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Sample records for high concentrations due

  1. An fMRI study on variation of visuospatial cognitive performance of young male due to highly concentrated oxygen administration

    Science.gov (United States)

    Chung, Soon Cheol; Kim, Ik Hyeon; Tack, Gye Rae; Sohn, Jin Hun

    2004-04-01

    This study investigated the effects of 30% oxygen administration on the visuospatial cognitive performance using fMRI. Eight college students (right-handed, average age 23.5) were selected as subjects for this study. Oxygen supply equipment which gives 21% and 30% oxygen at a constant rate of 8L/min was developed for this study. To measure the performance of visuospatial cognition, two questionnaires with similar difficulty containing 20 questions each were also developed. Experiment was designed as two runs: run for visuospatial cognition test with normal air (21% of oxygen) and run for visuospatial cognition test with highly concentrated air (30% of oxygen). Run consists of 4 blocks and each block has 8 control problems and 5 visuospatial problems. Functional brain images were taken from 3T MRI using single-shot EPI method. Activities of neural network due to performing visuospatial cognition test were identified using subtraction procedure, and activation areas while performing visuospatial cognition test were extracted using double subtraction procedure. Activities were observed at occipital lobe, parietal lobe, and frontal lobe when performing visuospatial cognition test following both 21% and 30% oxygen administration. But in case of only 30% oxygen administration there were more activities at left precuneus, left cuneus, right postcentral gyrus, bilateral middle frontal gyri, right inferior frontal gyrus, left superior frontal gyrus, bilateral uvula, bilateral pyramis, and nodule compared with 21% oxygen administration. From results of visuospatial cognition test, accuracy rate increased in case of 30% oxygen administration. Thus it could be concluded that highly concentrated oxygen administration has positive effects on the visuospatial cognitive performance.

  2. Record high peaks in PCB concentrations in the Arctic atmosphere due to long-range transport of biomass burning emissions

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    S. Eckhardt

    2007-05-01

    Full Text Available Soils and forests in the boreal region of the northern hemisphere are recognised as having a large capacity for storing air-borne Persistent Organic Pollutants (POPs, such as the polychlorinated biphenyls (PCBs. Following reductions of primary emissions of various legacy POPs, there is an increasing interest and debate about the relative importance of secondary re-emissions on the atmospheric levels of POPs. In spring of 2006, biomass burning emissions from agricultural fires in Eastern Europe were transported to the Zeppelin station on Svalbard, where record-high levels of many air pollutants were recorded (Stohl et al., 2007. Here we report on the extremely high concentrations of PCBs that were also measured during this period. 21 out of 32 PCB congeners were enhanced by more than two standard deviations above the long-term mean concentrations. In July 2004, about 5.8 million hectare of boreal forest burned in North America, emitting a pollution plume which reached the Zeppelin station after a travel time of 3–4 weeks (Stohl et al., 2006. Again, 12 PCB congeners were elevated above the long-term mean by more than two standard deviations, with the less chlorinated congeners being most strongly affected. We propose that these abnormally high concentrations were caused by biomass burning emissions. Based on enhancement ratios with carbon monoxide and known emissions factors for this species, we estimate that 130 and 66 μg PCBs were released per kilogram dry matter burned, respectively. To our knowledge, this is the first study relating atmospheric PCB enhancements with biomass burning. The strong effects on observed concentrations far away from the sources, suggest that biomass burning is an important source of PCBs for the atmosphere.

  3. Theoretical basis for convective invigoration due to increased aerosol concentration

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    Z. J. Lebo

    2011-06-01

    Full Text Available The potential effects of increased aerosol loading on the development of deep convective clouds and resulting precipitation amounts are studied by employing the Weather Research and Forecasting (WRF model as a detailed high-resolution cloud resolving model (CRM with both detailed bulk and bin microphysics schemes. Both models include a physically-based activation scheme that incorporates a size-resolved aerosol population. We demonstrate that the aerosol-induced effect is controlled by the balance between latent heating and the increase in condensed water aloft, each having opposing effects on buoyancy. It is also shown that under polluted conditions, increases in the CCN number concentration reduce the cumulative precipitation due to the competition between the sedimentation and evaporation/sublimation timescales. The effect of an increase in the IN number concentration on the dynamics of deep convective clouds is small and the resulting decrease in domain-averaged cumulative precipitation is shown not to be statistically significant, but may act to suppress precipitation. It is also shown that even in the presence of a decrease in the domain-averaged cumulative precipitation, an increase in the precipitation variance, or in other words, andincrease in rainfall intensity, may be expected in more polluted environments, especially in moist environments.

    A significant difference exists between the predictions based on the bin and bulk microphysics schemes of precipitation and the influence of aerosol perturbations on updraft velocity within the convective core. The bulk microphysics scheme shows little change in the latent heating rates due to an increase in the CCN number concentration, while the bin microphysics scheme demonstrates significant increases in the latent heating aloft with increasing CCN number concentration. This suggests that even a detailed two-bulk microphysics scheme, coupled to a detailed activation scheme, may not be

  4. Theoretical basis for convective invigoration due to increased aerosol concentration

    Directory of Open Access Journals (Sweden)

    Z. J. Lebo

    2011-01-01

    Full Text Available The potential effects of increased aerosol loading on the development of deep convective clouds and resulting precipitation amounts are studied by employing the Weather Research and Forecasting (WRF model as a detailed high-resolution cloud resolving model (CRM with both detailed bulk and bin microphysics schemes. The bulk microphysics scheme incorporates a physically based parameterization of cloud droplet activation as well as homogeneous and heterogeneous freezing in order to explicitly resolve the possible aerosol-induced effects on the cloud microphysics. These parameterizations allow one to segregate the effects of an increase in the aerosol number concentration into enhanced cloud condensation nuclei (CCN and/or ice nuclei (IN concentrations using bulk microphysics. The bin microphysics scheme, with its explicit calculations of cloud particle collisions, is shown to better predict cumulative precipitation. Increases in the CCN number concentration may not have a monotonic influence on the cumulative precipitation resulting from deep convective clouds. We demonstrate that the aerosol-induced effect is controlled by the balance between latent heating and the increase in condensed water aloft, each having opposing effects on buoyancy. It is also shown that under polluted conditions and in relatively dry environments, increases in the CCN number concentration reduce the cumulative precipitation due to the competition between the sedimentation and evaporation/sublimation timescales. The effect of an increase in the IN number concentration on the dynamics of deep convective clouds is small, but may act to suppress precipitation.

    A comparison of the predictions using the bin and bulk microphysics schemes demonstrate a significant difference between the predicted precipitation and the influence of aerosol perturbations on updraft velocity within the convective core. The bulk microphysics scheme is shown to be unable to capture the

  5. Flux concentrations on solar dynamic components due to mispointing

    Science.gov (United States)

    Rylicki, Daniel S.

    1992-01-01

    Mispointing of the solar dynamic (SD) concentrator designed for use on Space Station Freedom (SSF) causes the optical axis of the concentrator to be nonparallel to the incoming rays from the Sun. This causes solar flux not to be focused into the aperture hole of the receiver and may position the flux on other SSF components. A Rocketdyne analysis has determined the thermal impact of off-axis radiation due to mispointing on elements of the SD module and photovoltaic (PV) arrays. The conclusion was that flux distributions on some of the radiator components, the two-axis gimbal rings, the truss, and the PV arrays could present problems. The OFFSET computer code was used at Lewis Research Center to further investigate these flux distributions incident on components. The Lewis study included distributions for a greater range of mispoint angles than the Rocketdyne study.

  6. Optical loss due to diffraction by concentrator Fresnel lenses

    Energy Technology Data Exchange (ETDEWEB)

    Hornung, Thorsten, E-mail: thorsten.hornung@ise.fraunhofer.de; Nitz, Peter, E-mail: thorsten.hornung@ise.fraunhofer.de [Fraunhofer Institute for Solar Energy Systems ISE, Heidenhofstr. 2, 79110 Freiburg (Germany)

    2014-09-26

    Fresnel lenses are widely used in concentrating photovoltaic (CPV) systems as a primary optical element. They focus sunlight on small solar cells or on the entrance apertures of secondary optical elements. A Fresnel lens consists of several prism rings and diffraction by these prism rings is unavoidable. Some of the light that would reach a designated target area according to geometric optics will miss it due to diffraction. This diffraction loss may be of relevant magnitude for CPV applications. The results of published analytical calculations are evaluated, discussed, and compared to computer simulations and measurements.

  7. [Changes in platelet concentrates from dogs due to storage. II. Biochemical changes in concentrate plasma].

    Science.gov (United States)

    Klein, A; Adamik, A; Mischke, R

    1999-08-01

    Platelet concentrate (PC) obtained from dogs with an automatic cell separator was stored in C4-cell separation sets with low gasdiffusionable Polyvinylchlorid (PVC) storage containers or in C4L-sets developed for storage with high gasdiffusionable Polyolefin(PO) containers, respectively. PC were stored for 10 days under permanent agitation at 22 degrees C (C4/22 degrees C, n = 10; C4L/22 degrees C, n = 11) or at 4 degrees C (C4L/4 degrees C, n = 6), respectively. Measurements were carried out directly after production of the PC, after 6 hours and then daily during the 10-day storage period. In the second part of this paper the results of pH, the concentration of bicarbonate, glucose, lactate and potassium ions as well as the activity of lactate dehydrogenase (LDH) are presented. The varying duration and intensity of the energy metabolism of the platelets and different part of glycolysis became obvious by the consumption of glucose and production of lactate, which differed significantly between the different storage conditions. Resulting from this, the mean pH decreased under the limit prescribed for human PC (pH = 6.3) already after a storage period of 3 days due to the slight capacity of gas diffusion in PVC-containers (C4/22 degrees C). In the PO-containers the pH fell below this limit at 22 degrees C (C4L/22 degrees C) after a storage period of 5 days and at 4 degrees C (C4L/4 degrees C) after 10 days. The latter reflects the high gas diffusion capacity of the PO-containers and the decreased metabolism activity at 4 degrees C. The increase of activity of LDH and of the concentration of potassium ions, which are localized in the cytosol of platelets, depended also on the different storage conditions and, thereby, reflected the different rapidity of increasing membrane permeability or the destruction of the cell membrane, respectively. The results of this study nearly are in agreement with the changes of platelet function shown in part I. Biochemical changes occur

  8. Theoretical Basis for Convective Invigoration due to Increased Aerosol Concentration

    Science.gov (United States)

    Lebo, Z. J.; Chen, Y.; Seinfeld, J.

    2010-12-01

    Recent reports using a one-dimensional parcel model suggest that increases in aerosol number concentration may invigorate deep convection by mitigating the autoconversion process until air parcels reach the freezing level. This would lead to an increase in ice water aloft and the potential for enhanced upward heat transport due to phase changes, hence leading to invigorated convection. Other studies have proposed that an increase in aerosol loading may act to increase cloud top height, increasing the liquid water content, which ultimately increases the cumulative precipitation. Here we study the effect of aerosol perturbations on deep convection by employing the Weather Research and Forecasting model as a three-dimensional CRM with a two-moment, six-class bulk microphysics scheme. These results are corroborated using a newly developed bin microphysics scheme. The bulk microphysics scheme is augmented with a state-of-the-art activation scheme based on Köhler Theory and Population Splitting to analyze the effect of CCN perturbations on cloud development. Moreover, we include a physically-based parameterization for homogeneous and heterogeneous freezing to determine the effects of changes in IN number concentration on deep convective cloud development. We perform idealized simulations of deep convection over a wide range of CCN concentrations (i.e., 102 to 103 cm-3), which encompasses clean maritime conditions to polluted continental conditions, respectively. The detailed model calculations reveal that the CCN effect on precipitation in deep convective clouds depends strongly on the ambient water vapor mixing ratio profile. Our simulations suggest that under relatively dry conditions, an increase in aerosol number concentration leads to a decrease in precipitation (-4.2%), while under moist conditions, an increase in aerosol number concentration leads to an increase in precipitation (8.1%). However, when the water vapor in the mid- to upper-troposphere is depleted

  9. STRESS CONCENTRATION DUE TO A SPHERICAL VOID UNDER HERTZIAN CONTACT

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    Stelian ALACI,

    2010-06-01

    Full Text Available The present paper presents the method of estimating the stress concentrator effect of a spherical void from an elastic half-space. An essential part consists in estimation of FEM error by finding the contact pressure from half-plane using an analytical method. Next, the stress concentrator effect of the same void, except for placed into elastic space, is found.

  10. Edge Vortex Flow Due to Inhomogeneous Ion Concentration

    Science.gov (United States)

    Sugioka, Hideyuki

    2017-04-01

    The ion distribution of an open parallel electrode system is not known even though it is often used to measure the electrical characteristics of an electrolyte. Thus, for an open electrode system, we perform a non-steady direct multiphysics simulation based on the coupled Poisson-Nernst-Planck and Stokes equations and find that inhomogeneous ion concentrations at edges cause vortex flows and suppress the anomalous increase in the ion concentration near the electrodes. A surprising aspect of our findings is that the large vortex flows at the edges approximately maintain the ion-conserving condition, and thus the ion distribution of an open electrode system can be approximated by the solution of a closed electrode system that considers the ion-conserving condition rather than the Gouy-Chapman solution, which neglects the ion-conserving condition. We believe that our findings make a significant contribution to the understanding of surface science.

  11. High-efficiency solar concentrator

    Science.gov (United States)

    Lansing, F. L.; Dorman, J.

    1980-01-01

    A new type of solar concentrator is presented using liquid lenses and simple translational tracking mechanism. The concentrator achieves a 100:1 nominal concentration ratio and is compared in performance with a flat-plate collector having two sheets of glazing and non-selective coating. The results of the thermal analysis show that higher temperatures can be obtained with the concentrator than is possible with the non-concentrator flat-plate type. Furthermore, the thermal efficiency far exceeds that of the comparative flat-plate type for all operating conditions.

  12. Insights into Indoor/Outdoor PM Concentration Ratios due to Dust Storms in an Arid Region

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    Helena Krasnov

    2015-06-01

    Full Text Available Dust storms have impacts on both human and physical environments, associated with an increase in atmospheric particulate matter (PM concentrations. Most studies on exposure to PM have focused on the outdoor air, while information on indoor pollution, is still lacking. The aim of this study was to examine the impact of desert dust events on PM concentrations in indoor environments. A total of over 200 real time measurements of PM were conducted in houses in the Negev Desert during dust storms. Indoor and outdoor PM concentrations were characterized, as well as the relationships between the two datasets. The findings indicated that atmospheric PM10 concentrations can increase from 20–120 μg·m−3 on non-dust days to more than 1500 μg·m−3 during dust events. Indoor concentrations can reach as high as 1000 μg·m−3. The calculated indoor/outdoor (I/O PM ratio ranged from 0.79 for low-level storms to 0.58 during stronger events. Indoor PM concentrations were found to be dependent on the dust storm intensity (low, medium, high and duration with a time lag. The information obtained in this study is critical for assessment of policy interventions to reduce exposure risk and health effects due dust storms.

  13. Design and development of a high-concentration photovoltaic concentrator

    Energy Technology Data Exchange (ETDEWEB)

    Hodge, R C

    1982-04-01

    The design and development of a high concentration photovoltaic concentrator module is discussed. The design concept described herein incorporates a curved groove domed Fresnel lens, a high concentration etched multiple vertical junction (EMVJ) solar cell and a passively cooled direct-bonded copper cell mount all packaged in a plastic module. Two seven inch diameter 1200x domed Fresnel lenses were fabricated using single point diamond turning technology. Testing at both GE and Sandia confirmed optical transmission efficiencies of over 83%. Samples of the latest available EMVJ cells were mounted and installed, with a domed Fresnel lens, into a prototype module. Subsequent testing demonstrated net lens-cell efficiencies of 10 to 13%. As a result of this program, salient conclusions have been formulated as to this technology.

  14. A modeling study of effective radiative forcing and climate response due to increased methane concentration

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    Bing Xie

    2016-12-01

    Full Text Available An atmospheric general circulation model BCC_AGCM2.0 and observation data from ARIS were used to calculate the effective radiative forcing (ERF due to increased methane concentration since pre-industrial times and its impacts on climate. The ERF of methane from 1750 to 2011 was 0.46 W m−2 by taking it as a well-mixed greenhouse gas, and the inhomogeneity of methane increased its ERF by about 0.02 W m−2. The change of methane concentration since pre-industrial led to an increase of 0.31 °C in global mean surface air temperature and 0.02 mm d−1 in global mean precipitation. The warming was prominent over the middle and high latitudes of the Northern Hemisphere (with a maximum increase exceeding 1.4 °C. The precipitation notably increased (maximum increase of 1.8 mm d−1 over the ocean between 10°N and 20°N and significantly decreased (maximum decrease >–0.6 mm d−1 between 10°S and 10°N. These changes caused a northward movement of precipitation cell in the Intertropical Convergence Zone (ITCZ. Cloud cover significantly increased (by approximately 4% in the high latitudes in both hemispheres, and sharply decreased (by approximately 3% in tropical areas.

  15. Producing a highly concentrated coal suspension

    Energy Technology Data Exchange (ETDEWEB)

    Mokudzu, K.; Atsudzima, T.; Kiyedzuka, Y.

    1983-06-03

    Coal from wet and dry grinding is loaded into a mixer with a mixer arm with the acquisition of a highly concentrated suspension. Foamers (for instance, alkylbenzolsulfonate) and foam stabilizers (for instance diethanolamide of lauric acid) are added in a ratio of 10 to (2 to 5). The high fluidity of the suspension is maintained by injecting air into the suspension and an 80 percent concentration of the suspension is achieved.

  16. Cellulase Inhibition by High Concentrations of Monosaccharides

    DEFF Research Database (Denmark)

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

    2014-01-01

    that low free water availability contributes to cellulase inhibition. Of the hydrolytic enzymes involved, those acting on the cellulose substrate, that is, exo- and endoglucanases, were the most inhibited. The β -glucosidases were shown to be less sensitive to high monosaccharide concentrations except...

  17. High-dimensional entanglement concentration of twisted photon pairs High-dimensional entanglement concentration

    Science.gov (United States)

    Chen, L. X.; Wu, Q. P.

    2012-10-01

    Recently, Dada et al. reported on the experimental entanglement concentration and violation of generalized Bell inequalities with orbital angular momentum (OAM) [Nat. Phys. 7, 677 (2011)]. Here we demonstrate that the high-dimensional entanglement concentration can be performed in arbitrary OAM subspaces with selectivity. Instead of violating the generalized Bell inequalities, the working principle of present entanglement concentration is visualized by the biphoton OAM Klyshko picture, and its good performance is confirmed and quantified through the experimental Shannon dimensionalities after concentration.

  18. 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...

  19. Evaluation of Activity Concentration Values and Doses due to the Transport of Low Level Radioactive Material

    Energy Technology Data Exchange (ETDEWEB)

    Rawl, Richard R [ORNL; Scofield, Patricia A [ORNL; Leggett, Richard Wayne [ORNL; Eckerman, Keith F [ORNL

    2010-04-01

    The International Atomic Energy Agency (IAEA) initiated an international Coordinated Research Project (CRP) to evaluate the safety of transport of naturally occurring radioactive material (NORM). This report presents the United States contribution to that IAEA research program. The focus of this report is on the analysis of the potential doses resulting from the transport of low level radioactive material. Specific areas of research included: (1) an examination of the technical approach used in the derivation of exempt activity concentration values and a comparison of the doses associated with the transport of materials included or not included in the provisions of Paragraph 107(e) of the IAEA Safety Standards, Regulations for the Safe Transport of Radioactive Material, Safety Requirements No. TS-R-1; (2) determination of the doses resulting from different treatment of progeny for exempt values versus the A{sub 1}/A{sub 2} values; and (3) evaluation of the dose justifications for the provisions applicable to exempt materials and low specific activity materials (LSA-I). It was found that the 'previous or intended use' (PIU) provision in Paragraph 107(e) is not risk informed since doses to the most highly exposed persons (e.g., truck drivers) are comparable regardless of intended use of the transported material. The PIU clause can also have important economic implications for co-mined ores and products that are not intended for the fuel cycle but that have uranium extracted as part of their industrial processing. In examination of the footnotes in Table 2 of TS-R-1, which identifies the progeny included in the exempt or A1/A2 values, there is no explanation of how the progeny were selected. It is recommended that the progeny for both the exemption and A{sub 1}/A{sub 2} values should be similar regardless of application, and that the same physical information should be used in deriving the limits. Based on the evaluation of doses due to the transport of low

  20. Projecting future summer mortality due to ambient ozone concentration and temperature changes

    Science.gov (United States)

    Lee, Jae Young; Lee, Soo Hyun; Hong, Sung-Chul; Kim, Ho

    2017-05-01

    Climate change is known to affect the human health both directly by increased heat stress and indirectly by altering environments, particularly by altering the rate of ambient ozone formation in the atmosphere. Thus, the risks of climate change may be underestimated if the effects of both future temperature and ambient ozone concentrations are not considered. This study presents a projection of future summer non-accidental mortality in seven major cities of South Korea during the 2020s (2016-2025) and 2050s (2046-2055) considering changes in temperature and ozone concentration, which were predicted by using the HadGEM3-RA model and Integrated Climate and Air Quality Modeling System, respectively. Four Representative Concentration Pathway (RCP) scenarios (RCP 2.6, 4.5, 6.0, and 8.5) were considered. The result shows that non-accidental summer mortality will increase by 0.5%, 0.0%, 0.4%, and 0.4% in the 2020s, 1.9%, 1.5%, 1.2%, and 4.4% in the 2050s due to temperature change compared to the baseline mortality during 2001-2010, under RCP 2.6, 4.5, 6.0, and 8.5, respectively, whereas the mortality will increase by 0.0%, 0.5%, 0.0%, and 0.5% in the 2020s, and 0.2%, 0.2%, 0.4%, and 0.6% in the 2050s due to ozone concentration change. The projection result shows that the future summer morality in South Korea is increased due to changes in both temperature and ozone, and the magnitude of ozone-related increase is much smaller than that of temperature-related increase, especially in the 2050s.

  1. Radionuclide concentration in cabbage samples due to gamma radiation in Samsun, Turkey

    Science.gov (United States)

    Altıkulaç, Aydan; Gümüş, Hasan

    2016-11-01

    Establishing of radioactivity planes in foodstuff has emphasis because it allows the evaluation of population exposure to radiation by take nourishment. In this paper, the activity concentrations of 226Ra, 232Th, 40K and 137Cs were determined in cabbage samples collected from Samsun city of Turkey using a gamma ray spectrometry method with a HPGe detector. The mean concentration value of 226Ra, 232Th, 40K and 137Cs in cabbage samples were 1.11±0.03 Bqkg-1, 1.44±0.04 Bqkg-1, 743.75±21.21 Bqkg-1 and 0.18±0.003 Bqkg-1, respectively. The calculated total annual effective dose received from 226Ra, 232Th, 40K and 137Cs due to cabbage samples by population of Samsun province was quite lower than the World average value as suggested by UNSCEAR.

  2. Large concentration changes due to thermal diffusion effects in gas flow microsystems with temperature gradients

    DEFF Research Database (Denmark)

    Quaade, Ulrich; Johannessen, Tue; Jensen, Søren;

    Thermal diffusion, or Sorét diffusion, is shown to cause significant concentration changes and transients in gas flow microsystems with temperature gradients. In a silicon microsystem, a temperature gradient of about 100 oC/mm is measured to produce concentration transients of up to 13.......7 % in an argon/helium mixture, when the flow is abruptly changed from a high value to a low value. Finite element simulations of the thermal diffusion in a geometry similar to the experimental setup reproduce the measurements....

  3. 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.

  4. Biodegradation studies of oil sludge containing high hydrocarbons concentration

    Energy Technology Data Exchange (ETDEWEB)

    Olguin-Lora, P.; Munoz-Colunga, A.; Castorena-Cortes, G.; Roldan-Carrillo, T.; Quej Ake, L.; Reyes-Avila, J.; Zapata-Penasco, I.; Marin-Cruz, J.

    2009-07-01

    Oil industry has a significant impact on environment due to the emission of, dust, gases, waste water and solids generated during oil production all the way to basic petrochemical product manufacturing stages. the aim of this work was to evaluate the biodegradation of sludge containing high hydrocarbon concentration originated by a petroleum facility. A sludge sampling was done at the oil residuals pool (ORP) on a gas processing center. (Author)

  5. Vacancies driven magnetic ordering in ZnO nanoparticles due to low concentrated Co ions

    Science.gov (United States)

    Verma, Kuldeep Chand; Bhatia, Ravi; Kumar, Sanjeev; Kotnala, R. K.

    2016-07-01

    The lattice defects due to oxygen vacancies in ZnO nanoparticles with low doping of Co ions are investigated. The low concentrated Co ions in ZnO are responsible to the free charge carriers and oxygen vacancies to induce long-range ferromagnetic ordering. We have synthesized Zn1-x Co x O [x = 0.002, 0.004, 0.006 and 0.008] nanoparticles by a sol-gel process. X-ray fluorescence analysis detects the chemical composition of Zn, Co and O atoms. Rietveld refinement of x-ray diffraction pattern could confirm the wurtzite ZnO structure and the lattice constants with Co doping. The nanoparticles dimensions as well lattice spacing of ZnO are enhanced with Co substitution. Fourier transform infrared vibrational modes involve some organic groups to induce lattice defects and the ionic coordination among Zn, Co and O atoms. The room temperature Raman active mode E2 indicates frequency shifting with Co to induce stress in the wurtzite lattice. Photoluminescence spectra have a strong near-band-edge emission due to band gap energy and defects related to oxygen vacancies. X-ray photoelectron spectra confirm that the low dopant Co ions in ZnO lattice occupied Zn atoms by introducing oxygen vacancies and the valance states Zn2+, Co2,3+. The zero-field and field cooling magnetic measurement at 500 Oe in Co:ZnO samples indicate long-range ferromagnetism that is enhanced at 10 K due to antiferromagnetic-ferromagnetic ordering. The lattice defects/vacancies due to oxygen act as the medium of magnetic interactions which is explained by the bound magnetic polaron model.

  6. Displacements and stresses in composite multi-layered media due to varying temperature and concentrated load

    Institute of Scientific and Technical Information of China (English)

    M. K. Ghosh; M. Kanoria

    2007-01-01

    This paper deals with the determination of the thermo-elastic displacements and stresses in a multi-layered body set up in different layers of different thickness having different elastic properties due to the application of heat and a concentrated load in the uppermost surface of the medium. Each layer is assumed to be made of homogeneous and isotropic elastic material. The relevant displacement components for each layer are taken to be axisymmetric about a line, which is perpendicular to the plane surfaces of all layers. The stress function for each layer, therefore, satisfies a single equation in absence of any body forces. The equation is then solved by integral transform technique. Analytical expressions for thermo-elastic displacements and stresses in the underlying mass and the corresponding numerical codes are constructed for any number of layers. However, the numerical comparison is made for three and four layers.

  7. Less-studied TCE: are their environmental concentrations increasing due to their use in new technologies?

    Science.gov (United States)

    Filella, M; Rodríguez-Murillo, J C

    2017-09-01

    The possible environmental impact of the recent increase in use of a group of technology-critical elements (Nb, Ta, Ga, In, Ge and Te) is analysed by reviewing published concentration profiles in environmental archives (ice cores, ombrotrophic peat bogs, freshwater sediments and moss surveys) and evaluating temporal trends in surface waters. No increase has so far been recorded. The low potential direct emissions of these elements, resulting from their absolute low production levels, make it unlikely that the increasing use of these elements in modern technology has any noticeable effect on their environmental concentrations on a global scale. This holds particularly true for those of these elements that are probably emitted in relatively high amounts from other human activities (i.e., coal combustion and non-ferrous smelting), such as In, the most studied element of the group. Copyright © 2017 Elsevier Ltd. All rights reserved.

  8. Hypernatremic Dehydration Due to Concentrated Infant Formula: Report of Two Cases

    Directory of Open Access Journals (Sweden)

    Cheung Leung

    2009-04-01

    Full Text Available Hypernatremic dehydration is a rare but serious clinical condition in newborns and small infants. It is usually caused by diarrhea, improperly prepared infant formula, decreased fluid intake, or exclusive breastfeeding. Symptoms are usually masked until neurological symptoms occur. We report two infants who presented with fever and hypernatremic dehydration caused by concentrating infant formula to alleviate symptoms of constipation, and careless formula preparation due to confusion over spoon sizes, respectively. In the first case, status epilepticus occurred during early treatment, despite close serum sodium monitoring, though the infant was asymptomatic and thriving 4 years after discharge, with no identified neurodevelopmental deficits. The course of treatment was smooth in the second case, and no neurological complications developed. The practice of concentrating infant formula to relieve symptoms of constipation, although temporarily effective, is hazardous to newborns or young infants and can cause hypernatremic dehydration. Spoon sizes supplied with commercial infant formulas (30 mL/spoonful or 60 mL/spoonful should be unified to avoid mistakes during preparation, especially by inexperienced and teenage mothers.

  9. Physical chemistry of highly concentrated emulsions.

    Science.gov (United States)

    Foudazi, Reza; Qavi, Sahar; Masalova, Irina; Malkin, Alexander Ya

    2015-06-01

    This review explores the physics underlying the rheology of highly concentrated emulsions (HCEs) to determine the relationship between elasticity and HCE stability, and to consider whether it is possible to describe all physicochemical properties of HCEs on the basis of a unique physical approach. We define HCEs as emulsions with a volume fraction above the maximum closest packing fraction of monodisperse spheres, φm=0.74, even if droplets are not of polyhedron shape. The solid-like rheological behavior of HCEs is characterized by yield stress and elasticity, properties which depend on droplet polydispersity and which are affected by caging at volume fractions about the jamming concentration, φj. A bimodal size distribution in HCEs diminishes caging and facilitates droplet movement, resulting in HCEs with negligible yield stress and no plateau in storage modulus. Thermodynamic forces automatically move HCEs toward the lowest free energy state, but since interdroplet forces create local minimums - points beyond which free energy temporarily increases before it reaches the global minimum of the system - the free energy of HCEs will settle at a local minimum unless additional energy is added. Several attempts have been undertaken to predict the elasticity of HCEs. In many cases, the elastic modulus of HCEs is higher than the one predicted from classical models, which only take into account spatial repulsion (or simply interfacial energy). Improved models based on free energy calculation should be developed to consider the disjoining pressure and interfacial rheology in addition to spatial repulsion. The disjoining pressure and interfacial viscoelasticity, which result in the deviation of elasticity from the classical model, can be regarded as parameters for quantifying the stability of HCEs. Copyright © 2015 Elsevier B.V. All rights reserved.

  10. High-Temperature, High-Concentration Solar Thermoelectric Generators

    Science.gov (United States)

    Warren, Emily; Baranowski, Lauryn; Olsen, Michele; Ndione, Paul; Netter, Judy; Goodrich, Alan; Gray, Matthew; Parilla, Philip; Ginley, David; Toberer, Eric

    2014-03-01

    Solar thermoelectric generators (STEGs) powered with concentrated solar energy have potential for use as primary energy converters or as topping-cycles for more conventional concentrated solar power (CSP) technologies. Modeling based on current record modules from JPL suggests thermoelectric efficiencies of 18 % could be experimentally expected with a temperature gradient of 1000 - 100°C. Integrating these state-of-the-art TEGs with a concentrating solar receiver requires simultaneous optimization of optical, thermal, and thermoelectric systems. This talk will discuss the modeling, design, and experimental testing of STEG devices under concentrated sunlight. We have developed a model that combines thermal circuit modeling with optical ray tracing to design selective absorber coatings and cavities to minimize radiation losses from the system. We have fabricated selective absorber coatings and demonstrated that these selective absorber films can minimize blackbody radiation losses at high temperature and are stable after thermal cycling to 1000°C. On-sun testing of STEG devices and thermal simulators is ongoing and preliminary results will be discussed.

  11. Production of high concentrations of yeast

    Energy Technology Data Exchange (ETDEWEB)

    1981-11-10

    A microbe is aerobically cultured using O/sub 2/ or a gas rich in O/sub 2/. The grown cells are washed, concentrated and a portion of the cells used as a seed culture. Thus, Saccharomyces cerevisiae (bakers' yeast) was cultured in a jar fermentor by flow down system maintaining the dissolved O/sub 2/ at 2-5 mg/L; volume of the initial medium containing 30% glucose was 350 mL and the initial washed cell concentration was 50 g dry cells/L. After 12 hours of cultivation, the volume of the medium increased to 750 mL and the cell concentration rose to 102 g dry cells/L; the yield was 49% with respect to glucose. The cells were washed and the cultivation was repeated by use of the washed cells; cell concentration reached 105 g dry cells/L.

  12. 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.

  13. High estrogen concentrations in receiving river discharge from a concentrated livestock feedlot.

    Science.gov (United States)

    Chen, Te-San; Chen, Ting-Chien; Yeh, Kuei-Jyum C; Chao, How-Ran; Liaw, Ean-Tun; Hsieh, Chi-Ying; Chen, Kuan-Chung; Hsieh, Lien-Te; Yeh, Yi-Lung

    2010-07-15

    Environmental estrogenic chemicals interrupt endocrine systems and generate reproductive abnormalities in wildlife, especially natural and synthetic estrogenic steroid hormones such as 17beta-estradiol (E2), estrone (E1), estriol (E3), 17alpha-ethynylestradiol (EE2), and diethylstilbestrol (DES). Concentrated animal feedlot operations (CAFOs) are of particular concern since large amounts of naturally excreted estrogens are discharged into aquatic environments. This study investigated E2, E1, E3, EE2, and DES with high performance liquid chromatography/tandem mass (HPLC-MS/MS) analyses along Wulo Creek in southern Taiwan, near a concentrated livestock feedlot containing 1,030,000 broiler chickens, 934,000 laying hens, 85,000 pigs, and 1500 cattle. Sampling was performed from December 2008 to May 2009, in which 54 samples were collected. Experimental results indicate that concentrations of EE2 were lower than the limit of detection (LOD), and concentrations of DES were only detected twice. Concentrations ranged from 7.4 to 1267 ng/L for E1, from not detected (ND) to 313.6 ng/L for E2, and from ND to 210 ng/L for E3. E1 had the highest average mass fraction (72.2 + or - 3.6%), which was significantly higher than E3 (16.2 + or - 1.7%) and E2 (11.5 + or - 2.6%). Additionally, the mean E2 equivalent quotient (EEQ) ranged from 17.3 to 137.9 ng-E2/L. Despite having a markedly lower concentration than E1, E2 more significantly contributed (52.4 + or - 6.0%) EEQ than E1 (19.7 + or - 3.5%). Moreover, the concentrations of E2, E1, and E3 upstream were significantly higher than concentrations downstream, suggesting a high attenuation effect and fast degradation in the study water. Most concentrations in winter season were higher than those of spring season due to the low dilution effect and low microbial activity in the winter season. Based on the results of this study, we recommend further treatment of the wastewater discharge from the feedlot.

  14. Life at high salt concentrations, intracellular KCl concentrations, and acidic proteomes

    Directory of Open Access Journals (Sweden)

    Aharon eOren

    2013-11-01

    Full Text Available Extremely halophilic microorganisms that accumulate KCl for osmotic balance (the Halobacteriaceae, Salinibacter have a large excess of acidic amino acids in their proteins. This minireview explores the occurrence of acidic proteomes in halophiles of different physiology and phylogenetic affiliation. For fermentative bacteria of the order Halanaerobiales, known to accumulate KCl, an acidic proteome was predicted. However, this is not confirmed by genome analysis. The reported excess of acidic amino acids is due to a high content of Gln and Asn, which yield Glu and Asp upon acid hydrolysis. The closely related Halorhodospira halophila and Halorhodospira halochloris use different strategies to cope with high salt. The first has an acidic proteome and accumulates high KCl concentrations at high salt concentrations; the second does not accumulate KCl and lacks an acidic proteome. Acidic proteomes can be predicted from the genomes of some moderately halophilic aerobes that accumulate organic osmotic solutes (Halomonas elongata, Chromohalobacter salexigens and some marine bacteria. Based on the information on cultured species it is possible to understand the pI profiles predicted from metagenomic data from hypersaline environments.

  15. Increased chloride concentration in a lake due to deicing salt application.

    Science.gov (United States)

    Thunqvist, E L

    2003-01-01

    During winter, the Swedish National Road Administration uses on average 250,000 tonnes of sodium chloride for deicing purposes. Chloride concentration is a function of the amount of deicing salt applied during the winter season and the amount of water in which the salt can be diluted. An estimation of seasonal amount of deicing salt in relation to amount of run-off was used in order to identify the effects of deicing salt. The measured chloride concentration in a lake used as a municipal water supply was similar to the concentration estimated by a simple steady state method accounting for the catchment area. The simplified steady state method was a useful tool for estimating steady state concentrations on a regional level, including a non-influenced lake as a comparison.

  16. Physiological responses of sweet potato (Ipomoea batatas L. plants due to different copper concentrations

    Directory of Open Access Journals (Sweden)

    Cristina Copstein Cuchiara

    2015-12-01

    Full Text Available At low concentrations, Cu is considered as an essential micronutrient for plants and as a constituent and activator of several enzymes. However, when in excess, Cu can negatively affect plant growth and metabolism. Therefore, the aim of this study was to evaluate physiological responses of sweet potato plants at different Cu concentrations by measuring morphological parameters, antioxidant metabolism, stomatal characteristics, and mineral profile. For this purpose, sweet potato plants were grown hydroponically in complete nutrient solution for six days. Then, the plants were transferred to solutions containing different Cu concentrations, 0.041 (control, 0.082, and 0.164 mM, and maintained for nine days. The main effect of increased Cu concentration was observed in the roots. The sweet potato plants grown in 0.082 mM Cu solution showed increased activity of antioxidant enzymes and no changes in growth parameters. However, at a concentration of 0.164 mM, Cu was transported from the roots to the shoots. This concentration altered morpho-anatomical characteristics and activated the antioxidant system because of the stress generated by excess Cu. On the basis of the results, it can be concluded that the sweet potato plants were able to tolerate Cu toxicity until 0.082 mM.

  17. Effects of high nitrogen concentrations on the growth of submersed macrophytes at moderate phosphorus concentrations.

    Science.gov (United States)

    Yu, Qing; Wang, Hong-Zhu; Li, Yan; Shao, Jian-Chun; Liang, Xiao-Min; Jeppesen, Erik; Wang, Hai-Jun

    2015-10-15

    Eutrophication of lakes leading to loss of submersed macrophytes and higher turbidity is a worldwide phenomenon, attributed to excessive loading of phosphorus (P). However, recently, the role of nitrogen (N) for macrophyte recession has received increasing attention. Due to the close relationship between N and P loading, disentanglement of the specific effects of these two nutrients is often difficult, and some controversy still exists as to the effects of N. We studied the effects of N on submersed macrophytes represented by Vallisneria natans (Lour.) Hara in pots positioned at three depths (0.4 m, 0.8 m, and 1.2 m to form a gradient of underwater light conditions) in 10 large ponds having moderate concentrations of P (TP 0.03 ± 0.04 mg L(-1)) and five targeted concentrations of total nitrogen (TN) (0.5, 2, 10, 20, and 100 mg L(-1)), there were two ponds for each treatment. To study the potential shading effects of other primary producers, we also measured the biomass of phytoplankton (ChlaPhyt) and periphyton (ChlaPeri) expressed as chlorophyll a. We found that leaf length, leaf mass, and root length of macrophytes declined with increasing concentrations of TN and ammonium, while shoot number and root mass did not. All the measured growth indices of macrophytes declined significantly with ChlaPhyt, while none were significantly related to ChlaPeri. Neither ChlaPhyt nor ChlaPeri were, however, significantly negatively related to the various N concentrations. Our results indicate that shading by phytoplankton unrelated to the variation in N loading and perhaps toxic stress exerted by high nitrogen were responsible for the decline in macrophyte growth.

  18. Regional increase of mean chloride concentration in water due to the application of deicing salt.

    Science.gov (United States)

    Thunqvist, Eva-Lotta

    2004-06-05

    The Directive of the European Parliament and of the Council 2000/60/EC: Establishing a Framework for Community Action in the Field of Water Policy, states that it is necessary to consider human activities within a river basin in order to prevent and reduce the spreading of pollutants and to achieve good water status. This paper shows a simple method to estimate the environmental pressure from the deicing of roads as steady state chloride concentration in water. The data processed are presented using GIS. The result showed that the contribution of deicing salt is of importance for the chloride concentration on a regional scale. The increase in chloride concentration is also compared to the background concentration and other sources of chloride within the river basin. Road salt applied by the Swedish National Road Administration (SNRA) accounts for more than half of the total chloride load for the river basin investigated. The method presented may easily be generalised to a national scale for monitoring the environmental effects of deicing salt application.

  19. Quantification of the advected CO2 concentration due to upstream surface fluxes in aircraft vertical profiles

    Science.gov (United States)

    Font, A.; Morguí, J.-A.; Curcoll, R.; Rodó, X.

    2009-04-01

    A model framework which couples the Lagrangian Particle Dispersion Model FLEXPART (LPDM) with the new global surface flux inversion CarbonTracker from NOAA-ESRL (2007B release) is used to quantify the advected CO2 concentration from outbound surface fluxes to measured vertical profiles carried out during different seasons in 2006 at La Muela site in Spain (LMU; 41.60°N, 1.1°W). The Lagrangian Particle Dispersion Model FLEXPART (LPDM) calculates the influence of surface CO2 fluxes upwind of the study area, allowing us to identify those sources or sink areas that strongly modify the CO2 content of air masses that arrives at different altitudes of measured profiles. CarbonTracker is a new assimilation system that informs of global carbon fluxes at 1°x1° at 3 hours resolution. Coupling LPDM results with surface fluxes allows assessing the net CO2 contribution of identified areas to measured concentrations along the profiles above a reference or background concentration. Furthermore, it allows the quantification of the percentage of each component flux (biospheric, anthropogenic and oceanic) to each vertical layer. At LMU, biospheric fluxes account ~70% of total CO2 advection; fossil fuel ~25%; and ~5% is attributed to the oceanic ones. By far, late spring and summer profiles are largely influence by the biospheric component (~90%). Finally, the CO2 concentration above the background value of profiles measured on 22nd February, 13th October and 30th November 2006 are well explained by the advection of upstream surface fluxes. In other profiles examined, the variation of CO2 along the profile is partially explained by the advection of CO2 outbound fluxes.

  20. Marangoni instabilities in two-layer systems due to concentration dependent transfer properties

    Science.gov (United States)

    Trevelyan, P. M. J.; Pimienta, V.; Eckert, K.; de Wit, A.

    2008-11-01

    We consider a Hele-Shaw cell containing two immiscible liquids. A chemical species initially dissolved in an organic phase crosses the interface into the aqueous phase. In the aqueous phase this chemical reactant is involved in a reaction producing a surfactant which undergoes micellisation when the critical micelle concentration is reached. These micelles increase solubility which in turn increases the transfer rate and hence favours additional formation of micelles. To model such an autocatalytic increase of solubility, we consider here that the partition coefficient is a function of the surfactant concentration. Through the solutal Marangoni effect, this surfactant can induce tangential stresses leading to interfacial motion. The aim of our study is to theoretically examine the conditions for an instability in such a system. In particular, we seek to understand whether Marangoni effects can be observed because of a concentration dependent partition coefficient in a system that would be stable in the case of a constant partition coefficient according to the classical stability conditions of Sternling and Scriven (AIChE J., 5, p.514, 1959).

  1. Pan-Arctic enhancements of light absorbing aerosol concentrations due to North American boreal forest fires during summer 2004

    Science.gov (United States)

    Stohl, A.; Andrews, E.; Burkhart, J. F.; Forster, C.; Herber, A.; Hoch, S. W.; Kowal, D.; Lunder, C.; Mefford, T.; Ogren, J. A.; Sharma, S.; Spichtinger, N.; Stebel, K.; Stone, R.; StröM, J.; TøRseth, K.; Wehrli, C.; Yttri, K. E.

    2006-11-01

    During summer of 2004, about 2.7 million hectare of boreal forest burned in Alaska, the largest annual area burned on record, and another 3.1 million hectare burned in Canada. This study explores the impact of emissions from these fires on light absorbing aerosol concentration levels, aerosol optical depths (AOD), and albedo at the Arctic stations Barrow (Alaska), Alert (Canada), Summit (Greenland), and Zeppelin/Ny Ålesund on Spitsbergen (Norway). The Lagrangian particle dispersion model FLEXPART was run backward from these sites to identify periods that were influenced by forest fire pollution plumes. It is shown that the fires led to enhanced values of particle light absorption coefficients (σap) at all of these sites. Barrow, about 1000 km away from the fires, was affected by several fire pollution plumes, one leading to spectacularly high 3-hour mean σap values of up to 32 Mm-1, more than the highest values measured in Arctic Haze. AOD measurements for a wavelength of 500 nm saturated but were estimated at above 4-5 units, unprecedented in the station records. Fire plumes were transported through the atmospheric column over Summit continuously for 2 months, during which all measured AOD values were enhanced, with maxima up to 0.4-0.5 units. Equivalent black carbon concentrations at the surface at Summit were up to 600 ng m-3 during two major episodes, and Alert saw at least one event with enhanced σap values. FLEXPART results show that Zeppelin was located in a relatively unaffected part of the Arctic. Nevertheless, there was a 4-day period with daily mean σap > 0.3 Mm-1, the strongest episode of the summer half year, and enhanced AOD values. Elevated concentrations of the highly source-specific compound levoglucosan positively confirmed that biomass burning was the source of the aerosols at Zeppelin. In summary, this paper shows that boreal forest fires can lead to elevated concentrations of light absorbing aerosols throughout the entire Arctic. Enhanced

  2. Factors Impeding Enzymatic Wheat Gluten Hydrolysis at High Solid Concentrations

    NARCIS (Netherlands)

    Hardt, N.A.; Janssen, A.E.M.; Boom, R.M.; Goot, van der A.J.

    2014-01-01

    Enzymatic wheat gluten hydrolysis at high solid concentrations is advantageous from an environmental and economic point of view. However, increased wheat gluten concentrations result in a concentration effect with a decreased hydrolysis rate at constant enzyme-to-substrate ratios and a decreased

  3. Investigation of sulphur isotope variation due to different processes applied during uranium ore concentrate production.

    Science.gov (United States)

    Krajkó, Judit; Varga, Zsolt; Wallenius, Maria; Mayer, Klaus; Konings, Rudy

    The applicability and limitations of sulphur isotope ratio as a nuclear forensic signature have been studied. The typically applied leaching methods in uranium mining processes were simulated for five uranium ore samples and the n((34)S)/n((32)S) ratios were measured. The sulphur isotope ratio variation during uranium ore concentrate (UOC) production was also followed using two real-life sample sets obtained from industrial UOC production facilities. Once the major source of sulphur is revealed, its appropriate application for origin assessment can be established. Our results confirm the previous assumption that process reagents have a significant effect on the n((34)S)/n((32)S) ratio, thus the sulphur isotope ratio is in most cases a process-related signature.

  4. Preliminary Estimation of Radioactive Cesium Concentration due to Hypothetical Accident in East Sea

    Energy Technology Data Exchange (ETDEWEB)

    Min, Byung-Il; Kim, Sora; Park, Kihyun; Suh, Kyung-suk [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2015-10-15

    The sea has no large islands, bays or capes. Its water balance is mostly determined by the inflow (Korea Strait) and outflow (Tsugaru Strait and Soya Strait) through the straits connecting it to the neighboring seas and Pacific Ocean. All of the Korean nuclear power plants are located in the coastal area, 3 sites in the east coast and 1 site in the west coast. So the Korean nuclear power plants there may be possibility that such dangerous substances spread out of the East Sea. The East Sea is a fertile fishing ground for surrounding counties. The environmental radionuclides concentration estimation is important for fish and sea plants may be contaminated by those radioactive materials. In order to simplify the problem, the experiment has been considered the many simplifying assumptions. The bed sediments are uniform over all the model domain, using the monthly mean ocean current data set and ignored effect of the facilities for damage preventions.

  5. Refractive Secondary Solar Concentrator Demonstrated High-Temperature Operation

    Science.gov (United States)

    Wong, Wayne A.

    2002-01-01

    Space applications that utilize solar thermal energy--such as electric power conversion systems, thermal propulsion systems, and furnaces--require highly efficient solar concentration systems. The NASA Glenn Research Center is developing the refractive secondary concentrator, which uses refraction and total internal reflection to efficiently concentrate and direct solar energy. When used in combination with advanced lightweight primary concentrators, such as inflatable thin films, the refractive secondary concentrator enables very high system concentration ratios and very high temperatures. Last year, Glenn successfully demonstrated a secondary concentrator throughput efficiency of 87 percent, with a projected efficiency of 93 percent using an antireflective coating. Building on this achievement, Glenn recently successfully demonstrated high-temperature operation of the secondary concentrator when it was used to heat a rhenium receiver to 2330 F. The high-temperature demonstration of the concentrator was conducted in Glenn's 68-ft long Tank 6 thermal vacuum facility equipped with a solar simulator. The facility has a rigid panel primary concentrator that was used to concentrate the light from the solar simulator onto the refractive secondary concentrator. NASA Marshall Space Flight Center provided a rhenium cavity, part of a solar thermal propulsion engine, to serve as the high-temperature receiver. The prototype refractive secondary concentrator, measuring 3.5 in. in diameter and 11.2 in. long, is made of single-crystal sapphire. A water-cooled splash shield absorbs spillage light outside of the 3.5-in. concentrator aperture. Multilayer foil insulation composed of tungsten, molybdenum, and niobium is used to minimize heat loss from the hightemperature receiver. A liquid-cooled canister calorimeter is used to measure the heat loss through the multilayer foil insulation.

  6. [Elevated serum lithium concentration due to switch from parenteral nutrition alone to parenteral with enteral nutrition].

    Science.gov (United States)

    Goto, Hidekazu; Tomita, Takashi; Doki, Shotaro; Nakanishi, Rie; Kojima, Chikako; Yoneshima, Mihoko; Yoshida, Tadashi; Tanaka, Katsuya; Kohda, Yukinao

    2015-01-01

    We report a patient with elevated serum lithium concentration caused by switching from parenteral nutrition alone to parenteral with enteral nutrition. A 73-year-old female inpatient was treated with lithium carbonate 600 mg/d for manic episodes of bipolar disorder. Her serum lithium level was maintained at 0.57-0.79 mEq/L. She was administered total parenteral nutrition owing to difficulty in oral intake. Her diet contained 4.8-5.8 g/d of sodium chloride. After this, parenteral with enteral nutrition was initiated. The total sodium chloride intake decreased from 6.3 to 3.0-4.0 g/d following this change. On day 15 after initiation of parenteral with enteral nutrition, her serum lithium level increased to 1.17 mEq/L, which is closer to the upper therapeutic range limit. Therefore enteral nutrition was stopped immediately, and an electrolyte solution was administered instead of enteral nutrition. An antibiotic agent was also simultaneously administered because of infection. The total amount of sodium chloride administered was increased to 7.0 g/d during this treatment. Four days after treatment, the serum lithium level returned to 0.57 mEq/L. This case suggests that administration of appropriate sodium chloride nutrition is important during treatment with lithium carbonate, because disposition of lithium ion is paralleled to that of sodium.

  7. Exploring the uncertainty in attributing sediment contributions in fingerprinting studies due to uncertainty in determining element concentrations in source areas.

    Science.gov (United States)

    Gomez, Jose Alfonso; Owens, Phillip N.; Koiter, Alex J.; Lobb, David

    2016-04-01

    One of the major sources of uncertainty in attributing sediment sources in fingerprinting studies is the uncertainty in determining the concentrations of the elements used in the mixing model due to the variability of the concentrations of these elements in the source materials (e.g., Kraushaar et al., 2015). The uncertainty in determining the "true" concentration of a given element in each one of the source areas depends on several factors, among them the spatial variability of that element, the sampling procedure and sampling density. Researchers have limited control over these factors, and usually sampling density tends to be sparse, limited by time and the resources available. Monte Carlo analysis has been used regularly in fingerprinting studies to explore the probable solutions within the measured variability of the elements in the source areas, providing an appraisal of the probability of the different solutions (e.g., Collins et al., 2012). This problem can be considered analogous to the propagation of uncertainty in hydrologic models due to uncertainty in the determination of the values of the model parameters, and there are many examples of Monte Carlo analysis of this uncertainty (e.g., Freeze, 1980; Gómez et al., 2001). Some of these model analyses rely on the simulation of "virtual" situations that were calibrated from parameter values found in the literature, with the purpose of providing insight about the response of the model to different configurations of input parameters. This approach - evaluating the answer for a "virtual" problem whose solution could be known in advance - might be useful in evaluating the propagation of uncertainty in mixing models in sediment fingerprinting studies. In this communication, we present the preliminary results of an on-going study evaluating the effect of variability of element concentrations in source materials, sampling density, and the number of elements included in the mixing models. For this study a virtual

  8. Fabrication and tolerances of optics for high concentration photovoltaics

    OpenAIRE

    Benitez Gimenez, Pablo; Miñano Dominguez, Juan Carlos; Ahmadpanaih, Hamed; Mendes Lopes, Joao; Zamora Herranz, Pablo

    2014-01-01

    High Concentration Photovoltaics (HCPV) require an optical system with high efficiency, low cost and large tolerance. We describe the particularities of the HCPV applications, which constrain the optics design and the manufacturing techonologies.

  9. Effect of high soil copper concentration on mycorrhizal grapevines

    Science.gov (United States)

    Nogales, Amaia; Santos, Erika S.; Viegas, Wanda; Aran, Diego; Pereira, Sofia H.; Vidigal, Patricia; Lopes, Carlos M.; Abreu, M. Manuela

    2017-04-01

    dehydrogenase activity and the number of mycorrhizal infective propagules were evaluated in association with several plant physiological parameters (vegetative growth, NDVI‒Normalized Difference Vegetation Index and PRI‒Photochemical Reflectance Index, leaf nutrient content) and root mycorrhizal colonization percentage. Preliminary results indicate an overall decrease in soil microbial activity due to Cu addition, regardless of the presence or absence of the inoculated mycorrhizal fungus. High Cu concentrations in soil decreased plant shoot length, root fresh weight and NDVI and PRI values. However, differences between mycorrhizal treatments were detected on plant response to Cu stress. The usefulness of grapevine inoculation with AMF to enhance plant performance at high Cu levels in the soil is discussed.

  10. Pulsar high energy emission due to inverse Compton scattering

    Energy Technology Data Exchange (ETDEWEB)

    Lyutikov, Maxim

    2013-06-15

    We discuss growing evidence that pulsar high energy is emission is generated via Inverse Compton mechanism. We reproduce the broadband spectrum of Crab pulsar, from UV to very high energy gamma-rays - nearly ten decades in energy, within the framework of the cyclotron-self-Compton model. Emission is produced by two counter-streaming beams within the outer gaps, at distances above ∼ 20 NS radii. The outward moving beam produces UV-X-ray photons via Doppler-booster cyclotron emission, and GeV photons by Compton scattering the cyclotron photons produced by the inward going beam. The scattering occurs in the deep Klein-Nishina regime, whereby the IC component provides a direct measurement of particle distribution within the magnetosphere. The required plasma multiplicity is high, ∼10{sup 6} – 10{sup 7}, but is consistent with the average particle flux injected into the pulsar wind nebula.

  11. Extremely high Q -factor metamaterials due to anapole excitation

    Science.gov (United States)

    Basharin, Alexey A.; Chuguevsky, Vitaly; Volsky, Nikita; Kafesaki, Maria; Economou, Eleftherios N.

    2017-01-01

    We have designed and fabricated a metamaterial consisting of planar metamolecules which exhibit unusual, almost perfect anapole behavior in the sense that the electric dipole radiation is almost canceled by the toroidal dipole one, producing thus an extremely high Q -factor at the resonance frequency. Thus we have demonstrated theoretically and experimentally that metamaterials approaching ideal anapole behavior have very high Q -factor. The size of the system, at the millimeter range, and the parasitic magnetic quadrupole radiation are the factors limiting the size of the Q -factor. In spite of the very low radiation losses the estimated local fields at the metamolecules are extremely high, of the order of 104 higher than the external incoming field.

  12. Extremely High Q-factor metamaterials due to Anapole Excitation

    CERN Document Server

    Basharin, Alexey A; Volsky, Nikita; Kafesaki, Maria; Economou, Eleftherios N

    2016-01-01

    We demonstrate that ideal anapole metamaterials have infinite Q-factor. We have designed and fabricated a metamaterial consisting of planar metamolecules which exhibit anapole behavior in the sense that the electric dipole radiation is almost cancelled by the toroidal dipole one, producing thus an extremely high Q-factor at the resonance frequency. The size of the system, at the mm range, and the parasitic magnetic quadrupole radiation are the factors limiting the size of the Q-factor. In spite of the very low radiation losses the local fields at the metamolecules are extremely high, of the order of higher than the external incoming field.

  13. [Fatal electric arc accidents due to high voltage].

    Science.gov (United States)

    Strauch, Hansjürg; Wirth, Ingo

    2004-01-01

    The frequency of electric arc accidents has been successfully reduced owing to preventive measures taken by the professional association. However, the risk of accidents has continued to exist in private setting. Three fatal electric arc accidents caused by high voltage are reported with reference to the autopsy findings.

  14. Unwinding of a carbon nanoscroll due to high speed rotation

    Directory of Open Access Journals (Sweden)

    Hang Yin

    2015-10-01

    Full Text Available A carbon nanoscroll (CNS can be formed easily by rolling a graphene sheet around a carbon nanotube (CNT [Zhang and Li, 2010, APL, 97, 081909]. When the CNS is driven by the rotary CNT to rotate at a high speed, the attractive interaction within the CNS or between the CNS and CNT is crippled by the centrifugal force on the CNS. The unwinding of CNS is triggered when the kinetic energy increment approaches to the variation of interaction energy of the system during CNS formation. Numerical experiments also indicate that the unwinding of CNS happens earlier when the CNT has a higher rotational speed or the system is at a higher temperature.

  15. High Frequency QPOs due to Black Hole Spin

    Science.gov (United States)

    Kazanas, Demos; Fukumura, K.

    2009-01-01

    We present detailed computations of photon orbits emitted by flares at the innermost stable circular orbit (ISCO) of accretion disks around rotating black holes. We show that for sufficiently large spin parameter, i.e. a > 0.94 M, flare a sufficient number of photons arrive at an observer after multiple orbits around the black hole, to produce an "photon echo" of constant lag, i.e. independent of the relative phase between the black hole and the observer, of T approximates 14 M. This constant time delay, then, leads to a power spectrum with a QPO at a frequency nu approximates 1/14M, even for a totally random ensemble of such flares. Observation of such a QPO will provide incontrovertible evidence for the high spin of the black hole and a very accurate, independent, measurement of its mass.

  16. High Frequency QPOs due to Black Hole Spin

    Science.gov (United States)

    Kazanas, Demos; Fukumura, K.

    2009-01-01

    We present detailed computations of photon orbits emitted by flares at the innermost stable circular orbit (ISCO) of accretion disks around rotating black holes. We show that for sufficiently large spin parameter, i.e. a > 0.94 M, flare a sufficient number of photons arrive at an observer after multiple orbits around the black hole, to produce an "photon echo" of constant lag, i.e. independent of the relative phase between the black hole and the observer, of T approximates 14 M. This constant time delay, then, leads to a power spectrum with a QPO at a frequency nu approximates 1/14M, even for a totally random ensemble of such flares. Observation of such a QPO will provide incontrovertible evidence for the high spin of the black hole and a very accurate, independent, measurement of its mass.

  17. High Stokes shift perylene dyes for luminescent solar concentrators.

    Science.gov (United States)

    Sanguineti, Alessandro; Sassi, Mauro; Turrisi, Riccardo; Ruffo, Riccardo; Vaccaro, Gianfranco; Meinardi, Francesco; Beverina, Luca

    2013-02-25

    Highly efficient plastic based single layer Luminescent Solar Concentrators (LSCs) require the design of luminophores having complete spectral separation between absorption and emission spectra (large Stokes shift). We describe the design, synthesis and characterization of a new perylene dye possessing Stokes shift as high as 300 meV, fluorescent quantum yield in the LSC slab of 70% and high chemical and photochemical stability.

  18. Subsurface deuterium bubble formation in W due to low-energy high flux deuterium plasma exposure

    Science.gov (United States)

    Jia, Y. Z.; Liu, W.; Xu, B.; Qu, S. L.; Shi, L. Q.; Morgan, T. W.

    2017-03-01

    The deuterium (D) bubbles formed in W exposed to high flux D plasma were researched by scanning electron microscopy and transmission electron microscopy. After D plasma exposure at 500 K and 1000 K, a layer of nano-sized bubbles were homogenously distributed in W subsurface region. The D bubbles were homogenously nucleated due to the high D concentration, and the nucleation process is not related to the vacancy defects. At low temperature (500 K), D bubbles can grow by surface blistering, which caused different nano scale morphologies on different surfaces. At high temperature (1000 K), D bubbles mainly grow by vacancy clustering, which caused pinholes on the surface.

  19. Hair and toenail arsenic concentrations of residents living in areas with high environmental arsenic concentrations.

    OpenAIRE

    Hinwood, Andrea L; Sim, Malcolm R; Jolley, Damien; de Klerk, Nick; Bastone, Elisa B; Gerostamoulos, Jim; Drummer, Olaf H

    2003-01-01

    Surface soil and groundwater in Australia have been found to contain high concentrations of arsenic. The relative importance of long-term human exposure to these sources has not been established. Several studies have investigated long-term exposure to environmental arsenic concentrations using hair and toenails as the measure of exposure. Few have compared the difference in these measures of environmental sources of exposure. In this study we aimed to investigate risk factors for elevated hai...

  20. Applications of nonimaging optics for very high solar concentrations

    Energy Technology Data Exchange (ETDEWEB)

    O`Gallagher, J.; Winston, R.

    1997-12-31

    Using the principles and techniques of nonimaging optics, solar concentrations that approach the theoretical maximum can be achieved. This has applications in solar energy collection wherever concentration is desired. In this paper, we survey recent progress in attaining and using high and ultrahigh solar fluxes. We review a number of potential applications for highly concentrated solar energy and the current status of the associated technology. By making possible new and unique applications for intense solar flux, these techniques have opened a whole new frontier for research and development of potentially economic uses of solar energy.

  1. Design requirements for high-efficiency high concentration ratio space solar cells

    Science.gov (United States)

    Rauschenbach, H.; Patterson, R.

    1980-01-01

    A miniaturized Cassegrainian concentrator system concept was developed for low cost, multikilowatt space solar arrays. The system imposes some requirements on solar cells which are new and different from those imposed for conventional applications. The solar cells require a circular active area of approximately 4 mm in diameter. High reliability contacts are required on both front and back surfaces. The back area must be metallurgically bonded to a heat sink. The cell should be designed to achieve the highest practical efficiency at 100 AMO suns and at 80 C. The cell design must minimize losses due to nonuniform illumination intensity and nonnormal light incidence. The primary radiation concern is the omnidirectional proton environment.

  2. Electron beam treatment of exhaust gas with high NOx concentration

    Science.gov (United States)

    Licki, Janusz; Chmielewski, Andrzej G.; Pawelec, Andrzej; Zimek, Zbigniew; Witman, Sylwia

    2014-05-01

    Simulated exhaust gases with a high NOx concentration, ranging from 200 to 1700 ppmv, were irradiated by an electron beam from an accelerator. In the first part of this study, only exhaust gases were treated. Low NOx removal efficiencies were obtained for high NOx concentrations, even with high irradiation doses applied. In the second part of study, gaseous ammonia or/and vapor ethanol were added to the exhaust gas before its inlet to the plasma reactor. These additions significantly enhanced the NOx removal efficiency. The synergistic effect of high SO2 concentration on NOx removal was observed. The combination of electron beam treatment with the introduction of the above additions and with the performance of irradiation under optimal parameters ensured high NOx removal efficiency without the application of a solid-state catalyst.

  3. [Reasons of high concentration ammonium in Yellow River, China].

    Science.gov (United States)

    Zhang, Xue-qing; Xia, Xing-hui; Yang, Zhi-feng

    2007-07-01

    Ammonium nitrogen contamination is one of the major problems of the Yellow River in China. The speciation, concentration and sources of nitrogen compounds as well as the water environment conditions of the Yellow River had been analyzed to study the reasons for the fact that the ammonium nitrogen concentration was above the water quality standard. In addition, laboratory experiments had been carried out to investigate the effects of suspended sediment (SS) on nitrification rate. The results indicated that the presence of SS could accelerate the nitrification process, therefore, the effects of SS on nitrification rate was not the reason for the high level of ammonium nitrogen in the river. The excessive and continuous input of nitrogen contaminants to the river was the fundamental reason for the high concentration of ammonium nitrogen. Organic and ammonium nitrogen with high concentration inhibitted the nitrification processes. When the initial NH4+ -N concentrations were 10.1, 18.4 and 28.2 mg/L, nitrification efficiencies were 17.4%, 13.0% and 2.5%, respectively. When the initial organic nitrogen concentrations were 5.5 and 8.6 mg/L, the maximum concentrations of ammonium nitrogen produced by the oxidation of organic nitrogen would reach 0.47 and 1.69 mg/L and they would last for 2 days and 6 days, respectively. The oxygen-consuming organics and toxic substance existing in the river water could inhibit the activity of nitrifying bacteria, and thus lead to the accumulation of ammonium nitrogen. In addition, the high pH value of river water resulted in the high concentration of nonionic ammonium nitrogen which would reduce the activity of nitrifying bacteria and decrease the nitrification rates. Besides, low river runoff, low SS content and low activity of nitrifying bacteria resulted in the high level of ammonium nitrogen of the river in the low water season.

  4. Differences in Swallowing between High and Low Concentration Taste Stimuli

    Directory of Open Access Journals (Sweden)

    Ahmed Nagy

    2014-01-01

    Full Text Available Taste is a property that is thought to potentially modulate swallowing behavior. Whether such effects depend on taste, intensity remains unclear. This study explored differences in the amplitudes of tongue-palate pressures in swallowing as a function of taste stimulus concentration. Tongue-palate pressures were collected in 80 healthy women, in two age groups (under 40, over 60, stratified by genetic taste status (nontasters, supertasters. Liquids with different taste qualities (sweet, sour, salty, and bitter were presented in high and low concentrations. General labeled magnitude scale ratings captured perceived taste intensity and liking/disliking of the test liquids. Path analysis explored whether factors of taste, concentration, age group, and/or genetic taste status impacted: (1 perceived intensity; (2 palatability; and (3 swallowing pressures. Higher ratings of perceived intensity were found in supertasters and with higher concentrations, which were more liked/disliked than lower concentrations. Sweet stimuli were more palatable than sour, salty, or bitter stimuli. Higher concentrations elicited stronger tongue-palate pressures independently and in association with intensity ratings. The perceived intensity of a taste stimulus varies as a function of stimulus concentration, taste quality, participant age, and genetic taste status and influences swallowing pressure amplitudes. High-concentration salty and sour stimuli elicit the greatest tongue-palate pressures.

  5. High Black Carbon (BC) Concentrations along Indian National Highways

    Science.gov (United States)

    Kumar, S.; Singh, A. K.; Singh, R. P.

    2015-12-01

    Abstract:Black carbon (BC), the optically absorbing component of carbonaceous aerosol, has direct influence on radiation budget and global warming. Vehicular pollution is one of the main sources for poor air quality and also atmospheric pollution. The number of diesel vehicles has increased on the Indian National Highways during day and night; these vehicles are used for the transport of goods from one city to another city and also used for public transport. A smoke plume from the vehicles is a common feature on the highways. We have made measurements of BC mass concentrations along the Indian National Highways using a potable Aethalometer installed in a moving car. We have carried out measurements along Varanasi to Kanpur (NH-2), Varanasi to Durgapur (NH-2), Varanasi to Singrauli (SH-5A) and Varanasi to Ghazipur (NH-29). We have found high concentration of BC along highways, the average BC mass concentrations vary in the range 20 - 40 µg/m3 and found high BC mass concentrations up to 600 μg/m3. Along the highways high BC concentrations were characteristics of the presence of industrial area, power plants, brick kilns and slow or standing vehicles. The effect of increasing BC concentrations along the National Highways and its impact on the vegetation and human health will be presented. Key Words: Black Carbon; Aethalometer; mass concentration; Indian National Highways.

  6. Mice with neuropathic pain exhibit morphine tolerance due to a decrease in the morphine concentration in the brain.

    Science.gov (United States)

    Ochiai, Wataru; Kaneta, Mitsumasa; Nagae, Marina; Yuzuhara, Ami; Li, Xin; Suzuki, Haruka; Hanagata, Mika; Kitaoka, Satoshi; Suto, Wataru; Kusunoki, Yoshiki; Kon, Risako; Miyashita, Kazuhiko; Masukawa, Daiki; Ikarashi, Nobutomo; Narita, Minoru; Suzuki, Tsutomu; Sugiyama, Kiyoshi

    2016-09-20

    The chronic administration of morphine to patients with neuropathic pain results in the development of a gradual tolerance to morphine. Although the detailed mechanism of this effect has not yet been elucidated, one of the known causes is a decrease in μ-opioid receptor function with regard to the active metabolite of morphine, M-6-G(morphine-6-glucuronide), in the ventrotegmental area of the midbrain. In this study, the relationship between the concentration of morphine in the brain and its analgesic effect was examined after the administration of morphine in the presence of neuropathic pain. Morphine was orally administered to mice with neuropathic pain, and the relationship between morphine's analgesic effect and its concentration in the brain was analysed. In addition, the expression levels of the conjugation enzyme, UGT2B (uridine diphosphate glucuronosyltransferase), which has morphine as its substrate, and P-gp, which is a transporter involved in morphine excretion, were examined. In mice with neuropathic pain, the concentration of morphine in the brain was significantly decreased, and a correlation was found between this decrease and the decrease in the analgesic effect. It was considered possible that this decrease in the brain morphine concentration may be due to an increase in the expression level of P-gp in the small intestine and to an increase in the expression level and binding activity of UGT2B in the liver. The results of this study suggest the possibility that a sufficient analgesic effect may not be obtained when morphine is administered in the presence of neuropathic pain due to a decrease in the total amount of morphine and M-6-G that reach the brain. Copyright © 2016. Published by Elsevier B.V.

  7. Sterile Filtration of Highly Concentrated Protein Formulations: Impact of Protein Concentration, Formulation Composition, and Filter Material.

    Science.gov (United States)

    Allmendinger, Andrea; Mueller, Robert; Huwyler, Joerg; Mahler, Hanns-Christian; Fischer, Stefan

    2015-10-01

    Differences in filtration behavior of concentrated protein formulations were observed during aseptic drug product manufacturing of biologics dependent on formulation composition. The present study investigates filtration forces of monoclonal antibody formulations in a small-scale set-up using polyvinylidene difluoride (PVDF) or polyethersulfone (PES) filters. Different factors like formulation composition and protein concentration related to differences in viscosity, as well as different filtration rates were evaluated. The present study showed that filtration behavior was influenced by the presence or absence of a surfactant in the formulation, which defines the interaction between filter membrane and surface active formulation components. This can lead to a change in filter resistance (PES filter) independent on the buffer system used. Filtration behavior was additionally defined by rheological non-Newtonian flow behavior. The data showed that high shear rates resulting from small pore sizes and filtration pressure up to 1.0 bar led to shear-thinning behavior for highly concentrated protein formulations. Differences in non-Newtonian behavior were attributed to ionic strength related to differences in repulsive and attractive interactions. The present study showed that the interplay of formulation composition, filter material, and filtration rate can explain differences in filtration behavior/filtration flux observed for highly concentrated protein formulations thus guiding filter selection.

  8. Denitrification of fertilizer wastewater at high chloride concentration

    DEFF Research Database (Denmark)

    Ucisik, Ahmed Süheyl; Henze, Mogens

    g/l. The results of the experiments showed that biological denitrification was feasible at the extreme environmental conditions prevailing in fertilizer wastewater. Stable continuous biological denitrfication of the synthetic high chloride wastewater was performed up to 77.4 g Cl/l at 37 degree C......Wastewater from fertilizer industry is characterized by high contents of chloride concentration, which normally vary between 60 and 76 g/l. Experiments with bilogical denitrification were performed in lab-scale "fill and draw" reactors with synthetic wastewater with chloride concentrations up to 77.4...

  9. Biodegradation dynamics of high catechol concentrations by Aspergillus awamori.

    Science.gov (United States)

    Stanchev, Veselin; Stoilova, Ivanka; Krastanov, Albert

    2008-06-15

    The biodegradation process of high catechol concentrations by Aspergillus awamori was investigated. The values of the kinetic constants for a model of specific growth rate at different initial conditions were determined. At 1.0 g/L catechol concentration, the biodegradation process proceeded in the conditions of substrate limitation. At higher catechol concentrations (2.0 and 3.0 g/L) a presence of substrate inhibition was established. The dynamics of the specific catechol degradation rate was studied and the values of catechol and biomass concentrations, maximizing the specific catechol degradation rate, were estimated analytically. The specified ratio catechol/biomass could serve as a starting base for determination of the initial conditions for a batch process, for specifying the moment of feeding for a fed-batch process, and for monitoring and control of a continuous process by the aim of time-optimal control.

  10. High shear treatment of concentrates and drying conditions influence the solubility of milk protein concentrate powders.

    Science.gov (United States)

    Augustin, Mary Ann; Sanguansri, Peerasak; Williams, Roderick; Andrews, Helen

    2012-11-01

    The solubility of milk protein concentrate (MPC) powders was influenced by the method used for preparing the concentrate, drying conditions, and the type of dryer used. Increasing total solids of the ultrafiltered concentrates (23% total solids, TS) by diafiltration to 25% TS or evaporation to 31% TS decreased the solubility of MPC powders (80-83% protein, w/w dry basis), with ultrafiltration followed by evaporation to higher total solids having the greater detrimental effect on solubility. High shear treatment (homogenisation at 350/100 bar, microfluidisation at 800 bar or ultrasonication at 24 kHz, 600 watts) of ultrafiltered and diafiltered milk protein concentrates prior to spray drying increased the nitrogen solubility of MPC powders (82% protein, w/w dry basis). Of the treatments applied, microfluidisation was the most effective for increasing nitrogen solubility of MPC powders after manufacture and during storage. Manufacture of MPC powders (91% protein, w/w dry basis) prepared on two different pilot-scale dryers (single stage or two stage) from milk protein concentrates (20% TS) resulted in powders with different nitrogen solubility and an altered response to the effects of microfluidisation. Microfluidisation (400, 800 and 1200 bar) of the concentrate prior to drying resulted in increased long term solubility of MPC powders that were prepared on a single stage dryer but not those produced on a two stage spray dryer. This work demonstrates that microfluidisation can be used as a physical intervention for improving MPC powder solubility. Interactions between the method of preparation and treatment of concentrate prior to drying, the drying conditions and dryer type all influence MPC solubility characteristics.

  11. The risk of river pollution due to washout from contaminated floodplain water bodies during high floods

    Science.gov (United States)

    Lyubimova, Tatyana; Lepikhin, Anatoly; Parshakova, Yanina; Tiunov, Alexey

    2016-04-01

    Today, the potential impact of extremely high floods, which in the last years have become a rather frequent weather-related disaster, is the problem of primary concern. In studies of the potential impact of floods the emphasis is placed first of all on the estimation of possible flood zones and the analysis of the flow regimes in these zones. However, in some cases the hydrochemical parameters related to changes in the chemical composition of water are more important than the hydraulic parameters. It is generally believed that the higher is the flow rate, the more intensive is the process of dissolution, i.e. the lower is the concentration of limiting contaminants in water. However, this statement is valid provided that flooding does not activate new sources of water pollution such as contaminated floodplain water bodies located in the vicinity of water supply systems. Being quite reliable and safe at small and moderate discharges, in the case of extremely high level of river waters they become intensive sources of water pollution, essentially limiting the water consumption schedule for downstream water consumers. It should be noted that compared to the well-studied mechanisms of waste discharge due to failure of hydraulic engineering structures by flood waves, the mechanisms of pollutant washout from the contaminated floodplain water bodies by the flood waves is still poorly understood. We analyze the impacts of such weather-related events on the quality of water in the water intake system, taking as an example, the section of the Vyatka River located in the Prikamskaya lowland of the Russian Federation. The risk of river pollution due to washout from the contaminated floodplain water bodies during high floods is studied by hydrodynamical modeling in the framework of combined approach using one-, two- and three-dimensional hydrodynamic models are implemented and by in situ measurements. It is shown that during high floods the removal of pollutants from the

  12. High-concentration planar microtracking photovoltaic system exceeding 30% efficiency

    Science.gov (United States)

    Price, Jared S.; Grede, Alex J.; Wang, Baomin; Lipski, Michael V.; Fisher, Brent; Lee, Kyu-Tae; He, Junwen; Brulo, Gregory S.; Ma, Xiaokun; Burroughs, Scott; Rahn, Christopher D.; Nuzzo, Ralph G.; Rogers, John A.; Giebink, Noel C.

    2017-08-01

    Prospects for concentrating photovoltaic (CPV) power are growing as the market increasingly values high power conversion efficiency to leverage now-dominant balance of system and soft costs. This trend is particularly acute for rooftop photovoltaic power, where delivering the high efficiency of traditional CPV in the form factor of a standard rooftop photovoltaic panel could be transformative. Here, we demonstrate a fully automated planar microtracking CPV system solar cell at >660× concentration ratio over a 140∘ full field of view. In outdoor testing over the course of two sunny days, the system operates automatically from sunrise to sunset, outperforming a 17%-efficient commercial silicon solar cell by generating >50% more energy per unit area per day in a direct head-to-head competition. These results support the technical feasibility of planar microtracking CPV to deliver a step change in the efficiency of rooftop solar panels at a commercially relevant concentration ratio.

  13. Beryllium-10 concentrations in water samples of high northern latitudes

    Energy Technology Data Exchange (ETDEWEB)

    Strobl, C.; Eisenhauer, A.; Schulz, V.; Baumann, S.; Mangini, A. [Heidelberger Akademie der Wissenschaften, Heildelberg (Germany); Kubik, P.W. [Paul Scherrer Inst. (PSI), Villigen (Switzerland)

    1997-09-01

    {sup 10}Be concentrations in the water column of high northern latitudes were not available so far. We present different {sup 10}Be profiles from the Norwegian-Greenland Sea, the Arctic Ocean, and the Laptev Sea. (author) 3 fig., 3 refs.

  14. Optimization of Scatterer Concentration in High-Gain Scattering Media

    Institute of Scientific and Technical Information of China (English)

    ZHU Jiu-Gao; ZHU He-Yuan; SUN Die-Chi; DU Ge-Guo; LI Fu-Ming

    2001-01-01

    We report the scatterer concentration-dependent behaviour of laser action in high-gain scattering media. Amodified model of a random laser is proposed to explain the experimental results in good agreement. We mayuse this modified model to design and optimize the random laser system. A further detailed model is needed toquantitatively analyse the far-field distribution of random laser action.

  15. [Toxic effects of high concentrations of ammonia on Euglena gracilis].

    Science.gov (United States)

    Liu, Yan; Shi, Xiao-Rong; Cui, Yi-Bin; Li, Mei

    2013-11-01

    Ammonia is among the common contaminants in aquatic environments. The present study aimed at evaluation of the toxicity of ammonia at high concentration by detecting its effects on the growth, pigment contents, antioxidant enzyme activities, and DNA damage (comet assay) of a unicellular microalga, Euglena gracilis. Ammonia restrained the growth of E. gracilis, while at higher concentrations, ammonia showed notable inhibition effect, the growth at 2 000 mg x L(-1) was restrained to 55.7% compared with that of the control; The contents of photosynthetic pigments and protein went up with increasing ammonia dosage and decreased when the ammonia concentration was above 1000 mg x L(-1); In addition, there was an obvious increase in SOD and POD activities, at higher concentration (2 000 mg x L(-1)), activities of SOD and POD increased by 30.7% and 49.4% compared with those of the control, indicating that ammonia could promote activities of antioxidant enzymes in E. gracilis; The degree of DNA damage observed in the comet assay increased with increasing ammonia concentration, which suggested that high dose of ammonia may have potential mutagenicity on E. gracilis.

  16. Black carbon concentrations from a Tibetan Plateau ice core spanning 1843–1982: recent increases due to emissions and glacier melt

    Directory of Open Access Journals (Sweden)

    M. Jenkins

    2013-10-01

    Full Text Available Black carbon (BC deposited on snow and glacier surfaces can reduce albedo and lead to accelerated melt. An ice core recovered from Guoqu glacier on Mt. Geladaindong and analyzed using a Single Particle Soot Photometer provides the first long-term (1843–1982 record of BC concentrations from the Central Tibetan Plateau. The highest concentrations are observed from 1975–1982, which corresponds to a 2.0-fold and 2.4-fold increase in average and median values, respectively, relative to 1843–1940. BC concentrations post-1940 are also elevated relative to the earlier portion of the record. Causes for the higher BC concentrations include increased regional BC emissions and subsequent deposition, and melt induced enrichment of BC, with the melt potentially accelerated due to the presence of BC at the glacier surface. A qualitative comparison of the BC and Fe (used as a dust proxy records suggests that if changes in the concentrations of absorbing impurities at the glacier surface have influenced recent glacial melt, the melt may be due to the presence of BC rather than dust. Guoqu glacier has received no net ice accumulation since the 1980s, and is a potential example of a glacier where an increase in the equilibrium line altitude is exposing buried high impurity layers. That BC concentrations in the uppermost layers of the Geladaindong ice core are not substantially higher relative to deeper in the ice core suggests that some of the BC that must have been deposited on Guoqu glacier via wet or dry deposition between 1983 and 2005 has been removed from the surface of the glacier, potentially via supraglacial or englacial meltwater.

  17. High-efficiency organic solar concentrators for photovoltaics.

    Science.gov (United States)

    Currie, Michael J; Mapel, Jonathan K; Heidel, Timothy D; Goffri, Shalom; Baldo, Marc A

    2008-07-11

    The cost of photovoltaic power can be reduced with organic solar concentrators. These are planar waveguides with a thin-film organic coating on the face and inorganic solar cells attached to the edges. Light is absorbed by the coating and reemitted into waveguide modes for collection by the solar cells. We report single- and tandem-waveguide organic solar concentrators with quantum efficiencies exceeding 50% and projected power conversion efficiencies as high as 6.8%. The exploitation of near-field energy transfer, solid-state solvation, and phosphorescence enables 10-fold increases in the power obtained from photovoltaic cells, without the need for solar tracking.

  18. Bioleaching of marmatite in high concentration of iron

    Institute of Scientific and Technical Information of China (English)

    邱冠周; 吴伯增; 覃文庆; 蓝卓越

    2002-01-01

    Bioleaching of marmatite with a culture of Thiobacillus ferrooxidans and Thiobacillus thiooxidans in high concentration of iron was studied, the results show that the zinc leaching rate of the mixed culture is faster than that of the sole Thiobacillus ferrooxidans, the increasing iron concentration in leaching solution enhances the zinc leaching rate. The SEM analysis indicates that the chemical leaching residues is covered with porous solid layer of elemental sulfur, while elemental sulfur is not found in the bacterial leaching residues. The primary role of bacteria in bioleaching of sphalerite is to oxidize the chemical leaching products of ferrous ion and elemental sulfur, thus the indirect mechanism prevails in the bioleaching of marmatite.

  19. Transient Dynamics of Fluoride-Based High Concentration Erbium/Cerium Co-Doped Fiber Amplifier

    Institute of Scientific and Technical Information of China (English)

    S. S-H. Yam; Y. Akasaka; Y. Kubota; R. Huang; D. L. Harris; J. Pan

    2003-01-01

    We designed and evaluated a fluoride-based high concentration erbium/ cerium co-doped fiber amplifier. It is suitable for Metropolitan Area Networks due to faster transient, flatter (unfiltered) gain, smaller footprint and gain excursion than its silica-based counterpart.

  20. High concentration of calcium ions in Golgi apparatus

    Institute of Scientific and Technical Information of China (English)

    XUESHAOBAI; M.ROBERTNICOUD; 等

    1994-01-01

    The interphase NIH3T3 cells were vitally fluorescentstained with calcium indicator fluo-3 and Glogi probe C6-NBD-ceramide,and then the single cells were examined by laser scanning confocal microscopy(LSCFM) for subcellular distributions of Ca2+ and the location of Golgi apparatus.In these cells,the intracellular Ca2+ were found to be highly concentrated in the Golgi apparatus.The changes of distribution of cytosolic high Ca2+ region and the Golgi apparatus coincided with the cell cycle phase.In calcium free medium,when the plasma membrane of the cells which had been loaded with fluo-3/AM were permeated by digitonin,the fluorescence of the Golgi region decreased far less than that of the cytosol.Our results indicated that the Glogi lumen retained significantly high concentration of free calcium.

  1. Review of silicon solar cells for high concentrations

    Science.gov (United States)

    Schwartz, R. J.

    1982-06-01

    The factors that limit the performance of high concentration silicon solar cells are reviewed. The design of a conventional high concentration cell is discussed, together with the present state of the art. Unconventional cell designs that have been proposed to overcome the limitations of the conventional design are reviewed and compared. The current status of unconventional cells is reviewed. Among the unconventional cells discussed are the interdigitated back-contact cell, the double-sided cell, the polka dot cell, and the V-groove cell. It is noted that all the designs for unconventional cells require long diffusion lengths for high efficiency operation, even though the demands in this respect are less for those cells with the optical path longer than the diffusion path.

  2. Decomposition of high concentration SF6 using an electron beam

    Science.gov (United States)

    Son, Youn-Suk; Lee, Sung-Joo; Choi, Chang Yong; Park, Jun-Hyeong; Kim, Tak-Hyun; Jung, In-Ha

    2016-07-01

    In this study, high concentration SF6 (2-10%) was decomposed using an electron beam irradiation. Various influential factors were investigated to improve the destruction and removal efficiency (DRE) of SF6. The initial concentrations of SF6, absorbed doses, SF6/H2 ratios and retention times were the main factors of concern. As a result, the DRE increased as the adsorbed dose and retention time increased. The DRE of SF6 also increased up to 20% approximately when H2 was added to the reaction mixture. On the other hand, the DRE of SF6 decreased as initial concentrations of SF6 increased. Finally, the main by-product formed from SF6 decomposition by the electron beam was HF.

  3. Lygus hesperus (Heteroptera: Miridae) tolerates high concentrations of dietary nickel

    Institute of Scientific and Technical Information of China (English)

    ROBERT S. BOYD

    2007-01-01

    Nickel hyperaccumulator plants contain unusually elevated levels of Ni (> 1 000 μg Ni/g). Some insect herbivores, including Lygus hesperus (Western tarnished plant bug), have been observed feeding on the California Ni hyperaccumulator Streptanthus polygaloides. This bug may be able to utilize S. polygaloides as a host either through its feeding behavior or by physiological tolerance of Ni. This experiment determined the Ni tolerance of L. hesperus by offering insects artificial diet amended with 0,0.4, 1, 2, 4.5,10, 20 and 40 mmol Ni/L and recording survival. Survival varied due to Ni concentration, with diets containing 10 mmol Ni/L and greater resulting in significantly lower survival compared to the control (0 mmol Ni/L) treatment. Insects tolerated diet containing as much as 4.5 mmol Ni/L, a relatively elevated Ni concentration. I conclude that L. hesperus can feed on S. polygaloides because it is Ni-tolerant, probably due to physiological mechanisms that provide it with resistance to plant chemical defenses including elemental defenses such as hyperaccumulated Ni.

  4. SOIL N, P AND K CONCENTRATIONS AND RICE YIELD INCREASED DUE TO THE APPLICATION OF Azolla pinnata

    Directory of Open Access Journals (Sweden)

    A. Arivin Rivaie*

    2014-01-01

    Full Text Available Many studies showed that application of Azolla pinnata as biofertilizer improved soil fertility some agricultural crops, including rice, whereas farmers in Lampung consider that A. pinnata suppresses growth of rice seedlings, so they throw it field by raising irrigation water surface. Information on effects A. pinnata application on changes in nutrient availability and rice yield obtained from paddy fields of regions still rare. A study was carried out to investigate effects of different rates of A. pinnata on changes in N, P, K concentrations in paddy soils, N uptake, and rice yield. A well-irrigated paddy field was incorporated with A. pinnata, and then rice seedlings of Ciherang variety had been grown from June up to December 2009. Results: application of A. pinnata at dose of five t per ha increased concentration of N, P and K as well as rice yield. A. pinnata had a relatively high N content, ie 2.43 percent. Application of A. pinnata of 7.5 t per ha increased significantly available soil P, indicated that A. pinnata requires a fairly high P to grow optimally. Application of A. pinnata of 7.5 t per ha gave highest dry grain yield, suggests that application A. pinnata did not suppress rice yield, even use of A. pinnata as organic matter source will help to conserve fossil fuels and foreign exchange as well as will allow more paddy fields that can be fertilized by N.

  5. Particle sedimentation monitoring in high-concentration slurries

    Science.gov (United States)

    Nagasawa, Yoshihiro; Kato, Zenji; Tanaka, Satoshi

    2016-11-01

    In this study, the sedimentation states of particles in high-concentration slurries were elucidated by monitoring their internal states. We prepared transparent high-concentration silica slurries by adjusting the refractive index of the aqueous glycerol liquid in which the particles were dispersed to match that of the silica particles. In addition, a fluorescent dye was dissolved in the liquid. Then, we directly observed the individual and flocculated particles in the slurries during sedimentation by confocal laser scanning fluorescent microscopy. The particles were found to sediment very slowly while exhibiting fluctuating motion. The particle sedimentation rate in the high-concentration slurry with the aqueous glycerol solution (η =0.068 Pa. s ) and a particle volume fraction on the order of 0.3 was determined to be 1.58 ± 0.66 μ m. min-1 on the basis of the obtained image sequences for 24.9 h. In-situ observation provides a large amount of information about the sedimentation behavior of particles in condensed matter.

  6. Improved Dispersion of Carbon Nanotubes in Polymers at High Concentrations

    Science.gov (United States)

    Liu, Chao-Xuan; Choi, Jin-Woo

    2012-01-01

    The polymer nanocomposite used in this work comprises elastomer poly(dimethylsiloxane) (PDMS) as a polymer matrix and multi-walled carbon nanotubes (MWCNTs) as a conductive nanofiller. To achieve uniform distribution of carbon nanotubes within the polymer, an optimized dispersion process was developed, featuring a strong organic solvent—chloroform, which dissolved PDMS base polymer easily and allowed high quality dispersion of MWCNTs. At concentrations as high as 9 wt.%, MWCNTs were dispersed uniformly through the polymer matrix, which presented a major improvement over prior techniques. The dispersion procedure was optimized via extended experimentation, which is discussed in detail. PMID:28348312

  7. Feasibility Study on High Concentrating Photovoltaic Power Towers

    Science.gov (United States)

    Frohberger, Dirk; Jaus, Joachim; Wiesenfarth, Maike; Schramek, Philipp; Bett, Andreas W.

    2010-10-01

    This paper presents an analysis on the concept of high concentrating PV power towers. A feasibility study is conducted in order to evaluate the future potential of this technology. Objective of the analysis is to provide an improved basis for establishing research and development priorities for the PV power tower concept. Performance assessments and cost calculations for a 1 MW prototype PV tower power are derived. Based on the assumption of a highly homogeneously illuminated receiver, levelized costs of electricity of 0.29 €/kWh have been calculated for a prototype PV tower power.

  8. Wet oxidation of real coke wastewater containing high thiocyanate concentration.

    Science.gov (United States)

    Oulego, Paula; Collado, Sergio; Garrido, Laura; Laca, Adriana; Rendueles, Manuel; Díaz, Mario

    2014-01-01

    Coke wastewaters, in particular those with high thiocyanate concentrations, represent an important environmental problem because of their very low biodegradability. In this work, the treatment by wet oxidation of real coke wastewaters containing concentrations of thiocyanate above 17 mM has been studied in a 1-L semi-batch reactor at temperatures between 453 and 493 K, with total oxygen pressures in the range of 2.0-8.0 MPa. A positive effect of the matrix of real coke wastewater was observed, resulting in faster thiocyanate degradation than was obtained with synthetic wastewaters. Besides, the effect of oxygen concentration and temperature on thiocyanate wet oxidation was more noticeable in real effluents than in synthetic wastewaters containing only thiocyanate. It was also observed that the degree of mineralization of the matrix organic compounds was higher when the initial thiocyanate concentration increased. Taking into account the experimental data, kinetic models were obtained, and a mechanism implying free radicals was proposed for thiocyanate oxidation in the matrix considered. In all cases, sulphate, carbonates and ammonium were identified as the main reaction products of thiocyanate wet oxidation.

  9. 210Po and 210Pb Activity Concentrations in Cigarettes Produced in Vietnam and Their Estimated Dose Contribution Due to Smoking

    Science.gov (United States)

    Tran, Thuy-Ngan N.; Le, Cong-Hao; Chau, Van-Tao

    Smoking cigarettes contributes significantly to the increase of radiation in human body because 210Po and 210Pb exist relatively high in tobacco leaves. Therefore, these two radioisotopes in eighteen of the most frequently sold cigarette brands produced in Vietnam were examined in this study. 210Po was determined by alpha spectroscopy using a passivated implanted planar silicon (PIPS) detector after a procedure including radiochemical separation and spontaneous deposition of polonium on a copper disc (the deposition efficiency of 210Po on a copper disc was approximately 94%). Sequentially, 210Pb was determined through the ingrowth of 210Po after storing the sample solutions for approximately six months. The activity concentrations of 210Po in cigarettes ranged from 13.8 to 82.6 mBq/cigarette (the mean value was 26.4 mBq/cigarette) and the activity concentrations of 210Pb in cigarettes ranged from 13.9 to 78.8 mBq/cigarette (the mean value was 25.8 mBq/cigarette). The annual committed effective dose for smokers who smoke one pack per day was also estimated to be 295.4 µSv/year (223.0 µSv/year and 72.4 µSv/year from 210Po and 210Pb, respectively). These indicated that smoking increased the risk of developing lung cancer was approximately 60 times greater for smokers than for non-smokers.

  10. Metal concentrations in soil and seepage water due to infiltration of roof runoff by long term numerical modelling.

    Science.gov (United States)

    Zimmermann, J; Dierkes, C; Göbel, P; Klinger, C; Stubbe, H; Coldewey, W G

    2005-01-01

    The qualitative effects of stormwater infiltration on soil and seepage water are investigated with long term numerical modelling. The retention behaviour of different soils and materials used in infiltration devices is determined with batch and column tests. Results of the laboratory tests are adsorption isotherms which represent input data for numerical transport modelling. The long term simulations are performed with combinations of different solutions (types of roof runoff) and infiltration devices (swale and trench) under different hydrogeological conditions. The presented results contain the infiltration of low polluted roof runoff, runoff from a roof with zinc sheets and from a roof with copper sheets concerning the heavy metals zinc, copper and lead. The increase of concentrations in the infiltration body is high. For the infiltrated water, the results show a migration to groundwater only for the low adsorbing soil.

  11. Strategies for the production of high concentrations of bioethanol from seaweeds: production of high concentrations of bioethanol from seaweeds.

    Science.gov (United States)

    Yanagisawa, Mitsunori; Kawai, Shigeyuki; Murata, Kousaku

    2013-01-01

    Bioethanol has attracted attention as an alternative to petroleum-derived fuel. Seaweeds have been proposed as some of the most promising raw materials for bioethanol production because they have several advantages over lignocellulosic biomass. However, because seaweeds contain low contents of glucans, i.e., polysaccharides composed of glucose, the conversion of only the glucans from seaweed is not sufficient to produce high concentrations of ethanol. Therefore, it is also necessary to produce ethanol from other specific carbohydrate components of seaweeds, including sulfated polysaccharides, mannitol, alginate, agar and carrageenan. This review summarizes the current state of research on the production of ethanol from seaweed carbohydrates for which the conversion of carbohydrates to sugars is a key step and makes comparisons with the production of ethanol from lignocellulosic biomass. This review provides valuable information necessary for the production of high concentrations of ethanol from seaweeds.

  12. Iodine treatment in children with subclinical hypothyroidism due to chronic iodine deficiency decreases thyrotropin and C-peptide concentrations and improves the lipid profile.

    Science.gov (United States)

    Zimmermann, Michael B; Aeberli, Isabelle; Melse-Boonstra, Alida; Grimci, Lindita; Bridson, John; Chaouki, Noureddine; Mbhenyane, Xikombiso; Jooste, Pieter L

    2009-10-01

    Chronic iodine deficiency (ID) increases thyrotropin (TSH) concentrations and produces a thyroid hormone pattern consistent with subclinical hypothyroidism (ScH). ScH may be associated with cardiovascular disease risk factors. Thus, the study aim was to determine if iodine treatment of children with elevated TSH concentrations due to ID would affect their lipid profile, insulin (C-peptide) levels, and/or subclinical inflammation. In controlled intervention trials of oral iodized oil or iodized salt, 5-14-year-old children from Morocco, Albania, and South Africa with TSH concentrations > or = 2.5 mU/L (n = 262) received 400 mg iodine as oral iodized oil or household distribution of iodized salt containing 25 microg iodine/g salt. At baseline and after 5 or 6 months, urinary iodine (UI) and blood concentrations of total thyroxine, TSH, C-reactive protein (CRP), C-peptide, and lipids were measured. Median (range) UI at baseline was 46 (2-601) microg/L. Compared to the control group, iodine treatment significantly increased UI and total thyroxine and decreased TSH, C-peptide, and total and low-density lipoprotein cholesterol. The mean low-density lipoprotein/high-density lipoprotein cholesterol ratio fell from 3.3 to 2.4 after iodine treatment (p Iodine treatment had no significant effect on concentrations of high-density lipoprotein cholesterol, triglycerides, or C-reactive protein. Correction of ID-associated ScH improves the insulin and lipid profile and may thereby reduce risk for cardiovascular disease. This previously unrecognized benefit of iodine prophylaxis may be important because ID remains common in rapidly developing countries with increasing rates of obesity and cardiovascular disease.

  13. Novel DDR Processing of Corn Stover Achieves High Monomeric Sugar Concentrations from Enzymatic Hydrolysis (230 g/L) and High Ethanol Concentration (10% v/v) During Fermentation

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Xiaowen; Jennings, Ed; Shekiro, Joe; Kuhn, Erik M.; O' Brien, Marykate; Wang, Wei; Schell, Daniel J.; Himmel, Mike; Elander, Richard T.; Tucker, Melvin P.

    2015-04-03

    Distilling and purifying ethanol, butanol, and other products from second and later generation lignocellulosic biorefineries adds significant capital and operating cost for biofuels production. The energy costs associated with distillation affects plant gate and life cycle analysis costs. Lower titers in fermentation due to lower sugar concentrations from pretreatment increase both energy and production costs. In addition, higher titers decrease the volumes required for enzymatic hydrolysis and fermentation vessels. Therefore, increasing biofuels titers has been a research focus in renewable biofuels production for several decades. In this work, we achieved over 200 g/L of monomeric sugars after high solids enzymatic hydrolysis using the novel deacetylation and disc refining (DDR) process on corn stover. The high sugar concentrations and low chemical inhibitor concentrations from the DDR process allowed ethanol titers as high as 82 g/L in 22 hours, which translates into approximately 10 vol% ethanol. To our knowledge, this is the first time that 10 vol% ethanol in fermentation derived from corn stover without any sugar concentration or purification steps has been reported. Techno-economic analysis shows the higher titer ethanol achieved from the DDR process could significantly reduce the minimum ethanol selling price from cellulosic biomass.

  14. Chronic Diarrhea Associated with High Teriflunomide Blood Concentration

    OpenAIRE

    Duquette, André; Frenette, Anne Julie; Doré, Maxime

    2016-01-01

    Objective To report the case of a patient treated with leflunomide that presented with chronic diarrhea associated with high teriflunomide blood concentration. Case Summary An 84-year-old woman taking leflunomide 20 mg once daily for the past 2 years to treat rheumatoid arthritis (RA) was investigated for severe chronic diarrhea that had been worsening for the past 5 months. The patient’s general condition progressively deteriorated and included electrolyte imbalances and a transient loss of ...

  15. Particulate Matter Concentrations in East Oakland's High Street Corridor

    Science.gov (United States)

    Lei, P.; Jackson, J.; Lewis, R.; Marigny, A.; Mitchell, J. D.; Nguyen, R.; Philips, B.; Randle, D.; Romero, D.; Spears, D.; Telles, C.; Weissman, D.

    2012-12-01

    Particulate matter (PM) is a complex mixture of small solid pieces and/or liquid droplets in the air. High concentrations of PM can pose a serious health hazard because inhalation can result in breathing problems and/or aggravate asthma. Long term exposure can increase the likelihood of respiratory problems like asthma and emphysema as well as cancer. The smaller the particles, the deeper they can get into the respiratory system. For this reason, the smallest particles, those smaller than 2.5 micrometers in diameter (PM2.5), are the most dangerous. PM2.5 is largely emitted from motor vehicles burning fuels that don't break down fully. Our research team investigated the levels of PM2.5 as well as particles smaller than 10 micrometers (PM10) and total suspended particulate (TSP) along the northeast-southwest trending High Street Corridor, near Fremont High School in East Oakland, California. Using the Aerocet 531 mass particle counter, team members walked through neighborhoods and along major roads within a 1 mile radius of Fremont High School. The Aerocet 531 recorded two minute average measurements of all the relevant PM sizes, which are reported in mg/m3. Measurements were consistently taken in the morning, between 8:30 and 11:30 am. Preliminary results indicate maximum readings of all PM sizes at sites that are in close proximity to a major freeway (Interstate-880). These results support our initial hypothesis that proximity to major roads and freeways, especially those with high diesel-fuel burning truck traffic, would be the primary factor affecting PM concentration levels. Preliminary median and maximum readings all suggest particulate matter levels below what the EPA would consider unhealthy or risky.

  16. Reduction of Temperature in Concentrator Photovoltaic Module Using Coating with High Thermal Emissivity and Conductivity

    Directory of Open Access Journals (Sweden)

    Nakamura Satoshi

    2016-01-01

    Full Text Available The temperature of solar cells considerably increases under light-concentrating operations, and the conversion efficiency of solar cells decreases with increasing temperature. It is very important to reduce the cell temperature in concentrator photovoltaic modules. The thermal radiation layers with high thermal emissivity and thermal conductivity was coated on the aluminum samples which is used for the chassis of concentrator photovoltaic and the effect was evaluated under the conditions with wind. The temperature of sample with coating showed lower temperature than that without coating. In the condition with wind, the coated sample with high thermal emissivity and high thermal conductivity showed the lowest temperature due to the effect of thermal radiation and thermal conduction.

  17. High manganese concentrations in rocks at Gale crater, Mars

    Science.gov (United States)

    Lanza, Nina L.; Fischer, Woodward W.; Wiens, Roger C.; Grotzinger, John; Ollila, Ann M.; Anderson, Ryan B.; Clark, Benton C.; Gellert, Ralf; Mangold, Nicolas; Maurice, Sylvestre; Le Mouélic, Stéphane; Nachon, Marion; Schmidt, Mariek E.; Berger, Jeffrey; Clegg, Samuel M.; Forni, Olivier; Hardgrove, Craig; Melikechi, Noureddine; Newsom, Horton E.; Sautter, Violaine

    2014-01-01

    The surface of Mars has long been considered a relatively oxidizing environment, an idea supported by the abundance of ferric iron phases observed there. However, compared to iron, manganese is sensitive only to high redox potential oxidants, and when concentrated in rocks, it provides a more specific redox indicator of aqueous environments. Observations from the ChemCam instrument on the Curiosity rover indicate abundances of manganese in and on some rock targets that are 1–2 orders of magnitude higher than previously observed on Mars, suggesting the presence of an as-yet unidentified manganese-rich phase. These results show that the Martian surface has at some point in time hosted much more highly oxidizing conditions than has previously been recognized.

  18. Shock initiation studies on high concentration hydrogen peroxide

    Energy Technology Data Exchange (ETDEWEB)

    Sheffield, Stephen A [Los Alamos National Laboratory; Dattelbaum, Dana M [Los Alamos National Laboratory; Stahl, David B [Los Alamos National Laboratory; Gibson, L. Lee [Los Alamos National Laboratory; Bartram, Brian D. [Los Alamos National Laboratory

    2009-01-01

    Concentrated hydrogen peroxide (H{sub 2}O{sub 2}) has been known to detonate for many years. However, because of its reactivity and the difficulty in handling and confining it, along with the large critical diameter, few studies providing basic information about the initiation and detonation properties have been published. We are conducting a study to understand and quantify the initiation and detonation properties of highly concentrated H{sub 2}O{sub 2} using a gas-driven two-stage gun to produce well defined shock inputs. Multiple magnetic gauges are used to make in-situ measurements of the growth of reaction and subsequent detonation in the liquid. These experiments are designed to be one-dimensional to eliminate any difficulties that might be encountered with large critical diameters. Because of the concern of the reactivity of the H{sub 2}O{sub 2} with the confining materials, a remote loading system has been developed. The gun is pressurized, then the cell is filled and the experiment shot within less than three minutes. TV cameras are attached to the target so the cell filling can be monitored. Several experiments have been completed on {approx}98 wt % H{sub 2}O{sub 2}/H{sub 2}O mixtures; initiation has been observed in some experiments that shows homogeneous shock initiation behavior. The initial shock pressurizes and heats the mixture. After an induction time, a thermal explosion type reaction produces an evolving reactive wave that strengthens and eventually overdrives the first wave producing a detonation. From these measurements, we have determined unreacted Hugoniot information, times (distances) to detonation (Pop-plot points) that indicate low sensitivity, and detonation velocities of high concentration H{sub 2}O{sub 2}/H{sub 2}O solutions that agree with earlier estimates.

  19. Shock initiation studies on high concentration hydrogen peroxide

    Energy Technology Data Exchange (ETDEWEB)

    Sheffield, Stephen A [Los Alamos National Laboratory; Dattelbaum, Dana M [Los Alamos National Laboratory; Stahl, David B [Los Alamos National Laboratory; Gibson, L. Lee [Los Alamos National Laboratory; Bartram, Brian D. [Los Alamos National Laboratory

    2009-01-01

    Concentrated hydrogen peroxide (H{sub 2}O{sub 2}) has been known to detonate for many years. However, because of its reactivity and the difficulty in handling and confining it, along with the large critical diameter, few studies providing basic information about the initiation and detonation properties have been published. We are conducting a study to understand and quantify the initiation and detonation properties of highly concentrated H{sub 2}O{sub 2} using a gas-driven two-stage gun to produce well defined shock inputs. Multiple magnetic gauges are used to make in-situ measurements of the growth of reaction and subsequent detonation in the liquid. These experiments are designed to be one-dimensional to eliminate any difficulties that might be encountered with large critical diameters. Because of the concern of the reactivity of the H{sub 2}O{sub 2} with the confining materials, a remote loading system has been developed. The gun is pressurized, then the cell is filled and the experiment shot within less than three minutes. TV cameras are attached to the target so the cell filling can be monitored. Several experiments have been completed on {approx}98 wt % H{sub 2}O{sub 2}/H{sub 2}O mixtures; initiation has been observed in some experiments that shows homogeneous shock initiation behavior. The initial shock pressurizes and heats the mixture. After an induction time, a thermal explosion type reaction produces an evolving reactive wave that strengthens and eventually overdrives the first wave producing a detonation. From these measurements, we have determined unreacted Hugoniot information, times (distances) to detonation (Pop-plot points) that indicate low sensitivity, and detonation velocities of high concentration H{sub 2}O{sub 2}/H{sub 2}O solutions that agree with earlier estimates.

  20. Source identification of high glyme concentrations in the Oder River.

    Science.gov (United States)

    Stepien, D K; Püttmann, W

    2014-05-01

    The objective of the following study was to identify the source of high concentrations of glycol diethers (diglyme, triglyme, and tetraglyme) in the Oder River. Altogether four sampling campaigns were conducted and over 50 surface samples collected. During the first two samplings of the Oder River in the Oderbruch region (km 626-690), glymes were detected at concentrations reaching 0.065 μg L(-1) (diglyme), 0.54 μg L(-1) (triglyme) and 1.7 μg L(-1) (tetraglyme). The subsequent sampling of the Oder River, from the area close to the source to the Poland-Germany border (about 500 km) helped to identify the possible area of the dominating glyme entry into the river between km 310 and km 331. During that sampling, the maximum concentration of triglyme was 0.46 μg L(-1) and tetraglyme 2.2 μg L(-1); diglyme was not detected. The final sampling focused on the previously identified area of glyme entry, as well as on tributaries of the Oder River. Samples from Czarna Woda stream and Kaczawa River contained even higher concentrations of diglyme, triglyme, and tetraglyme, reaching 5.2 μg L(-1), 13 μg L(-1) and 81 μg L(-1), respectively. Finally, three water samples were analyzed from a wastewater treatment plant receiving influents from a Copper Smelter and Refinery; diglyme, triglyme, and tetraglyme were present at a maximum concentration of 1700 μg L(-1), 13,000 μg L(-1), and 190,000 μg L(-1), respectively. Further research helped to identify the source of glymes in the wastewater. The gas desulfurization process Solinox uses a mixture of glymes (Genosorb(®)1900) as a physical absorption medium to remove sulfur dioxide from off-gases from the power plant. The wastewater generated from the process and from the maintenance of the equipment is initially directed to the wastewater treatment plant where it undergoes mechanical and chemical treatment processes before being discharged to the tributaries of the Oder River. Although monoglyme was

  1. Design and Optimization of Fresnel Lens for High Concentration Photovoltaic System

    Directory of Open Access Journals (Sweden)

    Lei Jing

    2014-01-01

    Full Text Available A practical optimization design is proposed, in which the solar direct light spectrum and multijunction cell response range are taken into account in combination, particularly for the Fresnel concentrators with a high concentration and a small aspect ratio. In addition, the change of refractive index due to temperature variation in outdoor operation conditions is also considered in the design stage. The calculation results show that this novel Fresnel lens achieves an enhancement of energy efficiency of about 10% compared with conventional Fresnel lens for a given solar spectrum, solar cell response, and corrected sunshine hours of different ambient temperature intervals.

  2. Autotrophic denitrification for treatment of wastewater with high concentration of sulphur and nitrogen compounds

    OpenAIRE

    Fajardo Ortiz, María del Carmen

    2011-01-01

    Anthropogenic activities have contributed to the imbalance of nitrogen and sulphur natural cycles which causes many negative effects in nature due to the emissions of sulphur and nitrogen compounds and their transformations, e.g. rain acid, eutrophication, bad odours etc. To avoid such negative effects on environment, effluents containing high concentrations of both nitrogen and sulphur compounds must be treated previously to their discharge. Nitrification/denitrification is the conventio...

  3. An astigmatic corrected target-aligned heliostat for high concentration

    Energy Technology Data Exchange (ETDEWEB)

    Zaibel, R.; Dagan, E.; Karni, J. [Solar Research Facility, The Weizmann Institute of Science, Rehovot (Israel); Ries, Harald [Ludwig-Maximilians-Universitaet, Sektion Physik, Munich (Germany)

    1995-05-28

    Conventional heliostats suffer from astigmatism for non-normal incidence. For tangential rays the focal length is shortened while for sagittal rays it is longer than the nominal focal length. Due to this astigmatism it is impossible to produce a sharp image of the sun, and the rays will be spread over a larger area. In order to correct this the heliostat should have different curvature radii along the sagittal and tangential direction in the heliostat plane just like a non axial part of a paraboloid. In conventional heliostats, where the first axis, fixed with respect to the ground, is vertical while the second, fixed with respect to the reflector surface, is horizontal, such an astigmatism correction is not practical because the sagittal and tangential directions rotate with respect to the reflector. We suggest an alternative mount where the first axis is oriented towards the target. The second axis, perpendicular to the first and tangent to the reflector, coincides with the tangential direction. With this mounting sagittal and tangential direction are fixed with respect to the reflector during operation. Therefore a partial astigmatism compensation is possible. We calculate the optimum correction and show the performance of the heliostat. We also show predicted yearly average concentrations

  4. A method for analyzing on-line video images of crystallization at high-solid concentrations

    Institute of Scientific and Technical Information of China (English)

    Jian Wan; Cai Y.Ma; Xue Z.Wang

    2008-01-01

    Recent research has demonstrated that on-line video imaging is a very promising technique for monitoring crystallization processes. The bottleneck in applying the technique for real-time closed-loop control is considered as image analysis that needs to be robust, fast and able to handle varied image qualities due to temporal variations of operating conditions such as mixing and solid concentrations. Image analysis at high-solid concentrations turns out to be extremely challenging because crystals tend to overlap or attach to each other and the boundaries between the crystals are usually ambiguous. This paper presents an image segmentation algorithm that can effectively deal with images taken at high-solid concentrations. The method segments crystals attached to each other along the mostly related concave points on the contours of crystal blocks. The detailed procedure is introduced with application to crystallization of L-glutamic acid in a hot-stage reactor.

  5. Driving impairment due to propofol at effect-site concentrations relevant after short propofol-only sedation.

    Science.gov (United States)

    Telles, J L; Agarwal, S; Monagle, J; Stough, C; King, R; Downey, L

    2016-11-01

    Australian guidelines state "Following brief surgery or procedures with short acting anaesthetic drugs, the patient may be fit to drive after a normal night's sleep. After long surgery or procedures requiring longer lasting anaesthesia, it may not be safe to drive for 24 hours or more". The increasing use of the short-acting anaesthetic drug propofol as a solitary sedative medication for simple endoscopy procedures suggests a need to review this blanket policy. Thirty patients presenting for elective day surgery were recruited as volunteers for a pre-procedure driving simulation study and randomised to propofol or placebo arms. Driving ability was assessed at baseline and then, in the propofol group, at three effect-site concentrations. Driving impairment at these concentrations of propofol was compared to that of a third group of volunteers with a blood alcohol concentration of 0.05% (g/100 ml). Driving impairment at 0.2 µg/ml propofol effect-site concentration was not statistically different to placebo. Impairment increased with propofol effect-site concentration (P=0.002) and at 0.4 µg/ml it was similar to that found with a blood alcohol concentration of 50 mg/100 ml (0.05%). Plasma propofol concentrations of 0.2 µg/ml, as might be found approximately an hour after short (propofol-only sedation for endoscopy, were not associated with driving impairment in our young cohort of volunteers.

  6. Catalytic wet air oxidation of high concentration pharmaceutical wastewater.

    Science.gov (United States)

    Zhan, Wei; Wang, Xiaocong; Li, Daosheng; Ren, Yongzheng; Liu, Dongqi; Kang, Jianxiong

    2013-01-01

    In this study, we investigated the pretreatment of a high concentration pharmaceutical wastewater by catalytic wet air oxidation (CWAO) process. Different experiments were conducted to investigate the effects of the catalyst type, operating temperature, initial system pH, and oxygen partial pressure on the oxidation of the wastewater. Results show that the catalysts prepared by the co-precipitation method have better catalytic activity compared to others. Chemical oxygen demand (COD) conversion increased with the increase in temperature from 160 to 220 °C and decreased with the increase in pH. Moreover, the effect of the oxygen partial pressure on the COD conversion was significant only during the first 20 min of the reaction. Furthermore, the biodegradability of the wastewater improved greatly after CWAO, the ratio of BOD5/COD increased less than 0.1-0.75 when treated at 220 °C (BOD: biochemical oxygen demand).

  7. Acquisition and Analysis of Data from High Concentration Solutions

    KAUST Repository

    Besong, Tabot M.D.

    2016-05-13

    The problems associated with ultracentrifugal analysis of macromolecular solutions at high (>10 mg/ml) are reviewed. Especially for the case of solutes which are non-monodisperse, meaningful results are not readily achievable using sedimentation velocity approaches. It is shown however by both simulation and analysis of practical data that using a modified form of an algorithm (INVEQ) published in other contexts, sedimentation equilibrium (SE) profiles can be analysed successfully, enabling topics such as oligomer presence or formation to be defined.To achieve this, it is necessary to employ an approach in which the solution density, which in an SE profile is radius-dependent, is taken into consideration. Simulation suggests that any reasonable level of solute concentration can be analysed.

  8. Rheological properties of highly concentrated protein-stabilized emulsions.

    Science.gov (United States)

    Dimitrova, Tatiana D; Leal-Calderon, Fernando

    2004-05-20

    We prepared concentrated quasi monodisperse hexadecane-in-water emulsions stabilized by various proteins and investigated their rheological properties. Some protein-stabilized emulsions possess remarkably high elasticity and at the same time they are considerably fragile--they exhibit coalescence at yield strain and practically do not flow. The elastic storage modulus G' and the loss modulus G" of the emulsions were determined for different oil volume fractions above the random close packing. Surprisingly, the dimensionless elastic moduli G'/(sigma/a), sigma being the interfacial tension, and a being the mean drop radius, obtained for emulsions stabilized by different proteins do not collapse on a single master curve. They are almost always substantially higher than the corresponding values obtained for equivalent Sodium Dodecyl Sulfate (SDS)-stabilized emulsions. The unusually high elasticity cannot be attributed to a specificity of the continuous phase, because the osmotic equation of state of our emulsions is found identical to the one obtained for samples stabilized by classical surfactants. In parallel, we mimicked the thin films that separate the droplets in the concentrated emulsion and found that the protein adsorption layers contain a substantial number of sticky surface aggregates. These severely obstruct local rearrangements of individual drops in respect to their neighbors which leads to coalescence at yield strain. Furthermore, we found that G'/(sigma/a) is correlated (for a given oil volume fraction) to the dilatational elastic modulus, of the protein layer adsorbed on the droplets. The intrinsic elasticity of the protein layers, together with the blocked local rearrangements are considered as the main factors determining the unusual bulk elasticity of the studied emulsions.

  9. Do high concentrations of microcystin prevent Daphnia control of phytoplankton?

    Science.gov (United States)

    Chislock, Michael F; Sarnelle, Orlando; Jernigan, Lauren M; Wilson, Alan E

    2013-04-15

    Toxin-producing cyanobacteria have frequently been hypothesized to limit the ability of herbivorous zooplankton (such as Daphnia) to control phytoplankton biomass by inhibiting feeding, and in extreme cases, causing zooplankton mortality. Using limnocorral experiments in hyper-eutrophic ponds located in Alabama and Michigan (U.S.A.), we tested the hypothesis that high levels of cyanobacteria and microcystin, a class of hepatotoxins produced by several cyanobacterial genera, prevent Daphnia from strongly reducing phytoplankton abundance. At the start of the first experiment (Michigan), phytoplankton communities were dominated by toxic Microcystis and Anabaena (∼96% of total phytoplankton biomass), and concentrations of microcystin were ∼3 μg L⁻¹. Two weeks after adding Daphnia pulicaria from a nearby eutrophic lake, microcystin levels increased to ∼6.5 μg L⁻¹, yet Daphnia populations increased exponentially (r = 0.24 day⁻¹). By the third week, Daphnia had suppressed phytoplankton biomass by ∼74% relative to the no Daphnia controls and maintained reduced phytoplankton biomass until the conclusion of the five-week experiment. In the second experiment (Alabama), microcystin concentrations were greater than 100 μg L⁻¹, yet a mixture of three D. pulicaria clones from eutrophic lakes in southern MI increased and again reduced phytoplankton biomass, in this case by over 80%. The ability of Daphnia to increase in abundance and suppress phytoplankton biomass, despite high initial levels of cyanobacteria and microcystin, indicates that the latter does not prevent strong control of phytoplankton biomass by Daphnia genotypes that are adapted to environments with abundant cyanobacteria and associated cyanotoxins.

  10. Highly Concentrated Acetic Acid Poisoning: 400 Cases Reviewed

    Directory of Open Access Journals (Sweden)

    Konstantin Brusin

    2012-12-01

    Full Text Available Background: Caustic substance ingestion is known for causing a wide array of gastrointestinal and systemic complications. In Russia, ingestion of acetic acid is a major problem which annually affects 11.2 per 100,000 individuals. The objective of this study was to report and analyze main complications and outcomes of patients with 70% concentrated acetic acid poisoning. Methods: This was a retrospective study of patients with acetic acid ingestion who were treated at Sverdlovsk Regional Poisoning Treatment Center during 2006 to 2012. GI mucosal injury of each patient was assessed with endoscopy according to Zargar’s scale. Data analysis was performed to analyze the predictors of stricture formation and mortality. Results: A total of 400 patients with median age of 47 yr were included. GI injury grade I was found in 66 cases (16.5%, IIa in 117 (29.3%, IIb in 120 (30%, IIIa in 27 (16.7% and IIIb in 70 (17.5%. 11% of patients developed strictures and overall mortality rate was 21%. Main complications were hemolysis (55%, renal injury (35%, pneumonia (27% and bleeding during the first 3 days (27%. Predictors of mortality were age 60 to 79 years, grade IIIa and IIIb of GI injury, pneumonia, stages “I”, “F” and “L” of kidney damage according to the RIFLE scale and administration of prednisolone. Predictors of stricture formation were ingestion of over 100 mL of acetic acid and grade IIb and IIIa of GI injury. Conclusion: Highly concentrated acetic acid is still frequently ingested in Russia with a high mortality rate. Patients with higher grades of GI injury, pneumonia, renal injury and higher amount of acid ingested should be more carefully monitored as they are more susceptible to develop fatal consequences.          

  11. Modelling acceptance of sunlight in high and low photovoltaic concentration

    Energy Technology Data Exchange (ETDEWEB)

    Leutz, Ralf, E-mail: ralf.leutz@leopil.com [Leutz Optics and Illumination UG (haftungsbeschränkt), Marburg (Germany)

    2014-09-26

    A simple model incorporating linear radiation characteristics, along with the optical trains and geometrical concentration ratios of solar concentrators is presented with performance examples for optical trains of HCPV, LCPV and benchmark flat-plate PV.

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

    CSIR Research Space (South Africa)

    Roos, TH

    2010-09-01

    Full Text Available A compound parabolic concentrator (CPC) with a concentration ratio of 16:1 is under development at CSIR for volumetric receiver and solar fuels development. The ideal shape has been approximated by 6 and 12 facets in the longitudinal...

  13. High-performance deployable structures for the support of high-concentration ratio solar array modules

    Science.gov (United States)

    Mobrem, M.

    1985-01-01

    A study conducted on high-performance deployable structures for the support of high-concentration ratio solar array modules is discussed. Serious consideration is being given to the use of high-concentration ratio solar array modules or applications such as space stations. These concentrator solar array designs offer the potential of reduced cost, reduced electrical complexity, higher power per unit area, and improved survivability. Arrays of concentrators, such as the miniaturized Cassegrainian concentrator modules, present a serious challenge to the structural design because their mass per unit area (5.7 kg/square meters) is higher than that of flexible solar array blankets, and the requirement for accurate orientation towards the Sun (plus or minus 0.5 degree) requires structures with improved accuracy potentials. In addition, use on a space station requires relatively high structural natural frequencies to avoid deleterious interactions with control systems and other large structural components. The objective here is to identify and evaluate conceptual designs of structures suitable for deploying and accurately supporting high-concentration ratio solar array modules.

  14. Vitamin E Concentrations in Adults with HIV/AIDS on Highly Active Antiretroviral Therapy

    Directory of Open Access Journals (Sweden)

    Daniella J. Itinoseki Kaio

    2014-09-01

    Full Text Available HIV/AIDS patients are probably more predisposed to vitamin E deficiency, considering that they are more exposed to oxidative stress. Additionally, there are an extensive number of drugs in the highly active antiretroviral therapy (HAART regimens that may interfere with vitamin E concentrations. The objective of this study was to compare serum concentrations of alpha-tocopherol in 182 HIV/AIDS patients receiving different HAART regimens. The patients were divided into three groups according to regimen: nucleoside analog reverse-transcriptase inhibitors (NRTIs + non-nucleoside analog reverse-transcriptase inhibitors (NNRTIs; NRTIs + protease inhibitors + ritonavir; NRTIs + other classes. Alpha-tocopherol was assessed by high-performance liquid chromatography. Multiple linear regression analysis was used to evaluate the effects of HAART regimen, time of use, and compliance with the regimen on alpha-tocopherol concentrations. Alpha-tocopherol concentrations were on average 4.12 μmol/L lower for the NRTIs + other classes regimen when compared to the NRTIs + NNRTIs regimen (p = 0.037. A positive association (p < 0.001 was observed between alpha-tocopherol and cholesterol concentrations, a finding due, in part, to the relationship between liposoluble vitamins and lipid profile. This study demonstrated differences in alpha-tocopherol concentrations between patients using different HAART regimens, especially regimens involving the use of new drugs. Long-term prospective cohort studies are needed to monitor vitamin E status in HIV/AIDS patients since the beginning of treatment.

  15. Design and development of a high-concentration and high-efficiency photovoltaic concentrator using a curved Fresnel lens

    Energy Technology Data Exchange (ETDEWEB)

    Scharlack, R.S.; Moffat, A.

    1983-08-01

    Thermo Electron has designed a high concentration photovoltaic module that uses a domed, point-focus Fresnel lens. Their design, design optimization process, and results from lens and receiver tests are described in this report. A complete module has not been fabricated and probably will not be fabricated in the future; however, Thermo Electron's optical design, analysis, and testing of both secondary optical units and domed Fresnel lenses have made a significant contribution to our project. Tooling errors prevented the lens from reaching its potential efficiency by the end of the contract, and resolution of these tooling problems is currently being attempted with a follow-on contract, No. 68-9463.

  16. The quality of air pollutant concentrations in Kermanshah emphasizing PM10 due to the occurrence of dust (2011-2013

    Directory of Open Access Journals (Sweden)

    Meghdad Pirsaheb

    2015-02-01

    Full Text Available Particulate matter is one of the important parameters in air pollutant standard index. 1095 samples were taken during three years and various seasons from five stations belonging to Kermanshah Environment Protection Agency. The results showed that particulate matter concentration was in the range of standard conditions in 67.5% of the days of the year, and it was in the range of dangerous conditions in 1.6% of the days of the year. Spring season and April month had the worst air quality in terms of PM10 concentration, which can be attributed to the incidence and intensity of dust phenomenon during this time.

  17. Highly siderophile element (HSE) abundances in the mantle of Mars are due to core formation at high pressure and temperature

    Science.gov (United States)

    Righter, K.; Danielson, L. R.; Pando, K. M.; Williams, J.; Humayun, M.; Hervig, R. L.; Sharp, T. G.

    2015-04-01

    Highly siderophile elements (HSEs) can be used to understand accretion and core formation in differentiated bodies, due to their strong affinity for FeNi metal and sulfides. Coupling experimental studies of metal-silicate partitioning with analyses of HSE contents of Martian meteorites can thus offer important constraints on the early history of Mars. Here, we report new metal-silicate partitioning data for the PGEs and Au and Re across a wide range of pressure and temperature space, with three series designed to complement existing experimental data sets for HSE. The first series examines temperature effects for D(HSE) in two metallic liquid compositions—C-bearing and C-free. The second series examines temperature effects for D(Re) in FeO-bearing silicate melts and FeNi-rich alloys. The third series presents the first systematic study of high pressure and temperature effects for D(Au). We then combine our data with previously published partitioning data to derive predictive expressions for metal-silicate partitioning of the HSE, which are subsequently used to calculate HSE concentrations of the Martian mantle during continuous accretion of Mars. Our results show that at midmantle depths in an early magma ocean (equivalent to approximately 14 GPa, 2100 °C), the HSE contents of the silicate fraction are similar to those observed in the Martian meteorite suite. This is in concert with previous studies on moderately siderophile elements. We then consider model calculations that examine the role of melting, fractional crystallization, and sulfide saturation/undersaturation in establishing the range of HSE contents in Martian meteorites derived from melting of the postcore formation mantle. The core formation modeling indicates that the HSE contents can be established by metal-silicate equilibrium early in the history of Mars, thus obviating the need for a late veneer for HSE, and by extension volatile siderophile elements, or volatiles in general.

  18. Decreased carotenoid concentrations due to dietary sucrose polyesters do not affect possible markers of disease risk in humans

    NARCIS (Netherlands)

    Broekmans, W.M.R.; Klöpping-Ketelaars, I.A.A.; Weststrate, J.A.; Tijburg, L.B.M.; Poppel, G. van; Vink, A.A.; Berendschot, T.T.J.M.; Bots, M.L.; Castenmiller, W.A.M.; Kardinaal, A.F.M.

    2003-01-01

    Excessive consumption of energy and fat increases the risk for obesity. Snacks containing sucrose polyesters (SPE) as a dietary fat replacer are on the market in the United States. SPE products have been shown to lower concentrations of serum carotenoids in short-term studies. Experimental studies o

  19. Decreased carotenoid concentrations due to dietary sucrose polyesters do not affect possible markers of disease risk in humans

    NARCIS (Netherlands)

    Broekmans, W.M.R.; Klöpping-Ketelaars, I.A.A.; Weststrate, J.A.; Tijburg, L.B.M.; Poppel, G. van; Vink, A.A.; Berendschot, T.T.J.M.; Bots, M.L.; Castenmiller, W.A.M.; Kardinaal, A.F.M.

    2003-01-01

    Excessive consumption of energy and fat increases the risk for obesity. Snacks containing sucrose polyesters (SPE) as a dietary fat replacer are on the market in the United States. SPE products have been shown to lower concentrations of serum carotenoids in short-term studies. Experimental studies

  20. Increased serum C-reactive protein concentrations in dogs with congestive heart failure due to myxomatous mitral valve disease

    DEFF Research Database (Denmark)

    Reimann, M. J.; Ljungvall, I.; Hillstrom, A.

    2016-01-01

    Cardiovascular disease in humans and dogs is associated with mildly increased circulating concentrations of C-reactive protein (CRP). Few studies have evaluated associations between circulating CRP and canine myxomatous mitral valve disease (MMVD) and the results reported have been divergent...

  1. Carbon Nanofibers Modified Graphite Felt for High Performance Anode in High Substrate Concentration Microbial Fuel Cells

    Directory of Open Access Journals (Sweden)

    Youliang Shen

    2014-01-01

    Full Text Available Carbon nanofibers modified graphite fibers (CNFs/GF composite electrode was prepared for anode in high substrate concentration microbial fuel cells. Electrochemical tests showed that the CNFs/GF anode generated a peak current density of 2.42 mA cm−2 at a low acetate concentration of 20 mM, which was 54% higher than that from bare GF. Increase of the acetate concentration to 80 mM, in which the peak current density of the CNFs/GF anode greatly increased and was up to 3.57 mA cm−2, was seven times as that of GF anode. Morphology characterization revealed that the biofilms in the CNFs/GF anode were much denser than those in the bare GF. This result revealed that the nanostructure in the anode not only enhanced current generation but also could tolerate high substrate concentration.

  2. The risk of river pollution due to washout from contaminated floodplain water bodies during periods of high magnitude floods

    Science.gov (United States)

    Lyubimova, T.; Lepikhin, A.; Parshakova, Ya.; Tiunov, A.

    2016-03-01

    The risk of river pollution due to washout (removal of pollutants) from contaminated floodplain water bodies (floodplain lakes and quarries whose origin is related to the large-scale mining of nonmetallic building materials in the floodplain zone) during high magnitude flood periods is analyzed using a combination of one-, two- and three-dimensional hydrodynamic modeling and in situ measurements. The modeling performed for the floodplain water bodies contaminated by N compounds shows that during large magnitude floods washout occurs. The washout process consists of two stages: an initial rapid stage lasting about two hours during which the upper (3-4 m thick) layer is washed out, followed by a second stage when the concentration of NH4-N in the floodplain water body remains nearly constant. The maximum contaminant concentration in the river in the vicinity of a water intake for drinking water located 21 km downstream is attained about 9 h from the beginning of the flood; concentration of NH4-N can reach values several times larger than acceptable concentration guidelines. The initial primary peak in contaminant concentration at the water intake is followed by a slight decrease in contaminant concentration; a second peak related to the contaminant transport through the inundated floodplain subsequently occurs, after which the concentration slowly decreases, reaching acceptable values after 30-40 h. Contaminated floodplain water bodies located near drinking water supply systems are not significant sources of contamination during small and moderate floods, but during high magnitude floods, they can become sources of water pollution. Operational measures that can decrease potential health risks are discussed.

  3. An Automatic High Efficient Method for Dish Concentrator Alignment

    OpenAIRE

    Yong Wang; Song Li; Jinshan Xu; Yijiang Wang; Xu Cheng; Changgui Gu; Shengyong Chen; Bin Wan

    2014-01-01

    Alignment of dish concentrator is a key factor to the performance of solar energy system. We propose a new method for the alignment of faceted solar dish concentrator. The isosceles triangle configuration of facet’s footholds determines a fixed relation between light spot displacements and foothold movements, which allows an automatic determination of the amount of adjustments. Tests on a 25 kW Stirling Energy System dish concentrator verify the feasibility, accuracy, and efficiency of our...

  4. Decadal and seasonal trends of nutrient concentration and export from highly managed coastal catchments.

    Science.gov (United States)

    Wan, Yongshan; Wan, Lei; Li, Yuncong; Doering, Peter

    2017-05-15

    Understanding anthropogenic and hydro-climatic influences on nutrient concentrations and export from highly managed catchments often necessitates trend detection using long-term monitoring data. This study analyzed the temporal trend (1979-2014) of total nitrogen (TN) and total phosphorus (TP) concentrations and export from four adjacent coastal basins in south Florida where land and water resources are highly managed through an intricate canal network. The method of integrated seasonal-trend decomposition using LOESS (LOcally weighted regrESSion) was employed for trend detection. The results indicated that long-term trends in TN and TP concentrations (increasing/decreasing) varied with basins and nutrient species, reflecting the influence of basin specific land and water management practices. These long-term trends were intervened by short-term highs driven by high rainfall and discharges and lows associated with regional droughts. Seasonal variations in TP were more apparent than for TN. Nutrient export exhibited a chemostatic behavior for TN from all the basins, largely due to the biogenic nature of organic N associated with the ubiquity of organic materials in the managed canal network. Varying degrees of chemodynamic export was present for TP, reflecting complex biogeochemical responses to the legacy of long-term fertilization, low soil P holding capacity, and intensive stormwater management. The anthropogenic and hydro-climatic influences on nutrient concentration and export behavior had great implications in nutrient loading abatement strategies for aquatic ecosystem restoration of the downstream receiving waterbody. Published by Elsevier Ltd.

  5. Selection of common bean lines with high grain yield and high grain calcium and iron concentrations

    Directory of Open Access Journals (Sweden)

    Nerinéia Dalfollo Ribeiro

    2014-02-01

    Full Text Available Genetic improvement of common bean nutritional quality has advantages in marketing and can contribute to society as a food source. The objective of this study was to evaluate the genetic variability for grain yield, calcium and iron concentrations in grains of inbred common bean lines obtained by different breeding methods. For this, 136 F7 inbred lines were obtained using the Pedigree method and 136 F7 inbred lines were obtained using the Single-Seed Descent (SSD method. The lines showed genetic variability for grain yield, and concentrations of calcium and iron independently of the method of advancing segregating populations. The Pedigree method allows obtaining a greater number of lines with high grain yield. Selection using the SSD method allows the identification of a larger number of lines with high concentrations of calcium and iron in grains. Weak negative correlations were found between grain yield and calcium concentration (r = -0.0994 and grain yield and iron concentration (r = -0.3926. Several lines show genetic superiority for grain yield and concentrations of calcium and iron in grains and their selection can result in new common bean cultivars with high nutritional quality.

  6. The changing trend in nitrate concentrations in major aquifers due to historical nitrate loading from agricultural land across England and Wales from 1925 to 2150

    Energy Technology Data Exchange (ETDEWEB)

    Wang, L., E-mail: lei.wang@bgs.ac.uk [British Geological Survey, Keyworth, Nottingham NG12 5GG (United Kingdom); Stuart, M.E.; Lewis, M.A. [British Geological Survey, Maclean Building, Wallingford, Oxfordshire OX10 8BB (United Kingdom); Ward, R.S. [British Geological Survey, Keyworth, Nottingham NG12 5GG (United Kingdom); Skirvin, D. [ADAS UK Ltd., Pendeford House, Pendeford Business Park, Wobaston Road, Wolverhampton WV9 5AP (United Kingdom); Naden, P.S. [Centre for Ecology and Hydrology, Maclean Building, Wallingford, Oxfordshire OX10 8BB (United Kingdom); Collins, A.L. [Sustainable Soils and Grassland Systems Department, Rothamsted Research, North Wyke, Okehampton EX20 2SB (United Kingdom); Ascott, M.J. [British Geological Survey, Maclean Building, Wallingford, Oxfordshire OX10 8BB (United Kingdom)

    2016-01-15

    Nitrate is necessary for agricultural productivity, but can cause considerable problems if released into aquatic systems. Agricultural land is the major source of nitrates in UK groundwater. Due to the long time-lag in the groundwater system, it could take decades for leached nitrate from the soil to discharge into freshwaters. However, this nitrate time-lag has rarely been considered in environmental water management. Against this background, this paper presents an approach to modelling groundwater nitrate at the national scale, to simulate the impacts of historical nitrate loading from agricultural land on the evolution of groundwater nitrate concentrations. An additional process-based component was constructed for the saturated zone of significant aquifers in England and Wales. This uses a simple flow model which requires modelled recharge values, together with published aquifer properties and thickness data. A spatially distributed and temporally variable nitrate input function was also introduced. The sensitivity of parameters was analysed using Monte Carlo simulations. The model was calibrated using national nitrate monitoring data. Time series of annual average nitrate concentrations along with annual spatially distributed nitrate concentration maps from 1925 to 2150 were generated for 28 selected aquifer zones. The results show that 16 aquifer zones have an increasing trend in nitrate concentration, while average nitrate concentrations in the remaining 12 are declining. The results are also indicative of the trend in the flux of groundwater nitrate entering rivers through baseflow. The model thus enables the magnitude and timescale of groundwater nitrate response to be factored into source apportionment tools and to be taken into account alongside current planning of land-management options for reducing nitrate losses. - Highlights: • An approach to modelling groundwater nitrate at the national scale is presented. • The long time-lag for nitrate in the

  7. Iodine Treatment in Children with Subclinical Hypothyroidism Due to Chronic Iodine Deficiency Decreases Thyrotropin and C-Peptide Concentrations and Improves the Lipid Profile

    OpenAIRE

    M.B. Zimmermann; Aeberli, I; Boonstra, A.; Grimci, L.; Bridson, J; Chaouki, N.; Mbhenyane, X.; Jooste, P L

    2009-01-01

    Background: Chronic iodine deficiency (ID) increases thyrotropin (TSH) concentrations and produces a thyroid hormone pattern consistent with subclinical hypothyroidism (ScH). ScH may be associated with cardiovascular disease risk factors. Thus, the study aim was to determine if iodine treatment of children with elevated TSH concentrations due to ID would affect their lipid profile, insulin (C-peptide) levels, and/or subclinical inflammation. Methods: In controlled intervention trials of oral ...

  8. An Automatic High Efficient Method for Dish Concentrator Alignment

    Directory of Open Access Journals (Sweden)

    Yong Wang

    2014-01-01

    for the alignment of faceted solar dish concentrator. The isosceles triangle configuration of facet’s footholds determines a fixed relation between light spot displacements and foothold movements, which allows an automatic determination of the amount of adjustments. Tests on a 25 kW Stirling Energy System dish concentrator verify the feasibility, accuracy, and efficiency of our method.

  9. Starch source in high concentrate rations does not affect rumen pH, histamine and lipopolysaccharide concentrations in dairy cows

    NARCIS (Netherlands)

    Pilachai, R.; Schonewille, J.T.; Thamrongyoswittayakul, C.; Aiumlamai, S.; Wachirapakom, C.; Everts, H.; Hendriks, W.H.

    2012-01-01

    The replacement of ground corn by cassava meal on rumen pH, lipopolysaccharide (LPS) and histamine concentrations under typical Thai feeding conditions (high concentrate diets and rice straw as the sole source of roughage) was investigated. Four rumen-fistulated crossbred Holstein, non-pregnant, dry

  10. Bandgap Engineering in High-Efficiency Multijunction Concentrator Cells

    Energy Technology Data Exchange (ETDEWEB)

    King, R. R.; Sherif, R. A.; Kinsey, G. S.; Kurtz, S.; Fetzer, C. M.; Edmondson, K. M.; Law, D. C.; Cotal, H. L.; Krut, D. D.; Ermer, J. H.; Karam, N. H.

    2005-08-01

    This paper discusses semiconductor device research paths under investigation with the aim of reaching the milestone efficiency of 40%. A cost analysis shows that achieving very high cell efficiencies is crucial for the realization of cost-effective photovoltaics, because of the strongly leveraging effect of efficiency on module packaging and balance-of systems costs. Lattice-matched (LM) GaInP/ GaInAs/ Ge 3-junction cells have achieved the highest independently confirmed efficiency at 175 suns, 25?C, of 37.3% under the standard AM1.5D, low-AOD terrestrial spectrum. Lattice-mismatched, or metamorphic (MM), materials offer still higher potential efficiencies, if the crystal quality can be maintained. Theoretical efficiencies well over 50% are possible for a MM GaInP/ 1.17-eV GaInAs/ Ge 3-junction cell limited by radiative recombination at 500 suns. The bandgap - open circuit voltage offset, (Eg/q) - Voc, is used as a valuable theoretical and experimental tool to characterize multijunction cells with subcell bandgaps ranging from 0.7 to 2.1 eV. Experimental results are presented for prototype 6-junction cells employing an active {approx}1.1-eV dilute nitride GaInNAs subcell, with active-area efficiency greater than 23% and over 5.3 V open-circuit voltage under the 1-sun AM0 space spectrum. Such cell designs have theoretical efficiencies under the terrestrial spectrum at 500 suns concentration exceeding 55% efficiency, even for lattice-matched designs.

  11. LPWCO method for the treatment of high concentrated organic wastewater

    Institute of Scientific and Technical Information of China (English)

    1998-01-01

    Based on wet air oxidation (WAO) and Fenton reagent, thispaper raises a new low pressure wet catalytic oxidation(LPWCO)which requires low pressure for the treatment of highlyconcentrated and refractory organic wastewater. Compared withgeneral wet air oxidation, the pressure of the treatment(0.1-0.6MPa) is only one of tens to percentage of latter(3.5-10MPa). Inaddition, its temperature is no more than 180℃.Compared withFenton reagent, while H2O2/COD(weight ratio) less than 1.2, theremoval of COD in the treatment is over twenty percents more thanFenton's even the value of COD is more than 14000mg/L. In thispaper, we study the effect factor of COD removal and the mechanismof this treatment. The existence of synergistic effect (catalytic oxidation and carbonization) for COD removal in H2SO4-Fenton reagent system under the condition of applied pressure and heating (0.1-0.6MPa, 104-165℃) was verified. The best condition of this disposal are as follows:H2O2/COD(weight ratio)=0.2-1.0, Fe2+ 0.6×10-3 mol, H2SO4 0.5mol, COD>1×104mg/L, the operating pressure is 0.1-0.6MPa and temperature is 104-165℃. This method suit to dispose the high-concentrated refractory wastewater, especially to the wastewater containing H2SO produced in the manufacture of pesticide, dyestuff and petrochemical works.

  12. High Oxygen Concentrations Adversely Affect the Performance of Pulmonary Surfactant.

    Science.gov (United States)

    Smallwood, Craig D; Boloori-Zadeh, Parnian; Silva, Maricris R; Gouldstone, Andrew

    2017-08-01

    Although effective in the neonatal population, exogenous pulmonary surfactant has not demonstrated a benefit in pediatric and adult subjects with hypoxic lung injury despite a sound physiologic rationale. Importantly, neonatal surfactant replacement therapy is administered in conjunction with low fractional FIO2 while pediatric/adult therapy is administered with high FIO2 . We suspected a connection between FIO2 and surfactant performance. Therefore, we sought to assess a possible mechanism by which the activity of pulmonary surfactant is adversely affected by direct oxygen exposure in in vitro experiments. The mechanical performance of pulmonary surfactant was evaluated using 2 methods. First, Langmuir-Wilhelmy balance was utilized to study the reduction in surface area (δA) of surfactant to achieve a low bound value of surface tension after repeated compression and expansion cycles. Second, dynamic light scattering was utilized to measure the size of pulmonary surfactant particles in aqueous suspension. For both experiments, comparisons were made between surfactant exposed to 21% and 100% oxygen. The δA of surfactant was 21.1 ± 2.0% and 35.8 ± 2.0% during exposure to 21% and 100% oxygen, respectively (P = .02). Furthermore, dynamic light-scattering experiments revealed a micelle diameter of 336.0 ± 12.5 μm and 280.2 ± 11.0 μm in 21% and 100% oxygen, respectively (P < .001), corresponding to a ∼16% decrease in micelle diameter following exposure to 100% oxygen. The characteristics of pulmonary surfactant were adversely affected by short-term exposure to oxygen. Specifically, surface tension studies revealed that short-term exposure of surfactant film to high concentrations of oxygen expedited the frangibility of pulmonary surfactant, as shown with the δA. This suggests that reductions in pulmonary compliance and associated adverse effects could begin to take effect in a very short period of time. If these findings can be demonstrated in vivo, a role for

  13. Falsely elevated cyclosporin and tacrolimus concentrations over prolonged periods of time due to reversible adsorption to central venous catheters.

    Science.gov (United States)

    Hacker, Charlotte; Verbeek, Mareike; Schneider, Heike; Steimer, Werner

    2014-06-10

    Falsely elevated concentrations of immunosuppressants can be caused by reversible adsorption to central venous catheter (CVC) systems. If undetected, this may lead to dose reduction resulting in underdosage which may even entail graft-versus-host disease or organ rejection. We analyzed the adsorption and release for cyclosporine A (CsA) and tacrolimus (Tac) in vitro and in vivo. Four types of CVCs were examined in vitro: two made from polyurethane (PU), one from silicone and one from PU with an incorporated silver ion-based antimicrobial agent. All 26 CVCs analyzed in vitro showed significant reversible adsorption of CsA (n=13; p=0.001) and Tac (n=13; p=0.001, Wilcoxon signed rank test). Immediately after infusing the drugs, the mean concentrations of 6420ng/mL of CsA and 250ng/mL of Tac were measured. Flushing with NaCl lowered the drug release. Besides, blood samples of fifteen patients were taken simultaneously from all lumina of the CVC and via venipuncture. The samples from contaminated lumina showed the mean elevations by a factor of 11 for CsA (n=12) and 89 for Tac (n=3). Blood sampling for immunosuppressant monitoring should thus never be performed from lumina previously used for infusing the drug even after prolonged periods of time and extensive rinsing. Copyright © 2014 Elsevier B.V. All rights reserved.

  14. High-Efficiency Organic Solar Concentrators for Photovoltaics

    National Research Council Canada - National Science Library

    Michael J. Currie; Jonathan K. Mapel; Timothy D. Heidel; Shalom Goffri; Marc A. Baldo

    2008-01-01

    The cost of photovoltaic power can be reduced with organic solar concentrators. These are planar waveguides with a thin-film organic coating on the face and inorganic solar cells attached to the edges...

  15. Development of manufacturing capability for high-concentration, high-efficiency silicon solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Sinton, R.A.; Verlinden, P.J.; Crane, R.A.; Swanson, R.N. [SunPower Corp., Sunnyvale, CA (United States)

    1996-10-01

    This report presents a summary of the major results from a program to develop a manufacturable, high-efficiency silicon concentrator solar cell and a cost-effective manufacturing facility. The program was jointly funded by the Electric Power Research Institute, Sandia National Laboratories through the Concentrator Initiative, and SunPower Corporation. The key achievements of the program include the demonstration of 26%-efficient silicon concentrator solar cells with design-point (20 W/cm{sup 2}) efficiencies over 25%. High-performance front-surface passivations; that were developed to achieve this result were verified to be absolutely stable against degradation by 475 days of field exposure at twice the design concentration. SunPower demonstrated pilot production of more than 1500 of these cells. This cell technology was also applied to pilot production to supply 7000 17.7-cm{sup 2} one-sun cells (3500 yielded wafers) that demonstrated exceptional quality control. The average efficiency of 21.3% for these cells approaches the peak efficiency ever demonstrated for a single small laboratory cell within 2% (absolute). Extensive cost models were developed through this program and calibrated by the pilot-production project. The production levels achieved indicate that SunPower could produce 7-10 MW of concentrator cells per year in the current facility based upon the cell performance demonstrated during the program.

  16. Highly Sensitive Cadmium Concentration Sensor Using Long Period Grating

    Directory of Open Access Journals (Sweden)

    A. S. Lalasangi

    2011-08-01

    Full Text Available In this paper we have proposed a simple and effective Long Period Grating chemical sensor for detecting the traces of Cadmium (Cd++ in drinking water at ppm level. Long Period gratings (LPG were fabricated by point-by-point technique with CO2 laser. We have characterized the LPG concentration sensor sensitivity for different solutions of Cd concentrations varying from 0.01 ppm to 0.04 ppm by injecting white Light source and observed transmitted spectra using Optical Spectrum Analyzer (OSA. Proper reagents have been used in the solutions for detection of the Cd species. The overall shift in wavelength is 10 nm when surrounding medium gradually changed from water to 0.04 ppm of cadmium concentrations. A comparative study has been done using sophisticated spectroscopic atomic absorption spectrometer (AAS and Inductively Coupled Plasma (ICP instruments. The spectral sensitivity enhancement was done by modifying grating surface with gold nanoparticles.

  17. High variability of dissolved iron concentrations in the vicinity of Kerguelen Island (Southern Ocean

    Directory of Open Access Journals (Sweden)

    F. Quéroué

    2015-01-01

    Full Text Available Dissolved Fe (dFe concentrations were measured in the upper 1300 m of the water column in the vicinity of Kerguelen Island as part of the second Kerguelen Ocean Plateau compared Study (KEOPS2. Concentrations ranged from 0.06 nmol L−1 in offshore, Southern Ocean waters, to 3.82 nmol L−1 within Hillsborough Bay, on the north-eastern coast of Kerguelen Island. Direct island runoff, glacial melting and resuspended sediments were identified as important inputs of dFe that could potentially fertilize the northern part of the plateau. A significant deep dFe enrichment was observed over the plateau with dFe concentrations increasing up to 1.30 nmol L−1 close to the seafloor, probably due to sediment resuspension and pore water release. Biological uptake was identified as a likely explanation for the decrease in dFe concentrations between two visits (28 days apart at a station above the plateau. Our results allowed studying other processes and sources, such as atmospheric inputs, lateral advection of enriched seawater, remineralization processes and the influence of the Polar Front (PF as a vector for Fe transport. Overall, heterogeneous sources of Fe over and off the Kerguelen Plateau, in addition to strong variability in Fe supply by vertical or horizontal transport, may explain the high variability in dFe concentrations observed during this study.

  18. Changes in guava (Psidium guajava L. var. Paluma nectar volatile compounds concentration due to thermal processing and storage

    Directory of Open Access Journals (Sweden)

    Maria Ivaneide Coutinho Correa

    2010-12-01

    Full Text Available Guava nectars were formulated for approximately 10, 12, or 14 ºBrix, with 40% guava pulp. Sodium benzoate, 500 mg.kg-1 was used as preservative. The Brix value was adjusted with saturated sucrose syrup. The guava nectar was pasteurized (85 ºC/42 seconds in tubular heat exchanger and then hot filled in 500 mL white glass bottles. The products were stored either at room temperature (25 ± 5 ºC or refrigerated (5 ± 2 ºC under fluorescent light exposure and analyzed on the day after processing (time zero and also 40, 80, and 120 days of storage. Eight compounds were identified and quantified by Gas Chromatography (GC -Mass Spectrometry (MS: hexanal, (E-hex-2-enal, 1-hexenol, (Z-hex-3-enol, (Z-hex-3-enyl acetate, phenyl-3-propyl acetate, cinnamyl acetate, and acetic acid. There was no significant effect of thermal treatment on the volatile compound concentrations, except for a significant decrease (p = 0.0001 in hexanal and (Z-hex-3-enyl acetate (p = 0.0029. As for the storage time, there was a much greater decrease in the esters contents, such as (Z-hex-3-enyl and phenyl-3-propyl acetates. Cinnamyl acetate had the greatest decrease over storage time. Refrigeration was better than room temperature for guava nectar volatile compounds stability over storage time, mainly for esters compounds, which are important for the product aroma and flavor

  19. Methods and devices for high-throughput dielectrophoretic concentration

    Energy Technology Data Exchange (ETDEWEB)

    Simmons, Blake A. (San Francisco, CA); Cummings, Eric B. (Livermore, CA); Fiechtner, Gregory J. (Germantown, MD); Fintschenko, Yolanda (Livermore, CA); McGraw, Gregory J. (Ann Arbor, MI); Salmi, Allen (Escalon, CA)

    2010-02-23

    Disclosed herein are methods and devices for assaying and concentrating analytes in a fluid sample using dielectrophoresis. As disclosed, the methods and devices utilize substrates having a plurality of pores through which analytes can be selectively prevented from passing, or inhibited, on application of an appropriate electric field waveform. The pores of the substrate produce nonuniform electric field having local extrema located near the pores. These nonuniform fields drive dielectrophoresis, which produces the inhibition. Arrangements of electrodes and porous substrates support continuous, bulk, multi-dimensional, and staged selective concentration.

  20. Methods and devices for high-throughput dielectrophoretic concentration

    Science.gov (United States)

    Simmons, Blake A.; Cummings, Eric B.; Fiechtner, Gregory J.; Fintschenko, Yolanda; McGraw, Gregory J.; Salmi, Allen

    2010-02-23

    Disclosed herein are methods and devices for assaying and concentrating analytes in a fluid sample using dielectrophoresis. As disclosed, the methods and devices utilize substrates having a plurality of pores through which analytes can be selectively prevented from passing, or inhibited, on application of an appropriate electric field waveform. The pores of the substrate produce nonuniform electric field having local extrema located near the pores. These nonuniform fields drive dielectrophoresis, which produces the inhibition. Arrangements of electrodes and porous substrates support continuous, bulk, multi-dimensional, and staged selective concentration.

  1. Ring Structure Formation in Protoplanetary Disks due to the Two-Fluid Secular Gravitational Instability: An Indicator of Dust Concentration

    CERN Document Server

    Takahashi, Sanemichi Z

    2013-01-01

    The instability in protoplanetary disks due to gas-dust friction and self-gravity of gas and dust is investigated by linear analysis. For conditions typical of protoplanetaly disks, the instability grows, even in gravitationally stable disks, on a timescale of order $10^{4-5}$yr at a radius of order 100AU. If we ignore the dynamical feedback from dust grains in the gas equation of motion, the instability reduces to the so-called "secular gravitational instability", that was investigated previously as the instability of dust in a fixed background gas flow. In this work, we solve the equation of motion for both gas and dust consistently and find that long-wavelength perturbations are stable, in contrast to the secular gravitational instability in the simplified treatment. The instability is expected to form ring structures in protoplanetary disks. The width of the ring formed at a radius of 100 AU is a few tens of AU. Therefore, the instability is a candidate for the formation mechanism of observed ring-like st...

  2. Pulsed high harmonic generation of light due to pumped Bloch oscillations in noninteracting metals

    CERN Document Server

    Freericks, J K; Kemper, A F; Devereaux, T P; 10.1088/0031-8949/2012/T151/014062

    2012-01-01

    We derive a simple theory for high-order harmonic generation due to pumping a noninteracting metal with a large amplitude oscillating electric field. The model assumes that the radiated light field arises from the acceleration of electrons due to the time-varying current generated by the pump, and also assumes that the system has a constant density of photoexcited carriers, hence it ignores the dipole excitation between bands (which would create carriers in semiconductors). We examine the circumstances under which odd harmonic frequencies would be expected to dominate the spectrum of radiated light, and we also apply the model to real materials like ZnO, for which high-order harmonic generation has already been demonstrated in experiments.

  3. High Quantum Efficiency and High Concentration Erbium-Doped Silica Glasses Fabricated by Sintering Nanoporous Glasses

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    A new method was used to prepare erbium-doped high silica (SiO2%>96%) glasses by sintering nanoporous glasses. The concentration of erbium ions in high silica glasses can be considerably more than that in silica glasses prepared by using conventional methods. The fluorescence of 1532 nm has an FWHM (Full Wave at Half Maximum) of 50 nm, wider than 35 nm of EDSFA (erbium-doped silica fiber amplifer), and hence the glass possesses potential application in broadband fiber amplifiers. The Judd-Ofelt theoretical analysis reflects that the quantum efficiency of this erbium-doped glass is about 0.78, although the erbium concentration in this glass (6×103) is about twenty times higher than that in silica glass. These excellent characteristics of Er-doped high silica glass will be conducive to its usage in optical amplifiers and microchip lasers.

  4. High-voltage electrical burns due to copper theft - Case series.

    Science.gov (United States)

    Braga, M J; Oliveira, I; Egipto, P; Silva, A

    2016-03-31

    Electrical burns are among the most devastating trauma inflicted on the human body. These burns have a higher morbidity, length of stay and a much higher risk of amputation than any other type of burn. Electrical burns affect mostly young, working males because they are more frequently the result of a work accident. However, possibly due to the worldwide economic crisis, we are experiencing a new phenomenon: the theft of high-voltage copper wiring.

  5. High-voltage electrical burns due to copper theft – Case series

    Science.gov (United States)

    Braga, M.J.; Oliveira, I.; Egipto, P.; Silva, A.

    2016-01-01

    Summary Electrical burns are among the most devastating trauma inflicted on the human body. These burns have a higher morbidity, length of stay and a much higher risk of amputation than any other type of burn. Electrical burns affect mostly young, working males because they are more frequently the result of a work accident. However, possibly due to the worldwide economic crisis, we are experiencing a new phenomenon: the theft of high-voltage copper wiring. PMID:27857650

  6. A Rectourethral Fistula due to Transrectal High-Intensity Focused Ultrasound Treatment: Diagnosis and Management

    OpenAIRE

    2012-01-01

    Colovesical fistula (CVF) is an abnormal connection between the enteric and the urinary systems. The rectourethral fistula (RUF) is a possible but extremely rare complication of treatment of prostate cancer with “transrectal High-Intensity Focused Ultrasound (HIFU) treatment.” We present a case of CVF due to HIFU treatment of recurrent prostate cancer. The case was assessed with cystography completed with a pelvic CT scan—with MPR, MIP, and VR reconstruction—before emptying the bladder. Since...

  7. Concentration measurement of yeast suspensions using high frequency ultrasound backscattering.

    Science.gov (United States)

    Elvira, Luis; Vera, Pedro; Cañadas, Francisco Jesús; Shukla, Shiva Kant; Montero, Francisco

    2016-01-01

    This work proposes the use of an ultrasound based technique to measure the concentration of yeasts in liquid suspension. This measurement was achieved by the detection and quantification of ultrasonic echoes backscattered by the cells. More specifically, the technique was applied to the detection and quantification of Saccharomyces cerevisiae. A theoretical approach was proposed to get the average density and sound speed of the yeasts, which were found to be 1116 kg/m(3) and 1679 m/s, respectively. These parameters were needed to model the waves backscattered by each single cell. A pulse-echo arrangement working around 50 MHz, being able to detect echoes from single yeasts was used to characterize experimentally yeast solutions from 10(2) to 10(7)cells/ml. The Non-negative Matrix Factorization denoising technique was applied for data analysis. This technique required a previous learning of the spectral patterns of the echoes reflected from yeasts in solution and the base noise from the liquid medium. Comparison between pulse correlation (without denoising) and theoretical and experimental pattern learning was made to select the best signal processing. A linear relation between ultrasound output and concentration was obtained with correlation coefficient R(2)=0.996 for the experimental learning. Concentrations from 10(4) to 10(7)cells/ml were detected above the base noise. These results show the viability of using the ultrasound backscattering technique to detect yeasts and measure their concentration in liquid cultures, improving the sensitivity obtained using spectrophotometric methods by one order of magnitude.

  8. Dimerization in Highly Concentrated Solutions of Phosphoimidazolide Activated Monomucleotides

    Science.gov (United States)

    Kanavarioti, Anastassia

    1997-08-01

    Phosphoimidazolide activated ribomononucleotides (*pN) are useful substrates for the non-enzymatic synthesis of polynucleotides. However, dilute neutral aqueous solutions of *pN typically yield small amounts of dimers and traces of polymers; most of *pN hydrolyzes to yield nucleoside 5'-monophosphate. Here we report the self-condensation of nucleoside 5'-phosphate 2-methylimidazolide (2-MeImpN with N = cytidine, uridine or guanosine) in the presence of Mg2+ in concentrated solutions, such as might have been found in an evaporating lagoon on prebiotic Earth. The product distribution indicates that oligomerization is favored at the expense of hydrolysis. At 1.0 M, 2-MeImpU and 2-MeImpC produce about 65% of oligomers including 4% of the 3',5'-linked dimer. Examination of the product distribution of the three isomeric dimers in a self-condensation allows identification of reaction pathways that lead to dimer formation. Condensations in a concentrated mixture of all three nucleotides (U,C,G mixtures) is made possible by the enhanced solubility of 2-MeImpG in such mixtures. Although percent yield of internucleotide linked dimers is enhanced as a function of initial monomer concentration, pyrophosphate dimer yields remain practically unchanged at about 20% for 2-MeImpU, 16% for 2-MeImpC and 25% of the total pyrophosphate in the U,C,G mixtures. The efficiency by which oligomers are produced in these concentrated solutions makes the evaporating lagoon scenario a potentially interesting medium for the prebiotic synthesis of dimers and short RNAs.

  9. Transient pool boiling heat transfer due to increasing heat inputs in subcooled water at high pressures

    Energy Technology Data Exchange (ETDEWEB)

    Fukuda, K. [Kobe Univ. of Mercantile Marine (Japan); Shiotsu, M.; Sakurai, A. [Kyoto Univ. (Japan)

    1995-09-01

    Understanding of transient boiling phenomenon caused by increasing heat inputs in subcooled water at high pressures is necessary to predict correctly a severe accident due to a power burst in a water-cooled nuclear reactor. Transient maximum heat fluxes, q{sub max}, on a 1.2 mm diameter horizontal cylinder in a pool of saturated and subcooled water for exponential heat inputs, q{sub o}e{sup t/T}, with periods, {tau}, ranging from about 2 ms to 20 s at pressures from atmospheric up to 2063 kPa for water subcoolings from 0 to about 80 K were measured to obtain the extended data base to investigate the effect of high subcoolings on steady-state and transient maximum heat fluxes, q{sub max}. Two main mechanisms of q{sub max} exist depending on the exponential periods at low subcoolings. One is due to the time lag of the hydrodynamic instability which starts at steady-state maximum heat flux on fully developed nucleate boiling (FDNB), and the other is due to the heterogenous spontaneous nucleations (HSN) in flooded cavities which coexist with vapor bubbles growing up from active cavities. The shortest period corresponding to the maximum q{sub max} for long period range belonging to the former mechanism becomes longer and the q{sub max}mechanism for long period range shifts to that due the HSN on FDNB with the increase of subcooling and pressure. The longest period corresponding to the minimum q{sub max} for the short period range belonging to the latter mechanism becomes shorter with the increase in saturated pressure. On the contrary, the longest period becomes longer with the increase in subcooling at high pressures. Correlations for steady-state and transient maximum heat fluxes were presented for a wide range of pressure and subcooling.

  10. High concentrations of pepsin in bronchoalveolar lavage fluid from children with cystic fibrosis are associated with high interleukin-8 concentrations.

    LENUS (Irish Health Repository)

    McNally, P

    2012-02-01

    BACKGROUND: Gastro-oesophageal reflux is common in children with cystic fibrosis (CF) and is thought to be associated with pulmonary aspiration of gastric contents. The measurement of pepsin in bronchoalveolar lavage (BAL) fluid has recently been suggested to be a reliable indicator of aspiration. The prevalence of pulmonary aspiration in a group of children with CF was assessed and its association with lung inflammation investigated. METHODS: This was a cross-sectional case-control study. BAL fluid was collected from individuals with CF (n=31) and healthy controls (n=7). Interleukin-8 (IL-8), pepsin, neutrophil numbers and neutrophil elastase activity levels were measured in all samples. Clinical, microbiological and lung function data were collected from medical notes. RESULTS: The pepsin concentration in BAL fluid was higher in the CF group than in controls (mean (SD) 24.4 (27.4) ng\\/ml vs 4.3 (4.0) ng\\/ml, p=0.03). Those with CF who had raised pepsin concentrations had higher levels of IL-8 in the BAL fluid than those with a concentration comparable to controls (3.7 (2.7) ng\\/ml vs 1.4 (0.9) ng\\/ml, p=0.004). Within the CF group there was a moderate positive correlation between pepsin concentration and IL-8 in BAL fluid (r=0.48, p=0.04). There was no association between BAL fluid pepsin concentrations and age, sex, body mass index z score, forced expiratory volume in 1 s or Pseudomonas aeruginosa colonisation status. CONCLUSIONS: Many children with CF have increased levels of pepsin in the BAL fluid compared with normal controls. Increased pepsin levels were associated with higher IL-8 concentrations in BAL fluid. These data suggest that aspiration of gastric contents occurs in a subset of patients with CF and is associated with more pronounced lung inflammation.

  11. High pressure inertial focusing for separating and concentrating bacteria at high throughput

    Science.gov (United States)

    Cruz, J.; Hooshmand Zadeh, S.; Graells, T.; Andersson, M.; Malmström, J.; Wu, Z. G.; Hjort, K.

    2017-08-01

    Inertial focusing is a promising microfluidic technology for concentration and separation of particles by size. However, there is a strong correlation of increased pressure with decreased particle size. Theory and experimental results for larger particles were used to scale down the phenomenon and find the conditions that focus 1 µm particles. High pressure experiments in robust glass chips were used to demonstrate the alignment. We show how the technique works for 1 µm spherical polystyrene particles and for Escherichia coli, not being harmful for the bacteria at 50 µl min-1. The potential to focus bacteria, simplicity of use and high throughput make this technology interesting for healthcare applications, where concentration and purification of a sample may be required as an initial step.

  12. New PSA high concentration solar furnace SF40

    Science.gov (United States)

    Rodriguez, Jose; Cañadas, Inmaculada; Zarza, Eduardo

    2016-05-01

    A new solar furnace has been designed and built at Plataforma Solar de Almería. In this work, its main components such as heliostat, concentrator, attenuator and test table, and the method used to align them are described. Other equipment like the auxiliary systems necessary for the solar operation, vacuum chamber and gas system are outlined too. Finally, the thermal characteristics of the focus were measured during a test campaign, where different planes along the optical axis were scanned with a radiometer, and the peak flux was obtained and is presented in the last section of this report.

  13. The Effects of Nickel Concentration on Heat-Treated High-Speed Steel Magnetoelastic Torque Transducers

    Science.gov (United States)

    Franklin, Doug; Gordon, Ryan; Orris, Jason; Boley, Mark

    2003-03-01

    We have previously determined that a ferromagnetic high-speed maraging steel alloy of 18as C250) is one of the best materials for use in the construction of a "ring type" torque sensor on a non-ferromagnetic shaft used for power transmission applications. We created two distinct portions of the ring in which a high degree of oppositely polarized circumferential magnetization was maintained with a saturated alignment of the magnetic domains due to the high circumferential coercive force. Transducer sensitivities (field signal per applied torque) range from 14 - 31 mG/N-m following appropriate heat treatments of these rings. However, in many applications where a sensory ring would be impractical, the same type of magnetic arrangement, albeit with slightly lower sensitivities, can also be produced in a hollow ferromagnetic high-speed steel "shaft type" torque sensor. However, much lower nickel concentrations are required to prevent the shafts from being too brittle for most torque transfer applications; the downside of this is that we have found the transducer sensitivities to dramatically decrease with the nickel concentration. The three steel shafts we investigated had respective nickel concentrations of 0.20steel types W-1, O-1, and Kapstar. Their transducer sensitivities were found as 1.5, 5.5, and 8.5 mG/N-m, respectively, and also exhibited slight increases following the standard heat treatments of the steel. The area of the axial hysteresis curves for these three steels was found to decrease with nickel concentration, with relatively little change in the circumferential.

  14. High-performance flat-panel solar thermoelectric generators with high thermal concentration.

    Science.gov (United States)

    Kraemer, Daniel; Poudel, Bed; Feng, Hsien-Ping; Caylor, J Christopher; Yu, Bo; Yan, Xiao; Ma, Yi; Wang, Xiaowei; Wang, Dezhi; Muto, Andrew; McEnaney, Kenneth; Chiesa, Matteo; Ren, Zhifeng; Chen, Gang

    2011-05-01

    The conversion of sunlight into electricity has been dominated by photovoltaic and solar thermal power generation. Photovoltaic cells are deployed widely, mostly as flat panels, whereas solar thermal electricity generation relying on optical concentrators and mechanical heat engines is only seen in large-scale power plants. Here we demonstrate a promising flat-panel solar thermal to electric power conversion technology based on the Seebeck effect and high thermal concentration, thus enabling wider applications. The developed solar thermoelectric generators (STEGs) achieved a peak efficiency of 4.6% under AM1.5G (1 kW m(-2)) conditions. The efficiency is 7-8 times higher than the previously reported best value for a flat-panel STEG, and is enabled by the use of high-performance nanostructured thermoelectric materials and spectrally-selective solar absorbers in an innovative design that exploits high thermal concentration in an evacuated environment. Our work opens up a promising new approach which has the potential to achieve cost-effective conversion of solar energy into electricity.

  15. EFFECT OF HIGH CONCENTRATIONS OF 2.4-DCP ON ACTIVATED SLUDGE

    Directory of Open Access Journals (Sweden)

    Ayla Uysal

    2007-02-01

    Full Text Available Biodegradation of 2.4-dichlorophenol (2.4-DCP was investigated with a mixed culture in a continuous activated sludge bioreactor. Glucose was used as co-substrate. Experiments were carried out at the feed 2.4-DCP concentrations between 5-450 mg/l, and the removal efficiencies of 2.4-DCP and COD were determined. The removal efficiencies and specific removal rates of 2.4-DCP for feed 2.4-DCP concentration up to 350 mg/l varied between 96.3-98.6 % and 0.007-1.15 mg/mg X.day respectively. Removal efficiencies and specific removal rates ranged between 75.66-92.0 % and 0.43-1.29 mg/mg X.day for COD. When 2.4-DCP concentration was increased from 350 to 450 mg/l, the removal efficiency and specific removal rate of 2.4-DCP decreased to 42.6 % and 0.77 mg/mg X.day due to the substrate inhibition on the microorganisms. Also, these values decreased to 7.85 % and 0.18 mg/mg X.day for COD. These results indicate that the adaptation of activated sludge could tolerate as high as 350 mg/l 2.4-DCP concentration as to the removal of 2.4-DCP and COD.

  16. The ability of fungus Mucor racemosus Fresenius to degrade high concentration of detergent

    Directory of Open Access Journals (Sweden)

    Jakovljević Violeta D.

    2014-01-01

    Full Text Available The ability of fungus Mucor racemosus Fresenius to decompose high concentration of commercial detergent (MERIX, Henkel, Serbia was investigated in this study. Fungus was cultivated in liquid growth medium by Czapek with addition of detergent at concentration 0.5% during 16 days. The biochemical changes of pH, redox potential, amount of free and total organic acids, and activity of alkaline phosphatase were evaluated by analysis of fermentation broth. Simultaneously, biodegradation percentage of anionic surfactant of tested detergent was confirmed by MBAS assay. At the same time, the influence of detergent on fungal growth and total dry weight biomass was determined. Detergent at concentration 0.5% influenced on decreasing of pH value and increasing of redox potential as well as increasing of free and total organic acids. Enzyme activity of alkaline phosphatase was reduced by detergent at concentration 0.5%. The fungus was decomposed about 62% of anionic surfactant during 16 day. Due to fungus was produced higher dry weight biomass (53% in relation to control. [Projekat Ministarstva nauke Republike Srbije, br. III 43004

  17. Ionic Behavior in Highly Concentrated Aqueous Solutions Nanoconfined between Discretely Charged Silicon Surfaces.

    Science.gov (United States)

    Qiu, Yinghua; Ma, Jian; Chen, Yunfei

    2016-05-17

    Through molecular dynamics simulations considering thermal vibration of surface atoms, ionic behaviors in concentrated NaCl solutions confined between discretely charged silicon surfaces have been investigated. The electric double layer structure was found to be sensitive to the density and distribution of surface charges. Due to the discreteness of the surface charge, a slight charge inversion appeared which depended on the surface charge density, bulk concentration, and confinement. In the nanoconfined NaCl solutions concentrated from 0.2 to 4.0 M, the locations of accumulation layers for Na(+) and Cl(-) ions remained stable, but their peak values increased. The higher the concentration was, the more obvious the charge inversion appeared. In 4.0 M NaCl solution, Na(+) and Cl(-) ions show obvious alternating layered distributions which may correspond to the solidification found in experiments. By changing surface separation, the confinement had a large effect on the ionic distribution. As both surfaces approached each other, many ions and water molecules were squeezed out of the confined space. Two adjacent layers in ion or water distribution profiles can be forced closer to each other and merge together. From ionic hydration analysis, the coordination number of Na(+) ions in highly confined space was much lower than that in the bulk.

  18. High Energy Density Lithium Air Batteries for Oxygen Concentrators Project

    Data.gov (United States)

    National Aeronautics and Space Administration — For NASA's Exploration Medical Capabilities mission, extremely high specific energy power sources, with specific energy over 2000 Wh/kg, are urgently sought after....

  19. Highly Stable Operation of Lithium Metal Batteries Enabled by the Formation of a Transient High Concentration Electrolyte Layer

    Energy Technology Data Exchange (ETDEWEB)

    Zheng, Jianming; Yan, Pengfei; Mei, Donghai; Engelhard, Mark H.; Cartmell, Samuel S.; Polzin, Bryant; Wang, Chong M.; Zhang, Jiguang; Xu, Wu

    2016-02-08

    Lithium (Li) metal has been extensively investigated as an anode for rechargeable battery applications due to its ultrahigh specific capacity and the lowest redox potential. However, significant challenges including dendrite growth and low Coulombic efficiency are still hindering the practical applications of rechargeable Li metal batteries. Here, we demonstrate that long-term cycling of Li metal batteries can be realized by the formation of a transient high concentration electrolyte layer near the surface of Li metal anode during high rate discharge process. The highly concentrated Li+ ions in this transient layer will immediately solvate with the available solvent molecules and facilitate the formation of a stable and flexible SEI layer composed of a poly(ethylene carbonate) framework integrated with other organic/inorganic lithium salts. This SEI layer largely suppresses the corrosion of Li metal anode by free organic solvents and enables the long-term operation of Li metal batteries. The fundamental findings in this work provide a new direction for the development and operation of Li metal batteries that could be operated at high current densities for a wide range of applications.

  20. Celecoxib concentration predicts decrease in prostaglandin E2 concentrations in nipple aspirate fluid from high risk women

    Directory of Open Access Journals (Sweden)

    Flynn John T

    2008-02-01

    Full Text Available Abstract Background Epidemiologic studies suggest that long term low dose celecoxib use significantly lowers breast cancer risk. We previously demonstrated that 400 mg celecoxib taken twice daily for 2 weeks lowered circulating plasma and breast nipple aspirate fluid (NAF prostaglandin (PGE2 concentrations in post- but not premenopausal high risk women. We hypothesized that circulating concentrations of celecoxib influenced PGE2 response, and that plasma levels of the drug are influenced by menopausal status. To address these hypotheses, the aims of the study were to determine: 1 if circulating plasma concentrations of celecoxib correlated with the change in plasma or NAF PGE2 concentrations from baseline to end of treatment, and 2 whether menopausal status influenced circulating levels of celecoxib. Methods Matched NAF and plasma were collected from 46 high risk women who were administered celecoxib twice daily for two weeks, 20 subjects receiving 200 mg and 26 subjects 400 mg of the agent. NAF and plasma samples were collected before and 2 weeks after taking celecoxib. Results In women taking 400 mg bid celecoxib, plasma concentrations of the agent correlated inversely with the change in NAF PGE2 levels from pre- to posttreatment. Nonsignificant trends toward higher celecoxib levels were observed in post- compared to premenopausal women. There was a significant decrease in NAF but not plasma PGE2 concentrations in postmenopausal women who took 400 mg celecoxib (p = 0.03. Conclusion In high risk women taking 400 mg celecoxib twice daily, plasma concentrations of celecoxib correlated with downregulation of PGE2 production by breast tissue. Strategies synergistic with celecoxib to downregulate PGE2 are of interest, in order to minimize the celecoxib dose required to have an effect.

  1. High-efficiency deflection of high energy protons due to channeling along the axis of a bent silicon crystal

    Science.gov (United States)

    Scandale, W.; Arduini, G.; Butcher, M.; Cerutti, F.; Garattini, M.; Gilardoni, S.; Lechner, A.; Masi, A.; Mirarchi, D.; Montesano, S.; Redaelli, S.; Rossi, R.; Smirnov, G.; Breton, D.; Burmistrov, L.; Chaumat, V.; Dubos, S.; Maalmi, J.; Puill, V.; Stocchi, A.; Bagli, E.; Bandiera, L.; Germogli, G.; Guidi, V.; Mazzolari, A.; Dabagov, S.; Murtas, F.; Addesa, F.; Cavoto, G.; Iacoangeli, F.; Galluccio, F.; Afonin, A. G.; Chesnokov, Yu. A.; Durum, A. A.; Maisheev, V. A.; Sandomirskiy, Yu. E.; Yanovich, A. A.; Kovalenko, A. D.; Taratin, A. M.; Denisov, A. S.; Gavrikov, Yu. A.; Ivanov, Yu. M.; Lapina, L. P.; Malyarenko, L. G.; Skorobogatov, V. V.; James, T.; Hall, G.; Pesaresi, M.; Raymond, M.

    2016-09-01

    A deflection efficiency of about 61% was observed for 400 GeV/c protons due to channeling, most strongly along the axis of a bent silicon crystal. It is comparable with the deflection efficiency in planar channeling and considerably larger than in the case of the axis. The measured probability of inelastic nuclear interactions of protons in channeling along the axis is only about 10% of its amorphous level whereas in channeling along the (110) planes it is about 25%. High efficiency deflection and small beam losses make this axial orientation of a silicon crystal a useful tool for the beam steering of high energy charged particles.

  2. Sn migration control at high temperature due to high deposition speed for forming high-quality GeSn layer

    Science.gov (United States)

    Taoka, Noriyuki; Capellini, Giovanni; von den Driesch, Nils; Buca, Dan; Zaumseil, Peter; Schubert, Markus Andreas; Klesse, Wolfgang Matthias; Montanari, Michele; Schroeder, Thomas

    2016-03-01

    A key factor for controlling Sn migration during GeSn deposition at a high temperature of 400 °C was investigated. Calculated results with a simple model for the Sn migration and experimental results clarified that low-deposition-speed (vd) deposition with vd’s of 0.68 and 2.8 nm/min induces significant Sn precipitation, whereas high-deposition-speed (vd = 13 nm/min) deposition leads to high crystallinity and good photoluminescence spectrum of the GeSn layer. These results indicate that vd is a key parameter, and that control of Sn migration at a high temperature is possible. These results are of great relevance for the application of high-quality Sn-based alloys in future optoelectronics devices.

  3. Determination of water quality variables, endotoxin concentration, and enterobacteriaceae concentration and identification in Southern High Plains dairy lagoons

    Science.gov (United States)

    The objectives of this study were to determine the concentration of endotoxin, determine 20 water quality variables, and identify and enumerate fungal and bacterial pathogens from United States southern High Plains dairy lagoons and control lakes during summer and winter. Water samples were collecte...

  4. High-Performance Near-Infrared Luminescent Solar Concentrators.

    Science.gov (United States)

    Rondão, Raquel; Frias, Ana R; Correia, Sandra F H; Fu, Lianshe; de Zea Bermudez, Verónica; André, Paulo S; Ferreira, Rute A S; Carlos, Luís D

    2017-04-12

    Luminescent solar concentrators (LSCs) appear as candidates to enhance the performance of photovoltaic (PV) cells and contribute to reduce the size of PV systems, decreasing, therefore, the amount of material needed and thus the cost associated with energy conversion. One way to maximize the device performance is to explore near-infrared (NIR)-emitting centers, resonant with the maximum optical response of the most common Si-based PV cells. Nevertheless, very few examples in the literature demonstrate the feasibility of fabricating LSCs emitting in the NIR region. In this work, NIR-emitting LSCs are reported using silicon 2,3-naphthalocyanine bis(trihexylsilyloxide) (SiNc or NIR775) immobilized in an organic-inorganic tri-ureasil matrix (t-U(5000)). The photophysical properties of the SiNc dye incorporated into the tri-ureasil host closely resembled those of SiNc in tetrahydrofuran solution (an absolute emission quantum yield of ∼0.17 and a fluorescence lifetime of ∼3.6 ns). The LSC coupled to a Si-based PV device revealed an optical conversion efficiency of ∼1.5%, which is among the largest values known in the literature for NIR-emitting LSCs. The LSCs were posteriorly coupled to a Si-based commercial PV cell, and the synergy between the t-U(5000) and SiNc molecules enabled an effective increase in the external quantum efficiency of PV cells, exceeding 20% in the SiNc absorption region.

  5. Emulsifier development for high-concentrated reverse emulsions

    OpenAIRE

    Kovalenko, I. L.; V.P. Kuprin

    2016-01-01

    The reverse emulsions have found broad application in ore mining industry as matrixes of emulsion explosive substances and boring washing waters. The defining characteristic of reverse emulsions of industrial explosive substances is the high stability and immunity to crystallization. Aim: The aim of this work is to assess the mechanism of emulsifiers effect like SMO and some PIBSA-derivatives, that are most abundantly used in world practice, and also to develop an effective domestic emulsifie...

  6. High urinary phthalate concentration associated with delayed pubarche in girls

    DEFF Research Database (Denmark)

    Frederiksen, H; Sørensen, K; Mouritsen, A;

    2012-01-01

    Phthalates are a group of chemicals present in numerous consumer products. They have anti-androgenic properties in experimental studies and are suspected to be involved in human male reproductive health problems. A few studies have shown associations between phthalate exposure and changes...... and controls. We demonstrated that delayed pubarche, but not thelarche, was associated with high phthalate excretion in urine samples from 725 healthy school girls, which may suggest anti-androgenic actions of phthalates in our study group of girls....

  7. Deep Sea Memory of High Atmospheric CO2 Concentration

    Science.gov (United States)

    Mathesius, Sabine; Hofmann, Matthias; Caldeira, Ken; Schellnhuber, Hans Joachim

    2015-04-01

    Carbon dioxide removal (CDR) from the atmosphere has been proposed as a powerful measure to mitigate global warming and ocean acidification. Planetary-scale interventions of that kind are often portrayed as "last-resort strategies", which need to weigh in if humankind keeps on enhancing the climate-system stock of CO2. Yet even if CDR could restore atmospheric CO2 to substantially lower concentrations, would it really qualify to undo the critical impacts of past emissions? In the study presented here, we employed an Earth System Model of Intermediate Complexity (EMIC) to investigate how CDR might erase the emissions legacy in the marine environment, focusing on pH, temperature and dissolved oxygen. Against a background of a world following the RCP8.5 emissions path ("business-as-usual") for centuries, we simulated the effects of two massive CDR interventions with CO2 extraction rates of 5 GtC yr-1 and 25 GtC yr-1, respectively, starting in 2250. We found that the 5 GtC yr-1 scheme would have only minor ameliorative influence on the oceans, even after several centuries of application. By way of contrast, the extreme 25 GtC yr-1 scheme eventually leads to tangible improvements. However, even with such an aggressive measure, past CO2 emissions leave a substantial legacy in the marine environment within the simulated period (i.e., until 2700). In summary, our study demonstrates that anthropogenic alterations of the oceans, caused by continued business-as-usual emissions, may not be reversed on a multi-centennial time scale by the most aspirational geoengineering measures. We also found that a transition from the RCP8.5 state to the state of a strong mitigation scenario (RCP2.6) is not possible, even under the assumption of extreme extraction rates (25 GtC yr-1). This is explicitly demonstrated by simulating additional scenarios, starting CDR already in 2150 and operating until the atmospheric CO2 concentration reaches 280 ppm and 180 ppm, respectively. The simulated

  8. High plasma uric acid concentration: causes and consequences

    Directory of Open Access Journals (Sweden)

    de Oliveira Erick

    2012-04-01

    Full Text Available Abstract High plasma uric acid (UA is a precipitating factor for gout and renal calculi as well as a strong risk factor for Metabolic Syndrome and cardiovascular disease. The main causes for higher plasma UA are either lower excretion, higher synthesis or both. Higher waist circumference and the BMI are associated with higher insulin resistance and leptin production, and both reduce uric acid excretion. The synthesis of fatty acids (tryglicerides in the liver is associated with the de novo synthesis of purine, accelerating UA production. The role played by diet on hyperuricemia has not yet been fully clarified, but high intake of fructose-rich industrialized food and high alcohol intake (particularly beer seem to influence uricemia. It is not known whether UA would be a causal factor or an antioxidant protective response. Most authors do not consider the UA as a risk factor, but presenting antioxidant function. UA contributes to > 50% of the antioxidant capacity of the blood. There is still no consensus if UA is a protective or a risk factor, however, it seems that acute elevation is a protective factor, whereas chronic elevation a risk for disease.

  9. Damage evaluation in metal structures subjected to high energy deposition due to particle beams

    CERN Document Server

    Peroni, L; Dallocchio, A

    2011-01-01

    The unprecedented energy intensities of modern hadron accelerators yield special problems with the materials that are placed close to or into the high intensity beams. The energy stored in a single beam of LHC particle accelerator is equivalent to about 80 kg of TNT explosive, stored in a transverse beam area with a typical value of 0.2 mm×0.2 mm. The materials placed close to the beam are used at, or even beyond, their damage limits. However, it is very difficult to predict structural efficiency and robustness accurately: beam-induced damage for high energy and high intensity occurs in a regime where practical experience does not exist. The interaction between high energy particle beams and metals induces a sudden non uniform temperature increase. This provokes a dynamic response of the structure entailing thermal stress waves and thermally induced vibrations or even the failure of the component. This study is performed in order to estimate the damage on a copper component due to the impact with a 7 TeV pro...

  10. Calculating the X-Ray Fluorescence from the Planet Mercury Due to High-Energy Electrons

    Science.gov (United States)

    Burbine, T. H.; Trombka, J. I.; Bergstrom, P. M., Jr.; Christon, S. P.

    2005-01-01

    The least-studied terrestrial planet is Mercury due to its proximity to the Sun, which makes telescopic observations and spacecraft encounters difficult. Our lack of knowledge about Mercury should change in the near future due to the recent launching of MESSENGER, a Mercury orbiter. Another mission (BepiColombo) is currently being planned. The x-ray spectrometer on MESSENGER (and planned for BepiColombo) can characterize the elemental composition of a planetary surface by measuring emitted fluorescent x-rays. If electrons are ejected from an atom s inner shell by interaction with energetic particles such as photons, electrons, or ions, electrons from an outer shell can transfer to the inner shell. Characteristic x-rays are then emitted with energies that are the difference between the binding energy of the ion in its excited state and that of the ion in its ground state. Because each element has a unique set of energy levels, each element emits x-rays at a unique set of energies. Electrons and ions usually do not have the needed flux at high energies to cause significant x-ray fluorescence on most planetary bodies. This is not the case for Mercury where high-energy particles were detected during the Mariner 10 flybys. Mercury has an intrinsic magnetic field that deflects the solar wind, resulting in a bow shock in the solar wind and a magnetospheric cavity. Electrons and ions accelerated in the magnetosphere tend to follow its magnetic field lines and can impact the surface on Mercury s dark side Modeling has been done to determine if x-ray fluorescence resulting from the impact of high-energy electrons accelerated in Mercury's magnetosphere can be detected by MESSENGER. Our goal is to understand how much bulk chemical information can be obtained from x-ray fluorescence measurements on the dark side of Mercury.

  11. Characterization of blood donors with high haemoglobin concentration

    DEFF Research Database (Denmark)

    Magnussen, K; Hasselbalch, H C; Ullum, H;

    2013-01-01

    Background and Objectives  The literature contains little on the prevalence and causes of high predonation haemoglobin levels among blood donors. This study aimed to characterize and develop an algorithm to manage would-be donors with polycythaemia. Materials and Methods  Between November 2009......, erythropoietin, ferritin, platelet count and leucocyte count, JAK2 V617 and JAK2 exon12 analysis, as well as other routine measurements. Results  Among 46 such donors, 39 had a history of smoking, which contributes to erythrocytosis. Two had PV, five had severe hypertension, one of them because of renal artery...

  12. Waste to Energy Potential - A High Concentration Anaerobic Bioreactor

    Science.gov (United States)

    2012-05-23

    REPORT DATE 23 MAY 2012 2. REPORT TYPE 3. DATES COVERED 00-00-2012 to 00-00-2012 4. TITLE AND SUBTITLE Waste to Energy Potential - A High...and fermentative bacteria break down organic carbon to VFAs Acetogens break down VFAs to CH3CO2 − and H2 + Acetoclastic methanogens break...s -999999 999999 7 481 su -999999 999999 0 .. -999999 999999 HCA8 pti Flo$&-tdgc Tan.\\ feed su -999999 999999 0 .. -999999 999999 A-l>o -999999

  13. Regulation of fruit ascorbic acid concentrations during ripening in high and low vitamin C tomato cultivars

    Directory of Open Access Journals (Sweden)

    Mellidou Ifigeneia

    2012-12-01

    Full Text Available Abstract Background To gain insight into the regulation of fruit ascorbic acid (AsA pool in tomatoes, a combination of metabolite analyses, non-labelled and radiolabelled substrate feeding experiments, enzyme activity measurements and gene expression studies were carried out in fruits of the ‘low-’ and ‘high-AsA’ tomato cultivars ‘Ailsa Craig’ and ‘Santorini’ respectively. Results The two cultivars exhibited different profiles of total AsA (totAsA, AsA + dehydroascorbate and AsA accumulation during ripening, but both displayed a characteristic peak in concentrations at the breaker stage. Substrate feeding experiments demonstrated that the L-galactose pathway is the main AsA biosynthetic route in tomato fruits, but that substrates from alternative pathways can increase the AsA pool at specific developmental stages. In addition, we show that young fruits display a higher AsA biosynthetic capacity than mature ones, but this does not lead to higher AsA concentrations due to either enhanced rates of AsA breakdown (‘Ailsa Craig’ or decreased rates of AsA recycling (‘Santorini’, depending on the cultivar. In the later stages of ripening, differences in fruit totAsA-AsA concentrations of the two cultivars can be explained by differences in the rate of AsA recycling activities. Analysis of the expression of AsA metabolic genes showed that only the expression of one orthologue of GDP-L-galactose phosphorylase (SlGGP1, and of two monodehydroascorbate reductases (SlMDHAR1 and SlMDHAR3 correlated with the changes in fruit totAsA-AsA concentrations during fruit ripening in ‘Ailsa Craig’, and that only the expression of SlGGP1 was linked to the high AsA concentrations found in red ripe ‘Santorini’ fruits. Conclusions Results indicate that ‘Ailsa Craig’ and ‘Santorini’ use complementary mechanisms to maintain the fruit AsA pool. In the low-AsA cultivar (‘Ailsa Craig’, alternative routes of AsA biosynthesis may

  14. The salivary microbiome is altered in the presence of a high salivary glucose concentration

    Science.gov (United States)

    Hartman, Mor-Li; Shi, Ping; Hasturk, Hatice; Yaskell, Tina; Vargas, Jorel; Song, Xiaoqing; Cugini, Maryann; Barake, Roula; Alsmadi, Osama; Al-Mutawa, Sabiha; Ariga, Jitendra; Soparkar, Pramod; Behbehani, Jawad; Behbehani, Kazem

    2017-01-01

    Background Type II diabetes (T2D) has been associated with changes in oral bacterial diversity and frequency. It is not known whether these changes are part of the etiology of T2D, or one of its effects. Methods We measured the glucose concentration, bacterial counts, and relative frequencies of 42 bacterial species in whole saliva samples from 8,173 Kuwaiti adolescents (mean age 10.00 ± 0.67 years) using DNA probe analysis. In addition, clinical data related to obesity, dental caries, and gingivitis were collected. Data were compared between adolescents with high salivary glucose (HSG; glucose concentration ≥ 1.0 mg/d, n = 175) and those with low salivary glucose (LSG, glucose concentration gingivitis in the study population. The overall salivary bacterial load in saliva decreased with increasing salivary glucose concentration. Under HSG conditions, the bacterial count for 35 (83%) of 42 species was significantly reduced, and relative bacterial frequencies in 27 species (64%) were altered, as compared with LSG conditions. These alterations were stronger predictors of high salivary glucose than measures of oral disease, obesity, sleep or fitness. Conclusions HSG was associated with a reduction in overall bacterial load and alterations to many relative bacterial frequencies in saliva when compared with LSG in samples from adolescents. We propose that hyperglycemia due to obesity and/or T2D results in HSG and subsequent acidification of the oral environment, leading to a generalized perturbation in the oral microbiome. This suggests a basis for the observation that hyperglycemia is associated with an increased risk of dental erosion, dental caries, and gingivitis. We conclude that HSG in adolescents may be predicted from salivary microbial diversity or frequency, and that the changes in the oral microbial composition seen in adolescents with developing metabolic disease may the consequence of hyperglycemia. PMID:28249034

  15. Long term stability of Li-S batteries using high concentration lithium nitrate electrolytes

    Energy Technology Data Exchange (ETDEWEB)

    Adams, Brian DG; Carino, Emily V.; Connell, Justin G.; Han, Kee Sung; Cao, Ruiguo; Chen, Junzheng; Zheng, Jianming; Li, Qiuyan; Mueller, Karl T.; Henderson, Wesley A.; Zhang, Jiguang

    2017-09-08

    Lithium-sulfur (Li-S) battery is a very promising candidate for the next generation of energy storage systems required for electrical vehicles and grid energy storage applications due to its very high theoretical specific energy (2500 W h kg-1). However, the low coulombic efficiency (CE) during repeated Li plating/stripping of these processes have limited practical application of rechargeable Li-S batteries. In this work, a new electrolyte system based on high concentration of LiNO3 in diglyme solvent is developed which enables high CE of Li metal plating/stripping and high stability of Li anode in the sulfur containing electrolyte. Tailoring of electrolyte properties for the Li negative electrode has proven to be a successful strategy for improving the capacity retention and cycle life of Li-S batteries. This electrolyte provides a CE for Li plating/stripping of greater than 99% for over 200 cycles. In contrast, Li metal cycles for only less than 35 cycles at high CE in the standard 1 M LiTFSI + 2wt% LiNO3 in DOL:DME electrolyte under the same conditions. The stable Li metal anode enabled by the new electrolyte may accelerate the applications of high energy density Li-S batteries in both electrical vehicles and large-scale grid energy storage markets.

  16. Recent testing of secondary concentrators at NREL`s high-flux solar furnace

    Energy Technology Data Exchange (ETDEWEB)

    Jenkins, D.; Winston, R.; O`Gallagher, J. [Univ. of Chicago, IL (United States); Bingham, C.; Lewandowski, A.; Pitts, R.; Scholl, K. [National Renewable Energy Lab., Golden, CO (United States)

    1996-12-31

    Several tests have been completed on new secondary concentrators at the High-Flux Solar Furnace (HFSF) at the National Renewable Energy Laboratory (NREL). The first test measured the power from the exit of a High-Index secondary that achieves an average concentration of 50,000 suns. The second concentrator tested pumped an Nd:YAG laser crystal. The concentrator designs are presented, along with data from on-sun testing at the HFSF.

  17. Modeling and Mitigation for High Frequency Switching Transients Due to Energization in Offshore Wind Farms

    Directory of Open Access Journals (Sweden)

    Yanli Xin

    2016-12-01

    Full Text Available This paper presents a comprehensive investigation on high frequency (HF switching transients due to energization of vacuum circuit breakers (VCBs in offshore wind farms (OWFs. This research not only concerns the modeling of main components in collector grids of an OWF for transient analysis (including VCBs, wind turbine transformers (WTTs, submarine cables, but also compares the effectiveness between several mainstream switching overvoltage (SOV protection methods and a new mitigation method called smart choke. In order to accurately reproduce such HF switching transients considering the current chopping, dielectric strength (DS recovery capability and HF quenching capability of VCBs, three models are developed, i.e., a user–defined VCB model, a HF transformer terminal model and a three-core (TC frequency dependent model of submarine cables, which are validated through simulations and compared with measurements. Based on the above models and a real OWF configuration, a simulation model is built and several typical switching transient cases are investigated to analyze the switching transient process and phenomena. Subsequently, according to the characteristics of overvoltages, appropriate parameters of SOV mitigation methods are determined to improve their effectiveness. Simulation results indicate that the user–defined VCB model can satisfactorily simulate prestrikes and the proposed component models display HF characteristics, which are consistent with onsite measurement behaviors. Moreover, the employed protection methods can suppress induced SOVs, which have a steep front, a high oscillation frequency and a high amplitude, among which the smart choke presents a preferable HF damping effect.

  18. High-order optical nonlinearities in nanocomposite films dispersed with semiconductor quantum dots at high concentrations

    Science.gov (United States)

    Tomita, Yasuo; Matsushima, Shun-suke; Yamagami, Ryu-ichi; Jinzenji, Taka-aki; Sakuma, Shohei; Liu, Xiangming; Izuishi, Takuya; Shen, Qing

    2017-06-01

    We describe the nonlinear optical properties of inorganic-organic nanocomposite films in which semiconductor CdSe quantum dots as high as 6.8 vol.% are dispersed. Open/closed Z-scan measurements, degenerate multi-wave mixing and femtosecond pump-probe/transient grating measurements are conducted. It is shown that the observed fifth-order optical nonlinearity has the cascaded third-order contribution that becomes prominent at high concentrations of CdSe QDs. It is also shown that there are picosecond-scale intensity-dependent and nanosecond-scale intensity-independent decay components in absorptive and refractive nonlinearities. The former is caused by the Auger process, while the latter comes from the electron-hole recombination process.

  19. A Rectourethral Fistula due to Transrectal High-Intensity Focused Ultrasound Treatment: Diagnosis and Management.

    Science.gov (United States)

    Fiaschetti, Valeria; Manenti, Guglielmo; Di Poce, Isabelle; Fornari, Maria; Ricci, Aurora; Finazzi Agrò, Enrico; Simonetti, Giovanni

    2012-01-01

    Colovesical fistula (CVF) is an abnormal connection between the enteric and the urinary systems. The rectourethral fistula (RUF) is a possible but extremely rare complication of treatment of prostate cancer with "transrectal High-Intensity Focused Ultrasound (HIFU) treatment." We present a case of CVF due to HIFU treatment of recurrent prostate cancer. The case was assessed with cystography completed with a pelvic CT scan-with MPR, MIP, and VR reconstruction-before emptying the bladder. Since the CT scan confirmed that the fistula involved solely the urethra and excluded even a minimal involvement of the bladder, it was possible to employ a conservative treatment by positioning a Foley catheter of monthly duration, in order to allow the urethra to rest. Still today, after 6 months, the patient is in a good clinical condition and has not shown yet signs of a recurrence of the fistula.

  20. ANALYSIS OF HIGH FIELD NON-LINEAR LOSSES ON SRF SURFACES DUE TO SPECIFIC TOPOGRAPHIC ROUGHNESS

    Energy Technology Data Exchange (ETDEWEB)

    Chen Xu,Charles Reece,Michael Kelley

    2012-07-01

    The high-field performance of SRF cavities will eventually be limited by the realization of fundamental material limits, whether it is Hc1 or Hsh, or some derivative thereof, at which the superconductivity is lost. Before reaching this fundamental field limit at the macro level, it must be encountered at localized, perhaps microscopic, sites of field enhancement due to local topography. If such sites are small enough, they may produce thermally stabilized normal-conducting regions which contribute non-linear losses when viewed from the macro resonant field perspective, and thus produce degradation in Q0. We have undertaken a calculation of local surface magnetic field enhancement from specific fine topographic structure by conformal mapping method and numerically. A solution of the resulting normal conducting volume has been derived and the corresponding RF Ohmic loss simulated.

  1. A Rectourethral Fistula due to Transrectal High-Intensity Focused Ultrasound Treatment: Diagnosis and Management

    Directory of Open Access Journals (Sweden)

    Valeria Fiaschetti

    2012-01-01

    Full Text Available Colovesical fistula (CVF is an abnormal connection between the enteric and the urinary systems. The rectourethral fistula (RUF is a possible but extremely rare complication of treatment of prostate cancer with “transrectal High-Intensity Focused Ultrasound (HIFU treatment.” We present a case of CVF due to HIFU treatment of recurrent prostate cancer. The case was assessed with cystography completed with a pelvic CT scan—with MPR, MIP, and VR reconstruction—before emptying the bladder. Since the CT scan confirmed that the fistula involved solely the urethra and excluded even a minimal involvement of the bladder, it was possible to employ a conservative treatment by positioning a Foley catheter of monthly duration, in order to allow the urethra to rest. Still today, after 6 months, the patient is in a good clinical condition and has not shown yet signs of a recurrence of the fistula.

  2. Effect of substrate and IPTG concentrations on the burden to growth of Escherichia coli on glycerol due to the expression of Lac proteins.

    Science.gov (United States)

    Malakar, Pushkar; Venkatesh, K V

    2012-03-01

    Expression of proteins unneeded for growth diverts cellular resources from making necessary protein and leads to a reduction in the growth rate of an organism. This reduction in growth rate is termed as cost. Cost plays an important role in determining the selected expression of a protein in a particular environment. Characterization of cost is important in biotechnology industries where microorganisms are used to produce foreign proteins. We have used the lactose system in Escherichia coli to quantify the cost of growth on glycerol in the presence of isopropyl-β-D-thiogalactopyranoside (IPTG), an inducer of the lactose system. The effect of the concentration of the carbon source, glycerol, and the inducer of Lac enzymes, IPTG, is studied. The results show that the cost is dependent on the glycerol concentration with a decreasing trend with increasing concentration of glycerol. Also as expected, the cost increases and saturates at a higher concentration of IPTG. The studies also demonstrate that the cost is higher in early exponential phase relative to late exponential phase during the growth as has been reported in the literature. Hill equation fit yielded a typical Monod-type expression for growth on glycerol with and without IPTG. An apparent half-saturation constant was defined which was used to characterize the burden on growth due to protein expression.

  3. Conformational Analysis of Proteins in Highly Concentrated Solutions by Dialysis-Coupled Hydrogen/Deuterium Exchange Mass Spectrometry

    DEFF Research Database (Denmark)

    Houde, Damian; Esmail Nazari, Zeinab; Bou-Assaf, George M

    2016-01-01

    for these phenomena can be due to short range electrostatic and/or hydrophobic protein-protein interactions. Hydrogen/deuterium exchange mass spectrometry (HDX-MS) is a useful tool for investigating protein conformation, dynamics, and interactions. However, "traditional" continuous dilution labeling HDX......-MS experiments have limited utility for the direct analysis of solutions with high concentrations of protein. Here, we present a dialysis-based HDX-MS (di-HDX-MS) method as an alternative HDX-MS labeling format, which takes advantage of passive dialysis rather than the classic dilution workflow. We applied...... this approach to a highly concentrated antibody solution without dilution or significant sample manipulation, prior to analysis. Such a method could pave the way for a deeper understanding of the unusual behavior of proteins at high concentrations, which is highly relevant for development of biopharmaceuticals...

  4. EXPERIMENTAL INVESTIGATIONS ON DIFFUSION CHARACTERISTICS OF HIGH CONCENTRATION JET FLOW IN NEAR REGION

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    The diffusion characteristics of the high concentration jet flowissued from a round nozzle above the free surface into moving waterbody were experimentally investigated. By means of flow visualization technique, the diffusion behavior of the high concentration jet was observed and analysed, Concentration distribution in the near region was obtained by sampling and quantitative measurements. Experimental results indicate that the diffusion mechanics of the high concentration jet flow are greatly influenced by initial momentum, buoyancy, turbulent structure, ambient current and boundary conditions, showing complicated flow patterns and concentration distribution characteristics that are different from previous results for submerged jets.

  5. Mitigation of impedance changes due to electroporation therapy using bursts of high-frequency bipolar pulses.

    Science.gov (United States)

    Bhonsle, Suyashree P; Arena, Christopher B; Sweeney, Daniel C; Davalos, Rafael V

    2015-01-01

    For electroporation-based therapies, accurate modeling of the electric field distribution within the target tissue is important for predicting the treatment volume. In response to conventional, unipolar pulses, the electrical impedance of a tissue varies as a function of the local electric field, leading to a redistribution of the field. These dynamic impedance changes, which depend on the tissue type and the applied electric field, need to be quantified a priori, making mathematical modeling complicated. Here, it is shown that the impedance changes during high-frequency, bipolar electroporation therapy are reduced, and the electric field distribution can be approximated using the analytical solution to Laplace's equation that is valid for a homogeneous medium of constant conductivity. Two methods were used to examine the agreement between the analytical solution to Laplace's equation and the electric fields generated by 100 µs unipolar pulses and bursts of 1 µs bipolar pulses. First, pulses were applied to potato tuber tissue while an infrared camera was used to monitor the temperature distribution in real-time as a corollary to the electric field distribution. The analytical solution was overlaid on the thermal images for a qualitative assessment of the electric fields. Second, potato ablations were performed and the lesion size was measured along the x- and y-axes. These values were compared to the analytical solution to quantify its ability to predict treatment outcomes. To analyze the dynamic impedance changes due to electroporation at different frequencies, electrical impedance measurements (1 Hz to 1 MHz) were made before and after the treatment of potato tissue. For high-frequency bipolar burst treatment, the thermal images closely mirrored the constant electric field contours. The potato tissue lesions differed from the analytical solution by 39.7 ± 1.3 % (x-axis) and 6.87 ± 6.26 % (y-axis) for conventional unipolar pulses, and 15.46 ± 1.37 % (x

  6. Assessment of Concentration and Variations due to Seasonal Effect on the Presence of Heavy Metals in the Water of Upper Lake

    Directory of Open Access Journals (Sweden)

    Ranjana Talwar

    2014-08-01

    Full Text Available Water is the most precious gift of nature and is a valued natural resource for the existence of living beings. Management of this natural resource is thus of utmost importance. The present study was carried out to determine the presence of a few heavy metals viz, lead, chromium, copper and mercury in the various samples of Upper Lake, Bhopal. The samples were analyzed during both the pre-monsoon and the post-monsoon season. From the observations it was concluded that a general increase in the concentration was observed in the post monsoon season due to surface runoff coming into the lake water in the rainy season.

  7. Modified water solubility of milk protein concentrate powders through the application of static high pressure treatment.

    Science.gov (United States)

    Udabage, Punsandani; Puvanenthiran, Amirtha; Yoo, Jin Ah; Versteeg, Cornelis; Augustin, Mary Ann

    2012-02-01

    The effects of high pressure (HP) treatment (100-400 MPa at 10-60 °C) on the solubility of milk protein concentrate (MPC) powders were tested. The solubility, measured at 20 °C, of fresh MPC powders made with no HP treatment was 66%. It decreased by 10% when stored for 6 weeks at ambient temperature (~20 °C) and continued to decrease to less than 50% of its initial solubility after 12 months of storage. Of the combinations of pressure and heat used, a pressure of 200 MPa at 40 °C applied to the concentrate before spray drying was found to be the most beneficial for improved solubility of MPC powders. This combination of pressure/heat improved the initial cold water solubility to 85%. The solubility was maintained at this level after 6 weeks storage at ambient temperature and 85% of the initial solubility was preserved after 12 months. The improved solubility of MPC powders on manufacture and on storage are attributed to an altered surface composition arising from an increased concentration of non-micellar casein in the milk due to HP treatment prior to drying. The improved solubility of high protein powders (95% protein) made from blends of sodium caseinate and whey protein isolate compared with MPC powders (~85% protein) made from ultrafiltered/diafiltered milk confirmed the detrimental role of micellar casein on solubility. The results suggest that increasing the non-micellar casein content by HP treatment of milk or use of blends of sodium caseinate and whey proteins are strategies that may be used to obtain high protein milk powders with enhanced solubility.

  8. Emulsifier development for high-concentrated reverse emulsions

    Directory of Open Access Journals (Sweden)

    I.L. Kovalenko

    2016-05-01

    Full Text Available The reverse emulsions have found broad application in ore mining industry as matrixes of emulsion explosive substances and boring washing waters. The defining characteristic of reverse emulsions of industrial explosive substances is the high stability and immunity to crystallization. Aim: The aim of this work is to assess the mechanism of emulsifiers effect like SMO and some PIBSA-derivatives, that are most abundantly used in world practice, and also to develop an effective domestic emulsifier of reverse emulsions. Materials and methods: Using the semi-dynamic method with use of the reverse stalagmometer it was determined the decreasing in interfacial tension on “water / diesel fuel” border in the presence of 0.5 wt % sorbitan monooleate of various producers. Emulsions with use of the chosen emulsifiers using the dynamic mixer on the basis of monosolution of ammonium nitrate and diesel fuel have been produced. The emulsions have the following composition, wt %: ammonium nitrate – 76.8; water – 15.6; diesel fuel – 6.0; emulsifier – 1.6. Results: By the researches results of the interfacial tension “surfactant water / solution in diesel fuel”, the stability of emulsions using monosolution of ammonium nitrate and the IR spectrums of SMO of various producers it is established that presence in product of impurity of oleic acid, di- and trioleates leads to decreasing in interphase activity, increasing of emulsifier oil solubility and decreasing the resistance of emulsions to crystallization. On the basis of the spectral data analysis it is suggested about possibility of specific interaction on the mechanism of “spectral resonance” between emulsifiers of the PIBSA-MEA, LZX type and crystals nucleus of NH4NO3 ammonium nitrate in dispersed phase of emulsion. Amidation of vegetable oils by monoethanol amine is implemented at the reduced temperatures (90…100 °C. It was proved the availability mainly of fatty acids amides in product

  9. Combined use of ionophore and virginiamycin for finishing Nellore steers fed high concentrate diets

    Directory of Open Access Journals (Sweden)

    Amoracyr José Costa Nuñez

    2013-08-01

    Full Text Available Zebu cattle fed high concentrate diets may present inconsistent performance due to the occurrence of metabolic disorders, like acidosis. The isolated use of ionophores and virginiamycin in high grain diets can improve animal performance and reduce the incidence of such disorders, but recent studies suggested that their combination may have an additive effect. Thus, 72 Nellore steers, 389 ± 15 kg initial body weight (BW, were confined and fed for 79 days to evaluate the combination of virginiamycin and salinomycin on performance and carcass traits. Animals were allocated to a randomized complete block design by BW, in a 2 × 2 factorial arrangement of treatments, with two concentrate levels (73 and 91 % and two virginiamycin levels (0 and 15 mg kg-1, and salinomycin (13 mg kg-1 included in all diets. The interaction was not significant (p > 0.05. Dry matter intake (DMI, average daily gain (ADG, gain-to-feed ratio (G:F, starch consumed, and fecal starch content were higher (p 0.05 between treatments. Starch consumed and estimated dietary net energy for maintenance (NEm and gain (NEg were higher (p < 0.05 for virginiamycin-treated animals, with no substantial effects on carcass traits. The inclusion of virginiamycin in finishing diets containing salinomycin reduced DMI while maintaining ADG and improving NEm and NEg, suggesting an additive effect of virginiamycin and ionophores, but without affecting carcass quality.

  10. High-temperature photochemical destruction of toxic organic wastes using concentrated solar radiation

    Energy Technology Data Exchange (ETDEWEB)

    Dellinger, B.; Graham, J.L.; Berman, J.M.; Taylor, P.H. [Dayton Univ., OH (United States)

    1994-05-01

    Application of concentrated solar energy has been proposed to be a viable waste disposal option. Specifically, this concept of solar induced high-temperature photochemistry is based on the synergistic contribution of concentrated infrared (IR) radiation, which acts as an intense heating source, and near ultraviolet and visible (UV-VIS) radiation, which can induce destructive photochemical processes. Some significant advances have been made in the theoretical framework of high-temperature photochemical processes (Section 2) and development of experimental techniques for their study (Section 3). Basic thermal/photolytic studies have addressed the effect of temperature on the photochemical destruction of pure compounds (Section 4). Detailed studies of the destruction of reaction by-products have been conducted on selected waste molecules (Section 5). Some very limited results are available on the destruction of mixtures (Section 6). Fundamental spectroscopic studies have been recently initiated (Section 7). The results to date have been used to conduct some relatively simple scale-up studies of the solar detoxification process. More recent work has focused on destruction of compounds that do not directly absorb solar radiation. Research efforts have focused on homogeneous as well as heterogeneous methods of initiating destructive reaction pathways (Section 9). Although many conclusions at this point must be considered tentative due to lack of basic research, a clearer picture of the overall process is emerging (Section 10). However, much research remains to be performed and most follow several veins, including photochemical, spectroscopic, combustion kinetic, and engineering scale-up (Section 11).

  11. High speed velocimetry and concentration measurements in a microfluidic mixer using fluorescence confocal microscopy

    Science.gov (United States)

    Inguva, Venkatesh; Perot, Blair; Kathuria, Sagar; Rothstein, Jonathan; Bilsel, Osman

    2016-11-01

    This work experimentally examines the performance of a quasi-turbulent micro-mixer that was designed to produce rapid mixing for protein-folding experiments. The original design of the mixer was performed using Direct Numerical Simulation (DNS) of the flow field and LES of the high Sc number scalar field representing the protein. The experimental work is designed to validate the DNS results. Both the velocity field and the protein concentration require validation. Different experiments were carried out to measure these two quantities. Concentration measurements are performed using a 488nm continuous wave laser coupled with a confocal microscope to measure fluorescence intensity during mixing. This is calibrated using the case where no mixing occurs. The velocity measurements use a novel high speed velocimetry technique capable of measuring speeds on the order of 10 m/s in a micro channel. The technique involves creating a pulsed confocal volume from a Ti-Sapphire laser with a pulse width of 260ns and observing the decay of fluorescence due to the fluid motion. Results from both experiments will be presented along with a comparison to the DNS results. The work is supported by NSF IDBR Award No. 1353942.

  12. Experimental Study of Sorbitol Production by Zymomonas mobilis in High Sucrose Concentration

    OpenAIRE

    Rui Sérgio dos Santos Ferreira da Silva; João Batista Buzato; Maria Antonia Pedrine Colabone Celligoi; Marcos Roberto de Oliveira

    2004-01-01

    The sorbitol presents several industrial applications and its conventional production is of high cost and low yield. Sorbitol production by Zymomonas mobilis production has attracted attention as both production cost and environmental impact are low. The sorbitol plays an osmo-protective rule so that its production is promoted by high sugar concentrations. This work has evaluated the effect of high sucrose concentration in the sorbitol production. The raise of sucrose concentration from 100 t...

  13. Prediction of Stress Concentration effect under Thermal and Dynamic loads on a High Pressure Turbine Rotor

    Directory of Open Access Journals (Sweden)

    R.Nagendra Babu

    2010-08-01

    Full Text Available Geometric discontinuities cause a large variation of stress and produce a significant increase in stress. The high stress due to the variation of geometry is called as ‘stress concentration’. This will increase when the loads are further applied. There are many investigators who have studied the stress distribution around the notches, grooves, and other irregularities of various machine components. This paper analyses the effects of thermal and fatigue load on a steam turbine rotor under the operating conditions. Stresses due to thermal and dynamic loads of High Pressure Steam Turbine Rotor of 210MW power station are found in two stages. A source code is developed for calculating the nominal stress at each section of HPT rotor. Maximum stress is obtained using FEA at the corresponding section. Thermal and Fatigue Stress Concentration Factors at each section are calculated. It is observed that the SCFdue to the combined effect of thermal and dynamic loads at the temperatures beyond 5400C is exceeding the safe limits.

  14. Evaluation of pulmonary changes due to biomass fuels using high-resolution computed tomography

    Energy Technology Data Exchange (ETDEWEB)

    Kara, Mustafa; Tas, Fikret [Department of Radiology, Cumhuriyet University, 58140, Sivas (Turkey); Faculty of Medicine, Cumhuriyet University, 58140, Sivas (Turkey); Bulut, Sema [Department of Radiology, Cumhuriyet University, 58140, Sivas (Turkey); Akkurt, Ibrahim; Seyfikli, Zehra [Faculty of Medicine, Cumhuriyet University, 58140, Sivas (Turkey); Department of Respiratory Disease, Cumhuriyet University, 58140, Sivas (Turkey)

    2003-10-01

    Biomass fuels are frequently used in rural areas of the world for cooking and heating frequently. It has been reported that the use of these fuels causes hazardous effects on the lungs. In this study, we evaluated the pulmonary changes due to the use of biomass fuels in a female population that lives in our territory by high-resolution computed tomography (HRCT). The study analyzed three groups of women. The first group comprised those subjects who were exposed to biomass without respiratory symptoms (group 1; n=32). The second group comprised those individuals that were exposed to biomass and showed respiratory symptoms, such as cough, sputum production, and dyspnea (group 2; n=30). The third group was composed of women who were not exposed to biomass and also had no respiratory symptoms (group 3; n=30). Women with a history of concomitant pulmonary diseases were excluded from the study. All groups were examined with HRCT. Groups 1 and 2 (individuals exposed to biomass fuels) had more pathologic findings than group 3 (not exposed to biomass fuels). Ground-glass appearance was seen in 71.9% in group 1, 23.3% in group 2, and 3.3% in group 3. The difference between the groups was statistically significant (p<0.05). Fibrotic bands were seen 50% in group 1, 63.3% in group 2, and only 6.7% in group 3 (p<0.001). Exposure to biomass fuels was the cause or predisposing factor for many pulmonary diseases, ranging from chronic bronchitis to diffuse lung diseases. We believe that these pathological changes due to biomass fuels can be detected earlier by HRCT and the diseases might be prevented or treated earlier. (orig.)

  15. High catechin concentrations detected in Withania somnifera (ashwagandha by high performance liquid chromatography analysis

    Directory of Open Access Journals (Sweden)

    Sulaiman Siti

    2011-08-01

    Full Text Available Abstract Background Withania somnifera is an important medicinal plant traditionally used in the treatment of many diseases. The present study was carried out to characterize the phenolic acids, flavonoids and 1,1-diphenyl-2-picrylhydrazyl radical (DPPH scavenging activities in methanolic extracts of W. somnifera fruits, roots and leaves (WSFEt, WSREt and WSLEt. Methods WSFEt, WSREt and WSLEt was prepared by using 80% aqueous methanol and total polyphenols, flavonoids as well as DPPH radical scavenging activities were determined by spectrophotometric methods and phenolic acid profiles were determined by HPLC methods. Results High concentrations of both phenolics and flavonoids were detected in all parts of the plant with the former ranging between 17.80 ± 5.80 and 32.58 ± 3.16 mg/g (dry weight and the latter ranging between 15.49 ± 1.02 and 31.58 ± 5.07 mg/g. All of the three different plant parts showed strong DPPH radical scavenging activities (59.16 ± 1.20 to 91.84 ± 0.38%. Eight polyphenols (gallic, syringic, benzoic, p-coumaric and vanillic acids as well as catechin, kaempferol and naringenin have been identified by HPLC in parts of the plant as well. Among all the polyphenols, catechin was detected in the highest concentration (13.01 ± 8.93 to 30.61 ± 11.41 mg/g. Conclusion The results indicating that W. somnifera is a plant with strong therapeutic properties thus further supporting its traditional claims. All major parts of W. somnifera such as the roots, fruits and leaves provide potential benefits for human health because of its high content of polyphenols and antioxidant activities with the leaves containing the highest amounts of polyphenols specially catechin with strong antioxidant properties.

  16. Ozone concentrations at a selected high-elevation forest site downwind Mexico City

    Science.gov (United States)

    Torres-JArdon, R.

    2013-05-01

    July to September. Episodes of high concentrations occurred mainly during the dry warm months. Most of the year, nocturnal ozone levels were higher than those registered in the urban area due to the PMH altitude. As a great part of the mountain terrain regularly is above the nocturnal mixing layer formed each day on the valley floor, the ozone remanent levels above this layer in the mountains are kept isolated from urban NOx emissions generated at night. An evaluation of the AOT40 indicator shows that the forest zone is under a strong risk due to ozone pollution. A preliminary analysis of several ozone events in the PNMH shows the suppression of the diel peak, suggesting that a stratospheric intrusion of ozone occurs frequently in high-elevation sites surrounding MCMA.

  17. pH-Dependent Toxicity of High Aspect Ratio ZnO Nanowires in Macrophages Due to Intracellular Dissolution

    KAUST Repository

    H. Müller, Karin

    2010-11-23

    High-aspect ratio ZnO nanowires have become one of the most promising products in the nanosciences within the past few years with a multitude of applications at the interface of optics and electronics. The interaction of zinc with cells and organisms is complex, with both deficiency and excess causing severe effects. The emerging significance of zinc for many cellular processes makes it imperative to investigate the biological safety of ZnO nanowires in order to guarantee their safe economic exploitation. In this study, ZnO nanowires were found to be toxic to human monocyte macrophages (HMMs) at similar concentrations as ZnCl2. Confocal microscopy on live cells confirmed a rise in intracellular Zn2+ concentrations prior to cell death. In vitro, ZnO nanowires dissolved very rapidly in a simulated body fluid of lysosomal pH, whereas they were comparatively stable at extracellular pH. Bright-field transmission electron microscopy (TEM) showed a rapid macrophage uptake of ZnO nanowire aggregates by phagocytosis. Nanowire dissolution occurred within membrane-bound compartments, triggered by the acidic pH of the lysosomes. ZnO nanowire dissolution was confirmed by scanning electron microscopy/energy-dispersive X-ray spectrometry. Deposition of electron-dense material throughout the ZnO nanowire structures observed by TEM could indicate adsorption of cellular components onto the wires or localized zinc-induced protein precipitation. Our study demonstrates that ZnO nanowire toxicity in HMMs is due to pH-triggered, intracellular release of ionic Zn2+ rather than the high-aspect nature of the wires. Cell death had features of necrosis as well as apoptosis, with mitochondria displaying severe structural changes. The implications of these findings for the application of ZnO nanowires are discussed. © 2010 American Chemical Society.

  18. High-Efficiency Solar Thermal Vacuum Demonstration Completed for Refractive Secondary Concentrator

    Science.gov (United States)

    Wong, Wayne A.

    2001-01-01

    Common to many of the space applications that utilize solar thermal energy--such as electric power conversion, thermal propulsion, and furnaces--is a need for highly efficient, solar concentration systems. An effort is underway at the NASA Glenn Research Center to develop the refractive secondary concentrator, which uses refraction and total internal reflection to efficiently concentrate and direct solar energy. When used in combination with advanced lightweight primary concentrators, the refractive secondary concentrator enables very high system concentration ratios (10,000 to 1) and very high temperatures (>2000 K). The innovative refractive secondary concentrator offers significant advantages over all other types of secondary concentrators. The refractive secondary offers the highest throughput efficiency, provides for flux tailoring, requires no active cooling, relaxes the pointing and tracking requirements of the primary concentrator, and enables very high system concentration ratios. This technology has broad applicability to any system that requires the conversion of solar energy to heat. Glenn initiated the development of the refractive secondary concentrator in support of Shooting Star, a solar thermal propulsion flight experiment, and continued the development in support of Space Solar Power.

  19. High-sensitivity in situ QCLAS-based ammonia concentration sensor for high-temperature applications

    Science.gov (United States)

    Peng, W. Y.; Sur, R.; Strand, C. L.; Spearrin, R. M.; Jeffries, J. B.; Hanson, R. K.

    2016-07-01

    A novel quantum cascade laser (QCL) absorption sensor is presented for high-sensitivity in situ measurements of ammonia (hbox {NH}_3) in high-temperature environments, using scanned wavelength modulation spectroscopy (WMS) with first-harmonic-normalized second-harmonic detection (scanned WMS-2 f/1 f) to neutralize the effect of non-absorption losses in the harsh environment. The sensor utilized the sQ(9,9) transition of the fundamental symmetric stretch band of hbox {NH}_3 at 10.39 {\\upmu }hbox {m} and was sinusoidally modulated at 10 kHz and scanned across the peak of the absorption feature at 50 Hz, leading to a detection bandwidth of 100 Hz. A novel technique was used to select an optimal WMS modulation depth parameter that reduced the sensor's sensitivity to spectral interference from hbox {H}_2hbox {O} and hbox {CO}_2 without significantly sacrificing signal-to-noise ratio. The sensor performance was validated by measuring known concentrations of hbox {NH}_3 in a flowing gas cell. The sensor was then demonstrated in a laboratory-scale methane-air burner seeded with hbox {NH}_3, achieving a demonstrated detection limit of 2.8 ± 0.26 ppm hbox {NH}_3 by mole at a path length of 179 cm, equivalence ratio of 0.6, pressure of 1 atm, and temperatures of up to 600 K.

  20. High content analysis at single cell level identifies different cellular responses dependent on nanomaterial concentrations.

    Science.gov (United States)

    Manshian, Bella B; Munck, Sebastian; Agostinis, Patrizia; Himmelreich, Uwe; Soenen, Stefaan J

    2015-09-08

    A mechanistic understanding of nanomaterial (NM) interaction with biological environments is pivotal for the safe transition from basic science to applied nanomedicine. NM exposure results in varying levels of internalized NM in different neighboring cells, due to variances in cell size, cell cycle phase and NM agglomeration. Using high-content analysis, we investigated the cytotoxic effects of fluorescent quantum dots on cultured cells, where all effects were correlated with the concentration of NMs at the single cell level. Upon binning the single cell data into different categories related to NM concentration, this study demonstrates, for the first time, that quantum dots activate both cytoprotective and cytotoxic mechanisms, resulting in a zero net result on the overall cell population, yet with significant effects in cells with higher cellular NM levels. Our results suggest that future NM cytotoxicity studies should correlate NM toxicity with cellular NM numbers on the single cell level, as conflicting mechanisms in particular cell subpopulations are commonly overlooked using classical toxicological methods.

  1. High content analysis at single cell level identifies different cellular responses dependent on nanomaterial concentrations

    Science.gov (United States)

    Manshian, Bella B.; Munck, Sebastian; Agostinis, Patrizia; Himmelreich, Uwe; Soenen, Stefaan J.

    2015-09-01

    A mechanistic understanding of nanomaterial (NM) interaction with biological environments is pivotal for the safe transition from basic science to applied nanomedicine. NM exposure results in varying levels of internalized NM in different neighboring cells, due to variances in cell size, cell cycle phase and NM agglomeration. Using high-content analysis, we investigated the cytotoxic effects of fluorescent quantum dots on cultured cells, where all effects were correlated with the concentration of NMs at the single cell level. Upon binning the single cell data into different categories related to NM concentration, this study demonstrates, for the first time, that quantum dots activate both cytoprotective and cytotoxic mechanisms, resulting in a zero net result on the overall cell population, yet with significant effects in cells with higher cellular NM levels. Our results suggest that future NM cytotoxicity studies should correlate NM toxicity with cellular NM numbers on the single cell level, as conflicting mechanisms in particular cell subpopulations are commonly overlooked using classical toxicological methods.

  2. Serotonin mediates a learned increase in attraction to high concentrations of benzaldehyde in aged C. elegans.

    Science.gov (United States)

    Tsui, David; van der Kooy, Derek

    2008-11-01

    We utilized olfactory-mediated chemotaxis in Caenorhabditis elegans to examine the effect of aging on information processing and animal behavior. Wild-type (N2) young adults (day 4) initially approach and eventually avoid a point source of benzaldehyde. Aged adult animals (day 7) showed a stronger initial approach and a delayed avoidance to benzaldehyde compared with young adults. This delayed avoidance is due to an increased attraction rather than a decreased avoidance to benzaldehyde because (1) aged odr-3 mutants that are defective in odor attraction showed no delayed benzaldehyde avoidance, and (2) the delay in avoidance was also observed with another attractant diacetyl, but not the repellent octanol. Interestingly, the stronger expression of attractive behavior was only observed at benzaldehyde concentrations of 1% or higher. When worms were grown on nonbacterial growth media instead of Escherichia coli, thus removing the contingency between odors released from the food and the food itself, the increase in attraction to benzaldehyde disappeared. The increased attraction recovered after reinitiating the odor-food contingency by returning animals to E. coli food or supplementing axenic media with benzaldehyde. Moreover, serotonin-deficient mutants showed a deficit in the age-enhanced attraction. These results suggest that the increased attraction to benzaldehyde in aged worms is (1) serotonin mediated, (2) specific to high concentration of odorants, and (3) dependent on a learned association of odor metabolites with the presence of food. We propose that associative learning may selectively modify pathways at or downstream from a low-affinity olfactory receptor.

  3. Bone embrittlement and collagen modifications due to high-dose gamma-irradiation sterilization.

    Science.gov (United States)

    Burton, Brianne; Gaspar, Anne; Josey, David; Tupy, Jindra; Grynpas, Marc D; Willett, Thomas L

    2014-04-01

    Bone allografts are often used in orthopedic reconstruction of skeletal defects resulting from trauma, bone cancer or revision of joint arthroplasty. γ-Irradiation sterilization is a widely-used biological safety measure; however it is known to embrittle bone. Irradiation has been shown to affect the post-yield properties, which are attributed to the collagen component of bone. In order to find a solution to the loss of toughness in irradiated bone allografts, it is important to fully understand the effects of irradiation on bone collagen. The objective of this study was to evaluate changes in the structure and integrity of bone collagen as a result of γ-irradiation, with the hypothesis that irradiation fragments collagen molecules leading to a loss of collagen network connectivity and therefore loss of toughness. Using cortical bone from bovine tibiae, sample beams irradiated at 33kGy on dry ice were compared to native bone beams (paired controls). All beams were subjected to three-point bend testing to failure followed by characterization of the decalcified bone collagen, using differential scanning calorimetry (DSC), hydrothermal isometric tension testing (HIT), high performance liquid chromatography (HPLC) and gel electrophoresis (SDS-PAGE). The carbonyl content of demineralized bone collagen was also measured chemically to assess oxidative damage. Barium sulfate staining after single edge notch bending (SEN(B)) fracture testing was also performed on bovine tibia bone beams with a machined and sharpened notch to evaluate the fracture toughness and ability of irradiated bone to form micro-damage during fracture. Irradiation resulted in a 62% loss of work-to-fracture (p≤0.001). There was significantly less micro-damage formed during fracture propagation in the irradiated bone. HPLC showed no significant effect on pentosidine, pyridinoline, or hydroxypyridinoline levels suggesting that the loss of toughness is not due to changes in these stable crosslinks. For

  4. Future Projections of Aerosol Optical Depth, Radiative Forcing, and Climate Response Due to Declining Aerosol Emissions in the Representative Concentration Pathways

    Science.gov (United States)

    Westervelt, D. M.; Mauzerall, D. L.; Horowitz, L. W.; Naik, V.

    2014-12-01

    It is widely expected that global emissions of atmospheric aerosols and their precursors will decrease strongly throughout the remainder of the 21st century, due to emission reduction policies enacted based on human health concerns. However, the resulting decrease in atmospheric aerosol burden will have unintended climate consequences. Since aerosols generally exert a net cooling influence on the climate, their removal will lead to an unmasking of global warming as well as other changes to the climate system. Aerosol and precursor global emissions decrease by as much as 80% by the year 2100, according to projections in four Representative Concentration Pathway (RCP) scenarios. We use the Geophysical Fluid Dynamics Laboratory Climate Model version 3 (GFDL CM3) to simulate future climate over the 21st century with and without aerosol emission changes projected by the RCPs in order to isolate the radiative forcing and climate response due to the aerosol reductions. We find that up to 1 W m-2 of radiative forcing may be unmasked globally by 2100 due to reductions in aerosol and precursor emissions, leading to average global temperature increases up to 1 K and global precipitation rate increases up to 0.09 mm d-1 (3%). Regionally and locally, climate impacts are much larger, as RCP8.5 projects a 2.1 K warming over China, Japan, and Korea due to reduced aerosol emissions. Our results highlight the importance of crafting emissions control policies with both climate and air pollution benefits in mind. The expected unmasking of additional global warming from aerosol reductions highlights the importance of robust greenhouse gas mitigation policies and may require more aggressive policies than anticipated.

  5. High-pressure and high-temperature differential scanning calorimeter for combined pressure-concentration-temperature measurements of hydrides.

    Science.gov (United States)

    Mauron, Ph; Bielmann, M; Bissig, V; Remhof, A; Züttel, A

    2009-09-01

    The design and construction of a high-pressure (200 bar) and high-temperature (600 degrees C) heat-flow differential scanning calorimeter (DSC) for the in situ investigation of the hydrogenation and dehydrogenation reactions of hydrides is presented. In combination with a pressure-concentration-temperature (pcT) system, simultaneous thermodynamic and volumetric measurements become accessible. Due to the high thermal conductivity of hydrogen, only the sample cell and the reference cell are exposed to hydrogen and the remaining system is under ambient conditions. This separation has the advantage that the calibration factor is independent of the hydrogen pressure. The internal empty volume of the combined system is as low as possible to maximize the precision of the pcT measurements. The calorimetric block of the DSC is designed with a silver/copper alloy and the temperature measurements are made resistively with platinum temperature sensors (Pt 100). The instrument was calibrated and its operability was successfully studied on the example of the hydrogen sorption behavior of LaNi(5).

  6. Strategies to decolorize high concentrations of methyl orange using growing cells of Lactobacillus casei TISTR 1500.

    Science.gov (United States)

    Tantiwa, Nidtaya; Seesuriyachan, Phisit; Kuntiya, Ampin

    2013-01-01

    Batch, fed-batch, and continuous fermentation was used in the processing of methyl orange decolorization using growing cells of Lactobacillus casei TISTR 1500. This report presents the optimal conditions for methyl orange decolorization by the strain TISTR 1500 in modified MRS via a central composite design (CCD) experiment. In particular, the highest decolorization efficiencies were obtained with 13.41 g/L of meat extract, and with 10.89 g/L of yeast extract at pH 6.88 at 35 °C. Under the optimal conditions, the rate of decolorization increased to 322% of that obtained for un-optimized MRS medium. The high concentration of methyl orange (5 g/L) was completely degraded within 9 h in batch fermentation. The total methyl orange load with 8.075 g/L was also decolorized in fed-batch fermentation within 13 h, and the biomass of the strain dramatically decreased after an incubation time of 8 h due to a shortage of sucrose. In the continuous system with a dye-loading rate of 600 mg/L/h and a total of loaded azo dye of 7.2 g/L, high efficiency of methyl orange removal was significantly high, at 98%.

  7. Vitamin C at high concentrations induces cytotoxicity in malignant melanoma but promotes tumor growth at low concentrations.

    Science.gov (United States)

    Yang, Guang; Yan, Yao; Ma, Younan; Yang, Yixin

    2017-08-01

    Vitamin C has been used in complementary and alternative medicine for cancers regardless of its ineffectiveness in clinical trials and the paradoxical effects antioxidants have on cancer. Vitamin C was found to induce cytotoxicity against cancers. However, the mechanisms of action have not been fully elucidated, and the effects of vitamin C on human malignant melanoma have not been examined. This study revealed that vitamin C at millimolar concentrations significantly reduced the cell viability as well as invasiveness, and induced apoptosis in human malignant melanoma cells. Vitamin C displayed stronger cytotoxicity against the Vemurafenib-resistance cell line A2058 compared with SK-MEL-28. In contrast, vitamin C at micromolar concentrations promoted cell growth, migration and cell cycle progression, and protected against mitochondrial stress. Vemurafenib paradoxically activated the RAS-RAF-MEK-ERK signaling pathway in the Vemurafenib-resistant A2058, however, vitamin C abolished the activations. Vitamin C displayed synergistic cytotoxicity with Vemurafenib against the Vemurafenib-resistant A2058. In vivo assay suggested that lower dosage (equivalent to 0.5 g/70 kg) of vitamin C administered orally increased the melanoma growth. Therefore, vitamin C may exert pro- or anti-melanoma effect depending on concentration. The combination of vitamin C at high dosage and Vemurafenib is promising in overcoming the action of drug resistance. © 2017 Wiley Periodicals, Inc.

  8. Psychosocial impact of scars due to cutaneous leishmaniasis on high school students in Errachidia province, Morocco.

    Science.gov (United States)

    Bennis, Issam; Thys, Séverine; Filali, Hind; De Brouwere, Vincent; Sahibi, Hamid; Boelaert, Marleen

    2017-04-07

    In Morocco, cutaneous leishmaniasis (CL) is usually known to be a slowly healing localized skin disease, but in some cases, it can lead to mutilating scars. The outbreak of CL due to Leishmania major in the Errachidia province in southeastern Morocco between 2008 and 2010 left many adolescents with permanent scar tissue on the face or other exposed body parts. We studied the psychosocial impact of CL on these young people. In 2015 we conducted a cross-sectional survey among high-school students living in boarding schools in two CL-endemic areas of Errachidia: Rissani and Tinejdad. A self-administered questionnaire elicited responses about general knowledge of CL and related scars. An open-ended question focused on the possible psychosocial effects associated with these scars. The quantitative data were analyzed with Epi Info™ and the text data with NVivo software. Almost 20% of 448 respondents reported they had experienced a CL lesion and 87% said it could possibly or definitely lead to psychological consequences. The text analysis showed that girls more often than boys expanded on the negative psychological effects of CL. The students considered CL as "dangerous", "serious", and "deathly", and said it sometimes led to extreme suicidal ideations. The burden of CL in this age group is not negligible. The indelible CL scars lead to self-stigma and social stigma, and the emergence of negative psychological effects in this age group. While some students accepted their CL scars and related suffering as their "destiny", others were eagerly demanding protective measures against CL and treatment for the scars.

  9. Increases in external cause mortality due to high and low temperatures: evidence from northeastern Europe

    Science.gov (United States)

    Orru, Hans; Åström, Daniel Oudin

    2016-11-01

    The relationship between temperature and mortality is well established but has seldom been investigated in terms of external causes. In some Eastern European countries, external cause mortality is substantial. Deaths owing to external causes are the third largest cause of mortality in Estonia, after cardiovascular disease and cancer. Death rates owing to external causes may reflect behavioural changes among a population. The aim for the current study was to investigate if there is any association between temperature and external cause mortality, in Estonia. We collected daily information on deaths from external causes (ICD-10 diagnosis codes V00-Y99) and maximum temperatures over the period 1997-2013. The relationship between daily maximum temperature and mortality was investigated using Poisson regression, combined with a distributed lag non-linear model considering lag times of up to 10 days. We found significantly higher mortality owing to external causes on hot (the same and previous day) and cold days (with a lag of 1-3 days). The cumulative relative risks for heat (an increase in temperature from the 75th to 99th percentile) were 1.24 (95% confidence interval, 1.14-1.34) and for cold (a decrease from the 25th to 1st percentile) 1.19 (1.03-1.38). Deaths due to external causes might reflect changes in behaviour among a population during periods of extreme hot and cold temperatures and should therefore be investigated further, because such deaths have a severe impact on public health, especially in Eastern Europe where external mortality rates are high.

  10. Enhanced mass removal due to phase explosion during high irradiance nanosecond laser ablation of silicon

    Energy Technology Data Exchange (ETDEWEB)

    Yoo, Jong Hyun [Univ. of California, Berkeley, CA (United States)

    2000-05-01

    The morphology of craters resulting from high irradiance laser ablation of silicon was measured using a white light interferometry microscope. The craters show a dramatic increase in their depth and volume at a certain irradiance, indicating a change in the primary mechanism for mass removal. Laser shadowgraph imaging was used to characterize and differentiate the mass ejection processes for laser irradiances above and below the threshold value. Time-resolved images show distinct features of the mass ejected at irradiances above the threshold value including the presence of micron-sized particulates; this begins at approximately 300 ~ 400 ns after the start of laser heating. The analysis of the phenomena was carried out by using two models: a thermal evaporation model and a phase explosion model. Estimation of the crater depth due to the thermally evaporated mass led to a large underestimation of the crater depth for irradiances above the threshold. Above the threshold irradiance, the possibility of phase explosion was analyzed. Two important results are the thickness of the superheated liquid layer that is close to the critical temperature and the time for vapor bubbles that are generated in the superheated liquid to achieve a critical size. After reaching the critical size, vapor bubbles can grow spontaneously resulting in a violent ejection of liquid droplets from the superheated volume. The effects of an induced transparency, i.e. of liquid silicon turning into an optically transparent liquid dielectric medium, are also introduced. The estimated time for a bubble to reach the critical size is in agreement with the delay time measured for the initiation of large mass ejection. Also, the thickness of the superheated liquid layer that is close to the critical temperature at the time of the beginning of the large mass ejection is representative of the crater depth at the threshold irradiance. These results suggest that phase explosion is a plausible thermal

  11. Potential high temperature corrosion problems due to co-firing of biomass and fossil fuels

    DEFF Research Database (Denmark)

    Montgomery, Melanie; Vilhelmsen, T.; Jensen, S.A.

    2007-01-01

    , the internal sulphidation is much more significant than that revealed in the demonstration project. Avedøre 2 main boiler is fuelled with wood pellets + heavy fuel oil + gas. Some reaction products due to the presence of vanadium compounds in the heavy oil were detected, i.e. iron vanadates. However, the most...... significant corrosion attack was due to sulphidation attack at the grain boundaries of 18-8 steel after 3 years exposure. The corrosion mechanisms and corrosion rates are compared with biomass firing and coal firing. Potential corrosion problems due to co-firing biomass and fossil fuels are discussed....

  12. Quantitation of low concentrations of polysorbates in high protein concentration formulations by solid phase extraction and cobalt-thiocyanate derivatization.

    Science.gov (United States)

    Kim, Justin; Qiu, Jinshu

    2014-01-02

    A spectrophotometric method was developed to quantify low polysorbate (PS) levels in biopharmaceutical formulations containing high protein concentrations. In the method, Oasis HLB solid phase extraction (SPE) cartridge was used to extract PS from high protein concentration formulations. After loading a sample, the cartridge was washed with 4M guanidine HCl and 10% (v/v) methanol, and the retained PS was eluted by acetonitrile. Following the evaporation of acetonitrile, aqueous cobalt-thiocyanate reagent was added to react with the polyoxyethylene oxide chain of polysorbates to form a blue colored PS-cobaltothiocyante complex. This colored complex was then extracted into methylene chloride and measured spectrophotometrically at 620 nm. The method performance was evaluated on three products containing 30-40 mg L(-1) PS-20 and PS-80 in ≤70 g L(-1) protein formulations. The method was specific (no matrix interference identified in three types of protein formulations), sensitive (quantitation limit of 10 mg L(-1) PS) and robust with good precision (relative standard deviation ≤6.4%) and accuracy (spike recoveries from 95% to 101%). The linear range of the method for both PS-20 and PS-80 was 10 to 80 mg L(-1) PS. By diluting samples with 6M guanidine HCl and/or using different methylene chloride volumes to extract the colored complexes of standards and samples, the method could accurately and precisely quantify 40 mg L(-1) PS in up to 300 g L(-1) protein formulations.

  13. Higher concentrations of nanoscale zero-valent iron (nZVI) in soil induced rice chlorosis due to inhibited active iron transportation.

    Science.gov (United States)

    Wang, Jie; Fang, Zhanqiang; Cheng, Wen; Yan, Xiaomin; Tsang, Pokeung Eric; Zhao, Dongye

    2016-03-01

    In this study, the effects of concentrations 0, 100, 250, 500, 750 and 1000 mg kg(-1) of nanoscale zero-valent iron (nZVI) on germination, seedlings growth, physiology and toxicity mechanisms were investigated. The results showed that nZVI had no effect on germination, but inhibited the rice seedlings growth in higher concentrations (>500 mg kg(-1) nZVI). The highest suppression rate of the length of roots and shoots reached 46.9% and 57.5%, respectively. The 1000mg kg(-1) nZVI caused the highest suppression rates for chlorophyll and carotenoids, at 91.6% and 85.2%, respectively. In addition, the activity of antioxidant enzymes was altered by the translocation of nanoparticles and changes in active iron content. Visible symptoms of iron deficiency were observed at higher concentrations, at which the active iron content decreased 61.02% in the shoots, but the active iron content not decreased in roots. Interestingly, the total and available amounts of iron in the soil were not less than those in the control. Therefore, the plants iron deficiency was not caused by (i) deficiency of available iron in the soil and (ii) restraint of the absorption that plant takes in the available iron, while induced by (ⅲ) the transport of active iron from the root to the shoot was blocked. The cortex tissues were seriously damaged by nZVI which was transported from soil to the root, these were proved by scanning electron microscopy (SEM), transmission electron microscopy (TEM) and energy dispersive spectroscopy (EDS). This current study shows that the mechanism of iron deficiency in rice seedling was due to transport of active iron from the root to the shoot blocked, which was caused by the uptake of nZVI.

  14. Evaluation of ground level concentration of pollutant due to gas flaring by computer simulation: A case study of Niger - Delta area of Nigeria

    Directory of Open Access Journals (Sweden)

    A. S. ABDULKAREEM

    2005-01-01

    Full Text Available The disposal of associated gases through flaring has been a major problem for the Nigerian oil and gas industries and most of theses gases are flared due to the lack of commercial out lets. The resultant effects of gas flaring are the damaging effect of the environment due to acid rain formation, green house effect, global warming and ozone depletion.This writes up is aimed at evaluating ground level concentration of CO2, SO2, NO2 and total hydrocarbon (THC, which are product of gas flared in oil producing areas. Volumes of gas flared at different flow station were collected as well as geometrical parameters. The results of simulation of model developed based on the principles of gaseous dispersion by Gaussian showed a good agreement with dispersion pattern.The results showed that the dispersion pattern of pollutants at ground level depends on the volume of gas flared, wind speed, velocity of discharge and nearness to the source of flaring. The results shows that continuous gas flaring irrespective of the quantity deposited in the immediate environment will in long run lead to change in the physicochemical properties of soil.

  15. Conformational Analysis of Proteins in Highly Concentrated Solutions by Dialysis-Coupled Hydrogen/Deuterium Exchange Mass Spectrometry

    Science.gov (United States)

    Houde, Damian; Nazari, Zeinab E.; Bou-Assaf, George M.; Weiskopf, Andrew S.; Rand, Kasper D.

    2016-04-01

    When highly concentrated, an antibody solution can exhibit unusual behaviors, which can lead to unwanted properties, such as increased levels of protein aggregation and unusually high viscosity. Molecular modeling, along with many indirect biophysical measurements, has suggested that the cause for these phenomena can be due to short range electrostatic and/or hydrophobic protein-protein interactions. Hydrogen/deuterium exchange mass spectrometry (HDX-MS) is a useful tool for investigating protein conformation, dynamics, and interactions. However, "traditional" continuous dilution labeling HDX-MS experiments have limited utility for the direct analysis of solutions with high concentrations of protein. Here, we present a dialysis-based HDX-MS (di-HDX-MS) method as an alternative HDX-MS labeling format, which takes advantage of passive dialysis rather than the classic dilution workflow. We applied this approach to a highly concentrated antibody solution without dilution or significant sample manipulation, prior to analysis. Such a method could pave the way for a deeper understanding of the unusual behavior of proteins at high concentrations, which is highly relevant for development of biopharmaceuticals in industry.

  16. Design, Fabrication and Test of a High Efficiency Refractive Secondary Concentrator for Solar Applications

    Science.gov (United States)

    Wong, Wayne A.; Geng, Steven M.; Castle, Charles H.; Macosko, Robert P.

    2000-01-01

    Common to many of the space applications that utilize solar thermal energy such as electric power conversion, thermal propulsion, and furnaces, is a need for highly efficient, solar concentration systems. An effort is underway to develop the refractive secondary concentrator, which uses refraction and total internal reflection to efficiently concentrate and direct solar energy. When used in combination with advanced primary concentrators, the refractive secondary concentrator enables very high system concentration ratios (10,000 to 1) and very high temperatures (greater than 2000 K). Presented is an overview of the effort at the NASA Glenn Research Center to evaluate the performance of a prototype single crystal sapphire refractive secondary concentrator and to compare the performance with analytical models. The effort involves the design and fabrication of a secondary concentrator, design and fabrication of a calorimeter and its support hardware, calibration of the calorimeter, testing of the secondary concentrator in NASA Glenn's Tank 6 solar thermal vacuum facility, and comparing the test results with predictions. Test results indicate an average throughput efficiency of 87%. It is anticipated that reduction of a known reflection loss with an anti-reflective coating would result in a secondary concentrator throughput efficiency of approximately 93%.

  17. High concentrations of KCl release noradrenaline from noradrenergic neurons in the rat anococcygeus muscle

    Directory of Open Access Journals (Sweden)

    C.B.L. Araujo

    2003-01-01

    Full Text Available The aim of the present study was to investigate the effects of high concentrations of KCl in releasing noradrenaline from sympathetic nerves and its actions on postsynaptic alpha-adrenoceptors. We measured the isotonic contractions induced by KCl in the isolated rat anococcygeus muscle under different experimental conditions. The contractile responses induced by KCl were inhibited by alpha-adrenoceptor antagonists in 2.5 mM Ca2+ solution. Prazosin reduced the maximum effect from 100 to 53.9 ± 10.2% (P<0.05 while the pD2 values were not changed. The contractile responses induced by KCl were abolished by prazosin in Ca2+-free solution (P<0.05. Treatment of the rats with reserpine reduced the maximum effect induced by KCl as compared to the contractile responses induced by acetylcholine from 339.5 ± 157.8 to 167.3 ± 65.5% (P<0.05, and increased the pD2 from 1.57 ± 0.01 to 1.65 ± 0.006 (P<0.05, but abolished the inhibitory effect of prazosin (P<0.05. In contrast, L-NAME increased the contractile responses induced by 120 mM KCl by 6.2 ± 2.3% (P<0.05, indicating that KCl could stimulate the neurons that release nitric oxide, an inhibitory component of the contractile response induced by KCl. Our results indicate that high concentrations of KCl induce the release of noradrenaline from noradrenergic neurons, which interacts with alpha1-adrenoceptors in smooth muscle cells, producing a contractile response in 2.5 mM Ca2+ (100% and in Ca2+-free solution, part of which is due to a direct effect of KCl on the rat anococcygeus muscle.

  18. Expression Changes of Early Response Genes in Lung Due to High Volume Ventilation

    Institute of Scientific and Technical Information of China (English)

    WANG Yuelan; YAO Shanglong; XIONG Ping

    2005-01-01

    Summary: The expression changes of early response genes due to ventilation with high volume in adult rats in vivo were observed. Forty SD male rats were randomly divided into control and 30, 60, 90 and 120 min ventilation groups, respectively (n=8 in each group). The animals were ventilated with tidal volume of 42 ml/kg and a PEEP level of 0 cmH2O at a rate of 40 breaths per minute in room air with a ventilator was given to the small animals. The expression of Egr-1, C-jun and IL-1β mRNA and proteins was detected by RT-PCR and immunohistochemical technique, respectively. The pathological changes in lung tissues were examined by HE staining. The results indicated that the expression of Egr-1, C-jun and IL-1β mRNA was detectable at 30th min after overventilation, but there was no significant difference in comparison with that in control group until overventilation for 60 min. However, at 90 and 120 min there was a significent increase as compared with 30 min or control group (P<0.05). The expression of Egr-1, C-jun and IL-1β deteced by immunohistochemical assay also showed a similar tendency of the gradual increase. In the 120 min ventilation group, the expression intensity of Egr-1, C-jun and IL-1β proteins in lung cells was the strongest and the nuclear translocation was increased markedly in comparison with any other groups (P<0.05). HE staining suggested that the degree of lung injury was aggravated gradually with the ventialtion going on and had a similar tendency to the expression of these early response genes and proteins. The current data suggested that overventilation activated and upregulated the expression of early response genes and the expression of these genes may be taken as the early signal to predict the onset and degree of lung injury. These results may demonstrated partially that the expression of early response genes induced by the mechanical stretch is associated with biochamic lung injury.

  19. Quantitative analysis of the improvement in high zoom maritime tracking due to real-time image enhancement

    CSIR Research Space (South Africa)

    Bachoo, AK

    2011-04-01

    Full Text Available This work aims to evaluate the improvement in the performance of tracking small maritime targets due to real-time enhancement of the video streams from high zoom cameras on pan-tilt pedestal. Due to atmospheric conditions these images can frequently...

  20. G eobacter sp. SD-1 with enhanced electrochemical activity in high-salt concentration solutions

    KAUST Repository

    Sun, Dan

    2014-07-16

    © 2014 Society for Applied Microbiology and John Wiley & Sons Ltd. Summary: An isolate, designated strain SD-1, was obtained from a biofilm dominated by Geobacter sulfurreducens in a microbial fuel cell. The electrochemical activity of strain SD-1 was compared with type strains, G.sulfurreducensPCA and Geobacter metallireducensGS-15, and a mixed culture in microbial electrolysis cells. SD-1 produced a maximum current density of 290±29Am-3 in a high-concentration phosphate buffer solution (PBS-H, 200mM). This current density was significantly higher than that produced by the mixed culture (189±44Am-3) or the type strains (<70Am-3). In a highly saline water (SW; 50mM PBS and 650mM NaCl), current by SD-1 (158±4Am-3) was reduced by 28% compared with 50mM PBS (220±4Am-3), but it was still higher than that of the mixed culture (147±19Am-3), and strains PCA and GS-15 did not produce any current. Electrochemical tests showed that the improved performance of SD-1 was due to its lower charge transfer resistance and more negative potentials produced at higher current densities. These results show that the electrochemical activity of SD-1 was significantly different than other Geobacter strains and mixed cultures in terms of its salt tolerance.

  1. Origin of high ammonium, arsenic and boron concentrations in the proximity of a mine: Natural vs. anthropogenic processes

    Energy Technology Data Exchange (ETDEWEB)

    Scheiber, Laura, E-mail: scheiber.ls@gmail.com [Institute of Environmental Assessment and Water Research, CSIC, Jordi Girona 18. E-08034 Barcelona (Spain); Ayora, Carlos; Vázquez-Suñé, Enric [Institute of Environmental Assessment and Water Research, CSIC, Jordi Girona 18. E-08034 Barcelona (Spain); Cendón, Dioni I. [Australian Nuclear Science and Technology Organisation, Locked Bag 2001, Kirrawee DC, NSW 2232 (Australia); School of Biological, Earth and Environmental Sciences (BEES), University of New South Wales (UNSW), NSW 2052 (Australia); Soler, Albert [Departament de Cristallografia, Mineralogia i Dipòsits Minerals, Facultat de Geologia, Universitat de Barcelona, C/Martí Franquès, sn., Barcelona (Spain); Baquero, Juan Carlos [Cobre Las Cruces S.A., Carretera SE-3410 km 4, 41860 Gerena, Sevilla (Spain)

    2016-01-15

    of sufficient quality for human drinking; the second zone is downflow and contains groundwater suitable for continuous irrigation but not drinkable due to high ammonium concentrations; and the third zone contains groundwater of elevated salinity (up to 5940 μS cm{sup −1}) and is not useable due to high ammonium, arsenic and boron concentrations. - Highlights: • Differentiation between natural and anthropogenic sources of NH{sub 4}, As and B • Assessment of hydrogeochemical processes that control the presence of NH{sub 4}, As and B in groundwater • High NH{sub 4}, As and B concentrations in Niebla-Posadas aquifer • Contribution to scientific-based aquifer management • Aquifer zonation based on groundwater quality for its good management.

  2. Thermodynamically consistent description of the hydrodynamics of free surfaces covered by insoluble surfactants of high concentration

    OpenAIRE

    Thiele, Uwe; Archer, Andrew J.; Plapp, Mathis

    2012-01-01

    In this paper we propose several models that describe the dynamics of liquid films which are covered by a high concentration layer of insoluble surfactant. First, we briefly review the 'classical' hydrodynamic form of the coupled evolution equations for the film height and surfactant concentration that are well established for small concentrations. Then we re-formulate the basic model as a gradient dynamics based on an underlying free energy functional that accounts for wettability and capill...

  3. Incomplete Ion Dissociation Underlies the Weakened Attraction between DNA Helices at High Spermidine Concentrations

    OpenAIRE

    Yang,Jie; Rau, Donald C

    2005-01-01

    We have investigated the salt sensitivity of the hexagonal-to-cholesteric phase transition of spermidine-condensed DNA. This transition precedes the resolubilization of precipitated DNA that occurs at high spermidine concentration. The sensitivity of the critical spermidine concentration at the transition point to the anion species and the NaCl concentration indicates that ion pairing of this trivalent ion underlies this unusual transition. Osmotic pressure measurements of spermidine salt sol...

  4. Effect of digestion time on anaerobic digestion with high ammonia concentration

    Science.gov (United States)

    Oktavitri, Nur Indradewi; Purnobasuki, Hery; Kuncoro, Eko Prasetyo; Purnamasari, Indah; Semma Hadinnata, P.

    2016-03-01

    Anaerobic digestion was developed to treat high concentration organic compound efficiently in certain Digestion Time (DT). High ammonia concentration could influenced removal organic compound in digestion. This bench scale study investigated the effect of digestion time on anaerobic batch reactor with high ammonia concentration. Total Ammonia Nitrogen (TAN) concentration was adjusted 4000 and 5000 mg/1, Digestion time was ranged from 0-26 d, operation temperature was ranged from 28-29°C, inoculum was collected from slaughter house sludge. The degradation of Chemical Oxygen Demand (COD) correlated with digestion time. The concentration of TAN from synthetic wastewater contain 5000 mg/1 of TAN more fluctuated than those use 4000 mg/1 of TAN. However, the biogas production from wastewater contained 4000 mg/1 of TAN gradually increased until 24 d of DT. The reactor contain 5000 mg/1 of TAN only growth until 12 d and steady state at over 12 d of digestion time.

  5. Melatonin in Arabidopsis thaliana acts as plant growth regulator at low concentrations and preserves seed viability at high concentrations.

    Science.gov (United States)

    Hernández, Ismaél Gatica; Gomez, Federico José Vicente; Cerutti, Soledad; Arana, María Verónica; Silva, María Fernanda

    2015-09-01

    Since the discovery of melatonin in plants, several roles have been described for different species, organs, and developmental stages. Arabidopsis thaliana, being a model plant species, is adequate to contribute to the elucidation of the role of melatonin in plants. In this work, melatonin was monitored daily by UHPLC-MS/MS in leaves, in order to study its diurnal accumulation as well as the effects of natural and artificial light treatments on its concentration. Furthermore, the effects of exogenous application of melatonin to assess its role in seed viability after heat stress and as a regulator of growth and development of vegetative tissues were evaluated. Our results indicate that melatonin contents in Arabidopsis were higher in plants growing under natural radiation when compared to those growing under artificial conditions, and its levels were not diurnally-regulated. Exogenous melatonin applications prolonged seed viability after heat stress conditions. In addition, melatonin applications retarded leaf senescence. Its effects as growth promoter were dose and tissue-dependent; stimulating root growth at low concentrations and decreasing leaf area at high doses.

  6. Prodigious Effects of Concentration Intensification on Nanoparticle Synthesis: A High-Quality, Scalable Approach.

    Science.gov (United States)

    Williamson, Curtis B; Nevers, Douglas R; Hanrath, Tobias; Robinson, Richard D

    2015-12-23

    Realizing the promise of nanoparticle-based technologies demands more efficient, robust synthesis methods (i.e., process intensification) that consistently produce large quantities of high-quality nanoparticles (NPs). We explored NP synthesis via the heat-up method in a regime of previously unexplored high concentrations near the solubility limit of the precursors. We discovered that in this highly concentrated and viscous regime the NP synthesis parameters are less sensitive to experimental variability and thereby provide a robust, scalable, and size-focusing NP synthesis. Specifically, we synthesize high-quality metal sulfide NPs (200 g) relative to the current field of large-scale (0.1-5 g yields) and laboratory-scale (<0.1 g) efforts. Compared to conventional synthesis methods (hot injection with dilute precursor concentration) characterized by rapid growth and low yield, our highly concentrated NP system supplies remarkably controlled growth rates and a 10-fold increase in NP volumetric production capacity (86 g/L). The controlled growth, high yield, and robust nature of highly concentrated solutions can facilitate large-scale nanomanufacturing of NPs by relaxing the synthesis requirements to achieve monodisperse products. Mechanistically, our investigation of the thermal and rheological properties and growth rates reveals that this high concentration regime has reduced mass diffusion (a 5-fold increase in solution viscosity), is stable to thermal perturbations (∼64% increase in heat capacity), and is resistant to Ostwald ripening.

  7. Evaluating the impact of high Pluronic® F68 concentrations on antibody producing CHO cell lines.

    Science.gov (United States)

    Tharmalingam, Tharmala; Goudar, Chetan T

    2015-04-01

    Pluronic® F68 (P-F68) is an important component of chemically-defined cell culture medium because it protects cells from hydrodynamic and bubble-induced shear in the bioreactor. While P-F68 is typically used in cell culture medium at a concentration of 1 g/L (0.1%), higher concentrations can offer additional shear protection and have also been shown to be beneficial during cryopreservation. Recent industry experience with variability in P-F68-associated shear-protection has opened up the possibility of elevated P-F68 concentrations in cell culture media, a topic that has not been previously explored in the context of industrial cell culture processes. Recognizing this gap, we first evaluated the effect of 1-5 g/L P-F68 concentrations in shake flask cultures over ten 3-day passages for cell lines A and B. Increase in terminal cell density and cell size was seen over time at higher P-F68 concentrations but protein productivity was not impacted. Results from this preliminary screening study suggested no adverse impact of high P-F68 concentrations. Subsequently fed-batch bioreactor experiments were conducted at 1 and 5 g/L P-F68 concentrations with both cell lines where cell growth, viability, metabolism, and product quality were examined under process conditions reflective of a commercial process. Results from these bioreactor experiments confirmed findings from the preliminary screen and also indicated no impact of elevated P-F68 concentration on product quality. If additional shear protection is desired, either due to raw material variability, cell line sensitivity, or a high-shear cell culture process, our results suggest this can be accomplished by elevating the P-F68 concentration in the cell culture medium without impacting cell culture performance and product quality.

  8. High-concentration-gradient dispersion in porous media : experiments, analysis and approximations

    NARCIS (Netherlands)

    R.J. Schotting; H. Moser; S.M. Hassanizadeh

    1997-01-01

    textabstractVarious experimental and theoretical studies have shown that Fick's law, based on the assumption of a linear relation between solute dispersive mass flux and concentration gradient, is not valid when high concentration gradients are encountered in a porous medium. The value of the macrod

  9. Critical phenomena in ethylbenzene oxidation in acetic acid solution at high cobalt(II) concentrations

    NARCIS (Netherlands)

    Gavrichkov, AA; Zakharov, [No Value

    2005-01-01

    Critical phenomena in ethylbenzene oxidation in an acetic acid solution at high cobalt(ill) concentrations (from 0.01 to 0.2 mol L-1) were studied at 60-90 degrees C by the gasometric (O-2 absorption), spectrophotometric (Co-III accumulation), and chemiluminescence (relative concentration of radical

  10. Whey protein particles modulate mechanical properties of gels at high protein concentrations

    NARCIS (Netherlands)

    Saglam, D.; Venema, P.; Vries, de R.J.; Berg, van den L.; Linden, van der E.

    2014-01-01

    We have studied the influence of dense whey protein particles on the mechanical properties of whey protein isolate (WPI) gels at high protein concentrations (16–22% (w/w)). Incorporation of dense whey protein particles in the gel, while keeping the total protein concentration constant, leads to a co

  11. Rheology of dilute acid hydrolyzed corn stover at high solids concentration

    Science.gov (United States)

    M.R. Ehrhardt; T.O. Monz; T.W. Root; R.K. Connelly; Tim Scott; D.J. Klingenberg

    2010-01-01

    The rheological properties of acid hydrolyzed corn stover at high solids concentration (20–35 wt.%) were investigated using torque rheometry. These materials are yield stress fluids whose rheological properties can be well represented by the Bingham model. Yield stresses increase with increasing solids concentration and decrease with increasing hydrolysis reaction...

  12. Effect of dissolved oxygen concentration on the bioflocculation process in high loaded MBRs

    NARCIS (Netherlands)

    Faust, L.; Temmink, B.G.; Zwijnenburg, A.; Kemperman, A.J.B.; Rijnaarts, H.

    2014-01-01

    High-loaded membrane bioreactors (HL-MBRs), i.e. MBRs which are operated at extremely short sludge and hydraulic retention times, can be applied to flocculate and concentrate sewage organic matter. The concentrated organics can be used for energy recovery, or for the production of more valuable

  13. High physical and psychological load at work and sickness absence due to neck pain

    NARCIS (Netherlands)

    Ariëns, G.A.M.; Bongers, P.M.; Hoogendoorn, W.E.; Wal, G. van der; Mechelen, W. van

    2002-01-01

    Objectives This study investigates the relationship between physical and psychosocial load at work and sickness absence due to neck pain. Methods A prospective cohort study with a follow-up period of 3 years (1994-1998) was performed among a working population. At the beginning of the study, physica

  14. Specific features of waveguide heating due to transmission of high-power microwave signals

    Science.gov (United States)

    Kudryavtsev, I. V.; Gotselyuk, O. B.; Novikov, E. S.; Demin, V. G.

    2017-01-01

    Waveguide heating due to transmission of microwave signals is studied. Mathematical models are developed to evaluate heat liberation, and differential equations of thermal balance are derived with allowance for different working conditions of waveguides. The results prove the necessity of the further study of the effect of heat liberation in waveguides on strength and functional characteristics.

  15. A High-Efficiency Refractive Secondary Solar Concentrator for High Temperature Solar Thermal Applications

    Science.gov (United States)

    Piszczor, Michael F., Jr.; Macosko, Robert P.

    2000-01-01

    A refractive secondary solar concentrator is a non-imaging optical device that accepts focused solar energy from a primary concentrator and redirects that light, by means of refraction and total internal reflection (TIR) into a cavity where the solar energy is used for power and/or propulsion applications. This concept offers a variety of advantages compared to typical reflective secondary concentrators (or the use of no secondary at all): higher optical efficiency, minimal secondary cooling requirements, a smaller cavity aperture, a reduction of outgassing from the cavity and flux tailoring of the solar energy within the heat receiver. During the past 2 years, NASA Lewis has been aggressively developing this concept in support of the NASA Marshall Shooting Star Flight Experiment. This paper provides a brief overview of the advantages and technical challenges associated with the development of a refractive secondary concentrator and the fabrication of a working unit in support of the flight demonstration program.

  16. Investigating cold gelation properties of recombined highly concentrated micellar casein concentrate and cream for use in cheese making.

    Science.gov (United States)

    Lu, Y; McMahon, D J; Vollmer, A H

    2016-07-01

    Highly concentrated micellar casein concentrate (HC-MCC), a potential ingredient for cheese making, contains ~20% casein with ~70% of serum proteins removed by microfiltration and diafiltration of skim milk, followed by vacuum evaporation. Our objective was to investigate cold gelation properties of recombined concentrated milk (RCM) by mixing thawed frozen HC-MCC and cream under different casein levels, pH, and protein-to-fat ratios, and with addition of sodium citrate or calcium. The HC-MCC was recombined with cream using low shear at 50°C for 30 min, and rheological measurements were conducted. Cold-gelling temperature [the temperature at which storage modulus (G')=loss modulus (G″)] was linearly correlated with casein levels from 8.6 to 11.5% (R(2)=0.71), pH from 6.6 to 7.0 (R(2)=0.96), and addition of sodium citrate from 0 to 0.36mmol/g of casein (R(2)=0.80). At pH 7.0, gelation occurred at 12, 26, and 38°C with 9, 10, and 11% casein, respectively. At pH 6.6, 6.8, and 7.0, RCM with 12% casein gelled at a mean temperature of 12, 26, and 37°C, respectively. Adding calcium chloride at 0.17mmol/g of casein significantly increased cold-gelling temperature from 18 to ≥50°C, whereas no significant change was observed at levels up to 0.12mmol/g of casein. Different protein to fat ratios ranging from 0.8 to 1.2 did not significantly influence gelling temperature. In transmission electron micrographs of RCM with 12% casein, casein micelles were nonspherical and partially dissociated into small protein strands. Upon addition of calcium chloride at 0.21mmol/g of casein, casein micelles were more spherical and retained colloidal structure with the presence of aggregated casein micelles. These gelation processes of RCM with or without addition of trisodium citrate were both reversible. We propose that cold gelation of RCM occurs when protein strands that have been partially released from the casein micelles entangle, restrict their mobility, and form a fine

  17. Potassium double tungstate waveguides with high ytterbium concentration for optical amplification

    NARCIS (Netherlands)

    Yong, Yean-Sheng

    2017-01-01

    In this thesis, the research work concerning high ytterbium concentration potassium double tungstate waveguides catered for optical amplification purpose is presented. The scope of the research work includes the investigation of spectroscopic and optical gain properties in epitaxy layers with

  18. Methods to assess high-resolution subsurface gas concentrations and gas fluxes in wetland ecosystems

    DEFF Research Database (Denmark)

    Elberling, Bo; Kühl, Michael; Glud, Ronnie N.

    2013-01-01

    The need for measurements of soil gas concentrations and surface fluxes of greenhouse gases at high temporal and spatial resolution in wetland ecosystem has lead to the introduction of several new analytical techniques and methods. In addition to the automated flux chamber methodology for high......-resolution estimates of greenhouse gas fluxes across the soil-atmosphere interface, these high-resolution methods include microsensors for quantification of spatiotemporal concentration dynamics in O2 and N2O at micrometer scales, fiber-optic optodes for long-term continuous point measurements of O2 concentrations...... and peat soils are highly heterogeneous, containing a mosaic of dynamic macropore systems created by both macrofauna and flora leading to distinct spatial and temporal variations in gas concentration on a scale of millimeters and minutes. Applications of these new methodologies allow measurements...

  19. Concentration influences on recovery in a high gradient magnetic separation axial filter

    Energy Technology Data Exchange (ETDEWEB)

    Murariu, V.; Rezlescu, N.; Rotariu, O.; Badescu, V. [Inst. of Technical Physics, Iasi (Romania)

    1998-05-01

    The buildup differential equations for the case of a single wire in high gradient magnetic filtration (HGMF)-axial configuration taking into account the suspension concentration are solved. A new equation for the deposit contour surface at different moments and for different suspension concentrations are obtained. The existence of a particulate suspension concentration, for which the radial extension velocity of deposit is maximum, is evidenced. The recovery for an ordered ferromagnetic matrix is calculated. The influence of the solid particle concentration from suspension on the filtration efficiency is presented.

  20. Subcutaneous absorption kinetics of two highly concentrated preparations of recombinant human growth hormone

    DEFF Research Database (Denmark)

    Laursen, Torben; Jørgensen, Jens Otto Lunde; Susgaard, Søren;

    1993-01-01

    Abstract OBJECTIVE: The relative bioavailability of two highly concentrated (12 IU/ml) formulations of biosynthetic human growth hormone (GH) administered subcutaneously was compared. DESIGN: A randomized, crossover study. Conventional GH therapy was withdrawn 72 hours before each study period. T....... CONCLUSIONS: There is no significant difference between the absorption kinetics and short-term metabolic effects of these two highly concentrated formulations of biosynthetic GH. The two formulations are bioequivalent....

  1. Incomplete ion dissociation underlies the weakened attraction between DNA helices at high spermidine concentrations.

    Science.gov (United States)

    Yang, Jie; Rau, Donald C

    2005-09-01

    We have investigated the salt sensitivity of the hexagonal-to-cholesteric phase transition of spermidine-condensed DNA. This transition precedes the resolubilization of precipitated DNA that occurs at high spermidine concentration. The sensitivity of the critical spermidine concentration at the transition point to the anion species and the NaCl concentration indicates that ion pairing of this trivalent ion underlies this unusual transition. Osmotic pressure measurements of spermidine salt solutions are consistent with this interpretation. Spermidine salts are not fully dissociated at higher concentrations. The competition for DNA binding among the fully charged trivalent ion and the lesser charged complex species at higher concentrations significantly weakens attraction between DNA helices in the condensed state. This is contrary to the suggestion that the binding of spermidine at higher concentrations causes DNA overcharging and consequent electrostatic repulsion.

  2. Transcriptional analysis of adaptation to high glucose concentrations in Zymomonas mobilis.

    Science.gov (United States)

    Zhang, Kun; Shao, Huanhuan; Cao, Qinghua; He, Ming-Xiong; Wu, Bo; Feng, Hong

    2015-02-01

    The ethanologenic bacterium Zymomonas mobilis is usually tolerant to high concentrations of glucose. The addition of sorbitol decreases the lag phase and increases ethanol yield and productivity of the bacteria in high glucose concentrations. The molecular mechanisms of adaptation to high glucose concentrations and the effect of sorbitol are still unclear. In this study, microarray analysis was used to study the global transcriptional adaptation responses of Z. mobilis to high glucose concentrations. A total of 235 genes were differentially expressed when 220 g/L glucose was added with or without 10 mM sorbitol. These genes are involved in diverse aspects of cell metabolism and regulation, including membrane transporters, nitrogen metabolism, and plasmid-encoded genes. However, most differentially expressed genes were downregulated when sorbitol was added. Notably, the transcription of almost all genes involved in the Entner-Doudoroff and ethanol production pathways was not significantly affected. In addition, a prophage and a nitrogen-fixation cluster were significantly induced. These results revealed that Z. mobilis cells responded to high glucose concentrations by regulating the transcriptional levels of genes related to membrane channels and transporters, stress response mechanisms, and metabolic pathways. These data provide insight into the intracellular adaptation responses to high glucose concentrations and reveal strategies to engineer efficient ethanol fermentation in Z. mobilis.

  3. EXPERIMENTAL INVESTIGATIONS ON DIFFUSION CHARACTERISTICS OF HIGH CONCENTRATION JETS IN ENVIRONMENTAL CURRENTS

    Institute of Scientific and Technical Information of China (English)

    张燕; 王道增; 樊靖郁

    2002-01-01

    By means of flow visualization and quantitative measurement, the diffusionpattern and concentration distribution characteristics of high concentration jets verticallydischarged into shallow moving waterbody were experimentally investigated in waterchannel. The interactions between the high concentration jets and environmental flowconditions were analysed, and the formulae of impinging point coordinate and transversespread angle are gained from data analysis. Experimental results indicate that the jets showcomplicated flow patterns and diffusion characteristics in near region, which are differentfrom common submerged jets, and spread downstream in the manner of density currents.

  4. Simulation of hydrodynamic effects of salt rejection due to permafrost. Hydrogeological numerical model of density-driven mixing, at a regional scale, due to a high salinity pulse

    Energy Technology Data Exchange (ETDEWEB)

    Vidstrand, Patrik [BERGAB, Goeteborg (Sweden); Svensson, Urban [CFE AB, Norrkoeping (Sweden); Follin, Sven [SF GeoLogic AB, Taeby (Sweden)

    2006-10-15

    The main objective of this study is to support the safety assessment of the investigated candidate sites concerning hydrogeological and hydrogeochemical issues related to permafrost. However, a more specific objective of the study is to improve the assessment of processes in relation to permafrost scenarios. The model is based on a mathematical model that includes Darcy velocities, mass conservation, matrix diffusion, and salinity distribution. Gravitational effects are thus fully accounted for. A regional groundwater flow model (POM v1.1, Simpevarp) was used as basis for the simulations. The main results of the model include salinity distributions in time. The general conclusion is that density-driven mixing processes are contained within more permeable deformation zones and that these processes are fast as compared with preliminary permafrost growth rates. The results of the simulation suggest that a repository volume in the rock mass in-between the deterministic deformation zones, approximately 150 m below the permafrost will not experience a high salinity situation due to the salt rejection process.

  5. Relationship between paraoxonase 1 activity and high density lipoprotein concentration during naturally occurring babesiosis in dogs.

    Science.gov (United States)

    Rossi, G; Kuleš, J; Rafaj, R Barić; Mrljak, V; Lauzi, S; Giordano, A; Paltrinieri, S

    2014-10-01

    Paraoxonase 1 (PON1) is a negative acute phase protein bound to high density lipoproteins (HDL) and during the acute phase response (APR) protects HDL from peroxidation. The aim of this study was to assess the relationship between PON1 and HDL in canine babesiosis, a disease characterized by oxidative damages and by an APR. PON1, HDL and C-reactive protein (CRP), were measured in blood collected from 15 controls and 29 dogs with babesiosis sampled at admission, and on days 1 and 7 after treatment. At admission, PON1 and HDL were significantly lower in affected dogs. HDL concentration increased at day 1 while PON1 increased and CRP decreased at day 7. This suggests that the decrease of PON1 at admission is in part due to an increased consumption, the decreased HDL may depend on lipid peroxidation and its rapid increase after treatment may depend on the antioxidant activity of PON1. Copyright © 2014 Elsevier Ltd. All rights reserved.

  6. Origin of high ammonium, arsenic and boron concentrations in the proximity of a mine: Natural vs. anthropogenic processes.

    Science.gov (United States)

    Scheiber, Laura; Ayora, Carlos; Vázquez-Suñé, Enric; Cendón, Dioni I; Soler, Albert; Baquero, Juan Carlos

    2016-01-15

    human drinking; the second zone is downflow and contains groundwater suitable for continuous irrigation but not drinkable due to high ammonium concentrations; and the third zone contains groundwater of elevated salinity (up to 5940 μS cm(-1)) and is not useable due to high ammonium, arsenic and boron concentrations.

  7. Potential high temperature corrosion problems due to co-firing of biomass and fossil fuels

    DEFF Research Database (Denmark)

    Montgomery, Melanie; Vilhelmsen, T.; Jensen, S.A.

    2008-01-01

    in this environment, the internal sulphidation is much more significant than that revealed in the demonstration project. Avedøre 2 main boiler is fuelled with wood pelletsþheavy fuel oilþgas. Some reaction products resulting from the presence of vanadium compounds in the heavy oil were detected, i.e. iron vanadates....... However, the most significant corrosion attack was sulphidation attack at the grain boundaries of 18-8 steel after 3 years exposure. The corrosion mechanisms and corrosion rates are compared with biomass firing and coal firing. Potential corrosion problems due to co-firing biomass and fossil fuels...

  8. [Study of high temperature water vapor concentration measurement method based on absorption spectroscopy].

    Science.gov (United States)

    Chen, Jiu-ying; Liu, Jian-guo; He, Jun-feng; He, Ya-bai; Zhang, Guang-le; Xu, Zhen-yu; Gang, Qiang; Wang, Liao; Yao, Lu; Yuan, Song; Ruan, Jun; Dai, Yun-hai; Kan, Rui-feng

    2014-12-01

    Tunable diode laser absorption spectroscopy (TDLAS) has been developed to realize the real-time and dynamic measurement of the combustion temperature, gas component concentration, velocity and other flow parameters, owing to its high sensitivity, fast time response, non-invasive character and robust nature. In order to obtain accurate water vapor concentration at high temperature, several absorption spectra of water vapor near 1.39 μm from 773 to 1273 K under ordinary pressure were recorded in a high temperature experiment setup using a narrow band diode laser. The absorbance of high temperature absorption spectra was calculated by combined multi-line nonlinear least squares fitting method. Two water vapor absorption lines near 7154.35 and 7157.73 cm(-1) were selected for measurement of water vapor at high temperature. A model method for high temperature water vapor concentration was first proposed. Water vapor concentration from the model method at high temperature is in accordance with theoretical reasoning, concentration measurement standard error is less than 0.2%, and the relative error is less than 6%. The feasibility of this measuring method is verified by experiment.

  9. Trace element concentrations and gastrointestinal parasites of Arctic terns breeding in the Canadian High Arctic.

    Science.gov (United States)

    Provencher, J F; Braune, B M; Gilchrist, H G; Forbes, M R; Mallory, M L

    2014-04-01

    Baseline data on trace element concentrations are lacking for many species of Arctic marine birds. We measured essential and non-essential element concentrations in Arctic tern (Sterna paradisaea) liver tissue and brain tissue (mercury only) from Canada's High Arctic, and recorded the presence/absence of gastrointestinal parasites during four different phases of the breeding season. Arctic terns from northern Canada had similar trace element concentrations to other seabird species feeding at the same trophic level in the same region. Concentrations of bismuth, selenium, lead and mercury in Arctic terns were high compared to published threshold values for birds. Selenium and mercury concentrations were also higher in Arctic terns from northern Canada than bird species sampled in other Arctic areas. Selenium, mercury and arsenic concentrations varied across the time periods examined, suggesting potential regional differences in the exposure of biota to these elements. For unknown reasons, selenium concentrations were significantly higher in birds with gastrointestinal parasites as compared to those without parasites, while bismuth concentrations were higher in Arctic terns not infected with gastrointestinal parasites.

  10. Impact of high ytterbium(III) concentration in the shell on upconversion luminescence of core-shell nanocrystals.

    Science.gov (United States)

    Lei, Lei; Chen, Daqin; Zhu, Wenjuan; Xu, Ju; Wang, Yuansheng

    2014-10-01

    After coating 20 Yb/2 Er:NaGdF4 core nanocrystals with a NaYbF4 shell, upconversion emission of the rare earth ions weakens. So far, the exact reason for this phenomenon is still unclear due to lack of the direct evidence. In this report, a core@shell@shell sandwich-like structure is designed and fabricated to investigate this phenomenon. We find that high Yb(3+) concentration in the shell has mainly two adverse impacts: it promotes not only the deleterious back energy transfer from Er(3+) in the core to Yb(3+) in the shell but also the energy transfer from Yb(3+) in the core to Yb(3+) in the shell. To obtain nanocrystals with high upconversion efficency, appropriate Yb(3+) concentration should be introduced into the shell or the transition layer.

  11. High serum uric acid concentration predicts poor survival in patients with breast cancer.

    Science.gov (United States)

    Yue, Cai-Feng; Feng, Pin-Ning; Yao, Zhen-Rong; Yu, Xue-Gao; Lin, Wen-Bin; Qian, Yuan-Min; Guo, Yun-Miao; Li, Lai-Sheng; Liu, Min

    2017-08-26

    Uric acid is a product of purine metabolism. Recently, uric acid has gained much attraction in cancer. In this study, we aim to investigate the clinicopathological and prognostic significance of serum uric acid concentration in breast cancer patients. A total of 443 female patients with histopathologically diagnosed breast cancer were included. After a mean follow-up time of 56months, survival was analysed using the Kaplan-Meier method. To further evaluate the prognostic significance of uric acid concentrations, univariate and multivariate Cox regression analyses were applied. Of the clinicopathological parameters, uric acid concentration was associated with age, body mass index, ER status and PR status. Univariate analysis identified that patients with increased uric acid concentration had a significantly inferior overall survival (HR 2.13, 95% CI 1.15-3.94, p=0.016). In multivariate analysis, we found that high uric acid concentration is an independent prognostic factor predicting death, but insufficient to predict local relapse or distant metastasis. Kaplan-Meier analysis indicated that high uric acid concentration is related to the poor overall survival (p=0.013). High uric acid concentration predicts poor survival in patients with breast cancer, and might serve as a potential marker for appropriate management of breast cancer patients. Copyright © 2017. Published by Elsevier B.V.

  12. Visualizing the internal structure of subaqueous, high-concentration sediment-laden flows: implication of rheology to flow structure

    Science.gov (United States)

    Perillo, M. M.; Buttles, J.; Mohrig, D. C.; Kane, I.; Pontén, A.; Brown, D.; Minton, B. W.

    2013-12-01

    Subaqueous sediment-laden flows are thought to be the main mechanism transporting sediments to the deep sea. Understanding the processes governing these flows is crucial to building predictive models of flow behaviour, sediment transport and deposition and is applicable to a wide range of disciplines. Physical modelling using a wide range of experimental facilities and measurement techniques has significantly advanced our understanding of these sediment-laden flows and their ability to erode, transport and deposit sediments. However, for the case of high-sediment concentration flows, measuring flow and depositional properties is still a challenge. Here, we present results from an acoustic reflection technique that allows for direct and noninvasive visualization of the internal structure of high concentration, clay-rich, sand-laden flows with a range of initial yield strengths (0-26 Pa). As the acoustic signal travels through the sediment-laden flow, it encounters zones of varying acoustic impedance that are due to temporal and spatial changes in sediment concentration, grain size and sorting, and flow mixing. The reflected signal is processed and interpreted using seismic techniques developed in exploration geophysics. The ultrasonic reflection data captured two distinct flow stages, an active stage and a post-depositional creeping stage. The clay-rich sand-laden flows showed stratification expressed by three clear vertical zones: (a) an upper relatively dilute turbulent zone, (b) a zone with high sediment concentration and significantly reduced mixing and (c) an aggrading bed of static grains.

  13. Median Nerve Injury Due to High-Pressure Water Jet Injection: A Case Report and Review of Literature.

    Science.gov (United States)

    Emre, Ufuk; Unal, Aysun

    2009-08-01

    High-pressure injuries that occur accidentally are potentially destructive injuries that often affect the nondominant hands of young men. A variety of products such as paint, gasoline, grease, fuel oil, cement, thinner and solvents have been reported as destructive agents. High-pressure water jet injection injuries to soft tissues have rarely been reported. In this study, we present the first case of median nerve injury due to high-pressure water jet injection by a water spray gun.

  14. Analysis of surface degradation of high density polyethylene (HDPE) insulation material due to tracking

    Indian Academy of Sciences (India)

    R Sarathi; S Chandrasekar; V Sabari Giri; C Venkataseshaiah; R Velmurugan

    2004-06-01

    In the present work, tracking phenomena has been studied with HDPE material under a.c. voltage, with ammonium chloride as the contaminant. It is noticed that the tracking time depends on the conductivity and flow rate of the contaminant. The diffusion coefficient of the material was obtained. The thermal and chemical stability of the material were identified by carrying out a methodical experimental study. The physico-chemical analyses viz. wide angle X-ray diffraction (WAXD), differential scanning calorimetry (DSC) and dynamic mechanical analysis (DMA), were carried out and it was concluded that the mechanism of tracking process is due to the surface degradation. The surface condition of the insulation structure was characterized for any surface discharges or tracking, using the leakage current measurement, utilizing the wavelet concepts.

  15. Bedload monitoring under conditions of ultra-high suspended sediment concentrations

    Science.gov (United States)

    Liébault, F.; Jantzi, H.; Klotz, S.; Laronne, J. B.; Recking, A.

    2016-09-01

    The bedload response of the Moulin Ravine, a small alluvial system draining a very active Mediterranean badlands landscape entrenched into Jurassic black marls of the Southern French Prealps, has been investigated using an automatic Reid bedload slot sampler. This site is known for its exceptional sediment transport conditions thanks to a long-term monitoring program that started in the late 1980s, revealing a mean annual bedload yield of 2810 t km-2 yr-1, and suspended sediment concentrations (SSCs) during flow events commonly reaching 100 g L-1. With the deployment of the slot sampler, it has been possible to record instantaneous bedload fluxes during 10 s time increments and to investigate bedload response under flow conditions with ultra-high SSCs. Bedload records cover 4 flashy summer flow events induced by heavy convective storms including a 20-yr return period event. Due to the very high SSC conditions these events challenge bedload monitoring. Even if slot sampling has been recognized as insensitive to fine sediments (silts and clays), it has never been tested in such exceptional muddy flow conditions. The bedload slot sampler performed well in such conditions. A flow-invariant proportion of fines (∼15-20%) was captured in the slot sampler during flows. This proportion is equivalent to its content in the active bedload layer during summer flows, suggesting that fines enter the slot embedded with coarse particles. Instantaneous bedload fluxes recorded in the Moulin are amongst the highest hitherto reported values worldwide, providing evidence of the exceptional sediment transport conditions of marly alpine badlands. The dimensionless entrainment threshold is one order of magnitude higher than commonly reported for gravel-bed rivers, likely reflecting the cohesion effect of fines intruded in the channel surface and subsurface.

  16. Estimated Costs of Dental Care due to Dental Decay in Mexican High School Students

    OpenAIRE

    2010-01-01

    Objective: Estimate the cost of dental care generated by the dental decay prevalence in high school students at Universidad Nacional Autónoma de México (UNAM). Methods: A cross-sectional study was carried out with a population of 78,870 high schoolers (conducted between the years 2003 and 2005). The need for dental caries treatment was determined by the decayed, missing and filled teeth index (DMFT) as it is indicated at the Automated Medical Exam (EMA, acronym in Spanish). The estimation of ...

  17. An incidence of very high phosphate concentrations in the waters around Andaman Islands

    Digital Repository Service at National Institute of Oceanography (India)

    Reddy, C.V.G.; Murty, P.S.N.; Sankaranarayanan, V.N.

    at stations close to coasts; 2) vertical distribution of phosphates in 200 metre column does not appear to correspond to any regular accepted pattern and 3) all the phosphates having the abnormally high phosphate concentration were found to be highly turbid...

  18. Cupping Therapy for 103 Cases of High Fever due to Infection of the Upper Respiratory Tract

    Institute of Scientific and Technical Information of China (English)

    刘颖东

    2002-01-01

    @@ The cupping therapy has remarkable antipyretic effect in the treatment of fever. In recent years, the author has treated 103 cases of high fever caused by infection of the upper respiratory tract and obtained quite satisfactory therapeutic results. A report follows.

  19. Textile processing improvements due to high speed roller ginning of upland cotton

    Science.gov (United States)

    Selective breeding has improved upland cotton fiber properties. Processing capacities of new high-speed roller ginning technology approach that of saw ginning. Spinning mills are interested in mill performance data comparing new upland cultivars processed by both saw and roller ginning. Four dive...

  20. Residual gas entering high density hydrogen plasma: rarefaction due to rapid heating

    NARCIS (Netherlands)

    N. den Harder,; D.C. Schram,; W. J. Goedheer,; de Blank, H. J.; M. C. M. van de Sanden,; van Rooij, G. J.

    2015-01-01

    The interaction of background molecular hydrogen with magnetized (0.4 T) high density (1–5 × 10 20  m −3 ) low temperature (∼3 eV) hydrogen plasma was inferred from the Fulcher band emission in the linear plasma generator Pilot-PSI. In the plasma center,

  1. Student-Generated Protective Behaviors to Avert Severe Harm Due to High-Risk Alcohol Consumption

    Science.gov (United States)

    Smith, Sandi W.; LaPlante, Carolyn; Wibert, Wilma Novales; Mayer, Alex; Atkin, Charles K.; Klein, Katherine; Glazer, Edward; Martell, Dennis

    2011-01-01

    High-risk alcohol consumption is a significant problem on college campuses that many students see as a rite of passage in their development into adulthood. Developing effective prevention campaigns designed to lessen or avert the risks associated with alcohol consumption entails understanding how students perceive harmful consequences as well as…

  2. Student-Generated Protective Behaviors to Avert Severe Harm Due to High-Risk Alcohol Consumption

    Science.gov (United States)

    Smith, Sandi W.; LaPlante, Carolyn; Wibert, Wilma Novales; Mayer, Alex; Atkin, Charles K.; Klein, Katherine; Glazer, Edward; Martell, Dennis

    2011-01-01

    High-risk alcohol consumption is a significant problem on college campuses that many students see as a rite of passage in their development into adulthood. Developing effective prevention campaigns designed to lessen or avert the risks associated with alcohol consumption entails understanding how students perceive harmful consequences as well as…

  3. High levels of endocrine pollutants in US streams during low flow due to insufficient wastewater dilution

    Science.gov (United States)

    Rice, Jacelyn; Westerhoff, Paul

    2017-08-01

    Wastewater discharges from publicly owned treatment works are a significant source of endocrine disruptors and other contaminants to the aquatic environment in the US. Although remaining pollutants in wastewater pose environmental risks, treated wastewater is also a primary source of stream flow, which in turn is critical in maintaining many aquatic and riparian wildlife habitats. Here we calculate the dilution factor--the ratio of flow in the stream receiving discharge to the flow of wastewater discharge--for over 14,000 receiving streams in the continental US using streamflow observations and a spatially explicit watershed-scale hydraulic model. We found that wastewater discharges make up more than 50% of in-stream flow for over 900 streams. However, in 1,049 streams that experienced exceptional low-flow conditions, the dilution factors in 635 of those streams fell so low during those conditions that the safety threshold for concentrations of one endocrine disrupting compound was exceeded, and in roughly a third of those streams, the threshold was exceeded for two compounds. We suggest that streams are vulnerable to public wastewater discharge of contaminants under low-flow conditions, at a time when wastewater discharges are likely to be most important for maintaining stream flow for smaller sized river systems.

  4. Influence of Mechanical Activation on Acid Leaching Dephosphorization of High-phosphorus Iron Ore Concentrates

    Institute of Scientific and Technical Information of China (English)

    De-qing ZHU; Hao WANG; Jian PAN; Cong-cong YANG

    2016-01-01

    High pressure roll grinding (HPRG)and ball milling were compared to investigate the influence of me-chanical activation on the acid leaching dephosphorization of a high-phosphorus iron ore concentrate,which was man-ufactured through magnetizing roasting-magnetic separation of high-phosphorus oolitic iron ores.The results indica-ted that when high-phosphorus iron ore concentrates containing 54·92 mass% iron and 0·76 mass% phosphorus were directly processed through acid leaching,iron ore concentrates containing 55·74 mass% iron and 0·33 mass%phosphorus with an iron recovery of 84·64% and dephosphorization of 63·79% were obtained.When high-phosphor-us iron ore concentrates activated by ball milling were processed by acid leaching,iron ore concentrates containing 56·03 mass% iron and 0·21 mass% phosphorus with an iron recovery of 85·65% and dephosphorization of 77·49%were obtained.Meanwhile,when high-phosphorus iron ore concentrates activated by HPRG were processed by acid leaching,iron ore concentrates containing 58·02 mass% iron and 0·10 mass% phosphorus were obtained,with the iron recovery reaching 88·42% and the dephosphorization rate reaching 88·99%.Mechanistic studies demonstrated that ball milling can reduce the particle size,demonstrating a prominent reunion phenomenon.In contrast,HPRG pretreatment contributes to the formation of more cracks within the particles and selective dissociation of iron and P bearing minerals,which can provide the favorable kinetic conditions to accelerate the solid-liquid reaction rate.As such,the crystal structure is destroyed and the surface energy of mineral particles is strengthened by mechanical ac-tivation,further strengthening the dephosphorization.

  5. Prodigious Effects of Concentration Intensification on Nanoparticle Synthesis: A High-Quality, Scalable Approach

    KAUST Repository

    Williamson, Curtis B.

    2015-12-23

    © 2015 American Chemical Society. Realizing the promise of nanoparticle-based technologies demands more efficient, robust synthesis methods (i.e., process intensification) that consistently produce large quantities of high-quality nanoparticles (NPs). We explored NP synthesis via the heat-up method in a regime of previously unexplored high concentrations near the solubility limit of the precursors. We discovered that in this highly concentrated and viscous regime the NP synthesis parameters are less sensitive to experimental variability and thereby provide a robust, scalable, and size-focusing NP synthesis. Specifically, we synthesize high-quality metal sulfide NPs (<7% relative standard deviation for Cu2-xS and CdS), and demonstrate a 10-1000-fold increase in Cu2-xS NP production (>200 g) relative to the current field of large-scale (0.1-5 g yields) and laboratory-scale (<0.1 g) efforts. Compared to conventional synthesis methods (hot injection with dilute precursor concentration) characterized by rapid growth and low yield, our highly concentrated NP system supplies remarkably controlled growth rates and a 10-fold increase in NP volumetric production capacity (86 g/L). The controlled growth, high yield, and robust nature of highly concentrated solutions can facilitate large-scale nanomanufacturing of NPs by relaxing the synthesis requirements to achieve monodisperse products. Mechanistically, our investigation of the thermal and rheological properties and growth rates reveals that this high concentration regime has reduced mass diffusion (a 5-fold increase in solution viscosity), is stable to thermal perturbations (64% increase in heat capacity), and is resistant to Ostwald ripening.

  6. Design and Evaluation of the Highly Concentrated Human IgG Formulation Using Cyclodextrin Polypseudorotaxane Hydrogels.

    Science.gov (United States)

    Higashi, Taishi; Tajima, Anna; Ohshita, Naoko; Hirotsu, Tatsunori; Abu Hashim, Irhan Ibrahim; Motoyama, Keiichi; Koyama, Sawako; Iibuchi, Ruriko; Mieda, Shiuhei; Handa, Kenji; Kimoto, Tomoaki; Arima, Hidetoshi

    2015-12-01

    To achieve the potent therapeutic effects of human immunoglobulin G (IgG), highly concentrated formulations are required. However, the stabilization for highly concentrated human IgG is laborious work. In the present study, to investigate the potentials of polypseudorotaxane (PPRX) hydrogels consisting of polyethylene glycol (PEG) and α- or γ-cyclodextrin (α- or γ-CyD) as pharmaceutical materials for highly concentrated human IgG, we designed the PPRX hydrogels including human IgG and evaluated their pharmaceutical properties. The α- and γ-CyDs formed PPRX hydrogels with PEG (M.W. 20,000) even in the presence of highly concentrated human IgG (>100 mg/mL). According to the results of (1)H-NMR, powder X-ray diffraction, and Raman microscopy, the formation of human IgG/CyD PPRX hydrogels was based on physical cross-linking arising from their columnar structures. The release profiles of human IgG from the hydrogels were in accordance with the non-Fickian diffusion model. Importantly, the stabilities of human IgG included into the hydrogels against thermal and shaking stresses were markedly improved. These findings suggest that PEG/CyD PPRX hydrogels are useful to prepare the formulation for highly concentrated human IgG.

  7. High Concentrating GaAs Cell Operation Using Optical Waveguide Solar Energy System

    Science.gov (United States)

    Nakamura, T.; Case, J. A.; Timmons, M. L.

    2004-01-01

    This paper discusses the result of the concentrating photovoltaic (CPV) cell experiments conducted with the Optical Waveguide (OW) Solar Energy System. The high concentration GaAs cells developed by Research Triangle Institute (RTI) were combined with the OW system in a "fiber-on-cell" configuration. The sell performance was tested up to the solar concentration of 327. Detailed V-I characteristics, power density and efficiency data were collected. It was shown that the CPV cells combined with the OW solar energy system will be an effective electric power generation device.

  8. Photorespiration and carbon concentrating mechanisms: two adaptations to high O2, low CO2 conditions.

    Science.gov (United States)

    Moroney, James V; Jungnick, Nadine; Dimario, Robert J; Longstreth, David J

    2013-11-01

    This review presents an overview of the two ways that cyanobacteria, algae, and plants have adapted to high O2 and low CO2 concentrations in the environment. First, the process of photorespiration enables photosynthetic organisms to recycle phosphoglycolate formed by the oxygenase reaction catalyzed by ribulose-1,5-bisphosphate carboxylase/oxygenase (Rubisco). Second, there are a number of carbon concentrating mechanisms that increase the CO2 concentration around Rubisco which increases the carboxylase reaction enhancing CO2 fixation. This review also presents possibilities for the beneficial modification of these processes with the goal of improving future crop yields.

  9. Deviations from uniform power-law scaling due to exposure to high altitude

    Science.gov (United States)

    Posiewnik, A.

    2002-12-01

    A major challenge in biological physics is the analysis of time series that are typically highly nonstationary. Viswanathan et al. (Phys. Rev. E 55 (1) (1997) 845-899) using techniques based on the Fano factor and the Allan factor functions, as well as on detrended fluctuation analysis showed that the scaling properties of the dynamics of healthy physiological systems in normal conditions are more stable than those of pathological systems-there is underlying loss of uniform power-law scaling in disease. Here we test, using the same techniques as Viswanathan et al. (1997), the hypothesis that deviations from uniform power-law scaling, similar to those seen in heart failure and deep apnea syndrome occur also for healthy subjects under pathological conditions (hypoxaemic stress during exposure to high altitude, over 6000 m).

  10. A case of intoxication due to a highly cytotoxic Bacillus cereus strain isolated from cooked chicken.

    Science.gov (United States)

    López, Ana C; Minnaard, Jessica; Pérez, Pablo F; Alippi, Adriana M

    2015-04-01

    Outbreaks of Bacillus cereus infection/intoxication are not commonly reported because symptoms are often mild, and the disease is self-limiting. However, hypervirulent strains increase health risks. We report a case, which occurred in Argentina, of severe food poisoning illness on a healthy adult woman associated to B. cereus strain MVL2011. The studied strain was highly cytotoxic, showed high ability to detach Caco-2 cells and was positive for the hblA, hblB, and hblC genes of the hbl complex, bceT, entS and ces. As it is considered that B. cereus emetic cluster evolved from a panmictic population of diarrheal strains, B. cereus MVL2011 could constitute an intermediate strain between diarrheal and emetic strains.

  11. Aberrations due to solenoid focusing of a multiply charged high-current ion beam

    CERN Document Server

    Grégoire, G; Lisi, N; Schnuriger, J C; Scrivens, R; Tambini, J

    2000-01-01

    At the output of a laser ion source, a high current of highly charged ions with a large range of charge states is available. The focusing of such a beam by magnetic elements causes a nonlinear space-charge field to develop which can induce large aberrations and emittance growth in the beam. Simulation of the beam from the CERN laser ion source will be presented for an ideal magnetic and electrostatic system using a radially symmetric model. In addition, the three dimensional software KOBRA3 is used for the simulation of the solenoid line. The results of these simulations will be compared with experiments performed on the CERN laser ion source with solenoids (resulting in a hollow beam) and a series of gridded electrostatic lenses. (5 refs).

  12. Distributive shock due to systemic capillary leak syndrome treated with high-dose immunosuppression.

    Science.gov (United States)

    Sheehan, James Robert; Keating, Liza; Chan, Antoni; Walden, Andrew

    2013-04-09

    A female patient in her 60s presented with a history of malaise, chills, headache and vomiting. She was in shock on presentation with a high haematocrit and a low albumin with evidence of rhabdomyolysis. Severe limb and truncal oedema developed with worsening hypotension leading to intensive care unit admission for multiple organ support. Extensive radiological, microbiological and immunological work up was negative with the exception of a monoclonal gammopathy. A review of patient investigations led to a diagnosis of Clarkson's disease. Treatment with high-dose methylprednisolone and intravenous immunoglobulins led to a rapid decline in the creatine kinase (CK) level and vasopressor requirements. The patient was discharged home on long-term terbutaline and has made a good recovery.

  13. Refractory High Intracranial Pressure following Intraventricular Hemorrhage due to Moyamoya Disease in a Pregnant Caucasian Woman

    Science.gov (United States)

    Montiel, Virginie; Grandin, Cécile; Goffette, Pierre; Fomekong, Edward; Hantson, Philippe

    2009-01-01

    Intraventricular hemorrhage during pregnancy is usually followed by a poor recovery. When caused by moyamoya disease, ischemic or hemorrhagic episodes may complicate the management of high intracranial pressure. A 26-year-old Caucasian woman presented with generalized seizures and a Glasgow Coma Score (GCS) of 3 during the 36th week of pregnancy. The fetus was delivered by caesarean section. The brain CT in the mother revealed bilateral intraventricular hemorrhage, a callosal hematoma, hydrocephalus and right frontal ischemia. Refractory high intracranial pressure developed and required bilateral ventricular drainage and intensive care treatment with barbiturates and hypothermia. Magnetic resonance imaging and cerebral angiography revealed a moyamoya syndrome with rupture of the abnormal collateral vascular network as the cause of the hemorrhage. Intracranial pressure could only be controlled after the surgical removal of the clots after a large opening of the right ventricle. Despite an initially low GCS, this patient made a good functional recovery at one year follow-up. Management of refractory high intracranial pressure following moyamoya related intraventricular bleeding should require optimal removal of ventricular clots and appropriate control of cerebral hemodynamics to avoid ischemic or hemorrhagic complications. PMID:20508823

  14. Are high lags of accommodation in myopic children due to motor deficits?

    Science.gov (United States)

    Labhishetty, Vivek; Bobier, William R

    2017-01-01

    Children with a progressing myopia exhibit an abnormal pattern of high accommodative lags coupled with high accommodative convergence (AC/A) and high accommodative adaptation. This is not predicted by the current models of accommodation and vergence. Reduced accommodative plant gain and reduced sensitivity to blur have been suggested as potential causes for this abnormal behavior. These etiologies were tested by altering parameters (sensory, controller and plant gains) in the Simulink model of accommodation. Predictions were then compared to the static and dynamic blur accommodation (BA) measures taken using a Badal optical system on 12 children (6 emmetropes and 6 myopes, 8-13years) and 6 adults (20-35years). Other critical parameters such as CA/C, AC/A, and accommodative adaptation were also measured. Usable BA responses were classified as either typical or atypical. Typical accommodation data confirmed the abnormal pattern of myopia along with an unchanged CA/C. Main sequence relationship remained invariant between myopic and nonmyopic children. An overall reduction was noted in the response dynamics such as peak velocity and acceleration with age. Neither a reduced plant gain nor reduced blur sensitivity could predict the abnormal accommodative behavior. A model adjustment reflecting a reduced accommodative sensory gain (ASG) coupled with an increased AC cross-link gain and reduced vergence adaptive gain does predict the empirical findings. Empirical measures also showed a greater frequency of errors in accommodative response generation (atypical responses) in both myopic and control children compared to adults.

  15. Refractory High Intracranial Pressure following Intraventricular Hemorrhage due to Moyamoya Disease in a Pregnant Caucasian Woman

    Directory of Open Access Journals (Sweden)

    Virginie Montiel

    2009-02-01

    Full Text Available Intraventricular hemorrhage during pregnancy is usually followed by a poor recovery. When caused by moyamoya disease, ischemic or hemorrhagic episodes may complicate the management of high intracranial pressure. A 26-year-old Caucasian woman presented with generalized seizures and a Glasgow Coma Score (GCS of 3 during the 36th week of pregnancy. The fetus was delivered by caesarean section. The brain CT in the mother revealed bilateral intraventricular hemorrhage, a callosal hematoma, hydrocephalus and right frontal ischemia. Refractory high intracranial pressure developed and required bilateral ventricular drainage and intensive care treatment with barbiturates and hypothermia. Magnetic resonance imaging and cerebral angiography revealed a moyamoya syndrome with rupture of the abnormal collateral vascular network as the cause of the hemorrhage. Intracranial pressure could only be controlled after the surgical removal of the clots after a large opening of the right ventricle. Despite an initially low GCS, this patient made a good functional recovery at one year follow-up. Management of refractory high intracranial pressure following moyamoya related intraventricular bleeding should require optimal removal of ventricular clots and appropriate control of cerebral hemodynamics to avoid ischemic or hemorrhagic complications.

  16. High Voltage Solar Concentrator Experiment with Implications for Future Space Missions - S6a-35

    Science.gov (United States)

    George, I. S. Mehdi P. J.; O'Neill, M.; Matson, R.; Borckschmidt, A.

    2004-12-01

    This paper describes the design, development, fabrication, and test of a high performance, high voltage solar concentrator array. This assembly is believed to be the first ever terrestrial triple-junction-cell solar array rated at over 1 kW. The concentrator provides over 200 W/square meter power output at a nominal 600 Vdc while operating under terrestrial sunlight. Space-quality materials and fabrication techniques were used for the array, and the 3005-meter elevation installation below the Tropic of Cancer allowed testing as close as possible to space deployment without an actual launch. The array includes two concentrator modules, each with a 3 square meter aperture area. Each concentrator module uses a linear Fresnel lens to focus sunlight onto a photovoltaic receiver that uses 240 series-connected triple-junction solar cells. Operation of the two receivers in series can provide 1200 Vdc which would be adequate for the "direct drive" of some ion engines or microwave transmitters in space. Lens aperture width is 84 cm and the cell active width is 3.2 cm, corresponding to a geometric concentration ratio of 26X. The evaluation includes the concentrator modules, the solar cells, and the materials and techniques used to attach the solar cells to the receiver heat sink. For terrestrial applications, a finned aluminum extrusion was used for the heat sink for the solar cells, maintaining a low cell temperature so that solar cell efficiency remains high.

  17. Application of Hydrothermal Treatment to High Concentrated Sewage Sludge for Anaerobic Digestion Process

    Directory of Open Access Journals (Sweden)

    M. Orikawa

    2013-10-01

    Full Text Available Tomato and seaweed were produced by utilizing CO2 and heat discharged from power generation using biogas in Toyogawa biomass park, Japan. The biogas was obtained by anaerobic digestion with hydrothermal treatment. The hydrothermal treatment was applied to the high concentrated sewage sludge (22 % total solids (TS dewatered sludge. The purpose of this study is to clarify the effect of hydrothermal treatment on the qualities of high concentrated sewage sludge, by analyzing particulate organic carbon (POC and dissolved organic carbon (DOC. The hydrothermal treatment was investigated under 10-60 min of treatment time, 180-200 °C of temperature, 10-22 %-TS of sewage sludge concentration. The results showed that the DOC in each conditions increased through hydrothermal treatment. The highest DOC obtained was 67 % of total carbon concentration, when the temperature was 180 °C, treatment time was 60 min and sewage sludge concentration was 10 %-TS. Furthermore, the viscosity of treated sewage sludge was decreased by hydrothermal treatment. In batch anaerobic digestion test, methane gas production was confirmed. In addition, this study evaluated the energy balance of this system. Thus, the results of this study indicated that the possibility of application of hydrothermal treatment to high concentrated sewage sludge for anaerobic digestion process. Keywords: anaerobic reaction, hydrothermal treatment, sewage sludge, solubilization

  18. High concentrations of myeloperoxidase in the equine uterus as an indicator of endometritis.

    Science.gov (United States)

    Parrilla-Hernandez, Sonia; Ponthier, Jérôme; Franck, Thierry Y; Serteyn, Didier D; Deleuze, Stéfan C

    2014-04-15

    Intraluminal fluid and excessive abnormal hyperedema are regularly used for the diagnosis of endometritis in the mare, which is routinely confirmed by the presence of neutrophils on endometrial smears. Studies show a relation between neutrophils and myeloperoxidase (MPO), an enzyme contained in and released by neutrophils during degranulation or after cell lysis. This enzyme has been found in many fluids and tissues, and associated with different inflammatory pathologies in the horse. The aims of this study were to assess the presence and concentration of MPO in the equine uterus, and to investigate its relation with neutrophils, and other clinical signs of endometritis. Mares (n = 51) were evaluated for the presence of intraluminal fluid and excessive endometrial edema before breeding, and a small volume lavage and cytology samples were obtained. From 69 cycles, supernatant of the uterine flushes was analyzed with a specific equine MPO ELISA assay to measure MPO concentration. Cytology samples were used for the diagnosis of endometritis. Myeloperoxidase was present in the uterus of all estrus mares in highly variable concentrations. Myeloperoxidase concentrations were significantly (P < 0.05) higher in samples with positive cytologies and in the presence of intraluminal fluid. Occasionally, some samples with negative cytologies showed high MPO concentration, but the opposite was never observed. Cycles presenting hyperedema weren't associated with high concentration of MPO, intraluminal fluid, or positive cytology, making it a poor diagnostic tool of endometritis.

  19. Thermoacoustic contrast of prostate cancer due to heating by very high frequency irradiation

    Science.gov (United States)

    Patch, S. K.; Hull, D.; Thomas, M.; Griep, SK; Jacobsohn, K.; See, WA

    2015-01-01

    Applying the thermoacoustic (TA) effect to diagnostic imaging was first proposed in the 1980s. The object under test is irradiated by high-power pulses of electromagnetic energy, which heat tissue and cause thermal expansion. Outgoing TA pressure pulses are detected by ultrasound transducers and reconstructed to provide images of the object. The TA contrast mechanism is strongly dependent upon the frequency of the irradiating electromagnetic pulse. When very high frequency (VHF) electromagnetic irradiation is utilized, TA signal production is driven by ionic content. Prostatic fluids contain high levels of ionic metabolites, including citrate, zinc, calcium, and magnesium. Healthy prostate glands produce more ionic metabolites than diseased glands. VHF pulses are therefore expected to generate stronger TA signal in healthy prostate glands than in diseased glands. A benchtop system for performing ex vivo TA computed tomography with VHF energy is described and images are presented. The system utilizes irradiation pulses of 700 ns duration exceeding 20 kW power. Reconstructions frequently visualize anatomic landmarks such as the urethra and verumontanum. TA reconstructions from three freshly excised human prostate glands with little, moderate, and severe cancerous involvement are compared with histology. TA signal strength is negatively correlated with percent cancerous involvement in this small sample size. For the 45 regions of interest analyzed, a reconstruction value of 0.4 mV provides 100% sensitivity but only 29% specificity. This sample size is far too small to draw sweeping conclusions, but the results warrant a larger volume study including comparison of TA images to the gold standard, histology.

  20. High contrast switching of transmission due to electrohydrodynamic effect in stacked thin systems of liquid crystals.

    Science.gov (United States)

    Serak, Svetlana V; Hrozhyk, Uladzimir; Hwang, Jeoungyeon; Tabiryan, Nelson V; Steeves, Diane; Kimball, Brian R

    2016-10-20

    We study the opportunity of using electrohydrodynamic instabilities in a nematic liquid crystal mixture with negative dielectric anisotropy for controlling laser beams. Switching between naturally transparent and diffuse light scattering states is achieved by application of low frequency, low amplitude voltages. The specifics of diffuse light scattering state depending on the orientation and thickness of the liquid crystal layer are revealed. The switching occurs on a milliseconds time scale. Combination of thin, flexible liquid crystal cells allows polarization independent, high contrast, fast switching in a broad band of visible wavelengths.

  1. [Two Cases of Germ Cell Tumors with Hyperthyroidism Due to High Serum hCGLevels].

    Science.gov (United States)

    Chihara, Ichiro; Nitta, Satoshi; Kimura, Tomokazu; Kandori, Shuya; Kawahara, Takashi; Waku, Natsui; Kojima, Takahiro; Joraku, Akira; Miyazaki, Jun; Iwasaki, Hitoshi; Suzuki, Hiroaki; Kawai, Koji; Nishiyama, Hiroyuki

    2016-09-01

    We reported two cases of hyperthyroidism that developed during induction chemotherapy for advanced germ cell tumors with high serum human chorionic gonadotropin (hCG) levels. Case 1 : An 18-year-old man with mediastinal choriocarcinoma complained of tachycardia and tremor. His pretreatment serum hCG level was 1.37 million mIU/ml. The free thyroxine (fT4) level measured on day 2 of the first course of bleomycin, etoposide and cisplatin (BEP) was elevated to 7.8 ng/dl (<1.7 ng/dl), whereasthe thyroidstimulating hormone (TSH) level was undetectable. We diagnosed the patient with hyperthyroidism and started oral propranolol and thiamazole. Subsequently, his tachycardia and tremor disappeared. On day 12 of the first course of BEP, his hCG level decreased to less than 50,000 mIU/ml. Also, his fT4 level returned to the normal range. Case 2 : A 29-year-old man presented with a left scrotal mass. He was diagnosed with non-seminoma testicular cancer (embryonal carcinoma and choriocarcinoma) with multiple lung, liver and lymph node metastases. On the admission day, his serum hCG and fT4 levels were high ; 3.23 million mIU/ml and 2.2 ng/dl, respectively. The TSH level was low at 0.011 mIU/ml. On day 3 of the first course of BEP, his hCG and fT4 levels increased to 4.5 million mIU/ml and 3.0 ng/dl, respectively. He complained of tachycardia, tremor and hyperhydrosis. He was started on propranolol and potassium iodide. After the treatment, histachycardia, tremor and hyperhidrosisdis appeared. HisfT4 level normalized on day 17 of the first course of BEP. The TSH-like activity of hCG is considered to be responsible for paraneoplastic hyperthyroidism among germ cell cancer patients with high hCG levels. To our knowledge, thisisthe first report of such a case in Japan. However, thisphenomenon isnot rare among patients with extremely high hCG levels. Therefore, we should be careful of these patients.

  2. Bulk damage and absorption in fused silica due to high-power laser applications

    Science.gov (United States)

    Nürnberg, F.; Kühn, B.; Langner, A.; Altwein, M.; Schötz, G.; Takke, R.; Thomas, S.; Vydra, J.

    2015-11-01

    Laser fusion projects are heading for IR optics with high broadband transmission, high shock and temperature resistance, long laser durability, and best purity. For this application, fused silica is an excellent choice. The energy density threshold on IR laser optics is mainly influenced by the purity and homogeneity of the fused silica. The absorption behavior regarding the hydroxyl content was studied for various synthetic fused silica grades. The main absorption influenced by OH vibrational excitation leads to different IR attenuations for OH-rich and low-OH fused silica. Industrial laser systems aim for the maximum energy extraction possible. Heraeus Quarzglas developed an Yb-doped fused silica fiber to support this growing market. But the performance of laser welding and cutting systems is fundamentally limited by beam quality and stability of focus. Since absorption in the optical components of optical systems has a detrimental effect on the laser focus shift, the beam energy loss and the resulting heating has to be minimized both in the bulk materials and at the coated surfaces. In collaboration with a laser research institute, an optical finisher and end users, photo thermal absorption measurements on coated samples of different fused silica grades were performed to investigate the influence of basic material properties on the absorption level. High purity, synthetic fused silica is as well the material of choice for optical components designed for DUV applications (wavelength range 160 nm - 260 nm). For higher light intensities, e.g. provided by Excimer lasers, UV photons may generate defect centers that effect the optical properties during usage, resulting in an aging of the optical components (UV radiation damage). Powerful Excimer lasers require optical materials that can withstand photon energy close to the band gap and the high intensity of the short pulse length. The UV transmission loss is restricted to the DUV wavelength range below 300 nm and

  3. Circulation in the high-latitude thermosphere due to electric fields and Joule heating

    Science.gov (United States)

    Heaps, M. G.; Megill, L. R.

    1975-01-01

    Electric fields in the earth's upper atmosphere are capable of setting the neutral atmosphere in motion via ion-neutral collisions as well as pressure gradients from resultant Joule heating. By means of simple models for the high-latitude thermosphere and electric fields a simplified set of coupled equations is solved which show that moderate electric fields, when present for a period of several hours, are capable of displacing the neutral atmosphere of the order of 50 km in the vertical, a few hundred kilometers in the north-south direction and over 1000 km in the east-west direction.

  4. Highly Localized Acoustic Streaming and Size-Selective Submicrometer Particle Concentration Using High Frequency Microscale Focused Acoustic Fields.

    Science.gov (United States)

    Collins, David J; Ma, Zhichao; Ai, Ye

    2016-05-17

    Concentration and separation of particles and biological specimens are fundamental functions of micro/nanofluidic systems. Acoustic streaming is an effective and biocompatible way to create rapid microscale fluid motion and induce particle capture, though the >100 MHz frequencies required to directly generate acoustic body forces on the microscale have traditionally been difficult to generate and localize in a way that is amenable to efficient generation of streaming. Moreover, acoustic, hydrodynamic, and electrical forces as typically applied have difficulty manipulating specimens in the submicrometer regime. In this work, we introduce highly focused traveling surface acoustic waves (SAW) at high frequencies between 193 and 636 MHz for efficient and highly localized production of acoustic streaming vortices on microfluidic length scales. Concentration occurs via a novel mechanism, whereby the combined acoustic radiation and streaming field results in size-selective aggregation in fluid streamlines in the vicinity of a high-amplitude acoustic beam, as opposed to previous acoustic radiation induced particle concentration where objects typically migrate toward minimum pressure locations. Though the acoustic streaming is induced by a traveling wave, we are able to manipulate particles an order of magnitude smaller than possible using the traveling wave force alone. We experimentally and theoretically examine the range of particle sizes that can be captured in fluid streamlines using this technique, with rapid particle concentration demonstrated down to 300 nm diameters. We also demonstrate that locations of trapping and concentration are size-dependent, which is attributed to the combined effects of the acoustic streaming and acoustic forces.

  5. Microstructural evolution of nanocrystalline nickel thin films due to high-energy heavy-ion irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Rajasekhara, S. [Sandia National Laboratories, P.O. Box 5800 MS 1056, Albuquerque, NM, USA, 87185-1056 and Materials Science and Engineering Program, University of Texas, Austin, TX, 78712-1063 (United States); Ferreira, P. J. [Materials Science and Engineering Program, University of Texas, Austin, TX, 78712-1063 (United States); Hattar, K. [Sandia National Laboratories, P.O. Box 5800 MS 1056, Albuquerque, NM, 87185-1056 (United States)

    2013-04-19

    This initial feasibility study demonstrates that recent advancements in precession electron diffraction microscopy can be applied to nanostructured metals exposed to high displacement damage from a Tandem accelerator. In this study, high purity, nanocrystalline, free-standing nickel thin films produced by pulsed laser deposition were irradiated with approximately 3 Multiplication-Sign 10{sup 14} ions/cm{sup 2} of 35 MeV Ni{sup 6+} ions resulting in an approximately uniform damage profile to approximately 16 dpa. Pristine and ionirradiated regions of the nanocrystalline Ni films were characterized by conventional transmission electron microscopy and precession electron diffraction microscopy. Precession electron diffraction microscopy provided additional insight into the texture, phase, and grain boundary distribution resulting from the displacement damage that could not be obtained from traditional electron microscopy techniques. For the nanocrystalline nickel film studied, this included the growth in number and percentage of a metastable hexagonal closed packed phase grains and the formation of large <001> textured face centered cubic grains. The application of precession electron diffraction microscopy to characterize other nanocrystalline metals, which are being considered for radiation tolerant applications, will permit a comparison of materials that goes beyond the dominant length scale to consider the effects of local phase, texture, and grain boundary or interface information.

  6. Direct costs and benefits of multiple mating: Are high female mating rates due to ejaculate replenishment?

    Science.gov (United States)

    Worthington, Amy M; Kelly, Clint D

    2016-03-01

    Females often mate more than is necessary to ensure reproductive success even when they incur significant costs from doing so. Direct benefits are hypothesized to be the driving force of high female mating rates, yet species in which females only receive an ejaculate from their mate still realize increased fitness from multiple mating. Using the Texas field cricket, Gryllus texensis, we experimentally test the hypothesis that multiple mating via monandry or polyandry increases female fitness by replenishing ejaculates, thereby allowing females to produce more offspring for a longer period of time. We found that higher rates of female mating significantly increased lifetime fecundity and oviposition independent of whether females mated with one or two males. Further, although interactions with males significantly increased rates of injury or death, females that replenished ejaculates experienced an increased rate and duration of oviposition, demonstrating that the immediate benefits of multiple mating may greatly outweigh the long-term costs that mating poses to female condition and survival. We suggest that ejaculate replenishment is a driving factor of high mating rates in females that do not receive external direct benefits from mating and that a comparative study across taxa will provide additional insight into the role that ejaculate size plays in the evolution of female mating rates.

  7. Microstructural evolution of nanocrystalline nickel thin films due to high-energy heavy-ion irradiation

    Science.gov (United States)

    Rajasekhara, S.; Ferreira, P. J.; Hattar, K.

    2013-04-01

    This initial feasibility study demonstrates that recent advancements in precession electron diffraction microscopy can be applied to nanostructured metals exposed to high displacement damage from a Tandem accelerator. In this study, high purity, nanocrystalline, free-standing nickel thin films produced by pulsed laser deposition were irradiated with approximately 3 × 1014 ions/cm2 of 35 MeV Ni6+ ions resulting in an approximately uniform damage profile to approximately 16 dpa. Pristine and ionirradiated regions of the nanocrystalline Ni films were characterized by conventional transmission electron microscopy and precession electron diffraction microscopy. Precession electron diffraction microscopy provided additional insight into the texture, phase, and grain boundary distribution resulting from the displacement damage that could not be obtained from traditional electron microscopy techniques. For the nanocrystalline nickel film studied, this included the growth in number and percentage of a metastable hexagonal closed packed phase grains and the formation of large textured face centered cubic grains. The application of precession electron diffraction microscopy to characterize other nanocrystalline metals, which are being considered for radiation tolerant applications, will permit a comparison of materials that goes beyond the dominant length scale to consider the effects of local phase, texture, and grain boundary or interface information.

  8. Exceptionally high titres in atypical presentation of occult epididymo-orchitis due to brucellosis.

    Science.gov (United States)

    Purwar, Shashank; Metgud, S C; Gokale, Shilpa K

    2012-03-01

    A male patient of 32 years was referred for surgical drainage and orchidectomy of the right testis following a cycling injury. A Venereal Disease Research Laboratory (VDRL) test was requested by the surgery department to rule out secondary syphilis. Although serum samples gave a negative result in the VDRL test, qualitative screening was performed for Brucella antibodies, as per hospital policy, since brucellosis is endemic in this region. Following a positive reaction, a quantitative standard tube agglutination test was carried out yielding titres that were exceptionally high (STAT = 40 960 IU ml(-1); 2-ME = 1 : 5120). This finding correlated with the patient's history which included a number of predisposing factors for contracting brucellosis including exposure to cattle, consumption of raw milk and assisting in the parturition of cattle. Consequently, surgery was postponed and treatment was changed from injections of ceftriaxone to the WHO regimen for the treatment of brucellosis: 1 g streptomycin once daily, administered intra-muscularly, plus 100 mg doxycycline twice daily, taken orally. Following 3 days of this treatment, the testicular swelling reduced considerably and orchidectomy was not required. Indeed, after a week, swelling was completely resolved and the patient was discharged. To our knowledge, this is the first case of such high titres in a patient as a result of epididymo-orchitis without the typical clinical presentation of fever and joint pain that is normally associated with brucellosis.

  9. Experimental Study of Sorbitol Production by Zymomonas mobilis in High Sucrose Concentration

    Directory of Open Access Journals (Sweden)

    Rui Sérgio dos Santos Ferreira da Silva

    2004-01-01

    Full Text Available The sorbitol presents several industrial applications and its conventional production is of high cost and low yield. Sorbitol production by Zymomonas mobilis production has attracted attention as both production cost and environmental impact are low. The sorbitol plays an osmo-protective rule so that its production is promoted by high sugar concentrations. This work has evaluated the effect of high sucrose concentration in the sorbitol production. The raise of sucrose concentration from 100 to 300g/ L caused an increase in the sorbitol production from 4,979 to 20,633g/l. Statistic analysis showed that 95,5% in the variation in sorbitol production can be explained.

  10. Ethanol-Induced ADH Activity in Zebrafish: Differential Concentration-Dependent Effects on High- Versus Low-Affinity ADH Enzymes.

    Science.gov (United States)

    Tran, Steven; Nowicki, Magda; Facciol, Amanda; Chatterjee, Diptendu; Gerlai, Robert

    2016-04-01

    Zebrafish express enzymes that metabolize ethanol in a manner comparable to that of mammals, including humans. We previously demonstrated that acute ethanol exposure increases alcohol dehydrogenase (ADH) activity in an inverted U-shaped dose-dependent manner. It was hypothesized that the biphasic dose-response was due to the increased activity of a high-affinity ADH isoform following exposure to low concentrations of ethanol and increased activity of a low-affinity ADH isoform following exposure to higher concentrations of ethanol. To test this hypothesis, we exposed zebrafish to different concentrations of ethanol (0%, 0.25%, 0.5%, and 1.0% v/v) for 30 min and measured the total ADH activity in the zebrafish liver. However, we also repeated this enzyme activity assay using a low concentration of the substrate (ethanol) to determine the activity of high-affinity ADH isoforms. We found that total ADH activity in response to ethanol induces an inverted U-shaped dose-response similar to our previous study. Using a lower substrate level in our enzyme assay targeting high-affinity isozymes, we found a similar dose-response. However, the difference in activity between the high and low substrate assays (high substrate activity - low substrate activity), which provide an index of activity for low-affinity ADH isoforms, revealed no significant effect of ethanol exposure. Our results suggest that the inverted U-shaped dose-response for total ADH activity in response to ethanol is driven primarily by high-affinity isoforms of ADH.

  11. Effect of mixed moderately thermophilic adaptation on leachability and mechanism of high arsenic gold concentrate in an airlift bioreactor

    Institute of Scientific and Technical Information of China (English)

    余润兰; 吴发登; 陈安; 石丽娟; 曾伟民; 顾帼华; 覃文庆; 邱冠周

    2015-01-01

    A refractory gold concentrate with 19%arsenic was treated by a mixed moderately thermophiles in an airlift bioreactor through an adaptation protocol. The moderately thermophiles could respond well to 20%(w/v) pulp density with less than 10%loss of productivity, and resist arsenic up to 15 g/L. There were a lot of jarosite, arsenolite and sulfur, but not scorodite and ferric arsenate in the bioleached residue. Jarosite passivation and lower sulfur-oxidizing activity of the cells due to the toxicity of the high concentrations of soluble arsenic and iron ions at low pH value should mainly response for the incomplete extraction at high pulp density. The initial bacterial community did not change in nature except for new found P aeruginosa ANSC, but sulfur-oxidizing microorganisms have been dominant microorganisms after a long time of adaptation. Pseudomonas aeruginosa originating from the gold concentrate should be closely relative to the metabolism of the organic matters contained in the refractory gold concentrate.

  12. The ability of Typha domingensis to accumulate and tolerate high concentrations of Cr, Ni, and Zn.

    Science.gov (United States)

    Mufarrege, M M; Hadad, H R; Di Luca, G A; Maine, M A

    2015-01-01

    The tolerance and removal efficiency of Typha domingensis exposed to high concentrations of Cr, Ni, and Zn in single and combined treatments were studied. Sediment and two plants were disposed in each plastic reactor. The treatments were 100 and 500 mg L(-1) of Cr, Ni, and Zn (single solutions); 100 mg L(-1) Cr + Ni + Zn (multi-metal solutions) and 500 mg L(-1) Cr + Ni + Zn (multi-metal solutions); and a control. Even though the concentrations studied were extremely high, simulating an accidental metal dump, the three metals were efficiently removed from water. The highest removal was registered for Cr. The presence of other metals favored Cr and did not favor Ni and Zn removal from water. After 25 days, senescence and chlorosis of plants were observed in Ni and Comb500 treatments, while Cr and Zn only caused growth inhibition. T. domingensis accumulated high metal concentrations in tissues. The roots showed higher metal concentration than submerged parts of leaves. Cr translocation to aerial parts was enhanced by the presence of Ni and Zn. Our results demonstrate that in the case of an accidental dump of high Cr, Ni, and Zn concentrations, a wetland system dominated by T. domingensis is able to retain metals, and the macrophyte is able to tolerate them the time necessary to remove them from water. Thus, the environment will be preserved since the wetland would act as a cushion.

  13. Apoptosis Induced by High Concentrations of Nicotinamide in Tobacco Suspension Cells

    Institute of Scientific and Technical Information of China (English)

    张贵友; 朱瑞宇; 戴尧仁

    2004-01-01

    As an inhibitor of poly(ADP-ribose) polymerase (PARP), nicotinamide has a restraining effect on apoptosis at certain low concentrations. In our present study, apoptosis induced by high concentrations of nicotinamide was observed in tobacco suspension cells. When cells were preincubated with 250 mmol/L nicotinamide for 24 h, the hallmarks of apoptosis were detected, including DNA fragments increasing in size by multiples of 180-200 bp, the condensation and peripheral distribution of nuclear chromatin, and a positive reaction to the TUNEL assay. At the same time, the degradation of PARP and the reduction in the potential of the inner membrane of mitochondria appeared in apoptotic cells induced by high concentrations of nicotinamide. This result indicates that apoptosis induced by high concentrations of nicotinamide is associated with caspase-3-like activity and with the opening of mitochondrial permeability pores. These results partially support the hypothesis that high concentrations of PARP inhibitor could force cells to enter an apoptotic pathway by delay of DNA repair in replicating cells.

  14. Knowledge discovery from high-frequency stream nitrate concentrations: hydrology and biology contributions

    Science.gov (United States)

    Aubert, Alice H.; Thrun, Michael C.; Breuer, Lutz; Ultsch, Alfred

    2016-01-01

    High-frequency, in-situ monitoring provides large environmental datasets. These datasets will likely bring new insights in landscape functioning and process scale understanding. However, tailoring data analysis methods is necessary. Here, we detach our analysis from the usual temporal analysis performed in hydrology to determine if it is possible to infer general rules regarding hydrochemistry from available large datasets. We combined a 2-year in-stream nitrate concentration time series (time resolution of 15 min) with concurrent hydrological, meteorological and soil moisture data. We removed the low-frequency variations through low-pass filtering, which suppressed seasonality. We then analyzed the high-frequency variability component using Pareto Density Estimation, which to our knowledge has not been applied to hydrology. The resulting distribution of nitrate concentrations revealed three normally distributed modes: low, medium and high. Studying the environmental conditions for each mode revealed the main control of nitrate concentration: the saturation state of the riparian zone. We found low nitrate concentrations under conditions of hydrological connectivity and dominant denitrifying biological processes, and we found high nitrate concentrations under hydrological recession conditions and dominant nitrifying biological processes. These results generalize our understanding of hydro-biogeochemical nitrate flux controls and bring useful information to the development of nitrogen process-based models at the landscape scale. PMID:27572284

  15. Experimental studies on resistance characteristics of high concentration red mud in pipeline transport

    Institute of Scientific and Technical Information of China (English)

    WANG Xing; QU Yuan-yuan; HU Wei-wei; CHEN Jie; ZHAO Xue-yi; WU Miao

    2008-01-01

    Red mud will flow in paste form under high pressure during pipeline transport. It belongs to a two-phase flow of materials with high viscosity and a high concentration of non-sedimentation, homogeneous solid-liquids. In pipeline transport, its resistance char-acteristics will be influenced by such factors as grain size, velocity, concentration, density,grain composition and pipe diameter etc.. With the independently developed small-sized tube-type pressure resistance test facility, studied the resistance characteristics of red mud concerning the three influencing factors, paste concentration, velocity and pipe diameter,which attract the most attention in projects. The fine grain size of the red mud is d50=13.02 μm. According to the experimental results, the pressure loss in transport will in-crease along with the increase of velocity and will fall along with the increase of pipe di-ameter. A 1% difference in paste concentration will result in a 50%~100% difference in pipeline resistance loss. These experimental data is hoped to be direct guidance to the design of high concentration and viscous material pipeline transport system.

  16. Knowledge discovery from high-frequency stream nitrate concentrations: hydrology and biology contributions.

    Science.gov (United States)

    Aubert, Alice H; Thrun, Michael C; Breuer, Lutz; Ultsch, Alfred

    2016-08-30

    High-frequency, in-situ monitoring provides large environmental datasets. These datasets will likely bring new insights in landscape functioning and process scale understanding. However, tailoring data analysis methods is necessary. Here, we detach our analysis from the usual temporal analysis performed in hydrology to determine if it is possible to infer general rules regarding hydrochemistry from available large datasets. We combined a 2-year in-stream nitrate concentration time series (time resolution of 15 min) with concurrent hydrological, meteorological and soil moisture data. We removed the low-frequency variations through low-pass filtering, which suppressed seasonality. We then analyzed the high-frequency variability component using Pareto Density Estimation, which to our knowledge has not been applied to hydrology. The resulting distribution of nitrate concentrations revealed three normally distributed modes: low, medium and high. Studying the environmental conditions for each mode revealed the main control of nitrate concentration: the saturation state of the riparian zone. We found low nitrate concentrations under conditions of hydrological connectivity and dominant denitrifying biological processes, and we found high nitrate concentrations under hydrological recession conditions and dominant nitrifying biological processes. These results generalize our understanding of hydro-biogeochemical nitrate flux controls and bring useful information to the development of nitrogen process-based models at the landscape scale.

  17. Changes in mechanical properties due to gamma irradiation of high-density polyethylene (HDPE

    Directory of Open Access Journals (Sweden)

    S. S. Cota

    2007-06-01

    Full Text Available This paper presents an experimental analysis of the effect of dose and dose rate parameters during gamma irradiation of high-density polyethylene (HDPE samples. Considerations concerning the influence of these parameters on HDPE mechanical strength properties as a result of the predominance of oxidative degradation or of cross-linking are presented. The experimental results show an improvement of HDPE mechanical strength as dose increases, indicating the predominance of cross-linking over oxidative degradation and that lower doses are necessary to obtain a similar change in resistance parameters when radiation is applied at lower dose rates, showing that gamma radiation affects the HDPE in a more efficient way at lower dose rates.

  18. Changes in mechanical properties due to gamma irradiation of high-density polyethylene (HDPE)

    Energy Technology Data Exchange (ETDEWEB)

    Cota, S.S.; Vasconcelos, V.; Senne Junior, M.; Carvalho, L.L.; Rezende, D.B.; Correa, R.F. [Centro de Desenvolvimento da Tecnologia Nuclear (CDTN/CNEN-MG), Belo Horizonte, MG (Brazil)]. E-mail: sdsc@cdtn.br

    2007-04-15

    This paper presents an experimental analysis of the effect of dose and dose rate parameters during gamma irradiation of high-density polyethylene (HDPE) samples. Considerations concerning the influence of these parameters on HDPE mechanical strength properties as a result of the predominance of oxidative degradation or of cross-linking are presented. The experimental results show an improvement of HDPE mechanical strength as dose increases, indicating the predominance of cross-linking over oxidative degradation and that lower doses are necessary to obtain a similar change in resistance parameters when radiation is applied at lower dose rates, showing that gamma radiation affects the HDPE in a more efficient way at lower dose rates. (author)

  19. Severe Metabolic Acidosis and Hepatopathy due to Leukoencephalopathy with Thalamus and Brainstem Involvement and High Lactate.

    Science.gov (United States)

    Sellars, Elizabeth A; Balmakund, Tonya; Bosanko, Katherine; Nichols, Brandi L; Kahler, Stephen G; Zarate, Yuri A

    2017-04-01

    Leukoencephalopathy with thalamus and brainstem involvement and high lactate (LTBL) is a recently described autosomal recessive mitochondrial disease characterized by early onset of neurological symptoms, a biphasic clinical course, and distinctive neuroimaging. Pathogenic variants in the EARS2 gene that encode for mitochondrial glutamyl-tRNA synthetase are responsible for LTBL. Here, we describe the clinical course of an infant diagnosed with an acute crisis of LTBL and severe liver disease. This article illustrates the utility of blood lactate quantification in addition to basic metabolic testing and brain imaging in a child with low tone and poor growth. In addition, this case demonstrates the utility of current genetic diagnostic testing, in lieu of more invasive procedures, in obtaining rapid answers in this very complicated group of disorders. Georg Thieme Verlag KG Stuttgart · New York.

  20. Counting losses due to saturation effects of scintillation counters at high count rates

    CERN Document Server

    Hashimoto, K

    1999-01-01

    The counting statistics of a scintillation counter, with a preamplifier saturated by an overloading input, are investigated. First, the formulae for the variance and the mean number of counts, accumulated within a given gating time, are derived by considering counting-loss effects originating from the saturation and a finite resolving time of the electronic circuit. Numerical examples based on the formulae indicate that the saturation makes a positive contribution to the variance-to-mean ratio and that the contribution increases with count rate. Next the ratios are measured under high count rates when the preamplifier saturation can be observed. By fitting the present formula to the measured data, the counting-loss parameters can be evaluated. Corrections based on the parameters are made for various count rates measured in a nuclear reactor. As a result of the corrections, the linearity between count rate and reactor power can be restored.

  1. An outbreak of food-borne gastroenteritis due to sapovirus among junior high school students.

    Science.gov (United States)

    Usuku, Shuzo; Kumazaki, Makoto; Kitamura, Katsuhiko; Tochikubo, Osamu; Noguchi, Yuzo

    2008-11-01

    The human sapovirus (SaV) causes acute gastroenteritis mainly in infants and young children. A food-borne outbreak of gastroenteritis associated with SaV occurred among junior high school students in Yokohama, Japan, during and after a study trip. The nucleotide sequences of the partial capsid gene derived from the students exhibited 98% homology to a SaV genogroup IV strain, Hu/Angelholm/SW278/2004/SE, which was isolated from an adult with gastroenteritis in Solna, Sweden. An identical nucleotide sequence was detected from a food handler at the hotel restaurant, suggesting that the causative agent of the outbreak was transmitted from the food handler. This is the first description of a food-borne outbreak associated with the SaV genogroup IV strain in Japan.

  2. Effect of acoustic streaming on tissue heating due to high-intensity focused ultrasound

    CERN Document Server

    Solovchuk, Maxim A; Thiriet, Marc; Lin, Win-Li

    2011-01-01

    The influences of blood vessels and focused location on temperature distribution during high-intensity focused ultrasound (HIFU) ablation of liver tumors is studied. A three-dimensional acoustics-thermal-fluid coupling model is employed to compute the temperature field in the hepatic cancerous region. The model is based on the linear Westervelt and bioheat equations as well as the nonlinear Navier-Stokes equations for the liver parenchyma and blood vessels. The effect of acoustic streaming is also taken into account in the present HIFU simulation study. Different blood vessel diameters and focal point locations were investigated. We found from this three-dimensional numerical study that in large blood vessels both the convective cooling and acoustic streaming can change considerably the temperature field and the thermal lesion near blood vessels. If the blood vessel is located within the beam width, both acoustic streaming and blood flow cooling effects should be taken into account. The predicted temperature ...

  3. Stress and Damage in Polymer Matrix Composite Materials Due to Material Degradation at High Temperatures

    Science.gov (United States)

    McManus, Hugh L.; Chamis, Christos C.

    1996-01-01

    This report describes analytical methods for calculating stresses and damage caused by degradation of the matrix constituent in polymer matrix composite materials. Laminate geometry, material properties, and matrix degradation states are specified as functions of position and time. Matrix shrinkage and property changes are modeled as functions of the degradation states. The model is incorporated into an existing composite mechanics computer code. Stresses, strains, and deformations at the laminate, ply, and micro levels are calculated, and from these calculations it is determined if there is failure of any kind. The rationale for the model (based on published experimental work) is presented, its integration into the laminate analysis code is outlined, and example results are given, with comparisons to existing material and structural data. The mechanisms behind the changes in properties and in surface cracking during long-term aging of polyimide matrix composites are clarified. High-temperature-material test methods are also evaluated.

  4. High-frequency waves in the corona due to null points

    Science.gov (United States)

    Santamaria, I. C.; Khomenko, E.; Collados, M.; de Vicente, A.

    2017-06-01

    This work aims to understand the behavior of non-linear waves in the vicinity of a coronal null point. In previous works we have shown that high-frequency waves are generated in such a magnetic configuration. This paper studies those waves in detail in order to provide a plausible explanation of their generation. We demonstrate that slow magneto-acoustic shock waves generated in the chromosphere propagate through the null point and produce a train of secondary shocks that escape along the field lines. A particular combination of the shock wave speeds generates waves at a frequency of 80 mHz. We speculate that this frequency may be sensitive to the atmospheric parameters in the corona and therefore can be used to probe the structure of this solar layer. Movies attached to Figs 2 and 4 are available at http://www.aanda.org

  5. High surface hole concentration p-type GaN using Mg implantation

    CERN Document Server

    Long Tao; Zhang Guo Yi

    2001-01-01

    Mg ions were implanted on Mg-doped GaN grown by metalorganic chemical vapor deposition (MOCVD). The p-type GaN was achieved with high hole concentration (8.28 x 10 sup 1 sup 7 cm sup - sup 3) conformed by Van derpauw Hall measurement after annealing at 800 degree C for 1 h. this is the first experimental report of Mg implantation on Mg-doped GaN and achieving p-type GaN with high surface hole concentration

  6. High-concentration zeta potential measurements using light-scattering techniques.

    Science.gov (United States)

    Kaszuba, Michael; Corbett, Jason; Watson, Fraser Mcneil; Jones, Andrew

    2010-09-28

    Zeta potential is the key parameter that controls electrostatic interactions in particle dispersions. Laser Doppler electrophoresis is an accepted method for the measurement of particle electrophoretic mobility and hence zeta potential of dispersions of colloidal size materials. Traditionally, samples measured by this technique have to be optically transparent. Therefore, depending upon the size and optical properties of the particles, many samples will be too concentrated and will require dilution. The ability to measure samples at or close to their neat concentration would be desirable as it would minimize any changes in the zeta potential of the sample owing to dilution. However, the ability to measure turbid samples using light-scattering techniques presents a number of challenges. This paper discusses electrophoretic mobility measurements made on turbid samples at high concentration using a novel cell with reduced path length. Results are presented on two different sample types, titanium dioxide and a polyurethane dispersion, as a function of sample concentration. For both of the sample types studied, the electrophoretic mobility results show a gradual decrease as the sample concentration increases and the possible reasons for these observations are discussed. Further, a comparison of the data against theoretical models is presented and discussed. Conclusions and recommendations are made from the zeta potential values obtained at high concentrations.

  7. High Iridium concentration of alkaline rocks of Deccan and implications to K/T boundary

    Indian Academy of Sciences (India)

    P N Shukla; N Bhandari; Anirban Das; A D Shukla; J S Ray

    2001-06-01

    We report here an unusually high concentration of iridium in some alkali basalts and alkaline rocks of Deccan region having an age of about 65Ma, similar to the age of the Cretaceous-Tertiary boundary. The alkali basalts of Anjar, in the western periphery of Deccan province, have irid-ium concentration as high as 178pg/g whereas the alkaline rocks and basalts associated with the Amba Dongar carbonatite complex have concentrations ranging between 8 and 80 pg/g. Some of these values are more than an order of magnitude higher than the concentration in the tholeiiticbasalts of Deccan, indicating the significance of alkaline magmatism in the iridium inventory at the Cretaceous-Tertiary boundary. Despite higher concentration, their contribution to the global inventory of iridium in the Cretaceous-Tertiary boundary clays remains small. The concentration of iridium in uorites from Amba Dongar was found to be < 30 pg/g indicating that iridium is not incorporated during their formation in hydrothermal activity.

  8. Potential risk of mitomycin Cat high concentrations on peripheral nerve structure

    Institute of Scientific and Technical Information of China (English)

    Tao Sui; Jinhong Zhang; Shihao Du; Changhui Su; Jun Que; Xiaojian Cao

    2014-01-01

    Although the local application of mitomycin C may prevent epidural adhesion after laminectomy, mitomycin C can induce neurotoxicity in optic and acoustic nerves at high concentrations. To determine the safe concentration range for mitomycin C, cotton pads soaked with mitomycin C at different concentrations (0.1, 0.3, 0.5, and 0.7 mg/mL) were immediately applied for 5 minutes to the operation area of rats that had undergone laminectomy at L1. Rat sciatic nerves, instead of dorsal nerves, were used in this study. The results showed that mitomycin C at 0.1-0.5 mg/mL did not damage the structure and function of the sciatic nerve, while at 0.7 mg/mL, mitomycin C signiifcantly reduced the thickness of the sciatic nerve myelin sheath compared with lower concen-trations, though no functional change was found. These experimental ifndings indicate that the local application of mitomycin C at low concentrations is safe to prevent scar adhesion following laminectomy, but that mitomycin C at high concentrations (>0.7 mg/mL) has potential safety risks to peripheral nerve structures.

  9. Characterization of high-milk-protein powders upon rehydration under various salt concentrations.

    Science.gov (United States)

    Hussain, R; Gaiani, C; Aberkane, L; Scher, J

    2011-01-01

    Rehydration of native micellar casein and native whey isolate protein powders was followed in different ionic environments. Solutions of NaCl and CaCl2 in the concentration range of 0 to 12% (wt%) were used as rehydration media. The rehydration profiles obtained were interpreted in terms of wetting, swelling, and dispersion stages by using a turbidity method. Two behaviors were observed depending on the salt concentration. For native micellar casein powder, a significant change was observed between 3 and 6% NaCl and between 0.75 and 1.5% CaCl2. The first behavior (low salt concentration) presents a typical rehydration profile: quick wetting, swelling, and long dispersion stage. The dispersion stage of the second behavior (high salt concentration) was significantly shortened, indicating a strong modification of the protein backbone. The rehydration of whey protein powder was less influenced by salts. At low salt concentrations, a typical profile for whey powders was observed: wetting with lump formation and no swelling followed by a quick dispersion. At high CaCl2 concentrations, no turbidity stabilization was observed, indicating a possible protein unfolding and denaturation. Additionally, the changes in secondary structures of the 2 proteins upon salt increase were followed by Fourier transform infrared spectroscopy and confirmed the different profiles observed. Copyright © 2011 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

  10. High hydrostatic pressure enables almost 100% refolding of recombinant human ciliary neurotrophic factor from inclusion bodies at high concentration.

    Science.gov (United States)

    Wang, Qi; Liu, Yongdong; Zhang, Chun; Guo, Fangxia; Feng, Cui; Li, Xiunan; Shi, Hong; Su, Zhiguo

    2017-05-01

    Protein refolding from inclusion bodies (IBs) often encounters a problem of low recovery at high protein concentration. In this study, we demonstrated that high hydrostatic pressure (HHP) could simultaneously achieve high refolding concentration and high refolding yield for IBs of recombinant human ciliary neurotrophic factor (rhCNTF), a potential therapeutic for neurodegenerative diseases. The use of dilution refolding obtained 18% recovery at 3 mg/mL, even in the presence of 4 M urea. In contrast, HHP refolding could efficiently increase the recovery up to almost 100% even at 4 mg/mL. It was found that in the dilution, hydrophobic aggregates were the off-path products and their amount increased with the protein concentration. However, HHP could effectively minimize the formation of hydrophobic aggregates, leading to almost complete conversion of the rhCNTF IBs to the correct configuration. The stable operation range of concentration is 0.5-4.0 mg/mL, in which the refolding yield was almost 100%. Compared with the literatures where HHP failed to increase the refolding yield beyond 90%, the reason could be attributed to the structural difference that rhCNTF has no disulfide bond and is a monomeric protein. After purification by one-step of anionic chromatography, the purity of rhCNTF reached 95% with total process recovery of 54.1%. The purified rhCNTF showed similar structure and in vitro bioactivity to the native species. The whole process featured integration of solubilization/refolding, a high refolding yield of 100%, a high concentration of 4 mg/mL, and a simple chromatography to ensure a high productivity. Copyright © 2017 Elsevier Inc. All rights reserved.

  11. High energy gamma-radiation from the galactic center due to neutralino annihilation

    CERN Document Server

    Berezinsky, Veniamin Sergeevich; Mignola, G

    1994-01-01

    We study the NGS (Non-dissipative Gravitational Singularity) model, which successfully describes the non-linear stage of evolution of perturbations (see [1], [2] and references therein). This model predicts DM density distribution $\\rho(r) \\sim r^{-\\alpha}$ with $\\alpha \\simeq 1.8$ which holds from very small distances $r_{\\rm min} \\simeq 0.01~{\\rm pc}$ up to very large distances $r_{\\rm max} \\simeq 5~{\\rm Mpc}$. Assuming the neutralino to be a CDM particle, we calculate the annihilation of neutralinos in the vicinity of the singularity (Galactic Center). If neutralinos are the dominant component of DM in our Galaxy, the produced energy is enough to provide the whole observed activity of the GC. Neutralinos of the most general composition and of mass in the range $20~{\\rm GeV} \\leq m_\\c \\leq 1~{\\rm TeV}$ are considered. We find the neutralino compositions which give the relic density needed for the Mixed Dark Matter (MDM) model and we evaluate for these compositions the high-energy ($E_{\\gamma} > 100 ~{\\rm Me...

  12. Monitoring and modeling shoreline response due to shoreface nourishment on a high-energy coast

    Science.gov (United States)

    Barnard, P. L.; Erikson, Li H.; Hansen, J. E.

    2009-01-01

    Shoreface nourishment can be an efficient technique to feed sediment into the littoral zone without the order of magnitude cost increase incurred by directly nourishing the beach. An erosion hot spot at Ocean Beach in San Francisco, California, USA, threatens valuable public infrastructure as well as safe recreational use of the beach. In an effort to reduce the erosion at this location, a new beneficial reuse plan was implemented in May 2005 for the sediment dredged annually from the main shipping channel at the mouth of San Francisco Bay. From 2005 to 2007, approximately 230,000 m of sand was placed annually at depths between 9 and 14 m, in a location where strong tidal currents and open-ocean waves could potentially feed sediment onto the section of beach experiencing critical erosion. The evolution of the disposal mound and adjacent beach were monitored with 12 multibeam bathymetric surveys, and over 40 high-resolution beach topographic surveys. In addition, sediment transport processes were investigated using sediment grab samples, acoustic Doppler profilers, and two separate models: a cross-shore profile model (UNIBEST-TC) and a coastal area model (Delft3D). The results of the monitoring and modeling demonstrate that the disposal mound may be effective in dissipating wave energy striking this vulnerable stretch of coast with negligible shadowing effects, but a positive shoreline response can only be achieved by placing the sediment in water depths less than 5 m. 

  13. Confirmation of the sterilization effect using a high concentration of ozone gas for the bio-clean room.

    Science.gov (United States)

    Iwamura, Takuji; Nagano, Katsunori; Nogami, Toshihiro; Matsuki, Noritomo; Kosaka, Noriyoshi; Shintani, Hideharu; Katoh, Miyoshi

    2013-01-01

    A high-level aseptic environment must be maintained in bio-cleanrooms used for the manufacture of sterile products. In the past, formaldehyde gas was most commonly used to sterilize bio-cleanrooms, but due to strict residual limitations there has been a need to develop a less toxic alternative choice. The authors have developed a revolutionary new sterilization system using a high concentration of ozone gas and used this system to sterilize an actual bio-cleanroom. This system integrates the ozone gas generator with the air conditioning system by proper control. The design specifications for the system included an ozone gas concentration of 200 ppm or more, relative humidity of 80% or more, and a sterilizing time of 120 min. Blow vents and suction ports were placed to ensure a uniform airflow which would extend through the entire room during ozone gas sterilization. Tests regarding long-term material exposure to ozone gas were conducted when the system was introduced to distinguish usable and unusable materials. In an actually constructed cleanroom, simulations were used to predict the evenness of the diffusion of ozone gas concentration and relative humidity during ozone gas sterilization, and measurements of the actual indoor ozone gas concentration, temperature and relative humidity during sterilization revealed that the ozone concentration and relative humidity needed for sterilization had been achieved generally throughout the entire environment. In addition, the CT value (mg/m(3) (=ppm) × min) , derived by multiplying the ozone gas concentration during ozone gas sterilization by the sterilization time, was equal to or greater than the target value of 24 × 10(3) (ppm·min) . When the results of sterilization in a cleanroom were confirmed using a biological indicator (BI) , negative results were obtained at all measurement points, demonstrating that sterilization was being performed effectively in the actual factory at which the ozone gas sterilization system

  14. High Frequency Measurements of Methane Concentrations and Carbon Isotopes at a Marsh and Landfill

    Science.gov (United States)

    Mortazavi, B.; Wilson, B.; Chanton, J.; Eller, K.; Dong, F.; Baer, D. S.; Gupta, M.; Dzwonkowski, B.

    2012-12-01

    High frequency measurements of methane concentrations and carbon isotopes can help constrain the source strengths of methane emitted to the atmosphere. We report here methane concentrations and 13C values measured at 0.5 Hz with cavity enhanced laser absorption spectrometers (Los Gatos Research) deployed at a saltmarsh in Alabama and a landfill in Florida. Methane concentrations and 13C at the saltmarsh were monitored over a 2.5 day time period at 2 m, 0.5 m above the ground as well as from the outflow of a flow-through (2 L) chamber placed on the Spartina alterniflora dominated marsh. A typical measurement cycle included regular samples from two tanks of known methane concentrations and isotopic values and from ambient air samples. Over the 2.5-day measurement period methane concentrations and isotopic ratios at 2 m averaged 1.85 ppm and -43.57‰ (±0.34, 1 SE), respectively. The concentration and isotopic values from the chamber outflow varied from 1.92 to 5.81 ppm and -38.5 to -59.3‰, respectively. Methane flux from the marsh ranged from undetectable to 3.6 mgC m-2hr-1, with high fluxes measured during low tide. The 13δCH4 of the emitted CH4 from the marsh, determined from a mass balance equation using the chamber inflow and outflow concentration and isotopic values ranged from -62.1 to -93.9‰ and averaged -77‰ (±1.25, 1SE). At the landfill ambient methane concentrations and 13C ratios measured over multiple days varied from 4.25 to 11.91 ppm and from -58.81 to -45.12‰, respectively. At higher methane concentrations the δ13C of CH4 was more depleted consistent with previously observed relationship at this site made by more traditional techniques. Over a 30-minute measurement period CH4 concentrations at the landfill could vary by as much as 15 ppm. The high frequency continuous optical measurements with field-deployed instruments provide us with an unprecedented temporal resolution of CH4 concentrations and isotopic ratios. These measurements will

  15. Lysozyme refolding at high concentration by dilution and size-exclusion chromatography

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    This study of renaturation by dilution and size exclusion chromatography (SEC) addition of urea to improve yield as well as the initial and final protein concentrations showed that although urea decreased the rate of lysozyme refolding, it could suppress protein aggregation to sustain the pathway of correct refolding at high protein concentration; and that there existed an optimum urea concentration in renaturation buffer. Under the above conditions, lysozyme was successfully refolded from initial concentration of up to 40 mg/mL by dilution and 100 mg/mL by SEC, with the yield of the former being more than 40% and that of the latter being 34.8%. Especially, under the condition of 30 min interval time, i.e. τ>2(tR2-tR1), the efficiency was increased by 25% and the renaturation buffer could be recycled for SEC refolding in continuous operation of downstream process.

  16. High-efficiency thin and compact concentrator photovoltaics with micro-solar cells directly attached to a lens array.

    Science.gov (United States)

    Hayashi, Nobuhiko; Inoue, Daijiro; Matsumoto, Mitsuhiro; Matsushita, Akio; Higuchi, Hiroshi; Aya, Youichirou; Nakagawa, Tohru

    2015-06-01

    We propose a thin and compact concentrator photovoltaic (CPV) module, about 20 mm thick, one tenth thinner than those of conventional CPVs that are widely deployed for mega-solar systems, to broaden CPV application scenarios. We achieved an energy conversion efficiency of 37.1% at a module temperature of 25 °C under sunlight irradiation optimized for our module. Our CPV module has a lens array consisting of 10 mm-square unit lenses and micro solar cells that are directly attached to the lens array, to reduce the focal length of the concentrator and to reduce optical losses due to reflection. The optical loss of the lens in our module is about 9.0%, which is lower than that of conventional CPV modules with secondary optics. This low optical loss enables our CPV module to achieve a high energy conversion efficiency.

  17. Potential of membrane distillation for production of high quality fruit juice concentrate.

    Science.gov (United States)

    Onsekizoglu Bagci, Pelin

    2015-01-01

    Fruit juices are generally concentrated in order to improve the stability during storage and to reduce handling, packaging, and transportation costs. Thermal evaporation is the most widely used technique in industrial fruit juice concentrate production. In addition to high energy consumption, a large part of the characteristics determining the quality of the fresh juice including aroma, color, vitamins, and antioxidants undergoes remarkable alterations through the use of high operation temperatures. Increasing consumer demand for minimally or naturally processed stable products able to retain as much possible the uniqueness of the fresh fruit has engendered a growing interest for development of nonthermal approaches for fruit juice concentration. Among them, membrane distillation (MD) and its variants have attracted much attention for allowing very high concentrations to be reached under atmospheric pressure and temperatures near ambient temperature. This review will provide an overview of the current status and recent developments in the use of MD for concentration of fruit juices. In addition to the most basic concepts of MD variants, crucial suggestions for membrane selection and operating parameters will be presented. Challenges and future trends for industrial adaptation taking into account the possibility of integrating MD with other existing processes will be discussed.

  18. Investigating DOC export dynamics using high-frequency instream concentration measurements

    Science.gov (United States)

    Oosterwoud, Marieke; Keller, Toralf; Musolff, Andreas; Frei, Sven; Park, Ji-Hyung; Fleckenstein, Jan H.

    2014-05-01

    Being able to monitor DOC concentrations using in-situ high frequency measurements makes it possible to better understand concentration-discharge behavior under different hydrological conditions. We developed a UV-Vis probe setup for modified/adapted use under field conditions. The quasi mobile probe setup allows a more flexible probe deployment. New or existing monitoring sites can easily be equipped for quasi-continuous monitoring or measurements can be performed at changing locations, without the need for additional infrastructure. We were able to gather high frequency data on DOC dynamics for one year in two streams in the Harz mountains in Germany. It proved that obtaining accurate DOC concentrations from the UV-Vis probes required frequent maintenance and probe calibration. The advantage of the setup over standard monitoring protocols becomes evident when comparing net exports over a year. In addition to mass improved balance calculations the high-frequency measurements can reveal intricate hysteretic relationships between discharge and concentrations that can provide valuable insights into the hydrologic dynamics and mechanisms that govern the delivery of DOC to the receiving waters. Measurements with similar probes from two additional catchments in Southern Germany and South Korea will be used to illustrate different discharge-concentration relationships and what can be learned from them about the hydrologic mechanisms that control the dynamics of DOC export.

  19. Performance of solmacs, a high PV solar concentrator with efficient optics

    Science.gov (United States)

    Thibert, T.; Hellin, M.-L.; Loicq, J.; Mazy, E.; Jacques, L.; Verstraeten, D.; Gillis, J.-M.; Languy, F.; Emmerechts, C.; Beeckman, E.; Habraken, S.; Lecat, J.-H.

    2012-10-01

    A new solar panel with high concentration photovoltaic technology (x700) has been designed, prototyped and tested in the SOLMACS project. The quality of concentrating optics is a key factor for high module efficiency. Therefore new dedicated PMMA Fresnel lenses were studied and produced by injection molding. Lens design, material and production process were optimized to achieve a high optical yield of 86%. Thorough lens performance assessment in optical laboratory was completed with lifetime UV aging tests. Another important aspect is the thermal control of the hot spot created under the solar cell that receives the concentrated flux of 700 Suns. A dedicated heat spreader was developed to achieve passive thermal control with minimum mass and cost. This was supported by thermal models and tests at both cell and module level. 35% triple junction cells were implemented in the module. Micro-assembly technologies were used for the cell packaging and electrical connections. In support to the research, a continuous solar simulator was designed and built to assess the system performance, both at component and module level. The concentrator developments were integrated in a prototype and tested both indoor with the simulator and outdoor on the CSL solar test platform. The overall efficiency of the PV concentrator module is 28.5%.

  20. Assessment of the risk of failure of high voltage substations due to environmental conditions and pollution on insulators.

    Science.gov (United States)

    Castillo Sierra, Rafael; Oviedo-Trespalacios, Oscar; Candelo, John E; Soto, Jose D

    2015-07-01

    Pollution on electrical insulators is one of the greatest causes of failure of substations subjected to high levels of salinity and environmental pollution. Considering leakage current as the main indicator of pollution on insulators, this paper focuses on establishing the effect of the environmental conditions on the risk of failure due to pollution on insulators and determining the significant change in the magnitude of the pollution on the insulators during dry and humid periods. Hierarchical segmentation analysis was used to establish the effect of environmental conditions on the risk of failure due to pollution on insulators. The Kruskal-Wallis test was utilized to determine the significant changes in the magnitude of the pollution due to climate periods. An important result was the discovery that leakage current was more common on insulators during dry periods than humid ones. There was also a higher risk of failure due to pollution during dry periods. During the humid period, various temperatures and wind directions produced a small change in the risk of failure. As a technical result, operators of electrical substations can now identify the cause of an increase in risk of failure due to pollution in the area. The research provides a contribution towards the behaviour of the leakage current under conditions similar to those of the Colombian Caribbean coast and how they affect the risk of failure of the substation due to pollution.

  1. Shoes, Dues, and Other Barriers to College Attainment: Perspectives of Students Attending High-Poverty Urban High Schools

    Science.gov (United States)

    Drotos, Stephanie M.; Cilesiz, Sebnem

    2016-01-01

    Facilitating economically disadvantaged students' access to higher education is an important goal of educational policy. However, some practices toward this goal are based on theories and assumptions not informed by the students' conditions or needs. The purpose of this study was to understand the challenges faced by students from high poverty,…

  2. Residual Stress Development due to High-Frequency Post Weld Impact Treatments for High-Strength Steels

    NARCIS (Netherlands)

    Gao, H.

    2014-01-01

    Allseas Engineering bv is an engineering center of the Allseas group, a major player in the offshore pipe lay market and recently expanding the activities to the offshore heavy lift sector. Because of the necessity to design and build lifting structures and equipment of a tremendously high capacity,

  3. Inhibition effects of high calcium concentration on anaerobic biological treatment of MSW leachate.

    Science.gov (United States)

    Xia, Yi; He, Pin-Jing; Pu, Hong-Xia; Lü, Fan; Shao, Li-Ming; Zhang, Hua

    2016-04-01

    With the increasing use of municipal solid waste incineration (MSWI) and more stringent limits on landfilling of organic waste, more MSWI bottom ash is being landfilled, and the proportion of inorganic wastes in landfills is increasing, causing the increased Ca concentrations in landfill leachate. In this research, the inhibition effect of Ca concentration on the anaerobic treatment of landfill leachate was studied using a biochemical methane potential experiment. Slight inhibition of methane production occurred when the addition of Ca concentration was less than 2000 mg/L. When the addition of Ca concentration was between 6000 and 8000 mg/L, methane production was significantly reduced (to 29.4-34.8 % of that produced by the BLK reactor), and the lag phase was increased from 8.55 to 16.32 d. Moreover, when the dosage of Ca concentration increased from zero to 8000 mg/L, reductions in solution Ca concentration increased from 929 to 2611 mg/L, and the proportion of Ca in the residual sludge increased from 22.58 to 46.87 %. Based on the results, when the dosage of Ca concentration was less than 4000 mg/L, the formation of Ca precipitates on the surface of sludge appeared to prevent mass transfer and was the dominant reason for the reduction in methane production and sludge biomass. At higher Ca concentrations (6000-8000 mg/L), the severe inhibition of methane production appeared to be caused by the toxic effect of highly concentrated Ca on sludge as well as mass transfer blockage.

  4. Enhanced Enzymatic Production of Cephalexin at High Substrate Concentration with in situ Product Removal by Complexation

    Directory of Open Access Journals (Sweden)

    Dengchao Li

    2008-01-01

    Full Text Available Cephalexin (CEX was synthesized with 7-amino-3-deacetoxycephalosporanic acid (7-ADCA and D(–-phenylglycine methyl ester (PGME using immobilized penicillin G acylase from Escherichia coli. It was found that substrate concentration and in situ product could remarkably influence the ratio of synthesis to hydrolysis (S/H and the efficiency of CEX synthesis. The optimal ratio of enzyme to substrate was 65 IU/mM 7-ADCA. High substrate concentration improved the 7-ADCA conversion from 61 to 81 % in the process without in situ product removal (ISPR, while in the synthetic process with ISPR, high substrate concentration increased the 7-ADCA conversion from 88 to 98 %. CEX was easily separated from CEX/β-naphthol complex and its purity and overall yield were 99 and 70 %, respectively.

  5. Self-assembling semicrystalline polymer into highly ordered, microscopic concentric rings by evaporation.

    Science.gov (United States)

    Byun, Myunghwan; Hong, Suck Won; Zhu, Lei; Lin, Zhiqun

    2008-04-01

    A drop of semicrystalline polymer, poly(ethylene oxide) (PEO), solution was placed in a restricted geometry consisting of a sphere on a flat substrate (i.e., sphere-on-flat geometry). Upon solvent evaporation from the sphere-on-flat geometry, microscopic concentric rings of PEO with appropriate high molecular weight were produced via controlled, repetitive pinning ("stick") and depinning ("slip") cycles of the contact line. The evaporation-induced concentric rings of PEO exhibited a fibrillar-like surface morphology. Subsequent isothermal crystallization of rings at 40 and 58 degrees C led to the formation of multilayer of flat-on lamellae (i.e., spiral morphology). In between adjacent spirals, depletion zones were developed during crystallization, as revealed by AFM measurements. The present highly ordered, concentric PEO rings may serve as a platform to study cell adhesion and motility, neuron guidance, cell mechanotransduction, and other biological processes.

  6. Chlorinated pesticides (2,4-D and DDT) biodegradation at high concentrations using immobilized Pseudomonas fluorescens.

    Science.gov (United States)

    Santacruz, Germán; Bandala, Erick R; Torres, Luis G

    2005-01-01

    Degradation of two chlorinated pesticides (2,4-D and DDT) using a 54-mL glass column packed with tezontle (a low-cost basaltic scoria) was tested. Bacteria were cultured in YPG (yeast, peptone, and glucose) liquid medium at 32 degrees C. The rich medium was pumped during 24 h through the column to inoculate it. Later, the wasted medium was discharged and the pesticide added. Optical densities, TOC, and pesticide concentration were determined. Pesticide removals for 2,4-D (with initial concentration between 100 and 500 mg/L) were about 99%. DDT removal (at initial concentration of up to 150 mg/L) was as high as 55-99%. TOC removals for 2,4-D was in the 36-87% interval, whereas for DDT they were as high as 36-78%.

  7. Highly concentrated phenolic wastewater treatment by heterogeneous and homogeneous photocatalysis: mechanism study by FTIR-ATR.

    Science.gov (United States)

    Araña, J; Tello-Rendón, E; Doña-Rodríguez, J M; Campo, C V; Herrera-Melidán, J A; González-Díaz; Pérez-Peña, J

    2001-01-01

    The degradation of high phenol concentrations (1 g/L) in water solutions by TiO2 photocatalysis and the photo-Fenton reaction has been studied. From the obtained data it may be suggested that degradation of phenol by TiO2-UV takes place onto the catalyst surface by means of peroxo-compounds formation. At low phenol concentrations other mechanism, the insertion of OH. radicals, may be favored. On the other hand, highly concentrated phenol aqueous solutions treatment by the photo-Fenton reaction gives rise to the formation of polyphenolic polymers. These seem to reduce the process rate. Degradation intermediates have been identified by HPLC and FTIR. The FTIR study of the catalyst surface has shown infrared bands attributable to different chemisorbed peroxo-compounds, formates, ortho-formates and carboxylates that can inactivate the catalyst.

  8. High School and Employment Experiences of Vocational and Nonvocational Concentrators of the Idaho High School Graduating Class of 1983.

    Science.gov (United States)

    Riesenberg, Lou E.; Stenberg, Laurie A.

    1992-01-01

    Five years after graduation, responses from 519 nonvocational and 212 vocational Idaho graduates and 317 of their employers found no differences in satisfaction with curriculum; 40% nonvocational and 33% vocational jobs not related to high school plans; 89% nonvocational, 80% vocational concentrators satisfied with jobs; and no significant…

  9. Niacin alters the ruminal microbial composition of cattle under high-concentrate condition

    Directory of Open Access Journals (Sweden)

    Dan Luo

    2017-06-01

    Full Text Available To understand the effects of niacin on the ruminal microbial ecology of cattle under high-concentrate diet condition, Illumina MiSeq sequencing technology was used. Three cattle with rumen cannula were used in a 3 × 3 Latin-square design trial. Three diets were fed to these cattle during 3 periods for 3 days, respectively: high-forage diet (HF; forage-to-concentrate ratio = 80:20, high-concentrate diet (HC; forage-to-concentrate ratio = 20:80, and HC supplemented with 800 mg/kg niacin (HCN. Ruminal pH was measured before feeding and every 2 h after initiating feeding. Ruminal fluid was sampled at the end of each period for microbial DNA extraction. Overall, our findings revealed that subacute ruminal acidosis (SARA was induced and the α-diversity of ruminal bacterial community decreased in the cattle of HC group. Adding niacin in HC could relieve the symptoms of SARA in the cattle but the ruminal pH value and the Shannon index of ruminal bacterial community of HCN group were still lower than those of HF group. Whatever the diet was, the ruminal bacterial community of cattle was dominated by Bacteroidetes, Firmicutes and Proteobacteria. High-concentrate diet significantly increased the abundance of Prevotella, and decreased the abundance of Paraprevotella, Sporobacter, Ruminococcus and Treponema than HF. Compared with HC, HCN had a trend to decrease the percentage of Prevotella, and to increase the abundance of Succiniclasticum, Acetivibrio and Treponema. Increasing concentrate ratio could decrease ruminal pH value, and change the ruminal microbial composition. Adding niacin in HC could increase the ruminal pH value, alter the ruminal microbial composition.

  10. Evaluation of annual efficiencies of high temperature central receiver concentrated solar power plants with thermal energy storage.

    Energy Technology Data Exchange (ETDEWEB)

    Ehrhart, Brian David; Gill, David Dennis

    2013-07-01

    The current study has examined four cases of a central receiver concentrated solar power plant with thermal energy storage using the DELSOL and SOLERGY computer codes. The current state-of-the-art base case was compared with a theoretical high temperature case which was based on the scaling of some input parameters and the estimation of other parameters based on performance targets from the Department of Energy SunShot Initiative. This comparison was done for both current and high temperature cases in two configurations: a surround field with an external cylindrical receiver and a north field with a single cavity receiver. There is a fairly dramatic difference between the design point and annual average performance, especially in the solar field and receiver subsystems, and also in energy losses due to the thermal energy storage being full to capacity. Additionally, there are relatively small differences (<2%) in annual average efficiencies between the Base and High Temperature cases, despite an increase in thermal to electric conversion efficiency of over 8%. This is due the increased thermal losses at higher temperature and operational losses due to subsystem start-up and shut-down. Thermal energy storage can mitigate some of these losses by utilizing larger thermal energy storage to ensure that the electric power production system does not need to stop and re-start as often, but solar energy is inherently transient. Economic and cost considerations were not considered here, but will have a significant impact on solar thermal electric power production strategy and sizing.

  11. [Obesity and high health risk due to beberages consumption and obesity among high school students in méxico].

    Science.gov (United States)

    Caravalí-Meza, NurisYohana; Jiménez-Cruz, Arturo; Bacardí-Gascón, Montserrat; Gómez-Miranda, Luis Mario

    2015-05-01

    The purpose of this study was to identify the consumption of beverages among high school Mexican students and to determine obesity (OB) and abdominal obesity (AB). Differences in range and calorie beverage consumption between gender and BMI categories were calculated with the Mann-Whitney test. We assessed 1,677 students 15 to 17 yo. The prevalence of OB and AO was 15% and 53% in men and 12% and 47% in women. The consumption of energy, sugary drinks, and alcohol in milliliters and kilocalories per week, was higher in men (p = 0.001). More than 70% of students consumed per day more than 25 g/day of sugar from beverages, and more than 38% consumed more than 50 g/day of sugar. This high risk food consumption warrants immediate intervention.

  12. 509-45-1: A C. annuum Pepper germplasm containing high concentrations of capsinoids

    Science.gov (United States)

    This publication reports the public release of pepper (Capsicum annuum) germplasm ‘509-45-1’. Pepper germplasm 509-45-1 is a small-fruited, non-pungent single plant selection from PI 645509. Fruit of ‘509-45-1’ contain high concentrations of capsinoids [capsiate ((4-hydroxy-3-methoxybenzyl (E)-8...

  13. The preparation and ethanol fermentation of high-concentration sugars from steam-explosion corn stover.

    Science.gov (United States)

    Xie, Hui; Wang, Fengqin; Yin, Shuangyao; Ren, Tianbao; Song, Andong

    2015-05-01

    In the field of biofuel ethanol, high-concentration- reducing sugars made from cellulosic materials lay the foundation for high-concentration ethanol fermentation. In this study, corn stover was pre-treated in a process combining chemical methods and steam explosion; the cellulosic hydrolyzed sugars obtained by fed-batch saccharification were then used as the carbon source for high-concentration ethanol fermentation. Saccharomyces cerevisiae 1308, Angel yeast, and Issatchenkia orientalis were shake-cultured with Pachysolen tannophilus P-01 for fermentation. Results implied that the ethanol yields from the three types of mixed strains were 4.85 g/100 mL, 4.57 g/100 mL, and 5.02 g/100 mL (separately) at yield rates of 91.6, 89.3, and 92.2%, respectively. Therefore, it was inferred that shock-fermentation using mixed strains achieved a higher ethanol yield at a greater rate in a shorter fermentation period. This study provided a theoretical basis and technical guidance for the fermentation of industrial high-concentrated cellulosic ethanol.

  14. Low-Frequency Dielectric Dispersion of Highly Concentrated Spherical Particles in an Electrolyte Solution

    Institute of Scientific and Technical Information of China (English)

    倪福生; 顾国庆; 陈康民

    2002-01-01

    We deal with the problem of calculating the effective dielectric dispersion and electrical conductivity of colloidaldispersions. A comparison of the theoretical calculation of first principles with the experimental data of Schwanshows that our technique proposed here is no longer restricted to dilute solutions and is very effective for studyingthe dielectric properties of colloids with highly concentrated charged spherical particles in an electrolyte solution.

  15. Simplified yet highly accurate enzyme kinetics for cases of low substrate concentrations

    NARCIS (Netherlands)

    Härdin, H.M.; Zagaris, A.; Krab, K.; Westerhoff, H.V.

    2009-01-01

    Much of enzyme kinetics builds on simplifications enabled by the quasi-steady-state approximation and is highly useful when the concentration of the enzyme is much lower than that of its substrate. However, in vivo, this condition is often violated. In the present study, we show that, under conditio

  16. Continuum modeling of hydrodynamic particle–particle interactions in microfluidic high-concentration suspensions

    DEFF Research Database (Denmark)

    Ley, Mikkel Wennemoes Hvitfeld; Bruus, Henrik

    2016-01-01

    A continuum model is established for numerical studies of hydrodynamic particle–particle interactions in microfluidic high-concentration suspensions. A suspension of microparticles placed in a microfluidic channel and influenced by an external force, is described by a continuous particle...

  17. Analytical Study of High Concentration PCB Paint at the Heavy Water Components Test Reactor

    Energy Technology Data Exchange (ETDEWEB)

    Lowry, N.J.

    1998-10-21

    This report provides results of an analytical study of high concentration PCB paint in a shutdown nuclear test reactor located at the US Department of Energy's Savannah River Site (SRS). The study was designed to obtain data relevant for an evaluation of potential hazards associated with the use of and exposure to such paints.

  18. Interculturalism in Italian Primary Schools with a High Concentration of Immigrant Students

    Science.gov (United States)

    Catarci, Marco

    2013-01-01

    The present article focuses on quantitative research carried out on a statistically representative sample of Italian primary schools with a high concentration of immigrant students. Research data show that schools with a higher number of immigrant students offer a greater number and a wider variety of intercultural initiatives. The presence of…

  19. Production of ethanol from wheat straw by pretreatment and fermentation at high dry matter concentrations

    NARCIS (Netherlands)

    Groenestijn, J.W. van; Slomp, R.S.

    2011-01-01

    High concentrations of substrate and product are important for the economy of second-generation bioethanol production. By a dilute acid thermal pretreatment of large pieces of relatively dry wheat straw using a novel rapid heating method, followed by fed-batch preliquefaction with hydrolytic enzymes

  20. Simplified yet highly accurate enzyme kinetics for cases of low substrate concentrations

    NARCIS (Netherlands)

    Härdin, H.M.; Zagaris, A.; Krab, K.; Westerhoff, H.V.

    2009-01-01

    Much of enzyme kinetics builds on simplifications enabled by the quasi-steady-state approximation and is highly useful when the concentration of the enzyme is much lower than that of its substrate. However, in vivo, this condition is often violated. In the present study, we show that, under

  1. Coherence and anticoherence resonance in high-concentration erbium-doped fiber laser

    OpenAIRE

    Sergeyev, Sergey; O'Mahoney, Kieran; Popov, Sergei; Friberg, Ari T.

    2010-01-01

    We report an experimental study of low-frequency (~10 kHz) self-pulsing of the output intensity in a high- concentration erbium-doped fiber laser. We suggest that the fast intensity fluctuations caused by multimode and polarization instabilities play the role of an external noise source, leading to low-frequency auto-oscillations through a coherence resonance scenario.

  2. Low powdered activated carbon concentrations to improve MBR sludge filterability at high salinity and low temperature

    NARCIS (Netherlands)

    Remy, M.J.J.; Temmink, B.G.; Brink, van den P.; Rulkens, W.H.

    2011-01-01

    Previous research has demonstrated that powdered activated carbon (PAC), when applied at very low dosages and long SRTs, reduces membrane fouling in membrane bioreactor (MBRs). This effect was related to stronger flocs which are less sensitive to shear. Low temperature and high salt concentration ar

  3. Mapping the Life Satisfaction of Adolescents in Hong Kong Secondary Schools with High Ethnic Concentration

    Science.gov (United States)

    Yuen, Yuet Mui Celeste; Lee, Moosung

    2016-01-01

    The present study aims to map the life satisfaction of adolescents from ethnic minority/immigrant backgrounds in schools with high concentrations of co-ethnic peers by comparing them with their mainstream counterparts in Hong Kong. The life satisfaction of 1,522 students was measured by the validated Multidimensional Students' Life Satisfaction…

  4. Consolidated bioprocessing of highly concentrated Jerusalem artichoke tubers for simultaneous saccharification and ethanol fermentation.

    Science.gov (United States)

    Guo, Lihao; Zhang, Jian; Hu, Fengxian; Dy Ryu, Dewey; Bao, Jie

    2013-10-01

    Consolidated bioprocessing (CBP) of Jerusalem artichoke tuber (Jat) for ethanol production is one of the most promising options for an alternate biofuel technology development. The technical barriers include the weak saccharolytic enzyme (inulinase) activity of the fermentation strain, and the well mixing of the high viscous fermentation slurry at the highly concentrated Jat loading. In this study, Saccharomyces cerevisiae DQ1 was found to produce relatively large amount of inulinase for hydrolysis of inulin in Jat, and the helical ribbon stirring bioreactor used provided well mixing performance under the high Jat loading. Even a highly concentrated Jat loading up to 35% (w/w) in the helical ribbon bioreactor for CBP was allowed. The results obtained from this study have demonstrated a feasibility of developing a CBP process technology in the helical ribbon bioreactor for ethanol production at a high yield 128.7 g/L and the theoretical yield 73.5%, respectively. This level of ethanol yield from Jat is relatively higher than others reported so far. The results of this study could provide a practical CBP process technology in the helical ribbon bioreactor for economically sustainable alternate biofuel production using highly concentrated inulin containing biomass feedstock such as Jat, at least 35%. Copyright © 2013 Wiley Periodicals, Inc.

  5. Technical Note: Comparison between a direct and the standard, indirect method for dissolved organic nitrogen determination in freshwater environments with high dissolved inorganic nitrogen concentrations

    DEFF Research Database (Denmark)

    Graeber, Daniel; Gelbrecht, Jörg; Kronvang, Brian

    2012-01-01

    as the difference between total dissolved nitrogen (TDN) and DIN. In this standard approach to determine DON concentrations, even small relative measurement errors of the DIN and TDN concentrations propagate into high absolute errors of DON concentrations at high DIN : TDN ratios. To improve the DON measurement...... with and without DIN enrichment. We show that for the standard approach, large errors of the determined DON concentrations at DIN : TDN ratios >0.6 occur for both standard compounds and natural samples. In contrast, measurements of DON by SEC always gave low errors at high DIN : TDN ratios due to the successful...... accuracy at high DIN : TDN ratios, we investigated the DON measurement accuracy of this standard approach according to the DIN : TDN ratio and compared it to the direct measurement of DON by size-exclusion chromatography (SEC) for freshwater systems. For this, we used standard compounds and natural samples...

  6. Concentration-Induced Association in a Protein System Caused by a Highly Directional Patch Attraction.

    Science.gov (United States)

    Li, Weimin; Persson, Björn A; Lund, Mikael; Bergenholtz, Johan; Zackrisson Oskolkova, Malin

    2016-09-01

    Self-association of the protein lactoferrin is studied in solution using small-angle X-ray scattering techniques. Effective static structure factors have been shown to exhibit either a monotonic or a nonmonotonic dependence on protein concentration in the small wavevector limit, depending on salt concentration. The behavior correlates with a nonmonotonic dependence of the second virial coefficient on salt concentration, such that a maximum appears in the structure factor at a low protein concentration when the second virial coefficient is negative and close to a minimum. The results are interpreted in terms of an integral equation theory with explicit dimers, formulated by Wertheim, which provides a consistent framework able to explain the behavior in terms of a monomer-dimer equilibrium that appears because of a highly directional patch attraction. Short attraction ranges preclude trimer formation, which explains why the protein system behaves as if it were subject to a concentration-dependent isotropic protein-protein attraction. Superimposing an isotropic interaction, comprising screened Coulomb repulsion and van der Waals attraction, on the patch attraction allows for a semiquantitative modeling of the complete transition pathway from monomers in the dilute limit to monomer-dimer systems at somewhat higher protein concentrations.

  7. The molecular interaction of a protein in highly concentrated solution investigated by Raman spectroscopy.

    Science.gov (United States)

    Ota, Chikashi; Noguchi, Shintaro; Tsumoto, Kouhei

    2015-04-01

    We used Raman spectroscopy to investigate the structure and interactions of lysozyme molecules in solution over a wide range of concentrations (2.5-300 mg ml(-1)). No changes in the amide-I band were observed as the concentration was increased, but the width of the Trp band at 1555 cm(-1) and the ratios of the intensities of the Tyr bands at 856 and 837 cm(-1), the Trp bands at 870 and 877 cm(-1), and the bands at 2940 (CH stretching) and 3420 cm(-1) (OH stretching) changed as the concentration was changed. These results reveal that although the distance between lysozyme molecules changed by more than an order of magnitude over the tested concentration range, the secondary structure of the protein did not change. The changes in the molecular interactions occurred in a stepwise process as the order of magnitude of the distance between molecules changed. These results suggest that Raman bands can be used as markers to investigate the behavior of high-concentration solutions of proteins and that the use of Raman spectroscopy will lead to progress in our understanding not only of the basic science of protein behavior under concentrated (i.e., crowded) conditions but also of practical processes involving proteins, such as in the field of biopharmaceuticals. © 2014 Wiley Periodicals, Inc.

  8. Rapid estimation of concentration of aromatic classes in middistillate fuels by high-performance liquid chromatography

    Science.gov (United States)

    Otterson, D. A.; Seng, G. T.

    1985-01-01

    An high performance liquid chromatography (HPLC) method to estimate four aromatic classes in middistillate fuels is presented. Average refractive indices are used in a correlation to obtain the concentrations of each of the aromatic classes from HPLC data. The aromatic class concentrations can be obtained in about 15 min when the concentration of the aromatic group is known. Seven fuels with a wide range of compositions were used to test the method. Relative errors in the concentration of the two major aromatic classes were not over 10 percent. Absolute errors of the minor classes were all less than 0.3 percent. The data show that errors in group-type analyses using sulfuric acid derived standards are greater for fuels containing high concentrations of polycyclic aromatics. Corrections are based on the change in refractive index of the aromatic fraction which can occur when sulfuric acid and the fuel react. These corrections improved both the precision and the accuracy of the group-type results.

  9. Effects of exposure to high concentrations of waterborne Tl on K and Tl concentrations in Chironomus riparius larvae.

    Science.gov (United States)

    Belowitz, Ryan; Leonard, Erin M; O'Donnell, Michael J

    2014-11-01

    Thallium (Tl) is a non-essential metal which is released into the environment primarily as the result of anthropogenic activities such as fossil fuel burning and smelting of ores. The ionic radius of monovalent Tl⁺ is similar to that of K⁺ and Tl⁺ may thus interfere with K⁺-dependent processes. We determined that the acute (48 h) lethal concentration where 50% of the organisms do not survive (LC₅₀) of Tl for 4th instar Chironomus riparius larvae was 723 μmol L⁻¹. Accumulation of Tl by the whole animal was saturable, with a maximum accumulation (Jmax) of 4637 μmol kg⁻¹ wet mass, and K(D) of 670 μmol Tl l⁻¹. Tl accumulation by the gut appeared saturable at the lowest four Tl concentrations, with a Jmax of 2560 μmol kg⁻¹ wet mass and a K(D) of 54.5 μmol Tl l⁻¹. The saturable accumulation at the gut may be indicative of a limited capacity for intracellular detoxification, such as storage in lysosomes or complexation with metal-binding proteins. Tl accumulation by the hemolymph was found to be linear and Tl concentrations in the hemolymph were ~75% of the exposure concentration at Tl exposures >26.9 μmol L⁻¹. There was not a significant decrease in whole animal, gut or hemolymph K during exposure to waterborne Tl at any of the concentrations tested (up to 1500 μmol L⁻¹). The avoidance of hypokalemia by C. riparius larvae may contribute to survival during acute waterborne exposures to Tl. Copyright © 2014 Elsevier Inc. All rights reserved.

  10. Effects of prior acute exercise on circulating cytokine concentration responses to a high-fat meal.

    Science.gov (United States)

    Brandauer, Josef; Landers-Ramos, Rian Q; Jenkins, Nathan T; Spangenburg, Espen E; Hagberg, James M; Prior, Steven J

    2013-08-01

    High-fat meal consumption alters the circulating cytokine profile and contributes to cardiometabolic diseases. A prior bout of exercise can ameliorate the triglyceride response to a high-fat meal, but the interactive effects of exercise and high-fat meals on cytokines that mediate cardiometabolic risk are not fully understood. We investigated the effects of prior exercise on the responses of circulating tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6), IL-8, leptin, retinol-binding protein 4 (RBP4), vascular endothelial growth factor (VEGF), basic fibroblast growth factor (bFGF), placental growth factor (PlGF), and soluble fms-like tyrosine kinase-1 (sFlt-1) to a high-fat meal. Ten healthy men were studied before and 4 h after ingestion of a high-fat meal either with or without ∼50 min of endurance exercise at 70% of VO2 max on the preceding day. In response to the high-fat meal, lower leptin and higher VEGF, bFGF, IL-6, and IL-8 concentrations were evident (P exercise (P exercise and the high-fat meal on sFlt-1 (P exercise and 218% with prior exercise (P exercise does not affect all high-fat meal-induced changes in circulating cytokines, but does affect fasting or postprandial concentrations of IL-6, leptin, and sFlt-1. These data may reflect a salutary effect of prior exercise on metabolic responses to a high-fat meal.

  11. Plasma PCSK9 concentrations during an oral fat load and after short term high-fat, high-fat high-protein and high-fructose diets

    Directory of Open Access Journals (Sweden)

    Cariou Bertrand

    2013-01-01

    Full Text Available Abstract Background PCSK9 (Proprotein Convertase Subtilisin Kexin type 9 is a circulating protein that promotes hypercholesterolemia by decreasing hepatic LDL receptor protein. Under non interventional conditions, its expression is driven by sterol response element binding protein 2 (SREBP2 and follows a diurnal rhythm synchronous with cholesterol synthesis. Plasma PCSK9 is associated to LDL-C and to a lesser extent plasma triglycerides and insulin resistance. We aimed to verify the effect on plasma PCSK9 concentrations of dietary interventions that affect these parameters. Methods We performed nutritional interventions in young healthy male volunteers and offspring of type 2 diabetic (OffT2D patients that are more prone to develop insulin resistance, including: i acute post-prandial hyperlipidemic challenge (n=10, ii 4 days of high-fat (HF or high-fat/high-protein (HFHP (n=10, iii 7 (HFruc1, n=16 or 6 (HFruc2, n=9 days of hypercaloric high-fructose diets. An acute oral fat load was also performed in two patients bearing the R104C-V114A loss-of-function (LOF PCSK9 mutation. Plasma PCSK9 concentrations were measured by ELISA. For the HFruc1 study, intrahepatocellular (IHCL and intramyocellular lipids were measured by 1H magnetic resonance spectroscopy. Hepatic and whole-body insulin sensitivity was assessed with a two-step hyperinsulinemic-euglycemic clamp (0.3 and 1.0 mU.kg-1.min-1. Findings HF and HFHP short-term diets, as well as an acute hyperlipidemic oral load, did not significantly change PCSK9 concentrations. In addition, post-prandial plasma triglyceride excursion was not altered in two carriers of PCSK9 LOF mutation compared with non carriers. In contrast, hypercaloric 7-day HFruc1 diet increased plasma PCSK9 concentrations by 28% (p=0.05 in healthy volunteers and by 34% (p=0.001 in OffT2D patients. In another independent study, 6-day HFruc2 diet increased plasma PCSK9 levels by 93% (p Conclusions Plasma PCSK9 concentrations vary

  12. Optimal Dearsenification Parameters of Gold Sulfide Concentrate with a High As Content

    Institute of Scientific and Technical Information of China (English)

    Yaozhong LAN; Rose W. Smith

    2005-01-01

    The gold sulfide concentrate with a high As content in Liangshan District, Sichuan Province, China, is a potentially important resource. This paper describes experiments of dearsenification of gold concentrate in a weakly reduced atmosphere in a rotary pipe furnace. The results showed that the optimal parameters were a temperature range of 650~700℃, 15%~16% CO2 of gas and a reaction time of 30~40 min. The removal rate of arsenic and sulfur was over 95% and 25%~28%, respectively. With further oxidization and roasting, residue sulfur in the roasted materials was dropped to below 4%, and the cyanide leaching recovery of gold was over 92%.

  13. Enhanced Cycling Stability of Rechargeable Li-O2 Batteries Using High Concentration Electrolytes

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Bin; Xu, Wu; Yan, Pengfei; Sun, Xiuliang; Bowden, Mark E.; Read, Jeffrey; Qian, Jiangfeng; Mei, Donghai; Wang, Chong M.; Zhang, Jiguang

    2016-01-26

    The electrolyte stability against reactive reduced-oxygen species is crucial for the development of rechargeable Li-O2 batteries. In this work, we systematically investigated the effect of lithium salt concentration in 1,2-dimethoxyethane (DME)-based electrolytes on the cycling stability of Li-O2 batteries. Cells with high concentration electrolyte illustrate largely enhanced cycling stability under both the full discharge/charge (2.0-4.5 V vs. Li/Li+) and the capacity limited (at 1,000 mAh g-1) conditions. These cells also exhibit much less reaction-residual on the charged air electrode surface, and much less corrosion to the Li metal anode. The density functional theory calculations are conducted on the molecular orbital energies of the electrolyte components and the Gibbs activation barriers for superoxide radical anion to attack DME solvent and Li+-(DME)n solvates. In a highly concentrated electrolyte, all DME molecules have been coordinated with salt and the C-H bond scission of a DME molecule becomes more difficult. Therefore, the decomposition of highly concentrated electrolyte in a Li-O2 battery can be mitigated and both air-cathodes and Li-metal anodes exhibits much better reversibility. As a results, the cyclability of Li-O2 can be largely improved.

  14. High nitrogen supply and carbohydrate content reduce fungal endophyte and alkaloid concentration in Lolium perenne.

    Science.gov (United States)

    Rasmussen, Susanne; Parsons, Anthony J; Bassett, Shalome; Christensen, Michael J; Hume, David E; Johnson, Linda J; Johnson, Richard D; Simpson, Wayne R; Stacke, Christina; Voisey, Christine R; Xue, Hong; Newman, Jonathan A

    2007-01-01

    The relationship between cool-season grasses and fungal endophytes is widely regarded as mutualistic, but there is growing uncertainty about whether changes in resource supply and environment benefit both organisms to a similar extent. Here, we infected two perennial ryegrass (Lolium perenne) cultivars (AberDove, Fennema) that differ in carbohydrate content with three strains of Neotyphodium lolii (AR1, AR37, common strain) that differ intrinsically in alkaloid profile. We grew endophyte-free and infected plants under high and low nitrogen (N) supply and used quantitative PCR (qPCR) to estimate endophyte concentrations in harvested leaf tissues. Endophyte concentration was reduced by 40% under high N supply, and by 50% in the higher sugar cultivar. These two effects were additive (together resulting in 75% reduction). Alkaloid production was also reduced under both increased N supply and high sugar cultivar, and for three of the four alkaloids quantified, concentrations were linearly related to endophyte concentration. The results stress the need for wider quantification of fungal endophytes in the grassland-foliar endophyte context, and have implications for how introducing new cultivars, novel endophytes or increasing N inputs affect the role of endophytes in grassland ecosystems.

  15. Hyperproduction of Alcohol Using Yeast Fermentation in Highly Concentrated Molasses Medium

    Institute of Scientific and Technical Information of China (English)

    顾燕松; 周政懋; 乔敏; 周全; 陈国强

    2001-01-01

    Cane molasses, a major byproduct in the sugar industry, is generally consumed for alcohol production. However, the alcohol production process needs to overcome three major challenges including increasing the productivity of alcohol fermentation, lowering the energy consumption for alcohol conversion and decreasing the environmental pollution caused by the alcoholic yeast fermentation process. To meet these challenges, a screening process was conducted using 13 high osmotic tolerant yeast strains. Among the strains, a Saccharomyces cerevisiae strain 1912 was found to produce high alcohol concentrations during fermentation with high starting molasses concentrations such as 50% (W/V) molasses. In the test, 13.6% (V/V) alcohol was produced in the molasses fermentation broth after 72 h of incubation with an initial Yunnan molasses concentration of 50% in a 5 L fermentor. 15.0% (V/V) alcohol was obtained after 48 h of fermentation in shaking flasks containing 30% (W/V) initial total sugar concentration in diluted molasses. The performance of this strain in the shaking flasks was successfully scaled up to a 5-L fermentor vessel. Strain 1912 seems to be a better alcohol producer than the currently used alcohol production strain 2. 1190.

  16. Aggregation of normal and sickle hemoglobin in high concentration phosphate buffer.

    Science.gov (United States)

    Chen, Kejing; Ballas, Samir K; Hantgan, Roy R; Kim-Shapiro, Daniel B

    2004-12-01

    Sickle cell disease is caused by a mutant form of hemoglobin, hemoglobin S, that polymerizes under hypoxic conditions. The extent and mechanism of polymerization are thus the subject of many studies of the pathophysiology of the disease and potential treatment strategies. To facilitate such studies, a model system using high concentration phosphate buffer (1.5 M-1.8 M) has been developed. To properly interpret results from studies using this model it is important to understand the similarities and differences in hemoglobin S polymerization in the model compared to polymerization under physiological conditions. In this article, we show that hemoglobin S and normal adult hemoglobin, hemoglobin A, aggregate in high concentration phosphate buffer even when the concentration of hemoglobin is below the solubility defined for polymerization. This phenomenon was not observed using 0.05 M phosphate buffer or in another model system we studied that uses dextran to enhance polymerization. We have used static light scattering, dynamic light scattering, and differential interference contrast microscopy to confirm aggregation of deoxygenated and oxygenated hemoglobins below their solubility and have shown that this aggregation is not observable using turbidity measurements, a common technique for assessing polymerization. We have also shown that the aggregation increases with increasing temperature in the range of 15 degrees -37 degrees C and that it increases as the concentration of phosphate increases. These studies contribute to the working knowledge of how to properly apply studies of hemoglobin S polymerization that are conducted using the high phosphate model.

  17. Quality evaluation of moluodan concentrated pill using high-performance liquid chromatography fingerprinting coupled with chemometrics.

    Science.gov (United States)

    Tao, Lingyan; Zhang, Qing; Wu, Yongjiang; Liu, Xuesong

    2016-12-01

    In this study, a fast and effective high-performance liquid chromatography method was developed to obtain a fingerprint chromatogram and quantitative analysis simultaneously of four indexes including gallic acid, chlorogenic acid, albiflorin and paeoniflorin of the traditional Chinese medicine Moluodan Concentrated Pill. The method was performed by using a Waters X-bridge C18 reversed phase column on an Agilent 1200S high-performance liquid chromatography system coupled with diode array detection. The mobile phase of the high-performance liquid chromatography method was composed of 20 mmol/L phosphate solution and acetonitrile with a 1 mL/min eluent velocity, under a detection temperature of 30°C and a UV detection wavelength of 254 nm. After the methodology validation, 16 batches of Moluodan Concentrated Pill were analyzed by this high-performance liquid chromatography method and both qualitative and quantitative evaluation results were achieved by similarity analysis, principal component analysis and hierarchical cluster analysis. The results of these three chemometrics were in good agreement and all indicated that batch 10 and batch 16 showed significant differences with the other 14 batches. This suggested that the developed high-performance liquid chromatography method could be applied in the quality evaluation of Moluodan Concentrated Pill.

  18. High concentrations of H2O2 make aerobic glycolysis energetically more favourable than cellular respiration.

    Directory of Open Access Journals (Sweden)

    Hamid R Molavian

    2016-08-01

    Full Text Available Since the original observation of the Warburg Effect in cancer cells, over eight decades ago, the major question of why aerobic glycolysis is favored over oxidative phosphorylation has remained unresolved. An understanding of this phenomenon may well be the key to the development of more effective cancer therapies. In this paper, we use a semi-empirical method to throw light on this puzzle. We show that aerobic glycolysis is in fact energetically more favorable than oxidative phosphorylation for concentrations of peroxide (H2O2 above some critical threshold value. The fundamental reason for this is the activation and high engagement of the pentose phosphate pathway (PPP in response to the production of reactive oxygen species H2O2 by mitochondria and the high concentration of H2O2 (produced by mitochondria and other sources. This makes oxidative phosphorylation an inefficient source of energy since it leads (despite high levels of ATP production to a concomitant high energy consumption in order to respond to the hazardous waste products resulting from cellular processes associated with this metabolic pathway. We also demonstrate that the high concentration of H2O2 results in an increased glucose consumption, and also increases the lactate production in the case of glycolysis.

  19. Vasopressin activates Akt/mTOR pathway in smooth muscle cells cultured in high glucose concentration

    Energy Technology Data Exchange (ETDEWEB)

    Montes, Daniela K.; Brenet, Marianne; Muñoz, Vanessa C.; Burgos, Patricia V.; Villanueva, Carolina I. [Department of Physiology, Universidad Austral de Chile, Valdivia 509-9200 (Chile); Figueroa, Carlos D. [Department of Anatomy, Histology and Pathology, Universidad Austral de Chile, Valdivia 509-9200 (Chile); González, Carlos B., E-mail: cbgonzal@uach.cl [Department of Physiology, Universidad Austral de Chile, Valdivia 509-9200 (Chile); Department of Neuroscience and Cell Biology, University of Texas Medical Branch, Galveston, TX 77555 (United States)

    2013-11-29

    Highlights: •AVP induces mTOR phosphorylation in A-10 cells cultured in high glucose concentration. •The mTOR phosphorylation is mediated by the PI3K/Akt pathway activation. •The AVP-induced mTOR phosphorylation inhibited autophagy and stimulated cell proliferation. -- Abstract: Mammalian target of rapamycin (mTOR) complex is a key regulator of autophagy, cell growth and proliferation. Here, we studied the effects of arginine vasopressin (AVP) on mTOR activation in vascular smooth muscle cells cultured in high glucose concentration. AVP induced the mTOR phosphorylation in A-10 cells grown in high glucose, in contrast to cells cultured in normal glucose; wherein, only basal phosphorylation was observed. The AVP-induced mTOR phosphorylation was inhibited by a PI3K inhibitor. Moreover, the AVP-induced mTOR activation inhibited autophagy and increased thymidine incorporation in cells grown in high glucose. This increase was abolished by rapamycin which inhibits the mTORC1 complex formation. Our results suggest that AVP stimulates mTOR phosphorylation by activating the PI3K/Akt signaling pathway and, subsequently, inhibits autophagy and raises cell proliferation in A-10 cells maintained in high glucose concentration.

  20. The Effects of High Concentrations of Vitamin C on Cancer Cells

    Directory of Open Access Journals (Sweden)

    Seyeon Park

    2013-09-01

    Full Text Available The effect of high doses of vitamin C for the treatment of cancer has been controversial. Our previous studies, and studies by others, have reported that vitamin C at concentrations of 0.25–1.0 mM induced a dose- and time-dependent inhibition of proliferation in acute myeloid leukemia (AML cell lines and in leukemic cells from peripheral blood specimens obtained from patients with AML. Treatment of cells with high doses of vitamin C resulted in an immediate increase in intracellular total glutathione content and glutathione-S transferase activity that was accompanied by the uptake of cysteine. These results suggest a new role for high concentrations of vitamin C in modulation of intracellular sulfur containing compounds, such as glutathione and cysteine. This review, discussing biochemical pharmacologic studies, including pharmacogenomic and pharmacoproteomic studies, presents the different pharmacological effects of vitamin C currently under investigation.

  1. Influence of a High-Pressure Comminution Technology on Concentrate Yields in Copper Ore Flotation Processes

    Directory of Open Access Journals (Sweden)

    Saramak D.

    2014-10-01

    Full Text Available The article concerns the issues of flotation process effectiveness in relationship to the operating conditions of a high-pressure comminution process course. Experimental programme covering a flotation laboratory batch tests was a verification technique of a high-pressure crushing operations course. The most favorable values of flotation concentrate weight recoveries were obtained for the pressing force 6 kN and 4% of the feed moisture. It was also determined the model of the concentrate weight recovery as a function of pressing force in the press and feed moisture content. This model was the basis for the optimization of effects of copper ore flotation processes preceded in high-pressure crushing operation in roller presses.

  2. Fabrication of High Contrast Gratings for the Spectrum Splitting Dispersive Element in a Concentrated Photovoltaic System.

    Science.gov (United States)

    Yao, Yuhan; Liu, He; Wu, Wei

    2015-07-18

    High contrast gratings are designed and fabricated and its application is proposed in a parallel spectrum splitting dispersive element that can improve the solar conversion efficiency of a concentrated photovoltaic system. The proposed system will also lower the solar cell cost in the concentrated photovoltaic system by replacing the expensive tandem solar cells with the cost-effective single junction solar cells. The structures and the parameters of high contrast gratings for the dispersive elements were numerically optimized. The large-area fabrication of high contrast gratings was experimentally demonstrated using nanoimprint lithography and dry etching. The quality of grating material and the performance of the fabricated device were both experimentally characterized. By analyzing the measurement results, the possible side effects from the fabrication processes are discussed and several methods that have the potential to improve the fabrication processes are proposed, which can help to increase the optical efficiency of the fabricated devices.

  3. Spectral and Concentration Sensitivity of Multijunction Solar Cells at High Temperature: Preprint

    Energy Technology Data Exchange (ETDEWEB)

    Friedman, Daniel J.; Steiner, Myles A.; Perl, Emmett E.; Simon, John

    2017-06-14

    We model the performance of two-junction solar cells at very high temperatures of ~400 degrees C and beyond for applications such as hybrid PV/solar-thermal power production, and identify areas in which the design and performance characteristics behave significantly differently than at more conventional near-room-temperature operating conditions. We show that high-temperature operation reduces the sensitivity of the cell efficiency to spectral content, but increases the sensitivity to concentration, both of which have implications for energy yield in terrestrial PV applications. For other high-temperature applications such as near-sun space missions, our findings indicate that concentration may be a useful tool to enhance cell efficiency.

  4. Microstructural Changes in High-Protein Nutrition Bars Formulated with Extruded or Toasted Milk Protein Concentrate.

    Science.gov (United States)

    Banach, J C; Clark, S; Lamsal, B P

    2016-02-01

    Milk protein concentrates with more than 80% protein (that is, MPC80) are underutilized as the primary protein source in high-protein nutrition bars as they impart crumbliness and cause hardening during storage. High-protein nutrition bar texture changes are often associated with internal protein aggregations and macronutrient phase separation. These changes were investigated in model high-protein nutrition bars formulated with MPC80 and physically modified MPC80s. High-protein nutrition bars formulated with extruded MPC80s hardened slower than those formulated with toasted or unmodified MPC80. Extruded MPC80 had reduced free sulfhydryl group exposure, whereas measurable increases were seen in the toasted MPC80. High-protein nutrition bar textural performance may be related to the number of exposed free sulfhydryl groups in MPC80. Protein aggregations resulting from ingredient modification and high-protein nutrition bar storage were studied with sodium dodecyl sulfate polyacrylamide gel electrophoresis. Disulfide-based protein aggregations and changes in free sulfhydryl concentration were not consistently relatable to high-protein nutrition bar texture change. However, the high-protein nutrition bars formulated with extruded MPC80 were less prone to phase separations, as depicted by confocal laser scanning microscopy, and underwent less texture change during storage than those formulated with toasted or unmodified MPC80.

  5. Adaptation and acclimatization to formaldehyde in methylotrophs capable of high-concentration formaldehyde detoxification.

    Science.gov (United States)

    Chongcharoen, Rotsaman; Smith, Thomas J; Flint, Kenneth P; Dalton, Howard

    2005-08-01

    Formaldehyde is a highly toxic chemical common in industrial effluents, and it is also an intermediate in bacterial metabolism of one-carbon growth substrates, although its role as a bacterial growth substrate per se has not been extensively reported. This study investigated two highly formaldehyde-resistant formaldehyde utilizers, strains BIP and ROS1; the former strain has been used for industrial remediation of formaldehyde-containing effluents. The two strains were shown by means of 16S rRNA characterization to be closely related members of the genus Methylobacterium. Both strains were able to use formaldehyde, methanol and a range of multicarbon compounds as their principal growth substrate. Growth on formaldehyde was possible up to a concentration of at least 58 mM, and survival at up to 100 mM was possible after stepwise acclimatization by growth at increasing concentrations of formaldehyde. At such high concentrations of formaldehyde, the cultures underwent a period of formaldehyde removal without growth before the formaldehyde concentration fell below 60 mM, and growth could resume. Two-dimensional electrophoresis and MS characterization of formaldehyde-induced proteins in strain BIP revealed that the pathways of formaldehyde metabolism, and adaptations to methylotrophic growth, were very similar to those seen in the well-characterized methanol-utilizing methylotroph Methylobacterium extorquens AM1. Thus, it appears that many of the changes in protein expression that allow strain BIP to grow using high formaldehyde concentrations are associated with expression of the same enzymes used by M. extorquens AM1 to process formaldehyde as a metabolic intermediate during growth on methanol.

  6. Circulating adiponectin concentration and body composition are altered in response to high-intensity interval training.

    Science.gov (United States)

    Shing, Cecilia M; Webb, Jessica J; Driller, Matthew W; Williams, Andrew D; Fell, James W

    2013-08-01

    Adiponectin influences metabolic adaptations that would prove beneficial to endurance athletes, and yet to date there is little known about the response of adiponectin concentrations to exercise, and, in particular, the response of this hormone to training in an athlete population. This study aimed to determine the response of plasma adiponectin concentrations to acute exercise after 2 different training programs and to determine the influence of the training on body composition. Seven state-level representative rowers (age: 19 ± 1.2 years [mean ± SD], height: 1.77 ± 0.10 m, body mass: 74.0 ± 10.7 kg, VO2peak 62.1 ± 7.0 ml·kg·min) participated in the double-blind, randomized crossover investigation. Rowers performed an incremental graded exercise test before and after completing 4 weeks of high-intensity interval ergometer training and 4 weeks of traditional ergometer rowing training. Rowers' body composition was assessed at baseline and after each training program. Significant increases in plasma adiponectin concentration occurred in response to maximal exercise after completion of the high-intensity interval training (p = 0.016) but not after traditional ergometer rowing training (p = 0.69). The high-intensity interval training also resulted in significant increases in mean 4-minute power output (p = 0.002) and VO2peak (p = 0.05), and a decrease in body fat percentage (p = 0.022). Mean 4-minute power output, VO2peak, and body fat percentage were not significantly different after 4 weeks of traditional ergometer rowing training (p > 0.05). Four weeks of high-intensity interval training is associated with an increase in adiponectin concentration in response to maximal exercise and a reduction in body fat percentage. The potential for changes in adiponectin concentration to reflect positive training adaptations and athlete performance level should be further explored.

  7. Serum POP concentrations are highly predictive of inner blubber concentrations at two extremes of body condition in northern elephant seals.

    Science.gov (United States)

    Peterson, Michael G; Peterson, Sarah H; Debier, Cathy; Covaci, Adrian; Dirtu, Alin C; Malarvannan, Govindan; Crocker, Daniel E; Costa, Daniel P

    2016-11-01

    Long-lived, upper trophic level marine mammals are vulnerable to bioaccumulation of persistent organic pollutants (POPs). Internal tissues may accumulate and mobilize POP compounds at different rates related to the body condition of the animal and the chemical characteristics of individual POP compounds; however, collection of samples from multiple tissues is a major challenge to ecotoxicology studies of free-ranging marine mammals and the ability to predict POP concentrations in one tissue from another tissue remains rare. Northern elephant seals (Mirounga angustirostris) forage on mesopelagic fish and squid for months at a time in the northeastern Pacific Ocean, interspersed with two periods of fasting on land, which results in dramatic seasonal fluctuations in body condition. Using northern elephant seals, we examined commonly studied tissues in mammalian toxicology to describe relationships and determine predictive equations among tissues for a suite of POP compounds, including ΣDDTs, ΣPCBs, Σchlordanes, and ΣPBDEs. We collected paired blubber (inner and outer) and blood serum samples from adult female and male seals in 2012 and 2013 at Año Nuevo State Reserve (California, USA). For females (N = 24), we sampled the same seals before (late in molting fast) and after (early in breeding fast) their approximately seven month foraging trip. For males, we sampled different seals before (N = 14) and after (N = 15) their approximately four month foraging trip. We observed strong relationships among tissues for many, but not all compounds. Serum POP concentrations were strong predictors of inner blubber POP concentrations for both females and males, while serum was a more consistent predictor of outer blubber for males than females. The ability to estimate POP blubber concentrations from serum, or vice versa, has the potential to enhance toxicological assessment and physiological modeling. Furthermore, predictive equations may illuminate commonalities or

  8. Lidar detection of high concentrations of ozone and aerosol transported from northeastern Asia over Saga, Japan

    Science.gov (United States)

    Uchino, Osamu; Sakai, Tetsu; Izumi, Toshiharu; Nagai, Tomohiro; Morino, Isamu; Yamazaki, Akihiro; Deushi, Makoto; Yumimoto, Keiya; Maki, Takashi; Tanaka, Taichu Y.; Akaho, Taiga; Okumura, Hiroshi; Arai, Kohei; Nakatsuru, Takahiro; Matsunaga, Tsuneo; Yokota, Tatsuya

    2017-02-01

    To validate products of the Greenhouse gases Observing SATellite (GOSAT), we observed vertical profiles of aerosols, thin cirrus clouds, and tropospheric ozone with a mobile-lidar system that consisted of a two-wavelength (532 and 1064 nm) polarization lidar and a tropospheric ozone differential absorption lidar (DIAL). We used these lidars to make continuous measurements over Saga (33.24° N, 130.29° E) during 20-31 March 2015. High ozone and high aerosol concentrations were observed almost simultaneously in the altitude range 0.5-1.5 km from 03:00 to 20:00 Japan Standard Time (JST) on 22 March 2015. The maximum ozone volume mixing ratio was ˜ 110 ppbv. The maxima of the aerosol extinction coefficient and optical depth at 532 nm were 1.2 km-1 and 2.1, respectively. Backward trajectory analysis and the simulations by the Model of Aerosol Species IN the Global AtmospheRe (MASINGAR) mk-2 and the Meteorological Research Institute Chemistry-Climate Model, version 2 (MRI-CCM2), indicated that mineral dust particles from the Gobi Desert and an air mass with high ozone and aerosol (mainly sulfate) concentrations that originated from the North China Plain could have been transported over the measurement site within about 2 days. These high ozone and aerosol concentrations impacted surface air quality substantially in the afternoon of 22 March 2015. After some modifications of its physical and chemical parameters, MRI-CCM2 approximately reproduced the high ozone volume mixing ratio. MASINGAR mk-2 successfully predicted high aerosol concentrations, but the predicted peak aerosol optical thickness was about one-third of the observed value.

  9. Sulfuric acid doped poly diaminopyridine/graphene composite to remove high concentration of toxic Cr(VI).

    Science.gov (United States)

    Dinda, Diptiman; Kumar Saha, Shyamal

    2015-06-30

    Sulfuric acid doped diaminopyridine polymers are synthesized in situ on graphene oxide surface via mutual oxidation-reduction technique. Exploiting large and highly porous surface, we have used this polymer composite as an adsorbent to remove high concentration of toxic Cr(VI) from water. It shows very high adsorption capacity (609.76 mg g(-1)) during removal process. The composite takes only 100 min to remove high concentration of 500 mg L(-1) Cr(VI) from water. Interesting features for this material is the enhancement of removal efficiency at lower acidic condition due to the formation of acid doped emeraldine salt during polymerization. XPS and AAS measurements reveal that our prepared material mainly follows reduction mechanism at higher acidic condition while anions exchange mechanism at lower acidic condition during the removal experiments. Good recycling ability with ∼ 92% removal efficiency after fifth cycle is also noticed for this material. Easy preparation, superior stability in acidic condition, remarkable removal efficiency and excellent recycling ability make this polymer composite an efficient material for modern filtration units in waste water purification. Copyright © 2015 Elsevier B.V. All rights reserved.

  10. Material and Optical Design Rules for High Performance Luminescent Solar Concentrators

    Science.gov (United States)

    Bronstein, Noah Dylan

    This dissertation will highlight a path to achieve high photovoltaic conversion efficiency in luminescent solar concentrators, devices which absorb sunlight with a luminescent dye and then re-emit it into a waveguide where it is ultimately collected by a photovoltaic cell. Luminescent concentrators have been studied for more than three decades as potential low-cost but not high efficiency photovoltaics. Astute application of the blackbody radiation law indicates that photonic design is necessary to achieve high efficiency: a reflective filter must be used to trap luminescence at all angles while allowing higher energy photons to pass through. In addition, recent advances in the synthesis of colloidal nanomaterials have created the possibility for lumophores with broad absorption spectra, narrow-bandwidth emission, high luminescence quantum yield, tunable Stokes shifts and tunable Stokes ratios. Together, these factors allow luminescent solar concentrators to achieve the optical characteristics necessary for high efficiency. We have fabricated and tested the first generation of these devices. Our experiments demonstrate that the application of carefully matched photonic mirrors and luminescent quantum dots can allow luminescent concentration factors to reach record values while maintaining high photon collection efficiency. Finally, the photonic mirror dramatically mitigates the negative impact of scattering in the waveguide, allowing efficient photon collection over distances much longer than the scattering length of the waveguide. After demonstrating the possibility for high performance, we theoretically explore the efficacy of luminescent concentrators with dielectric reflectors as the high-bandgap top-junctions in two-junction devices. Simple thermodynamic calculations indicate that this approach can be nearly as good as a traditional vertically stacked tandem. The major barriers to such a device are the optical design of narrow-bandwidth, angle

  11. Treatment of retinal detachment due to macular hole in high myopia by vitrectomy with posterior sclera reinforcement

    Directory of Open Access Journals (Sweden)

    Hui-Ru Lin

    2015-05-01

    Full Text Available AIM: To evaluate the efficacy of the method of vitrectomy combined with posterior sclera reinforcement for retinal detachment due to macular hole in high myopia.METHODS: From January 2012 to December 2013, in 45 eyes of 45 high myopic patients with retinal detachment due to macular hole, 28 eyes were in group A of vitrectomy with posterior sclera reinforcement and 17 eyes were in group B of vitrectomy. Preoperative examinations included visual acuity, intraocular pressure, indirect ophthalmoscopy and OCT were performed. In follow-up 6 to 12mo, postoperative examinations of visual acuity, OCT were performed and effects of retinal reattachment and macular hole closure were compared between the two groups. RESULTS:(1Postoperative examinations: visual acuity was 1.19±0.39 in group A and 1.51±0.34 in group B. The differences were statistically significant(PP>0.05.(3The macular hole closure rate was 82% in group A and 53% in group B. The differences were statistically significant(PCONCLUSION: The treatment of vitrectomy with posterior sclera reinforcement is safe and feasible, which could improve visual acuity and increase the rate of macular hole closure in treating retinal detachment due to macular hole in high myopia.

  12. Effect of Temperature on Chinese Rice Wine Brewing with High Concentration Presteamed Whole Sticky Rice

    Directory of Open Access Journals (Sweden)

    Dengfeng Liu

    2014-01-01

    Full Text Available Production of high quality Chinese rice wine largely depends on fermentation temperature. However, there is no report on the ethanol, sugars, and acids kinetics in the fermentation mash of Chinese rice wine treated at various temperatures. The effects of fermentation temperatures on Chinese rice wine quality were investigated. The compositions and concentrations of ethanol, sugars, glycerol, and organic acids in the mash of Chinese rice wine samples were determined by HPLC method. The highest ethanol concentration and the highest glycerol concentration both were attained at the fermentation mash treated at 23°C. The highest peak value of maltose (90 g/L was obtained at 18°C. Lactic acid and acetic acid both achieved maximum values at 33°C. The experimental results indicated that temperature contributed significantly to the ethanol production, acid flavor contents, and sugar contents in the fermentation broth of the Chinese rice wines.

  13. Study of dopant concentrations on thermal induced mode instability in high power fiber amplifiers

    CERN Document Server

    Tao, Rumao; Wang, Xiaolin; Zhou, Pu; Liu, Zejin

    2015-01-01

    Dependence of mode instabilities (MI) on ytterbium dopant concentrations in high power fiber amplifiers has been investigated. It is theoretically shown that, by only varying the fiber length to maintain the same total small-signal pump absorption, the MI threshold is independent of dopant concentration. MI thresholds of gain fibers with ytterbium dopant concentration of 5.93X10^25/m3 and 1.02X10^26/m3 have been measured, which exhibit similar thresholds and agree with theoretical results. The result indicates that heavy doping of active fiber can be adopted to suppress nonlinear effects without decreasing MI threshold, which provides a method of maximizing the power output of fiber laser, taking into account the stimulated Brillouin scattering, stimulated Raman Scattering, and MI thresholds simultaneously.

  14. Determination of Ge content in high concentration Ge-doped Czochralski Si single crystals by FTIR

    Institute of Scientific and Technical Information of China (English)

    JIANG Zhongwei; ZHANG Weilian; NIU Xinhuan

    2005-01-01

    SiGe single crystals with different Ge concentrations were measured by Fourier transform infrared (FTIR) spectroscopy at room temperature (RT) and 10 K. A new peak appears at the wave number of 710 cm-1 and the spectroscopy becomes clearer with an increase in Ge content. The absorption strength and wave sharp of the 710 cm-1 peak are independent of temperature. The relation of the absorption coefficient amax, the band width of half maximum (BWHM) W1/2 of the 710 cm-1 peak, and the Ge concentration is determined with the Ge content obtained by SEM-EDX. The conversion factor is k = 1.211 at 10 K. Therefore, the Ge content in high concentration Ge doped CZ-Si single crystals can be determined by FTIR.

  15. Thermodynamically consistent description of the hydrodynamics of free surfaces covered by insoluble surfactants of high concentration

    CERN Document Server

    Thiele, Uwe; Plapp, Mathis

    2012-01-01

    In this paper we propose several models that describe the dynamics of liquid films which are covered by a high concentration layer of insoluble surfactant. First, we briefly review the 'classical' hydrodynamic form of the coupled evolution equations for the film height and surfactant concentration that are well established for small concentrations. Then we re-formulate the basic model as a gradient dynamics based on an underlying free energy functional that accounts for wettability and capillarity. Based on this re-formulation in the framework of nonequilibrium thermodynamics, we propose extensions of the basic hydrodynamic model that account for (i) nonlinear equations of state, (ii) surfactant-dependent wettability, (iii) surfactant phase transitions, and (iv) substrate-mediated condensation. In passing, we discuss important differences to most of the models found in the literature.

  16. Effect of tapioca starch and amyloglucosidase concentration on very high gravity simultaneous saccharification and fermentation (VHG-SSF) of bioethanol

    Science.gov (United States)

    Sugih, A. K.; Santoso, I. V.; Kristijarti, A. P.

    2015-12-01

    Tapioca starch is isolated from the root of cassava plant (Manihot esculenta). It is produced in a large quantity in Indonesia and other south east Asian countries. Tapioca starch has been commonly used as a feedstock for food as well as non-food industries. Due to its high carbohydrate content, tapioca starch has the potentiality to be used as a raw material for bioethanol production. In this research, a novel approach (Very High Gravity Simultaneous Sacharification and Fermentation/ VHG-SSF) to synthesise highly concentrated ethanol from tapioca starch was investigated. Tapioca starch suspension was first gelatinised for two hours at 90°C and hydrolised at the same temperature for another two hours using commercial α- amylase (Liquozyme Supra, 0.16%-v/ w starch). The pretreated suspension was sterilised and mixed with nitrogenous supplement. In order to start the fermentation, Saccharomyces cereviseae NRRL Y-132 inoculum (10%-v/v; 107 cells/ ml) and commercial amyloglucosidase (Dextrozyme GA, 35-105 AGU/ g starch) were added to the mixture. The initial total carbohydrate, yeast extract, and peptone concentrations of the fermentation broths were 30-40 %-w/v, 1%-w/v, and 2%-w/v, respectively. VHG-SSF was allowed to proceed for 6 days at 30°C with rotary shaker speed of 100 rpm. The concentration of glucose and ethanol during fermentation was monitored using HPLC. The experimental result shows that tapioca starch has been successfully converted to ethanol with a final concentration of 10.12-16.14 %-w/v, which is corresponding to yield of 34.68-56.83 %-w ethanol/ w-converted sugar. The result suggests that VHG-SSF is a prospective method to synthesise bioethanol from tapioca starch.

  17. Changing climate and nutrient transfers: Evidence from high temporal resolution concentration-flow dynamics in headwater catchments.

    Science.gov (United States)

    Ockenden, M C; Deasy, C E; Benskin, C McW H; Beven, K J; Burke, S; Collins, A L; Evans, R; Falloon, P D; Forber, K J; Hiscock, K M; Hollaway, M J; Kahana, R; Macleod, C J A; Reaney, S M; Snell, M A; Villamizar, M L; Wearing, C; Withers, P J A; Zhou, J G; Haygarth, P M

    2016-04-01

    We hypothesise that climate change, together with intensive agricultural systems, will increase the transfer of pollutants from land to water and impact on stream health. This study builds, for the first time, an integrated assessment of nutrient transfers, bringing together a) high-frequency data from the outlets of two surface water-dominated, headwater (~10km(2)) agricultural catchments, b) event-by-event analysis of nutrient transfers, c) concentration duration curves for comparison with EU Water Framework Directive water quality targets, d) event analysis of location-specific, sub-daily rainfall projections (UKCP, 2009), and e) a linear model relating storm rainfall to phosphorus load. These components, in combination, bring innovation and new insight into the estimation of future phosphorus transfers, which was not available from individual components. The data demonstrated two features of particular concern for climate change impacts. Firstly, the bulk of the suspended sediment and total phosphorus (TP) load (greater than 90% and 80% respectively) was transferred during the highest discharge events. The linear model of rainfall-driven TP transfers estimated that, with the projected increase in winter rainfall (+8% to +17% in the catchments by 2050s), annual event loads might increase by around 9% on average, if agricultural practices remain unchanged. Secondly, events following dry periods of several weeks, particularly in summer, were responsible for high concentrations of phosphorus, but relatively low loads. The high concentrations, associated with low flow, could become more frequent or last longer in the future, with a corresponding increase in the length of time that threshold concentrations (e.g. for water quality status) are exceeded. The results suggest that in order to build resilience in stream health and help mitigate potential increases in diffuse agricultural water pollution due to climate change, land management practices should target

  18. Biodegradation of high concentrations of phenol by baker’s yeast in anaerobic sequencing batch reactor

    Directory of Open Access Journals (Sweden)

    Ali Asghar Najafpoor

    2015-06-01

    Full Text Available Background: Phenol, as a pure substance, is used in many fields because of its disinfectant, germicidal, local anesthetic, and peptizing properties. Aqueous solutions of phenol are produced as waste in industries and discharged into the environment. Therefore, elevated concentrations of phenol may be found in air or water because of industrial discharge or the use of phenolic products. Method: The strains of Saccharomyces cerevisiae used in this project were natural strains previously purchased from Razavy company. They were grown at 30°C on Petri plates containing yeast extract glucose (YGC and then purified by being spread onto new plates, and isolated colonies were obtained. These colonies provided the basis of selection. Prepared strains were applied in anaerobic sequencing batch reactors (ASBRs as first seed. The experiment conditions were optimized using response surface methodology (RSM. After the determined runs were performed using Design-Expert software, data were analyzed using mentioned software as well. Results: This study evaluated the capability of baker’s yeast to remove phenol in high concentrations. The tested strains showed excellent tolerance to phenol toxicity at concentrations up to 6100 mg/L. Study of the batch degradation process showed that the phenol removal rate could exceed 99.9% in 24 hours at a concentration of 1000 mg/L. The results showed catechol is the first intermediate product of phenol degradation. In survey results of the Design–Expert software, R2 and Adeq precision were 0.97 and 25.65, respectively. Conclusion: The results demonstrated that ASBR performs robustly under variable influent concentrations of inhibitory compounds. The high removal performance despite the high phenol concentration may be a result of reactor operating strategies. Based on the progressive increase of inlet phenol concentration, allowing for an enhanced biomass acclimation in a short time, results at the microbiological levels

  19. Generation of high-titer viral preparations by concentration using successive rounds of ultracentrifugation

    Directory of Open Access Journals (Sweden)

    Ichim Christine V

    2011-08-01

    Full Text Available Abstract Background Viral vectors provide a method of stably introducing exogenous DNA into cells that are not easily transfectable allowing for the ectopic expression or silencing of genes for therapeutic or experimental purposes. However, some cell types, in particular bone marrow cells, dendritic cells and neurons are difficult to transduce with viral vectors. Successful transduction of such cells requires preparation of highly concentrated viral stocks, which permit a high virus concentration and multiplicity of infection (MOI during transduction. Pseudotyping with the vesicular stomatitis virus G (VSV-G envelope protein is common practice for both lentiviral and retroviral vectors. The VSV-G glycoprotein adds physical stability to retroviral particles, allowing concentration of virus by high-speed ultracentrifugation. Here we describe a method report for concentration of virus from large volumes of culture supernatant by means of successive rounds of ultracentrifugation into the same ultracentrifuge tube. Method Stable retrovirus producer cell lines were generated and large volumes of virus-containing supernatant were produced. We then tested the transduction ability of virus following varying rounds of concentration by ultra-centrifugation. In a second series of experiments lentivirus-containing supernatant was produced by transient transfection of 297T/17 cells and again we tested the transduction ability of virus following multiple rounds of ultra-centrifugation. Results We report being able to centrifuge VSV-G coated retrovirus for as many as four rounds of ultracentrifugation while observing an additive increase in viral titer. Even after four rounds of ultracentrifugation we did not reach a plateau in viral titer relative to viral supernatant concentrated to indicate that we had reached the maximum tolerated centrifugation time, implying that it may be possible to centrifuge VSV-G coated retrovirus even further should it be necessary

  20. Case study of the 9 April 2009 ‘brown’ cloud: Observations of usually high cloud droplet concentrations in Saudi Arabia

    Science.gov (United States)

    Delene, D. J.

    2009-12-01

    Cloud droplets nucleate on aerosol particles termed cloud condensation nuclei (CCN). It is well known that a larger number concentration of CCN results in a larger number concentration of droplets in developing cumulus clouds. However, the conditions where dust particles can serve as cloud condensation nuclei (CCN) and hence change cloud droplet concentration and precipitation formation processes is uncertain. Aircraft measurements of cloud droplet concentration between 13:20 and 13:30 UTC during the 9 April 2009 flight near Riyadh, Saudi Arabia, show total cloud droplet concentration (3-50 µm in diameter) of 800 to 1200 #/cm-3 at a altitude of 18000 ft. Typical cloud droplet concentration for this type of cloud in the Riyadh region is approximately 400 #/cm-3 and is typical of observation made between 13:00 and 13:20 UTC during the 9 April 2009 flight at 18,000 ft. Photographs of ice accumulation on the unprotected leading edge of the aircraft’s wing due to the freezing of super cooled droplets show a color changed from white during the time of low droplet number condensation to brown during the high droplet number concentration. It is hypothesized that high droplet number concentration observations were the result of ingestion of a large about of dust particles by the cloud. : Case Study of the 9 April 2009 ‘Brown’ Cloud: Observations of Usually High Cloud Droplet Concentrations in Saudi Arabia.

  1. The effects of high temperature level on square Bt protein concentration of Bt cotton

    Institute of Scientific and Technical Information of China (English)

    WANG Jun; CHEN Yuan; YAO Meng-hao; LI Yuan; WEN Yu-jin; ZHANG Xiang; CHEN De-hua

    2015-01-01

    Higher bol worm survival rates were detected after high temperature presented during square period in Bt cotton. The objective of this study was to investigate the effects of high temperature level on the Bt efifcacy of two different types of Bt cotton cultivars at squaring stage. During the 2011 to 2013 cotton growth seasons, high temperature treatments ranged from 34 to 44°C in climate chambers, and ifeld experiments under high temperature weather with various temperature levels were conducted to investigate the effects of the high temperature level on square Bt protein concentration and nitrogen metabolism. The climate chamber experiments showed that the square insecticidal protein contents reduced after 24 h elevated temperature treatments for both cultivars, whereas signiifcant declines of the square insecticidal protein contents were detected at temperature >38°C, and only slightly numerical reductions were observed when temperature below 38°C. Similar high temperature responses were also observed at the two ifeld experimental sites in 2013. Correspondingly, high temperature below 38°C seems have little effect on the square amino acid concentrations, soluble protein contents, glutam-ic-pyruvic transaminase (GPT) and glutamic-oxalacetic transaminase (GOT) activities as wel as protease and peptidase activities; however, when the temperature was above 38°C, reduced soluble protein contents, enhanced amino acid con-centrations, decreased GPT and GOT activities, bolstered protease and peptidase activities in square were detected. In general, the higher the temperature is (>38°C), the larger the changes for the above compound contents and key enzymes activities of the square protein cycle. The ifndings indicated that the unstable insect resistance of the square was related to high temperature level during square stage.

  2. Gulf of Bothnia receives high concentrations of potentially toxic metals from acid sulphate soils

    Energy Technology Data Exchange (ETDEWEB)

    Roos, M.; Aastroem, M. [Kalmar Univ., Kalmar (Sweden)

    2006-07-01

    An estimated 460000 ha of acid sulphate soil (AS soil) occur within the river catchments bordering the Gulf of Bothnia in Finland and Sweden. This soil type exists because extensive areas of sulphide-bearing Holocene sediments have been drained for agricultural purposes, resulting in oxidation of metal sulphides to sulphuric acid and the concomitant formation of these acidic, environmentally-unfriendly soils. The aim of this study was to compare median values of metal concentrations in rivers discharging into the Gulf of Bothnia and obtain a uniform picture of to what extent these rivers are affected by AS-soil leaching. Dissolved element concentrations for arsenic (As), cadmium (Cd), chromium (Cr), iron (Fe), nickel (Ni), lead (Pb), and zinc (Zn) were determined in 47 rivers (catchment size > 500 km2) discharging into Gulf of Bothnia (a few into Gulf of Finland) along the coastline of Finland and Sweden. Water chemistry data was obtained from the Environmental Information System (HERTTA) database at the Finnish Environment Institute, the publicly available online database at Swedish University of Agricultural Sciences, Department of Environmental Assessment, and from a previous study of the authors. One area in central-western Finland proved to have highly elevated concentrations of Cd, Ni and Zn, and they all occurred with a similar spatial pattern and had the highest concentrations in rivers Teuvanjoki and Maalahdenjoki. This is caused by AS-soil leaching. The metalloid As and the metals Cr, Fe, Pb did not display this pattern and are, therefore, in line with previous studies, not leached abundantly from the AS soils, although they overall occur at somewhat higher concentrations in the Finnish as compared with those in the Swedish rivers. Thorough planning of land-use operations (e.g. land reclamation through ditching, dredging of rivers and estuaries, etc.) in AS-soil landscapes should be necessary, which is currently not the case, to reduce the high

  3. Impact of High Concentration Solutions on Hydraulic Properties of Geosynthetic Clay Liner Materials

    Directory of Open Access Journals (Sweden)

    Lei Liu

    2012-11-01

    Full Text Available This study focuses on the impact of landfill high concentration solutions erosion on geosynthetic clay liner (GCL materials permeability. The permeation tests on the GCL, submerged using different kinds of solutions with different concentrations, were carried out systematically by taking these chemical solutions as permeant liquids. Based on seasonal variations of ion concentrations in Chenjiachong landfill leachate (Wuhan Province, CaCl2, MgCl2, NaCl, and KCl were selected as chemical attack solutions to carry out experimental investigations under three concentrations (50 mM, 100 mM, 200 mM and soak times (5, 10, and 20 days. The variation law of the GCL hydraulic conductivity under different operating conditions was analyzed. The relationship between GCL hydraulic conductivity, chemical solutions categories, concentrations, and soak times were further discussed. The GCL hydraulic conductivity, when soaked and permeated with high concentration chemical solutions, increases several times or exceeds two orders of magnitude, as compared with the permeation test under normal conditions that used water as the permeant liquid. This reveals that GCL is very susceptible to chemical attack. For four chemical solutions, the chemical attack effect on GCL hydraulic conductivity is CaCl2 > MgCl2 > KCl > NaCl. The impact of soak times on GCL hydraulic conductivity is the cooperative contribution of the liner chemical attack reaction and hydration swelling. A longer soak time results in a more advantageous hydration swelling effect. The chemical attack reaction restrains the hydration swelling of the GCL. Moreover, the GCL hydraulic conductivity exponentially decreases with the increased amplitude of thickness.

  4. Calculation of multicomponent ionic diffusion from zero to high concentration: II. Inclusion of associated ion species

    Science.gov (United States)

    Felmy, Andrew R.; Weare, John H.

    1991-01-01

    This paper presents a theoretical model of multicomponent ionic diffusion which is valid to high concentration for systems which show ion association. The development is completely general for species which do not react with the solvent. It is demonstrated that the Onsager phenomenological coefficients for associated ion species can be unambiguously determined only in solutions where the concentration of these species can be independently measured. In all other instances, only combinations of the Onsager coefficients for the bare ions and the ion pairs can be experimentally determined. The results of our formulations are contrasted with those of more simplified models for systems containing Na 2SO 4 and MgSO 4, as well as for multicomponent natural seawater. The differences between our model and simplified models are significant, especially at high concentration. Inconsistencies which may develop with the use of the simplified approaches are demonstrated. Our approach requires considerable data which are not available at temperatures other than 25°C. Therefore, other approaches which are based only on data at infinite dilution are of great interest. We show here that, if chemical potential derivatives are included in the infinite dilution model of Nernst and Hartley which uses only infinite dilution mobilities, the model can be extended to slightly concentrated solutions. This extended Nernst-Hartley model gives good agreement with all of the existing experimental mutual diffusion coefficient data at concentrations below about 0.2 M in the six component system Na-K-Ca-Mg-Cl-SO 4-H 2O. This may be the most reliable way to extend infinite dilution data into more concentrated regions. In the systems we have studied, the inclusion of ion-association species for weakly interacting species does not appear to provide significant improvement over our generalized Nernst-Hartley model.

  5. Iodine Treatment in Children with Subclinical Hypothyroidism Due to Chronic Iodine Deficiency Decreases Thyrotropin and C-Peptide Concentrations and Improves the Lipid Profile

    NARCIS (Netherlands)

    Zimmermann, M.B.; Aeberli, I.; Boonstra, A.; Grimci, L.; Bridson, J.; Chaouki, N.; Mbhenyane, X.; Jooste, P.L.

    2009-01-01

    Background: Chronic iodine deficiency (ID) increases thyrotropin (TSH) concentrations and produces a thyroid hormone pattern consistent with subclinical hypothyroidism (ScH). ScH may be associated with cardiovascular disease risk factors. Thus, the study aim was to determine if iodine treatment of c

  6. Iodine Treatment in Children with Subclinical Hypothyroidism Due to Chronic Iodine Deficiency Decreases Thyrotropin and C-Peptide Concentrations and Improves the Lipid Profile

    NARCIS (Netherlands)

    Zimmermann, M.B.; Aeberli, I.; Boonstra, A.; Grimci, L.; Bridson, J.; Chaouki, N.; Mbhenyane, X.; Jooste, P.L.

    2009-01-01

    Background: Chronic iodine deficiency (ID) increases thyrotropin (TSH) concentrations and produces a thyroid hormone pattern consistent with subclinical hypothyroidism (ScH). ScH may be associated with cardiovascular disease risk factors. Thus, the study aim was to determine if iodine treatment of

  7. Relationship between tap water hardness, magnesium, and calcium concentration and mortality due to ischemic heart disease or stroke in the Netherlands

    NARCIS (Netherlands)

    Leurs, L.J.; Schouten, L.J.; Mons, M.N.; Goldbohm, R.A.; Brandt, P.A. van den

    2010-01-01

    BACKGROUND: Conflicting results on the relationship between the hardness of drinking water and mortality related to ischemic heart disease (IHD) or stroke have been reported. OBJECTIVES: We investigated the possible association between tap water calcium or magnesium concentration and total hardness

  8. Relationship between tap water hardness, magnesium, and calcium concentration and mortality due to ischemic heart disease or stroke in the Netherlands

    NARCIS (Netherlands)

    Leurs, L.J.; Schouten, L.J.; Mons, M.N.; Goldbohm, R.A.; Brandt, P.A. van den

    2010-01-01

    BACKGROUND: Conflicting results on the relationship between the hardness of drinking water and mortality related to ischemic heart disease (IHD) or stroke have been reported. OBJECTIVES: We investigated the possible association between tap water calcium or magnesium concentration and total hardness

  9. Impact of family planning programs in reducing high-risk births due to younger and older maternal age, short birth intervals, and high parity.

    Science.gov (United States)

    Brown, Win; Ahmed, Saifuddin; Roche, Neil; Sonneveldt, Emily; Darmstadt, Gary L

    2015-08-01

    Several studies show that maternal and neonatal/infant mortality risks increase with younger and older maternal age (34 years), high parity (birth order >3), and short birth intervals (Oaxaca decomposition technique, we then examine the contributions of family planning program, economic development (GDP per capita), and educational improvement (secondary school completion rate) on the progress of MCPR in order to link the net contribution of family planning program to the reduction of high-risk births mediated through contraceptive use. Countries that had the fastest progress in improving MCPR experienced the greatest declines in high-risk births due to short birth intervals (3), and older maternal age (>35 years). Births among younger women <18 years, however, did not decline significantly during this period. The decomposition analysis suggests that 63% of the increase in MCPR was due to family planning program efforts, 21% due to economic development, and 17% due to social advancement through women's education. Improvement in MCPR, predominately due to family planning programs, is a major driver of the decline in the burden of high-risk births due to high parity, shorter birth intervals, and older maternal age in developing countries. The lack of progress in the decline of births in younger women <18 years of age underscores the need for more attention to ensure that quality contraceptive methods are available to adolescent women in order to delay first births. This study substantiates the significance of family planning programming as a major health intervention for preventing high-risk births and associated maternal and child mortality, but it highlights the need for concerted efforts to strengthen service provision for adolescents.

  10. Thermal stability of high concentration lysozyme across varying pH: A Fourier Transform Infrared study

    Directory of Open Access Journals (Sweden)

    Sathyadevi Venkataramani

    2013-01-01

    Full Text Available Aim: The current work is aimed at understanding the effect of pH on the thermal stability of hen egg white lysozyme (HEWL at high concentration (200 mg/mL. Materials and Methods: Fourier Transform Infrared (FTIR Spectroscopy with modified hardware and software to overcome some of the traditional challenges like water subtraction, sample evaporation, proper purging etc., are used in this study. Results: HEWL was subjected to thermal stress at pH 3.0-7.0 between 25°C and 95°C and monitored by FTIR spectroscopy. Calculated T m values showed that the enzyme exhibited maximum thermal stability at pH 5.0. Second derivative plots constructed in the amide I region suggested that at pH 5.0 the enzyme possessed higher amount of α-helix and lower amount of aggregates, when compared to other pHs. Conclusions: Considering the fact that HEWL has attractive applications in various industries and being processed under different experimental conditions including high temperatures, our work is able to reveal the reason behind the pH dependent thermal stability of HEWL at high concentration, when subjected to heat denaturation. In future, studies should aim at using various excipients that may help to increase the stability and activity of the enzyme at this high concentration.

  11. Carbon assimilation in Eucalyptus urophylla grown under high atmospheric CO2 concentrations: A proteomics perspective.

    Science.gov (United States)

    Santos, Bruna Marques Dos; Balbuena, Tiago Santana

    2017-01-06

    Photosynthetic organisms may be drastically affected by the future climate projections of a considerable increase in CO2 concentrations. Growth under a high concentration of CO2 could stimulate carbon assimilation-especially in C3-type plants. We used a proteomics approach to test the hypothesis of an increase in the abundance of the enzymes involved in carbon assimilation in Eucalyptus urophylla plants grown under conditions of high atmospheric CO2. Our strategy allowed the profiling of all Calvin-Benson cycle enzymes and associated protein species. Among the 816 isolated proteins, those involved in carbon fixation were found to be the most abundant ones. An increase in the abundance of six key enzymes out of the eleven core enzymes involved in carbon fixation was detected in plants grown at a high CO2 concentration. Proteome changes were corroborated by the detection of a decrease in the stomatal aperture and in the vascular bundle area in Eucalyptus urophylla plantlets grown in an environment of high atmospheric CO2. Our proteomics approach indicates a positive metabolic response regarding carbon fixation in a CO2-enriched atmosphere. The slight but significant increase in the abundance of the Calvin enzymes suggests that stomatal closure did not prevent an increase in the carbon assimilation rates.

  12. Lower Salinomycin Concentration Increases Apoptotic Detachment in High-Density Cancer Cells

    Directory of Open Access Journals (Sweden)

    Sungpil Yoon

    2012-10-01

    Full Text Available The present study identified a novel salinomycin (Sal sensitization mechanism in cancer. We tested whether Sal reduced proliferation in a high-density population by counting attached cell numbers after Sal treatment. Sal reduced proliferation in high-density cell populations. Longer exposure to Sal further reduced proliferation. Sal concentrations of 0.1 and 5 μM had similar sensitization effects, suggesting that Sal toxicity was minimal with longer exposure to a high-density cell population. The results suggest that Sal can be applied at a relatively low concentration for a longer time to overcome drug-resistant solid tumors. The 0.5 μM Sal treatment resulted in fewer attached cells than that of the 5 μM Sal treatment with a longer exposure. The lower Sal concentration mainly increased the number of easily detachable cells on the surface. In particular, 0.5 μM Sal increased cellular detachment of newly produced daughter cells. The easily-detachable cells were undergoing apoptosis. It seems that the 0.5 μM Sal treatment also increased cellular toxicity. These novel findings may contribute to the development of Sal-based therapy for patients with drug-resistant cancer or a high-density solid tumor.

  13. Anaerobic biotransformation of high concentrations of chloroform by an enrichment culture and two bacterial isolates.

    Science.gov (United States)

    Shan, Huifeng; Kurtz, Harry D; Mykytczuk, Nadia; Trevors, Jack T; Freedman, David L

    2010-10-01

    A fermentative enrichment culture (designated DHM-1) was developed that is capable of cometabolically biotransforming high concentrations of chloroform (CF) to nontoxic end products. Two Pantoea spp. were isolated from DHM-1 that also possess this dechlorination capability. Following acclimation to increasing levels of CF, corn syrup-grown DHM-1 was able to transform over 500 mg/liter CF in the presence of vitamin B(12) (approximately 3% of CF on a molar basis) at a rate as high as 22 mg/liter/day in a mineral salts medium. CO, CO(2), and organic acids were the predominant biodegradation products, suggesting that hydrolytic reactions predominate during CF transformation. DHM-1 was capable of growing on corn syrup in the presence of high concentrations of CF (as may be present near contaminant source zones in groundwater), which makes it a promising culture for bioaugmentation. Strains DHM-1B and DHM-1T transform CF at rates similar to that of the DHM-1 enrichment culture. The ability of these strains to grow in the presence of high concentrations of CF appears to be related to alteration of membrane fluidity or homeoviscous and homeophasic adaptation.

  14. Effects of High Ammonium Concentration on Growth and Nutrient Uptake of Lettuce Plants with Solution Culture

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    A nutrition solution experiment was conducted over two months to investigate the response of vegetable crops to high concentrations of ammonium, using lettuce (Lactuca sativa L. cv. Angustana Irish) as a test crop. Ammonium concentrations were designed in 5 levels, ranging from 12 mmol N L-1 to 22 mmol N L-1 and local tap water was used as water source. At the first culture stage (0-9 days), lettuce plants maintained normal growth while the lettuce roots were increasingly impaired. During the subsequent three stages the root structure was greatly damaged, and roots became brown or black through continuous supply of high concentration of ammonium. However, there was no obvious reduction of the aboveground biomass of the plants in the high ammonium treatments compared to those supplied with nitrate alone. In contrast to results obtained in another experiment from us with distilled water, the detrimental effect of high ammonium concentration on lettuce growth was greatly alleviated. Based on the results, it was postulated that the small amount of nitrate and the higher amount of bicarbonate existed in the tap water might mitigate the adverse effects of high ammonium N. The higher bicarbonate content in water and soil has usually been regarded as a major constraint factor limiting plant growth in calcareous soil areas. However, the reaction of bicarbonate to ammonium might produce positively interactive effect on reduction of both damages. The lettuce plants grown in ammonium solutions took up less P, K, Fe, Mn and Cu and more Ca than those grown in the nitrate nutrient solution. In conclusion, the results indicated that the N form imposed an obvious influence on absorption of cations and anions. Supplying ammonium-N stimulated transport of Ca, Mg and Mn to shoots of lettuce.

  15. Concentrations of Cd, Ni, V and Zn in Muscle and Caviar of Persian Sturgeon (Acipenser persicus with Emphasis on Risk Assessment Due to Consumption of Muscle

    Directory of Open Access Journals (Sweden)

    Abdulreza Mashroofeh

    2014-03-01

    Material and Methods: A total number of 24 samples of Persian sturgeon were collected from two important sturgeon fishery zones in Guilan and Mazandaran Provinces and were stored at −20°C until chemical analysis. About one gram of each sample dried was added to 10 ml of concentrated (65% supra-pure HNO3 (Merck, Darmstadt, Germany in a Teflon PTFE tube and then it was incubated for 1 h at 40 °C in a hot block digester, followed by heating at 140 °C for 3 h. The samples digested were diluted to a measured volume using double deionized water. Samples were filtered through Whatman No. 1 filter paper, and the filtrate was stored until metal determination. Results: Mean Cd, Ni, V and Zn concentrations in muscle tissues were 0.005 ± 0.002, 0.06 ± 0.03, 0.13 ± 0.04 and 7.49 ± 3.07 µg/g wet weight basis respectively. The mean Cd, Ni, V and Zn concentrations in caviar samples were 0.007 ± 0.006, 0.09 ± 0.07, 0.12 ± 0.15 and 21.23 ± 5.75 µg/g wet weight basis respectively. Conculation: The mean concentrations of Zn, Cd and V in caviar and muscle samples were less than the permissible limits proposed by the United Kingdom's Ministry of Agriculture, Fisheries and Food (MAFF 2000 and World Health Organization (W.H.O.. The guidelines for Cd, V and Zn are 0.2, 0.5 and 50 µg/g wet weight respectively. Therefore, the measured concentrations for these particular metals are below the published guidelines, and the levels would appear not to constitute any threat to the human population that may consume sturgeon or caviar obtained from these study locations.

  16. Deer exposed to exceptionally high concentrations of lead near the continental mine in Idaho, USA

    Science.gov (United States)

    Beyer, W.N.; Gaston, G.; Brazzle, R.; O'Connell, A.F.; Audet, D.J.

    2007-01-01

    Habitat surrounding the inactive Continental Mine in northern Idaho, USA, supports bear (Ursus arctos, Ursus americanus), moose (Alces alces), elk (Cervus elaphus), woodland caribou (Rangifer tarandus caribou), and abundant mule (Odocoileus hemionus) and white-tailed deer (Odocoileus virginianus). Tailings on the mining site were capped and remediated in 2003 to reduce environmental exposure of surrounding soil and sediments of Blue Joe Creek, downslope of the mine. Before capping, the mean Pb concentration in deer pellets collected on-site was 920 mg/kg of Pb (dry wt). This exposure, if chronic, would be comparable to an exposure that could be lethal to cattle or horses. Surprisingly, the mean pellet Pb concentration of 950 mg/kg in 2004 was as high as it was before remediation, and it was related to a high rate of soil ingestion. Mean soil content of the pellets collected from the capped site in 2004 was 22% dry weight, estimated from the acid-insoluble ash, a marker of soil ingestion. Clumps of sand and bits of rock were observed inside some of the pellets, and Pb concentrations in the pellets were correlated (p soil content. Although terrestrial risk assessments generally estimate exposure from diets and from incidentally ingested soil, the deer at this site were directly ingesting contaminated soil or mining waste. The mean Pb concentration of this ingested soil was estimated as 6,700 mg/kg and the maximum as 25,000 mg/kg, well above the Pb concentrations measured in the remediated cap. The deer seemed to be ingesting soil or mining waste from one or more small but highly contaminated sources located beyond the remediated cap.

  17. Enrichment and isolation of Flavobacterium strains with tolerance to high concentrations of cesium ion.

    Science.gov (United States)

    Kato, Souichiro; Goya, Eri; Tanaka, Michiko; Kitagawa, Wataru; Kikuchi, Yoshitomo; Asano, Kozo; Kamagata, Yoichi

    2016-02-17

    Interest in the interaction of microorganisms with cesium ions (Cs(+)) has arisen, especially in terms of their potent ability for radiocesium bioaccumulation and their important roles in biogeochemical cycling. Although high concentrations of Cs(+) display toxic effects on microorganisms, there have been only limited reports for Cs(+)-tolerant microorganisms. Here we report enrichment and isolation of Cs(+)-tolerant microorganisms from soil microbiota. Microbial community analysis revealed that bacteria within the phylum Bacteroidetes, especially Flavobacterium spp., dominated in enrichment cultures in the medium supplemented with 50 or 200 mM Cs(+), while Gammaproteobacteria was dominant in the control enrichment cultures (in the presence of 50 and 200 mM K(+) instead of Cs(+)). The dominant Flavobacterium sp. was successfully isolated from the enrichment culture and was closely related to Flavobacterium chungbukense with 99.5% identity. Growth experiments clearly demonstrated that the isolate has significantly higher tolerance to Cs(+) compared to its close relatives, suggesting the Cs(+)-tolerance is a specific trait of this strain, but not a universal trait in the genus Flavobacterium. Measurement of intracellular K(+) and Cs(+) concentrations of the Cs(+)-tolerant isolate and its close relatives suggested that the ability to maintain low intracellular Cs(+) concentration confers the tolerance against high concentrations of external Cs(+).

  18. High Pb concentration stress on Typha latifolia growth and Pb removal in microcosm wetlands.

    Science.gov (United States)

    Han, Jianqiu; Chen, Fengzhen; Zhou, Yumei; Wang, Chaohua

    2015-01-01

    When constructed wetlands are used to treat high-Pb wastewater, Pb may become a stress to wetland plants, which subsequently reduces treatment performance and the other ecosystem services. To facilitate the design and operation of constructed wetlands for treatment of Pb-rich wastewater, we investigated the irreversible inhibitory level of Pb for Typha latifolia through experiments in microcosm wetlands. Seven horizontal subsurface flow constructed wetlands were built with rectangular plastic tanks and packed with marble chips and sand. All wetlands were transplanted with nine stems of Typha latifolia each. The wetlands were batch operated in a greenhouse with artificial wastewater (10 L each) for 12 days. Influent to the seven wetlands had different concentrations of Pb: 0 mg/L, 10 mg/L, 25 mg/L, 50 mg/L, 100 mg/L, 200 mg/L, and 500 mg/L, respectively. The results suggested that leaf chlorophyll relative content, relative growth rate, photosynthetic characteristics, activities of superoxide dismutase, peroxidase, and content of malondialdehyde were not affected when initial Pb concentration was at 100 mg/L and below. But when initial Pb concentration was above 100 mg/L, all of them were seriously affected. We conclude that high Pb concentrations wastewater could inhibit the growth of Typha latifolia and decrease the removal rate of wetlands.

  19. A modified coaxial electrospinning for preparing fibers from a high concentration polymer solution

    Directory of Open Access Journals (Sweden)

    2011-08-01

    Full Text Available A new process technology modified from conventional coaxial electrospinning process has been developed to prepare polymer fibers from a high concentration solution. This process involves a pure solvent concentrically surrounding polymer fluid in the spinneret. The concentric spinneret was constructed simply by inserting a metal needle through a high elastic silica gel tube. Two syringe pumps were used to drive the core polymer solution and the sheath solvent. Using polyvinylpyrrolidone (PVP as the polymer model, which normally has an electrospinnable concentration of 10% w/v in ethanol, it was possible to electrospin 35% w/v of PVP in the same solvent, when pure N, N-dimethylacetamide (DMAc was used as sheath fluid. The resultant fibers have a smooth surface morphology and good structural uniformity. The diameter of the fibers was 2.0±0.25 µm when the DMAc-to-polymer-solution flow rate ratio was set as 0.1. The process technology reported here opens a new window to tune the polymer fibers obtained by the electrospinning, and is useful for improving productivity of the electrospinning process.

  20. Continuous Ethanol Production with a Membrane Bioreactor at High Acetic Acid Concentrations

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    Päivi Ylitervo

    2014-07-01

    Full Text Available The release of inhibitory concentrations of acetic acid from lignocellulosic raw materials during hydrolysis is one of the main concerns for 2nd generation ethanol production. The undissociated form of acetic acid can enter the cell by diffusion through the plasma membrane and trigger several toxic effects, such as uncoupling and lowered intracellular pH. The effect of acetic acid on the ethanol production was investigated in continuous cultivations by adding medium containing 2.5 to 20.0 g·L−1 acetic acid at pH 5.0, at a dilution rate of 0.5 h−1. The cultivations were performed at both high (~25 g·L−1 and very high (100–200 g·L−1 yeast concentration by retaining the yeast cells inside the reactor by a cross-flow membrane in a membrane bioreactor. The yeast was able to steadily produce ethanol from 25 g·L−1 sucrose, at volumetric rates of 5–6 g·L−1·h−1 at acetic acid concentrations up to 15.0 g·L−1. However, the yeast continued to produce ethanol also at a concentration of 20 g·L−1 acetic acid but at a declining rate. The study thereby demonstrates the great potential of the membrane bioreactor for improving the robustness of the ethanol production based on lignocellulosic raw materials.

  1. High-quality, highly concentrated semiconducting single-wall carbon nanotubes for use in field effect transistors and biosensors.

    Science.gov (United States)

    Li, Wen-Shan; Hou, Peng-Xiang; Liu, Chang; Sun, Dong-Ming; Yuan, Jiangtan; Zhao, Shi-Yong; Yin, Li-Chang; Cong, Hongtao; Cheng, Hui-Ming

    2013-08-27

    We developed a simple and scalable selective synthesis method of high-quality, highly concentrated semiconducting single-wall carbon nanotubes (s-SWCNTs) by in situ hydrogen etching. Samples containing ~93% s-SWCNTs were obtained in bulk. These s-SWCNTs with good structural integrity showed a high oxidation resistance temperature of ~800 °C. Thin-film transistors based on the s-SWCNTs demonstrated a high carrier mobility of 21.1 cm(2) V(-1) s(-1) at an on/off ratio of 1.1 × 10(4) and a high on/off ratio of 4.0 × 10(5) with a carrier mobility of 7.0 cm(2) V(-1) s(-1). A biosensor fabricated using the s-SWCNTs had a very low dopamine detection limit of 10(-18) mol/L at room temperature.

  2. Electro-thermal injuries due to high-current accidents with special regard to the skeletal muscles

    Energy Technology Data Exchange (ETDEWEB)

    Rausch, M.

    1982-02-25

    Seven patients suffering from high-current accidents with different degrees of severity are reported on. Damages to the striped musculature are preferentially considered. When the function of the cellular membrane is affected by an electric current, the Na/sup +//K/sup +/ mechanism collapses due to an increase of membrane permeability for calcium. Depolarisation, development of contractures, changes of the fibrillar structures and decay of the stripes or swelling of the Q (A) substance were found to indicate damage. A particular effect of electrothermal muscle damages is the affection of other organs, e.g. of the kidneys, provoked by an increased chromoprotein production and a higher output of myoglobin and hemoglobin. Since in case of an accident due to electric current affecting the musculature, more acid substances enter the vascular system, an acute renal damage provoked by an alkalinisation of the urine, shall be treated by drugs. In most cases, an anuria, occurring several days after deep burn of musculature, is a so-called constipational anuria, if it is not an anuria induced by a decrease of blood pressure or by shock. The therapy of wounds due to electrical burning depends on the size of the affected skin area and down to which depth the tissue is burnt. Particular attention must be paid to the affection of bones being situated in the depth of wounds due to burning. In the last part of the study possible reconstructive and ensuing rehabilitation measures are indicated.

  3. Simplification of Sun Tracking Mode to Gain High Concentration Solar Energy

    Directory of Open Access Journals (Sweden)

    Omar Aliman

    2007-01-01

    Full Text Available Power conversion from solar thermal energy to electrical energy is still very cost-intensive. Serious effort has to be given in the development of the concentrator or heliostat structure expenditure which contributing the most expensive component in a central receiver solar power plant. With current development to find alternatives and lower down the capital, a new mode of sun tracking has been developed and feasibility tested. As it applies a single stage collector replacing conventional double stages structure, the new technique has significantly benefits use in high temperature and high concentration solar energy applications. Meanwhile, the stationary or fixed target (receiver offers more convenient working environment for various applications. Large and heavy solar powered Stirling Engine could be placed at the stationary location. On the other advantage offers by the new technique, the optical alignment was reasonably easier and less time consuming.

  4. High Dietary Copper Increases Catecholamine Concentrations in the Hypothalami and Midbrains of Growing Pigs.

    Science.gov (United States)

    Yang, Wenyan; Zhao, Chunyu; Zhang, Cai; Yang, Lianyu

    2016-03-01

    The experiment was conducted to investigate the effect of high dietary copper on catecholamine concentration and dopamine-β-hydroxylase (DβH) activity in hypothalami and midbrains of growing pigs. Forty-five crossbred weanling pigs with an average body weight of 7.5 kg were randomly assigned to three groups of 15 each to receive a control diet containing 10 mg/kg Cu (diet A) and diets containing 125 (diet B) or 250 (diet C) mg Cu/kg DM for 45 days. Compared to the control, Cu supplementation at both 125 and 250 mg Cu/kg DM increased average daily gain (ADG), average daily feed intake (ADFI), and feed efficiency. High dietary copper increased midbrain and hypothalami dopamine (DA) and norepinephrine (NE) concentrations and midbrain dopamine-β-hydroxylase activity. However, increasing dietary Cu had no effect on hypothalami dopamine-β-hydroxylase activity.

  5. Mass Production of Ginseng (Panax ginseng) Embryoids on Media Containing High Concentrations of Sugar1.

    Science.gov (United States)

    Asaka, I; Ii, I; Hirotani, M; Asada, Y; Yoshokawa, T; Furuya, T

    1994-04-01

    A lot of ginseng embryoids were produced by culturing on high concentrations of sugar media from the embryogenic tissues obtained by moderately high temperature treatment. When the sucrose concentration was 100 g/l, the number of embryoids produced were over 100 pieces per g of inoculum weight. It was about ten times of that produced by culturing on 30 g/l of sucrose. Glucose showed an effect similar to sucrose on the basis of weight percentage. However, mannitol did not show this effect. The embryoids obtained by these processes redifferentiated to normal plantlets on culturing on the medium containing 30 g/l of sucrose. The saponin components of the tissue containing embryoids showed a similar pattern to those of natural GINSENG by HPLC.

  6. A study for the special Fresnel lens for high efficiency solar concentrators

    Science.gov (United States)

    Lin, Jian-Shian; Huang, Wei-Chih; Hsu, Hsiu-Chen; Chang, Ming-Wen; Liu, Chung-Ping

    2005-08-01

    Design a Fresnel lens for a concentrator to collect more sunlight onto the solar cell due to the efficiency and cost. Since 1970, the non-imaging concentrator was used for solar energy; most of them were reflecting mirrors. The non-imaging optical system provides large aperture and forgiving imaging requirements. The Fresnel lens used in non-imaging optical system was usually called non-imaging Fresnel lens. In this research, the Fresnel lenses were refracting optical elements but diffracting ones. According to the method of Ralf Leutz and Akio Suzuki [2], using minimum deviation and minimum dispersion to design a non-imaging Fresnel lens, which obeys the edge ray principle. Use optical software TracePro to simulate the non-imaging Fresnel lens, and each pitch size was 0.3mm and 200mm focus distant. Discusses the losses of non-imaging Fresnel lens and find out the relation of efficiency and F-Number. The optical concentration ratio could reach 15X (2-D) and 230X (3-D).

  7. Influence of Typha domingensis in the removal of high P concentrations from water.

    Science.gov (United States)

    Di Luca, G A; Maine, M A; Mufarrege, M M; Hadad, H R; Bonetto, C A

    2015-11-01

    A greenhouse experiment was conducted to evaluate the removal of high P concentration from water by vegetated and unvegetated wetlands. Reactors containing 4 kg of sediment and two plants of Typha domingensis (vegetated treatments) and reactors containing only sediment (unvegetated treatments) were arranged. Reactors were dosed with 100 and 500 mg L(-1) of P-PO4. The studied concentrations tried to simulate an accidental dump. Controls without P addition were also disposed. Water samples were collected periodically and analyzed for phosphorus. Sediment (0-3 (surface), 3-7 (medium) and 7-10 cm (deep)) and plant samples (roots, rhizomes, submerged leaves and aerial leaves) were collected at the beginning and at end of the experiment and were analyzed for total phosphorus. P fractionation was performed in the surface sediment layer. Relative growth rate (RGR) was calculated in each treatment considering initial and final plant height. P was efficiently removed from water in both, vegetated and unvegetated treatments. However, the major P removal was achieved in vegetated treatments. T. domingensis has a high capacity to tolerate and accumulate high P concentrations, especially in leaves, causing P accumulation in sediment to be significantly low in vegetated treatments. P accumulation was produced in the surface sediment layer (0-3 cm) in all treatments, mainly retained as iron-bound P. Present results point the large removal capacity of phosphate of systems planted with T. domingensis. Therefore T. domingensis is suitable for phytoremediation practice, being capable to tolerate high P concentration. Copyright © 2015 Elsevier Ltd. All rights reserved.

  8. The impact resistance of Kevlar woven fabrics impregnated with highly concentrated multiphase suspensions

    Institute of Scientific and Technical Information of China (English)

    Liu Jun; Xiong Dangsheng

    2016-01-01

    The stab and puncture resistance of Kevlar woven fabrics impregnated with different kinds of highly concentrated multiphase suspensions was studied with self-made dual-catheter drop-hammer tester. The results showed that the shear thickening of multiphase particles was possibly based on hydrocluster and particle jamming mechanism; the introduction of alumina silicate fibre can remarkably improve the composite spike resistance, and multiphase particles co-strengthening can provide best protection effect; otherwise, the stab resistance increases weakly.

  9. Macrocyclic olefin metathesis at high concentrations by using a phase-separation strategy.

    Science.gov (United States)

    Raymond, Michaël; Holtz-Mulholland, Michael; Collins, Shawn K

    2014-09-26

    Macrocyclic olefin metathesis has seen advances in the areas of stereochemistry, chemoselectivity, and catalyst stability, but strategies aimed at controlling dilution effects in macrocyclizations are rare. Herein, a protocol to promote macrocyclic olefin metathesis, one of the most common synthetic tools used to prepare macrocycles, at relatively high concentrations (up to 60 mM) is described by exploitation of a phase-separation strategy. A variety of macrocyclic skeletons could be prepared having either different alkyl, aryl, or amino acids spacers.

  10. The ionic product of water in highly concentrated sodium perchlorate solutions.

    Science.gov (United States)

    Turonek, M L; Hefter, G T; May, P M

    1998-03-01

    The ionic product of water, pK(w)=-log[H(+)][OH(-)], has been determined in aqueous solutions of sodium perchlorate over the concentration range of 1.0-8.0 M at 25 degrees C from high-precision potentiometric titrations carried out in cells with liquid junction using both glass and hydrogen electrodes. The glass electrode results are systematically lower probably as a result of interference by Na(+) ions.

  11. Bottom-Up Cost Analysis of a High Concentration PV Module

    Energy Technology Data Exchange (ETDEWEB)

    Horowitz, Kelsey A. W.; Woodhouse, Michael; Lee, Hohyun; Smestad, Greg P.

    2016-03-31

    We present a bottom-up model of III-V multi-junction cells, as well as a high concentration PV (HCPV) module. We calculate $0.59/W(DC) manufacturing costs for our model HCPV module design with today's capabilities, and find that reducing cell costs and increasing module efficiency offer the most promising paths for future cost reductions. Cell costs could be significantly reduced via substrate reuse and improved manufacturing yields.

  12. MODELING OF THE HIGH CONCENTRATION LAYER OF COHESIVE SEDIMENT UNDER THE ACTION OF WAVES AND CURRENTS

    Institute of Scientific and Technical Information of China (English)

    Qinghe ZHANG; Yongsheng WU; Jijian LIAN; Pingxing DING

    2001-01-01

    High concentration layer of cohesive sediment frequently occurs in muddy estuaries and coastal zones, and causes rapid siltation of the waterways. A one dimensional vertical coupled model describing the interactions between waves, currents and suspended cohesive sediment is developed in the present paper. The numerical results and analyses with field measurements reveal the mechanism of the formation and transport behaviors of the layer under the action of waves and currents.

  13. Particle characteristics and rheological constitutive relations of high concentration red mud

    Institute of Scientific and Technical Information of China (English)

    WANG Xing; QU Yuan-yuan; HU Wei-wei; CHEN Jie; ZHAO Xue-yi; WU Miao

    2008-01-01

    Red mud has relatively small solid particles (d50=13.02 μm) and will flow in paste form under high pressure during pipeline transport. Red mud belongs to a two-phase flow of materials with high viscosity and a high concentration of non-sedimentation, homogeneous solid-liquids. It is difficult to test its rheological properties under atmospheric pressure. Measurements such as rotational viscometry can not reflect the real state of the material when it is flowing in a pipe. Tested rheological parameters are somewhat higher than the actual values. In our investigation, grain shape, distinctive modality and grain size distribution of red mud were tested. Based on the principle of tube measurement, rheological experiments on red mud at different concentrations were carried out by using our independently developed tube-type pressure rheology test facility, and obtained constitutive equations. We conclude that red mud behaves as non-Newtonian pseudo-plastic fluid in pipe flows. Its consistency and power-law indices vary considerably with different concentrations.

  14. Cleaning Process Research of MVR High Concentration Salty Wastewater Treatment System

    Directory of Open Access Journals (Sweden)

    Wang Na

    2015-01-01

    Full Text Available A mechanical vapor re-compression (MVR evaporation system for the treatment of the highly-concentrated inorganic salt wastewater was investigated, and its process characteristics were analyzed taking sodium chloride salt wastewater as the treated solution. In this paper, by adding “H2O2 oxidation + filter +flash evaporation + hot filter” technology on the basis of original traditional MVR treatment system, the optimum technological conditions were determined through the experiment: The pH value is 8.5; the oxidation time is 24.0h; H2O2 amount accounting for 1% of the total wastewater under the condition of outlet test MVR system respectively fell 88.5% and 90.1% than the traditional process of effluent COD and NH3-N removal rate. MVR system for the sodium chloride salt qualified rate was increased from 83.2% to 98.2%. On the other hand, this process avoided the highly-concentrated outside of mother liquor by flashing evaporation recycling volatile solvent; the optimization process results were found to be consistent with published practical industrial data. Compared with the new process MVR system, the operation load of MVR system was lower. Therefore, the system can be used to treat the highly-concentrated inorganic salt wastewater and save energy. Therefore, the cleaning process can achieve remarkable energy saving and consumption, and reduce the pollution and the pollution and environmental protection effect.

  15. High concentrations of heavy metals in PM from ceramic factories of Southern Spain

    Science.gov (United States)

    Sánchez de la Campa, Ana M.; de la Rosa, Jesús D.; González-Castanedo, Yolanda; Fernández-Camacho, Rocío; Alastuey, Andrés; Querol, Xavier; Pio, Casimiro

    2010-06-01

    In this study, physicochemical characterization of Atmospheric Particulate Matter (PM) was performed in an urban-industrial site background (Bailén, Southern Spain), highly influenced by the impact of emission plumes from ceramic factories. This area is considered one of the towns with the highest PM 10 levels and average SO 2 concentration in Spain. A three stages methodology was used: 1) real-time measurements of levels of PM 10 and gaseous pollutants, and sampling of PM; 2) chemical characterization using ICP-MS, ICP-OES, CI and TOT, and source apportionment analysis (receptor modelling) of PM; and 3) chemical characterization of emission plumes derived from representative factories. High ambient air concentrations were found for most major components and trace elements compared with other industrialized towns in Spain. V and Ni are considered fingerprints of PM derived from the emissions of brick factories in this area, and were shown to be of particular interest. This highlights the high V and Ni concentrations in PM 10 (122 ngV/m 3 and 23.4 ngNi/m 3), with Ni exceeding the 2013 annual target value for the European Directive 2004/107/EC (20 ng/m 3). The methodology of this work can be used by Government departments responsible for Environment and Epidemiology in planning control strategies for improving air quality.

  16. Gamma ray heating rates due to chromium isotopes in stellar core during late stages of high mass stars (>10M⊙

    Directory of Open Access Journals (Sweden)

    Nabi Jameel-Un

    2017-01-01

    Full Text Available Gamma ray heating rates are thought to play a crucial role during the pre-supernova stage of high mass stars. Gamma ray heating rates, due to β±-decay and electron (positron capture on chromium isotopes, are calculated using proton-neutron quasiparticle random phase approximation theory. The electron capture significantly affects the lepton fraction (Ye and accelerates the core contraction. The gamma rays emitted as a result of weak processes heat the core and tend to hinder the cooling and contraction due to electron capture and neutrino emission. The emitted gamma rays tend to produce enormous entropy and set the convection to play its role at this stage. The gamma heating rates, on 50-60Cr, are calculated for the density range 10 < ρ (g.cm-3 < 1011 and temperature range 107 < T (K < 3.0×1010.

  17. Oxygenic Photosynthesis As A Protection Mechanism For Cyanobacteria Against Iron-Encrustation In Environments With High Fe2+ Concentrations

    Directory of Open Access Journals (Sweden)

    Danny eIonescu

    2014-09-01

    Full Text Available If O2 is available at circumneutral pH, Fe2+ is rapidly oxidized to Fe3+, which precipitates as FeO(OH. Neutrophilic iron oxidizing bacteria have evolved mechanisms to prevent self-encrustation in iron. Hitherto, no mechanism has been proposed for cyanobacteria from Fe2+ rich environments; these produce O2 but are seldom found encrusted in iron. We used two sets of illuminated reactors connected to two groundwater aquifers with different Fe2+ concentrations (0.9 µM vs. 26 µM in the Äspö Hard Rock Laboratory, Sweden. Cyanobacterial biofilms developed in all reactors and were phylogenetically different between the reactors. Unexpectedly, cyanobacteria growing in the Fe2+-poor reactors were encrusted in iron, whereas those in the Fe2+-rich reactors were not. In-situ microsensor measurements showed that O2 concentrations and pH near the surface of the cyanobacterial biofilms from the Fe2+-rich reactors were much higher than in the overlying water. This was not the case for the biofilms growing at low Fe2+ concentrations. Measurements with enrichement cultures showed that cyanobacteria from the Fe2+-rich environment increased their photosynthesis with increasing Fe2+ concentrations, whereas those from the low Fe2+ environment were inhibited at Fe2+ > 5 µM. Modeling based on in-situ O2 and pH profiles showed that cyanobacteria from the Fe2+-rich reactor were not exposed to significant Fe2+ concentrations. We propose that, due to limited mass transfer, high photosynthetic activity in Fe2+-rich environments forms a protective zone where Fe2+ precipitates abiotically at a non-lethal distance from the cyanobacteria. This mechanism sheds new light on the possible role of cyanobacteria in precipitation of banded iron formations.

  18. Inhalation exposures due to radon and thoron ((222)Rn and (220)Rn): Do they differ in high and normal background radiation areas in India?

    Science.gov (United States)

    Mishra, Rosaline; Sapra, B K; Prajith, R; Rout, R P; Jalaluddin, S; Mayya, Y S

    2015-09-01

    In India, High Background Radiation Areas (HBRAs) due to enhanced levels of naturally occurring radionuclides in soil (thorium and, to a lesser extent, uranium), are located along some parts of the coastal tracts viz. the coastal belt of Kerala, Tamilnadu and Odisha. It is conjectured that these deposits will result in higher emissions of radon isotopes ((222)Rn and (220)Rn) and their daughter products as compared to Normal Background Radiation Areas (NBRAs). While the annual external dose rates contributed by gamma radiations in these areas are about 5-10 times higher, the extent of increase in the inhalation dose rates attributable to (222)Rn and (220)Rn and their decay products is not well quantified. Towards this, systematic indoor surveys were conducted wherein simultaneous measurements of time integrated (222)Rn and (220)Rn gas and their decay product concentrations was carried out in around 800 houses in the HBRAs of Kerala and Odisha to estimate the inhalation doses. All gas measurements were carried out using pin-hole cup dosimeters while the progeny measurements were with samplers and systems based on the Direct radon/thoron Progeny sensors (DRPS/DTPS). To corroborate these passive measurements of decay products concentrations, active sampling was also carried out in a few houses. The results of the surveys provide a strong evidence to conclude that the inhalation doses due to (222)Rn and (220)Rn gas and their decay products in these HBRAs are in the same range as observed in the NBRAs in India.

  19. An Eulerian joint velocity-concentration PDF method for solute dispersion in highly heterogeneous porous media

    Science.gov (United States)

    Meyer, Daniel W.; Tchelepi, Hamdi A.; Jenny, Patrick

    2010-05-01

    In risk analysis applications involving heterogeneous formations, the knowledge of the solute concentration probability density function (PDF) at different spatial locations and times is crucial. We propose a new joint velocity-concentration PDF method applicable for highly heterogeneous porous media that accounts for advective transport, pore-scale dispersion and molecular diffusion. Unlike in low order approximation (LOA) methods that are valid for low conductivity variances ?Y 2 and where the one-point velocity PDF is typically assumed to be a Gaussian, the proposed joint PDF method honors the increasingly non-Gaussian velocity one-point PDF and the long-term velocity correlations that were reported in different Monte Carlo (MC) studies for ?Y 2 > 0.5 [e.g., Salandin, P. and V. Fiorotto, WRR, 1998. 34(5) and Trefry, M.G., F.P. Ruan, and D. McLaughlin, WRR, 2003. 39(3)]. Furthermore, the new joint PDF method does not involve any a-priori assumption about the shape of the resulting marginal concentration PDF. LOA methods that provide information on the concentration mean and variance [Fiori, A. and G. Dagan, Journal of Contaminant Hydrology, 2000. 45(1-2)] on the other hand are typically complemented by assuming that the concentration PDF has a β-PDF shape [Bellin, A. and D. Tonina, Journal of Contaminant Hydrology, 2007. 94(1-2)]. The Eulerian joint velocity-concentration PDF transport equation in our model is numerically solved with a computationally efficient particle method. The suggested joint PDF method is validated by comparison with MC data reported by Caroni and Fiorotto for Péclet numbers ranging from 10 to 104 and ?Y 2 = 1 and 2 [Caroni, E. and V. Fiorotto, Transport in Porous Media, 2005. 59(1)].

  20. Design considerations and performance characteristics of high concentration point-focussing photovoltaic modules

    Energy Technology Data Exchange (ETDEWEB)

    Sanders, J.A.; Broadbent, S.

    1984-05-01

    Through the auspices of the Department of Energy, the Fresnel lens point-focussing photovoltaic module has evolved into a commercially available, high efficiency low cost option for converting solar energy into electricity. The 15.4% efficient baseline module is undergoing several design improvements to achieve higher efficiencies at high concentrations and lower cost. A 16.5% module will be available in 1984 and 18% Gallium Arsenide modules in 1985. This paper describes the design details and performance characteristics of the baseline module and the design improvements.

  1. A SIMPLE WAY OF ACHIEVING A HIGH CELL CONCENTRATION IN RECOMBINANT Escherichia coli CULTIVATION

    Directory of Open Access Journals (Sweden)

    Gombert A.K.

    1997-01-01

    Full Text Available Abstract - A cultivation strategy based on some previous knowledge of the metabolism of Escherichia coli BL21 (DE3 pLysS containing the troponin C gene cloned into plasmid pET was developed and applied through the use of simple fermentation equipment and a feed-forward control strategy in order to achieve a high cell concentration ¾ 92 g l-1 dry cell weight ¾ and a high cell productivity ¾ 3.7 g l-1 h-1.

  2. On the peculiarities of LDA method in two-phase flows with high concentrations of particles

    Science.gov (United States)

    Poplavski, S. V.; Boiko, V. M.; Nesterov, A. U.

    2016-10-01

    Popular applications of laser Doppler anemometry (LDA) in gas dynamics are reviewed. It is shown that the most popular method cannot be used in supersonic flows and two-phase flows with high concentrations of particles. A new approach to implementation of the known LDA method based on direct spectral analysis, which offers better prospects for such problems, is presented. It is demonstrated that the method is suitable for gas-liquid jets. Owing to the progress in laser engineering, digital recording of spectra, and computer processing of data, the method is implemented at a higher technical level and provides new prospects of diagnostics of high-velocity dense two-phase flows.

  3. Reduced oxygen due to high-altitude exposure relates to atrophy in motor-function brain areas.

    Science.gov (United States)

    Di Paola, M; Paola, M D; Bozzali, M; Fadda, L; Musicco, M; Sabatini, U; Caltagirone, C

    2008-10-01

    At high altitudes barometric pressure is reduced and, thus, less oxygen is inhaled. Reduced oxygen concentration in brain tissue can lead to cerebral damage and neurological and cognitive deficits. The present study was designed to explore the effects of high-altitude exposure using a quantitative MRI technique, voxel-based morphometry. We studied nine world-class mountain climbers before (baseline) and after (follow-up) an extremely high-altitude ascent of Everest and K2. We investigated the effects of repeated extremely high-altitude exposures by comparing mountain climbers' scans at baseline with scans of 19 controls. In addition, we measured the effects of a single extremely high-altitude expedition by comparing mountain climbers' scans at baseline and follow-up. A region of reduced white matter density/volume was found in the left pyramidal tract near the primary (BA 4) and supplementary (BA 6) motor cortex when mountain climbers at baseline were compared with controls. Further, when mountain climbers' scans before and after the expedition were compared, a region of reduced grey matter density/volume was found in the left angular gyrus (BA 39). These findings suggest that extremely high-altitude exposures may cause subtle white and grey matter changes that mainly affect brain regions involved in motor activity.

  4. Measurement of CO2 concentration at high-temperature based on tunable diode laser absorption spectroscopy

    Science.gov (United States)

    Chen, Jiuying; Li, Chuanrong; Zhou, Mei; Liu, Jianguo; Kan, Ruifeng; Xu, Zhenyu

    2017-01-01

    A diode laser sensor based on absorption spectroscopy has been developed for sensitive measurement of CO2 concentration at high-temperature. Measurement of CO2 can provide information about the extent of combustion and mix in a combustor that may be used to improve fuel efficiency. Most methods of in-situ combustion measurement of CO2 use the spectroscopic parameters taken from database like HITEMP which is mainly derived from the theoretical calculation and remains a high degree of uncertainty in the spectroscopic parameters. A fiber-coupled diode laser system for measurement of CO2 in combustion environment by use of the high-temperature spectroscopic parameters which are obtained by experiment was proposed. Survey spectra of the R(50) line of CO2 at 5007.787 cm-1 were recorded at high-temperature and various pressures to determine line intensities. The line intensities form the theoretical foundation for future applications of this diode laser sensor system. Survey spectra of four test gas mixtures containing 5.01%CO2, 10.01%CO2, 20.08%CO2, and 49.82%CO2 were measured to verify the accuracy of the diode laser sensor system. The measured results indicate that this sensor can measure CO2 concentration with 2% uncertainty in high temperatures.

  5. A high-performance photovoltaic concentrator array - The mini-dome Fresnel lens concentrator with 30 percent efficient GaAs/GaSb tandem cells

    Science.gov (United States)

    Piszczor, M. F.; Brinker, D. J.; Flood, D. J.; Avery, J. E.; Fraas, L. M.; Fairbanks, E. S.; Yerkes, J. W.; O'Neill, M. J.

    1991-01-01

    A high-efficiency, lightweight space photovoltaic concentrator array is described. Previous work on the minidome Fresnel lens concentrator concept is being integrated with Boeing's 30 percent efficient tandem GaAs/GaSb concentrator cells into a high-performance photovoltaic array. Calculations indicate that, in the near term, such an array can achieve 300 W/sq m at a specific power of 100 W/kg. Emphasis of the program has now shifted to integrating the concentrator lens, tandem cell, and supporting panel structure into a space-qualifiable array. A description is presented of the current status of component and prototype panel testing and the development of a flight panel for the Photovoltaic Array Space Power Plus Diagnostics (PASP PLUS) flight experiment.

  6. Black carbon concentrations in the highly polluted Kathmandu Valley, Nepal: a three year monitoring with a dual-spot Aethalometer

    Science.gov (United States)

    Rupakheti, Maheswar; Drinovec, Luka; Puppala, SivaPraveen; Mahata, Khadak; Rupakheti, Dipesh; Kathayat, Bhogendra; Singdan, Pratik; Panday, Arnico; Lawrence, Mark

    2016-04-01

    Our knowledge about ambient black carbon (BC) in the vast Himalayan region, a region vulnerable to impacts of global warming, is very limited due to unavailability of a long-term ambient monitoring. Here we present results from a continuous monitoring of ambient BC concentrations, with a new generation Aethalometer (AE33), over a three year period (January 2013- January 2016) at a semi-urban site in the highly polluted Kathmandu Valley in the foothills of the central Himalaya, one of the most polluted cities in the world. This is the longest time series of BC concentrations that have been monitored with AE33 (which uses the dual-spot technique for a real-time filter loading compensation) in highly polluted ambient environment. The measurements were carried out under the framework of project SusKat (Sustainable Atmosphere for the Kathmandu Valley). BC concentrations were found to be extremely high, especially in winter and the pre-monsoon period, with the hourly-averaged values often exceeding 50 μg/m3. BC concentrations showed a clear diurnal cycle with a prominent peak around 8-9 am and a second peak around 8-9 pm local time in all four seasons. Night-time BC was also fairly high. The diurnal cycle was driven by a combination of increased emissions from traffic, cooking activities, garbage burning, and lower mixing heights (˜200 m) and reduced horizontal ventilation in the mornings and evenings. BC concentrations showed significant seasonal variations - a maximum in winter season and minimum during the monsoon (rainy) season, with monthly average values in the range 5-30 μg/m3. An increase in emissions from the operation of over 100 brick kilns in winter and spring, and an increase in the use of small but numerous diesel power generators during hours with power cuts contributed significantly to ambient BC concentrations in the valley. Fractional contributions of biomass burning and fossil fuel combustion to BC was estimated based on a real-time method for

  7. High-resolution magic angle spinning (1) H NMR measurement of ligand concentration in solvent-saturated chromatographic beads.

    Science.gov (United States)

    Elwinger, Fredrik; Furó, István

    2016-04-01

    A method based on (1) H high-resolution magic angle spinning NMR has been developed for measuring concentration accurately in heterogeneous materials like that of ligands in chromatography media. Ligand concentration is obtained by relating the peak integrals for a butyl ligand in the spectrum of a water-saturated chromatography medium to the integral of the added internal reference. The method is fast, with capacity of 10 min total sample preparation and analysis time per sample; precise, with a reproducibility expressed as 1.7% relative standard deviation; and accurate, as indicated by the excellent agreement of derived concentration with that obtained previously by (13) C single-pulse excitation MAS NMR. The effects of radiofrequency field inhomogeneity, spin rate, temperature increase due to spinning, and distribution and re-distribution of medium and reference solvent both inside the rotor during spinning and between bulk solvent and pore space are discussed in detail. © 2016 The Authors Magnetic Resonance in Chemistry published by John Wiley & Sons Ltd.

  8. Analysis of the electrolyte convection inside the concentration boundary layer during structured electrodeposition of copper in high magnetic gradient fields.

    Science.gov (United States)

    König, Jörg; Tschulik, Kristina; Büttner, Lars; Uhlemann, Margitta; Czarske, Jürgen

    2013-03-19

    To experimentally reveal the correlation between electrodeposited structure and electrolyte convection induced inside the concentration boundary layer, a highly inhomogeneous magnetic field, generated by a magnetized Fe-wire, has been applied to an electrochemical system. The influence of Lorentz and magnetic field gradient force to the local transport phenomena of copper ions has been studied using a novel two-component laser Doppler velocity profile sensor. With this sensor, the electrolyte convection within 500 μm of a horizontally aligned cathode is presented. The electrode-normal two-component velocity profiles below the electrodeposited structure show that electrolyte convection is induced and directed toward the rim of the Fe-wire. The measured deposited structure directly correlates to the observed boundary layer flow. As the local concentration of Cu(2+) ions is enhanced due to the induced convection, maximum deposit thicknesses can be found at the rim of the Fe-wire. Furthermore, a complex boundary layer flow structure was determined, indicating that electrolyte convection of second order is induced. Moreover, the Lorentz force-driven convection rapidly vanishes, while the electrolyte convection induced by the magnetic field gradient force is preserved much longer. The progress for research is the first direct experimental proof of the electrolyte convection inside the concentration boundary layer that correlates to the deposited structure and reveals that the magnetic field gradient force is responsible for the observed structuring effect.

  9. A Review on Level of Specific Absorption Rate Due to High Power Transmission Lines: Analysis toward Human Position Posture

    Directory of Open Access Journals (Sweden)

    Ghazali Z.

    2016-01-01

    Full Text Available The main contribution of this project is the development of a homogeneous model of a man to presents the specific absorption rate (SAR due to high power transmission line. As a low frequency application under high power transmission line of 50 Hz in electrical engineering, to studies the influence of human’s posture on specific absorption rate. This project designs two types of human body which one design uses most cylinder block and another design use brick block where both blocks have a different value of mesh cells. For each design has four types of posture are standing, sitting, arms up and arms out by using Computer Simulation Technology (CST Studio Software. This analysis does toward for four types of the human position postures because each posture has different value of specific absorption rate (SAR based on the size of the mesh cells of the design. Based on two designs of the human body, the lowest of the mesh cells value will reduce time to simulate SAR. For each posture has different value of SAR for each part of the human body because the whole human body has different types of tissues. Therefore, the CST studio software uses extremely to simulate the SAR value toward human position posture due to high power transmission line.

  10. High dielectric permittivity elastomers from well-dispersed expanded graphite in low concentrations

    DEFF Research Database (Denmark)

    Daugaard, Anders Egede; Hassouneh, Suzan Sager; Kostrzewska, Malgorzata;

    2013-01-01

    The development of elastomer materials with a high dielectric permittivity has attracted increased interest over the last years due to their use in for example dielectric electroactive polymers. For this particular use, both the electrically insulating properties - as well as the mechanical...... by the addition of traditional fillers in the necessary amounts would either lose their stability or their softness. Furthermore the influence of several mixing procedures on the electrical and mechanical properties is investigated. © 2013 SPIE....

  11. Thermal Shock Behavior of Single Crystal Oxide Refractive Concentrators for High Temperatures Solar Thermal Propulsion

    Science.gov (United States)

    Zhu, Dongming; Choi, Sung R.; Jacobson, Nathan S.; Miller, Robert A.

    1999-01-01

    Single crystal oxides such as yttria-stabilized zirconia (Y2O3-ZrO2), yttrium-aluminum-garnet (Y3Al5O12, or YAG), magnesium oxide (MgO) and sapphire (Al2O3) have been considered as refractive secondary concentrator materials for high temperature solar propulsion applications. However, thermal mechanical reliability of the oxide components in severe thermal environments during space mission sun/shade transitions is of great concern. In this paper, critical mechanical properties of these oxide crystals are determined by the indentation technique. Thermal shock resistance of the oxides is evaluated using a high power CO, laser under high temperature-high thermal gradients. Thermal stress fracture behavior and failure mechanisms of these oxide materials are investigated under various temperature and heating conditions.

  12. A highly concentrated diet increases biogas production and the agronomic value of young bull's manure.

    Science.gov (United States)

    Mendonça Costa, Mônica Sarolli Silva de; Lucas, Jorge de; Mendonça Costa, Luiz Antonio de; Orrico, Ana Carolina Amorim

    2016-02-01

    The increasing demand for animal protein has driven significant changes in cattle breeding systems, mainly in feedlots, with the use of young bulls fed on diets richer in concentrate (C) than in forage (F). These changes are likely to affect animal manure, demanding re-evaluation of the biogas production per kg of TS and VS added, as well as of its agronomic value as a biofertilizer, after anaerobic digestion. Here, we determined the biogas production and agronomic value (i.e., the macronutrient concentration in the final biofertilizer) of the manure of young bulls fed on diets with more (80% C+20% F; 'HighC' diet) or less (65% C+35% F; 'LowC' diet) concentrate, evaluating the effects of temperature (25, 35, and 40°C) and the use of an inoculum, during anaerobic digestion. A total of 24 benchtop reactors were used, operating in a semi-continuous system, with a 40-day hydraulic retention time (HRT). The manure from animals given the HighC diet had the greatest potential for biogas production, when digested with the use of an inoculum and at 35 or 40°C (0.6326 and 0.6207m(3)biogas/kg volatile solids, or VS, respectively). We observed the highest levels of the macronutrients N, P, and K in the biofertilizer from the manure of animals given HighC. Our results show that the manure of young bulls achieves its highest potential for biogas production and agronomic value when animals are fed diets richer in concentrate, and that biogas production increases if digestion is performed at higher temperatures, and with the use of an inoculum.

  13. High Concentrations of Ozone Air Pollution on Mount Everest: Health Implications for Sherpa Communities and Mountaineers.

    Science.gov (United States)

    Semple, John L; Moore, G W Kent; Koutrakis, Petros; Wolfson, Jack M; Cristofanelli, Paolo; Bonasoni, Paolo

    2016-12-01

    Semple, John L., G.W. Kent Moore, Petros Koutrakis, Jack M. Wolfson, Paolo Cristofanelli, and Paolo Bonasoni. High concentrations of ozone air pollution on Mount Everest: health implications for Sherpa communities and mountaineers. High Alt Med Biol. 17:365-369, 2016.-Introduction: Populations in remote mountain regions are increasingly vulnerable to multiple climate mechanisms that influence levels of air pollution. Few studies have reported on climate-sensitive health outcomes unique to high altitude ecosystems. In this study, we report on the discovery of high-surface ozone concentrations and the potential impact on health outcomes on Mount Everest and the high Himalaya. Surface ozone measurements were collected during ascending transects in the Mount Everest region of Nepal with passive nitrite-coated Ogawa filter samplers to obtain 8-hour personal exposures (2860-5364 m asl). In addition, the Nepal Climate Observatory-Pyramid, a GAW-WMO Global Station sited in the Khumbu Valley (5079 m asl), collected ozone mixing ratios with photometric gas analyzer. Surface ozone measurements increased with altitude with concentrations that exceed 100 ppb (8-hour exposure). Highest values were during the spring season and the result of diverse contributions: hemispheric background values, the descent of ozone-rich stratospheric air, and the transport of tropospheric pollutants occurring at different spatial scales. Multiple climate factors, including descending stratospheric ozone and imported anthropogenic air masses from the Indo-Gangetic Plain, contribute to ambient ozone exposure levels in the vicinity of Mount Everest that are similar to if not higher than those reported in industrialized cities.

  14. Chlorpromazine, haloperidol, metoclopramide and domperidone release prolactin through dopamine antagonism at low concentrations but paradoxically inhibit prolactin release at high concentrations.

    Science.gov (United States)

    Besser, G. M.; Delitala, G.; Grossman, A.; Stubbs, W. A.; Yeo, T.

    1980-01-01

    1. The effects of chlorpromazine, haloperidol, metoclopramide and domperidone on the release of prolactin from perfused columns of dispersed rat anterior pituitary cells were studied. 2. Chlorpromazine, haloperidol, metoclopramide and domperidone antagonized the dopamine-mediated inhibition of prolactin release at low concentrations. 3. Each dopamine antagonist displaced the dose-response curve for dopamine-induced suppression of prolactin release to the right in a parallel manner. 4. At higher concentrations, the four drugs became less effective as dopamine antagonists. 5. At high concentrations in the absence of dopamine, chlorpromazine, haloperidol, metoclopramide and domperidone paradoxically suppressed prolactin secretion by an unknown mechanism. PMID:6110459

  15. Impact of high pyruvate concentration on kinetics of rabbit muscle lactate dehydrogenase.

    Science.gov (United States)

    Eggert, Matthew Warren; Byrne, Mark E; Chambers, Robert P

    2011-09-01

    In order to evaluate the effectiveness of L: -lactate dehydrogenase (LDH) from rabbit muscle as a regenerative catalyst of the biologically important cofactor nicotinamide adenine dinucleotide (NAD), the kinetics over broad concentrations were studied to develop a suitable kinetic rate expression. Despite robust literature describing the intricate complexations, the mammalian rabbit muscle LDH lacks a quantitative kinetic rate expression accounting for simultaneous inhibition parameters, specifically at high pyruvate concentrations. Product inhibition by L: -lactate was observed to reduce activity at concentrations greater than 25 mM, while expected substrate inhibition by pyruvate was significant above 4.3 mM concentration. The combined effect of ternary and binary complexes of pyruvate and the coenzymes led to experimental rates as little as a third of expected activity. The convenience of the statistical software package JMP allowed for effective determination of experimental kinetic constants and simplification to a suitable rate expression: [formula: see text] where the last three terms represent the inhibition complex terms for lactate, pyruvate, and pyruvate-NAD, respectively. The corresponding values of K (I-Lac), K (I-Pyr), and K (I-Pyr-NAD) for rabbit muscle LDH are 487.33 mM(-1) and 29.91 mM and 97.47 mM at 22 °C and pH 7.8.

  16. Lysozyme refolding at high concentration by dilution and size—exclusion chromatography

    Institute of Scientific and Technical Information of China (English)

    高永贵; 关怡新; 姚善泾; CHOMan-gi

    2003-01-01

    This study of renaturation by dilution and size exclusion chromstography(SEC) addition of urea to improve yield as well as the initial and final protein concentrations showed that although urea decreased the rate of lysozyme refolding,it could suppress protein aggregation to sustain the pathway of correct refolding at high protein concentration;and that there existed an optimum urea concentration in renaturation buffer.Under the above conditions,lysozyme was successfully refolded from initial concentration of up tp 40 mg/mL by dilu-tion and 100 mg/mL by SEC,with the yield of the former being more than 40% and that of the latter being 34.8%.Especislly,under the condition of 30 min iterval time,i.e.τ>2(tR2-tR1),the efficiency was increased by 25% and the renaturation buffer could be recycled for SEC refolding in continuous operation of downstream process.

  17. Enhanced Efficiencies for High-Concentration, Multijunction PV Systems by Optimizing Grid Spacing under Nonuniform Illumination

    Directory of Open Access Journals (Sweden)

    Pratibha Sharma

    2014-01-01

    Full Text Available The design of a triple junction solar cell’s front contact grid can significantly affect cell conversion efficiency under high concentration. We consider one aspect of grid design, choosing a linear grid within a distributed resistance cell model to optimize finger spacings at concentrations between 500 and 2500 suns under uniform and nonuniform illumination. Optimization for maximum efficiency under Gaussian irradiance profiles is done by SPICE analysis. Relative to the optimized uniform illumination designs, we find enhancements of 0.5% to 2% in absolute efficiencies for uniform spacing. Efficiency enhancement with nonuniform spacing under nonuniform illumination is also evaluated. Our model suggests that, at lower concentrations (<1000 suns, the penalty for using uniformly spaced fingers instead of nonuniformly spaced fingers is <0.1%. However, at a concentration of 2500 suns the penalty increases to 0.3%. Thus, relative to a uniform irradiance optimization, an absolute efficiency increase of 2.3% can be attained for an optimized nonuniform spacing given the Gaussian irradiance profile under consideration.

  18. Preparation of monodisperse aqueous microspheres containing high concentration of l-ascorbic acid by microchannel emulsification.

    Science.gov (United States)

    Khalid, Nauman; Kobayashi, Isao; Neves, Marcos A; Uemura, Kunihiko; Nakajima, Mitsutoshi; Nabetani, Hiroshi

    2015-01-01

    Monodisperse aqueous microspheres containing high concentrations of l-ascorbic acid with different concentrations of sodium alginate (Na-ALG) and magnesium sulfate (MgSO4) were prepared by using microchannel emulsification (MCE). The continuous phase was water-saturated decane containing a 5% (w/w) hydrophobic emulsifier. The flow rate of the continuous phase was maintained at 10 mL h(-1), whereas the pressure applied to the disperse phase was varied between 3 and 25 kPa. The disperse phase optimized for successfully generating aqueous microspheres included 2% (w/w) Na-ALG and 1% (w/w) MgSO4. At a higher MgSO4 concentration, the generated microspheres resulted in coalescence and subsequent bursting. At a lower MgSO4 concentration, unstable and polydisperse microspheres were obtained. The aqueous microspheres generated from the MCs under optimized conditions had a mean particle diameter (dav) of 14-16 µm and a coefficient of variation (CV) of less than 8% at the disperse phase pressures of 5-15 kPa.

  19. High-efficiency atomic entanglement concentration for quantum communication network assisted by cavity QED

    Science.gov (United States)

    Wang, Guan-Yu; Li, Tao; Deng, Fu-Guo

    2015-04-01

    Quantum entanglement is the key resource in quantum information processing, especially in quantum communication network. However, affected by the environment noise, the maximally entangled states usually collapse into nonmaximally entangled ones or even mixed states. Here we present two high-efficiency schemes to complete the entanglement concentration of nonlocal two-atom systems. Our first scheme is used to concentrate the nonlocal atomic systems in the partially entangled states with known parameters, and it has the optimal success probability. The second scheme is used to concentrate the entanglement of the nonlocal two-atom systems in the partially entangled states with unknown parameters. Compared with the other schemes for the entanglement concentration of atomic systems, our two protocols are more efficient and practical. They require only an ancillary single photon to judge whether they succeed or not, and they work in a heralded way with detection inefficiency and absence of sophisticated single-photon detectors in practical applications. Moreover, they are insensitive to both the cavity decay and atomic spontaneous emission.

  20. Liquid high concentration IgG1 antibody formulations by precipitation.

    Science.gov (United States)

    Matheus, Susanne; Friess, Wolfgang; Schwartz, Daniel; Mahler, Hanns-Christian

    2009-09-01

    A manufacturing approach for liquid high concentration antibody formulations based on precipitation and subsequent re-dissolution was investigated. IgG1 antibody solutions were concentrated from 20 to 100 mg/mL by intermediate precipitation, with a recovery exceeding 95%, retention of the native secondary structure and binding activity as well as adequate stability. Quantitative, reproducible precipitation was performed using 1.45 M ammonium sulphate (pH 5.5 and 8.0), 0.67 M sodium citrate (pH 8.0) and 9% (w/v) PEG 4000 (pH 5.5 and 8.0). Scalability was confirmed from 1 to 100 mL. The concentrations achievable in the re-dissolution step were less affected by the re-dissolution medium, but limited by the residual precipitant. Both, improved removal of remaining precipitant liquid and larger precipitation scales were successful in increasing the final protein concentration. SEC and turbidity analysis directly after re-dissolution indicated that similar protein qualities were obtained, independent from the precipitant used. However, increased aggregate formation was observed after short term storage of the precipitated protein particles at either 2-8 degrees C or ambient temperature. An accelerated mechanical and thermal stability program verified comparable stability of the re-dissolved liquid 100 mg/mL formulations produced by intermediate precipitation to a control formulation obtained by standard ultrafiltration.

  1. High fetal plasma adenosine concentration: a role for the fetus in preeclampsia?

    LENUS (Irish Health Repository)

    Espinoza, Jimmy

    2012-02-01

    OBJECTIVE: Clinical observations suggest a role for the fetus in the maternal manifestations of preeclampsia, but the possible signaling mechanisms remain unclear. This study compares the fetal plasma concentrations of adenosine from normal pregnancies with those from preeclampsia. STUDY DESIGN: This secondary data analysis included normal pregnancies (n = 27) and patients with preeclampsia (n = 39). Patients with preeclampsia were subclassified into patients with (n = 25) and without (n = 14) abnormal uterine artery Doppler velocimetry (UADV). RESULTS: Fetal plasma concentrations of adenosine were significantly higher in patients with preeclampsia (1.35 +\\/- 0.09 mumol\\/L) than in normal pregnancies (0.52 +\\/- 0.06 mumol\\/L; P < .0001). Fetal plasma concentrations of adenosine in patients with preeclampsia with abnormal UADV (1.78 +\\/- 0.15 mumol\\/L), but not with normal UADV (0.58 +\\/- 0.14 mumol\\/L), were significantly higher than in normal pregnancies (P < .0001). CONCLUSION: Patients with preeclampsia with sonographic evidence of chronic uteroplacental ischemia have high fetal plasma concentrations of adenosine.

  2. Exploration of Quench Initiation Due to Intentional Geometrical Defects in a High Magnetic Field Region of an SRF Cavity

    Energy Technology Data Exchange (ETDEWEB)

    J. Dai, K. Zhao, G.V. Eremeev, R.L. Geng, A.D. Palczewski; Dai, J. [Thomas Jefferson National Accelerator Facility, Newport News, VA (United States); Palczewski, A. D. [Thomas Jefferson National Accelerator Facility, Newport News, VA (United States); Eremeev, G. V. [Thomas Jefferson National Accelerator Facility, Newport News, VA (United States); Geng, R. L. [Thomas Jefferson National Accelerator Facility, Newport News, VA (United States); Zhao, K. [Institute of Heavy Ion Physics, Peking University, Beijing (China)

    2011-07-01

    A computer program which was used to simulate and analyze the thermal behaviors of SRF cavities has been developed at Jefferson Lab using C++ code. This code was also used to verify the quench initiation due to geometrical defects in high magnetic field region of SRF cavities. We built a CEBAF single cell cavity with 4 artificial defects near equator, and this cavity has been tested with T-mapping. The preheating behavior and quench initiation analysis of this cavity will be presented here using the computer program.

  3. Adaptation of a mixed culture of acidophiles for a tank biooxidation of refractory gold concentrates containing a high concentration of arsenic.

    Science.gov (United States)

    Hong, Jeongsik; Silva, Rene A; Park, Jeonghyun; Lee, Eunseong; Park, Jayhyun; Kim, Hyunjung

    2016-05-01

    We adapted a mixed culture of acidophiles to high arsenic concentrations to confirm the possibility of achieving more than 70% biooxidation of refractory gold concentrates containing high arsenic (As) concentration. The biooxidation process was applied to refractory gold concentrates containing approximately 139.67 g/kg of total As in a stirred tank reactor using an adapted mixed culture of Acidithiobacillus ferrooxidans and Acidithiobacillus thiooxidans. The percentage of the biooxidation process was analyzed based on the total As removal efficiency. The As removal was monitored by inductively coupled plasma (ICP) analysis, conducted every 24 h. The results obtained with the adapted culture were compared with the percentage of biooxidation obtained with a non-adapted mixed culture of A. ferrooxidans and A. thiooxidans, and with their respective pure cultures. The percentages of biooxidation obtained during 358 h of reaction were 72.20%, 38.20%, 27.70%, and 11.45% for adapted culture, non-adapted culture, and pure cultures of A. thiooxidans and A. ferrooxidans, respectively. The adapted culture showed a peak maximum percentage of biooxidation of 77% at 120 h of reaction, confirming that it is possible to obtain biooxidation percentages over 70% in gold concentrates containing high As concentrations.

  4. Cardiometabolic risk factors are associated with high urinary enterolactone concentration, independent of urinary enterodiol concentration and dietary fiber intake in adults.

    Science.gov (United States)

    Frankenfeld, Cara L

    2014-09-01

    The study objective was to evaluate independent and interactive associations of dietary fiber intake and high urinary enterolignans with cardiometabolic risk factors. The analysis included 2260 adults (≥20 y of age) from the 2003-2010 NHANES. Logistic regression models were used to evaluate obesity and clinically defined cardiometabolic risk factors in relation to dietary fiber intake and urinary enterolignan concentrations. Three sets of models were created: 1) independent associations, 2) mutually adjusted associations, and 3) interactions. Models were adjusted for age, gender, race/ethnicity, education, smoking status, and energy intake. High concentrations were considered to be above the 90th percentile of urinary enterolignan concentrations. Increasing dietary fiber intake was associated with high blood pressure (P = 0.02) and low serum HDL cholesterol (P-trend = 0.03). High urinary enterodiol concentration was not associated with obesity or cardiometabolic risk factors. High urinary enterolactone concentration was inversely associated with obesity (OR: 0.44; 95% CI: 0.29, 0.66), abdominal obesity (OR: 0.58; 95% CI: 0.39, 0.87), high serum C-reactive protein (CRP; OR: 0.52; 95% CI: 0.37, 0.74), high serum triglycerides (OR: 0.39; 95% CI: 0.23, 0.61), low serum HDL cholesterol (OR: 0.37; 95% CI: 0.23, 0.61), and metabolic syndrome (OR: 0.47; 95% CI: 0.30, 0.74). In mutually adjusted models, enterolactone associations observed in independent models remained similar, but associations for dietary fiber intake were attenuated, with the exception of blood pressure. In interaction models, there were 2 significant interactions: between high urinary enterodiol concentration and dietary fiber intake for high serum CRP (P = 0.04) and high plasma glucose (P = 0.04). Overall, being in the highest 10% of urinary enterolactone concentration was associated with cardiometabolic risk factors, independent of dietary fiber intake and enterodiol concentration. Future studies are

  5. Changes of the hindgut microbiota due to high-starch diet can be associated with behavioral stress response in horses.

    Science.gov (United States)

    Destrez, Alexandra; Grimm, Pauline; Cézilly, Frank; Julliand, Véronique

    2015-10-01

    The digestive system of horses is adapted to a high-fiber diet consumed in small amounts over a long time. However, during training, high-starch and low-fiber diets are usually fed which may induce hindgut microbial disturbances and intestinal pain. These diets can be described as alimentary stress. The aim of the present study was to investigate to what extent changes in behavior are associated with alimentary stress and microbial composition changes of the cecal or colonic ecosystem. Six fistulated horses were used. The alimentary stress was a modification of diet from a high-fiber diet (100% hay) to a progressive low-fiber and high-starch diet (from 90% hay and 10% barley to 57% hay and 43% barley in 5 days). Cecal and colonic total anaerobic, cellulolytic, amylolytic and lactate-utilizing bacteria were enumerated three times (twice on high-fiber diet and once on 57% hay and 43% barley diet). The behavior of horses was assessed from continuous video recording over an 18-h time period. In addition two personality traits were measured: neophobia (assessed from the reaction to the presence of a novel object placed near a feeder in a test arena) and sociability (assessed from the reaction to an unfamiliar horse in a stall). Video recordings were analyzed by scan sampling every 10 min using the following behavioral categories: lying, resting, feeding and being vigilant. In addition, we recorded time spent feeding and time spent in vigilance during the neophobia test, and time spent in vigilance and time spent in interactions with the unfamiliar horse during the sociability test. The alimentary stress induced significant increases of colonic total anaerobic bacteria, lactate-utilizing bacteria and amylolytic bacteria concentrations. When horses were fed the 57% hay–43% barley diet, time spent in vigilance tended to be positively correlated with cecal and colonic amylolytic bacteria concentrations during the sociability test and with cecal lactate-utilizing and

  6. Metal dynamics and tolerance of Typha domingensis exposed to high concentrations of Cr, Ni and Zn.

    Science.gov (United States)

    Mufarrege, M M; Hadad, H R; Di Luca, G A; Maine, M A

    2014-07-01

    Typha domingensis was exposed to a 100mgL(-1) Cr+100mgL(-1) Ni+100mgL(-1) Zn solution. Metal tolerance and metal accumulation in plant tissues and sediment were studied over time. Although removal rates were different, the three metals were efficiently removed from water. Leaf and root tissues showed high metal concentration. However, the sediment showed the highest accumulation. During the first hours of contact, metals were not only accumulated by sediment and roots but they were also taken up by the leaves in direct contact with the solution. Over time, metals were translocated from roots to leaves and vice versa. Metals caused growth inhibition and a decrease in chlorophyll concentration and affected anatomical parameters. Despite these sub-lethal effects, T. domingensis demonstrated that it could accumulate Cr, Ni and Zn efficiently and survive an accidental dump of high concentrations of contaminants in systems such as natural and constructed wetlands. Copyright © 2014 Elsevier Inc. All rights reserved.

  7. Pretreatment solution recycling and high-concentration output for economical production of bioethanol.

    Science.gov (United States)

    Han, Minhee; Moon, Se-Kwon; Choi, Gi-Wook

    2014-11-01

    The purpose of this study was to enhance the economic efficiency of producing bioethanol. Pretreatment solution recycling is expected to increase economic efficiency by reducing the cost of pretreatment and the amount of wastewater. In addition, the production of high-concentration bioethanol could increase economic efficiency by reducing the energy cost of distillation. The pretreatment conditions were 95 °C, 0.72 M NaOH, 80 rpm twin-screw speed, and flow rate of 90 mL/min at 18 g/min of raw biomass feeding for pretreatment solution recycling. The pretreatment with NaOH solution recycling was conducted five times. All of the components and the pretreatment efficiency were similar, despite reuse. In addition, we developed a continuous biomass feeding system for production of high-concentration bioethanol. Using this reactor, the bioethanol productivity was investigated using various pretreated biomass feeding rates in a simultaneous saccharification and fermentation (SSF) process. The maximum ethanol concentration, yield, and productivity were 74.5 g/L, 89.5%, and 1.4 g/L h, respectively, at a pretreated biomass loading of approximately 25% (w/v) with an enzyme dosage of 30 FPU g/cellulose. The results presented here constitute an important contribution toward the production of bioethanol from Miscanthus.

  8. Research on high-temperature heat receiver in concentrated solar radiation system

    Directory of Open Access Journals (Sweden)

    Estera Przenzak

    2017-01-01

    Full Text Available The article presents the results of experimental and computer simulations studies of the high temperature heat receiver working in the concentrated solar radiation system. In order to study the radiation absorption process and heat exchange, the two types of computer simulations were carried out. The first one was used to find the best location for absorber in the concentrating installation. Ray Tracing Monte Carlo (RTMC method in Trace Pro software was used to perform the optical simulations. The results of these simulations were presented in the form of the solar radiation distribution map and chart. The data obtained in RTMC simulations were used as a second type boundary conditions for Computational Fluid Dynamics (CFD simulations. These studies were used to optimize the internal geometry of the receiver and also to select the most effective flow parameters of the working medium. In order to validate the computer simulations, high temperature heat receiver was tested in experimental conditions. The article presents the results of experimental measurements in the form of temperature, radiation intensity and power graphs. The tests were performed for varied flow rate and receiver location. The experimental and computer simulation studies presented in this article allowed to optimize the configuration of concentrating and heat receiving system.

  9. APPLICATION OF TRICKLING FILTER FOR SEWAGE TREATMENT WITH HIGH AMMONIA NITRO GEN CONCENTRATION

    Directory of Open Access Journals (Sweden)

    Wojciech Dąbrowski

    2016-05-01

    Full Text Available The article presents the results of research about the possibility of using trickling filter for high ammonia concentration sewage treatment. The study was conducted with the use of reject water generated during anaerobic sewage sludge stabilization in dairy wastewater treatment plant (WWTP. They are usually returned to the beginning of WWTP. The value of BOD in reject water was approximately the same as in domestic and municipal sewage. Ammonia nitrogen concentration was varied from 145,0 to 390,0 mgN-NH4+/l and phosphorus from 16.0 to 38.0 mgP/l. The study used the Gunt test system CE701e, which allows controlling basic parameters of the treatment with trickling filter. Significant reduction of organic matter, total nitrogen and ammonium was observed during treatment. Average removal efficiency of ammonia nitrogen ranged from 73.6 to 80.3%. In the case of the Kjeldahl nitrogen removal efficiencies ranged from 74.4 to 79.8%. Because of the aerobic conditions during the treatment of phosphorus removal efficiency was low and varied from 32.0 to 33.7%. The research confirmed the efficiency of trickling filter for treatment sewage with high concentration of ammonia nitrogen.

  10. A high temperature hybrid photovoltaic-thermal receiver employing spectral beam splitting for linear solar concentrators

    Science.gov (United States)

    Mojiri, Ahmad; Stanley, Cameron; Rosengarten, Gary

    2015-09-01

    Hybrid photovoltaic/thermal (PV-T) solar collectors are capable of delivering heat and electricity concurrently. Implementing such receivers in linear concentrators for high temperature applications need special considerations such as thermal decoupling of the photovoltaic (pv) cells from the thermal receiver. Spectral beam splitting of concentrated light provides an option for achieving this purpose. In this paper we introduce a relatively simple hybrid receiver configuration that spectrally splits the light between a high temperature thermal fluid and silicon pv cells using volumetric light filtering by semi-conductor doped glass and propylene glycol. We analysed the optical performance of this device theoretically using ray tracing and experimentally through the construction and testing of a full scale prototype. The receiver was mounted on a commercial parabolic trough concentrator in an outdoor experiment. The prototype receiver delivered heat and electricity at total thermal efficiency of 44% and electrical efficiency of 3.9% measured relative to the total beam energy incident on the primary mirror.

  11. Isotopic evidence for a link between agricultural irrigation and high arsenic concentrations in groundwater

    Science.gov (United States)

    Li, M.; Wang, Y.; Shock, E.

    2011-12-01

    An isotope-based survey was carried out in the Datong Basin, northern China to investigate the hydrogeology of groundwater with high arsenic concentrations. Oxygen isotope (δ18O), hydrogen isotope (δD) and radioactive hydrogen isotope (3H) measurements were conducted with the aim of characterizing the groundwater origins and flow dynamics in this arsenic-contaminated groundwater system. Groundwater dating results from 3H measurements show that groundwaters from 20m ~ 70m have a wide range of ages (10a~ 191a), indicating diverse groundwater sources. In contrast, deeper groundwaters (70m ~90m) display a narrower age range (35a ~ 47a). In addition, the shallow-aquifer (70m) possess relatively narrower isotopic ranges and mostly lighter isotopic ratios, from -12.8% to -8.88% and -97.6% to -71.7%, respectively. Comparison with the local meteoric water line shows that groundwater δ18O and δD values plot with a shallower slope, consistent with the arid-semiarid climate of the Datong Basin, as well as a meteoric origin of the groundwater, and points to precipitation as the dominant source of recharge to the deeper aquifers in the study area. Groundwaters with high arsenic concentrations (100μg/L ~ 309μg/L) mainly occur in aquifers at depths between 20m and 70m, while shallower (70m) groundwaters carry relatively lower arsenic concentrations (Science of the Total Environment 407(12): 3823-3835.

  12. Growth Inhibition Occurs Independently of Cell Mortality in Tomato (Solanum lycopersicum) Exposed to High Cadmium Concentrations

    Institute of Scientific and Technical Information of China (English)

    Christine Delpérée; Stanley Lutts

    2008-01-01

    In order to analyze the adaptation potential of tomato shoots to a sudden increase in Cd concentration, tomato plants (Solanum lycopersicum L. var. Ailsa Craig) were exposed under controlled environmental conditions to a high dose of this heavy metal (250 μM CdCl2>) in nutrient solution for 7 and 14 d. Both root and shoot growth was completely inhibited but all plants remained alive until the end of the treatment. Cell viability remained unaffected but the activity of the mitochondrial alternative pathway was stimulated by Cd stress at the expense of the cytochrome pathway. Cadmium concentration was higher in roots than in shoots and a decrease In the rate of net Cd translocation was noticed during the second week of stress. Cadmium decreased both leaf conductance (g1>) and chlorophyll concentration. However, the effect on net CO2 assimilation remained limited and soluble sugars accumulated in leaves. Photochemical efficiency of PSll (FvlFm) was not affected despite a decrease in the number of reaction centers and an inhibition of electron transfer to acceptors of PSII. It is concluded that tomato shoot may sustain short term exposure to high doses of cadmium despite growth inhibition. This property implies several physiological strategies linked to both avoidance and tolerance mechanisms.

  13. Factors influencing the crystallisation of highly concentrated water-in-oil emulsions: A DSC study

    Directory of Open Access Journals (Sweden)

    Irina Masalova

    2012-03-01

    Full Text Available Highly concentrated emulsions are used in a variety of applications, including the cosmetics, food and liquid explosives industries. The stability of these highly concentrated water-in-oil emulsions was studied by differential scanning calorimetry. Crystallisation of the emulsions was initiated by exposing the emulsions to a low temperature. The effects of surfactant type, electrolyte concentration and electrolyte composition in the aqueous phase on emulsion crystallisation temperature were studied. Surfactant type affected the emulsion crystallisation temperature in the following order: PIBSA-MEA=PIBSA-UREA < PIBSA-MEA/SMO < PIBSA-IMIDE < SMO. These results are in the same sequence as results obtained for the stability of these emulsions in aging studies, that is, PIBSA-MEA was the most stable with age and SMO was the least. The effect of the surfactant type on emulsion crystallisation can probably be attributed to the differing strengths of the surfactant–electrolyte interactions, which result in different molecular packing geometry and differing mobility of the surfactant lipophilic portion at the interface. These results enhance our understanding of the factors that affect the stability of explosive emulsions.

  14. High Efficiency Nanostructured III-V Photovoltaics for Solar Concentrator Application

    Energy Technology Data Exchange (ETDEWEB)

    Hubbard, Seth

    2012-09-12

    The High Efficiency Nanostructured III-V Photovoltaics for Solar Concentrators project seeks to provide new photovoltaic cells for Concentrator Photovoltaics (CPV) Systems with higher cell efficiency, more favorable temperature coefficients and less sensitivity to changes in spectral distribution. The main objective of this project is to provide high efficiency III-V solar cells that will reduce the overall cost per Watt for power generation using CPV systems.This work is focused both on a potential near term application, namely the use of indium arsenide (InAs) QDs to spectrally "tune" the middle (GaAs) cell of a SOA triple junction device to a more favorable effective bandgap, as well as the long term goal of demonstrating intermediate band solar cell effects. The QDs are confined within a high electric field i-region of a standard GaAs solar cell. The extended absorption spectrum (and thus enhanced short circuit current) of the QD solar cell results from the increase in the sub GaAs bandgap spectral response that is achievable as quantum dot layers are introduced into the i-region. We have grown InAs quantum dots by OMVPE technique and optimized the QD growth conditions. Arrays of up to 40 layers of strain balanced quantum dots have been experimentally demonstrated with good material quality, low residual stain and high PL intensity. Quantum dot enhanced solar cells were grown and tested under simulated one sun AM1.5 conditions. Concentrator solar cells have been grown and fabricated with 5-40 layers of QDs. Testing of these devices show the QD cells have improved efficiency compared to baseline devices without QDs. Device modeling and measurement of thermal properties were performed using Crosslight APSYS. Improvements in a triple junction solar cell with the insertion of QDs into the middle current limiting junction was shown to be as high as 29% under one sun illumination for a 10 layer stack QD enhanced triple junction solar cell. QD devices have strong

  15. High Dose Vaginal Misoprostol Versus Concentrated Oxytocin + Low Dose Vaginal Misoprostol for Mid-Trimester Labor Induction: A Randomized Trial

    Science.gov (United States)

    Nuthalapaty, Francis S.; Ramsey, Patrick S.; Biggio, Joseph R.; Owen, John

    2013-01-01

    Objective To compare the efficacy and side effects of a high-dose vaginal misoprostol regimen to concentrated intravenous oxytocin plus low-dose vaginal misoprostol for mid-trimester labor induction. Study Design Women at 14-24 weeks, with obstetric or fetal indications for delivery and no prior cesarean, were randomly assigned to receive either vaginal misoprostol 600 μg ×1, then 400 μg q 4 hr × 5 (Group 1) or escalating-dose concentrated oxytocin infusions (277-1667 mU/min) plus vaginal misoprostol 400 μg × 1, then 200 μg q 6 hr × 2, then 100 μg × 1 (Group 2). Analysis was by intent to treat. Primary outcomes were live birth rate and induction-to-delivery interval. Results The intended sample size was 70 women per group; however, the trial was terminated at the initial interim analysis due to a highly significant difference in one of the primary study outcomes. Twenty women were assigned to Group 1 and 18 were assigned to the Group 2. Median induction-to-delivery interval was significantly shorter in Group 1 (12 hr, range 4 - 44 hr) versus Group 2 (18 hr, range 7 - 36 hr; p=0.01). Induction success rate at 12 hours was significantly higher in the Group 1 (60%), compared to Group 2 (22%, p=.02). No significant difference was noted in the live birth rate between Group 1 and 2 (13%, 0%, p = 0.16). The incidence of retained placenta requiring curettage, chorioamnionitis, intrapartum fever, nausea, emesis, and diarrhea were similar between both groups. Conclusion Compared to concentrated oxytocin plus low-dose vaginal misoprostol, high-dose vaginal misoprostol significantly shortens mid-trimester labor inductions. PMID:16157113

  16. Ultra-Fast Low Concentration Detection of Candida Pathogens Utilizing High Resolution Micropore Chips

    Directory of Open Access Journals (Sweden)

    2009-03-01

    Full Text Available Although Candida species are the fourth most common cause of nosocomial blood stream infections in the United States, early diagnostic tools for invasive candidemia are lacking. Due to an increasing rate of candidemia, a new screening system is needed to detect the Candida species in a timely manner. Here we describe a novel method of detection using a solid-state micro-scale pore similar to the operational principles of a Coulter counter. With a steady electrolyte current flowing through the pore, measurements are taken of changes in the current corresponding to the shape of individual yeasts as they translocate or travel through the pore. The direct ultra-fast low concentration electrical addressing of C. albicans has established criteria for distinguishing individual yeast based on their structural properties, which may reduce the currently used methods’ complexity for both identification and quantification capabilities in mixed blood samples

  17. Measured and modelled cloud condensation nuclei number concentration at the high alpine site Jungfraujoch

    Directory of Open Access Journals (Sweden)

    Z. Jurányi

    2010-08-01

    Full Text Available Atmospheric aerosol particles are able to act as cloud condensation nuclei (CCN and are therefore important for the climate and the hydrological cycle, but their properties are not fully understood. Total CCN number concentrations at 10 different supersaturations in the range of SS=0.12–1.18% were measured in May 2008 at the remote high alpine research station, Jungfraujoch, Switzerland (3580 m a.s.l.. In this paper, we present a closure study between measured and predicted CCN number concentrations. CCN predictions were done using dry number size distribution (scanning particle mobility sizer, SMPS and bulk chemical composition data (aerosol mass spectrometer, AMS, and multi-angle absorption photometer, MAAP in a simplified Köhler theory. The predicted and the measured CCN number concentrations agree very well and are highly correlated. A sensitivity study showed that the temporal variability of the chemical composition at the Jungfraujoch can be neglected for a reliable CCN prediction, whereas it is important to know the mean chemical composition. The exact bias introduced by using a too low or too high hygroscopicity parameter for CCN prediction was further quantified and shown to be substantial for the lowest supersaturation.

    Despite the high average organic mass fraction (~45% in the fine mode, there was no indication that the surface tension was substantially reduced at the point of CCN activation. A comparison between hygroscopicity tandem differential mobility analyzer (HTDMA, AMS/MAAP, and CCN derived κ values showed that HTDMA measurements can be used to determine particle hygroscopicity required for CCN predictions if no suitable chemical composition data are available.

  18. Measured and modelled cloud condensation nuclei concentration at the high alpine site Jungfraujoch

    Science.gov (United States)

    Jurányi, Z.; Gysel, M.; Weingartner, E.; Decarlo, P. F.; Kammermann, L.; Baltensperger, U.

    2010-04-01

    Atmospheric aerosol particles are able to act as cloud condensation nuclei (CCN) and are therefore important for the climate and the hydrological cycle, but their properties are not fully understood. Total CCN number concentrations at 10 different supersaturations in the range of SS = 0.12-1.18% were measured in May 2008 at the remote high alpine research station, Jungfraujoch, Switzerland (3580 m asl.). In this paper, we present a closure study between measured and predicted CCN number concentrations. CCN predictions were done using number size distribution (scanning particle mobility sizer, SMPS) and bulk chemical composition data (aerosol mass spectrometer, AMS, and multi-angle absorption photometer, MAAP) in a simplified Köhler theory. The predicted and the measured CCN concentrations agree very well and are highly correlated. A sensitivity study showed that the temporal variability of the chemical composition at the Jungfraujoch can be neglected for a reliable CCN prediction, whereas it is important to know the mean chemical composition. The exact bias introduced by using a too low or too high hygroscopicity parameter for CCN prediction was further quantified and shown to be substantial for the lowest supersaturation. Despite the high average organic mass fraction (45%) during the measurement campaign, there was no indication that the surface tension was substantially reduced at the point of CCN activation. A comparison between hygroscopicity tandem differential mobility analyzer (HTDMA), AMS/MAAP, and CCN derived κ values showed that HTDMA measurements can be used as a chemical composition proxy for CCN predictions if no suitable chemical composition data are available.

  19. Measured and modelled cloud condensation nuclei concentration at the high alpine site Jungfraujoch

    Directory of Open Access Journals (Sweden)

    Z. Jurányi

    2010-04-01

    Full Text Available Atmospheric aerosol particles are able to act as cloud condensation nuclei (CCN and are therefore important for the climate and the hydrological cycle, but their properties are not fully understood. Total CCN number concentrations at 10 different supersaturations in the range of SS = 0.12–1.18% were measured in May 2008 at the remote high alpine research station, Jungfraujoch, Switzerland (3580 m asl.. In this paper, we present a closure study between measured and predicted CCN number concentrations. CCN predictions were done using number size distribution (scanning particle mobility sizer, SMPS and bulk chemical composition data (aerosol mass spectrometer, AMS, and multi-angle absorption photometer, MAAP in a simplified Köhler theory. The predicted and the measured CCN concentrations agree very well and are highly correlated. A sensitivity study showed that the temporal variability of the chemical composition at the Jungfraujoch can be neglected for a reliable CCN prediction, whereas it is important to know the mean chemical composition. The exact bias introduced by using a too low or too high hygroscopicity parameter for CCN prediction was further quantified and shown to be substantial for the lowest supersaturation.

    Despite the high average organic mass fraction (45% during the measurement campaign, there was no indication that the surface tension was substantially reduced at the point of CCN activation. A comparison between hygroscopicity tandem differential mobility analyzer (HTDMA, AMS/MAAP, and CCN derived κ values showed that HTDMA measurements can be used as a chemical composition proxy for CCN predictions if no suitable chemical composition data are available.

  20. Measured and modelled cloud condensation nuclei number concentration at the high alpine site Jungfraujoch

    Science.gov (United States)

    Jurányi, Z.; Gysel, M.; Weingartner, E.; Decarlo, P. F.; Kammermann, L.; Baltensperger, U.

    2010-08-01

    Atmospheric aerosol particles are able to act as cloud condensation nuclei (CCN) and are therefore important for the climate and the hydrological cycle, but their properties are not fully understood. Total CCN number concentrations at 10 different supersaturations in the range of SS=0.12-1.18% were measured in May 2008 at the remote high alpine research station, Jungfraujoch, Switzerland (3580 m a.s.l.). In this paper, we present a closure study between measured and predicted CCN number concentrations. CCN predictions were done using dry number size distribution (scanning particle mobility sizer, SMPS) and bulk chemical composition data (aerosol mass spectrometer, AMS, and multi-angle absorption photometer, MAAP) in a simplified Köhler theory. The predicted and the measured CCN number concentrations agree very well and are highly correlated. A sensitivity study showed that the temporal variability of the chemical composition at the Jungfraujoch can be neglected for a reliable CCN prediction, whereas it is important to know the mean chemical composition. The exact bias introduced by using a too low or too high hygroscopicity parameter for CCN prediction was further quantified and shown to be substantial for the lowest supersaturation. Despite the high average organic mass fraction (~45%) in the fine mode, there was no indication that the surface tension was substantially reduced at the point of CCN activation. A comparison between hygroscopicity tandem differential mobility analyzer (HTDMA), AMS/MAAP, and CCN derived κ values showed that HTDMA measurements can be used to determine particle hygroscopicity required for CCN predictions if no suitable chemical composition data are available.

  1. Carbon dioxide as working fluid for medium and high-temperature concentrated solar thermal systems

    Directory of Open Access Journals (Sweden)

    Van Duong

    2014-03-01

    Full Text Available This paper explores the benefits and drawbacks of using carbon dioxide in solar thermal systems at medium and high operating temperatures. For medium temperatures, application of CO2 in non-imaging-optics based compound parabolic concentrators (CPC combined with evacuated-tube collectors is studied. These collectors have been shown to obtain efficiencies higher than 40% operating at around 200℃ without the need of tracking. Validated numerical models of external compound parabolic concentrators (XCPCs are used to simulate their performance using CO2 as working fluid. For higher temperatures, a mathematical model is implemented to analyze the operating performance of a parabolic trough solar collector (PTC using CO2 at temperatures between 100℃ and 600℃.

  2. Phenomenon of energy concentration in high-energy family events of cosmic rays

    CERN Document Server

    Wang He; Dai Zhi Qiang; Xue Liang; Feng Cun Feng; Zhang Xue Yao; Li Jin; Zhang Nai Jian; He Mao; Wang Cheng Rui; Ren Jing Ru; Lu Sui Ling

    2002-01-01

    The phenomenon of energy concentration in high-energy family events of cosmic rays is studied by comparing the results of family events of total visible energies 100-400 TeV observed in the Kanbala emulsion chamber experiment with the Monte Carlo simulation data. The simulation is made by the program CORSIKA in which QGSJET is applied as the hadronic interaction model, and the chemical composition of primary cosmic rays is obtained from the rigidity-cut model and the extrapolation of new results of direct measurements. This shows that the whole distribution tendency of the rate of energy concentration of simulated family events is basically consistent with that of the experiment

  3. Synthesis of oligo- and polysaccharides by Lactobacillus reuteri 121 reuteransucrase at high concentrations of sucrose.

    Science.gov (United States)

    Meng, Xiangfeng; Dobruchowska, Justyna M; Gerwig, Gerrit J; Kamerling, Johannis P; Dijkhuizen, Lubbert

    2015-09-23

    GTFA, a glucansucrase enzyme of the probiotic bacterium Lactobacillus reuteri 121, is capable of synthesizing an α-glucan polysaccharide with (1 → 4) and (1 → 6) linkages from sucrose. With respect to its biosynthesis, the present study has shown that the ratio of oligosaccharide versus polysaccharide synthesized was directly proportional to the concentration of sucrose. It appears that the size distribution of products is kinetically controlled, but the linkage distribution in the polysaccharide material is not changed. At high sucrose concentrations the sucrose isomers leucrose and trehalulose were synthesized, using the accumulated fructose as acceptor, together with 4'- and 6'-α-D-glucosyl-leucrose and 6'-α-D-glucosyl-trehalulose. The finding of an additional branched hexasaccharide demonstrates that the enzyme is able to introduce branch-points already in relatively short oligosaccharides.

  4. Green synthesis of highly concentrated aqueous colloidal solutions of large starch-stabilised silver nanoplatelets.

    Science.gov (United States)

    Cheng, Fei; Betts, Jonathan W; Kelly, Stephen M; Hector, Andrew L

    2015-01-01

    A simple, environmentally friendly and cost-effective method has been developed to prepare a range of aqueous silver colloidal solutions, using ascorbic acid as a reducing agent, water-soluble starch as a combined crystallising, stabilising and solubilising agent, and water as the solvent. The diameter of silver nanoplatelets increases with higher concentrations of AgNO3 and starch. The silver nanoparticles are also more uniform in shape the greater the diameter of the nanoparticles. Colloidal solutions with a very high concentration of large, flat, hexagonal silver nanoplatelets (~230 nm in breadth) have been used to deposit and fix an antibacterial coating of these large starch-stabilised silver nanoplates on commercial cotton fibres, using a simple dip-coating process using water as the solvent, in order to study the dependence of the antibacterial properties of these nanoplatelets on their size.

  5. Effect of turbulence on the efficiency of separation in hydrocyclones at high feed solids concentrations

    Energy Technology Data Exchange (ETDEWEB)

    Neese, T.

    1986-01-01

    The model of turbulent cross-flow classification originally developed for dilute-flow separations (low solids concentration of the feed) in hydrocyclones can also be applied to dense- flow separations (high solids concentration of the feed). The sharpness of separation is characterized by a physically based normalized efficiency curve T(d/d/sub 50/). The determination of cut size starts from a relationship between the normalized efficiency curve and the empirically determined recovery of feed solids to underflow product. It is shown, that the cut size of dense-flow separations depends on the particle size distribution of feed, flow conditions during particle sedimentation as well as on recovery of solids and recovery of fluid to underflow product. A comparison between calculated and observed cut sizes has been made.

  6. TWO-PHASE FLOW OF HIGHLY CONCENTRATED SLURRY IN A PIPELINE

    Institute of Scientific and Technical Information of China (English)

    NI Fu-sheng; ZHAO Li-juan; MATOUSEK V.; VLASBLOM W. J.; ZWARTBOL A.

    2004-01-01

    Hydraulic transport of sand is one of the key processes in river, lake, harbor and waterway dredging engineering. Understanding the flow resistance, solid distribution, flow stratification, transport economy, etc., in the two-phase flow of sand-water mixture through a pipeline is crucial to the design and operation of power drives of a dredger, and to the construction of a dredging project. This paper presents the intensive laboratory experimental data and physical and numerical analyses on the highly concentrated slurry flow under an extended large range of slurry mean velocities for three narrow-graded sands of different sizes. The investigation indicates that the solids concentration and particle size strongly affect the slurry flow characteristics.

  7. Low temperature mechanical properties of steels containing high concentrations of helium

    Energy Technology Data Exchange (ETDEWEB)

    Ullmaier, H. [Forschungszentrum Juelich GmbH (Germany). Inst. fuer Festkoerperforschung; Camus, E. [Hahn-Meitner-Institut Berlin GmbH, Glienicker Strasse 100, D-14109 Berlin (Germany)

    1997-11-01

    Results of tensile tests and hardness measurements in the temperature range 25-400 C are reported for ferritic-martensitic steels and s.a. 316 L austenitic steel. Helium concentrations up to 1 at.% have beenintroduced into these materials by {alpha}-particle (0-25 MeV) implantation and He/Fe dual-beam (15/300 keV) irradiation, respectively. In the latter case displacement damage up to 50 dpa was produced simultaneously with the introduction of He. From a preliminary analysis of the results and a comparison with earlier data it may be concluded that for temperatures up to at least 400 C the observed hardening is dominated by displacement damage. Only for very high helium concentrations around 1 at.% a moderate further increase of hardness is found, indicating that helium does not have a drastic effect on the mechanical properties of the investigated alloys. (orig.). 31 refs.

  8. Subcutaneous absorption kinetics of two highly concentrated preparations of recombinant human growth hormone

    DEFF Research Database (Denmark)

    Laursen, Torben; Jørgensen, Jens Otto Lunde; Susgaard, Søren

    1993-01-01

    of signs of endogenous GH secretion. INTERVENTIONS: At the start of each study period, GH 3 IU/m2 was injected subcutaneously. The two formulations, PenFill and PenSet, differ in the buffers used and in the relative content of mannitol and glycine. Serum profiles of GH were monitored frequently for 24......Abstract OBJECTIVE: The relative bioavailability of two highly concentrated (12 IU/ml) formulations of biosynthetic human growth hormone (GH) administered subcutaneously was compared. DESIGN: A randomized, crossover study. Conventional GH therapy was withdrawn 72 hours before each study period...... not significantly differ from 1 (p = 0.13). Neither Cmax (p = 0.74) nor Tmax (p = 0.58) of the two formulations was significantly different. Injection of the two formulations induced similar increments in serum IFG-I (p = 0.48). Serum insulin and blood glucose concentrations were not significantly different...

  9. Phenomenon of Energy Concentration in High-Energy Family Events of Cosmic Rays

    Institute of Scientific and Technical Information of China (English)

    王河; 王永刚; 戴志强; 薛良; 冯存峰; 张学尧; 李金玉; 张乃健; 何瑁; 王承瑞; 任敬儒; 陆穗苓

    2002-01-01

    The phenomenon of energy concentration in high-energy family events of cosmic rays is studied by comparing the results of family events of total visible energies 100-400 TeV observed in the Kanbala emulsion chamber experiment with the Monte Carlo simulation data. The simulation is made by the program CORSIKA in which QGSJET is applied as the hadronic interaction model, and the chemical composition of primary cosmic rays is obtained from the rigidity-cut model and the extrapolation of new results of direct measurements. This shows that the whole distribution tendency of the rate of energy concentration of simulated family events is basically consistent with that of the experiment.

  10. Single-molecule detection at high concentrations with optical aperture nanoantennas

    Science.gov (United States)

    Alam, Md Shah; Karim, Farzia; Zhao, Chenglong

    2016-05-01

    Single-molecule detection has become an indispensable technology in life science, and medical research. In order to get meaningful information on many biological processes, single-molecule analysis is required in micro-molar concentrations. At such high concentrations, it is very challenging to isolate a single molecule with conventional diffraction-limited optics. Recently, optical aperture nanoantennas (OANs) have emerged as a powerful tool to enhance the single-molecule detection under a physiological environment. The OANs, which consist of nano-scale apertures on a metallic film, have the following unique properties: (1) nanoscale light confinement; (2) enhanced fluorescence emission; (3) tunable radiation pattern; (4) reduced background noise; and (5) massive parallel detection. This review presents the fundamentals, recent developments and future perspectives in this emerging field.

  11. High Variability of Plasma Drug Concentrations in Dual Protease Inhibitor Regimens

    Science.gov (United States)

    Guiard-Schmid, Jean-Baptiste; Poirier, Jean-Marie; Meynard, Jean-Luc; Bonnard, Philippe; Gbadoe, Ayi Hola; Amiel, Corinne; Calligaris, Frédérique; Abraham, Bruno; Pialoux, Gilles; Girard, Pierre-Marie; Jaillon, Patrice; Rozenbaum, Willy

    2003-01-01

    Ritonavir (RTV) strongly increases the concentrations of protease inhibitors (PIs) in plasma in patients given a combination of RTV and another PI. This pharmacological interaction is complex and poorly characterized and shows marked inter- and intraindividual variations. In addition, RTV interacts differently with saquinavir (SQV), indinavir (IDV), amprenavir (APV), and lopinavir (LPV). In this retrospective study on 542 human immunodeficiency virus-infected patients, we compared inter- and intraindividual variability of plasma PI concentrations and correlations between the Cmin (minimum concentration of drug in plasma) values for RTV and the coadministered PI Cmin values. Mean RTV Cmins are significantly lower in patients receiving combinations containing APV or LPV than in combinations with SQV or IDV. With the most common PI dose regimens (600 mg of IDV twice a day [BID], 800 mg of SQV BID, and 400 mg of LPV BID), the interindividual Cmin variability of patients treated with a PI and RTV seemed to be lower with APV and LPV than with IDV and SQV. As regards intraindividual variability, APV also differed from the other PIs, exhibiting lower Cmin variability than with the other combinations. Significant positive correlations between RTV Cmin and boosted PI Cmin were observed with IDV, SQV, and LPV, but not with APV. Individual dose adjustments must take into account the specificity the pharmacological interaction of each RTV/PI combination and the large inter- and intraindividual variability of plasma PI levels to avoid suboptimal plasma drug concentrations which may lead to treatment failure and too high concentrations which may induce toxicity and therefore reduce patient compliance. PMID:12604531

  12. High Ice Water Concentrations in the 19 August 2015 Coastal Mesoconvective System

    Science.gov (United States)

    Proctor, Fred H.; Harrah, Steven; Switzer, George F.; Strickland, Justin K.; Hunt, Patricia J.

    2017-01-01

    During August 2015, NASA's DC-8 research aircraft was flown into High Ice Water Content (HIWC) events as part of a three-week campaign to collect airborne radar data and to obtain measurements from microphysical probes. Goals for this flight campaign included improved characterization of HIWC events, especially from an airborne radar perspective. This paper focuses on one of the flight days, in which a coastal mesoscale convective system (MCS) was investigated for HIWC conditions. The system appears to have been maintained by bands of convection flowing in from the Gulf of Mexico. These convective bands were capped by a large cloud canopy, which masks the underlying structure if viewed from an infrared sensing satellite. The DC-8 was equipped with an IsoKinetic Probe that measured ice concentrations of up to 2.3 g m(exp -3) within the cloud canopy of this system. Sustained measurements of ice crystals with concentrations exceeding 1 g m(exp -3) were encountered for up to ten minutes of flight time. Airborne Radar reflectivity factors were found to be weak within these regions of high ice water concentrations, suggesting that Radar detection of HIWC would be a challenging endeavor. This case is then investigated using a three-dimensional numerical cloud model. Profiles of ice water concentrations and radar reflectivity factor demonstrate similar magnitudes and scales between the flight measurements and model simulation. Also discussed are recent modifications to the numerical model's ice-microphysics that are based on measurements during the flight campaign. The numerical model and its updated ice-microphysics are further validated with a simulation of a well-known case of a supercell hailstorm measured during the Cooperative Convective Precipitation Experiment. Differences in HIWC between the continental supercell and the coastal MCS are discussed.

  13. Root based responses account for Psidium guajava survival at high nickel concentration.

    Science.gov (United States)

    Bazihizina, Nadia; Redwan, Mirvat; Taiti, Cosimo; Giordano, Cristiana; Monetti, Emanuela; Masi, Elisa; Azzarello, Elisa; Mancuso, Stefano

    2015-02-01

    The presence of Psidium guajava in polluted environments has been reported in recent studies, suggesting that this species has a high tolerance to the metal stress. The present study aims at a physiological characterization of P. guajava response to high nickel (Ni) concentrations in the root-zone. Three hydroponic experiments were carried out to characterize the effects of toxic Ni concentrations on morphological and physiological parameters of P. guajava, focusing on Ni-induced damages at the root-level and root ion fluxes. With up to 300μM NiSO4 in the root-zone, plant growth was similar to that in control plants, whereas at concentrations higher than 1000μM NiSO4 there was a progressive decline in plant growth and leaf gas exchange parameters; this occurred despite, at all considered concentrations, plants limited Ni(2+) translocation to the shoot, therefore avoiding shoot Ni(2+) toxicity symptoms. Maintenance of plant growth with 300μM Ni(2+) was associated with the ability to retain K(+) in the roots meanwhile 1000 and 3000μM NiSO4 led to substantial K(+) losses. In this study, root responses mirror all plant performances suggesting a direct link between root functionality and Ni(2+) tolerance mechanisms and plant survival. Considering that Ni was mainly accumulated in the root system, the potential use of P. guajava for Ni(2+) phytoextraction in metal-polluted soils is limited; nevertheless, the observed physiological changes indicate a good Ni(2+) tolerance up to 300μM NiSO4 suggesting a potential role for the phytostabilization of polluted soils. Copyright © 2014 Elsevier GmbH. All rights reserved.

  14. Steric stabilization of nanoparticles with grafted low molecular weight ligands in highly concentrated brines including divalent ions.

    Science.gov (United States)

    Worthen, Andrew J; Tran, Vu; Cornell, Kevin A; Truskett, Thomas M; Johnston, Keith P

    2016-02-21

    Whereas numerous studies of stabilization of nanoparticles (NPs) in electrolytes have examined biological fluids, the interest has grown recently in media with much higher ionic strengths including seawater and brines relevant to environmental science and subsurface oil and gas reservoirs. Given that electrostatic repulsion is limited at extremely high ionic strengths due to charge screening, we have identified ligands that are well solvated in concentrated brine containing divalent cations and thus provide steric stabilization of silica nanoparticles. Specifically, the hydrodynamic diameter of silica nanoparticles with grafted low molecular weight ligands, a diol ether, [3-(2,3-dihydroxypropoxy)propyl]-trimethoxysilane, and a zwitterionic sulfobetaine, 3-([dimethyl(3-trimethoxysilyl)propyl]ammonio)propane-1-sulfonate, is shown with dynamic light scattering to remain essentially constant, indicating lack of aggregation, at room temperature and up to 80 °C for over 30 days. An extended DLVO model signifies that steric stabilization is strongly dominant against van der Waals attraction for ∼10 nm particles given that these ligands are well solvated even in highly concentrated brine. In contrast, polyethylene glycol oligomers do not provide steric stabilization at elevated temperatures, even at conditions where the ligands are soluble, indicating complicating factors including bridging of the ether oxygens by divalent cations.

  15. Factors affecting biotic mercury concentrations and biomagnification through lake food webs in the Canadian high Arctic

    Energy Technology Data Exchange (ETDEWEB)

    Lescord, Gretchen L., E-mail: glescord@gmail.com [University of New Brunswick/Canadian Rivers Institute, 100 Tucker Park Rd, Saint John, NB E2L 4A6 (Canada); Kidd, Karen A. [University of New Brunswick/Canadian Rivers Institute, 100 Tucker Park Rd, Saint John, NB E2L 4A6 (Canada); Kirk, Jane L. [Environment Canada, Aquatic Contaminants Research Division, 867 Lakeshore Rd, Burlington, ON L7S 1A1 (Canada); O' Driscoll, Nelson J. [Acadia University, 15 University Ave, Wolfville, NS B4P 2R6 (Canada); Wang, Xiaowa; Muir, Derek C.G. [Environment Canada, Aquatic Contaminants Research Division, 867 Lakeshore Rd, Burlington, ON L7S 1A1 (Canada)

    2015-03-15

    In temperate regions of Canada, mercury (Hg) concentrations in biota and the magnitude of Hg biomagnification through food webs vary between neighboring lakes and are related to water chemistry variables and physical lake features. However, few studies have examined factors affecting the variable Hg concentrations in landlocked Arctic char (Salvelinus alpinus) or the biomagnification of Hg through their food webs. We estimated the food web structure of six high Arctic lakes near Resolute Bay, Nunavut, Canada, using stable carbon (δ{sup 13}C) and nitrogen (δ{sup 15}N) isotopes and measured Hg (total Hg (THg) in char, the only fish species, and methylmercury (MeHg) in chironomids and zooplankton) concentrations in biota collected in 2010 and 2011. Across lakes, δ{sup 13}C showed that benthic carbon (chironomids) was the dominant food source for char. Regression models of log Hg versus δ{sup 15}N (of char and benthic invertebrates) showed positive and significant slopes, indicting Hg biomagnification in all lakes, and higher slopes in some lakes than others. However, no principal components (PC) generated using all water chemistry data and physical characteristics of the lakes predicted the different slopes. The PC dominated by aqueous ions was a negative predictor of MeHg concentrations in chironomids, suggesting that water chemistry affects Hg bioavailability and MeHg concentrations in these lower-trophic-level organisms. Furthermore, regression intercepts were predicted by the PCs dominated by catchment area, aqueous ions, and MeHg. Weaker relationships were also found between THg in small char or MeHg in pelagic invertebrates and the PCs dominated by catchment area, and aqueous nitrate and MeHg. Results from these high Arctic lakes suggest that Hg biomagnification differs between systems and that their physical and chemical characteristics affect Hg concentrations in lower-trophic-level biota. - Highlights: • Mercury (Hg) in Arctic char and invertebrates

  16. Solution behavior and activity of a halophilic esterase under high salt concentration.

    Directory of Open Access Journals (Sweden)

    Lang Rao

    Full Text Available BACKGROUND: Halophiles are extremophiles that thrive in environments with very high concentrations of salt. Although the salt reliance and physiology of these extremophiles have been widely investigated, the molecular working mechanisms of their enzymes under salty conditions have been little explored. METHODOLOGY/PRINCIPAL FINDINGS: A halophilic esterolytic enzyme LipC derived from archeaon Haloarcula marismortui was overexpressed from Escherichia coli BL21. The purified enzyme showed a range of hydrolytic activity towards the substrates of p-nitrophenyl esters with different alkyl chains (n = 2-16, with the highest activity being observed for p-nitrophenyl acetate, consistent with the basic character of an esterase. The optimal esterase activities were found to be at pH 9.5 and [NaCl] = 3.4 M or [KCl] = 3.0 M and at around 45 degrees C. Interestingly, the hydrolysis activity showed a clear reversibility against changes in salt concentration. At the ambient temperature of 22 degrees C, enzyme systems working under the optimal salt concentrations were very stable against time. Increase in temperature increased the activity but reduced its stability. Circular dichroism (CD, dynamic light scattering (DLS and small angle neutron scattering (SANS were deployed to determine the physical states of LipC in solution. As the salt concentration increased, DLS revealed substantial increase in aggregate sizes, but CD measurements revealed the maximal retention of the alpha-helical structure at the salt concentration matching the optimal activity. These observations were supported by SANS analysis that revealed the highest proportion of unimers and dimers around the optimal salt concentration, although the coexistent larger aggregates showed a trend of increasing size with salt concentration, consistent with the DLS data. CONCLUSIONS/SIGNIFICANCE: The solution alpha-helical structure and activity relation also matched the highest proportion of enzyme unimers

  17. Radiation crosslinking of carboxymethylcellulose of various degree of substitution at high concentration in aqueous solutions of natural pH

    Science.gov (United States)

    Wach, Radoslaw A.; Mitomo, Hiroshi; Nagasawa, Naotsugu; Yoshii, Fumio

    2003-12-01

    Carboxymethylcellulose (CMC) hydrogel formed by ionizing radiation at highly concentrated aqueous solutions was found to undergo swelling depending on the pH of the swelling media. Swelling increases at neutral and basic pH due to ionization of carboxymethyl groups on side chains. The presence of charges develops repulsive forces between polymer chains of the network causing its expansion. Hydrogel in relaxed state as well as dried gel reveals good mechanical properties. It was considered that intermolecular crosslinking reactions occur by a radical route. Radicals placed on anhydroglucose repeating unit as well as on side chains were distinguished from ESR spectra of CMC. A stable doublet signal with 2.0 mT splitting constant belongs to a radical placed on the α-carbon atom of the substituent group, R-O- rad CH-COO -. It was assumed that this species participates in intermolecular crosslinking.

  18. Production of high concentrated cellulosic ethanol by acetone/water oxidized pretreated beech wood.

    Science.gov (United States)

    Katsimpouras, Constantinos; Kalogiannis, Konstantinos G; Kalogianni, Aggeliki; Lappas, Angelos A; Topakas, Evangelos

    2017-01-01

    Lignocellulosic biomass is an abundant and inexpensive resource for biofuel production. Alongside its biotechnological conversion, pretreatment is essential to enable efficient enzymatic hydrolysis by making cellulose susceptible to cellulases. Wet oxidation of biomass, such as acetone/water oxidation, that employs hot acetone, water, and oxygen, has been found to be an attractive pretreatment method for removing lignin while producing less degradation products. The remaining enriched cellulose fraction has the potential to be utilized under high gravity enzymatic saccharification and fermentation processes for the cost-competing production of bioethanol. Beech wood residual biomass was pretreated following an acetone/water oxidation process aiming at the production of high concentration of cellulosic ethanol. The effect of pressure, reaction time, temperature, and acetone-to-water ratio on the final composition of the pretreated samples was studied for the efficient utilization of the lignocellulosic feedstock. The optimal conditions were acetone/water ratio 1:1, 40 atm initial pressure of 40 vol% O2 gas, and 64 atm at reaction temperature of 175 °C for 2 h incubation. The pretreated beech wood underwent an optimization step studying the effect of enzyme loading and solids content on the enzymatic liquefaction/saccharification prior to fermentation. In a custom designed free-fall mixer at 50 °C for either 6 or 12 h of prehydrolysis using an enzyme loading of 9 mg/g dry matter at 20 wt% initial solids content, high ethanol concentration of 75.9 g/L was obtained. The optimization of the pretreatment process allowed the efficient utilization of beech wood residual biomass for the production of high concentrations of cellulosic ethanol, while obtaining lignin that can be upgraded towards high-added-value chemicals. The threshold of 4 wt% ethanol concentration that is required for the sustainable bioethanol production was surpassed almost twofold

  19. Oxygen concentration control of dopamine-induced high uniformity surface coating chemistry.

    Science.gov (United States)

    Kim, Hyo Won; McCloskey, Bryan D; Choi, Tae Hwan; Lee, Changho; Kim, Min-Joung; Freeman, Benny D; Park, Ho Bum

    2013-01-23

    Material surface engineering has attracted great interest in important applications, including electronics, biomedicine, and membranes. More recently, dopamine has been widely exploited in solution-based chemistry to direct facile surface modification. However, unsolved questions remain about the chemical identity of the final products, their deposition kinetics and their binding mechanism. In particular, the dopamine oxidation reaction kinetics is a key to improving surface modification efficiency. Here, we demonstrate that high O(2) concentrations in the dopamine solution lead to highly homogeneous, thin layer deposition on any material surfaces via accelerated reaction kinetics, elucidated by Le Chatelier's principle toward dopamine oxidation steps in a Michael-addition reaction. As a result, highly uniform, ultra-smooth modified surfaces are achieved in much shorter deposition times. This finding provides new insights into the effect of reaction kinetics and molecular geometry on the uniformity of modifications for surface engineering techniques.

  20. Large-area, high-intensity PV arrays for systems using dish concentrating optics

    Energy Technology Data Exchange (ETDEWEB)

    Ward, J.S.; Duda, A.; Zweibel, K.; Coutts, T.J. [National Renewable Energy Lab., Golden, CO (United States)

    1998-09-01

    In this paper, the authors report on efforts to fabricate monolithic interconnected modules (MIMs) using III-V semiconductors with bandgaps appropriate for the terrestrial solar spectrum. The small size of the component cells comprising the MIM allows for operation at extremely high flux densities and relaxes the requirement for a small spot size to be generated by the optics. This makes possible a PV option for the large dish concentrator systems that have been developed by the solar thermal community for use with Stirling engines. Additionally, the highly effective back-surface reflector integrated into the MIM design is an effective tool for thermal management of the array. Development of this technology would radically alter the projections for PV manufacturing capacity because of the potential for extremely high power generation per unit area of semiconductor material.

  1. Study on Application of Novel Flocculating Agent in Treating Refinery Wastewater with High Concentration of Pollutants

    Institute of Scientific and Technical Information of China (English)

    Zhang Baoji; Qin Bing

    2009-01-01

    After conducting a lot of screening experiments the appropriate flocculating formulations for treating high-con-centration wastewater discharged fi'om a certain refinery were selected. The oil removal rate and COD removal achieved by these flocculating formulations were better than that achieved by the conventional compound formulation consisting of polyaluminium chloride (PAC) and polyactylamide (PAA). Addition of an oil/water separating agent to the formulation could improve its oil removal performance to facilitate the oil/water separation of the oil-in-water emulsion in the high-concentra-tion wastewater along with improved adaptability of the formulation to the wastewater containing high concentration of pollutants. This flocculating agent has promising prospects for commercial application.

  2. Tolerance of spermatogonia to oxidative stress is due to high levels of Zn and Cu/Zn superoxide dismutase.

    Directory of Open Access Journals (Sweden)

    Fritzie T Celino

    Full Text Available BACKGROUND: Spermatogonia are highly tolerant to reactive oxygen species (ROS attack while advanced-stage germ cells such as spermatozoa are much more susceptible, but the precise reason for this variation in ROS tolerance remains unknown. METHODOLOGY/PRINCIPAL FINDINGS: Using the Japanese eel testicular culture system that enables a complete spermatogenesis in vitro, we report that advanced-stage germ cells undergo intense apoptosis and exhibit strong signal for 8-hydroxy-2'-deoxyguanosine, an oxidative DNA damage marker, upon exposure to hypoxanthine-generated ROS while spermatogonia remain unaltered. Activity assay of antioxidant enzyme, superoxide dismutase (SOD and Western blot analysis using an anti-Copper/Zinc (Cu/Zn SOD antibody showed a high SOD activity and Cu/Zn SOD protein concentration during early spermatogenesis. Immunohistochemistry showed a strong expression for Cu/Zn SOD in spermatogonia but weak expression in advanced-stage germ cells. Zn deficiency reduced activity of the recombinant eel Cu/Zn SOD protein. Cu/Zn SOD siRNA decreased Cu/Zn SOD expression in spermatogonia and led to increased oxidative damage. CONCLUSIONS/SIGNIFICANCE: These data indicate that the presence of high levels of Cu/Zn SOD and Zn render spermatogonia resistant to ROS, and consequently protected from oxidative stress. These findings provide the biochemical basis for the high tolerance of spermatogonia to oxidative stress.

  3. Corrosion mechanism of 13Cr stainless steel in completion fluid of high temperature and high concentration bromine salt

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Yan [Corrosion and Protection Center, Key Laboratory for Environmental Fracture (MOE), Institute for Advanced Materials and Technology, University of Science and Technology Beijing, Beijing 100083 (China); Xu, Lining, E-mail: xulining@ustb.edu.cn [Corrosion and Protection Center, Key Laboratory for Environmental Fracture (MOE), Institute for Advanced Materials and Technology, University of Science and Technology Beijing, Beijing 100083 (China); Lu, Minxu [Corrosion and Protection Center, Key Laboratory for Environmental Fracture (MOE), Institute for Advanced Materials and Technology, University of Science and Technology Beijing, Beijing 100083 (China); Meng, Yao [Beijing Institute of Aeronautical Materials, Beijing 100095 (China); Zhu, Jinyang; Zhang, Lei [Corrosion and Protection Center, Key Laboratory for Environmental Fracture (MOE), Institute for Advanced Materials and Technology, University of Science and Technology Beijing, Beijing 100083 (China)

    2014-09-30

    Highlights: • The corrosion behavior of 13Cr steel exposed to bromine salt completion fluid containing high concentration bromine ions was investigated. • There are passive circles around pits on the 13Cr steel surface after 7 d of exposure. • Macroscopic galvanic corrosion formed between the passive halo and the pit. • The mechanism of pitting corrosion on 13Cr stainless steel exposed to heavy bromine brine was established. - Abstract: A series of corrosion tests of 13Cr stainless steel were conducted in a simulated completion fluid environment of high temperature and high concentration bromine salt. Corrosion behavior of specimens and the component of corrosion products were investigated by means of scanning electron microscope (SEM), confocal laser scanning microscopy (CLSM) and X-ray photoelectron spectroscopy (XPS). The results indicate that 13Cr steel suffers from severe local corrosion and there is always a passive halo around every pit. The formation mechanism of the passive halo is established. OH{sup −} ligand generates and adsorbs in a certain scale because of abundant OH{sup −} on the surface around the pits. Passive film forms around each pit, which leads to the occurrence of passivation in a certain region. Finally, the dissimilarities in properties and morphologies of regions, namely the pit and its corresponding passive halo, can result in different corrosion sensitivities and may promote the formation of macroscopic galvanic pairs.

  4. Assessment of Aspartame Exposure Due to Consumption of Some Imported Chewing Gums by Microwave Digestion and High Performance Liquid Chromatography Analysis

    Directory of Open Access Journals (Sweden)

    Zohreh Rasouli

    2016-06-01

    Full Text Available Aspartame is a widely used artificial sweetener, the long-term safety of which has been controversial ever since it was accepted for human consumption. The main aim of this research is assessment of aspartame exposure due to consumption of some imported chewing gums during summer 2015 to Iran by microwave digestion and HPLC analysis. Thirty chewing gums from highly consumed imported ones were collected from retail market in Tehran. Closed vessel microwave digestion was employed for sample preparation using a three phase temperature program. An aliquot of 20 μL of prepared samples was injected into the HPLC column and the aspartame was detected at 254 nm with an on-line detector. Concentration of aspartame in chewing gum samples was between 1.9 and 30.5 μg/g with an average of 11.1 μg/g. In conclusion, despite of existing aspartame in 76.6 percent of samples, however the effective amount of this artificial sweetener is not as high as the levels that international legislations recommended for exposing due to chewing gum consumption.

  5. Tropical soils with high aluminum concentrations cause oxidative stress in two tomato genotypes.

    Science.gov (United States)

    Nogueirol, Roberta Corrêa; Monteiro, Francisco Antonio; Gratão, Priscila Lupino; Borgo, Lucélia; Azevedo, Ricardo Antunes

    2015-03-01

    Tropical and subtropical soils are usually acidic and have high concentrations of aluminum (Al). Aluminum toxicity in plants is caused by the high affinity of the Al cation for cell walls, membranes, and metabolites. In this study, the response of the antioxidant-enzymatic system to Al was examined in two tomato genotypes: Solanum lycopersicum var. esculentum (Calabash Rouge) and Solanum lycopersicum var. cerasiforme (CNPH 0082) grown in tropical soils with varying levels of Al. Plant growth; activities of superoxide dismutase (SOD), catalase (CAT), ascorbate peroxidase (APX), guaiacol peroxidase (GPOX), and glutathione reductase (GR) enzymes; stress-indicating compounds (malondialdehyde (MDA) and hydrogen peroxide); and morphology (root length and surface area) were analyzed. Increased levels of Al in soils were correlated with reduced shoot and root biomass and with reduced root length and surface area. Calabash Rouge exhibited low Al concentrations and increased growth in soils with the highest levels of Al. Plants grown in soils with high availability of Al exhibited higher levels of stress indicators (MDA and hydrogen peroxide) and higher enzyme activity (CAT, APX, GPOX, and GR). Calabash Rouge absorbed less Al from soils than CNPH 0082, which suggests that the genotype may possess mechanisms for Al tolerance.

  6. Producing high sugar concentrations from loblolly pine using wet explosion pretreatment.

    Science.gov (United States)

    Rana, Diwakar; Rana, Vandana; Ahring, Birgitte K

    2012-10-01

    We present quantitative analysis of pretreatment for obtaining high conversion and release of sugars from loblolly pine. We use wet explosion (WEx): wet oxidation followed by steam explosion and enzymatic hydrolysis (EH) at high dry matter to solubilize sugars. WEx was conducted at 25% (w/w) solids in presence of oxygen at pressures 6.5-7.2 bar, temperatures 170-175°C and residence time from 20 to 22.5 min. EH of pretreated samples was performed by Cellic® Ctec2 (60 mg protein/g cellulose) and Cellic® Htec2 enzymes (10% of Ctec2) at 50°C for 72 h. At the optimal WEx condition 96% cellulose and nearly 100% hemicellulose yield were obtained. The final concentrations of monomeric sugars were 152 g/L of glucose, 67 g/L of xylose, and 67 g/L of minor sugars (galactose, arabinose and mannose). Compared to previous work WEx seems to be superior for releasing high concentrations of monomeric sugars.

  7. Application of falling-needle rheometry to highly concentrated DNA solutions.

    Science.gov (United States)

    Burger, Jessica; Yamamoto, Hideki; Suzuki, Takamasa; Laesecke, Arno

    2014-01-01

    High-concentration DNA solutions are common both in vitro and in vivo, and understanding the rheological properties is a critical area of bioscience. Our previous measurements on high-concentration DNA solutions (2-6 mg/ml) interestingly provided evidence for a viscosity maximum with temperature. Under the influence of temperature, the measured viscosities indicated distinct differences in the interactions of highly polymerized DNA in unbuffered and buffered aqueous solutions. Under the same conditions, the buffered solutions were always less viscous, and in addition the viscosity maximum was not observed. In this research we have utilized a falling-needle rheometer in order to gain more insight into the nature of the previously observed viscosity maxima. The shape of the flow curves for all the DNA solutions indicated that the solutions are shear-thinning and has allowed us to confirm the existence of the viscosity maximum in unbuffered DNA solutions. Also we have been able to measure flow curves at very low shear rates, solution, the lower is the temperature where the flow curves will intersect. Thus, the viscosity-temperature dependence is also a function of the shear rates experienced by the solution. Finally, as expected, the flow behavior of the DNA solutions becomes more Newtonian with increasing temperature, and there appears to be a small yield stress that decreases with increasing temperature.

  8. Experimental and modeling study of NO emission under high CO2 concentration

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    An experimental and numerical study of the NOx formation and reduction process in a designed coal combustion furnace under both traditional air atmosphere and O2/CO2 atmosphere was conducted, in an attempt to explore the chemistry mechanism of the experimentally observed NOx suppression under high CO2 concentration atmospheres. A simplified ‘chemically oriented’ approach, computational fluid dynamics (CFD)-chemical kinetics modeling method, was validated and used to model the experimental process. The high CO2 concentration’s chemical effect on NO reduction has been studied, and the differences in NOx reaction behaviors between O2/CO2 atmosphere and air atmosphere were analyzed by detailed chemical kinetic model. On the basis of investigations through elementary chemical reactions, it can be concluded that high CO2 concentration plays an important role on NOx conversion process during oxy-fuel combustion. Moreover, the dominant reaction steps and the most important reactions for NO conversion under different atmospheres were discussed. Under O2/CO2 atmosphere, the main active sequence for NO reaction includes: NO→N→N2, and the main active path for NO reaction under air atmosphere is through N2→N→NO.

  9. A method of batch-purifying microalgae with multiple antibiotics at extremely high concentrations

    Science.gov (United States)

    Han, Jichang; Wang, Song; Zhang, Lin; Yang, Guanpin; Zhao, Lu; Pan, Kehou

    2016-01-01

    Axenic microalgal strains are highly valued in diverse microalgal studies and applications. Antibiotics, alone or in combination, are often used to avoid bacterial contamination during microalgal isolation and culture. In our preliminary trials, we found that many microalgae ceased growing in antibiotics at extremely high concentrations but could resume growth quickly when returned to an antibiotics-free liquid medium and formed colonies when spread on a solid medium. We developed a simple and highly efficient method of obtaining axenic microalgal cultures based on this observation. First, microalgal strains of different species or strains were treated with a mixture of ampicillin, gentamycin sulfate, kanamycin, neomycin and streptomycin (each at a concentration of 600 mg/L) for 3 days; they were then transferred to antibiotics-free medium for 5 days; and finally they were spread on solid f/2 media to allow algal colonies to form. With this method, five strains of Nannochloropsis sp. (Eustigmatophyceae), two strains of Cylindrotheca sp. (Bacillariophyceae), two strains of Tetraselmis sp. (Chlorodendrophyceae) and one strain of Amphikrikos sp. (Trebouxiophyceae) were purified successfully. The method shows promise for batch-purifying microalgal cultures.

  10. Relationship between tap water hardness, magnesium, and calcium concentration and mortality due to ischemic heart disease or stroke in The Netherlands.

    Science.gov (United States)

    Leurs, Lina J; Schouten, Leo J; Mons, Margreet N; Goldbohm, R Alexandra; van den Brandt, Piet A

    2010-03-01

    Conflicting results on the relationship between the hardness of drinking water and mortality related to ischemic heart disease (IHD) or stroke have been reported. We investigated the possible association between tap water calcium or magnesium concentration and total hardness and IHD mortality or stroke mortality. In 1986, a cohort of 120,852 men and women aged 5569 years provided detailed information on dietary and other lifestyle habits. Follow-up for mortality until 1996 was established by linking data from the Central Bureau of Genealogy and Statistics Netherlands. We calculated tap water hardness for each postal code using information obtained from all pumping stations in the Netherlands. Tap water hardness was categorized as soft [hard (1.62.0 mmol/L CaCO3), and hard (> 2.0 mmol/L CaCO3). The multivariate case-cohort analysis was based on 1,944 IHD mortality and 779 stroke mortality cases and 4,114 subcohort members. For both men and women, we observed no relationship between tap water hardness and IHD mortality [hard vs. soft water: hazard ratio (HR) = 1.03; 95% confidence interval (CI), 0.851.28 for men and HR = 0.93; 95% CI, 0.711.21 for women) and stroke mortality (hard vs. soft water HR = 0.90; 95% CI, 0.661.21 and HR = 0.86; 95% CI, 0.621.20, respectively). For men with the 20% lowest dietary magnesium intake, an inverse association was observed between tap water magnesium intake and stroke mortality (HR per 1 mg/L intake = 0.75; 95% CI, 0.610.91), whereas for women with the 20% lowest dietary magnesium intake, the opposite was observed. We found no evidence for an overall significant association between tap water hardness, magnesium or calcium concentrations, and IHD mortality or stroke mortality. More research is needed to investigate the effect of tap water magnesium on IHD mortality or stroke mortality in subjects with low dietary magnesium intake.

  11. Culturable associated-bacteria of the sponge Theonella swinhoei show tolerance to high arsenic concentrations

    Directory of Open Access Journals (Sweden)

    Ray eKeren

    2015-02-01

    Full Text Available Sponges are potent filter feeders and as such are exposed to high fluxes of toxic trace elements, which can accumulate in their body over time. Such is the case of the Red Sea sponge Theonella swinhoei, which has been shown to accumulate up to 8500 mg/Kg of the highly toxic element arsenic. T. swinhoei is known to harbor a multitude of sponge-associated bacteria, so it is hypothesized that the associated-bacteria will be tolerant to high arsenic concentration. This study also investigates the fate of the arsenic accumulated in the sponge to test if the associated-bacteria have an important role in the arsenic accumulation process of their host, since bacteria are key players in the natural arsenic cycle. Separation of the sponge to sponge cells and bacteria enriched fractions showed that arsenic is accumulated by the bacteria. Sponge-associated, arsenic-tolerant bacteria were cultured in the presence of 5 mM of either arsenate or arsenite (equivalent to 6150 mg/Kg arsenic, dry weight. The 54 isolated bacteria were grouped to 15 OTUs and isolates belonging to 12 OTUs were assessed for tolerance to arsenate at increased concentrations up to 100 mM. Eight of the 12 OTUs tolerated an order of magnitude increase in the concentration of arsenate, and some exhibited external biomineralization of arsenic-magnesium salts. The biomineralization of this unique mineral was directly observed in bacteria for the first time. These results may provide an explanation for the ability of the sponge to accumulate considerable amounts of arsenic. Furthermore arsenic-mineralizing bacteria can potentially be used for the study of bioremediation, as arsenic toxicity affects millions of people worldwide.

  12. Mechanisms of astrocytic K(+) clearance and swelling under high extracellular K(+) concentrations.

    Science.gov (United States)

    Murakami, Shingo; Kurachi, Yoshihisa

    2016-03-01

    In response to the elevation of extracellular K(+) concentration ([K(+)]out), astrocytes clear excessive K(+) to maintain conditions necessary for neural activity. K(+) clearance in astrocytes occurs via two processes: K(+) uptake and K(+) spatial buffering. High [K(+)]out also induces swelling in astrocytes, leading to edema and cell death in the brain. Despite the importance of astrocytic K(+) clearance and swelling, the underlying mechanisms remain unclear. Here, we report results from a simulation analysis of astrocytic K(+) clearance and swelling. Astrocyte models were constructed by incorporating various mechanisms such as intra/extracellular ion concentrations of Na(+), K(+), and Cl(-), cell volume, and models of Na,K-ATPase, Na-K-Cl cotransporter (NKCC), K-Cl cotransporter, inwardly-rectifying K(+) (KIR) channel, passive Cl(-) current, and aquaporin channel. The simulated response of astrocyte models under the uniform distribution of high [K(+)]out revealed significant contributions of NKCC and Na,K-ATPase to increases of intracellular K(+) and Cl(-) concentrations, and swelling. Moreover, we found that, under the non-uniform distribution of high [K(+)]out, KIR channels localized at synaptic clefts absorbed excess K(+) by depolarizing the equivalent potential of K(+) (E K) above membrane potential, while K(+) released through perivascular KIR channels was enhanced by hyperpolarizing E K and depolarizing membrane potential. Further analysis of simulated drug effects revealed that astrocyte swelling was modulated by blocking each of the ion channels and transporters. Our simulation analysis revealed controversial mechanisms of astrocytic K(+) clearance and swelling resulting from complex interactions among ion channels and transporters.

  13. Elasto-Plastic Behavior of High RRR Niobium: Effects of Crystallographic Texture, Microstructure and Hydrogen Concentration

    Energy Technology Data Exchange (ETDEWEB)

    G.R. Myneni; S.R. Agnew

    2002-11-01

    Conventional assessments of the mechanical properties of polycrystalline high RRR niobium via tensile testing have revealed unusually low apparent Young's moduli and yield strength in annealed samples. These observations motivated the current investigation of a variety of possible contributors: crystallographic texture, grain size, and impurity concentration. It is shown that the crystallographic textures of a single lot of niobium are essentially unchanged by post-recrystallization anneals at temperatures up to 800 C. Ultrasonic measurements reveal that the elastic response is not degraded by annealing. Rather, the material's extremely low yield point gives the impression of a low elastic modulus during tensile testing.

  14. Effects of High Salt Concentration and Residue on Copper and Aluminum Corrosion

    Institute of Scientific and Technical Information of China (English)

    HUO Ying; TAN Mike; Yong jun; SHU Li

    2013-01-01

    Traditional researches on metal corrosion under salt solutions deposit conditions are usually carried out by visual,electron microscopic observations and simple electrochemical measurement via a traditional one-piece electrode.These techniques have difficulties in measuring localized corrosion that frequently occur in inhomogeneous media.This paper reports the results from the experiments using specially shaped coupons and a relatively new method of measuring heterogeneous electrochemical processes,namely,the wire beam electrode(WBE).Preliminary results from copper and aluminum corrosion in highly concentrated sodium chloride solutions with and without solid deposits show that the method is useful in simulating and studying corrosion especially localized corrosion in pipelines.

  15. The high incidence of acute hemolysis due to favism in Ahvaz, Iran-clinical features and laboratory findings

    Institute of Scientific and Technical Information of China (English)

    Seyyed Mohammad Hasan Aletayeb; Bashir Chomeili; Mehri Taheri; Tahereh Ziaei Kajbaf; Mehran Hakimzadeh; Majid Aminzadeh; Morteza Shojaei Moghadam; Susan Maleki

    2010-01-01

    Objective:To collect comprehensive information about the features of favic patients in Ahvaz (Capital of Khouzestan, Iran) and analyze the extent of the differences with their corresponding in other regions. Methods:A total of 103 patients with acute hemolysis admitted to pediatric division of Abouzar Hospital located in the city of Ahvaz, Iran during 21st of June 2008 to 20th of June 2009 were analyzed retrospectively. Results:95.14%of the patients had favism while 4.86%of them underwent hemolysis due to other reasons. These patients were male (68.93%) and female children (31.06%) admitted mostly during the spring season. The three main symptoms were urine discoloration, jaundice and vomiting. At the admission time, the main hematologic findings were as follows:G6PD sufficient status (45.63%), G6PD deficient status (54.36%) and hemoglobin concentration:2.5-11.8 (mean±SD:6.45±2.12) g/dL. Conclusions:In conclusion, Ahvaz was determined as a black zone for favism in which the disease can be considered a life threatening health problem. Moreover, slight differences were observed in the three main symptoms compared with favic patients in other regions.

  16. The Utilization of Indigofera sp as the sole foliage in goat diets supplemented with high carbohydrate or high protein concentrates

    Directory of Open Access Journals (Sweden)

    Simon P Ginting

    2010-12-01

    Full Text Available Indigofera sp is a tree leguminous forage species known to be adaptable to the drought climate and saline soil and so it has potential as alternative feed resource to support the ruminant animal production. This study aimed to study the responses of goats fed Indigofera sp as the sole foliages in their diets. Twenty male Boer x Kacang crossbred goats (6 months of age;16 ± 2,1 kg BW were randomly assigned to four dietary treatments containing fresh or wilted leaves of Indigifera sp. as the sole foliages and supplemented with high carbohydrate (HCC or protein (HPCconcentrates. Consumable parts i.e. leaves and twigs of about 8 to 10 months of age of Indigofera sp. were harvested by hand plucking every day in the morning. The experiment was a 2 x 2 factorial design arranged in a completely randomized design. The ruminal pH ranged from 6.14-6.85 and were not affected (P > 0.05 by wilting nor by the type of concentrates. Wilting did not affect (P > 0.05 the concentration of ruminal NH3-N, but it was significantly higher (P 0.05. Goats in the HCC group,however,numerically have higher total VFA concentration (178.5-183.75 mmol L-1 than those in the HPC group (142.21-174.64 mmol L-1. The apparent digestibility coeficients of DM, OM, CP and energy of the diet were not different (P > 0.05 when contained wilted or fresh Indigofera foliage. Significant increases (P 0.05 among dietary treatments, but the ADG of goats in the HCC group (60-63 g d-1 were significantly lower (P 0.05. BUN was not affected by wilting process, but providing high protein concentrates significantly (P < 0.05 increased the BUN concentration. It is concluded that foliage of Indigofera sp could be used as the sole forage in intensive production of goats. Wilting the foliage prior to feeding seemed to be unnecessary, since this process does not improve the animal productivity in term of daily gain and efficiency of feed utilization.

  17. High plasma concentrations of asymmetric dimethylarginine inhibit ischemic cardioprotection in hypercholesterolemic rats

    Energy Technology Data Exchange (ETDEWEB)

    Landim, M.B.P.; Dourado, P.M.M.; Casella-Filho, A.; Chagas, A.C.P.; Luz, P.L. da [Unidade de Aterosclerose, Instituto do Coração, Faculdade de Medicina, Universidade de São Paulo, São Paulo, SP (Brazil)

    2013-05-10

    A low concentration of nitric oxide associated with a high concentration of asymmetric dimethylarginine (ADMA) can explain the lack of ischemic cardioprotection observed in the presence of hypercholesterolemia. The objective of the present study was to evaluate the effect of hypercholesterolemia on ischemic pre- and postconditioning and its correlation with plasma concentrations of ADMA. Male Wistar rats (6-8 weeks old) fed a 2% cholesterol diet (n = 21) for 8 weeks were compared to controls (n = 25) and were subjected to experimental myocardial infarction and reperfusion, with ischemic pre- and postconditioning. Total cholesterol and ADMA were measured in plasma before the experimental infarct and the infarct area was quantified. Weight, total cholesterol and plasma ADMA (means ± SE; 1.20 ± 0.06, 1.27 ± 0.08 and 1.20 ± 0.08 vs 0.97 ± 0.04, 0.93 ± 0.05 and 0.97 ± 0.04 µM) were higher in animals on the hypercholesterolemic diet than in controls, respectively. Cardioprotection did not reduce infarct size in the hypercholesterolemic animals (pre: 13.55% and post: 8% compared to 7.95% observed in the group subjected only to ischemia and reperfusion), whereas infarct size was reduced in the animals on a normocholesterolemic diet (pre: 8.25% and post: 6.10% compared to 12.31%). Hypercholesterolemia elevated ADMA and eliminated the cardioprotective effects of ischemic pre- and postconditioning in rats.

  18. Numerical Modeling of the Stability of Face-Centered Cubic Metals with High Vacancy Concentration

    Energy Technology Data Exchange (ETDEWEB)

    Brian P. Somerday; M. I. Baskes

    1998-12-01

    The objective of this research is to assess the possibility of forming an atomically porous structure in a low-density metal, e.g., Al with vacancies up to 0.20/lattice site; and to examine the effects of hydrogen and vacancy concentration on the stability of an atomically porous structure that has been experimentally produced in nickel. The approach involves numerical modeling using the Embedded-Atom Method (EAM). High vacancy concentrations cause the Al lattice to disorder at 300K. In contrast, Ni retains the face-centered-cubic structure at 300K for vacancy concentrations up to 0.15 Vac/lattice site. Unexpectedly, the lattice with 0.15 Vac/lattice site is more stable than the lattice with 0.10 or 0.20 Vac/lattice site. The Ni systems with 0.10 and 0.15 Vac/lattice site exhibit domains consisting of uniform lattice rotations. The Ni lattice with 0.15 Vac/lattice site is more stable with an initial distribution of random vacancies compared to ordered vacancies. The equilibrium lattice structures of Ni a d Al containing vacancies and H are less ordered to structures with vacancies only at 300K.

  19. Bioconversion of high concentrations of hydrogen sulfide to elemental sulfur in airlift bioreactor.

    Science.gov (United States)

    Zytoon, Mohamed Abdel-Monaem; AlZahrani, Abdulraheem Ahmad; Noweir, Madbuli Hamed; El-Marakby, Fadia Ahmed

    2014-01-01

    Several bioreactor systems are used for biological treatment of hydrogen sulfide. Among these, airlift bioreactors are promising for the bioconversion of hydrogen sulfide into elemental sulfur. The performance of airlift bioreactors is not adequately understood, particularly when directly fed with hydrogen sulfide gas. The objective of this paper is to investigate the performance of an airlift bioreactor fed with high concentrations of H2S with special emphasis on the effect of pH in combination with other factors such as H2S loading rate, oxygen availability, and sulfide accumulation. H2S inlet concentrations between 1,008 ppm and 31,215 ppm were applied and elimination capacities up to 113 g H2S m(-3) h(-1) were achieved in the airlift bioreactor under investigation at a pH range 6.5-8.5. Acidic pH values reduced the elimination capacity. Elemental sulfur recovery up to 95% was achieved under oxygen limited conditions (DO bioreactor tolerated accumulated dissolved sulfide concentrations >500 mg/L at pH values 8.0-8.5, and near 100% removal efficiency was achieved. Overall, the resident microorganisms in the studied airlift bioreactor favored pH values in the alkaline range. The bioreactor performance in terms of elimination capacity and sulfur recovery was better at pH range 8-8.5.

  20. Indoor radon (Rn-222) concentration measurements in Cyprus using high-sensitivity portable detectors

    CERN Document Server

    Anastasiou, T; Christofides, S; Christodoulides, G

    2003-01-01

    Using high--sensitivity radon (Rn-222) portable detectors, the airborne Rn-222 concentration in the interior of various Cypriot buildings and dwellings was measured. For each preselected building and dwelling, a calibrated detector was put into a closed room, and the Rn-222 concentration was registered in sampling intervals of 2 to 4 hours for a total counting time of typically 48 hours. Rn-222 activity concentrations were found to be in the range of 6.2 to 102.8 Bq/m**3, with an overall arithmetic mean value of (19.3 +- 1.6) Bq/m**3. This value is by a factor of two below the world average (population-weighted) value of 39 Bq/m**3. The total annual effective dose equivalent to the Cypriot population was calculated to be between 0.16 and 2.6 mSv with an overall arithmetic mean value of (0.49 +- 0.04) mSv.