions II. Introduction III. Background-The Development and Use of Calcite -Type Coatings IV. Experimental

  10. Ketene Formation in Interstellar Ices: A Laboratory Study

    NASA Technical Reports Server (NTRS)

    Hudson, Reggie L.; Loeffler, Mark Josiah

    2013-01-01

    The formation of ketene (H2CCO, ethenone) in polar and apolar ices was studied with in situ 0.8 MeV proton irradiation, far-UVphotolysis, and infrared spectroscopic analyses at 10-20 K. Using isotopically enriched reagents, unequivocal evidencewas obtained for ketene synthesis in H2O-rich and CO2-rich ices, and several reaction products were identified. Results from scavenging experiments suggested that ketene was formed by free-radical pathways, as opposed to acid-base processes or redox reactions. Finally, we use our results to draw conclusions about the formation and stability of ketene in the interstellar medium.

  11. Laboratory Studies of Heterogeneous Chemical Processes of Atmospheric Importance

    NASA Technical Reports Server (NTRS)

    Molina, Mario J.

    2004-01-01

    The objective of this study is to conduct measurements of chemical kinetics parameters for heterogeneous reactions of importance in the stratosphere and the troposphere. It involves the elucidation of the mechanism of the interaction of HCl vapor with ice surfaces, which is the first step in the heterogeneous chlorine activation processes, as well as the investigation of the atmospheric oxidation mechanism of soot particles emitted by biomass and fossil fuels. The techniques being employed include turbulent flow-chemical ionization mass spectrometry and optical ellipsometry, among others.

  12. Biodegradation of petroleum sludge and petroleum polluted soil by a bacterial consortium: a laboratory study.

    PubMed

    Gojgic-Cvijovic, G D; Milic, J S; Solevic, T M; Beskoski, V P; Ilic, M V; Djokic, L S; Narancic, T M; Vrvic, M M

    2012-02-01

    This article presents a study of the efficiency and degradation pattern of samples of petroleum sludge and polluted sandy soil from an oil refinery. A bacterial consortium, consisting of strains from the genera Pseudomonas, Achromobacter, Bacillus and Micromonospora, was isolated from a petroleum sludge sample and characterized. The addition of nitrogen and phosphorus nutrients and a chemical surfactant to both the samples and bioaugmentation to the soil sample were applied under laboratory conditions. The extent of biodegradation was monitored by the gravimetric method and analysis of the residual oil by gas chromatography. Over a 12-week experiment, the achieved degree of TPH (total petroleum hydrocarbon) degradation amounted to 82-88% in the petroleum sludge and 86-91% in the polluted soil. Gas chromatography-mass spectrometry was utilized to determine the biodegradability and degradation rates of n-alkanes, isoprenoids, steranes, diasteranes and terpanes. Complete degradation of the n-alkanes and isoprenoids fractions occurred in both the samples. In addition, the intensities of the peaks corresponding to tricyclic terpenes and homohopanes were decreased, while significant changes were also observed in the distribution of diasteranes and steranes.

  13. Nucleobases in Space: Laboratory Studies of Polycyclic Aromatic Nitrogen Heterocycles

    NASA Technical Reports Server (NTRS)

    Elsila, Jamie; Mattioda, Andy; Bernstein, Max; Sandford, Scott; Hudgins, Doug

    2005-01-01

    Polycyclic Aromatic Nitrogen Heterocycles (PANHs) are heterocyclic aromatics Le., PAHs with carbon atoms replaced by a nitrogen atom. These molecules have been detected in meteorite extracts, and in general these nitrogen heterocycles are of astrobiological interest since this class of molecules include nucleobases, basic components of our nucleic acids. These compounds are predicted to be present in the interstellar medium and in Titan tholin, but have received relatively little attention. We will present spectra and reactions of PANHs, frozen in solid H2O at 12 K, conditions germane to astronomical observations. In contrast to simple PAHs, that do not interact strongly with solid H2O, the nitrogen atoms in PANHs are potentially capable of hydrogen bonding with H20 changing their spectra, complicating their remote detection on the surfaces of icy bodies. Moreover, we have studied the photo-chemistry of these interesting compounds under astrophysical conditions and will use our lab studies to assess a potential interstellar heritage of these compounds in carbonaceous chondrites.

  14. Laboratory Studies in UV and EUV Solar Physics

    NASA Technical Reports Server (NTRS)

    Parkinson, W. H.; Wagner, William J. (Technical Monitor)

    2002-01-01

    The Ion Beam Experiment at the Center for Astrophysics is dedicated to the study of ion-electron collision processes of importance in solar physics. The analysis of measurements of Electron Impact Excitation (EIE) from the 3s3p(exp 3)P(exp o) metastable state to the 3s3p(exp 1)P state of Si(2+) was completed during the past year and a paper describing the results is available as a preprint. Our current program is directed at measuring absolute cross sections for dielectronic recombination (DR) and EIE in Si(3+), one of the primary ions used for probing the solar transition region. Our study of DR is particularly concerned with the effects of electric and magnetic fields on the recombination rates. Measurements of silicon ions with charge greater than n=2 have necessitated upgrading the experiment with a new ion source. The new source is also suitable for producing C(2+) beams to be used for measurements of EIE and DR for that system. The source is expected to be capable of producing beams of more highly charged systems as well.

  15. Laboratory study of corrosion of steam generator tubes: Preliminary results

    SciTech Connect

    Sala, B.; Organista, M.; Henry, K.; Erre, R.; Gelpi, A.; Cattant, F.; Dupin, M.

    1995-12-31

    The secondary side intergranular attack (IGA) and intergranular stress corrosion cracking (IGSCC) of steam generator tubes often occurs in crevices where impurities are concentrated, due to local elevated temperatures and restricted water flow. From the analysis of tubes pulled from plants, it is believed that alumino-silicates deposits and/or organic species may play a role in the development of IGA in near neutral environments. New observations suggest that similar environments and similar processes are operative inside the corroded grain boundaries. A former study using autoclave tests was mainly devoted to the formation of alumino-silicate deposits similar to those observed in plants. The present work pursued the study of local environments responsible for IGA/SC. It confirms former results on the catalytic decomposition of organic species into acetates and presents more details on the mechanism of formation of alumino-silicate deposits on alloy 600, particularly on the role of iron and, to a lesser extent, nickel cations. It was showed that, under the alumino-silicate deposits and in the presence of some organic species, a non-protective chromium rich layer may grow instead of the usual protective spinel oxide. The mechanism responsible for the formation of this layer is believed to involve interaction between iron and, to a lesser extent, nickel with silica and/or possible interaction between chromium and acetates. Preliminary capsule tests indicate that these conditions may induce the initiation of IGA.

  16. Field, Laboratory and Numerical Study of Turbulent Dispersion in Built Environments

    NASA Astrophysics Data System (ADS)

    Princevac, M.; Pan, H.; Bartolome, C.

    2009-09-01

    Field measurements were conducted in seven southern Californian cities. These included SF6 tracer studies in Wilmington and Palm Springs and traffic related particulate measurements in Los Angeles, Long Beach, Anaheim, Pasadena and Huntington Beach. Urban areas were selected to cover five typical building arrangements which are 1) low density settlement, 2) low-rise settlement, 3) mid-rise settlement, 4) high-rise settlement, and 5) strip mall with surface parking. In addition to SF6 and particulate concentration extensive micrometeorological measurements were performed at each site. The field experiments were accompanied with systematical laboratory modeling in a water channel. Detailed velocity and concentration fields within model urban settings were simultaneously measured by Particle Image Velocimetry (PIV) and Planar Laser Induced Fluorescence (PLIF) system. Model buildings were created from transparent acrylic blocks to allow for the whole plane measurements inside the urban canopy. Complexity of modeled urban areas ranged from uniform cubical arrays to scaled downtowns of Los Angeles, Long Beach and Huntington Beach. Numerical simulations of flows and dispersion in these urban areas were performed using three fundamentally different models: 1) AERMOD - similarity based US EPA regulatory model, 2) CFD k-e model, and 3) QUIC - semi empirical, fast response model. Performance of each numerical model will be discussed and the advantages and challenges of utilizing laboratory experiments to model urban flows will be presented. Surface energy balance components, measured via net radiometer, krypton hygrometer, sonic anemometer and heat flux plates were utilized to develop new models for estimates of sensible, latent and ground fluxes over different surfaces and surroundings. This extensive study for the first time explained phenomena of lateral channeling in regular arrays which is responsible for a sudden plume spread at the entrance of the obstacle array.

  17. Laboratory Studies of Heterogeneous Chemical Processes of Atmospheric Importance

    NASA Technical Reports Server (NTRS)

    Molina, Mario J.

    2003-01-01

    The objective of this study is to conduct measurements of chemical kinetics parameters for heterogeneous reactions of importance in the stratosphere and the troposphere. It involves the elucidation of the mechanism of the interaction of HC1 vapor with ice surfaces, which is the first step in the heterogeneous chlorine activation processes, as well as the investigation of the atmospheric oxidation mechanism of soot particles emitted by biomass and fossil fuels. The techniques being employed include turbulent flow- chemical ionization mass spectrometry and optical ellipsometry, among others. The next section summarizes our research activities during the first year of the project, and the section that follows consists of the statement of work for the second year.

  18. KETENE FORMATION IN INTERSTELLAR ICES: A LABORATORY STUDY

    SciTech Connect

    Hudson, Reggie L.; Loeffler, Mark J.

    2013-08-20

    The formation of ketene (H{sub 2}CCO, ethenone) in polar and apolar ices was studied with in situ 0.8 MeV proton irradiation, far-UV photolysis, and infrared spectroscopic analyses at 10-20 K. Using isotopically enriched reagents, unequivocal evidence was obtained for ketene synthesis in H{sub 2}O-rich and CO{sub 2}-rich ices, and several reaction products were identified. Results from scavenging experiments suggested that ketene was formed by free-radical pathways, as opposed to acid-base processes or redox reactions. Finally, we use our results to draw conclusions about the formation and stability of ketene in the interstellar medium.

  19. Effect of polymers on the imbibition process; A laboratory study

    SciTech Connect

    Ghedan, S.G. ); Poettmann, F.H. )

    1991-02-01

    Polymer flooding of fractured reservoirs is common. In water-wet fractured reservoirs, the primary recovery mechanism may be imbibition. This paper presents results of an experimental study investigating the effect of polymers on the imbibition process. Two sets of experiments, static and dynamic, were performed. The static experiments showed that the amounts of oil ultimately recovered by water and polymer-solution imbibition are practically equal. The rate of oil recovery by the polymer solutions, however, is always less than the rate with water. The dynamic experiments consisted of flooding oil-saturated fractured cores through the fractures. The oil-recovery behavior in these experiments depended not only on the rate of injected fluid imbibition from the fracture into the matrix blocks, but also on the operating injection rate and the efficiency of the injected fluid in displacing the oil in the fracture.

  20. Atmospheric chemistry: Laboratory studies of kinetics of important reactions

    NASA Astrophysics Data System (ADS)

    Smith, S. J.

    Experiments to measure the rate constants for some reactions of the atmospherically important nitrate radical (NO3) are described using the discharge-flow technique. The nitrate radical was monitored by optical absorption at lambda = 662 nm. The reactions of NO3 with some stable organic and inorganic substrates are reported. The temperature dependences of some of the rate constants were also determined (298 less than T less than 523 K). In most cases, computer simulation was used to extract the rate constant for the primary process because the time-dependent behavior of (NO3) was affected by secondary reactions of NO3 with products of the primary interaction. The Arrhenius parameter for the reactions of NO3 with CH3CH3, CH2CH2, CH3OH, CHCl3, and HCl were determined. The activation energies for the reactions studied between NO3 and some alkynes are presented along with the corresponding pre-exponential factors. Some reactions were studied at room temperature (298 plus or minus 2 K) only and the rate constants found (in units of cubic cm/molecule sec) are: buta-1,3-diene (1.8 x 10 (exp -13), isobutene (2.8 x 10 (exp -13), HBr (1.3 x 10 (exp -15) and hex-2-yne (3.0 x 10 (exp -14). Non-Arrhenius behavior was found in the reactions of NO3 with n-butane, isobutane and propene. The empirical variation of these rate constants with temperature is presented. The curvature of the Arrhenius plots is discussed in terms of (1) a temperature-dependent pre-exponential factor, and (2) the possibility that two competing channels, possessing differing activation energies, exist for each reaction. The atmospheric implications of these reactions are discussed with reference to the nighttime production of nitric acid and the importance of the these reactions as loss processes for NO3.

  1. Multiple Intravenous Infusions Phase 2b: Laboratory Study

    PubMed Central

    Pinkney, Sonia; Fan, Mark; Chan, Katherine; Koczmara, Christine; Colvin, Christopher; Sasangohar, Farzan; Masino, Caterina; Easty, Anthony; Trbovich, Patricia

    2014-01-01

    Background Administering multiple intravenous (IV) infusions to a single patient via infusion pump occurs routinely in health care, but there has been little empirical research examining the risks associated with this practice or ways to mitigate those risks. Objectives To identify the risks associated with multiple IV infusions and assess the impact of interventions on nurses’ ability to safely administer them. Data Sources and Review Methods Forty nurses completed infusion-related tasks in a simulated adult intensive care unit, with and without interventions (i.e., repeated-measures design). Results Errors were observed in completing common tasks associated with the administration of multiple IV infusions, including the following (all values from baseline, which was current practice): setting up and programming multiple primary continuous IV infusions (e.g., 11.7% programming errors) identifying IV infusions (e.g., 7.7% line-tracing errors) managing dead volume (e.g., 96.0% flush rate errors following IV syringe dose administration) setting up a secondary intermittent IV infusion (e.g., 11.3% secondary clamp errors) administering an IV pump bolus (e.g., 11.5% programming errors) Of 10 interventions tested, 6 (1 practice, 3 technology, and 2 educational) significantly decreased or even eliminated errors compared to baseline. Limitations The simulation of an adult intensive care unit at 1 hospital limited the ability to generalize results. The study results were representative of nurses who received training in the interventions but had little experience using them. The longitudinal effects of the interventions were not studied. Conclusions Administering and managing multiple IV infusions is a complex and risk-prone activity. However, when a patient requires multiple IV infusions, targeted interventions can reduce identified risks. A combination of standardized practice, technology improvements, and targeted education is required. PMID:26316919

  2. Laboratory studies on secondary organic aerosol formation from terpenes.

    PubMed

    Iinuma, Yoshiteru; Böge, Olaf; Miao, Yunkun; Sierau, Berko; Gnauk, Thomas; Herrmann, Hartmut

    2005-01-01

    The formation of secondary organic aerosol (SOA) following the ozonolysis of terpene has been investigated intensively in recent years. The enhancement of SOA yields from the acid catalysed reactions of organics on aerosol surfaces or in the bulk particle phase has been receiving great attention. Recent studies show that the presence of acidic seed particles increases the SOA yield significantly (M. S. Jang and R. M. Kamens, Environ. Sci. Technol., 2001, 35, 4758, ref. 1; M. S. Jang, N. M. Czoschke, S. Lee and R. M. Kamens, Science, 2002, 298, 814, ref. 2; N. M. Czoschke, M. Jang and R. M. Kamens, Atmos. Environ., 2003, 37, 4287, ref. 3; M. S. Jang, B. Carroll, B. Chandramouli and R. M. Kamens, Environ. Sci. Technol., 2003, 37, 3828, ref. 4; Y. Iinuma, O. Böge, T. Gnauk and H. Herrmann, Atmos. Environ., 2004, 38, 761, ref. 5; S. Gao, M. Keywood, N. L. Ng, J. Surratt, V. Varutbangkul, R. Bahreini, R. C. Flagan and J. H. Seinfeld, J. Phys. Chem. A, 2004, 108, 10147, ref. 6). More detailed studies report the formation of higher molecular weight products in SOA (refs. 5 and 6; M. P. Tolocka, M. Jang, J. M. Ginter, F. J. Cox, R. M. Kamens and M. V. Johnston, Environ. Sci. Technol., 2004, 38, 1428, ref. 7; S. Gao, N. L. Ng, M. Keywood, V. Varutbangkul, R. Bahreini, A. Nenes, J. He, K. Y. Yoo, J. L. Beauchamp, R. P. Hodyss, R. C. Flagan and J. H. Seinfeld, Environ. Sci. Technol., 2004, 38, 6582, ref. 8) which could result in a non-reversible uptake of organics into the particle phase. Most of the past studies concentrated on the characterisation of the yields of enhanced SOA and its composition from ozonolysis of terpenes in the presence or absence of acidic and neutral seed particles. Recent findings from cyclohexene ozonolysis show that the presence of OH scavengers can also significantly influence the SOA yield. Our new results from the IfT chemistry department aerosol chamber on terpene ozonolysis in the presence of OH scavengers show that the presence of hydroxyl

  3. Laboratory Studies in UV and EUV Solar Physics

    NASA Technical Reports Server (NTRS)

    Parkinson, William

    2003-01-01

    The Ion Beam Experiment at the Center for Astrophysics is dedicated to the study of ion-electron collision processes of importance in solar physics. A paper describing our most recent measurement 'Absolute cross section for Si(2+)(3s3p(sup 3)Rho (sup 0) yields 3s3p(sup 1)Rho(sup 0)) electron-impact excitation' was published during the past year. Dr. Paul Janzen received his PhD. from the Harvard Physics Department on the basis of this and other work, such as the new electron cyclotron resonance (ECR) ion source. The ion source is producing stable beams with large currents for our present work on C(2+), and it also produces stable beams with large currents of more highly charged systems, for future work on systems such as O(4+). The past year has been focussed on our current program to measure absolute cross sections for Electron Impact Excitation (EIE) in C(2+), one of the primary ions used for probing the solar transition region. C(2+) beams produced by the ion source have been transported to the interaction region of the experiment, where the collisions are studied, and Visiting Scientist Dr. Adrian Daw is currently collecting data to measure the C(2+)(2s2p(sup 3)Rho(sup 0) yields 2p(sup 2)(sup 3)Rho) EIE cross section as a function of collision energy, under the guidance of Drs. John Kohl, Larry Gardner and Bill Parkinson. Also this year, modifications were made to the ECR ion source in order to produce greater currents of highly charged ions. Testing of the ion source was completed. Modifications were designed to extend the photon detection capabilities of the apparatus to shorter UV wavelengths, or EUV. Following the work on C(2+)(2s2p(sup 3)Pho(sup 0) yields 2p(sup 2)(sup 3)Rho), the extended UV detection capabilities will be used to measure the C(2+)(2s(sup 2)(sup 1)S yields 2s2p(sup 1)Rho(sup 0)) EIE cross section. The EUV modifications complement those of the new ion source, by enabling detection of EUV light generated by high charge state ions and putting

  4. Microseismicity Induced by Fluid Pressure Drop (Laboratory Study)

    NASA Astrophysics Data System (ADS)

    Turuntaev, Sergey; Zenchenko, Evgeny; Melchaeva, Olga

    2013-04-01

    Pore pressure change in saturated porous rocks may result in its fracturing (Maury et Fourmaintraux, 1993) and corresponding microseismic event occurrences. Microseismicity due to fluid injection is considered in numerous papers (Maxwell, 2010, Shapiro et al., 2005). Another type of the porous medium fracturing is related with rapid pore pressure drop at some boundary. The mechanism of such fracturing was considered by (Khristianovich, 1985) as a model of sudden coal blowing and by (Alidibirov, Panov, 1998) as a model of volcano eruptions. If the porous saturated medium has a boundary where it directly contacted with fluid under the high pressure (in a hydraulic fracture or in a borehole), and the pressure at that boundary is dropped, the conditions for tensile cracks can be achieved at some distance from the boundary. In the paper, the results of experimental study of saturated porous sample fracturing due to pore pressure rapid drop are discussed. The samples (82 mm high, ∅60 mm) were made of quartz sand, which was cemented by "liquid glass" glue with mass fraction 1%. The sample (porosity 35%, uniaxial unconfined compression strength 2.5 MPa) was placed in a mould and saturated by oil. The upper end of the sample contacted with the mould upper lid, the lower end contacted with fluid. The fluid pressure was increased to 10 MPa and then discharged through the bottom nipple. The pressure increases/drops were repeated 30-50 times. Pore pressure and acoustic emission (AE) were registered by transducers mounted into upper and bottom lids of the mould. It was found, that AE sources (corresponded to microfracturing) were spreading from the open end to the closed end of the sample, and that maximal number of AE events was registered at some distance from the opened end. The number of AE pulses increased with every next pressure drop, meanwhile the number of pulses with high amplitudes diminished. It was found that AE maximal rate corresponded to the fluid pressure

  5. Detection of Cryptosporidium and Giardia in clinical laboratories in Europe--a comparative study.

    PubMed

    Manser, M; Granlund, M; Edwards, H; Saez, A; Petersen, E; Evengard, B; Chiodini, P

    2014-01-01

    To determine the routine diagnostic methods used and compare the performance in detection of oocysts of Cryptosporidium species and cysts of Giardia intestinalis in faecal samples by European specialist parasitology laboratories and European clinical laboratories. Two sets of seven formalin-preserved faecal samples, one containing cysts of Giardia intestinalis and the other, containing oocysts of Cryptosporidium, were sent to 18 laboratories. Participants were asked to examine the specimens using their routine protocol for detecting these parasites and state the method(s) used. Eighteen laboratories answered the questionnaire. For detection of Giardia, 16 of them used sedimentation/concentration followed by light microscopy. Using this technique the lower limit of detection of Giardia was 17.2 cysts/mL of faeces in the best performing laboratories. Only three of 16 laboratories used fluorescent-conjugated antibody-based microscopy. For detection of Cryptosporidium acid-fast staining was used by 14 of the 17 laboratories that examined the samples. With this technique the lower limit of detection was 976 oocysts/mL of faeces. Fluorescent-conjugated antibody-based microscopy was used by only five of the 17 laboratories. There was variation in the lower limit of detection of cysts of Giardia and oocysts of Cryptosporidium between laboratories using the same basic microscopic methods. Fluorescent-conjugated antibody-based microscopy was not superior to light microscopy under the conditions of this study. There is a need for a larger-scale multi-site comparison of the methods used for the diagnosis of these parasites and the development of a Europe-wide laboratory protocol based upon its findings.

  6. [The external evaluation of study quality: the role in maintaining the reliability of laboratory information].

    PubMed

    Men'shikov, V V

    2013-08-01

    The external evaluation of quality of clinical laboratory examinations was gradually introduced in USSR medical laboratories since 1970s. In Russia, in the middle of 1990 a unified all-national system of external evaluation quality was organized known as the Federal center of external evaluation of quality at the basis of laboratory of the state research center of preventive medicine. The main positions of policy in this area were neatly formulated in the guidance documents of ministry of Health. Nowadays, the center of external evaluation of quality proposes 100 and more types of control studies and permanently extends their specter starting from interests of different disciplines of clinical medicine. The consistent participation of laboratories in the cycles of external evaluation of quality intrinsically promotes improvement of indicators of properness and precision of analysis results and increases reliability of laboratory information. However, a significant percentage of laboratories does not participate at all in external evaluation of quality or takes part in control process irregularly and in limited number of tests. The managers of a number of medical organizations disregard the application of the proposed possibilities to increase reliability of laboratory information and limit financing of studies in the field of quality control. The article proposes to adopt the national standard on the basis of ISO 17043 "Evaluation of compliance. The common requirements of professional competence testing".

  7. Atmospheric stability of levoglucosan: a detailed laboratory and modeling study.

    PubMed

    Hoffmann, D; Tilgner, A; Iinuma, Y; Herrmann, H

    2010-01-15

    Levoglucosan, an important molecular marker for biomass burning, represents an important fraction of the water-soluble organic carbon in atmospheric particles influenced by residential wood burning and wildfires. However, particle phase oxidation processes of levoglucosan by free radicals are not well-known. Hence, detailed kinetic studies on the reactivity of levoglucosan with OH, NO(3), and SO(4)(-) radicals in aqueous solutions were performed to better understand the levoglucosan oxidation in the deliquescent particles. The data obtained were implemented into a parcel model with detailed microphysics and complex multiphase chemistry to investigate the degradation fluxes of levoglucosan in cloud droplets and in deliquescent particles. The model calculations show that levoglucosan can be oxidized readily by OH radicals during daytime with mean degradation fluxes of about 7.2 ng m(-3) h(-1) in summer and 4.7 ng m(-3) h(-1) in winter for a polluted continental plume. This indicates that the oxidation of levoglucosan in atmospheric deliquescent particles is at least as fast as that of other atmospherically relevant organic compounds and levoglucosan may not be as stable as previously thought in the atmosphere, especially under high relative humidity conditions.

  8. Laboratory Studies on the Effects of Shear on Fish

    SciTech Connect

    Neitzel, Duane A.; Richmond, Marshall C.; Dauble, Dennis D.; Mueller, Robert P.; Moursund, Russell A.; Abernethy, Cary S.; Guensch, Greg R.

    2000-09-20

    The overall objective of our studies was to specify an index describing the hydraulic force that fish experience when subjected to a shear environment. Fluid shear is a phenomenon that is important to fish. However, elevated levels of shear may result in strain rates that injure or kill fish. At hydroelectric generating facilities, concerns have been expressed that strain rates associated with passage through turbines, spillways, and fish bypass systems may adversely affect migrating fish. Development of fish friendly hydroelectric turbines requires knowledge of the physical forces (injury mechanisms) that impact entrained fish and the fish's tolerance to these forces. It requires up-front, pre-design specifications for the environmental conditions that occur within the turbine system, in other words, determining or assuming that those conditions known to injure fish will provide the descriptions of conditions that engineers must consider in the design of a turbine system. These biological specifications must be carefully and thoroughly documented throughout the design of a fish friendly turbine. To address the development of biological specifications, we designed and built a test facility where juvenile fish could be subjected to a range of shear environments and quantified their biological response.

  9. Detonation chemistry studies of energetic materials using laboratory scale samples

    SciTech Connect

    Blais, N.C.; Greiner, N.R.; Fernandez, W.J.

    1989-01-01

    We describe an apparatus by which the detonation products of an explosive can be identified and whose relative concentrations can be determined quantitatively. These measurements can be made on products that have been formed in less than one microsecond after the passage of the detonation wave. The technique is based on the rapid quenching of chemical reactions by virtue of the free expansion of the products into vacuum. Of course, products that have been formed over a longer period of time and under different pressure/temperature conditions can also be studied. Time resolved molecular-beam mass spectrometry is used, so that whether detonation occurred or not in forming the products can be determined. We describe optical techniques, principally Schlieren photographs, that also confirm detonation. We report measurements made on six standard explosives, PETN, RDX, HMX, HNS, TNT and TATB, and one research explosive, nitric oxide. For none of the standard explosives do we measure product distributions that agree with model predictions based on equilibrium assumptions. A computer model of the free expansion is described briefly and its importance to the interpretation of the data is emphasized. 16 refs., 13 figs.

  10. Xenoendocrine disrupters: laboratory studies on male reproductive effects.

    PubMed

    Gray, L E

    1998-12-28

    Wildlife from ecosystems contaminated with endocrine disrupting chemicals (EDCs) display a variety of reproductive alterations including cryptorchidism in the Florida panther, small baculum in young male otters, small penises in alligators, sex reversal in fish, and altered social behavior in birds. It has been proposed that EDCs also may have contributed to increases in testicular cancer and hypospadias and the reported decline in human sperm counts. Combined in vivo and in vitro studies are necessary to fully characterize EDC induced alterations of reproduction. We have identified several pesticides (vinclozolin, procymidone, p,p'-DDE) which bind rat and human androgen receptors, block androgen-induced gene expression in vitro and in vivo, delay puberty, reduce sex accessory gland size and alter sex differentiation in the male rat. Some of the phthalates, which are estrogenic in vitro but not in vivo, cause malformations in male rats that appear to result from antagonism of androgens in utero. In contrast, xenoestrogens affect male offspring but they are not malformed or infertile. Prenatal administration of an Ah receptor agonist (2,3,7,8-TCDD or PCB 169) produces a different spectrum of effects including reduced ejaculated sperm numbers in male rats.

  11. Laboratory Experiments and Modeling for Interpreting Field Studies of Secondary Organic Aerosol Formation Using an Oxidation Flow Reactor

    SciTech Connect

    Jimenez, Jose-Luis

    2016-02-01

    This grant was originally funded for deployment of a suite of aerosol instrumentation by our group in collaboration with other research groups and DOE/ARM to the Ganges Valley in India (GVAX) to study aerosols sources and processing. Much of the first year of this grant was focused on preparations for GVAX. That campaign was cancelled due to political reasons and with the consultation with our program manager, the research of this grant was refocused to study the applications of oxidation flow reactors (OFRs) for investigating secondary organic aerosol (SOA) formation and organic aerosol (OA) processing in the field and laboratory through a series of laboratory and modeling studies. We developed a gas-phase photochemical model of an OFR which was used to 1) explore the sensitivities of key output variables (e.g., OH exposure, O3, HO2/OH) to controlling factors (e.g., water vapor, external reactivity, UV irradiation), 2) develop simplified OH exposure estimation equations, 3) investigate under what conditions non-OH chemistry may be important, and 4) help guide design of future experiments to avoid conditions with undesired chemistry for a wide range of conditions applicable to the ambient, laboratory, and source studies. Uncertainties in the model were quantified and modeled OH exposure was compared to tracer decay measurements of OH exposure in the lab and field. Laboratory studies using OFRs were conducted to explore aerosol yields and composition from anthropogenic and biogenic VOC as well as crude oil evaporates. Various aspects of the modeling and laboratory results and tools were applied to interpretation of ambient and source measurements using OFR. Additionally, novel measurement methods were used to study gas/particle partitioning. The research conducted was highly successful and details of the key results are summarized in this report through narrative text, figures, and a complete list of publications acknowledging this grant.

  12. Atmospheric Chemistry: Laboratory Studies of Kinetics of Important Reactions.

    NASA Astrophysics Data System (ADS)

    Smith, S. J.

    Available from UMI in association with The British Library. Requires signed TDF. This thesis describes the experiments to measure the rate constants for some reactions of the atmospherically important nitrate radical (NO_3) using the discharge-flow technique. The nitrate radical was monitored by optical absorption at lambda = 662 nm. The reactions of NO_3 with some stable organic and inorganic substrates are reported. The temperature dependences of some of the rate constants have also been determined (298 < T < 523 K). In most cases, computer simulation was used to extract the rate constant for the primary process because the time-dependent behaviour of (NO_3) was affected by secondary reactions of NO_3 with products of the primary interaction. The Arrhenius parameter in parentheses (E _{rm a}/kJ mol^ {-1}, A/cm^3 molecule ^{-1}s^ {-1} respectively) for the following reactions have been determined: ethane (37, 6.7 times 10^{-12}), ethylene (25.8, 6.3 times 10^ {-12}), CH_3OH (21.3, 1.2 times 10^ {-12}), CHCiota_3 (23.4, 8.6 times 10 ^{-13}) and HCl (27.7, 4 times 10^{-12}). The activation energies for the reactions studied between NO_3 and some alkynes are represented well by the value 25 +/- 3 kJ mol^{-1} and the corresponding pre-exponential factors (expressed as ln(10 ^{13}A/cm^3 molecule^{-1}s ^{-1}) are as follows: C_2H_2 (1.6 +/- 1.4), C_3H _4 (5.0 +/- 1.4), 1-C_4H_6 (5.8 +/- 1.0), 1-C_5 H_8 (5.7 +/- 0.6) and 1-C_6H _{10} (4.5 +/- 0.4). Some reactions were studied at room temperature _3(298 +/- 2 K) only and the rate constants found (in units of cm ^3 molecule^{ -1}s^{-1}) are: buta-1,3-diene (1.8 times 10 ^{-13}), isobutene (2.8 times 10^{-13 }), HBr (1.3 times 10 ^{-15}) and hex-2-yne (3.0 times 10^{-14 }). Non-Arrhenius behaviour was found in the reactions of NO_3 with n-butane, isobutane and propene. The empirical variation of these rate constants with temperature is well represented by the three parameter expressions:. k(T) = 1.2 times 10 ^{-46}T^{11

  13. Coronagraphic phase diversity: performance study and laboratory demonstration

    NASA Astrophysics Data System (ADS)

    Paul, B.; Sauvage, J.-F.; Mugnier, L. M.

    2013-04-01

    Context. The final performance of current and future instruments dedicated to exoplanet detection and characterization (such as SPHERE on the European Very Large Telescope, GPI on Gemini North, or future instruments on Extremely Large Telescopes) is limited by uncorrected quasi-static aberrations. These aberrations create long-lived speckles in the scientific image plane, which can easily be mistaken for planets. Aims: Common adaptive optics systems require dedicated components to perform wave-front analysis. The ultimate wave-front measurement performance is thus limited by the unavoidable differential aberrations between the wave-front sensor and the scientific camera. To reach the level of detectivity required by high-contrast imaging, these differential aberrations must be estimated and compensated for. In this paper, we characterize and experimentally validate a wave-front sensing method that relies on focal-plane data. Methods: Our method, called COFFEE (for COronagraphic Focal-plane wave-Front Estimation for Exoplanet detection), is based on a Bayesian approach, and it consists in an extension of phase diversity to high-contrast imaging. It estimates the differential aberrations using only two focal-plane coronagraphic images recorded from the scientific camera itself. Results: We first present a thorough characterization of COFFEE's performance by means of numerical simulations. This characterization is then compared with an experimental validation of COFFEE using an in-house adaptive optics bench and an apodized Roddier & Roddier phase mask coronagraph. An excellent match between experimental results and the theoretical study is found. Lastly, we present a preliminary validation of COFFEE's ability to compensate for the aberrations upstream of a coronagraph.

  14. Nitrogen limited biobarriers remove atrazine from contaminated water: laboratory studies.

    PubMed

    Hunter, William J; Shaner, Dale L

    2009-01-07

    Atrazine is one of the most frequently used herbicides. This usage coupled with its mobility and recalcitrant nature in deeper soils and aquifers makes it a frequently encountered groundwater contaminant. We formed biobarriers in sand filled columns by coating the sand with soybean oil; after which, we inoculated the barriers with a consortium of atrazine-degrading microorganisms and evaluated the ability of the barriers to remove atrazine from a simulated groundwater containing 1 mg L(-1) atrazine. The soybean oil provided a carbon rich and nitrogen poor substrate to the microbial consortium. Under these nitrogen-limiting conditions it was hypothesized that bacteria capable of using atrazine as a source of nitrogen would remove atrazine from the flowing water. Our hypothesis proved correct and the biobarriers were effective at removing atrazine when the nitrogen content of the influent water was low. Levels of atrazine in the biobarrier effluents declined with time and by the 24th week of the study no detectable atrazine was present (limit of detection<0.005 mg L(-1)). Larger amounts of atrazine were also removed by the biobarriers; when biobarriers were fed 16.3 mg L(-1) atrazine 97% was degraded. When nitrate (5 mg L(-1) N), an alternate source of nitrogen, was added to the influent water the atrazine removal efficiency of the barriers was reduced by almost 60%. This result supports the hypothesis that atrazine was degraded as a source of nitrogen. Poisoning of the biobarriers with mercury chloride resulted in an immediate and large increase in the amount of atrazine in the barrier effluents confirming that biological activity and not abiotic factors were responsible for most of the atrazine degradation. The presence of hydroxyatrazine in the barrier effluents indicated that dehalogenation was one of the pathways of atrazine degradation. Permeable barriers might be formed in-situ by the injection of innocuous vegetable oil emulsions into an aquifer or sandy soil

  15. Determination of Unknown Concentrations of Sodium Acetate Using the Method of Standard Addition and Proton NMR: An Experiment for the Undergraduate Analytical Chemistry Laboratory

    ERIC Educational Resources Information Center

    Rajabzadeh, Massy

    2012-01-01

    In this experiment, students learn how to find the unknown concentration of sodium acetate using both the graphical treatment of standard addition and the standard addition equation. In the graphical treatment of standard addition, the peak area of the methyl peak in each of the sodium acetate standard solutions is found by integration using…

  16. Laboratory studies on the effects of shear on fish: Final report

    SciTech Connect

    Neitzel, Duane A.; Richmond, M. C.; Dauble, D. D.; Mueller, R. P.; Moursund, R. A.; Abernethy, C. S.; Guensch, G. R.; Cada, G. F.

    2000-09-01

    The overall objective of these studies was to specify an index describing the hydraulic force that fish experience when subjected to a shear environment. Fluid shear is a phenomenon that is important to fish. However, elevated levels of shear may result in strain rates that injure or kill fish. At hydroelectric generating facilities, concerns have been expressed that strain rates associated with passage through turbines, spillways, and fish bypass systems may adversely affect migrating fish. Development of fish-friendly hydroelectric turbines requires knowledge of the physical forces (injury mechanisms) that impact entrained fish and the fish’s tolerance to these forces. It requires up-front, pre-design specifications for the environmental conditions that occur within the turbine system; in other words, determining or assuming conditions known to injure fish will assist engineers in the design of a fish-friendly turbine system. To address the development of biological specifications, this experiment designed and built a test facility where juvenile fish could be subjected to a range of shear environments and quantified their biological response. The test data reported here provide quantified strain rates and the relationship of these forces to direct and indirect biological effects on fish. The study concludes that juvenile salmonids and American shad should survive shear environments where strain rates do not exceed 500 cm/s/cm at a Dy of 1.8 cm. Additional studies are planned with a sensor fish to better link hydraulic conditions found within the laboratory and field environments.

  17. Design, development, testing and validation of a Photonics Virtual Laboratory for the study of LEDs

    NASA Astrophysics Data System (ADS)

    Naranjo, Francisco L.; Martínez, Guadalupe; Pérez, Ángel L.; Pardo, Pedro J.

    2014-07-01

    This work presents the design, development, testing and validation of a Photonic Virtual Laboratory, highlighting the study of LEDs. The study was conducted from a conceptual, experimental and didactic standpoint, using e-learning and m-learning platforms. Specifically, teaching tools that help ensure that our students perform significant learning have been developed. It has been brought together the scientific aspect, such as the study of LEDs, with techniques of generation and transfer of knowledge through the selection, hierarchization and structuring of information using concept maps. For the validation of the didactic materials developed, it has been used procedures with various assessment tools for the collection and processing of data, applied in the context of an experimental design. Additionally, it was performed a statistical analysis to determine the validity of the materials developed. The assessment has been designed to validate the contributions of the new materials developed over the traditional method of teaching, and to quantify the learning achieved by students, in order to draw conclusions that serve as a reference for its application in the teaching and learning processes, and comprehensively validate the work carried out.

  18. [Proposals for standardization of clinical laboratory studies: technology "cytological study of lymph node specimens"].

    PubMed

    Shabalova, I P; Morozova, V T; Dzhangirova, T V

    2010-11-01

    This proposal contains unique requirements for a cytological study of lymph node specimens at the cytological and clinical diagnostic laboratories of health care facilities certified for this kind of work. The paper gives requirements for the performance of technologies, for specialists and auxiliary personnel, specialists' knowledge and skills, medical staff safeguarding. The conditions for rendering a service, necessary equipment, ware, and reagents are described in details. The specific features of a pre-analytical stage, methods for the fixation and staining of smears, the interpretation and recording of findings, and the control of the quality of a performed study, as well as the cost characteristics in conventional units of man-hours. The developed technology may be of great importance to the health care facilities certified for rendering this service.

  19. A study of divergent TA teaching styles in inquiry-based laboratory education

    NASA Astrophysics Data System (ADS)

    Little, James H.

    This dissertation is a study of the divergent behaviors evidenced by different TAs teaching inquiry based physics laboratories with minimal preparation on how to use techniques such as Socratic dialogue, wait time, and time management. The revised physics laboratory curricula, a four semester laboratory sequence, were studied over the course of two years and one of the laboratory manuals was rewritten and new techniques of TA training developed in order to align TA behavior with the ideals of inquiry based education. This revision was only partially successful, aiding TAs dramatically in improving their time management skills and use of their time, however not yielding dramatic improvements in their use of Socratic dialogue or leading questions.

  20. Three cases of CLIPPERS: a serial clinical, laboratory and MRI follow-up study.

    PubMed

    Kastrup, O; van de Nes, J; Gasser, T; Keyvani, K

    2011-12-01

    The aim of the study was to further determine the pathophysiology, clinical course, MRI-features and response to therapy of chronic lymphocytic inflammation with pontine perivascular enhancement responsive to steroids (CLIPPERS), which has recently been proposed as a rare chronic inflammatory central nervous system disorder responsive to immunosuppressive therapy. Three patients with this rare entity underwent serial clinical and bimonthly MRI follow-up over a period of up to 16 months. Extensive laboratory work-up and brain biopsy were performed. Intravenous methylprednisolone or oral dexamethasone was administered as treatment, additionally cyclophosphamide in one patient. Clinically, diplopia, nystagmus, ataxia and facial paresthesia were the cardinal symptoms. Magnetic resonance imaging (MRI) disclosed patchy spot-like gadolinium enhancement in a "salt-and-pepper like appearance" in the pons, midbrain and cerebellum, in two cases with thalamic and in the other with spinal involvement. Brain biopsies demonstrated a predominantly angiocentric but also diffuse infiltration pattern by small mature lymphocytes. Treatment with steroids led to rapid clinical improvement and marked resolution of MRI lesions. As discontinuation of steroids led to clinical relapse, one patient was treated with a further course of steroids and the other with steroids and cyclophosphamide as immunosuppressive therapy. This led to stable remission with only mild clinical residue and normalization of MRI. Extensive laboratory and radiological work-up could not identify any other cause of the disease. Of note, in two cases a marked elevation of IgE in serum was found initially and throughout the course. CLIPPERS seems to be a distinct inflammatory central nervous system disorder. It shows characteristic MRI core features. Extrapontine involvement seems to be frequent. Histologically it is characterised by predominantly angiocentric infiltration by small mature lymphocytes. A pathogenetic

  1. Exotic Molecules in Space: A Coordinated Astronomical Laboratory and Theoretical Study

    NASA Technical Reports Server (NTRS)

    Springfellow, Guy (Technical Monitor); Shapiro, Irwin I.

    2004-01-01

    The present report covers the first year of a grant which represents a direct continuation of NASA NAG5-4050, with the same title as before. It is dedicated as before to the discovery and characterization of new astrophysical molecules. This year, has been extremely productive, yielding many new discoveries of astronomical interest at both radio and optical wavelengths, and the publication or submission of the 15 papers listed below. Nearly all of these articles have or will soon appear in the leading refereed journals of astrophysics, chemical physics, physics, or molecular spectroscopy. One is a major invited review for Molecular Physics. One of our other invited reviews published in Spectrochimica Acta in 2001 was recently awarded the Sir Harold Thompson Memorial Award, annually given to the best paper in that journal. During the past year significant advances have been made by our group in the laboratory study of exotic silicon and carbon molecules of astronomical interest. The most exciting discoveries include the pure silicon cluster Si3, several novel silicon hydrides, and the detection of phenyl radical, C6H5, a fundamental reactive organic ring. In addition, the rotational spectra of many carbon chains terminated with Si, N, O, and other heteroatoms have also been detected for the first time. The laboratory astrophysics of the whole set is complete in the sense that the entire radio spectrum of each species has now been measured or can be calculated to very high accuracy. Nearly all of these newly found molecules are plausible candidates for the detection by radio astronomers in the interstellar gas or in circumstellar sources because they are similar in structure and composition to known astronomical species, and because most are calculated to possess large permanent dipole moments.

  2. Exotic Molecules in Space: A Coordinated Astronomical Laboratory and Theoretical Study

    NASA Technical Reports Server (NTRS)

    Stringfellow, Guy (Technical Monitor); Thaddeus, Patrick

    2003-01-01

    The present report covers the third year of a grant which represents a direct continuation of NASA NAG5-4050, with the same title as before. It is dedicated as before to the discovery and characterization of new astrophysical molecules. This year, like the two before, has been extremely productive, yielding many new discoveries of astronomical interest at both radio and optical wavelengths, and the publication or submission of the 15 papers listed below. Nearly all of these articles have or will soon appear in the leading refereed journals of astrophysics, chemical physics, physics, or molecular spectroscopy. One is a major invited review for Molecular Physics. One of our other invited reviews published in Spectrochimica Acta in 2001 was recently awarded the Sir Harold Thompson Memorial Award, annually given to the best paper in that journal. During the past year significant advances have been made by our group in the laboratory study of exotic silicon and carbon molecules of astronomical interest. The most exciting discoveries include the pure silicon cluster Si3, several novel silicon hydrides, and the detection of phenyl radical, CsH5, a fundamental reactive organic ring. In addition, the rotational spectra of many carbon chains terminated with Si, N, O, and other heteroatoms have also been detected for the first time. The laboratory astrophysics of the whole set is complete in the sense that the entire radio spectrum of each species has now been measured or can be calculated to very high accuracy. Nearly all of these newly found molecules are plausible candidates for the detection by radio astronomers in the interstellar gas or in circumstellar sources because they are similar in structure and composition to known astronomical species, and because most are calculated to possess large permanent dipole moments.

  3. Impact of the addition of different plant residues on nitrogen mineralization-immobilization turnover and carbon content of a soil incubated under laboratory conditions

    NASA Astrophysics Data System (ADS)

    Kaleeem Abbasi, M.; Tahir, M. Mahmood; Sabir, N.; Khurshid, M.

    2015-02-01

    Application of plant residues as soil amendment may represent a valuable recycling strategy that affects carbon (C) and nitrogen (N) cycling in soil-plant systems. The amount and rate of nutrient release from plant residues depend on their quality characteristics and biochemical composition. A laboratory incubation experiment was conducted for 120 days under controlled conditions (25 °C and 58% water-filled pore space) to quantify initial biochemical composition and N mineralization of leguminous and non-leguminous plant residues, i.e., the roots, shoots and leaves of Glycine max, Trifolium repens, Zea mays, Populus euramericana, Robinia pseudoacacia and Elaeagnus umbellata, incorporated into the soil at the rate of 200 mg residue N kg-1 soil. The diverse plant residues showed a wide variation in total N, C, lignin, polyphenols and C / N ratio with higher polyphenol content in the leaves and higher lignin content in the roots. The shoot of Glycine max and the shoot and root of Trifolium repens displayed continuous mineralization by releasing a maximum of 109.8, 74.8 and 72.5 mg N kg-1 and representing a 55, 37 and 36% recovery of N that had been released from these added resources. The roots of Glycine max and Zea mays and the shoot of Zea mays showed continuous negative values throughout the incubation. After an initial immobilization, leaves of Populus euramericana, Robinia pseudoacacia and Elaeagnus umbellata exhibited net mineralization by releasing a maximum of 31.8, 63.1 and 65.1 mg N kg-1, respectively, and representing a 16, 32 and 33% N recovery, respectively. Nitrogen mineralization from all the treatments was positively correlated with the initial residue N contents (r = 0.89; p ≤ 0.01) and negatively correlated with lignin content (r = -0.84; p ≤ 0.01), C / N ratio (r = -0.69; p ≤ 0.05), lignin / N ratio (r = -0.68; p ≤ 0.05), polyphenol / N ratio (r = -0.73; p ≤ 0.05) and (lignin + polyphenol) : N ratio (r = -0.70; p ≤ 0.05) indicating a

  4. Impact of the addition of different plant residues on carbon-nitrogen content and nitrogen mineralization-immobilization turnover in a soil incubated under laboratory conditions

    NASA Astrophysics Data System (ADS)

    Abbasi, M. K.; Tahir, M. M.; Sabir, N.; Khurshid, M.

    2014-10-01

    Application of plant residues as soil amendment may represent a valuable recycling strategy that affects on carbon (C) and nitrogen (N) cycling, soil properties improvement and plant growth promotion. The amount and rate of nutrient release from plant residues depend on their quality characteristics and biochemical composition. A laboratory incubation experiment was conducted for 120 days under controlled conditions (25 °C and 58% water filled pore space (WFPS)) to quantify initial biochemical composition and N mineralization of leguminous and non-leguminous plant residues i.e. the roots, shoots and leaves of Glycine max, Trifolium repens, Zea mays, Poplus euramericana, Rubinia pseudoacacia and Elagnus umbellate incorporated into the soil at the rate of 200 mg residue N kg-1 soil. The diverse plant residues showed wide variation in total N, carbon, lignin, polyphenols and C/N ratio with higher polyphenol content in the leaves and higher lignin content in the roots. The shoot of G. max and the shoot and root of T. repens displayed continuous mineralization by releasing a maximum of 109.8, 74.8 and 72.5 mg N kg-1 and representing a 55, 37 and 36% of added N being released from these resources. The roots of G. max and Z. mays and the shoot of Z. mays showed continuous negative values throughout the incubation showing net immobilization. After an initial immobilization, leaves of P. euramericana, R. pseudoacacia and E. umbellate exhibited net mineralization by releasing a maximum of 31.8, 63.1 and 65.1 mg N kg-1, respectively and representing a 16, 32 and 33% of added N being released. Nitrogen mineralization from all the treatments was positively correlated with the initial residue N contents (r = 0.89; p ≤ 0.01), and negatively correlated with lignin content (r = -0.84; p ≤ 0.01), C/N ratio (r = -0.69; p ≤ 0.05), lignin/N ratio (r = -0.68; p ≤ 0.05), polyphenol/N ratio (r = -0.73; p ≤ 0.05) and ligin + polyphenol/N ratio (r = -0.70; p ≤ 0.05) indicating

  5. Biogas production from cheese whey wastewater: laboratory- and full-scale studies.

    PubMed

    Stamatelatou, K; Giantsiou, N; Diamantis, V; Alexandridis, C; Alexandridis, A; Aivasidis, A

    2014-01-01

    A two-phase system for biogas production from cheese whey wastewater (CWW) was designed, set up and operated at laboratory and full scale for a whole cheese production season (8-9 months). The high efficiency and stability of the laboratory-scale system was demonstrated under various organic loading rates (OLRs) reaching 13 g chemical oxygen demand (COD) L(-1)d(-1) and producing up to 9 L L(-1)d(-1) of biogas (approximately 55% in methane). The COD removal was above 95% and the pH was maintained above 6.3 without any chemical addition. The full-scale system was operated at lower OLRs than its normal capacity, following the good response and high stability in disturbances of the laboratory-scale unit.

  6. Evaluating Drugs and Food Additives for Public Use: A Case Studies Approach.

    ERIC Educational Resources Information Center

    Merritt, Sheridan V.

    1980-01-01

    Described is a case study used in an introductory college biology course that provides a basis for generating debate on an issue concerning the regulation of controversial food additives and prescription drugs. The case study contained within this article deals with drug screening, specifically with information related to thalidomide. (CS)

  7. Comparison of microbiological diagnosis of urinary tract infection in young children by routine health service laboratories and a research laboratory: Diagnostic cohort study

    PubMed Central

    Birnie, Kate; Hay, Alastair D.; Wootton, Mandy; Howe, Robin; MacGowan, Alasdair; Whiting, Penny; Lawton, Michael; Delaney, Brendan; Downing, Harriet; Dudley, Jan; Hollingworth, William; Lisles, Catherine; Little, Paul; O’Brien, Kathryn; Pickles, Timothy; Rumsby, Kate; Thomas-Jones, Emma; Van der Voort, Judith; Waldron, Cherry-Ann; Harman, Kim; Hood, Kerenza; Butler, Christopher C.; Sterne, Jonathan A. C.

    2017-01-01

    Objectives To compare the validity of diagnosis of urinary tract infection (UTI) through urine culture between samples processed in routine health service laboratories and those processed in a research laboratory. Population and methods We conducted a prospective diagnostic cohort study in 4808 acutely ill children aged <5 years attending UK primary health care. UTI, defined as pure/predominant growth ≥105 CFU/mL of a uropathogen (the reference standard), was diagnosed at routine health service laboratories and a central research laboratory by culture of urine samples. We calculated areas under the receiver-operator curve (AUC) for UTI predicted by pre-specified symptoms, signs and dipstick test results (the “index test”), separately according to whether samples were obtained by clean catch or nappy (diaper) pads. Results 251 (5.2%) and 88 (1.8%) children were classified as UTI positive by health service and research laboratories respectively. Agreement between laboratories was moderate (kappa = 0.36; 95% confidence interval [CI] 0.29, 0.43), and better for clean catch (0.54; 0.45, 0.63) than nappy pad samples (0.20; 0.12, 0.28). In clean catch samples, the AUC was lower for health service laboratories (AUC = 0.75; 95% CI 0.69, 0.80) than the research laboratory (0.86; 0.79, 0.92). Values of AUC were lower in nappy pad samples (0.65 [0.61, 0.70] and 0.79 [0.70, 0.88] for health service and research laboratory positivity, respectively) than clean catch samples. Conclusions The agreement of microbiological diagnosis of UTI comparing routine health service laboratories with a research laboratory was moderate for clean catch samples and poor for nappy pad samples and reliability is lower for nappy pad than for clean catch samples. Positive results from the research laboratory appear more likely to reflect real UTIs than those from routine health service laboratories, many of which (particularly from nappy pad samples) could be due to contamination. Health service

  8. Sorption, degradation and transport phenomena of alcohol ethoxysulfates in agricultural soils. Laboratory studies.

    PubMed

    Fernández-Ramos, C; Rodríguez-Gómez, R; Reis, M S; Zafra-Gómez, A; Verge, C; de Ferrer, J A; Pérez-Pascual, M; Vílchez, J L

    2017-03-01

    In the present work, laboratory studies were conducted in order to determine and model the sorption, degradation and transport processes of alcohol ethoxysulfates (AES), one of the most important groups of anionic surfactants. Adsorption/desorption isotherms were obtained for several structurally related AES ethoxymers (homologue AES-C12En with n = 0-10 ethoxymer units and homologue AES-C14En with n = 0-7 ethoxymer units) using a batch equilibrium method. Data were fitted to a linear and a Freundlich isotherm models. Additionally, experiments in continuous-flow soil columns were also carried out and the breakthrough curves observed for each compound were studied. Breakthrough curves were used to determine the fundamental parameters of the transport model (hydrodynamic dispersion coefficient, degradation rate constant and adsorption/desorption isotherm slope), that is the main phenomena that take place simultaneously when AES move through agricultural soil. When the results obtained for the AES ethoxymers are combined, they reveal a clear and consistent trend towards a sorption increase with the number of ethoxylated units and with the length of the alkyl chain that opens the possibility to estimate the values of the transport parameters for other structurally related ethoxymers.

  9. Laboratory-based versus non-laboratory-based method for assessment of cardiovascular disease risk: the NHANES I Follow-up Study cohort

    PubMed Central

    Gaziano, Thomas A; Young, Cynthia R; Fitzmaurice, Garrett; Atwood, Sidney; Gaziano, J Michael

    2008-01-01

    Summary Background Around 80% of all cardiovascular deaths occur in developing countries. Assessment of those patients at high risk is an important strategy for prevention. Since developing countries have limited resources for prevention strategies that require laboratory testing, we assessed if a risk prediction method that did not require any laboratory tests could be as accurate as one requiring laboratory information. Methods The National Health and Nutrition Examination Survey (NHANES) was a prospective cohort study of 14 407 US participants aged between 25–74 years at the time they were first examined (between 1971 and 1975). Our follow-up study population included participants with complete information on these surveys who did not report a history of cardiovascular disease (myocardial infarction, heart failure, stroke, angina) or cancer, yielding an analysis dataset N=6186. We compared how well either method could predict first-time fatal and non-fatal cardiovascular disease events in this cohort. For the laboratory-based model, which required blood testing, we used standard risk factors to assess risk of cardiovascular disease: age, systolic blood pressure, smoking status, total cholesterol, reported diabetes status, and current treatment for hypertension. For the non-laboratory-based model, we substituted body-mass index for cholesterol. Findings In the cohort of 6186, there were 1529 first-time cardiovascular events and 578 (38%) deaths due to cardiovascular disease over 21 years. In women, the laboratory-based model was useful for predicting events, with a c statistic of 0·829. The c statistic of the non-laboratory-based model was 0·831. In men, the results were similar (0·784 for the laboratory-based model and 0·783 for the non-laboratory-based model). Results were similar between the laboratory-based and non-laboratory-based models in both men and women when restricted to fatal events only. Interpretation A method that uses non-laboratory

  10. Pertinent case studies illustrating the need for laboratory accessibility for Doctors of Chiropractic: a clinical conundrum

    PubMed Central

    Crawford, John P; Gotlib, Allan C; Injeyan, H Stephen

    1997-01-01

    Current provincial legislation in various jurisdictions across Canada, serves to impede the utilization of the diagnostic laboratory by doctors of chiropractic. Chiropractic students both in Canada and the United States, are required to successfully complete an intensive course of study in the area of laboratory diagnosis, as a necessary aspect of the undergraduate educational curriculum. Unfortunately, Canadian graduate doctors of chiropractic and their patients, are not currently afforded the privilege of direct referral to a community diagnostic laboratory. Rather, chiropractors must enlist the assistance of other health care providers, namely medical doctors, to acquire various laboratory testing procedures. The premise of this paper is intended to demonstrate the necessity of revising such laws, in order to address the needs of those health care consumers who seek the services of the rapidly growing profession of chiropractic. Two clinical cases are presented as illustrative examples.

  11. [TG-FTIR study on pyrolysis of wheat-straw with abundant CaO additives].

    PubMed

    Han, Long; Wang, Qin-Hui; Yang, Yu-Kun; Yu, Chun-Jiang; Fang, Meng-Xiang; Luo, Zhong-Yang

    2011-04-01

    Biomass pyrolysis in presence of abundant CaO additives is a fundamental process prior to CaO sorption enhanced gasification in biomass-based zero emission system. In the present study, thermogravimetric Fourier transform infrared (TG-FTIR) analysis was adopted to examine the effects of CaO additives on the mass loss process and volatiles evolution of wheat-straw pyrolysis. Observations from TG and FTIR analyses simultaneously demonstrated a two-stage process for CaO catalyzed wheat-straw pyrolysis, different from the single stage process for pure wheat-straw pyrolysis. CaO additives could not only absorb the released CO2 but also reduce the yields of tar species such as toluene, phenol, and formic acid in the first stage, resulting in decreased mass loss and maximum mass loss rate in this stage with an increase in CaO addition. The second stage was attributed to the CaCO3 decomposition and the mass loss and maximum mass loss rate increased with increasing amount of CaO additives. The results of the present study demonstrated the great potential of CaO additives to capture CO2 and reduce tars yields in biomass-based zero emission system. The gasification temperature in the system should be lowered down to avoid CaCO3 decomposition.

  12. Studying Human Disease Genes in "Caenorhabditis Elegans": A Molecular Genetics Laboratory Project

    ERIC Educational Resources Information Center

    Cox-Paulson, Elisabeth A.; Grana, Theresa M.; Harris, Michelle A.; Batzli, Janet M.

    2012-01-01

    Scientists routinely integrate information from various channels to explore topics under study. We designed a 4-wk undergraduate laboratory module that used a multifaceted approach to study a question in molecular genetics. Specifically, students investigated whether "Caenorhabditis elegans" can be a useful model system for studying genes…

  13. Study raises questions about measurement of 'additionality,'or maintaining domestic health spending amid foreign donations.

    PubMed

    Garg, Charu C; Evans, David B; Dmytraczenko, Tania; Izazola-Licea, José-Antonio; Tangcharoensathien, Viroj; Ejeder, Tessa Tan-Torres

    2012-02-01

    Donor nations and philanthropic organizations increasingly require that funds provided for a specific health priority such as HIV should supplement domestic spending on that priority-a concept known as "additionality." We investigated the "additionality" concept using data from Honduras, Rwanda, and Thailand, and we found that the three countries increased funding for HIV in response to increased donor funding. In contrast, the study revealed that donors, faced with increased Global Fund resources for HIV in certain countries, tended to decrease their funding for HIV or shift funds for use in non-HIV health areas. More broadly, we found many problems in the measurement and interpretation of additionality. These findings suggest that it would be preferable for donors and countries to agree on how best to use available domestic and external funds to improve population health, and to develop better means of tracking outcomes, than to try to develop more sophisticated methods to track additionality.

  14. Past and Future Work on Radiobiology Mega-Studies: A Case Study At Argonne National Laboratory

    SciTech Connect

    Haley, Benjamin; Wang, Qiong; Wanzer, Beau; Vogt, Stefan; Finney, Lydia; Yang, Ping Liu; Paunesku, Tatjana; Woloschak, Gayle

    2011-09-06

    Between 1952 and 1992, more than 200 large radiobiology studies were conducted in research institutes throughout Europe, North America, and Japan to determine the effects of external irradiation and internal emitters on the lifespan and tissue toxicity development in animals. At Argonne National Laboratory, 22 external beam studies were conducted on nearly 700 beagle dogs and 50,000 mice between 1969 and 1992. These studies helped to characterize the effects of neutron and gamma irradiation on lifespan, tumorigenesis, and mutagenesis across a range of doses and dosing patterns. The records and tissues collected at Argonne during that time period have been carefully preserved and redisseminated. Using these archived data, ongoing statistical work has been done and continues to characterize quality of radiation, dose, dose rate, tissue, and gender-specific differences in the radiation responses of exposed animals. The ongoing application of newly-developed molecular biology techniques to the archived tissues has revealed gene-specific mutation rates following exposure to ionizing irradiation. The original and ongoing work with this tissue archive is presented here as a case study of a more general trend in the radiobiology megastudies. These experiments helped form the modern understanding of radiation responses in animals and continue to inform development of new radiation models. Recent archival efforts have facilitated open access to the data and materials produced by these studies, and so a unique opportunity exists to expand this continued research.

  15. Laboratory studies, analysis, and interpretation of the spectra of hydrocarbons present in planetary atmospheres including cyanoacetylene, acetylene, propane, and ethane

    NASA Technical Reports Server (NTRS)

    Blass, William E.; Daunt, Stephen J.; Peters, Antoni V.; Weber, Mark C.

    1990-01-01

    Combining broadband Fourier transform spectrometers (FTS) from the McMath facility at NSO and from NRC in Ottawa and narrow band TDL data from the laboratories with computational physics techniques has produced a broad range of results for the study of planetary atmospheres. Motivation for the effort flows from the Voyager/IRIS observations and the needs of Voyager analysis for laboratory results. In addition, anticipation of the Cassini mission adds incentive to pursue studies of observed and potentially observable constituents of planetary atmospheres. Current studies include cyanoacetylene, acetylene, propane, and ethane. Particular attention is devoted to cyanoacetylen (H3CN) which is observed in the atmosphere of Titan. The results of a high resolution infrared laboratory study of the line positions of the 663, 449, and 22.5/cm fundamental bands are presented. Line position, reproducible to better than 5 MHz for the first two bands, are available for infrared astrophysical searches. Intensity and broadening studies are in progress. Acetylene is a nearly ubiquitous atmospheric constituent of the outer planets and Titan due to the nature of methane photochemistry. Results of ambient temperature absolute intensity measurements are presented for the fundamental and two two-quantum hotband in the 730/cm region. Low temperature hotband intensity and linewidth measurements are planned.

  16. [Bootstrap method-based estimation on the confidence interval for additive interaction in cohort studies].

    PubMed

    Pan, Jin-ren; Chen, Kun

    2010-07-01

    Interaction assessment is an important step in epidemiological analysis. When etiological study is carried out, the logarithmic models such as logistic model or Cox proportional hazard model are commonly used to estimate the independent effects of the risk factors. However, estimating interaction between risk factors by the regression coefficient of the product term is on multiplicative scale, and for public-health purposes, it is supposed to be on additive scale or departure from additivity. This paper illustrates with a example of cohort study by fitting Cox proportional hazard model to estimate three measures for additive interaction which presented by Rothman. Adopting the S-Plus application with a built-in Bootstrap function, it is convenient to estimate the confidence interval for additive interaction. Furthermore, this method can avoid the exaggerated estimation by using ORs in a cohort study to gain better precision. When using the complex combination models between additive interaction and multiplicative interaction, it is reasonable to choose the former one when the result is inconsistent.

  17. Participation in Performance-Evaluation Studies by U.S. Geological Survey National Water Quality Laboratory

    USGS Publications Warehouse

    Glodt, Stephen R.; Pirkey, Kimberly D.

    1998-01-01

    Performance-evaluation studies provide customers of the U.S. Geological Survey National Water Quality Laboratory (NWQL) with data needed to evaluate performance and to compare of select laboratories for analytical work. The NWQL participates in national and international performance-evaluation (PE) studies that consist of samples of water, sediment, and aquatic biological materials for the analysis of inorganic constituents, organic compounds, and radionuclides. This Fact Sheet provides a summary of PE study results from January 1993 through April 1997. It should be of particular interest to USGS customers and potential customers of the NWQL, water-quality specialists, cooperators, and agencies of the Federal Government.

  18. [Studies on preanalytical phase errors in clinical chemistry in the Japanese clinical laboratory--now and the future].

    PubMed

    Tomita, Akio; Kizawa, Senji

    2007-05-01

    The Sampling Conference for the prevention of preanalytical phase errors was first held at Fukushima in 1987. Since then, The Sampling Conference has been held in several areas in Japan. For the same purpose, we started the Tokai Sampling Conference in the Tokai area including Aichi, Shizuoka, Gifu and Mie prefectures in 1990, and discussed clinical errors in laboratory measurements caused by physiological variations in age, sex and the season, influence of food, exercise, posture and medication, effects of anticoagulants, sample storage conditions and so on. We have studied many preanalytical errors at these conferences. Moreover, additional problems have been revealed at the conferences. Safety and risk management to avoid needle sticks and Vacutainer-induced infections have been discussed, and this information is thought to be important not only for laboratory workers but also for patients.

  19. Interoperability in hospital information systems: a return-on-investment study comparing CPOE with and without laboratory integration.

    PubMed

    Meyer, Rodolphe; Lovis, Christian

    2011-01-01

    Despite its many advantages, using a computerized patient record is still considered as a time consuming activity for care providers. In numerous situations, time is wasted because of the lack of interoperability between systems. In this study, we aim to assess the time gains that nursing teams could achieve with a tightly integrated computerized order entry system. Using a time-motion method, we compared expected versus effective time spent managing laboratory orders for two different computerized systems: one integrated, the other not integrated. Our results tend to show that nurses will complete their task an average of five times faster than their expected performance (p<0.001). We also showed that a tightly integrated system provides a threefold speed gain for nurses compared to a non-integrated CPOE with the laboratory information system (p<0.001). We evaluated the economic benefit of this gain, therefore arguing for a strong interoperability of systems, in addition to patient safety benefits.

  20. Comparative study of electrolyte additives using electrochemical impedance spectroscopy on symmetric cells

    NASA Astrophysics Data System (ADS)

    Petibon, R.; Sinha, N. N.; Burns, J. C.; Aiken, C. P.; Ye, Hui; VanElzen, Collette M.; Jain, Gaurav; Trussler, S.; Dahn, J. R.

    2014-04-01

    The effect of various electrolyte additives and additive combinations added to a 1 M LiPF6 EC:EMC electrolyte on the positive and negative electrodes surface of 1 year old wound LiCoO2/graphite cells and Li[Ni0.4Mn0.4Co0.2])O2/graphite cells was studied using electrochemical impedance spectroscopy (EIS) on symmetric cells. The additives tested were: vinylene carbonate (VC), trimethoxyboroxine (TMOBX), fluoroethylene carbonate (FEC), lithium bis(trifluoromethanesulfonyl)imide (LiTFSI), and H2O alone or in combination. In general, compared to control electrolyte, the additives tested reduced the impedance of the positive electrode and increased the impedance of the negative electrode with the exception of LiTFSI in Li[Ni0.4Mn0.4Co0.2]O2/graphite wound cells. Higher charge voltage led to higher positive electrode impedance, with the exception of 2%VC + 2% FEC, and 2% LiTFSI. In some cases, some additives when mixed with another controlled the formation of the SEI at one electrode, and shared the formation of the SEI at one electrode when mixed with a different additive.

  1. Water quality laboratories in Colombia: a GIS-based study of urban and rural accessibility.

    PubMed

    Wright, Jim; Liu, Jing; Bain, Robert; Perez, Andrea; Crocker, Jonny; Bartram, Jamie; Gundry, Stephen

    2014-07-01

    The objective of this study was to quantify sample transportation times associated with mandated microbiological monitoring of drinking-water in Colombia. World Health Organization Guidelines for Drinking-Water Quality recommend that samples spend no more than 6h between collection and analysis in a laboratory. Census data were used to estimate the minimum number of operational and surveillance samples required from piped water supplies under national regulations. Drive-times were then computed from each supply system to the nearest accredited laboratory and translated into sample holding times based on likely daily monitoring patterns. Of 62,502 surveillance samples required annually, 5694 (9.1%) were found to be more than 6 h from the nearest of 278 accredited laboratories. 612 samples (1.0%) were more than 24 hours' drive from the nearest accredited laboratory, the maximum sample holding time recommended by the World Health Organization. An estimated 30% of required rural samples would have to be stored for more than 6 h before reaching a laboratory. The analysis demonstrates the difficulty of undertaking microbiological monitoring in rural areas and small towns from a fixed laboratory network. Our GIS-based approach could be adapted to optimise monitoring strategies and support planning of testing and transportation infra-structure development. It could also be used to estimate sample transport and holding times in other countries.

  2. EFFECTS OF FOOD AVAILABILITY ON SURVIVAL, GROWTH, AND REPRODUCTION OF THE GRASS SHRIMP PALAEMONETES PUGIO: A LABORATORY STUDY

    EPA Science Inventory

    Grass shrimp are abundant, ecologically important inhabitants of estuarine ecosystems; adults and embryos have been used extensively in laboratory experiments, including studies of the impacts of environmental toxicants. However, optimal laboratory feeding conditions for grass sh...

  3. Are fish fed with cyanobacteria safe, nutritious and delicious? A laboratory study

    NASA Astrophysics Data System (ADS)

    Liang, Hualei; Zhou, Wenshan; Zhang, Yulei; Qiao, Qin; Zhang, Xuezhen

    2015-10-01

    Toxic cyanobacterial blooms, which produce cyclic heptapeptide toxins known as microcystins, are worldwide environmental problems. On the other hand, the cyanobacteria protein (30-50%) has been recommended as substitute protein for aquaculture. The present laboratory study verified the feasibility of cyanobacteria protein substitution and risk assessment. Goldfish were fed diets supplemented lyophilised cyanobacteria powder for 16 weeks with the various doses: 0% (control), 10%, 20%, 30% and 40%. Low doses (10% and 20%) promoted growth whereas high doses (30% and 40%) inhibited growth. In cyanobacteria treated fish, the proximate composition of ash, crude fat content and crude protein content decreased in 16 weeks; the saturated fatty acid (SFA) content significantly increased; the n-3 polyunsaturated fatty acid content, collagen content and muscle pH significantly decreased; cooking loss percents increased significantly. Muscle fiber diameter and myofibril length were negatively correlation. Additionally, flavour compounds (e.g., amino acids, nucleotides, organic acids and carnosine) changed significantly in the treated fish, and odour compounds geosmin and 2-methylisoborneol increased significantly. The estimated daily intake (EDI) of microcystins in muscle was close to or exceeded the World Health Organization (WHO) tolerable daily intake (TDI), representing a great health risk. Cyanobacterie is not feasible for protein sources use in aquaculture.

  4. Laboratory studies of low temperature rate coefficients: The atmospheric chemistry of the outer planets

    NASA Technical Reports Server (NTRS)

    Leone, Stephen R.

    1995-01-01

    The objectives of the research are to measure low temperature laboratory rate coefficients for key reactions relevant to the atmospheres of Titan and Saturn. These reactions are, for example, C2H + H2, CH4, C2H2, and other hydrocarbons which need to be measured at low temperatures, down to approximately 150 K. The results of this work are provided to NASA specialists who study modeling of the hydrocarbon chemistry of the outer planets. The apparatus for this work consists of a pulsed laser photolysis system and a tunable F-center probe laser to monitor the disappearance of C2H. A low temperature cell with a cryogenic circulating fluid in the outer jacket provides the gas handling system for this work. These elements have been described in detail in previous reports. Several new results are completed and the publications are just being prepared. The reaction of C2H with C2H2 has been measured with an improved apparatus down to 154 K. An Arrhenius plot indicates a clear increase in the rate coefficient at the lowest temperatures, most likely because of the long-lived (C4H3) intermediate. The capability to achieve the lowest temperatures in this work was made possible by construction of a new cell and addition of a multipass arrangement for the probe laser, as well as improvements to the laser system.

  5. Competition between nonindigenous ruffe and native yellow perch in laboratory studies

    USGS Publications Warehouse

    Savino, Jacqueline F.; Kolar, Cynthia S.

    1996-01-01

    The ruffe Gymnocephalus cernuus is a European percid that was accidently introduced in Duluth Harbor, Lake Superior. This nonindigenous species is closely related to yellow perch Perca flavescens, and because the two species have similar diets and habitat requirements, they are potential competitors. Laboratory studies in aquaria and pools were conducted to determine whether ruffe can compete with yellow perch for food. Ruffe had capture rates similar to those of yellow perch when food was unlimited. Ruffe spent more time than yellow perch over a feeding container before leaving it and searching again, and they also required less time to ingest (or handle) prey. However, the presence of yellow perch shortened the time ruffe spent over foraging areas when food was more limited. In addition, yellow perch were more active than ruffe, as indicated by their more frequent visits to a feeding container. Hence, the outcome of exploitative competition was not conclusive; ruffe appear to have the advantage in some behaviors, yellow perch in others. Ruffe were much more aggressive than yellow perch, and interference competition may be important in the interactions between these species. Our results indicate that ruffe might compete with native yellow perch.

  6. Laboratory Studies of Solid Carbon Dioxide in Planetary and Interstellar Ices

    NASA Technical Reports Server (NTRS)

    White, Douglas; Sandford, Scott A.; Mastrapa, Rachel M.

    2012-01-01

    Laboratory spectra have shown that CO2. is a powerful diagnostic tool for analyzing infrared data from remote observations, as it has been detected on icy moons in the outer solar system as well as dust grain surfaces in the interstellar medium. IR absorption profiles of CO2 wi thin ice mixtures containing H2O and CH30H change with respect to tem perature and mixture ratios. In this particular study, the CO2 stretch mode around 235O cm (exp -1) (4.3 rricrons) is systematically observ ed in different mixtures with H2O and CH30H in temperature ranges from 15K to 150 K, as well as vibrational modes in the near-IR such as th e combination bands near 3700 cm (exp -1) (2.7 microns) and 5080 (exp -1) (2.0 microns). Additionally, some high?temperature deposits (T > 50 K) of H2O, CH30H, and CO2 ice mixtures were performed to determine the maximum temperatures at which CO2 will deposit on the sample win dow. These data may then be used to interpret spectra obtained from remote IR observations. This research was sponsored by Oak Ridge Associ ated Universities (ORAU) through the NASA Postdoctoral Program (NPP) as well as Ames Research Center and the SETI institute who provided fa cilities and equipment.

  7. Are fish fed with cyanobacteria safe, nutritious and delicious? A laboratory study

    PubMed Central

    Liang, Hualei; Zhou, Wenshan; Zhang, Yulei; Qiao, Qin; Zhang, Xuezhen

    2015-01-01

    Toxic cyanobacterial blooms, which produce cyclic heptapeptide toxins known as microcystins, are worldwide environmental problems. On the other hand, the cyanobacteria protein (30–50%) has been recommended as substitute protein for aquaculture. The present laboratory study verified the feasibility of cyanobacteria protein substitution and risk assessment. Goldfish were fed diets supplemented lyophilised cyanobacteria powder for 16 weeks with the various doses: 0% (control), 10%, 20%, 30% and 40%. Low doses (10% and 20%) promoted growth whereas high doses (30% and 40%) inhibited growth. In cyanobacteria treated fish, the proximate composition of ash, crude fat content and crude protein content decreased in 16 weeks; the saturated fatty acid (SFA) content significantly increased; the n-3 polyunsaturated fatty acid content, collagen content and muscle pH significantly decreased; cooking loss percents increased significantly. Muscle fiber diameter and myofibril length were negatively correlation. Additionally, flavour compounds (e.g., amino acids, nucleotides, organic acids and carnosine) changed significantly in the treated fish, and odour compounds geosmin and 2-methylisoborneol increased significantly. The estimated daily intake (EDI) of microcystins in muscle was close to or exceeded the World Health Organization (WHO) tolerable daily intake (TDI), representing a great health risk. Cyanobacterie is not feasible for protein sources use in aquaculture. PMID:26470644

  8. Are fish fed with cyanobacteria safe, nutritious and delicious? A laboratory study.

    PubMed

    Liang, Hualei; Zhou, Wenshan; Zhang, Yulei; Qiao, Qin; Zhang, Xuezhen

    2015-10-16

    Toxic cyanobacterial blooms, which produce cyclic heptapeptide toxins known as microcystins, are worldwide environmental problems. On the other hand, the cyanobacteria protein (30-50%) has been recommended as substitute protein for aquaculture. The present laboratory study verified the feasibility of cyanobacteria protein substitution and risk assessment. Goldfish were fed diets supplemented lyophilised cyanobacteria powder for 16 weeks with the various doses: 0% (control), 10%, 20%, 30% and 40%. Low doses (10% and 20%) promoted growth whereas high doses (30% and 40%) inhibited growth. In cyanobacteria treated fish, the proximate composition of ash, crude fat content and crude protein content decreased in 16 weeks; the saturated fatty acid (SFA) content significantly increased; the n-3 polyunsaturated fatty acid content, collagen content and muscle pH significantly decreased; cooking loss percents increased significantly. Muscle fiber diameter and myofibril length were negatively correlation. Additionally, flavour compounds (e.g., amino acids, nucleotides, organic acids and carnosine) changed significantly in the treated fish, and odour compounds geosmin and 2-methylisoborneol increased significantly. The estimated daily intake (EDI) of microcystins in muscle was close to or exceeded the World Health Organization (WHO) tolerable daily intake (TDI), representing a great health risk. Cyanobacterie is not feasible for protein sources use in aquaculture.

  9. Laboratory Spectroscopy of Large Carbon Molecules and Ions in Support of Space Missions. A New Generation of Laboratory & Space Studies

    NASA Technical Reports Server (NTRS)

    Salama, Farid; Tan, Xiaofeng; Cami, Jan; Biennier, Ludovic; Remy, Jerome

    2006-01-01

    Polycyclic Aromatic Hydrocarbons (PAHs) are an important and ubiquitous component of carbon-bearing materials in space. A long-standing and major challenge for laboratory astrophysics has been to measure the spectra of large carbon molecules in laboratory environments that mimic (in a realistic way) the physical conditions that are associated with the interstellar emission and absorption regions [1]. This objective has been identified as one of the critical Laboratory Astrophysics objectives to optimize the data return from space missions [2]. An extensive laboratory program has been developed to assess the properties of PAHs in such environments and to describe how they influence the radiation and energy balance in space. We present and discuss the gas-phase electronic absorption spectra of neutral and ionized PAHs measured in the UV-Visible-NIR range in astrophysically relevant environments and discuss the implications for astrophysics [1]. The harsh physical conditions of the interstellar medium characterized by a low temperature, an absence of collisions and strong VUV radiation fields - have been simulated in the laboratory by associating a pulsed cavity ringdown spectrometer (CRDS) with a supersonic slit jet seeded with PAHs and an ionizing, penning-type, electronic discharge. We have measured for the {\\it first time} the spectra of a series of neutral [3,4] and ionized [5,6] interstellar PAHs analogs in the laboratory. An effort has also been attempted to quantify the mechanisms of ion and carbon nanoparticles production in the free jet expansion and to model our simulation of the diffuse interstellar medium in the laboratory [7]. These experiments provide {\\it unique} information on the spectra of free, large carbon-containing molecules and ions in the gas phase. We are now, for the first time, in the position to directly compare laboratory spectral data on free, cold, PAH ions and carbon nano-sized carbon particles with astronomical observations in the

  10. Generating Scenarios of Addition and Subtraction: A Study of Japanese University Students

    ERIC Educational Resources Information Center

    Kinda, Shigehiro

    2013-01-01

    Students are presented with problems involving three scenario types of addition and subtraction in elementary mathematics: one dynamic ("Change") and two static ("Combine, Compare"). Previous studies have indicated that the dynamic type is easier for school children, whereas the static types are more difficult and comprehended only gradually…

  11. Performance on Addition and Subtraction Problems: Results from Individual Interviews - Sandy Bay Study.

    ERIC Educational Resources Information Center

    Romberg, Thomas A.; And Others

    The purpose of this study was to relate children's cognitive processing capabilities and their grade level to their performance and to the strategies they used when working addition and subtraction problems. From two sets of data which assessed memory capacity and cognitive processing capacities, six groups of children with different cognitive…

  12. Using E-Learning to Enhance the Learning of Additional Languages--A Pilot Comparative Study

    ERIC Educational Resources Information Center

    Hilton, Gillian L. S.

    2013-01-01

    This paper is concerned with a small pilot study to ascertain the use of, and changes in the use of e-learning to promote the learning of foreign and additional languages in a variety of countries in Europe. It was undertaken by individual researchers in an attempt to examine how the drive towards the teaching of new languages, encouraged by the…

  13. Industry research on the use and effects of levulinic acid: a case study in cigarette additives.

    PubMed

    Keithly, Lois; Ferris Wayne, Geoffrey; Cullen, Doris M; Connolly, Gregory N

    2005-10-01

    Public health officials and tobacco researchers have raised concerns about the possible contributions of additives to the toxicity of cigarettes. However, little attention has been given to the process whereby additives promote initiation and addiction. Levulinic acid is a known cigarette additive. Review of internal tobacco industry documents indicates that levulinic acid was used to increase nicotine yields while enhancing perceptions of smoothness and mildness. Levulinic acid reduces the pH of cigarette smoke and desensitizes the upper respiratory tract, increasing the potential for cigarette smoke to be inhaled deeper into the lungs. Levulinic acid also may enhance the binding of nicotine to neurons that ordinarily would be unresponsive to nicotine. These findings held particular interest in the internal development of ultralight and so-called reduced-exposure cigarette prototypes. Industry studies found significantly increased peak plasma nicotine levels in smokers of ultralight cigarettes following addition of levulinic acid. Further, internal studies observed changes in mainstream and sidestream smoke composition that may present increased health risks. The use of levulinic acid illustrates the need for regulatory authority over tobacco products as well as better understanding of the role of additives in cigarettes and other tobacco products.

  14. A laboratory study of heavy oil recovery with CO/sub 2/ injection

    SciTech Connect

    Sankur, V.; Emanuel, A.S.

    1983-03-01

    Recovery of a California heavy oil by CO/sub 2/ injection was investigated using laboratory core floods and computer simulation. CO/sub 2/ drive and huff-n-puff techniques were studied for tertiary recovery of a 14/sup 0/ API gravity, 3000 cp viscosity oil from a waterflooded core. The core material was poorly consolidated sandstone under simulated reservoir stress. At 1250 psia, CO/sub 2/ drive recovered up to 54% of the remaining oil in place (ROIP), the recovery increasing with increasing slug size. The CO/sub 2/ utilization factors also increased with CO/sub 2/ slug size, ranging from 1.1 MSCF/BBL to 8.0 MSCF/BBL. The addition of 18% N/sub 2/ into CO/sub 2/ at this pressure resulted in earlier gas breakthrough and lower recoveries compared to pure CO/sub 2/ injection. At 750 psia a 3.0 PV slug of CO/sub 2/ recovered 20% of the ROIP, reflecting lower recoveries at lower pressures. The use of small slugs improved CO/sub 2/ utilization also at this pressure with an accompanying decrease in overall recovery to 16% of ROIP. The CO/sub 2/ huff-n-puff technique was tested on the same system at 1250 psia pressure. The first cycle recovered 6% of the ROIP with a CO/sub 2/ utilization factor of 11 MSCF/BBL. The second cycle recovered an additional 3% with a utilization factor of 33 MSCF/BBL. The core floods were simulated using a compositional simulator with a three-component Peng-Robinson model for fluid properties. The simulator predictions agree qualitatively with the experimental results. Calculated saturation profiles through the core are presented.

  15. LABORATORY STUDIES ON THE STABILITY AND TRANSPORT OF INORGANIC COLLOIDS THROUGH NATURAL AQUIFER MATERIAL

    EPA Science Inventory

    The stability and transport of radio-labeled Fe2O3 particles were studied using laboratory batch and column techniques. Core material collected from shallow sand and gravel aquifer was used as the immobile column matrix material. Variables in the study included flow rate, pH, i...

  16. Use of the LITEE Lorn Manufacturing Case Study in a Senior Chemical Engineering Unit Operations Laboratory

    ERIC Educational Resources Information Center

    Abraham, Nithin Susan; Abulencia, James Patrick

    2011-01-01

    This study focuses on the effectiveness of incorporating the Laboratory for Innovative Technology and Engineering Education (LITEE) Lorn Manufacturing case into a senior level chemical engineering unit operations course at Manhattan College. The purpose of using the case study is to demonstrate the relevance of ethics to chemical engineering…

  17. Laboratory Instructions and Study Guide for Human Anatomy. Part Two, Fourth Edition.

    ERIC Educational Resources Information Center

    Conrey, Kathleen

    During the process of studying the specific course content of human anatomy, students are being educated to expand their vocabulary, learn to deal successfully with complex tasks, and use a specific way of thinking. This is the second volume in a set of laboratory instructions and study notes which are designed to accompany a lecture series in…

  18. Laboratory Instructions and Study Guide for Human Anatomy. Part One, Fourth Edition.

    ERIC Educational Resources Information Center

    Conrey, Kathleen

    During the process of studying the specific course content of human anatomy, students are being educated to expand their vocabulary, deal successfully with complex tasks, and use a specific way of thinking. This is the first volume in a set of laboratory instructions and study notes which are designed to accompany a lecture series in human…

  19. Study of the atmospheric chemistry of radon progeny in laboratory and real indoor atmospheres

    SciTech Connect

    Hopke, P.K.

    1992-07-01

    This report describes studies on the chemical and physical behavior of the [sup 218]Po atom immediately following its formation by the alpha decay of radon. Because small changes in size for activity in the sub-10 nm size range result in large changes in the delivered dose per unit exposure, this behavior must be understood if the exposure to radon progeny and its dose to the cells in the respiratory tract are to be fully assessed. The specific tasks of the controlled laboratory studies are to determine the formation rates of [center dot]OH radicals formed by the radiolysis of air following radon decay, to examine the formation of particles by the radiolytic oxidation of substances like SO[sub 2] ethylene, and H[sub 2]S to lower vapor pressure compounds and determine the role of gas phase additives such as H[sub 2]O and NH[sub 3] in determining the particle size, to measure the rate of ion-induced nucleation using a thermal diffusion cloud chamber, and to measure the neutralization rate of [sup 218]Po[sub x][sup +] in O[sub 2] at low radon concentrations. Tasks of the exposure studies in occupied indoor spaces are to initiate measurements of the activity size distributions in actual homes with occupants present so that the variability of the indoor activity size distributions can be assessed with respect to indoor aerosol sources and general lifestyle variations of the occupants, to initiate a prospective study of the utility of measurement of deposited [sup 210]Pb embedded in glass surfaces as a measure of the long-term, integrated exposure of the population to radon, and to develop the methodology to determine the hygroscopicity of the indoor aerosol so that the changes in deposition efficiency of the radioactive indoor aerosol with hygroscopic growth in the respiratory tract can be assessed.

  20. Anatomically ordered tapping interferes more with one-digit addition than two-digit addition: a dual-task fMRI study.

    PubMed

    Soylu, Firat; Newman, Sharlene D

    2016-02-01

    Fingers are used as canonical representations for numbers across cultures. In previous imaging studies, it was shown that arithmetic processing activates neural resources that are known to participate in finger movements. Additionally, in one dual-task study, it was shown that anatomically ordered finger tapping disrupts addition and subtraction more than multiplication, possibly due to a long-lasting effect of early finger counting experiences on the neural correlates and organization of addition and subtraction processes. How arithmetic task difficulty and tapping complexity affect the concurrent performance is still unclear. If early finger counting experiences have bearing on the neural correlates of arithmetic in adults, then one would expect anatomically and non-anatomically ordered tapping to have different interference effects, given that finger counting is usually anatomically ordered. To unravel these issues, we studied how (1) arithmetic task difficulty and (2) the complexity of the finger tapping sequence (anatomical vs. non-anatomical ordering) affect concurrent performance and use of key neural circuits using a mixed block/event-related dual-task fMRI design with adult participants. The results suggest that complexity of the tapping sequence modulates interference on addition, and that one-digit addition (fact retrieval), compared to two-digit addition (calculation), is more affected from anatomically ordered tapping. The region-of-interest analysis showed higher left angular gyrus BOLD response for one-digit compared to two-digit addition, and in no-tapping conditions than dual tapping conditions. The results support a specific association between addition fact retrieval and anatomically ordered finger movements in adults, possibly due to finger counting strategies that deploy anatomically ordered finger movements early in the development.

  1. Oxidative addition of methane and benzene C--H bonds to rhodium center: A DFT study

    NASA Astrophysics Data System (ADS)

    Bi, Siwei; Zhang, Zhenwei; Zhu, Shufen

    2006-11-01

    A density functional theory study on mechanisms of the oxidative addition of methane and benzene C-H bonds to the rhodium center containing Cp and PMe 3 ligands has been performed. Our calculated results confirm that the C-H bond cleavage from a sigma complex to a hydride alkyl complex is the rate-determining step. Compared with the case of methane C-H bond, the oxidative addition of benzene C-H bond is more favorable kinetically and thermodynamically. Stronger backdonation from metal center to the σ ∗ antibonding orbital of benzene C-H bond is responsible for the observations.

  2. Advancing internal erosion monitoring using seismic methods in field and laboratory studies

    NASA Astrophysics Data System (ADS)

    Parekh, Minal L.

    embankment surface. Analysis of root mean squared amplitude and AE threshold counts indicated activity focused at the toe in locations matching the sand boils. This analysis also compared the various detection methods employed at the 2012 test to discuss a timeline of detection related to observable behaviors of the structure. The second area of research included designing and fabricating an instrumented laboratory apparatus for investigating active seismic wave propagation through soil samples. This dissertation includes a description of the rigid wall permeameter, instrumentation, control, and acquisitions systems along with descriptions of the custom-fabricated seismic sensors. A series of experiments (saturated sand, saturated sand with a known static anomaly placed near the center of the sample, and saturated sand with a diminishing anomaly near the center of the sample) indicated that shear wave velocity changes reflected changes in the state of stress of the soil. The mean effective stress was influenced by the applied vertical axial load, the frictional interaction between the soil and permeameter wall, and the degree of preloading. The frictional resistance was sizeable at the sidewall of the permeameter and decreased the mean effective stress with depth. This study also included flow tests to monitor changes in shear wave velocities as the internal erosion process started and developed. Shear wave velocity decreased at voids or lower density zones in the sample and increased as arching redistributes loads, though the two conditions compete. Finally, the social and political contexts surrounding nondestructive inspection were considered. An analogous approach utilized by the aerospace industry was introduced: a case study comparing the path toward adopting nondestructive tools as standard practices in monitoring aircraft safety. Additional lessons for dam and levee safety management were discussed from a Science, Technology, Engineering, and Policy (STEP

  3. Laboratories for the 21st Century: Case Studies; National Renewable Energy Laboratory, Science and Technology Facility, Golden, Colorado (Brochure)

    SciTech Connect

    Van Geet, O.

    2010-04-01

    As a Laboratories for the 21st Century (Labs21) partner, NREL set aggressive goals for energy savings, daylighting, and achieving a LEED Gold rating (through the U.S. Green Building Council's Leadership in Energy and Environmental Design program) for its S&TF building.

  4. A synchrotron study of microstructure gradient in laser additively formed epitaxial Ni-based superalloy

    PubMed Central

    Xue, Jiawei; Zhang, Anfeng; Li, Yao; Qian, Dan; Wan, Jingchun; Qi, Baolu; Tamura, Nobumichi; Song, Zhongxiao; Chen, Kai

    2015-01-01

    Laser additive forming is considered to be one of the promising techniques to repair single crystal Ni-based superalloy parts to extend their life and reduce the cost. Preservation of the single crystalline nature and prevention of thermal mechanical failure are two of the most essential issues for the application of this technique. Here we employ synchrotron X-ray microdiffraction to evaluate the quality in terms of crystal orientation and defect distribution of a Ni-based superalloy DZ125L directly formed by a laser additive process rooted from a single crystalline substrate of the same material. We show that a disorientation gradient caused by a high density of geometrically necessary dislocations and resultant subgrains exists in the interfacial region between the epitaxial and stray grains. This creates a potential relationship of stray grain formation and defect accumulation. The observation offers new directions on the study of performance control and reliability of the laser additive manufactured superalloys. PMID:26446425

  5. A synchrotron study of microstructure gradient in laser additively formed epitaxial Ni-based superalloy

    SciTech Connect

    Xue, Jiawei; Zhang, Anfeng; Li, Yao; Qian, Dan; Wan, Jingchun; Qi, Baolu; Tamura, Nobumichi; Song, Zhongxiao; Chen, Kai

    2015-10-08

    Laser additive forming is considered to be one of the promising techniques to repair single crystal Ni-based superalloy parts to extend their life and reduce the cost. Preservation of the single crystalline nature and prevention of thermal mechanical failure are two of the most essential issues for the application of this technique. Here we employ synchrotron X-ray microdiffraction to evaluate the quality in terms of crystal orientation and defect distribution of a Ni-based superalloy DZ125L directly formed by a laser additive process rooted from a single crystalline substrate of the same material. We show that a disorientation gradient caused by a high density of geometrically necessary dislocations and resultant subgrains exists in the interfacial region between the epitaxial and stray grains. This creates a potential relationship of stray grain formation and defect accumulation. In conclusion, the observation offers new directions on the study of performance control and reliability of the laser additive manufactured superalloys.

  6. Aquatic environment, housing, and management in the eighth edition of the Guide for the Care and Use of Laboratory Animals: additional considerations and recommendations.

    PubMed

    Mason, Timothy J; Matthews, Monte

    2012-05-01

    The eighth edition of the Guide for the Care and Use of Laboratory Animals recognizes the widespread use of aquatic and semiaquatic research animals by including, among other references, an entire section on aquatic animals in its chapter on environment, housing, and management. Recognizing the large number of aquatic and semiaquatic species used in research and the inherent diversity in animal needs, the Guide refers the reader to texts and journal reviews for specific recommendations and suggests consultations with persons experienced in caring for aquatic species. Here we present considerations that may add to the basic information presented in the Guide and offer some recommendations that may be useful for aquatic animal model caregivers and researchers.

  7. Aquatic Environment, Housing, and Management in the Eighth Edition of the Guide for the Care and Use of Laboratory Animals: Additional Considerations and Recommendations

    PubMed Central

    Mason, Timothy J; Matthews, Monte

    2012-01-01

    The eighth edition of the Guide for the Care and Use of Laboratory Animals recognizes the widespread use of aquatic and semiaquatic research animals by including, among other references, an entire section on aquatic animals in its chapter on environment, housing, and management. Recognizing the large number of aquatic and semiaquatic species used in research and the inherent diversity in animal needs, the Guide refers the reader to texts and journal reviews for specific recommendations and suggests consultations with persons experienced in caring for aquatic species. Here we present considerations that may add to the basic information presented in the Guide and offer some recommendations that may be useful for aquatic animal model caregivers and researchers. PMID:22776190

  8. Laboratory studies on N(2D) reactions of relevance to the chemistry of planetary atmospheres

    NASA Astrophysics Data System (ADS)

    Balucani, N.; Casavecchia, P.

    Molecular nitrogen is a very stable molecule, practically inert from a chemical point of view. For a nitrogen chemistry to occur in the planetary atmospheres which contain N2 , it is necessary to transform it into an active form, such as atoms or ions. As far as the production of atomic nitrogen in the upper atmospheres of planets (like Mars) or moons (like Titan) is concerned, several processes - as N2 dissociation induced by electron impact, EUV photolysis (λ <80 nm) and dissociative photoionization, or galactic cosmic ray absorption and N+ dissociative recombination all 2 lead to atomic nitrogen, notably in the ground, 4 S3/2 , and first electronically excited, 2 D3/2,5/2 , states with comparable yields. The radiative lifetimes of the metastable states 2 D3/2 and 2 D5/2 are quite long (12.3 and 48 hours, respectively), because the transition from a doublet to a quartet state is strongly forbidden. In addition, the physical quenching of N(2 D) is often a slow process and in some important cases the main fate of N(2 D) is chemical reaction with other constituents of the planetary atmospheres. The production of N atoms in the 2 D state is an important fact, because N(4 S) atoms exhibit very low reactivity with closed-shell molecules and the probability of collision with an open-shell radical is small. Unfortunately laboratory experiments on the gas-phase reactions of N(2 D) have been lacking until recently, because of serious experimental difficulties in studying these reactive systems. Accurate kinetic data on the reactions of N(2 D) with the some molecules of relevance to the chemistry of planetary atmospheres have finally become available in the late 90's, but a better knowledge of the reactive behavior requires a dynamical investigation of N(2 D) reactions. The capability of generating intense continuous beams of N(2 D) achieved in our laboratory some years ago has opened up the possibility of studying the reactive scattering of this species under single

  9. West Florida Shelf: A natural laboratory for the study of ocean acidificiation

    USGS Publications Warehouse

    Hallock, Pamela; Robbins, Lisa L.; Larson, Rebekka A.; Beck, Tanya; Schwing, Patrick; Martinez-Colon, Michael; Gooch, Brad

    2010-01-01

    Declining oceanic pH and carbonate-ion concentrations are well-known consequences of increased atmospheric and surface-ocean partial pressure of carbon dioxide (pCO2). The possible subject of shifts in seawater carbonate chemistry on biocalcification and survival rates of marine organisms provides questions amenable to both experimental and field study (Kleypas and Langdon, 2006). To date, limited quantitative data exist with which to formalize and test hypotheses regarding such impacts, particularly in continental-shelf settings. The continental shelves of Florida provide an ideal natural laboratory in which to test latitudinal (and temperature and depth) shifts in habitat ranges of calcifying organisms. Both the east and west Florida shelves extend from warm temperate to subtropical latitudes; additionally, the west Florida shelf has very little siliciclastic influx to mask the carbonate production. This study utilizes the natural laboratory of the west and southwest Florida shelf (fig 1.1) to examine the transition from foramol (predominately foraminifera and molluscan) carbonate sediments, characteristic of the west-central Florida shelf, to chlorozoan (algal and coral) sediments characteristic of the southwest Florida shelf. The west Florida shelf is a mixed siliciclastic carbonate ramp that to the south transitions to the carbonate-dominated southwest Florida shelf (Enos, 1977; Brooks and others, 2003). The west Florida shelf is a distally steepened carbonate ramp that is ~250 kilometers (km) wide (Read, 1985). It is covered by a veneer of unconsolidated sediment consisting of mainly biogenic carbonate and quartz in the near shore, with subordinate amounts of phosphate. The sediment-distribution pattern is largely a function of proximity to source, with physical processes playing a minor role in distribution. The carbonate sand-and-gravel fraction is produced by organisms within the depositional basin of the west Florida shelf (Brooks and others, 2003). The

  10. Studies of levels of biogenic amines in meat samples in relation to the content of additives.

    PubMed

    Jastrzębska, Aneta; Kowalska, Sylwia; Szłyk, Edward

    2016-01-01

    The impact of meat additives on the concentration of biogenic amines and the quality of meat was studied. Fresh white and red meat samples were fortified with the following food additives: citric and lactic acids, disodium diphosphate, sodium nitrite, sodium metabisulphite, potassium sorbate, sodium chloride, ascorbic acid, α-tocopherol, propyl 3,4,5-trihydroxybenzoate (propyl gallate) and butylated hydroxyanisole. The content of spermine, spermidine, putrescine, cadaverine, histamine, tyramine, tryptamine and 2-phenylethylamine was determined by capillary isotachophoretic methods in meat samples (fresh and fortified) during four days of storage at 4°C. The results were applied to estimate the impact of the tested additives on the formation of biogenic amines in white and red meat. For all tested meats, sodium nitrite, sodium chloride and disodium diphosphate showed the best inhibition. However, cadaverine and putrescine were characterised by the biggest changes in concentration during the storage time of all the additives. Based on the presented data for the content of biogenic amines in meat samples analysed as a function of storage time and additives, we suggest that cadaverine and putrescine have a significant impact on meat quality.

  11. Studying teacher attitudes and student perceptions of physics laboratories using a Q-type assessment instrument

    NASA Astrophysics Data System (ADS)

    Aubrecht, Gordon; Demaree, Dedra; Lin, Yuhfen; Zou, Xulie

    2004-10-01

    A modified version of the Laboratory Program Variables Inventory (LPVI),[1] a Q-type instrument originally developed to assess chemistry laboratories, has been used to study the correlation between instructor expectations and student descriptions. Careful study of the correlation among different classes shows that Q-type assessment is an effective tool for describing course types (as reported in a companion poster). Here we examine correlations between instructor expectations and student perceptions among different sections of the same course, as well as differences in student perceptions among the sections taught by the same instructor. This Q-type assessment tool may be used to diagnose problems in curriculum development and instructor education. 1. M. R. Abraham, `A descriptive instrument for use in investigating science laboratories,' Journal of Research in Science Teaching 19 (2) 155-165 (1982).

  12. Missing dose from mortality studies of radiation effects among workers at Oak Ridge National Laboratory.

    PubMed

    Kerr, G D

    1994-02-01

    Missing dose is a problem that has not been adequately addressed in the mortality studies of radiation effects among workers at Oak Ridge National Laboratory. The missing dose is a result of recording a zero for below-detectable doses, especially for frequent (weekly) film badge readings. To make the thorough dosimetry assessment needed in the current Oak Ridge National Laboratory worker studies, it will probably be necessary to consider all data at hand including personnel dose records, daily pocket meter readings used to supplement weekly and quarterly readings from other dosimeters, and monitoring results from both building surveys and fixed stations. The fixed-station data should be extremely useful in developing a better understanding of the unusual temporal variation of the external radiation doses to Oak Ridge National Laboratory workers during the high exposure-rate periods of the 1950s and early 1960s.

  13. Site Study Plan for laboratory soil mechanics, Deaf Smith County site, Texas: Revision 1

    SciTech Connect

    Not Available

    1987-12-01

    This Site Study Plan for laboratory soil mechanics describes the laboratory testing to be conducted on soil samples collected as part of the characterization of the Deaf Smith County site, Texas. This study provides for measurements of index, mechanical, thermal, hydrologic, chemical, and mineral properties of soils from boring throughout the site. Samples will be taken from Playa Borings/Trenching, Transportation/Utilities Foundation Borings, Repository Surface Facilities Design Foundation Borings, and Exploratory Shaft Facilities Design Foundation Borings. Data from the laboratory tests will be used for soil strata characterization, design of foundations for surface structures, design of transportation facilities and utility structures, design of impoundments, design of shaft lining, design of the shaft freeze wall, shaft permitting, performance assessment calculations, and other program requirements. A tentative testing schedule and milestone log are given. A quality assurance program will be utilized to assure that activities affecting quality are performed correctly and that appropriate documentation is maintained. 18 refs., 6 figs., 3 tabs.

  14. Study of energy conversion and partitioning in the magnetic reconnection layer of a laboratory plasma

    SciTech Connect

    Yamada, Masaaki; Yoo, Jongsoo; Jara-Almonte, Jonathan; Daughton, William; Ji, Hantao; Kulsrud, Russell M.; Myers, Clayton E.

    2015-05-15

    The most important feature of magnetic reconnection is that it energizes plasma particles by converting magnetic energy to particle energy, the exact mechanisms by which this happens are yet to be determined despite a long history of reconnection research. Recently, we have reported our results on the energy conversion and partitioning in a laboratory reconnection layer in a short communication [Yamada et al., Nat. Commun. 5, 4474 (2014)]. The present paper is a detailed elaboration of this report together with an additional dataset with different boundary sizes. Our experimental study of the reconnection layer is carried out in the two-fluid physics regime where ions and electrons move quite differently. We have observed that the conversion of magnetic energy occurs across a region significantly larger than the narrow electron diffusion region. A saddle shaped electrostatic potential profile exists in the reconnection plane, and ions are accelerated by the resulting electric field at the separatrices. These accelerated ions are then thermalized by re-magnetization in the downstream region. A quantitative inventory of the converted energy is presented in a reconnection layer with a well-defined, variable boundary. We also carried out a systematic study of the effects of boundary conditions on the energy inventory. This study concludes that about 50% of the inflowing magnetic energy is converted to particle energy, 2/3 of which is ultimately transferred to ions and 1/3 to electrons. When assisted by another set of magnetic reconnection experiment data and numerical simulations with different sizes of monitoring box, it is also observed that the observed features of energy conversion and partitioning do not depend on the size of monitoring boundary across the range of sizes tested from 1.5 to 4 ion skin depths.

  15. Microbial transformations of azaarenes in creosite-contaminated soil and ground water: Laboratory and field studies

    USGS Publications Warehouse

    Pereira, W.E.; Rostad, C.E.; Updegraff, D.M.; Bennett, J.L.

    1988-01-01

    Azaarenes or aromatic nitrogen heterocycles are a class of compounds found in wood-preservative wastes containing creosote. The fate and movement of these compounds in contaminated aquifers is not well understood. Water-quality studies in an aquifer contaminated with creosote near Pensacola, Florida, indicated that ground water was contaminated with several azaarenes and their oxygenated and alkylated derivatives, suggesting that these oxygenated compounds may be products of microbial transformation reactions. Accordingly, laboratory studies were designed to investigate the fate of these compounds. Under aerobic conditions, soil pseudomonads isolated from creosote-contaminated soil converted quinoline to 2(1H)quinoline that subsequently was degraded to unknown products. A methanogenic consortium isolated from an anaerobic sewage digestor, in presence of ground-water and creosote-contaminated soil, converted quinoline, isoquinoline, and 4-methylquinoline to their respective oxygenated analogs. In addition, N-, C-, and O-methylated analogs of oxygenated azaarenes were identified by gas chromatography-mass spectrometry (GC-MS) in aerobic cultures. Under the experimental conditions, 2-methylquinoline was biorefractory. Presence of similar biotransformation products in anaerobic cultures and contaminated ground water from the Pensacola site provided further evidence that these compounds indeed were mivrobial transformation products. Stable isotope labeling studies indicated that the source of the oxygen atom for this hydroxylation reaction under aerobic and anaerobic conditions was water. A mechanism was proposed for this hydroxylation reaction. Whereas parent azaarenes are biodegradable in both anaerobic and aerobic zones, oxygenated and alkylated analogs are more biorefractory and, hence, persistent in anaerobic zones of contaminated aquifers.

  16. Study of energy conversion and partitioning in the magnetic reconnection layer of a laboratory plasma

    DOE PAGES

    Yamada, Masaaki; Yoo, Jongsoo; Jara-Almonte, Jonathan; ...

    2015-05-15

    The most important feature of magnetic reconnection is that it energizes plasma particles by converting magnetic energy to particle energy, the exact mechanisms by which this happens are yet to be determined despite a long history of reconnection research. Recently, we have reported our results on the energy conversion and partitioning in a laboratory reconnection layer in a short communication [Yamada et al., Nat. Commun. 5, 4474 (2014)]. The present paper is a detailed elaboration of this report together with an additional dataset with different boundary sizes. Our experimental study of the reconnection layer is carried out in the two-fluidmore » physics regime where ions and electrons move quite differently. We have observed that the conversion of magnetic energy occurs across a region significantly larger than the narrow electron diffusion region. A saddle shaped electrostatic potential profile exists in the reconnection plane, and ions are accelerated by the resulting electric field at the separatrices. These accelerated ions are then thermalized by re-magnetization in the downstream region. A quantitative inventory of the converted energy is presented in a reconnection layer with a well-defined, variable boundary. We also carried out a systematic study of the effects of boundary conditions on the energy inventory. This study concludes that about 50% of the inflowing magnetic energy is converted to particle energy, 2/3 of which is ultimately transferred to ions and 1/3 to electrons. When assisted by another set of magnetic reconnection experiment data and numerical simulations with different sizes of monitoring box, it is also observed that the observed features of energy conversion and partitioning do not depend on the size of monitoring boundary across the range of sizes tested from 1.5 to 4 ion skin depths.« less

  17. Using epidemiology to regulate food additives: saccharin case-control studies.

    PubMed

    Cordle, F; Miller, S A

    1984-01-01

    The increasing use of nonnutritive sweeteners and the widely publicized 1969 ban on cyclamate led to additional investigations in rodents of the carcinogenic potential of saccharin. Preliminary results of a long-term feeding study indicated formation of bladder tumors in rodents, and collective experimental evidence has demonstrated that high doses of the synthetic sweetener saccharin can cause bladder cancer in rodents. Based on the results of that and other rodent studies indicating an increased risk of bladder cancer associated with saccharin, the Commissioner of the Food and Drug Administration announced the agency's intention to propose a ban on saccharin. This intention was made known in April 1977 under the Delaney Clause of the Food, Drug, and Cosmetic Act. The clause essentially states that no additive shall be deemed safe if it is found to induce cancer in man or animals, or if it is found, after tests appropriate for the evaluation of the safety of food additives, to induce cancer in man or animals. Also in 1977, a group of epidemiologists began to assess the available epidemiologic information to determine the potential human risk. This report describes the assessment of several human epidemiologic studies available then and the results of more recent epidemiologic studies.

  18. A kinetic study of struvite precipitation recycling technology with NaOH/Mg(OH)2 addition.

    PubMed

    Yu, Rongtai; Ren, Hongqiang; Wang, Yanru; Ding, Lili; Geng, Jingji; Xu, Ke; Zhang, Yan

    2013-09-01

    Struvite precipitation recycling technology is received wide attention in removal ammonium and phosphate out of wastewater. While past study focused on process efficiency, and less on kinetics. The kinetic study is essential for the design and optimization in the application of struvite precipitation recycling technology. The kinetics of struvite with NaOH/Mg(OH)2 addition were studied by thermogravimetry analysis with three rates (5, 10, 20 °C/min), using Friedman method and Ozawa-Flynn-Wall method, respectively. Degradation process of struvite with NaOH/Mg(OH)2 addition was three steps. The stripping of ammonia from struvite was mainly occurred at the first step. In the first step, the activation energy was about 70 kJ/mol, which has gradually declined as the reaction progress. By model fitting studies, the proper mechanism function for struvite decomposition process with NaOH/Mg(OH)2 addition was revealed. The mechanism function was f(α)=α(α)-(1-α)(n), a Prout-Tompkins nth order (Bna) model.

  19. Is it efficient to co-compost and co-vermicompost green waste with biochar and/or clay to reduce CO2 emissions? A short-term laboratory experiment on (vermi)composts with additives.

    NASA Astrophysics Data System (ADS)

    Barthod, Justine; Rumpel, Cornélia; Paradelo, Remigio; Dignac, Marie-France

    2016-04-01

    Intensive farming practices can lead to a depletion of soil organic matter, negatively impacting important soil properties such as structural stability, fertility and C storage. The addition of organic amendments such as compost and vermicompost, rich in carbon, helps maintaining soil organic matter levels or restoring degraded soils. Composting and vermicomposting are based on stabilization of organic matter through the mineralization of easily decomposable organic matter compounds, therefore releasing greenhouse gases, including CO2. The aim of this study was to evaluate the global potential reduction of such emissions by the use of additives (2:1 clay and/or biochar): during (vermi)composting processes and after use of the final products as soil amendments. We hypothesized that the interactions between the additives and organic matter may lead to carbon stabilization and that such interactions may be enhanced by the presence of worms (Eisenia). We added in different proportions clay (25% or 50%), biochar (10%) and a mixture of biochar (10%) with clay (25%) to pre-composted green waste. The CO2 emissions of the composting and vermicomposting processes were measured during 21 days. After that, the amendments were added to a loamy cambisol soil and the CO2 emissions were monitored during 30 days of a laboratory experiment. The most efficient treatments in terms of reducing global CO2 emissions were the co-vermicomposting process with 25% clay followed by co-composting with 50% clay and with 10% biochar plus 25% clay. In this treatment (vermicompost with 25% clay), the carbon emissions were decreased by up to 44% compared to regular compost. Addition of biochar reduced CO2 emissions only during composting. Co-composting with biochar could be a promising avenue to limit global CO2 emissions whereas in presence of worms clay additions are better suited. These findings suggest that the presence of worms increased the formation of organo-mineral associations and thus C

  20. Hanford waste-form release and sediment interaction: A status report with rationale and recommendations for additional studies

    SciTech Connect

    Serne, R.J. ); Wood, M.I. )

    1990-05-01

    This report documents the currently available geochemical data base for release and retardation for actual Hanford Site materials (wastes and/or sediments). The report also recommends specific laboratory tests and presents the rationale for the recommendations. The purpose of this document is threefold: to summarize currently available information, to provide a strategy for generating additional data, and to provide recommendations on specific data collection methods and tests matrices. This report outlines a data collection approach that relies on feedback from performance analyses to ascertain when adequate data have been collected. The data collection scheme emphasizes laboratory testing based on empiricism. 196 refs., 4 figs., 36 tabs.

  1. Study of asphalt/asphaltene precipitation during addition of solvents to West Sak crude

    SciTech Connect

    Jiang, J.C.; Patil, S.L.; Kamath, V.A. )

    1990-07-01

    In this study, experimental data on the amount of asphalt and asphaltene precipitation due to addition of solvents to West Sak crude were gathered. The first set of tests were conducted for two types of West Sak stock tank oils. Solvents used include: ethane, carbon dioxide, propane, n-butane, n-pentane, n-heptane, Prudhoe Bay natural gas (PBG) and natural gas liquids (NGL). Effect of solvent to oil dilution ratio on the amount of precipitation was studied. Alteration of crude oil composition due to asphalt precipitation was measured using gas-liquid chromatography. A second set of experiments were conducted to measure asphaltene precipitation due to addition of CO{sub 2} to live (recombined) West Sak crude.

  2. NETL Extreme Drilling Laboratory Studies High Pressure High Temperature Drilling Phenomena

    SciTech Connect

    Lyons, K.D.; Honeygan, S.; Moroz, T.H.

    2008-12-01

    The U.S. Department of Energy's National Energy Technology Laboratory (NETL) established the Extreme Drilling Laboratory to engineer effective and efficient drilling technologies viable at depths greater than 20,000 ft. This paper details the challenges of ultradeep drilling, documents reports of decreased drilling rates as a result of increasing fluid pressure and temperature, and describes NETL's research and development activities. NETL is invested in laboratory-scale physical simulation. Its physical simulator will have capability of circulating drilling fluids at 30,000 psi and 480°F around a single drill cutter. This simulator is not yet operational; therefore, the results will be limited to the identification of leading hypotheses of drilling phenomena and NETL's test plans to validate or refute such theories. Of particular interest to the Extreme Drilling Laboratory's studies are the combinatorial effects of drilling fluid pressure, drilling fluid properties, rock properties, pore pressure, and drilling parameters, such as cutter rotational speed, weight on bit, and hydraulics associated with drilling fluid introduction to the rock-cutter interface. A detailed discussion of how each variable is controlled in a laboratory setting will be part of the conference paper and presentation.

  3. MOLAB, a Mobile Laboratory for In Situ Non-Invasive Studies in Arts and Archaeology

    NASA Astrophysics Data System (ADS)

    Brunetti, B. G.; Matteini, Mauro; Miliani, C.; Pezzati, L.; Pinna, D.

    Mobile laboratory (MOLAB) is a unique joint collection of portable equipment for non-destructive in situ measurements. MOLAB activities are carried out within the frame of the Eu-ARTECH Integrated Infrastructure Initiative of the sixth F.P. In situ measurement is quite useful because it eliminates any risk connected to moving artworks or other precious objects to a laboratory. MOLAB instruments are accessible to European researchers through a peer-review selection of proposals. Starting from July 2004, MOLAB enabled non-destructive in situ studies of many precious artworks, such as paintings by Perugino, Raphael and Leonardo.

  4. The study of the thermal neutron flux in the deep underground laboratory DULB-4900

    NASA Astrophysics Data System (ADS)

    Alekseenko, V. V.; Gavrilyuk, Yu. M.; Gangapshev, A. M.; Gezhaev, A. M.; Dzhappuev, D. D.; Kazalov, V. V.; Kudzhaev, A. U.; Kuzminov, V. V.; Panasenko, S. I.; Ratkevich, S. S.; Tekueva, D. A.; Yakimenko, S. P.

    2017-01-01

    We report on the study of thermal neutron flux using monitors based on mixture of ZnS(Ag) and LiF enriched with a lithium-6 isotope at the deep underground laboratory DULB-4900 at the Baksan Neutrino Observatory. An annual modulation of thermal neutron flux in DULB-4900 is observed. Experimental evidences were obtained of correlation between the long-term thermal neutron flux variations and the absolute humidity of the air in laboratory. The amplitude of the modulation exceed 5% of total neutron flux.

  5. Treatment studies at the Process Waste Treatment Plant at Oak Ridge National Laboratory

    SciTech Connect

    Robinson, S.M.; Begovich, J.M.

    1991-03-01

    Precipitation and ion-exchange methods are being developed to decontaminate Oak Ridge National Laboratory process wastewaters containing small amounts of {sup 90}Sr and {sup 137}Cs while minimizing waste generation. Many potential processes have been examined in laboratory-scale screening tests. Based on these data, five process flowsheets were developed and are being evaluated under pilot- and full-scale operating conditions. Improvements in the existing treatment system based on this study have resulted in a 66 vol % reduction in waste generation. 19 refs., 26 figs., 45 tabs.

  6. Exotic Molecules in Space: A Coordinated Astronomical Laboratory and Theoretical Study

    NASA Technical Reports Server (NTRS)

    Thaddeus, Patrick; Stringfellow, Guy (Technical Monitor)

    2002-01-01

    This report details the work of NASA grant NAG5-9379 which is concerned with the discovery and characterization of new astrophysical molecules. Numerous papers have been or will be published on the laboratory detection of 21 molecules of astrophysical interest, nearly all not previously observed, and nearly all of astrophysical interest as plausible candidates for the interstellar gas and circumstellar shells. Also of interest include the laboratory detection of of optical molecular band exactly coinciding in frequency with the strongest and most widely studied optical diffuse interstellar band which remains an enigma in astrophysical spectroscopy. A new laser spectrometer has been developed and is now undergoing testing.

  7. Laboratory studies on the vulnerability of young white sturgeon to predation

    USGS Publications Warehouse

    Gadomski, D.M.; Parsley, M.J.

    2005-01-01

    Despite evidence of annual spawning by white sturgeon Acipenser transmontanus in rivers of the northwestern United States and Canada, in some years and locations little or no recruitment of age-0 white sturgeon has been observed. We examined the vulnerability of white sturgeon larvae and juveniles to predation to further understand possible causes of mortality. We were particularly interested in the vulnerability of older larvae and juveniles because at about 25 mm total length (TL) white sturgeon develop sharp dorsal and lateral scutes that may act as a morphological defense. In the laboratory, white sturgeon ranging from newly hatched larvae to about 170-mm TL juveniles were exposed to predatory fishes they might encounter in the natural environment. We found that channel catfish Ictalurus punctatus (mean TL = 464 mm) and northern pikeminnow Ptychocheilus oregonensis (mean TL = 472 mm) ate white sturgeon up to mean sizes of 121 and 134 mm TL, respectively. Conversely, similarly sized walleyes Sander vitreus ingested almost no white sturgeon, although juvenile walleyes (mean TL = 184 mm) ate white sturgeon up to 59 mm TL. The smallest predator we tested, prickly sculpins Cottus asper (mean TL = 126 mm), ate white sturgeon up to a mean TL of 50 mm. Our study demonstrated that predation is a likely cause of mortality of age-0 white sturgeon and may be contributing to the year-class failures that have been observed. In addition, the results from this study could be used to reduce the predation risk of artificially propagated white sturgeon released to augment declining populations since fish could be reared to sizes where their vulnerability is low.

  8. What Can We Learn From Laboratory Studies of Inorganic Sea Spray Aerosol?

    NASA Astrophysics Data System (ADS)

    Salter, M. E.; Zieger, P.; Acosta Navarro, J. C.; Grythe, H.; Kirkevag, A.; Rosati, B.; Riipinen, I.; Nilsson, E. D.

    2015-12-01

    Since 2013 we have been operating a temperature-controlled plunging-jet sea spray aerosol chamber at Stockholm University using inorganic artificial seawater. Using size-resolved measurements of the foam bubbles responsible for the aerosol production we were able to show that it is changes to these foam bubbles which drive the observed changes in aerosol production and size distribution as water temperature changes (Salter et al., 2014). Further, by combining size-resolved measurements of aerosol production as a function of water temperature with measurements of air entrainment by the plunging-jet we have developed a temperature-dependent sea spray source function for deployment in large-scale models (Salter et al., 2015). We have also studied the hygroscopicity, morphology, and chemical composition of the inorganic sea spray aerosol produced in the chamber. The sea spray aerosol generated from artificial seawater exhibited lower hygroscopic growth than both pure NaCl and output from the E-AIM aerosol thermodynamics model when all relevant inorganic ions in the sea salt were included. Results from sensitivity tests using a large-scale earth system model suggest that the lower hygroscopicity observed in our laboratory measurements has important implications for calculations of the radiative balance of the Earth. In addition, size-dependent chemical fractionation of several inorganic ions was observed relative to the artificial seawater with potentially important implications for the chemistry of the marine boundary layer. Each of these studies suggest that there is still much to be learned from rigorous experiments using inorganic seawater proxies. Salter et al., (2014), On the seawater temperature dependence of the sea spray aerosol generated by a continuous plunging jet. J. Geophys. Res. Atmos., 119, 9052-9072, doi: 10.1002/2013JD021376 Salter et al., (2015), An empirically derived inorganic sea spray source function incorporating sea surface temperature. Atmos

  9. Additive effects of neurofeedback on the treatment of ADHD: A randomized controlled study.

    PubMed

    Lee, Eun-Jeong; Jung, Chul-Ho

    2017-02-01

    Neurofeedback (NF) has been identified as a "possibly efficacious" treatment in current evidence-based reviews; therefore, more research is needed to determine its effects. The current study examined the potential additive effect of NF for children diagnosed with ADHD beginning a medication trial first. Thirty-six children (6-12 years) with a DSM-IV-TR diagnosis of ADHD were randomly assigned to an NF with medication (NF condition) or a medication only condition. Children in the NF group attended 20 twice-weekly sessions. Outcome measures included individual cognitive performance scores (ADS, K-WISC-III), ADHD rating scores completed by their parents (ARS, CRS) and brainwave indices of left and right hemispheres before and after NF treatment. Significant additive treatment effect in any of the symptom variables was found and a reduction of theta waves in both the right and left hemispheres was recorded in NF condition participants. However our randomized controlled study could not demonstrate superior effects of combined NF on intelligent functioning compared to the medication treatment only. This study suggested any possible evidence of positive and additive treatment effects of NF on brainwaves and ADHD symptomatology.

  10. A Study of the Clinical Laboratory Occupations. The UCLA Allied Health Professions Project.

    ERIC Educational Resources Information Center

    California Univ., Los Angeles. Div. of Vocational Education.

    The objectives of this study which was conducted as part of the UCLA Allied Health Professions Project were: (1) to determine the percent of medical laboratory workers who perform a comprehensive list of tasks and procedures; (2) to evaluate this performance in terms of certification and specialty area; and (3) on the basis of these data, to make…

  11. HYDRAULIC CHARACTERISTICS OF SEWER SEDIMENT GATE-FLUSHING TANKS: LABORATORY FLUME STUDIES

    EPA Science Inventory

    The objective of this study was to test the performance of gate-flushing tanks, simulated in a laboratory flume, to remove sediments from combined sewers and storage tanks. A significant amount of sediment/debris/sludge may accumulate at the bottom of a sewer during dry weather o...

  12. HYDRAULIC CHARACTERISTICS OF SEWER SEDIMENT GATE FLUSHING TANKS: LABORATORY FLUME STUDIES

    EPA Science Inventory

    The objective of this study was to test the performance of gate flushing tanks, simulated in a laboratory flume, to remove sediments from combined sewers and storage tanks. A significant amount of sediment/debris/sludge may accumulate at the bottom of a sewer during dry weather o...

  13. A Comparative Study of Two Laboratory Approaches in a General Education College Physical Science Course.

    ERIC Educational Resources Information Center

    Schellenberg, John Patrick

    The purpose of this study was to determine the relative effectiveness of two laboratory approaches in a general education physical science course: (1) the experimental method called the contemporary topics, and (2) the control method called the standard topics. The criterion instruments were an investigator-constructed subject content test, the…

  14. Folsomia Candida--An Ideal Organism for Population Studies in the Laboratory

    ERIC Educational Resources Information Center

    Usher, M. B.; Stoneman, C. F.

    1977-01-01

    Folsomia candida is presented as an ideal organism for population studies that can be carried out cheaply and easily in school laboratory conditions. Means of identifying, obtaining, and culturing these organisms are described together with some indication of the kinds of investigations which can be performed. (Author/MA)

  15. Motion of Electrons in Electric and Magnetic Fields: Introductory Laboratory and Computer Studies.

    ERIC Educational Resources Information Center

    Huggins, Elisha R.; Lelek, Jeffrey J.

    1979-01-01

    Describes a series of laboratory experiments and computer simulations of the motion of electrons in electric and magnetic fields. These experiments, which involve an inexpensive student-built electron gun, study the electron mean free path, magnetic focusing, and other aspects. (Author/HM)

  16. Laboratory Studies of Hydrogen Gas Generation Using the Cobalt Chloride Catalyzed Sodium Borohydride-Water Reaction

    DTIC Science & Technology

    2015-07-01

    TECHNICAL REPORT 2082 July 2015 Laboratory Studies of Hydrogen Gas Generation Using the Cobalt Chloride Catalyzed Sodium ...describes experiments to generate hydrogen gas using the cobalt chloride catalyzed sodium borohydride-water reaction. Space and Naval Warfare Systems...to inflate LTAs. Of the metal hydrides, we chose to explore the sodium borohydride chemistry. We chose this chemistry because of its energy density

  17. Environmental Effects of Hydrokinetic Turbines on Fish: Desktop and Laboratory Flume Studies

    SciTech Connect

    Jacobson, Paul T.; Amaral, Stephen V.; Castro-Santos, Theodore; Giza, Dan; Haro, Alexander J.; Hecker, George; McMahon, Brian; Perkins, Norman; Pioppi, Nick

    2013-06-01

    A primary issue of concern of regulatory and resource agencies is how the operation of hydrokinetic turbines will affect local and migratory fish populations. This collection of three reports describes desktop and laboratory flume studies that provide information to support assessment of the potential for injury and mortality of fish that encounter hydrokinetic turbines of various designs installed in tidal and river environments.

  18. Water analysis methods at the integrated Lake Watershed Acidification Study Laboratory, Raquette Lake, NY

    SciTech Connect

    Tokos, J.

    1980-09-01

    The materials, equipment, and methods used by Brookhaven National Laboratory personnel for routine chemical and biological analyses in the three lakes of the Integrated Lake Watershed Acidification Study are described. The procedures apply to pelagic samples taken from Panther, Sagamore, and Woods Lakes. Separate sections outlining benthic primary production and inlet-outlet methods are included.

  19. Particle in a Disk: A Spectroscopic and Computational Laboratory Exercise Studying the Polycyclic Aromatic Hydrocarbon Corannulene

    ERIC Educational Resources Information Center

    Frey, E. Ramsey; Sygula, Andrzej; Hammer, Nathan I.

    2014-01-01

    This laboratory exercise introduces undergraduate chemistry majors to the spectroscopic and theoretical study of the polycyclic aromatic hydrocarbon (PAH), corannulene. Students explore the spectroscopic properties of corannulene using UV-vis and Raman vibrational spectroscopies. They compare their experimental results to simulated vibrational…

  20. ENVIRONMENTAL FACTORS INFLUENCING METHANOGENESIS IN A SHALLOW ANOXIC AQUIFER: A FIELD AND LABORATORY STUDY

    EPA Science Inventory

    The environmental factors influencing methanogenesis in a shallow anoxic aquifer were probed in a combined field and laboratory study. Field data collected over a year revealed that in situ rates of methane production were depressed in winter and elevated in summer. Over the same...

  1. LABORATORY STUDY ON THE OXIDATION OF ARSENIC III TO ARSENIC V

    EPA Science Inventory

    A one-year laboratory study was performed to determine the ability of seven oxidants to oxidize As(III) to As(V). These included chlorine, permanganate, ozone, chlorine dioxide, monochloramine, a solid-phase oxidizing media, and 254 nm ultraviolet light. Chlorine and permanganate...

  2. DESIGN OF A SURFACTANT REMEDIATION FIELD DEMONSTRATION BASED ON LABORATORY AND MODELINE STUDIES

    EPA Science Inventory

    Surfactant-enhanced subsurface remediation is being evaluated as an innovative technology for expediting ground-water remediation. This paper reports on laboratory and modeling studies conducted in preparation for a pilot-scale field test of surfactant-enhanced subsurface remedia...

  3. CUNNER(TAUTOGOLABRUS ADSPERSUS) AS A MODEL FISH FOR REPRODUCTIVE STUDIES IN THE LABORATORY

    EPA Science Inventory

    Cunner (Tautogolabrus adspersus) are being studied at our laboratory as a model species to determine the effects of endocrine disrupting chemicals (EDCs) on estuarine fish populations. Cunner was selected because this species is common in estuarine areas, is easily obtainable, an...

  4. Final Report, "Laboratory Studies of the Role of Sea Salt Bromine in Determining Tropospheric Ozone"

    SciTech Connect

    B. J. Finlayson-Pitts

    2005-06-20

    This document is a final report for the project DE-FG03-98ER62578, "Laboratory Studies of the Role of Sea Salt Bromine in Determining Tropospheric Ozone". It includes a technical summary, collaborations, educational contributions and the peer-reviewed scientific publications that have resulted from this research.

  5. Fire vs. Metal: A Laboratory Study Demonstrating Microbial Responses to Soil Disturbances

    ERIC Educational Resources Information Center

    Stromberger, Mary E.

    2005-01-01

    Incubation studies are traditionally used in soil microbiology laboratory classes to demonstrate microbial respiration and N mineralization-immobilization processes. Sometimes these exercises are done to calculate a N balance in N fertilizer-amended soils. However, examining microbial responses to environmental perturbations would appeal to soil…

  6. ASSESSMENT OF GENETIC DAMAGE INDICATORS IN FISH IN LABORATORY, MESOCOSM AND WATERSHED STUDIES

    EPA Science Inventory

    The micronucleus (MN) and single cell gel electrophoresis (SCG) ("Comet") techniques for measuring DNA damage are being evaluated for their potential use as indicators of exposure of fish populations. Laboratory studies employed acute exposures of bluegill sunfish to five model g...

  7. Evaluation of the IVAC 560 volumetric pump. A clinical and laboratory study.

    PubMed

    Hutchinson, A; Yeoman, P M; Byrne, A J

    1985-10-01

    The performance of a new combined infusion pump and central venous pressure monitor, the IVAC 560, has been evaluated in laboratory and clinical studies. The pump performed accurately and reliably, and the pressure readings obtained from the pump correlated well with conventional methods of pressure measurement, although they lost accuracy when using 50% dextrose at higher venous pressures.

  8. A FMEA clinical laboratory case study: how to make problems and improvements measurable.

    PubMed

    Capunzo, Mario; Cavallo, Pierpaolo; Boccia, Giovanni; Brunetti, Luigi; Pizzuti, Sante

    2004-01-01

    The authors have experimented the application of the Failure Mode and Effect Analysis (FMEA) technique in a clinical laboratory. FMEA technique allows: a) to evaluate and measure the hazards of a process malfunction, b) to decide where to execute improvement actions, and c) to measure the outcome of those actions. A small sample of analytes has been studied: there have been determined the causes of the possible malfunctions of the analytical process, calculating the risk probability index (RPI), with a value between 1 and 1,000. Only for the cases of RPI > 400, improvement actions have been implemented that allowed a reduction of RPI values between 25% to 70% with a costs increment of < 1%. FMEA technique can be applied to the processes of a clinical laboratory, even if of small dimensions, and offers a high potential of improvement. Nevertheless, such activity needs a thorough planning because it is complex, even if the laboratory already operates an ISO 9000 Quality Management System.

  9. Subjective interpretation, laboratory error and the value of forensic DNA evidence: three case studies.

    PubMed

    Thompson, W C

    1995-01-01

    This article discusses two factors that may profoundly affect the value of DNA evidence for proving that two samples have a common source: uncertainty about the interpretation of test results and the possibility of laboratory error. Three case studies are presented to illustrate the importance of the analyst's subjective judgments in interpreting some RFLP-based forensic DNA tests. In each case, the likelihood ratio describing the value of DNA evidence is shown to be dramatically reduced by uncertainty about the scoring of bands and the possibility of laboratory error. The article concludes that statistical estimates of the frequency of matching genotypes can be a misleading index of the value of DNA evidence, and that more adequate indices are needed. It also argues that forensic laboratories should comply with the National Research Council's recommendation that forensic test results be scored in a blind or objective manner.

  10. Urine Radiobioassay Intercomparison Results From The Intercomparison Studies Program At Oak Ridge National Laboratory

    SciTech Connect

    Bores, Norman; Schultz, Michael K

    2008-01-01

    The Intercomparison Studies Program (ISP) at the Oak Ridge National Laboratory (ORNL, Oak Ridge, TN USA) provides natural-matrix human urine quality-assurance/quality-control (QA/QC) samples to radiobioassay analysis laboratories. Samples are provided to these laboratories as 'single-blind' or 'double-blind' unknowns, spiked with radioactive-solution standards at 'low' levels (e.g., 0-250 mBq {center_dot} kg{sup -1} for alpha-emitters). Participants use the results as a tool for self-evaluation and a measure of performance. In this paper, sample preparation and the results of testing during the years 2000-2004 for the radionuclides natural uranium (U-nat), {sup 238}Pu, {sup 239}Pu, and {sup 241}Am are presented and discussed.

  11. TEM and HRTEM studies of ball milled 6061 aluminium alloy powder with Zr addition.

    PubMed

    Lityńska-Dobrzyńska, L; Dutkiewicz, J; Maziarz, W; Rogal, Ł

    2010-03-01

    The effect of mechanical alloying on the microstructure of atomized 6061 aluminium alloy powder and 6061 powder with a zirconium addition was studied in the work. The atomized 6061 aluminium alloy powder and 6061 powder with addition of 2 wt.% Zr were milled in a planetary ball mill and investigated using X-ray diffraction measurements, conventional and high-resolution electron microscopy (TEM/HRTEM) and high-angle annular dark field scanning transmission electron microscopy combined with energy dispersive X-ray microanalysis. An increase of stresses was observed in milled powders after the refinement of crystallites beyond 100 nm. In the powder with zirconium addition, some part of the Zr atoms diffused in aluminium forming a solid solution containing up to 0.5 wt.% Zr. The remaining was found to form Zr-rich particles containing up to 88 wt.% Zr and were identified as face centred cubic (fcc) phase with lattice constant a= 0.48 nm. That fcc phase partially transformed into the L1(2) ordered phase. Eighty-hour milling brought an increase of microhardness (measured with Vickers method) from about 50 HV (168 MPa) for the initial 6061 powder to about 170 HV (552 MPa). The addition of zirconium had no influence on the microhardness.

  12. Hallux valgus: comparative study between two surgical techniques of proximal addition osteotomy

    PubMed Central

    Lara, Luiz Carlos Ribeiro; de Araujo, Bruno Vierno; Franco, Nelson; Hita, Roberto Minoru

    2012-01-01

    OBJECTIVE: To clinically and radiographically compare the results of treatment of hallux valgus, by two addition osteotomy techniques: one using resected exostosis, and the other using a plate fixation for addition wedge. METHODS: We evaluated 24 feet of 19 patients, mean age 51.3 years, affected by hallux valgus, with a mean follow-up of 50.1 months. 13 feet underwent addition osteotomy with resected exostosis (AORE) and 11 patients (11 feet) underwent addition osteotomy with plate (AOP). The AOFAS score, intermetatarsal 1 and 2 angles, and hallux valgus angle were evaluated before and after surgery. RESULTS: In the AORE technique, the mean preoperative AOFAS was 46.6, with IMA 14o and HVA 32o, while in the postoperative AOFAS it was 81.3, with IMA 9o and HVA 25o, and 92.3% satisfactory results. In the AOP technique, the mean preoperative AOFAS was 42.1, with IMA 15o and HVA 29o while in the postoperative AOFAS it was 77.4, with IMA 11o and HVA 23o and 81.8% of satisfactory results. CONCLUSIONS: Both techniques proved to be effective in the treatment of hallux valgus, both clinically and radiografically, with no statistical difference between them. Level of evidence III, Retrospective comparative study. PMID:24453631

  13. Towards the development of a fossil bone geochemical standard: an inter-laboratory study.

    PubMed

    Chavagnac, V; Milton, J A; Green, D R H; Breuer, J; Bruguier, O; Jacob, D E; Jong, T; Kamenov, G D; Le Huray, J; Liu, Y; Palmer, M R; Pourtalès, S; Roduhskin, I; Soldati, A; Trueman, C N; Yuan, H

    2007-09-19

    Ten international laboratories participated in an inter-laboratory comparison of a fossil bone composite with the objective of producing a matrix and structure-matched reference material for studies of the bio-mineralization of ancient fossil bone. We report the major and trace element compositions of the fossil bone composite, using in-situ method as well as various wet chemical digestion techniques. For major element concentrations, the intra-laboratory analytical precision (%RSD(r)) ranges from 7 to 18%, with higher percentages for Ti and K. The %RSD(r) are smaller than the inter-laboratory analytical precision (%RSD(R); <15-30%). Trace element concentrations vary by approximately 5 orders of magnitude (0.1 mg kg(-1) for Th to 10,000 mg kg(-1) for Ba). The intra-laboratory analytical precision %RSD(r) varies between 8 and 45%. The reproducibility values (%RSD(R)) range from 13 to <50%, although extreme value >100% was found for the high field strength elements (Hf, Th, Zr, Nb). The rare earth element (REE) concentrations, which vary over 3 orders of magnitude, have %RSD(r) and %RSD(R) values at 8-15% and 20-32%, respectively. However, the REE patterns (which are very important for paleo-environmental, taphonomic and paleo-oceanographic analyses) are much more consistent. These data suggest that the complex and unpredictable nature of the mineralogical and chemical composition of fossil bone makes it difficult to set-up and calibrate analytical instruments using conventional standards, and may result in non-spectral matrix effects. We propose an analytical protocol that can be employed in future inter-laboratory studies to produce a certified fossil bone geochemical standard.

  14. Studies on perilla, agarwood, and cinnamon through a combination of fieldwork and laboratory work.

    PubMed

    Ito, Michiho

    2008-10-01

    Fieldwork is one of the primary methods for studying medicinal plants and materials, and information thus obtained can be valuable for experiments performed in the laboratory. Meanwhile, results of experiments in the laboratory can be brought back to the field for verification and further investigation. A combination of field and laboratory work has led to effective progress in studies of medicinal plants in the field of pharmacognosy. However, the collection of samples with information through fieldwork is not easy, and it fundamentally requires a great deal of research experience. Geographical, ethnical, and political affairs often affect its performance, and to establish a good cooperative relationship with foreign localities is inevitably required. Beyond these difficulties, fieldwork can provide a framework for the research project and excellent and unique viewpoints concerning the target. This review article describes studies on perilla, agarwood, and cinnamon, focusing mainly on the results of fieldwork performed in Indochina on these species. All three of these medicinal plants contain essential oils, and their composition varieties, biosynthetic pathways, pharmacological activities, or induction mechanisms for production are principally investigated through shuttling between fieldwork and laboratory experiments.

  15. Radiofrequency field exposure and cancer: what do the laboratory studies suggest?

    PubMed Central

    Repacholi, M H

    1997-01-01

    Significant concern has been raised about possible health effects from exposure to radiofrequency (RF) electromagnetic fields, especially after the rapid introduction of mobile telecommunications systems. Parents are especially concerned with the possibility that children might develop cancer after exposure to the RF emissions from mobile telephone base stations erected in or near schools. These questions have followed scientific reports suggesting that residence near high voltage power lines may to be associated with an increased childhood leukemia risk. Epidemiologic studies have been plagued by poor RF exposure assessment and differences in methodology. There are no high-quality epidemiologic studies that can be used to evaluate health risks from RF exposure. Laboratory studies in this area have been somewhat confusing. Some animal studies suggest that RF fields accelerate the development of sarcoma colonies in the lung, mammary tumors, skin tumors, hepatomas, and sarcomas. A substantial RF-induced increase in lymphoma incidence in transgenic mice exposed for up to 18 months has also been reported. In contrast, other studies have not found carcinogenic effects. These conflicting results indicate the need for more well-conducted studies on laboratory animals, supplemented with high-quality in vitro studies to identify effects that need further research in vivo, and to characterize any acting mechanisms, especially at low RF field levels. This paper provides a review of the laboratory studies and indicates what conclusions about RF-induced cancer can be drawn. PMID:9467083

  16. Effect of Exogenous Phytase Addition on Soil Phosphatase Activities: a Fluorescence Spectroscopy Study.

    PubMed

    Yang, Xiao-zhu; Chen, Zhen-hua; Zhang, Yu-lan; Chen, Li-jun

    2015-05-01

    The utilization of organic phosphorus (P) has directly or indirectly improved after exogenous phytase was added to soil. However, the mechanism by which exogenous phytase affected the soil phosphatases (phosphomonoesterase and phosphodiesterase) activities was not clear. The present work was aimed to study red soil, brown soil and cinnamon soil phosphomonoesterase (acid and alkaline) (AcP and AlP) and phosphodiesterase (PD) activities responding to the addition of exogenous phytase (1 g phytase/50 g air dry soil sample) based on the measurements performed via a fluorescence detection method combined with 96 microplates using a TECAN Infinite 200 Multi-Mode Microplate Reader. The results indicated that the acid phosphomonoesterase activity was significantly enhanced in red soil (p≤0. 01), while it was significantly reduced in cinnamon soil; alkaline phosphomonoesterase activity was significantly enhanced in cinnamon soil (p≤ 0. 01), while it was significantly reduced in red soil; phosphodiesterase activity was increased in three soils but it was significantly increased in brown soil (p≤0. 01) after the addition of exogenous phytase. The activities still remained strong after eight days in different soils, which indicated that exogenous phytase addition could be enhance soil phosphatases activities effectively. This effect was not only related to soil properties, such as pH and phosphorus forms, but might also be related to the excreted enzyme amount of the stimulating microorganism. Using fluorescence spectroscopy to study exogenous phytase addition influence on soil phosphatase activities was the first time at home and abroad. Compared with the conventional spectrophotometric method, the fluorescence microplate method is an accurate, fast and simple to use method to determine the relationships among the soil phosphatases activities.

  17. Studying the hysteretic behaviour of unconsolidated sediments using an electroencephalography apparatus: a laboratory study.

    NASA Astrophysics Data System (ADS)

    Ruggeri, Paolo; Jougnot, Damien; Chavarriaga, Ricardo; Brandner, Catherine; del Rocio Millán Ruiz, José; Linde, Niklas

    2015-04-01

    In soil science, the hysteretic nature of the water retention curve plays an important role in describing a soil's propensity to retain water and conduct fluid flow. However, hysteresis effects remain difficult to study and to quantify. Geophysical methods provide suitable and non-invasive tools that could be used for this purpose. For example, the degree of water saturation in a soil can be determined by measuring its electrical resistivity, while a water flux through a soil generates a measureable electrical potential difference (streaming potential). The objective of this work is to study the hysteretic behaviour of unconsolidated sediments during repeated drainage and imbibition cycles under well-constrained laboratory conditions. Monitoring was performed using a 32-electrode electroencephalography (EEG) apparatus (Biosemi) coupled with a current injection system. We used a 150 cm high sand-filled column in which we monitored self-potential (SP) signals using 15 electrodes in direct contact with the medium (so-called "naked" electrodes), and 15 electrodes that were inserted in small porous pots that were filled with water of the same conductivity and chloride concentration as the water saturating the sand (so-called "chamber" electrodes). For both electrode types, the electrodes were placed between 5 and 145 cm height with an electrode spacing of 10 cm. Pressure (10 tensiometers) and mass, together with the temperature and the relative humidity in the room, were constantly monitored for the entire duration of the experiments. We performed ten cycles of drainage and imbibition by changing the water level of an external reservoir connected to the column. Each drainage and imbibition cycle took approximately 25 and 17 hours, respectively, for a total duration of the experiment of 24 days. After each imbibition and drainage cycle, we performed complex conductivity measurements by injecting a known electric current at two electrodes using a sine wave with varying

  18. Laboratory Study on Water Uptake by Freshly Emitted Peat Smoke Particles in Southeast Asia

    NASA Astrophysics Data System (ADS)

    Chen, J.; Kuwata, M.; Itoh, M.

    2015-12-01

    Tropical peatland burning activities in Southeast Asia, which can keep smouldering for a long time, have been becoming rather frequent during the last few decades. These combustions have released huge amounts of greenhouse gases and aerosol particles into the atmosphere, contributing large uncertainties to the global radiative forcing estimation. In addition, the gas and aerosol particles emitted from the peat-fire have caused environmental and human health issues. These regional and global impacts are closely tied to water uptake properties of aerosol particles, which alter their physical and chemical characteristics. However, hygroscopic property of peat burning aerosol particles has rarely been investigated. Here, we utilized a self-built Humidified Tandem Differential Mobility Analyzer (HTDMA) to measure diameter growth factors of fresh peat burning particles, which were generated during laboratory peat combustion experiments under controlled conditions. Particle number size distribution and chemical composition were also measured using a Scanning Mobility Particle Sizer (SMPS) and the Time of Flight - Aerosol Chemical Speciation Monitor (ToF-ACSM). Number size distribution demonstrated a bimodal pattern, with the mode diameters in the size ranges of 50-80 nm and 300-500 nm, respectively. The corresponding normalized volume size distribution was unimodal distributed with mode diameter at around 400-600nm. Water uptake of freshly emitted peat smoke aerosol particles was less hygroscopic, probably because fresh peat burning aerosol particles were predominantly composed of organic compounds and sulfates were negligible. The obtained information can be further applied into the studies on the influence of peat burning aerosol particles on regional and global climate.

  19. Class 1 Permit Modification Notification Addition of Structures within Technical Area 54, Area G, Pad 11, Dome 375 Los Alamos National Laboratory Hazardous Waste Facility Permit, July 2012

    SciTech Connect

    Vigil-Holterman, Luciana R.; Lechel, Robert A.

    2012-08-31

    The purpose of this letter is to notify the New Mexico Environment Department-Hazardous Waste Bureau (NMED-HWB) of a Class 1 Permit Modification to the Los Alamos National Laboratory (LANL) Hazardous Waste Facility Permit issued to the Department of Energy (DOE) and Los Alamos National Security, LLC (LANS) in November 2010. The modification adds structures to the container storage unit at Technical Area (TA) 54 Area G, Pad 11. Permit Section 3.1(3) requires that changes to the location of a structure that does not manage hazardous waste shall be changed within the Permit as a Class 1 modification without prior approval in accordance with Code of Federal Regulations, Title 40 (40 CFR), {section}270.42(a)(1). Structures have been added within Dome 375 located at TA-54, Area G, Pad 11 that will be used in support of waste management operations within Dome 375 and the modular panel containment structure located within Dome 375, but will not be used as waste management structures. The Class 1 Permit Modification revises Figure 36 in Attachment N, Figures; and Figure G.12-1 in Attachment G.12, Technical Area 54, Area G, Pad 11 Outdoor Container Storage Unit Closure Plan. Descriptions of the structures have also been added to Section A.4.2.9 in Attachment A, TA - Unit Descriptions; and Section 2.0 in Attachment G.12, Technical Area 54, Area G, Pad 11 Outdoor Container Storage Unit Closure Plan. Full description of the permit modification and the necessary changes are included in Enclosure 1. The modification has been prepared in accordance with 40 CFR {section}270.42(a)(l). This package includes this letter and an enclosure containing a description of the permit modification, text edits of the Permit sections, and the revised figures (collectively LA-UR-12-22808). Accordingly, a signed certification page is also enclosed. Three hard copies and one electronic copy of this submittal will be delivered to the NMED-HWB.

  20. Laboratory Studies of Steep and Breaking Deep Water Waves in a Convergent Channel

    DTIC Science & Technology

    2015-05-28

    TASK NO RR023- 11 TITLE (Include Security Classification) Laboratory Studies of Steep and Breaking Deep Water Waves in a Convergent Channel...These include the relative motion between the water and, say, a ship in the seaway or a cylindrical obstacle in a wavefield; wind blowing over the water ...in deep water . The present experiments were conducted to study the evolution of steep and breaking deep water waves. The waves were made to steepen

  1. Environmental Effects of Hydrokinetic Turbines on Fish: Desktop and Laboratory Flume Studies

    SciTech Connect

    Jacobson, Paul T.; Amaral, Stephen V.; Castro-Santos, Theodore; Giza, Dan; Haro, Alexander J.; Hecker, George; McMahon, Brian; Perkins, Norman; Pioppi, Nick

    2012-12-31

    90%) for fish less than 200 mm in length. Strike mortality was not predicted to occur during passage through a Welka UPG turbine at ambient current velocities less than about 2.5 m/s. Survival and Behavior of Juvenile Atlantic Salmon and Adult American Shad on Exposure to a Hydrokinetic Turbine This report describes a series of experiments designed to measure the effect of exposure to a full-scale, vertical axis hydrokinetic turbine on downstream migrating juvenile Atlantic salmon and upstream migrating adult American shad. Studies were performed in a large-scale, open-channel flume, and all individuals approached the turbine under volitional control. No injuries were observed, and there was no measurable increase in mortality associated with turbine passage. Exposure to the turbine elicited behavioral responses from both species, however, with salmon passing primarily over the downrunning blades. Shad movement was impeded in the presence of the device, as indicated by fewer attempts of shorter duration and reduced distance of ascent up the flume. More work should be performed in both laboratory and field conditions to determine the extent to which observed effects are likely to influence fish in riverine environments. Analysis is needed to assess the potential for multiple units to lead to greater mortality rates or impacts on fish movements and migrations. Additionally, future research should focus on expanding the existing data by developing better estimates of encounter and avoidance probabilities.

  2. Quality Assessment of Urinary Stone Analysis: Results of a Multicenter Study of Laboratories in Europe

    PubMed Central

    Siener, Roswitha; Buchholz, Noor; Daudon, Michel; Hess, Bernhard; Knoll, Thomas; Osther, Palle J.; Reis-Santos, José; Sarica, Kemal; Traxer, Olivier; Trinchieri, Alberto

    2016-01-01

    After stone removal, accurate analysis of urinary stone composition is the most crucial laboratory diagnostic procedure for the treatment and recurrence prevention in the stone-forming patient. The most common techniques for routine analysis of stones are infrared spectroscopy, X-ray diffraction and chemical analysis. The aim of the present study was to assess the quality of urinary stone analysis of laboratories in Europe. Nine laboratories from eight European countries participated in six quality control surveys for urinary calculi analyses of the Reference Institute for Bioanalytics, Bonn, Germany, between 2010 and 2014. Each participant received the same blinded test samples for stone analysis. A total of 24 samples, comprising pure substances and mixtures of two or three components, were analysed. The evaluation of the quality of the laboratory in the present study was based on the attainment of 75% of the maximum total points, i.e. 99 points. The methods of stone analysis used were infrared spectroscopy (n = 7), chemical analysis (n = 1) and X-ray diffraction (n = 1). In the present study only 56% of the laboratories, four using infrared spectroscopy and one using X-ray diffraction, fulfilled the quality requirements. According to the current standard, chemical analysis is considered to be insufficient for stone analysis, whereas infrared spectroscopy or X-ray diffraction is mandatory. However, the poor results of infrared spectroscopy highlight the importance of equipment, reference spectra and qualification of the staff for an accurate analysis of stone composition. Regular quality control is essential in carrying out routine stone analysis. PMID:27248840

  3. A synchrotron study of microstructure gradient in laser additively formed epitaxial Ni-based superalloy

    DOE PAGES

    Xue, Jiawei; Zhang, Anfeng; Li, Yao; ...

    2015-10-08

    Laser additive forming is considered to be one of the promising techniques to repair single crystal Ni-based superalloy parts to extend their life and reduce the cost. Preservation of the single crystalline nature and prevention of thermal mechanical failure are two of the most essential issues for the application of this technique. Here we employ synchrotron X-ray microdiffraction to evaluate the quality in terms of crystal orientation and defect distribution of a Ni-based superalloy DZ125L directly formed by a laser additive process rooted from a single crystalline substrate of the same material. We show that a disorientation gradient caused bymore » a high density of geometrically necessary dislocations and resultant subgrains exists in the interfacial region between the epitaxial and stray grains. This creates a potential relationship of stray grain formation and defect accumulation. In conclusion, the observation offers new directions on the study of performance control and reliability of the laser additive manufactured superalloys.« less

  4. Organic Contamination Baseline Study in NASA Johnson Space Center Astromaterials Curation Laboratories

    NASA Technical Reports Server (NTRS)

    Calaway, Michael J.; Allen, Carlton C.; Allton, Judith H.

    2014-01-01

    Future robotic and human spaceflight missions to the Moon, Mars, asteroids, and comets will require curating astromaterial samples with minimal inorganic and organic contamination to preserve the scientific integrity of each sample. 21st century sample return missions will focus on strict protocols for reducing organic contamination that have not been seen since the Apollo manned lunar landing program. To properly curate these materials, the Astromaterials Acquisition and Curation Office under the Astromaterial Research and Exploration Science Directorate at NASA Johnson Space Center houses and protects all extraterrestrial materials brought back to Earth that are controlled by the United States government. During fiscal year 2012, we conducted a year-long project to compile historical documentation and laboratory tests involving organic investigations at these facilities. In addition, we developed a plan to determine the current state of organic cleanliness in curation laboratories housing astromaterials. This was accomplished by focusing on current procedures and protocols for cleaning, sample handling, and storage. While the intention of this report is to give a comprehensive overview of the current state of organic cleanliness in JSC curation laboratories, it also provides a baseline for determining whether our cleaning procedures and sample handling protocols need to be adapted and/or augmented to meet the new requirements for future human spaceflight and robotic sample return missions.

  5. Couples Counseling in Alzheimer’s Disease: Additional Clinical Findings from a Novel Intervention Study

    PubMed Central

    AUCLAIR, URSULA; EPSTEIN, CYNTHIA; MITTELMAN, MARY

    2009-01-01

    This article describes the clinical findings of a study designed to assess the benefit of counseling for couples, one of whom is in the early stage of Alzheimer’s disease (AD). We previously reported our findings based on the first 12 couples that enrolled in the study. Based on the treatment of 30 additional couples, we have refined our treatment strategy to include concepts of Gestalt Therapy and Transactional Analysis and identified prevalent issues of concern to this cohort. The study design has remained as described in the earlier article (Epstein et al., 2006), and has proven to be appropriate to meet the goals of this intervention as indicated by our clinical experience and feedback from the participating couples. Case vignettes demonstrate how to conduct the sessions so that the experience of each member of the dyad is validated, while acknowledging the differential impact of the disease on them. PMID:19865591

  6. The Evaluation of Teaching the Nursing Process Using Traditional Lecture, Campus Laboratory, Clinical, and the Addition of High Fidelity Human Simulation (HFHS) Unfolding Scenarios

    ERIC Educational Resources Information Center

    Irwin, Ruth E.

    2013-01-01

    It is not sufficient to just make changes in a nursing curriculum without a plan to evaluate the impact on program outcomes. This study sought to determine the outcomes of teaching the nursing process to Foundation of Nursing students in an Associate Degree Nursing program using a factorial design study. Four groups of students were taught the…

  7. Bioremediation of weathered petroleum hydrocarbon soil contamination in the Canadian High Arctic: laboratory and field studies.

    PubMed

    Sanscartier, David; Laing, Tamsin; Reimer, Ken; Zeeb, Barbara

    2009-11-01

    The bioremediation of weathered medium- to high-molecular weight petroleum hydrocarbons (HCs) in the High Arctic was investigated. The polar desert climate, contaminant characteristics, and logistical constraints can make bioremediation of persistent HCs in the High Arctic challenging. Landfarming (0.3 m(3) plots) was tested in the field for three consecutive years with plots receiving very little maintenance. Application of surfactant and fertilizers, and passive warming using a greenhouse were investigated. The field study was complemented by a laboratory experiment to better understand HC removal mechanisms and limiting factors affecting bioremediation on site. Significant reduction of total petroleum HCs (TPH) was observed in both experiments. Preferential removal of compounds laboratory. In the laboratory, significant removal of compounds >nC16 occurred, whereas in the field, TPH reduction was mainly limited to removal of compounds nC16 was observed in the fertilized field plots only. The greenhouse increased average soil temperatures and extended the treatment season but did not enhance bioremediation. Findings suggest that temperature and low moisture content affected biodegradation of HCs in the field. Little volatilization was measured in the laboratory, but this process may have been predominant in the field. Low-maintenance landfarming may be best suited for remediation of HCs compounds

  8. Multi-Laboratory Study of Five Methods for the Determination of Brevetoxins in Shellfish Tissue Extracts

    PubMed Central

    Dickey, Robert W.; Plakas, Steven M.; Jester, Edward L.E.; El Said, Kathleen R.; Johannessen, Jan N.; Flewelling, Leanne J.; Scott, Paula; Hammond, Dan G.; Van Dolah, Frances M.; Leighfield, Tod A.; Bottein Dachraoui, Marie-Yasmine; Ramsdell, John S.; Pierce, Richard H.; Henry, Mike S.; Poli, Mark A.; Walker, Calvin; Kurtz, Jan; Naar, Jerome; Baden, Daniel G.; Musser, Steve M.; White, Kevin D.; Truman, Penelope; Miller, Aaron; Hawryluk, Timothy P.; Wekell, Marleen M.; Stirling, David; Quilliam, Michael A.; Lee, Jung K.

    2010-01-01

    A thirteen-laboratory comparative study tested the performance of four methods as alternatives to mouse bioassay for the determination of brevetoxins in shellfish. The methods were N2a neuroblastoma cell assay, two variations of the sodium channel receptor binding assay, competitive ELISA, and LC/MS. Three to five laboratories independently performed each method using centrally prepared spiked and naturally incurred test samples. Competitive ELISA and receptor binding (96-well format) compared most favorably with mouse bioassay. Between-laboratory relative standard deviations (RSDR) ranged from 10 to 20% for ELISA and 14 to 31% for receptor binding. Within-laboratory (RSDr) ranged from 6 to 15% for ELISA, and 5 to 31% for receptor binding. Cell assay was extremely sensitive but data variation rendered it unsuitable for statistical treatment. LC/MS performed as well as ELISA on spiked test samples but was inordinately affected by lack of toxin-metabolite standards, uniform instrumental parameters, or both, on incurred test samples. The ELISA and receptor binding assay are good alternatives to mouse bioassay for the determination of brevetoxins in shellfish. PMID:26436143

  9. Multi-Laboratory Study of Five Methods for the Determination of Brevetoxins in Shellfish Tissue Extracts.

    PubMed

    Dickey, Robert W; Plakas, Steven M; Jester, Edward L E; El Said, Kathleen R; Johannessen, Jan N; Flewelling, Leanne J; Scott, Paula; Hammond, Dan G; Van Dolah, Frances M; Leighfield, Tod A; Bottein Dachraoui, Marie-Yasmine; Ramsdell, John S; Pierce, Richard H; Henry, Mike S; Poli, Mark A; Walker, Calvin; Kurtz, Jan; Naar, Jerome; Baden, Daniel G; Musser, Steve M; White, Kevin D; Truman, Penelope; Miller, Aaron; Hawryluk, Timothy P; Wekell, Marleen M; Stirling, David; Quilliam, Michael A; Lee, Jung K

    A thirteen-laboratory comparative study tested the performance of four methods as alternatives to mouse bioassay for the determination of brevetoxins in shellfish. The methods were N2a neuroblastoma cell assay, two variations of the sodium channel receptor binding assay, competitive ELISA, and LC/MS. Three to five laboratories independently performed each method using centrally prepared spiked and naturally incurred test samples. Competitive ELISA and receptor binding (96-well format) compared most favorably with mouse bioassay. Between-laboratory relative standard deviations (RSDR) ranged from 10 to 20% for ELISA and 14 to 31% for receptor binding. Within-laboratory (RSDr) ranged from 6 to 15% for ELISA, and 5 to 31% for receptor binding. Cell assay was extremely sensitive but data variation rendered it unsuitable for statistical treatment. LC/MS performed as well as ELISA on spiked test samples but was inordinately affected by lack of toxin-metabolite standards, uniform instrumental parameters, or both, on incurred test samples. The ELISA and receptor binding assay are good alternatives to mouse bioassay for the determination of brevetoxins in shellfish.

  10. A comparative study of seismicity statistics in laboratory stick-slip experiments and nature: Implications for fault mechanics

    NASA Astrophysics Data System (ADS)

    Goebel, Thomas; Kwiatek, Grzegorz; Becker, Thorsten; Sammis, Charles; Dresen, Georg

    2016-04-01

    Fault properties can rarely be monitored under in-situ conditions at seismogenic depth. At these depths seismicity records are possibly the only high-resolution data that can provide insight into state of stress and mechanics of faulting. We analyze series of laboratory experiments on faults that developed during stick-slip on saw-cut and fractured surfaces under upper crustal stress conditions. Stick-slip experiments were performed on surfaces with varying roughness and fracture surfaces that evolved into fault zones with pronounced damage zones. We monitor and analyze acoustic emission events that exhibit many striking similarities to natural seismicity across all examined scales. These similarities include pronounced Gutenberg-Richter-type magnitude distributions, Omori-type aftershock decay, and off-fault seismicity distributions that decay as a power law with distance. In the laboratory, fault roughness and heterogeneity are critical in concentrating stresses that lead to local AE clustering, and differences in off-fault activities and lower b-values. Similar observations of earthquake clustering and b-value variations were made for natural faults such as the Parkfield segment of the San Andreas fault. In addition to seismicity statistics, we conducted a detailed analysis of moment tensors, focusing on relative contributions from isotropic and deviatoric components to laboratory seismicity. In contrast to natural seismicity, our results revealed a larger contribution from isotropic components. These contributions are a result of ongoing fracture processes within the evolving fault which are most pronounced after stick-slip events. Our study shows, that seismicity analyses in laboratory experiments can significantly advance our understanding of fault mechanics from the scale of single asperities to large fault zones.

  11. Molecular Response of Estuarine Fish to Hypoxia: A Comparative Study with Ruffe and Flounder from Field and Laboratory

    PubMed Central

    Tiedke, Jessica; Thiel, Ralf; Burmester, Thorsten

    2014-01-01

    On a global scale, the frequencies and magnitudes of hypoxic events in coastal and estuarine waters have increased dramatically over the past 20 years. Fish populations are suitable indicators for the assessment of the quality of aquatic ecosystems, as they are omnipresent and often comprise a variety of different lifestyles and adaption strategies. We have investigated on the molecular level the impact of hypoxia on two fish species typical of European estuaries. We monitored the expression of eleven putatively hypoxia-responsive genes by means of quantitative real-time RT-PCR in brains, gills and hearts of the ruffe (Gymnocephalus cernua) and the flounder (Platichthys flesus). We first investigated the effect of naturally occurring hypoxia in the Elbe estuary. In a second approach, expression changes in the response to hypoxia were monitored under controlled laboratory conditions. The genes that showed the strongest effect were two respiratory proteins, myoglobin and neuroglobin, as well as the apoptosis enzyme caspase 3. As previously observed in other fish, myoglobin, which was considered to be muscle-specific, was found in brain and gills as well. Comparison of field and laboratory studies showed that – with the exception of the heart of flounder – that mRNA levels of the selected genes were about the same, suggesting that laboratory conditions reflect natural conditions. Likewise, trends of gene expression changes under hypoxia were the same, although hypoxia response was more pronounced in the Elbe estuary. In general, the flounder displayed a stronger response to hypoxia than the ruffe, suggesting that the flounder is more susceptible to hypoxia. The most pronounced differences were found among tissues within a species, demonstrating that hypoxia response is largely tissue-specific. In summary, our data suggest that laboratory experiments essentially mimic field data, but additional environmental factors enhance hypoxia response in nature. PMID:24595439

  12. Federal laboratories for the 21st century

    SciTech Connect

    Gover, J.; Huray, P.G.

    1998-04-01

    Federal laboratories have successfully filled many roles for the public; however, as the 21st Century nears it is time to rethink and reevaluate how Federal laboratories can better support the public and identify new roles for this class of publicly-owned institutions. The productivity of the Federal laboratory system can be increased by making use of public outcome metrics, by benchmarking laboratories, by deploying innovative new governance models, by partnerships of Federal laboratories with universities and companies, and by accelerating the transition of federal laboratories and the agencies that own them into learning organizations. The authors must learn how government-owned laboratories in other countries serve their public. Taiwan`s government laboratory, Industrial Technology Research Institute, has been particularly successful in promoting economic growth. It is time to stop operating Federal laboratories as monopoly institutions; therefore, competition between Federal laboratories must be promoted. Additionally, Federal laboratories capable of addressing emerging 21st century public problems must be identified and given the challenge of serving the public in innovative new ways. Increased investment in case studies of particular programs at Federal laboratories and research on the public utility of a system of Federal laboratories could lead to increased productivity of laboratories. Elimination of risk-averse Federal laboratory and agency bureaucracies would also have dramatic impact on the productivity of the Federal laboratory system. Appropriately used, the US Federal laboratory system offers the US an innovative advantage over other nations.

  13. Laboratory Astrophysics Studies with the COSmIC Facility: Interstellar and Planetary Applications.

    NASA Astrophysics Data System (ADS)

    Salama, Farid; Contreras, Cesar S.; Sciamma-O'Brien, Ella; Bejaoui, Salma

    2015-08-01

    We present and discuss the characteristics and the capabilities of the laboratory facility, COSmIC, that was developed at NASA Ames to generate, process and analyze interstellar, circumstellar and planetary analogs in the laboratory [1]. COSmIC stands for “Cosmic Simulation Chamber” and is dedicated to the study of neutral and ionized molecules and nano particles under the low temperature and high vacuum conditions that are required to simulate space environments. COSmIC integrates a variety of state-of-the-art instruments that allow forming, processing and monitoring simulated space conditions for planetary, circumstellar and interstellar materials in the laboratory. COSmIC is composed of a Pulsed Discharge Nozzle (PDN) expansion that generates a plasma in free supersonic jet expansion coupled to two high-sensitivity, complementary in situ diagnostics: a Cavity Ring Down Spectroscopy (CRDS) and laser induced fluorescence (LIF) systems for photonic detection and a Reflectron Time-Of-Flight Mass Spectrometer (ReTOF-MS) for mass detection [2].Recent laboratory astrophysics results that were obtained using COSmIC will be presented, in particular the progress that has been achieved in the domain of the diffuse interstellar bands (DIBs) and in monitoring, in the laboratory, the formation of dust grains and aerosols from their gas-phase molecular precursors in environments as varied as stellar/circumstellar outflows [3] and planetary atmospheres [4]. Plans for future, next generation, laboratory experiments on cosmic molecules and grains in the growing field of laboratory astrophysics will also be addressed as well as the implications of the current studies for astronomy.References:[1] Salama F., In Organic Matter in Space, IAU Symposium 251, Kwok & Sandford Eds.Cambridge University Press, Vol. 4, S251, p. 357 (2008) and references therein.[2] Ricketts C., Contreras C., Walker, R., Salama F., Int. J. Mass Spec, 300, 26 (2011)[3] Cesar Contreras and Farid Salama, The

  14. A water soluble additive to suppress respirable dust from concrete-cutting chainsaws: a case study.

    PubMed

    Summers, Michael P; Parmigiani, John P

    2015-01-01

    Respirable dust is of particular concern in the construction industry because it contains crystalline silica. Respirable forms of silica are a severe health threat because they heighten the risk of numerous respirable diseases. Concrete cutting, a common work practice in the construction industry, is a major contributor to dust generation. No studies have been found that focus on the dust suppression of concrete-cutting chainsaws, presumably because, during normal operation water is supplied continuously and copiously to the dust generation points. However, there is a desire to better understand dust creation at low water flow rates. In this case study, a water-soluble surfactant additive was used in the chainsaw's water supply. Cutting was performed on a free-standing concrete wall in a covered outdoor lab with a hand-held, gas-powered, concrete-cutting chainsaw. Air was sampled at the operator's lapel, and around the concrete wall to simulate nearby personnel. Two additive concentrations were tested (2.0% and 0.2%), across a range of fluid flow rates (0.38-3.8 Lpm [0.1-1.0 gpm] at 0.38 Lpm [0.1 gpm] increments). Results indicate that when a lower concentration of additive is used exposure levels increase. However, all exposure levels, once adjusted for 3 hours of continuous cutting in an 8-hour work shift, are below the Occupational Safety and Health Administration (OSHA) permissible exposure limit (PEL) of 5 mg/m(3). Estimates were made using trend lines to predict the fluid flow rates that would cause respirable dust exposure to exceed both the OSHA PEL and the American Conference of Governmental Industrial Hygienists (ACGIH®) threshold limit value (TLV).

  15. Laboratory studies on formation and minimisation of polychlorinated dibenzodioxins and -furans (PCDD/F) in secondary aluminium process.

    PubMed

    Lenoir, Dieter; Klobasa, Oliver; Pandelova, Marchela; Henkelmann, Bernhard; Schramm, Karl-Werner

    2012-05-01

    The objectives of this work were to study the formation mechanisms of polychlorinated dibenzo-p-dioxins/polychlorinated dibenzofurans (PCDD/F) in thermal aluminium recycling processes by use of laboratory experiments. The pattern of isomers of PCDD/F indicates that de novo synthesis is important in aluminium smeltery. The mechanisms of PCDD/F formation in aluminium smelting are similar to that of various incineration processes of waste material. The results of bioanalysis (EROD-test) confirms the existence of de novo synthesis of PCDD/F, but points out to the existence to some additional, toxic compounds of unknown structure. To reduce the amount of PCDD/F the input of carbon at the metal should be reduced; in addition the metal smeltery plants should be cleaned from fly ash particles. It is suggested to use good primary methods in the technical plants like constant feeding of the metal into the oven will minimise PCDD/F concentration. The biological EROD-bioassay is a good tool to estimate PCDD/F-TEQ values also for this technical process simulated in the laboratory.

  16. 3H And 90Sr In Urine Radiobioassay Intercomparison Results From The Intercomparison Studies Program At Oak Ridge National Laboratory: Statistical Analysis Of Laboratory Performance

    SciTech Connect

    Bores, Norman; Schultz, Michael K

    2009-01-01

    The Intercomparison Studies Program (ISP) at the Oak Ridge National Laboratory (ORNL, Oak Ridge, TN USA) provides natural-matrix human urine quality-assurance/quality-control (QA/QC) samples to radiobioassay analysis laboratories. Samples are provided to these laboratories as 'single-blind' or 'double-blind' unknowns, spiked with radioactive-solution standards at 'low' levels (e.g., 0.7-7 Bq g{sup -1} for {sup 3}H and 0.7-7 Bq kg{sup -1} for {sup 90}Sr). Participants use the results as a tool for self-evaluation and a measure of performance. In this paper, sample preparation and the results of testing during the years 2001-2005 for {sup 3}H and {sup 90}Sr are presented and discussed.

  17. Prazosin addition to fluvoxamine: A preclinical study and open clinical trial in OCD.

    PubMed

    Feenstra, Matthijs G P; Klompmakers, André; Figee, Martijn; Fluitman, Sjoerd; Vulink, Nienke; Westenberg, Herman G M; Denys, Damiaan

    2016-02-01

    The efficacy of selective serotonin reuptake inhibitors (SRIs) in psychiatric disorders may be "augmented" through the addition of atypical antipsychotic drugs. A synergistic increase in dopamine (DA) release in the prefrontal cortex has been suggested to underlie this augmentation effect, though the mechanism of action is not clear yet. We used in vivo microdialysis in rats to study DA release following the administration of combinations of fluvoxamine (10 mg/kg) and quetiapine (10 mg/kg) with various monoamine-related drugs. The results confirmed that the selective 5-HT1A antagonist WAY-100635 (0.05 mg/kg) partially blocked the fluvoxamine-quetiapine synergistic effect (maximum DA increase dropped from 325% to 214%). A novel finding is that the α1-adrenergic blocker prazosin (1 mg/kg), combined with fluvoxamine, partially mimicked the effect of augmentation (maximum DA increase 205%; area-under-the-curve 163%). As this suggested that prazosin augmentation might be tested in a clinical study, we performed an open clinical trial of prazosin 20 mg addition to SRI in therapy-resistant patients with obsessive-compulsive disorder applying for neurosurgery. A small, non-significant reduction in Yale Brown Obsessive Compulsive Scale (Y-BOCS) scores was observed in 10 patients and one patient was classified as a responder with a reduction in Y-BOCS scores of more than 25%. We suggest that future clinical studies augmenting SRIs with an α1-adrenergic blocker in less treatment resistant cases should be considered. The clinical trial "Prazosin in combination with a serotonin reuptake inhibitor for patients with Obsessive Compulsive disorder: an open label study" was registered at 24/05/2011 under trial number ISRCTN61562706: http://www.controlled-trials.com/ISRCTN61562706.

  18. Laboratory grown subaerial biofilms on granite: application to the study of bioreceptivity.

    PubMed

    Vázquez-Nion, Daniel; Silva, Benita; Troiano, Federica; Prieto, Beatriz

    2017-01-01

    Simulated environmental colonisation of granite was induced under laboratory conditions in order to develop an experimental protocol for studying bioreceptivity. The experimental set-up proved suitable for producing subaerial biofilms by inoculating granite blocks with planktonic multi-species phototrophic cultures derived from natural biofilms. The ability of four different cultures to form biofilms was monitored over a three-month growth period via colour measurements, quantification of photosynthetic pigments and EPS, and CLSM observations. One of the cultures under study, which comprised several taxa including Bryophyta, Charophyta, Chlorophyta and Cyanobacteria, was particularly suitable as an inoculum, mainly because of its microbial richness, its rapid adaptability to the substratum and its high colonisation capacity. The use of this culture as an inoculum in the proposed experimental set-up to produce subaerial biofilms under laboratory conditions will contribute to standardising the protocols involved, thus enabling more objective assessment of the bioreceptivity of granite in further experiments.

  19. Using ecology to inform physiology studies: implications of high population density in the laboratory.

    PubMed

    Newman, Amy E M; Edmunds, Nicholas B; Ferraro, Shannon; Heffell, Quentin; Merritt, Gillian M; Pakkala, Jesse J; Schilling, Cory R; Schorno, Sarah

    2015-03-15

    Conspecific density is widely recognized as an important ecological factor across the animal kingdom; however, the physiological impacts are less thoroughly described. In fact, population density is rarely mentioned as a factor in physiological studies on captive animals and, when it is infrequently addressed, the animals used are reared and housed at densities far above those in nature, making the translation of results from the laboratory to natural systems difficult. We survey the literature to highlight this important ecophysiological gap and bring attention to the possibility that conspecific density prior to experimentation may be a critical factor influencing results. Across three taxa: mammals, birds, and fish, we present evidence from ecology that density influences glucocorticoid levels, immune function, and body condition with the intention of stimulating discussion and increasing consideration of population density in physiology studies. We conclude with several directives to improve the applicability of insights gained in the laboratory to organisms in the natural environment.

  20. Feasibility study of a zero-gravity (orbital) atmospheric cloud physics experiments laboratory

    NASA Technical Reports Server (NTRS)

    Hollinden, A. B.; Eaton, L. R.

    1972-01-01

    A feasibility and concepts study for a zero-gravity (orbital) atmospheric cloud physics experiment laboratory is discussed. The primary objective was to define a set of cloud physics experiments which will benefit from the near zero-gravity environment of an orbiting spacecraft, identify merits of this environment relative to those of groundbased laboratory facilities, and identify conceptual approaches for the accomplishment of the experiments in an orbiting spacecraft. Solicitation, classification and review of cloud physics experiments for which the advantages of a near zero-gravity environment are evident are described. Identification of experiments for potential early flight opportunities is provided. Several significant accomplishments achieved during the course of this study are presented.

  1. Studies of high energy density physics and laboratory astrophysics driven by intense lasers

    NASA Astrophysics Data System (ADS)

    Zhang, J.

    2016-10-01

    Laser plasmas are capable of creating unique physical conditions with extreme high energy density, which are not only closely relevant to inertial fusion energy studies, but also to laboratory simulation of some astrophysical processes. In this paper, we highlight some recent progress made by our research teams. The first part is about directional hot electron beam generation and transport for fast ignition of inertial confinement fusion, as well as a new scheme of fast ignition by use of a strong external DC magnetic field. The second part concerns laboratory modeling of some astrophysical phenomena, including 1) studies of the topological structure of magnetic reconnection/annihilation that relates closely to geomagnetic substorms, loop-top X-ray source and mass ejection in solar flares, and 2) magnetic field generation and evolution in collisionless shock formation.

  2. A combined toxicity study of zinc oxide nanoparticles and vitamin C in food additives

    NASA Astrophysics Data System (ADS)

    Wang, Yanli; Yuan, Lulu; Yao, Chenjie; Ding, Lin; Li, Chenchen; Fang, Jie; Sui, Keke; Liu, Yuanfang; Wu, Minghong

    2014-11-01

    At present, safety evaluation standards for nanofood additives are made based on the toxic effects of a single additive. Since the size, surface properties and chemical nature influence the toxicity of nanomaterials, the toxicity may have dramatically changed when nanomaterials are used as food additives in a complex system. Herein, we investigated the combined toxicity of zinc oxide nanoparticles (ZnO NPs) and vitamin C (Vc, ascorbic acid). The results showed that Vc increased the cytotoxicity significantly compared with that of the ZnO only NPs. When the cells were exposed to ZnO NPs at a concentration less than 15 mg L-1, or to Vc at a concentration less than 300 mg L-1, there was no significant cytotoxicity, both in the case of gastric epithelial cell line (GES-1) and neural stem cells (NSCs). However, when 15 mg L-1 of ZnO NPs and 300 mg L-1 of Vc were introduced to cells together, the cell viability decreased sharply indicating significant cytotoxicity. Moreover, the significant increase in toxicity was also shown in the in vivo experiments. The dose of the ZnO NPs and Vc used in the in vivo study was calculated according to the state of food and nutrition enhancer standard. After repeated oral exposure to ZnO NPs plus Vc, the injury of the liver and kidneys in mice has been indicated by the change of these indices. These findings demonstrate that the synergistic toxicity presented in a complex system is essential for the toxicological evaluation and safety assessment of nanofood.At present, safety evaluation standards for nanofood additives are made based on the toxic effects of a single additive. Since the size, surface properties and chemical nature influence the toxicity of nanomaterials, the toxicity may have dramatically changed when nanomaterials are used as food additives in a complex system. Herein, we investigated the combined toxicity of zinc oxide nanoparticles (ZnO NPs) and vitamin C (Vc, ascorbic acid). The results showed that Vc increased the

  3. A Study to Maximize the Learning Experience in the Physical Chemistry Laboratory

    DTIC Science & Technology

    1979-01-01

    designed to teach physical chemistry concepts in a laboratory setting, a portion of which was designed to teach thcse concepts exclusive of the L lecture...validation of a set of curriculum materials designed to teach certain physical chemistry concepts with little or no reinforcement from a lecture setting...8217 understanding of the discipline being studied. Anderson says not only is there a need for new perspectives for teaching science, but It is especially

  4. Rate Constants of Hydroperoxyl Radical Addition to Cyclic Nitrones: A DFT Study

    PubMed Central

    Villamena, Frederick A.; Merle, John K.; Hadad, Christopher M.; Zweier*, Jay L.

    2008-01-01

    Nitrones are potential synthetic antioxidants against the reduction of radical-mediated oxidative damage in cells, and as analytical reagent for the identification of HO2• and other such transient species. In this work, the PCM/B3LYP/6−31+G(d,p)//B3LYP/6−31G(d) and PCM/mPW1K/6−31+G(d,p) density functional theory (DFT) methods were employed to predict the reactivity of HO2• with various functionalized nitrones as spin traps. The calculated second-order rate constants and free energies of reaction at both levels of theory were in the range of 100−103 M−1 s−1 and 1 to −12 kcal mol−1, respectively, and the rate constants for some nitrones are on the same order of magnitude as those observed experimentally. The trend in HO2• reactivity to nitrones could not be explained solely on the basis of the relationship of the theoretical positive charge densities on the nitronyl-C, with their respective ionization potentials, electron affinities, rate constants, or free energies of reaction. However, various modes of intramolecular H-bonding interaction were observed at the transition state (TS) structures of HO2• addition to nitrones. The presence of intramolecular H-bonding interactions in the transition states were predicted and may play a significant role towards a facile addition of HO2• to nitrones. In general, HO2• addition to ethoxycarbonyl- and spirolactam- substituted nitrones, as well as those nitrones without electron-withdrawing substituents, such as 5,5-dimethyl-pyrroline N-oxide (DMPO) and 5-spirocyclopentyl-pyrroline N-oxide (CPPO), are most preferred compared to the methylcarbamoyl-substituted nitrones. This study suggests that the use of specific spin traps for efficient trapping of HO2• could pave the way toward improved radical detection and antioxidant protection. PMID:17845014

  5. A combined toxicity study of zinc oxide nanoparticles and vitamin C in food additives.

    PubMed

    Wang, Yanli; Yuan, Lulu; Yao, Chenjie; Ding, Lin; Li, Chenchen; Fang, Jie; Sui, Keke; Liu, Yuanfang; Wu, Minghong

    2014-12-21

    At present, safety evaluation standards for nanofood additives are made based on the toxic effects of a single additive. Since the size, surface properties and chemical nature influence the toxicity of nanomaterials, the toxicity may have dramatically changed when nanomaterials are used as food additives in a complex system. Herein, we investigated the combined toxicity of zinc oxide nanoparticles (ZnO NPs) and vitamin C (Vc, ascorbic acid). The results showed that Vc increased the cytotoxicity significantly compared with that of the ZnO only NPs. When the cells were exposed to ZnO NPs at a concentration less than 15 mg L(-1), or to Vc at a concentration less than 300 mg L(-1), there was no significant cytotoxicity, both in the case of gastric epithelial cell line (GES-1) and neural stem cells (NSCs). However, when 15 mg L(-1) of ZnO NPs and 300 mg L(-1) of Vc were introduced to cells together, the cell viability decreased sharply indicating significant cytotoxicity. Moreover, the significant increase in toxicity was also shown in the in vivo experiments. The dose of the ZnO NPs and Vc used in the in vivo study was calculated according to the state of food and nutrition enhancer standard. After repeated oral exposure to ZnO NPs plus Vc, the injury of the liver and kidneys in mice has been indicated by the change of these indices. These findings demonstrate that the synergistic toxicity presented in a complex system is essential for the toxicological evaluation and safety assessment of nanofood.

  6. A study of pyrazines in cigarettes and how additives might be used to enhance tobacco addiction

    PubMed Central

    Alpert, Hillel R; Agaku, Israel T; Connolly, Gregory N

    2016-01-01

    Background Nicotine is known as the drug that is responsible for the addicted behaviour of tobacco users, but it has poor reinforcing effects when administered alone. Tobacco product design features enhance abuse liability by (A) optimising the dynamic delivery of nicotine to central nervous system receptors, and affecting smokers’ withdrawal symptoms, mood and behaviour; and (B) effecting conditioned learning, through sensory cues, including aroma, touch and visual stimulation, to create perceptions of pending nicotine reward. This study examines the use of additives called ‘pyrazines’, which may enhance abuse potential, their introduction in ‘lights’ and subsequently in the highly market successful Marlboro Lights (Gold) cigarettes and eventually many major brands. Methods We conducted internal tobacco industry research using online databases in conjunction with published scientific literature research, based on an iterative feedback process. Results Tobacco manufacturers developed the use of a range of compounds, including pyrazines, in order to enhance ‘light’ cigarette products’ acceptance and sales. Pyrazines with chemosensory and pharmacological effects were incorporated in the first ‘full-flavour, low-tar’ product achieving high market success. Such additives may enhance dependence by helping to optimise nicotine delivery and dosing and through cueing and learned behaviour. Conclusions Cigarette additives and ingredients with chemosensory effects that promote addiction by acting synergistically with nicotine, increasing product appeal, easing smoking initiation, discouraging cessation or promoting relapse should be regulated by the US Food and Drug Administration. Current models of tobacco abuse liability could be revised to include more explicit roles with regard to non-nicotine constituents that enhance abuse potential. PMID:26063608

  7. Impact of contacting study authors to obtain additional data for systematic reviews: diagnostic accuracy studies for hepatic fibrosis

    PubMed Central

    2014-01-01

    Background Seventeen of 172 included studies in a recent systematic review of blood tests for hepatic fibrosis or cirrhosis reported diagnostic accuracy results discordant from 2 × 2 tables, and 60 studies reported inadequate data to construct 2 × 2 tables. This study explores the yield of contacting authors of diagnostic accuracy studies and impact on the systematic review findings. Methods Sixty-six corresponding authors were sent letters requesting additional information or clarification of data from 77 studies. Data received from the authors were synthesized with data included in the previous review, and diagnostic accuracy sensitivities, specificities, and positive and likelihood ratios were recalculated. Results Of the 66 authors, 68% were successfully contacted and 42% provided additional data for 29 out of 77 studies (38%). All authors who provided data at all did so by the third emailed request (ten authors provided data after one request). Authors of more recent studies were more likely to be located and provide data compared to authors of older studies. The effects of requests for additional data on the conclusions regarding the utility of blood tests to identify patients with clinically significant fibrosis or cirrhosis were generally small for ten out of 12 tests. Additional data resulted in reclassification (using median likelihood ratio estimates) from less useful to moderately useful or vice versa for the remaining two blood tests and enabled the calculation of an estimate for a third blood test for which previously the data had been insufficient to do so. We did not identify a clear pattern for the directional impact of additional data on estimates of diagnostic accuracy. Conclusions We successfully contacted and received results from 42% of authors who provided data for 38% of included studies. Contacting authors of studies evaluating the diagnostic accuracy of serum biomarkers for hepatic fibrosis and cirrhosis in hepatitis C patients

  8. A Mechanistic Study of Halogen Addition and Photoelimination from π-Conjugated Tellurophenes.

    PubMed

    Carrera, Elisa I; Lanterna, Anabel E; Lough, Alan J; Scaiano, Juan C; Seferos, Dwight S

    2016-03-02

    The ability to drive reactivity using visible light is of importance for many disciplines of chemistry and has significant implications for sustainable chemistry. Identifying photochemically active compounds and understanding photochemical mechanisms is important for the development of useful materials for synthesis and catalysis. Here we report a series of photoactive diphenyltellurophene compounds bearing electron-withdrawing and electron-donating substituents synthesized by alkyne coupling/ring closing or palladium-catalyzed ipso-arylation chemistry. The redox chemistry of these compounds was studied with respect to oxidative addition and photoelimination of bromine, which is of importance for energy storage reactions involving X2. The oxidative addition reaction mechanism was studied using density functional theory, the results of which support a three-step mechanism involving the formation of an initial η(1) association complex, a monobrominated intermediate, and finally the dibrominated product. All of the tellurophene derivatives undergo photoreduction using 430, 447, or 617 nm light depending on the absorption properties of the compound. Compounds bearing electron-withdrawing substituents have the highest photochemical quantum efficiencies in the presence of an alkene trap, with efficiencies of up to 42.4% for a pentafluorophenyl-functionalized tellurophene. The photoelimination reaction was studied in detail through bromine trapping experiments and laser flash photolysis, and a mechanism is proposed. The photoreaction, which occurs by release of bromine radicals, is competitive with intersystem crossing to the triplet state of the brominated species, as evidenced by the formation of singlet oxygen. These findings should be useful for the design of new photochemically active compounds supported by main-group elements.

  9. Hydrogen atom addition to the surface of graphene nanoflakes: A density functional theory study

    NASA Astrophysics Data System (ADS)

    Tachikawa, Hiroto

    2017-02-01

    Polycyclic aromatic hydrocarbons (PAHs) provide a 2-dimensional (2D) reaction surface in 3-dimensional (3D) interstellar space and have been utilized as a model of graphene surfaces. In the present study, the reaction of PAHs with atomic hydrogen was investigated by means of density functional theory (DFT) to systematically elucidate the binding nature of atomic hydrogen to graphene nanoflakes. PAHs with n = 4-37 were chosen, where n indicates the number of benzene rings. Activation energies of hydrogen addition to the graphene surface were calculated to be 5.2-7.0 kcal/mol at the CAM-B3LYP/6-311G(d,p) level, which is almost constant for all PAHs. The binding energies of hydrogen atom were slightly dependent on the size (n): 14.8-28.5 kcal/mol. The absorption spectra showed that a long tail is generated at the low-energy region after hydrogen addition to the graphene surface. The electronic states of hydrogenated graphenes were discussed on the basis of theoretical results.

  10. Resources allocation in healthcare for cancer: a case study using generalised additive mixed models.

    PubMed

    Musio, Monica; Sauleau, Erik A; Augustin, Nicole H

    2012-11-01

    Our aim is to develop a method for helping resources re-allocation in healthcare linked to cancer, in order to replan the allocation of providers. Ageing of the population has a considerable impact on the use of health resources because aged people require more specialised medical care due notably to cancer. We propose a method useful to monitor changes of cancer incidence in space and time taking into account two age categories, according to healthcar general organisation. We use generalised additive mixed models with a Poisson response, according to the methodology presented in Wood, Generalised additive models: an introduction with R. Chapman and Hall/CRC, 2006. Besides one-dimensional smooth functions accounting for non-linear effects of covariates, the space-time interaction can be modelled using scale invariant smoothers. Incidence data collected by a general cancer registry between 1992 and 2007 in a specific area of France is studied. Our best model exhibits a strong increase of the incidence of cancer along time and an obvious spatial pattern for people more than 70 years with a higher incidence in the central band of the region. This is a strong argument for re-allocating resources for old people cancer care in this sub-region.

  11. Covalent binding of aniline to humic substances. 2. 15N NMR studies of nucleophilic addition reactions

    USGS Publications Warehouse

    Thorn, K.A.; Pettigrew, P.J.; Goldenberg, W.S.; Weber, E.J.

    1996-01-01

    Aromatic amines are known to undergo covalent binding with humic substances in the environment. Although previous studies have examined reaction conditions and proposed mechanisms, there has been no direct spectroscopic evidence for the covalent binding of the amines to the functional groups in humic substances. In order to further elucidate the reaction mechanisms, the Suwannee River and IHSS soil fulvic and humic acids were reacted with 15N-labeled aniline at pH 6 and analyzed using 15N NMR spectrometry. Aniline underwent nucleophilic addition reactions with the quinone and other carbonyl groups in the samples and became incorporated in the form of anilinohydroquinone, anilinoquinone, anilide, imine, and heterocyclic nitrogen, the latter comprising 50% or more of the bound amine. The anilide and anilinohydroquinone nitrogens were determined to be susceptible to chemical exchange by ammonia. In the case of Suwannee River fulvic acid, reaction under anoxic conditions and pretreatment with sodium borohydride or hydroxylamine prior to reaction under oxic conditions resulted in a decrease in the proportion of anilinohydroquinone nitrogen incorporated. The relative decrease in the incorporation of anilinohydroquinone nitrogen with respect to anilinoquinone nitrogen under anoxic conditions suggested that inter- or intramolecular redox reactions accompanied the nucleophilic addition reactions.

  12. Effects of transgenic Bt rice on growth, reproduction, and superoxide dismutase activity of Folsomia candida (Collembola: Isotomidae) in laboratory studies.

    PubMed

    Bai, Yaoyu; Yan, Ruihong; Ke, Xin; Ye, Gongyin; Huang, Fangneng; Luo, Yongming; Cheng, Jiaan

    2011-12-01

    Transgenic rice expressing Bacillus thuringiensis (Bt) CrylAb protein is expected to be commercialized in China in the near future. The use of Bt rice for controlling insect pests sparks intensive debates regarding its biosafety. Folsomia candida is an euedaphic species and is often used as a "standard" test organism in assessing effects of environmental pollutants on soil organisms. In this study, growth, development, reproduction, and superoxide dismutase activity (SOD) of F. candida were investigated in the laboratory for populations reared on leaf tissue or leaf-soil mixtures of two CrylAb rice lines and a non-Bt rice isoline. Two independent tests were performed: 1) a 35-d test using petri dishes containing yeast diet (positive control) or fresh rice leaf tissue, and 2) a 28-d test in soil-litter microcosms containing yeast or a mixture of soil and rice leaf tissue. Biological parameters measured in both tests were number of progeny production, population growth rate, and SOD activity. For the petri dish test, data measured also included insect body length and number of exuviation. There were no significant differences between the populations reared on Bt and non-Bt rice leaf tissue in all measured parameters in both tests and for both Bt rice lines, suggesting no significant effects of the CrylAb protein in Bt rice on F. candida in the laboratory studies. Results of this study should add additional biosafety proofs for use of Bt rice to manage rice pests in China.

  13. Laboratory studies of immersion and deposition mode ice nucleation of ozone aged mineral dust particles

    NASA Astrophysics Data System (ADS)

    Kanji, Z. A.; Welti, A.; Chou, C.; Stetzer, O.; Lohmann, U.

    2013-04-01

    Ice nucleation in the atmosphere is central to the understanding the microphysical properties of mixed-phase and cirrus clouds. Ambient conditions such as temperature (T) and relative humidity (RH), as well as aerosol properties such as chemical composition and mixing state play an important role in predicting ice formation in the troposphere. Previous field studies have reported the absence of sulphate and organic compounds on mineral dust ice crystal residuals sampled at mountain top stations or aircraft based measurements despite the long range transport mineral dust is subjected to. We present laboratory studies of ice nucleation for immersion and deposition mode on ozone aged mineral dust particles for 233 < T < 263 K that will represent ageing but not internal mixing with in(organic) compounds. Heterogeneous ice nucleation of untreated kaolinite (Ka) and Arizona Test Dust (ATD) particles is compared to corresponding aged particles that are subjected to ozone exposures of 0.4-4.3 ppmv in a stainless steel aerosol tank. The portable ice nucleation counter (PINC) and immersion chamber combined with the Zurich ice nucleation chamber (IMCA - ZINC) are used to conduct deposition and immersion mode measurements respectively. Ice active fractions as well as ice active surface site densities (ns) are reported and observed to increase as a function of temperature. We present first results that demonstrate enhancement of the ice nucleation ability of aged mineral dust particles in both the deposition and immersion mode due to ageing. Additionally, these are also the first results to show a suppression of heterogeneous ice nucleation without the condensation of a coating of (in)organic material. In immersion mode, low exposure Ka particles showed enhanced ice activity requiring a median freezing temperature of 1.5 K warmer than that of untreated Ka whereas high exposure ATD particles showed suppressed ice nucleation requiring a median freezing temperature of 3 K colder

  14. Service Quality and Patient Satisfaction: An Exploratory Study of Pathology Laboratories in Jaipur.

    PubMed

    Agarwal, Anuradha; Singh, Maithili R P

    2016-01-01

    One of the most important parts of healthcare system is diagnostics. Nowadays, Indians have become more aware of their health, due to improved and better availability of health related information, increase in medical tourism, and expanding health insurance. The demand for better diagnostic facilities have increased with the increase in lifestyle related diseases, excesses use of chemicals in agriculture practices and change in food habits. It is expected that the Indian diagnostic market will grow from USD $5 billion in the year 2012 to USD $32 billion by the year 2020 with 20% CAGR (India Brand Equity Foundation 2015 ). Today patients have easy access of information regarding the health services and they have become more concerned about it as they look forward to receiving the maximum value for their money. To win the confidence of the patients and to maintain that trust, it is required to deliver the right services to the right person at the right time. The purpose of this study was to develop a scale to measure the service quality at pathology laboratory. A thorough review of literature revealed that there are studies related to healthcare service quality but there is no such established scale to measure service quality of pathology laboratory. Thus, the authors strived to develop a reliable and valid instrument to measure the patients' perception toward pathology laboratory service quality. For this exploratory study was conducted on the sample of 80 patients of the laboratories in Jaipur city. The reliability and factor structures were tested to purify the scale. The findings revealed 13 items, comprising of three dimensions of service quality: responsiveness, tangibility, and reliability.

  15. Plans and Preliminary Results of Fundamental Studies of Ice Crystal Icing Physics in the NASA Propulsion Systems Laboratory

    NASA Technical Reports Server (NTRS)

    Struk, Peter; Tsao, Jen-Ching; Bartkus, Tadas

    2016-01-01

    This presentation accompanies the paper titled Plans and Preliminary Results of Fundamental Studies of Ice Crystal Icing Physics in the NASA Propulsion Systems Laboratory. NASA is evaluating whether PSL, in addition to full-engine and motor-driven-rig tests, can be used for more fundamental ice-accretion studies that simulate the different mixed-phase icing conditions along the core flow passage of a turbo-fan engine compressor. The data from such fundamental accretion tests will be used to help develop and validate models of the accretion process. This presentation (and accompanying paper) presents data from some preliminary testing performed in May 2015 which examined how a mixed-phase cloud could be generated at PSL using evaporative cooling in a warmer-than-freezing environment.

  16. Significant light induced ozone loss on biomass burning aerosol: Evidence from chemistry-transport modeling based on new laboratory studies

    NASA Astrophysics Data System (ADS)

    Konovalov, I. B.; Beekmann, M.; D'Anna, B.; George, C.

    2012-09-01

    Recent laboratory studies indicated that a photo-induced heterogeneous reaction of ozone on the surface of aerosol containing humic like substances (HULIS) has the potential to affect the ozone budget in biomass burning plumes. To evaluate atmospheric significance of such heterogeneous light induced ozone loss, this process has been taken into account in the simulation of the extreme air pollution episode in the Moscow region during the 2010 mega fire event in western Russia. Results of the numerical experiments performed with the CHIMERE chemistry transport model indicate that photo induced removal of ozone could lead to significant (reaching several tens of percent) episodic decrease of the ozone concentration. The simulations also show that while wildfires provide reactive surface for the considered reaction, they strongly inhibit the photo-induced heterogeneous ozone loss by attenuating actinic fluxes through the “shielding” aerosol effect. The present results are calling for additional experimental and modelling studies.

  17. Study on Friction and Wear Properties of Silver Matrix Brush Material with Different Additives

    NASA Astrophysics Data System (ADS)

    Chen, Xiaoli; Wang, Wenfang; Hong, Yu; Wu, Yucheng

    2013-07-01

    Friction and wear processes of AgCuX (G, CF and AlN) composites-CuAgV alloy friction pair and effects of different additive content in silver based composite on friction and wear behavior are studied in this paper. The microstructure of the brush wear surface is observed by SEM. The results show that when graphite content is up to 9 wt.%, Ag-Cu-CF-G composite exhibits the best wear properties; when the content of aluminum nitride is up to 0.5 wt.%, Ag-Cu-AlN-G composites has the most comprehensive performance. The wear loss of both composites arises with the increase of both pressure and speed, but when speed reaches a critical value, the increased amplitude of wear loss tends to be steady.

  18. Spectroscopic studies of nucleic acid additions during seed-mediated growth of gold nanoparticles

    PubMed Central

    Tapp, Maeling; Sullivan, Rick; Dennis, Patrick; Naik, Rajesh R.

    2015-01-01

    The effect of adding nucleic acids to gold seeds during the growth stage of either nanospheres or nanorods was investigated using UV-Vis spectroscopy to reveal any oligonucleotide base or structure-specific effects on nanoparticle growth kinetics or plasmonic signatures. Spectral data indicate that the presence of DNA duplexes during seed ageing drastically accelerated nanosphere growth while the addition of single-stranded polyadenine at any point during seed ageing induces nanosphere aggregation. For seeds added to a gold nanorod growth solution, single-stranded polythymine induces a modest blue-shift in the longitudinal peak wavelength. Moreover, a particular sequence comprised of 50% thymine bases was found to induce a faster, more dramatic blue-shift in the longitudinal peak wavelength compared to any of the homopolymer incubation cases. Monomeric forms of the nucleic acids, however, do not yield discernable spectral differences in any of the gold suspensions studied. PMID:25960601

  19. Modular system for studying tonal sound excitation in resonators with heat addition and mean flow.

    PubMed

    Matveev, Konstantin I; Hernandez, Rafael

    2012-03-01

    An educational experimental system has been developed for studying tonal sound generation in acoustic resonators. Tones are excited by either heat addition or vortex shedding in the presence of mean flow. The system construction is straightforward and inexpensive. Several test arrangements and experimental data are described in this paper. The experimental setups include a modified Rijke tube, a standing-wave thermoacoustic engine, a baffled tube with mean flow, and an acoustic energy harvester with a piezoelement. Simplified mathematical models for interpreting data are discussed, and references are provided to literature with more advanced analyses. The developed system can assist both graduate and undergraduate students in understanding acoustic instabilities via conducting and analyzing interesting experiments.

  20. Laboratory Studies of the Effects of Static and Variable Magnetic Fields on Freshwater Fish

    SciTech Connect

    Cada, Glenn F; Bevelhimer, Mark S; Fortner, Allison M; Riemer, Kristina P; Schweizer, Peter E

    2012-04-01

    ). Those experiments found little indication that the behaviors of these freshwater species were altered by the static magnetic fields that would be created by submerged, direct current (DC)-transmitting electrical cables expected to be used by the HK developers. Laboratory experiments in FY 2011 examined the responses of additional fish species (sunfish, striped bass, and channel catfish) to the static magnetic fields. In addition, the effects of variable magnetic fields (that would be created by the HK generators and AC-transmitting cables) on swimming behavior of two electrosensitive fish species (paddlefish and lake sturgeon) were studied.

  1. Genetic Assessment of Additional Endophenotypes from the Consortium on the Genetics of Schizophrenia Family Study

    PubMed Central

    Greenwood, Tiffany A.; Lazzeroni, Laura C.; Calkins, Monica E.; Freedman, Robert; Green, Michael F.; Gur, Raquel E.; Gur, Ruben C.; Light, Gregory A.; Nuechterlein, Keith H.; Olincy, Ann; Radant, Allen D.; Seidman, Larry J.; Siever, Larry J.; Silverman, Jeremy M.; Stone, William S.; Sugar, Catherine A.; Swerdlow, Neal R.; Tsuang, Debby W.; Tsuang, Ming T.; Turetsky, Bruce I.; Braff, David L.

    2015-01-01

    The Consortium on the Genetics of Schizophrenia Family Study (COGS-1) has previously reported our efforts to characterize the genetic architecture of 12 primary endophenotypes for schizophrenia. We now report the characterization of 13 additional measures derived from the same endophenotype test paradigms in the COGS-1 families. Nine of the measures were found to discriminate between schizophrenia patients and controls, were significantly heritable (31 to 62%), and were sufficiently independent of previously assessed endophenotypes, demonstrating utility as additional endophenotypes. Genotyping via a custom array of 1536 SNPs from 94 candidate genes identified associations for CTNNA2, ERBB4, GRID1, GRID2, GRIK3, GRIK4, GRIN2B, NOS1AP, NRG1, and RELN across multiple endophenotypes. An experiment-wide p value of 0.003 suggested that the associations across all SNPs and endophenotypes collectively exceeded chance. Linkage analyses performed using a genome-wide SNP array further identified significant or suggestive linkage for six of the candidate endophenotypes, with several genes of interest located beneath the linkage peaks (e.g., CSMD1, DISC1, DLGAP2, GRIK2, GRIN3A, and SLC6A3). While the partial convergence of the association and linkage likely reflects differences in density of gene coverage provided by the distinct genotyping platforms, it is also likely an indication of the differential contribution of rare and common variants for some genes and methodological differences in detection ability. Still, many of the genes implicated by COGS through endophenotypes have been identified by independent studies of common, rare, and de novo variation in schizophrenia, all converging on a functional genetic network related to glutamatergic neurotransmission that warrants further investigation. PMID:26597662

  2. Mössbauer spectroscopy: an excellent additional tool for the study of magnetic soils and sediments

    NASA Astrophysics Data System (ADS)

    Vandenberghe, R. E.; Hus, J. J.; de Grave, E.

    2009-04-01

    Since the discovery a half century ago of the resonant gamma absorption, known as the Mössbauer effect, the derived spectroscopic method (MS) has proven to be a very suitable tool for the characterization of soil and rock minerals. From the conventional absorption spectra of iron containing compounds, so-called hyperfine parameters are derived which are more or less typical for each kind of mineral. So, MS has a certain analytical power for the characterization of iron-bearing minerals. This is especially true for magnetic minerals for which the spectrum contains an additional hyperfine parameter. Moreover, MS also allows retrieving information about the magnetic structure and behavior. Because the relative area of the spectra is to some extent proportional to the amount of iron atoms in their environment, MS yields not only quantitative information about the various minerals present but also about the iron in the different crystallographic sites. The power of MS as an excellent additional tool for the study of magnetic soils and sediments could be well demonstrated in the joint research with Jozef Hus (CPG-IRM, Dourbes). In our common work, the emphasis went mainly to the study of Chinese loess and soils. Using MS on magnetically separated samples the various magnetic species in a loess and its associated soil were for the first time discerned in a direct way. Further, magnetically enriched samples of four different loess/paleosol couplets from a loess sequence in Huangling have been systematically investigated by MS. From the obtained qualitative and quantitative information the neoformation of magnetite/maghemite in the soils, responsible for the increased observed remanence and susceptibility, could be evidenced.

  3. Spin-probe ESR and molecular modeling studies on calcium carbonate dispersions in overbased detergent additives.

    PubMed

    Montanari, Luciano; Frigerio, Francesco

    2010-08-15

    Oil-soluble calcium carbonate colloids are used as detergent additives in lubricating oils. They are colloidal dispersions of calcium carbonate particles stabilized by different surfactants; in this study alkyl-aryl-sulfonates and sulfurized alkyl-phenates, widely used in the synthesis of these additives, are considered. The physical properties of surfactant layers surrounding the surfaces of calcium carbonate particles were analyzed by using some nitroxide spin-probes (stable free radicals) and observing the corresponding ESR spectra. The spin-probe molecules contain polar groups which tend to tether them to the carbonate particle polar surface. They can reach these surfaces only if the surfactant layers are not very compact, hence the relative amounts of spin-probe molecules accessing carbonate surfaces are an index of the compactness of surfactant core. ESR signals of spin-probe molecules dissolved in oil or "locked" near the carbonate surfaces are different because of the different molecular mobility. Through deconvolution of the ESR spectra, the fraction of spin-probes penetrating surfactant shells have been calculated, and differences were observed according to the surfactant molecular structures. Moreover, by using specially labeled spin-probes based on stearic acids, functionalized at different separations from the carboxylic acid group, it was possible to interrogate the molecular physical behavior of surfactant shells at different distances from carbonate surfaces. Molecular modeling was applied to generate some three-dimensional micellar models of the colloidal stabilizations of the stabilized carbonate particles with different molecular structures of the surfactant. The diffusion of spin-probe molecules into the surfactant shells were studied by applying a starting force to push the molecules towards the carbonate surfaces and then observing the ensuing behavior. The simulations are in accordance with the ESR data and show that the geometrical

  4. Inside Solomon's house: an archaeological study of the Old Ashmolean chymical laboratory in Oxford.

    PubMed

    Martinón-Torres, Marcos

    2012-03-01

    This paper is based on the archaeological and analytical study of the laboratory remains from the Officina Chimica of the Old Ashmolean Museum in Oxford. Following a contextualisation of this laboratory, founded in the wake of Bacon's utopian idea of Solomon's Temple, it is argued that the assemblage is likely to date from the late seventeenth century and thus be connected to the work of Robert Plot, Christopher White, and, indirectly, Robert Boyle. The analytical study of the equipment reveals that the chymists at the Old Ashmolean obtained crucibles from the best manufacturers in Europe, and that they used these and other utensils for experiments involving mercury, sulphur, zinc, lead glass, manganese, and antimony. The importance of these elements for early modern chymistry is discussed in the light of relevant historical sources, including some of Boyle's chymical texts. Altogether, these finds illustrate some of the rich diversity of experiments that took place in one of the most prominent laboratories of the period, showing strong connections with longstanding alchemical concerns as well as with cutting-edge research and development ventures.

  5. Royal College of Pathologists' United Kingdom pilot study of laboratory accreditation. The College Accreditation Steering Committee.

    PubMed

    1990-02-01

    The Royal College of Pathologists recently commissioned a pilot study to assess the feasibility, desirability, and cost of establishing a national scheme for laboratory accreditation in the United Kingdom. Using a format similar to that designed by the College of American Pathologists, eight inspectors visited 24 laboratories comprising the major disciplines of two district hospitals, two teaching hospitals, a specialised (paediatric) hospital and a private hospital. Nine were considered accreditable without reservation, but 15 had deficiencies identified of differing importance which needed to be corrected before accreditation could be awarded. Problems identified were variable, but none related to technical performance and many did not require extra resources to correct. The exercise was conducted without organisational difficulty at an approximate direct cost of 300 pounds per laboratory. The study shows that the format used could form the basis of a cost effective nationwide strategy. The type of problems identified suggest that such a strategy is more likely to succeed if it is organised from within the pathology professions.

  6. Exhaust particles of modern gasoline vehicles: A laboratory and an on-road study

    NASA Astrophysics Data System (ADS)

    Karjalainen, Panu; Pirjola, Liisa; Heikkilä, Juha; Lähde, Tero; Tzamkiozis, Theodoros; Ntziachristos, Leonidas; Keskinen, Jorma; Rönkkö, Topi

    2014-11-01

    Vehicle technology development and upcoming particle emission limits have increased the need for detailed analyses of particle emissions of vehicles using gasoline direct injection (GDI) techniques. In this paper the particle emission characteristics of modern GDI passenger cars were studied in a laboratory and on the road, with the focus on exhaust particle number emissions, size distributions, volatility and morphology. Both during acceleration and steady conditions the number size distribution of nonvolatile exhaust particles consisted of two modes, one with mean particle size below 30 nm and the other with mean particle size approximately 70 nm. Results indicate that both of these particles modes consisted of soot but with different morphologies. Both in laboratory and on the road, significant emissions of exhaust particles were observed also during decelerations conducted by engine braking. These particles are most likely originating from lubricant oil ash components. The semivolatile nucleation particles were observed in the laboratory experiments at high engine load conditions. Thus, in general, the study indicates that a modern gasoline vehicle can emit four distinctive types of exhaust particles. The differences in particle characteristics and formation should be taken into account in the development of emission control strategies and technologies and, on the other hand, in the assessment of the impact of particle emissions on environment and human health.

  7. Biofilm resilience to desiccation in groundwater aquifers: a laboratory and field study.

    PubMed

    Weaver, L; Webber, J B; Hickson, A C; Abraham, P M; Close, M E

    2015-05-01

    Groundwater is used as a precious resource for drinking water worldwide. Increasing anthropogenic activity is putting increasing pressure on groundwater resources. One impact of increased groundwater abstraction coupled with increasing dry weather events is the lowering of groundwater levels within aquifers. Biofilms within groundwater aquifers offer protection to the groundwater by removing contaminants entering the aquifer systems from land use activities. The study presented investigated the impact of desiccation events on the biofilms present in groundwater aquifers using field and laboratory experiments. In both field and laboratory experiments a reduction in enzyme activity (glucosidase, esterase and phosphatase) was seen during desiccation compared to wet controls. However, comparing all the data together no significant differences were seen between either wet or desiccated samples or between the start and end of the experiments. In both field and laboratory experiments enzyme activity recovered to start levels after return to wet conditions. The study shows that biofilms within groundwater systems are resilient and can withstand periods of desiccation (4 months).

  8. Emotions beyond the laboratory: theoretical fundaments, study design, and analytic strategies for advanced ambulatory assessment.

    PubMed

    Wilhelm, Frank H; Grossman, Paul

    2010-07-01

    Questionnaire and interview assessment can provide reliable data on attitudes and self-perceptions on emotion, and experimental laboratory assessment can examine functional relations between stimuli and reactions under controlled conditions. On the other hand, ambulatory assessment is less constrained and provides naturalistic data on emotion in daily life, with the potential to (1) assure external validity of laboratory findings, (2) provide normative data on prevalence, quality and intensity of real-life emotion and associated processes, (3) characterize previously unidentified emotional phenomena, and (4) model real-life stimuli for representative laboratory research design. Technological innovations now allow for detailed ambulatory study of emotion across domains of subjective experience, overt behavior and physiology. However, methodological challenges abound that may compromise attempts to characterize biobehavioral aspects of emotion in the real world. For example, emotional effects can be masked by social engagement, mental and physical workloads, as well as by food intake and circadian and quasi-random variation in metabolic activity. The complexity of data streams and multitude of factors that influence them require a high degree of context specification for meaningful data interpretation. We consider possible solutions to typical and often overlooked issues related to ambulatory emotion research, including aspects of study design decisions, recording devices and channels, electronic diary implementation, and data analysis.

  9. DHM and serious games: a case-study oil and gas laboratories.

    PubMed

    Santos, V; Zamberlan, M; Streit, P; Oliveira, J; Guimarães, C; Pastura, F; Cid, G

    2012-01-01

    The aim in this paper is to present a research on the application of serious games for the design of laboratories in the oil and gas industries. The focus is in human virtual representation acquired from 3D scanning, human interaction, workspace layout and equipment designed considering ergonomics standards. The laboratory studies were simulated in Unity3D platform, which allows the users to control the DHM1 on the dynamic virtual scenario, in order to simulate work activities. This methodology can change the design process by improving the level of interaction between final users, managers and human factor teams. That helps to better visualize future work settings and improve the level of participation between all stakeholders.

  10. The Study of Indicatrices of Space Object Coatings in a Controlled Laboratory Environment

    NASA Astrophysics Data System (ADS)

    Koshkin, N.; Burlak, N.; Petrov, M.; Strakhova, S.

    The indicatrices of light scattering by radiation balance coatings used on space objects (SO) were determined in the laboratory experiment in a controlled condition. The laboratory device for the physical simulation of photometric observations of space objects in orbit, which was used in this case to study optical properties of coating samples, is described. The features of light reflection off plane coating samples, including multi-layer insulation (MLI) blankets, metal surfaces coated with several layers of enamel EP-140, special polyacrylate enamel AK-512 and matte finish Tp-CO-2, were determined. The indicated coatings are compound reflectors which exhibit both diffuse and specular reflections. The data obtained are to be used in the development of computer optical-geometric models of space objects or their fragments (space debris) to interpret the photometry results for real space objects.

  11. Canadian multicenter laboratory study for standardized second-line antimicrobial susceptibility testing of Mycobacterium tuberculosis.

    PubMed

    Sharma, Meenu; Thibert, Louise; Chedore, Pamela; Shandro, Cary; Jamieson, Frances; Tyrrell, Gregory; Christianson, Sara; Soualhine, Hafid; Wolfe, Joyce

    2011-12-01

    The purpose of this study was to establish a standardized protocol for second-line antimicrobial susceptibility testing of Mycobacterium tuberculosis using the Bactec MGIT 960 system in Canadian laboratories. Four Canadian public health laboratories compared the susceptibility testing results of 9 second-line antimicrobials between the Bactec 460 and Bactec MGIT 960 systems. Based on the data generated, we have established that the Bactec MGIT 960 system provides results comparable to those obtained with the previous Bactec 460 method. The critical concentrations established for the testing of the antimicrobials used are as follows: amikacin, 1 μg/ml; capreomycin, 2.5 μg/ml; ethionamide, 5 μg/ml; kanamycin, 2.5 μg/ml; linezolid, 1 μg/ml; moxifloxacin, 0.25 μg/ml; ofloxacin, 2 μg/ml; p-aminosalicylic acid, 4 μg/ml; rifabutin, 0.5 μg/ml.

  12. Statistical Analyses of Second Indoor Bio-Release Field Evaluation Study at Idaho National Laboratory

    SciTech Connect

    Amidan, Brett G.; Pulsipher, Brent A.; Matzke, Brett D.

    2009-12-17

    In September 2008 a large-scale testing operation (referred to as the INL-2 test) was performed within a two-story building (PBF-632) at the Idaho National Laboratory (INL). The report “Operational Observations on the INL-2 Experiment” defines the seven objectives for this test and discusses the results and conclusions. This is further discussed in the introduction of this report. The INL-2 test consisted of five tests (events) in which a floor (level) of the building was contaminated with the harmless biological warfare agent simulant Bg and samples were taken in most, if not all, of the rooms on the contaminated floor. After the sampling, the building was decontaminated, and the next test performed. Judgmental samples and probabilistic samples were determined and taken during each test. Vacuum, wipe, and swab samples were taken within each room. The purpose of this report is to study an additional four topics that were not within the scope of the original report. These topics are: 1) assess the quantitative assumptions about the data being normally or log-normally distributed; 2) evaluate differences and quantify the sample to sample variability within a room and across the rooms; 3) perform geostatistical types of analyses to study spatial correlations; and 4) quantify the differences observed between surface types and sampling methods for each scenario and study the consistency across the scenarios. The following four paragraphs summarize the results of each of the four additional analyses. All samples after decontamination came back negative. Because of this, it was not appropriate to determine if these clearance samples were normally distributed. As Table 1 shows, the characterization data consists of values between and inclusive of 0 and 100 CFU/cm2 (100 was the value assigned when the number is too numerous to count). The 100 values are generally much bigger than the rest of the data, causing the data to be right skewed. There are also a significant

  13. Photometric study of cometary analogs in the LOSSy laboratory at the University of Bern

    NASA Astrophysics Data System (ADS)

    Pommerol, A.; Thomas, N.; Jost, B.; Poch, O.

    2014-07-01

    We have set up the LOSSy laboratory (Laboratory for Outflow Studies of Sublimating Materials) to study the spectro-photometric properties of various analogs of planetary-object surfaces, with a special emphasis on icy samples and their evolution under simulated space conditions. This laboratory is currently equipped with two facilities: the PHIRE-2 radio-goniometer, designed to measure the bidirectional visible reflectance of samples under a wide range of geometries and the SCITEAS simulation chamber, designed to follow the evolution of icy samples subliming under low temperature and low pressure conditions by means of VIS-NIR hyperspectral imaging. We will report on the characterization of cometary analogs using both facilities. We produce these analogs by mixing in various proportions fine-grained ice, mineral and organic matter. Various preparation protocols have been defined to produce different textures of sample. Using the PHIRE-2 radio-goniometer, we are building a catalog of bidirectional reflectance data for various cometary analogs, varying by steps the different parameters susceptible to affect the reflectance phase function. In particular, we have recently upgraded the instrument to be able to characterize in detail the opposition effect by allowing measurements of the reflectance at very low phase angle. This laboratory dataset is intended to be used for the analysis of the data acquired by the OSIRIS imager onboard Rosetta. Using the SCITEAS simulation chamber, we have followed for 30 hours the evolution of a cometary analog placed under secondary vacuum (<10^{-6} mbar) and maintained at low temperature (170-200 K) for more than 30 hours. We analyzed the temporal evolution of the morphology and the photometry of the surface of the sample to identify which processes affect the surfaces of cometary nuclei during sublimation and how they affect their visible and near-infrared surface properties.

  14. Food additive carrageenan: Part II: A critical review of carrageenan in vivo safety studies.

    PubMed

    Weiner, Myra L

    2014-03-01

    Carrageenan (CGN) is a seaweed-derived high molecular weight (Mw) hydrocolloid, primarily used as a stabilizer and thickener in food. The safety of CGN regarding its use in food is reviewed. Based on experimental studies in animals, ingested CGN is excreted quantitatively in the feces. Studies have shown that CGN is not significantly degraded by low gastric pH or microflora in the gastrointestinal (GI) tract. Due to its Mw, structure and its stability when bound to protein, CGN is not significantly absorbed or metabolized. CGN also does not significantly affect the absorption of nutrients. Subchronic and chronic feeding studies in rodents indicate that CGN at doses up to 5% in the diet does not induce any toxicological effects other than soft stools or diarrhea, which are a common effect for non-digestible high molecular weight compounds. Review of several studies from numerous species indicates that food grade CGN does not produce intestinal ulceration at doses up to 5% in the diet. Effects of CGN on the immune system following parenteral administration are well known, but not relevant to food additive uses. The majority of the studies evaluating the immunotoxicity potential were conducted with CGN administered in drinking water or by oral gavage where CGN exists in a random, open structured molecular conformation, particularly the lambda form; hence, it has more exposure to the intestinal mucosa than when bound to protein in food. Based on the many animal subchronic and chronic toxicity studies, CGN has not been found to affect the immune system, as judged by lack of effects on organ histopathology, clinical chemistry, hematology, normal health, and the lack of target organ toxicities. In these studies, animals consumed CGN at orders of magnitude above levels of CGN in the human diet: ≥1000 mg/kg/d in animals compared to 18-40 mg/kg/d estimated in the human diet. Dietary CGN has been shown to lack carcinogenic, tumor promoter, genotoxic, developmental, and

  15. Sediment laboratory quality-assurance project: studies of methods and materials

    USGS Publications Warehouse

    Gordon, J.D.; Newland, C.A.; Gray, J.R.

    2001-01-01

    In August 1996 the U.S. Geological Survey initiated the Sediment Laboratory Quality-Assurance project. The Sediment Laboratory Quality Assurance project is part of the National Sediment Laboratory Quality-Assurance program. This paper addresses the fmdings of the sand/fme separation analysis completed for the single-blind reference sediment-sample project and differences in reported results between two different analytical procedures. From the results it is evident that an incomplete separation of fme- and sand-size material commonly occurs resulting in the classification of some of the fme-size material as sand-size material. Electron microscopy analysis supported the hypothesis that the negative bias for fme-size material and the positive bias for sand-size material is largely due to aggregation of some of the fine-size material into sand-size particles and adherence of fine-size material to the sand-size grains. Electron microscopy analysis showed that preserved river water, which was low in dissolved solids, specific conductance, and neutral pH, showed less aggregation and adhesion than preserved river water that was higher in dissolved solids and specific conductance with a basic pH. Bacteria were also found growing in the matrix, which may enhance fme-size material aggregation through their adhesive properties. Differences between sediment-analysis methods were also investigated as pan of this study. Suspended-sediment concentration results obtained from one participating laboratory that used a total-suspended solids (TSS) method had greater variability and larger negative biases than results obtained when this laboratory used a suspended-sediment concentration method. When TSS methods were used to analyze the reference samples, the median suspended sediment concentration percent difference was -18.04 percent. When the laboratory used a suspended-sediment concentration method, the median suspended-sediment concentration percent difference was -2

  16. Isolation gowns in health care settings: Laboratory studies, regulations and standards, and potential barriers of gown selection and use

    PubMed Central

    Kilinc Balci, F. Selcen

    2016-01-01

    Although they play an important role in infection prevention and control, textile materials and personal protective equipment (PPE) used in health care settings are known to be one of the sources of cross-infection. Gowns are recommended to prevent transmission of infectious diseases in certain settings; however, laboratory and field studies have produced mixed results of their efficacy. PPE used in health care is regulated as either class I (low risk) or class II (intermediate risk) devices in the United States. Many organizations have published guidelines for the use of PPE, including isolation gowns, in health care settings. In addition, the Association for the Advancement of Medical Instrumentation published a guidance document on the selection of gowns and a classification standard on liquid barrier performance for both surgical and isolation gowns. However, there is currently no existing standard specific to isolation gowns that considers not only the barrier resistance but also a wide array of end user desired attributes. As a result, infection preventionists and purchasing agents face several difficulties in the selection process, and end users have limited or no information on the levels of protection provided by isolation gowns. Lack of knowledge about the performance of protective clothing used in health care became more apparent during the 2014 Ebola epidemic. This article reviews laboratory studies, regulations, guidelines and standards pertaining to isolation gowns, characterization problems, and other potential barriers of isolation gown selection and use. PMID:26391468

  17. Venus as a laboratory for studying planetary surface, interior, and atmospheric evolution

    NASA Astrophysics Data System (ADS)

    Smrekar, S. E.; Hensley, S.; Helbert, J.

    2013-12-01

    As Earth's twin, Venus offers a laboratory for understanding what makes our home planet unique in our solar system. The Decadal Survey points to the role of Venus in answering questions such as the supply of water and its role in atmospheric evolution, its availability to support life, and the role of geology and dynamics in controlling volatiles and climate. On Earth, the mechanism of plate tectonics drives the deformation and volcanism that allows volatiles to escape from the interior to the atmosphere and be recycled into the interior. Magellan revealed that Venus lacks plate tectonics. The number and distribution of impact craters lead to the idea Venus resurfaced very rapidly, and inspired numerous models of lithospheric foundering and episodic plate tectonics. However we have no evidence that Venus ever experienced a plate tectonic regime. How is surface deformation affected if no volatiles are recycled into the interior? Although Venus is considered a ';stagnant' lid planet (lacking plate motion) today, we have evidence for recent volcanism. The VIRTIS instrument on Venus Express mapped the southern hemisphere at 1.02 microns, revealing areas likely to be unweathered, recent volcanic flows. Additionally, numerous studies have shown that the crater population is consistent with ongoing, regional resurfacing. How does deformation and volcanism occur in the absence of plates? At what rate is the planet resurfacing and thus outgassing? Does lithospheric recycling occur with plate tectonics? In the 25 years since Magellan, the design of Synthetic Aperture Radar has advanced tremendously, allowing order of magnitude improvements in altimetry and imaging. With these advanced tools, we can explore Venus' past and current tectonic states. Tesserae are highly deformed plateaus, thought to be possible remnants of Venus' earlier tectonic state. How did they form? Are they low in silica, like Earth's continents, indicating the presence of abundant water? Does the plains

  18. Oxy-acetylene driven laboratory scale shock tubes for studying blast wave effects

    NASA Astrophysics Data System (ADS)

    Courtney, Amy C.; Andrusiv, Lubov P.; Courtney, Michael W.

    2012-04-01

    This paper describes the development and characterization of modular, oxy-acetylene driven laboratory scale shock tubes. Such tools are needed to produce realistic blast waves in a laboratory setting. The pressure-time profiles measured at 1 MHz using high-speed piezoelectric pressure sensors have relevant durations and show a true shock front and exponential decay characteristic of free-field blast waves. Descriptions are included for shock tube diameters of 27-79 mm. A range of peak pressures from 204 kPa to 1187 kPa (with 0.5-5.6% standard error of the mean) were produced by selection of the driver section diameter and distance from the shock tube opening. The peak pressures varied predictably with distance from the shock tube opening while maintaining both a true blast wave profile and relevant pulse duration for distances up to about one diameter from the shock tube opening. This shock tube design provides a more realistic blast profile than current compression-driven shock tubes, and it does not have a large jet effect. In addition, operation does not require specialized personnel or facilities like most blast-driven shock tubes, which reduces operating costs and effort and permits greater throughput and accessibility. It is expected to be useful in assessing the response of various sensors to shock wave loading; assessing the reflection, transmission, and absorption properties of candidate armor materials; assessing material properties at high rates of loading; assessing the response of biological materials to shock wave exposure; and providing a means to validate numerical models of the interaction of shock waves with structures. All of these activities have been difficult to pursue in a laboratory setting due in part to lack of appropriate means to produce a realistic blast loading profile.

  19. Oxy-acetylene driven laboratory scale shock tubes for studying blast wave effects.

    PubMed

    Courtney, Amy C; Andrusiv, Lubov P; Courtney, Michael W

    2012-04-01

    This paper describes the development and characterization of modular, oxy-acetylene driven laboratory scale shock tubes. Such tools are needed to produce realistic blast waves in a laboratory setting. The pressure-time profiles measured at 1 MHz using high-speed piezoelectric pressure sensors have relevant durations and show a true shock front and exponential decay characteristic of free-field blast waves. Descriptions are included for shock tube diameters of 27-79 mm. A range of peak pressures from 204 kPa to 1187 kPa (with 0.5-5.6% standard error of the mean) were produced by selection of the driver section diameter and distance from the shock tube opening. The peak pressures varied predictably with distance from the shock tube opening while maintaining both a true blast wave profile and relevant pulse duration for distances up to about one diameter from the shock tube opening. This shock tube design provides a more realistic blast profile than current compression-driven shock tubes, and it does not have a large jet effect. In addition, operation does not require specialized personnel or facilities like most blast-driven shock tubes, which reduces operating costs and effort and permits greater throughput and accessibility. It is expected to be useful in assessing the response of various sensors to shock wave loading; assessing the reflection, transmission, and absorption properties of candidate armor materials; assessing material properties at high rates of loading; assessing the response of biological materials to shock wave exposure; and providing a means to validate numerical models of the interaction of shock waves with structures. All of these activities have been difficult to pursue in a laboratory setting due in part to lack of appropriate means to produce a realistic blast loading profile.

  20. Water Efficiency Improvements at Various Environmental Protection Agency Sites: Best Management Practice Case Study #12 - Laboratory/Medical Equipment (Brochure)

    SciTech Connect

    Blakley, H.

    2011-03-01

    The U.S. Environmental Protection Agency (EPA) built a successful water conservation program and reduced potable water use through a series of initiatives at EPA laboratories. The projects highlighted in this case study demonstrate EPA's ability to reduce water use in laboratory and medical equipment by implementing vacuum pump and steam sterilizer replacements and retrofits. Due to the success of the initial vacuum pump and steam sterilizer projects described here, EPA is implementing similar projects at several laboratories throughout the nation.

  1. Characterization of the activity and stability of amylase from saliva and detergent: laboratory practicals for studying the activity and stability of amylase from saliva and various commercial detergents.

    PubMed

    Valls, Cristina; Rojas, Cristina; Pujadas, Gerard; Garcia-Vallve, Santi; Mulero, Miquel

    2012-07-01

    This article presents two integrated laboratory exercises intended to show students the role of α-amylases (AAMYs) in saliva and detergents. These laboratory practicals are based on the determination of the enzymatic activity of amylase from saliva and different detergents using the Phadebas test (quantitative) and the Lugol test (qualitative) under different conditions (e.g. variations in temperature and alkalinity). This work also proposes the study of enzyme stability in the presence of several surfactants and oxidizing agents using the same technical approach. The proposed laboratory exercises promote the understanding of the physiological function of this enzyme and the biotechnological applications of AAMYs in the detergent industry. The exercises also promote the understanding that the enzymatic stability and performance are dependent on the organism of origin, and if necessary, these properties could be modified by genetic engineering. In addition, this article reinforces the development of laboratory skills, problem-solving capabilities, and the ability to write a laboratory report. The exercises are proposed primarily as an undergraduate project for advanced students in the biochemical and biotechnological sciences. These laboratory practicals are complementary to the previously published BAMBED article (Biochemistry and Molecular Biology Education Vol. 39, No. 4, pp. 280-290, 2011) on detergent proteases.

  2. A Survey of Laboratory and Statistical Issues Related to Farmworker Exposure Studies

    PubMed Central

    Barr, Dana B.; Landsittel, Doug; Nishioka, Marcia; Thomas, Kent; Curwin, Brian; Raymer, James; Donnelly, Kirby C.; McCauley, Linda; Ryan, P. Barry

    2006-01-01

    Developing internally valid, and perhaps generalizable, farmworker exposure studies is a complex process that involves many statistical and laboratory considerations. Statistics are an integral component of each study beginning with the design stage and continuing to the final data analysis and interpretation. Similarly, data quality plays a significant role in the overall value of the study. Data quality can be derived from several experimental parameters including statistical design of the study and quality of environmental and biological analytical measurements. We discuss statistical and analytic issues that should be addressed in every farmworker study. These issues include study design and sample size determination, analytical methods and quality control and assurance, treatment of missing data or data below the method’s limits of detection, and post-hoc analyses of data from multiple studies. PMID:16760001

  3. The impact of bismuth addition to sequential treatment on Helicobacter pylori eradication: A pilot study.

    PubMed

    Basyigit, Sebahat; Kefeli, Ayse; Sapmaz, Ferdane; Yeniova, Abdullah Ozgür; Asilturk, Zeliha; Hokkaomeroglu, Murat; Uzman, Metin; Nazligul, Yasar

    2015-10-25

    The success of the current anti-Helicobacter pylori (H. pylori) treatment protocols is reported to decrease by years, and research is needed to strengthen the H. pylori eradication treatment. Sequential treatment (ST), one of the treatment modalities for H. pylori eradication, includes amoxicillin 1 gr b.i.d and proton pump inhibitor b.i.d for first 5 days and then includes clarithromycin 500 mg b.i.d, metronidazole 500 mg b.i.d and a proton pump inhibitor b.i.d for remaining 5 days. In this study, we investigated efficacy and tolerability of bismuth addition in to ST. We included patients that underwent upper gastrointestinal endoscopy in which H. pylori infection was diagnosed by histological examination of antral and corporal gastric mucosa biopsy. Participants were randomly administered ST or bismuth containing ST (BST) protocols for the first-line H. pylori eradication therapy. Participants have been tested by urea breath test for eradication success 6 weeks after the completion of treatment. One hundred and fifty patients (93 female, 57 male) were enrolled. There were no significant differences in eradication rates for both intention to treat population (70.2%, 95% confidence interval [CI]: 66.3-74.1% vs. 71.8%, 95% CI: 61.8-81.7%, for ST and BST, respectively, p>0.05) and per protocol population (74.6%, 95% CI: 63.2-85.8% vs. 73.7%, 95% CI: 63.9-83.5% for ST and BST, respectively, p>0.05). Despite the undeniable effect of bismuth, there may be several possible reasons of unsatisfactory eradication success. Drug administration time, coadministration of other drugs, possible H. pylori resistance to bismuth may affect the eradication success. The addition of bismuth subcitrate to ST regimen does not provide significant increase in eradication rates.

  4. Experimental Study of Disruption of Columnar Grains During Rapid Solidification in Additive Manufacturing

    NASA Astrophysics Data System (ADS)

    Manogharan, Guha; Yelamanchi, Bharat; Aman, Ronald; Mahbooba, Zaynab

    2016-03-01

    Over the years, many studies have been conducted to study and analyze the grain structures of metal alloys during additive manufacturing to improve mechanical properties. In particular, columnar grains are observed predominantly during rapid solidification of molten metal. This leads to lower mechanical properties and requires expensive secondary heat-treatment processes. This study is aimed at disrupting the formation of columnar grain growth during rapid solidification using ultrasonic vibration and analyzes the effects on grain structure and mechanical properties. A gas-metal arc welder mounted on a Rep-Rap-based low-cost metal 3 Dimension printer was used to deposit ER70S-6 mild steel layers on a plate. A contact-type ultrasonic transducer with a control system to vary the frequency and power of the vibration was used. The effects of ultrasonic vibration were determined from the statistical analysis of microstructure and micro-indentation techniques on the deposited layer and heat-affected zone. It was found that both frequency and interaction between frequency and power had significant impact on the refinement of average grain size up to 10.64% and increased the number of grains by approximately 41.78%. Analysis of micro-indentation tests showed that there was an increase of approximately 14.30% in micro-hardness due to the applied frequency during rapid solidification. A pole diagram shows that application of vibration causes randomization of grain orientation. Along with the results from this study, further efforts in modeling and experimentation of multi-directional vibrations would lead to a better understanding of disrupting columnar grains in applications that use mechanical vibrations, such as welding, directed energy deposition, brazing, etc.

  5. Feasibility study of a Megaton-scale Underground Laboratory at the Frejus site

    SciTech Connect

    MOSCA, L.

    2007-11-08

    After a brief review of the main scientific motivations of LAGUNA, European cooperation projects (GLACIER, LENA and MEMPHYS), and of the virtues of the Frejus site, a preliminary feasibility study for a Megaton-scale Underground Laboratory at Frejus is presented and its positive results discussed. The need for a future more detailed investigation (Design Study), which will be performed in the framework of the LAGUNA collaboration, is stressed. The excellent opportunity presented by the recently approved Frejus Safety Tunnel (d = 8 m) project is also underlined.

  6. Field and laboratory study of cold-asphalt-mix recycling in Ohio. Final report

    SciTech Connect

    Majidzadeh, K.; Ilves, G.J.; Abdulshafi, A.; Kaloush, K.

    1987-09-01

    The report presents a study initiated in 1984 to develop specification guidelines and mix-design recommendations and to obtain performance data on cold-mix recycling projects in Ohio. Two mainline, low-volume roads and one shoulder pavement were selected for the study. Documentation and evaluation of the projects are discussed generally in two parts. The first part includes the site-selection criteria, pre-construction evaluation, mix designs, construction specifications and construction monitoring. The second part discusses performance evaluation through field inspection, data collection, and laboratory evaluation of material properties.

  7. Personnel-dosimetry intercomparison studies at the Oak Ridge National Laboratory

    SciTech Connect

    Swaja, R.E.; Sims, C.S.

    1982-01-01

    Since 1974, seven annual personnel dosimetry intercomparison studies have been conducted at the Oak Ridge National Laboratory using the Health Physics Reactor. These studies have produced more than 2000 measurements by 72 participating organizations of neutron and gamma dose equivalents between 0.1 to 15.0 mSv in six mixed radiation fields. The relative performance of three basic types of personnel neutron dosimeters (nuclear emulsion film, thermoluminescent, and track-etch) and two basic types of gamma dosimeters (film and thermoluminescent) was assessed based on experimental results obtained during the seven intercomparisons.

  8. Mapping Soil Surface Macropores Using Infrared Thermography: An Exploratory Laboratory Study

    PubMed Central

    de Lima, João L. M. P.; Abrantes, João R. C. B.; Silva, Valdemir P.; de Lima, M. Isabel P.; Montenegro, Abelardo A. A.

    2014-01-01

    Macropores and water flow in soils and substrates are complex and are related to topics like preferential flow, nonequilibrium flow, and dual-continuum. Hence, the quantification of the number of macropores and the determination of their geometry are expected to provide a better understanding on the effects of pores on the soil's physical and hydraulic properties. This exploratory study aimed at evaluating the potential of using infrared thermography for mapping macroporosity at the soil surface and estimating the number and size of such macropores. The presented technique was applied to a small scale study (laboratory soil flume). PMID:25371915

  9. Laboratory study of sonic booms and their scaling laws. [ballistic range simulation

    NASA Technical Reports Server (NTRS)

    Toong, T. Y.

    1974-01-01

    This program undertook to seek a basic understanding of non-linear effects associated with caustics, through laboratory simulation experiments of sonic booms in a ballistic range and a coordinated theoretical study of scaling laws. Two cases of superbooms or enhanced sonic booms at caustics have been studied. The first case, referred to as acceleration superbooms, is related to the enhanced sonic booms generated during the acceleration maneuvers of supersonic aircrafts. The second case, referred to as refraction superbooms, involves the superbooms that are generated as a result of atmospheric refraction. Important theoretical and experimental results are briefly reported.

  10. Percutaneous Dorsal Instrumentation of Vertebral Burst Fractures: Value of Additional Percutaneous Intravertebral Reposition—Cadaver Study

    PubMed Central

    Krüger, Antonio; Schmuck, Maya; Noriega, David C.; Ruchholtz, Steffen; Baroud, Gamal; Oberkircher, Ludwig

    2015-01-01

    Purpose. The treatment of vertebral burst fractures is still controversial. The aim of the study is to evaluate the purpose of additional percutaneous intravertebral reduction when combined with dorsal instrumentation. Methods. In this biomechanical cadaver study twenty-eight spine segments (T11-L3) were used (male donors, mean age 64.9 ± 6.5 years). Burst fractures of L1 were generated using a standardised protocol. After fracture all spines were allocated to four similar groups and randomised according to surgical techniques (posterior instrumentation; posterior instrumentation + intravertebral reduction device + cement augmentation; posterior instrumentation + intravertebral reduction device without cement; and intravertebral reduction device + cement augmentation). After treatment, 100000 cycles (100–600 N, 3 Hz) were applied using a servohydraulic loading frame. Results. Overall anatomical restoration was better in all groups where the intravertebral reduction device was used (p < 0.05). In particular, it was possible to restore central endplates (p > 0.05). All techniques decreased narrowing of the spinal canal. After loading, clearance could be maintained in all groups fitted with the intravertebral reduction device. Narrowing increased in the group treated with dorsal instrumentation. Conclusions. For height and anatomical restoration, the combination of an intravertebral reduction device with dorsal instrumentation showed significantly better results than sole dorsal instrumentation. PMID:26137481

  11. Evaluating the addition of positive reinforcement for learning a frightening task: a pilot study with horses.

    PubMed

    Heleski, Camie; Bauson, Laura; Bello, Nora

    2008-01-01

    Horse training often relies upon negative reinforcement (NR). This study tested the hypothesis that adding positive reinforcement (PR) to NR would enhance learning in horses (n = 34) being taught to walk over a tarp (novel/typically frightening task). Subjects were Arabians, and the same person handled all of them. This person handled half "traditionally" (NR only)--that is, halter/lead were pulled; when horse stepped forward, pressure was released; process repeated until criterion met (horse crossed the tarp with little/no obvious anxiety). The same person handled the other half traditionally--but with addition of PR < food + verbal praise > (NR + PR). Subjects "failed" the task if they refused to walk onto the tarp after 10 min. Nine horses failed; 6 of 9 failures were from NR only--no significant difference detected (p = .41). The study detected no difference in time to first crossing of the tarp (p = .30) or total time to achieve calmness criterion (p = .67). Overall, adding PR did not significantly enhance learning this task. However, there were practical implications--adding PR made the task safer/less fatiguing for the handler.

  12. Synthesis, Characterization, Molecular Modeling, and DNA Interaction Studies of Copper Complex Containing Food Additive Carmoisine Dye.

    PubMed

    Shahabadi, Nahid; Akbari, Alireza; Jamshidbeigi, Mina; Khodarahmi, Reza

    2016-06-02

    A copper complex of carmoisine dye; [Cu(carmoisine)2(H2O)2]; was synthesized and characterized by using physico-chemical and spectroscopic methods. The binding of this complex with calf thymus (ct) DNA was investigated by circular dichroism, absorption studies, emission spectroscopy, and viscosity measurements. UV-vis results confirmed that the Cu complex interacted with DNA to form a ground-state complex and the observed binding constant (2× 10(4) M(-1)) is more in keeping with the groove bindings with DNA. Furthermore, the viscosity measurement result showed that the addition of complex causes no significant change on DNA viscosity and it indicated that the intercalation mode is ruled out. The thermodynamic parameters are calculated by van't Hoff equation, which demonstrated that hydrogen bonds and van der Waals interactions played major roles in the reaction. The results of circular dichroism (CD) suggested that the complex can change the conformation of DNA from B-like form toward A-like conformation. The cytotoxicity studies of the carmoisine dye and its copper complex indicated that both of them had anticancer effects on HT-29 (colon cancer) cell line and they may be new candidates for treatment of the colon cancer.

  13. Density functional theory study of the effects of alloying additions on sulfur adsorption on nickel surfaces

    NASA Astrophysics Data System (ADS)

    Malyi, Oleksandr I.; Chen, Zhong; Kulish, Vadym V.; Bai, Kewu; Wu, Ping

    2013-01-01

    Reactions of hydrogen sulfide (H2S) with Nickel/Ytrria-doped zirconia (Ni/YDZ) anode materials might cause degradation of the performance of solid oxide fuel cells when S containing fuels are used. In this paper, we employ density functional theory to investigate S adsorption on metal (M)-doped and undoped Ni(0 0 1) and Ni(1 1 1) surfaces. Based on the performed calculations, we analyze the effects of 12 alloying additions (Ag, Au, Al, Bi, Cd, Co, Cu, Fe, Sn, Sb, V, and Zn) on the temperature of transition between clean (S atoms do not adsorb on the surfaces) and contaminated (S atoms can adsorb on the surfaces spontaneously) M-doped Ni surfaces for different concentrations of H2S in the fuel. Predicted results are consistent with many experimental studies relevant to S poisoning of both Ni/YDZ and M-doped Ni/YDZ anode materials. This study is important to understand S poisoning phenomena and to develop new S tolerant anode materials.

  14. An fMRI study of magnitude comparison and exact addition in children.

    PubMed

    Meintjes, Ernesta M; Jacobson, Sandra W; Molteno, Christopher D; Gatenby, J Christopher; Warton, Christopher; Cannistraci, Christopher J; Gore, John C; Jacobson, Joseph L

    2010-04-01

    By contrast to the adult literature, in which a consistent parietofrontal network for number processing has been identified, the data from studies of number processing in children have been less consistent, probably due to differences in study design and control conditions. Number processing was examined using functional magnetic resonance imaging in 18 right-handed children (8-12 years) from the Cape Coloured community in Cape Town, South Africa, using Proximity Judgment and Exact Addition (EA) tasks. The findings were consistent with the hypothesis that, as in adults, the anterior horizontal intraparietal sulcus (HIPS) plays a major role in the representation and manipulation of quantity in children. The posterior medial frontal cortex, believed to be involved in performance monitoring in more complex arithmetic manipulations in adults, was extensively activated even for relatively simple symbolic number processing in the children. Other areas activated to a greater degree in the children included the left precentral sulcus, which may mediate number knowledge and, for EA, the head of the caudate nucleus, which is part of a fronto-subcortical circuit involved in the behavioral execution of sequences. Two regions that have been linked to number processing in adults - the angular gyrus and posterior superior parietal lobule - were not activated in the children. The data are consistent with the inference that although the functional specialization of the anterior HIPS may increase as symbolic number processing becomes increasingly automatic, this region and other elements of the parietofrontal network identified in adults are already reliably and robustly activated by middle childhood.

  15. NETL Extreme Drilling Laboratory Studies High Pressure High Temperature Drilling Phenomena

    SciTech Connect

    Lyons, K.D.; Honeygan, S.; Moroz, T

    2007-06-01

    The U.S. Department of Energy’s National Energy Technology Laboratory (NETL) established an Extreme Drilling Lab to engineer effective and efficient drilling technologies viable at depths greater than 20,000 feet. This paper details the challenges of ultra-deep drilling, documents reports of decreased drilling rates as a result of increasing fluid pressure and temperature, and describes NETL’s Research and Development activities. NETL is invested in laboratory-scale physical simulation. Their physical simulator will have capability of circulating drilling fluids at 30,000 psi and 480 °F around a single drill cutter. This simulator will not yet be operational by the planned conference dates; therefore, the results will be limited to identification of leading hypotheses of drilling phenomena and NETL’s test plans to validate or refute such theories. Of particular interest to the Extreme Drilling Lab’s studies are the combinatorial effects of drilling fluid pressure, drilling fluid properties, rock properties, pore pressure, and drilling parameters, such as cutter rotational speed, weight on bit, and hydraulics associated with drilling fluid introduction to the rock-cutter interface. A detailed discussion of how each variable is controlled in a laboratory setting will be part of the conference paper and presentation.

  16. Understanding laboratory testing in diagnostic uncertainty: a qualitative study in general practice.

    PubMed Central

    van der Weijden, Trudy; van Bokhoven, Marloes A; Dinant, Geert-Jan; van Hasselt, Cathelijne M; Grol, Richard P T M

    2002-01-01

    BACKGROUND: Better knowledge of the professional's motives for ordering laboratory tests in the case of diagnostic uncertainty may lead to interventions directed at reducing unnecessary testing. AIM: To gain insight into the general practitioner's (GP's) motives for ordering laboratory tests for patients presenting with unexplained complaints. DESIGN OF STUDY: Semi-structured interviews based on surgery observations. SETTING: Twenty-one general practices in rural and urban areas of The Netherlands. METHOD: Investigation of the GP's perception of determinants of test-ordering behaviour in the situation of diagnostic uncertainty. The interviews were structured by evaluating the consultations and test-ordering performance of that day. RESULTS: Dutch GPs vary considerably in their motives for ordering tests. Numerous motives emerged from the data. Some examples of important themes include: personal routines; tolerance of diagnostic uncertainty; time pressure; and tactical motives for test ordering. Complying with the perceived needs of the patient for reassurance through testing is seen as an easy, cost- and time-effective strategy. A clear hierarchy in the determinants was not found. CONCLUSION: The decision to request laboratory testing is the result of a complex interaction of considerations that are often conflicting. Designers of interventions meant to improve the ordering of tests should be aware of the numerous determinants, and take contextual variables into account. PMID:12528582

  17. An evaluation of outcomes following the replacement of traditional histology laboratories with self-study modules.

    PubMed

    Thompson, Andrew R; Lowrie, D J

    2016-10-31

    Changes in medical school curricula often require educators to develop teaching strategies that decrease contact hours while maintaining effective pedagogical methods. When faced with this challenge, faculty at the University of Cincinnati College of Medicine converted the majority of in-person histology laboratory sessions to self-study modules that utilize multiple audiovisual modalities and a virtual microscope platform. Outcomes related to this shift were investigated through performance on in-house examinations, results of the United States Medical Licensing Examination(®) (USMLE(®) ) Step 1 Examination, and student feedback. Medical School College Admissions Test(®) (MCAT(®) ) scores were used as a covariate when comparing in-house examinations. Results revealed no significant change in performance on in-house examinations when the content being assessed was controlled (F(2, 506) = 0.676, P = 0.51). A significant improvement in overall practical examination grade averages was associated with the self-study modules (F(6, 1164) = 10.213, P < 0.01), but gradual changes in examination content may explain this finding. The histology and cell biology portion of USMLE Step 1 Examination remained consistent throughout the time period that was investigated. Student feedback regarding the self-study modules was positive and suggested that features such as instructor narrated videos were an important component of the self-study modules because they helped recreate the experience of in-person laboratory sessions. Positive outcomes from the student perspective and no drop in examination performance suggests that utilizing self-study modules for histology laboratory content may be an option for educators faced with the challenge of reducing contact hours without eliminating content. Anat Sci Educ. © 2016 American Association of Anatomists.

  18. Laboratory accreditation.

    PubMed

    Bradway, D E; Siegelman, F L

    1994-09-01

    An investigation of alleged data fraud at a pesticide analytical laboratory led EPA to take a closer look at the Good Laboratory Practice (GLP) inspection program. There was special focus on changes which might be made in the program to enhance the chances of detecting fraud in regulated studies. To this end, the Assistant Administrator of the Office of Prevention, Pesticides and Toxic Substances (OPPTS) requested EPA's Office of Inspector General (OIG) to examine the GLP program. Several reports were issued by the OIG, including the recommendation that a laboratory accreditation program be adopted. EPA has been examining ways to implement the OIG's recommendations, including (1) laboratory accreditation consisting of three components: document submission and assessment, site visit and assessment, and proficiency assessment; and (2) mandatory registration of all facilities participating in GLP-regulated studies, based on document submission and assessment. These two alternatives are compared, and the advantages and disadvantages of each are discussed.

  19. Theoretical study of ignition reactions of linear symmetrical monoethers as potential diesel fuel additives: DFT calculations

    NASA Astrophysics Data System (ADS)

    Marrouni, Karim El; Abou-Rachid, Hakima; Kaliaguine, Serge

    This work investigates the chemical reactivity of four linear symmetrical monoethers with molecular oxygen. Such oxygenated compounds may be considered as potential diesel fuel additives in order to reduce the ignition delay in diesel fuel engines. For this purpose, a kinetic study is proposed to clarify the relation between the molecular structure of the fuel molecule and its ignition properties. To this end, DFT calculations were performed for these reactions using B3LYP/6-311G(d,p) and BH&HLYP/6-311G(d,p) to determine structures, energies, and vibrational frequencies of stationary points as well as activated complexes involved in each gas-phase combustion initiation reaction of the monoethers CH3OCH3, C2H5OC2H5, C3H7OC3H7, or C4H9OC4H9 with molecular oxygen. This theoretical kinetic study was carried out using electronic structure results and the transition state theory, to assess the rate constants for all studied combustion reactions. As it has been shown in our previous work [Abou-Rachid et al., J Mol Struct (Theochem) 2003, 621, 293], the cetane number (CN) of a pure organic molecule depends on the initiation rate of its homogeneous gas-phase reaction with molecular oxygen. Indeed, the calculated initiation rate constants of the H-abstraction process of linear monoethers with O2 show a very good correlation with experimental CN data of these pure compounds at T D 1,000 K. This temperature is representative of the operating conditions of a diesel fuel engine.0

  20. Experimental study of enhanced heat transfer by addition of CuO nanoparticle

    NASA Astrophysics Data System (ADS)

    Jesumathy, Stella; Udayakumar, M.; Suresh, S.

    2012-06-01

    An energy storage system has been designed to study the thermal characteristics of paraffin wax with an embedded nano size copper oxide (CuO) particle. This paper presents studies conducted on phase transition times, heat fraction as well as heat transfer characteristics of paraffin wax as phase change material (PCM) embedded with CuO nanoparticles. 40 nm mean size CuO particles of 2, 5 and 10% by weight were dispersed in PCM for this study. Experiments were performed on a heat exchanger with 1.5-10 l/min of heat transfer fluid (HTF) flow. Time-based variations of the temperature distributions are revealed from the results of observations of melting and solidification curves. The results strongly suggested that the thermal conductivity enhances 6, 6.7 and 7.8% in liquid state and in dynamic viscosity it enhances by 5, 14 and 30% with increasing mass fraction of the CNEPs. The thermal conductivity ratio of the composites can be augmented by a factor up to 1.3. The heat transfer coefficient during solidification increased about 78% for the maximum flow rate. The analysis of experimental results reveals that the addition of copper oxide nanoparticles to the paraffin wax enhances both the conduction and natural convection very effectively in composites and in paraffin wax. The paraffin wax-based composites have great potential for energy storage applications like industrial waste heat recovery, solar thermal applications and solar based dynamic space power generation with optimal fraction of copper oxide nanoparticles.