WorldWideScience

Sample records for cassegrainian concentrators

  1. Tailored edge-ray concentrator for a solar furnace at the Plataforma Solar de Almeria

    Science.gov (United States)

    Collares-Pereira, Manuel; Mendes, Joao F.; Rabl, Ari; Ries, Harald

    1995-08-01

    The use of two stage optical designs, with reasonably compact devices, is required for being close to the thermodynamic limit to optical concentration of solar collectors. In this work we will present the design and the first test results of a second stage concentrator to be added to the existing primary of the solar furnace of Plataforma Solar de Almeria (PSA), designed to improve the final concentration and to increase its working temperature. Different options have been considered, including CPC, CEC, Trumpet, Cassegrainian, and tailored edge-ray devices. For the geometry of the PSA solar furnace, the tailored edge ray comes closest to the thermodynamic limits. It also is the most suitable from a practical point of view.

  2. Concentration device

    DEFF Research Database (Denmark)

    2013-01-01

    A concentration device (2) for filter filtration concentration of particles (4) from a volume of a fluid (6). The concentration device (2) comprises a filter (8) configured to filter particles (4) of a predefined size in the volume of the fluid (6). The concentration device (2) comprises...

  3. Concentration risk

    Directory of Open Access Journals (Sweden)

    Matić Vesna

    2016-01-01

    Full Text Available Concentration risk has been gaining a special dimension in the contemporary financial and economic environment. Financial institutions are exposed to this risk mainly in the field of lending, mostly through their credit activities and concentration of credit portfolios. This refers to the concentration of different exposures within a single risk category (credit risk, market risk, operational risk, liquidity risk.

  4. Concentrator Photovoltaics

    CERN Document Server

    Luque, Antonio L

    2007-01-01

    Photovoltaic solar-energy conversion is one of the most promising technologies for generating renewable energy, and conversion of concentrated sunlight can lead to reduced cost for solar electricity. In fact, photovoltaic conversion of concentrated sunlight insures an efficient and cost-effective sustainable power resource. This book gives an overview of all components, e.g. cells, concentrators, modules and systems, for systems of concentrator photovoltaics. The authors report on significant results related to design, technology, and applications, and also cover the fundamental physics and market considerations. Specific contributions include: theory and practice of sunlight concentrators; an overview of concentrator PV activities; a description of concentrator solar cells; design and technology of modules and systems; manufacturing aspects; and a market study.

  5. Concentrating Radioactivity

    Science.gov (United States)

    Herrmann, Richard A.

    1974-01-01

    By concentrating radioactivity contained on luminous dials, a teacher can make a high reading source for classroom experiments on radiation. The preparation of the source and its uses are described. (DT)

  6. Air Data - Concentration Map

    Science.gov (United States)

    Make a map of daily concentrations over several days. The daily air quality can be displayed in terms of the Air Quality Index or in concentration ranges for certain PM species like organic carbon, nitrates, and sulfates.

  7. Urine concentration test

    Science.gov (United States)

    ... page: //medlineplus.gov/ency/article/003608.htm Urine concentration test To use the sharing features on this page, please enable JavaScript. A urine concentration test measures the ability of the kidneys to ...

  8. Rheology of concentrated biomass

    Science.gov (United States)

    J.R. Samaniuk; J. Wang; T.W. Root; C.T. Scott; D.J. Klingenberg

    2011-01-01

    Economic processing of lignocellulosic biomass requires handling the biomass at high solids concentration. This creates challenges because concentrated biomass behaves as a Bingham-like material with large yield stresses. Here we employ torque rheometry to measure the rheological properties of concentrated lignocellulosic biomass (corn stover). Yield stresses obtained...

  9. Solar cell concentrating system

    International Nuclear Information System (INIS)

    Garg, H.P.; Sharma, V.K.; Agarwal, R.K.

    1986-11-01

    This study reviews fabrication techniques and testing facilities for different solar cells under concentration which have been developed and tested. It is also aimed to examine solar energy concentrators which are prospective candidates for photovoltaic concentrator systems. This may provide an impetus to the scientists working in the area of solar cell technology

  10. Concentrators using fluorescent substances

    Energy Technology Data Exchange (ETDEWEB)

    Hayashibara, M.; Tsukamoto, M. (Hitachi Seisakusho K.K., Tokyo (Japan))

    1990-01-01

    In luminescent concentrators - plates of polymethylmethacrylate (PMMA) or other transparent material with a fluorescent compound dispersed within them - incident light is trapped and concentrated by internal reflection, and shifted to a longer wavelength, as it interacts with fluorescent particles. Experience with the use of luminescent concentrators for electricity generation in conjunction with solar cells, in solar heaters, in amplifiers for light intensity, in long-wave converters and in display panels is discussed. Solar energy conversion efficiencies of 4-5% have been obtained in generating systems combining concentrators containing Fluorol 555 or Rhodamin 6G with GaAs solar cells. (author).

  11. Strategies to Support Concentration

    Science.gov (United States)

    Haines, Annette

    2017-01-01

    Annette Haines provides a comprehensive overview of concentration across the planes. She first lays the foundation for thinking about student engagement: It must be understood that concentration is found through the interest of the child, which is guided by the sensitive periods. When we understand the child's development in this way, we can offer…

  12. Blood lead concentrations age.

    Science.gov (United States)

    Jusko, Todd A; Henderson, Charles R; Lanphear, Bruce P; Cory-Slechta, Deborah A; Parsons, Patrick J; Canfield, Richard L

    2008-02-01

    Few studies provide data directly relevant to the question of whether blood lead concentrations affect children's cognitive function. We examined the association between blood lead concentrations assessed throughout early childhood and children's IQ at 6 years of age. Children were followed from 6 months to 6 years of age, with determination of blood lead concentrations at 6, 12, 18, and 24 months, and 3, 4, 5, and 6 years of age. At 6 years of age, intelligence was assessed in 194 children using the Wechsler Preschool and Primary Scale of Intelligence-Revised. We used general linear and semiparametic models to estimate and test the association between blood lead concentration and IQ. After adjustment for maternal IQ, HOME scale scores, and other potential confounding factors, lifetime average blood lead concentration (mean = 7.2 microg/dL; median = 6.2 microg/dL) was inversely associated with Full-Scale IQ (p = 0.006) and Performance IQ scores (p = 0.002). Compared with children who had lifetime average blood lead concentrations IQ (91.3 vs. 86.4, p = 0.03). Nonlinear modeling of the peak blood lead concentration revealed an inverse association (p = 0.003) between peak blood lead levels and Full-Scale IQ down to 2.1 microg/dL, the lowest observed peak blood lead concentration in our study. Evidence from this cohort indicates that children's intellectual functioning at 6 years of age is impaired by blood lead concentrations well below 10 microg/dL, the Centers for Disease Control and Prevention definition of an elevated blood lead level.

  13. Concentrating photovoltaic solar panel

    Science.gov (United States)

    Cashion, Steven A; Bowser, Michael R; Farrelly, Mark B; Hines, Braden E; Holmes, Howard C; Johnson, Jr., Richard L; Russell, Richard J; Turk, Michael F

    2014-04-15

    The present invention relates to photovoltaic power systems, photovoltaic concentrator modules, and related methods. In particular, the present invention features concentrator modules having interior points of attachment for an articulating mechanism and/or an articulating mechanism that has a unique arrangement of chassis members so as to isolate bending, etc. from being transferred among the chassis members. The present invention also features adjustable solar panel mounting features and/or mounting features with two or more degrees of freedom. The present invention also features a mechanical fastener for secondary optics in a concentrator module.

  14. Concentration of Hydrogen Peroxide

    Science.gov (United States)

    Parrish, Clyde F. (Inventor)

    2006-01-01

    Methods for concentrating hydrogen peroxide solutions have been described. The methods utilize a polymeric membrane separating a hydrogen peroxide solution from a sweep gas or permeate. The membrane is selective to the permeability of water over the permeability of hydrogen peroxide, thereby facilitating the concentration of the hydrogen peroxide solution through the transport of water through the membrane to the permeate. By utilizing methods in accordance with the invention, hydrogen peroxide solutions of up to 85% by volume or higher may be generated at a point of use without storing substantial quantities of the highly concentrated solutions and without requiring temperatures that would produce explosive mixtures of hydrogen peroxide vapors.

  15. Concentrated Differential Privacy

    OpenAIRE

    Dwork, Cynthia; Rothblum, Guy N.

    2016-01-01

    We introduce Concentrated Differential Privacy, a relaxation of Differential Privacy enjoying better accuracy than both pure differential privacy and its popular "(epsilon,delta)" relaxation without compromising on cumulative privacy loss over multiple computations.

  16. Rheology of concentrated biomass

    Science.gov (United States)

    Samaniuk, J. R.; Wang, J.; Root, T. W.; Scott, C. T.; Klingenberg, D. J.

    2011-12-01

    Economic processing of lignocellulosic biomass requires handling the biomass at high solids concentration. This creates challenges because concentrated biomass behaves as a Bingham-like material with large yield stresses. Here we employ torque rheometry to measure the rheological properties of concentrated lignocellulosic biomass (corn stover). Yield stresses obtained using torque rheometry agree with those obtained using other rheometric methods, but torque rheometry can be used at much larger solids concentration (weight fractions of insoluble solids greater than 0.2). Yield stresses decrease with severity of hydrolysis, decrease when water-soluble polymers are added (for nonhydrolyzed biomass), and increase with particle length. Experimental results are qualitatively consistent with those obtained from particle-level simulations.

  17. Concentrations of Indicator Organisms

    Data.gov (United States)

    U.S. Environmental Protection Agency — It is a compilation of organism concentrations of 16 sampling events conducted between July 2015 and February 2016. It also includes statistical analysis such as...

  18. CMAQ predicted concentration files

    Data.gov (United States)

    U.S. Environmental Protection Agency — model predicted concentrations. This dataset is associated with the following publication: Muñiz-Unamunzaga, M., R. Borge, G. Sarwar, B. Gantt, D. de la Paz, C....

  19. Computer designed solar concentrator

    Energy Technology Data Exchange (ETDEWEB)

    Aliman, O.; Daut, I.; Lim, C.S.; Isa, M.; Adzman, M.R. [Kolej Univ. Kejuruteraan Utara Malaysia, Perlis (Malaysia). School of Electrical System Engineering

    2007-07-01

    A new method of sun tracking has been proposed and demonstrated at the University of Technology Malaysia. The heliostat not only tracks the sun but also concentrates all of the sun images from its mirrors into a single image at a stationary target. Because of this, the target image can be made small enough so that a relatively small concentrator or receiver is required to collect the solar energy. A single cylinder, beta type Stirling engine has been built to work with this heliostat as a whole system. This paper discussed the computer designed optical concentrator, that was providing efficient solar energy transfer to a Stirling engine. The paper discussed the development of a prototype optical concentrator. The computer-simulated characteristics of the receiver as well as the experimental data of its performance were presented. It was concluded that coupling with a non-imaging focusing heliostat, the prototype optical concentrator was successful in running a small scale Stirling engine. The contribution of the optical concentrator to heliostat application was encouraging. 3 refs., 1 tab., 10 figs.

  20. Photovoltaic solar concentrator

    Science.gov (United States)

    Nielson, Gregory N.; Gupta, Vipin P.; Okandan, Murat; Watts, Michael R.

    2016-03-15

    A photovoltaic solar concentrator is disclosed with one or more transverse-junction solar cells (also termed point contact solar cells) and a lens located above each solar cell to concentrate sunlight onto the solar cell to generate electricity. Piezoelectric actuators tilt or translate each lens to track the sun using a feedback-control circuit which senses the electricity generated by one or more of the solar cells. The piezoelectric actuators can be coupled through a displacement-multiplier linkage to provide an increased range of movement of each lens. Each lens in the solar concentrator can be supported on a frame (also termed a tilt plate) having three legs, with the movement of the legs being controlled by the piezoelectric actuators.

  1. Pollutant concentrations in placenta

    DEFF Research Database (Denmark)

    Leino, O.; Kiviranta, H.; Karjalainen, A. K.

    2013-01-01

    Unborn children are exposed to environmental pollutants via the placenta, and there is a causal relationship between maternal intake of pollutants and fetal exposure. Placental examination is an effective way for acquiring data for estimating fetal exposure. We analyzed the concentrations of 104...... congeners of persistent organic pollutants, seven organotin compounds, five heavy metals, and methylmercury in 130 randomly selected placentas. Additionally, we examined similarities between pollutant concentrations by analyzing correlations between their placental concentrations. Our results yield new...... information for conducting contaminant risk assessments for the prenatal period. Out of the 117 individual persistent organic pollutants or metals assayed, 46 could be detected in more than half of the placentas. Moreover, dichlorodiphenyldichloroethylene (p,p'-DDE) was found in all placentas. The data...

  2. Hydrogen Peroxide Concentrator

    Science.gov (United States)

    Parrish, Clyde F.

    2007-01-01

    A relatively simple and economical process and apparatus for concentrating hydrogen peroxide from aqueous solution at the point of use have been invented. The heart of the apparatus is a vessel comprising an outer shell containing tubular membranes made of a polymer that is significantly more permeable by water than by hydrogen peroxide. The aqueous solution of hydrogen peroxide to be concentrated is fed through the interstitial spaces between the tubular membranes. An initially dry sweep gas is pumped through the interiors of the tubular membranes. Water diffuses through the membranes and is carried away as water vapor mixed into the sweep gas. Because of the removal of water, the hydrogen peroxide solution flowing from the vessel at the outlet end is more concentrated than that fed into the vessel at the inlet end. The sweep gas can be air, nitrogen, or any other gas that can be conveniently supplied in dry form and does not react chemically with hydrogen peroxide.

  3. Photovoltaic solar concentrator

    Science.gov (United States)

    Nielson, Gregory N.; Okandan, Murat; Resnick, Paul J.; Cruz-Campa, Jose Luis

    2012-12-11

    A photovoltaic solar concentrator is disclosed with one or more transverse-junction solar cells (also termed point contact solar cells) and a lens located above each solar cell to concentrate sunlight onto the solar cell to generate electricity. Piezoelectric actuators tilt or translate each lens to track the sun using a feedback-control circuit which senses the electricity generated by one or more of the solar cells. The piezoelectric actuators can be coupled through a displacement-multiplier linkage to provide an increased range of movement of each lens. Each lens in the solar concentrator can be supported on a frame (also termed a tilt plate) having three legs, with the movement of the legs being controlled by the piezoelectric actuators.

  4. Vacancy Concentration in Ice

    DEFF Research Database (Denmark)

    Mogensen, O. E.; Eldrup, Morten Mostgaard

    1977-01-01

    Based on the diffusion constant for self-diffusion in ice, which is believed to take place by a vacancy mechanism, we estimate the relative vacancy concentration near the melting point to be at least ∼ 10−6, i.e. much higher than previous estimates of about 10−10.......Based on the diffusion constant for self-diffusion in ice, which is believed to take place by a vacancy mechanism, we estimate the relative vacancy concentration near the melting point to be at least ∼ 10−6, i.e. much higher than previous estimates of about 10−10....

  5. Concentrated loads on concrete

    DEFF Research Database (Denmark)

    Lorenzen, Karen Grøndahl; Nielsen, Mogens Peter

    1997-01-01

    This report deals with concentrated loads on concrete.A new upper bound solution in the axisymmetrical case of a point load in the center of the end face of a cylinder is developed.Based on previous work dealing with failure mechanisms and upper bound solutions, new approximate formulas are devel......This report deals with concentrated loads on concrete.A new upper bound solution in the axisymmetrical case of a point load in the center of the end face of a cylinder is developed.Based on previous work dealing with failure mechanisms and upper bound solutions, new approximate formulas...

  6. Theory of Concentrated Vortices

    DEFF Research Database (Denmark)

    Alekseenko, Sergey; Kuibin, Pavel; Okulov, Valery

    This book presents comprehensive and authoritative coverage of the wide field of concentrated vortices observed in nature and technique. The methods for research of their kinematics and dynamics are considered. Special attention is paid to the flows with helical symmetry. The authors have describ...

  7. THE CONTROL OF CONCENTRATIONS

    Directory of Open Access Journals (Sweden)

    Ovidiu – Horia Maican

    2013-11-01

    Full Text Available Concentrations of companies have developed in the last 40 years, as an effect of open borders within the European Union. The question from the point of view of competition is if setting up a new group or entity may have the same restrictive effects of an agreement. In addition, that may lead to monopoly or oligopoly, which prevents effective competition. Concentrations are situations when one or more companies acquire control of other companies, changing the structure of the companies involved and of the market. The most important forms of concentrations of undertakings are the holding by a company of the capital of another company or of other companies, the total or partial acquisitions by a company of the assets of other companies and the merger of two or more companies which are legally independent into a new company. Sometimes, where the concentration in an industry exceeds certain limits it can lead to monopoly or oligopoly structures, which restrict competition and jeopardise consumers' interests. The legal basis for EU merger control is Council Regulation (EC No 139/2004. The regulation prohibits mergers and acquisitions which would significantly reduce competition in the Single Market, if they would create dominant companies and are likely to raise prices for consumers.

  8. Theory of Concentrated Vortices

    DEFF Research Database (Denmark)

    Alekseenko, Sergey; Kuibin, Pavel; Okulov, Valery

    This book presents comprehensive and authoritative coverage of the wide field of concentrated vortices observed in nature and technique. The methods for research of their kinematics and dynamics are considered. Special attention is paid to the flows with helical symmetry. The authors have described...

  9. Scattering Solar Thermal Concentrators

    Energy Technology Data Exchange (ETDEWEB)

    Giebink, Noel C. [Pennsylvania State Univ., State College, PA (United States)

    2015-01-31

    This program set out to explore a scattering-based approach to concentrate sunlight with the aim of improving collector field reliability and of eliminating wind loading and gross mechanical movement through the use of a stationary collection optic. The approach is based on scattering sunlight from the focal point of a fixed collection optic into the confined modes of a sliding planar waveguide, where it is transported to stationary tubular heat transfer elements located at the edges. Optical design for the first stage of solar concentration, which entails focusing sunlight within a plane over a wide range of incidence angles (>120 degree full field of view) at fixed tilt, led to the development of a new, folded-path collection optic that dramatically out-performs the current state-of-the-art in scattering concentration. Rigorous optical simulation and experimental testing of this collection optic have validated its performance. In the course of this work, we also identified an opportunity for concentrating photovoltaics involving the use of high efficiency microcells made in collaboration with partners at the University of Illinois. This opportunity exploited the same collection optic design as used for the scattering solar thermal concentrator and was therefore pursued in parallel. This system was experimentally demonstrated to achieve >200x optical concentration with >70% optical efficiency over a full day by tracking with <1 cm of lateral movement at fixed latitude tilt. The entire scattering concentrator waveguide optical system has been simulated, tested, and assembled at small scale to verify ray tracing models. These models were subsequently used to predict the full system optical performance at larger, deployment scale ranging up to >1 meter aperture width. Simulations at an aperture widths less than approximately 0.5 m with geometric gains ~100x predict an overall optical efficiency in the range 60-70% for angles up to 50 degrees from normal. However, the

  10. Tritium concentration monitor

    International Nuclear Information System (INIS)

    Shono, Kosuke.

    1991-01-01

    A device for measuring the concentration of tritium in gaseous wastes in a power plant and a nuclear fuel reprocessing plant is reduced in the size and improved in performance. The device of the present invention pressurizes a sampling gas and cools it to a dew point. Water content in the sampling gas cooled to the dew point is condensated and recovered to a fine tube-like water content recovering container. The concentration of the recovered condensates is measured by a tritium density analyzer. With such procedures, since the specimen is pressurized, the dew point can be elevated. Accordingly, the size of the cooling device can be decreased, enabling to contribute to the reduction of the size of the entire device. Further, since the water content recovering device is formed as a fine tube, the area of contact between the specimen gas and the liquid condensated water can be reduced. Accordingly, evaporation of the liquid condensates can be prevented. (I.S.)

  11. Chlorination of zirconyte concentrate

    International Nuclear Information System (INIS)

    Costa, N.G.

    1988-01-01

    Chlorination experiments with zirconyte concentrate were carried out in order to study the effects of temperature, percentage of reducing agent and porosity on the gasification of ZrO 2 for 10 and 20 minutes of reaction. Factorial analysis was applied and the results indicated that temperature and percentage of reducing agent were the two only variables effecting the ZrO 2 gasification. (author) [pt

  12. Electrolyte Concentrates Treat Dehydration

    Science.gov (United States)

    2009-01-01

    Wellness Brands Inc. of Boulder, Colorado, exclusively licensed a unique electrolyte concentrate formula developed by Ames Research Center to treat and prevent dehydration in astronauts returning to Earth. Marketed as The Right Stuff, the company's NASA-derived formula is an ideal measure for athletes looking to combat dehydration and boost performance. Wellness Brands also plans to expand with products that make use of the formula's effective hydration properties to help treat conditions including heat stroke, altitude sickness, jet lag, and disease.

  13. Censored correlated cytokine concentrations

    DEFF Research Database (Denmark)

    Andersen, Andreas; Benn, Christine Stabell; Jørgensen, Mathias J

    2013-01-01

    Interest in cytokines as markers for the function of the immune system is increasing. Methods quantifying cytokine concentrations are often subject to detection limits, which lead to non-detectable observations and censored distributions. When distributions are skewed, geometric mean ratios (GMRs...... stacking method that uses clustered variance-covariance estimation allowing homogeneous (Stackc) or inhomogeneous (Stackh) variances. We compare it with direct estimation of the bivariate Tobit likelihood function (Bitobit) and multiple imputation. We assess sensitivity to inhomogeneity and non...

  14. Carbon Concentration of Austenite

    Directory of Open Access Journals (Sweden)

    Z. Ławrynowicz

    2007-07-01

    Full Text Available The investigation was carried out to examine the influence of temperature and times of austempering process on the maximum extend towhich the bainite reaction can proceed and the carbon content in retained austenite. It should be noted that a small percentage change in theaustenite carbon content can have a significant effect on the subsequent austempering reaction changing the volume fraction of the phasespresent and hence, the resulting mechanical properties. Specimens were prepared from an unalloyed ductile cast iron, austenitised at 950oCfor 60 minutes and austempered by the conventional single-step austempering process at four temperatures between BS and MS, eg., 250,300, 350 and 400oC. The samples were austempered at these temperatures for 15, 30, 60, 120 and 240 minutes and finally quenched toambient temperature. Volume fractions of retained austenite and carbon concentration in the residual austenite have been observed byusing X-ray diffraction. Additionally, carbon concentration in the residual austenite was calculated using volume fraction data of austeniteand a model developed by Bhadeshia based on the McLellan and Dunn quasi-chemical thermodynamic model. The comparison ofexperimental data with the T0, T0' and Ae3' phase boundaries suggests the likely mechanism of bainite reaction in cast iron is displacive rather than diffusional. The carbon concentration in retained austenite demonstrates that at the end of bainite reaction the microstructure must consist of not only ausferrite but additionally precipitated carbides.

  15. Concentrated Solar Thermoelectric Power

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Gang [MIT; Ren, Zhifeng [University of Houston

    2015-07-09

    The goal of this project is to demonstrate in the lab that solar thermoelectric generators (STEGs) can exceed 10% solar-to-electricity efficiency, and STEGs can be integrated with phase-change materials (PCM) for thermal storage, providing operation beyond daylight hours. This project achieved significant progress in many tasks necessary to achieving the overall project goals. An accurate Themoelectric Generator (TEG) model was developed, which included realistic treatment of contact materials, contact resistances and radiative losses. In terms of fabricating physical TEGs, high performance contact materials for skutterudite TE segments were developed, along with brazing and soldering methods to assemble segmented TEGs. Accurate measurement systems for determining device performance (in addition to just TE material performance) were built for this project and used to characterize our TEGs. From the optical components’ side, a spectrally selective cermet surface was developed with high solar absorptance and low thermal emittance, with thermal stability at high temperature. A measurement technique was also developed to determine absorptance and total hemispherical emittance at high temperature, and was used to characterize the fabricated spectrally selective surfaces. In addition, a novel reflective cavity was designed to reduce radiative absorber losses and achieve high receiver efficiency at low concentration ratios. A prototype cavity demonstrated that large reductions in radiative losses were possible through this technique. For the overall concentrating STEG system, a number of devices were fabricated and tested in a custom built test platform to characterize their efficiency performance. Additionally, testing was performed with integration of PCM thermal storage, and the storage time of the lab scale system was evaluated. Our latest testing results showed a STEG efficiency of 9.6%, indicating promising potential for high performance concentrated STEGs.

  16. Vapor concentration monitor

    Science.gov (United States)

    Bayly, John G.; Booth, Ronald J.

    1977-01-01

    An apparatus for monitoring the concentration of a vapor, such as heavy water, having at least one narrow bandwidth in its absorption spectrum, in a sample gas such as air. The air is drawn into a chamber in which the vapor content is measured by means of its radiation absorption spectrum. High sensitivity is obtained by modulating the wavelength at a relatively high frequency without changing its optical path, while high stability against zero drift is obtained by the low frequency interchange of the sample gas to be monitored and of a reference sample. The variable HDO background due to natural humidity is automatically corrected.

  17. Uranium concentration in fossils

    International Nuclear Information System (INIS)

    Okano, J.; Uyeda, C.

    1988-01-01

    Recently it is known that fossil bones tend to accumulate uranium. The uranium concentration, C u in fossils has been measured so far by γ ray spectroscopy or by fission track method. The authors applied secondary ion mass spectrometry, SIMS, to detect the uranium in fossil samples. The purpose of this work is to investigate the possibility of semi-quantitative analyses of uranium in fossils, and to study the correlation between C u and the age of fossil bones. The further purpose of this work is to apply SIMS to measure the distribution of C u in fossil teeth

  18. Boric acid concentration monitoring

    International Nuclear Information System (INIS)

    Kysela, J.; Mickal, V.; Racek, J.

    1978-01-01

    Boric acid concentration was measured by thermal neutron absorption in the study of the boric acid sorption and desorption curves on an anion exchange resin. Ra-Be 18.5 GBq and Am-Be 111 GBq sources and water as a moderator were used. The SNM 12 cylindrical corona detector with 10 B placed in the middle of the measuring cell was used for neutron flux measurement. The HP 9600 E computer system was used for measured data collection and evaluation. (Ha)

  19. Dual temperature concentration system

    International Nuclear Information System (INIS)

    Spevack, J.S.

    1975-01-01

    In a dual temperature isotope exchange system--exemplified by exchange of deuterium and protium between water and hydrogen sulfide gas in hot and cold towers, in which the feed stream (water) containing the desired isotope is passed through a pair of towers maintained at different temperatures wherein it effects isotope exchange with countercurrently circulated auxiliary fluid (H 2 S) and is impoverished in said isotope and then disposed of, e.g. discharged to waste,--the flow of isotope enriched auxiliary fluid between said towers (hot H 2 S saturated with water vapor) is divided and a part thereof is adjusted in its temperature (to cold tower conditions) and then passed to the auxiliary fluid impoverishing (cold) tower, while the remainder of the divided flow of such enriched auxiliary fluid is passed through a subsequent isotope concentration treatment to produce a product more highly enriched in the desired isotope and wherein it is also adjusted in its temperature and is impoverished in said isotope during said subsequent treatment before it is delivered to the said auxiliary fluid impoverishing (cold) tower. Certain provisions are made for returning to the hot tower liquid carried as vapor by the remainder of the divided flow to the subsequent isotope concentration treatment, for recovering sensible and latent heat, and for reducing passage of auxiliary fluid to waste

  20. The luminescent concentrator illuminated

    Energy Technology Data Exchange (ETDEWEB)

    Slooff, L.H.; Kinderman, R.; Burgers, A.R.; Van Roosmalen, J.A.M. [ECN Solar Energy, Petten (Netherlands); Buechtemann, A.; Danz, R. [Fraunhofer Institute for Applied Polymer Research, Geiselbergstr. 69, D-14476 Golm (Germany); Meyer, T.B. [Solaronix SA, Rue de l' Ouriette 129, CH-1170 Aubonne (Switzerland); Chatten, A.J.; Farell, D.; Barnham, K.W.J. [Physics Department, Imperial College London, SW7 2BW (United Kingdom)

    2006-04-15

    Luminescent concentrator (LC) plates with different dyes were combined with standard multicrystalline silicon solar cells. External quantum efficiency measurements were performed, showing an increase in electrical current of the silicon cell (under AM1.5, 1 sun conditions, at normal incidence) compared to a bare cell. The influence of dye concentration and plate dimensions are addressed. The best results show a 1.7 times increase in the current from the LC/silicon cell compared to the silicon cell alone. This corresponds to an increase in power conversion efficiency of the silicon cell from 15 to 25%. To broaden the absorption spectrum of the LC, a second dye was incorporated in the LC plates. This results in a relative increase of 5-8% with respect to the one dye LC, giving a maximum power conversion efficiency of 26% on cell area. Using an extended ray-tracing model transmission, reflection and external quantum efficiency spectra were simulated and compared with measured spectra. The simulations deliver the luminescent quantum efficiencies of the two dyes as well as the background absorption by the polymer host. It is found that the quantum efficiency of the red emitting dye is 87%, which is one of the major loss factors in the measured LC. Using ray-tracing simulations it can be predicted that increasing the quantum efficiency to 95% would reduce this loss by almost 30%.

  1. Luminescent solar concentrator

    Directory of Open Access Journals (Sweden)

    Tugce Tosun

    2015-07-01

    Full Text Available Luminescent solar concentrator (LSC is a device that has luminescent molecules embedding or topping polymeric or glass waveguide to generate electricity from sunlight with a photovoltaic cell attachment. LSCs can be employed both in small and large scale projects, independent on the direction or angle of the surface with respect to the sun, promising more freedom for integration in urban environments compared to the traditional PV systems. The aim of the SEB&C PDEng project is to investigate the applicability of this innovative technology in the built environment and to bridge the gap of knowledge linking societal, design and technological aspects. The final goal is to exhibit potential application concepts of LSC developed by co-creative methods at SPARK campus which is a hub for open innovation in built environment. Necessity of a paradigm shift towards sustainable and smart cities came into being due to the significant increase in energy demand of the buildings. The challenge is to increase renewable sources in the energy mix while designing aesthetic environments. Thus, building integrated renewable energy technologies represent a great opportunity to help overcome this current challenge. Smart energy, energy efficiency and use of renewable sources are key aspects to be considered nowadays and many innovative technologies need further exploitation to be commercially viable, such as luminescent solar concentrator.

  2. Concentration solar thermal power

    International Nuclear Information System (INIS)

    Livet, F.

    2011-01-01

    As the production of electricity by concentration solar power (CSP) installations is said to be a source of energy for the future, the author discusses past experiments (notably the French Thermis project), and the different techniques which are currently being used. He indicates the regions which appear to be the most appropriate for this technique. He presents the three main techniques: parabolic cylinder, tower, and Stirling cycle installations. He discusses the issue of intermittency. He proposes an assessment of prices and of their evolution, and indicates the investments made in different installations (in Italy, Spain, Germany and Portugal). He comments the case of hybrid installations (sun and gas), evokes the Desertec project proposed by the German industry which comprises a set of hybrid installations. He notices that there is no significant technological evolution for this process

  3. Stress concentration at notches

    CERN Document Server

    Savruk, Mykhaylo P

    2017-01-01

    This book compiles solutions of linear theory of elasticity problems for isotropic and anisotropic bodies with sharp and rounded notches. It contains an overview of established and recent achievements, and presents the authors’ original solutions in the field considered with extensive discussion. The volume demonstrates through numerous, useful examples the effectiveness of singular integral equations for obtaining exact solutions of boundary problems of the theory of elasticity for bodies with cracks and notches. Incorporating analytical and numerical solutions of the problems of stress concentrations in solid bodies with crack-like defects, this volume is ideal for scientists and PhD students dealing with the problems of theory of elasticity and fracture mechanics. Stands as a modern and extensive compendium of solutions to the problems of linear theory of elasticity of isotropic and anisotropic bodies with sharp and rounded notches; Adopts a highly reader-friendly layout of tables, charts, approximation ...

  4. Concentrating Solar Power

    Energy Technology Data Exchange (ETDEWEB)

    Weinstein, Lee A.; Loomis, James; Bhatia, Bikram; Bierman, David M.; Wang, Evelyn N.; Chen, Gang

    2015-12-09

    Solar energy is a bountiful renewable energy resource: the energy in the sunlight that reaches Earth in an hour exceeds the energy consumed by all of humanity in a year.(1) While the phrase “solar energy conversion” probably brings photovoltaic (PV) cells to mind first, PV is not the only option for generating electricity from sunlight. Another promising technology for solar energy conversion is solar–thermal conversion, commonly referred to as concentrating solar power (CSP).(2) The first utility-scale CSP plants were constructed in the 1980s, but in the two decades that followed, CSP saw little expansion.(3, 4) More recent years, however, have seen a CSP renaissance due to unprecedented growth in the adoption of CSP.(3, 5) Photographs of two operating CSP plants, a parabolic trough collector plant and a central receiver (or “power tower”), are shown here.

  5. Concentrating solar thermal power.

    Science.gov (United States)

    Müller-Steinhagen, Hans

    2013-08-13

    In addition to wind and photovoltaic power, concentrating solar thermal power (CSP) will make a major contribution to electricity provision from renewable energies. Drawing on almost 30 years of operational experience in the multi-megawatt range, CSP is now a proven technology with a reliable cost and performance record. In conjunction with thermal energy storage, electricity can be provided according to demand. To date, solar thermal power plants with a total capacity of 1.3 GW are in operation worldwide, with an additional 2.3 GW under construction and 31.7 GW in advanced planning stage. Depending on the concentration factors, temperatures up to 1000°C can be reached to produce saturated or superheated steam for steam turbine cycles or compressed hot gas for gas turbine cycles. The heat rejected from these thermodynamic cycles can be used for sea water desalination, process heat and centralized provision of chilled water. While electricity generation from CSP plants is still more expensive than from wind turbines or photovoltaic panels, its independence from fluctuations and daily variation of wind speed and solar radiation provides it with a higher value. To become competitive with mid-load electricity from conventional power plants within the next 10-15 years, mass production of components, increased plant size and planning/operating experience will be accompanied by technological innovations. On 30 October 2009, a number of major industrial companies joined forces to establish the so-called DESERTEC Industry Initiative, which aims at providing by 2050 15 per cent of European electricity from renewable energy sources in North Africa, while at the same time securing energy, water, income and employment for this region. Solar thermal power plants are in the heart of this concept.

  6. Workplace Concentration of Immigrants

    Science.gov (United States)

    Andersson, Fredrik; García-Pérez, Mónica; Haltiwanger, John; McCue, Kristin; Sanders, Seth

    2014-01-01

    Casual observation suggests that in most U.S. urban labor markets, immigrants have more immigrant coworkers than native-born workers do. While seeming obvious, this excess tendency to work together has not been precisely measured, nor have its sources been quantified. Using matched employer–employee data from the U.S. Census Bureau Longitudinal Employer-Household Dynamics (LEHD) database on a set of metropolitan statistical areas (MSAs) with substantial immigrant populations, we find that, on average, 37% of an immigrant’s coworkers are themselves immigrants; in contrast, only 14% of a native-born worker’s coworkers are immigrants. We decompose this difference into the probability of working with compatriots versus with immigrants from other source countries. Using human capital, employer, and location characteristics, we narrow the mechanisms that might explain immigrant concentration. We find that industry, language, and residential segregation collectively explain almost all the excess tendency to work with immigrants from other source countries, but they have limited power to explain work with compatriots. This large unexplained compatriot component suggests an important role for unmeasured country-specific factors, such as social networks. PMID:25425452

  7. Conical electromagnetic radiation flux concentrator

    Science.gov (United States)

    Miller, E. R.

    1972-01-01

    Concentrator provides method of concentrating a beam of electromagnetic radiation into a smaller beam, presenting a higher flux density. Smaller beam may be made larger by sending radiation through the device in the reverse direction.

  8. Concentrating on caustic

    International Nuclear Information System (INIS)

    Collins, Richard

    2010-01-01

    Full text: First there was the Beer Battery, which aimed to generate electricity from brewery wastewater using a microbial fuel cell (MFC). Trials at Foster's Yatala brewery in Queensland in 2007 ran into challenges around the cost of electricity and duration of treatment, but they also revealed a new possibility. Komeel Rabaey, a University of Queensland specialist in microbial dynamics with a particular passion for bioelectrochemical systems, recognised the potential to extract sodium hydroxide - caustic soda - out of wastewater in a form suitable for reuse. In 2008 he converted such a system into a lab-scale caustic recovery plant, then upsized it to a one litre test reactor, which is again running at the Yatala brewery. The concept flips wastewater treatment on its head, seeing the discharge as a resource to be harvested rather than a cost and a contaminant load to be managed. “We typically aim to make a concentration of about four per cent caustic. That is what is easily achievable with the system and you will also note a lot of industries use caustic at four per cent,” said Dr Rabaey. “So you can use the wastewater from the plant to drive caustic production, with the extra advantage of removing enormous amounts of sodium.” Sodium hydroxide is a ubiquitous industrial compound used in pH regulation, as a cleaning agent in clean-in-place systems and variously in pulp and paper, textiles and food processing. Dr Rabaey wants to close the loop on caustic. Industries along the Murray-Darling basin, for example, truck in a lot of it from outside the area and then discharge it with their wastewater into the salt-sensitive river system. “If you use a bioelectrochemical system to recover the sodium hydroxide, you are not even importing the sodium into the area but recycling the sodium the whole time on-site,” he told WME. Get the technology right and he reckons a three-year payback on investment is readily achievable. A microbial fuel cell oxidises

  9. [Ozone concentration distribution of urban].

    Science.gov (United States)

    Yin, Yong-quan; Li, Chang-mei; Ma, Gui-xia; Cui, Zhao-jie

    2004-11-01

    The increase of ozone concentration in urban is one of the most important research topics on environmental science. With the increase of nitrogen oxides and hydrogen-carbon compounds which are exhausted from cars, the ozone concentration in urban is obviously increased on sunlight, and threat of photochemistry smog will be possible. Therefore, it is very important to monitor and study the ozone concentration distribution in urban. The frequency-distribution, diurnal variation and monthly variation of ozone concentration were studied on the campus of Shandong University during six months monitoring. The influence of solar radiation and weather conditions on ozone concentration were discussed. The frequency of ozone concentration less than 200 microg/m3 is 96.88%. The ozone concentration has an obvious diurnal variation. The ozone concentration in the afternoon is higher than in the morning and in the evening. The maximum appears in June, when it is the strong solar radiation and high air-temperature. The weather conditions also influence the ozone concentration. The ozone concentration in clear day is higher than in rainy and cloudy day.

  10. Low concentrator PV optics optimization

    Science.gov (United States)

    Sharp, Leonard; Chang, Ben

    2008-08-01

    Purpose: Cost reduction is a major focus of the solar industry. Thin film technologies and concentration systems are viable ways to reducing cost, with unique strengths and weakness for both. Most of the concentrating PV work focuses on high concentration systems for reducing energy cost. Meanwhile, many believe that low concentrators provide significant cost reduction potential while addressing the mainstream PV market with a product that acts as a flat panel replacement. This paper analyzes the relative benefit of asymmetric vs. symmetric optics for low-concentrators in light of specific PV applications. Approach: Symmetric and asymmetric concentrating PV module performance is evaluated using computer simulation to determine potential value across various geographic locations and applications. The selected optic design is modeled against standard cSi flat panels and thin film to determine application fit, system level energy density and economic value. Results: While symmetric designs may seem ideal, asymmetric designs have an advantage in energy density. Both designs are assessed for aperture, optimum concentration ratio, and ideal system array configuration. Analysis of performance across climate specific effects (diffuse, direct and circumsolar) and location specific effects (sunpath) are also presented. The energy density and energy production of low concentrators provide a compelling value proposition. More significantly, the choice of optics for a low concentrating design can affect real world performance. With the goal of maximizing energy density and return on investment, this paper presents the advantages of asymmetric optic concentration and illustrates the value of this design within specific PV applications.

  11. Bruise chromophore concentrations over time

    Science.gov (United States)

    Duckworth, Mark G.; Caspall, Jayme J.; Mappus, Rudolph L., IV; Kong, Linghua; Yi, Dingrong; Sprigle, Stephen H.

    2008-03-01

    During investigations of potential child and elder abuse, clinicians and forensic practitioners are often asked to offer opinions about the age of a bruise. A commonality between existing methods of bruise aging is analysis of bruise color or estimation of chromophore concentration. Relative chromophore concentration is an underlying factor that determines bruise color. We investigate a method of chromophore concentration estimation that can be employed in a handheld imaging spectrometer with a small number of wavelengths. The method, based on absorbance properties defined by Beer-Lambert's law, allows estimation of differential chromophore concentration between bruised and normal skin. Absorption coefficient data for each chromophore are required to make the estimation. Two different sources of this data are used in the analysis- generated using Independent Component Analysis and taken from published values. Differential concentration values over time, generated using both sources, show correlation to published models of bruise color change over time and total chromophore concentration over time.

  12. Rhenium concentration during petroleum deasphalting

    International Nuclear Information System (INIS)

    Troshkina, I.D.; Bel'kova, M.N.

    1994-01-01

    Rhenium distribution and concentration during fractional distillation of certain types of petroleum and natural bitumens from Tatarstan are studied. Rhenium concentration in the process of oil deasphalting is examined for petroleum produced by different techniques, as well as for heavy residues from petroleum distillation. Optimum conditions for the process are revealed fractions of resinous-asphaltene substances concentrating rhenium compounds are found. 5 refs., 3 tabs

  13. Ideal 3D asymmetric concentrator

    Energy Technology Data Exchange (ETDEWEB)

    Garcia-Botella, Angel [Departamento Fisica Aplicada a los Recursos Naturales, Universidad Politecnica de Madrid, E.T.S.I. de Montes, Ciudad Universitaria s/n, 28040 Madrid (Spain); Fernandez-Balbuena, Antonio Alvarez; Vazquez, Daniel; Bernabeu, Eusebio [Departamento de Optica, Universidad Complutense de Madrid, Fac. CC. Fisicas, Ciudad Universitaria s/n, 28040 Madrid (Spain)

    2009-01-15

    Nonimaging optics is a field devoted to the design of optical components for applications such as solar concentration or illumination. In this field, many different techniques have been used for producing reflective and refractive optical devices, including reverse engineering techniques. In this paper we apply photometric field theory and elliptic ray bundles method to study 3D asymmetric - without rotational or translational symmetry - concentrators, which can be useful components for nontracking solar applications. We study the one-sheet hyperbolic concentrator and we demonstrate its behaviour as ideal 3D asymmetric concentrator. (author)

  14. Fructosamine concentrations in hyperglycemic cats.

    Science.gov (United States)

    Lutz, T A; Rand, J S; Ryan, E

    1995-03-01

    The aims of this study were 1) to establish a reference range for fructosamine in cats using a commercial fructosamine kit; 2) to demonstrate that the fructosamine concentration is not increased by transient hyperglycemia of 90 min duration, simulating hyperglycemia of acute stress; and 3) to determine what percentage of blood samples submitted to a commercial laboratory from 95 sick cats had evidence of persistent hyperglycemia based on an elevated fructosamine concentration. Reference intervals for the serum fructosamine concentration were established in healthy, normoglycemic cats using a second generation kit designed for the measurement of the fructosamine concentration in humans. Transient hyperglycemia of 90 min duration was induced by IV glucose injection in healthy cats. Multisourced blood samples that were submitted to a commercial veterinary laboratory either as fluoride oxalated plasma or serum were used to determine the percentage of hyperglycemic cats having persistent hyperglycemia. The reference interval for the serum fructosamine concentration was 249 to 406 mumol/L. Transient hyperglycemia of 90 min duration did not increase the fructosamine concentration and there was no correlation between fructosamine and blood glucose. In contrast, the fructosamine concentration was correlated with the glucose concentration in sick hyper- and normoglycemic cats. It is concluded that the fructosamine concentration is a useful marker for the detection of persistent hyperglycemia and its differentiation from transient stress hyperglycemia. Fructosamine determinations should be considered when blood glucose is 12 to 20 mmol/L and only a single blood sample is available for analysis.

  15. Aplanatic optics for solar concentration.

    Science.gov (United States)

    Gordon, Jeffrey M

    2010-04-26

    Aplanats are imaging optics that completely eliminate both spherical aberration and coma. They can fulfill the practical virtues of permitting sizable gaps between the absorber and the optic, as well as compactness. However, the ability of aplanats to efficiently approach the thermodynamic limit to flux concentration and optical tolerance had remained unrecognized. Both fundamental and applied aspects of dual-mirror aplanats are reviewed and elaborated, motivated by the exigencies of tenable, maximum-performance solar concentrators, including examples from commercial concentrator photovoltaics (CPV). Promising designs for future photovoltaic concentrators are also identified, illustrating how pragmatic constraints translate into devising fundamentally new optics.

  16. Continuous flow dielectrophoretic particle concentrator

    Science.gov (United States)

    Cummings, Eric B [Livermore, CA

    2007-04-17

    A continuous-flow filter/concentrator for separating and/or concentrating particles in a fluid is disclosed. The filter is a three-port device an inlet port, an filter port and a concentrate port. The filter separates particles into two streams by the ratio of their dielectrophoretic mobility to their electrokinetic, advective, or diffusive mobility if the dominant transport mechanism is electrokinesis, advection, or diffusion, respectively.Also disclosed is a device for separating and/or concentrating particles by dielectrophoretic trapping of the particles.

  17. concentration

    Directory of Open Access Journals (Sweden)

    Seth F. Oppenheimer

    1999-01-01

    Full Text Available We consider a model for biochemical oxygen demand (BOD in a semi-infinite river where the BOD is prescribed by a time varying function at the left endpoint. That is, we study the problem with a time varying boundary loading. We obtain the well-posedness for the model when the boundary loading is smooth in time. We also obtain various qualitative results such as ordering, positivity, and boundedness. Of greatest interest, we show that a periodic loading function admits a unique asymptotically attracting periodic solution. For non-smooth loading functions, we obtain weak solutions. Finally, for certain special cases, we show how to obtain explicit solutions in the form of infinite series.

  18. Optimal concentrations in transport systems

    Science.gov (United States)

    Jensen, Kaare H.; Kim, Wonjung; Holbrook, N. Michele; Bush, John W. M.

    2013-01-01

    Many biological and man-made systems rely on transport systems for the distribution of material, for example matter and energy. Material transfer in these systems is determined by the flow rate and the concentration of material. While the most concentrated solutions offer the greatest potential in terms of material transfer, impedance typically increases with concentration, thus making them the most difficult to transport. We develop a general framework for describing systems for which impedance increases with concentration, and consider material flow in four different natural systems: blood flow in vertebrates, sugar transport in vascular plants and two modes of nectar drinking in birds and insects. The model provides a simple method for determining the optimum concentration copt in these systems. The model further suggests that the impedance at the optimum concentration μopt may be expressed in terms of the impedance of the pure (c = 0) carrier medium μ0 as μopt∼2αμ0, where the power α is prescribed by the specific flow constraints, for example constant pressure for blood flow (α = 1) or constant work rate for certain nectar-drinking insects (α = 6). Comparing the model predictions with experimental data from more than 100 animal and plant species, we find that the simple model rationalizes the observed concentrations and impedances. The model provides a universal framework for studying flows impeded by concentration, and yields insight into optimization in engineered systems, such as traffic flow. PMID:23594815

  19. Radon concentration in The Netherlands

    International Nuclear Information System (INIS)

    Meijer, R.J. de; Put, L.W.; Veldhuizen, A.

    1986-02-01

    In 1000 dwellings, which can be assumed to be an reasonable representation of the average Dutch dwellings, time averaged radon concentrations, radon daughter concentrations and gamma-exposure tempi are determined during a year with passive dosemeters. They are also determined outdoor at circa 200 measure points. (Auth.)

  20. School concentration and school travel

    NARCIS (Netherlands)

    De Boer, E.

    2010-01-01

    The purpose of the research as described in this Doctor’s thesis is twofold. Firstly it is to define in how far Dutch facilities for primary and secondary education were subjected to spatial concentration during recent decades. Secondly it is intended to assess what this concentration implied for

  1. Concentrations of Polychlorinated Biphenyls (PCBs ...

    African Journals Online (AJOL)

    MICHAEL

    ABSTRACT: Concentrations of polychlorinated biphenyls (PCBs), polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs), and polybrominated diphenyl ethers (PBDEs) were examined as a function of depth in killer whale (Orcinus orca) blubber samples. Lipid-normalized concentrations of PCBs, PCDD/Fs, and ...

  2. Ownership concentration and bank profitability

    Directory of Open Access Journals (Sweden)

    Peterson Kitakogelu Ozili

    2017-12-01

    Full Text Available We investigate whether ownership concentration influences bank profitability in a developing country context. We focus on bank ownership concentration measured as the amount of direct equity held by a majority shareholder categorised into: high ownership concentration, moderate ownership concentration and disperse ownership. We find that banks with high ownership concentration have higher return on assets, higher net interest margin and higher recurring earning power while banks with dispersed ownership have lower return on assets but have higher return on equity. Also, higher cost efficiency improves the return on assets of widely-held banks and the return on equity of banks with moderate ownership. The findings have implications. JEL: Code: G3, G34, G31, Keywords: Corporate governance, Ownership structure, Agency theory, Profitability, Firm performance, Banks, Return on asset, Return on equity

  3. Ion climate and radon concentration

    International Nuclear Information System (INIS)

    Busbarna, L.

    1981-01-01

    Characteristic values of radon concentration in natural ion climate and in open air were compared and the effect of artificially produced negative ion excess on the radon concentration of air was studied. The results show that the radon concentration measurable at the rise of negative ion excess is smaller than that in the case of natural equilibrium. This effect can be utilized lowering the background of the scintillation chambers, thus increasing their sensitivity. The negative ions of the artificial ion climate lower radon concentration in closed space. The question arises whether only the ion climate is responsible for the effects on the organism and on the nervous system or the radon concentration of the air also contributes to them. (author)

  4. Altering prolactin concentrations in sows.

    Science.gov (United States)

    Farmer, C

    2016-07-01

    Prolactin has a multiplicity of actions, but it is of particular importance in gestating and lactating animals. In sows, it is involved in the control of mammary development and also holds essential roles in the lactogenic and galactopoietic processes. Furthermore, low circulating concentrations of prolactin are associated with the agalactia syndrome. The crucial role of prolactin makes it important to understand the various factors that can alter its secretion. Regulation of prolactin secretion is largely under the negative control of dopamine, and dopamine agonists consistently decrease prolactin concentrations in sows. On the other hand, injections of dopamine antagonists can enhance circulating prolactin concentrations. Besides pharmacologic agents, many other factors can also alter prolactin concentrations in sows. The use of Chinese-derived breeds, for instance, leads to increased prolactin concentrations in lactating sows compared with standard European white breeds. Numerous husbandry and feeding practices also have a potential impact on prolactin concentrations in sows. Factors, such as provision of nest-building material prepartum, housing at farrowing, high ambient temperature, stress, transient weaning, exogenous thyrotropin-releasing factor, exogenous growth hormone-releasing factor, nursing frequency, prolonged photoperiod, fasting, increased protein and/or energy intake, altered energy sources, feeding high-fiber diets, sorghum ergot or plant extracts, were all studied with respect to their prolactinemic properties. Although some of these practices do indeed affect circulating prolactin concentrations, none leads to changes as drastic as those brought about by dopamine agonists or antagonists. It appears that the numerous factors regulating prolactin concentrations in sows are still not fully elucidated, and that studies to develop novel applicable ways of increasing prolactin concentrations in sows are warranted. Crown Copyright © 2015. Published

  5. Maximum Permissible Concentrations and Negligible Concentrations for metals, taking background concentrations into account

    NARCIS (Netherlands)

    Crommentuijn T; Polder MD; Plassche EJ van de; CSR

    1997-01-01

    Maximum Permissible Concentrations (MPCs) and Negligible Concentrations (NCs) have been derived for a series of heavy metals. For some of the metals, the Ministry of Housing, Spatial Planning and the Environment (VROM) used earlier MPCs and NCs to set Environmental Quality Objectives for water,

  6. Concentrator cell status and projections

    Energy Technology Data Exchange (ETDEWEB)

    Arvizu, D.E.

    1984-08-01

    Over the last few years much work has been directed at improving conventional single crystal silicon cells for concentrator application. Although 20% efficient concentrator cells have been fabricated, the current thinking indicates that conventional silicon devices are approaching theoretical maximums. The primary emphasis of today's Federal program for concentrating photovoltaics is directed at advanced high efficiency devices. Advanced device approaches that are being pursued include patterned diffusion silicon designs with practical efficiency limits greater than 25%, optimized conventional GaAs devices with efficiency limits near 28%, and multiple-junction structures with efficiency limits over 35%. Progress in each of these areas are reviewed.

  7. Qualification testing of photovoltaic concentrators

    International Nuclear Information System (INIS)

    Richards, E.H.; Barlow, R.S.

    1987-01-01

    Sandia has developed a revised set of specifications for qualification testing of passively-cooled photovoltaic concentrator modules. The purpose of the tests is to screen new concentrator designs and new production runs for susceptibility to known failure mechanisms; concentrator hardware must be qualified prior to array-level installation at Sandia's Photovoltaic Advanced System Test Facility (PASTF). Tests for cell assemblies and receiver sections, as well as for complete modules, are specified. They include ultraviolet radiation testing of materials, characterization of electrical performance, checks to assure safety and structural integrity of modules, and accelerated environmental aging or cycling

  8. The luminescent concentrator. Stability issues

    Energy Technology Data Exchange (ETDEWEB)

    Slooff, L.H.; Budel, T.; Burgers, A.R.; Bakker, N.J. [ECN Solar Energy, P.O.Box 1, 1755 ZG Petten (Netherlands); Buechtemann, A.; Danz, R. [Fraunhofer-Institute for Applied Polymer Research, Geiselbergstr.69, D-14476 Golm (Germany); Meyer, T.; Meyer, A. [Solaronix SA, Rue de l' Ouriette 129, CH-1170 Aubonne (Switzerland)

    2007-08-15

    One of the major challenges in the research on luminescent concentrators is the lifetime of the luminescent polymer plates. There are some commercial plates available, but data on lifetime are very limited, especially when dedicated to applications like the luminescent concentrator. In this paper we report stability experiments on luminescent concentrator plates, aged under continuous white light illumination, outdoor conditions and high intensity monochromatic illumination. The results show that the lifetime strongly depends on the organic luminescent dye in the plate. The best materials exhibit an initial decrease in performance of about 20% and then remain more or less stable. It is shown that the degradation is not caused by UV illumination.

  9. Tank waste concentration mechanism study

    International Nuclear Information System (INIS)

    Pan, L.C.; Johnson, L.J.

    1994-09-01

    This study determines whether the existing 242-A Evaporator should continue to be used to concentrate the Hanford Site radioactive liquid tank wastes or be replaced by an alternative waste concentration process. Using the same philosophy, the study also determines what the waste concentration mechanism should be for the future TWRS program. Excess water from liquid DST waste should be removed to reduce the volume of waste feed for pretreatment, immobilization, and to free up storage capacity in existing tanks to support interim stabilization of SSTS, terminal cleanout of excess facilities, and other site remediation activities

  10. Biodegradation kinetics at low concentrations (

    DEFF Research Database (Denmark)

    Toräng, Lars; Albrechtsen, Hans-Jørgen; Nyholm, Niels

    2000-01-01

    Aerobic biodegradation of 2,4-dichlorophenoxyacetic acid (2,4-D) was studied in groundwater added sediment fines. At concentrations at or below 1 mu g/L of 2,4-D degradation kinetic was of true first order without significant growth of specific degraders and with half-life for mineralization...... in the order of 200 days. Higher concentrations of 2,4-D resulted in a grossly overestimate of the actual degradation rate for concentrations characteristic for Danish found in groundwater....

  11. Overview of photovoltaic concentrator technology

    Energy Technology Data Exchange (ETDEWEB)

    Arvizu, D.E.; Edenburn, M.W.

    1984-01-01

    Concentrator photovoltaics is one of several photovoltaic approaches that could, in the future, provide reliable commercial electric power at a cost competitive with conventional sources. Since the path to providing cost competitive energy is dependent on both the conversion efficiency of the system and its installed cost, concentrators feature a unique approach in that both of these areas are pursued simultaneously. Concentrator technology has been supported by the US Department of Energy's Federal Program for nearly a decade. In that time several systems have been fielded and research has continued to push the development of high efficiency systems. This paper will present the current status and research direction of concentrator photovoltaic technology.

  12. Mie Scattering by Concentric Multilayers

    Science.gov (United States)

    Smith, David D.; Fuller, Kirk A.; Curreri, Peter A. (Technical Monitor)

    2002-01-01

    The Mie formulation for homogeneous spheres is generalized to handle concentric multilayers in a manner that exploits an analogy with stratified planar systems, enabling these structures to be treated as photonic bandgap materials.

  13. Anodic Concentration Polarization in SOFCs

    Energy Technology Data Exchange (ETDEWEB)

    Williford, Rick E.; Chick, Lawrence A.; Maupin, Gary D.; Simner, Steve P.; Stevenson, Jeffry W.; Khaleel, Mohammad A.; Wachsman, ED, et al

    2003-08-01

    Concentration polarization is important because it determines the maximum power output of a solid oxide fuel cell (SOFC) at high fuel utilization. Anodic concentration polarization occurs when the demand for reactants exceeds the capacity of the porous ceramic anode to supply them by gas diffusion mechanisms. High tortuosities (bulk diffusion resistances) are often assumed to explain this behavior. However, recent experiments show that anodic concentration polarization originates in the immediate vicinity of the reactive triple phase boundary (TPB) sites near the anode/electrolyte interface. A model is proposed to describe how concentration polarization is controlled by two localized phenomena: competitive adsorption of reactants in areas adjacent to the reactive TPB sites, followed by relatively slow surface diffusion to the reactive sites. Results suggest that future SOFC design improvements should focus on optimization of the reactive area, adsorption, and surface diffusion at the anode/electrolyte interface.

  14. Mitragynine concentrations in two fatalities.

    Science.gov (United States)

    Domingo, Olwen; Roider, Gabriele; Stöver, Andreas; Graw, Matthias; Musshoff, Frank; Sachs, Hans; Bicker, Wolfgang

    2017-02-01

    Two cases of fatalities are reported of which the recreational use of Mitragyna speciosa ("kratom") could be confirmed. One of these cases presents with one of the highest postmortem mitragynine concentrations published to date. Our results show that even extremely high mitragynine blood concentrations following the consumption of kratom do not necessarily have to be the direct cause of death in such fatalities as a result of an acute overdose. The two cases are compared with regard to the differences in mitragynine concentrations detected and the role of mitragynine in the death of the subjects. Irrespective of the big differences in mitragynine concentrations in the postmortem blood samples, mitragynine was not the primary cause of death in either of the two cases reported here. Additionally, by rough estimation, a significant difference in ratio of mitragynine to its diastereomers in the blood and urine samples between the two cases could be seen. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

  15. Fructosamine concentrations in hyperglycemic cats.

    OpenAIRE

    Lutz, T A; Rand, J S; Ryan, E

    1995-01-01

    The aims of this study were 1) to establish a reference range for fructosamine in cats using a commercial fructosamine kit; 2) to demonstrate that the fructosamine concentration is not increased by transient hyperglycemia of 90 min duration, simulating hyperglycemia of acute stress; and 3) to determine what percentage of blood samples submitted to a commercial laboratory from 95 sick cats had evidence of persistent hyperglycemia based on an elevated fructosamine concentration. Reference inter...

  16. Combined processing of lead concentrates

    Science.gov (United States)

    Kubasov, V. L.; Paretskii, V. M.; Sidorin, G. N.; Travkin, V. F.

    2013-06-01

    A combined scheme of processing of lead concentrates with the production of pure metallic lead and the important components containing in these concentrates is considered. This scheme includes sulfating roasting of the lead concentrates and two-stage leaching of the formed cinder with the formation of a sulfate solution and lead sulfate. When transformed into a carbonate form, lead sulfate is used for the production of pure metallic lead. Silver, indium, copper, cadmium, nickel, cobalt, and other important components are separately extracted from a solution. At the last stage, zinc is extracted by either extraction followed by electrolytic extraction of a metal or the return of the forming solution of sulfuric acid to cinder leaching.

  17. Concentrator-solar-cell development

    Science.gov (United States)

    Grenon, L.

    1982-07-01

    A program is described which is a continuation of earlier programs for the development of high-efficiency, low-cost, silicon concentrator solar cells. The base-line process steps and process sequences identified in these earlier contracts were evaluated and specific processes reviewed. In particular, emphasis on the use of Czochralski-grown silicon wafers rather than float-zone wafers were examined. Additionally, a study of the trade-offs between textured and nontextured cells was initiated, and the limits within which the low-cost plated nickel copper metallization can be used in concentrator solar cell applications was identified.

  18. Positron flux concentrator - an update

    International Nuclear Information System (INIS)

    Bulos, F.

    1984-01-01

    The type of concentrator that has been under study (on and off) for the last two years is shown. The work was started by Dave Sherden and Co., and the object of the study was (and still is) to determine the correct parameters which will give the correct field in the central region which captures the maximum number of e + 's from the target. This note contains two sections. The first is a simplified model which seems to agree with most of the measurements carried out. The second describes the set up, a typical example of the field's shape and amplitude and the electrical requirements for the final concentrator

  19. Improved ATIR concentrator photovoltaic module

    Science.gov (United States)

    Adriani, Paul M.; Mao, Erwang

    2013-09-01

    Novel aggregated total internal reflection (ATIR) concentrator photovoltaic module design comprises 2-D shaped primary and secondary optics that effectively combine optical efficiency, low profile, convenient range of acceptance angles, reliability, and manufacturability. This novel optical design builds upon previous investigations by improving the shapes of primary and secondary optics to enable improved long-term reliability and manufacturability. This low profile, low concentration (5x to 10x) design fits well with one-axis trackers that are often used for flat plate crystalline silicon photovoltaic modules in large scale ground mount installations. Standard mounting points, materials, and procedures apply without changes from flat plate modules.

  20. Gravimetric determination of phospholipid concentration.

    Science.gov (United States)

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

    2012-09-01

    Accurate determination of lipid concentrations is an obligatory routine in a research laboratory engaged in studies using this class of biomaterials. For phospholipids, this is frequently accomplished using the phosphate assay (Bartlett, G.R. Phosphorus Assay in Column Chromatography. J. Biol. Chem. 234, 466-468, 1959). Given the purity of the currently commercially available synthetic and isolated natural lipids, we have observed that determination of the dry weight of lipid stock solutions provides the fastest, most accurate, and generic method to assay their concentrations. The protocol described here takes advantage of the high resolution and accuracy obtained by modern weighing technology. We assayed by this technique the concentrations of a number of phosphatidylcholine samples, with different degrees of acyl chain saturation and length, and in different organic solvents. The results were compared with those from Bartlett assay, (31)P NMR, and Langmuir compression isotherms. The data obtained show that the gravimetric assay yields lipid concentrations with a resolution similar or better than obtained by the other techniques. Copyright © 2012 Elsevier Ireland Ltd. All rights reserved.

  1. Flow properties of concentrated suspensions

    Science.gov (United States)

    Hattori, K.; Izumi, K.

    1984-04-01

    The viscosity and flow behavior of a concentrated suspension, with special emphasis on fresh concrete containing a superplasticizer, is analyzed according to Newton's law of viscosity. The authors interpreted Newton's law in a new way, and explain non-Newton flow from Newton's law. The outline of this new theory is given. Viscosity of suspensions, and the effect of dispersants are analyzed.

  2. Particle interactions in concentrated suspensions

    International Nuclear Information System (INIS)

    Mondy, L.A.; Graham, A.L.; Abbott, J.R.; Brenner, H.

    1993-01-01

    An overview is presented of research that focuses on slow flows of suspensions in which colloidal and inertial effects are negligibly small. The authors describe nuclear magnetic resonance imaging experiments to quantitatively measure particle migration occurring in concentrated suspensions undergoing a flow with a nonuniform shear rate. These experiments address the issue of how the flow field affects the microstructure of suspensions. In order to understand the local viscosity in a suspension with such a flow-induced, spatially varying concentration, one must know how the viscosity of a homogeneous suspension depends on such variables as solids concentration and particle orientation. The authors suggest the technique of falling ball viscometry, using small balls, as a method to determine the effective viscosity of a suspension without affecting the original microstructure significantly. They also describe data from experiments in which the detailed fluctuations of a falling ball's velocity indicate the noncontinuum nature of the suspension and may lead to more insights into the effects of suspension microstructure on macroscopic properties. Finally, they briefly describe other experiments that can be performed in quiescent suspensions (in contrast to the use of conventional shear rotational viscometers) in order to learn more about boundary effects in concentrated suspensions

  3. Lime, agent to uranium concentration

    International Nuclear Information System (INIS)

    Mouret, P.; Le Bris, J.; Kremer, M.

    1958-01-01

    Choice of the process according to health requirements. Description of the process: dissolution of uranium by sulfuric leaching of ores, precipitation of uranium by lime, re-dissolution of the concentrate with nitric ions, purification by T.B.P. finally resulting in pure uranyl nitrate solution containing 400 g/litre. (author) [fr

  4. Quantum Dot Luminescent Concentrator Cavity Exhibiting 30-fold Concentration

    Energy Technology Data Exchange (ETDEWEB)

    Bronstein, Noah D.; Yao, Yuan; Xu, Lu; O’Brien, Erin; Powers, Alexander S.; Ferry, Vivian E. [Department; Alivisatos, A. Paul [Materials; Nuzzo, Ralph G.

    2015-08-21

    Luminescent solar concentrators doped with CdSe/CdS quantum dots provide a potentially low-cost and high-performance alternative to costly high-band-gap III–V semiconductor materials to serve as a top junction in multijunction photovoltaic devices for efficient utilization of blue photons. In this study, a photonic mirror was coupled with such a luminescent waveguide to form an optical cavity where emitted luminescence was trapped omnidirectionally. By mitigating escape cone and scattering losses, 82% of luminesced photons travel the length of the waveguide, creating a concentration ratio of 30.3 for blue photons in a waveguide with a geometric gain of 61. Further, we study the photon transport inside the luminescent waveguide, showing unimpeded photon collection across the entire length of the waveguide.

  5. Rotating concentric homogeneous turbulence centrifuge

    International Nuclear Information System (INIS)

    Leith, W.C.

    1976-01-01

    A gas centrifuge and a method are described for the separation of isotopic gaseous mixtures, particularly for the enrichment of uranium by the evaporative, concurrent-flow and countercurrent-flow principles using Taylor circular Couette motion. Gaseous isotopes either alone or mixed with a carrier gas, more particularly uranium isotopes in mixture with uranium hexafluoride carrier gas, are fed to a rotor assembly of a gas centrifuge which comprises two concentric cylinders which may be rotated at the same or at different angular velocities and in the same or opposite directions to create centrifugal forces sufficient to diffuse the heavier fraction of the gas mixture to the periphery of the assembly and the lighter fraction towards the axial portion of the assembly. The rotor comprises an inner, perforate, rotatable cylinder and an outer, continuous, smooth-walled, rotatable cylinder concentric with the inner cylinder and defining an annulus therebetween. 14 claims, 5 figures

  6. Concentrations: Recent Developments in Italy

    Directory of Open Access Journals (Sweden)

    Claudio Tesauro

    2015-10-01

    Full Text Available Recent Italian developments in antitrust concentrations was the topic I was assigned to address at the conference held on 23 April to celebrate the first anniversary of the Italian Antitrust Review. What is immediately clear is that far fewer concentrations have been notified over the last few years. This is probably due to the economic crisis, which caused a reduction in corporate transactions; but also the changes to the turnover thresholds for notification seem to have had a significant impact. Consequently, an interesting debate is underway regarding the need for further changes the threshold system. Moreover, the drastic market developments and the subsequent increased number of decisions to revise remedies should also be further examined. These two issues are the subject of this paper.

  7. Concentrated solar power: an overview

    International Nuclear Information System (INIS)

    Najam, Z.; Khan, M.I.

    2011-01-01

    Solar thermal power is a relatively new technology and a fine arrangement for the provision of Electrical Energy and Clean Energy in general .The concentrated solar offers a viable option for the Sunny Zones of the world. The efficiency of the System depends on a few factors like Area, Intensity of Sunlight, Type of receiver, Hybridisation etc. Solar Thermal Systems employ lenses or mirrors to focus a large area of sunlight onto a small area. Electrical power is produced when the concentrated light is impugned onto photovoltaic cell made surfaces or used to heat a transfer fluid for a conventional power plant. In this paper we give a brief overview of a baseline Solar Thermal Power Plant, Technological details, Cost and Benefit analysis, a glimpse of solar thermal power and future of solar thermal power. (author)

  8. Nanocrystals for luminescent solar concentrators.

    Science.gov (United States)

    Bradshaw, Liam R; Knowles, Kathryn E; McDowall, Stephen; Gamelin, Daniel R

    2015-02-11

    Luminescent solar concentrators (LSCs) harvest sunlight over large areas and concentrate this energy onto photovoltaics or for other uses by transporting photons through macroscopic waveguides. Although attractive for lowering solar energy costs, LSCs remain severely limited by luminophore reabsorption losses. Here, we report a quantitative comparison of four types of nanocrystal (NC) phosphors recently proposed to minimize reabsorption in large-scale LSCs: two nanocrystal heterostructures and two doped nanocrystals. Experimental and numerical analyses both show that even the small core absorption of the leading NC heterostructures causes major reabsorption losses at relatively short transport lengths. Doped NCs outperform the heterostructures substantially in this critical property. A new LSC phosphor is introduced, nanocrystalline Cd(1-x)Cu(x)Se, that outperforms all other leading NCs by a significant margin in both small- and large-scale LSCs under full-spectrum conditions.

  9. Biological concentration of 3H

    International Nuclear Information System (INIS)

    Moghissi, A.A.; Bretthauer, E.W.; Patzer, R.G.

    1987-01-01

    In a three-year study, the possible biological concentration of 3 H in rabbits was investigated. Tritiated water was used to grow alfalfa that was used exclusively as feed for the rabbits. Feed and water were kept at a constant 3 H-to- 1 H ratio. The foundation group consisted of 18 female rabbits maintained on a 3 H diet for 2 wk before mating. The subsequent generations were maintained with tritiated water and feed. At appropriate intervals, animals were sacrificed and selected tissues were analyzed for 3 H. The specific activity of 3 H in aqueous and organic fractions of tissues of all the animals remained essentially equal to that in the original water and feed. Results of this experiment indicate that under the steady-state equilibrium conditions of the experiment, no preferential concentration of 3 H in animals occurred

  10. Hydrodynamic interactions in concentrated solutions

    International Nuclear Information System (INIS)

    Walrand, Stephan

    1986-01-01

    This research thesis addresses the dynamics of concentrated solutions processed within the frame of the primitive model: charged spherical particles immersed in a viscous solvent. At high concentration, dynamics is determined by hydrodynamic interactions of n bodies. As a direct exploitation of these interactions is impossible, the author used an average field theory based on the use of effective mobility tensor, solution of the screened Navier-Stokes equation. The tensor is explicitly calculated by using the induced force formalism developed by Mazur and van Saarloos. The author also addressed the influence of chemical exchange on the diffusion coefficient. The Ackerson microscopic theory is generalized to include these exchanges. Thus, the mass action law is obtained through a kinetic way [fr

  11. Experience in handling concentrated tritium

    International Nuclear Information System (INIS)

    Holtslander, W.J.

    1985-12-01

    The notes describe the experience in handling concentrated tritium in the hydrogen form accumulated in the Chalk River Nuclear Laboratories Tritium Laboratory. The techniques of box operation, pumping systems, hydriding and dehydriding operations, and analysis of tritium are discussed. Information on the Chalk River Tritium Extraction Plant is included as a collection of reprints of papers presented at the Dayton Meeting on Tritium Technology, 1985 April 30 - May 2

  12. Advanced high efficiency concentrator cells

    Energy Technology Data Exchange (ETDEWEB)

    Gale, R. (Varian Associates, Inc., Palo Alto, CA (United States). Varian Research Center)

    1992-06-01

    This report describes research to develop the technology needed to demonstrate a monolithic, multijunction, two-terminal, concentrator solar cell with a terrestrial power conversion efficiency greater than 35%. Under three previous subcontracts, Varian developed many of the aspects of a technology needed to fabricate very high efficiency concentrator cells. The current project was aimed at exploiting the new understanding of high efficiency solar cells. Key results covered in this report are as follows. (1) A 1.93-eV AlGaAs/1.42-eV GaAs metal-interconnected cascade cell was manufactured with a one-sun efficiency at 27.6% at air mass 1.5 (AM1.5) global. (2) A 1.0eV InGaAs cell was fabricated on the reverse'' side of a low-doped GaAs substrate with a one-sun efficiency of 2.5% AM1.5 diffuse and a short-circuit current of 14.4 mA/cm{sup 2}. (3) Small-scale manufacturing of GaAs p/n concentrator cells was attempted and obtained an excellent yield of high-efficiency cells. (4) Grown-in tunnel junction cell interconnects that are transparent and thermally stable using C and Si dopants were developed. 10 refs.

  13. Photovoltaic concentrator module improvements study

    Energy Technology Data Exchange (ETDEWEB)

    Levy, S.L.; Kerschen, K.A. (Black and Veatch, Kansas City, MO (United States)); Hutchison, G. (Solar Kinetics, Inc., Dallas, TX (United States)); Nowlan, M.J. (Spire Corp., Bedford, MA (United States))

    1991-08-01

    This report presents results of a project to design and fabricate an improved photovoltaic concentrator module. Using previous work as a baseline, this study conducted analyses and testing to select major module components and design features. The lens parquet and concentrator solar cell were selected from the highest performing, available components. A single 185X point-focus module was fabricated by the project team and tested at Sandia. Major module characteristics include a 6 by 4 compression-molded acrylic lens parquet (0.737 m{sup 2} area), twenty-four 0.2 ohms-cm, FZ, p-Si solar cells (1.56 cm{sup 2} area) soldered to ceramic substrates and copper heat spreaders, and an aluminized steel housing with corrugated bottom. This project marked the first attempt to use prismatic covers on solar cells in a high-concentration, point-focus application. Cells with 15 percent metallization were obtained, but problems with the fabrication and placement of prismatic covers on these cells lead to the decision not to use covers in the prototype module. Cell assembly fabrication, module fabrication, and module optical design activities are presented here. Test results are also presented for bare cells, cell assemblies, and module. At operating conditions of 981 watts/m{sup 2} DNI and an estimated cell temperature of 65{degrees}C, the module demonstrated an efficiency of 13.9 percent prior to stressed environmental exposure. 12 refs., 56 figs., 7 tabs.

  14. Liquids concentration process and equipment

    International Nuclear Information System (INIS)

    Chirico, A.N.

    1977-01-01

    Process for disposing of aqueous radioactive waste, consisting in heating the waste until the water it contains vaporises, passing the steam and all the droplets of radioactive water entrained into several water separators in succession, such separators being spaced out vertically and having cross section areas decreasing in the direction of flow of the steam, eliminating this steam, allowing the separated radioactive water to drop under gravity into a water recovery area, sending the radioactive water from this area to the heated liquid and eliminating the concentrated residual radioactive waster in order to discard it [fr

  15. Concentrated photovoltaics, a case study

    Directory of Open Access Journals (Sweden)

    Antonini Piergiorgio

    2014-01-01

    Full Text Available Concentrated Photovoltaics (CPV, once a niche technology, has now reached the maturity and reliability for large scale power generation. Especially in regions where temperatures are very high, the use of high efficiency triple junction solar cells with concentrating optics allows stable energy yield. Thus CPV can be seen as complementary and not in concurrence with silicon photovoltaics. The state of the art, the advantages and limitations of this technology will be shown. Among the main advantages of CPV is the possibility of a much higher energy supply, when compared to silicon photovoltaics, both comparing CPV and silicon with same area or the same installed power. The use of recycled and recyclable materials allows a more environmentally friendly production. The possibility to couple CPV with desalination facilities, energy storage will be analysed. As an example a case study of a CPV installation in Northern Italy is discussed. Here the use of mature technologies, derived from automotive and lighting sectors resulted in a simple and efficient module.

  16. Technology Roadmaps: Concentrating Solar Power

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2010-07-01

    The emerging technology known as concentrating solar power, or CSP, holds much promise for countries with plenty of sunshine and clear skies. Its electrical output matches well the shifting daily demand for electricity in places where airconditioning systems are spreading. When backed up by thermal storage facilities and combustible fuel, it offers utilities electricity that can be dispatched when required, enabling it to be used for base, shoulder and peak loads. Within about one to two decades, it will be able to compete with coal plants that emit high levels of CO2. The sunniest regions, such as North Africa, may be able to export surplus solar electricity to neighbouring regions, such as Europe, where demand for electricity from renewable sources is strong. In the medium-to-longer term, concentrating solar facilities can also produce hydrogen, which can be blended with natural gas, and provide low-carbon liquid fuels for transport and other end-use sectors. For CSP to claim its share of the coming energy revolution, concerted action is required over the next ten years by scientists, industry, governments, financing institutions and the public. This roadmap is intended to help drive these indispensable developments.

  17. Mercury concentration in bivalve molluscs

    Directory of Open Access Journals (Sweden)

    Szkoda Józef

    2015-09-01

    Full Text Available A total of 85 mussel samples of eight species were examined. Analysis of mercury in the freeze-dried samples was carried out by atomic absorption spectrometry method using direct mercury analyser AMA 254. The analytical procedure for determination of mercury was covered by the quality assurance programme of research and participation in national and international proficiency tests. Concentrations of total mercury in all investigated samples were found to be generally low, in the range of 0.033-0.577 mg/kg of dry weight and of 0.003-0.045 mg/kg of wet weight. The results indicate that obtained levels of mercury in bivalve molluscs are not likely to pose a risk to the health of consumers.

  18. Congestion management utilizing concentric relaxation

    Directory of Open Access Journals (Sweden)

    Škokljev Ivan

    2007-01-01

    Full Text Available In the market-oriented power system environment, congestion management is a novel term connoting the power system steady state security functions. A large number of transmission transactions are dispatched in the regional day-ahead market and traverse the network adding to the power flow loading of the grid elements. Congestion is defined as a network security limit violation prospective due to transactions. Congestion management is a set of measures aimed at solving the congestion problem. This paper devises the concentric relaxation assisted approach to open access transmission network congestion management. The DC load flow symbolic simulator generates line power transfer functions. Congestion management is a systematic procedure based on linear programming. The DC load flow symbolic simulator generates all constraints and the black-box optimization library function is used to solve the problem of congestion on a sample IEEE RTS power system.

  19. 49 CFR 382.201 - Alcohol concentration.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 5 2010-10-01 2010-10-01 false Alcohol concentration. 382.201 Section 382.201... ALCOHOL USE AND TESTING Prohibitions § 382.201 Alcohol concentration. No driver shall report for duty or... concentration of 0.04 or greater. No employer having actual knowledge that a driver has an alcohol concentration...

  20. Analysis of Photovoltaic Concentrating Solar Energy Systems

    OpenAIRE

    Garo Pilawjian

    2012-01-01

    In this paper the photovoltaic concentrating solar energy systems are analyzed. Both the Fresnel lens light refraction and mirror light reflection concentrating optical systems are considered. The main parameters and properties of photovoltaic concentrating solar energy systems are outlined. It is shown that the multi-parameter cost optimization is necessary to conduct to reduce the cost of photovoltaic concentrating solar energy systems.

  1. The concentration of retail in Poland

    Directory of Open Access Journals (Sweden)

    Michał Gazdecki

    2010-01-01

    Full Text Available The article discusses the processes of concentration taking place in retail in Poland. In spite of strong concentration processes, which took place after 2000, Poland still remains a country of dispersed retail structure. In the nearest years we can expect capital concentration (mainly takeovers in modern trade and contract concentration (for example, merchants’ societies in traditional trade.

  2. Concentrators Enhance Solar Power Systems

    Science.gov (United States)

    2013-01-01

    "Right now, solar electric propulsion is being looked at very seriously," says Michael Piszczor, chief of the photovoltaic and power technologies branch at Glen Research Center. The reason, he explains, originates with a unique NASA mission from the late 1990s. In 1998, the Deep Space 1 spacecraft launched from Kennedy Space Center to test a dozen different space technologies, including SCARLET, or the Solar Concentrator Array with Refractive Linear Element Technology. As a solar array that focused sunlight on a smaller solar cell to generate electric power, SCARLET not only powered Deep Space 1 s instruments but also powered its ion engine, which propelled the spacecraft throughout its journey. Deep Space 1 was the first spacecraft powered by a refractive concentrator design like SCARLET, and also utilized multi-junction solar cells, or cells made of multiple layers of different materials. For the duration of its 38-month mission, SCARLET performed flawlessly, even as Deep Space 1 flew by Comet Borrelly and Asteroid Braille. "Everyone remembers the ion engine on Deep Space 1, but they tend to forget that the SCARLET array powered it," says Piszczor. "Not only did both technologies work as designed, but the synergy between the two, solar power and propulsion together, is really the important aspect of this technology demonstration mission. It was the first successful use of solar electric propulsion for primary propulsion." More than a decade later, NASA is keenly interested in using solar electric propulsion (SEP) for future space missions. A key issue is cost, and SEP has the potential to substantially reduce cost compared to conventional chemical propulsion technology. "SEP allows you to use spacecraft that are smaller, lighter, and less costly," says Piszczor. "Even though it might take longer to get somewhere using SEP, if you are willing to trade time for cost and smaller vehicles, it s a good trade." Potentially, SEP could be used on future science missions

  3. Urinary concentrating processes in vertebrates.

    Science.gov (United States)

    Schmidt-Nielsen, B.

    1979-01-01

    Avian and mammalian kidneys can produce a urine hyperosmotic to the blood by means of a renal countercurrent system. Birds are uricotelic; mammals are ureotelic. It is proposed that the inner medulla present in mammalian, but not in avian kidneys serves specifically to accumulate urea in the inner and outer medulla. Among mammalian kidneys the degree to which urea accumulates in the inner medulla is inversely related to the complexity of the vascular bundles (in the outer medulla) and the cortical urea recycling index. A model is proposed for urea recycling via the vascular bundles. The renal pelvis varies in size among mammals. Its relative size is unrelated to the type of vascular bundles, cortical recycling index; or urea accumulation in the inner medulla. Since urine refluxes into the renal pelvis during rising urine flow only, the function of the pelvis could be that of bringing the more dilute urine into contact with the outer medulla and underlying capillaries, thereby aiding in reducing the urea concentration in outer and inner medulla during rising urine flow. The size of the renal pelvis may be related to the volume of the inner medulla. Other factors may also be involved. Images FIG. 1 FIG. 3 FIG. 5 FIG. 6 FIG. 9 FIG. 10 FIG. 11 FIG. 12 FIG. 13 PMID:538955

  4. Chapter 11: Concentrating Solar Power

    Energy Technology Data Exchange (ETDEWEB)

    Turchi, Craig S [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Stekli, J. [U.S. Department of Energy; Bueno, P. C. [Southwest Research Institute

    2017-01-02

    This chapter summarizes the applications of the supercritical CO2 (sCO2) Brayton cycle in concentrating solar power (CSP) plants. The design and operation of CSP plants are reviewed to highlight the requirements for the power cycle and attributes that are advantageous for the solar-thermal application. The sCO2 Brayton cycle offers the potential of higher cycle efficiency versus superheated or supercritical steam cycles at temperatures relevant for CSP applications. In addition, Brayton cycle systems using sCO2 are anticipated to have smaller weight and volume, lower thermal mass, and less complex power blocks compared with Rankine cycles due to the higher density of the fluid and simpler cycle design. The simpler machinery and compact size of the sCO2 process may also reduce the installation, maintenance, and operation cost of the system. Power cycle capacities in the range of 10-150 MWe are anticipated for the CSP application. In this chapter, we explore sCO2 Brayton cycle configurations that have attributes that are desirable from the perspective of a CSP application, such as the ability to accommodate dry cooling and daily cycling, as well as integration with thermal energy storage.

  5. Concentrating Solar Power. Technology Roadmap

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2010-10-15

    Concentrating solar power can contribute significantly to the world's energy supply. As shown in this roadmap, this decade is a critical window of opportunity during which CSP could become a competitive source of electrical power to meet peak and intermediate loads in the sunniest parts of the world. This roadmap identifies technology, economy and policy goals and milestones needed to support the development and deployment of CSP, as well as ongoing advanced research in CSF. It also sets out the need for governments to implement strong, balanced policies that favour rapid technological progress, cost reductions and expanded industrial manufacturing of CSP equipment to enable mass deployment. Importantly, this roadmap also establishes a foundation for greater international collaboration. The overall aim of this roadmap is to identify actions required - on the part of all stakeholders - to accelerate CSP deployment globally. Many countries, particularly in emerging regions, are only just beginning to develop CSP. Accordingly, milestone dates should be considered as indicative of urgency, rather than as absolutes. This roadmap is a work in progress. As global CSP efforts advance and an increasing number of CSP applications are developed, new data will provide the basis for updated analysis. The IEA will continue to track the evolution of CSP technology and its impacts on markets, the power sector and regulatory environments, and will update its analysis and set additional tasks and milestones as new learning comes to light.

  6. Summary of Dissolved Concentration Limits

    International Nuclear Information System (INIS)

    Yueting Chen

    2001-01-01

    According to the Technical Work Plan titled Technical Work Plan for Waste Form Degradation Process Model Report for SR (CRWMS M and O 2000a), the purpose of this study is to perform abstractions on solubility limits of radioactive elements based on the process-level information and thermodynamic databases provided by Natural Environment Program Operations (NEPO) and Waste Package Operations (WPO). The scope of this analysis is to produce solubility limits as functions, distributions, or constants for all transported radioactive elements identified by the Performance Assessment Operations (PAO) radioisotope screening. Results from an expert elicitation for solubility limits of most radioactive elements were used in the previous Total System Performance Assessments (TSPAs). However, the elicitation conducted in 1993 does not meet the criteria set forth by the U.S. Nuclear Regulatory Commission (NRC) due to lack of documentation and traceability (Kotra et al. 1996, Section 3). Therefore, at the Waste Form Abstraction Workshop held on February 2-4, 1999, at Albuquerque, New Mexico, the Yucca Mountain Site Characterization Project (YMP) decided to develop geochemical models to study solubility for the proposed Monitored Geologic Repository. WPO/NEPO is to develop process-level solubility models, including review and compilation of relevant thermodynamic data. PAO's responsibility is to perform abstractions based on the process models and chemical conditions and to produce solubility distributions or response surfaces applicable to the proposed repository. The results of this analysis and conceptual model will feed the performance assessment for Total System Performance Assessment--Site Recommendation (TSPA-SR) and Total System Performance Assessment--License Application (TSPA-LA), and to the Waste Form Degradation Process Model Report section on concentration limits

  7. Summary of Dissolved Concentration Limits

    Energy Technology Data Exchange (ETDEWEB)

    Yueting Chen

    2001-06-11

    According to the Technical Work Plan titled Technical Work Plan for Waste Form Degradation Process Model Report for SR (CRWMS M&O 2000a), the purpose of this study is to perform abstractions on solubility limits of radioactive elements based on the process-level information and thermodynamic databases provided by Natural Environment Program Operations (NEPO) and Waste Package Operations (WPO). The scope of this analysis is to produce solubility limits as functions, distributions, or constants for all transported radioactive elements identified by the Performance Assessment Operations (PAO) radioisotope screening. Results from an expert elicitation for solubility limits of most radioactive elements were used in the previous Total System Performance Assessments (TSPAs). However, the elicitation conducted in 1993 does not meet the criteria set forth by the U.S. Nuclear Regulatory Commission (NRC) due to lack of documentation and traceability (Kotra et al. 1996, Section 3). Therefore, at the Waste Form Abstraction Workshop held on February 2-4, 1999, at Albuquerque, New Mexico, the Yucca Mountain Site Characterization Project (YMP) decided to develop geochemical models to study solubility for the proposed Monitored Geologic Repository. WPO/NEPO is to develop process-level solubility models, including review and compilation of relevant thermodynamic data. PAO's responsibility is to perform abstractions based on the process models and chemical conditions and to produce solubility distributions or response surfaces applicable to the proposed repository. The results of this analysis and conceptual model will feed the performance assessment for Total System Performance Assessment--Site Recommendation (TSPA-SR) and Total System Performance Assessment--License Application (TSPA-LA), and to the Waste Form Degradation Process Model Report section on concentration limits.

  8. Know Concentration Before Giving Acetaminophen to Infants

    Science.gov (United States)

    ... For Consumers Home For Consumers Consumer Updates Know Concentration Before Giving Acetaminophen to Infants Share Tweet Linkedin ... infants has only been available in a stronger concentration that doesn’t require giving the infants as ...

  9. POTENTIAL DIMETHYLMERCURY CONCENTRATION IN WATER & ORGANIC CONDENSATE

    Energy Technology Data Exchange (ETDEWEB)

    MEACHAM, J.E.

    2004-12-28

    This document bounds potential dimethylmercury concentration in water or organic condensate that might form in ventilation systems or cooler tank regions. Dimethylmercury concentrations were extremely low and would be below drinking water standards in the water condensate.

  10. Basic investigation of concentrator using fluorescent substance

    Energy Technology Data Exchange (ETDEWEB)

    Hayashibara, Mitsuo

    1986-12-01

    A concentrator was manufactured on an experimental basis to improve the performance of the concentrator using fluorescent substance and the analysis based on the test result of optical characteristics of the materials composing the concentrator was made. The concentrator is composed of fluorescent substance sandwiched between two acrylic sheets. Organic fluorescent solution prepared by dissolving eosin to alcohol and capsulating with transparent encapsulant was used as the fluorescent substance. The concentration ratio based on the characteristic tests of the fluorescent substance and material of acrylic sheet composing the concentrator and the numerical calculation model was calculated. The results show that the difference between the experimental and calculated values is 10%. The result of calculation based on the numerical model indicates that the energy efficiency is decreased through the concentration ratio is increased in a thin concentrator, because the fluorescence is decreased by the absorption during passing more frequently through the fluorescent layer. (1 ref, 10 figs)

  11. Installation package for concentrating solar collector panels

    Science.gov (United States)

    1978-01-01

    The concentrating solar collector panels comprise a complete package array consisting of collector panels using modified Fresnel prismatic lenses for a 10 to 1 concentrating ratio, supporting framework, fluid manifolding and tracking drive system, and unassembled components for field erection.

  12. 2011 NATA - Risks and Annual Ambient Concentrations

    Data.gov (United States)

    U.S. Environmental Protection Agency — This dataset includes the modeled annual ambient concentrations and risks at the census tract level for the 2011 National Air Toxics Assessment. All concentrations...

  13. Suspended sediment concentration and particle size distribution ...

    Indian Academy of Sciences (India)

    , zinc and nickel) transported in ... Suspended sediment concentration; heavy metal concentration; regression model; particle size distribution;. Kojour watershed; Iran. ..... contaminants in a uranium mine pite–Lake; Water Res. 39 3055–3061.

  14. Photovoltaic Concentrator Receiver and Its Use

    OpenAIRE

    Wiesenfarth, M.; Wolf, O.; Jaus, J.; Peharz, G.; Eltermann, F.

    2012-01-01

    The present invention relates to a photovoltaic (PV) concentrator receiver for concentrated illumination which comprises a substrate with at least one solar cell, wherein on the front surface of the substrate and the at least one solar cell an encapsulation material and a cover plate are disposed. The edges of the receiver are protected by a frame. The inventive PV concentrator receiver can be used for producing electricity from concentrated solar radiation.

  15. Color corrected Fresnel lens for solar concentration

    International Nuclear Information System (INIS)

    Kritchman, E.M.

    1979-01-01

    A new linear convex Fresnel lens with its groove side down is described. The design philosophy is similar to the highly concentrating two focal Fresnel lens but including a correction for chromatic aberration. A solar concentration ratio as high as 80 is achieved. For wide acceptance angles the concentration nears the theoretical maximum. (author)

  16. 21 CFR 131.115 - Concentrated milk.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 2 2010-04-01 2010-04-01 false Concentrated milk. 131.115 Section 131.115 Food... HUMAN CONSUMPTION MILK AND CREAM Requirements for Specific Standardized Milk and Cream § 131.115 Concentrated milk. (a) Description. Concentrated milk is the liquid food obtained by partial removal of water...

  17. 7 CFR 58.921 - Concentration.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 3 2010-01-01 2010-01-01 false Concentration. 58.921 Section 58.921 Agriculture Regulations of the Department of Agriculture (Continued) AGRICULTURAL MARKETING SERVICE (Standards... Procedures § 58.921 Concentration. Concentrating by evaporation shall be accomplished with a minimum of...

  18. Relationship between silicon concentration and creatinine clearance

    International Nuclear Information System (INIS)

    Miura, Y.; Nakai, K.; Itoh, C.; Horikiri, J.; Sera, K.; Sato, M.

    1998-01-01

    Silicon levels in dialysis patients are markedly increasing. Using PIXE we determined the relationship between silicon concentration and creatinine clearance in 30 samples. Urine silicon concentration were significantly correlated to creatinine clearance (p<0.001). And also serum silicon concentration were significantly correlated to creatinine clearance (p<0.0001). (author)

  19. Determination of Ciprofloxacin Hydrochloride Concentration in ...

    African Journals Online (AJOL)

    user

    ABSTRACT. The concentration of ciprofloxacin hydrochloride tablets in the Nigerian market was analyzed using both back-titration and UV-visible spectrophotometric methods. The results obtained showed that different brands contained different concentrations of the drug; some brands contained lower concentrations while ...

  20. Heavy Metal Concentrations in Maltese Potable Water

    Directory of Open Access Journals (Sweden)

    Roberta Bugeja

    2015-05-01

    Full Text Available This study evaluates the levels of aluminum (Al, cadmium (Cd, chromium (Cr, copper (Cu, iron (Fe, lead (Pb, nickel (Ni and zinc (Zn in tap water samples of forty localities from around the Maltese Islands together with their corresponding service supply reservoirs. The heavy metal concentrations obtained indicated that concentrations of the elements were generally below the maximum allowed concentration established by the Maltese legislation. In terms of the Maltese and EU water quality regulations, 17.5% of the localities sampled yielded water that failed the acceptance criteria for a single metal in drinking water. Higher concentrations of some metals were observed in samples obtained at the end of the distribution network, when compared to the concentrations at the source. The observed changes in metal concentrations between the localities’ samples and the corresponding supply reservoirs were significant. The higher metal concentrations obtained in the samples from the localities can be attributed to leaching in the distribution network.

  1. Retention of Ascorbic Acid and Solid Concentration via Centrifugal Freeze Concentration of Orange Juice

    Directory of Open Access Journals (Sweden)

    P. Orellana-Palma

    2017-01-01

    Full Text Available Freeze concentration of liquid foods produces high-quality concentrates while retaining the heat-labile compounds found in fresh samples. Centrifugal freeze concentration is a cryoconcentration method assisted by an external force, centrifugation, to enhance the separation of concentrate from the ice. When applying centrifugal freeze concentration to orange juice, after the third cryoconcentration cycle, the ascorbic acid content in the concentrate showed retention close to 70% of the initial value. After the third cycle, the solutes in the concentrate increased 4 times the initial value of the fresh sample with 70% efficiency. The color evaluation showed that the final concentrated fraction was darker than the fresh juice. The centrifugal freeze concentration in orange juice was effective for obtaining a high-quality concentrate with a higher concentration of solids and ascorbic acid retention.

  2. Lubricant additive concentrate containing isomerized jojoba oil

    Energy Technology Data Exchange (ETDEWEB)

    Arndt, G.

    1987-05-12

    This patent describes a crankcase motor oil additive concentrate intended to be added to a conventional crankcase motor oil to improve its ability to lubricate and protect the engine. The additive concentrate comprises the following components: A petroleum base stock of lubricating quality and viscosity. The base stock comprises from about 13.5 to 90 weight percent of the additive concentrate; a detergent-inhibitor package. The package is present at from about 7 to about 40 weight percent of the concentrate; a supplemental antiwear additive selected from the salts of dialkyl dithiophosporic acids. The additive is present at a level of from about 1 to about 10 weight percent of the concentrate; and a supplemental antiwear additive selected from the class of sulfurized olefins. The additive is present at a level of from about 1 to about 10 weight percent of the concentrate.

  3. Causality Between Urban Concentration and Environmental Quality

    Directory of Open Access Journals (Sweden)

    Amin Pujiati

    2015-08-01

    Full Text Available Population is concentrated in urban areas can cause the external diseconomies on environment if it exceeds the carrying capacity of the space and the urban economy. Otherwise the quality of the environment is getting better, led to the concentration of population in urban areas are increasingly high. This study aims to analyze the relationship of causality between the urban concentration and environmental quality in urban agglomeration areas. The data used in the study of secondary data obtained from the Central Bureau of statistics and the City Government from 2000 to 2013. The analytical method used is the Granger causality and descriptive. Granger causality study results showed no pattern of reciprocal causality, between urban concentration and the quality of the environment, but there unidirectional relationship between the urban concentration and environmental quality. This means that increasing urban concentration led to decreased environmental quality.

  4. [Plasma ionized magnesium concentration following cardiopulmonary bypass].

    Science.gov (United States)

    Amaya, Fumimasa; Fukui, Michihiko; Tsuruta, Hiroshi; Kooguchi, Kunihiko; Shimosato, Goshun

    2002-06-01

    We performed a retrospective study to analyze plasma ionized magnesium concentration following cardiopulmonary bypass. Severe decrease of ionized magnesium concentration associated with frequent abnormal ECG sign was found in a patient with magnesium-free cardioplegia. Cardioplegia containing 16 mmol.l-1 of magnesium ion maintained ionized magnesium concentration within normal ranges without postoperative magnesium loading. Use of cardioplegia containing magnesium or adequate magnesium supplement is thought to be essential for patients receiving cardiopulmonary bypass.

  5. Neonicotinoid concentrations in UK honey from 2013.

    Science.gov (United States)

    Jones, Ainsley; Turnbull, Gordon

    2016-10-01

    Concentrations of the neonicotinoid insecticides clothianidin, thiamethoxam and imidacloprid were determined in honey collected in Spring 2013 from a variety of locations in England. The honey was produced before the moratorium in the EU on the use of neonicotinoids in pollinator-attractive crops became effective. Neither imidacloprid nor its metabolites were detected in any honey samples. Concentrations of clothianidin ranged from Neonicotinoid concentrations were below those likely to cause any chronic mortality. The concentrations detected should provide a useful baseline against which the effectiveness of the moratorium in reducing exposure of honeybees can be measured. © 2016 Society of Chemical Industry. © 2016 Society of Chemical Industry.

  6. Light funnel concentrator panel for solar power

    Science.gov (United States)

    1987-01-01

    The solar concentrator design concept provides a theoretical concentration efficiency of 96 percent with power-to-weight ratios as high as 50 W/kg. Further, it eliminates the need for fragile reflective coatings and is very tolerant to pointing inaccuracies. The concept differs from conventional reflective mirrors and lens design in that is uses the principle of total internal reflection in order to funnel incident sunlight into a concentrator photovoltaic cell. The feasibility of the light funnel concentrator concept was determined through a balanced approach of analysis, development, and fabrication of prototypes, and testing of components. A three-dimensional optical model of the light funnel concentrator and photovoltaic cell was developed in order to assess the ultimate performance of such systems. In addition, a thermal and structural analysis of a typical unit was made. Techniques of fabricating the light funnel cones, optically coupling them to GaAs concentrator cells, bonding the funnels to GaAs cells, making electrical interconnects, and bonding substrates was explored and a prototype light funnel concentrator unit was fabricated and tested. Testing of the system included measurements of optical concentrating efficiency, optical concentrator to cell coupling efficiency, and electrical efficiency.

  7. Artificial Neural Networks and Concentration Residual Augmented ...

    African Journals Online (AJOL)

    Artificial Neural Networks and Concentration Residual Augmented Classical Least Squares for the Simultaneous Determination of Diphenhydramine, Benzonatate, Guaifenesin and Phenylephrine in their Quaternary Mixture.

  8. Air Force concentrating photovoltaic array program

    International Nuclear Information System (INIS)

    Geis, J.W.

    1987-01-01

    A summary is given of Air Force solar concentrator projects beginning with the Rockwell International study program in 1977. The Satellite Materials Hardening Programs (SMATH) explored and developed techniques for hardening planar solar cell array power systems to the combined nuclear and laser radiation threat environments. A portion of program dollars was devoted to developing a preliminary design for a hardened solar concentrator. The results of the Survivable Concentrating Photovoltaic Array (SCOPA) program, and the design, fabrication and flight qualification of a hardened concentrator panel are discussed

  9. Effects of concentrated sunlight on organic photovoltaics

    DEFF Research Database (Denmark)

    Tromholt, Thomas; Katz, Eugene A.; Hirsch, Baruch

    2010-01-01

    We report the effects of concentrated sunlight on key photovoltaic parameters and stability of organic photovoltaics (OPV). Sunlight collected and concentrated outdoors was focused into an optical fiber and delivered onto a 1 cm2 bulk-heterojunction cell. Sunlight concentration C was varied...... gradually from 0.2 to 27 suns. Power conversion efficiency exhibited slow increase with C that was followed by saturation around 2% at C = 0.5–2.5 suns and subsequent strong reduction. Possible OPV applications in stationary solar concentrators (C ≤ 2 suns) are discussed. Finally, experiments at C = 55...

  10. HYPOLIPEMIC THERAPY AND LOW SERUM CHOLESTEROL CONCENTRATION

    Directory of Open Access Journals (Sweden)

    Vladmila Bojanic

    2004-01-01

    Full Text Available Low concentration of plasma lipoproteins (hypolipoproteinemia presents decreasing concentrations of all or particular lipids components. Classification of hypolipoproteinemia (hypoLP divides them into: primary (hereditary and secondary. Primary hipoLP are rare diseases and their main characteristic is disorder of apolipoproteins synthesis, which leads to low serum cholesterol concentration. Secondary hipoLP are presented in many diseases. They have diagnostic, prognostic significance and present good therapeutic marker. However, modern therapeutic approaches for aggressive lipid lowering pointed out many questions about physiological limits for cholesterol lowering. These approaches, also, open many questions about consequences of low serum concentration of total cholesterol and triglicerides.

  11. Horizontally staggered lightguide solar concentrator with lateral displacement tracking for high concentration applications.

    Science.gov (United States)

    Ma, Hongcai; Wu, Lin

    2015-07-10

    We present the design of a horizontally staggered lightguide solar concentrator with lateral displacement tracking for high concentration applications. This solar concentrator consists of an array of telecentric primary concentrators, a horizontally staggered lightguide layer, and a vertically tapered lightguide layer. The primary concentrator is realized by two plano-aspheric lenses with lateral movement and maintains a high F-number over an angle range of ±23.5°. The results of the simulations show that the solar concentrator achieves a high concentration ratio of 500× with ±0.5° of acceptance angle by a single-axis tracker and dual lateral translation stages.

  12. Status of concentrator collector and high-efficiency concentrator cell development

    Energy Technology Data Exchange (ETDEWEB)

    Gee, J.M.

    1990-01-01

    Photovoltaic concentrator collectors are an attractive option for utility-scale photovoltaic power plants. This paper reviews the current status of photovoltaic concentrator collector and cell development. Included in the review is a discussion of the economic motivation for concentrators, a summary of recent concentrator collector and cell development, and a description of a major new program to accelerate development and commercial introduction of concentrator collectors. 21 refs., 1 fig., 3 tabs.

  13. Inflammation Is Associated with Voriconazole Trough Concentrations

    Science.gov (United States)

    van Wanrooy, Marjolijn J. P.; Span, Lambert F. R.; Rodgers, Michael G. G.; van den Heuvel, Edwin R.; Uges, Donald R. A.; van der Werf, Tjip S.; Kosterink, Jos G. W.

    2014-01-01

    Voriconazole concentrations display a large variability, which cannot completely be explained by known factors. Inflammation may be a contributing factor, as inflammatory stimuli can change the activities and expression levels of cytochrome P450 isoenzymes. We explored the correlation between inflammation, reflected by C-reactive protein (CRP) concentrations, and voriconazole trough concentrations. A retrospective chart review of patients with at least one steady-state voriconazole trough concentration and a CRP concentration measured on the same day was performed. A total of 128 patients were included. A significantly (P voriconazole trough concentration was observed in patients with severe inflammation (6.2 mg/liter; interquartile range [IQR], 3.4 to 8.7 mg/liter; n = 20) than in patients with moderate inflammation (3.4 mg/liter; IQR, 1.6 to 5.4 mg/liter; n = 60) and in patients with no to mild inflammation (1.6 mg/liter; IQR, 0.8 to 3.0 mg/liter; n = 48). The patients in all three groups received similar voriconazole doses based on mg/kg body weight (P = 0.368). Linear regression analyses, both unadjusted and adjusted for covariates of gender, age, dose, route of administration, liver enzymes, and interacting coadministered medications, showed a significant association between voriconazole and CRP concentration (P voriconazole trough concentration increased by 0.015 mg/liter (unadjusted 95% confidence interval [CI], 0.011 to 0.020 mg/liter; adjusted 95% CI, 0.011 to 0.019 mg/liter). Inflammation, reflected by the C-reactive protein concentration, is associated with voriconazole trough concentrations. Further research is necessary to assess if taking the inflammatory status of a patient into account is helpful in therapeutic drug monitoring of voriconazole to maintain concentrations in the therapeutic window, thereby possibly preventing suboptimal treatment or adverse events. PMID:25223994

  14. General Electric point focus solar concentrator status

    Science.gov (United States)

    Zimmerman, J.

    1981-01-01

    The concentrator design approach evolved by a systemmatic process of examining the operating requirements particular to the solar application, minimizing material content through detail structural design and structurally efficient subsystem features, and utilizing materials and processes compatible with high volume production techniques. The design approach, the present concentrator configuration and the status of the hardware development are described.

  15. Universal distortion-free entanglement concentration

    International Nuclear Information System (INIS)

    Matsumoto, Keiji; Hayashi, Masahito

    2007-01-01

    We propose a new protocol of universal entanglement concentration, which converts many copies of an unknown pure state to an exact maximally entangled state. The yield of the protocol, which is outputted as a classical information, is probabilistic, and achieves the entropy rate with high probability, just as nonuniversal entanglement concentration protocols do

  16. Concentration inequalities for random fields via coupling

    NARCIS (Netherlands)

    Chazottes, J. R.; Collet, P.; Kuelske, C.; Redig, F.

    We present a new and simple approach to concentration inequalities in the context of dependent random processes and random fields. Our method is based on coupling and does not use information inequalities. In case one has a uniform control on the coupling, one obtains exponential concentration

  17. Market power, industrial concentration and innovative activity

    NARCIS (Netherlands)

    Vossen, RW

    1999-01-01

    This paper discusses the paradox between the positive effect of industrial concentration on R & D spending, and its non-positive effect on the number of innovations. Also, I analyze whether concentration has different effects on small- and large-firm R & D. The analysis shows that the positive

  18. Concentrated sunlight for organic solar cells

    DEFF Research Database (Denmark)

    Tromholt, Thomas

    2010-01-01

    . A high solar intensity study of inverted P3HT:PCBM solar cells is presented. Performance peak positions were found to be in the range of 1-5 suns, with smaller cells peaking at higher solar concentrations. Additionally, concentrated sunlight is demonstrated as a practical tool for accelerated stability...

  19. Cream concentrated latex for foam rubber products

    Science.gov (United States)

    Suksup, R.; Imkaew, C.; Smitthipong, W.

    2017-12-01

    Fresh natural latex (around 40% rubber and 60% water) can be transformed to concentrated natural latex (around 60% rubber and 40% water) in order to realise economical transportation and easier latex product’s preparation. The concentrated natural latex is an extremely valuable material. It can be applied for many types of products, for example, foam rubber as pillow and mattress, elastic band, etc. Industrially, the concentrated natural latex can be prepared by centrifugation which requires an enormous expensive machine. From the eco-friendly products point of view, most of rubber entrepreneurs in the world try to develop a green rubber product. So, the main objective of this study is to prepare the cream concentrated latex without any sophisticated machine. Thus, we work on a simple, cheap and green method that does not use any expensive machine but uses water-based chemical as sodium alginate to prepare the cream concentrated latex. The optimal amount of sodium alginate in the latex was studied. The main characteristics of the cream concentrated latex were tested by various technics, such as alkalinity, total solid content (TSC), dry rubber content (DRC), etc. We found that there are no significant differences of results between fresh natural latex and cream concentrated latex, except for the TSC and DRC. The TSC and DRC of cream latex are higher than those of fresh natural latex. Finally, we propose a model of natural rubber particle and sodium alginate to form the cream concentrated latex.

  20. Filterability and Sludge Concentration in Membrane Bioreactors

    NARCIS (Netherlands)

    Lousada-Ferreira, M.

    2011-01-01

    The Thesis entitled “Filterability and Sludge Concentration in Membrane Bioreactors” aims at explaining the relation between Mixed Liquid Suspended Solids (MLSS) concentration, the amount of solids in the wastewater being treated, also designated as sludge, and filterability, being the ability of

  1. Uranium concentrations in fossils measured by SIMS

    International Nuclear Information System (INIS)

    Uyeda, Chiaki; Okano, Jun

    1988-01-01

    Semiquantitative analyses of uranium in fossil bones and teeth were carried out by SIMS. The results show a tendency that uranium concentrations in the fossils increase with the ages of the fossils. It is noticed that fossil bones and teeth having uranium concentration of more than several hundred ppm are not rare. (author)

  2. Refractive Secondary Concentrators for Solar Thermal Applications

    Science.gov (United States)

    Wong, Wayne A.; Macosko, Robert P.

    1999-01-01

    The NASA Glenn Research Center is developing technologies that utilize solar energy for various space applications including electrical power conversion, thermal propulsion, and furnaces. Common to all of these applications is the need for highly efficient, solar concentration systems. An effort is underway to develop the innovative single crystal refractive secondary concentrator, which uses refraction and total internal reflection to efficiently concentrate and direct solar energy. The refractive secondary offers very high throughput efficiencies (greater than 90%), and when used in combination with advanced primary concentrators, enables very high concentration ratios (10,0(X) to 1) and very high temperatures (greater than 2000 K). Presented is an overview of the refractive secondary concentrator development effort at the NASA Glenn Research Center, including optical design and analysis techniques, thermal modeling capabilities, crystal materials characterization testing, optical coatings evaluation, and component testing. Also presented is a discussion of potential future activity and technical issues yet to be resolved. Much of the work performed to date has been in support of the NASA Marshall Space Flight Center's Solar Thermal Propulsion Program. The many benefits of a refractive secondary concentrator that enable efficient, high temperature thermal propulsion system designs, apply equally well to other solar applications including furnaces and power generation systems such as solar dynamics, concentrated thermal photovoltaics, and thermionics.

  3. IMPACTS OF DIFFERENT CONCENTRATIONS OF SPENT ...

    African Journals Online (AJOL)

    DJFLEX

    The impacts of different concentrations of spent carbide waste on the growth and yield of Zea mays Linn. (maize) and Arachis hypogea Linn. (groundnut) were studied at the screen house, Botanic garden, University of Port. Harcourt, Nigeria. The crops were planted in carbide waste concentrations of 40g, 80g, 120g, and ...

  4. Size segregated aerosol mass concentration measurements over ...

    Indian Academy of Sciences (India)

    significant variations were observed over central and northern Arabian Sea as well as close to .... Arabian Sea. 4. Results and discussion. Total aerosol mass concentration (MT = Σmi, where mi is the mass concentration on the individ- ual stages) varied from the ..... Twomey S A 1977 The influence of pollution on the short-.

  5. Polycyclic aromatic hydrocarbon concentrations in The Netherlands

    NARCIS (Netherlands)

    Brasser, L.J.

    1981-01-01

    Starting in the winter 1964-1965, the TNO Research Institute for Environmental Hygiene has determined the PAH-concentrations of the atmosphere at several locations in The Netherlands. Long series of data are available for several stations. The trend in the concentrations is spectacular: the

  6. Electrochemical phosphate recovery from nanofiltration concentrates

    NARCIS (Netherlands)

    Kappel, C.; Yasadi, K.; Temmink, H.; Metz, S.J.; Kemperman, Antonius J.B.; Nijmeijer, Dorothea C.; Zwijnenburg, A.; Witkamp, G.J.; Rijnaarts, H.H.M.

    2013-01-01

    The high total phosphorus content of raw domestic wastewater with its significant eutrophication potential offers an excellent possibility for phosphate recovery. Continuous recirculation of NF concentrate to an MBR and simultaneous phosphate recovery from the NF concentrate can be applied to

  7. Soft lithography for concentrator photovoltaic CPV - system's ...

    African Journals Online (AJOL)

    Soft lithography for concentrator photovoltaic CPV - system's application. ... Soft lithography for concentrator photovoltaic CPV - system's application. N.L. Chiromawa, K Ibrahim, M.H. Ali, U.M. Gana, A.O. Musa, N.I. Mannawi, A.A. ... Abstract. No Abstract. Keywords: Micro-Fresnel lens,Photovoltaic, Solar cells, PMMA, PDMS ...

  8. 49 CFR 199.215 - Alcohol concentration.

    Science.gov (United States)

    2010-10-01

    ... ADMINISTRATION, DEPARTMENT OF TRANSPORTATION (CONTINUED) PIPELINE SAFETY DRUG AND ALCOHOL TESTING Alcohol Misuse Prevention Program § 199.215 Alcohol concentration. Each operator shall prohibit a covered employee from... 49 Transportation 3 2010-10-01 2010-10-01 false Alcohol concentration. 199.215 Section 199.215...

  9. Diagnostic patch test concentration for Kathon CG.

    Science.gov (United States)

    Maibach, H I

    1985-10-01

    Patch test studies, 21-day cumulative irritancy assays and Draize repeat insult patch tests with Kathon CG, were used to ascertain an appropriate diagnostic patch test concentration. A dilution of 100 ppm a.i. (aq. or pet.) appears to have low irritancy potential. Further observations are required to verify if this concentration is high enough to detect most cases of sensitization.

  10. Influence of surfactant concentration on nanohydroxyapatite growth

    Indian Academy of Sciences (India)

    Nanohydroxyapatite particles with different morphologies were synthesized through a microwave coupled hydrothermal method using CTAB as a template. A successful synthesis of nanosized HAP spheres, rods and fibres is achieved through this method by controlling the concentration of the surfactant. The concentration ...

  11. EFFECTIVE SEPARATION OF GALENA CONCENTRATE FROM ...

    African Journals Online (AJOL)

    Separation of a clean galena (lead sulphide) concentrate from the mixture of galena and quartz by tabling operation has been investigated. The Nigerian Lead ore composed mainly lead sulphide and quartz. Tabling method was employed on the ore as a method of gravity concentration. The mineral constituents of the ore ...

  12. Measuring surfactant concentration in plating solutions

    Science.gov (United States)

    Bonivert, William D.; Farmer, Joseph C.; Hachman, John T.

    1989-01-01

    An arrangement for measuring the concentration of surfactants in a electrolyte containing metal ions includes applying a DC bias voltage and a modulated voltage to a counter electrode. The phase angle between the modulated voltage and the current response to the modulated voltage at a working electrode is correlated to the surfactant concentration.

  13. Metal concentrations in water column, benthic macroinvertebrates ...

    African Journals Online (AJOL)

    Concentrations of some metals in the water, benthic macroinvertebrates and the muscle tissue of the Nile tilapia from river Delimi, Nigeria were investigated from January 1998 to June 1998. Samplings were done monthly at 3 different sites. The concentrations of the metals were determined using the atomic absorption ...

  14. Influence of surfactant concentration on nanohydroxyapatite growth

    Indian Academy of Sciences (India)

    4Corrosion Science and Technology Division, Indira Gandhi Centre for Atomic Research, Kalpakkam 603 012, India. MS received 17 ... fibres is achieved through this method by controlling the concentration of the surfactant. The concentration of the ... shown that many clinical applications of HAp mainly depend on shape ...

  15. Postmortem Femoral Blood Concentrations of Risperidone

    DEFF Research Database (Denmark)

    Linnet, Kristian; Johansen, Sys Stybe

    2014-01-01

    Postmortem femoral blood concentrations of the antipsychotic drug risperidone and the active metabolite 9-hydroxyrisperidone were determined by an achiral LC-MS/MS method in 38 cases. The cause of death was classified as unrelated to risperidone in 30 cases, in which the sum of the concentration...... of the drug and metabolite ranged from below the limit of quantification to 0.058 mg/kg (median 0.0098 mg/kg). This concentration range, which largely corresponds to published in vivo plasmalevels under therapy, may serve as a reference for judgment of postmortem cases involving risperidone. In one case......, risperidone was judged to be a contributing factor to death, and the sum of concentrations was 0.29 mg/kg. This concentration is of the same order of magnitude as observed for plasma levels in clinical intoxication cases. For the remaining seven cases, the cause of death was unclear. The measurements observed...

  16. Concentration inequalities for sums and martingales

    CERN Document Server

    Bercu, Bernard; Rio, Emmanuel

    2015-01-01

    The purpose of this book is to provide an overview of historical and recent results on concentration inequalities for sums of independent random variables and for martingales. The first chapter is devoted to classical asymptotic results in probability such as the strong law of large numbers and the central limit theorem. Our goal is to show that it is really interesting to make use of concentration inequalities for sums and martingales. The second chapter deals with classical concentration inequalities for sums of independent random variables such as the famous Hoeffding, Bennett, Bernstein and Talagrand inequalities. Further results and improvements are also provided such as the missing factors in those inequalities. The third chapter concerns concentration inequalities for martingales such as Azuma-Hoeffding, Freedman and De la Pena inequalities. Several extensions are also provided. The fourth chapter is devoted to applications of concentration inequalities in probability and statistics.

  17. Current Status of Concentrator Photovoltaic (CPV) Technology

    Energy Technology Data Exchange (ETDEWEB)

    Philipps, Simon P. [Fraunhofer Inst. for Solar Energy Systems ISE, Freiburg (Germany); Bett, Andreas W. [Fraunhofer Inst. for Solar Energy Systems ISE, Freiburg (Germany); Horowitz, Kelsey [National Renewable Energy Lab. (NREL), Golden, CO (United States); Kurtz, Sarah [National Renewable Energy Lab. (NREL), Golden, CO (United States)

    2015-12-01

    This report summarizes the status of the concentrator photovoltaic (CPV) market and industry as well as current trends in research and technology. This report is intended to guide research agendas for Fraunhofer ISE, the National Renewable Energy Laboratory (NREL), and other R&D organizations. Version 1.1 of this report includes recent progress in CPV. The recent record module efficiency of 38.9% at Concentrator Standard Test Conditions (CSTC) is an impressive result, demonstrating the continuing opportunity for CPV technology to improve. 38.9% at Concentrator Standard Test Conditions (CSTC) is an impressive result, demonstrating the continuing opportunity for CPV technology to improve. 38.9% at Concentrator Standard Test Conditions (CSTC) is an impressive result, demonstrating the continuing opportunity for CPV technology to improve. 38.9% at Concentrator Standard Test Conditions (CSTC) is an impressive result, demonstrating the continuing opportunity for CPV technology to improve.

  18. Plasma fibronectin concentrations in morbidly obese patients

    DEFF Research Database (Denmark)

    Dejgaard, A; Andersen, T; Christoffersen, Pernille Yde

    1984-01-01

    Plasma fibronectin concentrations and liver morphology were investigated in 45 morbidly obese subjects (median overweight 88%) and in 42 normal weight controls, matched for sex and age. A significantly (P less than 0.01) raised plasma fibronectin concentration (median 464 mg/l, range 276-862 mg....../l) was found in the obese subjects when compared with concentrations in the controls (median 348 mg/l, range 164-536 mg/l). Plasma fibronectin concentrations of the obese patients correlated significantly to their degree of overweight (r = 0.33, P less than 0.05) as well as to the degree of fatty change found...... in their liver biopsies (r = 0.33, P less than 0.05). Significantly (P less than 0.05) elevated plasma fibronectin concentrations even in obese subjects without hepatic fatty change indicate that liver fat accumulation is no prerequisite of the obesity-related elevation of plasma fibronectin. Raised plasma...

  19. Radiocaesium concentrations in mushrooms collected in Japan

    International Nuclear Information System (INIS)

    Yoshida, S.; Muramatsu, Y.

    1994-01-01

    A variety of mushrooms and soils collected in Japan was analyzed for 137 Cs, 134 Cs and 40 K. The levels of 137 Cs in mushrooms varied very widely ranging from 40 K were relatively constant. The median concentrations of 137 Cs and 40 K were 44 and 1100 Bq/kg (dry wt), respectively. In many samples, concentrations of 134 Cs were under the detection limit (usually 5 cm). The third group of mushrooms (surface soil layer) showed the highest average concentration of 137 Cs, which might reflect its high concentration in the surface soil layer. Habitat of mycelium seemed to be one of the most important factors controlling radiocesium concentration in mushrooms. Average soil-mushroom transfer factors of each group were in the range of 5.5-13. (Author)

  20. Obtain of uranium concentrates from fertil liquids

    International Nuclear Information System (INIS)

    Narvaez Castillo, W.A.

    1992-01-01

    This research tried to encounter the form to remove uranium from the rock in the best way, for that it was used different process like leaching, extraction, concentration and precipitation. To leach the mineral was chosen basic leaching, using a mixture of carbonate-sodium bicarbonate, this method is more adequated for the basic nature of the mineral. In extraction was used specific uranium ionic interchanges, so was chosen a tertiary amine like Alamina 336. The concentration phase is intimately binding with the extraction by ionic interchange, for the capability of resine's extraction to obtain concentrated liquids. When the liquids were obtained with high concentration of uranium in the same time were purified and then were precipitated, for that we employed a precipitant agent like: Sodium hydroxide, Amonium hydroxide, Magnesium hydroxide, Hydrogen peroxide and phosphates. With all concentrates we obtain the YELLOW CAKE

  1. [Relationship between dust mass concentration and fiber number concentration of refractory ceramic fibers].

    Science.gov (United States)

    Zhu, Xiaojun; Li, Tao; Wang, Hongfei

    2015-04-01

    To explore the quantitative relationship between the dust mass concentration and fiber number concentration of refractory ceramic fibres. A typical refractory ceramic fiber plant was selected as the study site. Fifty-three paired samples of total dust mass concentration and fiber number concentration were collected using the long-time fixed site mode. The total dust mass concentration was measured according to the GBZ/T 192.1-2007 (Measurement of dust in the air of workplace, part 1: Total dust concentration). Membrane filter method/phase-contrast optical microscopy was used to determine the fiber number concentration. Univariate analysis was used to describe the distribution of the two concentrations and their ratio. Spearman rank correlation, as well as linear regression, logarithmic curve, polynomial, power function, and exponential curve model, were used to explore the relationship between the two concentrations. Results The range of the total dust mass concentration (x) was 0.45-13.82 mg/m3. The range of the fiber number concentration (y) was 0.01-1.04 f/ml. The range of the ratio (x/y) was 4-158. All of the three parameters did not follow normal distribution (Pfiber number concentration of refractory ceramic fibers. However, there is no fixed regression relationship between the two concentrations, and neither is a definite coefficient which can be used to convert each other. The two concentrations cannot be replaced by each other.

  2. The concentrations of uranium in marine organisms

    International Nuclear Information System (INIS)

    Matsuba, Mitsue; Ishii, Toshiaki; Nakahara, Motokazu; Nakamura, Ryoichi; Watabe, Teruhisa; Hirano, Shigeki

    2000-01-01

    Determination of uranium in sixty-one species of marine organisms was carried out by inductively coupled plasma mass spectrometry to obtain concentration factors and to estimate the internal radiation dose. The concentrations of uranium in soft tissues of marine animals were ranged from 0.077 to 5040 ng/g wet wt. Especially, the branchial heart of cephalopod molluscs showed the specific accumulation of uranium. The concentration factor of the branchial heart of Octopus vulgaris, which indicated the highest value, was calculated to be about 1.6 x 10 3 , comparing with that (3.1 ng/ml) in coastal seawaters of Japan. The concentrations of uranium in hard tissues of marine invertebrates such as clam and sea urchin were similar to those in soft tissues. In contrast, hard tissues like bone, scale, fin, etc. of fishes showed much higher concentrations of uranium than soft tissues like muscle. The concentrations of uranium of twenty-two species of algae were ranged from 2 to 310 ng/g wet wt. Particularly, the brown alga Undaria pinnatifida showed the highest value of the uranium content in the algae and its concentration factor was calculated to be 10 2 . (author)

  3. Interpreting Tacrolimus Concentrations During Pregnancy and Postpartum

    Science.gov (United States)

    Hebert, Mary F.; Zheng, Songmao; Hays, Karen; Shen, Danny D.; Davis, Connie L.; Umans, Jason G.; Miodovnik, Menachem; Thummel, Kenneth E.; Easterling, Thomas R.

    2012-01-01

    Summary Pregnancy following solid organ transplantation, although considered high risk for maternal, fetal and neonatal complications, has been quite successful. Tacrolimus pharmacokinetic changes during pregnancy make interpretation of whole blood trough concentrations particularly challenging. There are multiple factors that can increase the fraction of unbound tacrolimus, including but not limited to low albumin concentration and low RBC count. The clinical titration of dosage to maintain whole blood tacrolimus trough concentrations in the usual therapeutic range can lead to elevated unbound concentrations and possibly toxicity in pregnant women with anemia and hypoalbuminemia. Measurement of plasma or unbound tacrolimus concentrations for pregnant women might better reflect the active form of the drug, though these are technically-challenging and often unavailable in usual clinical practice. Tacrolimus crosses the placenta with in utero exposure being approximately 71% of maternal blood concentrations. The lower fetal blood concentrations are likely due to active efflux transport of tacrolimus from the fetus toward the mother by placental P-glycoprotein. To date, tacrolimus has not been linked to congenital malformations, but can cause reversible nephrotoxicity and hyperkalemia in the newborn. In contrast, very small amounts of tacrolimus are excreted in the breast milk and are unlikely to elicit adverse effects in the nursing infant. PMID:23274970

  4. Central tetrahydrobiopterin concentration in neurodevelopmental disorders

    Directory of Open Access Journals (Sweden)

    Richard E Frye

    2010-07-01

    Full Text Available Tetrahydrobiopterin (BH4 is a naturally occurring cofactor essential for critical metabolic pathways. Studies suggest that BH4 supplementation may ameliorate autism symptoms; the biological mechanism for such an effect is unknown. To help understand the relation between central BH4 concentration and systemic metabolism and to develop a biomarker of central BH4 concentration, the relationship between cerebrospinal fluid BH4 concentration and serum amino acids was studied. BH4 concentration was found to be distributed in two groups, a lower and higher BH4 concentration group. Two serum amino acids, citrulline and methionine, differentiated these groups, and the ratio of serum citrulline-to-methionine was found to correlate with the cerebrospinal fluid BH4 concentration (r = -0.67, p < 0.05. Both citrulline and methionine are substrates in inflammation and oxidative stress pathways - two pathways that utilize BH4 and are abnormally activated in autism. These data suggests that central BH4 concentration may be related to systemic inflammation and oxidative stress pathways.

  5. The concentrations of uranium in marine organisms

    Energy Technology Data Exchange (ETDEWEB)

    Matsuba, Mitsue; Ishii, Toshiaki; Nakahara, Motokazu; Nakamura, Ryoichi; Watabe, Teruhisa; Hirano, Shigeki [National Inst. of Radiological Sciences, Hitachinaka, Ibaraki (Japan). Laboratory for Radioecology

    2000-07-01

    Determination of uranium in sixty-one species of marine organisms was carried out by inductively coupled plasma mass spectrometry to obtain concentration factors and to estimate the internal radiation dose. The concentrations of uranium in soft tissues of marine animals were ranged from 0.077 to 5040 ng/g wet wt. Especially, the branchial heart of cephalopod molluscs showed the specific accumulation of uranium. The concentration factor of the branchial heart of Octopus vulgaris, which indicated the highest value, was calculated to be about 1.6 x 10{sup 3}, comparing with that (3.1 ng/ml) in coastal seawaters of Japan. The concentrations of uranium in hard tissues of marine invertebrates such as clam and sea urchin were similar to those in soft tissues. In contrast, hard tissues like bone, scale, fin, etc. of fishes showed much higher concentrations of uranium than soft tissues like muscle. The concentrations of uranium of twenty-two species of algae were ranged from 2 to 310 ng/g wet wt. Particularly, the brown alga Undaria pinnatifida showed the highest value of the uranium content in the algae and its concentration factor was calculated to be 10{sup 2}. (author)

  6. Hydrophobicity and charge shape cellular metabolite concentrations.

    Directory of Open Access Journals (Sweden)

    Arren Bar-Even

    2011-10-01

    Full Text Available What governs the concentrations of metabolites within living cells? Beyond specific metabolic and enzymatic considerations, are there global trends that affect their values? We hypothesize that the physico-chemical properties of metabolites considerably affect their in-vivo concentrations. The recently achieved experimental capability to measure the concentrations of many metabolites simultaneously has made the testing of this hypothesis possible. Here, we analyze such recently available data sets of metabolite concentrations within E. coli, S. cerevisiae, B. subtilis and human. Overall, these data sets encompass more than twenty conditions, each containing dozens (28-108 of simultaneously measured metabolites. We test for correlations with various physico-chemical properties and find that the number of charged atoms, non-polar surface area, lipophilicity and solubility consistently correlate with concentration. In most data sets, a change in one of these properties elicits a ~100 fold increase in metabolite concentrations. We find that the non-polar surface area and number of charged atoms account for almost half of the variation in concentrations in the most reliable and comprehensive data set. Analyzing specific groups of metabolites, such as amino-acids or phosphorylated nucleotides, reveals even a higher dependence of concentration on hydrophobicity. We suggest that these findings can be explained by evolutionary constraints imposed on metabolite concentrations and discuss possible selective pressures that can account for them. These include the reduction of solute leakage through the lipid membrane, avoidance of deleterious aggregates and reduction of non-specific hydrophobic binding. By highlighting the global constraints imposed on metabolic pathways, future research could shed light onto aspects of biochemical evolution and the chemical constraints that bound metabolic engineering efforts.

  7. Post-mortem quetiapine concentrations in hair segments of psychiatric patients - Correlation between hair concentration, dose and concentration in blood.

    Science.gov (United States)

    Günther, Kamilla Nyborg; Johansen, Sys Stybe; Nielsen, Marie Katrine Klose; Wicktor, Petra; Banner, Jytte; Linnet, Kristian

    2018-04-01

    Drug analysis in hair is useful when seeking to establish drug intake over a period of months to years. Segmental hair analysis can also document whether psychiatric patients are receiving a stable intake of antipsychotics. This study describes segmental analysis of the antipsychotic drug quetiapine in post-mortem hair samples from long-term quetiapine users by ultra-high performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS) analysis. The aim was to obtain more knowledge on quetiapine concentrations in hair and to relate the concentration in hair to the administered dose and the post-mortem concentration in femoral blood. We analyzed hair samples from 22 deceased quetiapine-treated individuals, who were divided into two groups: natural hair colour and dyed/bleached hair. Two to six 1cm long segments were analyzed per individual, depending on the length of the hair, with 6cm corresponding to the last six months before death. The average daily quetiapine dose and average concentration in hair for the last six months prior to death were examined for potential correlation. Estimated doses ranged from 45 to 1040mg quetiapine daily over the period, and the average concentration in hair ranged from 0.18 to 13ng/mg. A significant positive correlation was observed between estimated daily dosage of quetiapine and average concentration in hair for individuals with natural hair colour (p=0.00005), but statistical significance was not reached for individuals with dyed/bleached hair (p=0.31). The individual coefficient of variation (CV) of the quetiapine concentrations between segments ranged from 3 to 34% for individuals with natural hair colour and 22-62% for individuals with dyed/bleached hair. Dose-adjusted concentrations in hair were significantly lower in females with dyed/bleached hair than in individuals with natural hair colour. The quetiapine concentrations in post-mortem femoral blood and in the proximal hair segment, segment 1 (S1), representing

  8. Increasing the efficiency of fluorescent concentrator systems

    Energy Technology Data Exchange (ETDEWEB)

    Goldschmidt, Jan Christoph; Peters, Marius; Boesch, Armin; Helmers, Henning; Dimroth, Frank; Glunz, Stefan W.; Willeke, Gerhard [Fraunhofer Institute for Solar Energy Systems, Heidenhofstr. 2, 79110 Freiburg (Germany)

    2009-02-15

    This study examines concepts for increasing the efficiency of fluorescent concentrator systems. Different system sizes and configurations are investigated in detail by external quantum efficiency measurements, light-beam-induced current maps and by I-V measurements. A photonic structure that serves as a bandstop reflection filter for light emitted from dyes in the fluorescent concentrator increases the system efficiency relatively by 20%. Such photonic structures are especially beneficial for larger systems. The combination of two fluorescent concentrators made with different dyes in one stack increases the system efficiency from 5.1% with only one dye to 6.7% for the stack. (author)

  9. Aspects of reduction clorination of pyrochlore concentrates

    International Nuclear Information System (INIS)

    Gameiro, D.H.; Brocchi, E.A.

    1985-01-01

    Reduction chlorination experiments were carried out with two different Brazilian pyrochlore concentrates in order to evaluate the effects of some variables on the extent of niobium pentoxide gaseification as well as to compare the behavior of concentrate under the same chlorination conditions. The pyrochlore concentrates from Araxa (MG) and Catalao (GO), Brazil, were submitted to X ray diffraction and X ray fluorescence analysis for determining their chemical compositions. Kinetic curves were obtained with the main variables being temperature and percentage of reducing agent. Analysis of the condensed material in terms of Nb 2 O 5 indicated that chlorination can be used to produce niobium pentoxide. (Author) [pt

  10. Body and Gender in Nazi Concentration Camps

    Directory of Open Access Journals (Sweden)

    Bożena Karwowska

    2009-01-01

    Full Text Available The article Body and Gender in Nazi Concentration Camps is an attempt to discuss difficult issues of human sexuality and sexually marked behaviors in the context of the concentration camps, and their descriptions in the memoirs of the survivors. Using notions and concepts of the so called "black American feminism" the author (referring extensively to books by Stanisław Grzesiuk and Zofia Romanowiczowa shows how in the concentration camp the human body became the only space of a relative privacy of the prisoner. At the same time the body becomes a territory on which all - both biological and socially constructed - human fates cross.

  11. Plasma fibronectin concentrations in morbidly obese patients

    DEFF Research Database (Denmark)

    Dejgaard, A; Andersen, T; Christoffersen, Pernille Yde

    1984-01-01

    Plasma fibronectin concentrations and liver morphology were investigated in 45 morbidly obese subjects (median overweight 88%) and in 42 normal weight controls, matched for sex and age. A significantly (P less than 0.01) raised plasma fibronectin concentration (median 464 mg/l, range 276-862 mg...... in their liver biopsies (r = 0.33, P less than 0.05). Significantly (P less than 0.05) elevated plasma fibronectin concentrations even in obese subjects without hepatic fatty change indicate that liver fat accumulation is no prerequisite of the obesity-related elevation of plasma fibronectin. Raised plasma...

  12. Maximum phytoplankton concentrations in the sea

    DEFF Research Database (Denmark)

    Jackson, G.A.; Kiørboe, Thomas

    2008-01-01

    A simplification of plankton dynamics using coagulation theory provides predictions of the maximum algal concentration sustainable in aquatic systems. These predictions have previously been tested successfully against results from iron fertilization experiments. We extend the test to data collected...... in the North Atlantic as part of the Bermuda Atlantic Time Series program as well as data collected off Southern California as part of the Southern California Bight Study program. The observed maximum particulate organic carbon and volumetric particle concentrations are consistent with the predictions....... The results imply that physical processes control maximum particle concentrations in planktonic systems....

  13. Non-concentrating and asymmetric compound parabolic concentrating building facade integrated photovoltaics: An experimental comparison

    Energy Technology Data Exchange (ETDEWEB)

    Mallick, Tapas K.; Eames, Philip C. [Centre for Sustainable Technologies, School of Built Environment, University of Ulster, Newtownabbey BT37 0QB, N.I (United Kingdom); Norton, Brian [Dublin Institute of Technology, Aungier Street, Dublin-2 (Ireland)

    2006-07-15

    Concentration of solar energy increases the illuminated flux on the photovoltaic (PV) surface thus less PV material is required. A novel asymmetric compound parabolic photovoltaic concentrator has been characterised experimentally with a similar non-concentrating system. Different numbers of PV strings connected within the system have been analysed and a power ratio of 1.62 measured compared to a similar non-concentrating PV panel with the same cell area. The solar to electrical conversion efficiency of 8.6% and 6.8% was achieved for the non-concentrating panel the concentrating system, respectively. The measured average solar cell temperature of the PV in the concentrator system was only 12{sup o}C higher than that of the similar non-concentrating system with same cell area. (author)

  14. Advancing Concentrating Solar Power Research (Fact Sheet)

    Energy Technology Data Exchange (ETDEWEB)

    None, None

    2014-02-01

    Researchers at the National Renewable Energy Laboratory (NREL) provide scientific, engineering, and analytical expertise to help advance innovation in concentrating solar power (CSP). This fact sheet summarizes how NREL is advancing CSP research.

  15. Inflammation Is Associated with Voriconazole Trough Concentrations

    NARCIS (Netherlands)

    van Wanrooy, Marjolijn J. P.; Span, Lambert F. R.; Rodgers, Michael G. G.; van den Heuvel, Edwin R.; Uges, Donald R. A.; van der Werf, Tjip S.; Kosterink, Jos G. W.; Alffenaar, Jan-Willem C.

    2014-01-01

    Voriconazole concentrations display a large variability, which cannot completely be explained by known factors. Inflammation may be a contributing factor, as inflammatory stimuli can change the activities and expression levels of cytochrome P450 isoenzymes. We explored the correlation between

  16. Seasonal Composite Chlorophyll Concentrations - Gulf of Maine

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This personal geodatabase contains raster images of chlorophyll concentrations in the Gulf of Maine. These raster images are seasonal composites, and were calculated...

  17. ISLSCP II Global Sea Ice Concentration

    Data.gov (United States)

    National Aeronautics and Space Administration — This International Satellite Land Surface Climatology Project (ISLSCP) Initiative II data set, ISLSCP II Global Sea Ice Concentration, is based on the Goddard Space...

  18. Blood metabolite concentrations and postpartum resumption of ...

    African Journals Online (AJOL)

    , late cycling or non-cycling. The plasma glucose, cholesterol, total protein, albumin and globulin concentrations recorded were similar in the early cycling, late cycling and non-cycling cows. The mean blood glucose, cholesterol, total protein, ...

  19. Tritium concentration in foods and human tissues

    International Nuclear Information System (INIS)

    Hisamatsu, S.; Takizawa, Y.; Katsumata, T.

    1991-01-01

    Tritium concentrations in diet samples at Akita City, northern Japan, and in human tissue samples from general population in Akita Prefecture were analyzed to study fallout 3 H transfer from diet to human body. The 3 H concentration in free water form as well as that in tissue-bound form were determined separately. The specific activity ratios of tissue bound 3 H to free water 3 H in the diet and human soft tissue samples were found to be close to unity in significant contrast with those reported in Italy and the US during the period of 1970s and early 1980s. The free water 3 H concentrations in human tissues agreed well with those in diet including tap water. Tissue-bound 3 H concentrations in human bone samples were found to be higher than those in the soft tissues, and suggest the longer biological half-life of 3 H in bone than the soft tissues

  20. Side Effects - Memory or Concentration Problems

    Science.gov (United States)

    Cancer treatments, such as chemo, may cause difficulty thinking, concentrating, or other cognitive problems. Learn about steps people with cancer can take to manage these side effects. See a list of helpful questions for families to ask the doctor.

  1. Monitoring of radon concentration in dwellings

    International Nuclear Information System (INIS)

    Kurosawa, Ryuhei

    1991-01-01

    Radon problems in dwellings have recently received much attention. Radon concentration in dwellings, as well as in the general environment, varies with various factors such as meteorological conditions and soil components. Therefore, a long term monitoring of radon concentration is required to obtain an average concentration. This paper reviews a passive type radon monitor that is handy and allows a long term radon monitoring. It provides the structure and principle of the radon monitor, covering the type, filter function, sensitivity of diffusion collecting type (cup type), electrostatic collecting type, adsorption collecting type, and detector of radon monitor. Actual examples of the radon monitor are also given. Radon daughter nuclides will have become major foci of exposure countermeasures. In the future, the development of a passive type monitor for determining potential alpha energy concentration is required. (N.K.)

  2. [Nitrate concentrations in tap water in Spain].

    Science.gov (United States)

    Vitoria, Isidro; Maraver, Francisco; Sánchez-Valverde, Félix; Armijo, Francisco

    2015-01-01

    To determine nitrate concentrations in drinking water in a sample of Spanish cities. We used ion chromatography to analyze the nitrate concentrations of public drinking water in 108 Spanish municipalities with more than 50,000 inhabitants (supplying 21,290,707 potential individuals). The samples were collected between January and April 2012. The total number of samples tested was 324. The median nitrate concentration was 3.47 mg/L (range: 0.38-66.76; interquartile range: 4.51). The water from 94% of the municipalities contained less than 15 mg/L. The concentration was higher than 25mg/L in only 3 municipalities and was greater than 50mg/L in one. Nitrate levels in most public drinking water supplies in municipalities inhabited by almost half of the Spanish population are below 15 mg/L. Copyright © 2014 SESPAS. Published by Elsevier Espana. All rights reserved.

  3. Ownership Concentration, Top Management and Board Compensation

    Directory of Open Access Journals (Sweden)

    Marcos Barbosa Pinto

    2013-05-01

    Full Text Available The degree of ownership concentration may influence executive and board compensation (Bebchuk & Fried, 2003. This article analyzes this relationship. Detailed information about top management and board compensation became available starting in 2010 through new Securities Commission filings. Linear regression models applied to a sample of 315 Brazilian companies traded on the national exchange indicate a negative and statistically significant economic correlation between executive compensation and the degree of ownership concentration. Ceteris paribus, companies with a lower degree of ownership concentration pay higher compensation to top executives. Family controlled companies pay more to their chief executive, but not to the managerial team as a whole, and the compensation of directors increases with a greater proportion of control group members or their relatives on the board. There was support for the Managerial Power Hypothesis in companies with a lower degree of ownership concentration and for the extraction of private benefits in companies where it is greater.

  4. New ideas for new solar concentrators

    Science.gov (United States)

    Chaves, Julio; Collares-Pereira, Manuel

    1999-10-01

    New ideas for the production of optical devices capable of concentrating solar radiation to a degree useful for an application like solar frying of food, but still retaining the ability to remain stationary for extended periods, are presented and discussed.

  5. Arctic and Southern Ocean Sea Ice Concentrations

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Monthly sea ice concentration for Arctic (1901 to 1995) and Southern oceans (1973 to 1990) were digitized on a standard 1-degree grid (cylindrical projection) to...

  6. Odor concentration invariance by chemical ratio coding

    Directory of Open Access Journals (Sweden)

    Naoshige Uchida

    2008-08-01

    Full Text Available Many animal species rely on chemical signals to extract ecologically important information from the environment. Yet in natural conditions chemical signals will frequently undergo concentration changes that produce differences in both level and pattern of activation of olfactory receptor neurons. Thus, a central problem in olfactory processing is how the system is able to recognize the same stimulus across different concentrations. To signal species identity for mate recognition, some insects use the ratio of two components in a binary chemical mixture to produce a code that is invariant to dilution. Here, using psychophysical methods, we show that rats also classify binary odor mixtures according to the molar ratios of their components, spontaneously generalizing over at least a tenfold concentration range. These results indicate that extracting chemical ratio information is not restricted to pheromone signaling and suggest a general solution for concentration-invariant odor recognition by the mammalian olfactory system.

  7. Protein solutions: concentration by a rapid method.

    Science.gov (United States)

    Blatt, W F; Feinberg, M P; Hopfenberg, H B; Saravis, C A

    1965-10-08

    Protein solutions were concentrated, with no evidence of denaturation, by means of membranes formed from the complex interaction product of polyanions and polycations (Diaplex). The technique is considerably more rapid than conventional ultrafiltration with Visking tubing.

  8. Building integrated concentrating photovoltaics: A review

    International Nuclear Information System (INIS)

    Chemisana, Daniel

    2011-01-01

    For building integration, Concentrating Photovoltaic (CPV) systems can offer a host of advantages over conventional flat panel devices, the most notable being: a higher electrical conversion efficiency in the PV cells, better use of space, ease of recycling of constituent materials, and reduced use of toxic products involved in the PV cells' production process. However, the viability of Building-Integrated Concentrating PV (BICPV) systems is dependent on their ability to offer a comparative economic advantage over flat panel photovoltaic technologies whose market prices are decreasing from day to day and which offer other advantages such as ease of replacement of structural elements. A comparative analysis is presented of the main existing CPV systems' suitability for use in buildings, in which the different challenges specific to integration of each system are discussed. The systems are categorized by type of concentration technology and concentration factor. (author)

  9. An Experimental Test of the Concentration Index

    Science.gov (United States)

    Bleichrodt, Han; Rohde, Kirsten I.M.; Van Ourti, Tom

    2016-01-01

    The concentration index is widely used to measure income-related inequality in health. No insight exists, however, whether the concentration index connects with people's preferences about distributions of income and health and whether a reduction in the concentration index reflects an increase in social welfare. We explored this question by testing the central assumption underlying the concentration index and found that it was systematically violated. We also tested the validity of alternative health inequality measures that have been proposed in the literature. Our data showed that decreases in the spread of income and health were considered socially desirable, but decreases in the correlation between income and health not necessarily. Support for a condition implying that the inequality in the distribution of income and in the distribution of health can be considered separately was mixed. PMID:22307035

  10. ISLSCP II Globalview: Atmospheric CO2 Concentrations

    Data.gov (United States)

    National Aeronautics and Space Administration — The GlobalView Carbon Dioxide (CO2) data product contains synchronized and smoothed time series of atmospheric CO2 concentrations at selected sites that were created...

  11. Bioaerosol concentrations - Figure 3 and Figure 4

    Data.gov (United States)

    U.S. Environmental Protection Agency — Bioaerosol concentrations. This dataset is associated with the following publication: Chattopadhyay, S., S. Perkins, M. Shaw, and T. Nichols. Evaluation of Exposure...

  12. Concentration of stable elements in food products

    Energy Technology Data Exchange (ETDEWEB)

    Montford, M.A.; Shank, K.E.; Hendricks, C.; Oakes, T.W.

    1980-01-01

    Food samples were taken from commercial markets and analyzed for stable element content. The concentrations of most stable elements (Ag, Al, As, Au, Ba, Br, Ca, Ce, Cl, Co, Cr, Cs, Cu, Fe, Hf, I, K, La, Mg, Mn, Mo, Na, Rb, Sb, Sc, Se, Sr, Ta, Th, Ti, V, Zn, Zr) were determined using multiple-element neutron activation analysis, while the concentrations of other elements (Cd, Hg, Ni, Pb) were determined using atomic absorption. The relevance of the concentrations found are noted in relation to other literature values. An earlier study was extended to include the determination of the concentration of stable elements in home-grown products in the vicinity of the Oak Ridge National Laboratory. Comparisons between the commercial and local food-stuff values are discussed.

  13. Uranium recovery from phosphate rocks concentrated

    International Nuclear Information System (INIS)

    Azevedo, M.F. de.

    1986-01-01

    The reserves, geological data, chemical data and technical flowsheet from COPEBRAS and Goiasfertil ores are described, including the process of mining ore concentration. Samples of Goiasfertil ores are analysed by gravimetric analysis, for phosphate, and spectrofluorimetry for uranium. (author)

  14. Effect of pesticides on surface ozone concentration

    International Nuclear Information System (INIS)

    Farag, S.A.; Rizk, H.F.S.; Elbahnasawy, R.M.; Meleigy, M.I.

    1992-01-01

    A comparative study through seasonal variation of surface ozone concentration was carried out recently (1991-1992) at a background area free from expected urban pollutants (Shebin ElKom) and industrial and urban areas (Cairo). Surface ozone concentrations in ppb were generally lower in such area compared with urban or industrial areas studied through the comparative seasonal variations. Notable smog values (>100 ppb) of hourly surface ozone concentrations appeared during summer season in this rural area; during this season, some pesticides were sprayed over cotton and other crops fields in near by agricultural areas. The unexpected jump in the values of diurnal concentrations of surface ozone in that area may be due to the photochemical reactions of these organic pesticides in the atmosphere. 1 fig, 3 tab

  15. ISLSCP II Globalview: Atmospheric CO2 Concentrations

    Data.gov (United States)

    National Aeronautics and Space Administration — ABSTRACT: The GlobalView Carbon Dioxide (CO2) data product contains synchronized and smoothed time series of atmospheric CO2 concentrations at selected sites that...

  16. Retrieve Aerosol Concentration Based On Surface Model and Distribution of Concentration of PM2.5

    Science.gov (United States)

    Cui, Hongzhi

    2017-04-01

    As China's economy continues to grow, urbanization continues to advance, along with growth in all areas to pollutant emissions in the air industry, air quality also continued to deteriorate. Aerosol concentrations as a measure of air quality of the most important part of are more and more people's attention. Traditional monitoring stations measuring aerosol concentration method is accurate, but time-consuming and can't be done simultaneously measure a large area, can only rely on data from several monitoring sites to predict the concentration of the panorama. Remote Sensing Technology retrieves aerosol concentrations being by virtue of their efficient, fast advantages gradually into sight. In this paper, by the method of surface model to start with the physical processes of atmospheric transport, innovative aerosol concentration coefficient proposed to replace the traditional aerosol concentrations, pushed to a set of retrieval of aerosol concentration coefficient method, enabling fast and efficient Get accurate air pollution target area. At the same paper also monitoring data for PM2.5 in Beijing were analyzed from different angles, from the perspective of the data summarized in Beijing PM2.5 concentration of time, space, geographical distribution and concentration of PM2.5 and explored the relationship between aerosol concentration coefficient and concentration of PM2.5. Key words,Air Pollution, Aerosol concentration , PM2.5 , Retrieve

  17. Boron removal and its concentration in aqueous solution through progressive freeze concentration.

    Science.gov (United States)

    Wang, Li Pang

    2017-09-01

    This study explored the feasibility of progressive freeze concentration in boron removal and its concentration in aqueous solution. The influence of three key parameters in progressive freeze concentration on boron removal and concentration, namely, the advance speed of the ice front, the circumferential velocity of the stirrer, and the initial boron concentration, are investigated by conducting batch experiments. The results show that the effectiveness of boron removal increases with a lower advance speed of the ice front, a higher circumferential velocity of the stirrer, and a lower initial boron concentration. For a model boron solution with an initial concentration of 100 mg/L, the boron concentration in the ice phase after progressive freeze concentration is below 1 mg/L when the advance speed of the ice front is lower than 1 cm/h and the circumferential velocity of the stirrer is higher than 0.12 m/s. In addition, the concentration of boron in the liquid phase occurs simultaneously with progressive freeze concentration. Furthermore, the results also suggest that this method can be applied to the purification and concentration of not only organic molecules but also inorganic ions.

  18. Concentric Polycyclic Regrowth Pattern in Alopecia Areata.

    Science.gov (United States)

    Delorenze, Lilian Mathias; Gavazzoni-Dias, Maria Fernanada Reis; Teixeira, Marcelo S; Aide, Marcia Kalil

    2016-01-01

    Alopecia areata (AA) is a common form of autoimmune nonscarring hair loss of scalp and/or body. Atypical hair regrowth in AA is considered a rare phenomenon. It includes atypical pattern of hair growth (sudden graying, perinevoid alopecia, Renbok phenomenon, castling phenomenon, and concentric or targetoid regrowth) and atypical dark color hair regrowth. We report a case of AA that resulted in a concentric targetoid hair regrowth and discuss the possible related theories regarding the significance of this phenomenon.

  19. A Continuous Process for RO Concentrate Desupersaturation

    OpenAIRE

    Lei, Jack

    2016-01-01

    Reverse osmosis (RO) desalination of inland brackish water can replenish dwindling water supplies in various regions around the world. However, successful implementation of RO technology requires high product water recovery (>85%) in order to minimize the volume of generated concentrate brine. Therefore, brine management is a critical aspect of inland water desalination. At high water recovery, dissolved mineral salts (e.g. CaSO4, CaCO3) may concentrate above their solubility limits and may c...

  20. Quantification of Fluorine Content in AFFF Concentrates

    Science.gov (United States)

    2017-09-29

    expensive and time consuming . Newer analytical methods focus on detection and measurement of the fluorine- containing molecule which frequently...formulations, an analysis 19F NMR spectra wherein profiles somewhat unique to individual commercial AFFF can be identified and a fluorine content comparison...establishing a volatiles profile along with a non- volatiles or solids content for an AFFF concentrate. These concentrates have a strong potential

  1. Geogenic heavy metal concentrations in German soils

    International Nuclear Information System (INIS)

    Hindel, R.; Fleige, H.

    1990-01-01

    In the area of the German Federal Republic, 6,300 soil samples of 526 soil profiles were examined for the concentrations of lead, copper, zinc, cadmium, nickel, cobalt, mercury, antimony, arsenic and lithium. The soil profiles were selected so that the prevailing loose and solid rock floors of the German Federal Republic were represented. The analysis data of these samples formed the basis for the calculation of average geogenic heavy metal concentrations in the soils of the German Federal Republic. (orig.) [de

  2. Radon concentration in a house of Calvados

    International Nuclear Information System (INIS)

    Leleyter, L.; Riffault, B.; Mazenc, B.

    2010-01-01

    Recent studies indicate a link between the risk of lung cancer and residential radon exposure. However, in France, awareness of this problem was made relatively late. Accordingly this study examines the radon concentration in a private home in Calvados (Normandy region). Findings show that the presence of a fireplace in a house can accelerate radon convective transfer, and that simple adjustments to interior and exterior accommodation can significantly reduce radon concentrations in the home. (authors)

  3. Unfolded aplanats for high-concentration photovoltaics.

    Science.gov (United States)

    Gordon, Jeffrey M; Feuermann, Daniel; Young, Pete

    2008-05-15

    The exigencies of high-concentration photovoltaics motivate optics that (1) obviate the need for optical bonds, (2) exhibit maximal optical tolerance, (3) are not damaged at off-axis orientation, and (4) allow convenient location of the solar cell and heat sink. We show that dual-mirror unfolded aplanats can satisfy all these criteria. Lens enhancement improves compactness and, with millimeter-scale cells, concentrator depth is only a few centimeters, amenable to precise large-volume fabrication.

  4. Spectral converters and luminescent solar concentrators

    Energy Technology Data Exchange (ETDEWEB)

    Scudo, Petra F.; Abbondanza, Luigi; Fusco, Roberto; Caccianotti, Luciano [Eni S.p.A, Research Center for Non-Conventional Energies - Istituto ENI Donegani, Via G.Fauser 4, 28100 Novara (Italy)

    2010-07-15

    In this paper we present a comprehensive theoretical description of molecular spectral converters in the specific context of luminescent solar concentrators (LSCs). The theoretical model is an extension to a three-level system interacting with a solar radiation bath of the standard quantum theory of atomic radiative processes. We derive the equilibrium equations of the conversion process and provide specific examples of application of this principle to the development of solar concentration devices. (author)

  5. Concentration of actinides in the food chain

    International Nuclear Information System (INIS)

    Bulman, R.A.

    1976-06-01

    Considerable concern is now being expressed over the discharge of actinides into the environment. This report presents a brief review of the chemistry of the actinides and examines the evidence for interaction of the actinides with some naturally-occurring chelating agents and other factors which might stimulate actinide concentration in the food chain of man. This report also reviews the evidence for concentration of actinides in plants and for uptake through the gastrointestinal tract. (author)

  6. Potassium concentration in bone of Beijing residents

    International Nuclear Information System (INIS)

    Lin Lianqing

    1994-01-01

    The author presents the measuring results of K concentration in bone ash samples of 65 residents in Beijing area by atomic absorption spectrum. The results indicate that the K concentrations in bone ash is logarithmic normal distribution, ranging level is 0.75-8.44 g/kg ash, the average and standard deviation is respectively 2.40 and 1.52 g/kg ash. The highest concentration (4.88 g/kg ash) appears in infantile stage (< 1y), the lowest concentration (1.59 g/kg ash) appears in young stage (2-5 y). The lower concentration (1.88 g/kg ash) appears in adolescence (11-20 y). The K concentration in wet bone as a percentage of weight is 0.067%. The specific activities of K-40 in bone is about 22 mBq/g wet bone. The total radioactivity of K-40 in whole bone is 220 Bq. The annual absorbed dose is received in adult bone from K-40 is estimated to be 95 μGy

  7. Blood lead concentration after a shotgun accident.

    Science.gov (United States)

    Gerhardsson, Lars; Dahlin, Lars; Knebel, Richard; Schütz, Andrejs

    2002-01-01

    In an accidental shooting, a man in his late forties was hit in his left shoulder region by about 60 lead pellets from a shotgun. He had injuries to the vessels, the clavicle, muscles, and nerves, with total paralysis of the left arm due to axonal injury. After several surgical revisions and temporary cover with split skin, reconstructive surgery was carried out 54 days after the accident. The brachial plexus was swollen, but the continuity of the nerve trunks was not broken (no neuroma present). We determined the blood lead (BPb) concentration during a follow-up period of 12 months. The BPb concentration increased considerably during the first months. Although 30 lead pellets were removed during the reconstructive surgery, the BPb concentration continued to rise, and reached a peak of 62 microg/dL (3.0 micromol/L) on day 81. Thereafter it started to decline. Twelve months after the accident, BPb had leveled off at about 30 microg/dL. At that time, muscle and sensory functions had partially recovered. The BPb concentration exceeded 30 microg/dL for 9 months, which may have influenced the recovery rate of nerve function. Subjects with a large number of lead pellets or fragments embedded in the body after shooting accidents should be followed for many years by regular determinations of BPb. To obtain a more stable basis for risk assessment, the BPb concentrations should be corrected for variations in the subject's hemoglobin concentration or erythrocyte volume fraction.

  8. Potentiometric Determination of Fluoride Concentration in Beers.

    Science.gov (United States)

    Jaudenes, Juan Ramón; Hardisson, Arturo; Paz, Soraya; Rubio, Carmen; Gutiérrez, Angel José; Burgos, Antonio; Revert, Consuelo

    2018-01-01

    Beer is a widely consumed drink throughout the world, and because its manufacture involves the use of water, beer can be, in some cases, a source of fluorides. For this reason, the objective of this study was to determine the concentration of fluorides in 50 samples of beers from different sources sold in two different types of container (aluminum can and glass bottle). The possible significant differences between the different types of packaging and the intake of fluoride from the consumption of these beers were evaluated. The concentration of fluoride in beers has been determined using the potentiometric method of fluoride determination by standard addition. The concentration of fluoride ranged between 0.06 and 1.77 mg/L. In general, the concentration was below 1 mg/L, except for three beer samples from Ireland and the USA, whose concentration was over 1.5 mg/L. No significant differences were found between the types of packaging. The contribution of fluoride to the diet from beer consumption is not high (<27%); however, it is necessary to warn consumers whenever they are in areas of high concentrations of fluoride in the water supply.

  9. Isoflurane minimum alveolar concentration reduction by fentanyl.

    Science.gov (United States)

    McEwan, A I; Smith, C; Dyar, O; Goodman, D; Smith, L R; Glass, P S

    1993-05-01

    Isoflurane is commonly combined with fentanyl during anesthesia. Because of hysteresis between plasma and effect site, bolus administration of fentanyl does not accurately describe the interaction between these drugs. The purpose of this study was to determine the MAC reduction of isoflurane by fentanyl when both drugs had reached steady biophase concentrations. Seventy-seven patients were randomly allocated to receive either no fentanyl or fentanyl at several predetermined plasma concentrations. Fentanyl was administered using a computer-assisted continuous infusion device. Patients were also randomly allocated to receive a predetermined steady state end-tidal concentration of isoflurane. Blood samples for fentanyl concentration were taken at 10 min after initiation of the infusion and before and immediately after skin incision. A minimum of 20 min was allowed between the start of the fentanyl infusion and skin incision. The reduction in the MAC of isoflurane by the measured fentanyl concentration was calculated using a maximum likelihood solution to a logistic regression model. There was an initial steep reduction in the MAC of isoflurane by fentanyl, with 3 ng/ml resulting in a 63% MAC reduction. A ceiling effect was observed with 10 ng/ml providing only a further 19% reduction in MAC. A 50% decrease in MAC was produced by a fentanyl concentration of 1.67 ng/ml. Defining the MAC reduction of isoflurane by all the opioids allows their more rational administration with inhalational anesthetics and provides a comparison of their relative anesthetic potencies.

  10. Uranium concentration monitor manual, secondary intermediate evaporator

    International Nuclear Information System (INIS)

    Russo, P.A.; Sprinkle, J.K. Jr.; Slice, R.W.; Strittmatter, R.B.

    1985-08-01

    This manual describes the design, operation, and measurement control procedures for the automated uranium concentration monitor on the secondary intermediate evaporator at the Oak Ridge Y-12 Plant. The nonintrusive monitor provides a near-real time readout of uranium concentration in the return loop of time recirculating evaporator for purposes of process monitoring and control. A detector installed near the bottom of the return loop is used to acquire spectra of gamma rays from the evaporator solutions during operation. Pulse height analysis of each spectrum gives the information required to deduce the concentration of uranium in the evaporator solution in near-real time. The visual readout of concentration is updated at the end of every assay cycle. The readout includes an alphanumeric display of uranium concentration and an illuminated, colored LED (in an array of colored LEDs) indicating whether the measured concentration is within (or above or below) the desired range. An alphanumeric display of evaporator solution acid molarity is also available to the operator. 9 refs., 16 figs., 4 tabs

  11. Concentration of trace elements in marine organisms

    International Nuclear Information System (INIS)

    Ishii, Takaaki; Suzuki, Hamaji; Iimura, Mitsue; Koyanagi, Taku

    1976-01-01

    Information on the quality and quantity of stable trace elements in marine environments is frequently required to analyze the radioecological behavior of radionuclides released from nuclear facilities into the sea. In the present work, special attention was concentrated in determination of stable Mn, Fe, Co, Zn, Rb and Cs in marine organisms to estimate the concentration factors for these elements and corresponding radionuclides. Marine organisms (fishes, marine invertebrates and seaweeds) were collected at the seashore of Ibaragi prefecture and provided for chemical analysis after dry-ashing and wet-ashing. Atomic absorption spectrophotometry and neutron activation analysis were applied to determine the concentration of elements. The concentration of stable elements in fish muscle was independent on species of the fishes though slightly higher trends were observed in ''Usumebaru'', Sebastes nivosus for Cs, ''Ishimochi'', Nibea mitsukurii for Zn and Fe compared with other species. The concentration of Co, Zn and Fe in muscle of marine invertebrates was one order of magnitude higher than fish muscles especially in shellfishes for Co. Seaweeds showed peculiar species specificity for the concentration of stable trace elements and remarkable differences was observed between the species even among the same genus. (auth.)

  12. Agricultural Spray Drift Concentrations in Rainwater, Stemflow ...

    Science.gov (United States)

    In order to study spray drift contribution to non-targeted habitats, pesticide concentrations were measured in stemflow (water flowing down the trunk of a tree during a rain event), rainfall, and amphibians in an agriculturally impacted wetland area near Tifton, Georgia, USA. Agricultural fields and sampling locations were located on the University of Georgia's Gibbs research farm. Samples were analyzed for >150 pesticides and over 20 different pesticides were detected in these matrices. Data indicated that herbicides (metolachlor and atrazine) and fungicides (tebuconazole) were present with the highest concentrations in stemflow, followed by those in rainfall and amphibian tissue samples. Metolachlor had the highest frequency of detection and highest concentration in rainfall and stemflow samples. Higher concentrations of pesticides were observed in stemflow for a longer period than rainfall. Furthermore, rainfall and stemflow concentrations were compared against aquatic life benchmarks and environmental water screening values to determine if adverse effects would potentially occur for non-targeted organisms. Of the pesticides detected, several had concentrations that exceeded the aquatic life benchmark value. The majority of the time mixtures were present in the different matrices, making it difficult to determine the potential adverse effects that these compounds will have on non-target species, due to unknown potentiating effects. These data help assess the

  13. Estimation of the freezing point of concentrated fruit juices for application in freeze concentration

    OpenAIRE

    Auleda Amorós, Josep Maria; Raventós Santamaria, Mercè; Sánchez Machado, José; Hernández Yáñez, Eduard

    2011-01-01

    In freeze concentration operations the fluids remain at temperatures below 0 °C. For a good study of this concentration operation is very important to know the values of freezing point. The aim of this work was to establish a model that predicts the freezing point of fruit juices at various concentrations within the range of interest for freeze concentration (10–40 °Brix). The model proposed relates the freezing point of a juice with the concentrations of main sugars present in the juice: suc...

  14. Flight Experience from Space Photovoltaic Concentrator Arrays and its Implication on Terrestrial Concentrator Systems

    Science.gov (United States)

    Piszczor, Michael F., Jr.

    2003-01-01

    Nearly all photovoltaic solar arrays flown in space have used a planar (non- concentrating) design. However, there have been a few notable exceptions where photovoltaic concentrators have been tested and used as the mission s primary power source. Among these are the success experienced by the SCARLET (Solar Concentrator Array with Refractive Linear Element Technology) concept used to power NASA's Deep Space 1 mission and the problems encountered by the original Boeing 702 reflective trough concentrator design. This presentation will give a brief overview of past photovoltaic concentrator systems that have flown in space, specifically addressing the valuable lessons learned from flight experience, and other viable concentrator concepts that are being proposed for the future. The general trends of this flight experience will be noted and discussed with regard to its implications on terrestrial photovoltaic concentrator designs.

  15. False positive acetaminophen concentrations in icteric serum

    Directory of Open Access Journals (Sweden)

    L. de Jong

    2016-04-01

    Full Text Available Introduction: Serum concentrations of acetaminophen are measured to predict the risk of hepatotoxicity in cases of acetaminophen overdose and to identify acetaminophen use in patients with acute liver injury without a known cause. The acetaminophen concentration determines if treatment with N-acetyl cysteine, the antidote for acetaminophen poisoning, is warranted. Description: A 49-year-old woman was admitted to our hospital with a hepatic encephalopathy and a total serum bilirubin concentration of 442 µmol/l. The acetaminophen concentration of 11.5 mg/l was measured with an enzymatic-colorimetric assay, thus treatment with N-acetyl cysteine was started. Interestingly, the acetaminophen concentration remained unchanged (11.5–12.3 mg/l during a period of 4 consecutive days. In contrast, the acetaminophen concentration measured by HPLC, a chromatographic technique, remained undetectable Discussion: In the presented case, elevated bilirubin was the most likely candidate to interfere with acetaminophen assay causing false positive results. Bilirubin has intense absorbance in the ultraviolet and visible regions of the electromagnetic spectrum and for that reason it causes interference in an enzymatic-colorimetric assay. Conclusion: False positive acetaminophen laboratory test results may be found in icteric serum, when enzymatic-colorimetric assays are used for determination of an acetaminophen concentration. Questionable acetaminophen results in icteric serum should be confirmed by a non-enzymatic method, by means of ultrafiltration of the serum, or by dilution studies. Keywords: Acetaminophen, Enzymatic-colorimetric assays, HPLC, Bilirubin, Interference, Paracetamol, Liver failure, Jaundice

  16. Urine methanol concentration and alcohol hangover severity.

    Science.gov (United States)

    Mackus, M; Van de Loo, A J A E; Korte-Bouws, G A H; Van Neer, R H P; Wang, X; Nguyen, T T; Brookhuis, K A; Garssen, J; Verster, J C

    2017-03-01

    Congeners are substances, other than ethanol, that are produced during fermentation. Previous research found that the consumption of congener-rich drinks contributes to the severity of alcohol hangover. Methanol is such a congener that has been related to alcohol hangover. Therefore, the aim of this study was to examine the relationship between urine methanol concentration and alcohol hangover severity. N = 36 healthy social drinkers (22 females, 14 males), aged 18-30 years old, participated in a naturalistic study, comprising a hangover day and a control day (no alcohol consumed the previous day). N = 18 of them had regular hangovers (the hangover group), while the other N = 18 claimed to be hangover-immune (hangover-immune group). Overall hangover severity was assessed, and that of 23 individual hangover symptoms. Urine methanol concentrations on the hangover and control days were compared, and correlated to hangover (symptom) severity. Urine methanol concentration was significantly higher on hangover days compared to control days (p = 0.0001). No significant differences in urine methanol concentration were found between the hangover group and hangover-immune group. However, urine methanol concentration did not significantly correlate with overall hangover severity (r = -0.011, p = 0.948), nor with any of the individual hangover symptoms. These findings were observed also when analyzing the data separately for the hangover-immune group. In the hangover group, a significant correlation with urine methanol concentration was found only with vomiting (r = 0.489, p = 0.037). No significant correlation was observed between urine methanol concentration and hangover severity, nor with individual core hangover symptoms. Copyright © 2016 Elsevier Inc. All rights reserved.

  17. The scaling of crime concentration in cities

    Science.gov (United States)

    Bastos-Filho, Carmelo; Menezes, Ronaldo

    2017-01-01

    Crime is a major threat to society’s well-being but lacks a statistical characterization that could lead to uncovering some of its underlying mechanisms. Evidence of nonlinear scaling of urban indicators in cities, such as wages and serious crime, has motivated the understanding of cities as complex systems—a perspective that offers insights into resources limits and sustainability, but that usually neglects details of the indicators themselves. Notably, since the nineteenth century, criminal activities have been known to occur unevenly within a city; crime concentrates in such way that most of the offenses take place in few regions of the city. Though confirmed by different studies, this concentration lacks broad analyses on its characteristics, which hinders not only the comprehension of crime dynamics but also the proposal of sounding counter-measures. Here, we developed a framework to characterize crime concentration which divides cities into regions with the same population size. We used disaggregated criminal data from 25 locations in the U.S. and the U.K., spanning from 2 to 15 years of longitudinal data. Our results confirmed that crime concentrates regardless of city and revealed that the level of concentration does not scale with city size. We found that the distribution of crime in a city can be approximated by a power-law distribution with exponent α that depends on the type of crime. In particular, our results showed that thefts tend to concentrate more than robberies, and robberies more than burglaries. Though criminal activities present regularities of concentration, we found that criminal ranks have the tendency to change continuously over time—features that support the perspective of crime as a complex system and demand analyses and evolving urban policies covering the city as a whole. PMID:28800604

  18. Urea concentration in sheep’s milk

    Directory of Open Access Journals (Sweden)

    Jasmina Havranek

    2009-03-01

    Full Text Available Determining urea concentration in milk is a useful indicator for controlling supply of proteins to organisms, as well as the relationship of energy and protein in the food, thus it is finding more and more ways of practical use. The concentration of urea in milk, along with the feeding process, is influenced by a number of other factors such as: breed, stage and sequence of lactation, body mass, daily production and chemical structure of milk, number of somatic cells, season, milking.The goal of the research was to establish the influence of the breed (Island of Krk, East Frisian, lactation stage (beginning, middle and the end and the herd (3 to the concentration of urea in milk during lactation.For each breed there has been established daily quantity of milk, protein share and the concentration of urea in milk.Statistical analysis of data was conducted by using General Linear Models procedure, SAS program system (1999.The breed of sheep considerably (P<0.001 influenced daily quantity of milk, protein share and the concentration of urea in the milk.East Frisian sheep produced on average almost double the daily quantities of milk (1070 mL compared to the Krk sheep (588 mL.Protein share and the urea concentration in Krk sheep milk were higher (5.99 % and 35.97 mg/100 mL then in the milk of East Frisian sheep (5.12 % and 33.31 mg/100 mL.For both breeds the significant influence of lactation stage to the daily milk quantity has been established (0.001, that is also for the urea concentration in the milk of Krk sheep (0.001, as well as protein share in the milk of East Frisian sheep (0.001.Herd influence significantly affected daily milk quantities (0.001 and concentration of urea in the milk (0.05.The defining of the urea concentration in sheep milk should be occasionally carried out in the Republic of Croatia to establish the standard physiological values typical for the particular sheep breed.

  19. Serum concentrations of perfluorinated compounds (PFC) ...

    Science.gov (United States)

    Perfluorinated compounds (PFCs) have been widely used in industrial applications and consumer products. Their persistent nature and potential health impacts are of concern. Given the high cost of collecting serum samples, this study is to understand whether we can quantify PFC serum concentrations using factors extracted from questionnaire responses and indirect measurements, and whether a single serum measurement can be used to classify an individual′s exposure over a one-year period. The study population included three demographic groups: young children (2–8 years old) (N=67), parents of young children (55 years old) (N=59). PFC serum concentrations, house dust concentrations, and questionnaires were collected. The geometric mean of perfluorooctane sulfonic acid (PFOS) was highest for the older adults. In contrast, the geometric mean of perfluorooctanoic acid (PFOA) was highest for children. Serum concentrations of the parent and the child from the same family were moderately correlated (Spearman correlation (r)=0.26–0.79, padults, age, having occupational exposure or having used fire extinguisher, frequencies of consuming butter/margarine, pork, canned meat entrées, tuna and white fish, freshwater fish, and whether they ate microwave popcorn were significantly positively associated with serum concentrations of individual PFCs. For children, residential dust

  20. Natural radionuclides concentration in underground mine materials

    Energy Technology Data Exchange (ETDEWEB)

    Santos, T.O.; Rocha, Z.; Taveira, N.F.; Takahashi, L.C.; Pineiro, M.M., E-mail: talitaolsantos@yahoo.com.br, E-mail: rochaz@cdtn.br, E-mail: mayarapinheiroduarte@gmail.com, E-mail: lauratakahashi@hotmail.com, E-mail: natyfontaveira@hotmail.com [Centro de Desenvolvimento da Tecnologia Nuclear (CDTN/CNEN-MG), Belo Horizonte, MG (Brazil); Borges, P.F.; Cruz, P.; Gouvea, V.A.; Siqueira, J.B., E-mail: vgouvea@cnen.gov.br, E-mail: flavia.borges@cnen.gov.br, E-mail: pcruz@cnen.gov.br, E-mail: jbsiquei@cnen.gov.br [Comissão Nacional de Energia Nuclear (CNEN), Rio de Janeiro, RJ (Brazil)

    2017-07-01

    Natural Radionuclides are present in earth's environment since its origin. The main radionuclides present are {sup 40}K, as well as, {sup 238}U and {sup 232}Th with their decay products. These radionuclides occur in minerals in different activity concentration associated with geological and geochemical conditions, appearing at different levels from point to point in the world. Underground mines may present a high natural background radiation which is due to the presence of these radiogenic heavy minerals. To address this concern, this work outlines on the characterization of the natural radionuclides presence in underground mines in Brazil which are located in many cases on higher radiation levels bed rocks. The radon concentration was measured by using E-PERM Electrets Ion Chamber, AlphaGUARD and CR-39 track etch detectors. The radon progeny was determined by using DOSEman detector. Radon concentration measurement in groundwater was performed by using RAD7 detector. The {sup 238}U and {sup 232}Th activity concentration in ore and soil samples were determined by using Neutron Activation Analysis using TRIGA MARK I IPR-R1 Reactor. Gamma spectrometry was used to determine {sup 226}Ra, {sup 228}Ra and {sup 40}K activity concentrations. The results show that the natural radioactivity varies considerably from mine to mine and that there are not risks of radiological damage for exposed workers in these cases. Based on these data, recommendations for Brazilian regulatory standards are presented. (author)

  1. Holographic lenses for building integrated concentrating photovoltaics

    International Nuclear Information System (INIS)

    Chemisana, Daniel; Collados, Ma Victoria; Quintanilla, Manuel; Atencia, Jesús

    2013-01-01

    Highlights: • A holographic solar concentrator has been designed, constructed and characterised. • The system configuration is suitable for building integration. • The holographic lens diffracts in the bandwidth to which the cell is more sensitive. • The system prevents the cell overheating. • The use of the holographic element increases the electrical efficiency of the system. - Abstract: A volume transmission phase holographic element was designed and constructed to perform as a building integrated photovoltaic concentrator. The holographic lens diffracts light in the spectral bandwidth to which the cell presents the highest sensitivity with a concentration factor of 3.6X. In this way, the cell is protected from overheating because the infrared for which the solar cell is not sensitive is not concentrated. In addition, based on the asymmetric angular selectivity of the volume hologram and based on the linear concentration, only single-axis tracking is needed. The use of the holographic element increases the efficiency of the PV cell by 3% and the fill factor by 8%

  2. Sodium concentration of water from softeners.

    Science.gov (United States)

    Yarows, S A; Fusilier, W E; Weder, A B

    1997-01-27

    To determine whether water is safe for consumption after it has passed through a water softener and whether there are any health and environmental implications of cationic water softeners. Sodium concentration was measured in 59 water samples that had passed through a water softener and was compared with the sodium concentration of 5 samples from 4 different local municipal sources. The mean +/- SD sodium concentration of softened well water was 278 +/- 186 mg/L (range, 46-1219 mg/L). There were 10 (17%) households with sodium levels greater than 400 mg/L. The mean +/- SD sodium concentration of municipal, nonsoftened water was 110 +/- 98 mg/L (range, 0-253 mg/L). Softened well water in our area on average contained a 2.5-times-higher concentration of sodium than local municipal water, comparable with previous reports. It is unlikely that the increased sodium from softened water would have any health risks for most people. This may not be true for people on severely sodium-restricted diets.

  3. Carbon monoxide concentration forecasting in Santiago, Chile.

    Science.gov (United States)

    Perez, Patricio; Palacios, Rodrigo; Castillo, Alejandro

    2004-08-01

    In the city of Santiago, Chile, air quality is defined in terms of particulate matter with an aerodynamic diameter < or = 10 microm (PM10) concentrations. An air quality forecasting model based on past concentrations of PM10 and meteorological conditions currently is used by the metropolitan agency for the environment, which allows restrictions to emissions to be imposed in advance. This model, however, fails to forecast between 40 and 50% of the days considered to be harmful for the inhabitants every year. Given that a high correlation between particulate matter and carbon monoxide (CO) concentrations is observed at monitoring stations in the city, a model for CO concentration forecasting would be a useful tool to complement information about expected air quality in the city. Here, the results of a neural network-based model aimed to forecast maximum values of the 8-hr moving average of CO concentrations for the next day are presented. Forecasts from the neural network model are compared with those produced with linear regressions. The neural network model seems to leave more room to adjust free parameters with 1-yr data to predict the following year's values. We have worked with 3 yr of data measured at the monitoring station located in the zone with the worst air quality in the city of Santiago, Chile.

  4. Plasma Glutamine Concentrations in Liver Failure.

    Directory of Open Access Journals (Sweden)

    Gunnel Helling

    Full Text Available Higher than normal plasma glutamine concentration at admission to an intensive care unit is associated with an unfavorable outcome. Very high plasma glutamine levels are sometimes seen in both acute and chronic liver failure. We aimed to systematically explore the relation between different types of liver failure and plasma glutamine concentrations.Four different groups of patients were studies; chronic liver failure (n = 40, acute on chronic liver failure (n = 20, acute fulminant liver failure (n = 20, and post-hepatectomy liver failure (n = 20. Child-Pugh and Model for End-stage Liver Disease (MELD scores were assessed as indices of liver function. All groups except the chronic liver failure group were followed longitudinally during hospitalisation. Outcomes were recorded up to 48 months after study inclusion.All groups had individuals with very high plasma glutamine concentrations. In the total group of patients (n = 100, severity of liver failure correlated significantly with plasma glutamine concentration, but the correlation was not strong.Liver failure, regardless of severity and course of illness, may be associated with a high plasma glutamine concentration. Further studies are needed to understand whether high glutamine levels should be regarded as a biomarker or as a contributor to symptomatology in liver failure.

  5. A Review of Solar Photovoltaic Concentrators

    Directory of Open Access Journals (Sweden)

    Mehrdad Khamooshi

    2014-01-01

    Full Text Available Throughout the recent centuries, the limits of using energy resources due to the cost and environmental issues became one of the scientists’ concerns. Because of the huge amount of energy received by the Earth from the sun, the application of photovoltaic solar cells has become popular in the world. The photovoltaic (PV efficiency can be increased by several factors; concentrating photovoltaic (CPV system is one of the important tools for efficiency improvement and enables for a reduction in the cell area requirement. The limits of the PV area can reduce the amount of absorbing irradiation; CPV systems can concentrate a large amount of sunlight into a smaller one by applying lenses or curved and flat mirrors. However, the additional costs on concentrating optics and cooling systems made CPV less common than nonconcentrated photovoltaic. This paper reviews the different types of PV concentrators, their performance with advantages and disadvantages, concentration ratio, acceptance angle, brief comparison between their efficiencies, and appropriate cooling system.

  6. Concentration and limit behaviors of stationary measures

    Science.gov (United States)

    Huang, Wen; Ji, Min; Liu, Zhenxin; Yi, Yingfei

    2018-04-01

    In this paper, we study limit behaviors of stationary measures of the Fokker-Planck equations associated with a system of ordinary differential equations perturbed by a class of multiplicative noise including additive white noise case. As the noises are vanishing, various results on the invariance and concentration of the limit measures are obtained. In particular, we show that if the noise perturbed systems admit a uniform Lyapunov function, then the stationary measures form a relatively sequentially compact set whose weak∗-limits are invariant measures of the unperturbed system concentrated on its global attractor. In the case that the global attractor contains a strong local attractor, we further show that there exists a family of admissible multiplicative noises with respect to which all limit measures are actually concentrated on the local attractor; and on the contrary, in the presence of a strong local repeller in the global attractor, there exists a family of admissible multiplicative noises with respect to which no limit measure can be concentrated on the local repeller. Moreover, we show that if there is a strongly repelling equilibrium in the global attractor, then limit measures with respect to typical families of multiplicative noises are always concentrated away from the equilibrium. As applications of these results, an example of stochastic Hopf bifurcation and an example with non-decomposable ω-limit sets are provided. Our study is closely related to the problem of noise stability of compact invariant sets and invariant measures of the unperturbed system.

  7. High concentration agglomerate dynamics at high temperatures.

    Science.gov (United States)

    Heine, M C; Pratsinis, S E

    2006-11-21

    The dynamics of agglomerate aerosols are investigated at high solids concentrations that are typical in industrial scale manufacture of fine particles (precursor mole fraction larger than 10 mol %). In particular, formation and growth of fumed silica at such concentrations by chemical reaction, coagulation, and sintering is simulated at nonisothermal conditions and compared to limited experimental data and commercial product specifications. Using recent chemical kinetics for silica formation by SiCl4 hydrolysis and neglecting aerosol polydispersity, the evolution of the diameter of primary particles (specific surface area, SSA), hard- and soft-agglomerates, along with agglomerate effective volume fraction (volume occupied by agglomerate) is investigated. Classic Smoluchowski theory is fundamentally limited for description of soft-agglomerate Brownian coagulation at high solids concentrations. In fact, these high concentrations affect little the primary particle diameter (or SSA) but dominate the soft-agglomerate diameter, structure, and volume fraction, leading to gelation consistent with experimental data. This indicates that restructuring and fragmentation should affect product particle characteristics during high-temperature synthesis of nanostructured particles at high concentrations in aerosol flow reactors.

  8. Uranium concentration monitor manual: 2300 system

    International Nuclear Information System (INIS)

    Russo, P.A.; Sprinkle, J.K. Jr.; Stephens, M.M.

    1985-04-01

    This manual describes the design, operation, and procedures for measurement control for the automated uranium concentration monitor on the 2300 solvent extraction system at the Oak Ridge Y-12 Plant. The nonintrusive monitor provides a near-real time readout of uranium concentration at two locations simultaneously in the solvent extraction system for process monitoring and control. Detectors installed at the top of the extraction column and at the bottom of the backwash column acquire spectra of gamma rays from the solvent extraction solutions in the columns. Pulse-height analysis of these spectra gives the concentration of uranium in the organic product of the extraction column and in the aqueous product of the solvent extraction system. The visual readouts of concentrations for process monitoring are updated every 2 min for both detection systems. Simultaneously, the concentration results are shipped to a remote computer that has been installed by Y-12 to demonstrate automatic control of the solvent extraction system based on input of near-real time process operation information. 8 refs., 13 figs., 4 tabs

  9. Effects of various dietary arginine and lysine concentrations on plasma and liver cholesterol concentrations in rats.

    Science.gov (United States)

    Spielmann, Julia; Noatsch, Anne; Brandsch, Corinna; Stangl, Gabriele I; Eder, Klaus

    2008-01-01

    It has been hypothesized that the arginine:lysine ratio of dietary proteins influences cholesterol concentrations in plasma and liver of men and animals. This study was performed to test this hypothesis in rats by using diets with various concentrations of arginine and lysine, differing in their arginine:lysine ratios. Two experiments with growing rats were performed, some of which received diets containing 4.5, 9 or 18 g arginine/kg and 9 or 18 g lysine/kg, respectively, for a period of 21 days. In the first experiment, a cholesterol-free diet was used; in the second experiment, a diet supplemented with cholesterol and sodium cholate as hypercholesterolaemic compounds was used. In experiment 1, increasing the arginine concentration lowered HDL and plasma cholesterol concentration; however, cholesterol concentrations in liver, LDL and VLDL remained unchanged. In experiment 2, increasing the arginine concentration lowered HDL cholesterol and increased liver cholesterol (plysine concentration concerned the effect on VLDL and liver cholesterol concentration, which were both lower in rats fed the diets with 18 g lysine/kg than in those fed the diets with 9 g lysine/kg (parginine:lysine ratio between 0.25 and 2.0 had no influence on cholesterol concentration in LDL and VLDL in both experiments; HDL cholesterol concentration was lowered by increasing this ratio (parginine:lysine ratio causes hypocholesterolaemic effects in rats. Copyright 2008 S. Karger AG, Basel.

  10. Analysis of cream formation in green tea concentrates with different solid concentrations.

    Science.gov (United States)

    Xu, Yong-Quan; Chen, Su-Qin; Yuan, Hai-Bo; Tang, Ping; Yin, Jun-Feng

    2012-06-01

    The formation of tea cream in the green tea concentrates of different solid concentrations (5, 10, 20, 30, 40, 50 and 60°Brix) was investigated. The results showed a good positive correlation (γ = 0.98, p ≤ 0.05) between the amount of tea cream and the solid concentrations from 5 to 40°Brix, while the amount of tea cream in the tea concentrates of 50 and 60°Brix decreased acutely. Total sugar, caffeine and catechins were found to be the main chemical components of tea cream in the green tea concentrate. The large decrease of the amount of tea cream in the tea concentrates of 50 and 60°Brix may be induced by a sharp increase of the viscosity of the tea concentrates, which helped to improve the stability of tea concentrate. It may be indicated that the stability of green tea concentrate enhanced when the concentration higher than 50°Brix, which helped to restrain the formation of tea cream.

  11. Environmental impact of low concentrated wastes

    International Nuclear Information System (INIS)

    Barescut, J.C.

    1998-01-01

    A means to reduce the impact of a waste landfill is to limit its content so that after a reasonably short time, its radioactivity does not significantly exceed the natural level. For this means to be effective, it must be demonstrated that the system will not, in the long run, spontaneously evolve towards local sports of higher concentration. This process would require considerable converging migrations that would offer many opportunities for mixing and thus be inconsistent with concentration. Moreover, concentration is an energy-demanding process that will be limited by the availability of energy, especially in chemical form. For these reasons, it is wise to avoid placing a landfill where energy is likely to be more readily available than on the average. It is also advisable to avoid artificial protections, if their future evolution is not fully understood, since they necessarily contain an excess of energy relative to the undisturbed natural state. (author)

  12. Single Atoms in Nearly Concentric Cavity

    Science.gov (United States)

    Utama, Adrian Nugraha; Nguyen, Chi Huan; Lewty, Nick; Kurtsiefer, Christian; Quantum Optics Group Team

    2017-04-01

    Strong interaction between photons and neutral single atoms are usually observed in cavity quantum electrodynamics (CQED) systems with high finesse mirrors and small physical volume. We demonstrate another approach that employs a near concentric cavity with relatively low finesse mirrors ( 100) and large physical separation between mirrors ( 10 mm). The transmission spectrum of our CQED system with trapped single atoms is observed to exhibit two resolved normal mode peaks, in which the single atom cooperativity is estimated to be around 0.4. The cooperativity of the system can be improved further by increasing the finesse of the mirrors or moving the cavity closer to the concentric point. The successful realization of concentric CQED systems will open opportunities for scaling up with applications in quantum computing. This work is supported by the National Research Foundation and Ministry of Education, Singapore.

  13. Wafer integrated micro-scale concentrating photovoltaics

    Science.gov (United States)

    Gu, Tian; Li, Duanhui; Li, Lan; Jared, Bradley; Keeler, Gordon; Miller, Bill; Sweatt, William; Paap, Scott; Saavedra, Michael; Das, Ujjwal; Hegedus, Steve; Tauke-Pedretti, Anna; Hu, Juejun

    2017-09-01

    Recent development of a novel micro-scale PV/CPV technology is presented. The Wafer Integrated Micro-scale PV approach (WPV) seamlessly integrates multijunction micro-cells with a multi-functional silicon platform that provides optical micro-concentration, hybrid photovoltaic, and mechanical micro-assembly. The wafer-embedded micro-concentrating elements is shown to considerably improve the concentration-acceptance-angle product, potentially leading to dramatically reduced module materials and fabrication costs, sufficient angular tolerance for low-cost trackers, and an ultra-compact optical architecture, which makes the WPV module compatible with commercial flat panel infrastructures. The PV/CPV hybrid architecture further allows the collection of both direct and diffuse sunlight, thus extending the geographic and market domains for cost-effective PV system deployment. The WPV approach can potentially benefits from both the high performance of multijunction cells and the low cost of flat plate Si PV systems.

  14. Formaldehyde concentration in diagnostic patch testing

    DEFF Research Database (Denmark)

    Trattner, A; Johansen, J D; Menné, T

    1998-01-01

    Exposure to formaldehyde is common from both consumer products and industry. The reliability of the patch test is essential for the diagnosis of formaldehyde allergy as it is difficult to suspect from the patient's history. The recommended formaldehyde patch test concentration has been reduced over......% in consecutively patch-tested patients, with respect to frequency of positive patch test reactions, strength of patch test reactions to different formaldehyde test concentrations, irritancy and relevance. The study included 3734 consecutively patch tested patients. 121 gave a positive reaction to 1% and/or 2...... gave few additional positive cases compared to D 3/4. Problems related to relevance are discussed. Based on present knowledge, a 1% patch test concentration for formaldehyde is recommended....

  15. Theory of concentrated vortices an introduction

    CERN Document Server

    Alekseenko, S V; Okulov, V L

    2007-01-01

    Vortex motion is one of the basic states of a flowing continuum. Intere- ingly, in many cases vorticity is space-localized, generating concentrated vortices. Vortex filaments having extremely diverse dynamics are the most characteristic examples of such vortices. Notable examples, in particular, include such phenomena as self-inducted motion, various instabilities, wave generation, and vortex breakdown. These effects are typically ma- fested as a spiral (or helical) configuration of a vortex axis. Many publications in the field of hydrodynamics are focused on vortex motion and vortex effects. Only a few books are devoted entirely to v- tices, and even fewer to concentrated vortices. This work aims to highlight the key problems of vortex formation and behavior. The experimental - servations of the authors, the impressive visualizations of concentrated vortices (including helical and spiral) and pictures of vortex breakdown primarily motivated the authors to begin this work. Later, the approach based on the hel...

  16. Metrology of radon and thoron concentrations

    International Nuclear Information System (INIS)

    Durcik, M; Vicanova, M.

    1998-01-01

    The alpha spectrometry measurements of radon (radon-222) and thoron (radon-220) concentrations by ionisation chamber, used only in laboratory conditions are described in this paper. For the measurements of radon and thoron in dwellings and work areas was proposed diffusion double chamber detector with track detector. The described dosimeter is very useful for routine measurement and would be applied in measuring of radon and thoron concentrations in caves and dwellings. Big disadvantage of the dosimeter is small holes in cover and it could not be used in dusty areas. From previous measurements of the equilibrium equivalent thoron concentrations by semiconductor detector the measured values ranged from 0.1 to 5.6 Bq m -3 in the Slovak kindergartens were obtained

  17. Method of concentrating radioactive liquid waste

    International Nuclear Information System (INIS)

    Yasumura, Keijiro

    1990-01-01

    Radioactive liquid wastes generated from nuclear power facilities are caused to flow into a vessel incorporated with first hydrophobic porous membranes. Then, the radioactive liquid wastes are passed through the first hydrophobic porous membranes under an elevated or reduced pressure to remove fine particles contained in the liquid wastes. The radioactive liquid wastes passed through the first membranes are stored in a temporary store a vessel and steams generated under heating are passed through the second hydrophobic porous membranes and then cooled and concentrated as condensates. In this case, the first and the second hydrophobic porous membranes have a property of passing steams but not water and, for example, are made of tetrafluoroethylen resin type thin membranes. Accordingly, since the fine particles can be removed by the first hydrophobic porous membranes, lowering of the concentration rate due to the deposition of solid contents to the membranes upon concentration can be prevented. (I.S.)

  18. Stretched Lens Array Photovoltaic Concentrator Technology Developed

    Science.gov (United States)

    Piszczor, Michael F., Jr.; O'Neill, Mark J.

    2004-01-01

    Solar arrays have been and continue to be the mainstay in providing power to nearly all commercial and government spacecraft. Light from the Sun is directly converted into electrical energy using solar cells. One way to reduce the cost of future space power systems is by minimizing the size and number of expensive solar cells by focusing the sunlight onto smaller cells using concentrator optics. The stretched lens array (SLA) is a unique concept that uses arched Fresnel lens concentrators to focus sunlight onto a line of high-efficiency solar cells located directly beneath. The SLA concept is based on the Solar Concentrator Array with Refractive Linear Element Technology (SCARLET) design that was used on NASA's New Millennium Deep Space 1 mission. The highly successful asteroid/comet rendezvous mission (1998 to 2001) demonstrated the performance and long-term durability of the SCARLET/SLA solar array design and set the foundation for further improvements to optimize its performance.

  19. Thermogravimetric study of rare earth concentrates

    International Nuclear Information System (INIS)

    Delyagejd, V.V.; Anisimova, V.N.; Eremenko, Z.V.; Kutsev, V.S.

    1974-01-01

    Methods of thermogravimetric, chemical and phase analysis were used in measuring the concentration of rare-earth elements of different origins. At temperatures 400-800 deg C a gradual decomposition of fluorocarbonates takes place leading to the formation of derivatives of corresponding oxides and oxyfluorides. For concentrates containing siderite the process takes place at 550-600 deg C followed by oxidation of bivalent iron into trivalent state. Reaction of rare-earth elements with sodium carbonate and the increase in the concentration of the latter results in a narrowing down of the interval of temperatures at which decomposition takes place. Under these conditions an intense reaction and a fusion take place leading to the formation of eutectic at 500-600 deg C and further synthesis of sodium fluoride and oxyfluoride derivatives of calcium and rare-earth elements

  20. Fourth-generation photovoltaic concentrator system development

    Energy Technology Data Exchange (ETDEWEB)

    O`Neill, M.J.; McDanal, A.J. [ENTECH, Inc., Dallas-Fort Worth Airport, TX (United States)

    1995-10-01

    In 1991, under a contract with Sandia for the Concentrator Initiative, the ENTECH team initiated the design and development of a fourth-generation concentrator module. In 1992, Sandia also contracted with ENTECH to develop a new control and drive system for the ENTECH array. This report documents the design and development work performed under both contracts. Manufacturing processes for the new module were developed at the same time under a complementary PVMaT contract with the National Renewable Energy Laboratory. Two 100-kW power plants were deployed in 1995 in Texas using the newly developed fourth-generation concentrator technology, one at the CSW Solar Park near Ft. Davis and one at TUE Energy Park in Dallas. Technology developed under the Sandia contracts has made a successful transition from the laboratory to the production line to the field.

  1. Mechanisms of urine concentration and dilution (1961)

    International Nuclear Information System (INIS)

    Morel, F.; Guinnebault, M.

    1961-01-01

    This paper is devoted to the analysis of a problem in the field of renal physiology which has shown many new developments during the course of the last few years. The following are treated successively: a) the data obtained from measurements of free water clearance and their interpretation; b) the data provided by nephron morphology and the comparative anatomy of the kidney ; c) the data relative to the existence of an intrarenal osmotic gradient; d) the principle of concentration multiplication by a counter current technique; e) the present day theory of counter current concentration of urine, and f) the physiological check on dilution and concentration mechanisms in urine. Lastly, the advantages of the modern theory and the unknown factors which remain are discussed. (authors) [fr

  2. Transparent Solar Concentrator for Flat Panel Display

    Science.gov (United States)

    Yeh, Chia-Hung; Chang, Fuh-Yu; Young, Hong-Tsu; Hsieh, Tsung-Yen; Chang, Chia-Hsiung

    2012-06-01

    A new concept of the transparent solar concentrator for flat panel display is experimentally demonstrated without adversely affecting the visual effects. The solar concentrator is based on a solar light-guide plate with micro prisms, not only increasing the absorption area of solar energy but also enhancing the conversion efficiency. The incident light is guided by the designed solar light-guide plate according to the total internal reflection (TIR), and converted into electrical power by photovoltaic solar cells. The designed transparent solar concentrator was made and measured with high transparency, namely 94.8%. The developed solar energy system for display can store energy and supply the bias voltage to light on two light-emitting diodes (LEDs) successfully.

  3. A cellular glass substrate solar concentrator

    Science.gov (United States)

    Bedard, R.; Bell, D.

    1980-01-01

    The design of a second generation point focusing solar concentration is discussed. The design is based on reflective gores fabricated of thin glass mirror bonded continuously to a contoured substrate of cellular glass. The concentrator aperture and structural stiffness was optimized for minimum concentrator cost given the performance requirement of delivering 56 kWth to a 22 cm diameter receiver aperture with a direct normal insolation of 845 watts sq m and an operating wind of 50 kmph. The reflective panel, support structure, drives, foundation and instrumentation and control subsystem designs, optimized for minimum cost, are summarized. The use of cellular glass as a reflective panel substrate material is shown to offer significant weight and cost advantages compared to existing technology materials.

  4. Organic Wheat Farming Improves Grain Zinc Concentration

    Science.gov (United States)

    Helfenstein, Julian; Müller, Isabel; Grüter, Roman; Bhullar, Gurbir; Mandloi, Lokendra; Papritz, Andreas; Siegrist, Michael; Schulin, Rainer; Frossard, Emmanuel

    2016-01-01

    Zinc (Zn) nutrition is of key relevance in India, as a large fraction of the population suffers from Zn malnutrition and many soils contain little plant available Zn. In this study we compared organic and conventional wheat cropping systems with respect to DTPA (diethylene triamine pentaacetic acid)-extractable Zn as a proxy for plant available Zn, yield, and grain Zn concentration. We analyzed soil and wheat grain samples from 30 organic and 30 conventional farms in Madhya Pradesh (central India), and conducted farmer interviews to elucidate sociological and management variables. Total and DTPA-extractable soil Zn concentrations and grain yield (3400 kg ha-1) did not differ between the two farming systems, but with 32 and 28 mg kg-1 respectively, grain Zn concentrations were higher on organic than conventional farms (t = -2.2, p = 0.03). Furthermore, multiple linear regression analyses revealed that (a) total soil zinc and sulfur concentrations were the best predictors of DTPA-extractable soil Zn, (b) Olsen phosphate taken as a proxy for available soil phosphorus, exchangeable soil potassium, harvest date, training of farmers in nutrient management, and soil silt content were the best predictors of yield, and (c) yield, Olsen phosphate, grain nitrogen, farmyard manure availability, and the type of cropping system were the best predictors of grain Zn concentration. Results suggested that organic wheat contained more Zn despite same yield level due to higher nutrient efficiency. Higher nutrient efficiency was also seen in organic wheat for P, N and S. The study thus suggests that appropriate farm management can lead to competitive yield and improved Zn concentration in wheat grains on organic farms. PMID:27537548

  5. CONCENTRATION OF WORLD EXPORTS OF FOREST PRODUCTS

    Directory of Open Access Journals (Sweden)

    Luiz Moreira Coelho Junior

    2013-12-01

    Full Text Available http://dx.doi.org/10.5902/1980509812353This study analyzed the degree of concentration in worldwide exports of forest products in the period rangingfrom 1961 to 2008. The data used are available at the United Nations Food and Agriculture Organization(FAO. The concentration was determined by the concentration ratio [HR (k], the Herfindahl-HirschmanIndex (HHI, Theil Entropy Index (E and the Gini index (G. The main conclusions were: The aggregateBrazilian share in the world exports of forest products is increasing over time; the most important sectors inthe aggregate world exports of forest products, in decreasing order, were pulp, lumber, paper and cardboard,wooden panels, saw and fire wood. According to Bain, the concentration ratio of the four and eight largestexporters of forest products is moderately low; the HHI and Theil Entropy (E show a reduction in theconcentration of world exports of forest products and greater competition among the countries that sell suchproducts; the Gini index indicates that despite the increase in export of forest products over the period ofanalysis, a smaller number of competitors concentrate increasingly larger shares of international exports of these products; summary indices (HHI, E and G indicated that increased competition has not led to a moreequitable distribution of forest products so as to bring down inequalities and concentration of profits in thesector; despite the downward trend in CR (4 and CR (8, there is an increase in G, probably because theeconomies of scale in the international trade have been held by few competitors; caution is recommendedin the analysis of summary indices (HHI, E and G which had better be checked jointly with the partialindices [CR (k] in order to avoid wrong conclusions; countries with a significant share in total exports, suchas Brazil, should seek business strategies to retain competitive advantages, especially those arising fromeconomies of scale.

  6. Organic Wheat Farming Improves Grain Zinc Concentration.

    Directory of Open Access Journals (Sweden)

    Julian Helfenstein

    Full Text Available Zinc (Zn nutrition is of key relevance in India, as a large fraction of the population suffers from Zn malnutrition and many soils contain little plant available Zn. In this study we compared organic and conventional wheat cropping systems with respect to DTPA (diethylene triamine pentaacetic acid-extractable Zn as a proxy for plant available Zn, yield, and grain Zn concentration. We analyzed soil and wheat grain samples from 30 organic and 30 conventional farms in Madhya Pradesh (central India, and conducted farmer interviews to elucidate sociological and management variables. Total and DTPA-extractable soil Zn concentrations and grain yield (3400 kg ha-1 did not differ between the two farming systems, but with 32 and 28 mg kg-1 respectively, grain Zn concentrations were higher on organic than conventional farms (t = -2.2, p = 0.03. Furthermore, multiple linear regression analyses revealed that (a total soil zinc and sulfur concentrations were the best predictors of DTPA-extractable soil Zn, (b Olsen phosphate taken as a proxy for available soil phosphorus, exchangeable soil potassium, harvest date, training of farmers in nutrient management, and soil silt content were the best predictors of yield, and (c yield, Olsen phosphate, grain nitrogen, farmyard manure availability, and the type of cropping system were the best predictors of grain Zn concentration. Results suggested that organic wheat contained more Zn despite same yield level due to higher nutrient efficiency. Higher nutrient efficiency was also seen in organic wheat for P, N and S. The study thus suggests that appropriate farm management can lead to competitive yield and improved Zn concentration in wheat grains on organic farms.

  7. Beryllium concentration in pharyngeal tonsils in children

    Directory of Open Access Journals (Sweden)

    Ewa Nogaj

    2014-06-01

    Full Text Available Power plant dust is believed to be the main source of the increased presence of the element beryllium in the environment which has been detected in the atmospheric air, surface waters, groundwater, soil, food, and cigarette smoke. In humans, beryllium absorption occurs mainly via the respiratory system. The pharyngeal tonsils are located on the roof of the nasopharynx and are in direct contact with dust particles in inhaled air. As a result, the concentration levels of beryllium in the pharyngeal tonsils are likely to be a good indicator of concentration levels in the air. The presented study had two primary aims: to investigate the beryllium concentration in pharyngeal tonsils in children living in southern Poland, and the appropriate reference range for this element in children’s pharyngeal tonsils. Pharyngeal tonsils were extracted from a total of 379 children (age 2–17 years, mean 6.2 ± 2.7 years living in southern Poland. Tonsil samples were mineralized in a closed cycle in a pressure mineralizer PDS 6, using 65% spectrally pure nitric acid. Beryllium concentration was determined using the ICP-AES method with a Perkin Elmer Optima 5300DVTM. The software Statistica v. 9 was used for the statistical analysis. It was found that girls had a significantly greater beryllium concentration in their pharyngeal tonsils than boys. Beryllium concentration varies greatly, mostly according to the place of residence. Based on the study results, the reference value for beryllium in pharyngeal tonsils of children is recommended to be determined at 0.02–0.04 µg/g.

  8. OZONE CONCENTRATION ATTRIBUTABLE PREMATURE DEATH IN POLAND

    Directory of Open Access Journals (Sweden)

    Krzysztof Skotak

    2010-03-01

    Full Text Available Ozone in the lower part of the atmosphere (troposphere, strong photochemical oxidant, is not directly emitted to the atmosphere but formed through a series of complex reactions. Ozone concentrations depends on ozone precursors air contamination (mainly nitrogen dioxide and non-methane volatile organic compounds and meteorological conditions (temperature and solar radiation. The main sectors emitted ozone precursors are road transport, power and heat generation plants, household (heating, industry, and petrol storage and distribution. Ozone and some of its precursors are also transported long distances in the atmosphere and are therefore considered a transboundary problem. As a result, the ozone concentrations are often low in busy urban areas and higher in suburban and rural areas. Nowadays, instead of particulate matter, ozone is one of the most widespread global air pollution problems. In and around urban areas, relatively large gradients of ozone can be observed. Because of its high reactivity in elevated concentrations ozone causes serious health problems and damage to ecosystems, agricultural crops and materials. Main ill-health endpoints as a results of ozone concentrations can be characterised as an effect of pulmonary and cardiovascular system, time morbidity and mortality series, development of atherosclerosis and asthma and finally reduction in life expectancy. The associations with increased daily mortality due to ozone concentrations are confirmed by many researches and epidemiological studies. Estimation of the level selected ill-health endpoints (mortality in total and due to cardiovascular and respiratory causes as a result of the short-term ozone exposure in Poland was the main aim of the project. Final results have been done based on estimation method elaborated by WHO, ozone measurements from National Air Quality Monitoring System and statistical information such as mortality rate and populations. All analysis have been done in

  9. Stress Concentration around Holes in Anistropic Sheets

    DEFF Research Database (Denmark)

    Krenk, Steen

    1979-01-01

    of singularities on smooth curves is then treated, and general formulae for the stress discontinuities are given. Finally, the integral equations arising from stress boundary conditions are discussed, and the characteristics and numerical solution of one of the types are treated in detail.......The formulation of stress concentration problems of plane anisotropic elasticity in terms of integral equations is discussed. First the singular solutions of a concentrated force and a dislocation are formulated so that they remain valid in the case of double roots. The distribution...

  10. Preparation of counterion stabilized concentrated silver sols.

    Science.gov (United States)

    LaPlante, Sylas; Halaciuga, Ionel; Goia, Dan V

    2011-07-01

    A strategy for obtaining stable concentrated silver dispersions without dedicated stabilizing agents is presented. This approach consists of rapidly mixing aqueous solutions of silver salicylate and ascorbic acid. By using salicylate as Ag(+) counterion, it is possible to prepare stable sols with metal concentrations up to two orders of magnitude higher than with silver nitrate. The stabilizing effect of the counterion is the result of a decreased ionic strength due to salicylate protonation and its adsorption on the surface of silver. Both effects increase the range of the electrostatic repulsive forces by expanding the electrical double layer. Copyright © 2011 Elsevier Inc. All rights reserved.

  11. Seasonal Variation in Human Salivary Cortisol Concentration

    DEFF Research Database (Denmark)

    Persson, Roger; Garde, Anne Helene; Hansen, Åse Marie

    2008-01-01

    is the lack of observations of the impact of seasonal changes on cortisol excretion. For this reason, the month-to-month changes in diurnal cortisol concentration, the awakening cortisol response (ACR), maximum morning concentration, and fall during the day were studied in a group of 24 healthy men and women...... 32 to 61 yrs of age engaged in active work. On one workday for 12 consecutive months, participants collected saliva at four time points for determination of cortisol: at awakening, +30 min, +8 h, and at 21:00 h. Data were analyzed by a repeated measures design with month (12 levels) and time...

  12. Plasma concentration of acetylcholine in young women

    International Nuclear Information System (INIS)

    Kawashima, K.; Oohata, H.; Fujimoto, K.; Suzuki, T.

    1987-01-01

    A sensitive and specific radioimmunoassay was applied to the determination of acetylcholine (ACh) in plasma. The concentration of ACh in plasma sampled from 32 young women was 456.1+-53.1 (mean +-S.E.M.) pg/ml. No significant correlations were observed between plasma concentrations of ACh and acetylcholinesterase (AChE) activity, or gonadal hormones. These data demonstrate that an amount of ACh measurable by radioimmunoassay is present in plasma and plasma ACh is not regulated by AChE activity and the menstrual cycle in young women. The origin and physiological as well as pathophysiological significance of ACh in plasma remain to be clarified. 13 refs. (Author)

  13. Serum potassium concentrations: Importance of normokalaemia.

    Science.gov (United States)

    Heras, Manuel; Fernández-Reyes, María José

    2017-06-21

    Abnormalities in potassium concentrations are associated with morbidity and mortality. In recent years it has been considered that small variations in serum potassium concentrations within normal intervals may also be associated with mortality. Strategies for achieving normokalaemia include dietary measures, limiting the use of potassium retaining drugs, and use of conventional cation exchange resins (calcium/sodium polystyrene sulfonate) and/or the new non-absorbed cation exchange polymer (patiromer). Copyright © 2017 Elsevier España, S.L.U. All rights reserved.

  14. High efficiency compound semiconductor concentrator photovoltaics

    Science.gov (United States)

    Borden, P.; Gregory, P.; Saxena, R.; Owen, R.; Moore, O.

    1980-01-01

    Special emphasis was given to the high yield pilot production of packaged AlGaAs/GaAs concentrator solar cells, using organometallic VPE for materials growth, the demonstration of a concentrator module using 12 of these cells which achieved 16.4 percent conversion efficiency at 50 C coolant inlet temperature, and the demonstration of a spectral splitting converter module that achieved in excess of 20 percent efficiency. This converter employed ten silicon and ten AlGaAs cells with a dichroic filter functioning as the beam splitter. A monolithic array of AlGaAs/GaAs solar cells is described.

  15. Resonance-shifting luminescent solar concentrators

    Energy Technology Data Exchange (ETDEWEB)

    Giebink, Noel Christopher; Wiederrecht, Gary P; Wasielewski, Michael R

    2014-09-23

    An optical system and method to overcome luminescent solar concentrator inefficiencies by resonance-shifting, in which sharply directed emission from a bi-layer cavity into a glass substrate returns to interact with the cavity off-resonance at each subsequent reflection, significantly reducing reabsorption loss en route to the edges. In one embodiment, the system comprises a luminescent solar concentrator comprising a transparent substrate, a luminescent film having a variable thickness; and a low refractive index layer disposed between the transparent substrate and the luminescent film.

  16. Time-series analysis for ambient concentrations

    Science.gov (United States)

    González-Manteiga, W.; Prada-Sánchez, J. M.; Cao, R.; García-Jurado, I.; Febrero-Bande, M.; Lucas-Domínguez, T.

    In this paper we present a dynamic system which has been implemented to predict, every 5 min, the ambient concentrations of SO 2 in the neighbourhood of a power station run by ENDESA, the National Electricity Company of Spain, in As Pontes. This prediction task is very important in order to prevent a high ground-level of concentration of SO 2. For forecasting we use a mixed model which has a parametric component and a nonparametric one. We also construct confidence intervals for future observations using bootstrap and classical techniques.

  17. Stress concentrations in nanoscale defective graphene

    Science.gov (United States)

    Wang, Congwei; Wang, Junzhong; Barber, Asa H.

    2017-11-01

    Defect-free graphene nanosheets are the strongest material known but manufactured graphene tends to contain flaws of different forms and dimensions, leading to the degradation of mechanical performance. Here we report a quantitative mechanical approach to quantitatively evaluate the influence of defects within exfoliated pristine graphene sheets. Results indicate stress concentrations around defects within graphene sheets that lower strength. The description of stress concentration broadly follows a Griffith strength approach for continuum materials, despite the non-continuum structure of graphene, but has little impact on the Young's modulus.

  18. Resonance-shifting luminescent solar concentrators

    Energy Technology Data Exchange (ETDEWEB)

    Giebink, Noel Christopher; Wiederrecht, Gary P.; Wasielewski, Michael R.

    2018-01-23

    An optical system and method to overcome luminescent solar concentrator inefficiencies by resonance-shifting, in which sharply directed emission from a bi-layer cavity into a glass substrate returns to interact with the cavity off-resonance at each subsequent reflection, significantly reducing reabsorption loss en route to the edges. In one embodiment, the system comprises a luminescent solar concentrator comprising a transparent substrate, a luminescent film having a variable thickness; and a low refractive index layer disposed between the transparent substrate and the luminescent film.

  19. Advertising and Concentration in the Brewing Industry

    DEFF Research Database (Denmark)

    Madsen, Erik Strøjer; Wu, Yanqing

    2014-01-01

    The paper tracks the development in industry concentrations from 2002 to 2012, discusses some of the main drivers behind this development and points to economies of scale in advertising as a main pay-off from mergers and acquisitions. Using firm-level data both from the American market and the wo......The paper tracks the development in industry concentrations from 2002 to 2012, discusses some of the main drivers behind this development and points to economies of scale in advertising as a main pay-off from mergers and acquisitions. Using firm-level data both from the American market...

  20. Design package for concentrating solar collector panels

    Energy Technology Data Exchange (ETDEWEB)

    1978-08-01

    Information used to evaluate the design of the Northrup concentrating collector is presented. Included are the system performance specifications, the applications manual, and the detailed design drawings of the collector. The Northrup concentrating solar collector is a water/glycol/working fluid type, dipped galvanized steel housing, transparent acrylic Fresnel lens cover, copper absorber tube, fiber glass insulation and weighs 98 pounds. The gross collector area is about 29.4/sup 2/ per collector. A collector assembly includes four collector units within a tracking mount array.

  1. Leaching of copper concentrates using NaCl and soluble copper contributed by the own concentrate

    International Nuclear Information System (INIS)

    Herrero, O.; Bernal, N.; Quiroz, R.; Fuentes, G.; Vinals, J.

    2005-01-01

    Leaching of copper concentrates using cupric chloro complexes, generated in situ by the reaction between Cu(II), aported by the soluble copper content of the concentrate, and sodium chloride in acid media was studied. The concentrate samples were obtained from mineral processing plants from Antofagasta, Chile. Chemical and mineralogical characterization from original concentrates was made. Typical variable such as a chloride concentration, soluble copper concentration, leaching time, solid percentage and temperature were studied. DRX and EDS analyzed some of the residues. the experimental results indicated that it is possible to obtain solutions having high copper content (15 to 35 g/L) and 2 to 5 g/L free acid in order to submit this solution directly to a solvent extraction stage. The leaching tests use common reactive and low cost such as sodium chloride and sulfuric acid. (Author) 16 refs

  2. Concentrating Photovoltaic Module Testing at NREL's Concentrating Solar Radiation Users Facility

    Energy Technology Data Exchange (ETDEWEB)

    Bingham, C.; Lewandowski, A.; Stone, K.; Sherif, R.; Ortabasi, U.; Kusek, S.

    2003-05-01

    There has been much recent interest in photovoltaic modules designed to operate with concentrated sunlight (>100 suns). Concentrating photovoltaic (CPV) technology offers an exciting new opportunity as a viable alternative to dish Stirling engines. Advantages of CPV include potential for>40% cell efficiency in the long term (25% now), no moving parts, no intervening heat transfer surface, near-ambient temperature operation, no thermal mass, fast response, concentration reduces cost of cells relative to optics, and scalable to a range of sizes. Over the last few years, we have conducted testing of several CPV modules for DOEs Concentrating Solar Power (CSP) program. The testing facilities are located at the Concentrating Solar Radiation Users Facility (CRULF) and consist the 10 kW High-Flux Solar Furnace (HFSF) and a 14m2 Concentrating Technologies, LLC (CTEK) dish. This paper will primarily describe the test capabilities; module test results will be detailed in the presentation.

  3. Experimental characterization of a concentrating photovoltaic system varying the light concentration

    International Nuclear Information System (INIS)

    Renno, C.; Petito, F.; Landi, G.; Neitzert, H.C.

    2017-01-01

    Highlights: • Experimental characterization of a concentrating photovoltaic system. • Analysis of the point-focus concentrating system performances. • Photovoltaic system parameters as function of the concentration factor. - Abstract: The concentrating photovoltaic system represents one of the most promising solar technologies because it allows a more efficient energy conversion. When a CPV system is designed, the main parameter which has to be considered is the concentration factor that affects both the system energy performances and its configuration. An experimental characterization of a CPV system previously realized at the University of Salerno, is presented in this paper considering several aspects related to the optical configuration, the concentration factor and the solar cell used. In particular, the parameters of an Indium Gallium Phosphide/Gallium Arsenide/Germanium triple-junction solar cell are investigated as function of the concentration factor determined by means of an experimental procedure that uses different optical configurations. The maximum concentration factor reached by the CPV system is 310 suns. The cell parameters dependence on the concentration is reported together with an electroluminescence analysis of the Indium Gallium Phosphide/Gallium Arsenide/Germanium cell. A monitoring of the electrical power provided by the system during its working is also presented corresponding to different direct irradiance values. A mean power of 2.95 W with an average efficiency of 32.8% is obtained referring to a mean irradiance of 930 W/m 2 ; lower values are obtained when the irradiance is highly fluctuating. The concentrating photovoltaic system electric energy output is estimated considering different concentration levels; the maximal obtained value is 23.5 W h on a sunny day at 310×. Finally, the temperature of the triple-junction solar cell is evaluated for different months in order to evaluate the potential annual thermal energy production

  4. Effect of Crude Protein Levels in Concentrate and Concentrate Levels in Diet on Fermentation

    Directory of Open Access Journals (Sweden)

    Dinh Van Dung

    2014-06-01

    Full Text Available The effect of concentrate mixtures with crude protein (CP levels 10%, 13%, 16%, and 19% and diets with roughage to concentrate ratios 80:20, 60:40, 40:60, and 20:80 (w/w were determined on dry matter (DM and organic matter (OM digestibility, and fermentation metabolites using an in vitro fermentation technique. In vitro fermented attributes were measured after 4, 24, and 48 h of incubation respectively. The digestibility of DM and OM, and total volatile fatty acid (VFA increased whereas pH decreased with the increased amount of concentrate in the diet (p<0.001, however CP levels of concentrate did not have any influence on these attributes. Gas production reduced with increased CP levels, while it increased with increasing concentrate levels. Ammonia nitrogen (NH3-N concentration and microbial CP production increased significantly (p<0.05 by increasing CP levels and with increasing concentrate levels in diet as well, however, no significant difference was found between 16% and 19% CP levels. Therefore, 16% CP in concentrate and increasing proportion of concentrate up to 80% in diet all had improved digestibility of DM and organic matter, and higher microbial protein production, with improved fermentation characteristics.

  5. Analysis of cream formation in green tea concentrates with different solid concentrations

    OpenAIRE

    Xu, Yong-Quan; Chen, Su-Qin; Yuan, Hai-Bo; Tang, Ping; Yin, Jun-Feng

    2011-01-01

    The formation of tea cream in the green tea concentrates of different solid concentrations (5, 10, 20, 30, 40, 50 and 60°Brix) was investigated. The results showed a good positive correlation (γ = 0.98, p ≤ 0.05) between the amount of tea cream and the solid concentrations from 5 to 40°Brix, while the amount of tea cream in the tea concentrates of 50 and 60°Brix decreased acutely. Total sugar, caffeine and catechins were found to be the main chemical components of tea cream in the green tea c...

  6. Determination of acrylamide concentration in processed food ...

    African Journals Online (AJOL)

    Currently, acrylamide concentration in processed food products have become a very serious health issue. The World Health Organization (WHO) and the Scientific Committee for Food (SCF) of the European Union also confirmed this concern. In laboratory scale, it was found that acrylamide causes tumors in animals.

  7. Failure Analysis of Sapphire Refractive Secondary Concentrators

    Science.gov (United States)

    Salem, Jonathan A.; Quinn, George D.

    2009-01-01

    Failure analysis was performed on two sapphire, refractive secondary concentrators (RSC) that failed during elevated temperature testing. Both concentrators failed from machining/handling damage on the lens face. The first concentrator, which failed during testing to 1300 C, exhibited a large r-plane twin extending from the lens through much of the cone. The second concentrator, which was an attempt to reduce temperature gradients and failed during testing to 649 C, exhibited a few small twins on the lens face. The twins were not located at the origin, but represent another mode of failure that needs to be considered in the design of sapphire components. In order to estimate the fracture stress from fractographic evidence, branching constants were measured on sapphire strength specimens. The fractographic analysis indicated radial tensile stresses of 44 to 65 MPa on the lens faces near the origins. Finite element analysis indicated similar stresses for the first RSC, but lower stresses for the second RSC. Better machining and handling might have prevented the fractures, however, temperature gradients and resultant thermal stresses need to be reduced to prevent twinning.

  8. RHEOLOGY OF CONCENTRATED SOLUTIONS OF HYPERBRANCHED POLYESTERS

    Science.gov (United States)

    The solution rheology of different generations of hyperbranched polyesters in N-methyl-2- pyrrolidinone (NMP) solvent was examined in this study. The solutions exhibited Newtonian behavior over a wide range of polyester concentrations. Also, the relative viscosities of poly(amido...

  9. Formoterol concentrations in blood and urine

    DEFF Research Database (Denmark)

    Eibye, Kasper; Elers, Jimmi; Pedersen, Lars

    2013-01-01

    We examined urinary and serum concentrations of formoterol in asthmatic and healthy individuals after a single dose of 18 μg inhaled formoterol and after repeated inhaled doses in healthy individuals. Results were evaluated using the World Anti-Doping Agency (WADA) 2012 threshold for formoterol....

  10. Concentration of 210Po in cigars

    International Nuclear Information System (INIS)

    Kelecom, Alphonse; Gouvea, Rita C.S.; Santos, Pedro L.

    2000-01-01

    210 Po concentrations have been determined in 57 different cigar brands manufactured in 11 countries. Cuban and American cigars showed the lowest 210 Po content. The mean levels of 210 Po in Brazilian cigars were almost equal to those of European and Dominican cigars, and somewhat lower than cigars from Central American countries. (author)

  11. Serum testosterone concentration in chloroquine- treated rats ...

    African Journals Online (AJOL)

    ONOS

    2010-07-05

    Jul 5, 2010 ... The effects of ascorbic acid (vitamin C) and alpha-tocopherol (vitamin E) were studied on serum testosterone ... chloroquine are probably mediated via the generation of free radicals. ... Effects of ascorbic acid and alpha-tocopherol on serum testosterone concentration in chloroquine-treated rats. Groups.

  12. Atmospheric Concentrations of Organochlorine Pesticides in the ...

    African Journals Online (AJOL)

    Organochlorine pesticides may still be in use in the Eastern African region for agricultural purposes and for the control of mosquitoes. Atmospheric concentrations of organochlorine pesticides are expected to be higher in the tropics compared to temperate regions due to prevailing high temperatures. However, no study has ...

  13. 75 FR 23764 - Correspondent Concentration Risks

    Science.gov (United States)

    2010-05-04

    ... Concentration. \\1\\ There are 5 derivative contracts with a mark-to-market fair value position as follows.... \\1\\ There are 5 derivative contracts with a mark-to-market fair value position as follows: Contract 1... competitive disadvantage to large institutions due to a perception of large institutions being ``too big to...

  14. Ozone concentration dependent autohaemotherapy effects on ...

    African Journals Online (AJOL)

    Although ozone is widely used as an alternative medicine, its safety and efficiency are met with scepticism. To shed some light on this, we assessed the effect of ozone-autohaemotherapy, using an. O2/O3 gas mixture containing three different O3 concentrations (20, 40 and 80 ìg/ml), on the antioxidant status and lymphocyte ...

  15. Characterization of ethanol concentrations at ultraviolet wavelength ...

    African Journals Online (AJOL)

    This paper presents the measurement of optical absorption spectrum for different concentrations of ethanol at ultraviolet wavelength. Ethanol absorption spectrum was measured using portable spectroscopy setup from Avantes. It consists of Balanced Deuterium Halogen light source and spectrometer. The light source can ...

  16. Estimation of suspended sediment concentration by acoustic ...

    African Journals Online (AJOL)

    concentration of sediments such as glass spheres or sand. However, the acoustic properties of natural sediments vary and depend on many parameters such as particle size, shape, mineralogy and distribution of those parameters in sample. Therefore, this study was conducted to determine the possibility of soil sediment ...

  17. Size segregated aerosol mass concentration measurements over ...

    Indian Academy of Sciences (India)

    Mass concentration and mass size distribution of total (composite) aerosols near the surface are essential inputs needed in developing aerosol models for radiative forcing estimation as well as to infer the environment and air quality. Using extensive measurements onboard the oceanographic research vessel, Sagar Kanya ...

  18. Investigation on the Methaemoglobin Concentration of Three ...

    African Journals Online (AJOL)

    Investigation to ascertain the levels of methaemoglobin concentration of three human erythrocyte genotypes (HbAA, HbAS and HbSS) obtained from apparently healthy and clinically confirmed malarious subjects/volunteers was carried out. Spectrophotometric method was used for the determination of erythrocyte ...

  19. Concentrating or scattering management in agricultural landscapes

    NARCIS (Netherlands)

    Hammers, Martijn; Müskens, Gerard J.D.M.; Kats, van Ruud J.M.; Teunissen, Wolf A.; Kleijn, David

    2016-01-01

    A key issue in conservation is where and how much management should be implemented to obtain optimal biodiversity benefits. Cost-effective conservation requires knowledge on whether biodiversity benefits are higher when management is concentrated in a few core areas or scattered across the

  20. Serum testosterone concentration in chloroquinetreated rats: effects ...

    African Journals Online (AJOL)

    The effects of ascorbic acid (vitamin C) and alpha-tocopherol (vitamin E) were studied on serum testosterone concentration in chloroquine-treated rats. Thirty five (35) adult male rats weighing 160 - 200 g were divided into seven groups of five (5) rats each. Group I rats served as the control and received 2 ml/kg of normal ...

  1. Tritium concentrations in some European foods

    International Nuclear Information System (INIS)

    Hisamatsu, Shun'ichi; Takizawa, Yukio

    1989-01-01

    Tritium concentrations in some European foods imported into Japan are reported here. The specific activity ratio of so-called tissue-bound 3 H to free water 3 H was found to be lower than that previously reported by European and American research groups. This discrepancy might be caused by the difference in sampling year and/or by analytical problems. (author)

  2. Urine ethanol concentration and alcohol hangover severity

    NARCIS (Netherlands)

    Brookhuis, Karel; Van De Loo, Aurora; Mackus, M.; Verster, Joris

    Background The aim of this study was to examine the relationship between urine ethanol concentration and alcohol hangover severity. Methods N = 36 healthy social drinkers participated in a naturalistic study, comprising a hangover day and a control day. N = 18 of them have regular hangovers (the

  3. Effect of Concentrate Supplementation on Reproductive ...

    African Journals Online (AJOL)

    A study was conducted in Rungwe district in Tanzania, to assess the effect of concentrate supplementation on reproductive performance of smallholder dairy cattle. Cattle used were crossbreds, mainly between Friesian (Bos taurus) and indigenous Tanzania Short Horn Zebu (Bos indicus). All animals were managed under ...

  4. Cutting feedwater oxygen concentrations by catalysis

    International Nuclear Information System (INIS)

    Anon.

    1987-01-01

    Designed to reduce oxygen concentrations in water storage and makeup systems from fully aerated conditions of 8000ppb to 10ppb in a single pass, the Westinghouse catalytic oxygen removal system (CORS) is a proven alternative to other methods of deoxygenation. (author)

  5. Estimation of Toxicity Equivalent Concentration (TEQ) of ...

    African Journals Online (AJOL)

    Estimation of Toxicity Equivalent Concentration (TEQ) of carcinogenic polycyclic aromatic hydrocarbons in soils from Idu Ekpeye playground and University of Port ... Effective soil remediation and detoxification method like Dispersion by chemical reaction technology should be deployed to clean-up sites to avoid soil toxicity ...

  6. 21 CFR 155.191 - Tomato concentrates.

    Science.gov (United States)

    2010-04-01

    ... material is restored to a pH of 4.2±0.2. Water may be added to adjust the final composition. The food... considered added salt). (ii) Lemon juice, concentrated lemon juice, or organic acids. (iii) Sodium bicarbonate. (iv) Water, as provided for in paragraph (a)(1) of this section. (v) Spices. (vi) Flavoring. (3...

  7. Self absorption in luminescent solar concentrators

    NARCIS (Netherlands)

    Krumer, Z.

    2014-01-01

    Luminescent solar concentrators are photovoltaic devices made of thin transparent material, in which luminescent particles are dispersed. The incident light enters the device through its large facets and is subsequently absorbed by the luminescent particles, which re-emit it whilst changing its

  8. The concentrations of methaemoglobin, carboxyhaemoglobin and ...

    African Journals Online (AJOL)

    Methaemoglobin, carboxyhaemoglobin concentrations and some haematological parameters were studied in fifty tobacco snuff addicts (40 males and 10 females) in some villages of Anambra State, Nigeria. The aim was to investigate possible adverse effects of tobacco snuff in addicts in Igbos of Anambra State.

  9. Concentration of lemon pectin extract by ultrafiltration

    Directory of Open Access Journals (Sweden)

    Damián Stechina

    2012-09-01

    Full Text Available Current annual lemon production in Argentina is about 900 thousand t. 75% is used industrially to obtain pasteurized juice concentrate. Since 40 - 45 % of citrus fruit content is peel and seeds, the annual lemon residue yield is 360 thousand t. Lemon peel contains about 30% (B.S. of peptic substances with an important commercial value due to its gelling and thickening properties for food, chemical, pharmacological and cosmetic products. Membrane processes have many applications in food manufacture. The objective of this study is to analyze the influence of ultrafiltration operating variables on instant permeate flow (Fp and on the energy requirement for pectin extract concentration from lemon peel. A DDS lab module was used, lab 20-772 model with synthetic material membranes, 9 kDa, shear force, the intrinsic membrane resistance (Rm being 3*1013 m -1 . Results show that Fp decrease caused by polarization induced resistance occurrence and the influence of operating variables on Fp offer relevant data to estimate the energy requirement in relation to feeding flow at constant temperature, which may be compared to pectin concentration increase in the retained flow in relation to initial extract concentration.

  10. Multiple-Panel Cylindrical Solar Concentrator

    Science.gov (United States)

    Brown, E. M.

    1983-01-01

    Trough composed of many panels concentrates Sun's energy on solar cells, even when trough is not pointed directly at Sun. Tolerates deviation as great as 5 degrees from direction of sun. For terrestrial applications, multiple-flat-plate design offers potential cost reduction and ease of fabrication.

  11. Heat stability of concentrated skim milk

    NARCIS (Netherlands)

    Nieuwenhuijse, J.A.

    1992-01-01

    Heat-induced coagulation of concentrated skim milk was studied. Heat-induced changes in partition between serum and colloidal particles of calcium and phosphate and of the various proteins were investigated as a function of heating time and conditions like pH, addition of phosphate and

  12. Electromyographic comparison of concentric and eccentric ...

    African Journals Online (AJOL)

    The study was conducted to compare the Electromyographic (EMG) activity variation of contractions (concentric and eccentric) during three different abdominal exercises (sit-up) exercises on rectus abdominal (upper and lower rectus). The sit-up exercises were: straight leg sit-up, bent leg sit-up and crunches. The EMG ...

  13. Body weight, scrotal circumference and testosterone concentration ...

    African Journals Online (AJOL)

    The aim of this study was to compare testosterone concentration, body weight, scrotal circumference and age to penis detachment from days 30 to 240 in young Boer goat males (n = 22) born during the dry (n = 11) and the rainy (n = 11) seasons. In the dry season the parameters varied as follows: body weight from 3.7 ± 1.1 ...

  14. Electronic design of air dust concentration gauge

    International Nuclear Information System (INIS)

    Machaj, B.; Strzalkowski, J.; Krawczynska, B.

    1993-01-01

    A new version of isotope dust concentration gauge for monitoring airborne dust pollution of air employs a ready made personal computer as the control and processing unit in the gauge instead of specialized electronics. That solution of the gauge reduces the needed specialized electronics to a simple computer interface coupling the computer to the measuring head. This also reduced electronics of the measuring head itself, i.e. GM detector circuit, power supplies and electronic circuits to switch on/off driving motors. The functioning and operation of the gauge is controlled by the computer program that can be easily modified if needed. The computer program for the gauge enables automatic measurements of dust concentration. Up to fifty measuring cycles can be easily programmed for a day. The results of measurements are presented in the form of data collection, diagram of dust concentration distribution during one day, diagram of dust distribution during 30 successive days or diagram of average dust concentration distribution during a day which may be computed by combining data of the selected number of measurements. Recalibration of the gauge and checking up of the gauge are also carried out under the program control. (author). 6 refs, 9 figs

  15. Low chemical concentrating steam generating cycle

    Science.gov (United States)

    Mangus, James D.

    1983-01-01

    A steam cycle for a nuclear power plant having two optional modes of operation. A once-through mode of operation uses direct feed of coolant water to an evaporator avoiding excessive chemical concentration buildup. A recirculation mode of operation uses a recirculation loop to direct a portion of flow from the evaporator back through the evaporator to effectively increase evaporator flow.

  16. Plasma Ascorbic Acid Concentration and some Haematological ...

    African Journals Online (AJOL)

    Aim: To determine the plasma ascorbic acid concentration, haematocrit, reticulocyte count and blood cell morphology in homozygous sickle cell disease in Enugu metropolis. Materals and Methods: Forty known sickle cell anaemia patients (HbSS) and ten non-sicklers (HbAA) were used as tests and controls respectively.

  17. AUDIT MARKET CONCENTRATION – EVIDENCE FROM CROATIA

    Directory of Open Access Journals (Sweden)

    Sanja Sever Mališ

    2015-12-01

    Full Text Available Statutory audit is designated to protect the public interest and has a significant impact on the overall economy. There are concerns that the Big Four audit firms have become too dominant and that the collapse of one of these firms would disrupt the whole financial system. In terms of revenues received, the total market share of the Big Four audit firms for listed companies exceeds 90% in a vast majority of European Union Member States. Prior studies have shown that high audit market concentration limits the choice of auditor for large companies and sets a high barrier of entry for mid-tier audit firms, while the effect on audit quality and audit fees is still unclear. Therefore, the regulators are considering reforms to dilute the Big Four’s dominance and improve competition in the audit market. The paper reviews the proposed and implemented measures that are the most common, together with their advantages and drawbacks. In addition, the characteristics of the audit market in Croatia are investigated, with a focus on market concentration measured by standard measures such as the Concentration rate, the Herfindahl Hirschman Index and the Gini coefficient. According to market shares based on total clients’ assets and revenues, the audit market for listed companies is moderately to highly concentrated, with a decrease in the five-year period (2013 compared to 2008.

  18. VISCOSITY OF CONCENTRATED POTATO-STARCH PASTES

    NARCIS (Netherlands)

    LAMMERS, G; BEENACKERS, AACM

    1994-01-01

    A new viscosity equation for the description of the viscosity of concentrated aqueous starch pastes is proposed: eta(app) = Ke([Bmstarch+(C/T)-DW+(n-1)ln gamma]) with: m(starch) = mass fraction starch in paste, T = temperature, W = amount of work performed on the starch, n = power-law index, K =

  19. Multistate Luminescent Solar Concentrator "Smart" Windows

    NARCIS (Netherlands)

    Sol, Jeroen A.H.P.; Timmermans, Gilles H.; Breugel, van Abraham J.; Schenning, Albertus P.H.J.; Debije, Michael G.

    2018-01-01

    A supertwist liquid crystalline luminescent solar concentrator (LSC) "smart" window is fabricated which can be switched electrically between three states: one designed for increased light absorption and electrical generation (the "dark" state), one for transparency (the "light" state), and one for

  20. Colloidal Electrolytes and the Critical Micelle Concentration

    Science.gov (United States)

    Knowlton, L. G.

    1970-01-01

    Describes methods for determining the Critical Micelle Concentration of Colloidal Electrolytes; methods described are: (1) methods based on Colligative Properties, (2) methods based on the Electrical Conductivity of Colloidal Electrolytic Solutions, (3) Dye Method, (4) Dye Solubilization Method, and (5) Surface Tension Method. (BR)

  1. Variation in Asparagine Concentration in Nebraska Wheat

    Science.gov (United States)

    The concentration of asparagine in wheat grain depends on both genetics and environmental factors, therefore study of different wheat cultivars, growing locations and crops years is needed for proper evaluation of potential risks of acrylamide formation in baked products made from Nebraska wheats. T...

  2. Relationship between bank ownership concentration on capital ...

    African Journals Online (AJOL)

    In this study we explore the effects of ownership concentration on the risk-taking behavior of banks. Our analysis focuses on East Asian countries because these nations have successfully implemented the Basel standards and have demonstrated a high degree of regulatory convergence. For the period from 2005 to 2009, ...

  3. Associations between plasma tenofovir concentration and renal ...

    African Journals Online (AJOL)

    Background: Tenofovir disoproxil fumarate (TDF) has been associated with kidney tubular dysfunction and reduced renal function. Limited studies were performed in Europe and Asia that related plasma tenofovir (TFV) concentration with renal function; no such studies to date have been performed on Africans. Objective: To ...

  4. Studies on osmotic concentration of radioactive effluents

    International Nuclear Information System (INIS)

    Thomas, K.C.; Ramachandhran, V.; Misra, B.M.

    1986-01-01

    The potential of direct osmosis for concentrating radioactive effluents is examined on the laboratory scale. Studies were carried out using asymmetric cellulose acetate membranes of a range of porosities under varying salinity gradients. A suitable bench scale osmotic concentrator employing tubular membrane systems has been fabricated and tested. An attempt to understand the mechanism of water permeation under osmotic and hydrostatic gradients has been made based on the irreversible thermodynamic approach. The solute separation of sodium chloride and radionuclides under osmosis is in the range of 85 to 95% for various osmotic sink solutions. The osmotic water flux is observed to be lower than the hydraulic water flux under reverse osmosis conditions. While the solute separation increases with an increase in annealing temperature, water flux decreases for both osmosis and reverse osmosis systems for various feed salinities. The effect of concentration polarization is analysed, and the effect of feed and osmotic sink velocity on the performance of the osmotic concentrator has also been studied. (orig.)

  5. Influence of surfactant concentration on nanohydroxyapatite growth

    Indian Academy of Sciences (India)

    Abstract. Nanohydroxyapatite particles with different morphologies were synthesized through a microwave cou- pled hydrothermal method using CTAB as a template. A successful synthesis of nanosized HAP spheres, rods and fibres is achieved through this method by controlling the concentration of the surfactant.

  6. Gastric Acid Secretion, Mucus Concentration and Ulceration ...

    African Journals Online (AJOL)

    This study was carried out to evaluate the effect of consumption (ingestion) of Cannabis sativa on the gastrointestinal tract using mucus concentration, acid secretion and ulceration in animal (rats) model as indices. Three groups of six (6) rats each were used. The control group were fed on rat chow only while another group ...

  7. Suicides in the Nazi Concentration Camps.

    Science.gov (United States)

    Ryn, Zdzislaw

    1986-01-01

    On the basis of psychiatric interviews with 69 former prisoners of the Auschwitz-Birkenau concentration camp, this paper describes the circumstances, motives, and ways of committing suicide in the camp. The interviews made it clear that thousands of prisoners perished by suicide. The number of committed suicides was larger than that of attempted…

  8. PREDICTION OF STRESS CONCENTRATION FACTORS IN

    African Journals Online (AJOL)

    ES OBE

    The gain in using this form of solution technique is that less core memory is used at each instance of the elimination and back substitution process. After the solution was carried out the results were presented element by element. 4.0 INVESTIGATION OF STRESS. CONCENTRATIONS. Due to symmetry, only hall the 'K' joint.

  9. Blood metabolite concentrations and postpartum resumption of ...

    African Journals Online (AJOL)

    Fred

    2014-01-29

    Jan 29, 2014 ... Abstract. An experiment was conducted to investigate the effect of concentrations of certain blood nutrient- sensitive metabolites and the resumption of postpartum ovarian cyclicity in 16 Sanga cows (mean BCS 5). Blood samples were taken from cows from weeks 1 to 13 (90 days) postpartum, processed ...

  10. Lung concentrations of telithromycin after oral dosing.

    Science.gov (United States)

    Khair, O A; Andrews, J M; Honeybourne, D; Jevons, G; Vacheron, F; Wise, R

    2001-06-01

    Concentrations of telithromycin were measured in plasma, bronchial mucosa (BM), epithelial lining fluid (ELF) and alveolar macrophages (AM) following multiple oral doses. Concentrations were determined using a microbiological assay. There were 20 subjects in the study, allocated to three nominal time periods: 2, 12 and 24 h. Mean concentrations in plasma, BM, ELF and AM for 2, 12 and 24 h were as follows: 2 h, 1.86 mg/L, 3.88 mg/kg, 14.89 mg/L and 69.32 mg/L; 12 h, 0.23 mg/L, 1.41 mg/kg, 3.27 mg/L and 318.1 mg/L; and 24 h, 0.08 mg/L, 0.78 mg/kg, 0.97 mg/L and 161.57 mg/L. These concentrations of telithromycin in BM and ELF exceeded for 24 h the mean MIC90s of the common respiratory pathogens Streptococcus pneumoniae (0.12 mg/L) and Moraxella catarrhalis (0.03 mg/L), as well as the atypical microorganism Mycoplasma pneumoniae (0.001 mg/L), and suggest that telithromycin may be effective for the treatment of community-acquired pneumonia and chronic obstructive pulmonary disease.

  11. Determination of cyanide concentration in blood and ...

    African Journals Online (AJOL)

    There were no clinical manifestation of cyanide poisoning in the animals and the Analysis of Variance (ANOVA) shows that haematological and biochemical parameters were not significantly different (p<0.05) across the 4 diets. High concentration of cyanide (80 ppm) was observed in the blood of animals fed Diet 4.

  12. SLC positron source flux concentrator modulator

    International Nuclear Information System (INIS)

    de Lamare, J.; Kulikov, A.; Cassel, R.; Nesterov, V.

    1991-06-01

    The modulator for the SLC e+ source flux concentrator provides 16 kA in a 5 μs sinusoidal half wave current for a pure inductive load, at 120 Hz. The modulator incorporates 10 EEV CX1622 thyratrons in a switching network. It provides reliable operation with acceptable thyratron lifetime. 3 refs., 3 figs., 1 tab

  13. Proximate composition and cholesterol concentrations of ...

    African Journals Online (AJOL)

    Proximate composition and cholesterol concentrations of Rhynchophorus phoenicis and Oryctes monoceros larvae subjected to different heat treatments. ... 514.63 mg/100g dry weight basis (DWB) for raw and fried samples, respectively, but decreased to 295.20 mg/100 g DWB in the smoke-dried samples. Similarly, the ...

  14. Measurement of tritium concentration in urine

    International Nuclear Information System (INIS)

    Sekiyama, Shigenobu; Deshimaru, Takehide

    1979-01-01

    Concerning the safety management of the advanced thermal reactor ''Fugen'', the internal exposure management for tritium is important, because heavy water is used as the moderator in the reactor, and tritium is produced in the heavy water. Tritium is the radioactive nuclide with the maximum β-ray energy of 18 keV, and the radiation exposure is limited to the internal exposure in human bodies, as tritium is taken in through the skin and by breathing. The tritium concentration in urine of the operators of the Fugen plant was measured. As for tritium measurement, the analysis of raw urine, the analysis after passing through mixed ion exchange resin and the analysis after distillation are applied. The scintillator, the liquid scintillation counter, the ion exchange resin and the distillator are introduced. The preliminary survey was conducted on the urine sample, the scintillator the calibration, etc. The measuring condition, the measurement of efficiency, and the limitation of detection with various background are explained, with the many experimental data and the calculating formula. Concerning the measured tritium concentration in urine, the tritium concentrations in distilled urine, raw urine and the urine refined with ion exchange resin were compared, and the correlation formulae are presented. The actual tritium concentration value in urine was less than 50 pci/ml. The measuring methods of raw urine and the urine refined with ion exchange resin are adequate as they are quick and accurate. (Nakai, Y.)

  15. Changes in endogenous hormone concentrations during ...

    African Journals Online (AJOL)

    Results showed that application of ethephon increased the level of endogenous ethylene (C2H4), abscisic acid (ABA) and 2-isopentyl adenine (2-iP) while it decreased the concentration of indole-3-acetic acid (IAA), gibberellic acid (GA3) and zeatin (ZT), and led to the transition of vegetative growth to inflorescence initiation ...

  16. Qualification standard for photovoltaic concentrator modules

    Energy Technology Data Exchange (ETDEWEB)

    McConnell, R.; Kurtz, S.; Bottenberg, W. R.; Hammond, R.; Jochums, S. W.; McDanal, A. J.; Roubideaux, D.; Whitaker, C.; Wohlgemuth, J.

    2000-05-05

    The paper describes a proposed qualification standard for photovoltaic concentrator modules. The standard's purpose is to provide stress tests and procedures to identify any component weakness in photovoltaic concentrator modules intended for power generation applications. If no weaknesses are identified during qualification, both the manufacturer and the customer can expect a more reliable product. The qualification test program for the standard includes thermal cycles, humidity-freeze cycles, water spray, off-axis beam damage, hail impact, hot-spot endurance, as well as electrical tests for performance, ground continuity, isolation, wet insulation resistance, and bypass diodes. Because concentrator module performance can not be verified using solar simulator and reference cell procedures suitable for flat-plate modules, the standard specifies an outdoor I-V test analysis allowing a performance comparison before and after a test procedure. Two options to this complex analysis are the use of a reference concentrator module for side-by-side outdoor comparison with modules undergoing various tests and a dark I-V performance check.

  17. Greenhouse Gases Concentrations in the Atmosphere Along ...

    African Journals Online (AJOL)

    This study investigated effect of vehicular emission on greenhouse gases concentrations along selected roads of different traffic densities in Abeokuta, Ogun State, Nigeria. Nine roads comprised highway, commercial and residential were selected. Greenhouse Gases (GHGs) were determined from both sides of the roads by ...

  18. Concentration profiles near an activated enzyme.

    Science.gov (United States)

    Park, Soohyung; Agmon, Noam

    2008-09-25

    When a resting enzyme is activated, substrate concentration profile evolves in its vicinity, ultimately tending to steady state. We use modern theories for many-body effects on diffusion-influenced reactions to derive approximate analytical expressions for the steady-state profile and the Laplace transform of the transient concentration profiles. These show excellent agreement with accurate many-particle Brownian-dynamics simulations for the Michaelis-Menten kinetics. The steady-state profile has a hyperbolic dependence on the distance of the substrate from the enzyme, albeit with a prefactor containing the complexity of the many-body effects. These are most conspicuous for the substrate concentration at the surface of the enzyme. It shows an interesting transition as a function of the enzyme turnover rate. When it is high, the contact concentration decays monotonically to steady state. However, for slow turnover it is nonmonotonic, showing a minimum due to reversible substrate binding, then a maximum due to diffusion of new substrate toward the enzyme, and finally decay to steady state. Under certain conditions one can obtain a good estimate for the critical value of the turnover rate constant at the transition.

  19. Determination of Rn concentration in groundwater

    International Nuclear Information System (INIS)

    Takada, Shigeru; Handa, Madoka; Okano, Yasuhiro; Saito, Masaaki; Suzuki, Takashi

    1984-01-01

    The method of prediction of earthquakes by the change of concentration of Rn in groundwater was developed by U.S.S.R. and People's Republic of China, and was not known clearly. Since 1975, the research works on this subject were commenced by University of Tokyo, Geological Survey of Agency of Industrial Science and Technology and Tokyo Metropolitan Isotopic Research Center. Along with the development of an automatic continuous measuring apparatus with high reliability, the systems for the measurement of the Rn concentration in groundwater were established. At the time of the earthquake off Izu-Oshima on January 14, 1978, clear precursor was found in an artesian flowing well in Nakaizu 0f Izu Peninsula, and the unusual phenomena which seemed be the precursor of an earthquake were recognized in other districts of Izu and Tokai. On August 8, 1983, an earthquake of magnitude 6 occurred in the boundary region of Yamanashi and Kanagawa Prefectures. Preceding the earthquake, the unusual change of the concentration of Rn was recognized at several observation wells in Tokyo, and the unusual change was observed after the earthquake also. The possibility that the unusual change of the Rn concentration in groundwater is the precursor of earthquakes is high, and this phenomenon is expected to make contribution for the prediction of earthquakes, though there remain many problems to be solved. Further works are scheduled to establish the practical method of predicting earthquakes. (Isimitsu, A.)

  20. Serum immunoreactive calcitonin concentration in hepatocellular carcinoma

    International Nuclear Information System (INIS)

    Dugard, J.; Kew, M.C.; Da Fonseca, M.; Levin, J.

    1982-01-01

    Having found raised serum calcitonin concentrations is 94% of patients with hepatocellular carcinoma when using a dextran-coated-charcoal radio-immunoassay, we have now repeated the study, using a double-antibody radio-immunoassay, in 102 further patients with hepatocellular carcinoma and 35 matched controls. Serum immunoreactive calcitonin concentrations (iCT) in the controls ranged from 10 to 310 pg/ml (mean 154,6 pg/ml). Values in the tumour patients ranged from 10 to 1 650 pg/ml (mean 302,6 pg/ml). The mean figures were significantly higher in the tumour patients (P smaller than 0,001), 35,5% of them having values above 310 pg/ml. In 65 of the patients serum iCT concentrations were also determined by dextran-coated-charcoal radio-immunoassay. Values ranged from 10 to 10780 pg/ml (mean 2 179 pg/ml). If 1 000 pg/ml is taken as the upper limit of normal, 69% of the patients had raised iCT concentrations. There was a good correlation (r=0,67; P smaller than 0,001) between serum iCT values measured with both methods in 50 patients. If measured by the double-antibody radio-immunoassay method, the serum calcitonin value is not useful as a marker for hepatocellular carcinoma

  1. USE CELLULOSE FOR CLEANING CONCENTRATED SUGAR SOLUTIONS

    Directory of Open Access Journals (Sweden)

    N. G. Kul’neva

    2015-01-01

    Full Text Available Summary. Producing high quality intermediate products in the boiling-crystallization station is an actual problem of sugar production. In the production of white sugar brown sugar syrup is not further purified that decreases the quality of the end product. Studies have been conducted using cellulose as an adsorbent for the purification of concentrated sugar solutions, having affinity to dyes and other impurities. Research have been carried out with the intermediate products of the Lebedyan sugar plant. Test results have shown cellulose ability to adsorb the dyes in sugar production. The influence of the adsorbent concentration and the mass fraction of solids in the syrup on the decolorization effect has been studied; rational process parameters have been obtained. It has been found that proceeding an additional adsorption purification of brown sugars syrup allows to reduce the solution color, increase the amount and quality of the end product. Adsorbing means, received from production wastes on the basis of organic resources, have many advantages: economical, environmentally friendly for disposal, safe to use, reliable and efficient in use. Conducted research on using cellulose as adsorbent for treatment of concentrated sugar solutions, having an affinity for colouring matter and other impurities. The experiments were carried out on the intermediates Lebedyanskiy sugar factory. The test results showed the ability of cellulose to adsorb coloring matter of sugar production. To evaluate the effect of bleaching depending on the mass fraction of dry substances prepared yellow juice filtration of sugar concentration of 55, 60, 65 % with subsequent adsorption purification of cellulose. The results of the experiment built adsorption isotherm of dyestuffs. The influence of the concentration of the adsorbent and a mass fraction of solids of juice filtration on the efficiency of decolorization obtained by rational parameters of the process. It is

  2. Uranium concentrations in groundwater, northeastern Washington

    Science.gov (United States)

    Kahle, Sue C.; Welch, Wendy B.; Tecca, Alison E.; Eliason, Devin M.

    2018-04-18

    A study of uranium in groundwater in northeastern Washington was conducted to make a preliminary assessment of naturally occurring uranium in groundwater relying on existing information and limited reconnaissance sampling. Naturally occurring uranium is associated with granitic and metasedimentary rocks, as well as younger sedimentary deposits, that occur in this region. The occurrence and distribution of uranium in groundwater is poorly understood. U.S. Environmental Protection Agency (EPA) regulates uranium in Group A community water systems at a maximum contaminant level (MCL) of 30 μg/L in order to reduce uranium exposure, protect from toxic kidney effects of uranium, and reduce the risk of cancer. However, most existing private wells in the study area, generally for single family use, have not been sampled for uranium. This document presents available uranium concentration data from throughout a multi-county region, identifies data gaps, and suggests further study aimed at understanding the occurrence of uranium in groundwater.The study encompasses about 13,000 square miles (mi2) in the northeastern part of Washington with a 2010 population of about 563,000. Other than the City of Spokane, most of the study area is rural with small towns interspersed throughout the region. The study area also includes three Indian Reservations with small towns and scattered population. The area has a history of uranium exploration and mining, with two inactive uranium mines on the Spokane Indian Reservation and one smaller inactive mine on the outskirts of Spokane. Historical (1977–2016) uranium in groundwater concentration data were used to describe and illustrate the general occurrence and distribution of uranium in groundwater, as well as to identify data deficiencies. Uranium concentrations were detected at greater than 1 microgram per liter (μg/L) in 60 percent of the 2,382 historical samples (from wells and springs). Uranium concentrations ranged from less than 1 to

  3. Concentrating Solar Power. Report April 2009

    Energy Technology Data Exchange (ETDEWEB)

    Pihl, Erik (Chalmers Univ. of Technology, Enery and Environment, Goeteborg (Sweden))

    2009-04-15

    Concentrating solar power (CSP) technologies offer ways to utilise solar radiation by concentrating the light. In a concentrated form, the light can be utilised more cost efficiently. It is focused with mirrors or lenses and used either as a heat source in thermal power cycles (thermal CSP) or as a light source for high efficiency photovoltaic cells (concentrating photovoltaics, CPV). All concentrating systems use tracking to follow the movement of the sun, in two or three dimensions, and require direct sunlight (no diffusing clouds). CSP plants are often more complex, component wise than those based on flat PV. The extra cost of complexity is generally more than offset by the larger scales, the less need for expensive materials such as purified silicon and a better fit with the current energy infrastructure. Some thermal CSP plants offer great possibilities to deal with the intermittency of solar energy, as the heat generated can be stored in the form of a heated liquid in large tanks for many hours with little additional cost, and drive the thermal power generation also during cloudy periods or at night. CSP is growing rapidly and can be an important portion of future low-carbon energy systems. A prerequisite is that expected cost reductions are, at least largely, realised. In regions with good solar conditions (Mediterranean countries, US Southwest, Middle East, Australia etc), CSP systems already in the short-term future can satisfy significant shares of the power demand, to decrease CO{sub 2} emissions. Less solar-intensive regions (Northern Europe, much of North America etc) can be supplied with CSP power from solar-rich regions by using long distance power grids, for instance the high voltage DC cables being deployed and developed today

  4. Modeled atmospheric radon concentrations from uranium mines

    International Nuclear Information System (INIS)

    Droppo, J.G.

    1985-04-01

    Uranium mining and milling operations result in the release of radon from numerous sources of various types and strengths. The US Environmental Protection Agency (EPA) under the Clean Air Act, is assessing the health impact of air emissions of radon from underground uranium mines. In this case, the radon emissions may impact workers and residents in the mine vicinity. To aid in this assessment, the EPA needs to know how mine releases can affect the radon concentrations at populated locations. To obtain this type of information, Pacific Northwest Laboratory used the radon emissions, release characteristics and local meterological conditions for a number of mines to model incremental radon concentrations. Long-term, average, incremental radon concentrations were computed based on the best available information on release rates, plume rise parameters, number and locations of vents, and local dispersion climatology. Calculations are made for a model mine, individual mines, and multiple mines. Our approach was to start with a general case and then consider specific cases for comparison. A model underground uranium mine was used to provide definition of the order of magnitude of typical impacts. Then computations were made for specific mines using the best mine-specific information available for each mine. These case study results are expressed as predicted incremental radon concentration contours plotted on maps with local population data from a previous study. Finally, the effect of possible overlap of radon releases from nearby mines was studied by calculating cumulative radon concentrations for multiple mines in a region with many mines. The dispersion model, modeling assumptions, data sources, computational procedures, and results are documented in this report. 7 refs., 27 figs., 18 tabs

  5. Measurement of concentration of heavy water

    International Nuclear Information System (INIS)

    Tsukamoto, Yuichi; Kondo, Mitsuo; Sakurai, Naoyuki

    1979-01-01

    The concentration of heavy water is measured as one of the technical management in the Fugen plant. The heavy water is used as the moderator in the reactor. The measuring method depends on the theory of light absorption. The light absorption range of heavy water spreads from near infrared to infrared zone. The near infrared absorption was adopted for the purpose, as the absorption is much larger in infrared zone, and the measurement has to be conducted, limiting the apparent absorption. This measuring method is available to determine the concentration of heavy water in the broad range exactly. The preparation of heavy water sample and the measurement of the absorption spectra of near infrared ray are explained, as the experimental procedure. The sample cell was made of quartz, and the spectroscope was the Hitachi 323 type. The resolving power is 100 nm and 27 nm for the wave length of 1000 nm and 2500 nm, respectively. Concerning the measured results, the absorption was recorded in the wave length range from 600 nm to 2600 nm, and for the heavy water concentration range from 0 to 99.77 wt. %. The peaks of absorption were located at the wave length of 1450, 1660, 1920, 1970, 2020 and 2600 nm. The three kinds of fundamental vibration mode of the molecules of both light and heavy water are shown, and the peaks belong to H 2 O, HDO and D 2 O, respectively. The relation between the absorption and the heavy water concentration, and that between the transmissivity and the wave length are shown, when the cell thickness was varied to 5 mm and 20 mm, and the heavy water concentration to 21%, 62% and 99.85%. (Nakai, Y.)

  6. Concentrated insulins: the new basal insulins

    Directory of Open Access Journals (Sweden)

    Lamos EM

    2016-03-01

    Full Text Available Elizabeth M Lamos,1 Lisa M Younk,2 Stephen N Davis3 1Division of Endocrinology, Diabetes and Nutrition, 2Department of Medicine, University of Maryland School of Medicine, 3Department of Medicine, University of Maryland Medical Center, Baltimore, MD, USA Introduction: Insulin therapy plays a critical role in the treatment of type 1 and type 2 diabetes mellitus. However, there is still a need to find basal insulins with 24-hour coverage and reduced risk of hypoglycemia. Additionally, with increasing obesity and insulin resistance, the ability to provide clinically necessary high doses of insulin at low volume is also needed. Areas covered: This review highlights the published reports of the pharmacokinetic (PK and glucodynamic properties of concentrated insulins: Humulin-R U500, insulin degludec U200, and insulin glargine U300, describes the clinical efficacy, risk of hypoglycemic, and metabolic changes observed, and finally, discusses observations about the complexity of introducing a new generation of concentrated insulins to the therapeutic market. Conclusion: Humulin-R U500 has a similar onset but longer duration of action compared with U100 regular insulin. Insulin glargine U300 has differential PK/pharmacodynamic effects when compared with insulin glargine U100. In noninferiority studies, glycemic control with degludec U200 and glargine U300 is similar to insulin glargine U100 and nocturnal hypoglycemia is reduced. Concentrated formulations appear to behave as separate molecular entities when compared with earlier U100 insulin analog compounds. In the review of available published data, newer concentrated basal insulins may offer an advantage in terms of reduced intraindividual variability as well as reducing the injection burden in individuals requiring high-dose and large volume insulin therapy. Understanding the PK and pharmacodynamic properties of this new generation of insulins is critical to safe dosing, dispensing, and administration

  7. Radioimmunoassay of thyrotropin concentrated from serum

    International Nuclear Information System (INIS)

    Nisula, B.C.; Louvet, J.P.

    1978-01-01

    A method for concentrating human TSH (hTSH) from serum for use in RIAs is described. The method takes advantage of the affinity of the plant lectin, concanavalin A, for the carbohydrate portion of the hTSH molecule. The hTSH from 2.5 ml serum was adsorbed to concanavalin A covalently linked to sepharose and then radioimmunoassayed using the hTSH antiserum and hTSH for iodination distributed by the National Pituitary Agency. For the RIA standard curve, the hTSH reference preparation was concentrated from a serum wwith undetectable hTSH in order to correct for recovery and to control for nonspecific effects. The percentage of serum hTSH extracted from 2.5 ml serum with the concentration procedure was 76.6 +- 3.4% (mean +- SD). The coefficient of correlation between serum hTSH, determined with the concentration procedure, and serum hTSH determined without was 0.979 (P < 0.001). Over 95% of normal adult men and women had detectable levels of serum hTSH, ranging from < 0.56 to 4.0 μU/ml. The mean of detectable serum hTSH levels in normal adult women (n = 11) was 1.54 +- 1.03 μU/ml (mean +- SD) and in normal men (n = 9) was 2.02 +- 1.15 μU/ml (mean +- SD). Clinically hyperthyroid patients with diffuse and nodular toxic goiters (n = 8) and patients with hypothyroidism secondary to pituitary disease (n = 6), four of whom were taking replacement doses of thyroid hormone, had undetectable serum hTSH levels. Serum hTSH in patients with primary hypothyroidism uniformly exceeded the normal range. This hTSH concentrating procedure enhances the effective sensitivity and, therefore, the clinical utility of the RIA for hTSH in serum

  8. Maximum Permissible Concentrations and Negligible Concentrations for Rare Earth Elements (REEs)

    NARCIS (Netherlands)

    Sneller FEC; Kalf DF; Weltje L; Wezel AP van; CSR

    2000-01-01

    In this report maximum permissible concentrations (MPCs) and negligible concentrations (NCs) are derived for Rare Earth Elements (REEs), which are also known as lanthanides. The REEs selected for derivation of environmental risk limits in this report are Yttrium (Y), Lanthanum (La), Cerium (Ce),

  9. Compensation of self-absorption losses in luminescent solar concentrators by increasing luminophore concentration

    NARCIS (Netherlands)

    Krumer, Zachar; van Sark, Wilfried G.J.H.M.; Schropp, Ruud E.I.; de Mello Donegá, Celso

    2017-01-01

    Self-absorption in luminophores is considered a major obstacle on the way towards efficient luminescent solar concentrators (LSCs). It is commonly expected that upon increasing luminophore concentration in an LSC the absorption of the luminophores increases as well and therefore self-absorption

  10. Preovulatory progesterone concentration associates significantly to follicle number and LH concentration but not to pregnancy rate

    DEFF Research Database (Denmark)

    Yding Andersen, Claus; Bungum, Leif; Nyboe Andersen, Anders

    2011-01-01

    with or without rLH administration from day 6 of stimulation. There was no significant association between the late-follicular-phase progesterone concentration and the clinical pregnancy rate. However, progesterone concentration was strongly associated with the number of follicles and retrieved oocytes. Late...

  11. Linear concentration system; Sistema de concentracion lineal

    Energy Technology Data Exchange (ETDEWEB)

    Gonzalez Lugo, J.I; Leon Rovira, N; Aguayo Tellez, H [Instituto Tecnologico y de Estudios Superiores de Monterrey, Monterrey, Nuevo Leon (Mexico)]. E-mails: a00812662@itesm.mx; noel.leon@itesm.mx; haguayo@itesm.mx

    2013-03-15

    Solar linear concentration technologies to generate high temperatures are limited to the ranges of 200 to 500 degrees Celsius. While its performance has been tested through prototypes and pilot plants around the world, there are still areas of opportunity that can be exploited to obtain a linear concentration that achieves temperatures above this range in order to have a better use of the available solar energy. Because of this: It is possible to develop a linear concentration system that can track the sun with minimal movement of the absorber-receiver while maintaining temperatures above 850 degrees Celsius sufficient for industrial processes that require that temperature. The methodology consists of a series of stages (conceptual design, simulation, evaluation, development concept, results and validation) through which concepts are generated that allow design and evaluation of solar concentrator configurations with the help of simulation software. We have designed a linear parabolic concentrating system which comprises a set of mirrors segments with different focal lengths that works within the range of 600 degrees Celsius; however, it is advancing in the development of a double concentration to reach 850 degrees Celsius. [Spanish] Las tecnologias de concentracion lineal solar para generar altas temperaturas se ven limitadas a los rangos de 200 a 500 grados centigrados. Si bien su funcionamiento ha sido probado a traves de prototipos y plantas piloto alrededor del mundo, aun existen areas de oportunidad que pueden ser aprovechadas para obtener un sistema de concentracion lineal que permita alcanzar temperaturas mayores a este rango para asi tener un mejor aprovechamiento de la energia solar disponible. Debido a esto: Es posible desarrollar un sistema de concentracion lineal capaz de seguir la trayectoria del Sol con minimo movimiento del absorbedor-recibidor al mismo tiempo que mantiene temperaturas superiores a los 850 grados centigrados suficientes para

  12. Intercomparison of passive microwave sea ice concentration retrievals over the high-concentration Arctic sea ice

    DEFF Research Database (Denmark)

    andersen, susanne; Tonboe, R.; Kaleschke, L.

    2007-01-01

    [1] Measurements of sea ice concentration from the Special Sensor Microwave Imager (SSM/I) using seven different algorithms are compared to ship observations, sea ice divergence estimates from the Radarsat Geophysical Processor System, and ice and water surface type classification of 59 wide......-swath synthetic aperture radar (SAR) scenes. The analysis is confined to the high-concentration Arctic sea ice, where the ice cover is near 100%. During winter the results indicate that the variability of the SSM/I concentration estimates is larger than the true variability of ice concentration. Results from...... a trusted subset of the SAR scenes across the central Arctic allow the separation of the ice concentration uncertainty due to emissivity variations and sensor noise from other error sources during the winter of 2003-2004. Depending on the algorithm, error standard deviations from 2.5 to 5.0% are found...

  13. Estimation of surface area concentration of workplace incidental nanoparticles based on number and mass concentrations

    Science.gov (United States)

    Park, J. Y.; Ramachandran, G.; Raynor, P. C.; Kim, S. W.

    2011-10-01

    Surface area was estimated by three different methods using number and/or mass concentrations obtained from either two or three instruments that are commonly used in the field. The estimated surface area concentrations were compared with reference surface area concentrations (SAREF) calculated from the particle size distributions obtained from a scanning mobility particle sizer and an optical particle counter (OPC). The first estimation method (SAPSD) used particle size distribution measured by a condensation particle counter (CPC) and an OPC. The second method (SAINV1) used an inversion routine based on PM1.0, PM2.5, and number concentrations to reconstruct assumed lognormal size distributions by minimizing the difference between measurements and calculated values. The third method (SAINV2) utilized a simpler inversion method that used PM1.0 and number concentrations to construct a lognormal size distribution with an assumed value of geometric standard deviation. All estimated surface area concentrations were calculated from the reconstructed size distributions. These methods were evaluated using particle measurements obtained in a restaurant, an aluminum die-casting factory, and a diesel engine laboratory. SAPSD was 0.7-1.8 times higher and SAINV1 and SAINV2 were 2.2-8 times higher than SAREF in the restaurant and diesel engine laboratory. In the die casting facility, all estimated surface area concentrations were lower than SAREF. However, the estimated surface area concentration using all three methods had qualitatively similar exposure trends and rankings to those using SAREF within a workplace. This study suggests that surface area concentration estimation based on particle size distribution (SAPSD) is a more accurate and convenient method to estimate surface area concentrations than estimation methods using inversion routines and may be feasible to use for classifying exposure groups and identifying exposure trends.

  14. Estimation of surface area concentration of workplace incidental nanoparticles based on number and mass concentrations

    International Nuclear Information System (INIS)

    Park, J. Y.; Ramachandran, G.; Raynor, P. C.; Kim, S. W.

    2011-01-01

    Surface area was estimated by three different methods using number and/or mass concentrations obtained from either two or three instruments that are commonly used in the field. The estimated surface area concentrations were compared with reference surface area concentrations (SA REF ) calculated from the particle size distributions obtained from a scanning mobility particle sizer and an optical particle counter (OPC). The first estimation method (SA PSD ) used particle size distribution measured by a condensation particle counter (CPC) and an OPC. The second method (SA INV1 ) used an inversion routine based on PM1.0, PM2.5, and number concentrations to reconstruct assumed lognormal size distributions by minimizing the difference between measurements and calculated values. The third method (SA INV2 ) utilized a simpler inversion method that used PM1.0 and number concentrations to construct a lognormal size distribution with an assumed value of geometric standard deviation. All estimated surface area concentrations were calculated from the reconstructed size distributions. These methods were evaluated using particle measurements obtained in a restaurant, an aluminum die-casting factory, and a diesel engine laboratory. SA PSD was 0.7–1.8 times higher and SA INV1 and SA INV2 were 2.2–8 times higher than SA REF in the restaurant and diesel engine laboratory. In the die casting facility, all estimated surface area concentrations were lower than SA REF . However, the estimated surface area concentration using all three methods had qualitatively similar exposure trends and rankings to those using SA REF within a workplace. This study suggests that surface area concentration estimation based on particle size distribution (SA PSD ) is a more accurate and convenient method to estimate surface area concentrations than estimation methods using inversion routines and may be feasible to use for classifying exposure groups and identifying exposure trends.

  15. Three-dimensional transparent parabolic concentrator for photovoltaics

    OpenAIRE

    Huichuan Lin; Peng Xie; Yong Liu; Xiang Zhou; Baojun Li

    2015-01-01

    A three-dimensional transparent parabolic concentrator made of polymethylmethacrylate (PMMA) was designed and fabricated for photovoltaic applications. The measured maximum concentration ratio of the concentrator is 8.31, which means that for normal incident light, optical energy can be concentrated as high as 8.31 times by the concentrator. Even for oblique incident lights with an incident angle of between 5° and 15°, the concentrator maintains a concentration ratio of between 6.81 and 3.72....

  16. Vacuum drying plant for evaporator concentrates

    Energy Technology Data Exchange (ETDEWEB)

    Benavides, E. [ENSA, Madrid (Spain)

    2001-07-01

    Volume reduction systems applied to evaporator concentrates in PWR and BWR save a significant amount of drums. The concentration to dry product is a technique that reaches the maximum volume reduction, compared to conventional techniques (cementation, polymerisation). Four Spanish N.P.P. (3 PWR and 1 BWR) have selected ENSA's process by means of fixed ''in drum vacuum drying system''. A 130-litre steel drum is used for drying without any additional requirement except vacuum resistance. This steel drum is introduced into a standard 200-litre drum. Five centimeters concrete shielding cylinder exists between both drums. Final package is classified as 19 GO according to ENRESA's acceptance code (dry waste with 5 cm concrete between 130-l and 200-l drum). The generation of cemented waste in five N.P.P. versus dried waste will be reduced 83%. This reduction will save a considerable amount in disposal costs. (authors)

  17. Thermal regeneration of an electrochemical concentration cell

    Science.gov (United States)

    Krumpelt, M.; Bates, J.K.

    1980-05-09

    A system and method are described for thermally regenerating an electrochemical concentration cell having first and second aluminum electrodes respectively positioned in contact with first and second electrolytes separated by an ion exchange member, the first and second electrolytes being composed of different concentrations of an ionic solvent and a salt, preferably an aluminum halide. The ionic solvent may be either organic or inorganic with a relatively low melting point, the ionic solvent and the salt form a complex wherein the free energy of formation of said complex is less than about -5 kcal/mole. A distillation column using solar heat or low grade industrial waste heat receives the first and second electrolytes and thermally decomposes the salt-solvent complex to provide feed material for the two half cells.

  18. On the pelletizing of sulfide molybdenite concentrate

    International Nuclear Information System (INIS)

    Palant, A.A.

    2007-01-01

    Investigation results are discussed on the process of pelletizing with the use of various binders (water, syrup, sulfite-alcoholic residue and bentonite) for flotation sulfide molybdenite concentrate (∼84 % MoS 2 ) of the Mongolian deposit. It is established that with the use of syrup rather strong pellets (>300 g/p) of desired size (2-3 mm) can be obtained at a binder flowrate of 1 kg per 100 kg of concentrate. The main advantage of using syrup instead of bentonite lies in the fact that in this instance no depletion of a molybdenum calcine obtained by oxidizing roasting of raw ore takes place due to syrup complete burning out. This affects positively subsequent hydrometallurgical conversion because of decreasing molybdenum losses with waste cakes [ru

  19. Turbidimetry for measurement of radon concentration

    Energy Technology Data Exchange (ETDEWEB)

    Wang Huanqiang [HuBei Provincial Academy of Medical Sciences, WuHan (China). Inst. of Radioactive Protection

    1993-12-31

    This paper describes a turbidimetric technique counting the tracks registered on CR-39 foils exposed to radon. Instead of eyeview through microscope, by using the differential spectrophotometer, strong correlation between the radon cumulative concentration and track turbidence was observed(r=0.999). Under the etching condition of 7.07 mol{center_dot}L{sup -1} KOH water solution at 80{sup o}C for 16 hr, linear regression showed that the ratio of track turbidence and cumulative concentration of radon exposure was 1.99 x 10{sup -1} turbidence (KBq m{sup -1}h){sup -1} and the determination limit was 36 KBq m{sup -3}h. The details of the experiments are represented in this paper. (Author).

  20. Environmental natural radioactivity concentrations of Tekirdag

    International Nuclear Information System (INIS)

    Yarar, Y.; Kam, E.

    2004-01-01

    Full text: In this study, the environmental natural radioactivity concentrations of Tekirdag, a city in the region of Marmara in Turkey, have been measured. Gamma spectrometric analysis of the soil samples collected from 40 points of Tekirdag was performed by using an HPGe detector and the radionuclide concentrations of the decay products of 238 U and 232 Th series, 40K and 137 Cs were determined. Gross alpha and gross beta activities of the water samples taken from municipal supplies, springs, wells and fountains were performed by using the Berthold, LB770-PC 10, a gas-flow proportional counter. Gamma exposure dose rates were measured by using an Eberline Smart Portable scintillation detector and the annual effective dose equivalents caused by exposure gamma dose rates were calculated

  1. Characterization of a low concentrator photovoltaics module

    International Nuclear Information System (INIS)

    Butler, B.A.; Dyk, E.E. van; Vorster, F.J.; Okullo, W.; Munji, M.K.; Booysen, P.

    2012-01-01

    Low concentration photovoltaic (LCPV) systems have the potential to reduce the cost per kWh of electricity compared to conventional flat-plate photovoltaics (PV) by up to 50%. The cost-savings are realised by replacing expensive PV cells with relatively cheaper optical components to concentrate incident solar irradiance onto a receiver and by tracking the sun along either 1 axis or 2 axes. A LCPV module consists of three interrelated subsystems, viz., the optical, electrical and the thermal subsystems, which must be considered for optimal module design and performance. Successful integration of these subsystems requires the balancing of cost, performance and reliability. In this study LCPV experimental prototype modules were designed, built and evaluated with respect to optimisation of the three subsystems and overall performance. This paper reports on the optical and electrical evaluation of a prototype LCPV module.

  2. Characterization of a low concentrator photovoltaics module

    Energy Technology Data Exchange (ETDEWEB)

    Butler, B.A. [Department of Physics, Nelson Mandela Metropolitan University, P. O. Box 77000, Port Elizabeth 6031 (South Africa); Dyk, E.E. van, E-mail: ernest.vandyk@nmmu.ac.za [Department of Physics, Nelson Mandela Metropolitan University, P. O. Box 77000, Port Elizabeth 6031 (South Africa); Vorster, F.J.; Okullo, W.; Munji, M.K. [Department of Physics, Nelson Mandela Metropolitan University, P. O. Box 77000, Port Elizabeth 6031 (South Africa); Booysen, P. [Setsolar, P. O. Box 15934, Panorama 7506 (South Africa)

    2012-05-15

    Low concentration photovoltaic (LCPV) systems have the potential to reduce the cost per kWh of electricity compared to conventional flat-plate photovoltaics (PV) by up to 50%. The cost-savings are realised by replacing expensive PV cells with relatively cheaper optical components to concentrate incident solar irradiance onto a receiver and by tracking the sun along either 1 axis or 2 axes. A LCPV module consists of three interrelated subsystems, viz., the optical, electrical and the thermal subsystems, which must be considered for optimal module design and performance. Successful integration of these subsystems requires the balancing of cost, performance and reliability. In this study LCPV experimental prototype modules were designed, built and evaluated with respect to optimisation of the three subsystems and overall performance. This paper reports on the optical and electrical evaluation of a prototype LCPV module.

  3. Optimization of bolt thread stress concentrations

    DEFF Research Database (Denmark)

    Pedersen, Niels Leergaard

    2013-01-01

    , and a study is performed to establish the need for contact modeling with regard to finding the correct stress concentration factor. Optimization is performed with a simple parameterization with two design variables. Stress reduction of up to 9% is found in the optimization process, and some similarities...... are found in the optimized designs leading to the proposal of a new standard. The reductions in the stress are achieved by rather simple changes made to the cutting tool.......Designs of threaded fasteners are controlled by different standards, and the number of different thread definitions is large. The most commonly used thread is probably the metric ISO thread, and this design is therefore used in the present paper. Thread root design controls the stress concentration...

  4. Determining lower threshold concentrations for synergistic effects.

    Science.gov (United States)

    Bjergager, Maj-Britt Andersen; Dalhoff, Kristoffer; Kretschmann, Andreas; Nørgaard, Katrine Banke; Mayer, Philipp; Cedergreen, Nina

    2017-01-01

    Though only occurring rarely, synergistic interactions between chemicals in mixtures have long been a point of focus. Most studies analyzing synergistic interactions used unrealistically high chemical concentrations. The aim of the present study is to determine the threshold concentration below which proven synergists cease to act as synergists towards the aquatic crustacean Daphnia magna. To do this, we compared several approaches and test-setups to evaluate which approach gives the most conservative estimate for the lower threshold for synergy for three known azole synergists. We focus on synergistic interactions between the pyrethroid insecticide, alpha-cypermethrin, and one of the three azole fungicides prochloraz, propiconazole or epoxiconazole measured on Daphnia magna immobilization. Three different experimental setups were applied: A standard 48h acute toxicity test, an adapted 48h test using passive dosing for constant chemical exposure concentrations, and a 14-day test. Synergy was defined as occuring in mixtures where either EC 50 values decreased more than two-fold below what was predicted by concentration addition (horizontal assessment) or as mixtures where the fraction of immobile organisms increased more than two-fold above what was predicted by independent action (vertical assessment). All three tests confirmed the hypothesis of the existence of a lower azole threshold concentration below which no synergistic interaction was observed. The lower threshold concentration, however, decreased with increasing test duration from 0.026±0.013μM (9.794±4.897μgL -1 ), 0.425±0.089μM (145.435±30.46μgL -1 ) and 0.757±0.253μM (249.659±83.44μgL -1 ) for prochloraz, propiconazole and epoxiconazole in standard 48h toxicity tests to 0.015±0.004μM (5.651±1.507μgL -1 ), 0.145±0.025μM (49.619±8.555μgL -1 ) and 0.122±0.0417μM (40.236±13.75μgL -1 ), respectively, in the 14-days tests. Testing synergy in relation to concentration addition provided

  5. Thermal regeneration of an electrochemical concentration cell

    Science.gov (United States)

    Krumpelt, Michael; Bates, John K.

    1981-01-01

    A system and method for thermally regenerating an electrochemical concentration cell having first and second aluminum electrodes respectively positioned in contact with first and second electrolytes separated by an ion exchange member, the first and second electrolytes being composed of different concentrations of an ionic solvent and a salt, preferably an aluminum halide. The ionic solvent may be either organic or inorganic with a relatively low melting point, the ionic solvent and the salt form a complex wherein the free energy of formation of said complex is less than about -5 Kcal/mole. A distillation column using solar heat or low grade industrial waste heat receives the first and second electrolytes and thermally decomposes the salt-solvent complex to provide feed material for the two half cells.

  6. Multijunction cells for concentrators: Technology prospects

    Science.gov (United States)

    Ferber, R. R. (Compiler); Costogue, E. N. (Compiler); Shimada, K. (Compiler)

    1984-01-01

    Development of high-efficiency multijunction solar cells for concentrator applications is a key step in achieving the goals of the U.S. Department of Energy National Photovoltaics Program. This report summarizes findings of an issue study conducted by the Jet Propulsion Laboratory Photovoltaic Analysis and Integration Center, with the assistance of the Solar Energy Research Institute and Sandia National laboratoies, which surveyed multijunction cell research for concentrators undertaken by federal agencies and by private industry. The team evaluated the potentials of research activities sponsored by DOE and by corporate funding to achieve projected high-efficiency goals and developed summary statements regarding industry expectations. Recommendations are made for the direction of future work to address specific unresolved aspects of multijunction cell technology.

  7. Methods and systems for concentrated solar power

    Science.gov (United States)

    Ma, Zhiwen

    2016-05-24

    Embodiments described herein relate to a method of producing energy from concentrated solar flux. The method includes dropping granular solid particles through a solar flux receiver configured to transfer energy from concentrated solar flux incident on the solar flux receiver to the granular solid particles as heat. The method also includes fluidizing the granular solid particles from the solar flux receiver to produce a gas-solid fluid. The gas-solid fluid is passed through a heat exchanger to transfer heat from the solid particles in the gas-solid fluid to a working fluid. The granular solid particles are extracted from the gas-solid fluid such that the granular solid particles can be dropped through the solar flux receiver again.

  8. Recent developments in luminescent solar concentrators

    Science.gov (United States)

    van Sark, W. G. J. H. M.

    2014-10-01

    High efficiency photovoltaic devices combine full solar spectrum absorption and effective generation and collection of charge carriers, while commercial success depends on cost effectiveness in manufacturing. Spectrum modification using down shifting has been demonstrated in luminescent solar concentrators (LSCs) since the 1970s, as a cheap alternative for standard c-Si technology. LSCs consist of a highly transparent plastic plate, in which luminescent species are dispersed, which absorb incident light and emit light at a red-shifted wavelength, with high quantum efficiency. Material issues have hampered efficiency improvements, in particular re-absorption of light emitted by luminescent species and stability of these species. In this contribution, approaches are reviewed on minimizing re-absorption, which should allow surpassing the 10% luminescent solar concentrator efficiency barrier.

  9. Characterization of a low concentrator photovoltaics module

    Science.gov (United States)

    Butler, B. A.; van Dyk, E. E.; Vorster, F. J.; Okullo, W.; Munji, M. K.; Booysen, P.

    2012-05-01

    Low concentration photovoltaic (LCPV) systems have the potential to reduce the cost per kWh of electricity compared to conventional flat-plate photovoltaics (PV) by up to 50%. The cost-savings are realised by replacing expensive PV cells with relatively cheaper optical components to concentrate incident solar irradiance onto a receiver and by tracking the sun along either 1 axis or 2 axes. A LCPV module consists of three interrelated subsystems, viz., the optical, electrical and the thermal subsystems, which must be considered for optimal module design and performance. Successful integration of these subsystems requires the balancing of cost, performance and reliability. In this study LCPV experimental prototype modules were designed, built and evaluated with respect to optimisation of the three subsystems and overall performance. This paper reports on the optical and electrical evaluation of a prototype LCPV module.

  10. Overflow Concentration and Sedimentation in Hoppers

    DEFF Research Database (Denmark)

    Hjelmager Jensen, Jacob; Saremi, Sina

    2014-01-01

    at the inflow. The hopper constitutes a complex system despite its geometrical regularity; the complexities are largely from the settling processes in concentrated polydisperse mixtures. These settling processes can, however, be captured by employing available settling formulas applicable for multifractional...... mixtures, the former analytically. Although assumptions tied to the mathematical model are fulfilled best for hoppers rigged with a multiple-inflow system, the model accurately predicts measured concentrations in the final stage of overflow for single-inflow systems. The model can be used...... sediment mixtures (i.e., polydispersions). Strictly speaking, these formulas have been validated for homogeneous and unenergetic mixtures only, but the hopper system fulfills these criteria reasonably well. A proper description of the compositional transformation during filling and subsequent overflow...

  11. Radon concentration measurements in therapeutic spring water

    International Nuclear Information System (INIS)

    Deak, N.; Horvath, A.; Sajo B, L.; Marx, G.

    1996-01-01

    It is believed that people undergoing a curative cycle in a given spa, may receive a dose in the range of 400 mSv/year which is many times the average annual dose so that their risk of lung cancer may increase by 3% or more. To determine the risk due to the natural radioactivity, of the most frequented spas in Budapest (H), we selected four and some others located on the country side being of particular interest. Results of the radon concentration in spring water are presented, with the evidence that some spas have a high radon concentration. We conclude that patients receiving treatment may be exposed to an additional dose in the range of 29-76 mSv/year that at the bronchia could be between 445-1182 mSv/year. (authors). 6 refs., 2 figs., 2 tabs

  12. Mathematical model of concentrating solar cooker

    OpenAIRE

    Avilés, Mauricio González; Avilés, José Juan González

    2013-01-01

    The main purpose of this work is to obtain a mathematical model consistent with the thermal behavior of concentrating solar cookers, such as Jorhejpataranskua. We also want to simulate different conditions respect to the parameters involved of several materials for its construction and efficiency. The model is expressed in terms of a coupled nonlinear system of differential equations which are solved using Mathematica 8. The results obtained by our model are compared with measurements of sola...

  13. Zirconium oxide obtainment from brazilian zircon concentrate

    International Nuclear Information System (INIS)

    Ribeiro, S.; Martins, A.H.

    1991-01-01

    This work presents the experimental results of studies about alkaline melting, acid leaching and sulfation steps for obtention of zirconium oxide and partially stabilized zirconia by yttrium and rare-earth coprecipitation in chlorine medium, starting from the brazilian zircon concentrate. Using statistical methods of factorial design and the Packett-Burman approach, the results are discussed and the optimal conditions of the production steps were determined. (author)

  14. Degadation of semiconducting polymers by concentrated sunlight

    DEFF Research Database (Denmark)

    Tromholt, Thomas; Manceau, Matthieu; Petersen, Martin Helgesen

    2011-01-01

    A lens based sunlight concentration setup was used to accelerate the degradation of semiconducting polymers. Sunlight was collected outdoor and focused into an optical fiber bundle allowing for indoor experimental work. Photo-degradation of several polymers was studied by UV–vis absorbance...... was carried out in a materials study employing five different conjugated polymers relevant to polymer solar cells for which acceleration factors in the range 19–55 were obtained....

  15. Quantized Concentration Gradient in Picoliter Scale

    Science.gov (United States)

    Hong, Jong Wook

    2010-10-01

    Generation of concentration gradient is of paramount importance in the success of reactions for cell biology, molecular biology, biochemistry, drug-discovery, chemotaxis, cell culture, biomaterials synthesis, and tissue engineering. In conventional method of conducting reactions, the concentration gradients is achieved by using pipettes, test tubes, 96-well assay plates, and robotic systems. Conventional methods require milliliter or microliter volumes of samples for typical experiments with multiple and sequential reactions. It is a challenge to carry out experiments with precious samples that have strict limitations with the amount of samples or the price to pay for the amount. In order to overcome this challenge faced by the conventional methods, fluidic devices with micrometer scale channels have been developed. These devices, however, cause restrictions on changing the concentration due to the fixed gradient set based on fixed fluidic channels.ootnotetextJambovane, S.; Duin, E. C.; Kim, S-K.; Hong, J. W., Determination of Kinetic Parameters, KM and kcat, with a Single Experiment on a Chip. textitAnalytical Chemistry, 81, (9), 3239-3245, 2009.^,ootnotetextJambovane, S.; Hong, J. W., Lorenz-like Chatotic System on a Chip In The 14th International Conference on Miniaturized Systems for Chemistry and Life Sciences (MicroTAS), The Netherlands, October, 2010. Here, we present a unique microfluidic system that can generate quantized concentration gradient by using series of droplets generated by a mechanical valve based injection method.ootnotetextJambovane, S.; Rho, H.; Hong, J., Fluidic Circuit based Predictive Model of Microdroplet Generation through Mechanical Cutting. In ASME International Mechanical Engineering Congress & Exposition, Lake Buena Vista, Florida, USA, October, 2009.^,ootnotetextLee, W.; Jambovane, S.; Kim, D.; Hong, J., Predictive Model on Micro Droplet Generation through Mechanical Cutting. Microfluidics and Nanofluidics, 7, (3), 431-438, 2009

  16. Radon concentration inversions in the troposphere

    International Nuclear Information System (INIS)

    Pereira, E.B.

    1987-07-01

    Vertical concentrations of radon in the lower troposphere were obtained in Southern Brazil up to 7Km high and have shown unexpected inverted profiles. The presence of low pressure center systems southwest to the flight path suggested that inversions might have been originated by a vertical transport mechanism based on the large scale circulation of developing synoptic systems. A simple friction-driven circulation model was contructed and the transport equation was solved. (author) [pt

  17. Cellulase Inhibition by High Concentrations of Monosaccharides

    DEFF Research Database (Denmark)

    Hsieh, Chia-Wen; Cannella, David; Jørgensen, Henning

    2014-01-01

    Biological degradation of biomass on an industrial scale culminates in high concentrations of end products. It is known that the accumulation of glucose and cellobiose, end products of hydrolysis, inhibit cellulases and decrease glucose yields. Aside from these end products, however, other monosa...... glucose. Protein adsorption studies showed that this inhibition e ff ect was most likely due to catalytic, and not binding, inhibition of the cellulases....

  18. Building a parabolic solar concentrator prototype

    Energy Technology Data Exchange (ETDEWEB)

    Escobar-Romero, J F M; Montiel, S Vazquez y; Granados-AgustIn, F; Rodriguez-Rivera, E; Martinez-Yanez, L [INAOE, Luis Enrique Erro 1, Tonantzintla, Pue., 72840 (Mexico); Cruz-Martinez, V M, E-mail: jfmescobar@yahoo.com [Universidad Tecnologica de la Mixteca, Camino a Acatilma Km 2.5, Huajuapan de Leon, Oax., 69000 (Mexico)

    2011-01-01

    In order to not further degrade the environment, people have been seeking to replace non-renewable natural resources such as fossil fuels by developing technologies that are based on renewable resources. An example of these technologies is solar energy. In this paper, we show the building and test of a solar parabolic concentrator as a prototype for the production of steam that can be coupled to a turbine to generate electricity or a steam engine in any particular industrial process.

  19. Structural Health Monitoring for Concentrated Solar Plants

    OpenAIRE

    Gómez Muñoz, Carlos Quiterio; Trapero Arenas, Juan Ramón; García Márquez, Fausto Pedro

    2014-01-01

    Renewable energy is being one of the options to cover the demand due to the environmental restrictions. One of the most relevant renewable energy sources is the solar energy, where the concentrated solar power is nowadays the source that is getting more importance. The correct performance of solar receiver is crucial because its failure can result in significant costs and availability of the energy service. Non-destructive testing is broadly used in structural health monitoring systems in ord...

  20. Concentration of Resources and Economic Growth

    Directory of Open Access Journals (Sweden)

    David Castells-Quintana

    2015-05-01

    Full Text Available In this letter I summarise the main results and contributions from my Ph.D. thesis on concentration of resources and economic development. The empirical analysis performed in the thesis, and summarised here, focuses on two mayor world trends in modern economic development, namely increasing agglomeration and rising inequalities within countries. In particular, the impact of both trends on long-run economic growth is studied, and results are discussed in light of relevant policy debate.

  1. Détermination de la concentration micellaire

    African Journals Online (AJOL)

    SARAH

    30 nov. 2014 ... compenser la répulsion électrique existant entre les groupements de tête ionique ainsi que la diminution d'entropie qui accompagne cette agrégation. Les valeurs de concentration auxquelles l'agrégation commence augmentent avec la température car l'énergie cinétique des monomères augmente aussi.

  2. Hair dehydroepiandrosterone (DHEA concentrations in newborn dogs

    Directory of Open Access Journals (Sweden)

    Barbara Bolis

    2015-07-01

    Full Text Available During the last intrauterine fetal stage of development and the neonatal period the hypothalamic-pituitary-adrenal axis (HPA is a key system. Apart of cortisol, the adrenals produce dehydroepiandrosterone (DHEA, the major steroid produced by the fetus itself, so that it could be considered as a marker of offspring HPA activity. Non invasive, long time-frame retrospective hormonal levels analysis were performed in the hair of humans and animals, but not in newborn puppies, and DHEA never investigated in puppies. This study was aimed to assess DHEA concentrations in the hair of newborn puppies, and to evaluate the influence of newborn age, gender, and breed size on DHEA concentrations. The study enrolled 116 spontaneously dead puppies, grouped on the base of mother bodyweight to small or medium-large breeds, and on the base of age at death. Hair samples were collected by shaving, and stored at room temperature until RIA analysis. The overall hair DHEA concentrations were 46.8±14.8 pg/mg. DHEA levels were 48.6±15.66 pg/mg in females vs 45.1±13.73 pg/mg in males, without significant differences. DHEA levels were 45.5±13.61 pg/mg in small size puppies and 47.8±15.61 pg/mg in medium-large size puppies, with no significant differences. DHEA concentrations in premature puppies (52.5±15.12 pg/mg were significant higher (p<0.05 than in puppies dead between 1 and 30 days after birth (44.5±17.78 pg/mg, but similar to fresh term born-dead puppies (46.2±16.5 pg/mg.  This study demonstrated that DHEA is quantifiable in the hair of newborn dogs, and that DHEA levels are significantly influenced by the puppies age.

  3. Design package for concentrating solar collector panels

    Science.gov (United States)

    1978-01-01

    Information used to evaluate the design of the Northrup concentrating collector is presented. Included are the system performance specifications, the applications manual, and the detailed design drawings of the collector. The collector is a water/glycol/working fluid type, with a dipped galvanized steel housing, transparent acrylic Fresnel lens cover, copper absorber tube, and fiber glass insulation. It weights 98 pounds. A collector assembly includes four collector units within a tracking mount array.

  4. Assessment of radioactivity concentrations and effective of ...

    African Journals Online (AJOL)

    They find their ways in to the plants through the leaves and absorption of nutrients and water from the soil through the roots. ... The highest concentrations of 40K, 238U and 232Th were from pineapple of value 102.36 ± 10.81Bqkg-1, orange of value 12.18 ± 4.36Bqkg-1 and mango of value 8.01 ± 3.25 Bqkg-1 respectively.

  5. Material for a luminescent solar concentrator

    Science.gov (United States)

    Andrews, L.J.

    1984-01-01

    A material for use in a luminescent solar concentrator, formed by ceramitizing the luminescent ion Cr/sup 3 +/ with a transparent ceramic glass containing mullite. The resultant material has tiny Cr/sup 3 +/-bearing crystallites dispersed uniformly through an amorphous glass. The invention combines the high luminescent efficiency of Cr/sup 3 +/ in the crystalline phase with the practical and economical advantages of glass technology.

  6. Photovoltaic concentrator assembly with optically active cover

    Science.gov (United States)

    Plesniak, Adam P

    2014-01-21

    A photovoltaic concentrator assembly that includes a housing that defines an internal volume and includes a rim, wherein the rim defines an opening into the internal volume, a photovoltaic cell positioned in the internal volume, and an optical element that includes an optically active body and a flange extending outward from the body, wherein the flange is sealingly engaged with the rim of the housing to enclose the internal volume.

  7. Blood lactate concentration in diabetic dogs

    OpenAIRE

    Claus, Poliana; Gimenes, André M.; Castro, Jacqueline R.; Mantovani, Matheus M.; Kanayama, Khadine K.; Simões, Denise M.N.; Schwartz, Denise S.

    2017-01-01

    Human diabetic patients may have increased lactate levels compared to non-diabetics. Despite the use of lactate levels in critical care assessment, information is lacking for diabetic dogs. Therefore, this prospective cross-sectional clinical study aimed to determine lactate concentrations in 75 diabetic dogs [25 newly diagnosed non-ketotic diabetics, 25 under insulin treatment, and 25 in diabetic ketoacidosis (DKA)], compared to 25 non-diabetic dogs. Lactate levels (mmol/L) were not differen...

  8. Optical constants of concentrated aqueous ammonium sulfate.

    Science.gov (United States)

    Remsberg, E. E.

    1973-01-01

    Using experimental data obtained from applying spectroscopy to a 39-wt-% aqueous ammonium sulfate solution, it is shown that, even though specific aerosol optical constants appear quite accurate, spectral variations may exist as functions of material composition or concentration or both. Prudent users of optical constant data must then include liberal data error estimates when performing calculations or in interpreting spectroscopic surveys of collected aerosol material.

  9. Concentrated solar power generation using solar receivers

    Science.gov (United States)

    Anderson, Bruce N.; Treece, William Dean; Brown, Dan; Bennhold, Florian; Hilgert, Christoph

    2017-08-08

    Inventive concentrated solar power systems using solar receivers, and related devices and methods, are generally described. Low pressure solar receivers are provided that function to convert solar radiation energy to thermal energy of a working fluid, e.g., a working fluid of a power generation or thermal storage system. In some embodiments, low pressure solar receivers are provided herein that are useful in conjunction with gas turbine based power generation systems.

  10. On the application of concentration factor

    International Nuclear Information System (INIS)

    Shimizu, Makoto

    1981-01-01

    Concentration factor is used to estimate internal dose through consumption of fish and shellfish. The amount of nuclide intake is estimated as ''radioactivity in ambient water x concentration factor x consumption of fish and shellfish''. These parameters involved are usually treated as constants but these actually are variables. Here the significance of their variation on dose assessment is examined. Concentration factors are varied according to various environmental as well as biological factors. For example, Hg, Cs, and As in the muscle of Galeus nipponensis increase as total length increases and, on the contrary, Cu, Zn, Fe and Co show negative correlation with total length. We should examine these cases and determine what value should be used in dose assessment. More important is to build up models to interprete these phenomena totally. Significance of variation in ambient radioactivity was examined by a simulation of nuclide accumulation in biota exposed to intermittent release and compared with that to continuous release. Variations either within a day or within a year were not shown to have much effect. On the variations in sea food consumption, several examples were given. Problem to be solved is how to consider these variations on assessing internal dose due to fish consumption. In conclusion it is necessary to get more of such kind of informations on the variations of parameters. And also we should determine the precision of each parameter in the whole picture of dose assessment. (author)

  11. Portable method of measuring gaseous acetone concentrations.

    Science.gov (United States)

    Worrall, Adam D; Bernstein, Jonathan A; Angelopoulos, Anastasios P

    2013-08-15

    Measurement of acetone in human breath samples has been previously shown to provide significant non-invasive diagnostic insight into the control of a patient's diabetic condition. In patients with diabetes mellitus, the body produces excess amounts of ketones such as acetone, which are then exhaled during respiration. Using various breath analysis methods has allowed for the accurate determination of acetone concentrations in exhaled breath. However, many of these methods require instrumentation and pre-concentration steps not suitable for point-of-care use. We have found that by immobilizing resorcinol reagent into a perfluorosulfonic acid polymer membrane, a controlled organic synthesis reaction occurs with acetone in a dry carrier gas. The immobilized, highly selective product of this reaction (a flavan) is found to produce a visible spectrum color change which could measure acetone concentrations to less than ppm. We here demonstrate how this approach can be used to produce a portable optical sensing device for real-time, non-invasive acetone analysis. Copyright © 2013 Elsevier B.V. All rights reserved.

  12. Radiative cooling for concentrating photovoltaic systems

    Science.gov (United States)

    Sun, Yubo; Zhou, Zhiguang; Jin, Xin; Sun, Xingshu; Alam, Muhammad Ashraful; Bermel, Peter

    2017-09-01

    Radiative cooling, a unique and uncommon passive cooling method for devices operating outdoors, has recently been demonstrated to be effective for photovoltaic thermal management. In this work, we investigate the effect of radiative cooling as a complement to existing passive cooling methods like convective cooling in a related system with much higher heat loads: a high-concentration photovoltaic (HCPV) system. A feasible radiative cooler design addressing the thermal management challenges here is proposed. It consists of low-iron soda-lime glass with a porous layer on top as an antireflection coating and a diamond layer as heat spreader. It is found that the proposed structure has strong mid-IR emittance as well as high solar transmission, allowing radiative cooling under direct sunlight and low loss in the concentrated solar irradiance. A systematic simulation with realistic considerations is then performed. Compared with a conventional copper cooler, the lowest temperature reached by the proposed radiative cooler is 14 K lower. Furthermore, less area of the proposed cooler is needed to reach a standard target temperature (333.15 K) for steady-state operation under high concentrations for the crystalline silicon PV module. In order to compare the coolers quantitatively, a figure of merit - cooling power per weight - is introduced. At the target temperature, the proposed cooler is determined to have a cooling power per weight of 75 W/kg, around 3.7 times higher than that of the conventional copper cooler.

  13. White butterflies as solar photovoltaic concentrators

    Science.gov (United States)

    Shanks, Katie; Senthilarasu, S.; Ffrench-Constant, Richard H.; Mallick, Tapas K.

    2015-07-01

    Man’s harvesting of photovoltaic energy requires the deployment of extensive arrays of solar panels. To improve both the gathering of thermal and photovoltaic energy from the sun we have examined the concept of biomimicry in white butterflies of the family Pieridae. We tested the hypothesis that the V-shaped posture of basking white butterflies mimics the V-trough concentrator which is designed to increase solar input to photovoltaic cells. These solar concentrators improve harvesting efficiency but are both heavy and bulky, severely limiting their deployment. Here, we show that the attachment of butterfly wings to a solar cell increases its output power by 42.3%, proving that the wings are indeed highly reflective. Importantly, and relative to current concentrators, the wings improve the power to weight ratio of the overall structure 17-fold, vastly expanding their potential application. Moreover, a single mono-layer of scale cells removed from the butterflies’ wings maintained this high reflectivity showing that a single layer of scale cell-like structures can also form a useful coating. As predicted, the wings increased the temperature of the butterflies’ thorax dramatically, showing that the V-shaped basking posture of white butterflies has indeed evolved to increase the temperature of their flight muscles prior to take-off.

  14. Defect clustering in concentrated alloys during irradiation

    International Nuclear Information System (INIS)

    Hashimoto, T.; Shigenaka, N.; Fuse, M.

    1992-01-01

    A rate theory based model is presented to investigate the kinetics of interstitial clustering processes in a face-centered cubic (fcc) binary alloy containing A- and B-atoms. Three types of interstitial dumbbells, AA-, BB- and AB-type dumbbells, are considered. Conversions between these interstitial dumbbells are explicitly introduced into the formulation, based on the consideration of dumbbell configurations and movements. A di- interstitial is assumed to be the nucleus of a dislocation loop. Reactions of point defect production by irradiation, mutual recombination of an interstitial and a vacancy, dislocation loop nucleation and their growth are included in the model. Parameter values are chosen based on the atom size of the alloy elements, and dislocation loop formation kinetics are investigated while varying alloy compositions. Two different types of kinetics are obtained in accordance with the dominant loop nucleus types. Conversions between interstitial dumbbells are important in the determination of the interstitial dumbbell concentration ratios, of the dominant nucleus types, and consequently, the loop formation kinetics. Dislocation loop concentration decreases with increasing undersized atom content, but dose rate and temperature dependence of loop concentration are insensitive to alloy compositions. (author)

  15. Integrated Solar Concentrator and Shielded Radiator

    Science.gov (United States)

    Clark, David Larry

    2010-01-01

    A shielded radiator is integrated within a solar concentrator for applications that require protection from high ambient temperatures with little convective heat transfer. This innovation uses a reflective surface to deflect ambient thermal radiation, shielding the radiator. The interior of the shield is also reflective to provide a view factor to deep space. A key feature of the shield is the parabolic shape that focuses incoming solar radiation to a line above the radiator along the length of the trough. This keeps the solar energy from adding to the radiator load. By placing solar cells along this focal line, the concentration of solar energy reduces the number and mass of required cells. By shielding the radiator, the effective reject temperature is much lower, allowing lower radiator temperatures. This is particularly important for lower-temperature processes, like habitat heat rejection and fuel cell operations where a high radiator temperature is not feasible. Adding the solar cells in the focal line uses the concentrating effect of the shield to advantage to accomplish two processes with a single device. This shield can be a deployable, lightweight Mylar structure for compact transport.

  16. Microfluidic distillation chip for methanol concentration detection.

    Science.gov (United States)

    Wang, Yao-Nan; Liu, Chan-Chiung; Yang, Ruey-Jen; Ju, Wei-Jhong; Fu, Lung-Ming

    2016-03-17

    An integrated microfluidic distillation system is proposed for separating a mixed ethanol-methanol-water solution into its constituent components. The microfluidic chip is fabricated using a CO2 laser system and comprises a serpentine channel, a boiling zone, a heating zone, and a cooled collection chamber filled with de-ionized (DI) water. In the proposed device, the ethanol-methanol-water solution is injected into the microfluidic chip and driven through the serpentine channel and into the collection chamber by means of a nitrogen carrier gas. Following the distillation process, the ethanol-methanol vapor flows into the collection chamber and condenses into the DI water. The resulting solution is removed from the collection tank and reacted with a mixed indicator. Finally, the methanol concentration is inversely derived from the absorbance measurements obtained using a spectrophotometer. The experimental results show the proposed microfluidic system achieves an average methanol distillation efficiency of 97%. The practicality of the proposed device is demonstrated by detecting the methanol concentrations of two commercial fruit wines. It is shown that the measured concentration values deviate by no more than 3% from those obtained using a conventional bench top system. Copyright © 2016 Elsevier B.V. All rights reserved.

  17. RHEOLOGY OF CHICKPEA PROTEIN CONCENTRATE DISPERSIONS

    Directory of Open Access Journals (Sweden)

    Aurelia Ionescu

    2011-12-01

    Full Text Available Chickpea proteins are used as ingredients in comminuted sausage products and many oriental textured foods. Rheological behaviour of chickpea protein concentrate was studied using a controlled stress rheometer. The protein dispersion prepared with phosphate buffer at pH 7.0 presented non-Newtonian shear thinning behaviour and rheological data well fitted to the Sisko, Carreau and Cross models. The viscoelastic properties of the chickpea protein suspensions were estimated by measuring the storage and loss moduli in oscillatory frequency conditions (0.1-10 Hz at 20°C. Moreover, thermally induced gelation of the chickpea proteins (16, 24 and 36% was studied at pH 7.0 and 4.5 in the temperature range 50 to 100oC and salt concentration ranging from 0 to 1 M. Gelling behaviour was quantified by means of dynamic rheological measurements. Gels formation was preceded by the decrease of storage modulus and loss moduli, coupled with the increase of the phase angle (delta. The beginning of thermal gelation was influenced by protein concentration, pH and salt level. In all studied cases, storage modulus increased rapidly in the temperature range 70-90°C. All rheological parameters measured at 90°C were significantly higher at pH 4.5 compared to pH 7.0.

  18. Hyaluronic acid concentration in liver diseases.

    Science.gov (United States)

    Gudowska, Monika; Gruszewska, Ewa; Panasiuk, Anatol; Cylwik, Bogdan; Flisiak, Robert; Świderska, Magdalena; Szmitkowski, Maciej; Chrostek, Lech

    2016-11-01

    The aim of this study was to evaluate the effect of liver diseases of different etiologies and clinical severity of liver cirrhosis on the serum level of hyaluronic acid. The results were compared with noninvasive markers of liver fibrosis: APRI, GAPRI, HAPRI, FIB-4 and Forn's index. Serum samples were obtained from 20 healthy volunteers and patients suffering from alcoholic cirrhosis (AC)-57 patients, non-alcoholic cirrhosis (NAC)-30 and toxic hepatitis (HT)-22. Cirrhotic patients were classified according to Child-Pugh score. Hyaluronic acid concentration was measured by the immunochemical method. Non-patented indicators were calculated using special formulas. The mean serum hyaluronic acid concentration was significantly higher in AC, NAC and HT group in comparison with the control group. There were significant differences in the serum hyaluronic acid levels between liver diseases, and in AC they were significantly higher than those in NAC and HT group. The serum hyaluronic acid level differs significantly due to the severity of cirrhosis and was the highest in Child-Pugh class C. The sensitivity, specificity, accuracy, positive and negative predictive values and the area under the ROC curve for hyaluronic acid and all non-patented algorithms were high and similar to each other. We conclude that the concentration of hyaluronic acid changes in liver diseases and is affected by the severity of liver cirrhosis. Serum hyaluronic acid should be considered as a good marker for noninvasive diagnosis of liver damage, but the combination of markers is more useful.

  19. Low-Altitude Aerial Methane Concentration Mapping

    Directory of Open Access Journals (Sweden)

    Bara J. Emran

    2017-08-01

    Full Text Available Detection of leaks of fugitive greenhouse gases (GHGs from landfills and natural gas infrastructure is critical for not only their safe operation but also for protecting the environment. Current inspection practices involve moving a methane detector within the target area by a person or vehicle. This procedure is dangerous, time consuming, labor intensive and above all unavailable when access to the desired area is limited. Remote sensing by an unmanned aerial vehicle (UAV equipped with a methane detector is a cost-effective and fast method for methane detection and monitoring, especially for vast and remote areas. This paper describes the integration of an off-the-shelf laser-based methane detector into a multi-rotor UAV and demonstrates its efficacy in generating an aerial methane concentration map of a landfill. The UAV flies a preset flight path measuring methane concentrations in a vertical air column between the UAV and the ground surface. Measurements were taken at 10 Hz giving a typical distance between measurements of 0.2 m when flying at 2 m/s. The UAV was set to fly at 25 to 30 m above the ground. We conclude that besides its utility in landfill monitoring, the proposed method is ready for other environmental applications as well as the inspection of natural gas infrastructure that can release methane with much higher concentrations.

  20. White butterflies as solar photovoltaic concentrators.

    Science.gov (United States)

    Shanks, Katie; Senthilarasu, S; Ffrench-Constant, Richard H; Mallick, Tapas K

    2015-07-31

    Man's harvesting of photovoltaic energy requires the deployment of extensive arrays of solar panels. To improve both the gathering of thermal and photovoltaic energy from the sun we have examined the concept of biomimicry in white butterflies of the family Pieridae. We tested the hypothesis that the V-shaped posture of basking white butterflies mimics the V-trough concentrator which is designed to increase solar input to photovoltaic cells. These solar concentrators improve harvesting efficiency but are both heavy and bulky, severely limiting their deployment. Here, we show that the attachment of butterfly wings to a solar cell increases its output power by 42.3%, proving that the wings are indeed highly reflective. Importantly, and relative to current concentrators, the wings improve the power to weight ratio of the overall structure 17-fold, vastly expanding their potential application. Moreover, a single mono-layer of scale cells removed from the butterflies' wings maintained this high reflectivity showing that a single layer of scale cell-like structures can also form a useful coating. As predicted, the wings increased the temperature of the butterflies' thorax dramatically, showing that the V-shaped basking posture of white butterflies has indeed evolved to increase the temperature of their flight muscles prior to take-off.

  1. Methods for macro concentration speciation (>106 M)

    International Nuclear Information System (INIS)

    2001-01-01

    The range of topics covered by the term 'speciation' varies from the determination of isotopic composition, through whether an element or nuclide is present and under which form, to the full identification of the molecular compound present or the isolation of species. Therefore, it is quite understandable that a rather large range of techniques may be applicable for speciation purposes and that none may be sufficient by itself to cover all purposes. We tried in this report to review on technologies available for speciation purposes in nuclear fuel cycle activities and to provide a reference document to guide researchers in choosing the most useful technique for his purposes by summarizing their characteristics. Particular attention was given to highlight the advantages and disadvantages/limitations of a given technique as well as, when suitable, expected or necessary future improvements. It was also attempted to indicate a 'recommended' application field, though this was not an easy task. In the present part, we concentrate on techniques available for macro concentration speciation with an arbitrary limit fixed around 10 -6 M. However, one should be aware that some of the techniques discussed in the present may be also applicable for lower concentration (overlap with over Partim. of the whole report) and vice-versa. Then, we consider that the scope of the present can only be achieved considering the whole parts discussed at the OECD/NEA Workshop on evaluation of speciation technology held in October 1999 at JAERI/Tokai-mura. (author)

  2. Carrier concentration induced ferromagnetism in semiconductors

    International Nuclear Information System (INIS)

    Story, T.

    2007-01-01

    In semiconductor spintronics the key materials issue concerns ferromagnetic semiconductors that would, in particular, permit an integration (in a single multilayer heterostructure) of standard electronic functions of semiconductors with magnetic memory function. Although classical semiconductor materials, such as Si or GaAs, are nonmagnetic, upon substitutional incorporation of magnetic ions (typically of a few atomic percents of Mn 2+ ions) and very heavy doping with conducting carriers (at the level of 10 20 - 10 21 cm -3 ) a ferromagnetic transition can be induced in such diluted magnetic semiconductors (also known as semimagnetic semiconductors). In the lecture the spectacular experimental observations of carrier concentration induced ferromagnetism will be discussed for three model semiconductor crystals. p - Ga 1-x Mn x As currently the most actively studied and most perspective ferromagnetic semiconductor of III-V group, in which ferromagnetism appears due to Mn ions providing both local magnetic moments and acting as acceptor centers. p - Sn 1-x Mn x Te and p - Ge 1-x Mn x Te classical diluted magnetic semiconductors of IV-VI group, in which paramagnet-ferromagnet and ferromagnet-spin glass transitions are found for very high hole concentration. n - Eu 1-x Gd x Te mixed magnetic crystals, in which the substitution of Gd 3+ ions for Eu 2+ ions creates very high electron concentration and transforms antiferromagnetic EuTe (insulating compound) into ferromagnetic n-type semiconductor alloy. For each of these materials systems the key physical features will be discussed concerning: local magnetic moments formation, magnetic phase diagram as a function of magnetic ions and carrier concentration as well as Curie temperature and magnetic anisotropy engineering. Various theoretical models proposed to explain the effect of carrier concentration induced ferromagnetism in semiconductors will be briefly discussed involving mean field approaches based on Zener and RKKY

  3. Point-focus spectral splitting solar concentrator for multiple cells concentrating photovoltaic system

    International Nuclear Information System (INIS)

    Maragliano, Carlo; Chiesa, Matteo; Stefancich, Marco

    2015-01-01

    In this paper we present and experimentally validate a low-cost design of a spectral splitting concentrator for the efficient conversion of solar energy. The optical device consists of a dispersive prismatic lens made of polycarbonate designed to simultaneously concentrate solar light and split it into its spectral components. With respect to our previous implementation, this device concentrates light along two axes and generates a light pattern compatible with the dimensions of a set of concentrating photovoltaic cells, while providing a higher concentration ratio. The mathematical framework and the constructive approach used for the design are presented and the device performance is simulated using ray-tracing software. We obtain spectral separation in the visible range within a 3 × 1 cm 2 area and a maximum concentration of 210× for a single wavelength. The device is fabricated by injection molding and its performance is experimentally investigated. We measure an optical transmissivity above 90% in the range 400–800 nm and we observe a spectral distribution in good accordance with simulations. Our results demonstrate the feasibility of the device for cost effective high efficiency concentrated photovoltaic systems. (paper)

  4. Preovulatory progesterone concentration associates significantly to follicle number and LH concentration but not to pregnancy rate

    DEFF Research Database (Denmark)

    Yding Andersen, Claus; Bungum, Leif; Andersen, Anders Nyboe

    2011-01-01

    of HCG administration and the probability of clinical pregnancy in women undergoing ovarian stimulation with GnRH agonists and gonadotrophins for assisted reproduction treatment.Instead, late-follicular-phase progesterone concentration appears to be governed by the number of preovulatory follicles and LH...... with or without rLH administration from day 6 of stimulation. There was no significant association between the late-follicular-phase progesterone concentration and the clinical pregnancy rate. However, progesterone concentration was strongly associated with the number of follicles and retrieved oocytes. Late...

  5. Performance investigation of a concentrating photovoltaic/thermal system with transmissive Fresnel solar concentrator

    International Nuclear Information System (INIS)

    Feng, Chaoqing; Zheng, Hongfei; Wang, Rui; Ma, Xinglong

    2016-01-01

    Highlights: • A common design method of a cycloidal transmissive Fresnel solar concentrator was presented. • The gallium arsenide high concentrated solar was used as the receiver. • High efficiency of electric generating could be achieved at noon. • Fresnel solar concentrator was studied and compared in hazy weather and clear weather. - Abstract: A design method of a cycloidal transmissive Fresnel solar concentrator which can provide a certain width focal line was presented in this study. Based on the optical principle of refraction, the dimensions of each wedge-shaped element of Fresnel lens are calculated. An optical simulation has been done to obtain the optical efficiency of the concentrator for different tracking error and axial incidence angle. It has been found that about 80% of the incident sunlight can still be gathered by the absorber when the tracking error is within 0.7°. When the axial angle of incidence is within 10°, it almost has no influence to the receiving rate. The concentrating photovoltaic/thermal system with transmissive Fresnel solar concentrator has been designed in this paper. Take the gallium arsenide high concentrated battery as the receiver, experimental research about cylindrical Fresnel concentrating photovoltaic/thermal system is undertaken in the real sky. Main parameters are tested such as the temperature distribution on receiver, electric energy and thermal energy outputs of concentrating photovoltaic/thermal system, the efficiency of multipurpose utilization of electric and heat, and so on. The test results in clear weather show that maximum electric generating efficiency is about 18% at noon, the maximum heat receiving rate of cooling water is about 45%. At noon time (11:00–13:00), the total efficiency of thermal and electricity can reach more than 55%. Performance of this concentrating photovoltaic/thermal system with transmissive Fresnel solar concentrator is studied and compared in two types typical weather, hazy

  6. Optical characterization of nonimaging dish concentrator for the application of dense-array concentrator photovoltaic system.

    Science.gov (United States)

    Tan, Ming-Hui; Chong, Kok-Keong; Wong, Chee-Woon

    2014-01-20

    Optimization of the design of a nonimaging dish concentrator (NIDC) for a dense-array concentrator photovoltaic system is presented. A new algorithm has been developed to determine configuration of facet mirrors in a NIDC. Analytical formulas were derived to analyze the optical performance of a NIDC and then compared with a simulated result obtained from a numerical method. Comprehensive analysis of optical performance via analytical method has been carried out based on facet dimension and focal distance of the concentrator with a total reflective area of 120 m2. The result shows that a facet dimension of 49.8 cm, focal distance of 8 m, and solar concentration ratio of 411.8 suns is the most optimized design for the lowest cost-per-output power, which is US$1.93 per watt.

  7. Preovulatory progesterone concentration associates significantly to follicle number and LH concentration but not to pregnancy rate

    DEFF Research Database (Denmark)

    Yding Andersen, Claus; Bungum, Leif; Nyboe Andersen, Anders

    2011-01-01

    Using data from a large prospective randomized controlled trial that evaluated the effect of recombinant LH (rLH)co-administration for ovarian stimulation, the present study assessed whether progesterone concentration on the day of human chorionic gonadotrophin (HCG) administration was associated...... with or without rLH administration from day 6 of stimulation. There was no significant association between the late-follicular-phase progesterone concentration and the clinical pregnancy rate. However, progesterone concentration was strongly associated with the number of follicles and retrieved oocytes. Late...... of HCG administration and the probability of clinical pregnancy in women undergoing ovarian stimulation with GnRH agonists and gonadotrophins for assisted reproduction treatment.Instead, late-follicular-phase progesterone concentration appears to be governed by the number of preovulatory follicles and LH...

  8. Atmospheric ammonia measurements at low concentration ...

    Science.gov (United States)

    We evaluated the relative importance of dry deposition of ammonia (NH3) gas at several headwater areas of the Susquehanna River, the largest single source of nitrogen pollution to Chesapeake Bay, including three that are remote from major sources of NH3 emissions (CTH, ARN, and KEF) and one (HFD) that is near a major agricultural source. We also examined the importance of nitrogen dioxide (NO2) deposition at one of these sites. Over the past decade, increasing evidence has suggested that NH3 deposition, in particular, may be an important contributor to total nitrogen deposition and to downstream nitrogen pollution. We used Ogawa passive samplers to measure NH3 concentrations over several years (2006–2011) for CTH, and primarily in 2008 and 2009 for the other sites. NO2 was measured at CTH mainly in 2007. Chamber calibration studies for NH3 and NO2, and field comparisons with annular denuders for NH3, validated the use of these passive samplers over a range of temperatures and humidity observed in the field, if attention is given to field and laboratory blank issues. The annual mean NH3 concentrations for the forested sites were 0.41 ± 0.03, 0.41 ± 0.06 and 0.25 ± 0.08 µg NH3/m3 for CTH, ARN and KEF, respectively. NO2 passive sampler mean annual concentration was 3.19 ± 0.42 µg NO2/m3 at CTH. Direct comparison of our measured values with the widely used Community Multiscale Air Quality (CMAQ) model (v4.7.1) show reasonably good agreement. However, the mod

  9. Fluorescence lifetime to image epidermal ionic concentrations

    Science.gov (United States)

    Behne, Martin J.; Barry, Nicholas P.; Moll, Ingrid; Gratton, Enrico; Mauro, Theodora M.

    2004-09-01

    Measurements of ionic concentrations in skin have traditionally been performed with an array of methods which either did not reveal detailed localization information, or only provided qualitative, not quantitative information. FLIM combines a number of advantages into a method ideally suited to visualize concentrations of ions such as H+ in intact, unperturbed epidermis and stratum corneum (SC). Fluorescence lifetime is dye concentration-independent, the method requires only low light intensities and is therefore not prone to photobleaching or phototoxic artifacts, and because multiphoton lasers of IR wavelength are used, light penetrates deep into intact tissue. The standard method to measure SC pH is the flat pH electrode, which provides reliable information only about surface pH changes, without further vertical or subcellular spatial resolution; i.e., specific microdomains such as the corneocyte interstices are not resolved, and the deeper SC is inaccessible without resorting to inherently disruptive stripping methods. Furthermore, the concept of a gradient of pH through the SC stems from such stripping experiments, but other confirmation for this concept is lacking. Our investigations into the SC pH distribution so far have revealed the crucial role of the Sodium/Hydrogen Antiporter NHE1 in generation of SC acidity, the colocalization of enzymatic lipid processing activity in the SC with acidic domains of the SC, and the timing and localization of emerging acidity in the SC of newborns. Together, these results have led to an improved understanding of the SC pH, its distribution, origin, and regulation. Future uses for this method include measurements of other ions important for epidermal processes, such as Ca2+, and a quantitative approach to topical drug penetration.

  10. Estimating soil zinc concentrations using reflectance spectroscopy

    Science.gov (United States)

    Sun, Weichao; Zhang, Xia

    2017-06-01

    Soil contamination by heavy metals has been an increasingly severe threat to nature environment and human health. Efficiently investigation of contamination status is essential to soil protection and remediation. Visible and near-infrared reflectance spectroscopy (VNIRS) has been regarded as an alternative for monitoring soil contamination by heavy metals. Generally, the entire VNIR spectral bands are employed to estimate heavy metal concentration, which lacks interpretability and requires much calculation. In this study, 74 soil samples were collected from Hunan Province, China and their reflectance spectra were used to estimate zinc (Zn) concentration in soil. Organic matter and clay minerals have strong adsorption for Zn in soil. Spectral bands associated with organic matter and clay minerals were used for estimation with genetic algorithm based partial least square regression (GA-PLSR). The entire VNIR spectral bands, the bands associated with organic matter and the bands associated with clay minerals were incorporated as comparisons. Root mean square error of prediction, residual prediction deviation, and coefficient of determination (R2) for the model developed using combined bands of organic matter and clay minerals were 329.65 mg kg-1, 1.96 and 0.73, which is better than 341.88 mg kg-1, 1.89 and 0.71 for the entire VNIR spectral bands, 492.65 mg kg-1, 1.31 and 0.40 for the organic matter, and 430.26 mg kg-1, 1.50 and 0.54 for the clay minerals. Additionally, in consideration of atmospheric water vapor absorption in field spectra measurement, combined bands of organic matter and absorption around 2200 nm were used for estimation and achieved high prediction accuracy with R2 reached 0.640. The results indicate huge potential of soil reflectance spectroscopy in estimating Zn concentrations in soil.

  11. Increased plasma fibronectin concentrations in obesity

    DEFF Research Database (Denmark)

    Andersen, T; Dejgaard, A; Astrup, A

    1987-01-01

    In 23 morbidly obese patients we investigated the influence of a large weight loss (30.6 kg, range 17.5-90.8) on the plasma fibronectin concentrations. Further, changes in plasma fibronectin were related to serum insulin levels and to liver biochemistry. Between the measurements patients had been...... with the degree of hepatic fatty change, declined (p less than 0.01), but the individual change was unrelated with the change in plasma fibronectin. In conclusion, the elevated plasma fibronectin levels in morbidly obese subjects seem to normalize during weight loss. We suggest the normalization to be mediated...

  12. Colligative Properties of Solutions: I. Fixed Concentrations

    Science.gov (United States)

    Alexander, Kenneth S.; Biskup, Marek; Chayes, Lincoln

    2005-05-01

    Using the formalism of rigorous statistical mechanics, we study the phenomena of phase separation and freezing-point depression upon freezing of solutions. Specifically, we devise an Ising-based model of a solvent--solute system and show that, in the ensemble with a fixed amount of solute, a macroscopic phase separation occurs in an interval of values of the chemical potential of the solvent. The boundaries of the phase separation domain in the phase diagram are characterized and shown to asymptotically agree with the formulas used in heuristic analyses of freezing-point depression. The limit of infinitesimal concentrations is described in a subsequent paper.

  13. Colligative properties of solutions: II. Vanishing concentrations

    OpenAIRE

    Alexander, Kenneth; Biskup, Marek; Chayes, Lincoln

    2004-01-01

    We continue our study of colligative properties of solutions initiated in math-ph/0407034. We focus on the situations where, in a system of linear size $L$, the concentration and the chemical potential scale like $c=\\xi/L$ and $h=b/L$, respectively. We find that there exists a critical value $\\xit$ such that no phase separation occurs for $\\xi\\le\\xit$ while, for $\\xi>\\xit$, the two phases of the solvent coexist for an interval of values of $b$. Moreover, phase separation begins abruptly in th...

  14. Apparatus for concentrating by dual temperature exchange

    International Nuclear Information System (INIS)

    Spevack, J.S.

    1975-01-01

    Improvements in an apparatus for isotope concentration by dual temperature exchange between feed and auxiliary fluids in a multistage system are described. The first fluid is a vaporizable liquid and the auxiliary fluid a gas, the apparatus having means for cascading the auxiliary fluid and the feed fluid in vapor and preferably also in liquid form. The apparatus also contains new combinations of means for improving the heating and/or cooling and/or humidifying and/or dehumidifying operations of the system. The reactants in the example given are hydrogen sulfide gas and liquid water

  15. Concentrating lightguide for threshold Cherenkov counters

    International Nuclear Information System (INIS)

    Gavrishchuk, O.P.; Onuchin, V.A.; Semenov, V.K.; Suzdalev, V.I.

    1991-01-01

    A method of manufacturing lightguides (Winston lenses) is proposed to increase the effective area of light collection on photodetectors (with diameter of detectiving area from 45 to 120 mm) and to broaden angular range of radiation detection in threshold Cherenkov counters. The concentrating lightguides with height and diameter up to 300 mm were pressure formed of 3 to 5 mm thick plexiglass sheets. Dependences of the light reflection coefficient on the wavelength (for wavelengths between 185 and 650 nm) of the deposited lightguide are presented. 10 refs.; 4 figs

  16. Acoustic concentration of particles in fluid flow

    Science.gov (United States)

    Ward, Michael D.; Kaduchak, Gregory

    2010-11-23

    An apparatus for acoustic concentration of particles in a fluid flow includes a substantially acoustically transparent membrane and a vibration generator that define a fluid flow path therebetween. The fluid flow path is in fluid communication with a fluid source and a fluid outlet and the vibration generator is disposed adjacent the fluid flow path and is capable of producing an acoustic field in the fluid flow path. The acoustic field produces at least one pressure minima in the fluid flow path at a predetermined location within the fluid flow path and forces predetermined particles in the fluid flow path to the at least one pressure minima.

  17. Acoustic concentration of particles in fluid flow

    Science.gov (United States)

    Ward, Michael W.; Kaduchak, Gregory

    2017-08-15

    Disclosed herein is a acoustic concentration of particles in a fluid flow that includes a substantially acoustically transparent membrane and a vibration generator that define a fluid flow path therebetween. The fluid flow path is in fluid communication with a fluid source and a fluid outlet and the vibration generator is disposed adjacent the fluid flow path and is capable of producing an acoustic field in the fluid flow path. The acoustic field produces at least one pressure minima in the fluid flow path at a predetermined location within the fluid flow path and forces predetermined particles in the fluid flow path to the at least one pressure minima.

  18. Suspension Hydrogen Reduction of Iron Oxide Concentrates

    Energy Technology Data Exchange (ETDEWEB)

    H.Y. Sohn

    2008-03-31

    The objective of the project is to develop a new ironmaking technology based on hydrogen and fine iron oxide concentrates in a suspension reduction process. The ultimate objective of the new technology is to replace the blast furnace and to drastically reduce CO2 emissions in the steel industry. The goals of this phase of development are; the performance of detailed material and energy balances, thermochemical and equilibrium calculations for sulfur and phosphorus impurities, the determination of the complete kinetics of hydrogen reduction and bench-scale testing of the suspension reduction process using a large laboratory flash reactor.

  19. Global variability of cloud condensation nuclei concentrations

    Science.gov (United States)

    Makkonen, Risto; Krüger, Olaf

    2017-04-01

    Atmospheric aerosols can influence cloud optical and dynamical processes by acting as cloud condensation nuclei (CCN). Globally, these indirect aerosol effects are significant to the radiative budget as well as a source of high uncertainty in anthropogenic radiative forcing. While historically many global climate models have fixed CCN concentrations to a certain level, most state-of-the-art models calculate aerosol-cloud interactions with sophisticated methodologies based on interactively simulated aerosol size distributions. However, due to scarcity of atmospheric observations simulated global CCN concentrations remain poorly constrained. Here we assess global CCN variability with a climate model, and attribute potential trends during 2000-2010 to changes in emissions and meteorological fields. Here we have used ECHAM5.5-HAM2 with model M7 microphysical aerosol model. The model has been upgraded with a secondary organic aerosol (SOA) scheme including ELVOCs. Dust and sea salt emissions are calculated online, based on wind speed and hydrology. Each experiment is 11 years, analysed after a 6-month spin-up period. The MODIS CCN product (Terra platform) is used to evaluate model performance throughout 2000-2010. While optical remote observation of CCN column includes several deficiencies, the products serves as a proxy for changes during the simulation period. In our analysis we utilize the observed and simulated vertical column integrated CCN concentration, and limit our analysis only over marine regions. Simulated annual CCN column densities reach 2ṡ108 cm-2 near strong source regions in central Africa, Arabian Sea, Bay of Bengal and China sea. The spatial concentration gradient in CCN(0.2%) is steep, and column densities drop to pattern of high temporal correlation is found over North Atlantic ocean, extending throughout Europe and up to Gulf of Mexico. All of these regions show a generally decreasing trend throughout the decade in control simulations and MODIS

  20. Elasticity and clustering in concentrated depletion gels.

    Science.gov (United States)

    Ramakrishnan, S; Chen, Y-L; Schweizer, K S; Zukoski, C F

    2004-10-01

    X-ray scattering and rheology are employed to study the volume fraction dependence of the collective structure and elastic moduli of concentrated nanoparticle-polymer depletion gels. The nonequilibrium gel structure consists of locally densified nonfractal clusters and narrow random interfaces. The elastic moduli display a power law dependence on volume fraction with effective exponents that decrease with increasing depletion attraction strength. A microscopic theory that combines local structural information with a dynamic treatment of gelation is in good agreement with the observations.

  1. Advertising and concentration in the brewing industry

    DEFF Research Database (Denmark)

    Madsen, Erik Strøjer; Wu, Yanqing

    The opening of the markets in East Asia and Eastern Europe in the 1990s changed the structure of the beer markets and in the following years a large wave of mergers and acquisitions took place. The paper tracks the development in industry concentrations from 2002 to 2012, discusses some of the main...... drivers behind this development and points to economies of scale in advertising as a main pay-off from mergers and acquisitions. Using firm-level data both from the American market and the world market, the estimations verify significant economies of scale in marketing and distribution costs. Based...

  2. Concentration Distribution in a Mixing Ventilated Room

    DEFF Research Database (Denmark)

    Jensen, Rasmus Lund; Pedersen, D. N.; Nielsen, Peter Vilhelm

    2001-01-01

    Today there is an increasing focus on the importance of a proper ventilation system to obtain good working conditions in the term of air and thermal quality to ensure high productivity. Different ventilation principles are used, e.g., mixing ventilation and displacement ventilation. In order...... that the air is fully mixed. The objective of this work is to determine the influence of the location of a pollutant, temperature differences and whether the room is furnished or not. It is also investigated if it is sufficient to determine the mean concentration in the room to determine the personal exposure...

  3. Effects of ambient oxygen concentration on soot temperature and concentration for biodiesel and diesel spray combustion

    KAUST Repository

    Zhang, Ji

    2015-06-01

    Ambient oxygen concentration, a key variable directly related to exhaust gas recirculation (EGR) levels in diesel engines, plays a significant role in particulate matter (PM) and nitrogen oxides (NOx) emissions. The utilization of biodiesel in diesel engines has been investigated over the last decades for its renewable characteristics and lower emissions compared to diesel. In an earlier work, we demonstrated that the soot temperature and concentration of biodiesel were lower than diesel under regular diesel engine conditions without EGR. Soot concentration was quantified by a parameter called KL factor. As a continuous effort, this paper presents an experimental investigation of the ambient oxygen concentration on soot temperature and KL factor during biodiesel and diesel spray combustion. The experiment was implemented in a constant volume chamber system, where the ambient oxygen concentration varied from 21 to 10% and the ambient temperature was kept to 1,000 K. A high speed two-color pyrometry technique was used to measure transient soot temperature and the KL factor of the spray flame. The soot temperature of biodiesel is found to be lower than that of diesel under the same conditions, which follows the same trend from our previous results found when the ambient temperature changes to 21% oxygen conditions. A reduction in ambient oxygen concentration generally reduces the soot temperature for both fuels. However, this is a complicated effect on soot processes as the change of oxygen concentration greatly affects the balance between soot formation and oxidation. The KL factor is observed to be the highest at 12% O2 for diesel and 18% O2 for biodiesel, respectively. On the other hand, the 10% O2 condition shows the lowest KL factor for both fuels. These results can provide quantitative experimental evidences to optimize the ambient oxygen concentration for diesel engines using different fuels for better emissions characteristics. © 2014 American Society of

  4. A Concentrator Photovoltaic System Based on a Combination of Prism-Compound Parabolic Concentrators

    Directory of Open Access Journals (Sweden)

    Ngoc Hai Vu

    2016-08-01

    Full Text Available We present a cost-effective concentrating photovoltaic system composed of a prism and a compound parabolic concentrator (P-CPC. In this approach, the primary collector consists of a prism, a solid compound parabolic concentrator (CPC, and a slab waveguide. The prism, which is placed on the input aperture of CPC, directs the incoming sunlight beam to be parallel with the main axes of parabolic rims of CPC. Then, the sunlight is reflected at the parabolic rims and concentrated at the focal point of these parabolas. A slab waveguide is coupled at the output aperture of the CPC to collect focused sunlight beams and to guide them to the solar cell. The optical system was modeled and simulated with commercial ray tracing software (LightTools™. Simulation results show that the optical efficiency of a P-CPC can achieve up to 89%. when the concentration ratio of the P-CPC is fixed at 50. We also determine an optimal geometric structure of P-CPC based on simulation. Because of the simplicity of the P-CPC structure, a lower-cost mass production process is possible. A simulation based on optimal structure of P-CPC was performed and the results also shown that P-CPC has high angular tolerance for input sunlight. The high tolerance of the input angle of sunlight allows P-CPC solar concentrator utilize a single sun tracking system instead of a highly precise dual suntracking system as cost effective solution.

  5. Simulation of an electrowetting solar concentration cell

    Science.gov (United States)

    Khan, Iftekhar; Rosengarten, Gary

    2015-09-01

    Electrowetting control of liquid lenses has emerged as a novel approach for solar tracking and concentration. Recent studies have demonstrated the concept of steering sunlight using thin electrowetting cells without the use of any bulky mechanical equipment. Effective application of this technique may facilitate designing thin and flat solar concentrators. Understanding the behavior of liquid-liquid and liquid-solid interface of the electrowetting cell through trial and error experimental processes is not efficient and is time consuming. In this paper, we present a simulation model to predict the liquid-liquid and liquid-solid interface behavior of electrowetting cell as a function of various parameters such as applied voltage, dielectric constant, cell size etc. We used Comsol Multiphysics simulations incorporating experimental data of different liquids. We have designed both two dimensional and three dimensional simulation models, which predict the shape of the liquid lenses. The model calculates the contact angle using the Young-Lippman equation and uses a moving mesh interface to solve the Navier-stokes equation with Navier slip wall boundary condition. Simulation of the electric field from the electrodes is coupled to the Young-Lippman equation. The model can also be used to determine operational characteristics of other MEMS electrowetting devices such as electrowetting display, optical switches, electronic paper, electrowetting Fresnel lens etc.

  6. Physicochemical properties of concentrated Martian surface waters

    Science.gov (United States)

    Tosca, Nicholas J.; McLennan, Scott M.; Lamb, Michael P.; Grotzinger, John P.

    2011-05-01

    Understanding the processes controlling chemical sedimentation is an important step in deciphering paleoclimatic conditions from the rock records preserved on both Earth and Mars. Clear evidence for subaqueous sedimentation at Meridiani Planum, widespread saline mineral deposits in the Valles Marineris region, and the possible role of saline waters in forming recent geomorphologic features all underscore the need to understand the physical properties of highly concentrated solutions on Mars in addition to, and as a function of, their distinct chemistry. Using thermodynamic models predicting saline mineral solubility, we generate likely brine compositions ranging from bicarbonate-dominated to sulfate-dominated and predict their saline mineralogy. For each brine composition, we then estimate a number of thermal, transport, and colligative properties using established models that have been developed for highly concentrated multicomponent electrolyte solutions. The available experimental data and theoretical models that allow estimation of these physicochemical properties encompass, for the most part, much of the anticipated variation in chemistry for likely Martian brines. These estimates allow significant progress in building a detailed analysis of physical sedimentation at the ancient Martian surface and allow more accurate predictions of thermal behavior and the diffusive transport of matter through chemically distinct solutions under comparatively nonstandard conditions.

  7. Optical monitor for water vapor concentration

    Science.gov (United States)

    Kebabian, P.

    1998-06-02

    A system for measuring and monitoring water vapor concentration in a sample uses as a light source an argon discharge lamp, which inherently emits light with a spectral line that is close to a water vapor absorption line. In a preferred embodiment, the argon line is split by a magnetic field parallel to the direction of light propagation from the lamp into sets of components of downshifted and upshifted frequencies of approximately 1575 Gauss. The downshifted components are centered on a water vapor absorption line and are thus readily absorbed by water vapor in the sample; the upshifted components are moved away from that absorption line and are minimally absorbed. A polarization modulator alternately selects the upshifted components or downshifted components and passes the selected components to the sample. After transmission through the sample, the transmitted intensity of a component of the argon line varies as a result of absorption by the water vapor. The system then determines the concentration of water vapor in the sample based on differences in the transmitted intensity between the two sets of components. In alternative embodiments alternate selection of sets of components is achieved by selectively reversing the polarity of the magnetic field or by selectively supplying the magnetic field to the emitting plasma. 5 figs.

  8. Minimal inhibitory concentrations of modern topical antimicrobials

    Directory of Open Access Journals (Sweden)

    T. N. Vorontsova

    2014-01-01

    Full Text Available Aim. To measure minimal inhibitory concentration (MIC values for modern topical antimicrobials against common ocular pathogens.Methods.Antimicrobials most commonly used in ophthalmology (fluoroquinolones and aminoglycosides are dose-dependent drugs, i.e., the rate of microbial death increases in direct proportion to their concentrations. To determine MICs, we applied Hi Comb MIC Test (E-test. 105 patients aged 2 months through 7 years which were diagnosed with various inflammatory disorders of anterior segment were  xamined. MIC values for most commonly used antimicrobials, i.e., ciprofloxacin / Cipromed (Sentiss Pharma, Gurgaon, India, ofloxacin / Floxal (Baush & Lomb, Rochester, New-York, levofloxacin / Signicef (Sentiss Pharma, Gurgaon, India, moxifloxacin / Vigamox (Alcon, Fort Worth, Texas, gatifloxacin / Zymar (Allergan, Irvine, California, and tobramycin / Tobrex (Alcon, Fort Worth, Texas, were measured.Results. The analysis revealed that the most effective antibacterial drug against microbial isolates in children (i.e., Staphylococci spp. was levofloxacin. MIC for this agent against Streptococci spp. and Gram-negative microbes was low as well. Moxifloxacin is preferred for the treatment of ocular inflammation provoked by Streptococci spp. as MIC of this antimicrobial against Streptococci spp. was the lowest. MIC of ciprofloxacin against Gram-negative flora was the lowest. These data demonstrate generally recognized high efficacy of this drug. MIC value for tobramycin against all bacterial isolates was the highest.

  9. Minimal inhibitory concentrations of modern topical antimicrobials

    Directory of Open Access Journals (Sweden)

    T. N. Vorontsova

    2014-10-01

    Full Text Available Aim. To measure minimal inhibitory concentration (MIC values for modern topical antimicrobials against common ocular pathogens.Methods.Antimicrobials most commonly used in ophthalmology (fluoroquinolones and aminoglycosides are dose-dependent drugs, i.e., the rate of microbial death increases in direct proportion to their concentrations. To determine MICs, we applied Hi Comb MIC Test (E-test. 105 patients aged 2 months through 7 years which were diagnosed with various inflammatory disorders of anterior segment were  xamined. MIC values for most commonly used antimicrobials, i.e., ciprofloxacin / Cipromed (Sentiss Pharma, Gurgaon, India, ofloxacin / Floxal (Baush & Lomb, Rochester, New-York, levofloxacin / Signicef (Sentiss Pharma, Gurgaon, India, moxifloxacin / Vigamox (Alcon, Fort Worth, Texas, gatifloxacin / Zymar (Allergan, Irvine, California, and tobramycin / Tobrex (Alcon, Fort Worth, Texas, were measured.Results. The analysis revealed that the most effective antibacterial drug against microbial isolates in children (i.e., Staphylococci spp. was levofloxacin. MIC for this agent against Streptococci spp. and Gram-negative microbes was low as well. Moxifloxacin is preferred for the treatment of ocular inflammation provoked by Streptococci spp. as MIC of this antimicrobial against Streptococci spp. was the lowest. MIC of ciprofloxacin against Gram-negative flora was the lowest. These data demonstrate generally recognized high efficacy of this drug. MIC value for tobramycin against all bacterial isolates was the highest.

  10. Erbium concentration dependent absorbance in tellurite glass

    Energy Technology Data Exchange (ETDEWEB)

    Sazali, E. S., E-mail: mdsupar@utm; Rohani, M. S., E-mail: mdsupar@utm; Sahar, M. R., E-mail: mdsupar@utm; Arifin, R., E-mail: mdsupar@utm; Ghoshal, S. K., E-mail: mdsupar@utm; Hamzah, K., E-mail: mdsupar@utm [Advanced Optical Material Research Group, Department of Physics, Faculty of Science, Universiti Teknologi Malaysia, 81310, Skudai, Johor Bahru, Johor (Malaysia)

    2014-09-25

    Enhancing the optical absorption cross-section in topically important rare earth doped tellurite glasses is challenging for photonic devices. Controlled synthesis and detailed characterizations of the optical properties of these glasses are important for the optimization. The influence of varying concentration of Er{sup 3+} ions on the absorbance characteristics of lead tellurite glasses synthesized via melt-quenching technique are investigated. The UV-Vis absorption spectra exhibits six prominent peaks centered at 490, 526, 652, 800, 982 and 1520 nm ascribed to the transitions in erbium ion from the ground state to the excited states {sup 4}F{sub 7/2}, {sup 2}H{sub 11/2}, {sup 4}F{sub 9/2}, {sup 4}I{sub 9/2}, {sup 2}H{sub 11/2} and {sup 4}I{sub 13/2}, respectively. The results are analyzed by means of optical band gap E{sub g} and Urbach energy E{sub u}. The values of the energy band gap are found decreased from 2.82 to 2.51 eV and the Urbach energy increased from 0.15 to 0.24 eV with the increase of the Er{sub 2}O{sub 3} concentration from 0 to 1.5 mol%. The excellent absorbance of the prepared tellurite glasses makes them suitable for fabricating solid state lasers.

  11. Direct seawater desalination by ion concentration polarization

    Science.gov (United States)

    Kim, Sung Jae; Ko, Sung Hee; Kang, Kwan Hyoung; Han, Jongyoon

    2010-04-01

    A shortage of fresh water is one of the acute challenges facing the world today. An energy-efficient approach to converting sea water into fresh water could be of substantial benefit, but current desalination methods require high power consumption and operating costs or large-scale infrastructures, which make them difficult to implement in resource-limited settings or in disaster scenarios. Here, we report a process for converting sea water (salinity ~500 mM or ~30,000 mg l-1) to fresh water (salinity water is divided into desalted and concentrated streams by ion concentration polarization, a phenomenon that occurs when an ion current is passed through ion-selective membranes. During operation, both salts and larger particles (cells, viruses and microorganisms) are pushed away from the membrane (a nanochannel or nanoporous membrane), which significantly reduces the possibility of membrane fouling and salt accumulation, thus avoiding two problems that plague other membrane filtration methods. To implement this approach, a simple microfluidic device was fabricated and shown to be capable of continuous desalination of sea water (~99% salt rejection at 50% recovery rate) at a power consumption of less than 3.5 Wh l-1, which is comparable to current state-of-the-art systems. Rather than competing with larger desalination plants, the method could be used to make small- or medium-scale systems, with the possibility of battery-powered operation.

  12. Ion Concentration Polarization by Bifurcated Current Path.

    Science.gov (United States)

    Kim, Junsuk; Cho, Inhee; Lee, Hyomin; Kim, Sung Jae

    2017-07-11

    Ion concentration polarization (ICP) is a fundamental electrokinetic process that occurs near a perm-selective membrane under dc bias. Overall process highly depends on the current transportation mechanisms such as electro-convection, surface conduction and diffusioosmosis and the fundamental characteristics can be significantly altered by external parameters, once the permselectivity was fixed. In this work, a new ICP device with a bifurcated current path as for the enhancement of the surface conduction was fabricated using a polymeric nanoporous material. It was protruded to the middle of a microchannel, while the material was exactly aligned at the interface between two microchannels in a conventional ICP device. Rigorous experiments revealed out that the propagation of ICP layer was initiated from the different locations of the protruded membrane according to the dominant current path which was determined by a bulk electrolyte concentration. Since the enhancement of surface conduction maintained the stability of ICP process, a strong electrokinetic flow associated with the amplified electric field inside ICP layer was significantly suppressed over the protruded membrane even at condensed limit. As a practical example of utilizing the protruded device, we successfully demonstrated a non-destructive micro/nanofluidic preconcentrator of fragile cellular species (i.e. red blood cells).

  13. Cast Stone Formulation At Higher Sodium Concentrations

    International Nuclear Information System (INIS)

    Fox, K. M.; Edwards, T. A.; Roberts, K. B.

    2013-01-01

    A low temperature waste form known as Cast Stone is being considered to provide supplemental Low Activity Waste (LAW) immobilization capacity for the Hanford site. Formulation of Cast Stone at high sodium concentrations is of interest since a significant reduction in the necessary volume of Cast Stone and subsequent disposal costs could be achieved if an acceptable waste form can be produced with a high sodium molarity salt solution combined with a high water to premix (or dry blend) ratio. The objectives of this study were to evaluate the factors involved with increasing the sodium concentration in Cast Stone, including production and performance properties and the retention and release of specific components of interest. Three factors were identified for the experimental matrix: the concentration of sodium in the simulated salt solution, the water to premix ratio, and the blast furnace slag portion of the premix. The salt solution simulants used in this study were formulated to represent the overall average waste composition. The cement, blast furnace slag, and fly ash were sourced from a supplier in the Hanford area in order to be representative. The test mixes were prepared in the laboratory and fresh properties were measured. Fresh density increased with increasing sodium molarity and with decreasing water to premix ratio, as expected given the individual densities of these components. Rheology measurements showed that all of the test mixes produced very fluid slurries. The fresh density and rheology data are of potential value in designing a future Cast Stone production facility. Standing water and density gradient testing showed that settling is not of particular concern for the high sodium compositions studied. Heat of hydration measurements may provide some insight into the reactions that occur within the test mixes, which may in turn be related to the properties and performance of the waste form. These measurements showed that increased sodium

  14. Pollution concentration estimates in ecologically important zones

    Energy Technology Data Exchange (ETDEWEB)

    Skiba, Y.N. [Mexico City Univ. (Mexico). Center for Atmospheric Sciences

    1995-12-31

    Method based on using the pollutant transport equation and the adjoint technique is described here for estimating the pollutant concentration level in ecologically important zones. The method directly relates the pollution level in such zones with the power of the pollution sources and the initial pollution field. Assuming that the wind or current velocities are known (from climatic data or dynamic model), the main and adjoint pollutant transport equations can be considered in a limited area to solve such theoretically and practically important problems as: (1) optimal location of new industries in a given region with the aim to minimize the pollution concentration in certain ecologically important zones, (2) optimization of emissions from operating industries, (3) detection of the plants violating sanitary regulations, (4) analysis of the emissions coming from the vehicle traffic (such emissions can be included in the model by means of the linear pollution sources located along the main roadways), (5) estimation of the oil pollution in various ecologically important oceanic (sea) zones in case of accident with the oil tanker, (6) evaluation of the sea water desalination level in estuary regions, and others. These equations considered in a spherical shell domain can also be applied to the problems of transporting the pollutants from a huge industrial complex, or from the zone of an ecological catastrophe similar to the Chernobyl one

  15. Diatomaceous earth lowers blood cholesterol concentrations.

    Science.gov (United States)

    Wachter, H; Lechleitner, M; Artner-Dworzak, E; Hausen, A; Jarosch, E; Widner, B; Patsch, J; Pfeiffer, K; Fuchs, D

    1998-04-08

    In this study a potential influence of diatomaceus earth to lower blood cholesterol was investigated. During 12 weeks we monitored serum lipid concentrations in 19 healthy individuals with a history of moderate hypercholesterinemia (9 females, 10 males, aged 35 - 67 years). Individuals administered orally 250 mg diatomaceous earth three-times daily during an 8 weeks observation period. Serum concentrations of cholesterol, high-density lipoprotein cholesterol, low-density lipoprotein cholesterol and triglycerides levels were measured before study entry, every second week during the period of diatomaceous earth intake and 4 weeks after stop of intake. Compared to baseline (285.8 +/- 37.5 mg/dl = 7.40 +/- 0.97 mM) diatomaceous earth intake was associated with a significant reduction of serum cholesterol at any time point, reaching a minimum on week 6 (248.1 mg/dl = 6.43 mM, -13.2% from baseline; pdiatomaceous earth was stopped, serum cholesterol, low-density lipoprotein cholesterol and triglycerides still remained low and also the increase of high-density lipoprotein cholesterol became significant (pDiatomaceous earth, a bioproduct, is capable of reducing blood cholesterol and positively influencing lipid metabolism in humans. Placebo-controlled studies will be necessary to confirm our findings.

  16. DISSOLVED CONCENTRATION LIMITS OF RADIOACTIVE ELEMENTS

    Energy Technology Data Exchange (ETDEWEB)

    NA

    2004-11-22

    The purpose of this study is to evaluate dissolved concentration limits (also referred to as solubility limits) of elements with radioactive isotopes under probable repository conditions, based on geochemical modeling calculations using geochemical modeling tools, thermodynamic databases, field measurements, and laboratory experiments. The scope of this modeling activity is to predict dissolved concentrations or solubility limits for 14 elements with radioactive isotopes (actinium, americium, carbon, cesium, iodine, lead, neptunium, plutonium, protactinium, radium, strontium, technetium, thorium, and uranium) important to calculated dose. Model outputs for uranium, plutonium, neptunium, thorium, americium, and protactinium are in the form of tabulated functions with pH and log (line integral) CO{sub 2} as independent variables, plus one or more uncertainty terms. The solubility limits for the remaining elements are either in the form of distributions or single values. The output data from this report are fundamental inputs for Total System Performance Assessment for the License Application (TSPA-LA) to determine the estimated release of these elements from waste packages and the engineered barrier system. Consistent modeling approaches and environmental conditions were used to develop solubility models for all of the actinides. These models cover broad ranges of environmental conditions so that they are applicable to both waste packages and the invert. Uncertainties from thermodynamic data, water chemistry, temperature variation, and activity coefficients have been quantified or otherwise addressed.

  17. Cast Stone Formulation At Higher Sodium Concentrations

    Energy Technology Data Exchange (ETDEWEB)

    Fox, K. M. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Roberts, K. A. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Edwards, T. B. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL)

    2014-02-28

    A low temperature waste form known as Cast Stone is being considered to provide supplemental Low Activity Waste (LAW) immobilization capacity for the Hanford site. Formulation of Cast Stone at high sodium concentrations is of interest since a significant reduction in the necessary volume of Cast Stone and subsequent disposal costs could be achieved if an acceptable waste form can be produced with a high sodium molarity salt solution combined with a high water to premix (or dry blend) ratio. The objectives of this study were to evaluate the factors involved with increasing the sodium concentration in Cast Stone, including production and performance properties and the retention and release of specific components of interest. Three factors were identified for the experimental matrix: the concentration of sodium in the simulated salt solution, the water to premix ratio, and the blast furnace slag portion of the premix. The salt solution simulants used in this study were formulated to represent the overall average waste composition. The cement, blast furnace slag, and fly ash were sourced from a supplier in the Hanford area in order to be representative. The test mixes were prepared in the laboratory and fresh properties were measured. Fresh density increased with increasing sodium molarity and with decreasing water to premix ratio, as expected given the individual densities of these components. Rheology measurements showed that all of the test mixes produced very fluid slurries. The fresh density and rheology data are of potential value in designing a future Cast Stone production facility. Standing water and density gradient testing showed that settling is not of particular concern for the high sodium compositions studied. Heat of hydration measurements may provide some insight into the reactions that occur within the test mixes, which may in turn be related to the properties and performance of the waste form. These measurements showed that increased sodium

  18. Cast Stone Formulation At Higher Sodium Concentrations

    Energy Technology Data Exchange (ETDEWEB)

    Fox, K. M.; Edwards, T. A.; Roberts, K. B.

    2013-10-02

    A low temperature waste form known as Cast Stone is being considered to provide supplemental Low Activity Waste (LAW) immobilization capacity for the Hanford site. Formulation of Cast Stone at high sodium concentrations is of interest since a significant reduction in the necessary volume of Cast Stone and subsequent disposal costs could be achieved if an acceptable waste form can be produced with a high sodium molarity salt solution combined with a high water to premix (or dry blend) ratio. The objectives of this study were to evaluate the factors involved with increasing the sodium concentration in Cast Stone, including production and performance properties and the retention and release of specific components of interest. Three factors were identified for the experimental matrix: the concentration of sodium in the simulated salt solution, the water to premix ratio, and the blast furnace slag portion of the premix. The salt solution simulants used in this study were formulated to represent the overall average waste composition. The cement, blast furnace slag, and fly ash were sourced from a supplier in the Hanford area in order to be representative. The test mixes were prepared in the laboratory and fresh properties were measured. Fresh density increased with increasing sodium molarity and with decreasing water to premix ratio, as expected given the individual densities of these components. Rheology measurements showed that all of the test mixes produced very fluid slurries. The fresh density and rheology data are of potential value in designing a future Cast Stone production facility. Standing water and density gradient testing showed that settling is not of particular concern for the high sodium compositions studied. Heat of hydration measurements may provide some insight into the reactions that occur within the test mixes, which may in turn be related to the properties and performance of the waste form. These measurements showed that increased sodium

  19. Cast Stone Formulation At Higher Sodium Concentrations

    Energy Technology Data Exchange (ETDEWEB)

    Fox, K. M.; Roberts, K. A.; Edwards, T. B.

    2013-09-17

    A low temperature waste form known as Cast Stone is being considered to provide supplemental Low Activity Waste (LAW) immobilization capacity for the Hanford site. Formulation of Cast Stone at high sodium concentrations is of interest since a significant reduction in the necessary volume of Cast Stone and subsequent disposal costs could be achieved if an acceptable waste form can be produced with a high sodium molarity salt solution combined with a high water to premix (or dry blend) ratio. The objectives of this study were to evaluate the factors involved with increasing the sodium concentration in Cast Stone, including production and performance properties and the retention and release of specific components of interest. Three factors were identified for the experimental matrix: the concentration of sodium in the simulated salt solution, the water to premix ratio, and the blast furnace slag portion of the premix. The salt solution simulants used in this study were formulated to represent the overall average waste composition. The cement, blast furnace slag, and fly ash were sourced from a supplier in the Hanford area in order to be representative. The test mixes were prepared in the laboratory and fresh properties were measured. Fresh density increased with increasing sodium molarity and with decreasing water to premix ratio, as expected given the individual densities of these components. Rheology measurements showed that all of the test mixes produced very fluid slurries. The fresh density and rheology data are of potential value in designing a future Cast Stone production facility. Standing water and density gradient testing showed that settling is not of particular concern for the high sodium compositions studied. Heat of hydration measurements may provide some insight into the reactions that occur within the test mixes, which may in turn be related to the properties and performance of the waste form. These measurements showed that increased sodium

  20. [Plasma amino acid concentrations in aggressive dogs].

    Science.gov (United States)

    Juhr, Norbert-Christian; Brand, Ulrike; Riedel, Eberhard

    2005-01-01

    Following the hypothesis that metabolic screens may be useful tools in the diagnosis of canine aggression we have investigated the blood plasma amino acid levels of dogs which have been found aggressive (N = 10) against dogs or men in comparison to non-aggressive dogs (N = 10). In summary, the aggressive dogs showed elevated plasma concentrations of the neurophysiological active aromatic amino acids tryptophan (46/171 micromol/l, p urea-cycle in the conversion of ornithine (17/34 micromol/l, p < 0.01) to citrulline (64/47 micromol/l). Higher levels of branched chain amino acids, especially leucine (122/150 micromol/l, p < 0.01), mainly metabolized in muscles, and isoleucin (60/71 micromol/l, p < 0.05) show a high energy potential. The acidose-stimulator methionine (48/78 micromol/l, p < 0.01) proved elevated. The results show that the changed behavior in the aggressive dogs is also reflected in their free amino acid plasma concentrations, independent of the question whether these data are the cause or the result of the aggressivity.

  1. A statistical evaluation of asbestos air concentrations

    International Nuclear Information System (INIS)

    Lange, J.H.

    1999-01-01

    Both area and personal air samples collected during an asbestos abatement project were matched and statistically analysed. Among the many parameters studied were fibre concentrations and their variability. Mean values for area and personal samples were 0.005 and 0.024 f cm - - 3 of air, respectively. Summary values for area and personal samples suggest that exposures are low with no single exposure value exceeding the current OSHA TWA value of 0.1 f cm -3 of air. Within- and between-worker analysis suggests that these data are homogeneous. Comparison of within- and between-worker values suggests that the exposure source and variability for abatement are more related to the process than individual practices. This supports the importance of control measures for abatement. Study results also suggest that area and personal samples are not statistically related, that is, there is no association observed for these two sampling methods when data are analysed by correlation or regression analysis. Personal samples were statistically higher in concentration than area samples. Area sampling cannot be used as a surrogate exposure for asbestos abatement workers. (author)

  2. Recent results for concentrator photovoltaics in Japan

    Science.gov (United States)

    Yamaguchi, Masafumi; Takamoto, Tatsuya; Araki, Kenji; Kojima, Nobuaki

    2016-04-01

    We summarize the Europe-Japan Collaborative Research Project on Concentrator Photovoltaics (CPV); NGCPV Project (a New Generation of Concentrator PhotoVoltaic cells, modules and systems). The aim of this project was to accelerate the move to very high efficiency and lower cost CPV technologies and to enhance the widespread deployment of CPV systems. Seven European partners and nine Japanese partners have contributed to this international collaboration. The following objectives have been reached: 1) a CPV cell with InGaP/GaAs/InGaAs three-junction world-record efficiency of 44.4% has been developed by Sharp, 2) 50 kW and 15 kW CPV plant operations with an average DC efficiency of 27.8% have been demonstrated in Spain (since mid-2012), 3) a new “Intrepid” CPV module with 31.3% efficiency has been developed by Daido Steel, 4) standard measurement of CPV cells has been established by FhG-ISE and AIST, and 46.0% efficiency has been confirmed for the direct-bonded GaInP/GaAs/GaInAsP/GaInAs four-junction solar cell under this project, 5) the fundamental research on novel materials and structures for CPV has also been conducted.

  3. Armoring confined bubbles in concentrated colloidal suspensions

    Science.gov (United States)

    Yu, Yingxian; Khodaparast, Sepideh; Stone, Howard

    2016-11-01

    Encapsulation of a bubble with microparticles is known to significantly improve the stability of the bubble. This phenomenon has recently gained increasing attention due to its application in a variety of technologies such as foam stabilization, drug encapsulation and colloidosomes. Nevertheless, the production of such colloidal armored bubble with controlled size and particle coverage ratio is still a great challenge industrially. We study the coating process of a long air bubble by microparticles in a circular tube filled with a concentrated microparticles colloidal suspension. As the bubble proceeds in the suspension of particles, a monolayer of micro-particles forms on the interface of the bubble, which eventually results in a fully armored bubble. We investigate the phenomenon that triggers and controls the evolution of the particle accumulation on the bubble interface. Moreover, we examine the effects of the mean flow velocity, the size of the colloids and concentration of the suspension on the dynamics of the armored bubble. The results of this study can potentially be applied to production of particle-encapsulated bubbles, surface-cleaning techniques, and gas-assisted injection molding.

  4. NO concentration imaging in turbulent nonpremixed flames

    Energy Technology Data Exchange (ETDEWEB)

    Schefer, R.W. [Sandia National Laboratories, Livermore, CA (United States)

    1993-12-01

    The importance of NO as a pollutant species is well known. An understanding of the formation characteristics of NO in turbulent hydrocarbon flames is important to both the desired reduction of pollutant emissions and the validation of proposed models for turbulent reacting flows. Of particular interest is the relationship between NO formation and the local flame zone, in which the fuel is oxidized and primary heat release occurs. Planar imaging of NO provides the multipoint statistics needed to relate NO formation to the both the flame zone and the local turbulence characteristics. Planar imaging of NO has been demonstrated in turbulent flames where NO was seeded into the flow at high concentrations (2000 ppm) to determine the gas temperature distribution. The NO concentrations in these experiments were significantly higher than those expected in typical hydrocarbon-air flames, which require a much lower detectability limit for NO measurements. An imaging technique based on laser-induced fluorescence with sufficient sensitivity to study the NO formation mechanism in the stabilization region of turbulent lifted-jet methane flames.

  5. The emission spectroscopy for evaluation of concentration of the metal vapor concentration in tokamak plasma

    International Nuclear Information System (INIS)

    Sarakovskis, A.; Gromuls, I.; Tale, I.

    2004-01-01

    Full text: Evaluation of the absolute concentration of the impurity metal vapors in plasma using emission spectroscopy requires development of the principles and procedure of in situ calibration of equipment. Several approaches can be used for calibration of the equipment. In the case the emission rate of single metal atom under ionizing conditions is known, the calibration of the spectroscopic equipment reduces to the calibration in radiometric units (irradiance). For unknown emission rate the routine calibration procedure involves use of the set of etalons of material under investigation with known concentration of impurity metal. For evaluation of impurity concentration in plasma it is necessary to develop a corresponding plasma source having certain plasma parameters - temperature and concentration of electrons and metal vapors in concentration, which can be measured independent procedure. Present report deals with problems of estimation of Ga impurity concentration in ISSTOK ( Portugal) tokamak plasma using decay data of atom emission lines. Emission spectra of Ga atoms show that collisions with hydrogen electrons and ions results in ionization of Ga followed by multi step radiative recombination. The main emission lines corresponds to the capture of electron to the 4s 2 5p (639 nm), transition 4s 2 5p - 4s 2 5s (1,211 μm ); and transition to the ground state 4s 2 5s - 4s 2 4p (403 nm). Some of the excited state lifetimes obtained from decay kinetics are reported. Analysis of emission line intensity ratios together with lifetime data will allow elaborate the procedure for evaluation of Ga impurity concentration in the tokamak plasma

  6. Iodine concentration in cow's milk and its relation with urinary iodine concentrations in the population.

    Science.gov (United States)

    Soriguer, Federico; Gutierrez-Repiso, Carolina; Gonzalez-Romero, Stella; Olveira, Gabriel; Garriga, Maria J; Velasco, Ines; Santiago, Piedad; de Escobar, Gabriella M; Garcia-Fuentes, Eduardo

    2011-02-01

    The importance of milk intake to the supply of dietary iodine is not fully known. We therefore undertook a study in Spain of the iodine concentration in cow's milk and the impact of the frequency of milk consumption on urinary iodine concentrations in three study populations. We studied the iodine concentration in 362 samples of milk from 45 commercial brands and compared it with the milk iodine status in studies undertaken 17 years earlier. The epidemiologic studies were performed in three different places in the south of Spain: two in school-age children (N = 757 and N = 1205 children) and one in adults (N = 1051). A milk consumption questionnaire was given and urinary iodine concentrations measured. The mean concentration of iodine in the milk rose from 1991 (117 ± 37 μg/L) to 2008 (259 ± 58 μg/L) (P milk (273 ± 52 μg/L) than in semi-skimmed milk (254 ± 57 μg/L) or whole milk (251 ± 61 μg/L) (P milk. The urinary iodine concentrations in all three epidemiologic studies were significantly associated with the frequency of milk intake. The concentration of iodine in cow's milk has risen over recent years, and it is higher in skimmed milk. The results also show that cow's milk is a relevant source of dietary iodine. Copyright © 2010 Elsevier Ltd and European Society for Clinical Nutrition and Metabolism. All rights reserved.

  7. Sedimentary cobalt concentrations track marine redox evolution

    Science.gov (United States)

    Swanner, Elizabeth; Planavsky, Noah; Lalonde, Stefan; Robbins, Jamie; Bekker, Andrey; Rouxel, Olivier; Konhauser, Kurt O.; Mojzsis, Stephen J.

    2013-04-01

    Oxygen production by photosynthesis drove the redox evolution of the atmosphere and ocean. Primary productivity by oxygenic photosynthesizers in the modern surface ocean is limited by trace nutrients such as iron, but previous studies have also observed high Co uptake associated with natural cyanobacterial populations. Constraining the size and variation of the oceanic reservoir of Co through time will help to understand the regulation of primary productivity and hence oxygenation through time. In this study, Co concentrations from iron formations (IF), shales and marine pyrites deposited over nearly 4 billion years of Earth's history are utilized to reconstruct secular changes in the mechanisms of Co removal from the oceanic reservoir. The Co reservoir prior to ~2 Ga was dominated by hydrothermal inputs and Fe(III)oxyhydroxides were likely involved in the removal of Co from the water column. Fe(II) oxidation in the water column resulted in the deposition of IF in the Archean and Paleoproterozoic, and the Co inventory of IF records a large oceanic reservoir of Co during this time. Lower Co concentrations in sediments during the Middle Proterozoic signify a decrease in the oceanic reservoir due to the expansion euxinic environments, corresponding to the results of previous studies. A transition to an oxidized deep ocean in the Phanerozoic is evidenced by correlation between Co and manganese (Mn) concentrations in hydrothermal and exhalative deposits, and in marine pyrites. This relationship between Co and Mn, signifying deposition of Co in association with Mn(IV)oxides, does not occur in the Precambrian. Mn(II) oxidation occurs at higher redox potentials than that required for Fe(II) oxidation, and the extent of Mn redox cycling prior to full ventilation of the oceans at the end of the Neoproterozoic was likely limited to spatially restricted oxic surface waters. In this regard, Co is another valuable redox proxy for tracking the growth and decline in oxygenated

  8. Comparative survey of outdoor, residential and workplace radon concentrations

    International Nuclear Information System (INIS)

    Barros, Nirmalla; Field, R. William; Field, Dan W.; Steck, Daniel J.

    2015-01-01

    This study investigated radon concentrations in above-ground (i.e. first floor) workplace in Missouri and compared them with above-ground radon concentrations in nearby homes and outdoor locations. This study also examined the potential utility of using home and outdoor radon concentrations to predict the radon concentration at a nearby workplace (e.g. county agencies and schools). Even though workplace radon concentrations were not statistically different from home radon concentrations, the radon concentration at a particular home, or outdoor location, was a poor predictor of the radon concentration at a nearby workplace. Overall, 9.6 and 9.9 % of homes and workplace, respectively, exhibited radon concentrations of ≥148 Bq m -3 . Because of the percentage of workplace with elevated radon concentrations, the results suggest that additional surveys of workplace radon concentrations are needed, especially in areas of high radon potential, to assess the contribution of workplace radon exposure to an individual's overall radon exposure. (authors)

  9. Microfluidic Paper-Based Sample Concentration Using Ion Concentration Polarization with Smartphone Detection

    Directory of Open Access Journals (Sweden)

    Xue Li

    2016-11-01

    Full Text Available A simple method for microfluidic paper-based sample concentration using ion concentration polarization (ICP with smartphone detection is developed. The concise and low-cost microfluidic paper-based ICP analytical device, which consists of a black backing layer, a nitrocellulose membrane, and two absorbent pads, is fabricated with the simple lamination method which is widely used for lateral flow strips. Sample concentration on the nitrocellulose membrane is monitored in real time by a smartphone whose camera is used to collect the fluorescence images from the ICP device. A custom image processing algorithm running on the smartphone is used to track the concentrated sample and obtain its fluorescence signal intensity for quantitative analysis. Two different methods for Nafion coating are evaluated and their performances are compared. The characteristics of the ICP analytical device especially with intentionally adjusted physical properties are fully evaluated to optimize its performance as well as to extend its potential applications. Experimental results show that significant concentration enhancement with fluorescence dye sample is obtained with the developed ICP device when a fast depletion of fluorescent dye is observed. The platform based on the simply laminated ICP device with smartphone detection is desired for point-of-care testing in settings with poor resources.

  10. Towards a flat 45%-efficient concentrator module

    Science.gov (United States)

    Mohedano, Rubén; Hernandez, Maikel; Vilaplana, Juan; Chaves, Julio; Miñano, Juan C.; Benitez, Pablo; Sorgato, S.; Falicoff, Waqidi

    2015-09-01

    The so-called CCS4FK is an ultra-flat photovoltaic system of high concentration and high efficiency, with potential to convert, ideally, the equivalent of a 45% of direct solar radiation into electricity by optimizing the usage of sun spectrum and by collecting part of the diffuse radiation, as a flat plate does. LPI has recently finished a design based on this concept and is now developing a prototype based on this technology, thanks to the support of FUNDACION REPSOL-Fondo de Emprendedores, which promotes entrepreneur projects in different areas linked to energy. This works shows some details of the actual design and preliminary potential performance expected, according to accurate spectral simulations.

  11. Scavenging ratios based on inflow air concentrations

    Energy Technology Data Exchange (ETDEWEB)

    Davis, W.E.; Dana, M.T.; Lee, R.N.; Slinn, W.G.N.; Thorp, J.M.

    1991-07-01

    Scavenging ratios were calculated from field measurements made during April 1985. Event precipitation samples were collected at the surface, but air chemistry measurements in the air mass feeding the precipitation were made from an aircraft. In contrast, ratios calculated in previous studies have used air concentration and precipitation chemistry data from only surface measurements. Average scavenging ratios were calculated for SO{sub 4}{sup 2{minus}}, NO{sub 3}{sup {minus}}, NH{sub 4}{sup +}, total sulfate, total nitrate, and total ammonium for 5 events; the geometric mean of these scavenging ratios were 8.5 {times} 10{sup 5}, 5.6 {times} 10{sup 6}, 4.3 {times} 10{sup 5}, 3.4 {times} 10{sup 5}, 2.4 {times} 10{sup 6}, and 9.7 {times} 10{sup 4}, respectively. These means are similar to but less variable than previous ratios formed using only surface data.

  12. Fibrinogen concentrate for bleeding - a systematic review

    DEFF Research Database (Denmark)

    Lunde, J; Stensballe, J; Wikkelsø, A

    2014-01-01

    included a control group. Three out of 11 found a reduction in transfusion requirements while mortality was reduced in two and bleeding in one. In the available RCTs, which all have substantial shortcomings, we found a significant reduction in bleeding and transfusions requirements. However, data......Fibrinogen concentrate as part of treatment protocols increasingly draws attention. Fibrinogen substitution in cases of hypofibrinogenaemia has the potential to reduce bleeding, transfusion requirement and subsequently reduce morbidity and mortality. A systematic search for randomised controlled...... determined to be of high risk of bias and none reported a significant effect on mortality. Two RCTs found a significant reduction in bleeding and five RCTs found a significant reduction in transfusion requirements. The 23 non-randomised studies included a total of 2825 patients, but only 11 of 23 studies...

  13. Spatial Concentration of Economic Activity in Russia

    Directory of Open Access Journals (Sweden)

    Eugenia Anatolyevna Kolomak

    2014-12-01

    Full Text Available The author studies the dynamics and factors of spatial concentration of economic activity in Russia and with the help of empirical methods tests the hypothesis of agglomeration economy. The analysis shows that Russia has growing inequality in distribution of resources and production and the growth rate of this process is quite high. Determinants of inter-regional divergence in Russia include the following: population density, the size and accessibility of markets, and economic structure; i.e. all these determinants have a market basis and they are key ones in agglomeration economy. The results show no effectiveness of interregional transfers and public investment in reducing differences across Russian territories. Agglomeration economy presupposes that effective conditions that stimulate centrifugal spatial trends correlate with reduction of inter-regional communication barriers which can have both physical and institutional nature

  14. Reduction of radon daughter concentrations in structures

    International Nuclear Information System (INIS)

    1982-12-01

    A structure was identified in Salt Lake City wherein uranium mill tailings had been used in the construction and where unusually high levels of radon daughter concentrations (RDC's) existed. The physical and radiological characteristics of the structure were assessed. Ventilation techniques were investigated to assess their effectiveness in reducing RDC's. A preferred set of equipment was identified, installed in the structure and operated to reduce RDC's. Parametric studies were conducted to determine if supplying fresh air or recirculating air through electrostatic precipitators is more effective in reducing RDC's. Fresh air was found to be more effective in reducing RDC's. RDC's have been reduced to levels at or near the target of 0.03 working level under optimal ventilation conditions. Natural gas consumption with the new equipment is about 39% higher than with the original equipment. Electrical energy usage and electrical demand are respectively 50 and 44% higher with the new equipment than with the original equipment. 16 refs., 14 figs., 8 tabs

  15. Towards a flat 45%-efficient concentrator module

    International Nuclear Information System (INIS)

    Mohedano, Rubén; Hernandez, Maikel; Vilaplana, Juan; Chaves, Julio; Sorgato, S.; Falicoff, Waqidi; Miñano, Juan C.; Benitez, Pablo

    2015-01-01

    The so-called CCS 4 FK is an ultra-flat photovoltaic system of high concentration and high efficiency, with potential to convert, ideally, the equivalent of a 45% of direct solar radiation into electricity by optimizing the usage of sun spectrum and by collecting part of the diffuse radiation, as a flat plate does. LPI has recently finished a design based on this concept and is now developing a prototype based on this technology, thanks to the support of FUNDACION REPSOL-Fondo de Emprendedores, which promotes entrepreneur projects in different areas linked to energy. This works shows some details of the actual design and preliminary potential performance expected, according to accurate spectral simulations

  16. A study of radon indoor concentration

    International Nuclear Information System (INIS)

    Pena, P.; Ruiz, W.; Segovia, N.; Ponciano, G.

    2000-01-01

    It was realized a study of radon concentration in houses of Mexico City and in a laboratory of the Nuclear Centre of Salazar, State of Mexico. The radon determination in air was realized with solid nuclear track detectors and with Honeywell and Alpha guard automatic equipment. The results show that the majority of houses have values under 148 Bq/m 3 obtaining some housings with upper values located in the Lomas zone. A study in smokers houses and another of controls showed very similar distributions. It was studied the day time fluctuations finding that radon increases considerably during the dawn. Some upper values obtained in a laboratory of the Nuclear Centre were remedied with ventilation. (Author)

  17. Aerobic growth at nanomolar oxygen concentrations

    DEFF Research Database (Denmark)

    Stolper, Daniel; Revsbech, Niels Peter; Canfield, Donald Eugene

    2010-01-01

    Molecular oxygen (O2) is the second most abundant gas in the Earth's atmosphere, but in many natural environments, its concentration is reduced to low or even undetectable levels. Although low-oxygen-adapted organisms define the ecology of low-oxygen environments, their capabilities are not fully...... known. These capabilities also provide a framework for reconstructing a critical period in the history of life, because low, but not negligible, atmospheric oxygen levels could have persisted before the "Great Oxidation" of the Earth's surface about 2.3 to 2.4 billion years ago. Here, we show...... that Escherichia coli K-12, chosen for its well-understood biochemistry, rapid growth rate, and low-oxygen-affinity terminal oxidase, grows at oxygen levels of ≤ 3 nM, two to three orders of magnitude lower than previously observed for aerobes. Our study expands both the environmental range and temporal history...

  18. Renewable Energy Essentials: Concentrating Solar Thermal Power

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2009-07-01

    Concentrated solar thermal power (CSP) is a re-emerging market. The Luz Company built 354 MWe of commercial plants in California, still in operations today, during 1984-1991. Activity re-started with the construction of an 11-MW plant in Spain, and a 64-MW plant in Nevada, by 2006. There are currently hundreds of MW under construction, and thousands of MW under development worldwide. Spain and the United States together represent 90% of the market. Algeria, Egypt and Morocco are building integrated solar combined cycle plants, while Australia, China, India, Iran, Israel, Italy, Jordan, Mexico, South Africa and the United Arab Emirates are finalising or considering projects. While trough technology remains the dominant technology, several important innovations took place over 2007-2009: the first commercial solar towers, the first commercial plants with multi-hour capacities, the first Linear Fresnel Reflector plants went into line.

  19. Modular off-axis solar concentrator

    Science.gov (United States)

    Plesniak, Adam P; Hall, John C

    2015-01-27

    A solar concentrator including a housing defining a vertical axis and including a receiving wall connected to a reflecting wall to define an internal volume and an opening into the internal volume, wherein the reflecting wall defines at least one primary optical element, and wherein at least a portion of the reflecting wall includes a layer of reflective material, the housing further including a cover connected to the receiving wall and the reflecting wall to seal the opening, and at least one receiver mounted on the receiving wall such that a vertical axis of the receiver is disposed at a non-zero angle relative to the vertical axis of the housing, the receiver including at least one photovoltaic cell.

  20. Enclosed, off-axis solar concentrator

    Science.gov (United States)

    Benitez, Pablo; Grip, Robert E; Minano, Juan C; Narayanan, Authi A; Plesniak, Adam; Schwartz, Joel A

    2013-11-26

    A solar concentrator including a housing having receiving wall, a reflecting wall and at least two end walls, the receiving, reflecting and end walls defining a three-dimensional volume having an inlet, wherein a vertical axis of the housing is generally perpendicular to the inlet, a receiver mounted on the receiving wall of the housing, the receiver including at least one photovoltaic cell, wherein a vertical axis of the receiver is disposed at a non-zero angle relative to the vertical axis of the housing, at least one clip disposed on the reflecting wall an optical element received within the three-dimensional volume, the optical element including at least one tab, the tab being engaged by the clip to align the optical element with the receiver, and a window received over the inlet to enclose the housing.

  1. Airfoil Pitch Control Using Trapped Vorticity Concentrations

    Science.gov (United States)

    Brzozowski, Daniel; Culp, John; Glezer, Ari

    2007-11-01

    Closed-loop feedback control of the attitude of a free pitching airfoil is effected without moving control surfaces by alternate actuation of nominally-symmetric trapped vorticity concentrations on the suction and pressure surfaces near the trailing edge. The pitching moment is varied with minimal lift and drag penalties over a broad range of angles of attack when the baseline flow is fully attached. Accumulation (trapping) and regulation of vorticity is managed by integrated hybrid actuators (each comprised of a miniature [O(0.01c)] obstruction and a synthetic jet actuator). In the present work, the model is trimmed using a position feedback loop and a servo motor actuator. Once the model is trimmed, the position feedback loop is opened and the servo motor acts like an inner loop control to alter the model's dynamic characteristics. Position control of the model is achieved using a reference model-based outer loop controller.

  2. Flow line asymmetric nonimaging concentrating optics

    Science.gov (United States)

    Jiang, Lun; Winston, Roland

    2016-09-01

    Nonimaging Optics has shown that it achieves the theoretical limits by utilizing thermodynamic principles rather than conventional optics. Hence in this paper the condition of the "best" design are both defined and fulfilled in the framework of thermodynamic arguments, which we believe has profound consequences for the designs of thermal and even photovoltaic systems, even illumination and optical communication tasks. This new way of looking at the problem of efficient concentration depends on probabilities, geometric flux field and radiative heat transfer while "optics" in the conventional sense recedes into the background. Some of the new development of flow line designs will be introduced and the connection between the thermodynamics and flow line design will be officially formulated in the framework of geometric flux field. A new way of using geometric flux to design nonimaging optics will be introduced. And finally, we discuss the possibility of 3D ideal nonimaing optics.

  3. Droplet Number Concentration Value-Added Product

    Energy Technology Data Exchange (ETDEWEB)

    Riihimaki, L. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); McFarlane, S. [DOE ARM Climate Research Facility, Washington, DC (United States); Sivaraman, C. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States)

    2014-06-01

    The ndrop_mfrsr value-added product (VAP) provides an estimate of the cloud droplet number concentration of overcast water clouds retrieved from cloud optical depth from the multi-filter rotating shadowband radiometer (MFRSR) instrument and liquid water path (LWP) retrieved from the microwave radiometer (MWR). When cloud layer information is available from vertically pointing lidar and radars in the Active Remote Sensing of Clouds (ARSCL) product, the VAP also provides estimates of the adiabatic LWP and an adiabatic parameter (beta) that indicates how divergent the LWP is from the adiabatic case. quality control (QC) flags (qc_drop_number_conc), an uncertainty estimate (drop_number_conc_toterr), and a cloud layer type flag (cloud_base_type) are useful indicators of the quality and accuracy of any given value of the retrieval. Examples of these major input and output variables are given in sample plots in section 6.0.

  4. Luminescent solar concentrators utilizing stimulated emission.

    Science.gov (United States)

    Kaysir, Md Rejvi; Fleming, Simon; MacQueen, Rowan W; Schmidt, Timothy W; Argyros, Alexander

    2016-03-21

    Luminescent solar concentrators (LSCs) are an emerging technology that aims primarily to reduce the cost of solar energy, with great potential for building integrated photovoltaic (PV) structures. However, realizing LSCs with commercially viable efficiency is currently hindered by reabsorption losses. Here, we introduce an approach to reducing reabsorption as well as improving directional emission in LSCs by using stimulated emission. Light from a seed laser (potentially an inexpensive laser diode) passes through the entire area of the LSC panel, modifying the emission spectrum of excited dye molecules such that it is spectrally narrower, at wavelengths that minimize reabsorption to allow net gain in the system, and directed towards a small PV cell. A mathematical model, taking into account thermodynamic considerations, of such a system is presented which identifies key parameters and allows evaluation in terms of net effective output power.

  5. Leukocyte removal filtration of platelet concentrates

    International Nuclear Information System (INIS)

    Wadenvik, H.; Kutti, J.; Lindholm, A.

    1991-01-01

    111 In labelled platelets and gamma camera scintigraphy were used for the study of the platelet loss during leukocyte removal filtration of stored platelets. Two different filters were examined, Imugard IG500 and Pall PL100, and platelet pools containing varying number of platelet concentrates were filtered. It was found that a sizeable amount of the platelets was trapped within the filter. Some of the trapped platelets could be recovered by rinsing the filters with normal saline. The most appropriate rinsing volume to recover lost platelets seemed to match with the ''dead space'' volume within the filter. It is concluded that radiolabelled platelets and gamma camera scintigraphy appears to be an excellent method to investigate the dynamic events of platelet loss during leukocyte removal filtration. This technique should be well applicable for the study of technological advances in filter construction. (author)

  6. Concentration of radionuclides by marine organisms

    International Nuclear Information System (INIS)

    Nakamura, Ryoichi

    1995-01-01

    The Japanese, who have ever been confronted with atomic bombs, are said to be very sensitive to the nuclear power, radioactivity and so on. However, the peaceful uses of the nuclear power are closely related to our daily lives. Consequently, we should recognize correctly the nuclear power, radioactivity and so on, without refusing emotion-ally or admitting uncritically. Many marine organisms have abilities to accumulate radionuclides to very high concentrations. But, the levels of man-made radioactivity of marine organisms in the sea around Japan have been decreased in recent years compared with those in the past. So, the annual internal dose equivalent for Japanese from seafood (marine organisms) are originated mainly from the natural radionuclides like 210 Po, 210 Pb and 40 K. Nevertheless, study on the marine radioecology must be progressed against the inadvertent radioactive contamination of the surrounding sea, due to the increase of nuclear facilities and nuclear weapons. (author)

  7. Prediction Methods for Blood Glucose Concentration

    DEFF Research Database (Denmark)

    , but the insulin amount is chosen using factors that account for this expectation. The increasing availability of more accurate continuous blood glucose measurement (CGM) systems is attracting much interest to the possibilities of explicit prediction of future BG values. Against this background, in 2014 a two......-day workshop on the design, use and evaluation of prediction methods for blood glucose concentration was held at the Johannes Kepler University Linz, Austria. One intention of the workshop was to bring together experts working in various fields on the same topic, in order to shed light from different angles...... Freckmann et al. discusses performance metrics used to characterize the accuracy of continuous glucose measurement devices. This topic is highly relevant for prediction models since many of them rely on the data given by the continuous sensors which are previously calibrated with blood glucose meter...

  8. Solids-based concentrated solar power receiver

    Energy Technology Data Exchange (ETDEWEB)

    None

    2018-04-10

    A concentrated solar power (CSP) system includes channels arranged to convey a flowing solids medium descending under gravity. The channels form a light-absorbing surface configured to absorb solar flux from a heliostat field. The channels may be independently supported, for example by suspension, and gaps between the channels are sized to accommodate thermal expansion. The light absorbing surface may be sloped so that the inside surfaces of the channels proximate to the light absorbing surface define downward-slanting channel floors, and the flowing solids medium flows along these floors. Baffles may be disposed inside the channels and oriented across the direction of descent of the flowing solids medium. The channels may include wedge-shaped walls forming the light-absorbing surface and defining multiple-reflection light paths for solar flux from the heliostat field incident on the light-absorbing surface.

  9. Prediction Methods for Blood Glucose Concentration

    DEFF Research Database (Denmark)

    “Recent Results on Glucose–Insulin Predictions by Means of a State Observer for Time-Delay Systems” by Pasquale Palumbo et al. introduces a prediction model which in real time predicts the insulin concentration in blood which in turn is used in a control system. The method is tested in simulation......Standard diabetes insulin therapy for type 1 diabetes and late stages of type 2 is based on the expected development of blood glucose (BG) both as a consequence of the metabolic glucose consumption as well as of meals and exogenous insulin intake. Traditionally, this is not done explicitly......, but the insulin amount is chosen using factors that account for this expectation. The increasing availability of more accurate continuous blood glucose measurement (CGM) systems is attracting much interest to the possibilities of explicit prediction of future BG values. Against this background, in 2014 a two...

  10. Inverse Kinematics of Concentric Tube Steerable Needles.

    Science.gov (United States)

    Sears, Patrick; Dupont, Pierre E

    2007-01-01

    Prior papers have introduced steerable needles composed of precurved concentric tubes. The curvature and extent of these needles can be controlled by the relative rotation and translation of the individual tubes. Under certain assumptions on the geometry and design of these needles, the forward kinematics problem can be solved in closed form by means of algebraic equations. The inverse kinematics problem, however, is not as straightforward owing to the nonlinear map between relative tube displacements and needle tip configuration as well as to the multiplicity of solutions as the number of tubes increases. This paper presents a general approach to solving the inverse kinematics problem using a pseudoinverse solution together with gradients of nullspace potential functions to enforce geometric and mechanical constraints.

  11. Low concentration solar louvres for building integration

    Science.gov (United States)

    Vincenzi, D.; Aldegheri, F.; Baricordi, S.; Bernardoni, P.; Calabrese, G.; Guidi, V.; Pozzetti, L.

    2013-09-01

    The building integration of CPV modules offers several advantages over the integration of flat panel systems, but the decreasing price trend of standard modules observed in the last years has hampered the market expansion of CPV systems, which still don't rely on a low-cost mass production supply chain. To overcome this contingent issue and to foster the diffusion of innovative PV systems we developed a low concentration BIPV module with added functionalities, such as sunlight shading and building illumination. The electrical performances, retrieved under outdoor conditions, and the lighting performances of the Solar F-Light are shown. The latter indicate that it is suitable for ambient lighting, with a very limited power draw.

  12. Concentrated solar power in the built environment

    Science.gov (United States)

    Montenon, Alaric C.; Fylaktos, Nestor; Montagnino, Fabio; Paredes, Filippo; Papanicolas, Costas N.

    2017-06-01

    Solar concentration systems are usually deployed in large open spaces for electricity generation; they are rarely used to address the pressing energy needs of the built environment sector. Fresnel technology offers interesting and challenging CSP energy pathways suitable for the built environment, due to its relatively light weight (system into the HVAC (Heating, Ventilation, and Air Conditioning) system of a recently constructed office & laboratory building, the Novel Technologies Laboratory (NTL). The multi-generative system will support cooling, heating and hot water production feeding the system of the NTL building, as a demonstration project, part of the STS-MED program (Small Scale Thermal Solar District Units for Mediterranean Communities) financed by the European Commission under the European Neighbourhood and Partnership Instrument (ENPI), CBCMED program.

  13. Towards a flat 45%-efficient concentrator module

    Energy Technology Data Exchange (ETDEWEB)

    Mohedano, Rubén, E-mail: rmohedano@lpi-europe.com; Hernandez, Maikel; Vilaplana, Juan; Chaves, Julio; Sorgato, S.; Falicoff, Waqidi [LPI, Altadena, CA, USA and Madrid (Spain); Miñano, Juan C.; Benitez, Pablo [LPI, Altadena, CA, USA and Madrid (Spain); Universidad Politécnica de Madrid (UPM), Campus de Montegancedo, Madrid (Spain)

    2015-09-28

    The so-called CCS{sup 4}FK is an ultra-flat photovoltaic system of high concentration and high efficiency, with potential to convert, ideally, the equivalent of a 45% of direct solar radiation into electricity by optimizing the usage of sun spectrum and by collecting part of the diffuse radiation, as a flat plate does. LPI has recently finished a design based on this concept and is now developing a prototype based on this technology, thanks to the support of FUNDACION REPSOL-Fondo de Emprendedores, which promotes entrepreneur projects in different areas linked to energy. This works shows some details of the actual design and preliminary potential performance expected, according to accurate spectral simulations.

  14. DISSOLVED CONCENTRATION LIMITS OF RADIOACTIVE ELEMENTS

    International Nuclear Information System (INIS)

    P. Bernot

    2005-01-01

    The purpose of this study is to evaluate dissolved concentration limits (also referred to as solubility limits) of elements with radioactive isotopes under probable repository conditions, based on geochemical modeling calculations using geochemical modeling tools, thermodynamic databases, field measurements, and laboratory experiments. The scope of this activity is to predict dissolved concentrations or solubility limits for elements with radioactive isotopes (actinium, americium, carbon, cesium, iodine, lead, neptunium, plutonium, protactinium, radium, strontium, technetium, thorium, and uranium) relevant to calculated dose. Model outputs for uranium, plutonium, neptunium, thorium, americium, and protactinium are provided in the form of tabulated functions with pH and log fCO 2 as independent variables, plus one or more uncertainty terms. The solubility limits for the remaining elements are either in the form of distributions or single values. Even though selection of an appropriate set of radionuclides documented in Radionuclide Screening (BSC 2002 [DIRS 160059]) includes actinium, transport of Ac is not modeled in the total system performance assessment for the license application (TSPA-LA) model because of its extremely short half-life. Actinium dose is calculated in the TSPA-LA by assuming secular equilibrium with 231 Pa (Section 6.10); therefore, Ac is not analyzed in this report. The output data from this report are fundamental inputs for TSPA-LA used to determine the estimated release of these elements from waste packages and the engineered barrier system. Consistent modeling approaches and environmental conditions were used to develop solubility models for the actinides discussed in this report. These models cover broad ranges of environmental conditions so they are applicable to both waste packages and the invert. Uncertainties from thermodynamic data, water chemistry, temperature variation, and activity coefficients have been quantified or otherwise

  15. Toxicity Data to Determine Refrigerant Concentration Limits

    Energy Technology Data Exchange (ETDEWEB)

    Calm, James M.

    2000-09-30

    This report reviews toxicity data, identifies sources for them, and presents resulting exposure limits for refrigerants for consideration by qualified parties in developing safety guides, standards, codes, and regulations. It outlines a method to calculate an acute toxicity exposure limit (ATEL) and from it a recommended refrigerant concentration limit (RCL) for emergency exposures. The report focuses on acute toxicity with particular attention to lethality, cardiac sensitization, anesthetic and central nervous system effects, and other escape-impairing effects. It addresses R-11, R-12, R-22, R-23, R-113, R-114, R-116, R-123, R-124, R-125, R-134, R-134a, R-E134, R-141b, R-142b, R-143a, R-152a, R-218, R-227ea, R-236fa, R-245ca, R-245fa, R-290, R-500, R-502, R-600a, R-717, and R-744. It summarizes additional data for R-14, R-115, R-170 (ethane), R-C318, R-600 (n-butane), and R-1270 (propylene) to enable calculation of limits for blends incorporating them. The report summarizes the data a nd related safety information, including classifications and flammability data. It also presents a series of tables with proposed ATEL and RCL concentrations-in dimensionless form and the latter also in both metric (SI) and inch-pound (IP) units of measure-for both the cited refrigerants and 66 zerotropic and azeotropic blends. They include common refrigerants, such as R-404A, R-407C, R-410A, and R-507A, as well as others in commercial or developmental status. Appendices provide profiles for the cited single-compound refrigerants and for R-500 and R-502 as well as narrative toxicity summaries for common refrigerants. The report includes an extensive set of references.

  16. Diverse microbial species survive high ammonia concentrations

    Science.gov (United States)

    Kelly, Laura C.; Cockell, Charles S.; Summers, Stephen

    2012-04-01

    Planetary protection regulations are in place to control the contamination of planets and moons with terrestrial micro-organisms in order to avoid jeopardizing future scientific investigations relating to the search for life. One environmental chemical factor of relevance in extraterrestrial environments, specifically in the moons of the outer solar system, is ammonia (NH3). Ammonia is known to be highly toxic to micro-organisms and may disrupt proton motive force, interfere with cellular redox reactions or cause an increase of cell pH. To test the survival potential of terrestrial micro-organisms exposed to such cold, ammonia-rich environments, and to judge whether current planetary protection regulations are sufficient, soil samples were exposed to concentrations of NH3 from 5 to 35% (v/v) at -80°C and room temperature for periods up to 11 months. Following exposure to 35% NH3, diverse spore-forming taxa survived, including representatives of the Firmicutes (Bacillus, Sporosarcina, Viridibacillus, Paenibacillus, Staphylococcus and Brevibacillus) and Actinobacteria (Streptomyces). Non-spore forming organisms also survived, including Proteobacteria (Pseudomonas) and Actinobacteria (Arthrobacter) that are known to have environmentally resistant resting states. Clostridium spp. were isolated from the exposed soil under anaerobic culture. High NH3 was shown to cause a reduction in viability of spores over time, but spore morphology was not visibly altered. In addition to its implications for planetary protection, these data show that a large number of bacteria, potentially including spore-forming pathogens, but also environmentally resistant non-spore-formers, can survive high ammonia concentrations.

  17. Dissolved Concentration Limits of Radioactive Elements

    Energy Technology Data Exchange (ETDEWEB)

    Y. Chen; E.R. Thomas; F.J. Pearson; P.L. Cloke; T.L. Steinborn; P.V. Brady

    2003-06-20

    The purpose of this study is to evaluate dissolved concentration limits (also referred to as solubility limits) of radioactive elements under possible repository conditions, based on geochemical modeling calculations using geochemical modeling tools, thermodynamic databases, and measurements made in laboratory experiments and field work. The scope of this modeling activity is to predict dissolved concentrations or solubility limits for 14 radioactive elements (actinium, americium, carbon, cesium, iodine, lead, neptunium, plutonium, protactinium, radium, strontium, technetium, thorium, and uranium), which are important to calculated dose. Model outputs are mainly in the form of look-up tables plus one or more uncertainty terms. The rest are either in the form of distributions or single values. The results of this analysis are fundamental inputs for total system performance assessment to constrain the release of these elements from waste packages and the engineered barrier system. Solubilities of plutonium, neptunium, uranium, americium, actinium, thorium, protactinium, lead, and radium have been re-evaluated using the newly updated thermodynamic database (Data0.ymp.R2). For all of the actinides, identical modeling approaches and consistent environmental conditions were used to develop solubility models in this revision. These models cover broad ranges of environmental conditions so that they are applicable to both waste packages and the invert. Uncertainties from thermodynamic data, water chemistry, temperature variation, activity coefficients, and selection of solubility controlling phase have been quantified or otherwise addressed. Moreover, a new blended plutonium solubility model has been developed in this revision, which gives a mean solubility that is three orders of magnitude lower than the plutonium solubility model used for the Total System Performance Assessment for the Site Recommendation. Two alternative neptunium solubility models have also been

  18. DISSOLVED CONCENTRATION LIMITS OF RADIOACTIVE ELEMENTS

    Energy Technology Data Exchange (ETDEWEB)

    P. Bernot

    2005-07-13

    The purpose of this study is to evaluate dissolved concentration limits (also referred to as solubility limits) of elements with radioactive isotopes under probable repository conditions, based on geochemical modeling calculations using geochemical modeling tools, thermodynamic databases, field measurements, and laboratory experiments. The scope of this activity is to predict dissolved concentrations or solubility limits for elements with radioactive isotopes (actinium, americium, carbon, cesium, iodine, lead, neptunium, plutonium, protactinium, radium, strontium, technetium, thorium, and uranium) relevant to calculated dose. Model outputs for uranium, plutonium, neptunium, thorium, americium, and protactinium are provided in the form of tabulated functions with pH and log fCO{sub 2} as independent variables, plus one or more uncertainty terms. The solubility limits for the remaining elements are either in the form of distributions or single values. Even though selection of an appropriate set of radionuclides documented in Radionuclide Screening (BSC 2002 [DIRS 160059]) includes actinium, transport of Ac is not modeled in the total system performance assessment for the license application (TSPA-LA) model because of its extremely short half-life. Actinium dose is calculated in the TSPA-LA by assuming secular equilibrium with {sup 231}Pa (Section 6.10); therefore, Ac is not analyzed in this report. The output data from this report are fundamental inputs for TSPA-LA used to determine the estimated release of these elements from waste packages and the engineered barrier system. Consistent modeling approaches and environmental conditions were used to develop solubility models for the actinides discussed in this report. These models cover broad ranges of environmental conditions so they are applicable to both waste packages and the invert. Uncertainties from thermodynamic data, water chemistry, temperature variation, and activity coefficients have been quantified or

  19. Measurement of radon activity concentration in buildings

    International Nuclear Information System (INIS)

    Godet, J.L.; Perrin, M.L.; Pineau, C.; Dechaux, E.

    2010-01-01

    Radon exposure, along with medical-related exposure, is the leading source of exposure to ionising radiation for the French population. Measurement campaigns are done in the action plan, drawn up by the French nuclear safety authority (ASN), in cooperation with the French directorate for housing, town planning and countryside (DHUP), the French radiation protection and nuclear safety institute (IRSN), the French health monitoring institute (InVS) and the French scientific and technical centre for construction (CSTB). The review of 2005-2008 measurement campaign shows that of the 7356 buildings screened, 84.8% had activity concentration levels below the 400 Bq/m 3 action level. For the other buildings (15.2%), action will be required to reduce human exposure to radon, possibly including building renovation/redevelopment work. In the 1999-2002 measurement campaign,12% of the 13,000 buildings screened had a radon activity concentration level higher than 400 Bq/m 3 . In addition, the ASN and the French general directorate of labour (DGT) are continuing to work on drawing up regulations for occupational risk management. The second national health and environment plan (PNSE 2) was published on 26 June 2009. It follows on from the actions initiated in PNSE 1, a document provided for under the Public Health Act dated 9 August 2004 and under the French 'Grenelle' environmental agreements. On the basis of guidelines laid out in PNSE 2, a radon action plan for 2009-2012 will be drawn up, enabling some of the actions to be continued, particularly in the fields of new building projects and dwellings. (author)

  20. Cadmium Concentration in Human Autopsy Tissues.

    Science.gov (United States)

    Lech, Teresa; Sadlik, Józefa K

    2017-10-01

    The concentration of cadmium in human tissues obtained on the basis of autopsies of non-poisoned Polish people (n = 150), aged from 1 to 80 years, examined between 1990 and 2010, is presented. The following values were found in wet digested samples by flame atomic absorption spectrometry (FAAS) (mean ± SD, median, and range, μg/g of wet weight): brain 0.020 ± 0.031, 0.084, 0-0.120 (n = 41); stomach 0.148 ± 0.195, 0.084, 0-1.25 (n = 89); small intestine 0.227 ± 0.231, 0.130, 0-0.830 (n = 39); liver 1.54 ± 1.55, 1.01, 0.015-9.65 (n = 99); kidney 16.0 ± 13.2, 14.0, 0.62-61.3 (n = 91); lung 0.304 ± 0.414, 0.130, 0-1.90 (n = 25); and heart 0.137 ± 0.107, 0.140, 0.017-0.250 (n = 4). Additionally, results (n = 13 people, aged from 2 to 83 years, 63 samples) obtained by inductively coupled plasma optical emission spectrometry (ICP OES) between 2010 and 2015 are given. The obtained data on Cd concentration in the human body can be used to estimate the amounts occurring in "healthy" people and those occurring in cases of chronic or acute poisonings with Cd compounds, which are examined for forensic purposes or to assess environmental exposure levels.

  1. Environmental concentration and migration of 129I

    International Nuclear Information System (INIS)

    Brauer, F.P.; Strebin, R.S. Jr.

    1982-01-01

    Local sources of 129 I suitable for study of migration in the environment are uranium ore bodies for long periods and nuclear fuel reprocessing operations for recent periods. Uranium ores produce 129 I from spontaneous and neutron-induced fission. Nuclear fuel reprocessing has resulted in releases of 129 I to both the atmosphere and the hydrosphere. The long-term fate of surface-deposited and groundwater 129 I was studied. Neutron activation analysis was used to measure the low levels of 129 I and natural 127 I in samples near and remote from nuclear fuel reprocessing facilities. Measurements were made on air samples, vegetation, soil, surface water, groundwater and uranium ore samples. Samples were collected both during reprocessing operations and after reprocessing activities had been discontinued for several years. The 129 I was found to accumulate in the top soil and litter layer. The surface concentrations of 129 I in forest communities were found to be several times higher than for nearby grass communities. The 129 I levels were found to persist in the environment after reprocessing activities had been discontinued. Measurable 129 I was found to be contained in uranium ore samples from a variety of locations and with a range of uranium concentrations. Thus ore bodies constitute a source of 129 I suitable for study of migration over long periods. Iodine-129 has entered surface and groundwater as the result of liquid and atmospheric discharges from nuclear fuel reprocessing facilities. The iodine in water samples was found to be anionic and travel with the water flow. Thus 129 I was found to provide high sensitivity for hydrology tracer studies and radioactivity migration surveillance. Once 129 I enters the hydrosphere it migrates with the water with little or no hold-up by exchange with cationic exchangers such as soil or silt

  2. Lime, agent to uranium concentration; La chaux comme agent de concentration de l'uranium

    Energy Technology Data Exchange (ETDEWEB)

    Mouret, P.; Le Bris, J.; Kremer, M. [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires; Gautier, R. [Etablissement Kuhlmann, Service d' Etudes et de Pilotages Industriels (France)

    1958-07-01

    Choice of the process according to health requirements. Description of the process: dissolution of uranium by sulfuric leaching of ores, precipitation of uranium by lime, re-dissolution of the concentrate with nitric ions, purification by T.B.P. finally resulting in pure uranyl nitrate solution containing 400 g/litre. (author)Fren. [French] Les raisons du choix du procede en fonction des imperatifs d'hygiene, sont exposees ainsi que le procede qui consiste en une dissolution de l'uranium des minerais par lixiviation sulfurique, precipitation de l'uranium par la chaux et redissolution du concentre en presence d'ions nitriques, purification par le T.B.P. et obtention d'un concentre final de nitrate d'uranyle pur a 400 g/litre. (auteur)

  3. Molecular basis of high viscosity in concentrated antibody solutions: Strategies for high concentration drug product development.

    Science.gov (United States)

    Tomar, Dheeraj S; Kumar, Sandeep; Singh, Satish K; Goswami, Sumit; Li, Li

    2016-01-01

    Effective translation of breakthrough discoveries into innovative products in the clinic requires proactive mitigation or elimination of several drug development challenges. These challenges can vary depending upon the type of drug molecule. In the case of therapeutic antibody candidates, a commonly encountered challenge is high viscosity of the concentrated antibody solutions. Concentration-dependent viscosity behaviors of mAbs and other biologic entities may depend on pairwise and higher-order intermolecular interactions, non-native aggregation, and concentration-dependent fluctuations of various antibody regions. This article reviews our current understanding of molecular origins of viscosity behaviors of antibody solutions. We discuss general strategies and guidelines to select low viscosity candidates or optimize lead candidates for lower viscosity at early drug discovery stages. Moreover, strategies for formulation optimization and excipient design are also presented for candidates already in advanced product development stages. Potential future directions for research in this field are also explored.

  4. Parametric analysis of a hybrid solar concentrating photovoltaic/concentrating solar power (CPV/CSP) system

    International Nuclear Information System (INIS)

    Han, Xue; Zhao, Guankun; Xu, Chao; Ju, Xing; Du, Xiaoze; Yang, Yongping

    2017-01-01

    Highlights: • Performance of the hybrid system is evaluated with the energy and exergy analyses. • Trapezoidal-shaped distribution of concentrated radiation flux density is adopted. • Effects of the influencing factors are investigated to optimize the design parameters. • Performance and reliability of the system with various DNIs are also discussed. - Abstract: This paper presents a parametric study of a recently proposed concentrating photovoltaic/concentrating solar power (CPV/CSP) hybrid system based on the energy and exergy analyses. A steady-state physical model is established for the hybrid system to carry out the energy and exergy analyses, in which a more general trapezoidal-shaped distribution of concentrated solar energy flux density is employed. Effects of various parameters are investigated including the average optical concentration ratio, the outlet temperature of R134a from the solar thermal receiver, and the coolant saturation vapor temperature. The results show that the generating efficiency and the power output of the hybrid system can increase by about 20% compared with the CPV-alone system, which indicates that the proposed hybrid system has a great potential to increase the utilization ratio of solar energy. Increasing the average optical concentration ratio or decreasing the outlet temperature of R134a from the solar thermal receiver can result in evident increases of both the energy efficiency and the exergy efficiency of the hybrid system. It is also shown that the energy and exergy efficiencies of the organic Rankine cycle (ORC) subsystem are nearly independent of the Direct Normal Irradiance (DNI), and the hybrid system can be always operated with a high efficiency despite of the DNI change at different moments or days.

  5. 21 CFR 169.178 - Concentrated vanilla flavoring.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 2 2010-04-01 2010-04-01 false Concentrated vanilla flavoring. 169.178 Section... Food Dressings and Flavorings § 169.178 Concentrated vanilla flavoring. (a) Concentrated vanilla... statement of ingredients prescribed for vanilla flavoring by § 169.177, except that it is concentrated to...

  6. 21 CFR 169.176 - Concentrated vanilla extract.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 2 2010-04-01 2010-04-01 false Concentrated vanilla extract. 169.176 Section 169... Dressings and Flavorings § 169.176 Concentrated vanilla extract. (a) Concentrated vanilla extract conforms... ingredients prescribed for vanilla extract by § 169.175, except that it is concentrated to remove part of the...

  7. 14 CFR 25.832 - Cabin ozone concentration.

    Science.gov (United States)

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Cabin ozone concentration. 25.832 Section... Cabin ozone concentration. (a) The airplane cabin ozone concentration during flight must be shown not to... concentrations exceeding the limits prescribed by paragraph (a) of this section; or (2) The airplane ventilation...

  8. 30 CFR 33.33 - Allowable limits of dust concentration.

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Allowable limits of dust concentration. 33.33... MINES Test Requirements § 33.33 Allowable limits of dust concentration. (a) The concentration of dust determined by the control sample shall be subtracted from the average concentration of dust determined by the...

  9. 30 CFR 33.32 - Determination of dust concentration.

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Determination of dust concentration. 33.32... MINES Test Requirements § 33.32 Determination of dust concentration. (a) Concentrations of airborne dust... microscopic technique shall be employed in determining concentrations of dust in terms of millions of...

  10. The effects of dietary energy and protein concentrations on ostrich ...

    African Journals Online (AJOL)

    The effects were investigated of energy and protein concentrations (with associated amino acid concentrations) in ostrich diets on leather quality of the skins of 50 ostriches. Energy concentrations were 9.0, 10.5 and 12.0 MJ ME/kg diet and protein concentrations were 130, 150 and 170 g/kg diet. The physical leather ...

  11. Design of planar light guide concentrators for building integrated photovoltaics

    Science.gov (United States)

    Fennig, Eryn; Schmidt, Greg; Moore, Duncan T.

    2017-11-01

    There are advantages to using planar light guide (PLG) concentrators instead of Fresnel concentrators for glass building façade photovoltaic systems. This paper details the main components of a PLG concentrator and describes how the concentrator works. The design of a PLG concentrator is constrained by the limitations of the diamond turning process used to make the microlens array. These manufacturing limitations and their effects on the lens design and system performance are reviewed. We report on the design of a 25 × 100 mm planar light guide concentrator with a 50x geometric concentration and an 85.0-88.1% theoretical optical efficiency for use in building integrated photovoltaics.

  12. Temporal associations of ambient PM2.5 elemental concentrations with indoor and personal concentrations

    NARCIS (Netherlands)

    Montagne, Denise|info:eu-repo/dai/nl/341752258; Hoek, Gerard|info:eu-repo/dai/nl/069553475; Nieuwenhuijsen, Mark; Lanki, Timo; Siponen, Taina; Portella, Meritxell; Meliefste, Kees; Brunekreef, Bert|info:eu-repo/dai/nl/067548180

    Time series studies increasingly evaluate health relevance of the elemental composition of particles smaller than 2.5 mu m (PM2.5). Validation studies have documented that temporal variation of outdoor PM2.5 concentration is correlated with temporal variation of personal exposure, but very few

  13. Polyaspartic Acid Concentration Controls the Rate of Calcium Phosphate Nanorod Formation in High Concentration Systems

    Energy Technology Data Exchange (ETDEWEB)

    Krogstad, Daniel V. [Biosystems and; Wang, Dongbo [Biosystems and; Lin-Gibson, Sheng [Biosystems and

    2017-08-31

    Polyelectrolytes are known to greatly affect calcium phosphate (CaP) mineralization. The reaction kinetics as well as the CaP phase, morphology and aggregation state depend on the relative concentrations of the polyelectrolyte and the inorganic ions in a complex, nonlinear manner. This study examines the structural evolution and kinetics of polyaspartic acid (pAsp) directed CaP mineralization at high concentrations of polyelectrolytes, calcium, and total phosphate (19–30 mg/mL pAsp, 50–100 mM Ca2+, Ca/P = 2). Using a novel combination of characterization techniques including cryogenic transmission electron microscopy (cryo-TEM), spectrophotometry, X-ray total scattering pair distribution function analysis, and attenuated total reflectance Fourier transform infrared spectroscopy (ATR-FTIR), it was determined that the CaP mineralization occurred over four transition steps. The steps include the formation of aggregates of pAsp stabilized CaP spherical nanoparticles (sNP), crystallization of sNP, oriented attachment of the sNP into nanorods, and further crystallization of the nanorods. The intermediate aggregate sizes and the reaction kinetics were found to be highly polymer concentration dependent while the sizes of the particles were not concentration dependent. This study demonstrates the complex role of pAsp in controlling the mechanism as well as the kinetics of CaP mineralization.

  14. Design philosophy and construction of a high concentration compound parabolic concentrator

    CSIR Research Space (South Africa)

    Roos, TH

    2010-09-01

    Full Text Available soda lime mirror glass used for the concentrator facets was measured using a uniform light source and an ASD FieldSpec(TM) spectroradiometer. This, together with the SMARTS solar spectrum model, was used in a ray tracing analysis which determined...

  15. Double Solvent for Extracting Rare Earth Concentrate

    International Nuclear Information System (INIS)

    Bintarti, AN; Bambang EHB

    2007-01-01

    An extraction process to rare earth concentrate which contain elements were yttrium (Y), lanthanum (La), cerium (Ce), neodymium (Nd), samarium (Sm), gadolinium (Gd) and dysprosium (Dy) which were dissolved in to nitric acid has been done. The experiment of the extraction by double solvent in batch to mix 10 ml of the feed with 10 ml solvent contained the pair of solvent was TBP and TOA, D2EHPA and TOA, TBP and D2EHPA in cyclohexane as tinner. It was selected a right pairs of solvent for doing variation such as the acidity of the feed from 2 - 6 M and the time of stirring from 5 - 25 minutes gave the good relatively extraction condition to Dy element such as using 10 % volume of TOA in D2EHPA and cyclohexane, the acidity of the feed 3 M and the time stirring 15 minutes produced coefficient distribution to dysprosium = 0.586 and separation factor Dy-Ce = ∼ (unlimited); Dy-Nd = 4.651. (author)

  16. Colligative Properties of Solutions: II. Vanishing Concentrations

    Science.gov (United States)

    Alexander, Kenneth S.; Biskup, Marek; Chayes, Lincoln

    2005-05-01

    We continue our study of colligative properties of solutions initiated in ref. 1. We focus on the situations where, in a system of linear size L, the concentration and the chemical potential scale like c=ξ/ L and h= b/ L, respectively. We find that there exists a critical value ξ t such that no phase separation occurs for ξ≤ξ t while, for ξ>ξ t, the two phases of the solvent coexist for an interval of values of b. Moreover, phase separation begins abruptly in the sense that a macroscopic fraction of the system suddenly freezes (or melts) forming a crystal (or droplet) of the complementary phase when b reaches a critical value. For certain values of system parameters, under "frozen" boundary conditions, phase separation also ends abruptly in the sense that the equilibrium droplet grows continuously with increasing b and then suddenly jumps in size to subsume the entire system. Our findings indicate that the onset of freezing-point depression is in fact a surface phenomenon.

  17. Melanin concentrating hormone in central hypersomnia.

    Science.gov (United States)

    Peyron, Christelle; Valentin, Françoise; Bayard, Sophie; Hanriot, Lucie; Bedetti, Christophe; Rousset, Bernard; Luppi, Pierre-Hervé; Dauvilliers, Yves

    2011-09-01

    Narcolepsy with cataplexy (NC) is a disabling disorder characterized by excessive daytime sleepiness and abnormal rapid eye movement (REM) sleep manifestations, due to a deficient hypocretin/orexin neurotransmission. Melanin concentrating hormone (MCH) neurons involved in the homeostatic regulation of REM sleep are intact. We hypothesized that an increased release of MCH in NC would be partly responsible for the abnormal REM sleep manifestations. Twenty-two untreated patients affected with central hypersomnia were included: 14 NC, six idiopathic hypersomnia with long sleep time, and two post-traumatic hypersomnia. Fourteen neurological patients without any sleep disorders were included as controls. Using radioimmunoassays, we measured hypocretin-1 and MCH levels in cerebrospinal fluid (CSF). The MCH level was slightly but significantly lower in patients with hypersomnia (98 ± 32 pg/ml) compared to controls (118 ± 20 pg/ml). After exclusion of patients affected with post-traumatic hypersomnia the difference became non-significant. We also failed to find any association between MCH level and hypocretin level, the severity of daytime sleepiness, the number of SOREMPs, the frequency of cataplexy, and the presence of hypnagogic hallucinations or sleep paralysis. This study reports the first measurement of MCH in CSF using radioimmunoassay technology. It appears to be a non-informative tool to differentiate etiologies of central hypersomnia with or without REM sleep dysregulation. Copyright © 2011 Elsevier B.V. All rights reserved.

  18. High-efficiency concentrator silicon solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Sinton, R.A.; Cuevas, A.; King, R.R.; Swanson, R.M. (Stanford Univ., CA (USA). Solid-State Electronics Lab.)

    1990-11-01

    This report presents results from extensive process development in high-efficiency Si solar cells. An advanced design for a 1.56-cm{sup 2} cell with front grids achieved 26% efficiency at 90 suns. This is especially significant since this cell does not require a prismatic cover glass. New designs for simplified backside-contact solar cells were advanced from a status of near-nonfunctionality to demonstrated 21--22% for one-sun cells in sizes up to 37.5 cm{sup 2}. An efficiency of 26% was achieved for similar 0.64-cm{sup 2} concentrator cells at 150 suns. More fundamental work on dopant-diffused regions is also presented here. The recombination vs. various process and physical parameters was studied in detail for boron and phosphorous diffusions. Emitter-design studies based solidly upon these new data indicate the performance vs design parameters for a variety of the cases of most interest to solar cell designers. Extractions of p-type bandgap narrowing and the surface recombination for p- and n-type regions from these studies have a generality that extends beyond solar cells into basic device modeling. 68 refs., 50 figs.

  19. Structural study of concentrated micellar solutions

    International Nuclear Information System (INIS)

    Zemb, Thomas

    1985-01-01

    This research thesis reports the study of the structure of concentrated soap-water binary micelles with a comparison of measurements of light, neutrons and X-ray scattering, and the relaxation induced by paramagnetic ions adsorbed at the interface. In the first part, the author discusses the specific sensitivity ranges of different experimental techniques, outlines the resolution which can be obtained with scattering experiments, and proposes a critical analysis of results published in the relevant literature. In a second part, the author discusses the compared results of the application of various techniques (magnetic resonance, X-light and neutron scattering) on the two most used model systems: sodium octanoate and sodium dodecyl sulfate (SDS) in solution. Then, the author addresses the case of ternary systems: study of the influence of the presence of a co-surfactant on the structure, study of the effect of interfacial charge on the micellar structure, use of the same previous quantitative methods to study the disturbances brought to the structure due to the presence of reactants [fr

  20. Concentration of uranium in seawater by flotation

    International Nuclear Information System (INIS)

    Nozaki, Toru; Yamashita, Hiroshi

    1986-01-01

    A method has been developed for the concentration of uranium in seawater by precipitation flotation-carbonate extraction-ion flotation. Uranium in seawater was coprecipitated with hydrated iron (III) oxide by adjusting the pH to 5.5 after addition of 1.0 x 10 -3 mol/l of iron (III) and agitating for 1 hr, and the precipitate was floated with 1.0 x 10 -5 mol/l of sodium oleate and 5.0 x 10 -5 mol/l of sodium lauryl sulfate by bubbling nitrogen through the seawater for 15 min. Uranium was extracted from the precipitate scum at the yield of 89 % with 100 ml of 1.8 % of ammonium carbonate solution by agitating for 2 hr, and floated with 1.2 x 10 -3 mol/l of cetylpyridinium chloride by bubbling nitrogen through the extract diluted 5-fold for 30 min in the recovery of about 100 %. The fairly selective recovery of uranium was obtained from 4 l of seawater at the yield of 87 % throughout the entire process. (author)

  1. Oxalate Concentrations in Human Gastrointestinal Fluid.

    Science.gov (United States)

    Reddy, Thanmaya G; Knight, John; Holmes, Ross P; Harvey, Lisa M; Mitchem, April L E; Wilcox, Charles M; Monkemuller, Klaus E; Assimos, Dean G

    2016-05-01

    Urinary oxalate excretion is a risk factor for nephrolithiasis and is a result of endogenous metabolism and gastrointestinal processes. Gastrointestinal absorption of oxalate has been well demonstrated but to our knowledge evidence for secretion of oxalate is absent in humans. The objective of this study was to measure the amount and conformation of oxalate in the stomach and small intestine of adult subjects undergoing gastrointestinal endoscopy. Eleven adults participated in this study. Gastrointestinal fluid was collected from the stomach and small intestine during endoscopy. A determination of the soluble and insoluble components of oxalate was made by centrifugation of the sample and subsequent acidification of the resultant pellet and supernatant. Samples were processed and the amount of oxalate was measured by ion chromatography, the limit of which is 1.6 μM. The majority of small intestinal samples contained some degree of oxalate. This is in contrast to the stomach where minimal oxalate was detected. There was a wide range of oxalate concentrations and a greater degree of insoluble oxalate in small intestinal samples. Our results suggest that some degree of oxalate secretion in the small intestine may occur in the fasted state while this is less likely in the stomach. Further studies are warranted to provide definitive evidence of gastrointestinal secretion of oxalate.

  2. Radon concentrations in Western Australian homes

    Energy Technology Data Exchange (ETDEWEB)

    Toussaint, L.F. [Health Dept. of Western Australia, Perth, WA (Australia). Radiation Health Branch

    1994-12-31

    Although there have been previous surveys of radon levels in some Western Australian homes, given the size of Western Australia (WA), it is desirable to carry out more measurements to better assess the likely radiation dose to the WA population. By monitoring a sufficient number of homes it will also be possible to identify any areas w here pockets of high radon concentrations exist in WA. An initial phase 1, radon survey, was carried out over the whole of the State. From the data gathered from phase 1 areas where higher radon levels might occur were identified. These areas of higher radon levels were investigated in phase 2 of the radon survey. Phase 2 involved dividing WA into 4 regions (based on electoral districts) and investigating radon levels in each region. For each region, approximately 500 homes were selected at random for radon monitoring. So far phase 1 has been completed and for phase 2 Regions 1 and 2 have been monitored. Data from phase 1 and Region 1 are presented. Initial data indicate a mean radon level of 15.7 Bqm{sup -3}, with 3 homes recording radon levels in excess of 100 Bqm{sup -3}. 11 refs., 1 tab., 2 figs.

  3. Peanut cake concentrations in massai grass silage

    Directory of Open Access Journals (Sweden)

    Luciano S. Lima

    2013-03-01

    Full Text Available Objective. This experiment was conducted to evaluate the best concentration of peanut cake in the ensiling of massai grass of the chemical-bromatological composition, fermentative characteristics, forage value rate, ingestion estimates, and digestibility of dry matter in the silage. Materials and methods. The experiment was carried out at the Experimental Farm of São Gonçalo dos Campos at the Federal University of Bahia, Brazil. The treatments consisted of massai grass that was cut at 40 days and dehydrated, in addition to 0%, 8%, 16%, and 24% peanut cake in the fresh matter and treatment without cake. The material was compressed in experimental silos (7 liter that were opened after 76 days. Results. The addition of 8-24% peanut cake improved the silage’s chemical-bromatological parameters, increased the dry matter and non-fiber carbohydrates and reduced the fibrous components. There was a linear increase in the estimated values of digestibility and the ingestion of dry matter depending on the levels of peanut cake in the silage. There was an improvement in the fermentative characteristics, with a quadratic effect positive for levels of ammoniacal nitrogen. The forage value rate increased linearly with the inclusion of peanut cake. Conclusions. The inclusion of up to 24% peanut cake during ensiling of massai grass increases the nutritive value of silage and improves fermentation characteristics.

  4. Determining lower threshold concentrations for synergistic effects

    DEFF Research Database (Denmark)

    Bjergager, Maj-Britt Andersen; Dalhoff, Kristoffer; Kretschmann, Andreas

    2017-01-01

    which proven synergists cease to act as synergists towards the aquatic crustacean Daphnia magna. To do this, we compared several approaches and test-setups to evaluate which approach gives the most conservative estimate for the lower threshold for synergy for three known azole synergists. We focus.......619±8.555μgL(-1)) and 0.122±0.0417μM (40.236±13.75μgL(-1)), respectively, in the 14-days tests. Testing synergy in relation to concentration addition provided the most conservative values. The threshold values for the vertical assessments in tests where the two could be compared were in general 1.2 to 4.......7 fold higher than the horizontal assessments. Using passive dosing rather than dilution series or spiking did not lower the threshold significantly. Below the threshold for synergy, slight antagony could often be observed. This is most likely due to induction of enzymes active in metabolization of alpha...

  5. Fallout Concentration Various Environmental Samples in Indonesia

    International Nuclear Information System (INIS)

    Sutarman

    2001-01-01

    The testing of nuclear weapons have been carried out by the advanced countries, such as United States, Russian Federation, United Kingdom, France, China, India and Pakistan, since about 1945 until 1998. Nuclear weapons tests were conducted at various locations, on and above the earth's surface or underground or on and under the ocean's surface. Nuclear explosions caused the radionuclides of fission product, such as 131 l, 89 Sr, 90 Sr, 134 Cs, 137 Cs, and 239 Pu released to the atmospheric layer. In the atmospheric layer, the long-lived radionuclides, i.e, 90 Sr dan 137 Cs will be distributed into the environment as the fallout radionuclides, and deposited in the various environmental samples (soil, water, and biota). In general, at several locations in Indonesia the 90 Sr and 137 Cs in the various environmental samples still can be detected. The data of measurement results of 90 Sr and 137 Cs concentrations were generally lower than that from some countries in the northern hemisphere. (author)

  6. Intercomparison of aerosol instruments: number concentration

    International Nuclear Information System (INIS)

    Knutson, E.O.; Sinclair, D.; Tu, K.W.; Hinchliffe, L.; Franklin, H.

    1982-05-01

    An intercomparison of aerosol instruments conducted February 23-27, 1981, at the Environmental Measurements Laboratory (EML) focused on five instruments: the Pollak and TSI condensation nucleus counters; the Active Scattering Aerosol Spectrometer (ASAS-X); and two aerosol electrometers. Test aerosols of sodium chloride and ammonium fluorescein generated by nebulization/electrostatic classification were used to obtain 195 lines of comparison data. Concentrations measured by the ASAS-X and the TSI aerosol electrometer averaged respectively 1.388 and 1.581 times that measured by the Pollak. These ratios were very stable during the week and there was little effect of particle size or material. Most other comparisons were equally stable. However, a review of past work at EML and elsewhere led to the disturbing conclusion that these ratios may change from year to year, or from season to season. A filter sample was taken from microscopy, concurrent with readings from the ASAS-X and the TSI condensation nucleus counters. In this sample, the two instruments differed by 20%. Within its 20% uncertainty, the filter result matched both the TSI and ASAS-X readings

  7. Ammonia Solubility in High Concentration Salt Solutions

    International Nuclear Information System (INIS)

    HEDENGREN, D.C.

    2000-01-01

    Solubility data for ammonia in water and various dilute solutions are abundant in the literature. However, there is a noticeable lack of ammonia solubility data for high salt, basic solutions of various mixtures of salts including those found in many of the Hanford Washington underground waste tanks. As a result, models based on solubility data for dilute salt solutions have been used to extrapolate to high salt solutions. These significant extrapolations need to be checked against actual laboratory data. Some indirect vapor measurements have been made. A more direct approach is to determine the ratio of solubility of ammonia in water to its solubility in high salt solutions. In various experiments, pairs of solutions, one of which is water and the other a high salt solution, are allowed to come to equilibrium with a common ammonia vapor pressure. The ratio of concentrations of ammonia in the two solutions is equal to the ratio of the respective ammonia solubilities (Henry's Law constants) at a given temperature. This information can then be used to refine the models that predict vapor space compositions of ammonia. Ammonia at Hanford is of concern because of its toxicity in the environment and its contribution to the flammability of vapor space gas mixtures in waste tanks

  8. Tracking-integrated systems for concentrating photovoltaics

    Science.gov (United States)

    Apostoleris, Harry; Stefancich, Marco; Chiesa, Matteo

    2016-04-01

    Concentrating photovoltaic (CPV) systems, which use optical elements to focus light onto small-area solar cells, have the potential to minimize the costs, while improving efficiency, of photovoltaic technology. However, CPV is limited by the need to track the apparent motion of the Sun. This is typically accomplished using high-precision mechanical trackers that rotate the entire module to maintain normal light incidence. These machines are large, heavy and expensive to build and maintain, deterring commercial interest and excluding CPV from the residential market. To avoid this issue, some attention has recently been devoted to the development of tracking-integrated systems, in which tracking is performed inside the CPV module itself. This creates a compact system geometry that could be less expensive and more suitable for rooftop installation than existing CPV trackers. We review the basic tracking principles and concepts exploited in these systems, describe and categorize the existing designs, and discuss the potential impact of tracking integration on CPV cost models and commercial potential.

  9. Blood lactate concentration in diabetic dogs

    Science.gov (United States)

    Claus, Poliana; Gimenes, André M.; Castro, Jacqueline R.; Mantovani, Matheus M.; Kanayama, Khadine K.; Simões, Denise M.N.; Schwartz, Denise S.

    2017-01-01

    Human diabetic patients may have increased lactate levels compared to non-diabetics. Despite the use of lactate levels in critical care assessment, information is lacking for diabetic dogs. Therefore, this prospective cross-sectional clinical study aimed to determine lactate concentrations in 75 diabetic dogs [25 newly diagnosed non-ketotic diabetics, 25 under insulin treatment, and 25 in diabetic ketoacidosis (DKA)], compared to 25 non-diabetic dogs. Lactate levels (mmol/L) were not different among groups (P = 0.20); median and 25th to 75th percentile were 2.23 and P25–75 = 1.46 to 2.83 for controls, 1.69 and P25–75 = 1.09 to 2.40 for newly diagnosed non-ketotic diabetics, 2.27 and P25–75 = 1.44 to 2.90 for dogs under insulin treatment for at least 30 days, and 2.40 and P25–75 = 1.58 to 3.01 for dogs in DKA. Longitudinal studies assessing both isomers (L- and D-lactate) are needed to better elucidate the role of lactate in the pathophysiology of diabetes acid-base status in dogs. PMID:28761186

  10. Luminescent Solar Concentrators in the Algal Industry

    Science.gov (United States)

    Hellier, Katie; Corrado, Carley; Carter, Sue; Detweiler, Angela; Bebout, Leslie

    2013-03-01

    Today's industry for renewable energy sources and highly efficient energy management systems is rapidly increasing. Development of increased efficiency Luminescent Solar Concentrators (LSCs) has brought about new applications for commercial interests, including greenhouses for agricultural crops. This project is taking first steps to explore the potential of LSCs to enhance production and reduce costs for algae and cyanobacteria used in biofuels and nutraceuticals. This pilot phase uses LSC filtered light for algal growth trials in greenhouses and laboratory experiments, creating specific wavelength combinations to determine effects of discrete solar light regimes on algal growth and the reduction of heating and water loss in the system. Enhancing the optimal spectra for specific algae will not only increase production, but has the potential to lessen contamination of large scale production due to competition from other algae and bacteria. Providing LSC filtered light will reduce evaporation and heating in regions with limited water supply, while the increased energy output from photovoltaic cells will reduce costs of heating and mixing cultures, thus creating a more efficient and cost effective production system.

  11. Solar thermal and concentrated solar power barometer

    International Nuclear Information System (INIS)

    2013-01-01

    The European concentrated solar power plant market is steeling itself for tough time ahead. The number of projects under construction is a pittance compared with 2012 that was an excellent year for installations (an additional 802.5 MW of capacity recorded). This drop is the result of the moratorium on renewable energy power plants introduced by the Spanish government. The European solar thermal market is hardly any more encouraging . EurObserv'ER holds that it slipped for the fourth year in a row (it dropped 5.5% between 2011 and 2012). The newly-installed solar thermal collector surface area in the EU now stands at 3.4 million m 2 , far short of its 2008 installation record of 4.6 million m 2 . The EU's solar thermal base to date at the end of 2012 is 29.6 GWth with 2.4 GWth installed during the year 2012. This article gives tables gathering the figures of the production for every European country for 2012 and describes the market and the general trend for every EU member

  12. Concentration limits from a technical standpoint

    International Nuclear Information System (INIS)

    Rennerfelt, Jan

    1987-01-01

    The discharge of hazardous substances in an industrial waste water can cause a number of negative effects in the sewers and in the treatment plants. The most important of these effects are: - Corrosion of sewers, pumping stations and treatment plants. Risk for explosion and fire. - Disturbances in the physical, biological and chemical treatment processes. - Disturbances in the stabilization and dewatering of sludge and increase of toxic components of the sludge leading to reduced usability in agriculture. - Detrimental impact on the ecosystem of the receiving streams and lakes. - Disturbances of the working environment for the operation staff, health risks, nuisance and inconvenience. Swedish requirements governing the discharge of hazardous substances from industries into municipal sewerage systems have been put together in a list of limit values published by the Swedish Water and Sewage Works Association, VAV. The list specifies the maximum concentrations that can be accepted at the connection point between the industrial plant and municipal network with regard to the effect on the sewers, and at the inlet to the treatment plant with regard to the treatment processes

  13. Platelet concentration in platelet concentrates and periodontal regeneration-unscrambling the ambiguity

    Directory of Open Access Journals (Sweden)

    A Suchetha

    2015-01-01

    Full Text Available Context: Platelet-rich-plasma (PRP and Platelet-rich-fibrin (PRF are extensively used autologous platelet concentrates in periodontal regeneration, and PRF has a better efficacy as compared to PRP. The rationale for this difference has often been attributed to the difference in the structure of the fibrin matrix. However, the effect of concentration of platelets on the regenerative potential of these concentrates is obscure. Aims: The study was conducted to evaluate and compare, clinically and radiographically, the efficacy of PRF and PRP in the treatment of periodontal endosseous defects and to assess the effect of platelet concentration on periodontal regeneration. Materials and Methods: Twenty intrabony defects were selected and divided into two groups randomly by the coin toss method. Group I received PRP and Group II subjects were treated with PRF. The platelet counts in PRP and PRF were analyzed. Clinical and radiological parameters were assessed at baseline and 3, 6, and 9 months postoperatively. Statistical Analysis: Kruskal–Wallis Chi-square test, Wilcoxon signed rank test, t-test, and Spearman's rank correlation were used for statistical analysis of data. Results: There was statistically significant improvement in all the parameters in the two groups except in relation to gingival recession. There was a statistically significant difference between the platelet count in Group I and Group II (P = 0.002. Conclusion: PRP and PRF appear to have nearly comparable effects in terms of periodontal regeneration. The concentration of platelets appears to play a paradoxical role in regeneration. The regenerative potential of platelets appears to be optimal within a limited range.

  14. Prevalence, concentration, spoilage, and mitigation of Alicyclobacillus spp. in tropical and subtropical fruit juice concentrates.

    Science.gov (United States)

    Danyluk, Michelle D; Friedrich, Loretta M; Jouquand, Celine; Goodrich-Schneider, Renee; Parish, Mickey E; Rouseff, Russell

    2011-05-01

    The presence of Alicyclobacillus in fruit juices and concentrates poses a serious problem for the juice industry. This study was undertaken to determine the (i) prevalence, concentration, and species of Alicyclobacillus in tropical and subtropical concentrates; (ii) efficacy of aqueous chlorine dioxide in reducing Alicyclobacillus spp. spores on tropical and subtropical fruit surfaces; and (iii) fate of and off-flavor production by Alicyclobacillus acidoterrestris in mango and pineapple juices. One hundred and eighty tropical and subtropical juice concentrates were screened for the presence and concentration of Alicyclobacillus spp. If found, the species of Alicyclobacillus was determined by 16S rDNA sequencing and analysis with NCI BLAST. Of these samples, 6.1% were positive for Alicyclobacillus, and nine A. acidoterrestris strains and two Alicyclobacillus acidocaldarius strains were identified. A five-strain cocktail of Alicyclobacillus spp. was inoculated onto the surface of fruits (grapefruit, guava, limes, mangoes, oranges and pineapple), which were then washed with 0, 50, or 100 ppm aqueous chlorine dioxide. Significant reductions due to chlorine dioxide were only seen on citrus fruits. A five-strain cocktail of A. acidoterrestris was inoculated into mango and pineapple juices. Microbial populations were enumerated over a 16-day period. Aroma compounds in the juice were analyzed by GC-olfactometry (GC-O) and confirmed using GC-MS. GC-O of mango juice identified previously reported medicinal/antiseptic compounds. GC-O of pineapple juice revealed an unexpected "cheese" off-aroma associated with 2-methylbutyric acid and 3-methylbutyric acid. Copyright © 2010 Elsevier Ltd. All rights reserved.

  15. Three-dimensional transparent parabolic concentrator for photovoltaics

    Directory of Open Access Journals (Sweden)

    Huichuan Lin

    2015-09-01

    Full Text Available A three-dimensional transparent parabolic concentrator made of polymethylmethacrylate (PMMA was designed and fabricated for photovoltaic applications. The measured maximum concentration ratio of the concentrator is 8.31, which means that for normal incident light, optical energy can be concentrated as high as 8.31 times by the concentrator. Even for oblique incident lights with an incident angle of between 5° and 15°, the concentrator maintains a concentration ratio of between 6.81 and 3.72. The concentrator was connected to Si cell, which increased the maximum output power of the Si cell by 12 times, compared with that of the bare cell. This indicates that the concentrator can increase the energy generated by Si cell by 12 times.

  16. Treatment of radioactive wastes from uranium concentrating

    International Nuclear Information System (INIS)

    Ashtari, Parviz.

    1995-06-01

    Radioactive wastes from uranium and thorium ore processing pose potential environmental and public health problems because of their radioactivity and chemical composition. The radionuclides exist in these wastes are those resulting from the uranium 238, uranium 235 and thorium 232 decay series. The most important radionuclide in U 238 decay series are uranium 234, thorium 230, radium 226 and some short lived radionuclides such as radon-222. Radium 226 is the nuclide of principal concern from the standpoint of the assessment and control of the radiological hazard associated with the wastes. Thus determination of uranium, thorium and radium concentration in wastes resulting from nuclear fuel cycle is very important because of its potential hazard. Various analytical methods such as fluorimetry, neutron activation analysis, radon emanation, spectrophotometry and spectroscopy are used for determination of these radionuclides. Uranium and thorium are separated from interfering element by ion exchange chromatography and measured by spectrophotometry method using arsenazo III and thorin as indicator. Radium is separated from interfering elements and α-emitters by coprecipitation of radium barium sulphate and measured by counting α-particles with surface barrier detector. Regarding to physical and chemical characteristic of waste being investigated, decontamination factors and treatment methods, chemical precipitation and coprecipitation procedure were carried out in this research work. By adding barium chloride, radium is separated from liquid waste and optimum condition were determined. Precipitation with lime and sodium-hydroxide were also studied and good result were obtained. The results show that by neutralization of waste by lime and sodium hydroxide more than 99.9% of activity was removed from stream. Advantage and disadvantage of each methods were studied and finally, effluent resulted from treatment were discharged after analysis with γ-spectroscopy and

  17. Concentrating Solar Power Gen3 Demonstration Roadmap

    Energy Technology Data Exchange (ETDEWEB)

    Mehos, Mark [National Renewable Energy Lab. (NREL), Golden, CO (United States); Turchi, Craig [National Renewable Energy Lab. (NREL), Golden, CO (United States); Vidal, Judith [National Renewable Energy Lab. (NREL), Golden, CO (United States); Wagner, Michael [National Renewable Energy Lab. (NREL), Golden, CO (United States); Ma, Zhiwen [National Renewable Energy Lab. (NREL), Golden, CO (United States); Ho, Clifford [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Kolb, William [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Andraka, Charles [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Kruizenga, Alan [Sandia National Lab. (SNL-CA), Livermore, CA (United States)

    2017-01-01

    Today's power-tower concentrating solar power (CSP) technology exists in large part as a result of Department of Energy (DOE) and utility industry funding of demonstration systems in the 1980s and 1990s. Today's most advanced towers are integrated with molten-salt thermal energy storage, delivering thermal energy at 565 degrees C for integration with conventional steam-Rankine cycles. The supercritical carbon dioxide power cycle has been identified as a likely successor to the steam-Rankine power cycle due to its potential for high efficiency when operating at elevated temperatures of 700 degrees C or greater. Over the course of the SunShot Initiative, DOE has supported a number of technology pathways that can operate efficiently at these temperatures and that hold promise to be reliable and cost effective. Three pathways - molten salt, particle, and gaseous - were selected for further investigation based on a two-day workshop held in August of 2016. The information contained in this roadmap identifies research and development challenges and lays out recommended research activities for each of the three pathways. DOE foresees that by successfully addressing the challenges identified in this roadmap, one or more technology pathways will be positioned for demonstration and subsequent commercialization within the next ten years. Based on current knowledge of the three power tower technologies, all three have the potential to achieve the SunShot goal of 6 cents/kilowatt-hour. Further development, modeling, and testing are now required to bring one or more of the technologies to a stage where integrated system tests and pilot demonstrations are feasible.

  18. Optimum Concentration Ratio Analysis Using Dynamic Thermal Model for Concentrated Photovoltaic System

    Science.gov (United States)

    2012-03-22

    different semiconductor material solar cells, such as GaAs, InGaP, CdTe , and other high-efficiency cell materials to investigate the thermal properties...Technology. Norwell, MA : Kluwer Academic Publishers, 1997. 39. Model of Photovoltaic Module in MATLAB. Gonzalez-Longatt, Francisco M. 2DO Congreso...of Hong Kong, 2010. 44. A Simple Passive Cooling Structure and its Heat Analysis for 500 X Concentration PV Module . Araki, Kenji, Uozumi, Hisafumi

  19. Effect on the concentration and metal ion concentration for the degradation of wastewater

    Science.gov (United States)

    Chen, M. T.; He, L. F.; Yu, W. Q.; Huo, J. H.; Xu, C. H.; Li, Z. Y.; Jiang, Z. X.

    2017-11-01

    The advanced oxidation technology based on the theory of sulfate radicals has been extensively studied. In this paper, the degradation of methyl orange over the transition metal catalysts and the catalytic effect on various metal ion catalysts were investigated. The wastewater degradation experiments were judged by the degradation rate and pH under the optimal conditions. In this study, the methyl orange was used as the simulation of the printing and dyeing wastewater, and the experiment was carried out. The vary concentration of methyl orange and metal ions were carried out.. The results showed that persulfate were activated by the metal salts the cobalt metal ions exhibited the strongest performance. The resulted indicated that the methyl orange degradation of 40 mg/L was the appropriate concentration. from varied from 40 mg/L to 120 mg/L interval 20 mg/L, and the catalytic activity of 2g m/L is the best dose at six metal concentrations of 0.5 mg/L, 1 mg/L, 2 mg/L, 3 mg/L, 4 mg/L and 5 mg/L, which provided a very rational basis for the treatment of the practical wastewater.

  20. Family-Concentrated Ownership in Chinese PLCs: Does Ownership Concentration Always Enhance Corporate Value?

    Directory of Open Access Journals (Sweden)

    Jin-Hui Luo

    2014-02-01

    Full Text Available In this paper we investigate the relationship between family ownership structure and corporate value across a sample of 1314 firm-year observations of China’s family publicly listed companies (PLCs, from 2004 to 2008. We find a significant inverse-U-shaped relationship between the controlling family’s ultimate cash-flow rights and corporate value; as measured by Tobin’s Q. That is, as family-ownership concentration increases, corporate value first increases and then decreases. This finding refreshes our understanding of the relationship between family-ownership concentration and corporate value in emerging economies such as found in China. We corroborate prior findings that when controlling families hold excess control over cash-flow rights, corporate value is significantly lowered, while multiple large shareholders structure is significantly associated with higher corporate value. In addition; board independence is found to significantly improve corporate value in the context of family-concentrated ownership. We also test for potential endogeneity between family ownership and corporate value and find our results to be robust.