Science.gov

Sample records for acid dew point

  1. On the acidity of dew

    NASA Astrophysics Data System (ADS)

    Pierson, William R.; Brachaczek, Wanda W.; Gorse, Robert A.; Japar, Steven M.; Norbeck, Joseph M.

    1986-03-01

    Nightly dew samples were collected on Allegheny Mountain in southwest Pennsylvania in August 1983. The dew was found to be acidic, with mean pH˜4.0. Free H+ comprised >80% of the total acidity, and the composition approximated an H2SO4/HNO3 mixture with average SO42-/NO3- mol ratio ˜1.3. The chemistry of the dew resembled that of rain at Allegheny, though the dew was generally more dilute. Atmospheric HNO3(g) was chiefly responsible for the dew NO3-. SO2 was the source of ˜80% of the dew SO42-. The allocation of dew H+ among atmospheric precursors was HNO3˜30%, SO2 ≥ 60%, aerosol H+ ≤ 10%. The most acidic dews were associated with wind from the west. Average deposition velocities (stated in centimeters per second) to dew were HNO3, 0.24; NO2, <0.02 SO2, ˜0.04; aerosol SO42-, ˜0.02; aerosol NH4+, 0.024; and aerosol species, 0.02-1. Comparison of the HNO3 deposition velocity with ten-fold higher summer daytime values reveals a pronounced diurnal variation. The 0.24 cm/s value for HNO3 may represent a maximum for any gas or submicron aerosol species whenever the atmosphere is strongly stable. Not all of the S(IV) in dew had been converted to SO42- by morning; thus the rate of oxidation must have been on a time scale of hours at nighttime ambient temperatures. In contrast, S(IV) in rain and fog samples was not evident. Deposition fluxes and cumulative deposition totals involving dew, rain, and settled fog water were compared. Rain proved by far the most important for deposition of all solute species, including acid.

  2. Accuracy of commercial dew-point hygrometers

    SciTech Connect

    Carotenuto, A.; Dell`Isola, M.; Crovini, L.; Actis, A.

    1995-12-31

    This paper presents an experimental evaluation of different types of commercial chilled-mirror dew-point hygrometers designed to verify their metrological behavior. Specifically, an analysis of their measurement uncertainties and long-term stability is carried out. A computing method is applied to estimate the measurement uncertainty of an indirect determination of the relative humidity using a chilled-mirror dew-point hygrometer and a dry-bulb temperature sensor.

  3. Dew and bubble point properties of air

    NASA Astrophysics Data System (ADS)

    Penoncello, S. G.; Jacobsen, R. T.; Lemmon, E. W.

    Four new ancillary functions for the calculation of pressures and densities of states at the bubble and dew points of air are presented. These functions were developed using experimental data and calculated values. The experimental data for the bubble and dew point pressures and densities of air are summarized and evaluated. In the absence of experimental data at high-pressure phase equilibrium states, a Leung-Griffiths model modified for ternary mixtures was used to calculate pseudo-data. This ternary mixture model was also used to calculate new values for the critical point, maxcondenbar and maxcondentherm for air. The calculated properties at the maxcondentherm were used as reducing parameters in the ancillary functions. Graphical comparisons of the ancillary equations to the experimental data and pseudo-data are presented to justify the estimated accuracies of the new ancillary functions. The equations presented here have been used to calculate dew and bubble point pressures and densities for the determination of the phase boundary for a wide-range equation of state for air treated as a pseudo-pure fluid.

  4. Chilled Mirror Dew Point Hygrometer (CM) Handbook

    SciTech Connect

    Ritsche, MT

    2005-01-01

    The CM systems have been developed for the ARM Program to act as a moisture standard traceable to National Institute of Standards and Technology (NIST). There are three CM systems that are each fully portable, self-contained, and require only 110 V AC power. The systems include a CM sensor, air sampling and filtration system, a secondary reference (Rotronic HP043 temperature and relative humidity sensor) to detect system malfunctions, a data acquisition system, and data storage for more than one month of 1-minute data. The CM sensor directly measures dew point temperature at 1 m, air temperature at 2 m, and relative humidity at 2 m. These measurements are intended to represent self-standing data streams that can be used independently or in combinations.

  5. New methods of subcooled water recognition in dew point hygrometers

    NASA Astrophysics Data System (ADS)

    Weremczuk, Jerzy; Jachowicz, Ryszard

    2001-08-01

    Two new methods of sub-cooled water recognition in dew point hygrometers are presented in this paper. The first one- impedance method use a new semiconductor mirror in which the dew point detector, the thermometer and the heaters were integrated all together. The second one an optical method based on a multi-section optical detector is discussed in the report. Experimental results of both methods are shown. New types of dew pont hydrometers of ability to recognized sub-cooled water were proposed.

  6. A micro dew point sensor with a thermal detection principle

    NASA Astrophysics Data System (ADS)

    Kunze, M.; Merz, J.; Hummel, W.-J.; Glosch, H.; Messner, S.; Zengerle, R.

    2012-01-01

    We present a dew point temperature sensor with the thermal detection of condensed water on a thin membrane, fabricated by silicon micromachining. The membrane (600 × 600 × ~1 µm3) is part of a silicon chip and contains a heating element as well as a thermopile for temperature measurement. By dynamically heating the membrane and simultaneously analyzing the transient increase of its temperature it is detected whether condensed water is on the membrane or not. To cool the membrane down, a peltier cooler is used and electronically controlled in a way that the temperature of the membrane is constantly held at a value where condensation of water begins. This temperature is measured and output as dew point temperature. The sensor system works in a wide range of dew point temperatures between 1 K and down to 44 K below air temperature. In experimental investigations it could be proven that the deviation of the measured dew point temperatures compared to reference values is below ±0.2 K in an air temperature range of 22 to 70 °C. At low dew point temperatures of -20 °C (air temperature = 22 °C) the deviation increases to nearly -1 K.

  7. Integrated CMOS dew point sensors for relative humidity measurement

    NASA Astrophysics Data System (ADS)

    Savalli, Nicolo; Baglio, Salvatore; Castorina, Salvatore; Sacco, Vincenzo; Tringali, Cristina

    2004-07-01

    This work deals with the development of integrated relative humidity dew point sensors realized by adopting standard CMOS technology for applications in various fields. The proposed system is composed by a suspended plate that is cooled by exploiting integrated Peltier cells. The cold junctions of the cells have been spread over the plate surface to improve the homogeneity of the temperature distribution over its surface, where cooling will cause the water condensation. The temperature at which water drops occur, named dew point temperature, is a function of the air humidity. Measurement of such dew point temperature and the ambient temperature allows to know the relative humidity. The detection of water drops is achieved by adopting a capacitive sensing strategy realized by interdigited fixed combs, composed by the upper layer of the adopted process. Such a capacitive sensor, together with its conditioning circuit, drives a trigger that stops the cooling of the plate and enables the reading of the dew point temperature. Temperature measurements are achieved by means of suitably integrated thermocouples. The analytical model of the proposed system has been developed and has been used to design a prototype device and to estimate its performances. In such a prototype, the thermoelectric cooler is composed by 56 Peltier cells, made by metal 1/poly 1 junctions. The plate has a square shape with 200 μm side, and it is realized by exploiting the oxide layers. Starting from the ambient temperature a temperature variation of ΔT = 15 K can be reached in 10 ms thus allowing to measure a relative humidity greater than 40%.

  8. Amino acids in dew - origin and seasonal variation

    NASA Astrophysics Data System (ADS)

    Scheller, Edwin

    At two sites in the Armenhof district, 10 km east of Fulda, Germany, dew samples were collected from June 1996 to June 1997 and investigated for free and protein-bound amino acids. On account of the high pollen content, at the beginning of June 1996 and in May 1997 total amino acid concentrations were 53-390 μmol l -1, in one sample 922 μmol l -1. At other times the concentration in dew was 8-164 μmol l -1. On 4 and 5 June 1996 the diluted free amino acid fraction (DFAA) of the total hydrolysed amino acids (THAA) at both sites amounted to 35-44% and was predominantly arginine, proline and glutamine/glutamate. Likewise on 11 March 1997 the fraction of DFAA was found to be 39.5% with extremely high arginine and proline fractions. At other times the DFAA-fraction was in the range 14-26%. From July 1996 to June 1997 the amino acid concentrations in the vapours rising from a meadow were also measured and it ranged from 8 to 51 μmol l -1. From July to October 1996 the amino acid composition in the hydrolysates of dew samples and meadow vapours collected overnight were almost identical. The DFAA fraction in the condensation water collected overnight from the meadow varied from 18 to 40%. From 4 to 6 June 1996, on 11 and 13 March 1997 and in the period 16-20 May 1997, the amino acid distribution in dew showed much variation. The percentage fraction of arginine and proline in the hydrolysate increased greatly, whereas that of glycine and serine decreased. The large increase in proline and arginine in hydrolysate is attributable solely to the large amounts of free arginine and proline. This effect occurred in both 1996 and 1997 over several days at both sites at any one time and therefore appears confirmed.

  9. Memory persistency and nonlinearity in daily mean dew point across India

    NASA Astrophysics Data System (ADS)

    Ray, Rajdeep; Khondekar, Mofazzal Hossain; Ghosh, Koushik; Bhattacharjee, Anup Kumar

    2016-04-01

    Enterprising endeavour has been taken in this work to realize and estimate the persistence in memory of the daily mean dew point time series obtained from seven different weather stations viz. Kolkata, Chennai (Madras), New Delhi, Mumbai (Bombay), Bhopal, Agartala and Ahmedabad representing different geographical zones in India. Hurst exponent values reveal an anti-persistent behaviour of these dew point series. To affirm the Hurst exponent values, five different scaling methods have been used and the corresponding results are compared to synthesize a finer and reliable conclusion out of it. The present analysis also bespeaks that the variation in daily mean dew point is governed by a non-stationary process with stationary increments. The delay vector variance (DVV) method has been exploited to investigate nonlinearity, and the present calculation confirms the presence of deterministic nonlinear profile in the daily mean dew point time series of the seven stations.

  10. An ultrahigh-accuracy Miniature Dew Point Sensor based on an Integrated Photonics Platform.

    PubMed

    Tao, Jifang; Luo, Yu; Wang, Li; Cai, Hong; Sun, Tao; Song, Junfeng; Liu, Hui; Gu, Yuandong

    2016-01-01

    The dew point is the temperature at which vapour begins to condense out of the gaseous phase. The deterministic relationship between the dew point and humidity is the basis for the industry-standard "chilled-mirror" dew point hygrometers used for highly accurate humidity measurements, which are essential for a broad range of industrial and metrological applications. However, these instruments have several limitations, such as high cost, large size and slow response. In this report, we demonstrate a compact, integrated photonic dew point sensor (DPS) that features high accuracy, a small footprint, and fast response. The fundamental component of this DPS is a partially exposed photonic micro-ring resonator, which serves two functions simultaneously: 1) sensing the condensed water droplets via evanescent fields and 2) functioning as a highly accurate, in situ temperature sensor based on the thermo-optic effect (TOE). This device virtually eliminates most of the temperature-related errors that affect conventional "chilled-mirror" hygrometers. Moreover, this DPS outperforms conventional "chilled-mirror" hygrometers with respect to size, cost and response time, paving the way for on-chip dew point detection and extension to applications for which the conventional technology is unsuitable because of size, cost, and other constraints. PMID:27417734

  11. An ultrahigh-accuracy Miniature Dew Point Sensor based on an Integrated Photonics Platform

    PubMed Central

    Tao, Jifang; Luo, Yu; Wang, Li; Cai, Hong; Sun, Tao; Song, Junfeng; Liu, Hui; Gu, Yuandong

    2016-01-01

    The dew point is the temperature at which vapour begins to condense out of the gaseous phase. The deterministic relationship between the dew point and humidity is the basis for the industry-standard “chilled-mirror” dew point hygrometers used for highly accurate humidity measurements, which are essential for a broad range of industrial and metrological applications. However, these instruments have several limitations, such as high cost, large size and slow response. In this report, we demonstrate a compact, integrated photonic dew point sensor (DPS) that features high accuracy, a small footprint, and fast response. The fundamental component of this DPS is a partially exposed photonic micro-ring resonator, which serves two functions simultaneously: 1) sensing the condensed water droplets via evanescent fields and 2) functioning as a highly accurate, in situ temperature sensor based on the thermo-optic effect (TOE). This device virtually eliminates most of the temperature-related errors that affect conventional “chilled-mirror” hygrometers. Moreover, this DPS outperforms conventional “chilled-mirror” hygrometers with respect to size, cost and response time, paving the way for on-chip dew point detection and extension to applications for which the conventional technology is unsuitable because of size, cost, and other constraints. PMID:27417734

  12. An ultrahigh-accuracy Miniature Dew Point Sensor based on an Integrated Photonics Platform.

    PubMed

    Tao, Jifang; Luo, Yu; Wang, Li; Cai, Hong; Sun, Tao; Song, Junfeng; Liu, Hui; Gu, Yuandong

    2016-01-01

    The dew point is the temperature at which vapour begins to condense out of the gaseous phase. The deterministic relationship between the dew point and humidity is the basis for the industry-standard "chilled-mirror" dew point hygrometers used for highly accurate humidity measurements, which are essential for a broad range of industrial and metrological applications. However, these instruments have several limitations, such as high cost, large size and slow response. In this report, we demonstrate a compact, integrated photonic dew point sensor (DPS) that features high accuracy, a small footprint, and fast response. The fundamental component of this DPS is a partially exposed photonic micro-ring resonator, which serves two functions simultaneously: 1) sensing the condensed water droplets via evanescent fields and 2) functioning as a highly accurate, in situ temperature sensor based on the thermo-optic effect (TOE). This device virtually eliminates most of the temperature-related errors that affect conventional "chilled-mirror" hygrometers. Moreover, this DPS outperforms conventional "chilled-mirror" hygrometers with respect to size, cost and response time, paving the way for on-chip dew point detection and extension to applications for which the conventional technology is unsuitable because of size, cost, and other constraints.

  13. An ultrahigh-accuracy Miniature Dew Point Sensor based on an Integrated Photonics Platform

    NASA Astrophysics Data System (ADS)

    Tao, Jifang; Luo, Yu; Wang, Li; Cai, Hong; Sun, Tao; Song, Junfeng; Liu, Hui; Gu, Yuandong

    2016-07-01

    The dew point is the temperature at which vapour begins to condense out of the gaseous phase. The deterministic relationship between the dew point and humidity is the basis for the industry-standard “chilled-mirror” dew point hygrometers used for highly accurate humidity measurements, which are essential for a broad range of industrial and metrological applications. However, these instruments have several limitations, such as high cost, large size and slow response. In this report, we demonstrate a compact, integrated photonic dew point sensor (DPS) that features high accuracy, a small footprint, and fast response. The fundamental component of this DPS is a partially exposed photonic micro-ring resonator, which serves two functions simultaneously: 1) sensing the condensed water droplets via evanescent fields and 2) functioning as a highly accurate, in situ temperature sensor based on the thermo-optic effect (TOE). This device virtually eliminates most of the temperature-related errors that affect conventional “chilled-mirror” hygrometers. Moreover, this DPS outperforms conventional “chilled-mirror” hygrometers with respect to size, cost and response time, paving the way for on-chip dew point detection and extension to applications for which the conventional technology is unsuitable because of size, cost, and other constraints.

  14. Effects of acid fog and dew on materials. Final report

    SciTech Connect

    Mansfeld, F.; Henry, R.; Vijayakumar, R.

    1989-10-01

    Field exposure tests have been carried out in order to separate the effects of acidic fog on materials damage from those caused by rain, dew and natural weathering. The test sites were McKittrick and Visalia in the Central Valley and West Casitas Pass in Ventura County. The field tests have been supported by laboratory tests in which materials damage has been determined during exposure to carefully controlled fog water chemistry. Analysis of the field exposure results for galvanized steel and the paint samples shows that the corrosivity of the atmosphere at the three test sites have been very low. The result is confirmed by the ACRM data which show very low corrosion activity. Since corrosion rates were so low approaching those for natural weathering, it was not possible to determine the effects of acidic fog. Based on the aerometric data and the observed corrosion behavior, it is doubtful that acidic fog conditions prevailed for significant times during the exposure period of 1/87 - 3/88 at Visalia and McKittrick. The results of the laboratory tests show that exposure to HNO3 at low pH and to high pollutant concentration increased the corrosion rate of galvanized steel to over 10 micro m/year. Exposure to HNO3 caused serious corrosion damage to anodized aluminum and the paint.

  15. Portable Dew Point Mass Spectrometry System for Real-Time Gas and Moisture Analysis

    NASA Technical Reports Server (NTRS)

    Arkin, C.; Gillespie, Stacey; Ratzel, Christopher

    2010-01-01

    A portable instrument incorporates both mass spectrometry and dew point measurement to provide real-time, quantitative gas measurements of helium, nitrogen, oxygen, argon, and carbon dioxide, along with real-time, quantitative moisture analysis. The Portable Dew Point Mass Spectrometry (PDP-MS) system comprises a single quadrupole mass spectrometer and a high vacuum system consisting of a turbopump and a diaphragm-backing pump. A capacitive membrane dew point sensor was placed upstream of the MS, but still within the pressure-flow control pneumatic region. Pressure-flow control was achieved with an upstream precision metering valve, a capacitance diaphragm gauge, and a downstream mass flow controller. User configurable LabVIEW software was developed to provide real-time concentration data for the MS, dew point monitor, and sample delivery system pressure control, pressure and flow monitoring, and recording. The system has been designed to include in situ, NIST-traceable calibration. Certain sample tubing retains sufficient water that even if the sample is dry, the sample tube will desorb water to an amount resulting in moisture concentration errors up to 500 ppm for as long as 10 minutes. It was determined that Bev-A-Line IV was the best sample line to use. As a result of this issue, it is prudent to add a high-level humidity sensor to PDP-MS so such events can be prevented in the future.

  16. Organic acids and aldehydes in throughfall and dew in a Japanese pine forest.

    PubMed

    Chiwa, Masaaki; Miyake, Takayuki; Kimura, Nobuhito; Sakugawa, Hiroshi

    2008-01-01

    We analyzed low molecular weight organic acids and aldehydes in throughfall under pine forest, and organic acids in dew on chemically inert surfaces and pine needle surfaces at urban- and mountain-facing sites of pine forest in western Japan. Low molecular weight organic acids and aldehydes accounted for less than 5% of the dissolved organic carbon in throughfall at both sites. Formaldehyde at both sites and formate at the mountain-facing site were found at significantly lower concentrations in throughfall than in rainfall, which may be explained by the degradation and/or retention of these components by the pine canopy as the incident precipitation passed through it. The oxalate concentration in throughfall was significantly higher than those in rainfall at both sites, suggesting that oxalate was derived from leaching from the pine foliage. At both sites, organic acid concentrations were higher in dew on the pine needles than in throughfall or dew on chemically inert surfaces. This could be due to the long contact time of dew on pine needles, during which leached substances from pine needles and dry deposits accumulated on their surfaces can dissolve into the small volume of dew. The role of enhanced concentrations of oxalate in an aqueous phase on the plant surfaces (e.g., dew) is discussed in relation to hydroxyl radical formation via the photo-Fenton reaction.

  17. Determination of water vapor content and hydrocarbon dew point in natural gas

    SciTech Connect

    Murphy, B.

    1984-04-01

    This paper discusses the principles of moisture analysis, and covers basic concepts, definitions and units followed by a description of the commonly used instrumental methods including their strengths and weaknesses. The effect of absolute pressure on the humidity measurement is reviewed. With analyzers that measure system dew point, the measurement will vary as the gas mixture is subjected to changes in pressure. Dalton's Law indicates that the partial pressure of water vapor will change in the same ratio as total pressure. This results in a direct change in dew point for any change in total pressure. The author emphasizes the importance of knowing both the process pressure and the pressure in the sensor for a complete evaluation of the measurement.

  18. The effect of water contamination on the dew-point temperature scale realization with humidity generators

    NASA Astrophysics Data System (ADS)

    Vilbaste, M.; Heinonen, M.; Saks, O.; Leito, I.

    2013-08-01

    The purpose of this paper is to study the effect of contaminated water in the context of humidity generators. Investigation of different methods to determine the drop in dew-point temperature due to contamination and experiments on actual contamination rates are reported. Different methods for calculating the dew-point temperature effect from electrical conductivity and density measurements are studied with high-purity water and aqueous solutions of NaCl and LiCl. The outcomes of the calculation methods are compared with the results of direct humidity measurements. The results show that the often applied Raoult's law based calculation method is in good agreement with other methods. For studying actual contamination, water samples were kept in glass, plastic, copper and stainless-steel vessels for up to 13 months to investigate natural ionic and organic contamination in vessels with different wall materials. The amount of ionic contamination was found to be higher in copper and glass vessels than in stainless-steel and plastic vessels. The amount of organic contamination was found to be highest in the plastic vessel. In all the cases, however, the corresponding drop in dew-point temperature due to natural contamination was found to be below 0.1 mK. The largest rate of change of dew-point temperature was 26 µK/month. Thus, if proper cleanness is maintained in a humidity generator the effect of contamination of water in the saturator is insignificant compared with the major uncertainty components even in the most accurate generators today.

  19. A Calibration Facility for Dew Point in Air up to 1 MPa

    NASA Astrophysics Data System (ADS)

    Carroll, P. A.; Bell, S. A.; Stevens, M.

    2015-12-01

    The provision of primary dew-point standards for humidified air and nitrogen at atmospheric pressure is well established, and measurement traceability to these standards provides confidence in a vast number of air humidity measurements. However, hygrometers are used industrially at a wide range of pressures. Both the performance of hygrometers and the properties of humid gases are known to vary with gas pressure. The pressure-dependence of gas non-ideality for air-water mixtures (water-vapor enhancement factor) is well enough known at moderate pressures, but there remains a need to characterize hygrometers at the pressure of use. To address this, a humidity calibration capability of wider scope is under development at the UK National Physical Laboratory (NPL). As an initial stage in the development of this capability, a humidity standard generating air or nitrogen in the dew-point range from -60° C to +10° C, at pressures up to 1 MPa (10 bar) has been validated for the calibration of hygrometers. The expanded uncertainty of the dew-point generator in this range with a coverage factor k= 2 is ± 0.07° C.

  20. Dew inspired breathing-based detection of genetic point mutation visualized by naked eye

    NASA Astrophysics Data System (ADS)

    Xie, Liping; Wang, Tongzhou; Huang, Tianqi; Hou, Wei; Huang, Guoliang; Du, Yanan

    2014-09-01

    A novel label-free method based on breathing-induced vapor condensation was developed for detection of genetic point mutation. The dew-inspired detection was realized by integration of target-induced DNA ligation with rolling circle amplification (RCA). The vapor condensation induced by breathing transduced the RCA-amplified variances in DNA contents into visible contrast. The image could be recorded by a cell phone for further or even remote analysis. This green assay offers a naked-eye-reading method potentially applied for point-of-care liver cancer diagnosis in resource-limited regions.

  1. Investigation of Primary Dew-Point Saturator Efficiency in Two Different Thermal Environments

    NASA Astrophysics Data System (ADS)

    Zvizdic, D.; Heinonen, M.; Sestan, D.

    2015-08-01

    The aim of this paper is to describe the evaluation process of the performance of the low-range saturator (LRS), when exposed to two different thermal environments. The examined saturator was designed, built, and tested at MIKES (Centre for Metrology and Accreditation, Finland), and then transported to the Laboratory for Process Measurement (LPM) in Croatia, where it was implemented in a new dew-point calibration system. The saturator works on a single-pressure-single-pass generation principle in the dew/frost-point temperature range between and . The purpose of the various tests performed at MIKES was to examine the efficiency and non-ideality of the saturator. As a test bath facility in Croatia differs from the one used in Finland, the same tests were repeated at LPM, and the effects of different thermal conditions on saturator performance were examined. Thermometers, pressure gauges, an air preparation system, and water for filling the saturator at LPM were also different than those used at MIKES. Results obtained by both laboratories indicate that the efficiency of the examined saturator was not affected either by the thermal conditions under which it was tested or by equipment used for the tests. Both laboratories concluded that LRS is efficient enough for a primary realization of the dew/frost-point temperature scale in the range from to , with flow rates between and . It is also shown that a considerable difference of the pre-saturator efficiency, indicated by two laboratories, did not have influence to the overall performance of the saturator. The results of the research are presented in graphical and tabular forms. This paper also gives a brief description of the design and operation principle of the investigated low-range saturator.

  2. Transport-induced shifts in condensate dew-point and composition in multicomponent systems with chemical reaction

    NASA Technical Reports Server (NTRS)

    Rosner, D. E.; Nagarajan, R.

    1985-01-01

    Partial heterogeneous condensation phenomena in multicomponent reacting systems are analyzed taking into consideration the chemical element transport phenomena. It is demonstrated that the dew-point surface temperature in chemically reactive systems is not a purely thermodynamic quantity, but is influenced by the multicomponent diffusion and Soret-mass diffusion phenomena. Several distinct dew-points are shown to exist in such systems and, as a result of transport constraints, the 'sharp' locus between two chemically distinct condensates is systematically moved to a difference mainstream composition.

  3. Report of preliminary analysis of data from dew-point hygrometer profiles during the ARM 1996 WVIOP

    SciTech Connect

    Porch, W.; Fernandez, A.; Spurgeon, W.

    1997-03-01

    Unique commercial light-weight chilled-mirror dew-point sensors were flown on tethered balloons during the Water Vapor Intensive Operation Period (WVIOP) in September 1996. Comparisons were made between in situ and remote sensing instruments that detect water vapor. We obtained a special waiver to fly the sensors up to 1 km both day and night from the FAA. Preliminary comparisons with tower mounted, surface-based temperature/relative humidity probes, rawinsonde, air-borne chilled-mirror dew point, and Raman lidar profiles are included. Profiles during nocturnal boundary layer wind jet occurrences are presented as special cases along with balloon-borne nephelometer light scattering profile comparisons.

  4. Use of dew-point detection for quantitative measurement of sweating rate

    NASA Technical Reports Server (NTRS)

    Brengelmann, G. L.; Mckeag, M.; Rowell, L. B.

    1975-01-01

    A method of measuring sweat rate (SR) based on detection of dew point (DP) is proposed which has advantages that may be attractive to other laboratories concerned with recording SR from selected areas of skin. It is similar to other methods in that dry gas is passed through a capsule which isolates several square centimeters of skin surface. The difference is in the means of determining how much gaseous water is carried off in the effluent moist gas. The DP detector used is free of the drawbacks of previous devices. DP is obtained through the fundamental technique of determining the temperature at which condensate forms on a mirror. Variations in DP are tracked rapidly, and accurately (+ or - 0.8 C nominal, sensitivity + or - 0.05 C) over a wide range ( -40 C to +50 C) without measurable hysteresis. The detector asembly is rugged and readily opened for cleaning and inspection.

  5. [Examination of upper airway function using the dew point hygrometer with semiconductor detector].

    PubMed

    Weremczuk, Jerzy; Paczesny, Daniel; Rapiejko, Piotr; Jachowicz, Ryszard; Jurkiewicz, Dariusz

    2005-09-01

    The nasal mucosa with blood capillary network has a remarkable role in respiration process. The most important nose functions are heating and humidifying to optimal level of reaching throat and lungs air and partly absorption of humidity and temperature from expired air. Variations of humidifying and heating processes can invoke some upper airways disorders. The paper presents dew point hygrometer which was specially design for laryngological purposes. The hygrometer can measure dynamic changes of humidity in upper airways. The device is fully automated, easy to operate and can communicate with external personal computer. Database application allows saving patient data with archive examination results and can display them easily. During ongoing clinical tests, still increasing amount of data will allow precisely investigate correlations between humidifying process and some diseases. The main advantage of the device is a short response time on humidity changing. The number of readings (detections) can reach 5 readings per second (slightly depending on humidity level) which is much faster than in available on the market hygrometers with sorption sensors. The paper also presents some results obtained in group of healthy volunteers and one patient with tracheostomy The tests figured out actual humidity in certain parts of upper airways: nose, throat, trachea in breathing cycles under various surrounding conditions. The constructed hygrometer can be used for air humidity measurement in upper airways during some diseases and for evaluation of an influence of some drugs and environmental conditions changing on air upper ways mucosa.

  6. [Examination of upper airway function using the dew point hygrometer with semiconductor detector].

    PubMed

    Weremczuk, Jerzy; Paczesny, Daniel; Rapiejko, Piotr; Jachowicz, Ryszard; Jurkiewicz, Dariusz

    2005-09-01

    The nasal mucosa with blood capillary network has a remarkable role in respiration process. The most important nose functions are heating and humidifying to optimal level of reaching throat and lungs air and partly absorption of humidity and temperature from expired air. Variations of humidifying and heating processes can invoke some upper airways disorders. The paper presents dew point hygrometer which was specially design for laryngological purposes. The hygrometer can measure dynamic changes of humidity in upper airways. The device is fully automated, easy to operate and can communicate with external personal computer. Database application allows saving patient data with archive examination results and can display them easily. During ongoing clinical tests, still increasing amount of data will allow precisely investigate correlations between humidifying process and some diseases. The main advantage of the device is a short response time on humidity changing. The number of readings (detections) can reach 5 readings per second (slightly depending on humidity level) which is much faster than in available on the market hygrometers with sorption sensors. The paper also presents some results obtained in group of healthy volunteers and one patient with tracheostomy The tests figured out actual humidity in certain parts of upper airways: nose, throat, trachea in breathing cycles under various surrounding conditions. The constructed hygrometer can be used for air humidity measurement in upper airways during some diseases and for evaluation of an influence of some drugs and environmental conditions changing on air upper ways mucosa. PMID:16358856

  7. Wet-bulb, dew point, and air temperature trends in Spain

    NASA Astrophysics Data System (ADS)

    Moratiel, R.; Soriano, B.; Centeno, A.; Spano, D.; Snyder, R. L.

    2016-08-01

    This study analyses trends of mean (T m), maximum (T x), minimum (T n), dew point (T d), and wet-bulb temperatures (T w) on an annual, seasonal, and monthly time scale over Spain during the period 1981-2010. The main purpose was to determine how temperature and humidity changes are impacting on T w, which is probably a better measure of climate change than temperature alone. In this study, 43 weather stations were used to detect data trends using the nonparametric Mann-Kendall test and the Sen method to estimate the slope of trends. Significant linear trends observed for T m, T x, and T n versus year were 56, 58, and 47 % of the weather stations, respectively, with temperature ranges between 0.2 and 0.4 °C per decade. The months with bigger trends were April, May, June, and July with the highest trend for T x. The spatial behaviour of T d and T w was variable, with various locations showing trends from -0.6 to +0.3 °C per decade for T d and from -0.4 to +0.5 °C per decade for T w. Both T d and T w showed negative trends for July, August, September, November, and December. Comparing the trends versus time of each variable versus each of the other variables exhibited poor relationships, which means you cannot predict the trend of one variable from the trend of another variable. The trend of T x was not related to the trend of T n. The trends of T x, T m, and T n versus time were unrelated to the trends versus time of either T d or T w. The trend of T w showed a high coefficient of determination with the trend of T d with an annual value of R 2 = 0.86. Therefore, the T w trend is more related to changes in humidity than temperature.

  8. Evaluation of alkali metal sulfate dew point measurement for detection of hot corrosion conditions in PFBC flue gas

    SciTech Connect

    Helt, J.E.

    1980-11-01

    Hot corrosion in combustion systems is, in general, the accelerated oxidation of nickel, cobalt, and iron-base alloys which occurs in the presence of small amounts of impurities - notably, sodium, sulfur, chlorine, and vanadium. There is no real consensus on which mechanisms are primarily responsible for high-temperature corrosion. One point generally accepted, however, is that corrosion reactions take place at an appreciable rate only in the presence of a liquid phase. When coal is the fuel for combustion, hot corrosion may occur in the form of accelerated sulfidation. It is generally agreed by investigators that molten alkali metal sulfates (Na/sub 2/SO/sub 4/ and K/sub 2/SO/sub 4/) are the principal agents responsible for the occurrence of sulfidation. Although molten sodium sulfate by itself appears to have little or no effect on the corrosion of metal alloys, its presence may increase the accessibility of the bare metal surface to the external atmosphere. If this atmosphere contains either a reductant and/or an oxide such as SiO/sub 2/, SO/sub 3/, or NaOH(Na/sub 2/O), corrosion is likely to occur. Alkali metal sulfate dew point measurement was evaluated as a means of anticipating hot corrosion in the gas turbine of a pressurized fluidized-bed combustion system. The hot corrosion mechanism and deposition rate theory were reviewed. Two methods of dew point measurement, electrical conductivity and remote optical techniques, were identified as having a potential for this application. Both techniques are outlined; practical measurement systems are suggested; and potential problem areas are identified.

  9. A technical basis to relax the dew point specification for the environment in the vapor space in DWPF canisters

    SciTech Connect

    Louthan, M.R. Jr.

    1995-05-01

    This memorandum establishes the technical basis to conclude that relaxing, from 0 C to 20 C, the dew point specification for the atmosphere in the vapor space (free volume) of a DWPF canister will not provide an environment that will cause significant amounts of corrosion induced degradation of the canister wall. The conclusion is based on engineering analysis, experience and review of the corrosion literature. The basic assumptions underlying the conclusion are: (1) the canister was fabricated from Type 304L stainless steel; (2) the corrosion behavior of the canister material, including base metal, fusion zones and heat effected zones, is typified by literature data for, and industrial experience with, 300 series austenitic stainless steels; and (3) the glass-metal crevices created during the pouring operation will not alter the basic corrosion resistance of the steel although such crevices might serve as sites for the initiation of minor amounts of corrosion on the canister wall.

  10. Acid dew and the role of chemistry in the dry deposition of reactive gases to wetted surfaces

    NASA Technical Reports Server (NTRS)

    Chameides, William L.

    1987-01-01

    A formalism is developed to describe the dry deposition of soluble reactive gases to wetted surfaces in terms of the relevant meteorological conditions, the surface roughness, the total amount of liquid water present on the surface, the rate of accumulation of this water, and the species' solubility and reactivity in the surface water. This formulation is then incorporated into a model designed to simulate the generation of acidic dew from the deposition of HNO3, SO2, S(IV) oxidants, H2O2, and O3. Similar to the observations of dew in the continental U.S., the model generates a dewdrop pH of about 4 by the end of the night; the pH can rapidly fall to toxic levels due to rapid evaporation after sunrise. Relatively low deposition velocities are predicted for the SO2 and O3 because of their lower solubilities and hence larger surface resistances than those of the other oxidants. Because the chemical lifetime of the SO2 in the dew is influenced by the atmospheric levels of H2O2, O3, and SO2, the SO2 deposition velocity is a strong function of these species' atmospheric abundances.

  11. Future PMPs Estimation in Korea under AR5 RCP 8.5 Climate Change Scenario: Focus on Dew Point Temperature Change

    NASA Astrophysics Data System (ADS)

    Okjeong, Lee; Sangdan, Kim

    2016-04-01

    According to future climate change scenarios, future temperature is expected to increase gradually. Therefore, it is necessary to reflect the effects of these climate changes to predict Probable Maximum Precipitations (PMPs). In this presentation, PMPs will be estimated with future dew point temperature change. After selecting 174 major storm events from 1981 to 2005, new PMPs will be proposed with respect to storm areas (25, 100, 225, 400, 900, 2,025, 4,900, 10,000 and 19,600 km2) and storm durations (1, 2, 4, 6, 8, 12, 18, 24, 48 and 72 hours) using the Korea hydro-meteorological method. Also, orographic transposition factor will be applied in place of the conventional terrain impact factor which has been used in previous Korean PMPs estimation reports. After estimating dew point temperature using future temperature and representative humidity information under the Korea Meteorological Administration AR5 RCP 8.5, changes in the PMPs under dew point temperature change will be investigated by comparison with present and future PMPs. This research was supported by a grant(14AWMP-B082564-01) from Advanced Water Management Research Program funded by Ministry of Land, Infrastructure and Transport of Korean government.

  12. Natural denitrification in drying process of dew

    SciTech Connect

    Takenaka, Norimichi; Suzue, Takahiko; Ohira, Kingo; Bandow, Hiroshi; Maeda, Yasuki; Morikawa, Tazuko

    1999-05-01

    This report is the first observation of natural chemical denitrification in the drying process of dew. Nitrogen compounds released in the atmosphere are considered to be subjected to oxidation to form nitric acid by the chemical process so far. The results here show that nitrous acid is reduced to N{sub 2} by drying of dew. Dew was collected at Osaka Prefecture University in Sakai City, Japan from 1996 to 1997. Concentrations of ammonium and nitrite ions in dew were very high related to those in rain, and pHs of dew were relatively high, pH ca. 6.5. The authors found that when dew was dried, most nitrite and ammonium ions included in dew were decomposed. It is well-known that concentrated ammonium nitrite aqueous solution is unstable and decomposes to N{sub 2} and H{sub 2}O. During the drying process of dew, nitrite and ammonium would be concentrated and react to form N{sub 2}, and as a result, nitrite and ammonia in the dried dew are lost, that is, natural denitrification occurs in the drying process of dew. The authors report here results of the natural denitrification.

  13. Investigation of the Equivalence of National Dew-Point Temperature Realizations in the -50 °C to + 20 °C Range

    NASA Astrophysics Data System (ADS)

    Heinonen, Martti; Anagnostou, Miltiadis; Bell, Stephanie; Stevens, Mark; Benyon, Robert; Bergerud, Reidun Anita; Bojkovski, Jovan; Bosma, Rien; Nielsen, Jan; Böse, Norbert; Cromwell, Plunkett; Kartal Dogan, Aliye; Aytekin, Seda; Uytun, Ali; Fernicola, Vito; Flakiewicz, Krzysztof; Blanquart, Bertrand; Hudoklin, Domen; Jacobson, Per; Kentved, Anders; Lóio, Isabel; Mamontov, George; Masarykova, Alexandra; Mitter, Helmut; Mnguni, Regina; Otych, Jan; Steiner, Anton; Szilágyi Zsófia, Nagyné; Zvizdic, Davor

    2012-09-01

    In the field of humidity quantities, the first CIPM key comparison, CCT-K6 is at its end. The corresponding European regional key comparison, EUROMET.T-K6, was completed in early 2008, about 4 years after the starting initial measurements in the project. In total, 24 NMIs from different countries took part in the comparison. This number includes 22 EURAMET countries, and Russia and South Africa. The comparison covered the dew-point temperature range from -50 °C to +20 °C. It was carried out in three parallel loops, each with two chilled mirror hygrometers as transfer standards in each loop. The comparison scheme was designed to ensure high quality results with evenly spread workload for the participants. It is shown that the standard uncertainty due to the long-term instability was smaller than 0.008 °C in all loops. The standard uncertainties due to links between the loops were found to be smaller than 0.025 °C at -50 °C and 0.010 °C elsewhere. Conclusions on the equivalence of the dew-point temperature standards are drawn on the basis of calculated bilateral degrees of equivalence and deviations from the EURAMET comparison reference values (ERV). Taking into account 16 different primary dew-point realizations and 8 secondary realizations, the results demonstrate the equivalence of a large number of laboratories at an uncertainty level that is better than achieved in other multilateral comparisons so far in the humidity field.

  14. Dew nucleation and growth

    NASA Astrophysics Data System (ADS)

    Beysens, Daniel

    2006-11-01

    Dew is the condensation of water vapor into liquid droplets on a substrate. It is characterized by an initial heterogeneous nucleation on a substrate and a further growth of droplets. The presence of a substrate that geometrically constrains the growth is the origin of the peculiarities and richness of the phenomenon. A key point is the drop interaction through drop fusion or coalescence, which leads to scaling in the growth and gives universality to the process. As a matter of fact, growth dynamics are only dependent on substrate and drop dimensionality. Coalescence events lead to temporal and spatio-temporal fluctuations in the substrate coverage, drop configuration, etc., which give rise to a very peculiar dynamics. When the substrate is a liquid or a liquid crystal, the drop pattern can exhibit special spatial order, such as crystalline, hexatic phases and fractal contours. Condensation on a solid substrate near its melting point can make the drop jump. The applications of monitoring dew formation are manifold. Examples can be found in medicine (sterilization process), agriculture (green houses) and hydrology (production of drinkable water). To cite this article: D. Beysens, C. R. Physique 7 (2006).

  15. The formation of dew

    NASA Astrophysics Data System (ADS)

    Beysens, D.

    Dew is the condensation into liquid droplets of water vapor on a substrate. The presence of a substrate is the origin of the peculiarities and richness of the phenomenon. We review the aspects related to heterogeneous nucleation and subsequent growth of water droplets. A key point is the drop interaction through drop fusion or coalescence, which leads to scaling in the growth and gives universality to the process. The effects of substrate heterogeneity and gravity effects are also considered. Coalescence events lead to temporal and spatio-temporal fluctuations in the substrate coverage, drop configuration, etc., which give rise to a very peculiar dynamics. When the substrate is a liquid or a liquid crystal, the drop pattern can exhibit special spatial orders, such as crystalline, hexatic phases and fractal contours. And condensation on a solid substrate near its melting point can make the drop jump. The applications of monitoring dew formation are manyfold. Examples can be found in nanoelectronics and optics (vapor deposition and thin films), medicine (sterilization process), agriculture (green houses). We here discuss in greater details the production of clean water by "atmospheric wells".

  16. BILATERAL KEY COMPARISON SIM.T-K6.1 ON HUMIDITY STANDARDS IN THE DEW/FROST-POINT TEMPERATURE RANGE FROM −25 °C TO +20 °C

    PubMed Central

    Meyer, C.W.; Hill, K.D.

    2015-01-01

    A Regional Metrology Organization (RMO) Key Comparison of dew/frost point temperatures was carried out by the National Institute of Standards and Technology (NIST, USA) and the National Research Council (NRC, Canada) between December 2014 and April, 2015. The results of this comparison are reported here, along with descriptions of the humidity laboratory standards for NIST and NRC and the uncertainty budget for these standards. This report also describes the protocol for the comparison and presents the data acquired. The results are analyzed, determining degree of equivalence between the dew/frost-point standards of NIST and NRC. PMID:26663952

  17. The chemistry of dews and frosts in indianapolis, Indiana

    NASA Astrophysics Data System (ADS)

    Foster, Jeffrey R.; Pribush, Robert A.; Carter, Bradley H.

    Dews and frosts forming on chemically clean Teflon surfaces were sampled for pH and ion concentrations during a 13-month period in urban Indianapolis, Indiana. We predicted that dews forming in this polluted atmosphere would be acidic due to absorption of SO 2, NO 2 and CO 2, but that frost pH would be neutral due to the lack of gas absorption. However, measured pH ranged from 6.0 to 7.2, and dew and frost pH were not significantly different. Anion and cation concentrations did not differ between dews and frosts, implying similar mechanisms and rates for scavenging of atmospheric chemicals. Sulfite and nitrite were present in many samples, indicating SO 2 and NO 2 absorption by both dews and frosts. The presence of ions (K +, Ca 2+, Mg 2+, Na +) lacking gaseous sources suggested that sedimentation of aerosols, primarily carbonates and salts, from surrounding agricultural lands occurred into dews and frosts as they formed. Carbonate deposition may have been responsible for near-neutral dew and frost pH. Dews sampled from sugar maple leaves were depleted of ammonium and enriched in other ions, but did not differ substantially in pH, compared to dews simultaneously sampled from Teflon. Temporal (overnight) sampling of dews on Teflon showed that dew chemistry changed substantially during the course of the night.

  18. Smart textile plasmonic fiber dew sensors.

    PubMed

    Esmaeilzadeh, Hamid; Rivard, Maxime; Arzi, Ezatollah; Légaré, François; Hassani, Alireza

    2015-06-01

    We propose a novel Surface Plasmon Resonance (SPR)-based sensor that detects dew formation in optical fiber-based smart textiles. The proposed SPR sensor facilitates the observation of two phenomena: condensation of moisture and evaporation of water molecules in air. This sensor detects dew formation in less than 0.25 s, and determines dew point temperature with an accuracy of 4%. It can be used to monitor water layer depth changes during dew formation and evaporation in the range of a plasmon depth probe, i.e., 250 nm, with a resolution of 7 nm. Further, it facilitates estimation of the relative humidity of a medium over a dynamic range of 30% to 70% by measuring the evaporation time via the plasmon depth probe. PMID:26072854

  19. Final report on CCT-K6: Comparison of local realisations of dew-point temperature scales in the range -50 °C to +20 °C

    NASA Astrophysics Data System (ADS)

    Bell, S.; Stevens, M.; Abe, H.; Benyon, R.; Bosma, R.; Fernicola, V.; Heinonen, M.; Huang, P.; Kitano, H.; Li, Z.; Nielsen, J.; Ochi, N.; Podmurnaya, O. A.; Scace, G.; Smorgon, D.; Vicente, T.; Vinge, A. F.; Wang, L.; Yi, H.

    2015-01-01

    A key comparison in dew-point temperature was carried out among the national standards held by NPL (pilot), NMIJ, INTA, VSL, INRIM, MIKES, NIST, NIM, VNIIFTRI-ESB and NMC. A pair of condensation-principle dew-point hygrometers was circulated and used to compare the local realisations of dew point for participant humidity generators in the range -50 °C to +20 °C. The duration of the comparison was prolonged by numerous problems with the hygrometers, requiring some repairs, and several additional check measurements by the pilot. Despite the problems and the extended timescale, the comparison was effective in providing evidence of equivalence. Agreement with the key comparison reference value was achieved in the majority of cases, and bilateral degrees of equivalence are also reported. Main text. To reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database kcdb.bipm.org/. The final report has been peer-reviewed and approved for publication by the CCT, according to the provisions of the CIPM Mutual Recognition Arrangement (CIPM MRA).

  20. [Indoor simulation on dew formation on plant leaves].

    PubMed

    Gao, Zhi-Yong; Wang, You-Ke; Wei, Xin-Guang; Liu, Shou-Yang; He, Zi-Li; Zhou, Yu-Hong

    2014-03-01

    Dew forming on plant leaves through water condensation plays a significant ecological role in arid and semi-arid areas as an ignorable fraction of water resources. In this study, an artificial intelligent climate chamber and an automatic temperature-control system for leaves were implemented to regulate the ambient temperature, the leaf surface temperature and the leaf inclination for dew formation. The impact of leaf inclination, ambient temperature and dew point-leaf temperature depression on the rate and quantity of dew accumulation on leaf surface were analyzed. The results indicated that the accumulation rate and the maximum volume of dew on leaves decreased with increasing the leaf inclination while increased with the increment of dew point-leaf temperature depression, ambient temperature and relative humidity. Under the horizontal configuration, dew accumulated linearly on leaf surface over time until the maximum volume (0.80 mm) was reached. However, dew would fall down after reaching the maximum volume when the leaf inclination existed (45 degrees or 90 degrees), significantly slowing down the accumulative rate, and the zigzag pattern for the dynamic of dew accumulation appeared.

  1. Bilateral key comparison SIM.T-K6.5 on humidity standards in the dew/frost-point temperature range from -30 °C to +20 °C

    NASA Astrophysics Data System (ADS)

    Meyer, C.; Solano, A.

    2016-01-01

    A Regional Metrology Organization (RMO) Key Comparison of dew/frost point temperatures was carried out by the National Institute of Standards and Technology (NIST, USA) and the Laboratorio Costarricense de Metrología (LACOMET, Costa Rica) between February 2015 and August 2015. The results of this comparison are reported here, along with descriptions of the humidity laboratory standards for NIST and LACOMET and the uncertainty budget for these standards. This report also describes the protocol for the comparison and presents the data acquired. The results are analyzed, determining degree of equivalence between the dew/frost-point standards of NIST and LACOMET. Main text To reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database kcdb.bipm.org/. The final report has been peer-reviewed and approved for publication by the CCT, according to the provisions of the CIPM Mutual Recognition Arrangement (CIPM MRA).

  2. Final report: Bilateral key comparison SIM.T-K6.3 on humidity standards in the dew/frost-point temperature range from -30°C to 20°C

    NASA Astrophysics Data System (ADS)

    Huang, Peter; Meyer, Christopher; Brionizio, Julio D.

    2015-01-01

    A Regional Metrology Organization (RMO) Key Comparison of dew/frost point temperatures was carried out by the National Institute of Standards and Technology (NIST, USA) and the Instituto Nacional de Metrologia, Qualidade e Tecnologia (INMETRO, Brazil) between October 2009 and March 2010. The results of this comparison are reported here, along with descriptions of the humidity laboratory standards for NIST and INMETRO and the uncertainty budget for these standards. This report also describes the protocol for the comparison and presents the data acquired. The results are analyzed, determining degree of equivalence between the dew/frost-point standards of NIST and INMETRO. Main text. To reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database kcdb.bipm.org/. The final report has been peer-reviewed and approved for publication by the CCT, according to the provisions of the CIPM Mutual Recognition Arrangement (CIPM MRA).

  3. Water harvest via dewing.

    PubMed

    Lee, Anna; Moon, Myoung-Woon; Lim, Hyuneui; Kim, Wan-Doo; Kim, Ho-Young

    2012-07-10

    Harvesting water from humid air via dewing can provide a viable solution to a water shortage problem where liquid-phase water is not available. Here we experimentally quantify the effects of wettability and geometry of the condensation substrate on the water harvest efficiency. Uniformly hydrophilic surfaces are found to exhibit higher rates of water condensation and collection than surfaces with lower wettability. This is in contrast to a fog basking method where the most efficient surface consists of hydrophilic islands surrounded by hydrophobic background. A thin drainage path in the lower portion of the condensation substrate is revealed to greatly enhance the water collection efficiency. The optimal surface conditions found in this work can be used to design a practical device that harvests water as its biological counterpart, a green tree frog, Litoria caerulea , does during the dry season in tropical northern Australia. PMID:22731870

  4. Spatial Variation of Dew over India

    NASA Astrophysics Data System (ADS)

    Madhavan, T.; Sharan, G.

    2010-07-01

    Dew harvest systems - devices to condense and collect dew water - have been developed for use in arid coastal region of the north-west India. These are installed over building roofs, over open ground and along boundary walls of large properties. Several installations, some as large as 850 m2 condensing surface, have been functioning in the region for several years. There is potential to deploy these in other areas where dew occurs and water is in short supply. However, lack of reliable data on dew occurrence hinders their adoption and diffusion. Indian Meteorological Department (IMD) monitors dew deposition using Duvdevani gauges at 79 locations in the country. Data includes dew fall amount over a six month span (October to March), number of dew nights. The north-east region has the highest dew resource. Other parts that have high accumulation are along the coast. Using data from 79 locations, spatial variation of dew amount has been characterized using variogram. Spatial clustering has been done to indicate areas with similar accumulation. Kriging is used to determine expected dew accumulation by extrapolation in areas for which measured data is not available but which lie near one or other monitoring station. The results of this analysis would be of use to those who need to assess the potential of dew harvesting in various parts of India especially in coastal zones.

  5. An Exploration of Distributed Leaf Wetness and Dew Detection Using Inexpensive Radios

    NASA Astrophysics Data System (ADS)

    Niemeier, J. J.; Rowlandson, T. L.; Kruger, A.; Hornbuckle, B. K.

    2009-12-01

    Our understanding of latent heat transfer between the soil surface and canopy is not complete. A major contributing factor to the uncertainty is the presence and amount of dew on the plant canopy. Improved measurements of dew duration, and possibly amount would help refine land surface process models. There are automated leaf wetness sensors available that consist of a simple sensor that attempts to simulate a single leaf. The electrical resistivity of the sensor is a function of the amount of liquid water that has condensed on its surface. These sensors generally provide reliable dew/no dew indication, but do not provide good information on dew amount. It may be possible to obtain dew amount from such sensors, but that would require careful calibration, because of the nonlinear relationship between dew amount and resistivity. The alternative is traditional measurements that require manually sampling and measuring dew amount. This latter is time-consuming and labor-intensive. Further, all these methods are point measurements that suffer from sampling errors. We are exploring the use of very inexpensive radios that operate in the unlicensed industrial, scientific, and medical (ISM) band as leaf wetness sensors. Our hypothesis is that dew on plant leafs attenuates the radio signals, and by recording the received signal strength, one can detect changes in leaf wetness. Further, such measurements are distributed/volume measurements that counter sampling errors inherent in point measurements. By using directional antennas, there is the exciting possibility to perform tomographic dew measurements. To test our hypothesis, we have deployed a number of radios operating at 2.4 GHz and 900 MHz, collocated with traditional leaf-wetness sensors in a corn field near Ames, Iowa. We have also made a large number of traditional leaf wetness/dew amount measurements at this location. Preliminary data analysis for the radio-based technique is promising. In this work, we present and

  6. The role of dew as a night-time reservoir and morning source for atmospheric ammonia

    NASA Astrophysics Data System (ADS)

    Wentworth, Gregory R.; Murphy, Jennifer G.; Benedict, Katherine B.; Bangs, Evelyn J.; Collett, Jeffrey L., Jr.

    2016-06-01

    nights with dew is approximately equal to the observed amount of NH4+ sequestered in dew at the onset of evaporation. Hence, there is strong evidence that dew is both a significant night-time reservoir and strong morning source of NH3. The possibility of rain evaporation as a source of NH3, as well as dew evaporation influencing species of similar water solubility (acetic acid, formic acid, and HONO), is also discussed. If release of NH3 from dew and rain evaporation is pervasive in many environments, then estimates of NH3 dry deposition and NHx ( ≡ NH3 + NH4+) wet deposition may be overestimated by models that assume that all NHx deposited in rain and dew remains at the surface.

  7. Wireless Sensor Network-Based Greenhouse Environment Monitoring and Automatic Control System for Dew Condensation Prevention

    PubMed Central

    Park, Dae-Heon; Park, Jang-Woo

    2011-01-01

    Dew condensation on the leaf surface of greenhouse crops can promote diseases caused by fungus and bacteria, affecting the growth of the crops. In this paper, we present a WSN (Wireless Sensor Network)-based automatic monitoring system to prevent dew condensation in a greenhouse environment. The system is composed of sensor nodes for collecting data, base nodes for processing collected data, relay nodes for driving devices for adjusting the environment inside greenhouse and an environment server for data storage and processing. Using the Barenbrug formula for calculating the dew point on the leaves, this system is realized to prevent dew condensation phenomena on the crop’s surface acting as an important element for prevention of diseases infections. We also constructed a physical model resembling the typical greenhouse in order to verify the performance of our system with regard to dew condensation control. PMID:22163813

  8. Dew Worms in the White Nights

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Lumbricus terrestris L. (the dew worm) forages, mates and migrates on the soil surface during the night. Its distribution covers a broad latitudinal gradient and variation in day length conditions. Since soil-surface activity is crucial for the survival and reproduction of dew worms, it is conceivab...

  9. Dew Formation and Chemistry Near a Motorway in Poland

    NASA Astrophysics Data System (ADS)

    Gałek, Grzegorz; Sobik, Mieczysław; Błaś, Marek; Polkowska, Żaneta; Cichała-Kamrowska, Katarzyna

    2012-05-01

    In this study, the influence of traffic intensity on dew formation efficiency and chemistry is presented. The measurements were conducted near the A4 motorway in SW Poland in almost flat land relief with intense agricultural activity. The dew/hoarfrost was collected by means of insulated plain passive radiative condensers at three sites: AN and AS located in the close vicinity of the motorway (30 m) on the opposite sides of the road, and AR, representing rural background conditions beyond the motorway influence. Measurements were conducted in two short campaigns in April and September 2009 with 9 and 10 collection days respectively. The average daily efficiency of dew formation was 0.179 L/m2. Its value for AN, AS and AR was on average 0.170, 0.199 and 0.173 L/m2, respectively. The efficiency of dew formation at measurement sites located on both sides of the road differed by up to about 200% during an individual dew episode. Maximum daily value reached 0.389 L/m2. The average volume-weighted pH was acidic and ranged from 4.29 (AS) to 4.58 (AR). The electric conductivity (EC) at all measurement sites was relatively low reaching on average 55.9 μS/cm for AN, 62.2 μS/cm for AS and 35.8 μS/cm for AR. The average volume-weighted TIC parameter (total ionic content) reached the value of 0.62 meq/L (AN and AS) and 0.38 meq/L (AR). Both EC and TIC values indicated strong influence of the motorway at sites located in its close vicinity (AN and AS). Depending on airflow direction during individual dew collection events, AN or AS sites were situated alternatively on windward or leeward side of the road, which distinctly influenced dew formation and chemistry: the leeward condenser was characterized by smaller water volume, higher EC and higher TIC when compared both with its windward counterpart and the background site. The ionic structure of the collected samples was similar at all measurement sites. The largest share had NO3 - anion (28-32%) and Ca2+ cation (22-25%). Thus

  10. Design of the diagnostic encyclopedia workstation (DEW).

    PubMed

    van Ginneken, A M; Smeulders, A W; Jansen, W; Baak, J P; Brooymans, I

    1990-01-01

    The Diagnostic Encyclopedia Workstation (DEW) contains reference knowledge for diagnostic support in pathology. Illustrations are accessible via a video disc device. DEW can hold more knowledge, pictures and case histories than books, and its information is accessible via several entries. Software for data entry has been written in MUMPS with use of the relational database toolkit AIDA, which is particularly suited for manipulation of free text. The graphical mouse-driven user interface is written in C using MetaWindows. The DEW contains 85 diagnoses in ovarian pathology, covering all frequent cases and many rarities, illustrated by approximately 3000 pictures, divided among 158 cases.

  11. Observation and modelling of urban dew

    NASA Astrophysics Data System (ADS)

    Richards, Katrina

    Despite its relevance to many aspects of urban climate and to several practical questions, urban dew has largely been ignored. Here, simple observations an out-of-doors scale model, and numerical simulation are used to investigate patterns of dewfall and surface moisture (dew + guttation) in urban environments. Observations and modelling were undertaken in Vancouver, B.C., primarily during the summers of 1993 and 1996. Surveys at several scales (0.02-25 km) show that the main controls on dew are weather, location and site configuration (geometry and surface materials). Weather effects are discussed using an empirical factor, FW . Maximum dew accumulation (up to ~ 0.2 mm per night) is seen on nights with moist air and high FW , i.e., cloudless conditions with light winds. Favoured sites are those with high Ysky and surfaces which cool rapidly after sunset, e.g., grass and well insulated roofs. A 1/8-scale model is designed, constructed, and run at an out-of-doors site to study dew patterns in an urban residential landscape which consists of house lots, a street and an open grassed park. The Internal Thermal Mass (ITM) approach is used to scale the thermal inertia of buildings. The model is validated using data from full-scale sites in Vancouver. Patterns in the model agree with those seen at the full-scale, i.e., dew distribution is governed by weather, site geometry and substrate conditions. Correlation is shown between Ysky and surface moisture accumulation. The feasibility of using a numerical model to simulate urban dew is investigated using a modified version of a rural dew model. Results for simple isolated surfaces-a deciduous tree leaf and an asphalt shingle roof-show promise, especially for built surfaces.

  12. The effects of haze on dew quality in the urban ecosystem of Changchun, Jilin Province, China.

    PubMed

    Xu, Yingying; Zhu, Hui; Tang, Jie

    2016-02-01

    Dew samples were collected during both normal weather and haze events (hazy days) to investigate the chemical characteristics of dew in Changchun, Jilin, China, from 2013 to 2015. The analysis included measures of the following parameters: pH, electrical conductivity (EC), total dissolved solid (TDS), and the concentration of PM2.5, PM10, major cations (NH4(+), Na(+), K(+), Ca(2+), and Mg(2+)), and major anions (F(-), Cl(-), SO4 (2-), and NO3(-)). The results demonstrated that dew water quality from hazy days was much lower quality than that on normal days with a lower mean pH during hazy days (5.75) when compared with that of normal days (6.56); that is, dew water was more acidic in stable atmospheric conditions. Both EC (542.71 μs/cm) and TDS (271.36 mg/L) of dew on hazy days were higher than that on normal days. The mean concentration of particulate matter <2.5 and 2.5-10 μm in diameter (PM2.5 and PM10, respectively) was 21.69 and 51.56 mg/L on normal days and were over 2.48 and 1.79 times higher on hazy days, respectively; that is, dew removed more fine particles on hazy days. On hazy days, the concentrations of water-soluble ions were 3.01-9.32 times higher than levels on normal days. The concentrations of secondary species and K(+) on hazy days were much higher than those of other ions. The results indicated dew mainly removed aerosols from automobile exhaust, and industrial waste gas emissions, while to a lesser extent dew did scavenge some water-soluble crustal ions. PMID:26832721

  13. Pollutant deposition via dew in urban and rural environment, Cracow, Poland

    NASA Astrophysics Data System (ADS)

    Muskała, Piotr; Sobik, Mieczysław; Błaś, Marek; Polkowska, Żaneta; Bokwa, Anita

    2015-01-01

    This study is a comparative analysis of dew in rural and urban environment. Dew samples were collected between May and October, 2009 in two reference stations in southern Poland: Cracow and Gaik-Brzezowa. The investigation included comparison of volume and chemistry of the collected samples. Due to its formation mechanisms, dew is a good indicator of air pollution. Following parameters were analyzed in 159 collected samples: pH, electric conductivity, concentration of formaldehyde and phenols, concentration of NH4+, Ca2 +, K+, Na+, and Mg2 + cations and NO2-, NO3-, SO42 -, Cl-, F-, and PO43 - anions. The frequency of dew was approximately the same, both in urban and rural conditions reaching 43% of the measurement period. Dew intensity, expressed by volume, was on average two times larger in rural environment than in urban conditions. Urban landuse was recognized as the main factor reducing dew intensity in the urban station in comparison to the rural. Furthermore, the intensity of dew depended on synoptic scale air circulation at both measurement sites. As expected, samples collected in Cracow were much more polluted than the ones from Gaik-Brzezowa. The average TIC (Total Ionic Content) parameter was approximately 50% higher at the urban station. The pH in the rural station was more acidic. NO3- anions and Ca2 + cations were predominant in both measurement sites, however the participation of Ca2 + in Cracow was higher. NO3- indicates pollutions emitted by transport and industrial sources. The concentration of the analytes in both stations, as the volume, depended on air circulation direction. For Gaik-Brzezowa the highest TIC was observed mainly within southern circulation, while for Cracow the highest TIC was noted within both northern and southern. In general the rural station represented background pollution for the whole region and the pollution in Cracow was more dependent on local urban sources as transport or industry.

  14. Dew condensation on desert beetle skin.

    PubMed

    Guadarrama-Cetina, J; Mongruel, A; Medici, M-G; Baquero, E; Parker, A R; Milimouk-Melnytchuk, I; González-Viñas, W; Beysens, D

    2014-11-01

    Some tenebrionind beetles inhabiting the Namib desert are known for using their body to collect water droplets from wind-blown fogs. We aim to determine whether dew water collection is also possible for desert insects. For this purpose, we investigated the infra-red emissivity, and the wetting and structural properties, of the surface of the elytra of a preserved specimen of Physasterna cribripes (Tenebrionidæ) beetle, where the macro-structure appears as a series of "bumps", with "valleys" between them. Dew formation experiments were carried out in a condensation chamber. The surface properties (infra-red emissivity, wetting properties) were dominated by the wax at the elytra surface and, to a lower extent, its micro-structure. We performed scanning electron microscope on histological sections and determined the infra-red emissivity using a scanning pyrometer. The emissivity measured (0.95±0.07 between 8-14 μm) was close to the black body value. Dew formation occurred on the insect's elytra, which can be explained by these surface properties. From the surface coverage of the condensed drops it was found that dew forms primarily in the valleys between the bumps. The difference in droplet nucleation rate between bumps and valleys can be attributed to the hexagonal microstructure on the surface of the valleys, whereas the surface of the bumps is smooth. The drops can slide when they reach a critical size, and be collected at the insect's mouth.

  15. Dew condensation on desert beetle skin.

    PubMed

    Guadarrama-Cetina, J; Mongruel, A; Medici, M-G; Baquero, E; Parker, A R; Milimouk-Melnytchuk, I; González-Viñas, W; Beysens, D

    2014-11-01

    Some tenebrionind beetles inhabiting the Namib desert are known for using their body to collect water droplets from wind-blown fogs. We aim to determine whether dew water collection is also possible for desert insects. For this purpose, we investigated the infra-red emissivity, and the wetting and structural properties, of the surface of the elytra of a preserved specimen of Physasterna cribripes (Tenebrionidæ) beetle, where the macro-structure appears as a series of "bumps", with "valleys" between them. Dew formation experiments were carried out in a condensation chamber. The surface properties (infra-red emissivity, wetting properties) were dominated by the wax at the elytra surface and, to a lower extent, its micro-structure. We performed scanning electron microscope on histological sections and determined the infra-red emissivity using a scanning pyrometer. The emissivity measured (0.95±0.07 between 8-14 μm) was close to the black body value. Dew formation occurred on the insect's elytra, which can be explained by these surface properties. From the surface coverage of the condensed drops it was found that dew forms primarily in the valleys between the bumps. The difference in droplet nucleation rate between bumps and valleys can be attributed to the hexagonal microstructure on the surface of the valleys, whereas the surface of the bumps is smooth. The drops can slide when they reach a critical size, and be collected at the insect's mouth. PMID:25403836

  16. Is dew water potable? Chemical and biological analyses of dew water in Ajaccio (Corsica Island, France).

    PubMed

    Muselli, Marc; Beysens, Daniel; Soyeux, Emmanuel; Clus, Owen

    2006-01-01

    To determine to what extent dew water is potable without further treatment, a thorough set of chemical and biological analyses were performed on 10 samples of dew water collected on a large scale radiative collector (29.83 m2) in Ajaccio (Corsica Island, France), between 21 May 2002 and 5 Mar. 2003. Samples were collected following four protocols according to the dew volume amount and 48 parameters (ions, minerals, and bacteria) were analyzed and compared to French and European Union legislation and also World Health Organization (WHO) recommendations. Aluminum and Fe were the main pollutants whose concentrations were significantly larger than recommended. Their presence is due to local deposition of aerosols coming from the Sahara (a characteristic of the Mediterranean basin). A large number of biologically cultivable microorganisms were found, together with bacteria typical of fecal contamination. For dew water to be potable with respect to present legislation at the Ajaccio site, it should be disinfected and treated for turbidity.

  17. Dew and rain water collection in the Dalmatian Coast, Croatia

    NASA Astrophysics Data System (ADS)

    Muselli, M.; Beysens, D.; Mileta, M.; Milimouk, I.

    2009-06-01

    Passive dew harvesting and rainwater collection requires a very small financial investment but can exploit a free, clean (outside urban/industrial zones) and inexhaustible source of water. This study investigates the relative contributions of dew and rain water in the Mediterranean Dalmatian coast and islands of Croatia, with emphasis on the dry summer season. In addition, we evaluate the utility of transforming abandoned roof rain collectors ("impluviums") to collect dew water too. Two sites were chosen, an exposed open site on the coast favourable to dew formation (Zadar) and a less favourable site in a cirque of mountains in Komiža (Vis Island). Between July 1, 2003 and October 31, 2006, dew was collected two or three times per day on a 1 m 2 inclined (30°) test dew condenser, together with standard meteorological data (air temperature and relative humidity, cloud cover, windspeed and direction). Maximum yields were 0.41 mm in Zadar and 0.6 mm in Komiža. The mean yearly cumulative dew yields were found to be 20 mm (Zadar) and 9.3 mm (Komiža). Because of its physical setting, Komiža represents a poor location for dew collection. However, during the dry season (May to October), monthly cumulative dew water yield can represent up to 38% of water collected by rainfall. In both July 2003 and 2006, dew water represented about 120% of the monthly cumulative rain water. Refurbishing the abandoned impluviums to permit dew collection could then provide useful supplementary water, especially during the dry season. As an example, the 1300 m 2 impluvium at Pod\\vspilje near Komiža could provide, in addition to rain water, 14,000 L dew water per year.

  18. The frequency and duration of dew occurrence over a year.

    NASA Astrophysics Data System (ADS)

    Janssen, L. H. J. M.; Römer, F. G.

    1991-11-01

    In this paper, a new dew model is presented which is easy to apply and requires only a very limited amount of synoptic data, viz., cloud cover, relative humidity, air temperature and wind velocity. In the dew model, the contribution of the fluxes of infrared radiation, sensible and latent heat to the energy balance of a dew plate are parametarised according to detailed micrometeorological measurements of Holtslag and De Bruin. The model is tested with measurements of dew on the glass surface of an automatic sequential dew sampler. Results of model calculations and measurements of dew occurrence show a fairly close correspondence. The frequency and duration of dew deposition over a year, for 3 places in the Netherlands, have been calculated with the model, using only synoptic data. The numbers of dewy nights and dewy hours were calculated for the year 1987. This resulted in about 220 dewy nights and 1600 dewy hours. Taking the hours of rain into account, it appears that about 75% of the time a surface is wet during the nocturnal hours because of dew or rain. This fact may be important for the quantification of the dry deposition of easily soluble air pollutants and for the effect of air pollutants on vegetation.

  19. Validation of acid washes as critical control points in hazard analysis and critical control point systems.

    PubMed

    Dormedy, E S; Brashears, M M; Cutter, C N; Burson, D E

    2000-12-01

    A 2% lactic acid wash used in a large meat-processing facility was validated as an effective critical control point (CCP) in a hazard analysis and critical control point (HACCP) plan. We examined the microbial profiles of beef carcasses before the acid wash, beef carcasses immediately after the acid wash, beef carcasses 24 h after the acid wash, beef subprimal cuts from the acid-washed carcasses, and on ground beef made from acid-washed carcasses. Total mesophilic, psychrotrophic, coliforms, generic Escherichia coli, lactic acid bacteria, pseudomonads, and acid-tolerant microorganisms were enumerated on all samples. The presence of Salmonella spp. was also determined. Acid washing significantly reduced all counts except for pseudomonads that were present at very low numbers before acid washing. All other counts continued to stay significantly lower (P < 0.05) than those on pre-acid-washed carcasses throughout all processing steps. Total bacteria, coliforms, and generic E. coli enumerated on ground beef samples were more than 1 log cycle lower than those reported in the U.S. Department of Agriculture Baseline data. This study suggests that acid washes may be effective CCPs in HACCP plans and can significantly reduce the total number of microorganisms present on the carcass and during further processing. PMID:11131890

  20. Study of dew water collection in humid tropical islands

    NASA Astrophysics Data System (ADS)

    Clus, O.; Ortega, P.; Muselli, M.; Milimouk, I.; Beysens, D.

    2008-10-01

    SummaryAn assessment of the potential for dew water to serve as a potable water source during a rainless season in a humid tropical climate was carried out in the Pacific islands of French Polynesia. The climate of these islands, in terms of diurnal and seasonal variations, wind and energy balance, is representative of the climate of the tropical Atlantic and Pacific oceans. Measurements were obtained at two characteristic sites of this region; a mountainous island (Punaauia, Tahiti Island) and an atoll (Tikehau, Tuamotu Archipelago). Dew was measured daily on a 30° tilted, 1 m 2 plane collector equipped with a thermally insulated radiative foil. In addition, an electronic balance placed at 1 m above the ground with a horizontal 0.16 m 2 condensing plate made of PolyTetraFluoroEthylene (Teflon) was used in Tahiti. Dew volume data, taken during the dry season from 16/5/2005 to 14/10/2005, were correlated with air temperature and relative humidity, wind speed, cloud cover and visible plus infrared radiometer measurements. The data were also fitted to a model. Dew formation in such a tropical climate is characterized by high absolute humidity, weak nocturnal temperature drop and strong Trade winds. These winds prevent dew from forming unless protected e.g. by natural vegetal windbreaks. In protected areas, dew can then form with winds as large as 7 m/s. Such strong winds also hamper at night the formation near the ground of a calm and cold air layer with high relative humidity. As the cooling power is lower than in the Mediterranean islands because of the high absolute humidity of the atmosphere, both effects combine to generate modest dew yields. However, dew events are frequent and provide accumulated amounts of water attractive for dew water harvesting. Slight modifications of existing rain collection devices on roofs can enhance dew formation and collection. Dew harvesting thus appears as an attractive possibility to provide the local population with a

  1. The role of dew in Negev Desert plants.

    PubMed

    Hill, Amber J; Dawson, Todd E; Shelef, Oren; Rachmilevitch, Shimon

    2015-06-01

    We investigated the possible use of dew as a water source for three desert plant species native to the Negev Desert: an annual Salsola inermis, and two perennials Artemisia sieberi and Haloxylon scoparium, with different rooting depths of 15, 30 and 90 cm, respectively. We quantified dew-water inputs and used stable isotope analyses to determine the proportion of dew as compared to the proportion of soil water each species utilized. Dew was isotopically enriched (δD values ranged from -25 to 5 ‰), relative to rainfall with δD values that ranged from -40 to -20 ‰ and relative to soil water with δD values that ranged from -65 to -35 ‰. Using a two-source isotope mixing model, we found that S. inermis, A. sieberi and H. scoparium used, on average, 56, 63 and 46 % of their water from dewfall, respectively. Our results suggest that dew-water utilization by Negev Desert plants is highly significant ecologically and thus may be more common than previously thought. In light of future predicted climate change, it may be increasingly important for plants of the Negev Desert to make use of dew as a water resource as it may play an important role in their ability to cope with the associated hydrological constraints predicted for the Negev region.

  2. Dew Point Evaporative Comfort Cooling: Report and Summary Report

    SciTech Connect

    Dean, J.; Herrmann, L.; Kozubal, E.; Geiger, J.; Eastment, M.; Slayzak, S.

    2012-11-01

    The project objective was to demonstrate the capabilities of the high-performance multi-staged IEC technology and its ability to enhance energy efficiency and interior comfort in dry climates, while substantially reducing electric-peak demand. The project was designed to test 24 cooling units in five commercial building types at Fort Carson Army Base in Colorado Springs, Colorado.

  3. Removal mechanisms of dew via self-propulsion off the gecko skin

    PubMed Central

    Watson, Gregory S.; Schwarzkopf, Lin; Cribb, Bronwen W.; Myhra, Sverre; Gellender, Marty; Watson, Jolanta A.

    2015-01-01

    Condensation resulting in the formation of water films or droplets is an unavoidable process on the cuticle or skin of many organisms. This process generally occurs under humid conditions when the temperature drops below the dew point. In this study, we have investigated dew conditions on the skin of the gecko Lucasium steindachneri. When condensation occurs, we show that small dew drops, as opposed to a thin film, form on the lizard's scales. As the droplets grow in size and merge, they can undergo self-propulsion off the skin and in the process can be carried away a sufficient distance to freely engage with external forces. We show that factors such as gravity, wind and fog provide mechanisms to remove these small droplets off the gecko skin surface. The formation of small droplets and subsequent removal from the skin may aid in reducing microbial contact (e.g. bacteria, fungi) and limit conducive growth conditions under humid environments. As well as providing an inhospitable microclimate for microorganisms, the formation and removal of small droplets may also potentially aid in other areas such as reduction and cleaning of some surface contaminants consisting of single or multiple aggregates of particles. PMID:25762647

  4. Removal mechanisms of dew via self-propulsion off the gecko skin.

    PubMed

    Watson, Gregory S; Schwarzkopf, Lin; Cribb, Bronwen W; Myhra, Sverre; Gellender, Marty; Watson, Jolanta A

    2015-04-01

    Condensation resulting in the formation of water films or droplets is an unavoidable process on the cuticle or skin of many organisms. This process generally occurs under humid conditions when the temperature drops below the dew point. In this study, we have investigated dew conditions on the skin of the gecko Lucasium steindachneri. When condensation occurs, we show that small dew drops, as opposed to a thin film, form on the lizard's scales. As the droplets grow in size and merge, they can undergo self-propulsion off the skin and in the process can be carried away a sufficient distance to freely engage with external forces. We show that factors such as gravity, wind and fog provide mechanisms to remove these small droplets off the gecko skin surface. The formation of small droplets and subsequent removal from the skin may aid in reducing microbial contact (e.g. bacteria, fungi) and limit conducive growth conditions under humid environments. As well as providing an inhospitable microclimate for microorganisms, the formation and removal of small droplets may also potentially aid in other areas such as reduction and cleaning of some surface contaminants consisting of single or multiple aggregates of particles.

  5. Partitioning the relative contribution of dew and fog to total occult precipitation across a decreasing fog inundation gradient in the Pajaro Valley, CA

    NASA Astrophysics Data System (ADS)

    Farlin, J. P.; Paw U, K. T.

    2015-12-01

    Traditionally, occult precipitation has been difficult to measure, especially given that it can take two predominant forms: fogs and dews. Recent studies have shown that estimates of fog deposition can be made using constructed fog collectors of various styles. Leaf-wetness sensors have also been deployed to try and estimate the relative wetness of leaves during fog events, but coastal systems can integrate both fog deposition and dew condensation, which cannot be differentiated with such sensors alone. We measured fog interception with Decagon Leaf Wetness Sensors (LWSs) outfitted with a 1m2 mesh passive fog collector in areas adjacent to the California Irrigation Management Information System (CIMIS) sites in the Pajaro Valley. The LWSs that were deployed were covered with a partial shield or left uncovered. Covering the LWS creates a microclimate that allows discrimination between fog events that horizontally advect droplets that impact individual leaves, and dew events, which condense once dew point temperature is reached. By measuring fog with a standard measurement device (mesh fog collector), and comparing it to LWSs that have either fog exposure or fog exclusion (covered LWSs), we can partition the relative contribution of dew to overall occult precipitation. This would be the first study quantifying the amount of water inputs (horizontally advecting fog) to the amount of recycled water (dew) to gain a greater understanding of the role of occult precipitation in catchment water balances across coastal California.

  6. Dew formation characteristics in a revegetation-stabilized desert ecosystem in Shapotou area, Northern China

    NASA Astrophysics Data System (ADS)

    Pan, Yan-xia; Wang, Xin-ping; Zhang, Ya-feng

    2010-06-01

    SummarySoil moisture in the upper layer plays an important role in arid desert ecosystems. Dew as an additional source of fresh water, may have a positive impact upon the ecosystems in arid and semi-arid zones. Measurements on dew formation amount and duration were carried out in the whole October of 2008 at different condensing surface types (bare dune sands, physical soil crusts and biological soil crusts) associated with different inter-space positions between plants, and at the area under plant canopy in a revegetation-stabilized arid desert ecosystem in Shapotou area, China. The results indicated that there was a positive linear correlation between dew amounts and relative humidity, while mean temperature was negatively linearly related to dew amounts and no significant relationship was found between dew amounts and wind speed. Clear and foggy mornings were characterized by higher dew amounts and longer dew duration, whereas less dew was recorded during cloudy and especially windy mornings. Crusts, especially the biological soil crusts, obtained significantly higher amounts of dew than that of bare moving sand dunes. It was more difficult for dew to condense under the canopy of the plants than on the bare sand dunes. At the first stage of ecological engineering projects, dew can renew the moisture losing through the evaporation of soil and transpiration of leaves, and thus can supply important source of water for xerophytic shrubs. The higher dew amount at the inter-space of re-vegetated plants is an important driving factor for the growth of microorganisms and spore plants, which further accelerate the formation of biological soil crusts and stabilization of moving sand dunes. The presence of biological soil crusts, in turn, helps to facilitate the formation of dew. Therefore, a mutual enhanced effect exists between dew and artificially revegetation ecosystems.

  7. The influence of biological soil crusts on dew deposition in Gurbantunggut Desert, Northwestern China

    NASA Astrophysics Data System (ADS)

    Zhang, Jing; Zhang, Yuan-ming; Downing, Alison; Cheng, Jun-hui; Zhou, Xiao-bing; Zhang, Bing-chang

    2009-12-01

    SummaryDew is an important source of moisture for plants, biological soil crusts, invertebrates and small vertebrates in desert environments. In this paper, measurements were taken to investigate the effects of three different types of biological soil crusts (cyanobacteria, lichen and moss) and bare sand on dew deposition in the Gurbantunggut Desert. Dew quantities were measured using micro-lysimeters with a diameter of 6 cm and a height of 3.5 cm. The results showed that the total amount of dew deposited increased with the development of soil crusts, from bare sand to cyanobacterial crust to lichen crust to moss crust. The average amount of dew deposited daily on the moss crust was the highest of all and it was significant higher than the other three soil surfaces (lichen crust, cyanobacterial crust and bare sand) ( p < 0.05). During the period of the study, for each type of crust studied, the maximum amount of dew recorded was several times greater than the minimum. Moss crust was characterized by having the greatest amount of dew at dawn and also the maximum amount of dew deposited, whereas bare sand yielded the lowest amount of dew, with lichen crust and cyanobacterial crust exhibiting intermediate values. However, this was not the case for dew duration, as bare sand retained moisture for the longest period of time, followed by cyanobacterial crust, moss crust and finally lichen crust. Dew continued to condense even after sunrise. Furthermore, the differences in dew deposition may be partially attributed to an effect of the biological soil crusts on surface area. This study demonstrates the important effect of biological soil crusts upon dew deposition and may assist in evaluating the role of dew in arid and semi-arid environments.

  8. Fog, cloud, and dew chemistry. Final report

    SciTech Connect

    Hoffmann, M.R.

    1989-02-28

    The spatial and temporal variations of fog/cloud chemistry were determined in the San Joaquin Valley, in the Los Angeles Basin, and in the Santa Barbara Channel area using automated fog- and cloudwater collectors that were designed and constructed for the project. A significant correlation was observed between the average nighttime cloud- and fogwater loadings of H/sup +/ and NO/sub 3//sup /minus// and the maximum levels of O/sub 3//sup /minus//. Higher aldehydes, a series of dicarbonyls, and a variety of sulfonic acid salts formed by reaction of S(IV) and aldehydes were quantitatively determined in the droplet phase.

  9. Dew, fog, drizzle and rain water in Baku (Azerbaijan)

    NASA Astrophysics Data System (ADS)

    Meunier, D.; Beysens, D.

    2016-09-01

    Dwindling supplies of fresh water and climate changes have drawn attention to the need to find alternative sources of water globally. This study examines the potential of the semi-arid region of Baku (Azerbaijan) to exploit in particular dew, but also fog, drizzle and rain water. The Absheron Peninsular suffers from scarceness of water and non-hazardous water sources. Measurements were taken in this region on a 30° inclined plane passive condenser over a year (1/4/2010-31/3/2011) to determine the contribution and validity of using these alternative sources of water. The results show a significant relative contribution from these sources during this period (rain: 84 mm; dew: 15 mm; fog: 6 mm; drizzle: 13 mm). The fact that rain was measured within 23 km from the main station leads to uncertainties in its relative contribution. However, at least for the year under study, there are fair indications that collecting dew, fog and drizzle in addition to rain can significantly increase the collected atmospheric water with value estimated on order 40% ± 20%.

  10. Dew chemistry near a motorway in SW Poland

    NASA Astrophysics Data System (ADS)

    Gałek, G.; Sobik, M.; Polkowska, Ż.; Błaś, M.

    2010-07-01

    The main goal of this project is to show the influence of a large linear source of air pollution on dew formation and chemistry. Dew sampling was performed during the growing season of 2009 at 3 sites near Wroclaw in SW Poland in the vicinity of A4 motorway which connects southern part of Poland with Germany and other EU countries. The road crosses in this part a rural landscape from WSW to ENE direction. The traffic is notoriously heavy, even at night, and lorries constitute about one third of vehicles. Two of the sampling sites were set in a distance of 30 meters from the motorway edge on the opposite sides (SE and NW) of the road to monitor dew efficiency and chemistry depending on wind direction. The third one was set 1.25 km to the NNW of the former pair to represent background rural conditions beyond the road influence. All three sites and the motorway are surrounded by vast arable grounds with intense agriculture activity. Three insulated plane radiative condensers, each 1 m2 in area, inclined at 15°, were installed at measurement sites. Two series of measurements were performed: the first in April lasted twenty days including several days without sampling, the second in September was continuous and lasted eleven days. Altogether there were nineteen dew or hoar frost sampling days, nine in April and ten in September. Basic meteorological data were gathered three times daily. Water yield of three condensers was compared to meteorological data and between each other. The research findings show that the most favorable weather conditions corresponding to high amounts of dew or hoar frost were characterized by synoptic scale warm air advection, high relative humidity, moderate wind speed i.e. 2-3 m/s and radiative weather. The samples from condenser located in calm air site usually had less volume than the other in windy place. The motorway heat source imposed a strong impact on efficiency of dew. The condenser on the leeward site of the road was characterized

  11. A Study on Amino Acids: Synthesis of Alpha-Aminophenylacetic Acid (Phenylglycine) and Determination of its Isoelectric Point.

    ERIC Educational Resources Information Center

    Barrelle, M.; And Others

    1983-01-01

    Background information and procedures are provided for an experimental study on aminophenylacetic acid (phenylglycine). These include physical chemistry (determination of isoelectric point by pH measurement) and organic chemistry (synthesis of an amino acid in racemic form) experiments. (JN)

  12. Dew as an Adaptation Measure to Meet Agricultural and Reforestation Water Demand in a Changing Climate

    NASA Astrophysics Data System (ADS)

    Tomaszkiewicz, Marlene; Abou Najm, Majdi; Alameddine, Ibrahim; El Fadel, Mutasem

    2014-05-01

    Dew harvesting, believed to be an ancient technique, has recently re-emerged as a viable and sustainable water resource. Nightly yields are relatively low, yet non-negligible, and dew events occur more frequently than rainfall promoting its effectiveness, particularly in arid and semi-arid regions. In this study, we demonstrate how dew can be harvested and subsequently used for small-scale irrigation to meet agricultural and reforestation water demand. Polyethylene dew harvesting systems were constructed and placed in the field. Dew was harvested as a result of the radiative cooling during the night, thus allowing dew formation under conditions of high humidity. Condensed dew formed upon the planar surface was collected by gravity. Water demand for selected crops and trees within a pilot study area (Lebanon) was estimated using a deficit irrigation model. Simulations of water demand requirements of various plants and surfaces were performed and compared to dew volumes to assess the ability of the system to meet all or in part the plant water demands across seasons. Data from the polyethylene low-cost dew condensers have shown that within the pilot study, average nightly dew yields were 0.1 L m-2 of condensing surface with a maximum yield of 0.4 L m-2. Dew events occurred generally more frequently than precipitation events, with an estimated 40% of nights producing dew condensate. This translates to 50 mm of equivalent rainfall on average (during dew nights), with a maximum of 200 mm in one night, if one assumes using drip irrigation over a seedling within a 20 cm2 area. Using a simple deficit irrigation model, it was demonstrated that crops such as the tomato plant, which typically has a growing season during the dry summer, can potentially be irrigated solely by dew, thus eliminating the need for traditional irrigation sources. Similarly, young tree seedlings, such as the cedar tree, can depend upon dew as a primary water resource. Moreover, based on similar

  13. Hydrogen peroxide deposition and decomposition in rain and dew waters

    NASA Astrophysics Data System (ADS)

    Ortiz, Vicky; Angélica Rubio, M.; Lissi, Eduardo A.

    Peroxides and hydrogen peroxide were determined by a fluorometric method in dew and rain collected in the atmosphere of Santiago of Chile city. The measured peroxides comprise hydrogen peroxide (the main component) and peroxides not decomposed by catalase. The collected natural peroxides readily decompose in the natural matrix, rendering difficult an estimation of the values present in real-time. In order to establish the kinetics of the process and the factors that condition their decomposition, the kinetics of the decay at several pHs and/or the presence of metal chelators were followed. The kinetics of hydrogen peroxide decomposition in the water matrix was evaluated employing the natural peroxides or hydrogen peroxide externally added. First-order kinetics was followed, with half decay times ranging from 80 to 2300 min. The addition of Fe(II) in the micromolar range increases the decomposition rate, while lowering the pH (<3) notably reduces the rate of the process. The contribution of metals to the decomposition of the peroxides in the natural waters was confirmed by the reduction in decomposition rate elicited by its treatment with Chelex-100. Dew and rain waters were collected in pre-acidified collectors, rendering values considerably higher than those measured in non-treated collectors. This indicates that acidification can be proposed as an easy procedure to stabilize the samples, reducing its decomposition during collection time and the time elapsed between collection and analysis. The weighted average concentration for total peroxides measured in pre-treated collectors was 5.4 μM in rains and 2.2 μM in dews.

  14. Projected climate change impacts upon dew yield in the Mediterranean basin.

    PubMed

    Tomaszkiewicz, M; Abou Najm, M; Beysens, D; Alameddine, I; Bou Zeid, E; El-Fadel, M

    2016-10-01

    Water scarcity is increasingly raising the need for non-conventional water resources, particularly in arid and semi-arid regions. In this context, atmospheric moisture can potentially be harvested in the form of dew, which is commonly disregarded from the water budget, although its impact may be significant when compared to rainfall during the dry season. In this study, a dew atlas for the Mediterranean region is presented illustrating dew yields using the yield data collected for the 2013 dry season. The results indicate that cumulative monthly dew yield in the region can exceed 2.8mm at the end of the dry season and 1.5mm during the driest months, compared to <1mm of rainfall during the same period in some areas. Dew yields were compared with potential evapotranspiration (PET) and actual evapotranspiration (ET) during summer months thus highlighting the role of dew to many native plants in the region. Furthermore, forecasted trends in temperature and relative humidity were used to estimate dew yields under future climatic scenarios. The results showed a 27% decline in dew yield during the critical summer months at the end of the century (2080).

  15. An Investigation of Implementing Drop Everything and Write (DEW) in Early Childhood/Elementary Classrooms

    ERIC Educational Resources Information Center

    Paquette, Kelli R.; Byrd, Charlene M.; Dragich, Denise

    2013-01-01

    This mixed-methods research study investigated the implementation of Drop Everything and Write (DEW) in early childhood/elementary classrooms. DEW is an activity in which students simply "drop everything and write." Teachers were interviewed at the completion of the school year about how they implemented the program, their perceived…

  16. Projected climate change impacts upon dew yield in the Mediterranean basin.

    PubMed

    Tomaszkiewicz, M; Abou Najm, M; Beysens, D; Alameddine, I; Bou Zeid, E; El-Fadel, M

    2016-10-01

    Water scarcity is increasingly raising the need for non-conventional water resources, particularly in arid and semi-arid regions. In this context, atmospheric moisture can potentially be harvested in the form of dew, which is commonly disregarded from the water budget, although its impact may be significant when compared to rainfall during the dry season. In this study, a dew atlas for the Mediterranean region is presented illustrating dew yields using the yield data collected for the 2013 dry season. The results indicate that cumulative monthly dew yield in the region can exceed 2.8mm at the end of the dry season and 1.5mm during the driest months, compared to <1mm of rainfall during the same period in some areas. Dew yields were compared with potential evapotranspiration (PET) and actual evapotranspiration (ET) during summer months thus highlighting the role of dew to many native plants in the region. Furthermore, forecasted trends in temperature and relative humidity were used to estimate dew yields under future climatic scenarios. The results showed a 27% decline in dew yield during the critical summer months at the end of the century (2080). PMID:27266520

  17. What Is the Boiling Point and Heat of Vaporization of Sulfuric Acid?

    ERIC Educational Resources Information Center

    Myers, R. Thomas

    1983-01-01

    Discusses the values presented in various handbooks for the boiling point and heat of vaporization of sulfuric acid, noting discrepencies. Analyzes various approaches to data presentation, discussing the data on sulfuric acid in light of the Trouton constant. Points out the need for a more critical use of tables. (JM)

  18. Dew measurements along a longitudinal sand dune transect, Negev Desert, Israel

    NASA Astrophysics Data System (ADS)

    Jacobs, A. F. G.; Heusinkveld, B. G.; Berkowicz, S. M.

    In a desert environment dew can serve as an important source of moisture for plants, biological crusts, insects and small animals. A measurement programme was carried out within a sand dune belt situated in the northwestern Negev desert, Israel, to measure daily amounts of dew deposition as well as micro-meteorological conditions during the dew formation and early-morning drying process. Dew quantities were measured by micro-lysimeters along a 200-m transect as well as by the eddy-correlation technique at a reference location. A simple physical model was constructed to simulate the dew deposition process as well as early-morning drying for the interdune area and the north- and south-facing dune slopes. Measurements carried out during September and October 1997 showed that the daily amounts of dew ranged between 0.1 mm/night and 0.3 mm/night within the interdune area. On the slopes, the amounts of dew were about 50% lower. Simulated results agreed well with the field data.

  19. Dew measurements along a longitudinal sand dune transect, Negev Desert, Israel.

    PubMed

    Jacobs, A F; Heusinkveld, B G; Berkowicz, S M

    2000-03-01

    In a desert environment dew can serve as an important source of moisture for plants, biological crusts, insects and small animals. A measurement programme was carried out within a sand dune belt situated in the northwestern Negev desert, Israel, to measure daily amounts of dew deposition as well as micro-meteorological conditions during the dew formation and early-morning drying process. Dew quantities were measured by micro-lysimeters along a 200-m transect as well as by the eddy-correlation technique at a reference location. A simple physical model was constructed to simulate the dew deposition process as well as early-morning drying for the interdune area and the north- and south-facing dune slopes. Measurements carried out during September and October 1997 showed that the daily amounts of dew ranged between 0.1 mm/night and 0.3 mm/night within the interdune area. On the slopes, the amounts of dew were about 50% lower. Simulated results agreed well with the field data. PMID:10789921

  20. Development of 3D control of a tiny dew droplet by scattered laser light

    NASA Astrophysics Data System (ADS)

    Matsumoto, Shigeaki

    2009-06-01

    In order to study dropwise condensation on a metal plate, the method for controlling a tiny dew droplet deposited on a copper plate has been developed by using scattered laser light. The method employed the proportional control combined with shifting movement by an integrator to control the intensity of the scattered laser light constantly. Also, the control simulation of the method has been developed to confirm the usefulness of the method and the simulated three-dimensional shape of controlled dew droplet was obtained with the control action. A tiny thin dew droplet, of which the diameter was of handreds micrometers and the mass was about 10-7 g, was controlled in the atmosphere at room temperature for 60 minutes at the preset level of the intensity of scattered laser light and the three-dimensional shape of the controlled dew droplet was shown from the interference fringes.

  1. Dew and hoarfrost frequency, formation efficiency and chemistry in Wroclaw, Poland

    NASA Astrophysics Data System (ADS)

    Gałek, G.; Sobik, M.; Błaś, M.; Polkowska, Ż.; Cichała-Kamrowska, K.; Wałaszek, K.

    2015-01-01

    This article presents the results of a research study concerning a comparison of frequency, formation efficiency and basic physico-chemical properties of dew and hoarfrost in urban conditions. Longer than two-year series of measurements was carried out from 1 February 2008 to 10 March 2010 in Wroclaw, Poland. Sampling of atmospheric deposits was made by means of insulated plain passive radiative condensers, which allowed to collect 222 dew and 96 hoarfrost samples. The results indicate that the frequency of dew days was about threefold greater than hoarfrost days. The formation efficiency of both types of deposits was almost the same, and reached a mean value of about 100 mL·m- 2 per day. The conducted analysis of several meteorological parameters showed that dew and hoarfrost, despite seasonal weather changes, were formed in very similar meteorological conditions. Only water vapor pressure values were in average twice higher in the case of dew and the impact of this parameter on dew and hoarfrost formation efficiency seems to be more complex than expected. The role of night duration in counterbalancing of smaller amount of available moisture in hoarfrost days is not clear. The investigation showed also, that there was an expected clear positive dependence of dew and hoarfrost formation efficiency on relative humidity, and not so evident in the case of temperature inversion, and wind velocity. The physico-chemical analysis indicated that the pH of dew was only slightly lower than the hoarfrost ones, regardless of the deposit formation intensity. Simultaneously, the lower pH values were much more frequent in the case of dew, which resulted from more effective absorption of anthropogenic NO3- and SO42 - ions. For both types of deposits, the average pH was low (4.5-4.8) in relation to majority of studies reported in literature. In spite of seasonal changes of pollutant concentration, various weather conditions and different mechanisms of pollutant absorption of dew

  2. Angle and aspect dependent dew and fog precipitation in the Negev desert

    NASA Astrophysics Data System (ADS)

    Kidron, Giora J.

    2005-01-01

    Knowledge regarding dew and fog precipitation in relation to angle and aspect may be of great importance to plant photosynthesis and to rock dwelling microorganisms, especially in arid land where water is highly limited. Measurements of dew and fog were carried out periodically during the fall of two years (1989, 1992) at a hilltop in the Negev Desert Highlands, Israel. Measurements were carried out using velvet-like cloths (6×6×0.15 cm) attached to the center of different angle sides of 5 pairs of wooden boxes (50×50×10 cm) and to the top of an additional pair (10×10×5 cm) that served as a control (horizontal surface). The sides of each pair of boxes had angles of 30, 45, 60, 75 and 90° facing north, east, south and west. Whereas fog showed an advective pattern of precipitation, with windward aspects receiving higher amounts, that was not the case with dew. When the dew values received in the different aspects within each angle were grouped together, surfaces at 30, 45, 60, 75 and 90° received 99.8 (SE±11.9), 78.2 (SE±17.9), 42.0 (SE±18.3), 33.8 (SE±10.8), and 25.6 (SE±9.7) percent of the amounts condensed on the horizontal surface, respectively. A positive linear relationship characterized the dew amounts with cos ( θ). The data also showed an increase in dew duration with west>north>south>east. The data thus imply that aspect and angle may play an important role in controlling dew and fog availability.

  3. Chromatographic profile of high boiling point organic acids in human urine.

    PubMed

    Brown, G K; Stokke, O; Jellum, E

    1978-03-01

    The profile of high boiling point organic acids in urine samples from both normal subjects and patients suspected of having some form of metabolic disorder has been determined by combined gas chromatography-mass spectrometry. Fifteen different compounds eluting after hippuric acid have been identified, including two, cinnamoylglycine and acetyltributylcitrate, which have not been recognised previously. Relative retention times and abbreviated mass spectra of the identified compounds are presented.

  4. Critical point analysis of phase envelope diagram

    SciTech Connect

    Soetikno, Darmadi; Siagian, Ucok W. R.; Kusdiantara, Rudy Puspita, Dila Sidarto, Kuntjoro A. Soewono, Edy; Gunawan, Agus Y.

    2014-03-24

    Phase diagram or phase envelope is a relation between temperature and pressure that shows the condition of equilibria between the different phases of chemical compounds, mixture of compounds, and solutions. Phase diagram is an important issue in chemical thermodynamics and hydrocarbon reservoir. It is very useful for process simulation, hydrocarbon reactor design, and petroleum engineering studies. It is constructed from the bubble line, dew line, and critical point. Bubble line and dew line are composed of bubble points and dew points, respectively. Bubble point is the first point at which the gas is formed when a liquid is heated. Meanwhile, dew point is the first point where the liquid is formed when the gas is cooled. Critical point is the point where all of the properties of gases and liquids are equal, such as temperature, pressure, amount of substance, and others. Critical point is very useful in fuel processing and dissolution of certain chemicals. Here in this paper, we will show the critical point analytically. Then, it will be compared with numerical calculations of Peng-Robinson equation by using Newton-Raphson method. As case studies, several hydrocarbon mixtures are simulated using by Matlab.

  5. Critical point analysis of phase envelope diagram

    NASA Astrophysics Data System (ADS)

    Soetikno, Darmadi; Kusdiantara, Rudy; Puspita, Dila; Sidarto, Kuntjoro A.; Siagian, Ucok W. R.; Soewono, Edy; Gunawan, Agus Y.

    2014-03-01

    Phase diagram or phase envelope is a relation between temperature and pressure that shows the condition of equilibria between the different phases of chemical compounds, mixture of compounds, and solutions. Phase diagram is an important issue in chemical thermodynamics and hydrocarbon reservoir. It is very useful for process simulation, hydrocarbon reactor design, and petroleum engineering studies. It is constructed from the bubble line, dew line, and critical point. Bubble line and dew line are composed of bubble points and dew points, respectively. Bubble point is the first point at which the gas is formed when a liquid is heated. Meanwhile, dew point is the first point where the liquid is formed when the gas is cooled. Critical point is the point where all of the properties of gases and liquids are equal, such as temperature, pressure, amount of substance, and others. Critical point is very useful in fuel processing and dissolution of certain chemicals. Here in this paper, we will show the critical point analytically. Then, it will be compared with numerical calculations of Peng-Robinson equation by using Newton-Raphson method. As case studies, several hydrocarbon mixtures are simulated using by Matlab.

  6. Chemical Characterization of Dew Water Collected in Different Geographic Regions of Poland

    PubMed Central

    Polkowska, Żaneta; Błaś, Marek; Klimaszewska, Kamila; Sobik, Mieczysław; Małek, Stanisław; Namieśnik, Jacek

    2008-01-01

    The results of a dew monitoring program performed in Poland with the aim to outline the chemical composition of dew water in meteorological context are presented. Dew samples were collected from eight measurement stations from August 2004 to November 2006. Taking into account the type of land use and characteristics of pollutant emission, sampling sites were divided into the following categories: rural, coastal urban and inland urban stations. Selected anions and cations as well as formaldehyde and sum of phenols were determined. The average TIC (Total Inorganic Ionic Content) values in dew samples ranged from 0.83 to 3.93 between individual stations with 10.9 meq/L as the highest daily value of TIC measured. The average TIC values observed in dew at all stations were at a similar level (2.46 meq/L) when compared with hoarfrost (2.86 meq/L). However, these values were much higher in comparison with other kinds of atmospheric water like precipitation (wet only; 0.37 meq/L) or fog/cloud (1.01 meq/L). The pH values of dew water ranged from 5.22 to 7.35 for urban coastal stations, from 5.67 to 8.02 for urban inland stations and from 4.16 to 8.76 for dew samples collected in the rural area. HCHO was found in 97 % of dew samples, with concentrations ranging from 0.010 to 5.40 meq/L. Excluding stations near the seashore, where the contribution of Na+ and Cl- increased, the most important ions were sulphates. A very low contribution of NO3- and noticeable increase of Ca2+ which were not observed in the case of precipitation and fog water, were typical in all stations. The contribution of ammonium ion was two times higher at rural stations as a result of agricultural ammonia emissions. The strongest correlations were noticed between the sum of acidifying anions SO42- + NO3- and Ca2+ ion for all urban and rural stations. A very strong correlation was also observed for Na+ and Cl- ions in urban coastal stations, as a natural consequence of the location of these stations close

  7. Isoelectric Point, Electric Charge, and Nomenclature of the Acid-Base Residues of Proteins

    ERIC Educational Resources Information Center

    Maldonado, Andres A.; Ribeiro, Joao M.; Sillero, Antonio

    2010-01-01

    The main object of this work is to present the pedagogical usefulness of the theoretical methods, developed in this laboratory, for the determination of the isoelectric point (pI) and the net electric charge of proteins together with some comments on the naming of the acid-base residues of proteins. (Contains 8 figures and 4 tables.)

  8. Effect of Finishing System on Subcutaneous Fat Melting Point and Fatty Acid Composition

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Angus-cross steers (n = 69) were used to determine the effect of finishing system on subcutaneous fat melting point and fatty acid composition. Three finishing systems were evaluated: 1) mixed pasture for 134 d [MP], 2) mixed pasture for 93 d and alfalfa for 41 d [AL], or 3) concentrate finishing f...

  9. Point mutation of H3/H4 histones affects acetic acid tolerance in Saccharomyces cerevisiae.

    PubMed

    Liu, Xiangyong; Zhang, Xiaohua; Zhang, Zhaojie

    2014-10-10

    The molecular mechanism of acetic acid tolerance in yeast remains unclear despite of its importance for efficient cellulosic ethanol production. In this study, we examined the effects of histone H3/H4 point mutations on yeast acetic acid tolerance by comprehensively screening a histone H3/H4 mutant library. A total of 24 histone H3/H4 mutants (six acetic acid resistant and 18 sensitive) were identified. Compared to the wild-type strain, the histone acetic acid-resistant mutants exhibited improved ethanol fermentation performance under acetic acid stress. Genome-wide transcriptome analysis revealed that changes in the gene expression in the acetic acid-resistant mutants H3 K37A and H4 K16Q were mainly related to energy production, antioxidative stress. Our results provide novel insights into yeast acetic acid tolerance on the basis of histone, and suggest a novel approach to improve ethanol production by altering the histone H3/H4 sequences.

  10. Behavioral Determinants of Drug Action: The Contributions of Peter B. Dews

    ERIC Educational Resources Information Center

    Barrett, James E.

    2006-01-01

    Peter B. Dews played a significant role in shaping the distinctive characteristics and defining the underlying principles of the discipline of behavioral pharmacology. His early and sophisticated use of schedules of reinforcement in the 1950s, incorporated from research in the experimental analysis of behavior and integrated into the discipline of…

  11. Hierarchical structures of cactus spines that aid in the directional movement of dew droplets.

    PubMed

    Malik, F T; Clement, R M; Gethin, D T; Kiernan, M; Goral, T; Griffiths, P; Beynon, D; Parker, A R

    2016-08-01

    Three species of cactus whose spines act as dew harvesters were chosen for this study: Copiapoa cinerea var. haseltoniana, Mammillaria columbiana subsp. yucatanensis and Parodia mammulosa and compared with Ferocactus wislizenii whose spines do not perform as dew harvesters. Time-lapse snapshots of C. cinerea showed movement of dew droplets from spine tips to their base, even against gravity. Spines emanating from one of the areoles of C. cinerea were submerged in water laced with fluorescent nanoparticles and this particular areole with its spines and a small area of stem was removed and imaged. These images clearly showed that fluorescent water had moved into the stem of the plant. Lines of vascular bundles radiating inwards from the surface areoles (from where the spines emanate) to the core of the stem were detected using magnetic resonance imaging, with the exception of F. wislizenii that does not harvest dew on its spines. Spine microstructures were examined using SEM images and surface roughness measurements (Ra and Rz) taken of the spines of C. cinerea It was found that a roughness gradient created by tapered microgrooves existed that could potentially direct surface water from a spine tip to its base.This article is part of the themed issue 'Bioinspired hierarchically structured surfaces for green science'.

  12. Hierarchical structures of cactus spines that aid in the directional movement of dew droplets.

    PubMed

    Malik, F T; Clement, R M; Gethin, D T; Kiernan, M; Goral, T; Griffiths, P; Beynon, D; Parker, A R

    2016-08-01

    Three species of cactus whose spines act as dew harvesters were chosen for this study: Copiapoa cinerea var. haseltoniana, Mammillaria columbiana subsp. yucatanensis and Parodia mammulosa and compared with Ferocactus wislizenii whose spines do not perform as dew harvesters. Time-lapse snapshots of C. cinerea showed movement of dew droplets from spine tips to their base, even against gravity. Spines emanating from one of the areoles of C. cinerea were submerged in water laced with fluorescent nanoparticles and this particular areole with its spines and a small area of stem was removed and imaged. These images clearly showed that fluorescent water had moved into the stem of the plant. Lines of vascular bundles radiating inwards from the surface areoles (from where the spines emanate) to the core of the stem were detected using magnetic resonance imaging, with the exception of F. wislizenii that does not harvest dew on its spines. Spine microstructures were examined using SEM images and surface roughness measurements (Ra and Rz) taken of the spines of C. cinerea It was found that a roughness gradient created by tapered microgrooves existed that could potentially direct surface water from a spine tip to its base.This article is part of the themed issue 'Bioinspired hierarchically structured surfaces for green science'. PMID:27354735

  13. A very large dew and rain ridge collector in the Kutch area (Gujarat, India)

    NASA Astrophysics Data System (ADS)

    Sharan, G.; Clus, O.; Singh, S.; Muselli, M.; Beysens, D.

    2011-07-01

    SummaryThe world's largest dew and rain collecting system, comprised of ridge-and-trough modules, was constructed in March 2006 at Panandhro in the semi-arid area of Kutch (NW India). The main goals were (i) to collect dew on a scale that could be beneficial to the local population (ii) to determine the efficiency of this new module shape, (iii) to determine whether results obtained from small measurement condensers can be projected to large condensers, (iv) to apply a computational fluid dynamic simulation to improve the condenser set-up. Preliminary studies performed with four standard plane condensers of 1 m 2 surface area, inclined 30° from horizontal, identified Panandhro as a promising site. The cumulated dew water during 192 days was 12.6 mm with a maximum of 0.556 mm/night. A large dew condenser (850 m 2 net total surface) was designed with 10 ridge-and-trough modules. The ridges are trapezoidal, 33 m long, 0.5 m wide at the top, 2.2 m wide at the base and sloping 30° from horizontal. The depth of the troughs between the ridges is 0.5 m. A 2.5 cm thick polystyrene foam rests on the surface as insulation with a radiative foil on top (similar to that developed by OPUR, see www.opur.fr). Numerical simulations using the computational fluid dynamic software PHOENICS were performed. The most profitable orientation was with the condenser oriented back to the wind direction, a configuration that lowers the wind velocity near the foil due to the combination of free convection and wind recirculation flows. A comparison of water yields over one year of measurements between four 1 m 2 plane condensers and a 850 m 2 ridge condenser showed a 42% lower yield on the large condenser. The difference is attributed mainly to folds in the plastic foil allowing water to fill the central ridge, thus decreasing radiative cooling. The output for 2007 was 6545 L, corresponding to 7.7 mm/day on average. The largest event was 251.4 L/night (0.3 mm). Such a condenser can also collect

  14. Large Dew water collectors in a village of S-Morocco (Idouasskssou)

    NASA Astrophysics Data System (ADS)

    Lekouch, I.; Clus, O.; Durand, M.; Lanfourmi, M.; Muselli, M.; Milimouk, I.; Beysens, D.

    2010-07-01

    With precipitations close to 227 mm/year in average, the coastal region of south Morocco presents a chronically shortage of drinkable and fresh water. Since 1994, in the Mirleft area (150 km south of Agadir), inhabitants are facing a critically drought event. In the year 2007, only 49 mm of rain was recorded. However, measurements in Mirleft in the same year, showed that the dew yield was on order of 40 % of rain fall. In order to show to the local population the interest of recovering dew water in addition to rain water, a small nearby village (Idouasskssou, 8 km SE of Mirleft) was equipped with three pilot condensers of 136 m2 total surface area. In order to ensure a good integration of the project by the village inhabitants, a local organization (Association IMRJANE) collaborated to the project. A concrete tank at ground level with a flat horizontal surface, easily accessible for inhabitants and also a model for traditional Morocco terrace roofings, has been equipped with two lines of condensers (40.6 m²). All roofing materials were from local shops. Only the special radiative and hydrophilic coating was coming from non local resources (see www.opur.fr). The top of a second tank (aside the first one) was renovated and covered with a 21.2 m² two slopes steel roof, insulated and painted with the special dew coating as above. These roofs represent a condensation surface comparable to that of a very little house. A third condenser, with 73.8 m² surface area, was implemented directly on the ground, ensuring minimal work and very cheap implementation costs. Dew was collected and measured in one of the concrete tanks. The water production during 6 months, from 15-12-2008 to 31-07-2009 (137 dew events, 47 % of days) was more than 3800 L (more than 0.2 mm/dew day). It is important to note that, while the devices are specifically designed to condense dew water, they also harvest rain and fog as well, thus providing to the population a valuable water resource.

  15. Chemisorptive enantioselectivity of chiral epoxides on tartaric-acid modified Pd(111): three-point bonding.

    PubMed

    Mahapatra, Mausumi; Tysoe, Wilfred T

    2015-02-21

    The chemisorption of two chiral molecules, propylene oxide and glycidol, is studied on tartaric-acid modified Pd(111) surfaces by using temperature-programmed desorption to measure adsorbate coverage. It is found that R-glycidol shows preferential enantioselective chemisorption on (S,S)-tartaric acid modified Pd(111) surfaces, while propylene oxide does not adsorb enantioselectively. The enantioselectivity of glycidol depends on the tartaric acid coverage, and is exhibited for low tartaric acid coverages indicating that the bitartrate phase is responsible for the chiral recognition. The lack of enantioselectivity when using propylene oxide as a chiral probe implies that the enantiospecific interaction between glycidol and bitartate species is due to hydrogen-bonding interactions of the -OH group of glycidol. Scanning tunneling microscopy images were collected for tartaric acid adsorbed on Pd(111) under the same experimental conditions as used for enantioselective experiments. When tartaric acid is dosed at room temperature and immediately cooled to 100 K for imaging, individual bitartrate molecules were found. Density functional theory (DFT) calculations show that bitartrate binds to Pd(111) through its carboxylate groups and the -OH groups are oriented along the long axis of the bitartrate molecule. An enantiospecific interaction is found between glycidol and bitartate species where R-glycidol binds more strongly than S-glycidol to (S,S)-bitartate species by simultaneously forming hydrogen bonds with both the hydroxyl and carboxylate groups, thereby providing three-point bonding.

  16. Satellite remote sensing and cloud modeling of St. Anthony, Minnesota storm clouds and dew point depression

    NASA Technical Reports Server (NTRS)

    Hung, R. J.; Tsao, Y. D.

    1988-01-01

    Rawinsonde data and geosynchronous satellite imagery were used to investigate the life cycles of St. Anthony, Minnesota's severe convective storms. It is found that the fully developed storm clouds, with overshooting cloud tops penetrating above the tropopause, collapsed about three minutes before the touchdown of the tornadoes. Results indicate that the probability of producing an outbreak of tornadoes causing greater damage increases when there are higher values of potential energy storage per unit area for overshooting cloud tops penetrating the tropopause. It is also found that there is less chance for clouds with a lower moisture content to be outgrown as a storm cloud than clouds with a higher moisture content.

  17. Equivalence-point electromigration acid-base titration via moving neutralization boundary electrophoresis.

    PubMed

    Yang, Qing; Fan, Liu-Yin; Huang, Shan-Sheng; Zhang, Wei; Cao, Cheng-Xi

    2011-04-01

    In this paper, we developed a novel method of acid-base titration, viz. the electromigration acid-base titration (EABT), via a moving neutralization boundary (MNR). With HCl and NaOH as the model strong acid and base, respectively, we conducted the experiments on the EABT via the method of moving neutralization boundary for the first time. The experiments revealed that (i) the concentration of agarose gel, the voltage used and the content of background electrolyte (KCl) had evident influence on the boundary movement; (ii) the movement length was a function of the running time under the constant acid and base concentrations; and (iii) there was a good linearity between the length and natural logarithmic concentration of HCl under the optimized conditions, and the linearity could be used to detect the concentration of acid. The experiments further manifested that (i) the RSD values of intra-day and inter-day runs were less than 1.59 and 3.76%, respectively, indicating similar precision and stability in capillary electrophoresis or HPLC; (ii) the indicators with different pK(a) values had no obvious effect on EABT, distinguishing strong influence on the judgment of equivalence-point titration in the classic one; and (iii) the constant equivalence-point titration always existed in the EABT, rather than the classic volumetric analysis. Additionally, the EABT could be put to good use for the determination of actual acid concentrations. The experimental results achieved herein showed a new general guidance for the development of classic volumetric analysis and element (e.g. nitrogen) content analysis in protein chemistry.

  18. A crystallographic fragment screen identifies cinnamic acid derivatives as starting points for potent Pim-1 inhibitors.

    PubMed

    Schulz, Michèle N; Fanghänel, Jörg; Schäfer, Martina; Badock, Volker; Briem, Hans; Boemer, Ulf; Nguyen, Duy; Husemann, Manfred; Hillig, Roman C

    2011-03-01

    A crystallographic fragment screen was carried out to identify starting points for the development of inhibitors of protein kinase Pim-1, a potential target for tumour therapy. All fragment hits identified via soaking in this study turned out to bind to the unusually hydrophobic pocket at the hinge region. The most potent fragments, two cinnamic acid derivatives (with a best IC(50) of 130 µM), additionally form a well defined hydrogen bond. The balance between hydrophobic and polar interactions makes these molecules good starting points for further optimization. Pim-2 inhibitors from a recently reported high-throughput screening campaign also feature a cinnamic acid moiety. Two of these Pim-2 inhibitors were synthesized, their potencies against Pim-1 were determined and their cocrystal structures were elucidated in order to determine to what degree the binding modes identified by fragment screening are conserved in optimized inhibitors. The structures show that the cinnamic acid moieties indeed adopt the same binding mode. Fragment screening thus correctly identified binding modes which are maintained when fragments are grown into larger and higher affinity inhibitors. The high-throughput screening-derived compound (E)-3-{3-[6-(4-aminocyclohexylamino)-pyrazin-2-yl]phenyl}acrylic acid (compound 1) is the most potent inhibitor of the cinnamic acid series for which the three-dimensional binding mode is known (IC(50) = 17 nM, K(d) = 28 nM). The structure reveals the molecular basis for the large gain in potency between the initial fragment hit and this optimized inhibitor.

  19. Determination of the Thermal Decomposition Products of Terephthalic Acid by Using Curie-Point Pyrolyzer

    NASA Astrophysics Data System (ADS)

    Begüm Elmas Kimyonok, A.; Ulutürk, Mehmet

    2016-04-01

    The thermal decomposition behavior of terephthalic acid (TA) was investigated by thermogravimetry/differential thermal analysis (TG/DTA) and Curie-point pyrolysis. TG/DTA analysis showed that TA is sublimed at 276°C prior to decomposition. Pyrolysis studies were carried out at various temperatures ranging from 160 to 764°C. Decomposition products were analyzed and their structures were determined by gas chromatography-mass spectrometry (GC-MS). A total of 11 degradation products were identified at 764°C, whereas no peak was observed below 445°C. Benzene, benzoic acid, and 1,1‧-biphenyl were identified as the major decomposition products, and other degradation products such as toluene, benzophenone, diphenylmethane, styrene, benzaldehyde, phenol, 9H-fluorene, and 9-phenyl 9H-fluorene were also detected. A pyrolysis mechanism was proposed based on the findings.

  20. Energy Balance, Evapo-transpiration and Dew deposition in the Dead Sea Valley

    NASA Astrophysics Data System (ADS)

    Metzger, Jutta; Corsmeier, Ulrich

    2016-04-01

    The Dead Sea is a unique place on earth. It is a terminal hypersaline lake, located at the lowest point on earth with a lake level of currently -429 m above mean sea level (amsl). It is located in a transition zone of semiarid to arid climate conditions, which makes it highly sensible to climate change (Alpert1997, Smiatek2011). The Virtual Institute DEad SEa Research Venue (DESERVE) is an international project funded by the German Helmholtz Association and was established to study coupled atmospheric hydrological, and lithospheric processes in the changing environment of the Dead Sea. At the moment the most prominent environmental change is the lake level decline of approximately 1 m / year due to anthropogenic interferences (Gertman, 2002). This leads to noticeable changes in the fractions of the existing terrestrial surfaces - water, bare soil and vegetated areas - in the valley. Thus, the partitioning of the net radiation in the valley changes as well. To thoroughly study the atmospheric and hydrological processes in the Dead Sea valley, which are driven by the energy balance components, sound data of the energy fluxes of the different surfaces are necessary. Before DESERVE no long-term monitoring network simultaneously measuring the energy balance components of the different surfaces in the Dead Sea valley was available. Therefore, three energy balance stations were installed at three characteristic sites at the coast-line, over bare soil, and within vegetation, measuring all energy balance components by using the eddy covariance method. The results show, that the partitioning of the energy into sensible and latent heat flux on a diurnal scale is totally different at the three sites. This results in gradients between the sites, which are e.g. responsible for the typical diurnal wind systems at the Dead Sea. Furthermore, driving forces of evapo-transpiration at the sites were identified and a detailed analysis of the daily evaporation and dew deposition rates

  1. The effect of substrate properties, size, position, sheltering and shading on dew: An experimental approach in the Negev Desert

    NASA Astrophysics Data System (ADS)

    Kidron, Giora J.

    2010-11-01

    Affected by the interrelationships between the air mass and the substrate properties, dew measurements entail numerous difficulties. Inattentiveness to the complexities involved may result in inconsistent and consequently unreliable data and thus in misleading conclusions. This is especially important in dew deserts such as the Negev where dew may be regarded as an important water source. In an attempt to highlight some of the factors that may affect dew condensation, an experimental approach was adapted during which dew condensation at different surfaces (smooth and ragged Plexiglas, bright limestone and dark flint cobbles), at various size substrata with identical axes (of 2.5, 5, 10, 20, 30 and 40 cm) or different size axes (of 10 × 20, 10 × 30 and 10 × 40 cm), and substrata at different heights and settings was measured. Some of the settings explored were also sheltered by a shrub, a cave, an 80-cm-tall cliff and neighboring cobbles. No significant differences were found in the dew amounts condensing on the limestone and the flint cobbles. Smooth Plexiglas surfaces yielded significantly higher amounts than a ragged Plexiglas surface. As for the substratum height and size, the dew amounts increased with height (from 0.7 to 10.0 cm) and size (from 2.5 × 2.5 cm to 40 × 40 cm). However, an increase in the long axis (a-axis) to 20, 30 and 40 cm while leaving the b-axis constant (at 10 cm) resulted in only a slight increase in the dew amounts in comparison to a 10 × 10 cm substratum. While confined to non-sheltered habitats, dew at partially sheltered habitats (such as the margin of a shrub or a cave, the vicinity of a cliff and on 7-cm-high cobble surrounded by 15-cm-high cobbles) was significantly lower than at the exposed habitats. The differences in dew amounts coincided with minute differences in the surface temperatures, explained as resulting from differences in the outgoing nocturnal longwave radiational cooling. The findings may shed light on the dew

  2. Dew water effects on leaf water using a stable isotope approach

    NASA Astrophysics Data System (ADS)

    Kim, K.; Lee, X.

    2009-12-01

    The presence of dew is a common meteorological phenomenon in field conditions and takes into account for significant portion of hydrologic processes in terrestrial ecosystems. The isotope composition of leaf water plays an important role in the isotopic water and carbon fluxes between terrestrial plants and the atmosphere. However, the consequence of dew formation in the plant-atmosphere relations has been ignored in many studies. The objective of this study is to improve our understanding of environmental and biological controls on the leaf water in equilibrium with dew water through laboratory experiments. Five species of plants (soybean, corn, sorghum, wheat, cotton) were grown hydroponically with water of a known isotopic content in a greenhouse. On the day of the experiment, they were first moved to ambient environment in full sunlight for at least 6 hr and then into a dark container inside the lab for up to 48 hr in which water vapor isotope ratios, temperature, and humidity were controlled. This arrangement created a step change in the forcing on the plant isotopic exchange. Leaves were sampled prior to the transfer to the dark container and 6 more times every 4 - 12 hr over the experiment. Humidity inside the container was saturated to mimic dew events in field conditions. Water from the leaf samples was extracted by a vacuum line and was analyzed for both δD and δ18O. The dataset will allow us to evaluate leaf water isotopic theories by exploring the transitions of the isotopic ratio of leaf water in response to the step change. Specifically, we are interested in whether the stomatal opening is an effective pathway for gaseous exchange in total darkness and how the transitional behaviors of the isotopic ratio of leaf water differ between the C3 and C4 photosynthesis pathways.

  3. The effects of surface wettability on the fog and dew moisture harvesting performance on tubular surfaces

    PubMed Central

    Seo, Donghyun; Lee, Junghun; Lee, Choongyeop; Nam, Youngsuk

    2016-01-01

    The efficient water harvesting from air-laden moisture has been a subject of great interest to address world-wide water shortage issues. Recently, it has been shown that tailoring surface wettability can enhance the moisture harvesting performance. However, depending on the harvesting condition, a different conclusion has often been reported and it remains unclear what type of surface wettability would be desirable for the efficient water harvesting under the given condition. Here we compare the water harvesting performance of the surfaces with various wettability under two different harvesting conditions–dewing and fogging, and show that the different harvesting efficiency of each surface under these two conditions can be understood by considering the relative importance of the water capturing and removal efficiency of the surface. At fogging, the moisture harvesting performance is determined by the water removal efficiency of the surface with the oil-infused surfaces exhibiting the best performance. Meanwhile, at dewing, both the water capturing and removal efficiency are crucial to the harvesting performance. And well-wetting surfaces with a lower barrier to nucleation of condensates exhibit a better harvesting performance due to the increasing importance of the water capture efficiency over the water removal efficiency at dewing. PMID:27063149

  4. The effects of surface wettability on the fog and dew moisture harvesting performance on tubular surfaces.

    PubMed

    Seo, Donghyun; Lee, Junghun; Lee, Choongyeop; Nam, Youngsuk

    2016-01-01

    The efficient water harvesting from air-laden moisture has been a subject of great interest to address world-wide water shortage issues. Recently, it has been shown that tailoring surface wettability can enhance the moisture harvesting performance. However, depending on the harvesting condition, a different conclusion has often been reported and it remains unclear what type of surface wettability would be desirable for the efficient water harvesting under the given condition. Here we compare the water harvesting performance of the surfaces with various wettability under two different harvesting conditions-dewing and fogging, and show that the different harvesting efficiency of each surface under these two conditions can be understood by considering the relative importance of the water capturing and removal efficiency of the surface. At fogging, the moisture harvesting performance is determined by the water removal efficiency of the surface with the oil-infused surfaces exhibiting the best performance. Meanwhile, at dewing, both the water capturing and removal efficiency are crucial to the harvesting performance. And well-wetting surfaces with a lower barrier to nucleation of condensates exhibit a better harvesting performance due to the increasing importance of the water capture efficiency over the water removal efficiency at dewing.

  5. The effects of surface wettability on the fog and dew moisture harvesting performance on tubular surfaces.

    PubMed

    Seo, Donghyun; Lee, Junghun; Lee, Choongyeop; Nam, Youngsuk

    2016-01-01

    The efficient water harvesting from air-laden moisture has been a subject of great interest to address world-wide water shortage issues. Recently, it has been shown that tailoring surface wettability can enhance the moisture harvesting performance. However, depending on the harvesting condition, a different conclusion has often been reported and it remains unclear what type of surface wettability would be desirable for the efficient water harvesting under the given condition. Here we compare the water harvesting performance of the surfaces with various wettability under two different harvesting conditions-dewing and fogging, and show that the different harvesting efficiency of each surface under these two conditions can be understood by considering the relative importance of the water capturing and removal efficiency of the surface. At fogging, the moisture harvesting performance is determined by the water removal efficiency of the surface with the oil-infused surfaces exhibiting the best performance. Meanwhile, at dewing, both the water capturing and removal efficiency are crucial to the harvesting performance. And well-wetting surfaces with a lower barrier to nucleation of condensates exhibit a better harvesting performance due to the increasing importance of the water capture efficiency over the water removal efficiency at dewing. PMID:27063149

  6. The effects of surface wettability on the fog and dew moisture harvesting performance on tubular surfaces

    NASA Astrophysics Data System (ADS)

    Seo, Donghyun; Lee, Junghun; Lee, Choongyeop; Nam, Youngsuk

    2016-04-01

    The efficient water harvesting from air-laden moisture has been a subject of great interest to address world-wide water shortage issues. Recently, it has been shown that tailoring surface wettability can enhance the moisture harvesting performance. However, depending on the harvesting condition, a different conclusion has often been reported and it remains unclear what type of surface wettability would be desirable for the efficient water harvesting under the given condition. Here we compare the water harvesting performance of the surfaces with various wettability under two different harvesting conditions–dewing and fogging, and show that the different harvesting efficiency of each surface under these two conditions can be understood by considering the relative importance of the water capturing and removal efficiency of the surface. At fogging, the moisture harvesting performance is determined by the water removal efficiency of the surface with the oil-infused surfaces exhibiting the best performance. Meanwhile, at dewing, both the water capturing and removal efficiency are crucial to the harvesting performance. And well-wetting surfaces with a lower barrier to nucleation of condensates exhibit a better harvesting performance due to the increasing importance of the water capture efficiency over the water removal efficiency at dewing.

  7. A chemical test of the principle of critical point universality: The solubility of nickel (II) oxide in isobutyric acid + water near the consolute point

    NASA Astrophysics Data System (ADS)

    Hu, Baichuan; Baird, James K.; Richey, Randi D.; Reddy, Ramana G.

    2011-04-01

    A mixture of isobutyric acid + water has an upper consolute point at 38.8 mass % isobutyric acid and temperature near 26 °C. Nickel (II) oxide dissolves in this mixture by reacting with the acid to produce water and nickel isobutyrate. The solubility of nickel (II) oxide in isobutyric acid + water has been measured as a function of temperature at compositions, 25, 38.8, and 60 mass % isobutyric acid. For values of the temperature, T, which were at least 2 K in excess of the liquid-liquid phase transition temperature, the measured values of the solubility, s, lie on a straight line when plotted in van't Hoff form with ln s versus 1/T. The slope, (∂ln s/∂(1/T)), of the line is negative indicating that the dissolution reaction is endothermic. When the temperature was within 2 K of the phase transition temperature, however, (∂ln s/∂(1/T)) diverged toward negative infinity. The principle of critical point universality predicts that when excess solid nickel (II) oxide is in dissolution equilibrium with liquid isobutyric acid + water, (∂ln s/∂(1/T)) should diverge upon approaching the consolute point along the critical isopleth at 38.8 mass % isobutyric acid. As determined by the sign of the enthalpy of solution, the sign of this divergence is expected to be negative. Not only do our experiments confirm these predictions, but they also show that identical behavior can be observed at both 25 and 60 mass % isobustyric acid, compositions which lie substantially to either side of the critical composition.

  8. The pH at the First Equivalence Point in the Titration of a Diprotic Acid

    NASA Astrophysics Data System (ADS)

    Ault, Addison

    2003-12-01

    Some readers will note a similarity between this approach and the one I took in a paper entitled “Do pH in Your Head” (2). In an example in that article the isoelectric pH of glycine (the pH at which the average charge of a glycine molecule is zero), has the value of 6.0, which is exactly half-way between 2.4, the pKa of the carboxyl group of glycine, and 9.6, the pKa of the ammonium group of glycine. This is what one would expect when realizing that a solution of neutral glycine right out of the bottle is equivalent to glycine obtained by titration of the conjugate acid of glycine to the first equivalence point. Those who are interested might want to consider why the isoelectric pH of an “acidic” amino acid, such as alanine, is exactly half-way between the pKa values of the two carboxyl groups, and why the isoelectric pH of a “basic” amino acid such as lysine is exactly half-way between the pKa values of the two ammonium groups.

  9. The free fractions of circulating docosahexaenoic acid and eicosapentenoic acid as optimal end-point of measure in bioavailability studies on n-3 fatty acids.

    PubMed

    Scarsi, Claudia; Levesque, Ann; Lisi, Lucia; Navarra, Pierluigi

    2015-05-01

    The high complexity of n-3 fatty acids absorption process, along with the huge amount of endogenous fraction, makes bioavailability studies with these agents very challenging and deserving special consideration. In this paper we report the results of a bioequivalence study between a new formulation of EPA+DHA ethyl esters developed by IBSA Institut Biochimique and reference medicinal product present on the Italian market. Bioequivalence was demonstrated according to the criteria established by the EMA Guideline on the Investigation of Bioequivalence. We found that the free fractions represent a better and more sensitive end-point for bioequivalence investigations on n-3 fatty acids, since: (i) the overall and intra-subject variability of PK parameters was markedly lower compared to the same variability calculated on the total DHA and EPA fractions; (ii) the absorption process was completed within 4h, and the whole PK profile could be drawn within 12-15 h from drug administration.

  10. A Comprehensive Evaluation of the Melting Points of Fatty Acids and Esters Determined by Differential Scanning Calorimetry

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The melting point is one of the most important physical properties of a chemical compound and plays a significant role in determining possible applications. For fatty acid esters the melting point is essential for a variety of food and non-food applications, the latter including biodiesel and its c...

  11. Novel ideas for maximising dew collection to aid plant establishment to combat desertification and restore degraded dry and arid lands

    NASA Astrophysics Data System (ADS)

    Kotzen, Benz

    2014-05-01

    This paper focuses on the potential of dew to provide water to plants and potentially to people as well in remote and difficult to reach areas where rainfall and underground water cannot be harvested. The combat of desertification and the restoration of degraded and desertified dry and arid lands has never been more urgent. A key practical component of this strategy is the restoration of habitat with planting. But for habitat and planting to survive there needs to be an adequate supply of water. In most cases providing water to the plant's roots is vital. In some areas where habitats have been destroyed, sufficient water is immediately available, for example through seasonal rainfall, or it can be harvested to concentrate adequate supplies of water to the roots. However, in arid and hyper arid areas, as well as in some dryland areas, a consistent and adequate supply of water cannot be provided by any conventional proven method. Thus, as the need to combat desertification and to restore desertified dry and arid land increases, so the need to find novel methods of establishing and maintaining planting and thus habitat increases. In more traditional land management scenarios this can be achieved through manipulating landform on a micro and macro scale, for example, by creating catchments, thereby collecting precipitation and directing it to the plants. Where this cannot be done, other means of water supply are usually required. Bainbridge (2007) and others have shown that supplying water to plants is possible through a number of traditional methods, for example, using clay pots. But most of these techniques require an introduced source of water, for example, obtained through water harvesting methods or by delivering water to site in tanks and by water bowser. This can work but requires continuous manpower. It is expensive and can be physically prohibitive in areas where access is difficult and/or remote. The concept of using dew to supply water in drylands is not new

  12. FURNACE INJECTION OF ALKALINE SORBENTS FOR SULFURIC ACID CONTROL

    SciTech Connect

    Gary M. Blythe

    2000-12-01

    A test program is being sponsored by the US Department of Energy (DOE), EPRI, FirstEnergy, and TVA to investigate furnace injection of alkaline sorbents as a means of reducing sulfuric acid concentrations in the flue gas from coal-fired boilers. This test program is being conducted at the FirstEnergy Bruce Mansfield Plant (BMP), although later testing will be conducted at a TVA plant. A sorbent injection test was conducted the week of April 18, 2000. The test was the first of several short-term (one- to two-week duration) tests to investigate the effectiveness of various alkaline sorbents for sulfuric acid control and the effects of these sorbents on boiler equipment performance. This first short-term test investigated the effect of injecting dry dolomite powder (CaCO{sub 3} {center_dot} MgCO{sub 3}), a mineral similar to limestone, into the furnace of Unit 2. During the test program, various analytical techniques were used to assess the effects of sorbent injection. These primarily included sampling with the controlled condensation system (CCS) for determining flue gas SO{sub 3} content and an acid dew-point (ADP) meter for determining the sulfuric acid dew point (and, indirectly, the concentration of sulfuric acid) of the flue gas. EPA Reference Method 26a was used for determining hydrochloric acid (HCl) and hydrofluoric acid (HF), as well and chlorine (Cl{sub 2}) and fluorine (F{sub 2}) concentrations in the flue gas. Fly ash resistivity was measured using a Southern Research Institute (SRI) point-to-plane resistivity probe, and unburned carbon in fly ash was determined by loss on ignition (LOI). Coal samples were also collected and analyzed for a variety of parameters. Finally, visual observations were made of boiler furnace and convective pass surfaces prior to and during sorbent injection.

  13. Dew Incidence: a Field Study (related to Corn) in Jeddah, Saudi Arabia with Comparisons to a Similar Experiment in Texas.

    NASA Astrophysics Data System (ADS)

    Al-Amodi, Ahmad Osman

    An experiment was designed, assembled and carried out at the Hada Al-Sham Experimental station in the dry western part of Saudi Arabia, to procure dew duration data at two different heights in a corn canopy, from the time of emergence (average plant heights about 30 cm) until harvest time (average height about 230 cm). Micrometeorological, together with canopy and additional environmental measurements, were taken to deduce the latent heat flux involved in dew onset and dry-off. The micrometeorological measurements included leaf and air temperatures, relative humidity, net radiation, wind speeds and direction, while other observations included canopy heights, leaf width, leaf area index (LAI), soil temperature, soil moisture, and dew duration. The energy balance approach (Penman-Monteith), along with boundary layer resistance theory around the leaf surface, were used to estimate the latent heat flux involved in the dew process. It was found that at the beginning of the season dew usually started to form on the lower part of the canopy at an average of three hours before it started to form in the upper part. On the other hand, as the canopy reached the mature stage, dew formation on the upper part of the canopy started an average of two hours before it started to form on the lower part. It took averages of one hour and an hour and half after sunrise, for the lower and upper part of the canopy to dry-off respectively. A linear regression analysis of the latent heat and environmental variables showed high correlations with net radiation, leaf and air temperatures, relative humidity, soil temperature at 2cm depth from top of the furrow at both canopy heights for the whole growing season, whereas wind speed showed high correlation for the upper part of the canopy only. It is suggested that many more studies are necessary to increase understanding of the dew process but less comprehensive instrumentation would probably be adequate.

  14. Ecosystem-scale compensation points of formic and acetic acid in the central Amazon

    NASA Astrophysics Data System (ADS)

    Jardine, K.; Yañez Serrano, A.; Arneth, A.; Abrell, L.; Jardine, A.; Artaxo, P.; Alves, E.; Kesselmeier, J.; Taylor, T.; Saleska, S.; Huxman, T.

    2011-09-01

    Organic acids, central to terrestrial carbon metabolism and atmospheric photochemistry, are ubiquitous in the troposphere in the gas, particle, and aqueous phases. As the dominant organic acids in the atmosphere, formic acid (FA, HCOOH) and acetic acid (AA, CH3COOH) control precipitation acidity in remote regions and may represent a critical link between the terrestrial carbon and water cycles by acting as key intermediates in plant carbon and energy metabolism and aerosol-cloud-precipitation interactions. However, our understanding of the exchange of these acids between terrestrial ecosystems and the atmosphere is limited by a lack of field observations, the existence of biogenic and anthropogenic primary and secondary sources whose relative importance is unclear, and the fact that vegetation can act as both a source and a sink. Here, we first present data obtained from the tropical rainforest mesocosm at Biosphere 2 which isolates primary vegetation sources. Strong light and temperature dependent emissions enriched in FA relative to AA were simultaneously observed from individual branches (FA/AA = 2.1 ± 0.6) and mesocosm ambient air (FA/AA = 1.4 ± 0.3). We also present long-term observations of vertical concentration gradients of FA and AA within and above a primary rainforest canopy in the central Amazon during the 2010 dry and 2011 wet seasons. We observed a seasonal switch from net ecosystem-scale deposition during the dry season to net emissions during the wet season. This switch was associated with reduced ambient concentrations in the wet season (FA < 1.3 nmol mol-1, AA < 2.0 nmol mol-1) relative to the dry season (FA up to 3.3 nmol mol-1, AA up to 6.0 nmol mol-1), and a simultaneous increase in the FA/AA ambient concentration ratios from 0.3-0.8 in the dry season to 1.0-2.1 in the wet season. These observations are consistent with a switch between a biomass burning dominated source in the dry season (FA/AA < 1.0) to a vegetation dominated source in the

  15. Ecosystem-scale compensation points of formic and acetic acid in the central Amazon

    NASA Astrophysics Data System (ADS)

    Jardine, K.; Yañez Serrano, A.; Arneth, A.; Abrell, L.; Jardine, A.; Artaxo, P.; Alves, E.; Kesselmeier, J.; Taylor, T.; Saleska, S.; Huxman, T.

    2011-12-01

    Organic acids, central to terrestrial carbon metabolism and atmospheric photochemistry, are ubiquitous in the troposphere in the gas, particle, and aqueous phases. As the dominant organic acids in the atmosphere, formic acid (FA, HCOOH) and acetic acid (AA, CH3COOH) control precipitation acidity in remote regions and may represent a critical link between the terrestrial carbon and water cycles by acting as key intermediates in plant carbon and energy metabolism and aerosol-cloud-precipitation interactions. However, our understanding of the exchange of these acids between terrestrial ecosystems and the atmosphere is limited by a lack of field observations, the existence of biogenic and anthropogenic primary and secondary sources whose relative importance is unclear, and the fact that vegetation can act as both a source and a sink. Here, we first present data obtained from the tropical rainforest mesocosm at Biosphere 2 which isolates primary vegetation sources. Strong light and temperature dependent emissions enriched in FA relative to AA were simultaneously observed from individual branches (FA/AA = 3.0 ± 0.7) and mesocosm ambient air (FA/AA = 1.4 ± 0.3). We also present long-term observations of vertical concentration gradients of FA and AA within and above a primary rainforest canopy in the central Amazon during the 2010 dry and 2011 wet seasons. We observed a seasonal switch from net ecosystem-scale deposition during the dry season to net emissions during the wet season. This switch was associated with reduced ambient concentrations in the wet season (FA < 1.3 nmol mol-1, AA < 2.0 nmol mol-1) relative to the dry season (FA up to 3.3 nmol mol-1, AA up to 6.0 nmol mol-1), and a simultaneous increase in the FA/AA ambient concentration ratios from 0.3-0.8 in the dry season to 1.0-2.1 in the wet season. These observations are consistent with a switch between a biomass burning dominated source in the dry season (FA/AA < 1.0) to a vegetation dominated source in the

  16. Ecosystem-Scale Compensation Point Analysis of Formic and Acetic Acid in the Central Amazon

    NASA Astrophysics Data System (ADS)

    Yanez-Serrano, A. M.; Jardine, K. J.; Arneth, A.; Abrell, L.; Jardine, A. B.; Artaxo, P.; Gomes, E.; Kesselmeier, J.; Saleska, S. R.; Huxman, T. E.

    2011-12-01

    Organic acids, central to terrestrial carbon metabolism and atmospheric photochemistry, are ubiquitous in the troposphere in the gas, particle, and aqueous phases. As the dominant organic acids in the atmosphere, formic acid (FA, HCOOH) and acetic acid (AA, CH3COOH) control precipitation acidity in remote regions and may represent a critical link between the terrestrial carbon and water cycles by acting as key intermediates in plant carbon and energy metabolism and aerosol-cloud-precipitation interactions. However, our understanding of the exchange of these acids between terrestrial ecosystems and the atmosphere is limited by a lack of field observations, the existence of biogenic and anthropogenic primary and secondary sources whose relative importance is unclear, and the fact that vegetation can act as both a source and a sink. Here, we present results from the tropical rainforest mescosom at Biosphere 2 which isolates primary vegetation sources. Strong light and temperature dependent emissions of FA and AA were simultaneously observed from individual branches and mesocosm ambient air with a strong enrichment in FA (FA/AA = 1.4 +/- 0.3, R2 of 0.89 +/- 0.10). We also present long-term observations of vertical concentration gradients of FA and AA within and above a primary rainforest canopy in central Amazonia during the 2010 dry and 2011 wet seasons. We observed a seasonal switch from net ecosystem-scale deposition during the dry season to net emissions during the wet season. This switch was associated with reduced ambient concentrations in the wet season (FA < 1.3 ppbv, AA < 2.0 ppbv) relative to the dry season (FA up to 3.3 ppbv, AA up to 6.0 ppbv), and a simultaneous increase in the FA/AA ambient concentration ratios from 0.3-0.8 in the dry season to 1.0-2.1 in the wet season. These observations are consistent with a switch between a biomass burning dominated source in the dry season (FA/AA < 1.0) to a vegetation dominated source in the wet season and call into

  17. Miniaturized nucleic acid amplification systems for rapid and point-of-care diagnostics: a review.

    PubMed

    Ahmad, Farhan; Hashsham, Syed A

    2012-07-01

    Point-of-care (POC) genetic diagnostics critically depends on miniaturization and integration of sample processing, nucleic acid amplification, and detection systems. Polymerase chain reaction (PCR) assays have extensively applied for the diagnosis of genetic markers of disease. Microfluidic chips for microPCR with different materials and designs have been reported. Temperature cycling systems with varying thermal masses and conductivities, thermal cycling times, flow-rates, and cross-sectional areas, have also been developed to reduce the nucleic acid amplification time. Similarly, isothermal amplification techniques (e.g., loop-mediated isothermal amplification or LAMP), which are still are emerging, have a better potential as an alternative to PCR for POC diagnostics. Isothermal amplification techniques have: (i) moderate incubation temperature leading to simplified heating and low power consumption, (ii) yield high amount of amplification products, which can be detected either visually or by simple detectors, (iii) allow direct genetic amplification from bacterial cells due to the superior tolerance to substances that typically inhibit PCR, (iv) have high specificity, and sensitivity, and (v) result in rapid detection often within 10-20 min. The aim of this review is to provide a better understanding of the advantages and limitations of microPCR and microLAMP systems for rapid and POC diagnostics. PMID:22704369

  18. The effect of sire breed on the melting point and fatty acid composition of subcutaneous fat in steers.

    PubMed

    Perry, D; Nicholls, P J; Thompson, J M

    1998-01-01

    Fatty acid composition and the melting point of subcutaneous fat was determined in 18 Hereford, 25 Brahman x Hereford, 22 Simmental x Hereford, and 15 Friesian x Hereford steers that were grown out on pasture at two sites and slaughtered when the mean weight of the Herefords at each site was ca. 450 kg. Multivariate and univariate analyses tested the relations of fatty acid composition, degree of saturation, and melting point with sire breed, environment, age, and carcass characteristics. Hereford and Brahman steers were fatter than the Simmental and Friesian steers. Fat from Brahman-sired steers had a melting point 2.5 degrees C lower than fat from the Bos taurus-sired steers at the same age and had a higher proportion of unsaturated fatty acids, independent of variation in carcass weight and fatness. Melting point and degree of saturation decreased as age increased. Step-down discriminant analyses identified a set of three acids (14:0, 16:0, and 17:1) that differed among sire breeds, independent of differences in melting point: the acids 14:0 and 16:0 discriminated between Brahman and Bos taurus steers and 17:1 between Hereford and Simmental and Friesian steers. Increase in fatness was associated with an increase in 17:1, but, at the same fatness, no acids discriminated among the Bos taurus-sired steers. The use of Bos indicus cattle or their crossbreeds in situations in which hard-setting fat is likely may mitigate the problem.

  19. Reduction of Acid-Fast and Non-Acid-Fast Bacteria by Point of Use Coagulation-Flocculation-Disinfection

    PubMed Central

    Casanova, Lisa M.; Sobsey, Mark D.

    2015-01-01

    Point of use (POU) household water treatment is increasingly being adopted as a solution for access to safe water. Non-tuberculous Mycobacteria (NTM) are found in water, but there is little research on whether NTM survive POU treatment. Mycobacteria may be removed by multi-barrier treatment systems that combine processes such as coagulation, settling and disinfection. This work evaluated removal of a non-tuberculous Mycobacterium (Mycobaterium terrae) and a Gram-negative non-acid-fast environmental bacterium (Aeromonas hydrophila) by combined coagulation-flocculation disinfection POU treatment. Aeromonas hydrophila showed 7.7 log10 reduction in demand free buffer, 6.8 log10 in natural surface water, and 4 log10 reduction in fecally contaminated surface water. Turbidity after treatment was <1 NTU. There was almost no reduction in levels of viable M. terrae by coagulant-flocculant-disinfectant in natural water after 30 minutes. The lack of Mycobacteria reduction was similar for both combined coagulant-flocculant-disinfectant and hypochlorite alone. A POU coagulant-flocculant-disinfectant treatment effectively reduced A. hydrophila from natural surface waters but not Mycobacteria. These results reinforce previous findings that POU coagulation-flocculation-disinfection is effective against gram-negative enteric bacteria. POU treatment and safe storage interventions may need to take into account risks from viable NTM in treated stored water and consider alternative treatment processes to achieve NTM reductions. PMID:26580632

  20. Reduction of Acid-Fast and Non-Acid-Fast Bacteria by Point of Use Coagulation-Flocculation-Disinfection.

    PubMed

    Casanova, Lisa M; Sobsey, Mark D

    2015-11-01

    Point of use (POU) household water treatment is increasingly being adopted as a solution for access to safe water. Non-tuberculous Mycobacteria (NTM) are found in water, but there is little research on whether NTM survive POU treatment. Mycobacteria may be removed by multi-barrier treatment systems that combine processes such as coagulation, settling and disinfection. This work evaluated removal of a non-tuberculous Mycobacterium (Mycobaterium terrae) and a Gram-negative non-acid-fast environmental bacterium (Aeromonas hydrophila) by combined coagulation-flocculation disinfection POU treatment. Aeromonas hydrophila showed 7.7 log10 reduction in demand free buffer, 6.8 log10 in natural surface water, and 4 log10 reduction in fecally contaminated surface water. Turbidity after treatment was <1 NTU. There was almost no reduction in levels of viable M. terrae by coagulant-flocculant-disinfectant in natural water after 30 minutes. The lack of Mycobacteria reduction was similar for both combined coagulant-flocculant-disinfectant and hypochlorite alone. A POU coagulant-flocculant-disinfectant treatment effectively reduced A. hydrophila from natural surface waters but not Mycobacteria. These results reinforce previous findings that POU coagulation-flocculation-disinfection is effective against gram-negative enteric bacteria. POU treatment and safe storage interventions may need to take into account risks from viable NTM in treated stored water and consider alternative treatment processes to achieve NTM reductions. PMID:26580632

  1. Reduction of Acid-Fast and Non-Acid-Fast Bacteria by Point of Use Coagulation-Flocculation-Disinfection.

    PubMed

    Casanova, Lisa M; Sobsey, Mark D

    2015-11-13

    Point of use (POU) household water treatment is increasingly being adopted as a solution for access to safe water. Non-tuberculous Mycobacteria (NTM) are found in water, but there is little research on whether NTM survive POU treatment. Mycobacteria may be removed by multi-barrier treatment systems that combine processes such as coagulation, settling and disinfection. This work evaluated removal of a non-tuberculous Mycobacterium (Mycobaterium terrae) and a Gram-negative non-acid-fast environmental bacterium (Aeromonas hydrophila) by combined coagulation-flocculation disinfection POU treatment. Aeromonas hydrophila showed 7.7 log10 reduction in demand free buffer, 6.8 log10 in natural surface water, and 4 log10 reduction in fecally contaminated surface water. Turbidity after treatment was <1 NTU. There was almost no reduction in levels of viable M. terrae by coagulant-flocculant-disinfectant in natural water after 30 minutes. The lack of Mycobacteria reduction was similar for both combined coagulant-flocculant-disinfectant and hypochlorite alone. A POU coagulant-flocculant-disinfectant treatment effectively reduced A. hydrophila from natural surface waters but not Mycobacteria. These results reinforce previous findings that POU coagulation-flocculation-disinfection is effective against gram-negative enteric bacteria. POU treatment and safe storage interventions may need to take into account risks from viable NTM in treated stored water and consider alternative treatment processes to achieve NTM reductions.

  2. Polarographic indication of the end-point in chelometric titrations with triethylenetetraminehexa-acetic acid.

    PubMed

    Kopanica, M; Stará, V

    1974-10-01

    The application of d.c. and square-wave polarographic measurements for the indication of the end-point in titrations with triethylenetetraminehexa-acetic acid (TTHA) has been studied. TTHA has ten co-ordinating groups and forms complexes with metal to ligand ratios of either 1:1 or 2:1, depending on the metal and experimental conditions. The shape of the titration curves, determined by the dependence of the limiting current (peak current of the square-wave polarographic curve) or of the half-wave potential (peak potential) on the amount of TTHA added indicates the composition of the complex formed in the titration. The composition of this complex as determined from the studied titration curves agrees with that predicted by theory. Titrations with polarographic indication of the end-point were also applied for direct titrations of binary mixtures of metal ions. The resulting titration curves indicated the existence of mixed dinuclear complexes and also the kinetic factors involved in the reactions between two different metal ions and TTHA.

  3. Cloud point extraction of uranium using H₂DEH[MDP] in acidic conditions.

    PubMed

    Labrecque, Charles; Potvin, Sabrina; Whitty-Léveillé, Laurence; Larivière, Dominic

    2013-03-30

    A procedure has been developed for the cloud point extraction (CPE) of uranium (VI) using H2DEH[MDP] (P,P-di(2-ethylhexyl) methanediphosphonic acid) with inductively coupled plasma coupled to mass spectrometry (ICP-MS). The method is based on the modification of the cloud point temperature using cetyl trimethyl ammonium bromide (CTAB) and KI. Optimal conditions of extraction were found using a cross-optimization of every parameter (non-ionic and ionic surfactant concentrations, chelating agent concentration, pH and the extraction, and phase separation temperatures). Furthermore, the figures of merit of the methodology were assessed (limit of detection, limit of quantification, recovery, sensibility, and linear range) and are reported. Quantitative extraction (99 ± 0.5%) was obtained in drinking water samples over a wide range of uranium concentrations. The approach was also validated using drinking (SCP EP-L-3 and SCP EP-H-3), and wastewater (SCP EU-L-3) certified materials. Interferences from most critical anions and cations were evaluated to determine the reliability of the method. The proposed method showed robustness since its performance is maintained over a wide range of pH and metal ion concentrations.

  4. Laboratory evaluation of the effect of nitric acid uptake on frost point hygrometer performance

    NASA Astrophysics Data System (ADS)

    Thornberry, T.; Gierczak, T.; Gao, R. S.; Vömel, H.; Watts, L. A.; Burkholder, J. B.; Fahey, D. W.

    2011-02-01

    Chilled mirror hygrometers (CMH) are widely used to measure water vapour in the troposphere and lower stratosphere from balloon-borne sondes. Systematic discrepancies among in situ water vapour instruments have been observed at low water vapour mixing ratios (<5 ppm) in the upper troposphere and lower stratosphere (UT/LS). Understanding the source of the measurement discrepancies is important for a more accurate and reliable determination of water vapour abundance in this region. We have conducted a laboratory study to investigate the potential interference of gas-phase nitric acid (HNO3) with the measurement of frost point temperature, and consequently the water vapour mixing ratio, determined by CMH under conditions representative of operation in the UT/LS. No detectable interference in the measured frost point temperature was found for HNO3 mixing ratios of up to 4 ppb for exposure times up to 150 min. HNO3 was observed to co-condense on the mirror frost, with the adsorbed mass increasing linearly with time at constant exposure levels. Over the duration of a typical balloon sonde ascent (90-120 min), the maximum accumulated HNO3 amounts were comparable to monolayer coverage of the geometric mirror surface area, which corresponds to only a small fraction of the actual frost layer surface area. This small amount of co-condensed HNO3 is consistent with the observed lack of HNO3 interference in the frost point measurement because the CMH utilizes significant reductions (>10%) in surface reflectivity by the condensate to determine H2O.

  5. Laboratory evaluation of the effect of nitric acid uptake on frost point hygrometer performance

    NASA Astrophysics Data System (ADS)

    Thornberry, T.; Gierczak, T.; Gao, R. S.; Vömel, H.; Watts, L. A.; Burkholder, J. B.; Fahey, D. W.

    2010-08-01

    Chilled mirror hygrometers (CMH) are widely used to measure water vapour in the troposphere and lower stratosphere from balloon-borne sondes. Systematic discrepancies among in situ water vapour instruments have been observed at low water vapour mixing ratios (<5 ppm) in the upper troposphere and lower stratosphere (UT/LS). Understanding the source of the measurement discrepancies is important for a more accurate and reliable determination of water vapour abundance in this region. We have conducted a laboratory study to investigate the potential interference of gas-phase nitric acid (HNO3) with the measurement of frost point temperature, and consequently the water vapour mixing ratio, determined by CMH under conditions representative of operation in the UT/LS. No detectable interference in the measured frost point temperature was found for HNO3 mixing ratios of up to 4 ppb for exposure times up to 150 min. HNO3 was observed to co-condense on the mirror frost, with the adsorbed mass increasing linearly with time at constant exposure levels. Over the duration of a typical balloon sonde ascent (90-120 min), the maximum accumulated HNO3 amounts were comparable to monolayer coverage of the geometric mirror surface area, which corresponds to only a small fraction of the actual frost layer surface area. This small amount of co-condensed HNO3 is consistent with the observed lack of HNO3 interference in the frost point measurement because the CMH utilizes significant reductions (>10%) in surface reflectivity by the condensate to determine H2O.

  6. Validation and results of a scale model of dew deposition in urban environments

    NASA Astrophysics Data System (ADS)

    Richards, K.; Oke, T. R.

    2002-12-01

    There is growing interest in urban dew and its significance in questions of urban climate and air pollution deposition, but little research has been undertaken to study it. In this study, a generic, urban residential neighbourhood is modelled out-of-doors at a scale of 0.125, using three wooden houses (1.08 m tall), a concrete pavement (1.0 m in width), a grassed park (7.5 m in half-width) and several small trees (up to 1.5 m tall). The thermal inertia of each house is inflated, according to the internal thermal mass (ITM) approach, so that nocturnal surface temperatures are conserved. First-order validation was achieved through comparison with data collected at nearby full-scale sites in Vancouver, BC, Canada. Moisture accumulation (measured by blotting on grass and by lysimetry) is found to be primarily controlled by nocturnal weather conditions and the intrinsic nature of each substrate, e.g. dewfall is abundant on nights with few clouds and light winds, and on surfaces such as grass and asphalt-shingle roofs, which cool rapidly after sunset. However, these responses are modified by location effects related to the net radiation balance of the surface, which itself is strongly linked to site geometry as expressed by sky view factor and whether surfaces are isolated from heat sources. The dominant mechanism is argued to be the systematic increase in longwave radiation loss that is associated with increased sky view. Results agree with those observed at the full scale and suggest that maps of sky view factor, and knowledge of dew at an open site, can potentially be used to create maps of dew distribution in urban and other complex environments.

  7. Total Acid Value Titration of Hydrotreated Biomass Fast Pyrolysis Oil: Determination of Carboxylic Acids and Phenolics with Multiple End-Point Detection

    SciTech Connect

    Christensen, E.; Alleman, T. L.; McCormick, R. L.

    2013-01-01

    Total acid value titration has long been used to estimate corrosive potential of petroleum crude oil and fuel oil products. The method commonly used for this measurement, ASTM D664, utilizes KOH in isopropanol as the titrant with potentiometric end point determination by pH sensing electrode and Ag/AgCl reference electrode with LiCl electrolyte. A natural application of the D664 method is titration of pyrolysis-derived bio-oil, which is a candidate for refinery upgrading to produce drop in fuels. Determining the total acid value of pyrolysis derived bio-oil has proven challenging and not necessarily amenable to the methodology employed for petroleum products due to the different nature of acids present. We presented an acid value titration for bio-oil products in our previous publication which also utilizes potentiometry using tetrabutylammonium hydroxide in place of KOH as the titrant and tetraethylammonium bromide in place of LiCl as the reference electrolyte to improve the detection of these types of acids. This method was shown to detect numerous end points in samples of bio-oil that were not detected by D664. These end points were attributed to carboxylic acids and phenolics based on the results of HPLC and GC-MS studies. Additional work has led to refinement of the method and it has been established that both carboxylic acids and phenolics can be determined accurately. Use of pH buffer calibration to determine half-neutralization potentials of acids in conjunction with the analysis of model compounds has allowed us to conclude that this titration method is suitable for the determination of total acid value of pyrolysis oil and can be used to differentiate and quantify weak acid species. The measurement of phenolics in bio-oil is subject to a relatively high limit of detection, which may limit the utility of titrimetric methodology for characterizing the acidic potential of pyrolysis oil and products.

  8. Relationship of amino acid composition and molecular weight of antifreeze glycopeptides to non-colligative freezing point depression.

    PubMed

    Schrag, J D; O'Grady, S M; DeVries, A L

    1982-08-01

    Many polar fishes synthesize a group of eight glycopeptides that exhibit a non-colligative lowering of the freezing point of water. These glycopeptides range in molecular weight between 2600 and 33 700. The largest glycopeptides [1-5] lower the freezing point more than the small ones on a weight basis and contain only two amino acids, alanine and threonine, with the disaccharide galactose-N-acetyl-galactosamine attached to threonine. The small glycopeptides, 6, 7, and 8, also lower the freezing point and contain proline, which periodically substitutes for alanine. Glycopeptides with similar antifreeze properties isolated from the saffron cod and the Atlantic tomcod contain an additional amino acid, arginine, which substitutes for threonine in glycopeptide 6. In this study we address the question of whether differences in amino acid composition or molecular weight between large and small glycopeptides are responsible for the reduced freezing point depressing capability of the low molecular weight glycopeptides. The results indicate that the degree of amino acid substitutions that occur in glycopeptides 6-8 do not have a significant effect on the unusual freezing point lowering and that the observed decrease in freezing point depression with smaller glycopeptides can be accounted for on the basis of molecular weight.

  9. Dew is a major factor affecting vegetation water use efficiency rather than a source of water in the eastern Mediterranean area

    NASA Astrophysics Data System (ADS)

    Ben-Asher, Jiftah; Alpert, Pinhas; Ben-Zvi, Arie

    2010-10-01

    The purpose here is to reexamine the ecological importance of dew in arid and semiarid regions with a focus on the eastern Mediterranean area. This reevaluation is of particular importance under the controversial perspective that dew is insufficient as a source of water for plants but is sufficient to promote the spread of plant diseases. Adana, Turkey, was selected as an appropriate semiarid test ground with well-documented meteorological data and a newly developed photosynthesis and transpiration rate monitor (PTM), which was used to detect the response of transpiration and photosynthesis to the presence of dew on the leaves. A convolution theoretical model was used to simulate no-dew days; simultaneously, PTM measurements were used to obtain actual situations with dew. Contrary to expectations, we detected separate, early peaks of photosynthesis and late peaks of transpiration, leading to an average ratio of about 2:1 units of water use efficiency (WUE) for dew-affected versus no-dew conditions. The impressive performance of the dew-affected WUE was explained by a synergy between (1) low transpiration during dew-affected morning hours and (2) high CO2 gradient toward the canopy. The first resulted from dew formation that created a humid environment in the near vicinity of the leaf followed by a low leaf to air vapor pressure deficit, which minimized transpiration. The second resulted from night respiration that induced a high CO2 gradient from the air toward the canopy. This synergy resulted in intensive carbon intake at a low water cost and explained the ecological importance of dew.

  10. A multi-point sensor based on optical fiber for the measurement of electrolyte density in lead-acid batteries.

    PubMed

    Cao-Paz, Ana M; Marcos-Acevedo, Jorge; del Río-Vázquez, Alfredo; Martínez-Peñalver, Carlos; Lago-Ferreiro, Alfonso; Nogueiras-Meléndez, Andrés A; Doval-Gandoy, Jesús

    2010-01-01

    This article describes a multi-point optical fiber-based sensor for the measurement of electrolyte density in lead-acid batteries. It is known that the battery charging process creates stratification, due to the different densities of sulphuric acid and water. In order to study this process, density measurements should be obtained at different depths. The sensor we describe in this paper, unlike traditional sensors, consists of several measurement points, allowing density measurements at different depths inside the battery. The obtained set of measurements helps in determining the charge (SoC) and state of health (SoH) of the battery. PMID:22319262

  11. A Multi-Point Sensor Based on Optical Fiber for the Measurement of Electrolyte Density in Lead-Acid Batteries

    PubMed Central

    Cao-Paz, Ana M.; Marcos-Acevedo, Jorge; del Río-Vázquez, Alfredo; Martínez-Peñalver, Carlos; Lago-Ferreiro, Alfonso; Nogueiras-Meléndez, Andrés A.; Doval-Gandoy, Jesús

    2010-01-01

    This article describes a multi-point optical fiber-based sensor for the measurement of electrolyte density in lead-acid batteries. It is known that the battery charging process creates stratification, due to the different densities of sulphuric acid and water. In order to study this process, density measurements should be obtained at different depths. The sensor we describe in this paper, unlike traditional sensors, consists of several measurement points, allowing density measurements at different depths inside the battery. The obtained set of measurements helps in determining the charge (SoC) and state of health (SoH) of the battery. PMID:22319262

  12. On the accuracy of acid-base determinations from potentiometric titrations using only a few points from the titration curve.

    PubMed

    Olin, A; Wallén, B

    1977-05-01

    There are several procedures which use only a few points on the titration curve for the calculation of equivalence volumes in acid-base titrations. The accuracy of such determinations will depend on the positions of the points on the titration curve. The effects of errors in the stability constants and in the pH measurements on the accuracy of the analysis have been considered, and the results are used to establish the conditions under which these errors are minimized.

  13. Novel ideas for maximising dew collection to aid plant establishment to combat desertification and restore degraded dry and arid lands

    NASA Astrophysics Data System (ADS)

    Kotzen, Benz

    2014-05-01

    This paper focuses on the potential of dew to provide water to plants and potentially to people as well in remote and difficult to reach areas where rainfall and underground water cannot be harvested. The combat of desertification and the restoration of degraded and desertified dry and arid lands has never been more urgent. A key practical component of this strategy is the restoration of habitat with planting. But for habitat and planting to survive there needs to be an adequate supply of water. In most cases providing water to the plant's roots is vital. In some areas where habitats have been destroyed, sufficient water is immediately available, for example through seasonal rainfall, or it can be harvested to concentrate adequate supplies of water to the roots. However, in arid and hyper arid areas, as well as in some dryland areas, a consistent and adequate supply of water cannot be provided by any conventional proven method. Thus, as the need to combat desertification and to restore desertified dry and arid land increases, so the need to find novel methods of establishing and maintaining planting and thus habitat increases. In more traditional land management scenarios this can be achieved through manipulating landform on a micro and macro scale, for example, by creating catchments, thereby collecting precipitation and directing it to the plants. Where this cannot be done, other means of water supply are usually required. Bainbridge (2007) and others have shown that supplying water to plants is possible through a number of traditional methods, for example, using clay pots. But most of these techniques require an introduced source of water, for example, obtained through water harvesting methods or by delivering water to site in tanks and by water bowser. This can work but requires continuous manpower. It is expensive and can be physically prohibitive in areas where access is difficult and/or remote. The concept of using dew to supply water in drylands is not new

  14. The effect of sire breed on the melting point and fatty acid composition of subcutaneous fat in steers.

    PubMed

    Perry, D; Nicholls, P J; Thompson, J M

    1998-01-01

    Fatty acid composition and the melting point of subcutaneous fat was determined in 18 Hereford, 25 Brahman x Hereford, 22 Simmental x Hereford, and 15 Friesian x Hereford steers that were grown out on pasture at two sites and slaughtered when the mean weight of the Herefords at each site was ca. 450 kg. Multivariate and univariate analyses tested the relations of fatty acid composition, degree of saturation, and melting point with sire breed, environment, age, and carcass characteristics. Hereford and Brahman steers were fatter than the Simmental and Friesian steers. Fat from Brahman-sired steers had a melting point 2.5 degrees C lower than fat from the Bos taurus-sired steers at the same age and had a higher proportion of unsaturated fatty acids, independent of variation in carcass weight and fatness. Melting point and degree of saturation decreased as age increased. Step-down discriminant analyses identified a set of three acids (14:0, 16:0, and 17:1) that differed among sire breeds, independent of differences in melting point: the acids 14:0 and 16:0 discriminated between Brahman and Bos taurus steers and 17:1 between Hereford and Simmental and Friesian steers. Increase in fatness was associated with an increase in 17:1, but, at the same fatness, no acids discriminated among the Bos taurus-sired steers. The use of Bos indicus cattle or their crossbreeds in situations in which hard-setting fat is likely may mitigate the problem. PMID:9464888

  15. Determination of Critical Point of pO2 Level in the Production of Lactic Acid by Lactobacillus rhamnosus

    NASA Astrophysics Data System (ADS)

    Mel, Maizirwan; Karim, Mohamed Ismail Abdul; Salleh, Mohamad Ramlan Mohamed; Abdullah, Rohane

    The study was conducted to determine the critical point of pO2 level in the production of lactic acid by Lactobacillus rhamnosus. The fermentation process was successfully carried out in laboratory scale fermenter/bioreactor using different pO2 level (the main parameter that significantly affects the growth of L. rhamnosus and lactic acid production) together with two other parameters; the agitation rate and pH. From the result, it was observed that the best production of lactic acid with the concentration of 16.85 g L-1 or 1.68% production yield has been obtained at the operating parameters of 5% pO2 level, agitation speed of 100 rpm and sample pH 6. The critical point of pO2 was found to be between 5 and 10%.

  16. Measurement of total acid number (TAN) and TAN boiling point distribution in petroleum products by electrospray ionization mass spectrometry.

    PubMed

    Qian, Kuangnan; Edwards, Kathleen E; Dechert, Gary J; Jaffe, Stephen B; Green, Larry A; Olmstead, William N

    2008-02-01

    We report a new method for rapid measurement of total acid number (TAN) and TAN boiling point (BP) distribution for petroleum crude and products. The technology is based on negative ion electrospray ionization mass spectrometry (ESI-MS) for selective ionization of petroleum acid and quantification of acid structures and molecular weight distributions. A chip-based nanoelectrospray system enables microscale (<200 mg) and higher throughput (20 samples/h) measurement. Naphthenic acid structures were assigned based on nominal masses of a set of predefined acid structures. Stearic acid is used as an internal standard to calibrate ESI-MS response factors for quantification purposes. With the use of structure-property correlations, boiling point distributions of TAN values can be calculated from the composition. The rapid measurement of TAN BP distributions by ESI is demonstrated for a series of high-TAN crudes and distillation cuts. TAN values determined by the technique agree well with those by the titration method. The distributed properties compare favorably with those measured by distillation and measurement of TAN of corresponding cuts.

  17. Point mutations in the S protein connect the sialic acid binding activity with the enteropathogenicity of transmissible gastroenteritis coronavirus.

    PubMed Central

    Krempl, C; Schultze, B; Laude, H; Herrler, G

    1997-01-01

    Enteropathogenic transmissible gastroenteritis virus (TGEV), a porcine coronavirus, is able to agglutinate erythrocytes because of sialic acid binding activity. Competitive inhibitors that may mask the sialic acid binding activity can be inactivated by sialidase treatment of virions. Here, we show that TGEV virions with efficient hemagglutinating activity were also obtained when cells were treated with sialidase prior to infection. This method was used to analyze TGEV mutants for hemagglutinating activity. Recently, mutants with strongly reduced enteropathogenicity that have point mutations or a deletion of four amino acids within residues 145 to 155 of the S protein have been described. Here, we show that in addition to their reduced pathogenicity, these mutants also have lost hemagglutinating activity. These results connect sialic acid binding activity with the enteropathogenicity of TGEV. PMID:9060696

  18. AMPHOTERIC BEHAVIOR OF COMPLEX SYSTEMS : IV. NOTE ON THE ISOELECTRIC POINT AND IONIZATION CONSTANTS OF SULFANILIC ACID.

    PubMed

    Stearn, A E

    1927-01-20

    From the solubility minimum the value of the basic ionization constant of sulfanilic acid is shown to lie probably between the values 1.7 x 10(-15) and 3.2 x 10(-15). From solubility measurements the value of this same constant is shown to lie probably between 2.0 and 2.2 x 10(-15), and the isoelectric point of sulfanilic acid is thus at a cH of 0.056 or a pH of 1.25. From conductivity ratios the acid ionization constant of sulfanilic acid is shown to be 7.05 x 10(-4) at room temperature (21 degrees C.). Calculations are made, from data published in preceding papers, of the ionization constants of glycine, K(a) being 2.3 x 10(-10), and K(b) being 2.2 x 10(-12).

  19. Methods for point-of-care detection of nucleic acid in a sample

    DOEpatents

    Bearinger, Jane P.; Dugan, Lawrence C.

    2015-12-29

    Provided herein are methods and apparatus for detecting a target nucleic acid in a sample and related methods and apparatus for diagnosing a condition in an individual. The condition is associated with presence of nucleic acid produced by certain pathogens in the individual.

  20. Apparatus for point-of-care detection of nucleic acid in a sample

    DOEpatents

    Bearinger, Jane P.; Dugan, Lawrence C.

    2016-04-19

    Provided herein are methods and apparatus for detecting a target nucleic acid in a sample and related methods and apparatus for diagnosing a condition in an individual. The condition is associated with presence of nucleic acid produced by certain pathogens in the individual.

  1. Increase of Unsaturated Fatty Acids (Low Melting Point) of Broiler Fatty Waste Obtained Through Staphylococcus xylosus Fermentation.

    PubMed

    Marques, Roger V; Duval, Eduarda H; Corrêa, Luciara B; Corrêa, Érico K

    2015-11-01

    The increasing rise in the production of meat around the world causes a significant generation of agro-industrial waste--most of it with a low value added. Fatty wastes have the potential of being converted into biodiesel, given the overcome of technological and economical barriers, as well as its presentation in solid form. Therefore, the aim of this work was to investigate the capacity of Staphylococcus xylosus strains to modify the chemical structure of chicken fatty wastes intending to reduce the melting points of the wastes to mild temperatures, thereby breaking new ground in the production of biodiesel from these sources in an economically attractive and sustainable manner. The effects in time of fermentation and concentration of the fat in the medium were investigated, assessing the melting point and profile of fatty acids. The melting temperature showed a decrease of approximately 22 °C in the best operational conditions, due to reduction in the content of saturated fatty acids (high melting point) and increase of unsaturated fatty acids (low melting point).

  2. Electrostatic precipitation of condensed acid mist

    SciTech Connect

    Not Available

    1990-01-01

    This project addresses the acid mist that is formed by condensation of sulfuric acid vapor in flue gas from coal-fired utility boilers. An acid mist can be formed whenever the flue gas temperature approaches the prevailing acid dew point. This commonly occurs when the gas is subjected to rapid adiabatic cooling in a wet scrubber system for flue gas desulfurization. Acid mists can also sometimes result from unexpected temperature excursions caused by air inleakage, load cycling, and start-up operations. A wet electrostatic precipitator (WESP) is the best control option for acid mist. The mist would blind a fabric filter and attach glass fiber fabrics. A wet ESP is required because the acid would quickly corrode the plates in a conventional dry ESP. The wet ESP also offers the advantages of no rapping reentrainment and no sensitivity to fly ash resistivity. Therefore, this program has been structured around the use of a compact, wet ESP to control acid mist emissions. Progress to date is discussed. 7 refs., 1 fig.

  3. Electrostatic precipitation of condensed acid mist

    SciTech Connect

    Not Available

    1990-01-01

    This project addresses the acid mist that is formed by condensation of sulfuric acid vapor in flue gas from coal-fired utility boilers. An acid mist can be formed whenever the flue gas temperature approaches the prevailing acid dew point. This commonly occurs when the gas is subjected to rapid adiabatic cooling in a wet scrubber system for flue gas desulfurization. Acid mists can also sometimes result from unexpected temperature excursions caused by air inleakage, load cycling, and start-up operations. A wet electrostatic precipitator (WESP) is the best control option for acid mist. The mist would blind a fabric filter and attack glass fiber fabrics. A wet ESP is required because the acid would quickly corrode the plates in a conventional dry ESP. The wet ESP also offers the advantages of no rapping reentrainment and no sensitivity to fly ash resistivity. Therefore, this program has been structured around the use of a compact, wet ESP to control acid mist emissions. 7 refs.

  4. The Achene Mucilage Hydrated in Desert Dew Assists Seed Cells in Maintaining DNA Integrity: Adaptive Strategy of Desert Plant Artemisia sphaerocephala

    PubMed Central

    Yang, Xuejun; Zhang, Wenhao; Dong, Ming; Boubriak, Ivan; Huang, Zhenying

    2011-01-01

    Despite proposed ecological importance of mucilage in seed dispersal, germination and seedling establishment, little is known about the role of mucilage in seed pre-germination processes. Here we investigated the role of mucilage in assisting achene cells to repair DNA damage during dew deposition in the desert. Artemisia sphaerocephala achenes were first treated γ-irradiation to induce DNA damage, and then they were repaired in situ in the desert dew. Dew deposition duration can be as long as 421 min in early mornings. Intact achenes absorbed more water than demucilaged achenes during dew deposition and also carried water for longer time following sunrise. After 4-d dew treatment, DNA damage of irradiated intact and demucilaged achenes was reduced to 24.38% and 46.84%, respectively. The irradiated intact achenes exhibited much higher DNA repair ratio than irradiated demucilaged achenes. Irradiated intact achenes showed an improved germination and decreased nonviable achenes after dew treatment, and significant differences in viability between the two types of achenes were detected after 1020 min of dew treatment. Achene mucilage presumably plays an ecologically important role in the life cycle of A. sphaerocephala by aiding DNA repair of achene cells in genomic-stressful habitats. PMID:21912689

  5. CMP-Sialic Acid Synthetase: The Point of Constriction in the Sialylation Pathway.

    PubMed

    Sellmeier, Melanie; Weinhold, Birgit; Münster-Kühnel, Anja

    2015-01-01

    Sialoglycoconjugates form the outermost layer of animal cells and play a crucial role in cellular communication processes. An essential step in the biosynthesis of sialylated glycoconjugates is the activation of sialic acid to the monophosphate diester CMP-sialic acid. Only the activated sugar is transported into the Golgi apparatus and serves as a substrate for the linkage-specific sialyltransferases. Interference with sugar activation abolishes sialylation and is embryonic lethal in mammals. In this chapter we focus on the enzyme catalyzing the activation of sialic acid, the CMP-sialic acid synthetase (CMAS), and compare the enzymatic properties of CMASs isolated from different species. Information concerning the reaction mechanism and active site architecture is included. Moreover, the unusual nuclear localization of vertebrate CMASs as well as the biotechnological application of bacterial CMAS enzymes is addressed.

  6. Point-of-care multiplexed assays of nucleic acids using microcapillary-based loop-mediated isothermal amplification.

    PubMed

    Zhang, Yi; Zhang, Lu; Sun, Jiashu; Liu, Yulei; Ma, Xingjie; Cui, Shangjin; Ma, Liying; Xi, Jianzhong Jeff; Jiang, Xingyu

    2014-07-15

    This report demonstrates a straightforward, robust, multiplexed and point-of-care microcapillary-based loop-mediated isothermal amplification (cLAMP) for assaying nucleic acids. This assay integrates capillaries (glass or plastic) to introduce and house sample/reagents, segments of water droplets to prevent contamination, pocket warmers to provide heat, and a hand-held flashlight for a visual readout of the fluorescent signal. The cLAMP system allows the simultaneous detection of two RNA targets of human immunodeficiency virus (HIV) from multiple plasma samples, and achieves a high sensitivity of two copies of standard plasmid. As few nucleic acid detection methods can be wholly independent of external power supply and equipment, our cLAMP holds great promise for point-of-care applications in resource-poor settings. PMID:24937125

  7. Investigating the significance of zero-point motion in small molecular clusters of sulphuric acid and water

    SciTech Connect

    Stinson, Jake L. Ford, Ian J.; Kathmann, Shawn M.

    2014-01-14

    The nucleation of particles from trace gases in the atmosphere is an important source of cloud condensation nuclei, and these are vital for the formation of clouds in view of the high supersaturations required for homogeneous water droplet nucleation. The methods of quantum chemistry have increasingly been employed to model nucleation due to their high accuracy and efficiency in calculating configurational energies; and nucleation rates can be obtained from the associated free energies of particle formation. However, even in such advanced approaches, it is typically assumed that the nuclei have a classical nature, which is questionable for some systems. The importance of zero-point motion (also known as quantum nuclear dynamics) in modelling small clusters of sulphuric acid and water is tested here using the path integral molecular dynamics method at the density functional level of theory. The general effect of zero-point motion is to distort the mean structure slightly, and to promote the extent of proton transfer with respect to classical behaviour. In a particular configuration of one sulphuric acid molecule with three waters, the range of positions explored by a proton between a sulphuric acid and a water molecule at 300 K (a broad range in contrast to the confinement suggested by geometry optimisation at 0 K) is clearly affected by the inclusion of zero point motion, and similar effects are observed for other configurations.

  8. Investigating the significance of zero-point motion in small molecular clusters of sulphuric acid and water.

    PubMed

    Stinson, Jake L; Kathmann, Shawn M; Ford, Ian J

    2014-01-14

    The nucleation of particles from trace gases in the atmosphere is an important source of cloud condensation nuclei, and these are vital for the formation of clouds in view of the high supersaturations required for homogeneous water droplet nucleation. The methods of quantum chemistry have increasingly been employed to model nucleation due to their high accuracy and efficiency in calculating configurational energies; and nucleation rates can be obtained from the associated free energies of particle formation. However, even in such advanced approaches, it is typically assumed that the nuclei have a classical nature, which is questionable for some systems. The importance of zero-point motion (also known as quantum nuclear dynamics) in modelling small clusters of sulphuric acid and water is tested here using the path integral molecular dynamics method at the density functional level of theory. The general effect of zero-point motion is to distort the mean structure slightly, and to promote the extent of proton transfer with respect to classical behaviour. In a particular configuration of one sulphuric acid molecule with three waters, the range of positions explored by a proton between a sulphuric acid and a water molecule at 300 K (a broad range in contrast to the confinement suggested by geometry optimisation at 0 K) is clearly affected by the inclusion of zero point motion, and similar effects are observed for other configurations.

  9. Voltammetric iodometric titration of ascorbic acid with dead-stop end-point detection in fresh vegetables and fruit samples.

    PubMed

    Verdini, R A; Lagier, C M

    2000-07-01

    The present work describes a method for determining ascorbic acid, which combines iodometry with a voltammetric technique to detect the end point of the titration. In addition, the validity of the method applied to natural vegetable or fruit samples was assessed. The results were compared with those obtained by an accurate method such as HPLC using UV detection. Similar values of ascorbic acid for different natural samples were obtained by means of this approach (p > 0.05). The limit of quantification was 0.1 mg. This technique presents the advantage of other electroanalytical methods such as avoiding filtration or ultracentrifugation steps, with the additional benefit of using the platinum electrodes, which are routinely used in the laboratory. These facts allow a rapid and efficient quantification of ascorbic acid with very low cost of reagents and equipment.

  10. TECHNICAL DESIGN NOTE: The method for controlling dew droplets deposited on a copper plate by scattered laser light

    NASA Astrophysics Data System (ADS)

    Matsumoto, Shigeaki

    2008-01-01

    Tiny dew droplets deposited on a copper plate were controlled constantly by a developed control technique using scattered laser light for studying initial dropwise condensation. The technique employs proportional control combined with shifting movement by an integrator. The droplets were controlled for 60 min at almost constant diameters in a range from only a few micrometers to tens of micrometers and were almost hemispherical in the initial condensation at room temperature.

  11. Nucleic-acid testing, new platforms and nanotechnology for point-of-decision diagnosis of animal pathogens.

    PubMed

    Teles, Fernando; Fonseca, Luís

    2015-01-01

    Accurate disease diagnosis in animals is crucial for animal well-being but also for preventing zoonosis transmission to humans. In particular, livestock diseases may constitute severe threats to humans due to the particularly high physical contact and exposure and, also, be the cause of important economic losses, even in non-endemic countries, where they often arise in the form of rapid and devastating epidemics. Rapid diagnostic tests have been used for a long time in field situations, particularly during outbreaks. However, they mostly rely on serological approaches, which may confirm the exposure to a particular pathogen but may be inappropriate for point-of-decision (point-of-care) settings when emergency responses supported on early and accurate diagnosis are required. Moreover, they often exhibit modest sensitivity and hence significantly depend on later result confirmation in central or reference laboratories. The impressive advances observed in recent years in materials sciences and in nanotechnology, as well as in nucleic-acid synthesis and engineering, have led to an outburst of new in-the-bench and prototype tests for nucleic-acid testing towards point-of-care diagnosis of genetic and infectious diseases. Manufacturing, commercial, regulatory, and technical nature issues for field applicability more likely have hindered their wider entrance into veterinary medicine and practice than have fundamental science gaps. This chapter begins by outlining the current situation, requirements, difficulties, and perspectives of point-of-care tests for diagnosing diseases of veterinary interest. Nucleic-acid testing, particularly for the point of care, is addressed subsequently. A range of valuable signal transduction mechanisms commonly employed in proof-of-concept schemes and techniques born on the analytical chemistry laboratories are also described. As the essential core of this chapter, sections dedicated to the principles and applications of microfluidics, lab

  12. Self-propulsion of dew drops on lotus leaves: a potential mechanism for self cleaning.

    PubMed

    Watson, Gregory S; Gellender, Marty; Watson, Jolanta A

    2014-01-01

    This study shows that condensation on the hierarchically structured lotus leaf can facilitate self-propulsion of water droplets off the surface. Droplets on leaves inclined at high angles can be completely removed from the surface by self-propulsion with the assistance of gravity. Due to the small size of mobile droplets, light breezes may also fully remove the propelled droplets, which are typically projected beyond the boundary layer of the leaf cuticle. Moreover the self-propelled droplets/condensate were able to remove contaminants (eg silica particles) from the leaf surface. The biological significance of this process may be associated with maintaining a healthy cuticle surface when the action of rain to clean the surface via the lotus effect is not possible (due to no precipitation). Indeed, the native lotus plants in this study were located in a region with extended time periods (several months) without rain. Thus, dew formation on the leaf may provide an alternative self-cleaning mechanism during times of drought and optimise the functional efficiency of the leaf surface as well as protecting the surface from long term exposure to pathogens such as bacteria and fungi. PMID:24628521

  13. Self-propulsion of dew drops on lotus leaves: a potential mechanism for self cleaning.

    PubMed

    Watson, Gregory S; Gellender, Marty; Watson, Jolanta A

    2014-01-01

    This study shows that condensation on the hierarchically structured lotus leaf can facilitate self-propulsion of water droplets off the surface. Droplets on leaves inclined at high angles can be completely removed from the surface by self-propulsion with the assistance of gravity. Due to the small size of mobile droplets, light breezes may also fully remove the propelled droplets, which are typically projected beyond the boundary layer of the leaf cuticle. Moreover the self-propelled droplets/condensate were able to remove contaminants (eg silica particles) from the leaf surface. The biological significance of this process may be associated with maintaining a healthy cuticle surface when the action of rain to clean the surface via the lotus effect is not possible (due to no precipitation). Indeed, the native lotus plants in this study were located in a region with extended time periods (several months) without rain. Thus, dew formation on the leaf may provide an alternative self-cleaning mechanism during times of drought and optimise the functional efficiency of the leaf surface as well as protecting the surface from long term exposure to pathogens such as bacteria and fungi.

  14. Optimization of a Nucleic Acids united-RESidue 2-Point model (NARES-2P) with a maximum-likelihood approach

    SciTech Connect

    He, Yi; Scheraga, Harold A.; Liwo, Adam

    2015-12-28

    Coarse-grained models are useful tools to investigate the structural and thermodynamic properties of biomolecules. They are obtained by merging several atoms into one interaction site. Such simplified models try to capture as much as possible information of the original biomolecular system in all-atom representation but the resulting parameters of these coarse-grained force fields still need further optimization. In this paper, a force field optimization method, which is based on maximum-likelihood fitting of the simulated to the experimental conformational ensembles and least-squares fitting of the simulated to the experimental heat-capacity curves, is applied to optimize the Nucleic Acid united-RESidue 2-point (NARES-2P) model for coarse-grained simulations of nucleic acids recently developed in our laboratory. The optimized NARES-2P force field reproduces the structural and thermodynamic data of small DNA molecules much better than the original force field.

  15. Optimization of a Nucleic Acids united-RESidue 2-Point model (NARES-2P) with a maximum-likelihood approach

    NASA Astrophysics Data System (ADS)

    He, Yi; Liwo, Adam; Scheraga, Harold A.

    2015-12-01

    Coarse-grained models are useful tools to investigate the structural and thermodynamic properties of biomolecules. They are obtained by merging several atoms into one interaction site. Such simplified models try to capture as much as possible information of the original biomolecular system in all-atom representation but the resulting parameters of these coarse-grained force fields still need further optimization. In this paper, a force field optimization method, which is based on maximum-likelihood fitting of the simulated to the experimental conformational ensembles and least-squares fitting of the simulated to the experimental heat-capacity curves, is applied to optimize the Nucleic Acid united-RESidue 2-point (NARES-2P) model for coarse-grained simulations of nucleic acids recently developed in our laboratory. The optimized NARES-2P force field reproduces the structural and thermodynamic data of small DNA molecules much better than the original force field.

  16. Freezing points and small-scale deicing tests for salts of levulinic acid made from grain sorghum.

    PubMed

    Ganjyal, G; Fang, Q; Hanna, M A

    2007-11-01

    Deicers from renewable resources are needed to overcome the disadvantages of using traditional deicers. Salts made from levulinic acid produced using grain sorghum as raw material were tested as road deicing agents. Freezing points of these salts viz., sodium levulinate, magnesium levulinate and calcium levulinate along with rock salt (sodium chloride) were determined according to American Society for Testing and Materials (ASTM) D 1177-94 standard at concentrations of 10, 20, 30 and 40 % w/w. There were significant differences among the freezing points of the salts. Freezing points for rock salt, sodium levulinate, calcium levulinate and magnesium levulinate, for different concentrations, were in the ranges of -6.6 to -20.5, -2.9 to -15.0, -2.1 to -7.8 and -1.5 to -6.5 degrees C, respectively. Deicing effectiveness of the salts of levulinic acid were investigated by conducting small-scale deicing tests with aqueous solutions of various salt concentrations (2%, 5% and 10%) in a laboratory freezer and by spraying the deicer on a graveled surface covered by ice and snow with the average temperature during the testing at -2.7 degrees C. Deicing capabilities of the three salts of levulinic acid differed. At -2.7 degrees C, all three salts caused melting of the ice. Among the different levulinates studied sodium levulinate was the most effective deicing agent. These salts of levulinates could be a viable replacement for traditional deicers and could help in reducing the disadvantages of traditional deicers.

  17. Inter-relationships between solubilities, distribution coefficients and melting points of some substituted benzoic and phenylacetic acids.

    PubMed

    Armstrong, N A; James, K C; Wong, C K

    1979-09-01

    Ten 4-hydroxy and 4-alkoxy benzoic and phenylalkanoic acids have been investigated. Solubilities in aqueous buffer at pH 1.2 were determined, together with distribution coefficients between the buffer and either octanol or isopropyl myristate. When plotted against the total number of carbon atoms in the side chains, log octanol/water distribution coefficients gave two parallel straight lines, one for the substituted benzoic acids, and the other for the substituted phenylalkanoic acids. The slopes approximated to 0.5, the generally accepted value for methylene. Similar plots could be obtained with isopropyl myristate, provided the hydroxy acid results were ignored, and also when log aqueous solubilities were plotted against carbon number, although there was considerable scatter. The differences between the distribution coefficient results were explained in terms of solute-solvent interactions, and the scatter attributed to variations in the heats of fusion of the solutes. Yalkowsky's equation (1977), linking aqueous solubilities and melting points with distribution coefficients, was applied to the results, and found to be of limited predictive value. PMID:41067

  18. Magnetic droplet manipulation platforms for nucleic acid detection at the point of care.

    PubMed

    Shin, Dong Jin; Wang, Tza-Huei

    2014-11-01

    This review summarizes recent developments in the use of magnetically actuated droplets in point-of-care molecular diagnostic platforms. We discuss the fundamentals of magnetic droplet manipulation and the various modes of actuation. The balance of forces acting on a droplet during transport and particle extraction, as well as the devices and instrumentation developed to perform these operations will be presented and discussed. Furthermore, we review some of the recent advances on the diagnostic applications of platforms utilizing magnetic manipulation for genetic assessment of biological samples.

  19. Acidic resin-catalysed conversion of fructose into furan derivatives in low boiling point solvents.

    PubMed

    Zhu, Hong; Cao, Quan; Li, Chunhu; Mu, Xindong

    2011-09-27

    Conversion of fructose into furan derivatives 5-hydroxymethylfurfural (HMF) and 5-methoxymethylfurfural (MMF) is performed in tetrahydrofuran (THF) and methanol-organic solvent systems, catalysed by an acidic resin Amberlyst-15. The melted fructose can be converted into HMF on the surface of the solid resin catalyst in the presence of THF as an extracting phase, which is a good solvent for HMF and other by-products. The solid resin catalyst can be reused eleven times without losing its catalytic ability, with an average HMF yield of approximately 50%. Upon the addition of methanol, the generated HMF can further react with methanol to form MMF, and the total yield of HMF and MMF could be promoted to 65%. GC-MS analysis confirms the formation of a small amount of methyl levulinate in methanolorganic solvent system.

  20. An integrated paper-based sample-to-answer biosensor for nucleic acid testing at the point of care.

    PubMed

    Choi, Jane Ru; Hu, Jie; Tang, Ruihua; Gong, Yan; Feng, Shangsheng; Ren, Hui; Wen, Ting; Li, XiuJun; Wan Abas, Wan Abu Bakar; Pingguan-Murphy, Belinda; Xu, Feng

    2016-02-01

    With advances in point-of-care testing (POCT), lateral flow assays (LFAs) have been explored for nucleic acid detection. However, biological samples generally contain complex compositions and low amounts of target nucleic acids, and currently require laborious off-chip nucleic acid extraction and amplification processes (e.g., tube-based extraction and polymerase chain reaction (PCR)) prior to detection. To the best of our knowledge, even though the integration of DNA extraction and amplification into a paper-based biosensor has been reported, a combination of LFA with the aforementioned steps for simple colorimetric readout has not yet been demonstrated. Here, we demonstrate for the first time an integrated paper-based biosensor incorporating nucleic acid extraction, amplification and visual detection or quantification using a smartphone. A handheld battery-powered heating device was specially developed for nucleic acid amplification in POC settings, which is coupled with this simple assay for rapid target detection. The biosensor can successfully detect Escherichia coli (as a model analyte) in spiked drinking water, milk, blood, and spinach with a detection limit of as low as 10-1000 CFU mL(-1), and Streptococcus pneumonia in clinical blood samples, highlighting its potential use in medical diagnostics, food safety analysis and environmental monitoring. As compared to the lengthy conventional assay, which requires more than 5 hours for the entire sample-to-answer process, it takes about 1 hour for our integrated biosensor. The integrated biosensor holds great potential for detection of various target analytes for wide applications in the near future.

  1. An integrated paper-based sample-to-answer biosensor for nucleic acid testing at the point of care.

    PubMed

    Choi, Jane Ru; Hu, Jie; Tang, Ruihua; Gong, Yan; Feng, Shangsheng; Ren, Hui; Wen, Ting; Li, XiuJun; Wan Abas, Wan Abu Bakar; Pingguan-Murphy, Belinda; Xu, Feng

    2016-02-01

    With advances in point-of-care testing (POCT), lateral flow assays (LFAs) have been explored for nucleic acid detection. However, biological samples generally contain complex compositions and low amounts of target nucleic acids, and currently require laborious off-chip nucleic acid extraction and amplification processes (e.g., tube-based extraction and polymerase chain reaction (PCR)) prior to detection. To the best of our knowledge, even though the integration of DNA extraction and amplification into a paper-based biosensor has been reported, a combination of LFA with the aforementioned steps for simple colorimetric readout has not yet been demonstrated. Here, we demonstrate for the first time an integrated paper-based biosensor incorporating nucleic acid extraction, amplification and visual detection or quantification using a smartphone. A handheld battery-powered heating device was specially developed for nucleic acid amplification in POC settings, which is coupled with this simple assay for rapid target detection. The biosensor can successfully detect Escherichia coli (as a model analyte) in spiked drinking water, milk, blood, and spinach with a detection limit of as low as 10-1000 CFU mL(-1), and Streptococcus pneumonia in clinical blood samples, highlighting its potential use in medical diagnostics, food safety analysis and environmental monitoring. As compared to the lengthy conventional assay, which requires more than 5 hours for the entire sample-to-answer process, it takes about 1 hour for our integrated biosensor. The integrated biosensor holds great potential for detection of various target analytes for wide applications in the near future. PMID:26759062

  2. Cloud point extraction of plutonium in environmental matrixes coupled to ICPMS and α spectrometry in highly acidic conditions.

    PubMed

    Labrecque, Charles; Whitty-Léveillé, Laurence; Larivière, Dominic

    2013-11-01

    A new cloud point extraction procedure has been developed for the quantification of plutonium(IV) in environmental samples. The separation procedure can be either coupled to inductively coupled plasma mass spectrometry (ICPMS) or α spectrometry for plutonium quantification. The method uses a combination of selective ligand (P,P'-di(2-ethylhexyl) methanediphosphonic acid (H2DEH[MDP])) and micelle shielding by bromine formation to enable quantitative extraction of Pu in highly acidic solutions. Cross-optimization of all parameters (nonionic and ionic surfactant, chelating agent, bromate, bromide, and pH) led to optimal of the extraction conditions. Figures of merit of the method for the detection using α spectrometry and ICPMS are reported (limit of detection, limit of quantification, minimal detectable activity, and recovery). Quantitative extractions (>95%) were obtained for a wide variety of aqueous and digested samples (synthetic urine, wastewater, drinking water, seawater, and soil samples). The method features the first successful coupling between α spectrometry and cloud point extraction and is the first demonstration of CPE suitability with metaborate fusion as a sample preparation approach, techniques used extensively in nuclear industries.

  3. Influence of cyclic dimer formation on the phase behavior of carboxylic acids. II. Cross-associating systems.

    PubMed

    Janeček, Jiří; Paricaud, Patrice

    2013-08-15

    The doubly bonded dimer association scheme (DBD) proposed by Sear and Jackson is extended to mixtures exhibiting both self- and cross-associations. The PC-SAFT equation of state is combined with the new DBD association contribution to describe the vapor-liquid equilibria of binary mixtures of carboxylic acids + associating compounds (water, alcohols, and carboxylic acids). The effect of doubly bonded dimers on the phase behavior in such systems is less important than in mixtures of carboxylic acids with nonassociating compounds, due to the cross-associations that compete with the formation of DBDs. Nevertheless, a clear improvement in the description of vapor-liquid coexistence curves is achieved over the classical 2B association model, particularly for the dew point curves.

  4. Quantifying diffuse and point inputs of perfluoroalkyl acids in a nonindustrial river catchment.

    PubMed

    Müller, Claudia E; Spiess, Nora; Gerecke, Andreas C; Scheringer, Martin; Hungerbühler, Konrad

    2011-12-01

    Recently, the role of diffuse inputs of perfluoroalkyl acids (PFAAs) into surface waters has been investigated. It has been observed that river loads increased during rain and that street runoff contained considerable loads of PFAAs. This study aims at quantifying these diffuse inputs and identifying the initial sources in a small nonindustrial river catchment. The river was sampled in three distinct subcatchments (rural, urban, and wastewater treatment plant) at high temporal resolution during two rain events and samples were analyzed for perfluorocarboxylates and perfluorosulfonates. Additionally, rain, stormwater runoff, wastewater effluent, and drinking water were sampled. PFAA concentrations in river water were all low (e.g., < 10 ng/L for perfluorooctanoate, PFOA), but increased during rainfall. PFAA concentrations and water discharge data were integrated into a mass balance assessment that shows that 30-60% of PFAA loads can be attributed to diffuse inputs. Rain contributed 10-50% of the overall loads, mobilization of dry deposition and outdoor release of PFAA from products with 20-60%. We estimated that within a year 2.5-5 g of PFOA originating from rain and surface runoff are emitted into this small catchment (6 km(2), 12,500 persons).

  5. Quantifying diffuse and point inputs of perfluoroalkyl acids in a nonindustrial river catchment.

    PubMed

    Müller, Claudia E; Spiess, Nora; Gerecke, Andreas C; Scheringer, Martin; Hungerbühler, Konrad

    2011-12-01

    Recently, the role of diffuse inputs of perfluoroalkyl acids (PFAAs) into surface waters has been investigated. It has been observed that river loads increased during rain and that street runoff contained considerable loads of PFAAs. This study aims at quantifying these diffuse inputs and identifying the initial sources in a small nonindustrial river catchment. The river was sampled in three distinct subcatchments (rural, urban, and wastewater treatment plant) at high temporal resolution during two rain events and samples were analyzed for perfluorocarboxylates and perfluorosulfonates. Additionally, rain, stormwater runoff, wastewater effluent, and drinking water were sampled. PFAA concentrations in river water were all low (e.g., < 10 ng/L for perfluorooctanoate, PFOA), but increased during rainfall. PFAA concentrations and water discharge data were integrated into a mass balance assessment that shows that 30-60% of PFAA loads can be attributed to diffuse inputs. Rain contributed 10-50% of the overall loads, mobilization of dry deposition and outdoor release of PFAA from products with 20-60%. We estimated that within a year 2.5-5 g of PFOA originating from rain and surface runoff are emitted into this small catchment (6 km(2), 12,500 persons). PMID:22035097

  6. OBITUARY: Eur.Ing. Professor David Dew-Hughes in memoriam

    NASA Astrophysics Data System (ADS)

    Campbell, Archie; Dew-Hughes, Denise; Donaldson, Gordon; Palmer, Richard

    2007-06-01

    We regret to announce the death of David Dew-Hughes, the second Honorary Editor of Superconductor Science and Technology, in Autumn 2006. He was born in Manchester, the eldest of three children, attended Manchester Grammar School and took his first degree in metallurgy at Birmingham, before undertaking a Doctorate of Engineering at Yale University. After initial work for IBM on semiconductors, he returned to England as a lecturer in metallurgy at Cambridge University. There he devoted his career to superconductivity long before it became fashionable, starting a group on the properties of what we now know as type II materials, with his students Jan Evetts, Archie Campbell and Anant Narlikar. Between them they paved the way to our understanding of the magnetic vortex properties of these materials, and thus to the development of modern practical materials for superconducting magnets. Eur.Ing. Professor David Dew-Hughes 1932-2006 In 1965 he became a founding Senior Lecturer in physics at Lancaster University, moving to Brookhaven National Laboratory in 1974. His final academic post was in engineering science at Oxford University where he also held a University College Tutorial Fellowship. As long ago as 1971 David wrote an authoritative review for Reports on Progress in Physics on 'The metallurgical enhancement of type II superconductors'. Following the discovery of high-Tc superconductivity, IOP Publishing launched Superconductor Science and Technology in 1988 and he was a founder member of its Editorial Board. When Jan Evetts retired as Honorary Editor in 1992, David was the natural choice as his successor. He served a five year term and remained on the Board as Deputy Editor until the end of 2000. To mark the 10th anniversary of high-temperature superconductivity in 1997, David edited a special issue of Superconductor Science and Technology in which past and present members of the Editorial Board contributed reviews of their specialities. He noted that at that time

  7. A Branch Point of Streptomyces Sulfur Amino Acid Metabolism Controls the Production of Albomycin

    PubMed Central

    Kulkarni, Aditya; Zeng, Yu; Zhou, Wei; Van Lanen, Steven; Zhang, Weiwen

    2015-01-01

    Albomycin (ABM), also known as grisein, is a sulfur-containing metabolite produced by Streptomyces griseus ATCC 700974. Genes predicted to be involved in the biosynthesis of ABM and ABM-like molecules are found in the genomes of other actinomycetes. ABM has potent antibacterial activity, and as a result, many attempts have been made to develop ABM into a drug since the last century. Although the productivity of S. griseus can be increased with random mutagenesis methods, understanding of Streptomyces sulfur amino acid (SAA) metabolism, which supplies a precursor for ABM biosynthesis, could lead to improved and stable production. We previously characterized the gene cluster (abm) in the genome-sequenced S. griseus strain and proposed that the sulfur atom of ABM is derived from either cysteine (Cys) or homocysteine (Hcy). The gene product, AbmD, appears to be an important link between primary and secondary sulfur metabolic pathways. Here, we show that propargylglycine or iron supplementation in growth media increased ABM production by significantly changing the relative concentrations of intracellular Cys and Hcy. An SAA metabolic network of S. griseus was constructed. Pathways toward increasing Hcy were shown to positively impact ABM production. The abmD gene and five genes that increased the Hcy/Cys ratio were assembled downstream of hrdBp promoter sequences and integrated into the chromosome for overexpression. The ABM titer of one engineered strain, SCAK3, in a chemically defined medium was consistently improved to levels ∼400% of the wild type. Finally, we analyzed the production and growth of SCAK3 in shake flasks for further process development. PMID:26519385

  8. Effect of proteins with different isoelectric points on the gene transfection efficiency mediated by stearic acid grafted chitosan oligosaccharide micelles.

    PubMed

    Yan, Jingjing; Du, Yong-Zhong; Chen, Feng-Ying; You, Jian; Yuan, Hong; Hu, Fu-Qiang

    2013-07-01

    A stearic acid-grafted chitosan oligosaccharide (CS-SA) micelle has been demonstrated as an effective gene carrier in vitro and in vivo. Although being advantageous for DNA package, protection, and excellent cellular internalization, a CS-SA based delivery system may lead to difficulties in the dissociation of polymer/DNA complexes in intracells. In this research, bovine serum albumin (BSA) with a different isoelectric point value (4.7, 6.0 and 9.3) was synthesized and incorporated into a CS-SA based gene delivery system. CS-SA/DNA binary complexes and CS-SA/BSA/DNA ternary complexes were then prepared and characterized. The binding ability of the CS-SA vector with DNA was not affected by the incorporation of BSA. However, referring to the transfection activity, the BSA of different isoelectric point value (pI) had a distinct influence on the CS-SA/BSA/DNA complexes. CS-SA/BSA(4.7)/DNA and CS-SA/BSA(6.0)/DNA complexes had better transfection efficiency than binary complexes, especially CS-SA/BSA(4.7)/DNA complexes which showed the highest transfection efficiency. On the contrary, CS-SA/BSA(9.3)/DNA complexes had undesirable performances. Interestingly, the incorporation of BSA(4.7) in CS-SA/DNA complexes significantly enhanced the dissociation of polymer/DNA complexes and improved the release of DNA intracellular without influencing their cellular uptake. The aforementioned results indicated that the acid group in protein played an important role in enhancing the transfection efficiency of CS/BSA/DNA complexes, and the study provided guidelines in the design of an efficient vector for DNA transfection.

  9. Effect of proteins with different isoelectric points on the gene transfection efficiency mediated by stearic acid grafted chitosan oligosaccharide micelles.

    PubMed

    Yan, Jingjing; Du, Yong-Zhong; Chen, Feng-Ying; You, Jian; Yuan, Hong; Hu, Fu-Qiang

    2013-07-01

    A stearic acid-grafted chitosan oligosaccharide (CS-SA) micelle has been demonstrated as an effective gene carrier in vitro and in vivo. Although being advantageous for DNA package, protection, and excellent cellular internalization, a CS-SA based delivery system may lead to difficulties in the dissociation of polymer/DNA complexes in intracells. In this research, bovine serum albumin (BSA) with a different isoelectric point value (4.7, 6.0 and 9.3) was synthesized and incorporated into a CS-SA based gene delivery system. CS-SA/DNA binary complexes and CS-SA/BSA/DNA ternary complexes were then prepared and characterized. The binding ability of the CS-SA vector with DNA was not affected by the incorporation of BSA. However, referring to the transfection activity, the BSA of different isoelectric point value (pI) had a distinct influence on the CS-SA/BSA/DNA complexes. CS-SA/BSA(4.7)/DNA and CS-SA/BSA(6.0)/DNA complexes had better transfection efficiency than binary complexes, especially CS-SA/BSA(4.7)/DNA complexes which showed the highest transfection efficiency. On the contrary, CS-SA/BSA(9.3)/DNA complexes had undesirable performances. Interestingly, the incorporation of BSA(4.7) in CS-SA/DNA complexes significantly enhanced the dissociation of polymer/DNA complexes and improved the release of DNA intracellular without influencing their cellular uptake. The aforementioned results indicated that the acid group in protein played an important role in enhancing the transfection efficiency of CS/BSA/DNA complexes, and the study provided guidelines in the design of an efficient vector for DNA transfection. PMID:23679858

  10. Point mutation of the xylose reductase (XR) gene reduces xylitol accumulation and increases citric acid production in Aspergillus carbonarius.

    PubMed

    Weyda, István; Lübeck, Mette; Ahring, Birgitte K; Lübeck, Peter S

    2014-04-01

    Aspergillus carbonarius accumulates xylitol when it grows on D-xylose. In fungi, D-xylose is reduced to xylitol by the NAD(P)H-dependent xylose reductase (XR). Xylitol is then further oxidized by the NAD(+)-dependent xylitol dehydrogenase (XDH). The cofactor impairment between the XR and XDH can lead to the accumulation of xylitol under oxygen-limiting conditions. Most of the XRs are NADPH dependent and contain a conserved Ile-Pro-Lys-Ser motif. The only known naturally occurring NADH-dependent XR (from Candida parapsilosis) carries an arginine residue instead of the lysine in this motif. In order to overcome xylitol accumulation in A. carbonarius a Lys-274 to Arg point mutation was introduced into the XR with the aim of changing the specificity toward NADH. The effect of the genetic engineering was examined in fermentation for citric acid production and xylitol accumulation by using D-xylose as the sole carbon source. Fermentation with the mutant strain showed a 2.8-fold reduction in xylitol accumulation and 4.5-fold increase in citric acid production compared to the wild-type strain. The fact that the mutant strain shows decreased xylitol levels is assumed to be associated with the capability of the mutated XR to use the NADH generated by the XDH, thus preventing the inhibition of XDH by the high levels of NADH and ensuring the flux of xylose through the pathway. This work shows that enhanced production of citric acid can be achieved using xylose as the sole carbon source by reducing accumulation of other by-products, such as xylitol.

  11. Point-of-service, quantitative analysis of ascorbic acid in aqueous humor for evaluating anterior globe integrity

    PubMed Central

    Gartia, Manas R.; Misra, Santosh K.; Ye, Mao; Schwartz-Duval, Aaron; Plucinski, Lisa; Zhou, Xiangfei; Kellner, David; Labriola, Leanne T.; Pan, Dipanjan

    2015-01-01

    Limited training, high cost, and low equipment mobility leads to inaccuracies in decision making and is concerning with serious ocular injuries such as suspected ruptured globe or post-operative infections. Here, we present a novel point-of-service (POS) quantitative ascorbic acid (AA) assay with use of the OcuCheck Biosensor. The present work describes the development and clinical testing of the paper-based biosensor that measures the changes in electrical resistance of the enzyme-plated interdigitated electrodes to quantify the level of AA present in ocular fluid. We have demonstrated the proof-of-concept of the biosensor testing 16 clinical samples collected from aqueous humor of patients undergoing therapeutic anterior chamber paracentesis. Comparing with gold standard colorimetric assay for AA concentration, OcuCheck showed accuracy of >80%, sensitivity of >88% and specificity of >71%. At present, there are no FDA-approved POS tests that can directly measures AA concentration levels in ocular fluid. We envisage that the device can be realized as a handheld, battery powered instrument that will have high impact on glaucoma care and point-of-care diagnostics of penetrating ocular globe injuries. PMID:26525715

  12. The pyruvate-tricarboxylic acid cycle node: a focal point of virulence control in the enteric pathogen Yersinia pseudotuberculosis.

    PubMed

    Bücker, René; Heroven, Ann Kathrin; Becker, Judith; Dersch, Petra; Wittmann, Christoph

    2014-10-24

    Despite our increasing knowledge of the specific pathogenicity factors in bacteria, the contribution of metabolic processes to virulence is largely unknown. Here, we elucidate a tight connection between pathogenicity and core metabolism in the enteric pathogen Yersinia pseudotuberculosis by integrated transcriptome and [(13)C]fluxome analysis of the wild type and virulence-regulator mutants. During aerobic growth on glucose, Y. pseudotuberculosis reveals an unusual flux distribution with a high level of secreted pyruvate. The absence of the transcriptional and post-transcriptional regulators RovA, CsrA, and Crp strongly perturbs the fluxes of carbon core metabolism at the level of pyruvate metabolism and the tricarboxylic acid (TCA) cycle, and these perturbations are accompanied by transcriptional changes in the corresponding enzymes. Knock-outs of regulators of this metabolic branch point and of its central enzyme, pyruvate kinase (ΔpykF), result in mutants with significantly reduced virulence in an oral mouse infection model. In summary, our work identifies the pyruvate-TCA cycle node as a focal point for controlling the host colonization and virulence of Yersinia.

  13. Point-of-service, quantitative analysis of ascorbic acid in aqueous humor for evaluating anterior globe integrity

    NASA Astrophysics Data System (ADS)

    Gartia, Manas R.; Misra, Santosh K.; Ye, Mao; Schwartz-Duval, Aaron; Plucinski, Lisa; Zhou, Xiangfei; Kellner, David; Labriola, Leanne T.; Pan, Dipanjan

    2015-11-01

    Limited training, high cost, and low equipment mobility leads to inaccuracies in decision making and is concerning with serious ocular injuries such as suspected ruptured globe or post-operative infections. Here, we present a novel point-of-service (POS) quantitative ascorbic acid (AA) assay with use of the OcuCheck Biosensor. The present work describes the development and clinical testing of the paper-based biosensor that measures the changes in electrical resistance of the enzyme-plated interdigitated electrodes to quantify the level of AA present in ocular fluid. We have demonstrated the proof-of-concept of the biosensor testing 16 clinical samples collected from aqueous humor of patients undergoing therapeutic anterior chamber paracentesis. Comparing with gold standard colorimetric assay for AA concentration, OcuCheck showed accuracy of >80%, sensitivity of >88% and specificity of >71%. At present, there are no FDA-approved POS tests that can directly measures AA concentration levels in ocular fluid. We envisage that the device can be realized as a handheld, battery powered instrument that will have high impact on glaucoma care and point-of-care diagnostics of penetrating ocular globe injuries.

  14. Cyanobacteria are confined to dewless habitats within a dew desert: Implications for past and future climate change for lithic microorganisms

    NASA Astrophysics Data System (ADS)

    Kidron, Giora J.; Starinsky, Abraham; Yaalon, Dan H.

    2014-11-01

    Although covering almost all rock outcrops around the world, little is known regarding the factors that govern the spatial distribution of lithic cyanobacteria and lichens. This is also the case in the Negev Desert, where cyanobacteria predominate on the rock outcrops of the south-facing slopes and lichens on the rock outcrops of the north-facing slopes. Hypothesizing that abiotic conditions determine their distribution, radiation, temperature, rain, dew and fog were monitored over a two-year period (2008-2010) at cyanobacteria- and lichen-dwelling habitats within a first-order drainage basin in the Negev Highlands. While non-significant differences characterized the rain amounts, substantial differences in substrate temperatures were recorded which resulted in turn in fundamental differences in the non-rainfall water regime. While dew condensed at the rock outcrops of the lichen habitat, no condensation took place at the cyanobacteria habitat. Contrary to the common belief, cyanobacteria were found to inhabit dewless habitats. As a result, cyanobacteria solely rely on rain precipitation for growth and can therefore serve as bioindicators for dewless habitats within the dewy Negev Desert. The findings may have important implications regarding Earth colonization, soil forming processes and geochemical processes following climate warming. They may explain lichen expansion and subsequent O2 increase during the mid Neoproterozoic providing indirect support for substantial photosynthetic activity and high weathering rates during this era.

  15. Investigating the significance of zero-point motion in small molecular clusters of sulphuric acid and water

    SciTech Connect

    Stinson, Jake L.; Kathmann, Shawn M.; Ford, Ian J.

    2014-01-14

    The nucleation of particles from trace gases in the atmosphere is an important source of cloud condensation nuclei (CCN), and these are vital for the formation of clouds in view of the high supersaturations required for homogeneous water droplet nucleation. The methods of quantum chemistry have increasingly been employed to model nucleation due to their high accuracy and efficiency in calculating configurational energies; and nucleation rates can be obtained from the associated free energies of particle formation. However, even in such advanced approaches, it is typically assumed that the nuclei have a classical nature, which is questionable for some systems. The importance of zero-point motion (also known as quantum nuclear dynamics) in modelling small clusters of sulphuric acid and water is tested here using the path integral molecular dynamics (PIMD) method at the density functional theory (DFT) level of theory. We observe a small zero-point effect on the the equilibrium structures of certain clusters. One configuration is found to display a bimodal behaviour at 300 K in contrast to the stable ionised state suggested from a zero temperature classical geometry optimisation. The general effect of zero-point motion is to promote the extent of proton transfer with respect to classical behaviour. We thank Prof. Angelos Michaelides and his group in University College London (UCL) for practical advice and helpful discussions. This work benefited from interactions with the Thomas Young Centre through seminar and discussions involving the PIMD method. SMK was supported by the U.S. Department of Energy, Office of Basic Energy Sciences, Division of Chemical Sciences, Geosciences, and Biosciences. JLS and IJF were supported by the IMPACT scheme at UCL and by the U.S. Department of Energy, Office of Basic Energy Sciences, Division of Chemical Sciences, Geosciences, and Biosciences. We are grateful for use of the UCL Legion High Performance Computing Facility and the

  16. Polydimethylsiloxane-Paper Hybrid Lateral Flow Assay for Highly Sensitive Point-of-Care Nucleic Acid Testing.

    PubMed

    Choi, Jane Ru; Liu, Zhi; Hu, Jie; Tang, Ruihua; Gong, Yan; Feng, Shangsheng; Ren, Hui; Wen, Ting; Yang, Hui; Qu, Zhiguo; Pingguan-Murphy, Belinda; Xu, Feng

    2016-06-21

    In nucleic acid testing (NAT), gold nanoparticle (AuNP)-based lateral flow assays (LFAs) have received significant attention due to their cost-effectiveness, rapidity, and the ability to produce a simple colorimetric readout. However, the poor sensitivity of AuNP-based LFAs limits its widespread applications. Even though various efforts have been made to improve the assay sensitivity, most methods are inappropriate for integration into LFA for sample-to-answer NAT at the point-of-care (POC), usually due to the complicated fabrication processes or incompatible chemicals used. To address this, we propose a novel strategy of integrating a simple fluidic control strategy into LFA. The strategy involves incorporating a piece of paper-based shunt and a polydimethylsiloxane (PDMS) barrier to the strip to achieve optimum fluidic delays for LFA signal enhancement, resulting in 10-fold signal enhancement over unmodified LFA. The phenomena of fluidic delay were also evaluated by mathematical simulation, through which we found the movement of fluid throughout the shunt and the tortuosity effects in the presence of PDMS barrier, which significantly affect the detection sensitivity. To demonstrate the potential of integrating this strategy into a LFA with sample-in-answer-out capability, we further applied this strategy into our prototype sample-to-answer LFA to sensitively detect the Hepatitis B virus (HBV) in clinical blood samples. The proposed strategy offers great potential for highly sensitive detection of various targets for wide application in the near future. PMID:27012657

  17. Antioxidant, Sugar, Mineral and Phytonutrient Concentrations Across Edible Fruit Tissues of Orange-Fleshed HoneyDew Melon (Cucumis melo L.)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Orange-fleshed honey dew melon (Cucumis melo L.) equatorial mesocarp was segmented into hypodermal (sub-peel), outer, middle, and inner (near the seed cavity) tissues and assayed for enzymatic antioxidants, fruit sugars, minerals, phytonutrients, and total protein concentrations. Moving inwards fro...

  18. Fatty Acid-binding Protein 4, a Point of Convergence for Angiogenic and Metabolic Signaling Pathways in Endothelial Cells*

    PubMed Central

    Harjes, Ulrike; Bridges, Esther; McIntyre, Alan; Fielding, Barbara A.; Harris, Adrian L.

    2014-01-01

    Fatty acid-binding protein 4 (FABP4) is an adipogenic protein and is implicated in atherosclerosis, insulin resistance, and cancer. In endothelial cells, FABP4 is induced by VEGFA, and inhibition of FABP4 blocks most of the VEGFA effects. We investigated the DLL4-NOTCH-dependent regulation of FABP4 in human umbilical vein endothelial cells by gene/protein expression and interaction analyses following inhibitor treatment and RNA interference. We found that FABP4 is directly induced by NOTCH. Stimulation of NOTCH signaling with human recombinant DLL4 led to FABP4 induction, independently of VEGFA. FABP4 induction by VEGFA was reduced by blockade of DLL4 binding to NOTCH or inhibition of NOTCH signal transduction. Chromatin immunoprecipitation of the NOTCH intracellular domain showed increased binding to two specific regions in the FABP4 promoter. The induction of FABP4 gene expression was dependent on the transcription factor FOXO1, which was essential for basal expression of FABP4, and FABP4 up-regulation following stimulation of the VEGFA and/or the NOTCH pathway. Thus, we show that the DLL4-NOTCH pathway mediates endothelial FABP4 expression. This indicates that induction of the angiogenesis-restricting DLL4-NOTCH can have pro-angiogenic effects via this pathway. It also provides a link between DLL4-NOTCH and FOXO1-mediated regulation of endothelial gene transcription, and it shows that DLL4-NOTCH is a nodal point in the integration of pro-angiogenic and metabolic signaling in endothelial cells. This may be crucial for angiogenesis in the tumor environment. PMID:24939870

  19. Rapid visual identification of PCR amplified nucleic acids by centrifugal gel separation: Potential use for molecular point-of-care tests.

    PubMed

    Hwang, Sang-Hyun; Kim, Dong-Eun; Im, Ji-Hyun; Kang, Su-Jin; Lee, Do-Hoon; Son, Sang Jun

    2016-05-15

    Recently, nucleic acid amplification and detection techniques have progressed based on advances in in microfluidics, microelectronics, and optical systems. Nucleic acids amplification based point-of-care test (POCT) in resource-limited settings requires simple visual detection methods. Several biosensing methods including lateral flow immunoassays (LFIA) were previously used to visually detect nucleic acids. However, prolonged assay time, several washing steps, and a need for specific antibodies limited their use. Here we developed a novel, rapid method to visualize amplified nucleic acids with naked eyes in clinical samples. First, we optimized conditions based on separation using very low centrifugal force and a density medium to detect human papillomavirus (HPV)-16 DNA in cervical specimens. After DNA extraction, HPV16 PCR was performed with biotin-labeled forward primer and Cy3-labeled reverse primer. PCR amplicon was mixed with streptavidin-magnetic beads, introduced into the density medium. After two-minute centrifugation, the result was visually identified. This system showed identical results with commercial HPV real-time PCR for 30 clinical samples and could detect up to 10(2)copies/mL of HPV DNA without any optical instruments. This robust and sensitive visual detection system is suitable for non-specialist personnel and point-of-care diagnosis in low-resource settings.

  20. A multiplexed nucleic acid microsystem for point-of-care detection of HIV co-infection with MTB and PCP.

    PubMed

    Xu, Lingjia; Kong, Jilie

    2013-12-15

    Many individuals infected with the human immunodeficiency virus (HIV), especially children in African countries, die of co-infections with Mycobacterium tuberculosis (MTB) (coinfection rate: 50%) or Pneumocystis carinii pneumonia (PCP) (coinfection rate: 81%). The present proposal describes a rapid, portable, low-cost, multiplexed point-of-care diagnostic technique for simultaneously detecting HIV, MTB, and PCP. This technique incorporates a creative micro-device (hardware) and a loop-mediated isothermal amplification strategy (software). PMID:24209377

  1. Determination of acid/base dissociation constants based on a rapid detection of the half equivalence point by feedback-based flow ratiometry.

    PubMed

    Tanaka, Hideji; Tachibana, Takahiro

    2004-06-01

    Acid dissociation constants (Ka) were determined through the rapid detection of the half equivalence point (EP1/2) based on a feedback-based flow ratiometry. A titrand, delivered at a constant flow rate, was merged with a titrant, whose flow rate was varied in response to a control voltage (Vc) from a controller. Downstream, the pH of the mixed solution was monitored. Initially, Vc was increased linearly. At the instance that the detector sensed EP1/2, the ramp direction of Vc changed downward. When EP1/2 was sensed again, Vc was increased again. This series of process was repeated automatically. The pH at EP1/2 was regarded as being pKa of the analyte after an activity correction. Satisfactory results were obtained for different acids in various matrices with good precision (RSD approximately 3%) at a throughput rate of 56 s/determination.

  2. A Portable, Pressure Driven, Room Temperature Nucleic Acid Extraction and Storage System for Point of Care Molecular Diagnostics.

    PubMed

    Byrnes, Samantha; Fan, Andy; Trueb, Jacob; Jareczek, Francis; Mazzochette, Mark; Sharon, Andre; Sauer-Budge, Alexis F; Klapperich, Catherine M

    2013-07-01

    Many new and exciting portable HIV viral load testing technologies are emerging for use in global medicine. While the potential to provide fast, isothermal, and quantitative molecular diagnostic information to clinicians in the field will soon be a reality, many of these technologies lack a robust front end for sample clean up and nucleic acid preparation. Such a technology would enable many different downstream molecular assays. Here, we present a portable system for centrifuge-free room temperature nucleic acid extraction from small volumes of whole blood (70 µL), using only thermally stable reagents compatible with storage and transport in low resource settings. Quantitative reverse transcriptase polymerase chain reaction (qRT-PCR) analysis of simulated samples demonstrate a lower limit of detection of 1000 copies/ml, with the ability to detect differences in viral load across four orders of magnitude. The system can also be used to store extracted RNA on detachable cartridges for up to one week at ambient temperature, and can be operated using only hand generated air pressure.

  3. A Portable, Pressure Driven, Room Temperature Nucleic Acid Extraction and Storage System for Point of Care Molecular Diagnostics

    PubMed Central

    Byrnes, Samantha; Fan, Andy; Trueb, Jacob; Jareczek, Francis; Mazzochette, Mark; Sharon, Andre; Sauer-Budge, Alexis F.; Klapperich, Catherine M.

    2013-01-01

    Many new and exciting portable HIV viral load testing technologies are emerging for use in global medicine. While the potential to provide fast, isothermal, and quantitative molecular diagnostic information to clinicians in the field will soon be a reality, many of these technologies lack a robust front end for sample clean up and nucleic acid preparation. Such a technology would enable many different downstream molecular assays. Here, we present a portable system for centrifuge-free room temperature nucleic acid extraction from small volumes of whole blood (70 µL), using only thermally stable reagents compatible with storage and transport in low resource settings. Quantitative reverse transcriptase polymerase chain reaction (qRT-PCR) analysis of simulated samples demonstrate a lower limit of detection of 1000 copies/ml, with the ability to detect differences in viral load across four orders of magnitude. The system can also be used to store extracted RNA on detachable cartridges for up to one week at ambient temperature, and can be operated using only hand generated air pressure. PMID:23914255

  4. STUDIES OF THE ACID-BASE EQUILIBRIUM IN DISEASE FROM THE POINT OF VIEW OF BLOOD GASES.

    PubMed

    Means, J H; Bock, A V; Woodwell, M N

    1921-01-31

    Carbon dioxide diagrams (Haggard and Henderson (9)) have been constructed for the blood of a series of hospital patients as a method of studying disturbances in their acid-base equilibrium. A diabetic with a low level of blood alkali, but with a normal blood reaction, a compensated acidosis in other words, showed a rapid return towards normal with no treatment but fasting and increased water and salt intake. A nephritic with a decompensated acidosis and a very low blood alkali was rapidly brought to a condition of decompensated alkalosis with a high blood alkali by the therapeutic administration of sodium bicarbonate. It is suggested that the therapeutic use of alkali in acidosis is probably only indicated in the decompensated variety, and that there it should be controlled carefully and the production of alkalosis avoided. The diagram obtained in three pneumonia patients suggested that they were suffering from a condition of carbonic acidosis, due perhaps to insufficient pulmonary ventilation. In two out of three cases of anemia the dissociation curve was found to lie at a higher level than normal. No explanation for this finding was offered. PMID:19868489

  5. Point of care nucleic acid detection of viable pathogenic bacteria with isothermal RNA amplification based paper biosensor

    NASA Astrophysics Data System (ADS)

    Liu, Hongxing; Xing, Da; Zhou, Xiaoming

    2014-09-01

    Food-borne pathogens such as Listeria monocytogenes have been recognized as a major cause of human infections worldwide, leading to substantial health problems. Food-borne pathogen identification needs to be simpler, cheaper and more reliable than the current traditional methods. Here, we have constructed a low-cost paper biosensor for the detection of viable pathogenic bacteria with the naked eye. In this study, an effective isothermal amplification method was used to amplify the hlyA mRNA gene, a specific RNA marker in Listeria monocytogenes. The amplification products were applied to the paper biosensor to perform a visual test, in which endpoint detection was performed using sandwich hybridization assays. When the RNA products migrated along the paper biosensor by capillary action, the gold nanoparticles accumulated at the designated Test line and Control line. Under optimized experimental conditions, as little as 0.5 pg/μL genomic RNA from Listeria monocytogenes could be detected. The whole assay process, including RNA extraction, amplification, and visualization, can be completed within several hours. The developed method is suitable for point-of-care applications to detect food-borne pathogens, as it can effectively overcome the false-positive results caused by amplifying nonviable Listeria monocytogenes.

  6. Disposable dry-reagent cotton thread-based point-of-care diagnosis devices for protein and nucleic acid test.

    PubMed

    Mao, Xun; Du, Ting-E; Wang, Yiyun; Meng, Lili

    2015-03-15

    We report here for the first time by using dry-reagent cotton thread-based point-of-care diagnosis devices for low-cost, sensitive and rapid detection of a lung cancer related biomarker, squamous cell carcinoma antigen (SCCA) and a human genetic disease, hereditary tyrosinemia type I related DNA sequences. A model system comprising SCCA as an analyte and a pair of monoclonal antibodies is used to demonstrate the proof-of-concept on the dry-reagent cotton thread based immunoassay device. An enhancement protocol was employed by using two kinds of gold nanoparticle labels for SCCA test which greatly improved the sensitivity of the device. The assay avoids the multiple incubation and washing steps performed in most conventional protein analyses, which is similar with the lateral flow strip technology. Under optimal conditions, the thread based immunoassay device was capable of measuring 1ng/mL SCCA in 20min which meet the requirement for clinical diagnosis. DNA detection was successfully realized by using a novel adenosine based molecular beacon probe as reporter probes in the cotton thread based device, the linear range is 75-3000fmol which is suitable for quantitative test.

  7. Performance evaluation of low cost microfluidic chips made using a digital craft cutter for point of care applications in nucleic acid tests.

    PubMed

    Ragavendar, M S; Jayaraman, Subhadra; Ramya, V M; Roy, Rohan; Manwani, Harsha

    2014-01-01

    A point of care (POC) diagnostic system development for nucleic acid testing (NAT) for developing countries faces several challenges and barriers among which affordability is a very critical one [1,4]. Hence a study was made to evaluate the effectiveness of microfluidic chips made from a digital craft cutter to be used as a disposable cartridge. Low cost materials like double sided tapes, transparent sheets and connectors were used to realize the microfluidic chip [2]. An in-house IVD sample preparation kit for nucleic acid extraction was used as a representative assay. Modifications were made to the assay workflow considering the feature sizes, design and volume of the microfluidic chip made from the paper cutter and other POC system requirements like turnaround time (TAT). The workflow was optimized by reducing overall TAT from 50min to 15min, sample volume from 150 μL to 12.5 μL and reduced reagent volumes. The method was also optimized to work at an isothermal condition. The results showed good correlation and yield in terms of both quality and quantity when compared to results obtained from the established baseline protocol. Thus microfluidic chips made using a digital craft cutter can very well be a low cost alternative to manufacture disposable chips for POC applications in nucleic acid tests.

  8. Transported acid aerosols measured in southern Ontario

    NASA Astrophysics Data System (ADS)

    Keeler, Gerald J.; Spengler, John D.; Koutrakis, Petros; Allen, George A.; Raizenne, Mark; Stern, Bonnie

    During the period 29 June 1986-9 August 1986, a field health study assessing the acute health effects of air pollutants on children was conducted at a summer girls' camp on the northern shore of Lake Erie in SW Ontario. Continuous air pollution measurements of SO 2, O 3, NO x, particulate sulfates, light scattering, and meteorological measurements including temperature, dew point, and wind speed and direction were made. Twelve-hour integrated samples of size fractioned particles were also obtained using dichotomous samplers and Harvard impactors equipped with an ammonia denuder for subsequent hydrogen ion determination. Particulate samples were analyzed for trace elements by X-ray fluorescence and Neutron Activation, and for organic and elemental carbon by a thermal/optical technique. The measured aerosol was periodically very acidic with observed 12-h averaged H + concentrations in the range < 10-560 nmoles m -3. The aerosol H + appeared to represent the net strong acidity after H 2SO 4 reaction with NH 3(g). Average daytime concentrations were higher than night-time for aerosol H +, sulfate, fine mass and ozone. Prolonged episodes of atmospheric acidity, sulfate, and ozone were associated with air masses arriving at the measurement site from the west and from the southwest over Lake Erie. Sulfate concentrations measured at the lakeshore camp were more than twice those measured at inland sites during extreme pollution episodes. The concentration gradient observed with onshore flow was potentially due to enhanced deposition near the lakeshore caused by discontinuities in the meteorological fields in this region.

  9. Polarization (ellipsometric) measurements of liquid condensate deposition and evaporation rates and dew points in flowing salt/ash-containing combustion gases

    NASA Technical Reports Server (NTRS)

    Seshadri, K.; Rosner, D. E.

    1985-01-01

    An application of an optical polarization technique in a combustion environment is demonstrated by following, in real-time, growth rates of boric oxide condensate on heated platinum ribbons exposed to seeded propane-air combustion gases. The results obtained agree with the results of earlier interference measurements and also with theoretical chemical vapor deposition predictions. In comparison with the interference method, the polarization technique places less stringent requirements on surface quality, which may justify the added optical components needed for such measurements.

  10. Estimation of surface heat and moisture fluxes over a prairie grassland. I - In situ energy budget measurements incorporating a cooled mirror dew point hygrometer

    NASA Technical Reports Server (NTRS)

    Smith, Eric A.; Crosson, William L.; Tanner, Bertrand D.

    1992-01-01

    Attention is focused on in situ measurements taken during FIFE required to support the development and validation of a biosphere model. Seasonal time series of surface flux measurements obtained from two surface radiation and energy budget stations utilized to support the FIFE surface flux measurement subprogram are examined. Data collection and processing procedures are discussed along with the measurement analysis for the complete 1987 test period.

  11. Acid rain and atmospheric chemistry at Allegheny Mountain

    SciTech Connect

    Pierson, W.R.; Brachaczek, W.W.; Gorse, R.A. Jr.; Japar, S.M.; Norbeck, J.M.; Keeler, G.J.

    1987-07-01

    Rain chemistry was measured in August 1983 on Allegheny Mountain and Larel Hill in southwester Pennsylvania. The average composition approximated an H/sub 2/SO/sub 5//HNO/sub 3/ mixture with a volume-weighted average pH of 3.5 and an SO/sub 4//sup 2 -//NO/sub 3//sup -/ mole ratio of 1.8. There was very little undissociated (weak) acidity and very little S(IV). The acidic rains were associated with air masses traversing SO/sub 2/ source regions west of the sites; stagnation and intervening precipitation were important influences. The geographic scale for a halving of rain SO/sub 4//sup 2 -/ concentration downwind of SO/sub 2/ sources was approx.440 km. Scavenging ratios were inferred for SO/sub 2/, aerosol SO/sub 4//sup 2 -/, and HNO/sub 3/. On average about half of the rain SO/sub 4//sup 2 -/ resulted from scavenging of SO/sub 2/, the rest from scavenging of SO/sub 4//sup 2 -/. The rain H/sup +/ was attributed about 25% to HNO/sub 3/, 55% to scavenging of SO/sub 2/, and 20% to scavenging of aerosol acid SO/sub 4//sup 2 -/. Cumulative deposition totals in rain were compared with deposition in fog and with dry deposition in the same experiment. A crude acid-deposition budget was calculated as follows: 47%, H/sub 2/SO/sub 4/ in rain; 23%, SO/sub 2/ dry deposition without dew; 16%, HNO/sub 3/ in rain; 11%, HNO/sub 3/ dry deposition without dew; 2%, HNO/sub 3/ and H/sub 2/SO/sub 4/ in fog and dew; 0.5%, aerosol dry deposition without dew. 86 references, 4 figures, 8 tables.

  12. Indirect fibre-optic colorimetric determination of ascorbic acid using 2-(5-bromo-2-pyridylazo)-5-diethylaminophenol and cloud point extraction.

    PubMed

    Filik, Hayati; Giray, Derya

    2013-04-01

    A new method has been developed for the indirect determination of ascorbic acid (AA) in commercial syrup preparations based on cloud point extraction (CPE) separation and preconcentration, and determination by molecular absorption spectrometry. The colorimetric method was based on the reduction of Fe(III) to Fe(II) and complexation of Fe(II) with 2-(5-bromo-2-pyridylazo)-5-diethylaminophenol (Br-PADAP), followed by its extraction into Triton X-114. Selectivity of the method was increased with the use of EDTA as a masking agent. The absorbance was measured at 742 nm. Various influencing factors on the separation and preconcentration of AA have been investigated systematically, and the optimized operation conditions were established. The proposed method allows the determination of AA in the range 5-200 µg L(-1) with a relative standard deviation of 3.0%. The detection limit was found to be 0.9 µg L(-1) for AA. This method has been applied to the determination of ascorbic acid in commercial pharmaceutical preparations.

  13. Process for producing and recovering elemental sulfur from acid gas

    SciTech Connect

    Reed, R. L.

    1985-03-26

    A system and process produce high actual levels of sulfur recovery from acid gas. The system includes two conventional Claus reactors and two cold bed adsorption (CBA) reactors. Four condensers are provided, one disposed before each of the catalytic reactors, and one disposed after the CBA reactor. The system includes a gas clean-up treatment zone for hydrogenation, drying and oxidation of gas to provide stoichiometric ratio of H/sub 2/S and SO/sub 2/. The gas is passed through the clean-up treatment zone prior to being fed to the first of the CBA reactors. The system is designed to operate either in a recovery mode or in a regeneration mode. In the recovery mode, the reactors are in series and the CBA reactors are operated below dew point of sulfur. In regeneration mode, effluent from the clean-up treatment zone is heated in a heat exchanger using effluent from the first catalytic reactor as the heat source. The resulting regeneration gas is fed to one of the two CBA reactors to vaporize sulfur and regenerate the catalyst. The vaporized sulfur is recovered in the condenser. The effluent from the condenser is passed to the other CBA reactor which is operated in the recovery mode during regeneration.

  14. Assessing the Risk That Phytophthora melonis Can Develop a Point Mutation (V1109L) in CesA3 Conferring Resistance to Carboxylic Acid Amide Fungicides

    PubMed Central

    Chen, Lei; Zhu, Shusheng; Lu, Xiaohong; Pang, Zhili; Cai, Meng; Liu, Xili

    2012-01-01

    The risk that the plant pathogen Phytophthora melonis develops resistance to carboxylic acid amide (CAA) fungicides was determined by measuring baseline sensitivities of field isolates, generating resistant mutants, and measuring the fitness of the resistant mutants. The baseline sensitivities of 80 isolates to flumorph, dimethomorph and iprovalicarb were described by unimodal curves, with mean EC50 values of 0.986 (±0.245), 0.284 (±0.060) and 0.327 (±0.068) µg/ml, respectively. Seven isolates with different genetic background (as indicated by RAPD markers) were selected to generate CAA-resistance. Fifty-five resistant mutants were obtained from three out of seven isolates by spontaneous selection and UV-mutagenesis with frequencies of 1×10−7 and 1×10−6, respectively. CAA-resistance was stable for all mutants. The resistance factors of these mutants ranged from 7 to 601. The compound fitness index (CFI  =  mycelial growth × zoospore production × pathogenicity) was often lower for the CAA-resistant isolates than for wild-type isolates, suggesting that the risk of P. melonis developing resistance to CAA fungicides is low to moderate. Among the CAA-resistant isolates, a negative correlation between EC50 values was found for iprovalicarb vs. flumorph and for iprovalicarb vs. dimethomorph. Comparison of the full-length cellulose synthase 3 (CesA3) between wild-type and CAA-resistant isolates revealed only one point mutation at codon position 1109: a valine residue (codon GTG in wild-type isolates) was converted to leucine (codon CTG in resistant mutants). This represents a novel point mutation with respect to mutations in CesA3 conferring resistance to CAA fungicides. Based on this mutation, an efficient allelic-specific PCR (AS-PCR) method was developed for rapid detection of CAA-resistance in P. melonis populations. PMID:22848705

  15. Comparative Study of Novel Ratio Spectra and Isoabsorptive Point Based Spectrophotometric Methods: Application on a Binary Mixture of Ascorbic Acid and Rutin

    PubMed Central

    Darwish, Hany W.; Bakheit, Ahmed H.; Naguib, Ibrahim A.

    2016-01-01

    This paper presents novel methods for spectrophotometric determination of ascorbic acid (AA) in presence of rutin (RU) (coformulated drug) in their combined pharmaceutical formulation. The seven methods are ratio difference (RD), isoabsorptive_RD (Iso_RD), amplitude summation (A_Sum), isoabsorptive point, first derivative of the ratio spectra (1DD), mean centering (MCN), and ratio subtraction (RS). On the other hand, RU was determined directly by measuring the absorbance at 358 nm in addition to the two novel Iso_RD and A_Sum methods. The work introduced in this paper aims to compare these different methods, showing the advantages for each and making a comparison of analysis results. The calibration curve is linear over the concentration range of 4–50 μg/mL for AA and RU. The results show the high performance of proposed methods for the analysis of the binary mixture. The optimum assay conditions were established and the proposed methods were successfully applied for the assay of the two drugs in laboratory prepared mixtures and combined pharmaceutical tablets with excellent recoveries. No interference was observed from common pharmaceutical additives. PMID:26885440

  16. Cloud point extraction-HPLC method for the determination and pharmacokinetic study of aristolochic acids in rat plasma after oral administration of Aristolochiae Fructus.

    PubMed

    Ren, Gang; Huang, Qun; Wu, Jiangang; Yuan, Jinbin; Yang, Gaihong; Yan, Zhihong; Yao, Shouzhuo

    2014-03-15

    Based on cloud-point extraction (CPE), a high performance liquid chromatography method (HPLC) was developed and validated for the determination of aristolochic acids (AAs) in rat plasma after oral administration of Aristolochiae Fructus (AF). Non-ionic surfactant Genapol X-080, an environmentally friendly solvent, was used for the micelle-mediated extraction. Various influencing factors on CPE process were investigated and optimized. AAs were extracted from rat plasma after adding 1ml of 4.5% (v/v) surfactant in the presence of 0.2mol/l HCl and 20mg NaCl, and the incubation temperature and time were 50°C and 10min, respectively. Base-line separation was obtained for the AAs in rat plasma with the optimized chromatography conditions. The detection limits (LOD) reached downward 10ng/ml. The intra-day and inter-day precisions were less than 7.8%, the accuracies were within ±5.5%, and the average recovery factors were in the range of 94.5-105.4%. In comparison with liquid-liquid extraction, the CPE method has a considerable LOD and higher recoveries. The proposed CPE-HPLC method was specific, sensitive and reliable, and could be an effective tool for the determination of AAs in biological matrixes. With the method the pharmacokinetics of AAs were investigated successfully after oral administration of AF by rats.

  17. Investigation on the pinch point position in heat exchangers

    NASA Astrophysics Data System (ADS)

    Pan, Lisheng; Shi, Weixiu

    2016-06-01

    The pinch point is important for analyzing heat transfer in thermodynamic cycles. With the aim to reveal the importance of determining the accurate pinch point, the research on the pinch point position is carried out by theoretical method. The results show that the pinch point position depends on the parameters of the heat transfer fluids and the major fluid properties. In most cases, the pinch point locates at the bubble point for the evaporator and the dew point for the condenser. However, the pinch point shifts to the supercooled liquid state in the near critical conditions for the evaporator. Similarly, it shifts to the superheated vapor state with the condensing temperature approaching the critical temperature for the condenser. It even can shift to the working fluid entrance of the evaporator or the supercritical heater when the heat source fluid temperature is very high compared with the absorbing heat temperature. A wrong position for the pinch point may generate serious mistake. In brief, the pinch point should be founded by the iterative method in all conditions rather than taking for granted.

  18. Aristolochic Acids

    MedlinePlus

    ... Sciences NIH-HHS www.niehs.nih.gov Aristolochic Acids Key Points Report on Carcinogens Status Known to be human carcinogens Aristolochia Clematitis Aristolochic Acids n Known human carcinogens n Found in certain ...

  19. Inhibition of tumor cell growth by low-boiling-point-saturated fatty acids isolated by molecular distillation and reversed phase liquid chromatography of hydrolysates of uncytotoxic wool grease secreted from sheep sebaceous gland.

    PubMed

    Nakamura, S; Nishimura, Y; Inagaki, K; Miwa, N

    1994-09-01

    We showed that massive growth of mouse Ehrlich ascites carcinoma (EAC) cells was not inhibited by wool grease secreted from the sheep sebaceous gland, whereas wool fatty acids separated by saponification of wool grease was growth-inhibitory. We then fractionated wool fatty acids into 9 fractions using molecular distillation (80-200 degrees C; 1 x 10(-2) mmHg) and found a marked antitumor activity in a low-boiling-point (< 80 degrees C) fraction (MW 200-300; C10-C20), which was further separated by reversed phase liquid chromatography on an octadecylisilica gel column, resulting in 5 fractions. The second most hydrophobic fraction (C8Si-4) obtained was the most growth-inhibitory to EAC cells cultured or implanted into mice, more marked than the antitumor glycopeptide bleomycin. C8Si-4 was suggested to be a mixture of a normal-chain C16-saturated fatty acid and two branched-chain kinds of saturated C16-iso- and C19-anteiso-fatty acids without hydroxyl groups according to gas chromatography-mass spectrographic analysis. Thus low-boiling-point saturated fatty acid moieties in some wool grease molecules were shown to become growth-inhibitory in vitro and in vivo only after released in the free acid form by esterolysis.

  20. Digital Earth Watch (DEW): How Mobile Apps Are Paving The Way Towards A Federated Web-Services Architecture For Citizen Science

    NASA Astrophysics Data System (ADS)

    Carrera, F.; Schloss, A. L.; Guerin, S.; Beaudry, J.; Pickle, J.

    2011-12-01

    Dozens of web-based initiatives allow citizens to provide information to programs that monitor the health of our environment. A concerned citizen can participate on-line as a weather "spotter", provide important phenological information to national databases, update bird counts in the area, or record the freezing of ponds, and much more. Many of these programs are developing mobile apps as companion tools to their web sites. Our group was involved in the development of one such companion app as an adjunct to the Picture Post project web site. Digital Earth Watch (DEW) and the Picture Post network support environmental monitoring through repeat digital photography and satellite imagery. A Picture Post is an eight-sided platform on a stand-alone post for taking a panoramic series of photographs. By taking pictures on a regular basis at Picture Post sites and by sharing these pictures on the program's web site (housed at the University of New Hampshire), citizen scientists are creating a photographic library of change-over-time in their local area and contributing to national monitoring programs. Our DEW Android application simplifies participation by allowing users to upload pictures instantly from their smart phone. The app also removes the constraint of the physical picture post, by allowing users to create a virtual post anywhere in the world. Posts have been set up to monitor trails, forests, water, wetlands, gardens and landscapes. The app uses the phone's GPS to position the virtual post in its geographic location and guides the user through the orientations thanks to the internal accelerometers and compass. To aid in the before-and-after comparison of images taken from the same orientation, the DEW app displays an "onionskin" of the prior image overlayed onto the camera viewfinder. With the transparent onionskin as a guide, the user can align the images more accurately, thus allowing differences between pictures to be detectable and measurable. The app

  1. Short communication: Diet-induced variations in milk fatty acid composition have minor effects on the estimated melting point of milk fat in cows, goats, and ewes: Insights from a meta-analysis.

    PubMed

    Toral, P G; Bernard, L; Chilliard, Y; Glasser, F

    2013-02-01

    In ruminants, the ability to maintain milk fat melting point within physiological values could play a role in the regulation of milk fat secretion when milk fatty acid (FA) composition varies, such as in response to feeding factors. However, the relationship between milk fat fluidity and changes in milk FA composition is difficult to study experimentally. A meta-analysis was therefore conducted to compare the magnitude of diet-induced variations in milk FA composition and the calculated melting point of milk FA (used as a proxy to estimate the variations in the melting point of milk fat) in 3 dairy ruminant species (cow, goat, and sheep). The coefficient of variation (CV), a scale-free measure of statistical dispersion, was used to compare the variability of criteria differing in their order of magnitude. The analysis of a database of milk FA profiles from cows, goats, and sheep fed different dietary treatments (unsupplemented diets and diets supplemented with lipids rich in oleic acid, linoleic acid, linolenic acid, or C20-22 polyunsaturated FA) revealed that the variability of the calculated melting point of milk FA was narrow (CV of 5%) compared with the variability of milk FA percentages (CV of 18 to 72%). The regulation of the melting point of milk fat is thus probably involved in the control of diet-induced variations in milk fat secretion. The calculated melting point of ewe milk FA was approximately 3°C lower than that of goats or cows across all types of diets, which might be linked to differences in milk fat content (higher in sheep) or the structure of milk triacylglycerides among these species. Lipid supplementation increased the calculated melting point of C18 FA in milk, whereas that of total FA was significantly reduced by supplements rich in oleic, linoleic, and linolenic acids but not C20-22 polyunsaturated FA. However, the slight effects of dietary treatments on the calculated melting point of milk FA did not differ between cows, goats, and ewes.

  2. Fatty acid ethyl esters in hair as alcohol markers: estimating a reliable cut-off point by evaluation of 1,057 autopsy cases.

    PubMed

    Hastedt, Martin; Bossers, Lydia; Krumbiegel, Franziska; Herre, Sieglinde; Hartwig, Sven

    2013-06-01

    Alcohol abuse is a widespread problem, especially in Western countries. Therefore, it is important to have markers of alcohol consumption with validated cut-off points. For many years research has focused on analysis of hair for alcohol markers, but data on the performance and reliability of cut-off values are still lacking. Evaluating 1,057 cases from 2005 to 2011, included a large sample group for the estimation of an applicable cut-off value when compared to earlier studies on fatty acid ethyl esters (FAEEs) in hair. The FAEEs concentrations in hair, police investigation reports, medical history, and the macroscopic and microscopic alcohol-typical results from autopsy, such as liver, pancreas, and cardiac findings, were taken into account in this study. In 80.2 % of all 1,057 cases pathologic findings that may be related to alcohol abuse were reported. The cases were divided into social drinkers (n = 168), alcohol abusers (n = 502), and cases without information on alcohol use. The median FAEEs concentration in the group of social drinkers was 0.302 ng/mg (range 0.008-14.3 ng/mg). In the group of alcohol abusers a median of 1.346 ng/mg (range 0.010-83.7 ng/mg) was found. Before June 2009 the hair FAEEs test was routinely applied to a proximal hair segment of 0-6 cm, changing to a routinely investigated hair length of 3 cm after 2009, as proposed by the Society of Hair Testing (SoHT). The method showed significant differences between the groups of social drinkers and alcoholics, leading to an improvement in the postmortem detection of alcohol abuse. Nevertheless, the performance of the method was rather poor, with an area under the curve calculated from receiver operating characteristic (ROC curve AUC) of 0.745. The optimum cut-off value for differentiation between social and chronic excessive drinking calculated for hair FAEEs was 1.08 ng/mg, with a sensitivity of 56 % and a specificity of 80 %. In relation to the "Consensus on Alcohol Markers 2012

  3. Evaluation of a clay-based acidic bedding conditioner for dairy cattle bedding.

    PubMed

    Proietto, R L; Hinckley, L S; Fox, L K; Andrew, S M

    2013-02-01

    This study investigated the effects of a clay-based acidic bedding conditioner on sawdust bedding pH, dry matter (DM), environmental pathogen counts, and environmental bacterial counts on teat ends of lactating dairy cows. Sixteen lactating Holstein cows were paired based on parity, days in milk, milk yield, and milk somatic cell count, and were negative for the presence of an intramammary pathogen. Within each pair, cows were randomly assigned to 1 of 2 treatments with 3-wk periods in a crossover design. Treatment groups consisted of 9 freestalls per group bedded with either untreated sawdust or sawdust with a clay-based acidic bedding conditioner, added at 3- to 4-d intervals over each 21-d period. Bedding and teat ends were aseptically sampled on d 0, 1, 2, 7, 14, and 21 for determination of environmental bacterial counts. At the same time points, bedding was sampled for DM and pH determination. The bacteria identified in the bedding material were total gram-negative bacteria, Streptococcus spp., and coliform bacteria. The bacteria identified on the teat ends were Streptococcus spp., coliform bacteria, and Klebsiella spp. Teat end score, milk somatic cell count, and intramammary pathogen presence were measured weekly. Bedding and teat cleanliness, environmental high and low temperatures, and dew point data were collected daily. The bedding conditioner reduced the pH, but not the DM, of the sawdust bedding compared with untreated sawdust. Overall environmental bacterial counts in bedding were lower for treated sawdust. Total bacterial counts in bedding and on teat ends increased with time over both periods. Compared with untreated sawdust, the treated bedding had lower counts of total gram-negative bacteria and streptococci, but not coliform counts. Teat end bacterial counts were lower for cows bedded on treated sawdust for streptococci, coliforms, and Klebsiella spp. compared with cows bedded on untreated sawdust. The clay-based acidic bedding conditioner

  4. The Oliktok Point Arctic Research Facility (OPARF)

    NASA Astrophysics Data System (ADS)

    Zak, B. D.; Ivey, M.

    2011-12-01

    For the past year, the US Department of Energy, through Sandia National Laboratories, has operated a Designated User Facility at Oliktok Point Alaska, on the Arctic Ocean coast near the western end of the Prudhoe Bay oil fields. The primary purpose of this user facility is to accommodate and support manned and unmanned airborne measurement platforms over the Arctic Ocean and adjacent coastline as the arctic sea ice recedes. The speed at which the sea ice is receding exceeds model-projected speeds considerably for reasons that are not fully understood. The ultimate objective is to incorporate improved understanding of the radiative and other processes impacting sea ice recession into the relevant climate models. OPARF is based at a USAF Long Range Radar Station, an old Distant Early Warning (DEW) radar station built during the height of the Cold War, but continuing to be operated to track air traffic over the pole. The USAF has graciously granted Sandia and DOE use of selected facilities at Oliktok on a non-interference basis. DOE also maintains FAA-granted Restricted Airspace over Oliktok Point and adjacent ocean. In addition, DOE has also requested that the FAA establish a Warning Area over international waters 30 miles wide and 700 miles long stretching from near Oliktok towards the North Pole. That request is currently being processed by the FAA, with the public comment period now closed. This paper will update OPARF developments for potential users of the Oliktok user facility and other interested researchers.

  5. Potentiometric study of reaction between periodate and iodide as their tetrabutylammonium salts in chloroform. Application to the determination of iodide and potentiometric detection of end points in acid-base titrations in chloroform.

    PubMed

    Pournaghi-Azar, M H; Farhadi, K

    1995-03-01

    A potentiometric method for the titration of tetrabutylammonium iodide (TBAI) in chloroform using tetrabutylammonium periodate (TBAPI) as a strong and suitable oxidizing reagent is described. The potentiometric conditions were optimized and the equilibrium constants of the reactions occurring during the titration were determined. The method was used for the determination of iodide both in chloroform and aqueous solutions after extraction into chloroform as ion-association with tetraphenylarsonium. The reaction between TBAPI and TBAI was also used as acid indicator for the potentiometric detection of end points of acid-base titrations in chloroform.

  6. Tipping Points

    NASA Astrophysics Data System (ADS)

    Hansen, J.

    2007-12-01

    A climate tipping point, at least as I have used the phrase, refers to a situation in which a changing climate forcing has reached a point such that little additional forcing (or global temperature change) is needed to cause large, relatively rapid, climate change. Present examples include potential loss of all Arctic sea ice and instability of the West Antarctic and Greenland ice sheets. Tipping points are characterized by ready feedbacks that amplify the effect of forcings. The notion that these may be runaway feedbacks is a misconception. However, present "unrealized" global warming, due to the climate system's thermal inertia, exacerbates the difficulty of avoiding global warming tipping points. I argue that prompt efforts to slow CO2 emissions and absolutely reduce non-CO2 forcings are both essential if we are to avoid tipping points that would be disastrous for humanity and creation, the planet as civilization knows it.

  7. Tipping Point

    MedlinePlus

    ... Tipping Point by CPSC Blogger September 22 appliance child Childproofing CPSC danger death electrical fall furniture head injury product safety television tipover tv Watch the video in Adobe Flash format. Almost weekly, we see ...

  8. Induction of thymidine phosphorylase as a pharmacodynamic end-point in patients with advanced carcinoma treated with 5-fluorouracil, folinic acid and interferon alpha

    PubMed Central

    Braybrooke, J P; Propper, D J; O’Byrne, K J; Koukourakis, M I; Patterson, A V; Houlbrook, S; Love, S D; Varcoe, S; Taylor, M; Ganesan, T S; Talbot, D C; Harris, A L

    2000-01-01

    Thymidine phosphorylase (TP) is an essential enzyme for the biochemical activation of 5-fluorouracil (5-FU). Interferon upregulates TP in vivo, although the dose and schedule of interferon for optimal biomodulation of 5-FU is not known. In this study, TP activity was measured in peripheral blood lymphocytes (PBLs) from patients with advanced carcinoma receiving treatment with 5-FU and folinic acid. Cohorts of patients were treated with interferon alpha (IFNα), immediately prior to 5-FU/folinic acid, at doses of 3 MIU m–2, 9 MIU m–2and 18 MIUm–2. IFNα was administered on day 0 cycle two, day –1 and day 0 cycle three and day –2, day –1 and day 0 cycle four. A fourth cohort was treated with IFNα 9 MIU m–2three times per week from cycle 2 onwards. Twenty-one patients were entered into the study with 19 evaluable for response. Six patients (32%) had stable disease and 13 (68%) progressive disease. There were no grade-IV toxicities. TP activity was detected in PBLs from all patients with wide interpatient variability in constitutive TP activity prior to chemotherapy, and in response to IFNα. 5-FU/folinic acid alone did not induce TP activity but a single dose of IFNα led to upregulation of TP within 2 h of administration with a further increase by 24 h (signed rank test, P = 0.006). TP activity remained elevated for at least 13 days (signed rank test, P = 0.02). There were no significant differences in TP activity between schedules or with additional doses of IFNα. A single dose of IFNα as low as 3 MIU m–2can cause sustained elevation of PBL TP activity in vivo indicating that biochemical markers are important pharmacodynamic endpoints for developing optimal schedules of IFNα for biomodulation of 5-FU. © 2000 Cancer Research Campaign PMID:10901374

  9. Point-Counterpoint: A Nucleic Acid Amplification Test for Streptococcus pyogenes Should Replace Antigen Detection and Culture for Detection of Bacterial Pharyngitis.

    PubMed

    Pritt, Bobbi S; Patel, Robin; Kirn, Thomas J; Thomson, Richard B

    2016-10-01

    Nucleic acid amplification tests (NAATs) have frequently been the standard diagnostic approach when specific infectious agents are sought in a clinic specimen. They can be applied for specific agents such as S. pyogenes, or commercial multiplex NAATs for detection of a variety of pathogens in gastrointestinal, bloodstream, and respiratory infections may be used. NAATs are both rapid and sensitive. For many years, S. pyogenes testing algorithms used a rapid and specific group A streptococcal antigen test to screen throat specimens, followed, in some clinical settings, by a throat culture for S. pyogenes to increase the sensitivity of its detection. Now S. pyogenes NAATs are being used with increasing frequency. Given their accuracy, rapidity, and ease of use, should they replace antigen detection and culture for the detection of bacterial pharyngitis? Bobbi Pritt and Robin Patel of the Mayo Clinic, where S. pyogenes NAATs have been used for well over a decade with great success, will explain the advantages of this approach, while Richard (Tom) Thomson and Tom Kirn of the NorthShore University HealthSystem will discuss their concerns about this approach to diagnosing bacterial pharyngitis.

  10. Analysis of ATP-citrate lyase and malic enzyme mutants of Yarrowia lipolytica points out the importance of mannitol metabolism in fatty acid synthesis.

    PubMed

    Dulermo, Thierry; Lazar, Zbigniew; Dulermo, Rémi; Rakicka, Magdalena; Haddouche, Ramedane; Nicaud, Jean-Marc

    2015-09-01

    The role of the two key enzymes of fatty acid (FA) synthesis, ATP-citrate lyase (Acl) and malic enzyme (Mae), was analyzed in the oleaginous yeast Yarrowia lipolytica. In most oleaginous yeasts, Acl and Mae are proposed to provide, respectively, acetyl-CoA and NADPH for FA synthesis. Acl was mainly studied at the biochemical level but no strain depleted for this enzyme was analyzed in oleaginous microorganisms. On the other hand the role of Mae in FA synthesis in Y. lipolytica remains unclear since it was proposed to be a mitochondrial NAD(H)-dependent enzyme and not a cytosolic NADP(H)-dependent enzyme. In this study, we analyzed for the first time strains inactivated for corresponding genes. Inactivation of ACL1 decreases FA synthesis by 60 to 80%, confirming its essential role in FA synthesis in Y. lipolytica. Conversely, inactivation of MAE1 has no effects on FA synthesis, except in a FA overaccumulating strain where it improves FA synthesis by 35%. This result definitively excludes Mae as a major key enzyme for FA synthesis in Y. lipolytica. During the analysis of both mutants, we observed a negative correlation between FA and mannitol level. As mannitol and FA pathways may compete for carbon storage, we inactivated YlSDR, encoding a mannitol dehydrogenase converting fructose and NADPH into mannitol and NADP+. The FA content of the resulting mutant was improved by 60% during growth on fructose, demonstrating that mannitol metabolism may modulate FA synthesis in Y. lipolytica.

  11. Detection of the change point in oxygen uptake during an incremental exercise test using recursive residuals: relationship to the plasma lactate accumulation and blood acid base balance.

    PubMed

    Zoladz, J A; Szkutnik, Z; Majerczak, J; Duda, K

    1998-09-01

    The purpose of this study was to develop a method to determine the power output at which oxygen uptake (VO2) during an incremental exercise test begins to rise non-linearly. A group of 26 healthy non-smoking men [mean age 22.1 (SD 1.4) years, body mass 73.6 (SD 7.4) kg, height 179.4 (SD 7.5) cm, maximal oxygen uptake (VO2max) 3.726 (SD 0.363) l x min(-1)], experienced in laboratory tests, were the subjects in this study. They performed an incremental exercise test on a cycle ergometer at a pedalling rate of 70 rev x min(-1). The test started at a power output of 30 W, followed by increases amounting to 30 W every 3 min. At 5 min prior to the first exercise intensity, at the end of each stage of exercise protocol, blood samples (1 ml each) were taken from an antecubital vein. The samples were analysed for plasma lactate concentration [La]pl, partial pressure of O2 and CO2 and hydrogen ion concentration [H+]b. The lactate threshold (LT) in this study was defined as the highest power output above which [La-]pl showed a sustained increase of more than 0.5 mmol x l(-1) x step(-1). The VO2 was measured breath-by-breath. In the analysis of the change point (CP) of VO2 during the incremental exercise test, a two-phase model was assumed for the 3rd-min-data of each step of the test: Xi = at(i) + b + epsilon(i) for i = 1,2, ..., T, and E(Xi) > at(i) + b for i = T + 1, ..., n, where X1, ..., Xn are independent and epsilon(i) approximately N(0, sigma2). In the first phase, a linear relationship between VO2 and power output was assumed, whereas in the second phase an additional increase in VO2 above the values expected from the linear model was allowed. The power output at which the first phase ended was called the change point in oxygen uptake (CP-VO2). The identification of the model consisted of two steps: testing for the existence of CP and estimating its location. Both procedures were based on suitably normalised recursive residuals. We showed that in 25 out of 26 subjects

  12. Evaluation of post-treatment filter, Part I: Experimental study of DMMP and DIMP filtration at high temperature and high dew point using activated carbon. Final report, November 1994-September 1995

    SciTech Connect

    Mahle, J.J.; Buettner, L.C.; Mauer, S.

    1996-08-01

    A series of experimental results are reported for breakthrough of the agent simulants DMMP and DIMP on coconut carbon. This adsorbent is used in filters for the Chemical Demiliterization program. The conditions were appropriate for a post treatment stack gas filter. Results indicate that high capacity and long filtration times are achievable under moderate humidity conditions up to 180 degrees F.

  13. Key amino acid residues involved in multi-point binding interactions between brazzein, a sweet protein, and the T1R2-T1R3 human sweet receptor.

    PubMed

    Assadi-Porter, Fariba M; Maillet, Emeline L; Radek, James T; Quijada, Jeniffer; Markley, John L; Max, Marianna

    2010-05-14

    The sweet protein brazzein [recombinant protein with sequence identical with the native protein lacking the N-terminal pyroglutamate (the numbering system used has Asp2 as the N-terminal residue)] activates the human sweet receptor, a heterodimeric G-protein-coupled receptor composed of subunits Taste type 1 Receptor 2 (T1R2) and Taste type 1 Receptor 3 (T1R3). In order to elucidate the key amino acid(s) responsible for this interaction, we mutated residues in brazzein and each of the two subunits of the receptor. The effects of brazzein mutations were assayed by a human taste panel and by an in vitro assay involving receptor subunits expressed recombinantly in human embryonic kidney cells; the effects of the receptor mutations were assayed by in vitro assay. We mutated surface residues of brazzein at three putative interaction sites: site 1 (Loop43), site 2 (N- and C-termini and adjacent Glu36, Loop33), and site 3 (Loop9-19). Basic residues in site 1 and acidic residues in site 2 were essential for positive responses from each assay. Mutation of Y39A (site 1) greatly reduced positive responses. A bulky side chain at position 54 (site 2), rather than a side chain with hydrogen-bonding potential, was required for positive responses, as was the presence of the native disulfide bond in Loop9-19 (site 3). Results from mutagenesis and chimeras of the receptor indicated that brazzein interacts with both T1R2 and T1R3 and that the Venus flytrap module of T1R2 is important for brazzein agonism. With one exception, all mutations of receptor residues at putative interaction sites predicted by wedge models failed to yield the expected decrease in brazzein response. The exception, hT1R2 (human T1R2 subunit of the sweet receptor):R217A/hT1R3 (human T1R3 subunit of the sweet receptor), which contained a substitution in lobe 2 at the interface between the two subunits, exhibited a small selective decrease in brazzein activity. However, because the mutation was found to increase

  14. Absolute quantification of the alleles in somatic point mutations by bioluminometric methods based on competitive polymerase chain reaction in the presence of a locked nucleic acid blocker or an allele-specific primer.

    PubMed

    Iliadi, Alexandra; Petropoulou, Margarita; Ioannou, Penelope C; Christopoulos, Theodore K; Anagnostopoulos, Nikolaos I; Kanavakis, Emmanuel; Traeger-Synodinos, Jan

    2011-09-01

    In somatic (acquired) point mutations, the challenge is to quantify minute amounts of the mutant allele in the presence of a large excess of the normal allele that differs only in a single base pair. We report two bioluminometric methods that enable absolute quantification of the alleles. The first method exploits the ability of a locked nucleic acid (LNA) oligonucleotide to bind to and inhibit effectively the polymerase chain reaction (PCR) amplification of the normal allele while the amplification of the mutant allele remains unaffected. The second method employs allele-specific PCR primers, thereby allowing the amplification of the corresponding allele only. DNA internal standards (competitors) are added to the PCR mixture to compensate for any sample-to-sample variation in the amplification efficiency. The amplification products from the two alleles and the internal standards are quantified by a microtiter well-based bioluminometric hybridization assay using the photoprotein aequorin as a reporter. The methods allow absolute quantification of less than 300 copies of the mutant allele even in samples containing less than 1% of the mutant allele.

  15. Ferulic Acid Administered at Various Time Points Protects against Cerebral Infarction by Activating p38 MAPK/p90RSK/CREB/Bcl-2 Anti-Apoptotic Signaling in the Subacute Phase of Cerebral Ischemia-Reperfusion Injury in Rats

    PubMed Central

    Cheng, Chin-Yi; Tang, Nou-Ying; Kao, Shung-Te; Hsieh, Ching-Liang

    2016-01-01

    Objectives This study aimed to evaluate the effects of ferulic acid (FA) administered at various time points before or after 30 min of middle cerebral artery occlusion (MCAo) followed by 7 d of reperfusion and to examine the involvement of mitogen-activated protein kinase (MAPK) signaling pathways in the cortical penumbra. Methods FA was intravenously administered to rats at a dose of 100 mg/kg 24 h before ischemia (B-FA), 2 h before ischemia (P-FA), immediately after ischemic insult (I-FA), 2 h after reperfusion (R-FA), or 24 h after reperfusion (D-FA). Results Our study results indicated that P-FA, I-FA, and R-FA effectively reduced cerebral infarct areas and neurological deficits. P-FA, I-FA, and R-FA significantly downregulated glial fibrillary acidic protein (GFAP), mitochondrial Bax, cytochrome c, and cleaved caspase-3 expression, and effectively restored the phospho-p38 MAPK (p-p38 MAPK)/p38 MAPK ratio, phospho-90 kDa ribosomal S6 kinase (p-p90RSK) expression, phospho-Bad (p-Bad) expression, the phospho-cAMP response element-binding protein (p-CREB)/CREB ratio, the cytosolic and mitochondrial Bcl-2/Bax ratios, and the cytosolic Bcl-xL/Bax ratio in the cortical penumbra 7 d after reperfusion. SB203580, a specific inhibitor of p38 MAPK, administered 30 min prior to ischemia abrogated the downregulating effects of I-FA on cerebral infarction, and mitochondrial Bax and cleaved caspase-3 expression, and the upregulating effects of I-FA on the p-p38 MAPK/p38 MAPK ratio, p-p90RSK expression, p-Bad expression, and the p-CREB/CREB, and cytosolic and mitochondrial Bcl-2/Bax ratios. Conclusions Our study results thus indicate that P-FA, I-FA, and R-FA effectively suppress reactive astrocytosis and exert neuroprotective effects against cerebral infarction by activating p38 MAPK signaling. The regulating effects of P-FA, I-FA, and R-FA on Bax-induced apoptosis result from activation of the p38 MAPK/p90RSK/CREB/Bcl-2 signaling pathway, and eventually contribute to

  16. Experimental and theoretical study of the phenomena of corrosion by carbon dioxide under dewing conditions at the top of a horizontal pipeline in the presence of a noncondensable gas

    NASA Astrophysics Data System (ADS)

    Vitse, Frederic

    2002-01-01

    Under a stratified flow regime and under dewing conditions, internal corrosion can occur at the top of horizontal pipelines. Corrosive gases such as carbon dioxide dissolve in the freshly condensed water on the inner pipewall where continuous injection of inhibitors of corrosion is not possible. In absence of such inhibitors, a thorough understanding of the phenomena of corrosion under dewing conditions is needed to predict the corrosion risk. The corrosion and condensation rates were studied experimentally in a full-scale flow-loop. The experimental data were compared with theoretical results obtained from a mechanistic model for the prediction of the corrosion rate during Top-of-the-Line Corrosion (TLC). This model solves the hydrodynamics of the condensed liquid and the heat and mass transfer in the gas phase to predict the condensation rate in a horizontal pipeline in the presence of a non-condensable gas. Further, the mass transfer in the condensed liquid is coupled to the thermodynamics of the vapor-liquid equilibrium and to an electrochemical model for the corrosion reaction at the wall. A Computational Fluid Dynamics (CFD) code was implemented to study the influence of mass transfer in the condensed water on the corrosion rate. Based on the chemistry of the condensed liquid the corrosion rate in the absence and in the presence of an iron carbonate scale is computed. The mechanistic model is tuned to a large set of experimental corrosion rates through the use of the superficial porosity accounting for the partial blockage of the corroding surface by the deposition of an iron carbonate scale. Increasing the gas temperature led to larger condensation and corrosion rates. However, at a higher temperature the corrosion rate was found to decrease due to the formation of a corrosion products scale. The gas velocity was found to influence the condensation rate, which, in turn, influenced the corrosion rate. The total pressure and partial pressure of CO2 played a

  17. Melting point, boiling point, and symmetry.

    PubMed

    Abramowitz, R; Yalkowsky, S H

    1990-09-01

    The relationship between the melting point of a compound and its chemical structure remains poorly understood. The melting point of a compound can be related to certain of its other physical chemical properties. The boiling point of a compound can be determined from additive constitutive properties, but the melting point can be estimated only with the aid of nonadditive constitutive parameters. The melting point of some non-hydrogen-bonding, rigid compounds can be estimated by the equation MP = 0.772 * BP + 110.8 * SIGMAL + 11.56 * ORTHO + 31.9 * EXPAN - 240.7 where MP is the melting point of the compound in Kelvin, BP is the boiling point, SIGMAL is the logarithm of the symmetry number, EXPAN is the cube of the eccentricity of the compound, and ORTHO indicates the number of groups that are ortho to another group.

  18. United States Air Force 611th Air Support Group/Civil Engineering Squadron Elmendorf AFB, Alaska. Risk assessment Bullen Point Radar Installation, Alaska. Final report

    SciTech Connect

    Karmi, S.

    1996-03-18

    This document contains the baseline human health risk assessment and the ecological risk assessment (ERA) for the Bullen Point Distant Early Warning (DEW) Line radar installation. Five sites at the Bullen Point radar installation underwent remedial investigations (RIs) during the summer of 1993. The presence of chemical contamination in the soil, sediments, and surface water at the installation was evaluated and reported in the Bullen Point Remedial Investigation/Feasibility Study (RI/FS) (U.S. Air Force 1996). The analytical data reported in the RI/FS form the basis for the human health and ecological risk assessments. The primary chemicals of concern (COCs) at the five sites are diesel and gasoline from past spills and/or leaks.

  19. Floating Point Control Library

    2007-08-02

    Floating Point Control is a Library that allows for the manipulation of floating point unit exception masking funtions control exceptions in both the Streaming "Single Instruction, Multiple Data" Extension 2 (SSE2) unit and the floating point unit simultaneously. FPC also provides macros to set floating point rounding and precision control.

  20. SPS antenna pointing control

    NASA Technical Reports Server (NTRS)

    Hung, J. C.

    1980-01-01

    The pointing control of a microwave antenna of the Satellite Power System was investigated emphasizing: (1) the SPS antenna pointing error sensing method; (2) a rigid body pointing control design; and (3) approaches for modeling the flexible body characteristics of the solar collector. Accuracy requirements for the antenna pointing control consist of a mechanical pointing control accuracy of three arc-minutes and an electronic phased array pointing accuracy of three arc-seconds. Results based on the factors considered in current analysis, show that the three arc-minute overall pointing control accuracy can be achieved in practice.

  1. Advancements, measurement uncertainties, and recent comparisons of the NOAA frost point hygrometer

    NASA Astrophysics Data System (ADS)

    Hall, Emrys G.; Jordan, Allen F.; Hurst, Dale F.; Oltmans, Samuel J.; Vömel, Holger; Kühnreich, Benjamin; Ebert, Volker

    2016-09-01

    The NOAA frost point hygrometer (FPH) is a balloon-borne instrument flown monthly at three sites to measure water vapor profiles up to 28 km. The FPH record from Boulder, Colorado, is the longest continuous stratospheric water vapor record. The instrument has an uncertainty in the stratosphere that is < 6 % and up to 12 % in the troposphere. A digital microcontroller version of the instrument improved upon the older versions in 2008 with sunlight filtering, better frost control, and resistance to radio frequency interference (RFI). A new thermistor calibration technique was implemented in 2014, decreasing the uncertainty in the thermistor calibration fit to less than 0.01 °C over the full range of frost - or dew point temperatures (-93 to +20 °C) measured during a profile. Results from multiple water vapor intercomparisons are presented, including the excellent agreement between the NOAA FPH and the direct tunable diode laser absorption spectrometer (dTDLAS) MC-PicT-1.4 during AquaVIT-2 chamber experiments over 6 days that provides confidence in the accuracy of the FPH measurements. Dual instrument flights with two FPHs or an FPH and a cryogenic frost point hygrometer (CFH) also show good agreement when launched on the same balloon. The results from these comparisons demonstrate the high level of accuracy of the NOAA FPH.

  2. Point by Point: Adding up Motivation

    ERIC Educational Resources Information Center

    Marchionda, Denise

    2010-01-01

    Students often view their course grades as a mysterious equation of teacher-given grades, teacher-given grace, and some other ethereal components based on luck. However, giving students the power to earn points based on numerous daily/weekly assignments and attendance makes the grading process objective and personal, freeing the instructor to…

  3. Point substitutions in Japanese alloalbumins.

    PubMed

    Arai, K; Madison, J; Huss, K; Ishioka, N; Satoh, C; Fujita, M; Neel, J V; Sakurabayashi, I; Putnam, F W

    1989-08-01

    We have completed the structural study of five rare types of inherited albumin variants (alloalbumins) discovered in the Biochemical Genetics Study of 15,581 unrelated children in Hiroshima and Nagasaki. We have also identified the structural change in five other alloalbumin specimens detected during clinical electrophoresis of sera from Japanese living near Tokyo. Each of the five albumin variants from Nagasaki and Hiroshima has a single amino acid substitution. All of these substitutions differ, and none has been reported in non-Japanese populations. No instances of proalbumin variants or of albumin B (the most frequent alloalbumins in Caucasians) were detected in the children in Hiroshima and Nagasaki. However, one instance of a variant proalbumin and two examples of albumin B occurred in Japanese from the vicinity of Tokyo. In addition a previously unreported point substitution was found in albumin Tochigi, which is present in two unrelated persons from Tochigi prefecture. Four of the point mutations in the Japanese alloalbumins are in close proximity in a short segment of the polypeptide chain (residues 354-382) in which three additional point substitutions have been reported in diverse populations. These results, combined with earlier data, suggest that point substitutions are grouped in certain segments of the albumin molecule.

  4. Point specificity in acupuncture

    PubMed Central

    2012-01-01

    The existence of point specificity in acupuncture is controversial, because many acupuncture studies using this principle to select control points have found that sham acupoints have similar effects to those of verum acupoints. Furthermore, the results of pain-related studies based on visual analogue scales have not supported the concept of point specificity. In contrast, hemodynamic, functional magnetic resonance imaging and neurophysiological studies evaluating the responses to stimulation of multiple points on the body surface have shown that point-specific actions are present. This review article focuses on clinical and laboratory studies supporting the existence of point specificity in acupuncture and also addresses studies that do not support this concept. Further research is needed to elucidate the point-specific actions of acupuncture. PMID:22373514

  5. Analysis of Loss-of-Function Mutants in Aspartate Kinase and Homoserine Dehydrogenase Genes Points to Complexity in the Regulation of Aspartate-Derived Amino Acid Contents1[OPEN

    PubMed Central

    Clark, Teresa J.; Lu, Yan

    2015-01-01

    Biosynthesis of aspartate (Asp)-derived amino acids lysine (Lys), methionine (Met), threonine (Thr), and isoleucine involves monofunctional Asp kinases (AKs) and dual-functional Asp kinase-homoserine dehydrogenases (AK-HSDHs). Four-week-old loss-of-function Arabidopsis (Arabidopsis thaliana) mutants in the AK-HSDH2 gene had increased amounts of Asp and Asp-derived amino acids, especially Thr, in leaves. To explore mechanisms behind this phenotype, we obtained single mutants for other AK and AK-HSDH genes, generated double mutants from ak-hsdh2 and ak mutants, and performed free and protein-bound amino acid profiling, transcript abundance, and activity assays. The increases of Asp, Lys, and Met in ak-hsdh2 were also observed in ak1-1, ak2-1, ak3-1, and ak-hsdh1-1. However, the Thr increase in ak-hsdh2 was observed in ak-hsdh1-1 but not in ak1-1, ak2-1, or ak3-1. Activity assays showed that AK2 and AK-HSDH1 are the major contributors to overall AK and HSDH activities, respectively. Pairwise correlation analysis revealed positive correlations between the amount of AK transcripts and Lys-sensitive AK activity and between the amount of AK-HSDH transcripts and both Thr-sensitive AK activity and total HSDH activity. In addition, the ratio of total AK activity to total HSDH activity negatively correlates with the ratio of Lys to the total amount of Met, Thr, and isoleucine. These data led to the hypothesis that the balance between Lys-sensitive AKs and Thr-sensitive AK-HSDHs is important for maintaining the amounts and ratios of Asp-derived amino acids. PMID:26063505

  6. Myofascial trigger points.

    PubMed

    Lavelle, Elizabeth Demers; Lavelle, William; Smith, Howard S

    2007-03-01

    Painful conditions of the musculoskeletal system, including myofascial pain syndrome, constitute some of the most important chronic problems encountered in a clinical practice. A myofascial trigger points is a hyperirritable spot, usually within a taut band of skeletal muscle, which is painful on compression and can give rise to characteristic referred pain, motor dysfunction, and autonomic phenomena. Trigger points may be relieved through noninvasive measures, such as spray and stretch, transcutaneous electrical stimulation, physical therapy, and massage. Invasive treatments for myofascial trigger points include injections with local anesthetics, corticosteroids, or botulism toxin or dry needling. The etiology, pathophysiology, and treatment of myofascial trigger points are addressed in this article.

  7. Analysis of Organic Acids.

    ERIC Educational Resources Information Center

    Griswold, John R.; Rauner, Richard A.

    1990-01-01

    Presented are the procedures and a discussion of the results for an experiment in which students select unknown carboxylic acids, determine their melting points, and investigate their solubility behavior in water and ethanol. A table of selected carboxylic acids is included. (CW)

  8. Mixed Acid Oxidation

    SciTech Connect

    Pierce, R.A.

    1999-10-26

    Several non-thermal processes have been developed to destroy organic waste compounds using chemicals with high oxidation potentials. These efforts have focused on developing technologies that work at low temperatures, relative to incineration, to overcome many of the regulatory issues associated with obtaining permits for waste incinerators. One such technique with great flexibility is mixed acid oxidation. Mixed acid oxidation, developed at the Savannah River Site, uses a mixture of an oxidant (nitric acid) and a carrier acid (phosphoric acid). The carrier acid acts as a non-volatile holding medium for the somewhat volatile oxidant. The combination of acids allows appreciable amounts of the concentrated oxidant to remain in the carrier acid well above the oxidant''s normal boiling point.

  9. Dew-driven folding of insect wings

    NASA Astrophysics Data System (ADS)

    Dickerson, Andrew; Beadles, Sam; Clement, Courtney; Hu, David

    2013-11-01

    Small insect wings fold into tacos when exposed to dewfall or fog for extended times. Such shapes are tightly held together and require great force or long evaporation times for the wings to unfold. In this experimental investigation, we use time-lapse and high-speed videography on a mosquito wing exposed to fog to characterize the folding process from a flat wing to a taco. We observe a taco is formed through a series of processes involving wing bending, unbending, and subsequent tight folding of the wing following the sliding of the drop off the wing. We use a simplified 2D model to determine the forces coalescing drops exert on the wing, and present folding-resistant design suggestions for micro-aerial vehicle wings.

  10. Nickel Curie Point Engine

    ERIC Educational Resources Information Center

    Chiaverina, Chris; Lisensky, George

    2014-01-01

    Ferromagnetic materials such as nickel, iron, or cobalt lose the electron alignment that makes them attracted to a magnet when sufficient thermal energy is added. The temperature at which this change occurs is called the "Curie temperature," or "Curie point." Nickel has a Curie point of 627 K, so a candle flame is a sufficient…

  11. Model Breaking Points Conceptualized

    ERIC Educational Resources Information Center

    Vig, Rozy; Murray, Eileen; Star, Jon R.

    2014-01-01

    Current curriculum initiatives (e.g., National Governors Association Center for Best Practices and Council of Chief State School Officers 2010) advocate that models be used in the mathematics classroom. However, despite their apparent promise, there comes a point when models break, a point in the mathematical problem space where the model cannot,…

  12. Key amino acid residues involved in multi-point binding interactions between brazzein, a sweet protein, and the T1R2-T1R3 human sweet receptor

    PubMed Central

    Assadi-Porter, Fariba M.; Maillet, Emeline L.; Radek, James T.; Quijada, Jeniffer; Markley, John L.; Max, Marianna

    2010-01-01

    The sweet protein brazzein activates the human sweet receptor, a heterodimeric G-protein coupled receptor (GPCR) composed of subunits T1R2 and T1R3. In order to elucidate the key amino acid(s) responsible for this interaction, we mutated residues in brazzein and each of the two subunits of the receptor. The effects of brazzein mutations were assayed by a human taste panel and by an in vitro assay involving receptor subunits expressed recombinantly in human embryonic kidney cells; the effects of the receptor mutations were assayed by the in vitro assay. We mutated surface residues of brazzein at three putative interaction sites: Site 1 (Loop43), Site 2 (N- and C-terminus and adjacent Glu36, Loop33), and Site 3 (Loop9–19). Basic residues in Site 1 and acidic residues in Site 2 were essential for positive responses from each assay. Mutation of Y39A (Site 1) greatly reduced positive responses. A bulky side chain at position 54 (Site 2), rather than a side chain with hydrogen bonding potential, was required for positive responses as was the presence of the native disulfide bond in Loop 9–19 (Site 3). Results from mutagenesis and chimeras of the receptor indicated that brazzein interacts with both T1R2 and T1R3 and that the Venus fly trap module of T1R2 is important for brazzein agonism. With one exception, all mutations of receptor residues at putative interaction sites predicted by wedge models failed to yield the expected decrease in the brazzein response. The exception, hT1R2:R217A-hT1R3, which contained a substitution in lobe 2 at the interface between the two subunits, exhibited a small selective decrease in brazzein activity. However, because the mutation was found to increase the positive cooperativity of binding by multiple ligands proposed to bind both T1R subunits (brazzein, monellin, and sucralose) but not those that bind to a single subunit (neotame and cyclamate), we suggest that this site in involved in subunit-subunit interaction rather than direct

  13. Critical-point nuclei

    SciTech Connect

    Clark, R.M.

    2004-10-01

    It has been suggested that a change of nuclear shape may be described in terms of a phase transition and that specific nuclei may lie close to the critical point of the transition. Analytical descriptions of such critical-point nuclei have been introduced recently and they are described briefly. The results of extensive searches for possible examples of critical-point behavior are presented. Alternative pictures, such as describing bands in the candidate nuclei using simple {Delta}K = 0 and {Delta}K = 2 rotational-coupling models, are discussed, and the limitations of the different approaches highlighted. A possible critical-point description of the transition from a vibrational to rotational pairing phase is suggested.

  14. Arctic climate tipping points.

    PubMed

    Lenton, Timothy M

    2012-02-01

    There is widespread concern that anthropogenic global warming will trigger Arctic climate tipping points. The Arctic has a long history of natural, abrupt climate changes, which together with current observations and model projections, can help us to identify which parts of the Arctic climate system might pass future tipping points. Here the climate tipping points are defined, noting that not all of them involve bifurcations leading to irreversible change. Past abrupt climate changes in the Arctic are briefly reviewed. Then, the current behaviour of a range of Arctic systems is summarised. Looking ahead, a range of potential tipping phenomena are described. This leads to a revised and expanded list of potential Arctic climate tipping elements, whose likelihood is assessed, in terms of how much warming will be required to tip them. Finally, the available responses are considered, especially the prospects for avoiding Arctic climate tipping points.

  15. Triple Point Topological Metals

    NASA Astrophysics Data System (ADS)

    Zhu, Ziming; Winkler, Georg W.; Wu, QuanSheng; Li, Ju; Soluyanov, Alexey A.

    2016-07-01

    Topologically protected fermionic quasiparticles appear in metals, where band degeneracies occur at the Fermi level, dictated by the band structure topology. While in some metals these quasiparticles are direct analogues of elementary fermionic particles of the relativistic quantum field theory, other metals can have symmetries that give rise to quasiparticles, fundamentally different from those known in high-energy physics. Here, we report on a new type of topological quasiparticles—triple point fermions—realized in metals with symmorphic crystal structure, which host crossings of three bands in the vicinity of the Fermi level protected by point group symmetries. We find two topologically different types of triple point fermions, both distinct from any other topological quasiparticles reported to date. We provide examples of existing materials that host triple point fermions of both types and discuss a variety of physical phenomena associated with these quasiparticles, such as the occurrence of topological surface Fermi arcs, transport anomalies, and topological Lifshitz transitions.

  16. Unpredictable points and chaos

    NASA Astrophysics Data System (ADS)

    Akhmet, Marat; Fen, Mehmet Onur

    2016-11-01

    It is revealed that a special kind of Poisson stable point, which we call an unpredictable point, gives rise to the existence of chaos in the quasi-minimal set. The existing definitions of chaos are formulated in sets of motions. This is the first time in the literature that description of chaos is initiated from a single motion. The theoretical results are exemplified by means of the symbolic dynamics.

  17. Reference Point Heterogeneity.

    PubMed

    Terzi, Ayse; Koedijk, Kees; Noussair, Charles N; Pownall, Rachel

    2016-01-01

    It is well-established that, when confronted with a decision to be taken under risk, individuals use reference payoff levels as important inputs. The purpose of this paper is to study which reference points characterize decisions in a setting in which there are several plausible reference levels of payoff. We report an experiment, in which we investigate which of four potential reference points: (1) a population average payoff level, (2) the announced expected payoff of peers in a similar decision situation, (3) a historical average level of earnings that others have received in the same task, and (4) an announced anticipated individual payoff level, best describes decisions in a decontextualized risky decision making task. We find heterogeneity among individuals in the reference points they employ. The population average payoff level is the modal reference point, followed by experimenter's stated expectation of a participant's individual earnings, followed in turn by the average earnings of other participants in previous sessions of the same experiment. A sizeable share of individuals show multiple reference points simultaneously. The reference point that best fits the choices of the individual is not affected by a shock to her income. PMID:27672374

  18. Reference Point Heterogeneity

    PubMed Central

    Terzi, Ayse; Koedijk, Kees; Noussair, Charles N.; Pownall, Rachel

    2016-01-01

    It is well-established that, when confronted with a decision to be taken under risk, individuals use reference payoff levels as important inputs. The purpose of this paper is to study which reference points characterize decisions in a setting in which there are several plausible reference levels of payoff. We report an experiment, in which we investigate which of four potential reference points: (1) a population average payoff level, (2) the announced expected payoff of peers in a similar decision situation, (3) a historical average level of earnings that others have received in the same task, and (4) an announced anticipated individual payoff level, best describes decisions in a decontextualized risky decision making task. We find heterogeneity among individuals in the reference points they employ. The population average payoff level is the modal reference point, followed by experimenter's stated expectation of a participant's individual earnings, followed in turn by the average earnings of other participants in previous sessions of the same experiment. A sizeable share of individuals show multiple reference points simultaneously. The reference point that best fits the choices of the individual is not affected by a shock to her income. PMID:27672374

  19. Human grasp point selection.

    PubMed

    Kleinholdermann, Urs; Franz, Volker H; Gegenfurtner, Karl R

    2013-07-25

    When we grasp an object, our visuomotor system has to solve an intricate problem: how to find the best out of an infinity of possible contact points of the fingers with the object? The contact point selection model (CoPS) we present here solves this problem and predicts human grasp point selection in precision grip grasping by combining a few basic rules that have been identified in human and robotic grasping. Usually, not all of the rules can be perfectly satisfied. Therefore, we assessed their relative importance by creating simple stimuli that put them into conflict with each other in pairs. Based on these conflict experiments we made model-based grasp point predictions for another experiment with a novel set of complexly shaped objects. The results show that our model predicts the human choice of grasp points very well, and that observers' preferences for their natural grasp angles is as important as physical stability constraints. Incorporating a human grasp point selection model like the one presented here could markedly improve current approaches to cortically guided arm and hand prostheses by making movements more natural while also allowing for a more efficient use of the available information.

  20. Reference Point Heterogeneity

    PubMed Central

    Terzi, Ayse; Koedijk, Kees; Noussair, Charles N.; Pownall, Rachel

    2016-01-01

    It is well-established that, when confronted with a decision to be taken under risk, individuals use reference payoff levels as important inputs. The purpose of this paper is to study which reference points characterize decisions in a setting in which there are several plausible reference levels of payoff. We report an experiment, in which we investigate which of four potential reference points: (1) a population average payoff level, (2) the announced expected payoff of peers in a similar decision situation, (3) a historical average level of earnings that others have received in the same task, and (4) an announced anticipated individual payoff level, best describes decisions in a decontextualized risky decision making task. We find heterogeneity among individuals in the reference points they employ. The population average payoff level is the modal reference point, followed by experimenter's stated expectation of a participant's individual earnings, followed in turn by the average earnings of other participants in previous sessions of the same experiment. A sizeable share of individuals show multiple reference points simultaneously. The reference point that best fits the choices of the individual is not affected by a shock to her income.

  1. An update on the uncertainties of water vapor measurements using cryogenic frost point hygrometers

    NASA Astrophysics Data System (ADS)

    Vömel, Holger; Naebert, Tatjana; Dirksen, Ruud; Sommer, Michael

    2016-08-01

    Long time series of observations of essential climate variables in the troposphere and stratosphere are often impacted by inconsistencies in instrumentation and ambiguities in the interpretation of the data. To reduce these problems of long-term data series, all measurements should include an estimate of their uncertainty and a description of their sources. Here we present an update of the uncertainties for tropospheric and stratospheric water vapor observations using the cryogenic frost point hygrometer (CFH). The largest source of measurement uncertainty is the controller stability, which is discussed here in detail. We describe a method to quantify this uncertainty for each profile based on the measurements. We also show the importance of a manufacturer-independent ground check, which is an essential tool to continuously monitor the uncertainty introduced by instrument variability. A small bias, which has previously been indicated in lower tropospheric measurements, is described here in detail and has been rectified. Under good conditions, the total from all sources of uncertainty of frost point or dew point measurements using the CFH can be better than 0.2 K. Systematic errors, which are most likely to impact long-term climate series, are verified to be less than 0.1 K. The impact of the radiosonde pressure uncertainty on the mixing ratio for properly processed radiosondes is considered small. The mixing ratio uncertainty may be as low as 2 to 3 %. The impact of the ambient temperature uncertainty on relative humidity (RH) is generally larger than that of the frost point uncertainty. The relative RH uncertainty may be as low as 2 % in the lower troposphere and 5 % in the tropical tropopause region.

  2. Charcot-Marie-Tooth neuropathy type 2 and P0 point mutations: two novel amino acid substitutions (Asp61Gly; Tyr119Cys) and a possible "hotspot" on Thr124Met.

    PubMed

    Senderek, J; Hermanns, B; Lehmann, U; Bergmann, C; Marx, G; Kabus, C; Timmerman, V; Stoltenburg-Didinger, G; Schröder, J M

    2000-04-01

    Mutations in the gene for the major protein component of peripheral nerve myelin, myelin protein zero (MPZ, P0), cause hereditary disorders of Schwann cell myelin such as Charcot-Marie-Tooth neuropathy type 1B (CMT1B), Dejerine-Sottas syndrome (DSS), and congenital hypomyelinating neuropathy (CHN). More recently, P0 mutations were identified in the axonal type of CMT neuropathy, CMT2, which is different from the demyelinating variants with respect to electroneurography and nerve pathology. We screened 49 patients with a clinical and histopathological diagnosis of CMT2 for mutations in the P0 gene. Three heterozygous single nucleotide changes were detected: two novel missense mutations, Asp61Gly and Tyr119Cys, and the known Thr124Met substitution, that has already been reported in several CMT patients from different European countries. Haplotype analysis for the P0 locus proved that our patients with the 124Met allele were not related to a cohort of patients with the same mutation, all of Belgian descent and all found to share a common ancestor. Our data suggest that P0 mutations account for a detectable proportion of CMT2 cases with virtually every patient harbouring a different mutation but recurrence of the Thr124Met amino acid substitution. The high frequency of this peculiar genotype in the European CMT population is presumably not only due to a founder effect but Thr124Met might constitute a mutation hotspot in the P0 gene as well. PMID:10764043

  3. A holographic critical point

    SciTech Connect

    DeWolfe, Oliver; Rosen, Christopher; Gubser, Steven S.

    2011-04-15

    We numerically construct a family of five-dimensional black holes exhibiting a line of first-order phase transitions terminating at a critical point at finite chemical potential and temperature. These black holes are constructed so that the equation of state and baryon susceptibilities approximately match QCD lattice data at vanishing chemical potential. The critical end point in the particular model we consider has temperature 143 MeV and chemical potential 783 MeV. Critical exponents are calculated, with results that are consistent with mean-field scaling relations.

  4. Precision Pointing System Development

    SciTech Connect

    BUGOS, ROBERT M.

    2003-03-01

    The development of precision pointing systems has been underway in Sandia's Electronic Systems Center for over thirty years. Important areas of emphasis are synthetic aperture radars and optical reconnaissance systems. Most applications are in the aerospace arena, with host vehicles including rockets, satellites, and manned and unmanned aircraft. Systems have been used on defense-related missions throughout the world. Presently in development are pointing systems with accuracy goals in the nanoradian regime. Future activity will include efforts to dramatically reduce system size and weight through measures such as the incorporation of advanced materials and MEMS inertial sensors.

  5. MountPointAttributes

    2001-06-16

    MountPointAttributes is a software component that provides client code with a technique to raise the local namespace of a file to a global namespace. Its abstractions and mechanisms allow the client code to gather global properties of a file and to use them in devising an effective storage access strategy on this file.

  6. EndPoints 2000

    2009-08-13

    The application leads the user through a logical framework to determine the minimum effort and cost necessary to reach the desired end state for each space, system, and facility. Endpoints are used to plan the project work, track and manage the determination, management, verification, and closure of D&D endpoints, consistent with DOE End Point guidance documents.

  7. Ideal Point Discriminant Analysis.

    ERIC Educational Resources Information Center

    Takane, Yoshio; And Others

    1987-01-01

    A new method of multiple discriminant analysis allows a mixture of continuous and discrete predictors. It handles conditional, joint, or separate sampling. Subjects and criterion groups are represented as points in a multidimensional Euclidean space. Advantages of the method, deriving from Akaike Information Criterion model evaluation, are…

  8. Optical Pointing Sensor

    NASA Technical Reports Server (NTRS)

    Shields, Joel F.; Metz, Brandon C.

    2010-01-01

    The optical pointing sensor provides a means of directly measuring the relative positions of JPL s Formation Control Testbed (FCT) vehicles without communication. This innovation is a steerable infrared (IR) rangefinder that gives measurements in terms of range and bearing to a passive retroreflector.

  9. EcoTipping Points

    ERIC Educational Resources Information Center

    Marten, Gerald G.; Matthews, Catherine E.

    2009-01-01

    Contrary to what we often hear and teach, there is good news to be found on the environmental front. Environmental success stories show us not only that sustainability is possible, but also how people have made it happen. We can make these stories and their lessons accessible to students with help from the EcoTipping Points Project, which has…

  10. The Lagrange Points

    ERIC Educational Resources Information Center

    Lovell, M.S.

    2007-01-01

    This paper presents a derivation of all five Lagrange points by methods accessible to sixth-form students, and provides a further opportunity to match Newtonian gravity with centripetal force. The predictive powers of good scientific theories are also discussed with regard to the philosophy of science. Methods for calculating the positions of the…

  11. GLAS Spacecraft Pointing Study

    NASA Technical Reports Server (NTRS)

    Born, George H.; Gold, Kenn; Ondrey, Michael; Kubitschek, Dan; Axelrad, Penina; Komjathy, Attila

    1998-01-01

    Science requirements for the GLAS mission demand that the laser altimeter be pointed to within 50 m of the location of the previous repeat ground track. The satellite will be flown in a repeat orbit of 182 days. Operationally, the required pointing information will be determined on the ground using the nominal ground track, to which pointing is desired, and the current propagated orbit of the satellite as inputs to the roll computation algorithm developed by CCAR. The roll profile will be used to generate a set of fit coefficients which can be uploaded on a daily basis and used by the on-board attitude control system. In addition, an algorithm has been developed for computation of the associated command quaternions which will be necessary when pointing at targets of opportunity. It may be desirable in the future to perform the roll calculation in an autonomous real-time mode on-board the spacecraft. GPS can provide near real-time tracking of the satellite, and the nominal ground track can be stored in the on-board computer. It will be necessary to choose the spacing of this nominal ground track to meet storage requirements in the on-board environment. Several methods for generating the roll profile from a sparse reference ground track are presented.

  12. Noncommutative Point Sources

    SciTech Connect

    Stern, A.

    2008-02-15

    We construct a perturbative solution to classical noncommutative gauge theory on R{sup 3} minus the origin using the Groenewald-Moyal star product. The result describes a noncommutative point charge. Applying it to the quantum mechanics of the noncommutative hydrogen atom gives shifts in the 1S hyperfine splitting which are first order in the noncommutativity parameter.

  13. Acne Yields Up Secret That Points to New Treatments

    MedlinePlus

    ... html Acne Yields Up Secret That Points to New Treatments Bacteria on skin sometimes release fatty acids ... News) -- In a finding that could lead to new treatments for acne, scientists say they've discovered ...

  14. The boiling point of stratospheric aerosols.

    NASA Technical Reports Server (NTRS)

    Rosen, J. M.

    1971-01-01

    A photoelectric particle counter was used for the measurement of aerosol boiling points. The operational principle involves raising the temperature of the aerosol by vigorously heating a portion of the intake tube. At or above the boiling point, the particles disintegrate rather quickly, and a noticeable effect on the size distribution and concentration is observed. Stratospheric aerosols appear to have the same volatility as a solution of 75% sulfuric acid. Chemical analysis of the aerosols indicates that there are other substances present, but that the sulfate radical is apparently the major constituent.

  15. Proximal Point Methods Revisited

    NASA Astrophysics Data System (ADS)

    Boikanyo, Oganeditse A.; Moroşanu, Gheorghe

    2011-09-01

    The proximal point methods have been widely used in the last decades to approximate the solutions of nonlinear equations associated with monotone operators. Inspired by the iterative procedure defined by B. Martinet (1970), R.T. Rockafellar introduced in 1976 the so-called proximal point algorithm (PPA) for a general maximal monotone operator. The sequence generated by this iterative method is weakly convergent under appropriate conditions, but not necessarily strongly convergent, as proved by O. Güler (1991). This fact explains the introduction of different modified versions of the PPA which generate strongly convergent sequences under appropriate conditions, including the contraction-PPA defined by H.K. Xu in 2002. Here we discuss Xu's modified PPA as well as some of its generalizations. Special attention is paid to the computational errors, in particular the original Rockafellar summability assumption is replaced by the condition that the error sequence converges to zero strongly.

  16. Quantum Change Point

    NASA Astrophysics Data System (ADS)

    Sentís, Gael; Bagan, Emilio; Calsamiglia, John; Chiribella, Giulio; Muñoz-Tapia, Ramon

    2016-10-01

    Sudden changes are ubiquitous in nature. Identifying them is crucial for a number of applications in biology, medicine, and social sciences. Here we take the problem of detecting sudden changes to the quantum domain. We consider a source that emits quantum particles in a default state, until a point where a mutation occurs that causes the source to switch to another state. The problem is then to find out where the change occurred. We determine the maximum probability of correctly identifying the change point, allowing for collective measurements on the whole sequence of particles emitted by the source. Then, we devise online strategies where the particles are measured individually and an answer is provided as soon as a new particle is received. We show that these online strategies substantially underperform the optimal quantum measurement, indicating that quantum sudden changes, although happening locally, are better detected globally.

  17. Floating point coprocessor upgrade

    SciTech Connect

    Weber, T.

    1987-04-01

    A method was developed to increase the throughput of the Hewlett Packard, 98635A floating point processor equipped, model 236C computer. The increase was carried out in three phases each with a clock and or chip change during the modification. Two programs were written to test the results and evaluate the increases in performance made to the computer. The first one shows reduction in processing times of 34.3%, while the other recorded 34.6%.

  18. At the Tipping Point

    SciTech Connect

    Wiley, H. S.

    2011-02-28

    There comes a time in every field of science when things suddenly change. While it might not be immediately apparent that things are different, a tipping point has occurred. Biology is now at such a point. The reason is the introduction of high-throughput genomics-based technologies. I am not talking about the consequences of the sequencing of the human genome (and every other genome within reach). The change is due to new technologies that generate an enormous amount of data about the molecular composition of cells. These include proteomics, transcriptional profiling by sequencing, and the ability to globally measure microRNAs and post-translational modifications of proteins. These mountains of digital data can be mapped to a common frame of reference: the organism’s genome. With the new high-throughput technologies, we can generate tens of thousands of data points from each sample. Data are now measured in terabytes and the time necessary to analyze data can now require years. Obviously, we can’t wait to interpret the data fully before the next experiment. In fact, we might never be able to even look at all of it, much less understand it. This volume of data requires sophisticated computational and statistical methods for its analysis and is forcing biologists to approach data interpretation as a collaborative venture.

  19. 21 CFR 172.130 - Dehydroacetic acid.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 3 2014-04-01 2014-04-01 false Dehydroacetic acid. 172.130 Section 172.130 Food... Dehydroacetic acid. The food additive dehydroacetic acid and/or its sodium salt may be safely used in accordance...: Dehydroacetic acid: Melting point, 109 °C-111 °C; assay, minimum 98 percent (dry basis). Sodium salt...

  20. 21 CFR 172.130 - Dehydroacetic acid.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 3 2011-04-01 2011-04-01 false Dehydroacetic acid. 172.130 Section 172.130 Food... Food Preservatives § 172.130 Dehydroacetic acid. The food additive dehydroacetic acid and/or its sodium... meets the following specifications: Dehydroacetic acid: Melting point, 109 °C-111 °C; assay, minimum...

  1. 21 CFR 172.130 - Dehydroacetic acid.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 3 2013-04-01 2013-04-01 false Dehydroacetic acid. 172.130 Section 172.130 Food... Food Preservatives § 172.130 Dehydroacetic acid. The food additive dehydroacetic acid and/or its sodium... meets the following specifications: Dehydroacetic acid: Melting point, 109 °C-111 °C; assay, minimum...

  2. 21 CFR 172.130 - Dehydroacetic acid.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 3 2012-04-01 2012-04-01 false Dehydroacetic acid. 172.130 Section 172.130 Food... Food Preservatives § 172.130 Dehydroacetic acid. The food additive dehydroacetic acid and/or its sodium... meets the following specifications: Dehydroacetic acid: Melting point, 109 °C-111 °C; assay, minimum...

  3. 21 CFR 172.130 - Dehydroacetic acid.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Dehydroacetic acid. 172.130 Section 172.130 Food... Food Preservatives § 172.130 Dehydroacetic acid. The food additive dehydroacetic acid and/or its sodium... meets the following specifications: Dehydroacetic acid: Melting point, 109 °C-111 °C; assay, minimum...

  4. Prelinguistic Vocalizations Distinguish Pointing Acts

    ERIC Educational Resources Information Center

    Grunloh, Thomas; Liszkowski, Ulf

    2015-01-01

    The current study investigated whether point-accompanying characteristics, like vocalizations and hand shape, differentiate infants' underlying motives of prelinguistic pointing. We elicited imperative (requestive) and declarative (expressive and informative) pointing acts in experimentally controlled situations, and analyzed accompanying…

  5. Vernal Point and Anthropocene

    NASA Astrophysics Data System (ADS)

    Chavez-Campos, Teodosio; Chavez S, Nadia; Chavez-Sumarriva, Israel

    2014-05-01

    The time scale was based on the internationally recognized formal chronostratigraphical /geochronological subdivisions of time: The Phanerozoic Eonathem/Eon; the Cenozoic Erathem/Era; the Quaternary System/Period; the Pleistocene and Holocene Series/Epoch. The Quaternary was divided into: (1) The Pleistocene that was characterized by cycles of glaciations (intervals between 40,000 and 100,000 years). (2) The Holocene that was an interglacial period that began about 12,000 years ago. It was believed that the Milankovitch cycles (eccentricity, axial tilt and the precession of the equinoxes) were responsible for the glacial and interglacial Holocene periods. The magnetostratigraphic units have been widely used for global correlations valid for Quaternary. The gravitational influence of the sun and moon on the equatorial bulges of the mantle of the rotating earth causes the precession of the earth. The retrograde motion of the vernal point through the zodiacal band is 26,000 years. The Vernal point passes through each constellation in an average of 2000 years and this period of time was correlated to Bond events that were North Atlantic climate fluctuations occurring every ≡1,470 ± 500 years throughout the Holocene. The vernal point retrogrades one precessional degree approximately in 72 years (Gleissberg-cycle) and approximately enters into the Aquarius constellation on March 20, 1940. On earth this entry was verify through: a) stability of the magnetic equator in the south central zone of Peru and in the north zone of Bolivia, b) the greater intensity of equatorial electrojet (EEJ) in Peru and Bolivia since 1940. With the completion of the Holocene and the beginning of the Anthropocene (widely popularized by Paul Crutzen) it was proposed the date of March 20, 1940 as the beginning of the Anthropocene. The date proposed was correlated to the work presented in IUGG (Italy 2007) with the title "Cusco base meridian for the study of geophysical data"; Cusco was

  6. Tipping point leadership.

    PubMed

    Kim, W Chan; Mauborgne, Renée

    2003-04-01

    When William Bratton was appointed police commissioner of New York City in 1994, turf wars over jurisdiction and funding were rife and crime was out of control. Yet in less than two years, and without an increase in his budget, Bratton turned New York into the safest large city in the nation. And the NYPD was only the latest of five law-enforcement agencies Bratton had turned around. In each case, he succeeded in record time despite limited resources, a demotivated staff, opposition from powerful vested interests, and an organization wedded to the status quo. Bratton's turnarounds demonstrate what the authors call tipping point leadership. The theory of tipping points hinges on the insight that in any organization, fundamental changes can occur quickly when the beliefs and energies of a critical mass of people create an epidemic movement toward an idea. Bratton begins by overcoming the cognitive hurdles that block organizations from recognizing the need for change. He does this by putting managers face-to-face with operational problems. Next, he manages around limitations on funds, staff, or equipment by concentrating resources on the areas that are most in need of change and that have the biggest payoffs. He meanwhile solves the motivation problem by singling out key influencers--people with disproportionate power due to their connections or persuasive abilities. Finally, he closes off resistance from powerful opponents. Not every CEO has the personality to be a Bill Bratton, but his successes are due to much more than his personality. He relies on a remarkably consistent method that any manager looking to turn around an organization can use to overcome the forces of inertia and reach the tipping point. PMID:12687920

  7. Pointing control for LDR

    NASA Technical Reports Server (NTRS)

    Yam, Y.; Briggs, C.

    1988-01-01

    One important aspect of the LDR control problem is the possible excitations of structural modes due to random disturbances, mirror chopping, and slewing maneuvers. An analysis was performed to yield a first order estimate of the effects of such dynamic excitations. The analysis involved a study of slewing jitters, chopping jitters, disturbance responses, and pointing errors, making use of a simplified planar LDR model which describes the LDR dynamics on a plane perpendicular to the primary reflector. Briefly, the results indicate that the command slewing profile plays an important role in minimizing the resultant jitter, even to a level acceptable without any control action. An optimal profile should therefore be studied.

  8. Pointing the SOFIA Telescope

    NASA Astrophysics Data System (ADS)

    Gross, M. A. K.; Rasmussen, J. J.; Moore, E. M.

    2010-12-01

    SOFIA is an airborne, gyroscopically stabilized 2.5m infrared telescope, mounted to a spherical bearing. Unlike its predecessors, SOFIA will work in absolute coordinates, despite its continually changing position and attitude. In order to manage this, SOFIA must relate equatorial and telescope coordinates using a combination of avionics data and star identification, manage field rotation and track sky images. We describe the algorithms and systems required to acquire and maintain the equatorial reference frame, relate it to tracking imagers and the science instrument, set up the oscillating secondary mirror, and aggregate pointings into relocatable nods and dithers.

  9. Trigger point therapy.

    PubMed

    Janssens, L A

    1992-03-01

    Trigger points (TP) are objectively demonstrable foci in muscles. They are painful on compression and trigger pain in a referred area. This area may be the only locus of complaint in humans. In dogs we cannot prove the existence of referred zones of pain. Therefore, we can only diagnose a TP-induced claudication if we cannot find bone, joint, or neurologic abnormalities, and we do find TP that disappear after treatment together with the original lameness. Several methods have been developed to demonstrate TP existence objectively. These are pressure algometry, pressure threshold measurements, magnetic resonance thermography, and histology. In humans, 71% of the TP described are acupuncture points. TP treatment consists of TP stimulation with non-invasive or invasive methods such as dry needling or injections. In the dog, ten TP are described in two categories of clinical patients. First, those with one or few TP reacting favorably on treatment (+/- 80% success in +/- 2-3 weeks). Second, those with many TPs reacting badly on treatment. Most probably the latter group are fibromyalgia patients.

  10. Deconfined quantum critical points.

    PubMed

    Senthil, T; Vishwanath, Ashvin; Balents, Leon; Sachdev, Subir; Fisher, Matthew P A

    2004-03-01

    The theory of second-order phase transitions is one of the foundations of modern statistical mechanics and condensed-matter theory. A central concept is the observable order parameter, whose nonzero average value characterizes one or more phases. At large distances and long times, fluctuations of the order parameter(s) are described by a continuum field theory, and these dominate the physics near such phase transitions. We show that near second-order quantum phase transitions, subtle quantum interference effects can invalidate this paradigm, and we present a theory of quantum critical points in a variety of experimentally relevant two-dimensional antiferromagnets. The critical points separate phases characterized by conventional "confining" order parameters. Nevertheless, the critical theory contains an emergent gauge field and "deconfined" degrees of freedom associated with fractionalization of the order parameters. We propose that this paradigm for quantum criticality may be the key to resolving a number of experimental puzzles in correlated electron systems and offer a new perspective on the properties of complex materials.

  11. Relative Critical Points

    NASA Astrophysics Data System (ADS)

    Lewis, Debra

    2013-05-01

    Relative equilibria of Lagrangian and Hamiltonian systems with symmetry are critical points of appropriate scalar functions parametrized by the Lie algebra (or its dual) of the symmetry group. Setting aside the structures - symplectic, Poisson, or variational - generating dynamical systems from such functions highlights the common features of their construction and analysis, and supports the construction of analogous functions in non-Hamiltonian settings. If the symmetry group is nonabelian, the functions are invariant only with respect to the isotropy subgroup of the given parameter value. Replacing the parametrized family of functions with a single function on the product manifold and extending the action using the (co)adjoint action on the algebra or its dual yields a fully invariant function. An invariant map can be used to reverse the usual perspective: rather than selecting a parametrized family of functions and finding their critical points, conditions under which functions will be critical on specific orbits, typically distinguished by isotropy class, can be derived. This strategy is illustrated using several well-known mechanical systems - the Lagrange top, the double spherical pendulum, the free rigid body, and the Riemann ellipsoids - and generalizations of these systems.

  12. HORSESHOE CURVE IN GLACIER POINT ROAD NEAR GLACIER POINT. HALF ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    HORSESHOE CURVE IN GLACIER POINT ROAD NEAR GLACIER POINT. HALF DOME AT CENTER REAR. SAME VIEW AT CA-157-2. LOOKING NNE. GIS: N-37' 43 44.3 / W-119 34 14.1 - Glacier Point Road, Between Chinquapin Flat & Glacier Point, Yosemite Village, Mariposa County, CA

  13. 2. HORSESHOE CURVE IN GLACIER POINT ROAD NEAR GLACIER POINT. ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    2. HORSESHOE CURVE IN GLACIER POINT ROAD NEAR GLACIER POINT. HALF DOME AT CENTER REAR. LOOKING NNE. GIS N-37 43 44.3 / W-119 34 14.1 - Glacier Point Road, Between Chinquapin Flat & Glacier Point, Yosemite Village, Mariposa County, CA

  14. GTE_TRACEP_DC8 Parameters 11

    Atmospheric Science Data Center

    2013-02-18

    ... True air speed Ground speed Heading Drift Pressure & radar altitude Dew point 1011 Dew point 300 Cabin altitude ... track Track error Track Vapor pressure (water) Vapor pressure (ice) Relative humidity (ice) Relative humidity ...

  15. Field evaluation of an acid rain-drought stress interaction.

    PubMed

    Banwart, W L

    1988-01-01

    Various methods have been proposed to simulate natural field conditions for growing agricultural crops while controlling conditions to study specific environmental effects. This report briefly describes the use of moveable rain exclusion shelters (10.4 x 40.9 m) to study the results of the interaction of acid rain and drought stress on corn and soybean yields. The rain exclusion shelters are constructed of galvanized pipe framing and covered with polyethylene film. Movement is automated by a rain switch to protect crops from ambient rainfall and to treat them with simulated acid rain The facility simulates a real environment with respect to variables such as solar exposure, wind movement, dew formation, and insect exposure, while allowing careful control of moisture regimes. Soybeans and corn were treated with average rainfall amounts, and with one-half and one-quarter of these rainfall amounts (drought stress) at two levels of rainfall acidity, pH 5.6 and 3.0. While drought stress resulted in considerable yield reduction for Amsoy and Williams soybeans, no additional reduction in yield was observed with rainfall of pH 3.0, as compared to rainfall of approximately pH 5.6. Similar results were observed for one corn cultivar, Pioneer 3377. For one year of the study however, yield of B73 x Mo17 (corn) was reduced 3139 kg ha(-1) by the most severe drought, and an additional 1883 kg ha(-1) by acid rain of pH 3.0, as compared to the control (pH 5.6). Yield reduction from acidic rain was considerably less at full water rates, resulting in a significant pH by drought stress interaction. However, during the second year of the experiment, no pH effect or drought by pH interaction was observed for this cultivar. The reason for the difference in the two years was not identified.

  16. Folic Acid

    MedlinePlus

    Folic acid is a B vitamin. It helps the body make healthy new cells. Everyone needs folic acid. For women who may get pregnant, it is really important. Getting enough folic acid before and during pregnancy can prevent major birth ...

  17. Folic Acid

    MedlinePlus

    Folic acid is used to treat or prevent folic acid deficiency. It is a B-complex vitamin needed by ... Folic acid comes in tablets. It usually is taken once a day. Follow the directions on your prescription label ...

  18. Latent myofascial trigger points.

    PubMed

    Ge, Hong-You; Arendt-Nielsen, Lars

    2011-10-01

    A latent myofascial trigger point (MTP) is defined as a focus of hyperirritability in a muscle taut band that is clinically associated with local twitch response and tenderness and/or referred pain upon manual examination. Current evidence suggests that the temporal profile of the spontaneous electrical activity at an MTP is similar to focal muscle fiber contraction and/or muscle cramp potentials, which contribute significantly to the induction of local tenderness and pain and motor dysfunctions. This review highlights the potential mechanisms underlying the sensory-motor dysfunctions associated with latent MTPs and discusses the contribution of central sensitization associated with latent MTPs and the MTP network to the spatial propagation of pain and motor dysfunctions. Treating latent MTPs in patients with musculoskeletal pain may not only decrease pain sensitivity and improve motor functions, but also prevent latent MTPs from transforming into active MTPs, and hence, prevent the development of myofascial pain syndrome.

  19. Repelling Point Bosons

    NASA Astrophysics Data System (ADS)

    McGuire, J. B.

    2011-12-01

    There is a body of conventional wisdom that holds that a solvable quantum problem, by virtue of its solvability, is pathological and thus irrelevant. It has been difficult to refute this view owing to the paucity of theoretical constructs and experimental results. Recent experiments involving equivalent ions trapped in a spatial conformation of extreme anisotropic confinement (longitudinal extension tens, hundreds or even thousands of times transverse extension) have modified the view of relevancy, and it is now possible to consider systems previously thought pathological, in particular point Bosons that repel in one dimension. It has been difficult for the experimentalists to utilize existing theory, mainly due to long-standing theoretical misunderstanding of the relevance of the permutation group, in particular the non-commutativity of translations (periodicity) and transpositions (permutation). This misunderstanding is most easily rectified in the case of repelling Bosons.

  20. Point Source All Sky

    NASA Technical Reports Server (NTRS)

    2003-01-01

    This panoramic view encompasses the entire sky as seen by Two Micron All-Sky Survey. The measured brightnesses of half a billion stars (points) have been combined into colors representing three distinct wavelengths of infrared light: blue at 1.2 microns, green at 1.6 microns, and red at 2.2 microns. This image is centered on the core of our own Milky Way galaxy, toward the constellation of Sagittarius. The reddish stars seemingly hovering in the middle of the Milky Way's disc -- many of them never observed before -- trace the densest dust clouds in our galaxy. The two faint smudges seen in the lower right quadrant are our neighboring galaxies, the Small and Large Magellanic Clouds.

  1. Amino acids

    MedlinePlus

    ... amino acids are: histidine, isoleucine, leucine, lysine, methionine, phenylalanine, threonine, tryptophan , and valine. Nonessential amino acids "Nonessential" means that our bodies produce an amino ...

  2. Measurement of Carbon Dioxide Compensation Points of Freshwater Algae 1

    PubMed Central

    Birmingham, Brendan C.; Colman, Brian

    1979-01-01

    A technique is described for the measurement of total dissolved inorganic carbon by acid release as CO2 followed by its conversion to methane and detection by flame ionization in a modified gas chromatograph. This method was used to determine the dissolved inorganic carbon concentration reached at compensation point when algae were allowed to photosynthesize in a closed system in a buffer at known pH, and the CO2 compensation point was calculated from this concentration. The CO2 compensation points of 16 freshwater algae were measured at acid and alkaline pH in air-saturated medium: at acid pH the CO2 compensation points ranged from 4.8 to 41.5 microliters per liter while at alkaline pH they ranged from 0.2 to 7.2 microliters per liter. Removal of O2 from the medium caused a slight lowering of compensation point at acid pH but had little effect at alkaline pH. These low, O2-insensitive compensation points are characteristic of C4 plants. It is suggested that these low CO2 compensation points are maintained by an active bicarbonate uptake by algae especially at alkaline pH. PMID:16661077

  3. Pointing to others: How the target gender influences pointing performance.

    PubMed

    Cleret de Langavant, Laurent; Jacquemot, Charlotte; Cruveiller, Virginie; Dupoux, Emmanuel; Bachoud-Lévi, Anne-Catherine

    2016-01-01

    Pointing is a communicative gesture that allows individuals to share information about surrounding objects with other humans. Patients with heterotopagnosia are specifically impaired in pointing to other humans' body parts but not in pointing to themselves or to objects. Here, we describe a female patient with heterotopagnosia who was more accurate in pointing to men's body parts than to women's body parts. We replicated this gender effect in healthy participants with faster reaction times for pointing to men's body parts than to women's body parts. We discuss the role of gender stereotypes in explaining why it is more difficult to point to women than to men. PMID:27593456

  4. Function Point Analysis Depot

    NASA Technical Reports Server (NTRS)

    Muniz, R.; Martinez, El; Szafran, J.; Dalton, A.

    2011-01-01

    The Function Point Analysis (FPA) Depot is a web application originally designed by one of the NE-C3 branch's engineers, Jamie Szafran, and created specifically for the Software Development team of the Launch Control Systems (LCS) project. The application consists of evaluating the work of each developer to be able to get a real estimate of the hours that is going to be assigned to a specific task of development. The Architect Team had made design change requests for the depot to change the schema of the application's information; that information, changed in the database, needed to be changed in the graphical user interface (GUI) (written in Ruby on Rails (RoR and the web service/server side in Java to match the database changes. These changes were made by two interns from NE-C, Ricardo Muniz from NE-C3, who made all the schema changes for the GUI in RoR and Edwin Martinez, from NE-C2, who made all the changes in the Java side.

  5. Focus point supersymmetry redux

    NASA Astrophysics Data System (ADS)

    Feng, Jonathan L.; Matchev, Konstantin T.; Sanford, David

    2012-04-01

    Recent results from Higgs boson and supersymmetry searches at the Large Hadron Collider provide strong new motivations for supersymmetric theories with heavy superpartners. We reconsider focus point supersymmetry (FP SUSY), in which all squarks and sleptons may have multi-TeV masses without introducing fine-tuning in the weak scale with respect to variations in the fundamental SUSY-breaking parameters. We examine both FP SUSY and its familiar special case, the FP region of minimal supergravity, also known as the constrained minimal supersymmetric standard model (mSUGRA/CMSSM), and show that they are beautifully consistent with all particle, astroparticle, and cosmological data, including Higgs boson mass limits, null results from SUSY searches, electric dipole moments, b→sγ, Bs→μ+μ-, the thermal relic density of neutralinos, and dark matter searches. The observed deviation of the muon’s anomalous magnetic moment from its standard model value may also be explained in FP SUSY, although not in the FP region of mSUGRA/CMSSM. In light of recent data, we advocate refined searches for FP SUSY and related scenarios with heavy squarks and sleptons, and we present a simplified parameter space within mSUGRA/CMSSM to aid such analyses.

  6. Acid Rain.

    ERIC Educational Resources Information Center

    Openshaw, Peter

    1987-01-01

    Provides some background information on acid deposition. Includes a historical perspective, describes some effects of acid precipitation, and discusses acid rain in the United Kingdom. Contains several experiments that deal with the effects of acid rain on water quality and soil. (TW)

  7. Acid rain

    SciTech Connect

    Not Available

    1985-01-01

    This report has four parts: they discuss acid rain in relation to acid soils, agriculture, forests, and aquatic ecosystems. Among findings: modern sources of acid deposition from the atmosphere for all the acid soils in the world, nor even chiefly responsible for those of northern U.S. Agriculture has its problems, but acid precipitation is probably not one of them. More research is needed to determine to what extent acid precipitation is responsible for forest declines and for smaller detrimental effects on forest growth where no damage to the foliage is evident. Many lakes and streams are extremely sensitive to added acids.

  8. United States Air Force 611th Air Support Group/Civil Engineering Squadron, Elmendorf AFB, Alaska. Risk assessment Point Lonely Radar Installation, Alaska. Final report

    SciTech Connect

    Karmi, S.

    1996-04-01

    This document contains the baseline human health risk assessment and the ecological risk assessment (ERA) for the Point Lonely Distant Early Warning (DEW) Line radar installation. Twelve sites at the Point Lonely radar installation underwent remedial investigations (RIs) during the summer of 1993. The Vehicle Storage Area (SS14) was combined with the Inactive Landfill because the two sites were essentially co-located and were sampled during the RI as a single unit. Therefore, 11 sites are discussed in this risk assessment. The presence of chemical contamination in the soil, sediments, and surface water at the installation was evaluated and reported in the Point Lonely Remedial Investigation/Feasibility Study (RI/FS). The analytical data reported in the RI/FS form the basis for the human health and ecological risk assessments. The primary chemicals of concern (COCs) at the 11 sites are diesel and gasoline from past spills and/or leaks, chlorinated solvents, and manganese. The 11 sites investigated and the types of samples collected at each site are presented.

  9. What's the Point? The Benefits of Grading without Points

    ERIC Educational Resources Information Center

    Brilleslyper, Mike; Ghrist, Michelle; Holcomb, Trae; Schaubroeck, Beth; Warner, Bradley; Williams, Scott

    2012-01-01

    Most instructors desire to create a learning environment conducive to deep learning. However, in courses where grades are based upon the accumulation of points, students may focus on collecting points rather than on learning and achieving the course objectives. We discuss an alternative points-free course design based on the development of clear…

  10. Radiometric acid-base titrations.

    PubMed

    Erdey, L; Gimesi, O; Szabadváry, F

    1969-03-01

    Acid-base titrations can be performed with radiometric end-point detection by use of labelled metal salts (e.g., ZnCl(2), HgCl(2)). Owing to the formation or dissolution of the corresponding hydroxide after the equivalence point, the activity of the titrated solution linearly increases or decreases as excess of standard solution is added. The end-point of the titration is determined graphically.

  11. On Pfaffian Random Point Fields

    NASA Astrophysics Data System (ADS)

    Kargin, V.

    2014-02-01

    We study Pfaffian random point fields by using the Moore-Dyson quaternion determinants. First, we give sufficient conditions that ensure that a self-dual quaternion kernel defines a valid random point field, and then we prove a CLT for Pfaffian point fields. The proofs are based on a new quaternion extension of the Cauchy-Binet determinantal identity. In addition, we derive the Fredholm determinantal formulas for the Pfaffian point fields which use the quaternion determinant.

  12. Ground point filtering of UAV-based photogrammetric point clouds

    NASA Astrophysics Data System (ADS)

    Anders, Niels; Seijmonsbergen, Arie; Masselink, Rens; Keesstra, Saskia

    2016-04-01

    Unmanned Aerial Vehicles (UAVs) have proved invaluable for generating high-resolution and multi-temporal imagery. Based on photographic surveys, 3D surface reconstructions can be derived photogrammetrically so producing point clouds, orthophotos and surface models. For geomorphological or ecological applications it may be necessary to separate ground points from vegetation points. Existing filtering methods are designed for point clouds derived using other methods, e.g. laser scanning. The purpose of this paper is to test three filtering algorithms for the extraction of ground points from point clouds derived from low-altitude aerial photography. Three subareas were selected from a single flight which represent different scenarios: 1) low relief, sparsely vegetated area, 2) low relief, moderately vegetated area, 3) medium relief and moderately vegetated area. The three filtering methods are used to classify ground points in different ways, based on 1) RGB color values from training samples, 2) TIN densification as implemented in LAStools, and 3) an iterative surface lowering algorithm. Ground points are then interpolated into a digital terrain model using inverse distance weighting. The results suggest that different landscapes require different filtering methods for optimal ground point extraction. While iterative surface lowering and TIN densification are fully automated, color-based classification require fine-tuning in order to optimize the filtering results. Finally, we conclude that filtering photogrammetric point clouds could provide a cheap alternative to laser scan surveys for creating digital terrain models in sparsely vegetated areas.

  13. Imaging study on acupuncture points

    NASA Astrophysics Data System (ADS)

    Yan, X. H.; Zhang, X. Y.; Liu, C. L.; Dang, R. S.; Ando, M.; Sugiyama, H.; Chen, H. S.; Ding, G. H.

    2009-09-01

    The topographic structures of acupuncture points were investigated by using the synchrotron radiation based Dark Field Image (DFI) method. Four following acupuncture points were studied: Sanyinjiao, Neiguan, Zusanli and Tianshu. We have found that at acupuncture point regions there exists the accumulation of micro-vessels. The images taken in the surrounding tissue out of the acupuncture points do not show such kind of structure. It is the first time to reveal directly the specific structure of acupuncture points by X-ray imaging.

  14. 40 CFR 417.140 - Applicability; description of the neutralization of sulfuric acid esters and sulfonic acids...

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... neutralization of sulfuric acid esters and sulfonic acids subcategory. 417.140 Section 417.140 Protection of... MANUFACTURING POINT SOURCE CATEGORY Neutralization of Sulfuric Acid Esters and Sulfonic Acids Subcategory § 417.140 Applicability; description of the neutralization of sulfuric acid esters and sulfonic...

  15. 40 CFR 417.140 - Applicability; description of the neutralization of sulfuric acid esters and sulfonic acids...

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... neutralization of sulfuric acid esters and sulfonic acids subcategory. 417.140 Section 417.140 Protection of... MANUFACTURING POINT SOURCE CATEGORY Neutralization of Sulfuric Acid Esters and Sulfonic Acids Subcategory § 417.140 Applicability; description of the neutralization of sulfuric acid esters and sulfonic...

  16. 40 CFR 417.140 - Applicability; description of the neutralization of sulfuric acid esters and sulfonic acids...

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... neutralization of sulfuric acid esters and sulfonic acids subcategory. 417.140 Section 417.140 Protection of... MANUFACTURING POINT SOURCE CATEGORY Neutralization of Sulfuric Acid Esters and Sulfonic Acids Subcategory § 417.140 Applicability; description of the neutralization of sulfuric acid esters and sulfonic...

  17. 40 CFR 417.140 - Applicability; description of the neutralization of sulfuric acid esters and sulfonic acids...

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... neutralization of sulfuric acid esters and sulfonic acids subcategory. 417.140 Section 417.140 Protection of... MANUFACTURING POINT SOURCE CATEGORY Neutralization of Sulfuric Acid Esters and Sulfonic Acids Subcategory § 417.140 Applicability; description of the neutralization of sulfuric acid esters and sulfonic...

  18. 40 CFR 417.140 - Applicability; description of the neutralization of sulfuric acid esters and sulfonic acids...

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... neutralization of sulfuric acid esters and sulfonic acids subcategory. 417.140 Section 417.140 Protection of... MANUFACTURING POINT SOURCE CATEGORY Neutralization of Sulfuric Acid Esters and Sulfonic Acids Subcategory § 417.140 Applicability; description of the neutralization of sulfuric acid esters and sulfonic...

  19. Point-based manifold harmonics.

    PubMed

    Liu, Yang; Prabhakaran, Balakrishnan; Guo, Xiaohu

    2012-10-01

    This paper proposes an algorithm to build a set of orthogonal Point-Based Manifold Harmonic Bases (PB-MHB) for spectral analysis over point-sampled manifold surfaces. To ensure that PB-MHB are orthogonal to each other, it is necessary to have symmetrizable discrete Laplace-Beltrami Operator (LBO) over the surfaces. Existing converging discrete LBO for point clouds, as proposed by Belkin et al., is not guaranteed to be symmetrizable. We build a new point-wisely discrete LBO over the point-sampled surface that is guaranteed to be symmetrizable, and prove its convergence. By solving the eigen problem related to the new operator, we define a set of orthogonal bases over the point cloud. Experiments show that the new operator is converging better than other symmetrizable discrete Laplacian operators (such as graph Laplacian) defined on point-sampled surfaces, and can provide orthogonal bases for further spectral geometric analysis and processing tasks.

  20. Aminocaproic Acid

    MedlinePlus

    Aminocaproic acid is used to control bleeding that occurs when blood clots are broken down too quickly. This type ... the baby is ready to be born). Aminocaproic acid is also used to control bleeding in the ...

  1. Ethacrynic Acid

    MedlinePlus

    Ethacrynic acid, a 'water pill,' is used to treat swelling and fluid retention caused by various medical problems. It ... Ethacrynic acid comes as a tablet to take by mouth. It is usually taken once or twice a day ...

  2. Obeticholic Acid

    MedlinePlus

    Obeticholic acid is used alone or in combination with ursodiol (Actigall, Urso) to treat primary biliary cholangitis (PBC; a ... were not treated successfully with ursodiol alone. Obeticholic acid is in a class of medications called farnesoid ...

  3. Acid mucopolysaccharides

    MedlinePlus

    ... this page: //medlineplus.gov/ency/article/003368.htm Acid mucopolysaccharides To use the sharing features on this page, please enable JavaScript. Acid mucopolysaccharides is a test that measures the amount ...

  4. The Point of No Return

    PubMed Central

    Logan, Gordon D.

    2015-01-01

    Bartlett (1958) described the point of no return as a point of irrevocable commitment to action, which was preceded by a period of gradually increasing commitment. As such, the point of no return reflects a fundamental limit on the ability to control thought and action. I review the literature on the point of no return, taking three perspectives. First, I consider the point of no return from the perspective of the controlled act, as a locus in the architecture and anatomy of the underlying processes. I review experiments from the stop-signal paradigm that suggest that the point of no return is located late in the response system. Then I consider the point of no return from the perspective of the act of control that tries to change the controlled act before it becomes irrevocable. From this perspective, the point of no return is a point in time that provides enough “lead time” for the act of control to take effect. I review experiments that measure the response time to the stop signal as the lead time required for response inhibition in the stop-signal paradigm. Finally, I consider the point of no return in hierarchically controlled tasks, in which there may be many points of no return at different levels of the hierarchy. I review experiments on skilled typing that suggest different points of no return for the commands that determine what is typed and the countermands that inhibit typing, with increasing commitment to action the lower the level in the hierarchy. I end by considering the point of no return in perception and thought as well as action. PMID:25633089

  5. Fermat's point from five perspectives

    NASA Astrophysics Data System (ADS)

    Park, Jungeun; Flores, Alfinio

    2015-04-01

    The Fermat point of a triangle is the point such that minimizes the sum of the distances from that point to the three vertices. Five approaches to study the Fermat point of a triangle are presented in this article. First, students use a mechanical device using masses, strings and pulleys to study the Fermat point as the one that minimizes the potential energy of the system. Second, students use soap films between parallel planes connecting three pegs. The tension on the film will be minimal when the sum of distances is minimal. Third, students use an empirical approach, measuring distances in an interactive GeoGebra page. Fourth, students use Euclidean geometry arguments for two proofs based on the Torricelli configuration, and one using Viviani's Theorem. And fifth, the kinematic method is used to gain additional insight on the size of the angles between the segments joining the Fermat point with the vertices.

  6. Method of forming pointed structures

    NASA Technical Reports Server (NTRS)

    Pugel, Diane E. (Inventor)

    2011-01-01

    A method of forming an array of pointed structures comprises depositing a ferrofluid on a substrate, applying a magnetic field to the ferrofluid to generate an array of surface protrusions, and solidifying the surface protrusions to form the array of pointed structures. The pointed structures may have a tip radius ranging from approximately 10 nm to approximately 25 micron. Solidifying the surface protrusions may be carried out at a temperature ranging from approximately 10 degrees C. to approximately 30 degrees C.

  7. Point contact silicon solar cells

    NASA Technical Reports Server (NTRS)

    Swanson, Richard M.

    1987-01-01

    A new type of silicon solar cell has been developed. It is called the point-contact cell because the metal semiconductor contacts are restricted to an array of small points on the back of the cell. The point contact cell has recently demonstrated 22 percent conversion efficiency at one sun and 27.5 percent at 100 suns under an AM1.5 spectrum.

  8. Fatty acids - trans fatty acids

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The data supporting a negative effect of dietary trans fatty acids on cardiovascular disease risk is consistent. The primary dietary sources of trans fatty acids include partially hydrogenated fat and rudiment fat. The adverse effect of trans fatty acids on plasma lipoprotein profiles is consisten...

  9. Portable nucleic acid thermocyclers.

    PubMed

    Almassian, David R; Cockrell, Lisa M; Nelson, William M

    2013-11-21

    A nucleic acid thermal cycler is considered to be portable if it is under ten pounds, easily carried by one individual, and battery powered. Nucleic acid amplification includes both polymerase chain reaction (e.g. PCR, RT-PCR) and isothermal amplification (e.g. RPA, HDA, LAMP, NASBA, RCA, ICAN, SMART, SDA). There are valuable applications for portable nucleic acid thermocyclers in fields that include clinical diagnostics, biothreat detection, and veterinary testing. A system that is portable allows for the distributed detection of targets at the point of care and a reduction of the time from sample to answer. The designer of a portable nucleic acid thermocycler must carefully consider both thermal control and the detection of amplification. In addition to thermal control and detection, the designer may consider the integration of a sample preparation subsystem with the nucleic acid thermocycler. There are a variety of technologies that can achieve accurate thermal control and the detection of nucleic acid amplification. Important evaluation criteria for each technology include maturity, power requirements, cost, sensitivity, speed, and manufacturability. Ultimately the needs of a particular market will lead to user requirements that drive the decision between available technologies.

  10. Utilization of acid tars

    SciTech Connect

    Frolov, A.F.; Denisova, T.L.; Aminov, A.N.

    1987-01-01

    Freshly produced acid tar (FPAT), obtained as refinery waste in treating petroleum oils with sulfuric acid and oleum, contains 80% or more sulfuric acid. Of such tars, pond acid tars, which contain up to 80% neutral petroleum products and sulfonated resins, are more stable, and have found applications in the production of binders for paving materials. In this article the authors are presenting results obtained in a study of the composition and reactivity of FPAT and its stability in storage in blends with asphalts obtained in deasphalting operations, and the possibility of using the FPAT in road construction has been examined. In this work, wastes were used which were obtained in treating the oils T-750, KhF-12, I-8A, and MS-14. Data on the change in group chemical composition of FPAT are shown, and the acidity, viscosity, needle penetration, and softening point of acid tars obtained from different grades of oils are plotted as functions of the storage time. It is also shown that the fresh and hardened FPATs differ in their solubilities in various solvents.

  11. NON-POINT SOURCE POLLUTION

    EPA Science Inventory

    Non-point source pollution is a diffuse source that is difficult to measure and is highly variable due to different rain patterns and other climatic conditions. In many areas, however, non-point source pollution is the greatest source of water quality degradation. Presently, stat...

  12. Inertial Pointing and Positioning System

    NASA Technical Reports Server (NTRS)

    Yee, Robert (Inventor); Robbins, Fred (Inventor)

    1998-01-01

    An inertial pointing and control system and method for pointing to a designated target with known coordinates from a platform to provide accurate position, steering, and command information. The system continuously receives GPS signals and corrects Inertial Navigation System (INS) dead reckoning or drift errors. An INS is mounted directly on a pointing instrument rather than in a remote location on the platform for-monitoring the terrestrial position and instrument attitude. and for pointing the instrument at designated celestial targets or ground based landmarks. As a result. the pointing instrument and die INS move independently in inertial space from the platform since the INS is decoupled from the platform. Another important characteristic of the present system is that selected INS measurements are combined with predefined coordinate transformation equations and control logic algorithms under computer control in order to generate inertial pointing commands to the pointing instrument. More specifically. the computer calculates the desired instrument angles (Phi, Theta. Psi). which are then compared to the Euler angles measured by the instrument- mounted INS. and forms the pointing command error angles as a result of the compared difference.

  13. Brocard Point and Euler Function

    ERIC Educational Resources Information Center

    Sastry, K. R. S.

    2007-01-01

    This paper takes a known point from Brocard geometry, a known result from the geometry of the equilateral triangle, and bring in Euler's [empty set] function. It then demonstrates how to obtain new Brocard Geometric number theory results from them. Furthermore, this paper aims to determine a [triangle]ABC whose Crelle-Brocard Point [omega]…

  14. Planetary system detection by POINTS

    NASA Technical Reports Server (NTRS)

    Reasenberg, Robert D.

    1993-01-01

    The final report and semiannual reports 1, 2, and 3 in response to the study of 'Planetary System Detection by POINTS' is presented. The grant covered the period from 15 Jun. 1988 through 31 Dec. 1989. The work during that period comprised the further development and refinement of the POINTS concept. The status of the POINTS development at the end of the Grant period was described by Reasenberg in a paper given at the JPL Workshop on Space Interferometry, 12-13 Mar. 1990, and distributed as CfA Preprint 3138. That paper, 'POINTS: a Small Astrometric Interferometer,' follows as Appendix-A. Our proposal P2276-7-09, dated July 1990, included a more detailed description of the state of the development of POINTS at the end of the tenure of Grant NAGW-1355. That proposal, which resulted in Grant NAGW-2497, is included by reference.

  15. Aspartic acid

    MedlinePlus

    ... Hormone production and release Normal nervous system function Plant sources of aspartic acid include: Legumes such as soybeans, garbanzo beans, and lentils Peanuts, almonds, walnuts, and flaxseeds Animal ...

  16. Pivots for Pointing: Visually-Monitored Pointing Has Higher Arm Elevations than Pointing Blindfolded

    ERIC Educational Resources Information Center

    Wnuczko, Marta; Kennedy, John M.

    2011-01-01

    Observers pointing to a target viewed directly may elevate their fingertip close to the line of sight. However, pointing blindfolded, after viewing the target, they may pivot lower, from the shoulder, aligning the arm with the target as if reaching to the target. Indeed, in Experiment 1 participants elevated their arms more in visually monitored…

  17. Plant Cuticles Are Polyelectrolytes with Isoelectric Points around Three 1

    PubMed Central

    Schönherr, Jörg; Huber, Rudolf

    1977-01-01

    The isoelectric points of isolated cuticles from Citrus aurantium L. (3.15), Prunus armeniaca L. (3.45), and Pyrus communis L. (2.90) leaves were determined from membrane potentials. At pH values below the isoelectric point, cuticular membranes carry a net positive charge and are permselective to anions (determined using 82Br−). Above the isoelectric point, they carry a net negative charge and are permselective to cations (determined using 24Na+). There are no gradients of fixed charges across the cuticular membranes as indicated by the absence of asymmetry potentials. Positive charges in the membranes originate from residues of basic amino acids of proteins or polypeptides contained in a nonextractable form within the cuticle. The exchange capacity of basic fixed groups in the cuticles of six species (Lycopersicon esculentum Mill., Capsicum annuum L. fruit cuticles, and Brassaia spec. leaf cuticles in addition to the above species) varied between 0.010 and 0.025 meq g−1 cuticle. Fixed acidic groups were donated by residues of acidic amino acids, polygalacturonic acid, and nonesterified -COOH groups of the cutin polymer. At pH 8, total cation exchange capacity as determined using 45Ca2+ varied between 0.26 (Citrus) and 0.30 (apricot) meq g−1. PMID:16659804

  18. NOTE: Do acupuncture points exist?

    NASA Astrophysics Data System (ADS)

    Yan, Xiaohui; Zhang, Xinyi; Liu, Chenglin; Dang, Ruishan; Huang, Yuying; He, Wei; Ding, Guanghong

    2009-05-01

    We used synchrotron x-ray fluorescence analysis to probe the distribution of four chemical elements in and around acupuncture points, two located in the forearm and two in the lower leg. Three of the four acupuncture points showed significantly elevated concentrations of elements Ca, Fe, Cu and Zn in relation to levels in the surrounding tissue, with similar elevation ratios for Cu and Fe. The mapped distribution of these elements implies that each acupuncture point seems to be elliptical with the long axis along the meridian.

  19. Positional nystagmus showing neutral points.

    PubMed

    Hiruma, Kiyoshi; Numata, Tsutomu

    2004-01-01

    We encountered patients who had their static direction-changing positional nystagmus canceled at about 20-30 degrees yaw head rotation from the supine position. This nystagmus was also canceled when the head was rotated 180 degrees from this position. We call these head positions neutral points. At the neutral points, the cupula of the horizontal semicircular canal of the affected ear is positioned vertical to the gravitational plane and no deflection of the cupula occurs. The positional nystagmus observed (except the neutral points) was thought to occur due to a "heavy cupula" or "light cupula", which may be determined by the specific gravity of its endolymph.

  20. Davies Critical Point and Tunneling

    NASA Astrophysics Data System (ADS)

    La, Hoseong

    2012-04-01

    From the point of view of tunneling, the physical meaning of the Davies critical point of a second-order phase transition in the black hole thermodynamics is clarified. At the critical point, the nonthermal contribution vanishes so that the black hole radiation is entirely thermal. It separates two phases: one with radiation enhanced by the nonthermal contribution, the other suppressed by the nonthermal contribution. We show this in both charged and rotating black holes. The phase transition is also analyzed in the cases in which emissions of charges and angular momenta are incorporated.

  1. Usnic acid.

    PubMed

    Ingólfsdóttir, K

    2002-12-01

    Since its first isolation in 1844, usnic acid [2,6-diacetyl-7,9-dihydroxy-8,9b-dimethyl-1,3(2H,9bH)-dibenzo-furandione] has become the most extensively studied lichen metabolite and one of the few that is commercially available. Usnic acid is uniquely found in lichens, and is especially abundant in genera such as Alectoria, Cladonia, Usnea, Lecanora, Ramalina and Evernia. Many lichens and extracts containing usnic acid have been utilized for medicinal, perfumery, cosmetic as well as ecological applications. Usnic acid as a pure substance has been formulated in creams, toothpaste, mouthwash, deodorants and sunscreen products, in some cases as an active principle, in others as a preservative. In addition to antimicrobial activity against human and plant pathogens, usnic acid has been shown to exhibit antiviral, antiprotozoal, antiproliferative, anti-inflammatory and analgesic activity. Ecological effects, such as antigrowth, antiherbivore and anti-insect properties, have also been demonstrated. A difference in biological activity has in some cases been observed between the two enantiomeric forms of usnic acid. Recently health food supplements containing usnic acid have been promoted for use in weight reduction, with little scientific support. The emphasis of the current review is on the chemistry and biological activity of usnic acid and its derivatives in addition to rational and ecologically acceptable methods for provision of this natural compound on a large scale.

  2. Acid rain

    SciTech Connect

    Elsworth, S.

    1985-01-01

    This book was written in a concise and readable style for the lay public. It's purpose was to make the public aware of the damage caused by acid rain and to mobilize public opinion to favor the elimination of the causes of acid rain.

  3. Acid rain

    SciTech Connect

    White, J.C. )

    1988-01-01

    This book presents the proceedings of the third annual conference sponsored by the Acid Rain Information Clearinghouse (ARIC). Topics covered include: Legal aspects of the source-receptor relationship: an energy perspective; Scientific uncertainty, agency inaction, and the courts; and Acid rain: the emerging legal framework.

  4. How Acidic Is Carbonic Acid?

    PubMed

    Pines, Dina; Ditkovich, Julia; Mukra, Tzach; Miller, Yifat; Kiefer, Philip M; Daschakraborty, Snehasis; Hynes, James T; Pines, Ehud

    2016-03-10

    Carbonic, lactic, and pyruvic acids have been generated in aqueous solution by the transient protonation of their corresponding conjugate bases by a tailor-made photoacid, the 6-hydroxy-1-sulfonate pyrene sodium salt molecule. A particular goal is to establish the pK(a) of carbonic acid H2CO3. The on-contact proton transfer (PT) reaction rate from the optically excited photoacid to the carboxylic bases was derived, with unprecedented precision, from time-correlated single-photon-counting measurements of the fluorescence lifetime of the photoacid in the presence of the proton acceptors. The time-dependent diffusion-assisted PT rate was analyzed using the Szabo-Collins-Kimball equation with a radiation boundary condition. The on-contact PT rates were found to follow the acidity order of the carboxylic acids: the stronger was the acid, the slower was the PT reaction to its conjugate base. The pK(a) of carbonic acid was found to be 3.49 ± 0.05 using both the Marcus and Kiefer-Hynes free energy correlations. This establishes H2CO3 as being 0.37 pK(a) units stronger and about 1 pK(a) unit weaker, respectively, than the physiologically important lactic and pyruvic acids. The considerable acid strength of intact carbonic acid indicates that it is an important protonation agent under physiological conditions. PMID:26862781

  5. NULL Convention Floating Point Multiplier

    PubMed Central

    Ramachandran, Seshasayanan

    2015-01-01

    Floating point multiplication is a critical part in high dynamic range and computational intensive digital signal processing applications which require high precision and low power. This paper presents the design of an IEEE 754 single precision floating point multiplier using asynchronous NULL convention logic paradigm. Rounding has not been implemented to suit high precision applications. The novelty of the research is that it is the first ever NULL convention logic multiplier, designed to perform floating point multiplication. The proposed multiplier offers substantial decrease in power consumption when compared with its synchronous version. Performance attributes of the NULL convention logic floating point multiplier, obtained from Xilinx simulation and Cadence, are compared with its equivalent synchronous implementation. PMID:25879069

  6. Detecting determinism from point processes

    NASA Astrophysics Data System (ADS)

    Andrzejak, Ralph G.; Mormann, Florian; Kreuz, Thomas

    2014-12-01

    The detection of a nonrandom structure from experimental data can be crucial for the classification, understanding, and interpretation of the generating process. We here introduce a rank-based nonlinear predictability score to detect determinism from point process data. Thanks to its modular nature, this approach can be adapted to whatever signature in the data one considers indicative of deterministic structure. After validating our approach using point process signals from deterministic and stochastic model dynamics, we show an application to neuronal spike trains recorded in the brain of an epilepsy patient. While we illustrate our approach in the context of temporal point processes, it can be readily applied to spatial point processes as well.

  7. Preliminary exposure study to determine the effects of acid deposition on coated steel substrates. Final report

    SciTech Connect

    Moran, P.J.; Simpson, T.C.; Hampel, H.; David, G.D.; Shaw, B.A.

    1990-04-01

    The project involves the evaluation of the effects of acidic pollutants on painted metal substrates. The project examined a commercially available alkyd paint/primer system applied to a low carbon steel substrate exposed under a variety of simulated acidic conditions to determine the micro/macro effects of such exposure. The techniques that were identified as those most sensitive and applicable during the study include tensile adhesion testing, electrochemical impedance spectroscopy, and x-ray photoelectron spectroscopy. A novel electrochemical monitor was developed during this program that allowed the continual monitoring of coating degradation during chamber exposure. It was further found that a good correlation existed between tensile adhesion strength measurements and electrochemical impedance parameters. The program determined that the rate of degradation of the alkyd painted steel coupons was accelerated in the presence of SO2. This effect was most pronounced on samples that contained defects (scribes), that were allowed to form condensed (dew) during the exposure period and that had a horizontal orientation during exposure.

  8. Acid rain

    SciTech Connect

    Sweet, W.

    1980-06-20

    Acid precipitation includes not only rain but also acidified snow, hail and frost, as well as sulfur and nitrogen dust. The principal source of acid precipitation is pollution emitted by power plants and smelters. Sulfur and nitrogen compounds contained in the emissions combine with moisture to form droplets with a high acid content - sometimes as acidic as vinegar. When sufficiently concentrated, these acids can kill fish and damage material structures. Under certain circumstances they may reduce crop and forest yields and cause or aggravate respiratory diseases in humans. During the summer, especially, pollutants tend to collect over the Great Lakes in high pressure systems. Since winds typically are westerly and rotate clockwise around high pressure systems, the pollutants gradually are dispersed throughout the eastern part of the continent.

  9. Asparagusic acid.

    PubMed

    Mitchell, Stephen C; Waring, Rosemary H

    2014-01-01

    Asparagusic acid (1,2-dithiolane-4-carboxylic acid) is a simple sulphur-containing 5-membered heterocyclic compound that appears unique to asparagus, though other dithiolane derivatives have been identified in non-food species. This molecule, apparently innocuous toxicologically to man, is the most probable culprit responsible for the curious excretion of odorous urine following asparagus ingestion. The presence of the two adjacent sulphur atoms leads to an enhanced chemical reactivity, endowing it with biological properties including the ability to substitute potentially for α-lipoic acid in α-keto-acid oxidation systems. This brief review collects the scattered data available in the literature concerning asparagusic acid and highlights its properties, intermediary metabolism and exploratory applications.

  10. Acid rain

    SciTech Connect

    Bess, F.D.

    1980-01-01

    The acid rain problem in the northeastern U.S. has been growing in severity and geographical areas affected. Acid rain has damaged, or will result in damage to visibility, physical structures and materials, aquatic life, timber, crops, and soils. The principal causes of acid rain in the northeastern U.S. are sulfur oxide and nitrogen oxide emissions from large power plants and smelters in the Ohio River Valley. Immediate corrective action and appropriate research are needed to reduce acid precipitation. Short-term programs that will define the rate of environmental deterioration, remaining environmental capacity to resist sudden deterioration, mechanisms of acid rain formation, and costs of various control options must be developed. (3 maps, 13 references, 1 table)

  11. Asparagusic acid.

    PubMed

    Mitchell, Stephen C; Waring, Rosemary H

    2014-01-01

    Asparagusic acid (1,2-dithiolane-4-carboxylic acid) is a simple sulphur-containing 5-membered heterocyclic compound that appears unique to asparagus, though other dithiolane derivatives have been identified in non-food species. This molecule, apparently innocuous toxicologically to man, is the most probable culprit responsible for the curious excretion of odorous urine following asparagus ingestion. The presence of the two adjacent sulphur atoms leads to an enhanced chemical reactivity, endowing it with biological properties including the ability to substitute potentially for α-lipoic acid in α-keto-acid oxidation systems. This brief review collects the scattered data available in the literature concerning asparagusic acid and highlights its properties, intermediary metabolism and exploratory applications. PMID:24099657

  12. Hermit Points on a Box

    ERIC Educational Resources Information Center

    Hess, Richard; Grinstead, Charles; Grindstead, Marshall; Bergstrand, Deborah

    2008-01-01

    Suppose that we are given a rectangular box in 3-space. Given any two points on the surface of this box, we can define the surface distance between them to be the length of the shortest path between them on the surface of the box. This paper determines the pairs of points of maximum surface distance for all boxes. It is often the case that these…

  13. Analysis of Bile Acids

    NASA Astrophysics Data System (ADS)

    Sjövall, Jan; Griffiths, William J.; Setchell, Kenneth D. R.; Mano, Nariyasu; Goto, Junichi

    Bile acids constitute a large family of steroids in vertebrates, normally formed from cholesterol and carrying a carboxyl group in a side-chain of variable length. Bile alcohols, also formed from cholesterol, have similar structures as bile acids, except for the absence of a carboxyl group in the steroid skeleton. The conversion of cholesterol to bile acids and/or bile alcohols is of major importance for maintenance of cholesterol homeostasis, both from quantitative and regulatory points of view (Chiang, 2004; Kalaany and Mangelsdorf, 2006; Moore, Kato, Xie, et al., 2006; Scotti, Gilardi, Godio, et al., 2007). Appropriately conjugated bile acids and bile alcohols (also referred to as bile salts) are secreted in bile and serve vital functions in the absorption of lipids and lipid-soluble compounds (Hofmann, 2007). Reliable analytical methods are required for studies of the functions and pathophysiological importance of the variety of bile acids and bile alcohols present in living organisms. When combined with genetic and proteomic studies, analysis of these small molecules (in today's terminology: metabolomics, steroidomics, sterolomics, cholanoidomics, etc.) will lead to a deeper understanding of the integrated metabolic processes in lipid metabolism.

  14. Characterizing configurations of fire ignition points through spatiotemporal point processes

    NASA Astrophysics Data System (ADS)

    Comas, C.; Costafreda-Aumedes, S.; Vega-Garcia, C.

    2014-04-01

    Human-caused forest fires are usually regarded as unpredictable but often exhibit trends towards clustering in certain locations and periods. Characterizing such configurations is crucial for understanding spatiotemporal fire dynamics and implementing preventive actions. Our objectives were to analyse the spatiotemporal point configuration and to test for spatiotemporal interaction. We characterized the spatiotemporal structure of 984 fire ignition points in a study area of Galicia, Spain, during 2007-2011 by the K-Ripley's function. Our results suggest the presence of spatiotemporal structures for time lags of less than two years and ignition point distances in the range 0-12 km. Ignition centre points at time lags of less than 100 days are aggregated for any inter-event distance. This cluster structure loses strength as the time lag increases, and at time lags of more than 365 days this cluster structure is not significant for any lag distance. Our results also suggest spatiotemporal interdependencies at time lags of less than 100 days and inter-event distances of less than 10 km. At time lags of up to 365 days spatiotemporal components are independent for any point distance. These results suggest that risk conditions occur locally and are short-lived in this study area.

  15. An Emprical Point Error Model for Tls Derived Point Clouds

    NASA Astrophysics Data System (ADS)

    Ozendi, Mustafa; Akca, Devrim; Topan, Hüseyin

    2016-06-01

    The random error pattern of point clouds has significant effect on the quality of final 3D model. The magnitude and distribution of random errors should be modelled numerically. This work aims at developing such an anisotropic point error model, specifically for the terrestrial laser scanner (TLS) acquired 3D point clouds. A priori precisions of basic TLS observations, which are the range, horizontal angle and vertical angle, are determined by predefined and practical measurement configurations, performed at real-world test environments. A priori precision of horizontal (𝜎𝜃) and vertical (𝜎𝛼) angles are constant for each point of a data set, and can directly be determined through the repetitive scanning of the same environment. In our practical tests, precisions of the horizontal and vertical angles were found as 𝜎𝜃=±36.6𝑐𝑐 and 𝜎𝛼=±17.8𝑐𝑐, respectively. On the other hand, a priori precision of the range observation (𝜎𝜌) is assumed to be a function of range, incidence angle of the incoming laser ray, and reflectivity of object surface. Hence, it is a variable, and computed for each point individually by employing an empirically developed formula varying as 𝜎𝜌=±2-12 𝑚𝑚 for a FARO Focus X330 laser scanner. This procedure was followed by the computation of error ellipsoids of each point using the law of variance-covariance propagation. The direction and size of the error ellipsoids were computed by the principal components transformation. The usability and feasibility of the model was investigated in real world scenarios. These investigations validated the suitability and practicality of the proposed method.

  16. Robot positioning based on point-to-point motion capability

    SciTech Connect

    Park, Y. S.; Cho, H. S.; Koh, K. C.

    2000-03-20

    This paper presents an optimal search method for determining the base location of a robot manipulator so that the robot can have a designated point-to-point (PTP) motion capabilities. Based on the topological characterization of the manipulator workspace and the definitions of various p-connectivity, a computational method is developed for enumerating various PTP motion capabilities into quantitative cost functions. Then an unconstrained search by minimizing the cost function yields the task feasible location of the robot base. This methodology is useful for placement of mobile manipulators and robotic workcell layout design.

  17. Acid fog

    SciTech Connect

    Hileman, B.

    1983-03-01

    Fog in areas of southern California previously thought to be pollution-free has been shown to have a pH as low as 1.69. It has been found to be most acidic after smoggy days, suggesting that it forms on the aerosol associated with the previously exiting smog. Studies on Whiteface Mountain in the Adirondacks show that fog water is often 10 times as acidic as rainwater. As a result of their studies, California plans to spend $4 million on acid deposition research in the coming year. (JMT)

  18. Trigger Points: An Anatomical Substratum

    PubMed Central

    Akamatsu, Flávia Emi; Ayres, Bernardo Rodrigues; Saleh, Samir Omar; Hojaij, Flávio; Andrade, Mauro; Hsing, Wu Tu; Jacomo, Alfredo Luiz

    2015-01-01

    This study aimed to bring the trapezius muscle knowledge of the locations where the accessory nerve branches enter the muscle belly to reach the motor endplates and find myofascial trigger points (MTrPs). Although anatomoclinical correlations represent a major feature of MTrP, no previous reports describing the distribution of the accessory nerve branches and their anatomical relationship with MTrP are found in the literature. Both trapezius muscles from twelve adult cadavers were carefully dissected by the authors (anatomy professors and medical graduate students) to observe the exact point where the branches of the spinal accessory nerve entered the muscle belly. Dissection was performed through stratigraphic layers to preserve the motor innervation of the trapezius muscle, which is located deep in the muscle. Seven points are described, four of which are motor points: in all cases, these locations corresponded to clinically described MTrPs. The four points were common in these twelve cadavers. This type of clinical correlation between spinal accessory nerve branching and MTrP is useful to achieve a better understanding of the anatomical correlation of MTrP and the physiopathology of these disorders and may provide a scientific basis for their treatment, rendering useful additional information to therapists to achieve better diagnoses and improve therapeutic approaches. PMID:25811029

  19. Remotely Sensed Ground Control Points

    NASA Astrophysics Data System (ADS)

    Hummel, P.

    2016-06-01

    Accurate ground control is required to georeferenced airborne and spaceborne images. The production of ortho-photogrammetric data requires ground control that is traditionally provided as Ground Control Points (GCPs) by GNSS measurements in the field. However, it can be difficult to acquire accurate ground control points due to required turn-around time, high costs or impossible access. CompassData, Inc. a specialist in ground control, has expanded its service to deliver Remotely Sensed Ground Control Points (RSGCPs®). TerraSAR-X and TanDEM-X are two satellites with such high accuracy of their orbital positions and SAR data that RSGCPs® can be produced to a sub-meter quality depending on certain parameters and circumstances. The technology and required parameters are discussed in this paper as well as the resulting accuracies.

  20. Equation predicts diesel cloud points

    SciTech Connect

    Tsang, C.Y.; Ker, V.S.F.; Miranda, R.D.; Wesch, J.C.

    1988-03-28

    Diesel fuel cloud points can be predicted by an empirical equation developed by NOCA/Husky Research Corp. The equation can accurately predict cloud points from feedstock and product data readily available in the refinery. The applicability of the equation to a full range of summer, winter, and arctic diesel blends was proven by studies conducted on data from four Canadian refineries that process a wide variety of conventional crude oils and synthetic crude from bitumen. Results of the studies show that the variance between equation predicted and measured cloud point values are within acceptable reproducibility of measured data. Considerable time can be saved in the refinery when the equation is used for optimizing diesel fuel blend formulations. Applicability ranges from daily blending calculations, to use in linear programs for long-term planning for distillate utilization.

  1. Tranexamic Acid

    MedlinePlus

    ... is used to treat heavy bleeding during the menstrual cycle (monthly periods) in women. Tranexamic acid is in ... tablets for more than 5 days in a menstrual cycle or take more than 6 tablets in a ...

  2. Mefenamic Acid

    MedlinePlus

    ... as mefenamic acid may cause ulcers, bleeding, or holes in the stomach or intestine. These problems may ... like coffee grounds, blood in the stool, or black and tarry stools.Keep all appointments with your ...

  3. Acid Precipitation

    ERIC Educational Resources Information Center

    Likens, Gene E.

    1976-01-01

    Discusses the fact that the acidity of rain and snow falling on parts of the U.S. and Europe has been rising. The reasons are still not entirely clear and the consequences have yet to be well evaluated. (MLH)

  4. Tipping Points in Texas Rivers

    NASA Astrophysics Data System (ADS)

    Phillips, Jonathan

    2016-04-01

    Anticipating geomorphic tipping points requires that we learn from the past. Major geomorphic changes in coastal plain rivers of Texas resulting in river metamorphosis or regime shifts were identified, and the major driving factors determined. Nine fluvial tipping points were identified from contemporary observations, historical records, and Quaternary reconstructions. Two of the tipping points (between general aggrading and degrading valley states) are associated with reversals in a fundamental system control (sea-level). One (stable or aggrading vs. degrading channels) is associated with an abrupt change in sediment supply due to dam construction, and two others (changes from meandering to anastomosing channel patterns, and different anastomosis styles) are similarly related to changes in sediment supply and/or transport capacity, but with additional elements of historical contingency. Three tipping points are related to avulsions. One, from a regime dominated to reoccupation of former channels to one dominated by progradation into flood basins, is driven by progressive long term filling of incised valleys. Another, nodal avulsions, are driven by disturbances associated with tectonics or listric faults. The third, avulsions and related valley metamorphosis in unfilled incised valleys, is due to fundamental dynamical instabilities within the fluvial system. This synthesis and analysis suggests that geomorphic tipping points are sometimes associated with general extrinsic or intrinsic (to the fluvial system) environmental change, independent of any disturbances or instabilities. Others are associated with natural (e.g., tectonic) or human (dams) disturbances, and still others with intrinsic geomorphic instabilities. This suggests that future tipping points will be equally diverse with respect to their drivers.

  5. Characterization of MIPAS elevation pointing

    NASA Astrophysics Data System (ADS)

    Kiefer, M.; von Clarmann, T.; Grabowski, U.; de Laurentis, M.; Mantovani, R.; Milz, M.; Ridolfi, M.

    2006-12-01

    Sufficient knowledge of the pointing is essential for analyses of limb emission measurements. The scientific retrieval processor for MIPAS operated at IMK allows to retrieve pointing information in terms of tangent altitudes along with temperature. The retrieved tangent altitudes are independent of the engineering Line-Of-Sight (LOS) information delivered with the ESA Level 1b product. The difference of pointing retrieved from the reprocessed high resolution MIPAS spectra and the engineering pointing information was examined with respect to spatial/temporal behaviour. Among others the following characteristics of MIPAS pointing could be identified: Generally the engineering tangent altitudes are too high by 0-1.8 km with conspicuous variations in this range over time. Prior to December of 2003 there was a drift of about 50-100 m/h, which was due to a slow change in the satellite attitude. A correction of this attitude is done twice a day, which led to discontinuities in the order of up to 2 km in the tangent altitudes. There is a systematic difference in the mispointing between the poles which amounts to 1.5-2 km, i.e. there is a conspicuous orbit-periodic feature. The analysis of the correlation between the instrument's viewing angle azimuth and differential mispointing supports the hypotheses that a major part of this latter phenomenon can be attributed to an uncorrected roll angle of the satellite/instrument system of approximately 54 mdeg. Complementary to this, ESA operational LOS calibration results were used to characterize MIPAS pointing. For this purpose MIPAS is used as a radiometer while the passage of infrared bright stars through the instrument's field of view is recorded. Deviation from expected time of passage gives information about mispointing. A pronounced seasonal variation of the LOS is seen before a correction of on-board software took place in December of 2003. Further a pitch bias of 24 mdeg with respect to the platform attitude information

  6. Acidic precipitation

    SciTech Connect

    Martin, H.C.

    1987-01-01

    At the International Symposium on Acidic Precipitation, over 400 papers were presented, and nearly 200 of them are included here. They provide an overview of the present state of the art of acid rain research. The Conference focused on atmospheric science (monitoring, source-receptor relationships), aquatic effects (marine eutrophication, lake acidification, impacts on plant and fish populations), and terrestrial effects (forest decline, soil acidification, etc.).

  7. Experiment pointing with magnetic suspension

    NASA Technical Reports Server (NTRS)

    Hamilton, B. J.

    1981-01-01

    A need has been identified for a payload auxilliary pointing system onboard the Space Shuttle which provides sub-arcsecond stability in the Shuttle disturbance environment. This paper describes such a pointing system, presently being developed by Sperry Flight Systems for the NASA Langley Research Center. At the core of the design is a non-contacting magnetic suspension which provides a high degree of isolation between payload and carrier. Design concepts and control laws will be discussed. Also, test results from full-scale protoflight hardware and planned system refinements will be presented.

  8. Point estimates for probability moments

    PubMed Central

    Rosenblueth, Emilio

    1975-01-01

    Given a well-behaved real function Y of a real random variable X and the first two or three moments of X, expressions are derived for the moments of Y as linear combinations of powers of the point estimates y(x+) and y(x-), where x+ and x- are specific values of X. Higher-order approximations and approximations for discontinuous Y using more point estimates are also given. Second-moment approximations are generalized to the case when Y is a function of several variables. PMID:16578731

  9. Critical Point in Complex Plasmas

    SciTech Connect

    Khrapak, S.A.; Morfill, G.E.; Ivlev, A.V.; Thomas, H.M.; Beysens, D.A.; Zappoli, B.; Fortov, V.E.; Lipaev, A.M.; Molotkov, V.I.

    2006-01-13

    The occurrence of liquid-vapor phase transition and the possible existence of a critical point in complex plasmas--systems that consist of charged micrograins in a neutralizing plasma background--is investigated theoretically. An analysis based on the consideration of the intergrain interaction potential suggests that under certain conditions systems near and at the critical point should be observable. Measurements under microgravity conditions would appear to be required. The analysis aims at determining the plasma parameter regime most suitable for planned experimental investigations.

  10. The educator's point of view

    NASA Astrophysics Data System (ADS)

    de Vargas, M. Eugenia Dengo

    1993-03-01

    The educator's point of view stresses the development potential of education, together with respect for human rights. It is seen that nations need to make clear policy statements in this respect, and the consequent planning and curricular issues, together with some relevant strategies, are indicated.

  11. Critical points of metal vapors

    SciTech Connect

    Khomkin, A. L. Shumikhin, A. S.

    2015-09-15

    A new method is proposed for calculating the parameters of critical points and binodals for the vapor–liquid (insulator–metal) phase transition in vapors of metals with multielectron valence shells. The method is based on a model developed earlier for the vapors of alkali metals, atomic hydrogen, and exciton gas, proceeding from the assumption that the cohesion determining the basic characteristics of metals under normal conditions is also responsible for their properties in the vicinity of the critical point. It is proposed to calculate the cohesion of multielectron atoms using well-known scaling relations for the binding energy, which are constructed for most metals in the periodic table by processing the results of many numerical calculations. The adopted model allows the parameters of critical points and binodals for the vapor–liquid phase transition in metal vapors to be calculated using published data on the properties of metals under normal conditions. The parameters of critical points have been calculated for a large number of metals and show satisfactory agreement with experimental data for alkali metals and with available estimates for all other metals. Binodals of metals have been calculated for the first time.

  12. Decimal Fractions: An Important Point

    ERIC Educational Resources Information Center

    Martinie, Sherri L.

    2014-01-01

    How can a simple dot--the decimal point--be the source of such frustration for students and teachers? As the author worked through her own frustrations, she found that her students seemed to fall into groups in terms of misconceptions that they revealed when talking about and working with decimals. When asking students to illustrate their thinking…

  13. High Points of Human Genetics

    ERIC Educational Resources Information Center

    Stern, Curt

    1975-01-01

    Discusses such high points of human genetics as the study of chromosomes, somatic cell hybrids, the population formula: the Hardy-Weinberg Law, biochemical genetics, the single-active X Theory, behavioral genetics and finally how genetics can serve humanity. (BR)

  14. The Mean as Balance Point

    ERIC Educational Resources Information Center

    O'Dell, Robin S.

    2012-01-01

    There are two primary interpretations of the mean: as a leveler of data (Uccellini 1996, pp. 113-114) and as a balance point of a data set. Typically, both interpretations of the mean are ignored in elementary school and middle school curricula. They are replaced with a rote emphasis on calculation using the standard algorithm. When students are…

  15. Fixed points of quantum gravity.

    PubMed

    Litim, Daniel F

    2004-05-21

    Euclidean quantum gravity is studied with renormalization group methods. Analytical results for a nontrivial ultraviolet fixed point are found for arbitrary dimensions and gauge fixing parameters in the Einstein-Hilbert truncation. Implications for quantum gravity in four dimensions are discussed.

  16. Characterization of MIPAS elevation pointing

    NASA Astrophysics Data System (ADS)

    Kiefer, M.; von Clarmann, T.; Grabowski, U.; de Laurentis, M.; Mantovani, R.; Milz, M.; Ridolfi, M.

    2007-03-01

    Sufficient knowledge of the pointing is essential for analyses of limb emission measurements. The scientific retrieval processor for MIPAS on ENVISAT operated at IMK allows the retrieval of pointing information in terms of tangent altitudes along with temperature. The retrieved tangent altitudes are independent of systematic offsets in the engineering Line-Of-Sight (LOS) information delivered with the ESA Level 1b product. The difference of pointing retrieved from the reprocessed high resolution MIPAS spectra and the engineering pointing information was examined with respect to spatial/temporal behaviour. Among others the following characteristics of MIPAS pointing could be identified: Generally the engineering tangent altitudes are too high by 0-1.8 km with conspicuous variations in this range over time. Prior to December of 2003 there was a drift of about 50-100 m/h, which was due to a slow change in the satellite attitude. A correction of this attitude is done twice a day, which leads to discontinuities in the order of 1-1.5 km in the tangent altitudes. Occasionally discontinuities up to 2.5 km are found, as already reported from MIPAS and SCIAMACHY observations. After an update of the orbit position software in December 2003 values of drift and jumps are much reduced. There is a systematic difference in the mispointing between the poles which amounts to 1.5-2 km, i.e. there is a conspicuous orbit-periodic feature. The analysis of the correlation between the instrument's viewing angle azimuth and differential mispointing supports the hypotheses that a major part of this latter phenomenon can be attributed to an error in the roll angle of the satellite/instrument system of approximately 42 mdeg. One conclusion is that ESA level 2 data should be compared to other data exclusively on tangent pressure levels. Complementary to IMK data, ESA operational LOS calibration results were used to characterize MIPAS pointing. For this purpose MIPAS is used as a radiometer

  17. Acid rain said to threaten Bay

    SciTech Connect

    Not Available

    1988-04-29

    A report on April 25, 1988 by the Environmental Defense Fund blames acid rain for pollution of Chesapeake Bay. The nitrates in the rain are reported to account for 25% of the nitrogen load of the bay. This increases the acidity of the bay, thereby acting as a fertilizer to promote algal growth. It is postulated that acid rain contributes as much nitrogen to the bay as point sources, which include raw sewage and industrial plants.

  18. Acid rain information book. Draft final report

    SciTech Connect

    1980-12-01

    Acid rain is one of the most widely publicized environmental issues of the day. The potential consequences of increasingly widespread acid rain demand that this phenomenon be carefully evaluated. Reveiw of the literature shows a rapidly growing body of knowledge, but also reveals major gaps in understanding that need to be narrowed. This document discusses major aspects of the acid rain phenomenon, points out areas of uncertainty, and summarizes current and projected research by responsible government agencies and other concerned organizations.

  19. Point contacts in encapsulated graphene

    SciTech Connect

    Handschin, Clevin; Fülöp, Bálint; Csonka, Szabolcs; Makk, Péter; Blanter, Sofya; Weiss, Markus; Schönenberger, Christian; Watanabe, Kenji; Taniguchi, Takashi

    2015-11-02

    We present a method to establish inner point contacts with dimensions as small as 100 nm on hexagonal boron nitride (hBN) encapsulated graphene heterostructures by pre-patterning the top-hBN in a separate step prior to dry-stacking. 2- and 4-terminal field effect measurements between different lead combinations are in qualitative agreement with an electrostatic model assuming point-like contacts. The measured contact resistances are 0.5–1.5 kΩ per contact, which is quite low for such small contacts. By applying a perpendicular magnetic field, an insulating behaviour in the quantum Hall regime was observed, as expected for inner contacts. The fabricated contacts are compatible with high mobility graphene structures and open up the field for the realization of several electron optical proposals.

  20. EBTR design-point selection

    SciTech Connect

    Krakowski, R.A.; Bathke, C.G.

    1981-01-01

    The procedure used to select the design point for the ELMO Bumpy Torus Reactor (EBTR) study is described. The models used in each phase of the selection process are described, with an emphasis placed on the parametric design curves produced by each model. The tradeoffs related to burn physics, stability/equilibrium, electron-ring physics, and magnetics design are discussed. The resulting design point indicates a plasma with a 35-m major radius and a 1-m minor radium operating at an average core-plasma beta of 0.17, which at approx. 30 keV produces an average neutron wall loading of 1.4 MW/m/sup 2/ while maintaining key magnet (< 10 T) and total power (less than or equal to 4000 MWt) constraints.

  1. Femtosecond photoelectron point projection microscope

    SciTech Connect

    Quinonez, Erik; Handali, Jonathan; Barwick, Brett

    2013-10-15

    By utilizing a nanometer ultrafast electron source in a point projection microscope we demonstrate that images of nanoparticles with spatial resolutions of the order of 100 nanometers can be obtained. The duration of the emission process of the photoemitted electrons used to make images is shown to be of the order of 100 fs using an autocorrelation technique. The compact geometry of this photoelectron point projection microscope does not preclude its use as a simple ultrafast electron microscope, and we use simple analytic models to estimate temporal resolutions that can be expected when using it as a pump-probe ultrafast electron microscope. These models show a significant increase in temporal resolution when comparing to ultrafast electron microscopes based on conventional designs. We also model the microscopes spectroscopic abilities to capture ultrafast phenomena such as the photon induced near field effect.

  2. What are cirrus point sources?

    NASA Technical Reports Server (NTRS)

    Heiles, Carl; Mccarthy, Patrick J.; Reach, William; Strauss, Michael A.

    1987-01-01

    Most cirrus point sources are associated with interstellar gas. A subset of these was isolated, together with other sources showing large band 4 to 3 flux density ratios, that are not associated with interstellar gas. Most of the point sources are associated with diffuse cirrus emissions. The sources appear to be distributed randomly on the sky, with the exception of six clusters, one of which is not associated with any known object. Six sources out of seventeen that were observed for redshifted H I at Arecibo were found to be associated with relatively nondescript external galaxies. Most of the sources do not appear on the Palomar Sky Survey. Deep optical observations of eight fields revealed some fairly distant galaxies, one object with a very peculiar optical spectrum, and several blank fields.

  3. Lensless reflective point diffraction interferometer.

    PubMed

    Zhu, Wenhua; Chen, Lei; Zheng, Donghui; Yang, Ying; Han, Zhigang; Li, Jinpeng

    2016-07-01

    A lensless reflective point diffraction interferometer (LRPDI) is proposed for dynamic wavefront measurement. The point diffraction interferometer is integrated on a small substrate with properly designed thin film, which is used for generating the interferogram with high carrier frequency at a CCD target. By lensless imaging, the complex amplitude at the CCD target can be propagated to the conjugated plane of the exit pupil of an incident wavefront, which not only avoids the edge diffraction in the interferogram, but also eliminates systematic error. The accuracy of LRPDI is demonstrated by simulation and experiment, and a precision better than 1/150 wavelength is achieved. The new design with lensless imaging processing is suitable for dynamic wavefront measurement. PMID:27409204

  4. Sensing with Superconducting Point Contacts

    PubMed Central

    Nurbawono, Argo; Zhang, Chun

    2012-01-01

    Superconducting point contacts have been used for measuring magnetic polarizations, identifying magnetic impurities, electronic structures, and even the vibrational modes of small molecules. Due to intrinsically small energy scale in the subgap structures of the supercurrent determined by the size of the superconducting energy gap, superconductors provide ultrahigh sensitivities for high resolution spectroscopies. The so-called Andreev reflection process between normal metal and superconductor carries complex and rich information which can be utilized as powerful sensor when fully exploited. In this review, we would discuss recent experimental and theoretical developments in the supercurrent transport through superconducting point contacts and their relevance to sensing applications, and we would highlight their current issues and potentials. A true utilization of the method based on Andreev reflection analysis opens up possibilities for a new class of ultrasensitive sensors. PMID:22778630

  5. Salicylic acids

    PubMed Central

    Hayat, Shamsul; Irfan, Mohd; Wani, Arif; Nasser, Alyemeni; Ahmad, Aqil

    2012-01-01

    Salicylic acid is well known phytohormone, emerging recently as a new paradigm of an array of manifestations of growth regulators. The area unleashed yet encompassed the applied agriculture sector to find the roles to strengthen the crops against plethora of abiotic and biotic stresses. The skipped part of integrated picture, however, was the evolutionary insight of salicylic acid to either allow or discard the microbial invasion depending upon various internal factors of two interactants under the prevailing external conditions. The metabolic status that allows the host invasion either as pathogenesis or symbiosis with possible intermediary stages in close systems has been tried to underpin here. PMID:22301975

  6. Turning points in reactor design

    SciTech Connect

    Beckjord, E.S.

    1995-09-01

    This article provides some historical aspects on nuclear reactor design, beginning with PWR development for Naval Propulsion and the first commercial application at Yankee Rowe. Five turning points in reactor design and some safety problems associated with them are reviewed: (1) stability of Dresden-1, (2) ECCS, (3) PRA, (4) TMI-2, and (5) advanced passive LWR designs. While the emphasis is on the thermal-hydraulic aspects, the discussion is also about reactor systems.

  7. Viviani Polytopes and Fermat Points

    ERIC Educational Resources Information Center

    Zhou, Li

    2012-01-01

    Given a set of oriented hyperplanes P = {p1, . . . , pk} in R[superscript n], define v : R[superscript n] [right arrow] R by v(X) = the sum of the signed distances from X to p[subscript 1], . . . , p[subscript k], for any point X [is a member of] R[superscript n]. We give a simple geometric characterization of P for which v is constant, leading to…

  8. The Critical Point Facility (CPF)

    NASA Technical Reports Server (NTRS)

    1992-01-01

    The Critical Point Facility (CPF) is an ESA multiuser facility designed for microgravity research onboard Spacelab. It has been conceived and built to offer investigators opportunities to conduct research on critical point phenomena in microgravity. This facility provides the high precision and stability temperature standards required in this field of research. It has been primarily designed for the purpose of optical investigations of transparent fluids. During a Spacelab mission, the CPF automatically processes several thermostats sequentially, each thermostat corresponding to an experiment. The CPF is now integrated in Spacelab at Kennedy Space Center, in preparation for the International Microgravity Lab. mission. The CPF was designed to submit transparent fluids to an adequate, user defined thermal scenario, and to monitor their behavior by using thermal and optical means. Because they are strongly affected by gravity, a good understanding of critical phenomena in fluids can only be gained in low gravity conditions. Fluids at the critical point become compressed under their own weight. The role played by gravity in the formation of interfaces between distinct phases is not clearly understood.

  9. Chemoprevention trials and surrogate end point biomarkers in the cervix.

    PubMed

    Mitchell, M F; Hittelman, W K; Lotan, R; Nishioka, K; Tortolero-Luna, G; Richards-Kortum, R; Wharton, J T; Hong, W K

    1995-11-15

    Cervical cancer is the second most common malignancy in women worldwide and remains a significant health problem for women, especially minority and underserved women. Despite an understanding of the epidemiologic risks, the screening Papanicolaou smear, and morbid and costly treatment, overall survival remains 40%. New strategies, based on the clinical and molecular aspects of cervical carcinogenesis, are desperately needed. Chemoprevention refers to the use of chemical agents to prevent or delay the development of cancer in healthy populations. Chemoprevention studies have several unique features that distinguish them from classic chemotherapeutic trials; these features touch on several disciplines and weave knowledge of the biology of carcinogenesis into the trial design. In the design of chemoprevention trials, four factors are important: high risk cohorts must be identified; suitable medications must be selected; study designs should include Phases I, II, and III; and studies should include the use of surrogate end point biomarkers. Surrogate end point biomarkers are sought because the cancer develops over a long period of time, and studies of chemopreventives would require a huge number of subjects followed for many years. Surrogate end point biomarkers serve as alternative end points for examination of the efficacy of chemopreventives in tissue. High risk cohorts include women with cervical intraepithelial neoplasia (CIN) or squamous intraepithelial lesions (SIL). Nutritional studies have helped define micronutrients of interest (folate, carotenoids, vitamin C, vitamin E). Other medications of interest include retinoids (4-hydroxyphenylretinamide [4-HPR], retinyl acetate gel, topical all-trans-retinoic acid), polyamine synthesis inhibitors (alpha-difluoromethylornithine [DFMO]), and nonsteroidal anti-inflammatory drugs (ibuprofen). Phase I chemoprevention studies of the cervix have tested retinyl acetate gel and all-trans-retinoic acid. Phase II trials of all

  10. Stearic Acid

    ERIC Educational Resources Information Center

    Young, Jay A.

    2004-01-01

    A chemical laboratory information profile (CLIP) is presented for the chemical, stearic acid. The profile lists the chemical's physical and harmful characteristics, exposure limits, and symptoms of major exposure, for the benefit of teachers and students, who use the chemical in the laboratory.

  11. Trichloroacetic acid

    Integrated Risk Information System (IRIS)

    Trichloroacetic acid ( TCA ) ; CASRN 76 - 03 - 9 Human health assessment information on a chemical substance is included in the IRIS database only after a comprehensive review of toxicity data , as outlined in the IRIS assessment development process . Sections I ( Health Hazard Assessments for Nonca

  12. Acrylic acid

    Integrated Risk Information System (IRIS)

    Acrylic acid ( CASRN 79 - 10 - 7 ) Human health assessment information on a chemical substance is included in the IRIS database only after a comprehensive review of toxicity data , as outlined in the IRIS assessment development process . Sections I ( Health Hazard Assessments for Noncarcinogenic Eff

  13. Selenious acid

    Integrated Risk Information System (IRIS)

    Selenious acid ; CASRN 7783 - 00 - 8 Human health assessment information on a chemical substance is included in the IRIS database only after a comprehensive review of toxicity data , as outlined in the IRIS assessment development process . Sections I ( Health Hazard Assessments for Noncarcinogenic E

  14. Dichloroacetic acid

    Integrated Risk Information System (IRIS)

    Dichloroacetic acid ; CASRN 79 - 43 - 6 Human health assessment information on a chemical substance is included in the IRIS database only after a comprehensive review of toxicity data , as outlined in the IRIS assessment development process . Sections I ( Health Hazard Assessments for Noncarcinogeni

  15. Cacodylic acid

    Integrated Risk Information System (IRIS)

    Cacodylic acid ; CASRN 75 - 60 - 5 Human health assessment information on a chemical substance is included in the IRIS database only after a comprehensive review of toxicity data , as outlined in the IRIS assessment development process . Sections I ( Health Hazard Assessments for Noncarcinogenic Eff

  16. Phosphoric acid

    Integrated Risk Information System (IRIS)

    Phosphoric acid ; CASRN 7664 - 38 - 2 Human health assessment information on a chemical substance is included in the IRIS database only after a comprehensive review of toxicity data , as outlined in the IRIS assessment development process . Sections I ( Health Hazard Assessments for Noncarcinogenic

  17. Benzoic acid

    Integrated Risk Information System (IRIS)

    Benzoic acid ; CASRN 65 - 85 - 0 Human health assessment information on a chemical substance is included in the IRIS database only after a comprehensive review of toxicity data , as outlined in the IRIS assessment development process . Sections I ( Health Hazard Assessments for Noncarcinogenic Effec

  18. Formic acid

    Integrated Risk Information System (IRIS)

    Formic acid ; CASRN 64 - 18 - 6 Human health assessment information on a chemical substance is included in the IRIS database only after a comprehensive review of toxicity data , as outlined in the IRIS assessment development process . Sections I ( Health Hazard Assessments for Noncarcinogenic Effect

  19. [Hyaluronic acid].

    PubMed

    Pomarede, N

    2008-01-01

    Hyaluronic Acid (HA) is now a leader product in esthetic procedures for the treatment of wrinkles and volumes. The structure of HA, its metabolism, its physiological function are foremost breaking down then its use in aesthetic dermatology: steps of injection, possible side effects, benefits and downsides of the use of HA in aesthetic dermatology.

  20. [Differences between myofascial trigger points and tender points].

    PubMed

    Mense, S

    2011-02-01

    The article describes and compares the characteristics of myofascial trigger points (MTrPs) of the myofascial pain syndrome and the tender points (TePs) of the fibromyalgia syndrome. Many statements are hypothetical, because not all aspects of the disorders have been clarified in solid studies. Signs and symptoms of MTrPs: (1) palpable nodule, often located close to the muscle belly, (2) often single, (3) allodynia and hyperalgesia at the MTrP, (4) referral of the MTrP pain, (5) normal pain sensitivity outside the MTrPs, (6) local twitch response, (7) local contracture in biopsy material, (8) peripheral mechanism probable. Signs and symptoms of TePs: (1) no palpable nodule, (2) location often close to the muscle attachments, (3) multiple by definition, (4) allodynia and hyperalgesia also outside the TePs, (5) enhanced pain under psychic stress, (6) unspecific histological changes in biopsy material, (7) central nervous mechanism probable. The multitude of differences speak against a common aetiology and pathophysiology.

  1. Linoleic acid: between doubts and certainties.

    PubMed

    Choque, Benjamin; Catheline, Daniel; Rioux, Vincent; Legrand, Philippe

    2014-01-01

    Linoleic acid is the most abundant polyunsaturated fatty acid in human nutrition and represents about 14 g per day in the US diet. Following the discovery of its essential functions in animals and humans in the early 1920's, studies are currently questioning the real requirement of linoleic acid. It seems now overestimated and creates controversy: how much linoleic acid should be consumed in a healthy diet? Beyond the necessity to redefine the dietary requirement of linoleic acid, many questions concerning the consequences of its excessive consumption on human health arise. Linoleic acid is a direct precursor of the bioactive oxidized linoleic acid metabolites. It is also a precursor of arachidonic acid, which produces pro-inflammatory eicosanoids and endocannabinoids. A majority of the studies on linoleic acid and its derivatives show a direct/indirect link with inflammation and metabolic diseases. Many authors claim that a high linoleic acid intake may promote inflammation in humans. This review tries to (i) highlight the importance of reconsidering the actual requirement of linoleic acid (ii) point out the lack of knowledge between dietary levels of linoleic acid and the molecular mechanisms explaining its physiological roles (iii) demonstrate the relevance of carrying out further human studies on the single variable linoleic acid.

  2. Non-Gimbaled Antenna Pointing

    NASA Technical Reports Server (NTRS)

    Vigil, Jeannine S.

    1997-01-01

    The small satellite community has been interested in accessing fixed ground stations for means of space-to-ground transmissions, although a problem arises from the limited global coverage. There is a growing interest for using the Space Network (SN) or Tracking and Data Relay Satellites (TDRS) as the primary support for communications because of the coverage it provides. This thesis will address the potential for satellite access of the Space Network with a non-gimbaled antenna configuration and low-power, coded transmission. The non-gimbaled antenna and the TDRS satellites, TDRS-East, TDRS-West, and TDRS-Zone of Exclusion, were configured in an orbital analysis software package called Satellite Tool Kit to emulate the three-dimensional position of the satellites. The access potential, which is the average number of contacts per day and the average time per contact, were obtained through simulations run over a 30-day period to gain all the possible orientations. The orbital altitude was varied from 600 km through 1200 km with the results being a function of orbital inclination angles varying from 20 deg through 100 deg and pointing half-angles of I0 deg through 40 deg. To compare the validity of the simulations, Jet Propulsion Laboratory granted the use of the TOPEX satellite. The TOPEX satellite was configured to emulate a spin-stabilized antenna with its communications antenna stowed in the zenith-pointing direction. This mimicked the antenna pointing spin-stabilized satellite in the simulations. To make valid comparisons, the TOPEX orbital parameters were entered into Satellite Tool Kit and simulated over five test times provided by Jet Propulsion Laboratory.

  3. Discontinuous dynamics with grazing points

    NASA Astrophysics Data System (ADS)

    Akhmet, M. U.; Kıvılcım, A.

    2016-09-01

    Discontinuous dynamical systems with grazing solutions are discussed. The group property, continuation of solutions, continuity and smoothness of solutions are thoroughly analyzed. A variational system around a grazing solution which depends on near solutions is constructed. Orbital stability of grazing cycles is examined by linearization. Small parameter method is extended for analysis of grazing orbits, and bifurcation of cycles is observed in an example. Linearization around an equilibrium grazing point is discussed. The results can be extended on functional differential equations, partial differential equations and others. Appropriate illustrations are depicted to support the theoretical results.

  4. Saddle point shapes of nuclei

    SciTech Connect

    Poenaru, D. N.; Plonski, I. H.; Greiner, W.

    2007-04-23

    Very general reflection asymmetrical saddle point nuclear shapes are obtained by solving an integro-differential equation without being necessary to specify a certain parametrization. This equation is derived as an Euler-Lagrange relationship associated to the variational problem of minimizing the potential energy with constraints (constant volume and given deformation parameter). The mass asymmetry in binary cold fission of Th and U isotopes is explained as the result of adding a phenomenological shell correction to the liquid drop model deformation energy. Applications to ternary fission are outlined.

  5. Investigation of Livingstone's curious point.

    PubMed

    Martin, Vaughan

    2007-12-01

    The explorer and missionary David Livingstone was identified after death by the appearances of his humerus which had been damaged in an encounter with a lion. In his writings Livingstone suggested that the consequences of the lion's attack were not as bad as he might have expected. He wondered if this was due to the fact that he was wearing a tartan jacket when he was attacked and suggested that this curious point should be investigated. This paper looks at some of the dyes used in tartans of the time and investigates their effect on the bacteria that might be present in the mouths of lions.

  6. ALMA finds dew drops in the dusty spider's web

    NASA Astrophysics Data System (ADS)

    Gullberg, Bitten; Lehnert, Matthew D.; De Breuck, Carlos; Branchu, Steve; Dannerbauer, Helmut; Drouart, Guillaume; Emonts, Bjorn; Guillard, Pierre; Hatch, Nina; Nesvadba, Nicole P. H.; Omont, Alain; Seymour, Nick; Vernet, Joël

    2016-06-01

    We present 0.̋5 resolution ALMA detections of the observed 246 GHz continuum, [CI] 3P2→3P1 fine structure line ([CI]2-1), CO(7-6), and H2O lines in the z = 2.161 radio galaxy MRC1138-262, the so-called Spiderweb galaxy. We detect strong [CI]2-1 emission both at the position of the radio core, and in a second component ~4 kpc away from it. The 1100 km s-1 broad [CI]2-1 line in this latter component, combined with its H2 mass of 1.6 × 1010 M⊙, implies that this emission must come from a compact region <60 pc, possibly containing a second active galactic nucleus (AGN). The combined H2 mass derived for both objects, using the [CI]2-1 emission, is 3.3 × 1010 M⊙. The total CO(7-6)/[CI]2-1 line flux ratio of 0.2 suggests a low excitation molecular gas reservoir and/or enhanced atomic carbon in cosmic ray dominated regions. We detect spatially-resolved H2O 211-202 emission - for the first time in a high-z unlensed galaxy - near the outer radio lobe to the east, and near the bend of the radio jet to the west of the radio galaxy. No underlying 246 GHz continuum emission is seen at either position. We suggest that the H2O emission is excited in the cooling region behind slow (10-40 km s-1) shocks in dense molecular gas (103-5 cm-3). The extended water emission is likely evidence of the radio jet's impact on cooling and forming molecules in the post-shocked gas in the halo and inter-cluster gas, similar to what is seen in low-z clusters and other high-z radio galaxies. These observations imply that the passage of the radio jet in the interstellar and inter-cluster medium not only heats gas to high temperatures, as is commonly assumed or found in simulations, but also induces cooling and dissipation, which can lead to substantial amounts of cold dense molecular gas. The formation of molecules and strong dissipation in the halo gas of MRC1138-262 may explain both the extended diffuse molecular gas and the young stars observed around MRC1138-262. The reduced data cubes are only available at the CDS via anonymous ftp to http://cdsarc.u-strasbg.fr (http://130.79.128.5) or via http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/591/A73

  7. Satellite dual antenna pointing system

    NASA Technical Reports Server (NTRS)

    Keigler, John E. (Inventor); Hartshorne, Frank A. (Inventor)

    1986-01-01

    A satellite antenna pointing system for separately pointing separated transmit and receive high gain antenna systems includes means for separately and sequentially applying a beacon signal to the transmit and receive antenna systems and a broad beam width antenna which has a coverage area greater than the overall coverage region of the spot beam antenna systems. The system includes ground stations located at or near the periphery of the overall coverage region adapted to receive these beacon signals. At a central control station these beacon signals are compared to provide first signals proportional to the ratio of said beacon signals received from said transmit antenna system and said broad beam width antenna and second signals proportional to the ratio of said beacon signals received from said satellite receive antenna system and said broad beam width antenna. The central station generates from said first signals transmit antenna control signals which are sent to the satellite to control the orientation of said transmit antenna system. Likewise, the central control station generates from the second signals receiver antenna control signals which are applied to the satellite to control the orientation of the satellite receive antenna system.

  8. Molten fatty acid based microemulsions.

    PubMed

    Noirjean, Cecile; Testard, Fabienne; Dejugnat, Christophe; Jestin, Jacques; Carriere, David

    2016-06-21

    We show that ternary mixtures of water (polar phase), myristic acid (MA, apolar phase) and cetyltrimethylammonium bromide (CTAB, cationic surfactant) studied above the melting point of myristic acid allow the preparation of microemulsions without adding a salt or a co-surfactant. The combination of SANS, SAXS/WAXS, DSC, and phase diagram determination allows a complete characterization of the structures and interactions between components in the molten fatty acid based microemulsions. For the different structures characterized (microemulsion, lamellar or hexagonal phases), a similar thermal behaviour is observed for all ternary MA/CTAB/water monophasic samples and for binary MA/CTAB mixtures without water: crystalline myristic acid melts at 52 °C, and a thermal transition at 70 °C is assigned to the breaking of hydrogen bounds inside the mixed myristic acid/CTAB complex (being the surfactant film in the ternary system). Water determines the film curvature, hence the structures observed at high temperature, but does not influence the thermal behaviour of the ternary system. Myristic acid is partitioned in two "species" that behave independently: pure myristic acid and myristic acid associated with CTAB to form an equimolar complex that plays the role of the surfactant film. We therefore show that myristic acid plays the role of a solvent (oil) and a co-surfactant allowing the fine tuning of the structure of oil and water mixtures. This solvosurfactant behaviour of long chain fatty acid opens the way for new formulations with a complex structure without the addition of any extra compound. PMID:27241163

  9. Detection of non-protein amino acids in the presence of protein amino acids. II.

    NASA Technical Reports Server (NTRS)

    Shapshak, P.; Okaji, M.

    1972-01-01

    Studies conducted with the JEOL 5AH amino acid analyzer are described. This instrument makes possible the programming of the chromatographic process. Data are presented showing the separations of seventeen non-protein amino acids in the presence of eighteen protein amino acids. It is pointed out that distinct separations could be obtained in the case of a number of chemically similar compounds, such as ornithine and lysine, N-amidino alanine and arginine, and iminodiacetic acid and S-carboxymethyl cysteine and aspartic acid.

  10. Points of regulation for auxin action.

    PubMed

    Zazimalova, E; Napier, R M

    2003-03-01

    There have been few examples of the application of our growing knowledge of hormone action to crop improvement. In this review we discuss what is known about the critical points regulating auxin action. We examine auxin metabolism, transport, perception and signalling and identify genes and proteins that might be keys to regulation, particularly the rate-limiting steps in various pathways. Certain mutants show that substrate flow in biosynthesis can be limiting. To date there is little information available on the genes and proteins of catabolism. There have been several auxin transport proteins and some elegant transport physiology described recently, and the potential for using transport proteins to manage free indole-3-acetic acid (IAA) concentrations is discussed. Free IAA is very mobile, and so while it may be more practical to control auxin action through managing the receptor and signalling pathways, the candidate genes and proteins through which this can be done remain largely unknown. From the available evidence, it is clear that the reason for so few commercial applications arising from the control of auxin action is that knowledge is still limited. PMID:12789411

  11. Hydroxycarboxylic acids and salts

    DOEpatents

    Kiely, Donald E; Hash, Kirk R; Kramer-Presta, Kylie; Smith, Tyler N

    2015-02-24

    Compositions which inhibit corrosion and alter the physical properties of concrete (admixtures) are prepared from salt mixtures of hydroxycarboxylic acids, carboxylic acids, and nitric acid. The salt mixtures are prepared by neutralizing acid product mixtures from the oxidation of polyols using nitric acid and oxygen as the oxidizing agents. Nitric acid is removed from the hydroxycarboxylic acids by evaporation and diffusion dialysis.

  12. Benefits of acid rain controls

    SciTech Connect

    Hawkins, D.G.

    1984-04-01

    The acid rain debate has been distorted by a mistaken political paradigm. This paradigm holds that acid rain controls will benefit only a few lakes and streams, mostly in the Adirondack Mountains in northeastern New York State. It holds that the costs of a control program will fall on the Midwest but that none of the benefits will occur there since no sensitive lakes and streams are found in that area. The author discussed this problem and pointed out that sulfur dioxide was responsible for several types of pollution damage and that all the states would benefit from the reduction of sulfur dioxide emissions.

  13. Dioxin. A case in point.

    PubMed

    Tedeschi, L G

    1980-06-01

    The dangers posed by herbicidal chemicals to organisms and the environment are pointed out in this review of their development beginning in World War II. In particular, the toxic results of the spraying of dioxin (Agent Orange) in Vietnam are detailed, with corroborating data from clinical and field studies and reports of related industrial accidents. Despite a recent ban imposed on all dioxin-containing herbicides by the Environmental Protection Agency, widespread domestic use of herbicides continues and acceptance of the dangers is incomplete. As a result, forensic scientists must remain alert to potential hazards stemming from the use of these contaminants in their communities at least until strict federal regulatory legislation can be enacted. PMID:7246507

  14. Chiral exceptional points in metasurfaces

    NASA Astrophysics Data System (ADS)

    Kang, Ming; Chen, Jing; Chong, Y. D.

    2016-09-01

    An exceptional point (EP) is a degeneracy occurring in a non-energy-conserving system, in which two eigenvectors of a non-Hermitian Hamiltonian coalesce. We explore how EPs can be realized in a metamaterial surface, or metasurface, consisting of a pair of lossy coupled linear antennas in each unit cell. EPs appear in the eigenvectors of the transmission matrix by tuning the frequency and the coupling and loss rates of the metasurface. Each EP is associated with the appearance of a circularly polarized transmission eigenstate; hence, within the parameter space of the system, the EPs lie along pairs of curves with distinct chirality. Our results are obtained using finite-difference time-domain simulations, as well as a fitted coupled-mode theory. The coupled-mode theory agrees well with the numerical results and is capable of accurately predicting the EP f curves.

  15. The Herschel Point Source Catalogue

    NASA Astrophysics Data System (ADS)

    Marton, Gabor; Schulz, Bernhard; Altieri, Bruno; Calzoletti, Luca; Kiss, Csaba; Lim, Tanya; Lu, Nanyao; Paladini, Roberta; Papageorgiou, Andreas; Pearson, Chris; Rector, John; Shupe, David; Valtchanov, Ivan; Verebélyi, Erika; Xu, Kevin

    2015-08-01

    The Herschel Space Observatory was the fourth cornerstone mission in the European Space Agency (ESA) science programme with excellent broad band imaging capabilities in the submillimetre and far-infrared part of the spectrum. Although the spacecraft finished its observations in 2013, it left a large legacy dataset that is far from having been fully scrutinized and still has potential for new scientific discoveries. This is specifically true for the photometric observations of the PACS and SPIRE instruments that scanned >10% of the sky at 70, 100, 160, 250, 350 and 500 microns. Some source catalogs have already been produced by individual observing programs, but there are many observations that would never be analyzed for their full source content. To maximize the science return of the SPIRE and PACS data sets, our international team of instrument experts is in the process of building the Herschel Point Source Catalog (HPSC) from all scan map observations. Our homogeneous source extraction enables a systematic and unbiased comparison of sensitivity across the different Herschel fields that single programs will generally not be able to provide. The extracted point sources will contain individual YSOs of our Galaxy, unresolved YSO clusters in resolved nearby galaxies and unresolved galaxies of the local and distant Universe that are related to star formation. Such a huge dataset will help scientists better understand the evolution from interstellar clouds to individual stars. Furthermore the analysis of stellar clusters and the star formation on galactic scales will add more details to the understanding of star formation laws through time.We present our findings on comparison of different source detection and photometric tools. First results of the extractions are shown along with the description of our pipelines and catalogue entries. We also provide an additional science product, the structure noise map, that is used for the quality assessment of the catalogue in

  16. Comment on comment on ''acid precipitation in historical perspective and effects of acid precipitation''

    SciTech Connect

    Henriksen, A.; Richter, D.D.

    1984-01-01

    The author criticizes the fact that some soil scientists have difficulties in accepting that lakes and stream waters have become acid due to acid rain, because the natural production of acidity in ecosystems is large compared to the contribution from acid rain. He points out that Richter concludes that many of the reported changes, where real, may well result from natural processes with relatively minor contributions from acid precipitation. The author also disagrees with Krug and Frink who recently suggested that SO/sub 4/ from acid rain is exchanged with organic anions originally present in the water, leaving pH essentially unchanged. The author rebuts Henriksen who he says appears to have misunderstood the intent of the original correspondence, which was not to document evidence but rather to assert two generalities; (1) adverse effects of acid deposition on ecosystems are commonly overstated, and (2) the biogeochemistry of ecosystems is easily oversimplified, and natural sources of acidity are often ignored.

  17. Satellite Power System (SPS) antenna pointing control

    NASA Technical Reports Server (NTRS)

    1980-01-01

    Accuracy requirements for the SPS antenna pointing control consists of a mechanical pointing accuracy of three arc minutes and an electronic phased array pointing accuracy of three arc seconds. Results of this study, based on the factors considered in current analysis, show that the three arc minute overall pointing control accuracy can be achieved for the SPS in practice.

  18. University Students' Grasp of Inflection Points

    ERIC Educational Resources Information Center

    Tsamir, Pessia; Ovodenko, Regina

    2013-01-01

    This paper describes university students' grasp of inflection points. The participants were asked what inflection points are, to mark inflection points on graphs, to judge the validity of related statements, and to find inflection points by investigating (1) a function, (2) the derivative, and (3) the graph of the derivative. We found four…

  19. Accurate pointing of tungsten welding electrodes

    NASA Technical Reports Server (NTRS)

    Ziegelmeier, P.

    1971-01-01

    Thoriated-tungsten is pointed accurately and quickly by using sodium nitrite. Point produced is smooth and no effort is necessary to hold the tungsten rod concentric. The chemically produced point can be used several times longer than ground points. This method reduces time and cost of preparing tungsten electrodes.

  20. Key Point Based Data Analysis Technique

    NASA Astrophysics Data System (ADS)

    Yang, Su; Zhang, Yong

    In this paper, a new framework for data analysis based on the "key points" in data distribution is proposed. Here, the key points contain three types of data points: bridge points, border points, and skeleton points, where our main contribution is the bridge points. For each type of key points, we have developed the corresponding detection algorithm and tested its effectiveness with several synthetic data sets. Meanwhile, we further developed a new hierarchical clustering algorithm SPHC (Skeleton Point based Hierarchical Clustering) to demonstrate the possible applications of the key points acquired. Based on some real-world data sets, we experimentally show that SPHC performs better compared with several classical clustering algorithms including Complete-Link Hierarchical Clustering, Single-Link Hierarchical Clustering, KMeans, Ncut, and DBSCAN.

  1. 49 CFR 236.327 - Switch, movable-point frog or split-point derail.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 49 Transportation 4 2013-10-01 2013-10-01 false Switch, movable-point frog or split-point derail..., AND APPLIANCES Interlocking Rules and Instructions § 236.327 Switch, movable-point frog or split-point derail. Switch, movable-point frog, or split-point derail equipped with lock rod shall be maintained...

  2. 49 CFR 236.327 - Switch, movable-point frog or split-point derail.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 49 Transportation 4 2012-10-01 2012-10-01 false Switch, movable-point frog or split-point derail..., AND APPLIANCES Interlocking Rules and Instructions § 236.327 Switch, movable-point frog or split-point derail. Switch, movable-point frog, or split-point derail equipped with lock rod shall be maintained...

  3. 49 CFR 236.327 - Switch, movable-point frog or split-point derail.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 49 Transportation 4 2011-10-01 2011-10-01 false Switch, movable-point frog or split-point derail..., AND APPLIANCES Interlocking Rules and Instructions § 236.327 Switch, movable-point frog or split-point derail. Switch, movable-point frog, or split-point derail equipped with lock rod shall be maintained...

  4. 49 CFR 236.327 - Switch, movable-point frog or split-point derail.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 49 Transportation 4 2014-10-01 2014-10-01 false Switch, movable-point frog or split-point derail..., AND APPLIANCES Interlocking Rules and Instructions § 236.327 Switch, movable-point frog or split-point derail. Switch, movable-point frog, or split-point derail equipped with lock rod shall be maintained...

  5. 49 CFR 236.327 - Switch, movable-point frog or split-point derail.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 49 Transportation 4 2010-10-01 2010-10-01 false Switch, movable-point frog or split-point derail..., AND APPLIANCES Interlocking Rules and Instructions § 236.327 Switch, movable-point frog or split-point derail. Switch, movable-point frog, or split-point derail equipped with lock rod shall be maintained...

  6. A New Look at Trigger Point Injections

    PubMed Central

    Wong, Clara S. M.; Wong, Steven H. S.

    2012-01-01

    Trigger point injections are commonly practised pain interventional techniques. However, there is still lack of objective diagnostic criteria for trigger points. The mechanisms of action of trigger point injection remain obscure and its efficacy remains heterogeneous. The advent of ultrasound technology in the noninvasive real-time imaging of soft tissues sheds new light on visualization of trigger points, explaining the effect of trigger point injection by blockade of peripheral nerves, and minimizing the complications of blind injection. PMID:21969825

  7. Wavefront sensing, control, and pointing

    NASA Technical Reports Server (NTRS)

    Pitts, Thomas; Sevaston, George; Agronin, Michael; Bely, Pierre; Colavita, Mark; Clampin, Mark; Harvey, James; Idell, Paul; Sandler, Dave; Ulmer, Melville

    1992-01-01

    A majority of future NASA astrophysics missions from orbiting interferometers to 16-m telescopes on the Moon have, as a common requirement, the need to bring light from a large entrance aperture to the focal plane in a way that preserves the spatial coherence properties of the starlight. Only by preserving the phase of the incoming wavefront, can many scientific observations be made, observations that range from measuring the red shift of quasi-stellar objects (QSO's) to detecting the IR emission of a planet in orbit around another star. New technologies for wavefront sensing, control, and pointing hold the key to advancing our observatories of the future from those already launched or currently under development. As the size of the optical system increases, either to increase the sensitivity or angular resolution of the instrument, traditional technologies for maintaining optical wavefront accuracy become prohibitively expensive or completely impractical. For space-based instruments, the low mass requirement and the large temperature excursions further challenge existing technologies. The Hubble Space Telescope (HST) is probably the last large space telescope to rely on passive means to keep its primary optics stable and the optical system aligned. One needs only look to the significant developments in wavefront sensing, control, and pointing that have occurred over the past several years to appreciate the potential of this technology for transforming the capability of future space observatories. Future developments in space-borne telescopes will be based in part on developments in ground-based systems. Telescopes with rigid primary mirrors much larger than 5 m in diameter are impractical because of gravity loading. New technologies are now being introduced, such as active optics, that address the scale problem and that allow very large telescopes to be built. One approach is a segmented design such as that being pioneered by the W.M. Keck telescope now under

  8. Condensing heat exchangers for maximum boiler efficiency

    SciTech Connect

    Johnson, D.W.; DiVitto, J.G.; Rakocy, M.E.

    1994-12-31

    Until now, boiler efficiency has been limited due to the minimum temperature allowed at the stack. Heat lost up the stack was in exchange for keeping the flue gas temperature above the water vapor dew point. If water vapor was allowed to condense out, rapid deterioration, due to acid corrosion, of the outlet duct and stack would result. With the development of the condensing heat exchanger, boiler efficiency can now exceed 90%. Approximately 1% gain in boiler efficiency can be expected for every 40 F (4.5 C) reduction in flue gas stack temperature. In the CHX{reg_sign} condensing heat exchanger, all gas wetted surfaces are covered with DuPont Teflon{reg_sign}. The Teflon covered heat exchanger surfaces are impervious to all acids normally resulting from the combustion of fossil fuels. This allows the flue gas to be cooled to below the water vapor dew point with no subsequent corrosion of the heat exchanger surfaces.

  9. Structure of seven organic salts assembled from 2,6-diaminopyridine with monocarboxylic acids, dicarboxylic acids, and tetracarboxylic acids

    NASA Astrophysics Data System (ADS)

    Gao, Xingjun; Zhang, Huan; Wen, Xianhong; Liu, Bin; Jin, Shouwen; Wang, Daqi

    2015-08-01

    Studies concentrating on non-covalent interactions between the organic base of 2,6-diaminopyridine, and carboxylic acids have led to an increased understanding of the role 2,6-diaminopyridine in binding with carboxylic acid derivatives. Here anhydrous and hydrated multi-component organic acid-base salts of 2,6-diaminopyridine have been prepared with the carboxylic acids as nicotinic acid, o-chlorobenzoic acid, 1,3-benzodioxole-5-carboxylic acid, 3,5-dinitrosalicylic acid, 4-nitro-phthalic acid, 1,4-cyclohexanedicarboxylic acid, and butane-1,2,3,4-tetracarboxylic acid. The seven crystalline compounds were characterized by X-ray diffraction analysis, infrared (IR), melting point (mp), and elemental analysis. All structures adopted the hetero R22(8) supramolecular synthons. The supramolecular architectures bear extensive Nsbnd H⋯N, Osbnd H⋯N, Osbnd H⋯O, Nsbnd H⋯O, and CH⋯O associations as well as other nonbonding contacts as CHsbnd N, CH2sbnd O, π-π, C-π, O-π, Cl-π, Clsbnd O, and Osbnd O interactions. The role of weak and strong hydrogen bonding in the crystal packing is ascertained.

  10. Proteins and acids from petroleum.

    PubMed

    Zaki, D; el-Badrawy, S

    1978-01-01

    The wax distillate fraction (boiling range 300 up to 400 degrees C) from the crude oil "El-Alameen" was found to be a good substrate for the biosynthesis of proteins and/or amino acids by bacteria under special culture conditions. The fermentation processes were accompanied by a refining effect to the oil fraction, elevating its refraction index and lowering its melting point, giving dewaxing effect to the oil fraction. PMID:735504

  11. Close to the tipping point.

    PubMed

    Hubley, Pam

    2010-12-01

    Nursing leaders play a critical role in creating and enacting a vision for collaborative practice with advanced practice nurses (APNs). In this special issue, Nancy Carter and colleagues have identified many important influences and outcomes of successful nursing leadership in the context of promoting advanced practice nursing roles. The authors make a strong case for the importance of nursing leadership to facilitate large-scale systems change, noting the multiple levels on which nursing leaders work to ensure advanced practice nursing roles are well introduced to improve patient care. Nursing leadership can move an innovation like advanced practice nursing practice forward toward the "tipping point," when the new idea takes hold and becomes socially acceptable and desired, when the early adopters have influenced the early majority and about 15 to 20% of the population have adopted the idea (Berwick 2003). In many ways our nursing leaders have achieved this with advanced practice nursing roles, and we should celebrate. APNs are now more common, and certainly members of the public are proud to speak of the roles APNs play in their health services. An idea that once captured the minds of a select few has spread, thanks in large part to the nursing leaders who had a vision, believed in an idea, fought for it and worked to embed the change in the system.

  12. Gravity and Zero Point Energy

    NASA Astrophysics Data System (ADS)

    Massie, U. W.

    When Planck introduced the 1/2 hv term to his 1911 black body equation he showed that there is a residual energy remaining at zero degree K after all thermal energy ceased. Other investigators, including Lamb, Casimir, and Dirac added to this information. Today zero point energy (ZPE) is accepted as an established condition. The purpose of this paper is to demonstrate that the density of the ZPE is given by the gravity constant (G) and the characteristics of its particles are revealed by the cosmic microwave background (CMB). Eddies of ZPE particles created by flow around mass bodies reduce the pressure normal to the eddy flow and are responsible for the force of gravity. Helium atoms resonate with ZPE particles at low temperature to produce superfluid helium. High velocity micro vortices of ZPE particles about a basic particle or particles are responsible for electromagnetic forces. The speed of light is the speed of the wave front in the ZPE and its value is a function of the temperature and density of the ZPE.

  13. Decision Point 1 Topical Report

    SciTech Connect

    Yablonsky, Al; Barsoumian, Shant; Legere, David

    2013-05-01

    This Topical Report addresses accomplishments achieved during Phase 2a of the SkyMine® Carbon Mineralization Pilot Project. The primary objectives of this project are to design, construct, and operate a system to capture CO2 from a slipstream of flue gas from a commercial coal-fired cement kiln, convert that CO2 to products having commercial value (i.e., beneficial use), show the economic viability of the CO2 capture and conversion process, and thereby advance the technology to the point of readiness for commercial scale demonstration and proliferation. The overall process is carbon negative, resulting in mineralization of CO2 that would otherwise be released into the atmosphere. The project will also substantiate market opportunities for the technology by sales of chemicals into existing markets, and identify opportunities to improve technology performance and reduce costs at the commercial scale. The project is being conducted in two phases. The primary objectives of Phase 1 were to elaborate proven SkyMine® process chemistry to commercial pilot-scale operation and complete the preliminary design for the pilot plant to be built and operated in Phase 2, complete a NEPA evaluation, and develop a comprehensive carbon life cycle analysis. The objective of the current Phase (2a) is to complete the detailed design of the pilot plant to be built in Phase 2b.

  14. Anesthesiology Point of Care project.

    PubMed

    McDonald, John S; Noback, Carl R; Cheng, Drew; Lee, T K; Nenov, Val

    2002-01-01

    We are developing a dynamic prototype visual communication system for the operating room environs. This has classically been viewed as an isolated and impenetrable workplace. All medical experiences and all teaching remain in a one to one closed loop with no recall or subsequent sharing for the training and education of other colleagues. The "Anesthesia Point of Care" (APOC) concept embraces the sharing of, recording of, and presentation of various physiological and pharmacological events so that real time memory can be shared at a later time for the edification of other colleagues who were not present at the time of the primary learning event. In addition it also provides a remarkably rapid tool for fellow faculty to respond to obvious stress and crisis events that can be broadcast instantly at the time of happening. Finally, it also serves as an efficient and effective means of paging and general communication throughout the daily routines among various healthcare providers in anesthesiology who work as a team unit; these include the staff, residents, CRNAs, physician assistants, and technicians. This system offers a unique opportunity to eventually develop future advanced ideas that can include training exercises, presurgical evaluations, surgical scheduling and improvements in efficiency based upon earlier than expected case completion or conversely later than expected case completion and even as a unique window to development of improved billing itemization and coordination.

  15. Methylmalonic acid blood test

    MedlinePlus

    ... acid is a substance produced when proteins, called amino acids, in the body break down. The health care ... Cederbaum S, Berry GT. Inborn errors of carbohydrate, ammonia, amino acid, and organic acid metabolism. In: Gleason CA, Devaskar ...

  16. Folic Acid and Pregnancy

    MedlinePlus

    ... 5 Things to Know About Zika & Pregnancy Folic Acid and Pregnancy KidsHealth > For Parents > Folic Acid and ... before conception and during early pregnancy . About Folic Acid Folic acid, sometimes called folate, is a B ...

  17. Synthesis of Hydroxymethylenebisphosphonic Acid Derivatives in Different Solvents.

    PubMed

    Nagy, Dávid Illés; Grün, Alajos; Garadnay, Sándor; Greiner, István; Keglevich, György

    2016-01-01

    The syntheses of hydroxymethylenebisphosphonic acid derivatives (dronic acid derivatives) starting from the corresponding substituted acetic acids and P-reagents, mainly phosphorus trichloride and phosphorous acid are surveyed according to the solvents applied. The nature of the solvent is a critical point due to the heterogeneity of the reaction mixtures. This review sheds light on the optimum choice and ratio of the P-reactants, and on the optimum conditions. PMID:27529200

  18. Understanding Acid Rain

    ERIC Educational Resources Information Center

    Damonte, Kathleen

    2004-01-01

    The term acid rain describes rain, snow, or fog that is more acidic than normal precipitation. To understand what acid rain is, it is first necessary to know what an acid is. Acids can be defined as substances that produce hydrogen ions (H+), when dissolved in water. Scientists indicate how acidic a substance is by a set of numbers called the pH…

  19. Effects of acid precipitation on crops

    SciTech Connect

    Lee, J.J.

    1981-01-01

    The effects of acid rain on crop yield have been studied using field-grown and potted plants. Results have shown that the chemicals in acid rain can affect crop growth and yield at ambient concentrations. For many crops, the dose-response curve probably has at least one peak and crossover point from stimulatory to inhibitory response may depend on other environmental factors. Plant parts often are affected differently, suggesting that acid rain can change the allocation of energy within plants. Available experimental results are not transferable to agricultural situations. The characteristics of acid rain which have the greatest influence on crop yield have not been determined. Interactions between acid rain and other environmental factors have scarcely been studied. Before a believable assessment of the economic impact of acid rain on crops can be done, the mechanisms of response have to be studied and the predictive capability enhanced and validated.

  20. Plant and Soil Emissions of Amines and Amino Acids: A Source of Secondary Aerosol Precursors

    NASA Astrophysics Data System (ADS)

    Jackson, M. L.; Doskey, P. V.; Pypker, T. G.

    2011-12-01

    Ammonia (NH3) is the most abundant alkaline gas in the atmosphere and forms secondary aerosol by neutralizing sulfuric and nitric acids that are released during combustion of fossil fuels. Ammonia is primarily emitted by cropping and livestock operations. However, C2 and C3 amines (pKb 3.3-3.4), which are stronger bases than NH3 (pKb 4.7) have been observed in nuclei mode aerosol that is the precursor to secondary aerosol. Mixtures of amines and amino acids have been identified in diverse environments in aerosol, fog water, cloud water, the soluble fraction of precipitation, and in dew. Glycine (pKb 4.2), serine (pKb 4.8) and alanine (pKb 3.7 and 4.1 for the D and L forms, respectively) are typically the most abundant species. The only reported values of gas-phase glycine, serine and alanine were in marine air and ranged from 6-14 pptv. The origin of atmospheric amines and amino acids has not been fully identified, although sources are likely similar to NH3. Nitrate assimilation in plants forms glycine, serine, and L-alanine, while D-alanine is present in bacterial cell walls. Glycine is converted to serine during C3 plant photorespiration, producing CO2 and NH3. Bacteria metabolize glycine and alanine to methylamine and ethylamine via decarboxylation. Likely sources of amino acids are plants and bacteria, thus concentrations near continental sources are likely greater than those measured in marine air. The overall goal of the research is to examine seasonal variations and relationships between the exchange of CO2, NH3, amines, and amino acids with a corn/soybean rotation in the Midwest Corn Belt. The study presents gaseous profiles of organic amine compounds from various species of vegetation using a mist chamber trapping technique and analysis of the derivatized species by high pressure liquid chromatography with fluorescence detection. Amino acid and amine profiles were obtained for red oak (Quercus rubra), sugar maple (Acer saccharinum), white pine (Pinus

  1. Theoretical prediction of physical and chemical characteristics of the first drop'' of condensate from superheated geothermal steam: Implications for corrosion and scaling in turbines

    SciTech Connect

    Andreussi, P. . Dipartimento Scienze e Tecnologie Chimiche); Corsi, R. ); Guidi, M.; Marini, L. )

    1994-06-01

    This paper describes a method for computing: (1) the chemical composition of the first drop of condensate which forms at dew-point temperature through expansion of superheated steam, and (2) the saturation index of the drop with respect to relevant solid phases, such as halite, amorphous silica, boric acid, borax and sal ammoniac. Boiling-point elevation is taken into account in these calculations. Preliminary application to some wells in the Larderello geothermal field indicate that: (1) the high concentration of HCl in the steam causes both the low pH and very high TDS of the first drop; (2) the lower the dew-point temperature, the higher the TDS of the first drop; (3) for a given chemical composition, the lower the steam pressure, the higher the risk of corrosion and scaling in the steam path.

  2. Iterative consolidation of unorganized point clouds.

    PubMed

    Liu, Shengjun; Chan, Kwan-Chung; Wang, Charlie C L

    2012-01-01

    Unorganized point clouds obtained from 3D shape acquisition devices usually present noise, outliers, and nonuniformities. The proposed framework consolidates unorganized points through an iterative procedure of interlaced downsampling and upsampling. Selection operations remove outliers while preserving geometric details. The framework improves the uniformity of points by moving the downsampled particles and refining point samples. Surface extrapolation fills missed regions. Moreover, an adaptive sampling strategy speeds up the iterations. Experimental results demonstrate the framework's effectiveness.

  3. Cryoprotection from lipoteichoic acid

    NASA Astrophysics Data System (ADS)

    Rice, Charles V.; Middaugh, Amy; Wickham, Jason R.; Friedline, Anthony; Thomas, Kieth J.; Johnson, Karen; Zachariah, Malcolm; Garimella, Ravindranth

    2012-10-01

    Numerous chemical additives lower the freezing point of water, but life at sub-zero temperatures is sustained by a limited number of biological cryoprotectants. Antifreeze proteins in fish, plants, and insects provide protection to a few degrees below freezing. Microbes have been found to survive at even lower temperatures, and with a few exceptions, antifreeze proteins are missing. Survival has been attributed to external factors, such as the high salt concentration of brine veins and adhesion to particulates or ice crystal defects. We have discovered an endogenous cryoprotectant in the cell wall of bacteria, lipoteichoic acid biopolymers. Adding 1% LTA to bacteria cultures immediately prior to freezing provides 50% survival rate, similar to the results obtained with 1% glycerol. In the absence of an additive, bacterial survival is negligible as measured with the resazurin cell viability assay. The mode of action for LTA cryoprotection is unknown. With a molecular weight of 3-5 kDa, it is unlikely to enter the cell cytoplasm. Our observations suggest that teichoic acids could provide a shell of liquid water around biofilms and planktonic bacteria, removing the need for brine veins to prevent bacterial freezing.

  4. Preparation of high dropping point lithium complex soap grease

    SciTech Connect

    Carley, D.A.; Witte, A.C. Jr.; Green, W.B.; Doerr, K.W.

    1986-04-15

    A process is described for preparing a lithium soap grease having a dropping point above 500/sup 0/F which consists of: (a) dissolving a C/sub 12/ to C/sub 24/ hydroxy fatty acid and a C/sub 4/ to C/sub 12/ aliphatic dicarboxylic acid in approximately a 3:1 to 0.5:1 ratio range in a lubricating oil to form an oil-acid mixture in which the amount of oil employed comprises greater than 50 weight percent of the total amount of oil employed in the finished composition; (b) adjusting the oil and acid mixture to a temperature below about the boiling temperature of water; (c) adding slowly at a controlled rate of below about 0.30 lbs/min. per 100 lb. of finished grease product, a concentrated aqueous solution of approximately 8 to 10 weight percent of lithium hydroxide in an amount slightly in excess of that required to neutralize the acid; (d) maintaining the reaction conditions for a period of time sufficient to obtain substantially complete saponification between the fatty acids and lithium hydroxide; (e) dehydrating the mixture of lubricating oil and lithium complex soap; (f) heating the mixture until it is uniformly at a temperature of from about 390/sup 0/F to about 430/sup 0/F; (g) rapidly cooling the mixture to about 390/sup 0/F. or below by quenching it with approximately 5 to 25 weight percent of the total amount of lubricating oil employed in the finished composition; (h) incorporating the remainder of the lubricating oil into the grease composition.

  5. The Convex Coordinates of the Symmedian Point

    ERIC Educational Resources Information Center

    Boyd, J. N.; Raychowdhury, P. N.

    2006-01-01

    In this note, we recall the convex (or barycentric) coordinates of the points of a closed triangular region. We relate the convex and trilinear coordinates of the interior points of the triangular region. We use the relationship between convex and trilinear coordinates to calculate the convex coordinates of the symmedian point of the triangular…

  6. NSDC Policy Points. Volume 1, Number 4

    ERIC Educational Resources Information Center

    National Staff Development Council, 2009

    2009-01-01

    "NSDC Policy Points" is a newsletter published by the National Staff Development Council (NSDC). This issue of "NSDC Policy Points" discusses why collaborative learning is critical to professional development. Included in this newsletter is an article about team learning in Cedar Rapids, Iowa. [For Volume 1, Number 3 of "NSDC Policy Points," see…

  7. Subject Access Points in Electronic Retrieval.

    ERIC Educational Resources Information Center

    Hjorland, Birger; Nielsen, Lykke Kyllesbech

    2001-01-01

    Discussion of subject access points in databases concentrates on the broader theoretical perspective. Topics include technology-driven stages in the development of subject access points; a taxonomy of subject access points; document titles; abstracts; references and citations; full text; and descriptors, identifiers, classification codes, and…

  8. How PowerPoint Is Killing Education

    ERIC Educational Resources Information Center

    Isseks, Marc

    2011-01-01

    Although it is essential to incorporate new technologies into the classroom, says Isseks, one trend has negatively affected instruction--the misuse of PowerPoint presentations. The author describes how poorly designed PowerPoint presentations reduce complex thoughts to bullet points and reduce the act of learning to transferring text from slide to…

  9. 47 CFR 22.325 - Control points.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 47 Telecommunication 2 2014-10-01 2014-10-01 false Control points. 22.325 Section 22.325... Operational and Technical Requirements Operational Requirements § 22.325 Control points. Each station in the Public Mobile Services must have at least one control point and a person on duty who is responsible...

  10. 47 CFR 22.325 - Control points.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 47 Telecommunication 2 2011-10-01 2011-10-01 false Control points. 22.325 Section 22.325... Operational and Technical Requirements Operational Requirements § 22.325 Control points. Each station in the Public Mobile Services must have at least one control point and a person on duty who is responsible...

  11. 47 CFR 22.325 - Control points.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 47 Telecommunication 2 2012-10-01 2012-10-01 false Control points. 22.325 Section 22.325... Operational and Technical Requirements Operational Requirements § 22.325 Control points. Each station in the Public Mobile Services must have at least one control point and a person on duty who is responsible...

  12. 47 CFR 22.325 - Control points.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 47 Telecommunication 2 2013-10-01 2013-10-01 false Control points. 22.325 Section 22.325... Operational and Technical Requirements Operational Requirements § 22.325 Control points. Each station in the Public Mobile Services must have at least one control point and a person on duty who is responsible...

  13. The Fermat point for a taxicab triangle

    NASA Astrophysics Data System (ADS)

    Hanson, J. R.

    2015-04-01

    The Fermat point P for a triangle ABC is the point P the sum of whose distances from the vertices A, B and C is a minimum. This note will show how to find the Fermat point for any triangle using the taxicab metric.

  14. A fourfold coordinated point defect in silicon.

    PubMed

    Goedecker, Stefan; Deutsch, Thierry; Billard, Luc

    2002-06-10

    Vacancies, interstitials, and Frenkel pairs are considered to be the basic point defects in silicon. We challenge this point of view by presenting density functional calculations that show that there is a stable point defect in silicon that has fourfold coordination and is lower in energy than the traditional defects.

  15. 47 CFR 22.325 - Control points.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 47 Telecommunication 2 2010-10-01 2010-10-01 false Control points. 22.325 Section 22.325... Operational and Technical Requirements Operational Requirements § 22.325 Control points. Each station in the Public Mobile Services must have at least one control point and a person on duty who is responsible...

  16. Venus clouds - A dirty hydrochloric acid model.

    NASA Technical Reports Server (NTRS)

    Hapke, B.

    1972-01-01

    The spectral and polarization data for Venus are consistent with micrometer-sized aerosol cloud particles of hydrochloric acid with soluble and insoluble iron compounds, whose source could be volcanic or crustal dust. The yellow color of the clouds could be due to absorption bands in the near UV involving ferric iron and chlorine complexes. It is pointed out that the UV features could arise from variations in the concentrations of iron and hydrochloric acid in the cloud particles.

  17. Detection and formation scenario of citric acid, pyruvic acid, and other possible metabolism precursors in carbonaceous meteorites.

    PubMed

    Cooper, George; Reed, Chris; Nguyen, Dang; Carter, Malika; Wang, Yi

    2011-08-23

    Carbonaceous meteorites deliver a variety of organic compounds to Earth that may have played a role in the origin and/or evolution of biochemical pathways. Some apparently ancient and critical metabolic processes require several compounds, some of which are relatively labile such as keto acids. Therefore, a prebiotic setting for any such individual process would have required either a continuous distant source for the entire suite of intact precursor molecules and/or an energetic and compact local synthesis, particularly of the more fragile members. To date, compounds such as pyruvic acid, oxaloacetic acid, citric acid, isocitric acid, and α-ketoglutaric acid (all members of the citric acid cycle) have not been identified in extraterrestrial sources or, as a group, as part of a "one pot" suite of compounds synthesized under plausibly prebiotic conditions. We have identified these compounds and others in carbonaceous meteorites and/or as low temperature (laboratory) reaction products of pyruvic acid. In meteorites, we observe many as part of three newly reported classes of compounds: keto acids (pyruvic acid and homologs), hydroxy tricarboxylic acids (citric acid and homologs), and tricarboxylic acids. Laboratory syntheses using (13)C-labeled reactants demonstrate that one compound alone, pyruvic acid, can produce several (nonenzymatic) members of the citric acid cycle including oxaloacetic acid. The isotopic composition of some of the meteoritic keto acids points to interstellar or presolar origins, indicating that such compounds might also exist in other planetary systems.

  18. Improved robust point matching with label consistency

    NASA Astrophysics Data System (ADS)

    Bhagalia, Roshni; Miller, James V.; Roy, Arunabha

    2010-03-01

    Robust point matching (RPM) jointly estimates correspondences and non-rigid warps between unstructured point-clouds. RPM does not, however, utilize information of the topological structure or group memberships of the data it is matching. In numerous medical imaging applications, each extracted point can be assigned group membership attributes or labels based on segmentation, partitioning, or clustering operations. For example, points on the cortical surface of the brain can be grouped according to the four lobes. Estimated warps should enforce the topological structure of such point-sets, e.g. points belonging to the temporal lobe in the two point-sets should be mapped onto each other. We extend the RPM objective function to incorporate group membership labels by including a Label Entropy (LE) term. LE discourages mappings that transform points within a single group in one point-set onto points from multiple distinct groups in the other point-set. The resulting Labeled Point Matching (LPM) algorithm requires a very simple modification to the standard RPM update rules. We demonstrate the performance of LPM on coronary trees extracted from cardiac CT images. We partitioned the point sets into coronary sections without a priori anatomical context, yielding potentially disparate labelings (e.g. [1,2,3] --> [a,b,c,d]). LPM simultaneously estimated label correspondences, point correspondences, and a non-linear warp. Non-matching branches were treated wholly through the standard RPM outlier process akin to non-matching points. Results show LPM produces warps that are more physically meaningful than RPM alone. In particular, LPM mitigates unrealistic branch crossings and results in more robust non-rigid warp estimates.

  19. Point detection of bacterial and viral pathogens using oral samples

    NASA Astrophysics Data System (ADS)

    Malamud, Daniel

    2008-04-01

    Oral samples, including saliva, offer an attractive alternative to serum or urine for diagnostic testing. This is particularly true for point-of-use detection systems. The various types of oral samples that have been reported in the literature are presented here along with the wide variety of analytes that have been measured in saliva and other oral samples. The paper focuses on utilizing point-detection of infectious disease agents, and presents work from our group on a rapid test for multiple bacterial and viral pathogens by monitoring a series of targets. It is thus possible in a single oral sample to identify multiple pathogens based on specific antigens, nucleic acids, and host antibodies to those pathogens. The value of such a technology for detecting agents of bioterrorism at remote sites is discussed.

  20. Renormalization Group Trajectories Between Two Fixed Points

    NASA Astrophysics Data System (ADS)

    Abdesselam, Abdelmalek

    2010-03-01

    We report on our recent rigorous construction of complete renormalization group trajectories between two fixed points for the three-dimensional phi-four model with modified propagator considered by Brydges, Mitter and Scoppola (BMS). These are discrete critical trajectories which connect the ultraviolet Gaussian fixed point to the nontrivial BMS infrared fixed point which is an analogue of the Wilson-Fisher fixed point. The renormalization group map is defined rigorously and nonperturbatively, without using the hierarchical approximation. The trajectories are constructed by a fixed point argument in a suitable Banach space of sequences, where one perturbs a nonlinear one-dimensional iteration.

  1. Antenna pointing systematic error model derivations

    NASA Technical Reports Server (NTRS)

    Guiar, C. N.; Lansing, F. L.; Riggs, R.

    1987-01-01

    The pointing model used to represent and correct systematic errors for the Deep Space Network (DSN) antennas is presented. Analytical expressions are given in both azimuth-elevation (az-el) and hour angle-declination (ha-dec) mounts for RF axis collimation error, encoder offset, nonorthogonality of axes, axis plane tilt, and structural flexure due to gravity loading. While the residual pointing errors (rms) after correction appear to be within the ten percent of the half-power beamwidth criterion commonly set for good pointing accuracy, the DSN has embarked on an extensive pointing improvement and modeling program aiming toward an order of magnitude higher pointing precision.

  2. Oil point pressure of Indian almond kernels

    NASA Astrophysics Data System (ADS)

    Aregbesola, O.; Olatunde, G.; Esuola, S.; Owolarafe, O.

    2012-07-01

    The effect of preprocessing conditions such as moisture content, heating temperature, heating time and particle size on oil point pressure of Indian almond kernel was investigated. Results showed that oil point pressure was significantly (P < 0.05) affected by above mentioned parameters. It was also observed that oil point pressure reduced with increase in heating temperature and heating time for both coarse and fine particles. Furthermore, an increase in moisture content resulted in increased oil point pressure for coarse particles while there was a reduction in oil point pressure with increase in moisture content for fine particles.

  3. 40 CFR 420.90 - Applicability; description of the acid pickling subcategory.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... owned treatment works resulting from sulfuric acid, hydrochloric acid, or combination acid pickling... 40 Protection of Environment 29 2011-07-01 2009-07-01 true Applicability; description of the acid... (CONTINUED) EFFLUENT GUIDELINES AND STANDARDS IRON AND STEEL MANUFACTURING POINT SOURCE CATEGORY...

  4. 40 CFR 420.90 - Applicability; description of the acid pickling subcategory.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... owned treatment works resulting from sulfuric acid, hydrochloric acid, or combination acid pickling... 40 Protection of Environment 30 2013-07-01 2012-07-01 true Applicability; description of the acid... (CONTINUED) EFFLUENT GUIDELINES AND STANDARDS IRON AND STEEL MANUFACTURING POINT SOURCE CATEGORY...

  5. 40 CFR 420.90 - Applicability; description of the acid pickling subcategory.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... owned treatment works resulting from sulfuric acid, hydrochloric acid, or combination acid pickling... 40 Protection of Environment 30 2012-07-01 2012-07-01 false Applicability; description of the acid... (CONTINUED) EFFLUENT GUIDELINES AND STANDARDS IRON AND STEEL MANUFACTURING POINT SOURCE CATEGORY...

  6. 40 CFR 420.90 - Applicability; description of the acid pickling subcategory.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... owned treatment works resulting from sulfuric acid, hydrochloric acid, or combination acid pickling... 40 Protection of Environment 29 2014-07-01 2012-07-01 true Applicability; description of the acid... (CONTINUED) EFFLUENT GUIDELINES AND STANDARDS IRON AND STEEL MANUFACTURING POINT SOURCE CATEGORY...

  7. Pointing control for the International Comet Mission

    NASA Technical Reports Server (NTRS)

    Leblanc, D. R.; Schumacher, L. L.

    1980-01-01

    The design of the pointing control system for the proposed International Comet Mission, intended to fly by Comet Halley and rendezvous with Comet Tempel-2 is presented. Following a review of mission objectives and the spacecraft configuration, design constraints on the pointing control system controlling the two-axis gimballed scan platform supporting the science instruments are discussed in relation to the scientific requirements of the mission. The primary design options considered for the pointing control system design for the baseline spacecraft are summarized, and the design selected, which employs a target-referenced, inertially stabilized control system, is described in detail. The four basic modes of operation of the pointing control subsystem (target acquisition, inertial hold, target track and slew) are discussed as they relate to operations at Halley and Tempel-2. It is pointed that the pointing control system design represents a significant advance in the state of the art of pointing controls for planetary missions.

  8. Use of Chimeras, Point Mutants, and Molecular Modeling to Map the Antagonist-binding Site of 4,4′,4″,4‴-(Carbonylbis-(imino-5,1,3-benzenetriylbis(carbonylimino)))tetrakisbenzene-1,3-disulfonic Acid (NF449) at P2X1 Receptors for ATP*

    PubMed Central

    Farmer, Louise K.; Schmid, Ralf; Evans, Richard J.

    2015-01-01

    P2X receptor subtype-selective antagonists are promising candidates for treatment of a range of pathophysiological conditions. However, in contrast to high resolution structural understanding of agonist action in the receptors, comparatively little is known about the molecular basis of antagonist binding. We have generated chimeras and point mutations in the extracellular ligand-binding loop of the human P2X1 receptor, which is inhibited by NF449, suramin, and pyridoxal-phosphate-6-azophenyl-2,4-disulfonate, with residues from the rat P2X4 receptor, which is insensitive to these antagonists. There was little or no effect on sensitivity to suramin and pyridoxal-phosphate-6-azophenyl-2,4-disulfonate in chimeric P2X1/4 receptors, indicating that a significant number of residues required for binding of these antagonists are present in the P2X4 receptor. Sensitivity to the P2X1 receptor-selective antagonist NF449 was reduced by ∼60- and ∼135-fold in chimeras replacing the cysteine-rich head, and the dorsal fin region below it in the adjacent subunit, respectively. Point mutants identified the importance of four positively charged residues at the base of the cysteine-rich head and two variant residues in the dorsal fin for high affinity NF449 binding. These six residues were used as the starting area for molecular docking. The four best potential NF449-binding poses were then discriminated by correspondence with the mutagenesis data and an additional mutant to validate the binding of one lobe of NF449 within the core conserved ATP-binding pocket and the other lobes coordinated by positive charge on the cysteine-rich head region and residues in the adjacent dorsal fin. PMID:25425641

  9. Precipitation: its acidic nature.

    PubMed

    Frohliger, J O; Kane, R

    1975-08-01

    A comparison of the free hydrogen ion concentration and the total hydrogen ion concentration of rain samples shows that rain is a weak acid. The weak acid nature of rain casts doubt on the concepts that the acidity of rain is increasing and that these increases are due to strong acids such as sulfuric acid.

  10. CONDUCTIVITY TITRATION OF GELATIN SOLUTIONS WITH ACIDS.

    PubMed

    Hitchcock, D I

    1923-11-20

    Titrations have been made, by the conductivity method, of gelatin solutions with hydrochloric and sulphuric acids. The results indicate an end-point at about 8.6 cc. of N/10 acid per gm. of gelatin, or a combining weight of about 1,160. These results are in fair agreement with those previously obtained by the hydrogen electrode method. Better agreement between the two methods was found in the case of deaminized gelatin. The data are in accord with a purely chemical conception of the combination between protein and acid.

  11. [Nicolas Lémery and acidity].

    PubMed

    Lafont, Olivier

    2002-01-01

    After a recalling of Lémery's biography, the history of acidity before Lémery is evoked. The opinions of Theophrastus, Libavius, Otto Techenius, Robert Boyle and François André are compared. According to Lémery's theory points of acids enter the pores of alkalis, giving salts which are different from a simple mixture. This theory was approved by the scientific community. The examples of J. Morin and Baron are given. A short description of the evolution of the concept of acidity after Lémery's period is also given. PMID:12141323

  12. A new acidic protein in porcine brain.

    PubMed

    Ishioka, N; Isobe, T; Okuyama, T; Numata, Y; Wada, H

    1980-10-21

    An extremely acidic protein has been isolated in a purified form from porcine rain extract, by (NH4)2SO4 fractionation followed by column chromatography on DEAE-Sephadex A-50 and on Sephadex G-75. The purified protein was tentatively named as glutamic acid-rich protein because it was characterized by its remarkably high content of glutamic acid which accounted for 49% of the total amino acid composition. The protein appeared to be a single polypeptide chain with a molecular weight of 56 000-58 000, and had an isoelectric point of 4.6. The N-terminal amino acid sequence was Asp-Glu-Pro-Pro-Ser-Glu-Gly. The immunochemical analysis using rabbit antiserum prepared to the porcine protein has suggested that it is present in the brain of human, cow, cat, dog and goat as well as in various goat organs including liver, kidney, heart, small intestine and spleen.

  13. Volatilization of iodine from nitric acid using peroxide

    DOEpatents

    Cathers, G.I.; Shipman, C.J.

    1975-10-21

    A method for removing radioactive iodine from nitric acid solution by adding hydrogen peroxide to the solution while concurrently holding the solution at the boiling point and distilling hydrogen iodide from the solution is reported.

  14. Amino Acid Metabolism Disorders

    MedlinePlus

    ... defects & other health conditions > Amino acid metabolism disorders Amino acid metabolism disorders E-mail to a friend Please ... baby’s newborn screening may include testing for certain amino acid metabolism disorders. These are rare health conditions that ...

  15. Carbolic acid poisoning

    MedlinePlus

    Phenol poisoning; Phenylic acid poisoning; Hydroxybenzene poisoning; Phenic acid poisoning; Benzenol poisoning ... Below are symptoms of carbolic acid poisoning in different parts of the ... urine Decreased urine output No urine output EYES, EARS, ...

  16. Azelaic Acid Topical

    MedlinePlus

    Azelaic acid gel is used to clear the bumps, lesions, and swelling caused by rosacea (a skin disease that ... redness, flushing, and pimples on the face). Azelaic acid cream is used to treat acne. Azelaic acid ...

  17. Uric acid test (image)

    MedlinePlus

    Uric acid urine test is performed to check for the amount of uric acid in urine. Urine is collected over a 24 ... testing. The most common reason for measuring uric acid levels is in the diagnosis or treatment of ...

  18. Facts about Folic Acid

    MedlinePlus

    ... Information For... Media Policy Makers Facts About Folic Acid Language: English Español (Spanish) Recommend on Facebook Tweet ... of the baby's brain and spine. About folic acid Folic acid is a B vitamin. Our bodies ...

  19. Acid Lipase Disease

    MedlinePlus

    ... Awards Enhancing Diversity Find People About NINDS NINDS Acid Lipase Disease Information Page Synonym(s): Cholesterol Ester Storage ... Trials Related NINDS Publications and Information What is Acid Lipase Disease ? Acid lipase disease or deficiency occurs ...

  20. Motion Estimation System Utilizing Point Cloud Registration

    NASA Technical Reports Server (NTRS)

    Chen, Qi (Inventor)

    2016-01-01

    A system and method of estimation motion of a machine is disclosed. The method may include determining a first point cloud and a second point cloud corresponding to an environment in a vicinity of the machine. The method may further include generating a first extended gaussian image (EGI) for the first point cloud and a second EGI for the second point cloud. The method may further include determining a first EGI segment based on the first EGI and a second EGI segment based on the second EGI. The method may further include determining a first two dimensional distribution for points in the first EGI segment and a second two dimensional distribution for points in the second EGI segment. The method may further include estimating motion of the machine based on the first and second two dimensional distributions.

  1. Continuation of point clouds via persistence diagrams

    NASA Astrophysics Data System (ADS)

    Gameiro, Marcio; Hiraoka, Yasuaki; Obayashi, Ippei

    2016-11-01

    In this paper, we present a mathematical and algorithmic framework for the continuation of point clouds by persistence diagrams. A key property used in the method is that the persistence map, which assigns a persistence diagram to a point cloud, is differentiable. This allows us to apply the Newton-Raphson continuation method in this setting. Given an original point cloud P, its persistence diagram D, and a target persistence diagram D‧, we gradually move from D to D‧, by successively computing intermediate point clouds until we finally find a point cloud P‧ having D‧ as its persistence diagram. Our method can be applied to a wide variety of situations in topological data analysis where it is necessary to solve an inverse problem, from persistence diagrams to point cloud data.

  2. 47 CFR 101.137 - Interconnection of private operational fixed point-to-point microwave stations.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... point-to-point microwave stations. 101.137 Section 101.137 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) SAFETY AND SPECIAL RADIO SERVICES FIXED MICROWAVE SERVICES Technical Standards § 101.137 Interconnection of private operational fixed point-to-point microwave stations....

  3. 47 CFR 101.137 - Interconnection of private operational fixed point-to-point microwave stations.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... point-to-point microwave stations. 101.137 Section 101.137 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) SAFETY AND SPECIAL RADIO SERVICES FIXED MICROWAVE SERVICES Technical Standards § 101.137 Interconnection of private operational fixed point-to-point microwave stations....

  4. 47 CFR 101.137 - Interconnection of private operational fixed point-to-point microwave stations.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... point-to-point microwave stations. 101.137 Section 101.137 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) SAFETY AND SPECIAL RADIO SERVICES FIXED MICROWAVE SERVICES Technical Standards § 101.137 Interconnection of private operational fixed point-to-point microwave stations....

  5. 47 CFR 101.137 - Interconnection of private operational fixed point-to-point microwave stations.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... point-to-point microwave stations. 101.137 Section 101.137 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) SAFETY AND SPECIAL RADIO SERVICES FIXED MICROWAVE SERVICES Technical Standards § 101.137 Interconnection of private operational fixed point-to-point microwave stations....

  6. 47 CFR 101.137 - Interconnection of private operational fixed point-to-point microwave stations.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 47 Telecommunication 5 2010-10-01 2010-10-01 false Interconnection of private operational fixed point-to-point microwave stations. 101.137 Section 101.137 Telecommunication FEDERAL COMMUNICATIONS....137 Interconnection of private operational fixed point-to-point microwave stations....

  7. The triple point of sulfur hexafluoride

    NASA Astrophysics Data System (ADS)

    Rourke, P. M. C.

    2016-04-01

    A cryogenic fixed point cell has been filled with high purity (99.999%) sulfur hexafluoride (SF6) and measured in an adiabatic closed-cycle cryostat system. Temperature measurements of the SF6 melting curve were performed using a capsule-type standard platinum resistance thermometer (CSPRT) calibrated over the International Temperature Scale of 1990 (ITS-90) subrange from the triple point of equilibrium hydrogen to the triple point of water. The measured temperatures were corrected by 0.37 mK for the effects of thermometer self-heating, and the liquidus-point temperature estimated by extrapolation to melted fraction F  =  1 of a simple linear regression versus melted fraction F in the range F  =  0.53 to 0.84. Based on this measurement, the temperature of the triple point of sulfur hexafluoride is shown to be 223.555 23(49) K (k  =  1) on the ITS-90. This value is in excellent agreement with the best prior measurements reported in the literature, but with considerably smaller uncertainty. An analysis of the detailed uncertainty budget of this measurement suggests that if the triple point of sulfur hexafluoride were to be included as a defining fixed point of the next revision of the International Temperature Scale, it could do so with a total realization uncertainty of approximately 0.43 mK, slightly larger than the realization uncertainties of the defining fixed points of the ITS-90. Since the combined standard uncertainty of this SF6 triple point temperature determination is dominated by chemical impurity effects, further research exploring gas purification techniques and the influence of specific impurity species on the SF6 triple point temperature may bring the realization uncertainty of SF6 as a fixed point material into the range of the defining fixed points of the ITS-90.

  8. The AIROscope pointing and stabilization system

    NASA Technical Reports Server (NTRS)

    Murphy, J. P.; Lorell, K. R.

    1974-01-01

    The AIROscope pointing and stabilization system is described. The system is configured with three gimbal axes and rate integrating gyro stabilization to provide a stable platform for infrared astronomy. Error signals for on and off-axis pointing are derived from a video sensor which also drives a ground station display. Other features of the system include direct drive torque motors and electronic suspension damping. Results of analysis and simulations used to design the control loops, and a pointing error analysis are presented.

  9. Hyperbolic Weyl Point in Reciprocal Chiral Metamaterials

    NASA Astrophysics Data System (ADS)

    Xiao, Meng; Lin, Qian; Fan, Shanhui

    2016-07-01

    We report the existence of Weyl points in a class of noncentral symmetric metamaterials, which has time reversal symmetry, but does not have inversion symmetry due to chiral coupling between electric and magnetic fields. This class of metamaterial exhibits either type-I or type-II Weyl points depending on its nonlocal response. We also provide a physical realization of such metamaterial consisting of an array of metal wires in the shape of elliptical helices which exhibits type-II Weyl points.

  10. The Annular Suspension and Pointing System /ASPS/

    NASA Technical Reports Server (NTRS)

    Anderson, W. W.; Woolley, C. T.

    1978-01-01

    The Annular Suspension and Pointing System (ASPS) may be attached to a carrier vehicle for orientation, mechanical isolation, and fine pointing purposes applicable to space experiments. It has subassemblies for both coarse and vernier pointing. A fourteen-degree-of-freedom simulation of the ASPS mounted on a Space Shuttle has yielded initial performance data. The simulation describes: the magnetic actuators, payload sensors, coarse gimbal assemblies, control algorithms, rigid body dynamic models of the payload and Shuttle, and a control system firing model.

  11. Leverage points in a computer model

    NASA Astrophysics Data System (ADS)

    Janošek, Michal

    2016-06-01

    This article is focused on the analysis of the leverage points (developed by D. Meadows) in a computer model. The goal is to find out if there is a possibility to find these points of leverage in a computer model (on the example of a predator-prey model) and to determine how the particular parameters, their ranges and monitored variables of the model are associated with the concept of leverage points.

  12. Deepstar 902 cloud point round robin

    SciTech Connect

    Williams, T.M.; Santamaria, M.M.

    1995-12-01

    Wax deposition is a problem in many oil fields and wells. Since wax precipitates and may cause deposition problems when the oil is cooled below its cloud point, an accurate method to determine an oil`s cloud point is needed. Samples of oil from three wells were collected and distributed to ten laboratories. The results indicate that cloud point temperature measurement is not as well defined as expected. The results of this study are discussed in this paper.

  13. Point Relay Scanner Utilizing Ellipsoidal Mirrors

    NASA Technical Reports Server (NTRS)

    Manhart, Paul K. (Inventor); Pagano, Robert J. (Inventor)

    1997-01-01

    A scanning system uses a polygonal mirror assembly with each facet of the polygon having an ellipsoidal mirror located thereon. One focal point of each ellipsoidal mirror is located at a common point on the axis of rotation of the polygonal mirror assembly. As the mirror assembly rotates. a second focal point of the ellipsoidal mirrors traces out a scan line. The scanner can be utilized for scanned output display of information or for scanning information to be detected.

  14. Hyperbolic Weyl Point in Reciprocal Chiral Metamaterials.

    PubMed

    Xiao, Meng; Lin, Qian; Fan, Shanhui

    2016-07-29

    We report the existence of Weyl points in a class of noncentral symmetric metamaterials, which has time reversal symmetry, but does not have inversion symmetry due to chiral coupling between electric and magnetic fields. This class of metamaterial exhibits either type-I or type-II Weyl points depending on its nonlocal response. We also provide a physical realization of such metamaterial consisting of an array of metal wires in the shape of elliptical helices which exhibits type-II Weyl points.

  15. Development of POINTS as a planetology instrument

    NASA Technical Reports Server (NTRS)

    Reasenberg, Robert D.

    1994-01-01

    During the reporting period, we carried out investigations required to enhance our design of POINTS as a tool for the search for and characterization of extra-solar planetary systems. The results of that work were included in a paper on POINTS as well as one on Newcomb, which will soon appear in the proceedings of SPIE Conference 2200. (Newcomb is a spinoff of POINTS. It is a small astrometric interferometer now being developed jointly by SAO and the U.S. Navy. It could help establish some of the technology needed for POINTS.) These papers are appended.

  16. Wolf Point Substation, Roosevelt County, Montana

    SciTech Connect

    Not Available

    1991-05-01

    The Western Area Power Administration (Western), an agency of the United States Department of Energy, is proposing to construct the 115-kV Wolf Point Substation near Wolf Point in Roosevelt County, Montana (Figure 1). As part of the construction project, Western's existing Wolf Point Substation would be taken out of service. The existing 115-kV Wolf Point Substation is located approximately 3 miles west of Wolf Point, Montana (Figure 2). The substation was constructed in 1949. The existing Wolf Point Substation serves as a Switching Station'' for the 115-kV transmission in the region. The need for substation improvements is based on operational and reliability issues. For this environmental assessment (EA), the environmental review of the proposed project took into account the removal of the old Wolf Point Substation, rerouting of the five Western lines and four lines from the Cooperatives and Montana-Dakota Utilities Company, and the new road into the proposed substation. Reference to the new proposed Wolf Point Substation in the EA includes these facilities as well as the old substation site. The environmental review looked at the impacts to all resource areas in the Wolf Point area. 7 refs., 6 figs.

  17. Development of POINTS as a planetology instrument

    NASA Astrophysics Data System (ADS)

    Reasenberg, Robert D.

    1994-05-01

    During the reporting period, we carried out investigations required to enhance our design of POINTS as a tool for the search for and characterization of extra-solar planetary systems. The results of that work were included in a paper on POINTS as well as one on Newcomb, which will soon appear in the proceedings of SPIE Conference 2200. (Newcomb is a spinoff of POINTS. It is a small astrometric interferometer now being developed jointly by SAO and the U.S. Navy. It could help establish some of the technology needed for POINTS.) These papers are appended.

  18. The Softmounted Inertially Reacting Pointing System (SIRPNT)

    NASA Astrophysics Data System (ADS)

    Sirlin, Samuel W.; Laskin, Robert A.

    A softmounted inertially reacting pointing system differs from traditional gimbal-based pointing system architecture in that: (1) the primary pointing control actuator does not need to apply torques on the basebody, and hence will not interact in a destabilizing way with basebody flexibility, and (2) the connection of the payload with the basebody is via a soft, low frequency structure, which acts as a two-way low pass filter for disturbances. Planar, linear analysis of a preliminary design of such a pointing system using the piezoelectric polymer material PVF2 as an active element in the softmount is presented demonstrating the potential performance in disturbance rich environments such as Space Station.

  19. Exceptional points in coupled dissipative dynamical systems.

    PubMed

    Ryu, Jung-Wan; Son, Woo-Sik; Hwang, Dong-Uk; Lee, Soo-Young; Kim, Sang Wook

    2015-05-01

    We study the transient behavior in coupled dissipative dynamical systems based on the linear analysis around the steady state. We find that the transient time is minimized at a specific set of system parameters and show that at this parameter set, two eigenvalues and two eigenvectors of the Jacobian matrix coalesce at the same time; this degenerate point is called the exceptional point. For the case of coupled limit-cycle oscillators, we investigate the transient behavior into the amplitude death state, and clarify that the exceptional point is associated with a critical point of frequency locking, as well as the transition of the envelope oscillation.

  20. Instrument Pointing Capabilities: Past, Present, and Future

    NASA Technical Reports Server (NTRS)

    Blackmore, Lars; Murray, Emmanuell; Scharf, Daniel P.; Aung, Mimi; Bayard, David; Brugarolas, Paul; Hadaegh, Fred; Lee, Allan; Milman, Mark; Sirlin, Sam; Kang, Bryan

    2011-01-01

    This paper surveys the instrument pointing capabilities of past, present and future space telescopes and interferometers. As an important aspect of this survey, we present a taxonomy for "apples-to-apples" comparisons of pointing performances. First, pointing errors are defined relative to either an inertial frame or a celestial target. Pointing error can then be further sub-divided into DC, that is, steady state, and AC components. We refer to the magnitude of the DC error relative to the inertial frame as absolute pointing accuracy, and we refer to the magnitude of the DC error relative to a celestial target as relative pointing accuracy. The magnitude of the AC error is referred to as pointing stability. While an AC/DC partition is not new, we leverage previous work by some of the authors to quantitatively clarify and compare varying definitions of jitter and time window averages. With this taxonomy and for sixteen past, present, and future missions, pointing accuracies and stabilities, both required and achieved, are presented. In addition, we describe the attitude control technologies used to and, for future missions, planned to achieve these pointing performances.

  1. Topological photonic crystal with equifrequency Weyl points

    NASA Astrophysics Data System (ADS)

    Wang, Luyang; Jian, Shao-Kai; Yao, Hong

    2016-06-01

    Weyl points in three-dimensional photonic crystals behave as monopoles of Berry flux in momentum space. Here, based on general symmetry analysis, we show that a minimal number of four symmetry-related (consequently equifrequency) Weyl points can be realized in time-reversal invariant photonic crystals. We further propose an experimentally feasible way to modify double-gyroid photonic crystals to realize four equifrequency Weyl points, which is explicitly confirmed by our first-principle photonic band-structure calculations. Remarkably, photonic crystals with equifrequency Weyl points are qualitatively advantageous in applications including angular selectivity, frequency selectivity, invisibility cloaking, and three-dimensional imaging.

  2. Topological photonic crystal with ideal Weyl points

    NASA Astrophysics Data System (ADS)

    Wang, Luyang; Jian, Shao-Kai; Yao, Hong

    Weyl points in three-dimensional photonic crystals behave as monopoles of Berry flux in momentum space. Here, based on symmetry analysis, we show that a minimal number of symmetry-related Weyl points can be realized in time-reversal invariant photonic crystals. We propose to realize these ``ideal'' Weyl points in modified double-gyroid photonic crystals, which is confirmed by our first-principle photonic band-structure calculations. Photonic crystals with ideal Weyl points are qualitatively advantageous in applications such as angular and frequency selectivity, broadband invisibility cloaking, and broadband 3D-imaging.

  3. Acid distribution in phosphoric acid fuel cells

    SciTech Connect

    Okae, I.; Seya, A.; Umemoto, M.

    1996-12-31

    Electrolyte acid distribution among each component of a cell is determined by capillary force when the cell is not in operation, but the distribution under the current load conditions had not been clear so far. Since the loss of electrolyte acid during operation is inevitable, it is necessary to store enough amount of acid in every cell. But it must be under the level of which the acid disturbs the diffusion of reactive gases. Accordingly to know the actual acid distribution during operation in a cell is very important. In this report, we carried out experiments to clarify the distribution using small single cells.

  4. 46 CFR 7.130 - Point Conception, CA to Point Sur, CA.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 46 Shipping 1 2010-10-01 2010-10-01 false Point Conception, CA to Point Sur, CA. 7.130 Section 7.130 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY PROCEDURES APPLICABLE TO THE PUBLIC BOUNDARY LINES Pacific Coast § 7.130 Point Conception, CA to Point Sur, CA. (a) A line drawn from the southernmost extremity of Fossil Point at longitude...

  5. Acid Rain Analysis by Standard Addition Titration.

    ERIC Educational Resources Information Center

    Ophardt, Charles E.

    1985-01-01

    The standard addition titration is a precise and rapid method for the determination of the acidity in rain or snow samples. The method requires use of a standard buret, a pH meter, and Gran's plot to determine the equivalence point. Experimental procedures used and typical results obtained are presented. (JN)

  6. Integrating Retinoic Acid Signaling with Brain Function

    ERIC Educational Resources Information Center

    Luo, Tuanlian; Wagner, Elisabeth; Drager, Ursula C.

    2009-01-01

    The vitamin A derivative retinoic acid (RA) regulates the transcription of about a 6th of the human genome. Compelling evidence indicates a role of RA in cognitive activities, but its integration with the molecular mechanisms of higher brain functions is not known. Here we describe the properties of RA signaling in the mouse, which point to…

  7. [Bile acids in the bile in diabetes mellitus].

    PubMed

    Slivka, O Ia; Zelinskiĭ, B A; Zelinskiĭ, S Ts

    1979-01-01

    Hepatic and gall bladder bile of healthy persons (8) and of patients with severe form of diabetes mellitus (17) was studied. Paer chromatography was applied for determination of cholic, chenodeoxycholic, deoxycholic bile acids and their conjugates with glycin and taurine. An absolute content and percentage of glycodeoxycholic and glycochenodeoxycholic bile acids were increased, and glycochenodeoxycholic acid content and taurates proportion were decreased in the gall bladder and hepatic bile of diabetic patients. The data obtained pointed to disturbed hepatic function in severe diabetes mellitus; it was expressed in suppression of bile acids synthesis and conjugation, and also in depression of transformation of deoxycholic into cholic acid.

  8. NSDC Policy Points. Volume 1, Number 3

    ERIC Educational Resources Information Center

    National Staff Development Council, 2009

    2009-01-01

    "NSDC Policy Points" is a newsletter published by the National Staff Development Council (NSDC). This issue of "NSDC Policy Points" features schools that practice effective professional development. Included in this newsletter are: (1) Surprise, Arizona: Coaches support classroom improvements; (2) Loveland, Colorado: Redefining time use to…

  9. The Psychic Organ Point of Autistic Syntax

    ERIC Educational Resources Information Center

    Amir, Dana

    2013-01-01

    This paper deals with autistic syntax and its expressions both in the fully fledged autistic structure and in the autistic zones of other personality structures. The musical notion of the organ point serves as a point of departure in an attempt to describe how autistic syntax transforms what was meant to constitute the substrate for linguistic…

  10. Pointing with Power or Creating with Chalk

    ERIC Educational Resources Information Center

    Rudow, Sasha R.; Finck, Joseph E.

    2015-01-01

    This study examines the attitudes of students on the use of PowerPoint and chalk/white boards in college science lecture classes. Students were asked to complete a survey regarding their experiences with PowerPoint and chalk/white boards in their science classes. Both multiple-choice and short answer questions were used. The multiple-choice…

  11. A New Look at Infant Pointing

    ERIC Educational Resources Information Center

    Tomasello, Michael; Carpenter, Malinda; Liszkowski, Ulf

    2007-01-01

    The current article proposes a new theory of infant pointing involving multiple layers of intentionality and shared intentionality. In the context of this theory, evidence is presented for a rich interpretation of prelinguistic communication, that is, one that posits that when 12-month-old infants point for an adult they are in some sense trying…

  12. Impedance analysis of acupuncture points and pathways

    NASA Astrophysics Data System (ADS)

    Teplan, Michal; Kukučka, Marek; Ondrejkovičová, Alena

    2011-12-01

    Investigation of impedance characteristics of acupuncture points from acoustic to radio frequency range is addressed. Discernment and localization of acupuncture points in initial single subject study was unsuccessfully attempted by impedance map technique. Vector impedance analyses determined possible resonant zones in MHz region.

  13. 14 CFR 71.5 - Reporting points.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 14 Aeronautics and Space 2 2010-01-01 2010-01-01 false Reporting points. 71.5 Section 71.5 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION (CONTINUED) AIRSPACE DESIGNATION OF CLASS A, B, C, D, AND E AIRSPACE AREAS; AIR TRAFFIC SERVICE ROUTES; AND REPORTING POINTS §...

  14. Determinants of College Grade Point Averages

    ERIC Educational Resources Information Center

    Bailey, Paul Dean

    2012-01-01

    Chapter 2: The Role of Class Difficulty in College Grade Point Averages. Grade Point Averages (GPAs) are widely used as a measure of college students' ability. Low GPAs can remove a students from eligibility for scholarships, and even continued enrollment at a university. However, GPAs are determined not only by student ability but also by…

  15. Universal Points Plus v1.1

    SciTech Connect

    Kertesz, Vilmos

    2013-03-14

    Software has built-in scan feature to acquire optical image of the surface to be analyzed and click-and-point selection of points of interest on the surface. Creates heatmaps of analytes of interests from collected MS files in a hand-off fashion.

  16. On an Integral with Two Branch Points

    ERIC Educational Resources Information Center

    de Oliveira, E. Capelas; Chiacchio, Ary O.

    2006-01-01

    The paper considers a class of real integrals performed by using a convenient integral in the complex plane. A complex integral containing a multi-valued function with two branch points is transformed into another integral containing a pole and a unique branch point. As a by-product we obtain a new class of integrals which can be calculated in a…

  17. The Tipping Point in School Culture

    ERIC Educational Resources Information Center

    Nelsen, Jeff; Hill, Bob

    2009-01-01

    Once changes or innovations reach the tipping point, they spread throughout an organization and become entrenched as part of the culture, becoming "just the way we do things around here." These authors see the tipping point at play with systemic improvement in two urban school districts with which they have worked. Here, they describe the lessons…

  18. NSDC Policy Points. Volume 1, Number 1

    ERIC Educational Resources Information Center

    National Staff Development Council, 2009

    2009-01-01

    "NSDC Policy Points" is a newsletter published by the National Staff Development Council (NSDC). This issue of "NSDC Policy Points" presents an interview with Sir Michael Barber, who worked for British Prime Minister Tony Blair on the implementation of his priority programs, including education. In his interview, Barber talked about policies and…

  19. 47 CFR 76.53 - Reference points.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 47 Telecommunication 4 2011-10-01 2011-10-01 false Reference points. 76.53 Section 76.53 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) BROADCAST RADIO SERVICES MULTICHANNEL VIDEO AND CABLE TELEVISION SERVICE Carriage of Television Broadcast Signals § 76.53 Reference points....

  20. 47 CFR 76.53 - Reference points.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 47 Telecommunication 4 2010-10-01 2010-10-01 false Reference points. 76.53 Section 76.53 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) BROADCAST RADIO SERVICES MULTICHANNEL VIDEO AND CABLE TELEVISION SERVICE Carriage of Television Broadcast Signals § 76.53 Reference points....