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Sample records for chemistry experiment ace

  1. Atmospheric Chemistry Experiment (ACE) Measurements of Tropospheric and Stratospheric Chemistry and Long-Term Trends

    Science.gov (United States)

    Rinsland, Curtis P.; Bernath, Peter; Boone, Chris; Nassar, Ray

    2007-01-01

    We highlight chemistry and trend measurement results from the Atmospheric Chemistry Experiment (ACE) which is providing precise middle troposphere to the lower thermosphere measurements with a 0.02/cm resolution Fourier transform spectrometer covering 750-4400/cm

  2. Validation of NO2 and NO from the Atmospheric Chemistry Experiment (ACE

    Directory of Open Access Journals (Sweden)

    M. Schneider

    2008-10-01

    Full Text Available Vertical profiles of NO2 and NO have been obtained from solar occultation measurements by the Atmospheric Chemistry Experiment (ACE, using an infrared Fourier Transform Spectrometer (ACE-FTS and (for NO2 an ultraviolet-visible-near-infrared spectrometer, MAESTRO (Measurement of Aerosol Extinction in the Stratosphere and Troposphere Retrieved by Occultation. In this paper, the quality of the ACE-FTS version 2.2 NO2 and NO and the MAESTRO version 1.2 NO2 data are assessed using other solar occultation measurements (HALOE, SAGE II, SAGE III, POAM III, SCIAMACHY, stellar occultation measurements (GOMOS, limb measurements (MIPAS, OSIRIS, nadir measurements (SCIAMACHY, balloon-borne measurements (SPIRALE, SAOZ and ground-based measurements (UV-VIS, FTIR. Time differences between the comparison measurements were reduced using either a tight coincidence criterion, or where possible, chemical box models. ACE-FTS NO2 and NO and the MAESTRO NO2 are generally consistent with the correlative data. The ACE-FTS and MAESTRO NO2 volume mixing ratio (VMR profiles agree with the profiles from other satellite data sets to within about 20% between 25 and 40 km, with the exception of MIPAS ESA (for ACE-FTS and SAGE II (for ACE-FTS (sunrise and MAESTRO and suggest a negative bias between 23 and 40 km of about 10%. MAESTRO reports larger VMR values than the ACE-FTS. In comparisons with HALOE, ACE-FTS NO VMRs typically (on average agree to ±8% from 22 to 64 km and to +10% from 93 to 105 km, with maxima of 21% and 36%, respectively. Partial column comparisons for NO2 show that there is quite good agreement between the ACE instruments and the FTIRs, with a mean difference of +7.3% for ACE-FTS and +12.8% for MAESTRO.

  3. Carbon Dioxide (CO2) Retrievals from Atmospheric Chemistry Experiment (ACE) Solar Occultation Measurements

    Science.gov (United States)

    Rinsland, Curtis P.; Chiou, Linda; Boone, Chris; Bernath, Peter

    2010-01-01

    The Atmospheric Chemistry Experiment ACE satellite (SCISAT-1) was launched into an inclined orbit on 12 August 2003 and is now recording high signal-to-noise 0.02 per centimeter resolution solar absorption spectra covering 750-4400 per centimeter (2.3-13 micrometers). A procedure has been developed for retrieving average dry air CO2 mole fractions (X(sub CO2)) in the altitude range 7-10 kilometers from the SCISAT-1 spectra. Using the N2 continuum absorption in a window region near 2500 per centimeter, altitude shifts are applied to the tangent heights retrieved in version 2.2 SCISAT-1 processing, while cloudy or aerosol-impacted measurements are eliminated. Monthly-mean XCO2 covering 60 S to 60 N latitude for February 2004 to March 2008 has been analyzed with consistent trends inferred in both hemispheres. The ACE XCO2 time series have been compared with previously-reported surface network measurements, predictions based on upper tropospheric aircraft measurements, and space-based measurements. The retrieved X(sub CO2) from the ACE-FTS spectra are higher on average by a factor of 1.07 plus or minus 0.025 in the northern hemisphere and by a factor of 1.09 plus or minus 0.019 on average in the southern hemisphere compared to surface station measurements covering the same time span. The ACE derived trend is approximately 0.2% per year higher than measured at surface stations during the same observation period.

  4. The ACE experiment

    CERN Multimedia

    Maximilien Brice

    2006-01-01

    The Antiproton Cell Experiment (ACE) as shown by Michael Holzscheiter (spokesperson), Niels Bassler (co-spokesperson) and Helge Knudsen. ACE is located on the Antiproton Decelerator (AD) at CERN. An antiproton annihilates a proton in the nucleus of a cancer cell, producing a pair of gamma rays, destroying the entire cell and some surrounding cells. Many fewer antiprotons are required in this treatment than in the equivalent proton hadron therapy, so there is less risk of healthy tissue damage.

  5. Technical Note: A trace gas climatology derived from the Atmospheric Chemistry Experiment Fourier Transform Spectrometer (ACE-FTS data set

    Directory of Open Access Journals (Sweden)

    A. Jones

    2012-06-01

    Full Text Available The Atmospheric Chemistry Experiment-Fourier Transform Spectrometer (ACE-FTS aboard the Canadian satellite SCISAT (launched in August 2003 was designed to investigate the composition of the upper troposphere, stratosphere, and mesosphere. ACE-FTS utilizes solar occultation to measure temperature and pressure as well as vertical profiles of over thirty chemical species including O3, H2O, CH4, N2O, CO, NO, NO2, N2O5, HNO3, HCl, ClONO2, CCl3F, CCl2F2, and HF. Global coverage for each species is obtained approximately over a three month period and measurements are made with a vertical resolution of typically 3–4 km. A quality-controlled climatology has been created for each of these 14 baseline species, where individual profiles are averaged over the period of February 2004 to February 2009. Measurements used are from the ACE-FTS version 2.2 data set including updates for O3 and N2O5. The climatological fields are provided on a monthly and three-monthly basis (DJF, MAM, JJA, SON at 5 degree latitude and equivalent latitude spacing and on 28 pressure surfaces (26 of which are defined by the Stratospheric Processes And their Role in Climate (SPARC Chemistry-Climate Model Validation Activity. The ACE-FTS climatological data set is available through the ACE website.

  6. Aerosol and melt chemistry in the ACE molten core-concrete interaction experiments

    International Nuclear Information System (INIS)

    Experimental results are discussed from the internationally sponsored Advanced Containment Experiments (ACE) Program on the melt behavior and aerosols released during the interaction of molten reactor core material with concrete. A broad range of parameters were addressed in the experimental program: Seven large-scale tests were performed using four types of concrete (siliceous, limestone/sand, serpentine, and limestone) and a range of metal oxidations for both boiling water and pressurized waster reactor core debris. The release aerosols contained mainly constitutents of the concrete. In the tests with metal and limestone/sand siliceous concrete, silicon compounds comprised 50% or more of the aerosol mass. Releases of uranium and low-volatility fission-product elements were small in all tests. Releases of tellurium and neutron absorber materials (silver, indium, and boron from boron carbide) were high

  7. Observations of peroxyacetyl nitrate (PAN in the upper troposphere by the Atmospheric Chemistry Experiment Fourier Transform Spectrometer (ACE-FTS

    Directory of Open Access Journals (Sweden)

    K. A. Tereszchuk

    2013-01-01

    Full Text Available Peroxyacetyl nitrate (CH3CO·O2NO2, abbreviated as PAN is a trace molecular species present in the troposphere and lower stratosphere due primarily to pollution from fuel combustion and the pyrogenic outflows from biomass burning. In the lower troposphere, PAN has a relatively short life-time and is principally destroyed within a few hours through thermolysis, but it can act as a reservoir and carrier of NOx in the colder temperatures of the upper troposphere where UV photolysis becomes the dominant loss mechanism. Pyroconvective updrafts from large biomass burning events can inject PAN into the upper troposphere and lower stratosphere (UTLS, providing a means for the long-range transport of NOx. Given the extended lifetimes at these higher altitudes, PAN is readily detectable via satellite remote sensing.

    A new PAN data product is now available for the Atmospheric Chemistry Experiment Fourier Transform Spectrometer (ACE-FTS Version 3.0 data set. We report measurements of PAN in Boreal biomass burning plumes recorded during the Quantifying the impact of BOReal forest fires on Tropospheric oxidants over the Atlantic using Aircraft and Satellites (BORTAS campaign. The retrieval method employed and errors analysis are described in full detail.

    The retrieved volume mixing ratio (VMR profiles are compared to coincident measurements made by the Michelson Interferometer for Passive Atmospheric Sounding (MIPAS instrument on the European Space Agency (ESA ENVIronmental SATellite (ENVISAT. Three ACE-FTS occultations containing measurements of Boreal biomass burning outflows, recorded during BORTAS, were identified as having coincident measurements with MIPAS. In each case, the MIPAS measurements demonstrated good agreement with the ACE-FTS VMR profiles for PAN.

    The ACE-FTS PAN data set is used to obtain zonal mean distributions of seasonal averages from ~5 to 20 km. A strong

  8. Validation of HNO3, ClONO2, and N2O5 from the Atmospheric Chemistry Experiment Fourier Transform Spectrometer (ACE-FTS

    Directory of Open Access Journals (Sweden)

    M. Ridolfi

    2008-02-01

    Full Text Available The Atmospheric Chemistry Experiment (ACE satellite was launched on 12 August 2003. Its two instruments measure vertical profiles of over 30 atmospheric trace gases by analyzing solar occultation spectra in the ultraviolet/visible and infrared wavelength regions. The reservoir gases HNO3, ClONO2, and N2O5 are three of the key species provided by the primary instrument, the ACE Fourier Transform Spectrometer (ACE-FTS. This paper describes the ACE-FTS version 2.2 data products, including the N2O5 update, for the three species and presents validation comparisons with available observations. We have compared volume mixing ratio (VMR profiles of HNO3, ClONO2, and N2O5 with measurements by other satellite instruments (SMR, MLS, MIPAS, aircraft measurements (ASUR, and single balloon-flights (SPIRALE, FIRS-2. Partial columns of HNO3 and ClONO2 were also compared with measurements by ground-based Fourier Transform Infrared (FTIR spectrometers. Overall the quality of the ACE-FTS v2.2 HNO3 VMR profiles is good from 18 to 35 km. For the statistical satellite comparisons, the mean absolute differences are generally within ±1 ppbv (±20% from 18 to 35 km. For MIPAS and MLS comparisons only, mean relative differences lie within ±10% between 10 and 36 km. ACE-FTS HNO3 partial columns (~15–30 km show a slight negative bias of −1.3% relative to the ground-based FTIRs at latitudes ranging from 77.8° S–76.5° N. Good agreement between ACE-FTS ClONO2 and MIPAS, using the Institut für Meteorologie und Klimaforschung and Instituto de Astrofísica de Andalucía (IMK-IAA data processor is seen. Mean absolute differences are typically within ±0.01 ppbv between 16 and 27 km and less than +0.09 ppbv between 27 and 34 km. The ClONO2 partial column comparisons show varying degrees of agreement, depending on the location and the quality of the FTIR measurements. Good agreement was found for the comparisons with the midlatitude Jungfraujoch partial columns for which

  9. Validation of HNO3, ClONO2, and N2O5 from the Atmospheric Chemistry Experiment Fourier Transform Spectrometer (ACE-FTS

    Directory of Open Access Journals (Sweden)

    P. Raspollini

    2008-07-01

    Full Text Available The Atmospheric Chemistry Experiment (ACE satellite was launched on 12 August 2003. Its two instruments measure vertical profiles of over 30 atmospheric trace gases by analyzing solar occultation spectra in the ultraviolet/visible and infrared wavelength regions. The reservoir gases HNO3, ClONO2, and N2O5 are three of the key species provided by the primary instrument, the ACE Fourier Transform Spectrometer (ACE-FTS. This paper describes the ACE-FTS version 2.2 data products, including the N2O5 update, for the three species and presents validation comparisons with available observations. We have compared volume mixing ratio (VMR profiles of HNO3, ClONO2, and N2O5 with measurements by other satellite instruments (SMR, MLS, MIPAS, aircraft measurements (ASUR, and single balloon-flights (SPIRALE, FIRS-2. Partial columns of HNO3 and ClONO2 were also compared with measurements by ground-based Fourier Transform Infrared (FTIR spectrometers. Overall the quality of the ACE-FTS v2.2 HNO3 VMR profiles is good from 18 to 35 km. For the statistical satellite comparisons, the mean absolute differences are generally within ±1 ppbv ±20% from 18 to 35 km. For MIPAS and MLS comparisons only, mean relative differences lie within±10% between 10 and 36 km. ACE-FTS HNO3 partial columns (~15–30 km show a slight negative bias of −1.3% relative to the ground-based FTIRs at latitudes ranging from 77.8° S–76.5° N. Good agreement between ACE-FTS ClONO2 and MIPAS, using the Institut für Meteorologie und Klimaforschung and Instituto de Astrofísica de Andalucía (IMK-IAA data processor is seen. Mean absolute differences are typically within ±0.01 ppbv between 16 and 27 km and less than +0.09 ppbv between 27 and 34 km. The ClONO2 partial column comparisons show varying degrees of agreement, depending on the location and the quality of the FTIR measurements. Good agreement was found for the comparisons with the midlatitude Jungfraujoch partial columns for which

  10. General relativistic observables for the ACES experiment

    CERN Document Server

    Turyshev, Slava G; Toth, Viktor T

    2015-01-01

    We develop a high-precision model for relativistic observables of the Atomic Clock Ensemble in Space (ACES) experiment on the International Space Station (ISS). We develop all relativistic coordinate transformations that are needed to describe the motion of ACES in Earth orbit and to compute observable quantities. We analyze the accuracy of the required model as it applies to the proper-to-coordinate time transformations, light time equation, and spacecraft equations of motion. We consider various sources of nongravitational noise and their effects on ACES. We estimate the accuracy of orbit reconstruction that is needed to satisfy the ACES science objectives. Based on our analysis, we derive models for the relativistic observables of ACES, which also account for the contribution of atmospheric drag on the clock rate. We include the Earth's oblateness coefficient $J_2$ and the effects of major nongravitational forces on the orbit of the ISS. We demonstrate that the ACES reference frame is pseudo-inertial at th...

  11. Iodine chemistry and transport calculations for the radioiodine test facility experiments (ACE-RTF) using the MITIMAKS code and the LIRIC data base

    International Nuclear Information System (INIS)

    Models for predicting the time-dependent release of iodine from aqueous solutions in the RTF experiments have been assembled using elementary chemical reactions and rate constants available in the LIRIC data base. Results from the computer code MITIMAKS, a new version of the MAKSIMA-CHEMIST code, are discussed and preliminarily compared with other computer analysis. RTF experiments are part of the international ACE (advanced containment experiments) program. The present calculations provide a prediction analysis for a benchmark exercise, with different 'iodine-transport' codes, promoted in the frame of the ACE program itself. (author) 148 figs., 41 tabs., 11 refs

  12. Global stratospheric chlorine inventories for 2004–2009 from Atmospheric Chemistry Experiment Fourier Transform Spectrometer (ACE-FTS measurements

    Directory of Open Access Journals (Sweden)

    A. T. Brown

    2013-09-01

    Full Text Available We present chlorine budgets calculated between 2004 and 2009 for four latitude bands (70° N–30° N, 30° N–0° N, 0° N–30° S, and 30° S–70° S. The budgets were calculated using ACE-FTS version 3.0 retrievals of the volume mixing ratios (VMRs of 9 chlorine-containing species: CCl4, CFC-12 (CCl2F2, CFC-11 (CCl3F, COCl2, COClF, HCFC-22 (CHF2Cl, CH3Cl, HCl and ClONO2. These data were supplemented with calculated VMRs from the SLIMCAT 3-D chemical transport model (CFC-113, CFC-114, CFC-115, H-1211, H-1301, HCFC-141b, HCFC-142b, ClO and HOCl. The total chlorine profiles are dominated by chlorofluorocarbons (CFCs and halons up to 24 km in the tropics and 19 km in the extra-tropics. In this altitude range CFCs and halons account for 58% of the total chlorine VMR. Above this altitude HCl increasingly dominates the total chlorine profile, reaching a maximum of 95% of total chlorine at 54 km. All total chlorine profiles exhibit a positive slope with altitude, suggesting that the total chlorine VMR is now decreasing with time. This conclusion is supported by the time series of the mean stratospheric total chlorine budgets which show mean decreases in total stratospheric chlorine of 0.38 ± 0.03% per year in the Northern Hemisphere extra-tropics, 0.35 ± 0.07% per year in the Northern Hemisphere tropical stratosphere, 0.54 ± 0.16% per year in the Southern Hemisphere tropics and 0.53 ± 0.12% per year in the Southern Hemisphere extra-tropical stratosphere for 2004–2009. Globally stratospheric chlorine is decreasing by 0.46 ± 0.02% per year. Both global warming potential-weighted chlorine and ozone depletion potential-weighted chlorine are decreasing at all latitudes. These results show that the Montreal Protocol has had a significant effect in reducing emissions of both ozone-depleting substances and greenhouse gases.

  13. Global stratospheric fluorine inventories for 2004–2009 from Atmospheric Chemistry Experiment Fourier Transform Spectrometer (ACE-FTS measurements

    Directory of Open Access Journals (Sweden)

    A. T. Brown

    2013-06-01

    Full Text Available Fluorine-containing species can be extremely effective atmospheric greenhouse gases. We present fluorine budgets using organic and inorganic species retrieved by the ACE-FTS satellite instrument supplemented with output from the SLIMCAT 3D chemical transport model. The budgets are calculated between 2004 and 2009 for a number of latitude bands: 70–30° N, 30–0° N, 0–30° S, and 30–70° S. At lower altitudes total fluorine profiles are dominated by the contribution from CFC-12, up to an altitude of 20 km in the extra-tropics and 29 km in the tropics, above these altitudes the profiles are dominated by HF. Our data show that total fluorine profiles at all locations have a negative slope with altitude, providing evidence that overall fluorine emissions (measured by their F content have been increasing with time. Total stratospheric fluorine is increasing at a similar rate in the tropics; 32.5 ± 4.9 ppt yr−1 (1.31 ± 0.20% per year in the Northern Hemisphere (NH and 29.8 ± 5.3 ppt yr−1 (1.21 ± 0.22% per year in the Southern Hemisphere (SH. Extra-tropical total stratospheric fluorine is also increasing at a similar rate in both the NH and SH; 28.3 ± 2.7 ppt per year (1.12 ± 0.11% per year in the NH and 24.3 ± 3.1 ppt per year (0.96 ± 0.12% per year in the SH. The volume mixing ratio of each species used in this study was weighted by its global warming potential (GWP, relative molecular mass and the atmospheric pressure to produce a GWP-weighted total fluorine trend. These trends show mean changes of 0.02 ± 0.08% per year in the NH, and 0.07 ± 0.05% per year in the SH. Overall, GWP-weighted fluorine remains roughly constant globally. However, the decreasing trends in the mixing ratios of halons and CFCs, due to their prohibition under the Montreal Protocol, have suppressed an increase in total fluorine caused by increasing mixing ratios of HFCs. This has reduced the impact of fluorine containing species on global warming.

  14. Advanced Colloids Experiment (ACE-T1)

    Science.gov (United States)

    Meyer, William V.; Sicker, Ron; Brown, Dan; Eustace, John

    2015-01-01

    Increment 45 - 46 Science Symposium presentation of Advanced Colloids Experiment (ACE-T1) to RPO. The purpose of this event is for Principal Investigators to present their science objectives, testing approach, and measurement methods to agency scientists, managers, and other investigators.

  15. ACE-2 HILLCLOUD. An overview of the ACE-2 ground-based cloud experiment

    DEFF Research Database (Denmark)

    Bower, B.K.N.; Choularton, T.W.; Gallagher, M.W.;

    2000-01-01

    excess over SO2 throughout the experiment). Occasions of significant aerosol growth following cloud processing were observed, particularly in cleaner cases. Observations and modelling suggested this was due mainly to the take up of nitric acid, hydrochloric acid and ammonia by the smallest activated......The ACE-2 HILLCLOUD experiment was carried out on the island of Tenerife in June-July 1997 to investigate the interaction of the boundary layer aerosol with a hill cap cloud forming over a ridge to the north-east of the island. The cloud was used as a natural flow through reactor to investigate the...... dependence of the cloud microphysics and chemistry on the characteristics of the aerosols and trace gases entering cloud, and to simultaneously study the influence of the physical and chemical processes occurring within the cloud on the size distribution, chemical and hygroscopic properties of the aerosol...

  16. Advanced Colloids Experiment (ACE) Science Overview

    Science.gov (United States)

    Meyer, William V.; Sicker, Ronald J.; Chiaramonte, Francis P.; Luna, Unique J.; Chaiken, Paul M.; Hollingsworth, Andrew; Secanna, Stefano; Weitz, David; Lu, Peter; Yodh, Arjun; Yunker, Peter; Lohr, Matthew; Gratale, Matthew; Lynch, Matthew; Kodger, Thomas; Piazza, Roberto; Buzzaccaro, Stefano; Cipelletti, Luca; Schall, Peter; Veen, Sandra; Wegdam, Gerhard; Lee, Chand-Soo; Choi, Chang-Hyung; Paul, Anna-Lisa; Ferl, Robert J.; Cohen, Jacob

    2013-01-01

    accessible with the availability of the Light Microscopy Module (LMM) on ISS. To meet these goals, the ACE experiment is being built-up in stages, with the availability of confocal microscopy being the ultimate objective. Supported by NASAs Physical Sciences Research Program, ESAESTEC, and the authors respective governments.

  17. Report on Experiment AD-4/ACE

    CERN Document Server

    Holzscheiter, M H

    2014-01-01

    After 7 years running the AD-4 Experiment at antiproton momentum of 502 MeV/c we have now assembled a complete data set and are preparing to combine all years into a single analysis of RBE vs. Depth for an antiproton beam stopping in water. We describe experimental challenges and computational issues which need to be resolved to achieve this final step.

  18. Status Report for Experiment AD-4/ACE

    CERN Document Server

    Holzscheiter, M

    2011-01-01

    The overall goal of the AD-4 Experiment is to study whether antiprotons might be a better tool for controlling localized cancer tumors than protons or heavy ions. This idea is based on four observations: 1.\tCompared with protons, the physical dose should be augmented near the end of range due to the additional energy deposited locally when antiprotons annihilate. 2.\tSome of the additional energy deposited results from low energy heavy ion recoils produced in the annihilation event, which are expected to exhibit a high biological efficiency. 3.\tAntiprotons deposit less energy than heavy ions in the entrance channel. 4.\tPions and high-energy photons generated in the annihilation events can be used to detect in real time the exact location of the treatment. This report describes progress to date and highlights critical issues in combining independent measurements into on final meta analysis

  19. Experiments in physical chemistry

    CERN Document Server

    Wilson, J M; Denaro, A R

    1968-01-01

    Experiments in Physical Chemistry, Second Edition provides a compilation of experiments concerning physical chemistry. This book illustrates the link between the theory and practice of physical chemistry. Organized into three parts, this edition begins with an overview of those experiments that generally have a simple theoretical background. Part II contains experiments that are associated with more advanced theory or more developed techniques, or which require a greater degree of experimental skill. Part III consists of experiments that are in the nature of investigations wherein these invest

  20. The advanced containment experiments (ACE) radioiodine test facility experimental program

    International Nuclear Information System (INIS)

    Results of the Advanced Containment Experiments (ACE) Radioiodine Test Facility (RTF) program are reported. This study consisted of four intermediate-scale experiments that investigated the effects of radiation, pH, surfaces and initial iodine speciation on iodine behaviour. The tests revealed that, in high radiation fields, the long-term volatility of iodine is independent of the initial iodine speciation (CsI, I2, CH3I). This is presumably because radiolytic reactions inter-convert aqueous iodine species; I- was the predominant aqueous iodine species after an absorbed dose of about 30-40 kGy. Tests at pH 9 and 5.5 demonstrated that iodine volatility increased significantly with decreasing pH. In addition, this study demonstrated that containment surfaces can play an important role in determining iodine volatility, gas and aqueous phase iodine speciation, and surface adsorption. In summary: The ACE/RTF experiments have demonstrated the importance of several factors on iodine behaviour within containment under reactor accident conditions. One of the most important factors was radiation. Without radiation, the volatility of iodine was dependent on the initial speciation of iodine, presumably because inter-conversion of iodine species by non-radiolytic reactions is relatively slow. In contrast, in the presence of radiation, the long-term volatility of iodine was independent of initial speciation. This is attributed to aqueous phase radiolytic reactions that result in rapid inter-conversion of iodine species. Iodine volatility was shown to increase significantly with decreasing pH. However, changing the pH from acidic to alkaline conditions did not result in rapid decreases in iodine volatility. This may have been due to desorption of volatile iodine species from surfaces, in the case of stainless steel, and the influence of organics in the epoxy tests. Surfaces were shown to influence iodine volatility and speciation. Higher gas phase iodine concentrations were

  1. ACES: The ASCENDS CarbonHawk Experiment Simulator

    Science.gov (United States)

    Obland, M. D.; Prasad, N. S.; Harrison, F. W.; Browell, E. V.; Ismail, S.; Dobler, J. T.; Moore, B.; Zaccheo, T.; Campbell, J.; Chen, S.; Cleckner, C. S.; DiJoseph, M.; Little, A.; Notari, A.; Refaat, T. F.; Rosenbaum, D.; Vanek, M. D.; Bender, J.; Braun, M.; Chavez-Pirson, A.; Neal, M.; Rayner, P. J.; Rosiewicz, A.; Shure, M.; Welch, W.

    2012-12-01

    The ASCENDS CarbonHawk Experiment Simulator (ACES) is a NASA Langley Research Center project funded by NASA's Earth Science Technology Office (ESTO) Instrument Incubator Program (IIP) that seeks to advance technologies critical to measuring atmospheric column carbon dioxide (CO2) mixing ratios in support of the NASA Active Sensing of CO2 Emissions over Nights, Days, and Seasons (ASCENDS) mission. The technologies being advanced are: (1) a high bandwidth detector, (2) a multi-aperture telescope assembly, (3) advanced algorithms for cloud and aerosol discrimination, and (4) high-efficiency, multiple-amplifier CO2 and O2 laser transmitters. The instrument architecture will be developed to operate on a high-altitude aircraft and will be directly scalable to meet the ASCENDS mission requirements. These technologies are viewed as critical towards developing an airborne simulator and eventual spaceborne instrument with lower size, mass, and power consumption, and improved performance. The detector effort will improve the existing detector subsystem by increasing its bandwidth to a goal of 5 MHz, reducing its overall mass from 18 lbs to 24 hrs. The development goals are to permit higher laser modulation rates, which provides greater flexibility for implementing thin-cloud discrimination algorithms as well as improving range resolution and error reduction, and to enable long flights on a high-altitude unmanned aerial vehicle (UAV). The telescope development consists of a three-telescope design built for the constraints of the Global Hawk aircraft. This task addresses the ability of multiple smaller telescopes to provide equal or greater collection efficiency compared with a single larger telescope with a reduced impact on launch mass and cost. The telescope assembly also integrates fiber-coupled transmit collimators for all of the laser transmitters and fiber-coupled optical signal output to the aft optics and detector package. The cloud/aerosol discrimination work features

  2. O_3-N_2O correlations from the Atmospheric Chemistry Experiment: revisiting a diagnostic of transport and chemistry in the stratosphere

    OpenAIRE

    Hegglin, Michaela I.; Shepherd, Theodore G

    2007-01-01

    Our knowledge of stratospheric O3-N2O correlations is extended, and their potential for model-measurement comparison assessed, using data from the Atmospheric Chemistry Experiment (ACE) satellite and the Canadian Middle Atmosphere Model (CMAM). ACE provides the first comprehensive data set for the investigation of interhemispheric, interseasonal, and height-resolved differences of the O_3-N_2O correlation structure. By subsampling the CMAM data, the representativeness of the ACE data is evalu...

  3. GPS Antenna Characterization Experiment (ACE): Receiver Design and Initial Results

    Science.gov (United States)

    Martzen, Phillip; Highsmith, Dolan E.; Valdez, Jennifer E.; Parker, Joel J. K.; Moreau, Michael C.

    2015-01-01

    The GPS Antenna Characterization Experiment (ACE) is a research collaboration between Aerospace and NASA Goddard to characterize the gain patterns of the GPS L1 transmit antennas. High altitude GPS observations are collected at a ground station through a transponder-based or "bent-pipe" architecture where the GPS L1 RF spectrum is received at a platform in geosynchronous orbit and relayed to the ground for processing. The focus of this paper is the unique receiver algorithm design and implementation. The high-sensitivity GPS C/A-code receiver uses high fidelity code and carrier estimates and externally supplied GPS message bit data in a batch algorithm with settings for a 0 dB-Hz threshold. The resulting carrier-to-noise measurements are used in a GPS L1 transmit antenna pattern reconstruction. This paper shows initial transmit gain patterns averaged over each block of GPS satellites, including comparisons to available pre-flight gain measurements from the GPS vehicle contractors. These results provide never-before-seen assessments of the full, in-flight transmit gain patterns.

  4. Results of the Advanced Containment Experiments Program (ACE/MACE)

    International Nuclear Information System (INIS)

    The ACE project consists of four independent parts (phases): Phase A: Containment filtration systems tests; Phase B: Iodine behavior and retention; Phase C: Fission product release during Molten Corium Concrete Interactions (MCCI); Phase D: Coolability of spreaded molten corium during MCCI - the MACE program. The experimental work of phases A-C has been accomplished within 1991. Documentation and some additional tests will be completed during 1992. After the closure of Phase A-C, Phase D is scheduled to continue until approx. 1993. (orig.)

  5. Status Report for Experiment AD-4/ACE Biological Effectiveness of Antiproton Annihilation

    CERN Document Server

    Holzscheiter, M H; Angelopoulos, Angelo; Bassler, Niels; Beyer, Gerd; Currell, Fred; De Marco, John; Doser, Michael; Hajdukovic, Dragan; Hartley, Oliver; Kavanagh, Joy; Iwamoto, Kei; Jäkel, Oliver; Kantemiris, Ioannis; Knudsen, Helge; Kovacevic, Sandra; McBride, Bill; Møller, Søren Pape; Overgaard, Jens; Petersen, Jørgen; Ratib, Osman; Schettino, Giuseppe; Timson, David; Singers-Sørensen, Brita; Solberg, Timothy; Vranjes, Sanja; Wouters, Brad

    2009-01-01

    Status report for experiment AD-4/ACE showing recent progress in RBE measurements for V79 Chinese Hamster cells irradiated with antiprotons. Also discussed are initial test experiments using the H2AX assay to study DNA damage to cells and initial experiments using liquid ionization chambers.

  6. ACE program Phase C: Molten corium concrete interaction (MCCI) and corium melt coolability experiments

    International Nuclear Information System (INIS)

    A series of experiments are being performed at Argonne National Laboratory (ANL), investigating the interaction of molten core material with concrete and its coolability with water. The experiments are being performed under the auspices of the ACE (Advanced Containment Experiments) and the MACE (Melt Attack and Coolability Experiments) Projects, which are sponsored by a consortium of 10 foreign countries and four domestic organizations. The general objectives of the ACE MCCI experiments are to measure: (1) the releases of refractory fission product species i.e., oxides of lanthanum, barium, cerium and strontium; (2) the physical and chemical character of the aerosols generated; and (3) the thermal-hydraulic aspects of the interaction, including the concrete ablation rate. The motivation for performing these relatively complex experiments arose because of the lack of data, and the very different estimates of the releases predicted by the extant codes e.g., VANESA and MAAP for similar conditions of the MCCI. Both the PWR and BWR corium composition and the various concrete compositions are represented and the initial Zr oxidation is varied from 30 to 100%

  7. The latest general chemistry experiment

    International Nuclear Information System (INIS)

    This book lists thirty-nine experiments, safety regulations in the laboratory and method of experiments. The contents of experiments are hut and bolt for chemistry, separation of mixture, molecular weight and vapor density, solubility and fractional crystallization, colloid, pH and an indicator, properties of acid-base, reaction speed, synthesizing of Nylon, synthesizing of aspirin, reaction of alcohol, a natural substance ; extraction of caffeine, extraction of solvent, chromatography, refining water and water analysis and periodicity of the periodic table of the elements.

  8. Intercomparisons of Aura MLS, ACE, and HALOE Observations of Long-Lived Trace Species Using the Langley Lagrangian Chemistry and Transport Model

    Science.gov (United States)

    Considine, David B.; Natarajan, Murali; Fairlie, T. D.; Lingenfelser, Gretchen S.; Bernath, Peter

    2007-01-01

    We use the LaRC Lagrangian Chemistry and Transport Model (LCTM) [Considine et al., 2007; Pierce et al., 2003] to intercompare ACE, Aura, and HALOE observations of long-lived trace species. The LCTM calculates the transport, mixing, and photochemical evolution of an ensemble of parcels that have been initialized from ACE-FTS measurements. Here we focus on late November, 2004 comparisons, due to the previous 3-week period of continuous HALOE observations and MLS v2.2 data on November 29, 2004.

  9. Technology advancement for the ASCENDS mission using the ASCENDS CarbonHawk Experiment Simulator (ACES)

    Science.gov (United States)

    Obland, M. D.; Antill, C.; Browell, E. V.; Campbell, J. F.; CHEN, S.; Cleckner, C.; Dijoseph, M. S.; Harrison, F. W.; Ismail, S.; Lin, B.; Meadows, B. L.; Mills, C.; Nehrir, A. R.; Notari, A.; Prasad, N. S.; Kooi, S. A.; Vitullo, N.; Dobler, J. T.; Bender, J.; Blume, N.; Braun, M.; Horney, S.; McGregor, D.; Neal, M.; Shure, M.; Zaccheo, T.; Moore, B.; Crowell, S.; Rayner, P. J.; Welch, W.

    2013-12-01

    The ASCENDS CarbonHawk Experiment Simulator (ACES) is a NASA Langley Research Center project funded by NASA's Earth Science Technology Office that seeks to advance technologies critical to measuring atmospheric column carbon dioxide (CO2) mixing ratios in support of the NASA Active Sensing of CO2 Emissions over Nights, Days, and Seasons (ASCENDS) mission. The technologies being advanced are: (1) multiple transmitter and telescope-aperture operations, (2) high-efficiency CO2 laser transmitters, (3) a high bandwidth detector and transimpedance amplifier (TIA), and (4) advanced algorithms for cloud and aerosol discrimination. The instrument architecture is being developed for ACES to operate on a high-altitude aircraft, and it will be directly scalable to meet the ASCENDS mission requirements. The above technologies are critical for developing an airborne simulator and spaceborne instrument with lower platform consumption of size, mass, and power, and with improved performance. This design employs several laser transmitters and telescope-apertures to demonstrate column CO2 retrievals with alignment of multiple laser beams in the far-field. ACES will transmit five laser beams: three from commercial lasers operating near 1.57-microns, and two from the Exelis atmospheric oxygen (O2) fiber laser amplifier system operating near 1.26-microns. The Master Oscillator Power Amplifier at 1.57-microns measures CO2 column concentrations using an Integrated-Path Differential Absorption (IPDA) lidar approach. O2 column amounts needed for calculating the CO2 mixing ratio will be retrieved using the Exelis laser system with a similar IPDA approach. The three aperture telescope design was built to meet the constraints of the Global Hawk high-altitude unmanned aerial vehicle (UAV). This assembly integrates fiber-coupled transmit collimators for all of the laser transmitters and fiber-coupled optical signals from the three telescopes to the aft optics and detector package. The detector

  10. A Discovery Chemistry Experiment on Buffers

    Science.gov (United States)

    Kulevich, Suzanne E.; Herrick, Richard S.; Mills, Kenneth V.

    2014-01-01

    The Holy Cross Chemistry Department has designed and implemented an experiment on buffers as part of our Discovery Chemistry curriculum. The pedagogical philosophy of Discovery Chemistry is to make the laboratory the focal point of learning for students in their first two years of undergraduate instruction. We first pose questions in prelaboratory…

  11. Micro-polymer Chemistry Experiment Teaching Research

    Institute of Scientific and Technical Information of China (English)

    李青山

    2009-01-01

    For nearly thirty years,there has been made great progress in micro-polymer chemistry experiment teaching which has these characteristics that using less reagents,less pollution and more portable in comparison with the conventional experiment.In China,Zhou Ninghuai and others began to go on micro-scale experiment research firstly and Professor Li Qingshan who brought this innovation to polymer organic synthesis experiment has done a lot of works in micro-polymer chemistry experiment teaching.To carry out the study ofmicro-polymer chemistry experiments not only accords with teaching methods and reform,but also conforms to the trend of the times of green chemistry.So the research and application of micro-polymer chemistry experiment have broad prospects.

  12. Technical Note: A trace gas climatology derived from the Atmospheric Chemistry Experiment Fourier Transform Spectrometer dataset

    Directory of Open Access Journals (Sweden)

    A. Jones

    2011-11-01

    Full Text Available The Atmospheric Chemistry Experiment-Fourier Transform Spectrometer (ACE-FTS aboard the Canadian satellite SCISAT (launched in August 2003 was designed to investigate the composition of the upper troposphere, stratosphere, and mesosphere. ACE-FTS utilizes solar occultation to measure temperature and pressure as well as vertical profiles of over thirty chemical species including O3, H2O, CH4, N2O, CO, NO, NO2, N2O5, HNO3, HCl, ClONO2, CCl3F, CCl2F2, and HF. Global coverage for each species is obtained approximately over a three month period and measurements are made with a vertical resolution of typically 3–4 km. A quality-controlled climatology has been created for each of these 14 baseline species, where individual profiles are averaged over the period of February 2004 to February 2009. Measurements used are from the ACE-FTS version 2.2 data set including updates for O3 and N2O5. The climatological fields are provided on a monthly and three-monthly basis (DJF, MAM, JJA, SON at 5 degree latitude and equivalent latitude spacing and on 28 pressure surfaces (26 of which are defined by the Stratospheric Processes And their Role in Climate (SPARC Chemistry Climate Model validation activity. The ACE-FTS climatological dataset is available through the ACE website.

  13. ACE program Phases C and D: Molten corium concrete interaction (MCCI) experiments and corium melt coolability experiments (MACE)

    International Nuclear Information System (INIS)

    A series of experiments are being performed at Argonne National Laboratory (ANL) investigating the interaction of molten core material with concrete and its coolability with water. The work is supported by the ACE (Advanced Containment Experiments) International Consortium. This consortium consists of 19 countries; with the US participation shared by Nuclear Regulatory Commission (NRC), Department of Energy (DOE), Electric Power Research Institute (EPRI) and Westinghouse. The project is managed by EPRI. The general objectives of the molten core concrete interaction (MCCI) experiments are to measure: (1) the releases of refractory fission product species, i.e., oxides of lanthanum, barium, cesium and strontium; (2) the physical and chemical character of the aerosols generated; and (3) the thermal-hydraulic aspects of the interaction, including the concrete ablation rate. The principal objectives of the melt attack and coolability experiments (MACE) project are to: (1) obtain data on coolability with water of corium melt interacting with basemat concrete; and (2) develop models for insertion in the industry and NRC-sponsored codes

  14. ACE Program Phase D: Melt Attack and Coolability Experiments (MACE) Program

    International Nuclear Information System (INIS)

    A series of large-scale experiments are being performed at Argonne National Laboratory (ANL) investigating the coolability of molten-corium by water during its interaction with concrete. The principal objectives of the MACE Program are to: 1) obtain data on heat transfer from corium melt to the overlying water and underlying concrete; and 2) develop models describing the coolability process for insertion in the U.S. and international codes on molten corium concrete interaction (MCCI). This paper will provide an overview of the melt coolability issue, describe the MACE program and the capabilities of the experimental facility constructed. The MACE Program is managed by the Electric Power Research Institute (EPRI) and supported by U.S. NRC, U.S. DOE, EPRI and an international consortium. The MACE Program was started in 1989 under EPRI sponsorship and the scoping test Mo was performed in August of that year. This was followed by the test M1, performed in November 1991. The results of these tests are described in an accompanying paper. Briefly, the test M0 was conducted as specified, except for power input, which was much greater than specified. The test M0 did not cool since a crust was formed and supported by the electrodes, which unfortunately bent due to the excessive thermal loading. The test M1 design corrected for the deficiencies of test M0, however, in the operation of the test, the specified initial condition that the corium powder be completely molten to the top surface was not attained. The top surface remained as a sintered powder layer and did not allow water-melt contact. Post-test examination of test M1 confirmed these findings. Test M1 will be repeated as test M1B in April 1992 with the heatup procedure found to be successful in the ACE Phase C tests

  15. Examination of the aerosol indirect effect under contrasting environments during the ACE-2 experiment

    Directory of Open Access Journals (Sweden)

    H. Guo

    2007-01-01

    Full Text Available The Active Tracer High-resolution Atmospheric Model (ATHAM has been adopted to examine the aerosol indirect effect in contrasting clean and polluted cloudy boundary layers during the Second Aerosol Characterization Experiment (ACE-2. Model results are in good agreement with available in-situ observations, which provides confidence in the results of ATHAM. Sensitivity tests have been conducted to examine the response of the cloud fraction (CF, cloud liquid water path (LWP, and cloud optical depth (COD to changes in aerosols in the clean and polluted cases. It is shown for two cases that CF and LWP would decrease or remain nearly constant with an increase in aerosols, a result which shows that the second aerosol indirect effect is positive or negligibly small in these cases. Further investigation indicates that the background meteorological conditions play a critical role in the response of CF and LWP to aerosols. When large-scale subsidence is weak as in the clean case, the dry overlying air above the cloud is more efficiently entrained into the cloud, and in so doing, removes cloud water more efficiently, and results in lower CF and LWP when aerosol burden increases. However, when the large-scale subsidence is strong as in the polluted case, the growth of the cloud top is suppressed and the entrainment drying makes no significant difference when aerosol burden increases. Therefore, the CF and LWP remain nearly constant. In both the clean and polluted cases, the COD tends to increase with aerosols, and the total aerosol indirect effect (AIE is negative even when the CF and LWP decrease with an increase in aerosols. Therefore, the first AIE dominates the response of the cloud to aerosols.

  16. Water chemistry experiences with VVERs at Kudankulam

    International Nuclear Information System (INIS)

    Kudankulam Nuclear Power Project - 1 and 2 (Kudankulam NPP - 1 and 2) are pressurised water cooled VVERs of 1000 MWe each. Kudankulam NPP Unit - 1 is presently on its first cycle of operation and Kudankulam NPP Unit - 2 is on the advanced stage of commissioning with the successful completion of hot run related Functional tests. Water Chemistry aspects during various phases of commissioning of Kudankulam NPP Unit - 1 such as Hot Run, Boric acid flushing, initial fuel Loading (IFL), First approach to Criticality (FAC) are discussed. The main objectives of the use of controlled primary water chemistry programme during the hot functional tests are reviewed. The importance of the relevant water chemistry parameters were ensured to have the quality of the passive layer formed on the primary coolant system surfaces. The operational experiences during the 1st cycle of operation of primary water chemistry, radioactivity transport and build-up are presented. The operational experience of some VVER units in the field of the primary water chemistry, radioactivity transport and build-up are presented as a comparison to VVER at Kudankulam NPP. The effects of the initial passivated layer formed on metal surfaces during hot run, activated corrosion products levels in the primary coolant under controlled water chemistry regime and the contamination/radiation situation are discussed. This report also includes the water chemistry related issues of secondary water systems. (author)

  17. Experiments in the Chemistry of Food.

    Science.gov (United States)

    Weaver, Elbert C.

    This booklet presents 18 experiments in the chemistry of food, suitable for elementary and secondary school science classes. Experiments deal with an analysis of milk, determinations of the amounts of sulfur dioxide, iron, and fat in foods, and the concentration of vitamin C in fruit juice and iodine in salt. Tests are provided for fats,…

  18. Detector Data Simulation and Filtering Strategy for the European Laser Timing (ELT) Experiment On-board ACES

    Science.gov (United States)

    Bamann, Christoph; Schlicht, Anja; Hugentobler, Urs; Pühl, Magdalena

    2015-04-01

    Due to the rapid progress of frequency standards in the optical domain and increasingly demanding applications in metrology and fundamental physics studies, accuracy requirements on frequency and time transfer are continuously increasing. Most present satellite based clock comparison systems work in the microwave domain and are based on GPS and TWSTFT (Two-Way Satellite Time and Frequency Transfer). Recently, systems such as LASSO (LAser Synchronization from a Stationary Orbit) and T2L2 (Time Transfer by Laser Link) promised even better performance in the optical domain. In 2016 the ESA mission ACES (Atomic Clock Ensemble in Space) will bring a new generation of atomic clocks into the microgravity environment of the ISS, which will distribute a stable and accurate time base. In the frame of this mission an optical link called ELT (European Laser Timing) is presently under study, which is subject of our work. The on-board hardware of ELT consists of a corner cube retro-reflector (CCR), a single-photon avalanche diode (SPAD), and an event timer connected to the ACES time scale. The SPAD detects laser pulses fired towards the payload and the CCR reflects these pulses back to the ground station. The detection dates are recorded in the ACES time scale, while the two-way time of flight can be used for precise ranging. Consequently, time transfer and clock analysis can be performed based on data triplets comprising the time of transmission of a laser pulse, its time of reception at the ELT-detector and its time of reception back at the station-detector. We present simulations of these triplets based on simple ISS orbits including preset attitude and accurate Earth orientation data. In addition, we consider experimentally derived detector, reflector, and background noise characteristics as well as simulations of the ACES clocks. The ELT data center, which will be hosted by our institution, will have to extract the data triplets from the large amount of noisy detector dates

  19. Laser experiments for chemistry and physics

    CERN Document Server

    Compton, Robert N

    2016-01-01

    Lasers are employed throughout science and technology, in fundamental research, the remote sensing of atmospheric gases or pollutants, communications, medical diagnostics and therapies, and the manufacturing of microelectronic devices. Understanding the principles of their operation, which underlie all of these areas, is essential for a modern scientific education. This text introduces the characteristics and operation of lasers through laboratory experiments designed for the undergraduate curricula in chemistry and physics. Introductory chapters describe the properties of light, the history of laser invention, the atomic, molecular, and optical principles behind how lasers work, and the kinds of lasers available today. Other chapters include the basic theory of spectroscopy and computational chemistry used to interpret laser experiments. Experiments range from simple in-class demonstrations to more elaborate configurations for advanced students. Each chapter has historical and theoretical background, as well...

  20. Hot functional test chemistry - long term experience

    Energy Technology Data Exchange (ETDEWEB)

    Vonkova, K.; Kysela, J., E-mail: von@ujv.cz [Nuclear Research Inst. Rez plc, Husinec-Rez (Czech Republic); Marcinsky, M. [ENEL-SE, NPP Mochovce, Mochovce (Slovakia); Martykan, M. [CEZ-ETE, NPP Temelin, Temelin (Czech Republic)

    2010-07-01

    Primary circuit materials undergo general corrosion in high temperature, deoxygenated, neutral or mildly alkaline solutions to form thin oxide films. These oxide layers (films) serve as protective film and mitigate the further corrosion of primary materials. Inner chromium-rich oxide layer has low cation diffusion coefficients and thus control iron and nickel transport from the metal surface to the outer layer and their dissolution into the coolant. Much less corrosion products are generated by the compact, integral and stable oxide (passivation) layer. For the latest Czech and Slovak stations commissioned (Temelin and Mochovce) a modified Hot Functional Test (HFT) chemistry was developed in the NRI Rez. Chromium rich surface layer formatted due to modified HTF chemistry ensures lower corrosion rates and radiation field formation and thus also mitigates crud formation during operation. This procedure was also designed to prepare the commissioned unit for the further proper water chemistry practise. Mochovce 1 (SK) was the first station commissioned using these recommendations in 1998. Mochovce 2 (1999) and Temelin 1 and 2 (CZ - 2000 and 2002) were subsequently commissioned using these guidelines too. The main principles of the controlled primary water chemistry applied during the hot functional tests are reviewed and importance of the water chemistry, technological and other relevant parameters is stressed regarding to the quality of the passive layer formed on the primary system surfaces. Samples from Mochovce indicated that duplex oxide layers up to 20 μm thick were produced, which were mainly magnetite substituted with nickel and chromium (e.g. 60-65% Fe, 18-28% Cr, 9-12% Ni, <1% Mn and 1-2% Si on a stainless steel primary circuit sample). Long term operation experience from both nuclear power plants are discussed in this paper. Radiation field, occupational radiation exposure and corrosion layers evolution during the first c. ten years of operation are

  1. Hot functional test chemistry - long term experience

    International Nuclear Information System (INIS)

    Primary circuit materials undergo general corrosion in high temperature, deoxygenated, neutral or mildly alkaline solutions to form thin oxide films. These oxide layers (films) serve as protective film and mitigate the further corrosion of primary materials. Inner chromium-rich oxide layer has low cation diffusion coefficients and thus control iron and nickel transport from the metal surface to the outer layer and their dissolution into the coolant. Much less corrosion products are generated by the compact, integral and stable oxide (passivation) layer. For the latest Czech and Slovak stations commissioned (Temelin and Mochovce) a modified Hot Functional Test (HFT) chemistry was developed in the NRI Rez. Chromium rich surface layer formatted due to modified HTF chemistry ensures lower corrosion rates and radiation field formation and thus also mitigates crud formation during operation. This procedure was also designed to prepare the commissioned unit for the further proper water chemistry practise. Mochovce 1 (SK) was the first station commissioned using these recommendations in 1998. Mochovce 2 (1999) and Temelin 1 and 2 (CZ - 2000 and 2002) were subsequently commissioned using these guidelines too. The main principles of the controlled primary water chemistry applied during the hot functional tests are reviewed and importance of the water chemistry, technological and other relevant parameters is stressed regarding to the quality of the passive layer formed on the primary system surfaces. Samples from Mochovce indicated that duplex oxide layers up to 20 μm thick were produced, which were mainly magnetite substituted with nickel and chromium (e.g. 60-65% Fe, 18-28% Cr, 9-12% Ni, <1% Mn and 1-2% Si on a stainless steel primary circuit sample). Long term operation experience from both nuclear power plants are discussed in this paper. Radiation field, occupational radiation exposure and corrosion layers evolution during the first c. ten years of operation are

  2. Optical properties of aerosols during APEX and ACE-Asia experiments

    Science.gov (United States)

    Sano, Itaru; Mukai, Sonoyo; Okada, Yasuhiko; Holben, Brent N.; Ohta, Sachio; Takamura, Tamio

    2003-12-01

    Sun/sky photometry and polarimetry of atmospheric light have been undertaken by multispectral photometers (CE-318-1 and -2, Cimel Electronique, France) and a polarimeter (PSR-1000, Opto Research, Japan) over Amami, Noto, and Shirahama, Japan, during APEX-E1, -E2, and ACE-Asia field campaigns. Radiometers provide us with the optical thickness of aerosols and Ångström exponent. Other aerosol characteristics, e.g., size distribution, refractive index, etc., are retrieved based on each inversion method corresponding each equipment. The former takes a standard AERONET processing, and the latter is according to our own procedure to analyze the polarimetry with PSR-1000. After several aerosol parameters are derived, the HYSPLIT4 backward trajectory analysis is adopted to search the origin of aerosols. It is shown from these ground measurements that aerosol optical thickness, Ångström exponent, and refractive index are classified into two typical categories as a background type detected in winter, and a soil dust type appeared in Asian dust events in spring. Further, it is found that the obtained size distribution of Asian dust indicates the dominance of large particles.

  3. Simulation of ACE and MACE experiments with a phase segregation model using the TOLBIAC code

    International Nuclear Information System (INIS)

    The paper presents an interpretation of the ACE and MACE MCCI tests with the TOLBIAC code. The phase segregation approach has been introduced in this code. The main physical assumptions are described. Chemical reactions with Zr are believed to be achieved when the ablation of concrete begins. Mass losses from the melt due to melt splattering are taken into account, as well as formation of lateral crusts. The calculated evolution of melt temperature fits well with measurements. The model predicts well the effect of a power increase on the melt temperature; it is stated that the usual model (without phase segregation) approach for heat transfer is not able to reproduce this effect. Sensitivity calculations are performed. It is concluded that initial conditions, melt sparging and presence of lateral crusts have a significant effect on melt temperature; on the contrary, physical properties (viscosity, with reasonable variation range) and power split have a small effect on melt temperature. Finally, the points in favour of the phase segregation approach are summarised. Further development needs for TOLBIAC are also outlined. (orig.)

  4. Titan's organic chemistry: Results of simulation experiments

    Science.gov (United States)

    Sagan, Carl; Thompson, W. Reid; Khare, Bishun N.

    1992-01-01

    Recent low pressure continuous low plasma discharge simulations of the auroral electron driven organic chemistry in Titan's mesosphere are reviewed. These simulations yielded results in good accord with Voyager observations of gas phase organic species. Optical constants of the brownish solid tholins produced in similar experiments are in good accord with Voyager observations of the Titan haze. Titan tholins are rich in prebiotic organic constituents; the Huygens entry probe may shed light on some of the processes that led to the origin of life on Earth.

  5. Beginning RPG Maker VX Ace

    CERN Document Server

    Perez, Darrin

    2014-01-01

    Beginning RPG Maker VX Ace takes you through the process of using the RPG Maker VX Ace game development engine to create your very own role playing game. The book has been designed with the complete beginner in mind who has little to no experience with the engine. Tutorials and exercises will take you from installing the software to putting the final touches upon your first project. Game design can be quite a daunting challenge, as it generally involves a large amount of programming know-how on top of having to plan everything out that makes a good game what it is. RPG Maker VX Ace

  6. O3-N2O correlations from the Atmospheric Chemistry Experiment: Revisiting a diagnostic of transport and chemistry in the stratosphere

    Science.gov (United States)

    Hegglin, Michaela I.; Shepherd, Theodore G.

    2007-10-01

    Our knowledge of stratospheric O3-N2O correlations is extended, and their potential for model-measurement comparison assessed, using data from the Atmospheric Chemistry Experiment (ACE) satellite and the Canadian Middle Atmosphere Model (CMAM). ACE provides the first comprehensive data set for the investigation of interhemispheric, interseasonal, and height-resolved differences of the O3-N2O correlation structure. By subsampling the CMAM data, the representativeness of the ACE data is evaluated. In the middle stratosphere, where the correlations are not compact and therefore mainly reflect the data sampling, joint probability density functions provide a detailed picture of key aspects of transport and mixing, but also trace polar ozone loss. CMAM captures these important features, but exhibits a displacement of the tropical pipe into the Southern Hemisphere (SH). Below about 21 km, the ACE data generally confirm the compactness of the correlations, although chemical ozone loss tends to destroy the compactness during late winter/spring, especially in the SH. This allows a quantitative comparison of the correlation slopes in the lower and lowermost stratosphere (LMS), which exhibit distinct seasonal cycles that reveal the different balances between diabatic descent and horizontal mixing in these two regions in the Northern Hemisphere (NH), reconciling differences found in aircraft measurements, and the strong role of chemical ozone loss in the SH. The seasonal cycles are qualitatively well reproduced by CMAM, although their amplitude is too weak in the NH LMS. The correlation slopes allow a "chemical" definition of the LMS, which is found to vary substantially in vertical extent with season.

  7. Microstructures for physics and chemistry experiments

    International Nuclear Information System (INIS)

    For the past 15 years we have been using integrated circuit (IC) technology to fabricate targets and diagnostic devices for physics and chemistry experiments at LLNL. Some of the features that make this technology attractive for this purpose are: the advanced state of computer aided design which makes arrays and design variation possible, the ability to print and etch feature sizes in the micron and sub-micron range, the purity of the materials used, the ample supply of equipment and procedures associated with the IC industry. Examples of the more popular devises include x-ray transmissive windows, diffraction grating, Fresnel zone plates, resolution and alignment targets, small apertures, laser targets, field emission points, and microchannel coolers. This paper discusses the fabrication of these devices and show several examples

  8. Cocrystal Controlled Solid-State Synthesis: A Green Chemistry Experiment for Undergraduate Organic Chemistry

    Science.gov (United States)

    Cheney, Miranda L.; Zaworotko, Michael J.; Beaton, Steve; Singer, Robert D.

    2008-01-01

    Green chemistry has become an important area of concern for all chemists from practitioners in the pharmaceutical industry to professors and the students they teach and is now being incorporated into lectures of general and organic chemistry courses. However, there are relatively few green chemistry experiments that are easily incorporated into…

  9. Promoting Chemistry Learning through Undergraduate Work Experience in the Chemistry Lab: A Practical Approach

    Science.gov (United States)

    Yu, Hong-Bin

    2015-01-01

    Hiring undergraduate lab assistants in chemistry departments is common in college. However, few studies have focused on promoting undergraduate chemistry learning and thinking skills through this work experience in chemistry teaching laboratories. This article discusses the strategy we implemented in the lab assistant program. The…

  10. Greener Approaches to Undergraduate Chemistry Experiments.

    Science.gov (United States)

    Kirchhoff, Mary, Ed.; Ryan, Mary Ann, Ed.

    This laboratory manual introduces the idea of Green Chemistry, which is the design of chemical products and processes that reduce or eliminate the use and generation of hazardous substances. Instructional samples are included to help teachers integrate green chemistry into the college chemistry curriculum. Each laboratory includes: (1) a…

  11. ACE-FTS version 3.0 data set: validation and data processing update

    Directory of Open Access Journals (Sweden)

    Claire Waymark

    2014-01-01

    Full Text Available On 12 August 2003, the Canadian-led Atmospheric Chemistry Experiment (ACE was launched into a 74° inclination orbit at 650 km with the mission objective to measure atmospheric composition using infrared and UV-visible spectroscopy (Bernath et al. 2005. The ACE mission consists of two main instruments, ACE-FTS and MAESTRO (McElroy et al. 2007, which are being used to investigate the chemistry and dynamics of the Earth’s atmosphere.  Here, we focus on the high resolution (0.02 cm-1 infrared Fourier Transform Spectrometer, ACE-FTS, that measures in the 750-4400 cm-1 (2.2 to 13.3 µm spectral region.  This instrument has been making regular solar occultation observations for more than nine years.  The current ACE-FTS data version (version 3.0 provides profiles of temperature and volume mixing ratios (VMRs of more than 30 atmospheric trace gas species, as well as 20 subsidiary isotopologues of the most abundant trace atmospheric constituents over a latitude range of ~85°N to ~85°S.  This letter describes the current data version and recent validation comparisons and provides a description of our planned updates for the ACE-FTS data set. [...

  12. Adverse Childhood Experiences (ACE) and Health-Risk Behaviors among Adults in a Developing Country Setting

    Science.gov (United States)

    Ramiro, Laurie S.; Madrid, Bernadette J.; Brown, David W.

    2010-01-01

    Objective: This study aimed to examine the association among adverse childhood experiences, health-risk behaviors, and chronic disease conditions in adult life. Study population: One thousand and sixty-eight (1,068) males and females aged 35 years and older, and residing in selected urban communities in Metro Manila participated in the…

  13. Teaching Lab Report Writing through Inquiry: A Green Chemistry Stoichiometry Experiment for General Chemistry

    Science.gov (United States)

    Cacciatore, Kristen L.; Sevian, Hannah

    2006-01-01

    We present an alternative to a traditional first-year chemistry laboratory experiment. This experiment has four key features: students utilize stoichiometry, learn and apply principles of green chemistry, engage in authentic scientific inquiry, and discover why each part of a scientific lab report is necessary. The importance and essential…

  14. ACE program phase D: melt attack and coolability experiments (MACE) program

    International Nuclear Information System (INIS)

    A series of large-scale experiments are being performed at ANL investigating the coolability of molten-corium by water during its interaction with concrete. The principal objectives of the MACE Program are to: 1) Obtain data on heat transfer from corium melt to the overlying water and underlying concrete; and 2) develop models describing the coolability process for insertion in the U.S. and international codes on molten corium concrete interaction (MCCI). This paper provides an overview of the melt coolability issue, describe the MACE program and the capabilities of the experimental facility constructed. The MACE Program is managed by the EPRI and supported by U.S. NRC, U.S. DOE, EPRI and an international consortium. (orig./HP)

  15. Validation of ACE and OSIRIS ozone and NO2 measurements using ground-based instruments at 80° N

    OpenAIRE

    Adams, C.; Strong, K.; Batchelor, R. L.; P. F. Bernath; S. Brohede; C. Boone; Degenstein, D.; Daffer, W. H.; J. R. Drummond; Fogal, P. F.; Farahani, E.; C. Fayt; Fraser, A; Goutail, F.; Hendrick, F.

    2012-01-01

    The Optical Spectrograph and Infra-Red Imager System (OSIRIS) and the Atmospheric Chemistry Experiment (ACE) have been taking measurements from space since 2001 and 2003, respectively. This paper presents intercomparisons between ozone and NO2 measured by the ACE and OSIRIS satellite instruments and by ground-based instruments at the Polar Environment Atmospheric Research Laboratory (PEARL), which is located at Eureka, Canada (80° N, 86° W) and is operated by the Canadian Ne...

  16. Validation of ACE and OSIRIS ozone and NO2 measurements using ground-based instruments at 80° N

    OpenAIRE

    Pazmino, A; B. Pavlovic; J.-H. Park; C. A. McLinden; Mendonca, J.; C. T. McElroy; G. Manney; Lindenmaier, R.; F. Kolonjari; Hendrick, F.; Goutail, F.; Fraser, A; C. Fayt; Farahani, E.; Fogal, P. F.

    2012-01-01

    The Optical Spectrograph and Infra-Red Imager System (OSIRIS) and the Atmospheric Chemistry Experiment (ACE) have been taking measurements from space since 2001 and 2003, respectively. This paper presents intercomparisons between ozone and NO2 measured by the ACE and OSIRIS satellite instruments and by ground-based instruments at the Polar Environment Atmospheric Research Laboratory (PEARL), which is located at Eureka, Canada (80° N, 86° W) and is operated by the Canadian Network for the Dete...

  17. Synthesis of Ethyl Nalidixate: A Medicinal Chemistry Experiment

    Science.gov (United States)

    Leslie, Ray; Leeb, Elaine; Smith, Robert B.

    2012-01-01

    A series of laboratory experiments that complement a medicinal chemistry lecture course in drug design and development have been developed. The synthesis of ethyl nalidixate covers three separate experimental procedures, all of which can be completed in three, standard three-hour lab classes and incorporate aspects of green chemistry such as…

  18. Synthesis of Aspirin: A General Chemistry Experiment.

    Science.gov (United States)

    Olmsted, John III

    1998-01-01

    Describes the redesign of the first semester general chemistry laboratory at the college level. An organic component is included in the redesign and it provides students with explicit examples of several types of operations in which chemists engage. Contains 16 references. (DDR)

  19. An overview of KANUPP operating experience in chemistry

    International Nuclear Information System (INIS)

    KANUPP is a small CANDU® type PHWR (137MWe), commissioned in 1972 and now operating after life extension (PLEX) since 2004. This paper contains an overview of the plant operating experience in chemistry control over the past year including life extension period. Emphasis is on: Success story; Practices; Future improvements in chemistry programs. Considerable efforts are underway to maintain plant equipment and systems to mitigate the effect of plant ageing. The improvements that have been made at the station are as under: Heat transport system (HTS) chemistry, its effects on construction material; Feed water chemistry on secondary side (considering the condenser leaks). Strict chemistry control is being exercised for the heat transport system (HTS) for its better chemistry control. For short term, the changes are limited to pH adjustments of HTS. This change decreases the rate of thinning of outlet feeders as noted in some CANDUs® due to flow accelerated corrosion (FAC). Water Treatment Plant has been refurbished to get very low total dissolved solids (TDS) de-mineralized water for secondary side systems of the plant. Experience of steam generators flushing before startup, sludge pile analyses mapping, verification of pH from different sampling points of SGs, are the short term mitigating actions to address sludge pile problem in steam generators (SGs). The R and D on HTS and SGs is multifaceted and is aimed at achieving optimum chemistry control. Study is being conducted for improving chemistry control for the material, equipment and systems of the plant. (author)

  20. Advanced Undergraduate Experiments in Thermoanalytical Chemistry.

    Science.gov (United States)

    Hill, J. O.; Magee, R. J.

    1988-01-01

    Describes several experiments using the techniques of thermal analysis and thermometric titrimetry. Defines thermal analysis and several recent branches of the technique. Notes most of the experiments use simple equipment and standard laboratory techniques. (MVL)

  1. BWR and PWR chemistry operating experience and perspectives

    International Nuclear Information System (INIS)

    It is well recognized that proper control of water chemistry plays a critical role in ensuring the safe and reliable operation of Boiling Water Reactors (BWRs) and Pressurized Water Reactors (PWRs). State-of-the-art water chemistry programs reduce general and localized corrosion of reactor coolant system, steam cycle equipment, and fuel cladding materials; ensure continued integrity of cycle components; and reduce radiation fields. Once a particular nuclear plant component has been installed or plant system constructed, proper water chemistry provides a global tool to mitigate materials degradation problems, thereby reducing the need for costly repairs or replacements. Recognizing the importance of proper chemistry control and the value in understanding the relationship between chemistry guidance and actual operating experience, EPRI continues to collect, monitor, and evaluate operating data from BWRs and PWRs around the world. More than 900 cycles of valuable BWR and PWR operating chemistry data has been collected, including online, startup and shutdown chemistry data over more than 10 years (> 20 years for BWRs). This paper will provide an overview of current trends in BWR and PWR chemistry, focusing on plants in the U.S.. Important chemistry parameters will be highlighted and discussed in the context of the EPRI Water Chemistry Guidelines requirements (i.e., those parameters considered to be of key importance as related to the major goals identified in the EPRI Guidelines: materials integrity; fuel integrity; and minimizing plant radiation fields). Perspectives will be provided in light of recent industry initiatives and changes in the EPRI BWR and PWR Water Chemistry Guidelines. (author)

  2. Epoxide Chemistry: Guided Inquiry Experiment Emphasizing Structure Determination and Mechanism

    Science.gov (United States)

    Krishnamurty, H. G.; Jain, Niveta; Samby, Kiran

    2000-04-01

    This paper presents an operationally simple three-step synthesis of an a-hydroxy acid based on epoxide chemistry. The focus of the experiment is on the preparation of the chalcone epoxide and its reaction with hot alcoholic alkali. The experiment leads to an unpredicted reaction product. Its structure is established as 2-benzyl-2-phenylglycollic acid by chemical and spectroscopic analysis. The hydroxyacid is a good example to bring home an important NMR principle: the nonequivalence of hydrogens adjacent to a stereogenic center. The formation of the alpha-hydroxy acid is a mechanistic puzzle. A stepwise mechanism can be developed applying lecture-based organic chemistry concepts. On the other hand, acid-catalyzed (H2SO4, BF3) reaction of the chalcone epoxide gives benzoylphenylacetaldehyde. The exercise can be used as a multistep organic chemistry experiment. It also gives students a research-type experience.

  3. Spectroelectrochemical Sensing of Aqueous Iron: An Experiment for Analytical Chemistry

    Science.gov (United States)

    Shtoyko, Tanya; Stuart, Dean; Gray, H. Neil

    2007-01-01

    We have designed a laboratory experiment to illustrate the use of spectroelectrochemical techniques for determination of aqueous iron. The experiment described in this article is applicable to an undergraduate laboratory course in analytical chemistry. Students are asked to fabricate spectroelectrochemical sensors, make electrochemical and optical…

  4. Biodiesel Synthesis and Evaluation: An Organic Chemistry Experiment

    Science.gov (United States)

    Bucholtz, Ehren C.

    2007-01-01

    A new lab esterification reaction based on biodiesel preparation and viscosity, which provides a model experience of industrial process to understand oxidation of vicinal alcohols by periodic acid, is presented. This new desertification experiment and periodate analysis of glycerol for the introductory organic chemistry laboratory provides an…

  5. Simultaneous atmospheric measurements using two Fourier transform infrared spectrometers at the Polar Environment Atmospheric Research Laboratory during spring 2006, and comparisons with the Atmospheric Chemistry Experiment-Fourier Transform Spectrometer

    OpenAIRE

    D. Fu; K. A. Walker; R. L. Mittermeier; Strong, K.; Sung, K.; H. Fast; Bernath, P. F.; C. D. Boone; W. H. Daffer; Fogal, P.; Kolonjari, F.; P. Loewen; Manney, G. L.; O. Mikhailov

    2008-01-01

    The 2006 Canadian Arctic ACE (Atmospheric Chemistry Experiment) Validation Campaign collected measurements at the Polar Environment Atmospheric Research Laboratory (PEARL, 80.05° N, 86.42° W, 610 m above sea level) at Eureka, Canada from 17 February to 31 March 2006. Two of the ten instruments involved in the campaign, both Fourier transform spectrometers (FTSs), were operated simultaneously, recording atmospheric solar absorption spectra. The first instrument was an ABB Bomem...

  6. Solution Calorimetry Experiments for Physical Chemistry.

    Science.gov (United States)

    Raizen, Deborah A.; And Others

    1988-01-01

    Presents two experiments: the first one measures the heat of an exothermic reaction by the reduction of permanganate by the ferris ion; the second one measures the heat of an endothermic process, the mixing of ethanol and cyclohexane. Lists tables to aid in the use of the solution calorimeter. (MVL)

  7. A General Chemistry Experiment Incorporating Synthesis and Structural Determination

    Science.gov (United States)

    van Ryswyk, Hal

    1997-07-01

    An experiment for the general chemistry laboratory is described wherein gas chromatography-mass spectroscopy (GC-MS) and diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS) are used to characterize the products of a series of microscale reactions on vanillin. A single sophisticated instrument can be incorporated into the laboratory given sufficient attention to the use of sampling accessories and software macros. Synthetic experiments coupled with modern instrumental techniques can be used in the general chemistry laboratory to illustrate the concepts of synthesis, structure, bonding, and spectroscopy.

  8. Sensitivity analysis using DECOMP and METOXA subroutines of the MAAP code in modelling core concrete interaction phenomena and post test calculations for ACE-MCCI experiment L-5

    International Nuclear Information System (INIS)

    A parametric analysis approach was chosen in order to study core-concrete interaction phenomena. The analysis was performed using a stand-alone version of the MAAP-DECOMP model (DOE version). This analysis covered only those parameters known to have the largest effect on thermohydraulics and fission product aerosol release. Even though the main purpose of the effort was model validation, it eventually resulted in a better understanding of the core-concrete interaction physics and to a more correct interpretation of the ACE-MCCI L5 experimental data. Unusual low heat transfer fluxes from the debris pool to the cavity (corium surrounding volume) were modeled in order to have a good benchmark with the experimental data. Therefore, higher debris pool temperatures were predicted. In case of water flooding, as a consequence of the critical heat flux through the upper crust and the increase of the crust thickness, resulting high debris pool temperatures cause an increase in the concrete ablation rate in the short term. DECOMP model predicts a quick increase of the crust thickness and as a result, causes the quenching of the molten mass. However, especially for fast transient, phenomena of crust bridge formation can occur. Thus, the upward directed heat flux is minimized and the concrete erosion rate remains conspicuous also in the long term. The model validation is based, in these calculations, on post-test predictions using the MCCI L5 test data: these data are derived from results of the 'Molten Core Concrete Interaction' (MCCI) experiments, which in turn are part of the larger Advanced Containment Experiment (ACE) program. Other calculations were also performed for the new proposed MACE (Melt Debris Attack and Coolability) experiments simulating the water flooding of the cavity. Those calculations are preliminarily compared with the recent MACE scoping test results. (author) 4 tabs., 59 figs., 5 refs

  9. Ace Inhibitors and Angioedema

    NARCIS (Netherlands)

    Vleeming W; van Amsterdam JGC; de Wildt DJ; Stricker B; TOX

    1995-01-01

    Dit rapport beschrijft de risico's die verbonden zijn aan het gebruik van angiotensine converting enzym (ACE) remmers. Hierbij staat de bijwerking angio-oedeem centraal. De benodigde literatuur is verzameld aan de hand van een zoekaktie middels MEDLINE. ACE-remmers zijn in gebruik ter behand

  10. Marketing ACE in Victoria.

    Science.gov (United States)

    2001

    This publication presents options raised through various forums for marketing adult and community education (ACE) in Victoria, Australia, and suggested strategies. After an introduction (chapter 1), chapters 2 and 3 provide a broad view of the current situation for marketing ACE. Chapter 2 discusses general issues in the current position--ACE…

  11. Synthesis of Bisphenol Z: An Organic Chemistry Experiment

    Science.gov (United States)

    Gregor, Richard W.

    2012-01-01

    A student achievable synthesis of bisphenol Z, 4,4'-(cyclohexane-1,1-diyl)diphenol, from the acid-catalyzed reaction of phenol with cyclohexanone is presented. The experiment exemplifies all the usual pedagogy for the standard topic of electrophilic aromatic substitution present in the undergraduate organic chemistry curriculum, while providing…

  12. Ionic Liquids and Green Chemistry: A Lab Experiment

    Science.gov (United States)

    Stark, Annegret; Ott, Denise; Kralisch, Dana; Kreisel, Guenter; Ondruschka, Bernd

    2010-01-01

    Although ionic liquids have been investigated as solvents for many applications and are starting to be used in industrial processes, only a few lab experiments are available to introduce students to these materials. Ionic liquids have been discussed in the context of green chemistry, but few investigations have actually assessed the degree of…

  13. Biodiesel from Seeds: An Experiment for Organic Chemistry

    Science.gov (United States)

    Goldstein, Steven W.

    2014-01-01

    Plants can store the chemical energy required by their developing offspring in the form of triglycerides. These lipids can be isolated from seeds and then converted into biodiesel through a transesterification reaction. This second-year undergraduate organic chemistry laboratory experiment exemplifies the conversion of an agricultural energy…

  14. Experience on KKNPP VVER 1000 MWe water chemistry

    International Nuclear Information System (INIS)

    Kudankulam Nuclear Power Project consists of pressurized water reactor (VVER) 2 x 1000 MWe constructed in collaboration with Russian Federation at Kudankulam in Tirunelveli District, Tamilnadu. Unit - 1 attained criticality on July 13th 2013 and the unit was synchronized to grid on 22nd October 2013. This paper highlights experience gained on water chemistry regime for primary and secondary circuit. (author)

  15. A Physical Chemistry Experiment in Polymer Crystallization Kinetics

    Science.gov (United States)

    Singfield, Kathy L.; Chisholm, Roderick A.; King, Thomas L.

    2012-01-01

    A laboratory experiment currently used in an undergraduate physical chemistry lab to investigate the rates of crystallization of a polymer is described. Specifically, the radial growth rates of typical disc-shaped crystals, called spherulites, growing between microscope glass slides are measured and the data are treated according to polymer…

  16. Spanish-Speaking English Language Learners' Experiences in High School Chemistry Education

    Science.gov (United States)

    Flores, Annette; Smith, K. Christopher

    2013-01-01

    This article reports on the experiences of Spanish-speaking English language learners in high school chemistry courses, focusing largely on experiences in learning the English language, experiences learning chemistry, and experiences learning chemistry in the English language. The findings illustrate the cognitive processes the students undertake…

  17. An EPR Experiment for the Undergraduate Physical Chemistry Laboratory

    Science.gov (United States)

    Butera, R. A.; Waldeck, D. H.

    2000-11-01

    An experiment that illustrates the principles of electron paramagnetic resonance spectroscopy in the undergraduate physical chemistry laboratory is described. Students measure the value of g for DPPH and use it to determine the value of g for two inorganic complexes, Cu(acac)2 and VO(acac)2. The students use two instruments: an instructional device that illustrates the principles of EPR and a commercial Varian E4 spectrometer. This approach allows an elucidation of the principles of the method and provides experience with a more sophisticated research-grade instrument.

  18. Aerosol physical properties and processes in the lower marine boundary layer: a comparison of shipboard sub-micron data from ACE-1 and ACE-2

    OpenAIRE

    Bates, Timothy S.; Quinn, Patricia K.; Covert, David S.; Coffman, Derek J; Johnson, James E.; Wiedensohler, Alfred

    2011-01-01

    The goals of the IGAC Aerosol Characterization Experiments (ACE) are to determine and understand the properties and controlling processes of the aerosol in a globally representative range of natural and anthropogenically perturbed environments. ACE-1 was conducted in the remote marine atmosphere south of Australia while ACE-2 was conducted in the anthropogenically modified atmosphere of the Eastern North Atlantic. In-situ shipboard measurements from the RV Discoverer(ACE-1) and the RV Profess...

  19. Climatology and variability of trace gases in extratropical double-tropopause regions from MLS, HIRDLS, and ACE-FTS measurements

    OpenAIRE

    M. J. Schwartz; Manney, G. L.; Hegglin, M. I.; N. J. Livesey; M. L. Santee; W. H. Daffer

    2015-01-01

    Upper tropospheric and lower stratospheric measurements from the Aura Microwave Limb Sounder (MLS), the Aura High Resolution Dynamics Limb Sounder (HIRDLS), and the Atmospheric Chemistry Experiment-Fourier transform spectrometer (ACE-FTS) are used to present the first global climatological comparison of extratropical, nonpolar trace gas distributions in double-tropopause (DT) and single-tropopause (ST) regions. Stratospheric tracers, O3, HNO3, and HCl, have lower mixing ratios ∼2–8 km above t...

  20. Validation of ACE-FTS satellite data in the upper troposphere/lower stratosphere (UTLS) using non-coincident measurements

    OpenAIRE

    Hegglin, M. I.; Bernath, P. F.; C. D. Boone; W. H. Daffer; Hoor, P.; Manney, G. L.; Schiller, C.; Strong, K.; K. A. Walker

    2008-01-01

    CO, O3, and H2O data in the upper troposphere/lower stratosphere (UTLS) measured by the Atmospheric Chemistry Experiment Fourier Transform Spectrometer (ACE-FTS) on Canada's SCISAT-1 satellite are validated using aircraft and ozonesonde measurements. In the UTLS, validation of chemical trace gas measurements is a challenging task due to small-scale variability in the tracer fields, strong gradients of the tracers across the tropopause, and sc...

  1. Matrix fluid chemistry experiment. Final report June 1998 - March 2003

    International Nuclear Information System (INIS)

    The Matrix Fluid Chemistry Experiment set out to determine the composition and evolution of matrix pore fluids/waters in low permeable rock located at repository depths in the Aespoe Hard Rock Laboratory (HRL). Matrix pore fluids/waters can be highly saline in composition and, if accessible, may influence the near-field groundwater chemistry of a repository system. Characterising pore fluids/waters involved in-situ borehole sampling and analysis integrated with laboratory studies and experiments on rock matrix drill core material. Relating the rate of in-situ pore water accumulation during sampling to the measured rock porosity indicated a hydraulic conductivity of 10-14-10-13 m/s for the rock matrix. This was in accordance with earlier estimated predictions. The sampled matrix pore water, brackish in type, mostly represents older palaeo- groundwater mixtures preserved in the rock matrix and dating back to at least the last glaciation. A component of matrix pore 'fluid' is also present. One borehole section suggests a younger groundwater component which has accessed the rock matrix during the experiment. There is little evidence that the salinity of the matrix pore waters has been influenced significantly by fluid inclusion populations hosted by quartz. Crush/leach, cation exchange, pore water diffusion and pore water displacement laboratory experiments were carried out to compare extracted/calculated matrix pore fluids/waters with in-situ sampling. Of these the pore water diffusion experiments appear to be the most promising approach and a recommended site characterisation protocol has been formulated. The main conclusions from the Matrix Fluid Chemistry Experiment are: Groundwater movement within the bedrock hosting the experimental site has been enhanced by increased hydraulic gradients generated by the presence of the tunnel, and to a much lesser extent by the borehole itself. Over experimental timescales ∼4 years) solute transport through the rock matrix is

  2. Matrix fluid chemistry experiment. Final report June 1998 - March 2003

    Energy Technology Data Exchange (ETDEWEB)

    Smellie, John A.T. [Conterra AB, Luleaa (Sweden); Waber, H. Niklaus [Univ. of Bern (Switzerland). Inst. of Geology; Frape, Shaun K. [Univ. of Waterloo (Canada). Dept. of Earth Sciences

    2003-06-01

    The Matrix Fluid Chemistry Experiment set out to determine the composition and evolution of matrix pore fluids/waters in low permeable rock located at repository depths in the Aespoe Hard Rock Laboratory (HRL). Matrix pore fluids/waters can be highly saline in composition and, if accessible, may influence the near-field groundwater chemistry of a repository system. Characterising pore fluids/waters involved in-situ borehole sampling and analysis integrated with laboratory studies and experiments on rock matrix drill core material. Relating the rate of in-situ pore water accumulation during sampling to the measured rock porosity indicated a hydraulic conductivity of 10{sup -14}-10{sup -13} m/s for the rock matrix. This was in accordance with earlier estimated predictions. The sampled matrix pore water, brackish in type, mostly represents older palaeo- groundwater mixtures preserved in the rock matrix and dating back to at least the last glaciation. A component of matrix pore 'fluid' is also present. One borehole section suggests a younger groundwater component which has accessed the rock matrix during the experiment. There is little evidence that the salinity of the matrix pore waters has been influenced significantly by fluid inclusion populations hosted by quartz. Crush/leach, cation exchange, pore water diffusion and pore water displacement laboratory experiments were carried out to compare extracted/calculated matrix pore fluids/waters with in-situ sampling. Of these the pore water diffusion experiments appear to be the most promising approach and a recommended site characterisation protocol has been formulated. The main conclusions from the Matrix Fluid Chemistry Experiment are: Groundwater movement within the bedrock hosting the experimental site has been enhanced by increased hydraulic gradients generated by the presence of the tunnel, and to a much lesser extent by the borehole itself. Over experimental timescales {approx}4 years) solute transport

  3. Seasonal variability of upper tropospheric acetone using ACE-FTS observations and LMDz-INCA model simulations

    Science.gov (United States)

    Dufour, Gaëlle; Harrison, Jeremy; Szopa, Sophie; Bernath, Peter

    2014-05-01

    The vertically-resolved distributions of oxygenated organic compounds (oVOCs) are mainly inferred from surface and airborne measurements with limited spatial and temporal coverage. This results in a limited understanding of the atmospheric budget of these compounds and of their impact on the upper tropospheric chemistry. In the last decade, satellite observations which complement in-situ measurements have become available, providing global distributions of several oVOCs. For example, Scisat-1, also known as the Atmospheric Chemistry Experiment (ACE) has measured several oVOCs including methanol and formaldehyde. ACE is a Canadian-led satellite mission for remote sensing of the Earth's atmosphere that has been in operation since 2004. The primary instrument on board is a Fourier transform spectrometer (FTS) featuring broad spectral coverage in the infrared (750-4400 cm-1) with high spectral resolution (0.02 cm-1). The FTS instrument can measure down to 5 km altitude with a high signal-to-noise ratio using solar occultation. The ACE-FTS has the ability to measure seasonal and height-resolved distributions of minor tropospheric constituents on a near-global scale and provides the opportunity to evaluate our understanding of important atmospheric oxygenated organic species. ACE-FTS acetone retrievals will be presented. The spatial distribution and seasonal variability of acetone will be described and compared to LMDz-INCA model simulations.

  4. Investigating the Effects of Project-Oriented Chemistry Experiments on Some Affective and Cognitive Field Components

    Directory of Open Access Journals (Sweden)

    İnci MORGİL

    2009-04-01

    Full Text Available The general aim of this study is to prepare project-based chemistry experiments related to various chemistry topics via group study by pre-service chemistry teachers. Also it is tried to find answers to the following questions:1. Did pre-service teachers’ performance change after mentioned applications? 2. Had conducted applications effect on pre-service teachers’ attitude towards chemistry, attitudes towards chemistry laboratory, anxieties and scientific process skills? 3. How was the physical condition of laboratory where project-based chemistry experiment applications were conducted and what were the difficulties encountered by pre-service teachers in laboratory studies?

  5. Nadir measurements of the Earth's atmosphere with the ACE FTS: first results

    Directory of Open Access Journals (Sweden)

    W. F. J. Evans

    2008-07-01

    Full Text Available The primary objective of the Canadian SCISAT mission is to investigate the processes that control the distribution of ozone in the stratosphere. The SCISAT satellite consists of two major science instruments: an Atmospheric Chemistry Experiment (ACE high-resolution Fourier-transform spectrometer (FTS and an ultraviolet/visible/near-infrared spectrograph. These instruments primarily function in occultation mode; however, during the dark portion of the orbit the Earth passes between the sun and the satellite. This configuration provides the opportunity to acquire some nadir-view FTIR spectra of the Earth. Nadir spectra obtained with the ACE FTS are presented and analyzed for methane, ozone and nitrous oxide. The measurements show that the instrument should have sufficient signal-to-noise ratio to determine column gas amounts of the major trace constituents in the atmosphere. Possible applications of these measurements to the study of global warming and air pollution monitoring are discussed.

  6. Clouds in the Tropical Lowermost Stratosphere Observed by ACE

    Science.gov (United States)

    Sloan, J. J.; Galkina, I.; Sioris, C. E.; Nowlan, C. R.; McElroy, T.; Zou, J.; Hu, J.; Drummond, J. R.; McLinden, C. A.

    2008-12-01

    Evidence for the occurrence of cloud particles in the tropical lowermost stratosphere in the 2004-2007 period is presented. This study is based on measurements by the three Atmospheric Chemistry Experiment (ACE) instruments onboard SCI-SAT. The Vis & NIR Imagers are used to determine the presence of clouds and their top height. The Fourier Transform Spectrometer (FTS) observations are used to determine the size distribution and composition of the aerosols. The FTS has a 4 km field-of-view. Measurements of Aerosol Extinction in the Stratosphere and Troposphere Retrieved by Occultation (MAESTRO) provide more precise altitude determination of the thermal tropopause and the cloud tops by virtue of its smaller FOV (~1 km). Clouds in the tropical lower stratosphere are a rare occurrence but April 2005 produced a few such cases, consistent with previous observations by OSIRIS. We discuss several individual case studies that demonstrate the presence of large particles (mode radius of ~8 microns) clearly above the tropopause.

  7. Striking a Balance: Experiment and Concept in Undergraduate Inorganic Chemistry.

    Science.gov (United States)

    Frey, John E.

    1990-01-01

    Described is an inorganic chemistry course based on the premise that a balanced understanding of inorganic chemistry requires knowledge of the experimental, theoretical, and technological aspects of the subject. A detailed description of lectures and laboratories is included. (KR)

  8. ACE INHIBITORS: A COMPREHENSIVE REVIEW

    Directory of Open Access Journals (Sweden)

    Pradeep Kumar Arora* and Ashish Chauhan

    2013-02-01

    Full Text Available Hypertension is a chronic increase in blood pressure, characterized as primary and secondary hypertension. The disorder is associated with various risk factors like obesity, diabetes, age, lack of exercise etc. Hypertension is being treated since ancient times by Ayurvedic, Chinese and Unani medicine. Now various allopathic drugs are available which include diuretics, calcium channel blockers, α-blockers, β-blockers, vasodilators, central sympatholytics and ACE-inhibitors. Non-pharmacological treatments include weight reduction, dietary sodium reduction, increased potassium intake and reduction in alcohol consumption. ACE-inhibitors are widely used in the treatment of hypertension by inhibiting the angiotensin converting enzyme responsible for the conversion of angiotensin I to angiotensin II (responsible for vasoconstriction. Various structure activity relationship studies led to the synthesis of ACE-inhibitors, some are under clinical development. This comprehensive review gives various guidelines on classification of hypertension, hypertension therapy including ancient, pharmacological, non-pharmacological therapies, pharmacoeconomics, historical perspectives of ACE, renin, renin angiotensin system (circulating vs local RAS, mechanism of ACE inhibitors, and development of ACE inhibitors. Review also emphasizes on the recent advancements on ACE inhibitors including drugs in clinical trials, computational studies on ACE-inhibitors, peptidomimetics, dual, natural, multi-functional ACE inhibitors, and conformational requirements for ACE-inhibitors.

  9. A School-Community Science Experience: Great Valley's Chemistry-Industry Awareness Program.

    Science.gov (United States)

    Clapper, Thomas W.

    1980-01-01

    Describes the Chemistry-Industry Awareness Program, a community-related program implemented at Great Valley High School in Malvern, Pa., which provides opportunities and work experiences for second-year chemistry students that may aid in career decision making in chemistry-related occupations. (CS)

  10. Validation of ACE-FTS satellite data in the upper troposphere/lower stratosphere (UTLS using non-coincident measurements

    Directory of Open Access Journals (Sweden)

    M. I. Hegglin

    2007-09-01

    Full Text Available CO, O3, and H2O data in the upper troposphere/lower stratosphere (UTLS measured by the Atmospheric Chemistry Experiment Fourier Transform Spectrometer (ACE-FTS on Canada's SCISAT-1 satellite are validated using aircraft measurements. In the UTLS, validation of chemical trace gas measurements is a challenging task due to small-scale variability in the tracer fields, strong gradients of the tracers across the tropopause, and scarcity of measurements suitable for validation purposes. Two alternative methods for the validation of the satellite data are introduced, which avoid the usual need for coincident measurements: tracer-tracer correlations, and vertical profiles relative to the tropopause height. Both largely reduce geophysical variability and thereby provide an "instantaneous climatology", allowing measurement comparison with non-coincident data which yields information about the precision, and a statistically meaningful error-assessment of the ACE-FTS satellite data. We found that the ACE-FTS CO and lower stratospheric O3 agree with the aircraft measurements within ±10% and ±5%, respectively. The ACE-FTS O3 in the UT exhibits a high bias of up to 40%. H2O indicates a low bias with relative differences of around 20% in the LS and 40% in the UT, respectively. When taking into account the smearing effect of the vertically limited spacing between measurements of the ACE-FTS instrument, the errors decrease by 5–15% around the tropopause. The ACE-FTS instrument hence offers unprecedented precision and vertical resolution in the UTLS, that will allow a new global perspective on UTLS tracer distributions.

  11. The Integration of Green Chemistry Experiments with Sustainable Development Concepts in Pre-Service Teachers' Curriculum: Experiences from Malaysia

    Science.gov (United States)

    Karpudewan, Mageswary; Ismail, Zurida Hg; Mohamed, Norita

    2009-01-01

    Purpose: The purpose of this paper is to introduce green chemistry experiments as laboratory-based pedagogy and to evaluate effectiveness of green chemistry experiments in delivering sustainable development concepts (SDCs) and traditional environmental concepts (TECs). Design/methodology/approach: Repeated measure design was employed to evaluate…

  12. Creatine Synthesis: An Undergraduate Organic Chemistry Laboratory Experiment

    Science.gov (United States)

    Smith, Andri L.; Tan, Paula

    2006-01-01

    Students in introductory chemistry classes typically appreciate seeing the connection between course content and the "real world". For this reason, we have developed a synthesis of creatine monohydrate--a popular supplement used in sports requiring short bursts of energy--for introductory organic chemistry laboratory courses. Creatine monohydrate…

  13. Geothermal injection treatment: process chemistry, field experiences, and design options

    Energy Technology Data Exchange (ETDEWEB)

    Kindle, C.H.; Mercer, B.W.; Elmore, R.P.; Blair, S.C.; Myers, D.A.

    1984-09-01

    The successful development of geothermal reservoirs to generate electric power will require the injection disposal of approximately 700,000 gal/h (2.6 x 10/sup 6/ 1/h) of heat-depleted brine for every 50,000 kW of generating capacity. To maintain injectability, the spent brine must be compatible with the receiving formation. The factors that influence this brine/formation compatibility and tests to quantify them are discussed in this report. Some form of treatment will be necessary prior to injection for most situations; the process chemistry involved to avoid and/or accelerate the formation of precipitate particles is also discussed. The treatment processes, either avoidance or controlled precipitation approaches, are described in terms of their principles and demonstrated applications in the geothermal field and, when such experience is limited, in other industrial use. Monitoring techniques for tracking particulate growth, the effect of process parameters on corrosion and well injectability are presented. Examples of brine injection, preinjection treatment, and recovery from injectivity loss are examined and related to the aspects listed above.

  14. Making Sense of Olive Oil: Simple Experiments to Connect Sensory Observations with the Underlying Chemistry

    Science.gov (United States)

    Blatchly, Richard A.; Delen, Zeynep; O'Hara, Patricia B.

    2014-01-01

    In the last decade, our understanding of the chemistry of olive oil has dramatically improved. Here, the essential chemistry of olive oil and its important minor constituents is described and related to the typical sensory categories used to rate and experience oils: color, aroma, bitterness, and pungency. We also describe experiments to explore…

  15. Guided-Inquiry Experiments for Physical Chemistry: The POGIL-PCL Model

    Science.gov (United States)

    Hunnicutt, Sally S.; Grushow, Alexander; Whitnell, Robert

    2015-01-01

    The POGIL-PCL project implements the principles of process-oriented, guided-inquiry learning (POGIL) in order to improve student learning in the physical chemistry laboratory (PCL) course. The inquiry-based physical chemistry experiments being developed emphasize modeling of chemical phenomena. In each experiment, students work through at least…

  16. CO measurements from the ACE-FTS satellite instrument: data analysis and validation using ground-based, airborne and spaceborne observations

    Directory of Open Access Journals (Sweden)

    C. Clerbaux

    2008-05-01

    Full Text Available The Atmospheric Chemistry Experiment (ACE mission was launched in August 2003 to sound the atmosphere by solar occultation. Carbon monoxide (CO, a good tracer of pollution plumes and atmospheric dynamics, is one of the key species provided by the primary instrument, the ACE-Fourier Transform Spectrometer (ACE-FTS. This instrument performs measurements in both the CO 1-0 and 2-0 ro-vibrational bands, from which vertically resolved CO concentration profiles are retrieved, from the mid-troposphere to the thermosphere. This paper presents an updated description of the ACE-FTS version 2.2 CO data product, along with a comprehensive validation of these profiles using available observations (February 2004 to December 2006. We have compared the CO partial columns with ground-based measurements using Fourier transform infrared spectroscopy and millimeter wave radiometry, and the volume mixing ratio profiles with airborne (both high-altitude balloon flight and airplane observations. CO satellite observations provided by nadir-looking instruments (MOPITT and TES as well as limb-viewing remote sensors (MIPAS, SMR and MLS were also compared with the ACE-FTS CO products. We show that the ACE-FTS measurements provide CO profiles with small retrieval errors (better than 5% from the upper troposphere to 40 km, and better than 10% above. These observations agree well with the correlative measurements, considering the rather loose coincidence criteria in some cases. Based on the validation exercise we assess the following uncertainties to the ACE-FTS measurement data: better than 15% in the upper troposphere (8–12 km, than 30% in the lower stratosphere (12–30 km, and than 25% from 30 to 100 km.

  17. Touring the Tomato: A Suite of Chemistry Laboratory Experiments

    Science.gov (United States)

    Sarkar, Sayantani; Chatterjee, Subhasish; Medina, Nancy; Stark, Ruth E.

    2013-01-01

    An eight-session interdisciplinary laboratory curriculum has been designed using a suite of analytical chemistry techniques to study biomaterials derived from an inexpensive source such as the tomato fruit. A logical

  18. Laboratory experiments in the study of the chemistry of the outer planets

    Science.gov (United States)

    Scattergood, T. W.

    It is shown that much information about planetary chemistry and physics can be gained through laboratory work. The types of experiments relevant to planetary research concern fundamental properties, spectral/optical properties, 'Miller-Urey' syntheses, and detailed syntheses. Specific examples of studies of the chemistry in the atmosphere of Titan are described with attention given to gas phase chemistry in the troposphere and the composition of model Titan aerosols. A list of work that still needs to be done is provided.

  19. Japanese Language Education for Science Students : Introductory Training through Chemistry Experiments

    Science.gov (United States)

    Takai, Kazuhiko

    This paper describes a course in Japanese language instruction for first year students in the Department of Applied Chemistry, Okayama University. The course is part of a guidance program and consists of (1) technical writing in Japanese for science students, (2) experimental report writing, and (3) project-based learning through chemistry experiments.

  20. Filtrates & Residues: Hemoglobinometry--A Biochemistry Experiment that Utilizes the Principles of Transition Metal Chemistry.

    Science.gov (United States)

    Giuliano, Vincenzo; Rieck, John Paul

    1987-01-01

    Describes a chemistry experiment dealing with hemoglobinometry that can apply to transition metal chemistry, colorimetry, and biochemistry. Provides a detailed description of the experimental procedure, including discussions of the preparation of the cyanide reagent, colorimetric measurements, and waste disposal and treatment. (TW)

  1. Investigating Affective Experiences in the Undergraduate Chemistry Laboratory: Students' Perceptions of Control and Responsibility

    Science.gov (United States)

    Galloway, Kelli R.; Malakpa, Zoebedeh; Bretz, Stacey Lowery

    2016-01-01

    Meaningful learning requires the integration of cognitive and affective learning with the psychomotor, i.e., hands-on learning. The undergraduate chemistry laboratory is an ideal place for meaningful learning to occur. However, accurately characterizing students' affective experiences in the chemistry laboratory can be a very difficult task. While…

  2. Operating experience driven advancements in plant chemistry practices and standards

    International Nuclear Information System (INIS)

    Improved water chemistry control is essential to: Minimize materials degradation (e.g., stress corrosion cracking (SCC) of steam generator (SG) tubes, primary water stress corrosion cracking (PWSCC), corrosion of fuel); Minimize corrosion product transport (e.g., transport into the SGs where it can foul tube surfaces and create crevice environments for the concentration of corrosive impurities, transport and deposition on the fuel); and, Minimize dose rates. Water chemistry control must be optimized to provide overall improvement considering the sometimes variant constraints of the goals listed above. New approaches to mitigate materials degradation, reduce corrosion product transport, and minimize plant dose rates are continually sought. The industry needs to address system integrity issues through application of promising, innovative chemistry initiatives; focusing on long-term integrity and viability while maintaining fuel integrity and minimizing dose rates. This presentation will summarize some of the major initiatives with respect to PWR primary and secondary system chemistry to effectively address these goals, as they pertain to SGs. (author)

  3. Preparation of Gold Nanoparticles Using Tea: A Green Chemistry Experiment

    Science.gov (United States)

    Sharma, R. K.; Gulati, Shikha; Mehta, Shilpa

    2012-01-01

    Assimilating green chemistry principles in nanotechnology is a developing area of nanoscience research nowadays. Thus, there is a growing demand to develop environmentally friendly and sustainable methods for the synthesis of nanoparticles that utilize nontoxic chemicals, environmentally benign solvents, and renewable materials to avoid their…

  4. Insight into solution chemistry from gas-phase experiments

    Czech Academy of Sciences Publication Activity Database

    Agrawal, Divya; Schröder, Detlef

    2011-01-01

    Roč. 30, č. 1 (2011), s. 32-35. ISSN 0276-7333 Grant ostatní: European Research Council(XE) AdG HORIZOMS Institutional research plan: CEZ:AV0Z40550506 Keywords : catalysis * electrospray ionization * mass spectrometry * organometallics Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 3.963, year: 2011

  5. Advanced Cathode Electrolyzer (ACE) Project

    Data.gov (United States)

    National Aeronautics and Space Administration — The proposed innovation is a static, cathode-fed, 2000 psi, balanced-pressure Advanced Cathode Electrolyzer (ACE) based on PEM electrolysis technology. It...

  6. Fission-product chemistry in severe reactor accidents: Review of relevant integral experiments

    International Nuclear Information System (INIS)

    The attenuation of the radioactive fission-product emission from a severe reactor accident will depend on a combination of chemical, physical and thermal-hydraulic effects. Chemical species stabilised under the prevailing conditions will determine the extent of aerosol formation and any subsequent interaction, so defining the magnitude and physical forms of the eventual release into the environment. While several important integral tests have taken place in recent years, these experiments have tended to focus on the generation of mass-balance and aerosol-related data to test and validate materials-transport codes rather than study the impact of important chemical phenomena. This emphasis on thermal hydraulics, fuel behaviour and aerosol properties has occurred in many test (e.g. PBF, DEMONA, Marviken-V, LACE and ACE). Nevertheless, the generation and reaction of the chemical species in all of these programmes determined the transport properties of the resulting vapours and aerosols. Chemical effects have been studied in measurements somewhat subsidiary to the main aims of the tests. This work has been reviewed in detail with respect to Marviken-V, LACE, ACE and Falcon. Specific issues remain to be addressed, and these are discussed in terms of the proposed Phebus-FB programme. (author). 58 refs, 9 figs, 1 tab

  7. ACE spectrum of LDPC codes

    Directory of Open Access Journals (Sweden)

    Vukobratović Dejan

    2006-01-01

    Full Text Available Construction of short-length LDPC codes with good, both waterfall and error-floor, behavior is still an attractive research problem. Recently proposed construction algorithms in this field are based on remarkably simple ideas, but yet, their effectiveness can still be questioned. In this paper we investigate a novel measure of goodness of a given LDPC code namely its ACE spectrum, based on a previously introduced ACE metrics associated with each cycle in LDPC code graph.

  8. Imidazole as a pH Probe: An NMR Experiment for the General Chemistry Laboratory

    Science.gov (United States)

    Hagan, William J., Jr.; Edie, Dennis L.; Cooley, Linda B.

    2007-01-01

    The analysis describes an NMR experiment for the general chemistry laboratory, which employs an unknown imidazole solution to measure the pH values. The described mechanism can also be used for measuring the acidity within the isolated cells.

  9. The Impact of Nursing Students' Prior Chemistry Experience on Academic Performance and Perception of Relevance in a Health Science Course

    Science.gov (United States)

    Boddey, Kerrie; de Berg, Kevin

    2015-01-01

    Nursing students have typically found the study of chemistry to be one of their major challenges in a nursing course. This mixed method study was designed to explore how prior experiences in chemistry might impact chemistry achievement during a health science unit. Nursing students (N = 101) studying chemistry as part of a health science unit were…

  10. Electron transfer reactions in chemistry. Theory and experiment

    OpenAIRE

    Marcus, Rudolph A.

    1997-01-01

    Since the late 1940s, the field of electron transfer processes has grown enormously, both in chemistry and biology. The development of the field, experimentally and theoretically, as well as its relation to the study of other kinds of chemical reactions, represents to us an intriguing history, one in which many threads have been brought together. In this lecture, some history, recent trends, and my own involvement in this research are described.

  11. Chemistry

    International Nuclear Information System (INIS)

    The chemical research and development efforts related to the design and ultimate operation of molten-salt breeder reactor systems are concentrated on fuel- and coolant-salt chemistry, including the development of analytical methods for use in these systems. The chemistry of tellurium in fuel salt is being studied to help elucidate the role of this element in the intergranular cracking of Hastelloy N. Studies were continued of the effect of oxygen-containing species on the equilibrium between dissolved UF3 and dissolved UF4, and, in some cases, between the dissolved uranium fluorides and graphite, and the UC2. Several aspects of coolant-salt chemistry are under investigation. Hydroxy and oxy compounds that could be formed in molten NaBF4 are being synthesized and characterized. Studies of the chemistry of chromium (III) compounds in fluoroborate melts were continued as part of a systematic investigation of the corrosion of structural alloys by coolant salt. An in-line voltammetric method for determining U4+/U3+ ratios in fuel salt was tested in a forced-convection loop over a six-month period. (LK)

  12. New temperature and pressure retrieval algorithm for high-resolution infrared solar occultation spectroscopy: analysis and validation against ACE-FTS and COSMIC

    Directory of Open Access Journals (Sweden)

    K. S. Olsen

    2015-10-01

    Full Text Available Motivated by the initial selection of a high-resolution solar occultation Fourier transform spectrometer (FTS to fly to Mars on the ExoMars Trace Gas Orbiter, we have been developing algorithms for retrieving volume mixing ratio vertical profiles of trace gases, the primary component of which is a new algorithm and software for retrieving vertical profiles of temperature and pressure from the spectra. In contrast to Earth-observing instruments, which can rely on accurate meteorological models, a priori information, and spacecraft position, Mars retrievals require a method with minimal reliance on such data. The temperature and pressure retrieval algorithms developed for this work were evaluated using Earth-observing spectra from the Atmospheric Chemistry Experiment (ACE FTS, a solar occultation instrument in orbit since 2003, and the basis for the instrument selected for a Mars mission. ACE-FTS makes multiple measurements during an occultation, separated in altitude by 1.5–5 km, and we analyze 10 CO2 vibration-rotation bands at each altitude, each with a different usable altitude range. We describe the algorithms and present results of their application and their comparison to the ACE-FTS data products. The Constellation Observing System for Meteorology, Ionosphere, and Climate (COSMIC provides vertical profiles of temperature up to 40 km with high vertical resolution. Using six satellites and GPS radio occultation, COSMIC's data product has excellent temporal and spatial coverage, allowing us to find coincident measurements with ACE with very tight criteria: less than 1.5 h and 150 km. We present an inter-comparison of temperature profiles retrieved from ACE-FTS using our algorithm, that of the ACE Science Team (v3.5, and from COSMIC. When our retrievals are compared to ACE-FTS v3.5, we find mean differences between −5 and +2 K, and that our retrieved profiles have no seasonal or zonal biases, but do have a warm bias in the stratosphere and

  13. New temperature and pressure retrieval algorithm for high-resolution infrared solar occultation spectroscopy: analysis and validation against ACE-FTS and COSMIC

    Science.gov (United States)

    Olsen, Kevin S.; Toon, Geoffrey C.; Boone, Chris D.; Strong, Kimberly

    2016-03-01

    Motivated by the initial selection of a high-resolution solar occultation Fourier transform spectrometer (FTS) to fly to Mars on the ExoMars Trace Gas Orbiter, we have been developing algorithms for retrieving volume mixing ratio vertical profiles of trace gases, the primary component of which is a new algorithm and software for retrieving vertical profiles of temperature and pressure from the spectra. In contrast to Earth-observing instruments, which can rely on accurate meteorological models, a priori information, and spacecraft position, Mars retrievals require a method with minimal reliance on such data. The temperature and pressure retrieval algorithms developed for this work were evaluated using Earth-observing spectra from the Atmospheric Chemistry Experiment (ACE) FTS, a solar occultation instrument in orbit since 2003, and the basis for the instrument selected for a Mars mission. ACE-FTS makes multiple measurements during an occultation, separated in altitude by 1.5-5 km, and we analyse 10 CO2 vibration-rotation bands at each altitude, each with a different usable altitude range. We describe the algorithms and present results of their application and their comparison to the ACE-FTS data products. The Constellation Observing System for Meteorology, Ionosphere, and Climate (COSMIC) provides vertical profiles of temperature up to 40 km with high vertical resolution. Using six satellites and GPS radio occultation, COSMIC's data product has excellent temporal and spatial coverage, allowing us to find coincident measurements with ACE with very tight criteria: less than 1.5 h and 150 km. We present an intercomparison of temperature profiles retrieved from ACE-FTS using our algorithm, that of the ACE Science Team (v3.5), and from COSMIC. When our retrievals are compared to ACE-FTS v3.5, we find mean differences between -5 and +2 K and that our retrieved profiles have no seasonal or zonal biases but do have a warm bias in the stratosphere and a cold bias in the

  14. ETA chemistry experience and assessment on CPP in Korea

    International Nuclear Information System (INIS)

    To reduce FAC of carbon steel in secondary system, water treatment chemistry was converted to ETA at Kori unit 1. Full scale tests to choose the optimum concentration of ETA were conducted and the evaluation after one cycle operation with ETA was also performed. Optimum concentration of ETA in final feed water was determined as 1.8 ppm. At this condition, iron concentration was reduced by 69.8% in final feed water and 69.7% in heater drain compared to ammonia-AVT. The amount of sludge removed from each steam generator was 11.3 kg, which was 88.2% lower than that of ammonia-AVT. With successful results of Kori unit 1, Applications of ETA were extended to other PWRs. Iron transport was found to be reduced significantly. Also, the output of electric power increased by 9 MWe at Young-Kwang unit 1. However, fouling of ion exchange resin in CPP was appeared. ETA appears to have a solvent function in the initial stage of ETA chemistry. Resin was restored when the fouling was removed with hot water and sodium bicarbonates. In particular, the MR type anion resin may be effective in resistance to fouling when ETA-chemistry is used. (authors)

  15. A teaching intervention for reading laboratory experiments in college-level introductory chemistry

    Science.gov (United States)

    Kirk, Maria Kristine

    The purpose of this study was to determine the effects that a pre-laboratory guide, conceptualized as a "scientific story grammar," has on college chemistry students' learning when they read an introductory chemistry laboratory manual and perform the experiments in the chemistry laboratory. The participants (N = 56) were students enrolled in four existing general chemistry laboratory sections taught by two instructors at a women's liberal arts college. The pre-laboratory guide consisted of eight questions about the experiment, including the purpose, chemical species, variables, chemical method, procedure, and hypothesis. The effects of the intervention were compared with those of the traditional pre-laboratory assignment for the eight chemistry experiments. Measures included quizzes, tests, chemistry achievement test, science process skills test, laboratory reports, laboratory average, and semester grade. The covariates were mathematical aptitude and prior knowledge of chemistry and science processes, on which the groups differed significantly. The study captured students' perceptions of their experience in general chemistry through a survey and interviews with eight students. The only significant differences in the treatment group's performance were in some subscores on lecture items and laboratory items on the quizzes. An apparent induction period was noted, in that significant measures occurred in mid-semester. Voluntary study with the pre-laboratory guide by control students precluded significant differences on measures given later in the semester. The groups' responses to the survey were similar. Significant instructor effects on three survey items were corroborated by the interviews. The researcher's students were more positive about their pre-laboratory tasks, enjoyed the laboratory sessions more, and were more confident about doing chemistry experiments than the laboratory instructor's groups due to differences in scaffolding by the instructors.

  16. Looking beyond Lewis Structures: A General Chemistry Molecular Modeling Experiment Focusing on Physical Properties and Geometry

    Science.gov (United States)

    Linenberger, Kimberly J.; Cole, Renee S.; Sarkar, Somnath

    2011-01-01

    We present a guided-inquiry experiment using Spartan Student Version, ready to be adapted and implemented into a general chemistry laboratory course. The experiment provides students an experience with Spartan Molecular Modeling software while discovering the relationships between the structure and properties of molecules. Topics discussed within…

  17. Validation of ACE and OSIRIS ozone and NO2 measurements using ground-based instruments at 80° N

    Directory of Open Access Journals (Sweden)

    A. Pazmino

    2012-05-01

    Full Text Available The Optical Spectrograph and Infra-Red Imager System (OSIRIS and the Atmospheric Chemistry Experiment (ACE have been taking measurements from space since 2001 and 2003, respectively. This paper presents intercomparisons between ozone and NO2 measured by the ACE and OSIRIS satellite instruments and by ground-based instruments at the Polar Environment Atmospheric Research Laboratory (PEARL, which is located at Eureka, Canada (80° N, 86° W and is operated by the Canadian Network for the Detection of Atmospheric Change (CANDAC. The ground-based instruments included in this study are four zenith-sky differential optical absorption spectroscopy (DOAS instruments, one Bruker Fourier transform infrared spectrometer (FTIR and four Brewer spectrophotometers. Ozone total columns measured by the DOAS instruments were retrieved using new Network for the Detection of Atmospheric Composition Change (NDACC guidelines and agree to within 3.2%. The DOAS ozone columns agree with the Brewer spectrophotometers with mean relative differences that are smaller than 1.5%. This suggests that for these instruments the new NDACC data guidelines were successful in producing a homogenous and accurate ozone dataset at 80° N. Satellite 14–52 km ozone and 17–40 km NO2 partial columns within 500 km of PEARL were calculated for ACE-FTS Version 2.2 (v2.2 plus updates, ACE-FTS v3.0, ACE-MAESTRO (Measurements of Aerosol Extinction in the Stratosphere and Troposphere Retrieved by Occultation v1.2 and OSIRIS SaskMART v5.0x ozone and Optimal Estimation v3.0 NO2 data products. The new ACE-FTS v3.0 and the validated ACE-FTS v2.2 partial columns are nearly identical, with mean relative differences of 0.0 ± 0.2% and −0.2 ± 0.1% for v2.2 minus v3.0 ozone and NO2, respectively. Ozone columns were constructed from 14–52 km satellite and 0–14 km ozonesonde partial columns and compared with the ground-based total column measurements. The satellite-plus-sonde measurements agree

  18. Validation of ACE and OSIRIS ozone and NO2 measurements using ground-based instruments at 80° N

    Science.gov (United States)

    Adams, C.; Strong, K.; Batchelor, R. L.; Bernath, P. F.; Brohede, S.; Boone, C.; Degenstein, D.; Daffer, W. H.; Drummond, J. R.; Fogal, P. F.; Farahani, E.; Fayt, C.; Fraser, A.; Goutail, F.; Hendrick, F.; Kolonjari, F.; Lindenmaier, R.; Manney, G.; McElroy, C. T.; McLinden, C. A.; Mendonca, J.; Park, J.-H.; Pavlovic, B.; Pazmino, A.; Roth, C.; Savastiouk, V.; Walker, K. A.; Weaver, D.; Zhao, X.

    2012-05-01

    The Optical Spectrograph and Infra-Red Imager System (OSIRIS) and the Atmospheric Chemistry Experiment (ACE) have been taking measurements from space since 2001 and 2003, respectively. This paper presents intercomparisons between ozone and NO2 measured by the ACE and OSIRIS satellite instruments and by ground-based instruments at the Polar Environment Atmospheric Research Laboratory (PEARL), which is located at Eureka, Canada (80° N, 86° W) and is operated by the Canadian Network for the Detection of Atmospheric Change (CANDAC). The ground-based instruments included in this study are four zenith-sky differential optical absorption spectroscopy (DOAS) instruments, one Bruker Fourier transform infrared spectrometer (FTIR) and four Brewer spectrophotometers. Ozone total columns measured by the DOAS instruments were retrieved using new Network for the Detection of Atmospheric Composition Change (NDACC) guidelines and agree to within 3.2%. The DOAS ozone columns agree with the Brewer spectrophotometers with mean relative differences that are smaller than 1.5%. This suggests that for these instruments the new NDACC data guidelines were successful in producing a homogenous and accurate ozone dataset at 80° N. Satellite 14-52 km ozone and 17-40 km NO2 partial columns within 500 km of PEARL were calculated for ACE-FTS Version 2.2 (v2.2) plus updates, ACE-FTS v3.0, ACE-MAESTRO (Measurements of Aerosol Extinction in the Stratosphere and Troposphere Retrieved by Occultation) v1.2 and OSIRIS SaskMART v5.0x ozone and Optimal Estimation v3.0 NO2 data products. The new ACE-FTS v3.0 and the validated ACE-FTS v2.2 partial columns are nearly identical, with mean relative differences of 0.0 ± 0.2% and -0.2 ± 0.1% for v2.2 minus v3.0 ozone and NO2, respectively. Ozone columns were constructed from 14-52 km satellite and 0-14 km ozonesonde partial columns and compared with the ground-based total column measurements. The satellite-plus-sonde measurements agree with the ground

  19. Validation of ACE and OSIRIS ozone and NO2 measurements using ground-based instruments at 80° N

    Directory of Open Access Journals (Sweden)

    A. Pazmino

    2012-01-01

    Full Text Available The Optical Spectrograph and Infra-Red Imager System (OSIRIS and the Atmospheric Chemistry Experiment (ACE have been taking measurements from space since 2001 and 2003, respectively. This paper presents intercomparisons between ozone and NO2 measured by the ACE and OSIRIS satellite instruments and by ground-based instruments at the Polar Environment Atmospheric Research Laboratory (PEARL, which is located at Eureka, Canada (80° N, 86° W and is operated by the Canadian Network for the Detection of Atmospheric Change (CANDAC. The ground-based instruments included in this study are four zenith-sky differential optical absorption spectroscopy (DOAS instruments, one Bruker Fourier transform infrared spectrometer (FTIR and four Brewer spectrophotometers. Ozone total columns measured by the DOAS instruments were retrieved using new Network for the Detection of Atmospheric Composition Change (NDACC guidelines and agree to within 3.2%. The DOAS ozone columns agree with the Brewer spectrophotometers with mean relative differences that are smaller than 1.5%. This suggests that for these instruments the new NDACC data guidelines were successful in producing a homogenous and accurate ozone dataset at 80° N. Satellite 14–52 km ozone and 17–40 km NO2 partial columns within 500 km of PEARL were calculated for ACE-FTS Version 2.2 (v2.2 plus updates, ACE-FTS v3.0, ACE-MAESTRO (Measurements of Aerosol Extinction in the Stratosphere and Troposphere Retrieved by Occultation v1.2 and OSIRIS SaskMART v5.0x ozone and Optimal Estimation v3.0 NO2 data products. The new ACE-FTS v3.0 and the validated ACE-FTS v2.2 partial columns are nearly identical, with mean relative differences of 0.0 ± 0.2% for ozone and −0.2 ± 0.1% for v2.2 minus v3.3 NO2. Ozone columns were constructed from 14–52 km satellite and 0–14 km ozonesonde partial columns and compared with the ground-based total column measurements. The satellite-plus-sonde measurements agree with the ground

  20. Art, Meet Chemistry; Chemistry, Meet Art: Case Studies, Current Literature, and Instrumental Methods Combined to Create a Hands-On Experience for Nonmajors and Instrumental Analysis Students

    Science.gov (United States)

    Nivens, Delana A.; Padgett, Clifford W.; Chase, Jeffery M.; Verges, Katie J.; Jamieson, Deborah S.

    2010-01-01

    Case studies and current literature are combined with spectroscopic analysis to provide a unique chemistry experience for art history students and to provide a unique inquiry-based laboratory experiment for analytical chemistry students. The XRF analysis method was used to demonstrate to nonscience majors (art history students) a powerful…

  1. Validation of ACE-FTS satellite data in the upper troposphere/lower stratosphere (UTLS using non-coincident measurements

    Directory of Open Access Journals (Sweden)

    P. Hoor

    2008-03-01

    Full Text Available CO, O3, and H2O data in the upper troposphere/lower stratosphere (UTLS measured by the Atmospheric Chemistry Experiment Fourier Transform Spectrometer (ACE-FTS on Canada's SCISAT-1 satellite are validated using aircraft and ozonesonde measurements. In the UTLS, validation of chemical trace gas measurements is a challenging task due to small-scale variability in the tracer fields, strong gradients of the tracers across the tropopause, and scarcity of measurements suitable for validation purposes. Validation based on coincidences therefore suffers from geophysical noise. Two alternative methods for the validation of satellite data are introduced, which avoid the usual need for coincident measurements: tracer-tracer correlations, and vertical tracer profiles relative to tropopause height. Both are increasingly being used for model validation as they strongly suppress geophysical variability and thereby provide an "instantaneous climatology". This allows comparison of measurements between non-coincident data sets which yields information about the precision and a statistically meaningful error-assessment of the ACE-FTS satellite data in the UTLS. By defining a trade-off factor, we show that the measurement errors can be reduced by including more measurements obtained over a wider longitude range into the comparison, despite the increased geophysical variability. Applying the methods then yields the following upper bounds to the relative differences in the mean found between the ACE-FTS and SPURT aircraft measurements in the upper troposphere (UT and lower stratosphere (LS, respectively: for CO ±9% and ±12%, for H2O ±30% and ±18%, and for O3 ±25% and ±19%. The relative differences for O3 can be narrowed down by using a larger dataset obtained from ozonesondes, yielding a high bias in the ACE-FTS measurements of 18% in the UT and relative differences of ±8% for measurements in the LS

  2. Validation of ACE-FTS satellite data in the upper troposphere/lower stratosphere (UTLS) using non-coincident measurements

    Science.gov (United States)

    Hegglin, M. I.; Boone, C. D.; Manney, G. L.; Shepherd, T. G.; Walker, K. A.; Bernath, P. F.; Daffer, W. H.; Hoor, P.; Schiller, C.

    2008-03-01

    CO, O3, and H2O data in the upper troposphere/lower stratosphere (UTLS) measured by the Atmospheric Chemistry Experiment Fourier Transform Spectrometer (ACE-FTS) on Canada's SCISAT-1 satellite are validated using aircraft and ozonesonde measurements. In the UTLS, validation of chemical trace gas measurements is a challenging task due to small-scale variability in the tracer fields, strong gradients of the tracers across the tropopause, and scarcity of measurements suitable for validation purposes. Validation based on coincidences therefore suffers from geophysical noise. Two alternative methods for the validation of satellite data are introduced, which avoid the usual need for coincident measurements: tracer-tracer correlations, and vertical tracer profiles relative to tropopause height. Both are increasingly being used for model validation as they strongly suppress geophysical variability and thereby provide an "instantaneous climatology". This allows comparison of measurements between non-coincident data sets which yields information about the precision and a statistically meaningful error-assessment of the ACE-FTS satellite data in the UTLS. By defining a trade-off factor, we show that the measurement errors can be reduced by including more measurements obtained over a wider longitude range into the comparison, despite the increased geophysical variability. Applying the methods then yields the following upper bounds to the relative differences in the mean found between the ACE-FTS and SPURT aircraft measurements in the upper troposphere (UT) and lower stratosphere (LS), respectively: for CO ±9% and ±12%, for H2O ±30% and ±18%, and for O3 ±25% and ±19%. The relative differences for O3 can be narrowed down by using a larger dataset obtained from ozonesondes, yielding a high bias in the ACE-FTS measurements of 18% in the UT and relative differences of ±8% for measurements in the LS. When taking into account the smearing effect of the vertically limited

  3. Preparation of targets for nuclear chemistry experiments at DANCE

    International Nuclear Information System (INIS)

    In this paper, we describe the separation chemistry and electrodepositions conducted for the preparation of 241Am, 243Am and 233U targets used for cross-section measurements at DANCE. Thick, adherent deposits were prepared using molecular plating from isopropyl alcohol solutions. Improved yields and thicknesses were observed for 241Am electrodeposition after the material was purified using TRU resin from Eichrom. Similarly, 233U deposits were improved after purification with an anion exchange column in 9 M HBr followed by purification using UTEVA resin from Eichrom. (author)

  4. An intercomparison study of isotopic ozone profiles from the ACE-FTS, JEM-SMILES, and Odin-SMR instruments

    Science.gov (United States)

    Jones, A.; Walker, K. A.; Suzuki, M.; Kasai, Y.; Shiotani, M.; Urban, J.; Bernath, P. F.; Manney, G. L.

    2012-12-01

    Observations of various atmospheric isotopologue species are a valuable source of information, as they can improve our current understanding of the atmosphere. For example, isotopic signatures in atmospheric profiles can be used to investigate atmospheric dynamical processes, while differences in the isotopic composition of atmospheric trace gases can be traced to effects due to their sources and sinks. This study focuses on the intercomparison of three satellite missions that provide measurements of isotopic species. The Atmospheric Chemistry Experiment-Fourier Transform Spectrometer (ACE-FTS) aboard the Canadian satellite SCISAT (launched in August 2003) was designed to investigate the composition of the upper troposphere, stratosphere, and mesosphere. ACE-FTS utilizes solar occultation to measure temperature, pressure, and vertical profiles of over thirty chemical species, including isotopologue profiles for; O3, H2O, CH4, N2O, CO, CO2 and NO. Global coverage for each species is obtained approximately over one year and with a vertical resolution of typically 3-4 km. ACE-FTS O3 isotopologue volume mixing ratio profiles are firstly compared to data measured by the Superconducting Sub-Millimeter-wave Limb Emission Sounder (SMILES), onboard the Japanese Experiment Module (JEM) of the International Space Station (ISS), and the Sub-Millimetre Radiometer (SMR) aboard the Swedish Odin satellite. Secondly, we intercompare the isotopic fractionation profiles for each ozone isotopologue product measured by the three instruments to further ascertain a level of confidence in the measurements.

  5. ACE to Ulysses Coherences

    Science.gov (United States)

    Thomson, D. J.; Maclennan, C. G.; Lanzerotti, L. J.

    2006-12-01

    The EPAM charged particle instrument on ACE is the backup for the HISCALE instrument on Ulysses making the two ideally suited for spatial coherence studies over large heliosphere distances. Fluxes of low-energy ( ~50 - 200 keV) electrons are detected in eight spatial sectors on both spacecraft. A spherical harmonic description of the particle flux as a function of time using only the l=0 and l=1 degree coefficients describes most of the observed flux. Here we concentrate on the three l=1 coefficients for the 60--100 kev electrons.Between the two spacecraft these result in nine coherence estimates that are all typically moderately coherent, but the fact that the different coefficients at each spacecraft are also coherent with each other makes interpretation difficult. To avoid this difficulty we estimated the canonical coherences between the two groups of three series. This, in effect, chooses an optimum coordinate system at each spacecraft and for each frequency and estimates the coherence in this frame. Using one--minute data, we find that the canonical coherences are generally larger at high frequencies (3 mHz and above) than they are at low frequencies. This appears to be generally true and does not depend particularly on time, range, etc. However, if the data segment is chosen too long, say > 30 days with 1--minute sampling, the coherence at high frequencies drops. This may be because the spatial and temporal features of the mode are confounded, or possibly because the solar modes p--modes are known to change frequency with solar activity, so do not appear coherent on long blocks.The coherences are not smooth functions of frequency, but have a bimodal distribution particularly in the 100 μHz to 5 mHz range. Classifying the data at frequencies where the canonical coherences are high in terms of apparent polarization and orientation, we note two major families of modes that appear to be organized by the Parker spiral. The magnetic field data on the two

  6. Radio chemistry as a diagnostic in laser fusion experiments

    International Nuclear Information System (INIS)

    Nuclear chemistry techniques have been employed in an attempt to measure the density of high compression laser fusion targets. Radioactive 28Al atoms formed in the 28Si(n,p)28Al reaction arising from the interaction of the 14 MeV neutrons with the silicon atoms in the glass microsphere have been counted at Lawrence Livermore Laboratory using a β-γ coincidence method. The detection system that is employed allows activities corresponding to 100 aluminum atoms to be measured. From the observed number of activated atoms, neutron yields, and code calculations, information on the density of the compressed fuel can be obtained. This method is particularly valuable when the target compression becomes great enough to prohibit previously employed diagnostic techniques to be used. In addition, technique which utilizes a radioactive tracer to measure the isotropy of the target debris blowoff will also be discussed

  7. Microgravity experiments in the field of physical chemistry in Japan

    International Nuclear Information System (INIS)

    Japan has been operating 'KIBO' ('hope' in Japanese) as Japanese experimental module on ISS (International Space Station) to perform researches on physical, life, medical, space sciences in space. Several research racks and facilities have already been accommodated in the pressurized module of 'KIBO' and some researches have already been carried out. Japan currently has 17 ISS flight projects (including 4 candidates) in the field of physical sciences and also incubates new projects through are search support program named as 'research WG (Working Group)', where 25 research WGs are active in the field of physical sciences. Those include 1 flight candidate and 2 research WGs in the field of physical chemistry. The article introduces those to promote international collaborations.

  8. Chemistry

    International Nuclear Information System (INIS)

    Research progress is reported in programs on fuel-salt chemistry, properties of compounds in the Li--Te system, Te spectroscopy UF4--H equilibria, porous electrode studies of molten salts, fuel salt-coolant salt reactions, thermodynamic properties of transition-metal fluorides, and properties of sodium fluoroborate. Developmental work on analytical methods is summarized including in-line analysis of molten MSBR fuel, analysis of coolant-salts for tritium, analysis of molten LiF--BeF2--ThF4 for Fe and analysis of LiF--BeF--ThF4 for Te

  9. Operational experience, evolution and developments in water chemistry in Indian Nuclear Power Plants - an overview

    International Nuclear Information System (INIS)

    Lessons learnt from the experiences at nuclear power plants have enriched the understanding of corrosion behaviour in water systems. The need for proper water chemistry control not only during operation but also during fabrication and preoperational tests is clearly seen. It should not be construed that maintenance of proper water chemistry is a panacea for all corrosion and other associated problems. Unless adequate care is taken in selection of material and sound design and fabrication practices are followed, no regime of water chemistry can help in eliminating failure due to corrosion

  10. Educational laboratory experiments on chemistry in a nuclear engineering school

    International Nuclear Information System (INIS)

    An educational laboratory experiment on radiochemistry was investigated by students in the general course of the Nuclear Engineering School of Japan Atomic Energy Research Institute. Most of them are not chemical engineers, but electrical and mechanical engineers. Therefore, the educational experiment was designed for them by introducing a ''word experiment'' in the initial stage and by reducing the chemical procedure as far as possible. It began with calculations on a simple solvent extraction process-the ''word experiment''--followed by the chemical separation of 144Pr from 144Ce with tri-n-butyl phosphate in a nitric acid system and then measurement of the radioactive decay and growth of the separated 144Pr and 144Ce, respectively. The chemical procedure was explained by the phenomenon but not by the mechanism of chelation. Most students thought the experiment was an exercise in solvent extraction or radiochemical separation rather than a radioactive equilibrium experiment. However, a pure chemist considered it as a sort of physical experiment, where the chemical procedure was used only for preparation of measuring samples. Another experiment, where 137Cs was measured after isolation with ammonium phosphomolybdate, was also investigated. The experiment eliminated the need for students who were not chemists to know how to use radioactive tracers. These students appreciated the realization that they could understand the radioactivity in the environmental samples in a chemical frame of reference even though they were not chemists

  11. On CO2 pertubation experiments: over-determination of carbonate chemistry reveals inconsistencies

    OpenAIRE

    Hoppe, C. J. M.; Langer, G.; S. D. Rokitta; Wolf-Gladrow, D. A.; Rost, B.

    2010-01-01

    Seawater carbonate chemistry is typically calculated from two measured parameters. Depending on the choice of these input parameters, discrepancies in calculated pCO2 have been recognized by marine chemists, but the significance of this phenomenon for CO2 perturbation experiments has so far not been determined. To mimic different pCO2 scenarios, two common perturbation methods for seawater carbonate chemistry (changing either DIC or TA) were applied using state-of-the-art pr...

  12. An Enzymatic Clinical Chemistry Laboratory Experiment Incorporating an Introduction to Mathematical Method Comparison Techniques

    Science.gov (United States)

    Duxbury, Mark

    2004-01-01

    An enzymatic laboratory experiment based on the analysis of serum is described that is suitable for students of clinical chemistry. The experiment incorporates an introduction to mathematical method-comparison techniques in which three different clinical glucose analysis methods are compared using linear regression and Bland-Altman difference…

  13. Connecting Solubility, Equilibrium, and Periodicity in a Green, Inquiry Experiment for the General Chemistry Laboratory

    Science.gov (United States)

    Cacciatore, Kristen L.; Amado, Jose; Evans, Jason J.; Sevian, Hannah

    2008-01-01

    We present a novel first-year chemistry laboratory experiment that connects solubility, equilibrium, and chemical periodicity concepts. It employs a unique format that asks students to replicate experiments described in different sample lab reports, each lacking some essential information, rather than follow a scripted procedure. This structure is…

  14. Enquiry-Based Learning: Experiences of First Year Chemistry Students Learning Spectroscopy

    Science.gov (United States)

    Lucas, Timothy; Rowley, Natalie M.

    2011-01-01

    We explored the experiences of first year chemistry students of an Enquiry-Based Learning (EBL) approach to learning spectroscopy. An investigation of how students' perceived confidences changed as a result of their experience of using EBL in the spectroscopy course was carried out. Changes in the students' perceived confidence, both in their…

  15. Size Exclusion Chromatography: An Experiment for High School and Community College Chemistry and Biotechnology Laboratory Programs

    Science.gov (United States)

    Brunauer, Linda S.; Davis, Kathryn K.

    2008-01-01

    A simple multiday laboratory exercise suitable for use in a high school or community college chemistry course or a biotechnology advanced placement biology course is described. In this experiment students gain experience in the use of column chromatography as a tool for the separation and characterization of biomolecules, thus expanding their…

  16. GC-MS Analysis of [gamma]-Hydroxybutyric Acid Analogs: A Forensic Chemistry Experiment

    Science.gov (United States)

    Henck, Colin; Nally, Luke

    2007-01-01

    An upper-division forensic chemistry experiment is described. It involves using glycolic acid and sodium glycolate as analogs of [gamma]-hydroxybutyric acid and its sodium salt. The experiment shows the use of silylation in GC-MS analysis and gives students the opportunity to work with a commonly used silylating reagent,…

  17. Lysozyme Thermal Denaturation and Self-Interaction: Four Integrated Thermodynamic Experiments for the Physical Chemistry Laboratory

    Science.gov (United States)

    Schwinefus, Jeffrey J.; Schaefle, Nathaniel J.; Muth, Gregory W.; Miessler, Gary L.; Clark, Christopher A.

    2008-01-01

    As part of an effort to infuse our physical chemistry laboratory with biologically relevant, investigative experiments, we detail four integrated thermodynamic experiments that characterize the denaturation (or unfolding) and self-interaction of hen egg white lysozyme as a function of pH and ionic strength. Students first use Protein Explorer to…

  18. 50-Minute Experiment: Soil Analysis for High School Chemistry Students.

    Science.gov (United States)

    Baruch, Gerard, Ed.; And Others

    1980-01-01

    Lists equipment and materials needed and procedures for analyzing soil, in which secondary school students experience practical applications to acid-base reactions, pH, oxidation-reduction, precipitation and solubility. (CS)

  19. The Heat Capacity of Metals: A Physical Chemistry Experiment.

    Science.gov (United States)

    Shigeishi, R. A.

    1979-01-01

    Presented here are improvements in the original design of an introductory statistical thermodynamics experiment with the result that heat capacities of metals are routinely obtained within ten percent of literature values. (BB)

  20. Insertion/deletion polymorphism of the ACE gene and adherence to ACE inhibitors

    NARCIS (Netherlands)

    Schelleman, H; Klungel, O H; van Duijn, C M; Witteman, J C M; Hofman, A; de Boer, A; Stricker, B H Ch

    2005-01-01

    AIMS: We investigated whether the insertion/deletion (I/D) polymorphism of the ACE gene modified the adherence to ACE inhibitors as measured by the discontinuation of an ACE inhibitor, or addition of another antihypertensive drug. METHODS: This was a cohort study among 239 subjects who started ACE i

  1. Discovering Factors that Influence the Decision to Pursue a Chemistry-Related Career: A Comparative Analysis of the Experiences of Non Scientist Adults and Chemistry Teachers in Greece

    Science.gov (United States)

    Salta, Katerina; Gekos, Michael; Petsimeri, Irene; Koulougliotis, Dionysios

    2012-01-01

    This study aims at identifying factors that influence students' choice not to pursue a chemistry-related career by analyzing the experiences of secondary education chemistry teachers in Greece and of Greek adults who have not pursued studies related to science. Data collection was done with the method of individual structured interviews. The…

  2. VVER operational experience - effect of preconditioning and primary water chemistry on radioactivity build-up

    International Nuclear Information System (INIS)

    The primary coolant technology approaches currently used in VVER units are reviewed and compared with those used in PWR units. Standard and modified water chemistries differing in boron-potassium control are discussed. Preparation of the VVER Primary Water Chemistry Guidelines in the Czech Republic is noted. Operational experience of some VVER units, operated in the Czech Republic and Slovakia, in the field of the primary water chemistry, and radioactivity transport and build-up are presented. In Mochovce and Temelin units, a surface preconditioning (passivation) procedure has been applied during hot functional tests. The main principles of the controlled primary water chemistry applied during the hot functional tests are reviewed and importance of the water chemistry, technological and other relevant parameters is stressed regarding to the quality of the passive layer formed on the primary system surfaces. The first operational experience obtained in the course of beginning of these units operation is presented mainly with respect to the corrosion products coolant and surface activities. Effect of the initial passivation performed during hot functional tests and the primary water chemistry on corrosion products radioactivity level and radiation situation is discussed. (author)

  3. Electrochemistry in a Nutshell: A General Chemistry Experiment.

    Science.gov (United States)

    Baca, Glenn; Lewis, Dennis A.

    1978-01-01

    This experiment uses a nine-chambered plexiglas unit to facilitate rapid construction of galvanic cells and measurement of cell voltage. Using this procedure, a pair of students can construct and obtain the cell voltages of two precipitation cells, three concentration cells, and six redox cells in 30-40 minutes. (BB)

  4. Foam Fractionation of Lycopene: An Undergraduate Chemistry Experiment

    Science.gov (United States)

    Wang, Yan; Zhang, Mingjie; Hu, Yongliang

    2010-01-01

    A novel experiment for the extraction of lycopene from tomato paste by foam fractionation is described. Foam fractionation is a process for separating and concentrating chemicals by utilizing differences in their surface activities. Extraction of lycopene by foam fractionation is a new method that has not been previously reported in the…

  5. Laser-Induced Molecular Fluorescence: A Physical Chemistry Experiment.

    Science.gov (United States)

    Tellinghuisen, Joel

    1981-01-01

    Describes a companion experiment to the experimental study of the di-iodide visible absorption spectrum. Experimental details, interpretation, and data analysis are provided for an analysis of the di-iodide fluorescence excited by a visible laser, using a Raman instrument. (CS)

  6. An Enzyme Kinetics Experiment for the Undergraduate Organic Chemistry Laboratory

    Science.gov (United States)

    Olsen, Robert J.; Olsen, Julie A.; Giles, Greta A.

    2010-01-01

    An experiment using [superscript 1]H NMR spectroscopy to observe the kinetics of the acylase 1-catalyzed hydrolysis of "N"-acetyl-DL-methionine has been developed for the organic laboratory. The L-enantiomer of the reactant is hydrolyzed completely in less than 2 h, and [superscript 1]H NMR spectroscopic data from a single sample can be worked up…

  7. Cation Hydration Constants by Proton NMR: A Physical Chemistry Experiment.

    Science.gov (United States)

    Smith, Robert L.; And Others

    1988-01-01

    Studies the polarization effect on water by cations and anions. Describes an experiment to illustrate the polarization effect of sodium, lithium, calcium, and strontium ions on the water molecule in the hydration spheres of the ions. Analysis is performed by proton NMR. (MVL)

  8. Synthesis and Metalation of a Ligand: An Interdisciplinary Laboratory Experiment for Second-Year Organic and Introductory Inorganic Chemistry Students

    Science.gov (United States)

    Kasting, Benjamin J.; Bowser, Andrew K.; Anderson-Wile, Amelia M.; Wile, Bradley M.

    2015-01-01

    An interdisciplinary laboratory experiment involving second-year undergraduate organic chemistry and introductory inorganic chemistry undergraduate students is described. Organic chemistry students prepare a series of amine-bis(phenols) via a Mannich reaction, and characterize their products using melting point; FTIR; and [superscript 1]H,…

  9. Recent progress in trans-actinide chemistry: cutting-edge chemistry experiments with heaviest elements

    International Nuclear Information System (INIS)

    Motivated by the recent claims from the Flerov Laboratory of Nuclear Reactions (FLNR) at Dubna, Russia, on the discovery of several long-lived isotopes of elements up to atomic number 118, chemists have started to develop ideas about possible future investigations on chemical properties of these new members of the periodic table. Most of these elements should exhibit chemical properties typical for p-elements. Theoretical calculations indicate that element 114, due to a strong spin-orbit splitting and its filled 7p1/2 subshell, should reveal a rather noble behaviour, possibly being like a noble-gas. The same is already expected for element 112 with its filled 6d10 shell. In the course of previous studies of element 108 (hassium) a technique has been developed to investigate this element in form of its very volatile tetroxide. This technique, called IVO (In-situ Volatilisation and On-line detection) is able to separate continuously and detect on-line and SF-decaying products in a thermo-chromatographic device. IVO was used in recent years to investigate chemical properties of element 112, assumed it to be gaseous in an inert gas and containment (e.g. quartz) at ambient conditions. Since a prediction claimed that this element should interact with noble metal surfaces (e.g. Au) with an adsorption enthalpy between those of the systems Hg on Au and Rn on Au a detector array was built (COLD), composed of PIN diodes covered with a thin Au layer, along which a temperature gradient was applied between room temperature and -185 0C. A first chemical investigation of element 112 performed at FLNR with a slightly different gas chemical technique indicated that this element does not behave like Hg but more like Rn. In two more recent IVO experiments controversial results were obtained. In a first experiment the data were interpreted as an indication for a behaviour of element like Rn and seemed to confirm the data. In a second experiment, however, this observation could not be

  10. Chemistry Graduate Teaching Assistants' Experiences in Academic Laboratories and Development of a Teaching Self-image

    Science.gov (United States)

    Gatlin, Todd Adam

    Graduate teaching assistants (GTAs) play a prominent role in chemistry laboratory instruction at research based universities. They teach almost all undergraduate chemistry laboratory courses. However, their role in laboratory instruction has often been overlooked in educational research. Interest in chemistry GTAs has been placed on training and their perceived expectations, but less attention has been paid to their experiences or their potential benefits from teaching. This work was designed to investigate GTAs' experiences in and benefits from laboratory instructional environments. This dissertation includes three related studies on GTAs' experiences teaching in general chemistry laboratories. Qualitative methods were used for each study. First, phenomenological analysis was used to explore GTAs' experiences in an expository laboratory program. Post-teaching interviews were the primary data source. GTAs experiences were described in three dimensions: doing, knowing, and transferring. Gains available to GTAs revolved around general teaching skills. However, no gains specifically related to scientific development were found in this laboratory format. Case-study methods were used to explore and illustrate ways GTAs develop a GTA self-image---the way they see themselves as instructors. Two general chemistry laboratory programs that represent two very different instructional frameworks were chosen for the context of this study. The first program used a cooperative project-based approach. The second program used weekly, verification-type activities. End of the semester interviews were collected and served as the primary data source. A follow-up case study of a new cohort of GTAs in the cooperative problem-based laboratory was undertaken to investigate changes in GTAs' self-images over the course of one semester. Pre-semester and post-semester interviews served as the primary data source. Findings suggest that GTAs' construction of their self-image is shaped through the

  11. Eliciting Metacognitive Experiences and Reflection in a Year 11 Chemistry Classroom: An Activity Theory Perspective

    Science.gov (United States)

    Thomas, Gregory P.; McRobbie, Campbell J.

    2013-06-01

    Concerns regarding students' learning and reasoning in chemistry classrooms are well documented. Students' reasoning in chemistry should be characterized by conscious consideration of chemical phenomenon from laboratory work at macroscopic, molecular/sub-micro and symbolic levels. Further, students should develop metacognition in relation to such ways of reasoning about chemistry phenomena. Classroom change eliciting metacognitive experiences and metacognitive reflection is necessary to shift entrenched views of teaching and learning in students. In this study, Activity Theory is used as the framework for interpreting changes to the rules/customs and tools of the activity systems of two different classes of students taught by the same teacher, Frances, who was teaching chemical equilibrium to those classes in consecutive years. An interpretive methodology involving multiple data sources was employed. Frances explicitly changed her pedagogy in the second year to direct students attention to increasingly consider chemical phenomena at the molecular/sub-micro level. Additionally, she asked students not to use the textbook until toward the end of the equilibrium unit and sought to engage them in using their prior knowledge of chemistry to understand their observations from experiments. Frances' changed pedagogy elicited metacognitive experiences and reflection in students and challenged them to reconsider their metacognitive beliefs about learning chemistry and how it might be achieved. While teacher change is essential for science education reform, students are not passive players in change efforts and they need to be convinced of the viability of teacher pedagogical change in the context of their goals, intentions, and beliefs.

  12. ATTITUDES AND VIEWS OF CHEMICAL ENGINEERING STUDENTS TOWARDS SCHOOL EXPERIENCE AND CHEMISTRY LESSONS IN INDIAN EDUCATION SYSTEM

    OpenAIRE

    Soumya

    2015-01-01

    Chemistry is the backbone for the chemical engineering students. Basic chemistry learnt in schools till 12th standard makes framework for chemical engineering, hence their understanging of chemistry during school education is important. In present paper, the data of 64 students of Chemical Engineering have been collected and analyzed with respect to to their school experience of 10th and 12th standard of school and chemistry lessons learnt during that period

  13. Chemistry

    International Nuclear Information System (INIS)

    Research and development activities dealing with the chemical problems related to design and ultimate operation of molten-salt reactor systems are described. An experimental test stand was constructed to expose metallurgical test specimens to Te2 vapor at defined temperatures and deposition rates. To better define the chemistry of fluoroborate coolant, several aspects are being investigated. The behavior of hydroxy and oxy compounds in molten NaBF4 is being investigated to define reactions and compounds that may be involved in corrosion and/or could be involved in methods for trapping tritium. Two corrosion products of Hastelloy N, Na3CrF6 and Na5Cr3F14, were identified from fluoroborate systems. The evaluation of fluoroborate and alternate coolants continued. Research on the behavior of hydrogen and its isotopes is summarized. The solubilities of hydrogen, deuterium, and helium in Li2BeF4 are very low. The sorption of tritium on graphite was found to be significant (a few milligrams of tritium per kilogram of graphite), possibly providing a means of sequestering a portion of the tritium produced. Development of analytical methods continued with emphasis on voltammetric and spectrophotometric techniques for the in-line analysis of corrosion products such as Fe2+ and Cr3+ and the determination of the U3+/U4+ ratio in MSBR fuel salt. Similar studies were conducted with the NaBF4--NaF coolant salt. Information developed during the previous operation of the CSTF has been assessed and used to formulate plans for evaluation of in-line analytical methods in future CSTF operations. Electroanalytical and spectrophotometric research suggests that an electroactive protonic species is present in molten NaBF4--NaF, and that this species rapidly equilibrates with a volatile proton-containing species. Data obtained from the CSTF indicated that tritium was concentrated in the volatile species. (JGB)

  14. Validation of ACE-FTS measurements of CFC-11, CFC-12, and HCFC-22 using ground-based FTIR spectrometers

    Science.gov (United States)

    Kolonjari, F.; Walker, K. A.; Mahieu, E.; Batchelor, R. L.; Bernath, P. F.; Boone, C.; Conway, S. A.; Dan, L.; Griffin, D.; Harrett, A.; Kasai, Y.; Kagawa, A.; Lindenmaier, R.; Strong, K.; Whaley, C.

    2013-12-01

    Satellite datasets can be an effective global monitoring tool for long-lived compounds in the atmosphere. The Atmospheric Chemistry Experiment (ACE) is a mission on-board the Canadian satellite SCISAT-1. The primary instrument on SCISAT-1 is a high-resolution infrared Fourier transform spectrometer (ACE-FTS) which is capable of measuring a range of gases including key chlorofluorocarbon (CFC) and hydrochlorofluorocarbon (HCFC) species. These families of species are of interest because of their significant contribution to anthropogenic ozone depletion and to global warming. To assess the quality of data derived from satellite measurements, validation using other data sources is essential. Ground-based Fourier transform infrared (FTIR) spectrometers are particularly useful for this purpose. In this study, five FTIR spectrometers located at four sites around the world are used to validate the CFC-11 (CCl3F), CFC-12 (CCl2F2), and HCFC-22 (CHClF2) retrieved profiles from ACE-FTS measurements. These species are related because HCFC-22 was the primary replacement for CFC-11 and CFC-12 in refrigerant and propellant applications. The FTIR spectrometers used in this study record solar absorption spectra at Eureka (Canada), Jungfraujoch (Switzerland), Poker Flat (USA), and Toronto (Canada). The retrieval of CFC-11, CFC-12, and HCFC-22 are not standard products for many of these instruments, and as such, a harmonization of retrieval parameters between the sites has been conducted. The retrievals of these species from the FTIR spectra are sensitive from the surface to approximately 20 km, while the ACE-FTS profiles extend from approximately 6 to 30 km. For each site, partial column comparisons between coincident measurements of the three species and a validation of the observed trends will be discussed.

  15. Technical Note: Feasibility of CO2 profile retrieval from limb viewing solar occultation made by the ACE-FTS instrument

    Directory of Open Access Journals (Sweden)

    C. D. Boone

    2009-04-01

    Full Text Available Major limitations of our present knowledge of the global distribution of CO2 in the atmosphere are the uncertainty in atmospheric transport mixing and the sparseness of in situ concentration measurements. Limb viewing space-borne sounders, observing the atmosphere along tangential optical paths, offer a vertical resolution of a few kilometers for profiles, which is much better than currently flying or planned nadir sounding instruments can achieve. In this paper, we analyse the feasibility of obtaining CO2 vertical profiles in the 5–25 km altitude range from the Atmospheric Chemistry Experiment Fourier Transform Spectrometer (ACE-FTS, launched in August 2003, high spectral resolution solar occultation measurements. Two main difficulties must be overcome: (i the accurate determination of the instrument pointing parameters (tangent heights and pressure/temperature profiles independently from an a priori CO2 profile, and (ii the potential impact of uncertainties in the temperature knowledge on the retrieved CO2 profile. The first difficulty has been solved using the N collision-induced continuum absorption near 4 μm to determine tangent heights, pressure and temperature from the ACE-FTS spectra. The second difficulty has been solved by a careful selection of CO2 spectral micro-windows. Retrievals using synthetic spectra made under realistic simulation conditions show a vertical resolution close to 2.5 km and accuracy of the order of 2 ppm after averaging over 25 profiles. These results open the way to promising studies of transport mechanisms and carbon fluxes from the ACE-FTS measurements. First CO2 vertical profiles retrieved from real ACE-FTS occultations shown in this paper confirm the robustness of the method and applicability to real measurements.

  16. Preparation of americium targets for nuclear chemistry experiments at DANCE

    International Nuclear Information System (INIS)

    Using 1 gram of 241Am from LANL stocks, the purification steps required to obtain a solution of 241Am from the original material are described. Part of the purified solution was submitted for purity analysis by mass spectrometry, radiochemistry and trace metals analysis. The impurities were expected to be 239Pu and 237Np. A second fraction of this material was used for electroplating three samples onto titanium disks that were suitable for insertion into an instrument package to be placed into the DANCE detector. The purification methods used, the electroplating setup and the solutions to various problems that were encountered in making these targets are discussed. The analytical results are discussed as well as the yields from the electrodeposition process. Comparison of these yields with those from similar experiments utilizing 235U and 243Am are also discussed. (author)

  17. Solvent-Free Wittig Reaction: A Green Organic Chemistry Laboratory Experiment

    Science.gov (United States)

    Leung, Sam H.; Angel, Stephen A.

    2004-01-01

    Some Wittig reactions can be carried out by grinding the reactants in a mortar with a pestle for about 20 minutes, as per investigation. A laboratory experiment involving a solvent-free Wittig reaction that can be completed in a three-hour sophomore organic chemistry laboratory class period, are developed.

  18. Application of Calibrated Peer Review (CPR) Writing Assignments to Enhance Experiments with an Environmental Chemistry Focus

    Science.gov (United States)

    Margerum, Lawrence D.; Gulsrud, Maren; Manlapez, Ronald; Rebong, Rachelle; Love, Austin

    2007-01-01

    The browser-based software program, Calibrated Peer Review (CPR) developed by the Molecular Science Project enables instructors to create structured writing assignments in which students learn by writing and reading for content. Though the CPR project covers only one experiment in general chemistry, it might provide lab instructors with a method…

  19. X-Ray Diffraction of Intermetallic Compounds: A Physical Chemistry Laboratory Experiment

    Science.gov (United States)

    Varberg, Thomas D.; Skakuj, Kacper

    2015-01-01

    Here we describe an experiment for the undergraduate physical chemistry laboratory in which students synthesize the intermetallic compounds AlNi and AlNi3 and study them by X-ray diffractometry. The compounds are synthesized in a simple one-step reaction occurring in the solid state. Powder X-ray diffractograms are recorded for the two compounds…

  20. Molecular Orbitals of NO, NO[superscript+], and NO[superscript-]: A Computational Quantum Chemistry Experiment

    Science.gov (United States)

    Orenha, Renato P.; Galembeck, Sérgio E.

    2014-01-01

    This computational experiment presents qualitative molecular orbital (QMO) and computational quantum chemistry exercises of NO, NO[superscript+], and NO[superscript-]. Initially students explore several properties of the target molecules by Lewis diagrams and the QMO theory. Then, they compare qualitative conclusions with EHT and DFT calculations…

  1. Determination of Mercury in Milk by Cold Vapor Atomic Fluorescence: A Green Analytical Chemistry Laboratory Experiment

    Science.gov (United States)

    Armenta, Sergio; de la Guardia, Miguel

    2011-01-01

    Green analytical chemistry principles were introduced to undergraduate students in a laboratory experiment focused on determining the mercury concentration in cow and goat milk. In addition to traditional goals, such as accuracy, precision, sensitivity, and limits of detection in method selection and development, attention was paid to the…

  2. Absorption and Scattering Coefficients: A Biophysical-Chemistry Experiment Using Reflectance Spectroscopy

    Science.gov (United States)

    Cordon, Gabriela B.; Lagorio, M. Gabriela

    2007-01-01

    A biophysical-chemistry experiment, based on the reflectance spectroscopy for calculating the absorption and scattering coefficients of leaves is described. The results show that different plants species exhibit different values for both the coefficients because of their different pigment composition.

  3. Coloring a Superabsorbent Polymer with Metal Ions: An Undergraduate Chemistry Experiment

    Science.gov (United States)

    Yaung, Jing-Fun; Chen, Yueh-Huey

    2009-01-01

    A novel undergraduate chemistry experiment involving superabsorbent polymers commonly used in diapers and other personal care products is described. Students observe the removal of divalent transition-metal ions from aqueous solutions by the polymers. With the procedures provided, students are able to color the superabsorbent polymers with metal…

  4. Assessment of Antioxidant Capacities in Foods: A Research Experience for General Chemistry Students

    Science.gov (United States)

    Hoch, Matthew A.; Russell, Cianan B.; Steffen, Debora M.; Weaver, Gabriela C.; Burgess, John R.

    2009-01-01

    With the booming interest in health food and nutrition, investigations of the antioxidant capacities of various foods have come to the forefront of food science. This general chemistry laboratory curriculum provides students with an opportunity to design and implement their own experiments relating to antioxidants in food. The curriculum is six…

  5. A Cost-Effective Two-Part Experiment for Teaching Introductory Organic Chemistry Techniques

    Science.gov (United States)

    Sadek, Christopher M.; Brown, Brenna A.; Wan, Hayley

    2011-01-01

    This two-part laboratory experiment is designed to be a cost-effective method for teaching basic organic laboratory techniques (recrystallization, thin-layer chromatography, column chromatography, vacuum filtration, and melting point determination) to large classes of introductory organic chemistry students. Students are exposed to different…

  6. An Attenuated Total Reflectance Sensor for Copper: An Experiment for Analytical or Physical Chemistry

    Science.gov (United States)

    Shtoyko, Tanya; Zudans, Imants; Seliskar, Carl J.; Heineman, William R.; Richardson, John N.

    2004-01-01

    A sensor experiment which can be applied to advanced undergraduate laboratory course in physical or analytical chemistry is described along with certain concepts like the demonstration of chemical sensing, preparation of thin films on a substrate, microtitration, optical determination of complex ion stoichiometry and isosbestic point. It is seen…

  7. Experience with maintenance of feed-water chemistry for FBTR once through steam generator

    International Nuclear Information System (INIS)

    Once through steam generators utilised for fast reactors are critical components requiring stringent control on water quality. This paper details the experience in maintenance of feed water chemistry during various phases of power operation in fast breeder test reactor (FBTR). (author). 1 ref., 2 figs., 1 tab

  8. Chemistry Laboratory--A Self-Paced Project Approach with Traditional Experiments.

    Science.gov (United States)

    Faber, Gary C.; Martin, Elizabeth M.

    1983-01-01

    Citing problems with a traditional introductory chemistry laboratory program, discusses a two-semester, project-oriented laboratory program using traditional experiments. A series of slide/tape programs discussing/illustrating potentially difficult concepts and techniques is used to facilitate instruction. Includes list of topics covered in the…

  9. Liquid-Liquid Extraction of Insecticides from Juice: An Analytical Chemistry Laboratory Experiment

    Science.gov (United States)

    Radford, Samantha A.; Hunter, Ronald E., Jr.; Barr, Dana Boyd; Ryan, P. Barry

    2013-01-01

    A laboratory experiment was developed to target analytical chemistry students and to teach them about insecticides in food, sample extraction, and cleanup. Micro concentrations (sub-microgram/mL levels) of 12 insecticides spiked into apple juice samples are extracted using liquid-liquid extraction and cleaned up using either a primary-secondary…

  10. Analysis of a Natural Yellow Dye: An Experiment for Analytical Organic Chemistry

    NARCIS (Netherlands)

    Villela, A.; Derksen, G.C.H.; Beek, van T.A.

    2014-01-01

    This experiment exposes second-year undergraduate students taking a course in analytical organic chemistry to high-performance liquid chromatography (HPLC) and quantitative analysis using the internal standard method. This is accomplished using the real-world application of natural dyes for textiles

  11. Transitioning from Expository Laboratory Experiments to Course-Based Undergraduate Research in General Chemistry

    Science.gov (United States)

    Clark, Ted M.; Ricciardo, Rebecca; Weaver, Tyler

    2016-01-01

    General chemistry courses predominantly use expository experiments that shape student expectations of what a laboratory activity entails. Shifting within a semester to course-based undergraduate research activities that include greater decision-making, collaborative work, and "messy" real-world data necessitates a change in student…

  12. An Environmental Chemistry Experiment: The Determination of Radon Levels in Water.

    Science.gov (United States)

    Welch, Lawrence E.; Mossman, Daniel M.

    1994-01-01

    Describes a radiation experiment developed to complement a new environmental chemistry laboratory curriculum. A scintillation counter is used to measure radon in water. The procedure relies on the fact that toluene will preferentially extract radon from water. Sample preparation is complete in less than 90 minutes. Because the level of…

  13. Nitration of Phenols Using Cu(NO[subscript 3])[subscript 2]: Green Chemistry Laboratory Experiment

    Science.gov (United States)

    Yadav, Urvashi; Mande, Hemant; Ghalsasi, Prasanna

    2012-01-01

    An easy-to-complete, microwave-assisted, green chemistry, electrophilic nitration method for phenol using Cu(NO[subscript 3])[subscript 2] in acetic acid is discussed. With this experiment, students clearly understand the mechanism underlying the nitration reaction in one laboratory session. (Contains 4 schemes.)

  14. Solventless and One-Pot Synthesis of Cu(II) Phthalocyanine Complex: A Green Chemistry Experiment

    Science.gov (United States)

    Sharma, R. K.; Sharma, Chetna; Sidhwani, Indu Tucker

    2011-01-01

    With the growing awareness of green chemistry, it is increasingly important for students to understand this concept in the context of laboratory experiments. Although microwave-assisted organic synthesis has become a common and invaluable technique in recent years, there have been few procedures published for microwave-assisted inorganic synthesis…

  15. Measurement of the Compressibility Factor of Gases: A Physical Chemistry Laboratory Experiment

    Science.gov (United States)

    Varberg, Thomas D.; Bendelsmith, Andrew J.; Kuwata, Keith T.

    2011-01-01

    In this article, we describe an experiment for the undergraduate physical chemistry laboratory in which students measure the compressibility factor of two gases, helium and carbon dioxide, as a function of pressure at constant temperature. The experimental apparatus is relatively inexpensive to construct and is described and diagrammed in detail.…

  16. A Stopped-Flow Kinetics Experiment for the Physical Chemistry Laboratory Using Noncorrosive Reagents

    Science.gov (United States)

    Prigodich, Richard V.

    2014-01-01

    Stopped-flow kinetics techniques are important to the study of rapid chemical and biochemical reactions. Incorporation of a stopped-flow kinetics experiment into the physical chemistry laboratory curriculum would therefore be an instructive addition. However, the usual reactions studied in such exercises employ a corrosive reagent that can over…

  17. Computational Modeling of the Optical Rotation of Amino Acids: An "in Silico" Experiment for Physical Chemistry

    Science.gov (United States)

    Simpson, Scott; Autschbach, Jochen; Zurek, Eva

    2013-01-01

    A computational experiment that investigates the optical activity of the amino acid valine has been developed for an upper-level undergraduate physical chemistry laboratory course. Hybrid density functional theory calculations were carried out for valine to confirm the rule that adding a strong acid to a solution of an amino acid in the l…

  18. Developments for transactinide chemistry experiments behind the gas-filled separator TASCA

    OpenAIRE

    Even, Julia

    2011-01-01

    Topic of this thesis is the development of experiments behind the gas-filled separator TASCA(TransActinide Separator and Chemistry Apparatus) to study the chemical properties of the transactinide elements.rnIn the first part of the thesis, the electrodepositions of short-lived isotopes of ruthenium and osmium on gold electrodes were studied as model experiments for hassium. From literature it is known that the deposition potential of single atoms differs significantly from the potential predi...

  19. ACE INHIBITORS: A COMPREHENSIVE REVIEW

    OpenAIRE

    Pradeep Kumar Arora* and Ashish Chauhan

    2013-01-01

    Hypertension is a chronic increase in blood pressure, characterized as primary and secondary hypertension. The disorder is associated with various risk factors like obesity, diabetes, age, lack of exercise etc. Hypertension is being treated since ancient times by Ayurvedic, Chinese and Unani medicine. Now various allopathic drugs are available which include diuretics, calcium channel blockers, α-blockers, β-blockers, vasodilators, central sympatholytics and ACE-inhibitors. Non-pharmacological...

  20. Advanced Collaborative Emissions Study (ACES)

    Energy Technology Data Exchange (ETDEWEB)

    Greenbaum, Daniel; Costantini, Maria; Van Erp, Annemoon; Shaikh, Rashid; Bailey, Brent; Tennant, Chris; Khalek, Imad; Mauderly, Joe; McDonald, Jacob; Zielinska, Barbara; Bemis, Jeffrey; Storey, John; Hallberg, Lance; Clark, Nigel

    2013-12-31

    The objective of the Advanced Collaborative Emissions Study (ACES) was to determine before widespread commercial deployment whether or not the new, energy-efficient, heavy duty diesel engines (2007 and 2010 EPA Emissions Standards Compliant) may generate anticipated toxic emissions that could adversely affect the environment and human health. ACES was planned to take place in three phases. In Phase 1, extensive emissions characterization of four production-intent prototype engine and control systems designed to meet 2007 standards for nitrogen oxides (NOx) and particulate matter (PM) was conducted at an existing emissions characterization facility: Southwest Research Institute (SwRI). One of the tested engines was selected (at random, after careful comparison of results) for health testing in Phase 3. In Phase 2, extensive emission characterization of three production-intent prototype engine and control systems meeting the 2010 standards (including more advanced NOx controls to meet the more stringent 2010 NOx standards) was conducted at the same test facility. In Phase 3, one engine/aftertreatment system selected from Phase 1 was further characterized during health effects studies (at an existing inhalation toxicology laboratory: Lovelace Respiratory Research Institute, [LRRI]) to form the basis of the ACES safety assessment. The Department of Energy (DOE) award provided funding for emissions characterization in Phases 1 and 2 as well as exposure characterization in Phase 3. The main health analyses in Phase 3 were funded separately and are not reported here.

  1. Fitting It All In: Adapting a Green Chemistry Extraction Experiment for Inclusion in an Undergraduate Analytical Laboratory

    Science.gov (United States)

    Buckley, Heather L.; Beck, Annelise R.; Mulvihill, Martin J.; Douskey, Michelle C.

    2013-01-01

    Several principles of green chemistry are introduced through this experiment designed for use in the undergraduate analytical chemistry laboratory. An established experiment of liquid CO2 extraction of D-limonene has been adapted to include a quantitative analysis by gas chromatography. This facilitates drop-in incorporation of an exciting…

  2. Photolysis of 4-Phenyl-1,3-dioxolan-2-one: An Undergraduate Experiment in Free Radical Chemistry.

    Science.gov (United States)

    White, Rick C.; Ma, Sha

    1988-01-01

    Describes a photochemistry experiment designed to introduce photochemical techniques and experience free radical chemistry. Selects Nuclear Magnetic Resonance spectroscopy for the analysis. This activity is suggested for use in an upper level undergraduate organic course. (MVL)

  3. Upper troposphere and stratosphere distribution of hydrocarbon species in ACE-FTS measurements and GEOS-Chem simulations

    Science.gov (United States)

    Koo, Ja-Ho; Walker, Kaley A.; Jones, Dylan B. A.; Jones, Ashley; Sheese, Patrick E.; Boone, Chris D.; Bernath, Peter F.; Manney, Gloria L.

    2016-04-01

    Measurements of carbon-containing species, referred to herein as "hydrocarbons", are important components needed for describing and understanding the influence of natural and anthropogenic emissions on atmospheric chemistry. Analysis of the global pattern of hydrocarbons contributes to our understanding of the influence of regional and seasonal variation in air pollution and natural fire events. The Atmospheric Chemistry Experiment Fourier Transform Spectrometer (ACE-FTS) has monitored trace gases in the upper troposphere and stratosphere based on solar occultation measurements for more than ten years. In this study, we investigate the global pattern of seven "hydrocarbon" species (CO, C2H6, C2H2, HCN, H2CO, CH3OH, and HCOOH) and OCS using the ACE-FTS version 3.5 dataset from 2004 to 2013. All hydrocarbons show strong seasonal variation and regional differences, but the detailed pattern differs according to the speciation of the hydrocarbons. For example, in the Northern Hemisphere, CO, C2H6, and C2H2 show the highest mixing ratios in winter, but high CH3OH and HCOOH appear in summer. In the Southern hemisphere, H2CO, HCN, and HCOOH show high mixing ratios in springtime. These patterns indicate the impact of different emission sources including fuel combustion, wildfire emission, and chemical production. By calculating correlations with CO, these results can provide useful information to characterize each hydrocarbon emission. The ACE-FTS measurements have also been compared with GEOS-Chem output to examine the model performance and spatiotemporal patterns in the simulations.

  4. Methane cross-validation between three Fourier transform spectrometers: SCISAT ACE-FTS, GOSAT TANSO-FTS, and ground-based FTS measurements in the Canadian high Arctic

    Science.gov (United States)

    Holl, Gerrit; Walker, Kaley A.; Conway, Stephanie; Saitoh, Naoko; Boone, Chris D.; Strong, Kimberly; Drummond, James R.

    2016-05-01

    We present cross-validation of remote sensing measurements of methane profiles in the Canadian high Arctic. Accurate and precise measurements of methane are essential to understand quantitatively its role in the climate system and in global change. Here, we show a cross-validation between three data sets: two from spaceborne instruments and one from a ground-based instrument. All are Fourier transform spectrometers (FTSs). We consider the Canadian SCISAT Atmospheric Chemistry Experiment (ACE)-FTS, a solar occultation infrared spectrometer operating since 2004, and the thermal infrared band of the Japanese Greenhouse Gases Observing Satellite (GOSAT) Thermal And Near infrared Sensor for carbon Observation (TANSO)-FTS, a nadir/off-nadir scanning FTS instrument operating at solar and terrestrial infrared wavelengths, since 2009. The ground-based instrument is a Bruker 125HR Fourier transform infrared (FTIR) spectrometer, measuring mid-infrared solar absorption spectra at the Polar Environment Atmospheric Research Laboratory (PEARL) Ridge Laboratory at Eureka, Nunavut (80° N, 86° W) since 2006. For each pair of instruments, measurements are collocated within 500 km and 24 h. An additional collocation criterion based on potential vorticity values was found not to significantly affect differences between measurements. Profiles are regridded to a common vertical grid for each comparison set. To account for differing vertical resolutions, ACE-FTS measurements are smoothed to the resolution of either PEARL-FTS or TANSO-FTS, and PEARL-FTS measurements are smoothed to the TANSO-FTS resolution. Differences for each pair are examined in terms of profile and partial columns. During the period considered, the number of collocations for each pair is large enough to obtain a good sample size (from several hundred to tens of thousands depending on pair and configuration). Considering full profiles, the degrees of freedom for signal (DOFS) are between 0.2 and 0.7 for TANSO-FTS and

  5. Insertion/deletion polymorphism of the ACE gene and adherence to ACE inhibitors

    NARCIS (Netherlands)

    H. Schelleman (Hedi); O.H. Klungel (Olaf); C.M. van Duijn (Cock); J.C.M. Witteman (Jacqueline); A. Hofman (Albert); A. de Boer (Anthonius); B.H.Ch. Stricker (Bruno)

    2005-01-01

    textabstractAims: We investigated whether the insertion/deletion (I/D) polymorphism of the ACE gene modified the adherence to ACE inhibitors as measured by the discontinuation of an ACE inhibitor, or addition of another antihypertensive drug. Methods: This was a cohort study among 239 subjects who s

  6. PWR water chemistry controls: a perspective on industry initiatives and trends relative to operating experience and the EPRI PWR water chemistry guidelines

    International Nuclear Information System (INIS)

    An effective PWR water chemistry control program must address the following goals: Minimize materials degradation (e.g., PWSCC, corrosion of fuel, corrosion damage of steam generator (SG) tubes); Maintain fuel integrity and good performance; Minimize corrosion product transport (e.g., transport and deposition on the fuel, transport into the SGs where it can foul tube surfaces and create crevice environments for the concentration of corrosive impurities); Minimize dose rates. Water chemistry control must be optimized to provide overall improvement considering the sometimes variant constraints of the goals listed above. New technologies are developed for continued mitigation of materials degradation, continued fuel integrity and good performance, continued reduction of corrosion product transport, and continued minimization of plant dose rates. The EPRI chemistry program, in coordination with other EPRI programs, strives to improve these areas through application of chemistry initiatives, focusing on these goals. This paper highlights the major initiatives and issues with respect to PWR primary and secondary system chemistry and outlines the recent, on-going, and proposed work to effectively address them. These initiatives are presented in light of recent operating experience, as derived from EPRI's PWR chemistry monitoring and assessment program, and EPRI's water chemistry guidelines. (author)

  7. POMB/ACE chemotherapy for mediastinal germ cell tumours.

    Science.gov (United States)

    Bower, M; Brock, C; Holden, L; Nelstrop, A; Makey, A R; Rustin, G J; Newlands, E S

    1997-05-01

    Mediastinal germ cell tumours (MGCT) are rare and most published series reflect the experiences of individual institutions over many years. Since 1979, we have treated 16 men (12 non-seminomatous germ cell tumours and 4 seminomas) with newly diagnosed primary MGCT with POMB/ACE chemotherapy and elective surgical resection of residual masses. This approach yielded complete remissions in 15/16 (94%) patients. The median follow-up was 6.0 years and no relapses occurred more than 2 years after treatment. The 5 year overall survival in the non-seminomatous germ cell tumours (NSGCT) is 73% (95% confidence interval 43-90%). One patient with NSGCT developed drug-resistant disease and died without achieving remission and 2 patients died of relapsed disease. In addition, 4 patients with bulky and/or metastatic seminoma were treated with POMB/ACE. One died of treatment-related neutropenic sepsis in complete remission and one died of relapsed disease. Finally, 4 patients (2 NSGCT and 2 seminomas) referred at relapse were treated with POMB/ACE and one was successfully salvaged. The combination of POMB/ACE chemotherapy and surgery is effective management for MGCT producing high long-term survival rates. PMID:9291802

  8. ACE/ACE2 Ratio and MMP-9 Activity as Potential Biomarkers in Tuberculous Pleural Effusions

    Directory of Open Access Journals (Sweden)

    Wen-Yeh Hsieh, Tang-Ching Kuan, Kun-Shan Cheng, Yan-Chiou Liao, Mu-Yuan Chen, Pei-Heng Lin, Yuan-Chang Hsu, Chen-Yi Huang, Wei-Hua Hsu, Sheng-Yao Yu, Chih-Sheng Lin

    2012-01-01

    Full Text Available Objective: Pleural effusion is common problem, but the rapid and reliable diagnosis for specific pathogenic effusions are lacking. This study aimed to identify the diagnosis based on clinical variables to differentiate pleural tuberculous exudates from other pleural effusions. We also investigated the role of renin-angiotensin system (RAS and matrix metalloproteinase (MMPs in the pathogenesis of pleural exudates.Experimental design: The major components in RAS and extracellular matrix metabolism, including angiotensin converting enzyme (ACE, ACE2, MMP-2 and MMP-9 activities, were measured and compared in the patients with transudative (n = 45 and exudative (n = 80 effusions. The exudative effusions were come from the patients with tuberculosis (n = 20, pneumonia (n = 32, and adenocarcinoma (n = 28.Results: Increased ACE and equivalent ACE2 activities, resulting in a significantly increased ACE/ACE2 ratio in exudates, were detected compared to these values in transudates. MMP-9 activity in exudates was significantly higher than that in transudates. The significant correlation between ACE and ACE2 activity that was found in transudates was not found in exudates. Advanced analyses showed significantly increased ACE and MMP-9 activities, and decreased ACE2 activity in tuberculous pleural effusions compared with those in pneumonia and adenocarcinoma effusions. The results indicate that increased ACE and MMP-9 activities found in the exudates were mainly contributed from a higher level of both enzyme activities in the tuberculous pleural effusions.Conclusion: Interplay between ACE and ACE2, essential functions in the RAS, and abnormal regulation of MMP-9 probably play a pivotal role in the development of exudative effusions. Moreover, the ACE/ACE2 ratio combined with MMP-9 activity in pleural fluid may be potential biomarkers for diagnosing tuberculous pleurisy.

  9. The Effect of Guided-Inquiry Laboratory Experiments on Science Education Students' Chemistry Laboratory Attitudes, Anxiety and Achievement

    Science.gov (United States)

    Ural, Evrim

    2016-01-01

    The study aims to search the effect of guided inquiry laboratory experiments on students' attitudes towards chemistry laboratory, chemistry laboratory anxiety and their academic achievement in the laboratory. The study has been carried out with 37 third-year, undergraduate science education students, as a part of their Science Education Laboratory…

  10. Introduction to Homogenous Catalysis with Ruthenium-Catalyzed Oxidation of Alcohols: An Experiment for Undergraduate Advanced Inorganic Chemistry Students

    Science.gov (United States)

    Miecznikowski, John R.; Caradonna, John P.; Foley, Kathleen M.; Kwiecien, Daniel J.; Lisi, George P.; Martinez, Anthony M.

    2011-01-01

    A three-week laboratory experiment, which introduces students in an advanced inorganic chemistry course to air-sensitive chemistry and catalysis, is described. During the first week, the students synthesize RuCl[subscript 2](PPh[subscript 3])[subscript 3]. During the second and third weeks, the students characterize the formed coordination…

  11. Differential regulation of renal angiotensin-converting enzyme (ACE) and ACE2 during ACE inhibition and dietary sodium restriction in healthy rats

    NARCIS (Netherlands)

    Hamming, I.; van Goor, H.; Turner, A. J.; Rushworth, C. A.; Michaud, A. A.; Corvol, P.; Navis, G.

    2008-01-01

    Angiotensin-converting enzyme (ACE) 2 is thought to counterbalance ACE by breakdown of angiotensin (Ang) II and formation of Ang(1-7). Both enzymes are highly expressed in the kidney, but reports on their regulation differ. To enhance our understanding of the regulation of renal ACE and ACE2, we inv

  12. BWR shutdown and startup chemistry experience and application Sourcebook. BWRVIP-225, Rev. 1

    International Nuclear Information System (INIS)

    provides highlights from the Sourcebook on shutdown and startup industry experience, shutdown data correlations and chemistry control recommendations during shutdown and startup. (author)

  13. General Chemistry and Cellular and Molecular Biology: An Experiment in Curricular Symbiosis

    Science.gov (United States)

    Truman Schwartz, A.; Serie, Jan

    2001-11-01

    During the 1998-99 academic year, with the support of the Howard Hughes Medical Institute, we co-taught integrated courses in general chemistry and cell biology to 23 first-year students. The double course was organized around six units: I. Energetics: Harvesting (Bio)Chemical Energy; II. The Regulation of Biological Processes: Chemical Kinetics and Equilibrium; III. Membranes and Electrochemical Gradients; IV. Acids and Bases and the Regulation of pH; V. Intracellular Compartments and Transport; and VI. Cellular Communication. The chemistry and biology were both taught in a manner meant to enhance understanding of these major themes and to emphasize the relationships between the two disciplines. Both of us were present for all class sessions and shared teaching responsibilities. The examinations, which corresponded to the units, also stressed the interdependence of biology and chemistry. The laboratory components were not integrated; rather the students were dispersed among laboratory sections shared with students from more traditional lecture sections. The paper reports on this experiment in curricular symbiosis, which proved to be a challenging and rewarding learning experience for both the students and us.

  14. ACE project Phases C and D: ACE/MCCI and MACE tests

    International Nuclear Information System (INIS)

    Programs of experiments and related analysis are underway at Argonne National Laboratory investigating the interaction of molten core material with concrete and its coolability. The major objectives are: (1) obtain data on fission product release during molten corium concrete interactions (MCCI); and (2) investigate the conditions for successful cooling and stabilization of core melt attacking the concrete basemat. The fission product release tests have been completed, and data analysis is in progress. The experiments will be analyzed by several groups to validate the various MCCI codes, e.g., CORCON and VANESA, WECHSL and MAAP-DECOMP. A scoping melt attach and coolability experiment (MACE) involving the addition of water atop an on-going MCCI has been performed. A facility to conduct larger scale tests is currently being constructed, and two addition tests are planned to be completed before the end of CY91. This paper describes the progress of the MCCI and the MACE testing programs in the ACE project

  15. Irradiation capability of Japanese materials test reactor for water chemistry experiments

    International Nuclear Information System (INIS)

    Appropriate understanding of water chemistry in the core of LWRs is essential as chemical species generated due to water radiolysis by neutron and gamma-ray irradiation govern corrosive environment of structural materials in the core and its periphery, causing material degradation such as stress corrosion cracking. Theoretical model calculation such as water radiolysis calculation gives comprehensive understanding of water chemistry at irradiation field where we cannot directly monitor. For enhancement of the technology, accuracy verification of theoretical models under wide range of irradiation conditions, i.e. dose rate, temperature etc., with well quantified in-pile measurement data is essential. Japan Atomic Energy Agency (JAEA) has decided to launch water chemistry experiments for obtaining data that applicable to model verification as well as model benchmarking, by using an in-pile loop which will be installed in the Japan Materials Testing Reactor (JMTR). In order to clarify the irradiation capability of the JMTR for water chemistry experiments, preliminary investigations by water radiolysis / ECP model calculations were performed. One of the important irradiation conditions for the experiments, i.e. dose rate by neutron and gamma-ray, can be controlled by selecting irradiation position in the core. In this preliminary study, several representative irradiation positions that cover from highest to low absorption dose rate were chosen and absorption dose rate at the irradiation positions were evaluated by MCNP calculations. As a result of the calculations, it became clear that the JMTR could provide the irradiation conditions close to the BWR. The calculated absorption dose rate at each irradiation position was provided to water radiolysis calculations. The radiolysis calculations were performed under various conditions by changing absorption dose rate, water chemistry of feeding water etc. parametrically. Qualitatively, the concentration of H2O2, O2 and H2 at

  16. Determining the EDTA Content in a Consumer Shower Cleaner. An Introductory Chemistry Laboratory Experiment

    Science.gov (United States)

    Weigand, Willis A.

    2000-10-01

    At Altoona College, Chemistry 11 is offered to students as a preparatory course for the University's Chemical Principles course, Chem 12. A relevant laboratory is a source of motivation for the students to learn the chemistry. One way of making the laboratory relevant is to analyze the chemical components of consumer products. Several new shower-cleaning products have been introduced, which advertise that cleaning the shower is no longer necessary. The cleaners work using a combination of surfactants, alcohols, and a chelating agent. The Web site of a popular shower cleaner lists EDTA (ethylenediamine tetraacetate ion) as the chelating agent. The classic EDTA/calcium complexometric titration can be used to determine the EDTA content of the cleaner. This article describes the experiment to determine the EDTA content in a shower-cleaning product.

  17. Research and Teaching: Computational Methods in General Chemistry--Perceptions of Programming, Prior Experience, and Student Outcomes

    Science.gov (United States)

    Wheeler, Lindsay B.; Chiu, Jennie L.; Grisham, Charles M.

    2016-01-01

    This article explores how integrating computational tools into a general chemistry laboratory course can influence student perceptions of programming and investigates relationships among student perceptions, prior experience, and student outcomes.

  18. Demystifying the Chemistry Literature: Building Information Literacy in First-Year Chemistry Students through Student-Centered Learning and Experiment Design

    Science.gov (United States)

    Bruehl, Margaret; Pan, Denise; Ferrer-Vinent, Ignacio J.

    2015-01-01

    This paper describes curriculum modules developed for first-year general chemistry laboratory courses that use scientific literature and creative experiment design to build information literacy in a student-centered learning environment. Two curriculum units are discussed: Exploring Scientific Literature and Design Your Own General Chemistry…

  19. Angiotensin converting enzyme 2 (ACE2) activity in fetal calf serum: implications for cell culture research

    OpenAIRE

    Lubel, J. S.; Herath, C. B.; Velkoska, E.; Casley, D. J.; Burrell, L. M.; Angus, P. W.

    2008-01-01

    Cell culture experiments often employ the use of culture media that contain fetal calf serum (FCS). The angiotensin peptides angiotensin II and angiotensin 1–7 have opposing effects with angiotensin converting enzyme 2 (ACE2) being the enzyme predominantly responsible for generating angiotensin 1–7 from angiotensin II. The effect of FCS on angiotensin peptides has not previously been described. We have shown that FCS has ACE2 enzyme activity capable of degrading angiotensin II and generating ...

  20. Learner Experiences of Online Pre-lecture Resources for an Introductory Chemistry Course at an Irish Higher Education Institution

    OpenAIRE

    McDonnell, Claire

    2011-01-01

    The principal aim of this case study was to investigate students’ experiences of using online pre-lecture resources and their perceptions of their learning environment for the Introductory Chemistry module concerned. A subsidiary aim was to probe the experience of the lecturer involved of designing and piloting these resources and his perception of their impact on students’ learning. The student cohort who participated were a group of 49 first year level 8 undergraduate chemistry students at ...

  1. A global view of the extratropical tropopause transition layer from Atmospheric Chemistry Experiment Fourier Transform Spectrometer O3, H2O, and CO

    Science.gov (United States)

    Hegglin, M. I.; Boone, C. D.; Manney, G. L.; Walker, K. A.

    2009-04-01

    The global behavior of the extratropical tropopause transition layer (ExTL) is investigated using O3, H2O, and CO measurements from the Atmospheric Chemistry Experiment Fourier Transform Spectrometer (ACE-FTS) on Canada's SCISAT-1 satellite obtained between February 2004 and May 2007. The ExTL depth is derived using H2O-O3 and CO-O3 correlations. The ExTL top derived from H2O-O3 shows an increase from roughly 1-1.5 km above the thermal tropopause in the subtropics to 3-4 km (2.5-3.5 km) in the north (south) polar region, implying somewhat weaker troposphere-stratosphere-transport in the Southern Hemisphere. The ExTL bottom extends ˜1 km below the thermal tropopause, indicating a persistent stratospheric influence on the troposphere at all latitudes. The ExTL top derived from the CO-O3 correlation is lower, at 2 km or ˜345 K (1.5 km or ˜335 K) in the Northern (Southern) Hemisphere. Its annual mean coincides with the relative temperature maximum just above the thermal tropopause. The vertical CO gradient maximizes at the thermal tropopause, indicating a local minimum in mixing within the tropopause region. The seasonal changes in and the scales of the vertical H2O gradients show a similar pattern as the static stability structure of the tropopause inversion layer (TIL), which provides observational support for the hypothesis that H2O plays a radiative role in forcing and maintaining the structure of the TIL.

  2. The 1953 Stanley L. Miller Experiment: Fifty Years of Prebiotic Organic Chemistry

    Science.gov (United States)

    Lazcano, Antonio; Bada, Jeffrey L.

    2003-01-01

    The field of prebiotic chemistry effectively began with a publication in Science 50 years ago by Stanley L. Miller on the spark discharge synthesis of amino acids and other compounds using a mixture of reduced gases that were thought to represent the components of the atmosphere on the primitive Earth. On the anniversary of this landmark publication, we provide here an accounting of the events leading to the publication of the paper. We also discuss the historical aspects that lead up to the landmark Miller experiment.

  3. Design performances and chemistry program supporting the FA3 /UKEPRTM activity management: experience and modeling balance

    International Nuclear Information System (INIS)

    EPRTM reactor accounts with an evolutionary design that provides the appropriate features to ensure the safety implementation of different chemistry and radiochemistry options. ALARP considerations have been taken into account by EDF-AREVA for making decisions relating to the activity management in the primary circuit of Flamanville 3-EPRTM and UK-EPRTM reactors. The water chemistry and radiochemistry concept implemented in FA3-EPRTM and UK-EPRTM reactors is the result of an exhaustive selection process based on the balance between the theoretical developments, the laboratory tests and the NPP experience concerning the diverse areas associated with: - The source term identification and characterization: The understanding of the origin and behavior of fission products/actinides, corrosion products and activation products constitutes the essential support for the selection of suitable parameters and criteria to monitor the system integrity, the tramp-uranium and radiation build-up and the discharges to the environment. - The source term quantification: The balance between the baseline data from PWR forerunner reactors and the assessments performed by modeling constitutes the major demonstration of the source term accuracy. This approach ensures that activity risks are understood and can be managed with the EPRTM design options. - The EPRTM design options evaluation: The sensitivity analysis results show the influence of the fuel management, the material choice and the chemistry conditioning on several domains such as the activity coolant and the fuel/ex-core crud management. EDF-AREVA demonstrates by means of this process that the design, sizing and chemistry conditioning of EPRTM reactor primary circuit are adapted to guarantee the correct activity management. The methodology developed, based on qualitative and quantitative assessments, intends to propose to the Nuclear Industry several alternatives for evaluating and/or improving the compliance with requirements

  4. Technical Note: Feasibility of CO2 profile retrieval from limb viewing solar occultation made by the ACE-FTS instrument

    Directory of Open Access Journals (Sweden)

    C. D. Boone

    2009-01-01

    Full Text Available Major limitations of our present knowledge of the global distribution of CO2 in the atmosphere are the uncertainty in atmospheric transport mixing and the sparseness of in situ concentration measurements. Limb viewing space-borne sounders, observing the atmosphere along tangential optical paths, offer a vertical resolution of a few kilometres for profiles, which is much better than currently flying or planned nadir sounding instruments can achieve. In this paper, we analyse the feasibility of obtaining CO2 vertical profiles in the 5–25 km altitude range from the Atmospheric Chemistry Experiment Fourier Transform Spectrometer (ACE-FTS, launched in August 2003, high spectral resolution solar occultation measurements. Two main difficulties must be overcome: (i the accurate determination of the instrument pointing parameters (tangent heights and pressure/temperature profiles independently from an a priori CO2 profile, and (ii the potential impact of uncertainties in the temperature knowledge on the retrieved CO2 profile. The first difficulty has been solved using the N2 collision-induced continuum absorption near 4 μm to determine tangent heights, pressure and temperature from the ACE-FTS spectra. The second difficulty has been solved by a careful selection of CO2 spectral micro-windows. Retrievals using synthetic spectra made under realistic simulation conditions show a vertical resolution close to 2.5 km and accuracy of the order of 2 ppm after averaging over 25 profiles. These results open the way to promising studies of transport mechanisms and carbon fluxes from the ACE-FTS measurements.

  5. Characterization of PM2.5 aerosols dominated by local pollution and Asian dust observed at an urban site in Korea during aerosol characterization experiments (ACE)--Asia Project.

    Science.gov (United States)

    Park, Seung Shik; Kim, Young J; Cho, Sung Yong; Kim, Seung Jai

    2007-04-01

    Daily fine particulate matter (PM2.5) samples were collected at Gwangju, Korea, during the Aerosol Characterization Experiments (ACE)-Asia Project to determine the chemical properties of PM2.5 originating from local pollution and Asian dust (AD) storms. During the study period, two significant events occurred on April 10-13 and 24-25, 2001, and a minor event occurred on April 19, 2001. Based on air mass transport pathways identified by back-trajectory calculation, the PM2.5 dataset was classified into three types of aerosol populations: local pollution and two AD aerosol types. The two AD types were transported along different pathways. One originated from Gobi desert area in Mongolia, passing through Hunshandake desert in Northern Inner Mongolia, urban and polluted regions of China (AD1), and the other originated in sandy deserts located in the Northeast Inner Mongolia Plateau and then flowed southward through the Korean peninsula (AD2). During the AD2 event, a smoke plume that originated in North Korea was transported to our study site. Mass balance closures show that crustal materials were the most significant species during both AD events, contributing -48% to the PM2.5 mass; sulfate aerosols (19.1%) and organic matter (OM; 24.6%) were the second greatest contributors during the AD1 and AD2 periods, respectively, indicating that aerosol properties were dependent on the transport pathway. The sulfate concentration constituted only 6.4% (4.5 microg/m3) of the AD2 PM2.5 mass. OM was the major chemical species in the local pollution-dominated PM2.5 aerosols, accounting for 28.7% of the measured PM2.5 mass, followed by sulfate (21.4%), nitrate (15%), ammonium (12.8%), elemental carbon (8.9%), and crustal material (6.5%). Together with substantial enhancement of the crustal elements (Mg, Al, K, Ca, Sc, Ti, Mn, Fe, Sr, Zr, Ba, and Ce), higher concentrations of pollution elements (S, V, Ni, Zn, As, Cd, and Pb) were observed during AD1 and AD2 than during the local

  6. ATR-FTIR Spectroscopy in the Undergraduate Chemistry Laboratory: Part II--A Physical Chemistry Laboratory Experiment on Surface Adsorption

    Science.gov (United States)

    Schuttlefield, Jennifer D.; Larsen, Sarah C.; Grassian, Vicki H.

    2008-01-01

    Attenuated total reflectance-Fourier transform infrared (ATR-FTIR) spectroscopy is a useful technique for measuring the infrared spectra of solids and liquids as well as probing adsorption on particle surfaces. The use of FTIR-ATR spectroscopy in organic and inorganic chemistry laboratory courses as well as in undergraduate research was presented…

  7. The Discovery-Oriented Approach to Organic Chemistry. 7. Rearrangement of "trans"-Stilbene Oxide with Bismuth Trifluoromethanesulfonate and Other Metal Triflates: A Microscale Green Organic Chemistry Laboratory Experiment

    Science.gov (United States)

    Christensen, James E.; Huddle, Matthew G.; Rogers, Jamie L.; Yung, Herbie; Mohan, Ram S.

    2008-01-01

    Although green chemistry principles are increasingly stressed in the undergraduate curriculum, there are only a few lab experiments wherein the toxicity of reagents is taken into consideration in the design of the experiment. We report a microscale green organic chemistry laboratory experiment that illustrates the utility of metal triflates,…

  8. Developments for transactinide chemistry experiments behind the gas-filled separator TASCA

    International Nuclear Information System (INIS)

    Topic of this thesis is the development of experiments behind the gas-filled separator TASCA (TransActinide Separator and Chemistry Apparatus) to study the chemical properties of the transactinide elements. In the first part of the thesis, the electrodepositions of short-lived isotopes of ruthenium and osmium on gold electrodes were studied as model experiments for hassium. From literature it is known that the deposition potential of single atoms differs significantly from the potential predicted by the Nernst equation. This shift of the potential depends on the adsorption enthalpy of therndeposited element on the electrode material. If the adsorption on the electrode-material is favoured over the adsorption on a surface made of the same element as the deposited atom, the electrode potential is shifted to higher potentials. This phenomenon is called underpotential deposition. Possibilities to automatize an electro chemistry experiment behind the gas-filled separator were explored for later studies with transactinide elements. The second part of this thesis is about the in-situ synthesis of transition-metal-carbonyl complexes with nuclear reaction products. Fission products of uranium-235 and californium-249 were produced at the TRIGA Mainz reactor and thermalized in a carbon-monoxide containing atmosphere. The formed volatile metal-carbonyl complexes could be transported in a gas-stream. Furthermore, short-lived isotopes of tungsten, rhenium, osmium, and iridium were synthesised at the linear accelerator UNILAC at GSI Helmholtzzentrum fuer Schwerionenforschung, Darmstadt. The recoiling fusion products were separated from the primary beam and the transfer products in the gas-filled separator TASCA. The fusion products were stopped in the focal plane of TASCA in a recoil transfer chamber. This chamber contained a carbon-monoxide - helium gas mixture. The formed metal-carbonyl complexes could be transported in a gas stream to various experimental setups. All

  9. Major Successes of Theory-and-Experiment-Combined Studies in Surface Chemistry and Heterogeneous Catalysis.

    Energy Technology Data Exchange (ETDEWEB)

    Somorjai, Gabor A.; Li, Yimin

    2009-11-21

    Experimental discoveries followed by theoretical interpretations that pave the way of further advances by experimentalists is a developing pattern in modern surface chemistry and catalysis. The revolution of modern surface science started with the development of surface-sensitive techniques such as LEED, XPS, AES, ISS and SIMS, in which the close collaboration between experimentalists and theorists led to the quantitative determination of surface structure and composition. The experimental discovery of the chemical activity of surface defects and the trends in the reactivity of transitional metals followed by the explanations from the theoretical studies led to the molecular level understanding of active sites in catalysis. The molecular level knowledge, in turn, provided a guide for experiments to search for new generation of catalysts. These and many other examples of successes in experiment-and-theory-combined studies demonstrate the importance of the collaboration between experimentalists and theorists in the development of modern surface science.

  10. A new Geoengineering Model Intercomparison Project (GeoMIP experiment designed for climate and chemistry models

    Directory of Open Access Journals (Sweden)

    S. Tilmes

    2014-08-01

    Full Text Available A new Geoengineering Model Intercomparison Project (GeoMIP experiment "G4 specified stratospheric aerosols" (short name: G4SSA is proposed to investigate the impact of stratospheric aerosol geoengineering on atmospheric composition, climate, and the environment. In contrast to the earlier G4 GeoMIP experiment, which requires an emission of sulphur dioxide (SO2 into the model, a prescribed aerosol forcing file is provided to the community, to be consistently applied to future model experiments between 2020 and 2100. This stratospheric aerosol distribution, with a total burden of about 2 Tg S has been derived using the ECHAM5-HAM microphysical model, based on a continuous annual tropical emission of 8 Tg SO2 year−1. A ramp-up of geoengineering in 2020 and a ramp-down in 2070 over a period of two years are included in the distribution, while a background aerosol burden should be used for the last 3 decades of the experiment. The performance of this experiment using climate and chemistry models in a multi-model comparison framework will allow us to better understand the significance of the impact of geoengineering and the abrupt termination after 50 years on climate and composition of the atmosphere in a changing environment. The zonal and monthly mean stratospheric aerosol input dataset is available at https://www2.acd.ucar.edu/gcm/geomip-g4-specified-stratospheric-aerosol-data-set.

  11. The Aerosol/Cloud/Ecosystems Mission (ACE)

    Science.gov (United States)

    Schoeberl, Mark

    2008-01-01

    The goals and measurement strategy of the Aerosol/Cloud/Ecosystems Mission (ACE) are described. ACE will help to answer fundamental science questions associated with aerosols, clouds, air quality and global ocean ecosystems. Specifically, the goals of ACE are: 1) to quantify aerosol-cloud interactions and to assess the impact of aerosols on the hydrological cycle and 2) determine Ocean Carbon Cycling and other ocean biological processes. It is expected that ACE will: narrow the uncertainty in aerosol-cloud-precipitation interaction and quantify the role of aerosols in climate change; measure the ocean ecosystem changes and precisely quantify ocean carbon uptake; and, improve air quality forecasting by determining the height and type of aerosols being transported long distances. Overviews are provided of the aerosol-cloud community measurement strategy, aerosol and cloud observations over South Asia, and ocean biology research goals. Instruments used in the measurement strategy of the ACE mission are also highlighted, including: multi-beam lidar, multiwavelength high spectra resolution lidar, the ocean color instrument (ORCA)--a spectroradiometer for ocean remote sensing, dual frequency cloud radar and high- and low-frequency micron-wave radiometer. Future steps for the ACE mission include refining measurement requirements and carrying out additional instrument and payload studies.

  12. PWR Secondary Water Chemistry Control Status: A Summary of Industry Initiatives, Experience and Trends Relative to the EPRI PWR Secondary Water Chemistry Guidelines

    International Nuclear Information System (INIS)

    The latest revision of the EPRI Pressurized Water Reactor (PWR) Secondary Water Chemistry Guidelines was issued in February 2009. The Guidelines continue to focus on minimizing stress corrosion cracking (SCC) of steam generator tubes, as well as minimizing degradation of other major components / subsystems of the secondary system. The Guidelines provide a technically-based framework for a plant-specific and effective PWR secondary water chemistry program. With the issuance of Revision 7 of the Guidelines in 2009, many plants have implemented changes that allow greater flexibility on startup. For example, the previous Guidelines (Revision 6) contained a possible low power hold at 5% power and a possible mid power hold at approximately 30% power based on chemistry constraints. Revision 7 has established a range over which a plant-specific value can be chosen for the possible low power hold (between 5% and 15%) and mid power hold (between 30% and 50%). This has provided plants the ability to establish significant plant evolutions prior to reaching the possible power hold; such as establishing seal steam to the condenser, placing feed pumps in service, or initiating forward flow of heater drains. The application of this flexibility in the industry will be explored. This paper also highlights the major initiatives and industry trends with respect to PWR secondary chemistry; and outlines the recent work to effectively address them. These will be presented in light of recent operating experience, as derived from EPRI's PWR Chemistry Monitoring and Assessment (CMA) program (which contains more than 400 cycles of operating chemistry data). (authors)

  13. LWR severe accident simulation: Iodine behaviour in FPT2 experiment and advances on containment iodine chemistry

    International Nuclear Information System (INIS)

    Highlights: ► Short term gaseous iodine fraction can be produced either in primary circuit or on containment condensing surfaces. ► Gaseous radiolytic reactions convert volatile iodine into non-volatile iodine oxide particulates. ► Alkaline and evaporating sump decrease the iodine volatility in containment. ► Release of volatile iodine from containment surfaces explained the long term stationary residual gaseous iodine concentration. - Abstract: The Phebus Fission Product (FP) Program studies key phenomena of severe accidents in water-cooled nuclear reactors. In the framework of the Phebus program, five in-pile experiments have been performed that cover fuel rod degradation and behaviour of fission products released via the coolant circuit into the containment vessel. The focus of this paper is on iodine behaviour during the Phebus FPT2 test. FPT2 used a 33 GWd/t uranium dioxide fuel enriched to 4.5%, re-irradiated in situ for 7 days to a burn-up of 130 MWd/t. This test was performed to study the impact of steam-poor conditions and boric acid on the fission product chemistry. For the containment vessel, more specifically, the objective was to study iodine chemistry in an alkaline sump under evaporating conditions. The iodine results of the Phebus FPT2 test confirmed many of the essential features of iodine behaviour in the containment vessel provided by the first two Phebus tests, FPT0 and FPT1. These are the existence of an early gaseous iodine fraction, the persistence of low gaseous iodine concentrations and the importance of the sump in suppressing the iodine partitioning from sump to atmosphere. The main new insights provided by the Phebus FPT2 test were the iodine desorption from stainless steel walls deposits and the role of the evaporating sump in further iodine depletion in the containment atmosphere. The current paper presents an interpretation of the iodine behaviour in the FPT2 containment vessel based on dedicated small-scale analytical

  14. Development and Implementation of a Simple, Engaging Acid Rain Neutralization Experiment and Corresponding Animated Instructional Video for Introductory Chemistry Students

    Science.gov (United States)

    Rand, Danielle; Yennie, Craig J.; Lynch, Patrick; Lowry, Gregory; Budarz, James; Zhu, Wenlei; Wang, Li-Qiong

    2016-01-01

    Here we describe an acid rain neutralization laboratory experiment and its corresponding instructional video. This experiment has been developed and implemented for use in the teaching laboratory of a large introductory chemistry course at Brown University. It provides a contextually relevant example to introduce beginner-level students with…

  15. Synthesis of 10-Ethyl Flavin: A Multistep Synthesis Organic Chemistry Laboratory Experiment for Upper-Division Undergraduate Students

    Science.gov (United States)

    Sichula, Vincent A.

    2015-01-01

    A multistep synthesis of 10-ethyl flavin was developed as an organic chemistry laboratory experiment for upper-division undergraduate students. Students synthesize 10-ethyl flavin as a bright yellow solid via a five-step sequence. The experiment introduces students to various hands-on experimental organic synthetic techniques, such as column…

  16. Characterization of High Explosives and Other Energetic Compounds by Computational Chemistry and Molecular Modeling: Experiments for Undergraduate Curriculum

    Science.gov (United States)

    Bumpus, John A.; Lewis, Anne; Stotts, Corey; Cramer, Christopher J.

    2007-01-01

    Experiments suited for the undergraduate instructional laboratory in which the heats of formation of several aliphatic and aromatic compounds are calculated, are described. The experiments could be used to introduce students to commercially available computational chemistry and its thermodynamics, while assess and compare the energy content of…

  17. Electrochemistry of (Dihapto-Buckminster-Fullerene) Pentacarbonyl Tungsten(0): An Experiment for the Inorganic Chemistry Laboratory, Part III

    Science.gov (United States)

    Igartua-Nieves, Elvin; Ocasio-Delgado, Yessenia; Rivera-Pagan, Jose; Cortes-Figueroa, Jose E.

    2007-01-01

    Cyclic voltammetry experiments on [60]fullerene, (C[subscript 60]), and (dihapto-[60]fullerene) pentacarbonyl tungsten(0), ([eta][superscript 2]-C[subscript 60])W(CO)[subscript 5], constitute an educational experiment for the inorganic chemistry laboratory with a primary objective to teach the chemical interpretation of a voltammogram, in…

  18. A Precise, Simple, and Low-Cost Experiment to Determine the Isobaric Expansion Coefficient for Physical Chemistry Students

    Science.gov (United States)

    Pe´rez, Eduardo

    2015-01-01

    The procedure of a physical chemistry experiment for university students must be designed in a way that the accuracy and precision of the measurements is properly maintained. However, in many cases, that requires costly and sophisticated equipment not readily available in developing countries. A simple, low-cost experiment to determine isobaric…

  19. Development of water chemistry data management system and its operational experience

    International Nuclear Information System (INIS)

    The demands on the water chemistry data management in a nuclear power plant have increased every year to ensure the safe and stabilized operation of the nuclear power plant. To increase the reliability of the fuel and equipment, dose reduction, and reduce radioactive waste are some of its objectives. Chemical data evaluation and diagnosis have been conducted by personnel experienced in water chemistry management. In view of these, we planned the development of data processing system which diagnoses the plant by detecting minute indications at an early stage to support the plant operation division and the chemical engineering division. A prototype system has been introduced into Tsuruga Power Station No. 2 unit (PWR, 1.160 MWe), in 1986. Based on this experience, a new system has been developed for both Tsuruga Power Station No. 1 unit (BWR, 357 MWe) and Tokai Second Power Station (BWR, 1.100 MWe), which diagnose the plants by means of chemical symptoms in addition to the same functions as Tsuruga Power Station unit No. 2 has had. This system has been being under partial operation since Apr. 1993. The development and situation after the introduction are reported as follows. (authors). 1 fig., 1 tab., 2 refs

  20. Transient groundwater chemistry near a river: Effects on U(VI) transport in laboratory column experiments

    Science.gov (United States)

    Yin, Jun; Haggerty, Roy; Stoliker, Deborah L.; Kent, Douglas B.; Istok, Jonathan D.; Greskowiak, Janek; Zachara, John M.

    2011-01-01

    In the 300 Area of a U(VI)-contaminated aquifer at Hanford, Washington, USA, inorganic carbon and major cations, which have large impacts on U(VI) transport, change on an hourly and seasonal basis near the Columbia River. Batch and column experiments were conducted to investigate the factors controlling U(VI) adsorption/desorption by changing chemical conditions over time. Low alkalinity and low Ca concentrations (Columbia River water) enhanced adsorption and reduced aqueous concentrations. Conversely, high alkalinity and high Ca concentrations (Hanford groundwater) reduced adsorption and increased aqueous concentrations of U(VI). An equilibrium surface complexation model calibrated using laboratory batch experiments accounted for the decrease in U(VI) adsorption observed with increasing (bi)carbonate concentrations and other aqueous chemical conditions. In the column experiment, alternating pulses of river and groundwater caused swings in aqueous U(VI) concentration. A multispecies multirate surface complexation reactive transport model simulated most of the major U(VI) changes in two column experiments. The modeling results also indicated that U(VI) transport in the studied sediment could be simulated by using a single kinetic rate without loss of accuracy in the simulations. Moreover, the capability of the model to predict U(VI) transport in Hanford groundwater under transient chemical conditions depends significantly on the knowledge of real-time change of local groundwater chemistry.

  1. New Aspects of Ace Inhibition: Importance of ACE co-localization with angiotensin and bradykinin receptors

    NARCIS (Netherlands)

    B. Tom (Beril)

    2003-01-01

    textabstractThe beneficial effect of angiotensin-converting enzyme (ACE) inhibitors in hypertension and heart failure may relate, at least in part, to their capacity to interfere with bradykinin metabolism. In addition, recent studies have provided evidence for bradykinin-potentiating effects of ACE

  2. Color Changes in Indicator Solutions. An Intriguing and Elucidative General Chemistry Experiment

    Science.gov (United States)

    Silva, César R.; Pereira, Renato B.; Sabadini, Edvaldo

    2001-07-01

    The simple dilution of an aqueous solution of the indicator (In) bromocresol green is proposed as an intriguing experiment for students of chemistry. As the solution is diluted with water, its color changes strikingly from reddish to pale blue. These changes are related to changes in the absorption bands in the visible electronic spectra. The pKIn can be determined through the Henderson-Hasselbalch equation by plotting the pH values as a function of log([In-]/[HIn]). The concentration, in mol L-1, of the HIn species can be determined by measuring the absorbance at 440 nm and using the e value determined from the Beer's law plot. [In-] is calculated from the difference between the initial HIn concentration and the observed [HIn]. Students will be able to conclude that the dissociated fraction of a weak acid increases with dilution. See Letter re: this article.

  3. Reducing cognitive load in the chemistry laboratory by using technology-driven guided inquiry experiments

    Science.gov (United States)

    Hubacz, Frank, Jr.

    The chemistry laboratory is an integral component of the learning experience for students enrolled in college-level general chemistry courses. Science education research has shown that guided inquiry investigations provide students with an optimum learning environment within the laboratory. These investigations reflect the basic tenets of constructivism by engaging students in a learning environment that allows them to experience what they learn and to then construct, in their own minds, a meaningful understanding of the ideas and concepts investigated. However, educational research also indicates that the physical plant of the laboratory environment combined with the procedural requirements of the investigation itself often produces a great demand upon a student's working memory. This demand, which is often superfluous to the chemical concept under investigation, creates a sensory overload or extraneous cognitive load within the working memory and becomes a significant obstacle to student learning. Extraneous cognitive load inhibits necessary schema formation within the learner's working memory thereby impeding the transfer of ideas to the learner's long-term memory. Cognitive Load Theory suggests that instructional material developed to reduce extraneous cognitive load leads to an improved learning environment for the student which better allows for schema formation. This study first compared the cognitive load demand, as measured by mental effort, experienced by 33 participants enrolled in a first-year general chemistry course in which the treatment group, using technology based investigations, and the non-treatment group, using traditional labware, investigated identical chemical concepts on five different exercises. Mental effort was measured via a mental effort survey, a statistical comparison of individual survey results to a procedural step count, and an analysis of fourteen post-treatment interviews. Next, a statistical analysis of achievement was

  4. Developments for transactinide chemistry experiments behind the gas-filled separator TASCA

    Energy Technology Data Exchange (ETDEWEB)

    Even, Julia

    2011-12-13

    Topic of this thesis is the development of experiments behind the gas-filled separator TASCA (TransActinide Separator and Chemistry Apparatus) to study the chemical properties of the transactinide elements. In the first part of the thesis, the electrodepositions of short-lived isotopes of ruthenium and osmium on gold electrodes were studied as model experiments for hassium. From literature it is known that the deposition potential of single atoms differs significantly from the potential predicted by the Nernst equation. This shift of the potential depends on the adsorption enthalpy of therndeposited element on the electrode material. If the adsorption on the electrode-material is favoured over the adsorption on a surface made of the same element as the deposited atom, the electrode potential is shifted to higher potentials. This phenomenon is called underpotential deposition. Possibilities to automatize an electro chemistry experiment behind the gas-filled separator were explored for later studies with transactinide elements. The second part of this thesis is about the in-situ synthesis of transition-metal-carbonyl complexes with nuclear reaction products. Fission products of uranium-235 and californium-249 were produced at the TRIGA Mainz reactor and thermalized in a carbon-monoxide containing atmosphere. The formed volatile metal-carbonyl complexes could be transported in a gas-stream. Furthermore, short-lived isotopes of tungsten, rhenium, osmium, and iridium were synthesised at the linear accelerator UNILAC at GSI Helmholtzzentrum fuer Schwerionenforschung, Darmstadt. The recoiling fusion products were separated from the primary beam and the transfer products in the gas-filled separator TASCA. The fusion products were stopped in the focal plane of TASCA in a recoil transfer chamber. This chamber contained a carbon-monoxide - helium gas mixture. The formed metal-carbonyl complexes could be transported in a gas stream to various experimental setups. All

  5. Chemistry Rocks: Redox Chemistry as a Geologic Tool.

    Science.gov (United States)

    Burns, Mary Sue

    2001-01-01

    Applies chemistry to earth science, uses rocks in chemistry laboratories, and teaches about transition metal chemistry, oxidation states, and oxidation-reduction reactions from firsthand experiences. (YDS)

  6. Combined experiment and theory approach in surface chemistry: Stairway to heaven?

    Science.gov (United States)

    Exner, Kai S.; Heß, Franziska; Over, Herbert; Seitsonen, Ari Paavo

    2015-10-01

    In this perspective we discuss how an intimate interaction of experiments with theory is able to deepen our insight into the catalytic reaction system on the molecular level. This strategy is illustrated by discussing various examples from our own research of surface chemistry and model catalysis. The particular examples were carefully chosen to balance the specific strength of both approaches - theory and experiment - and emphasize the benefit of this combined approach. We start with the determination of complex surface structures, where diffraction techniques in combination with theory are clear-cut. The promoter action of alkali metals in heterogeneous catalysis is rationalized with theory and experiment for the case of CO coadsorption. Predictive power of theory is limited as demonstrated with the apparent activity of chlorinated TiO2(110) in the oxidation of HCl: Even if we know all elementary reaction steps of a catalytic reaction mechanism, the overall kinetics may remain elusive and require the application kinetic Monte Carlo simulations. Catalysts are not always stable under reaction conditions and may chemically transform as discussed for the CO oxidation reaction over ruthenium. Under oxidizing reaction conditions ruthenium transforms into RuO2, a process which is hardly understood on the molecular level. Lastly we focus on electrochemical reactions. Here theory is clearly ahead since spectroscopic methods are not available to resolve the processes at the electrode surface.

  7. Introductory Chemistry: A Molar Relaxivity Experiment in the High School Classroom.

    Science.gov (United States)

    Dawsey, Anna C; Hathaway, Kathryn L; Kim, Susie; Williams, Travis J

    2013-07-01

    Dotarem and Magnevist, two clinically available magnetic resonance imaging (MRI) contrast agents, were assessed in a high school science classroom with respect to which is the better contrast agent. Magnevist, the more efficacious contrast agent, has negative side effects because its gadolinium center can escape from its ligand. However, Dotarem, though a less efficacious contrast agent, is a safer drug choice. After the experiment, students are confronted with the FDA warning on Magnevist, which enabled a discussion of drug efficacy versus safety. We describe a laboratory experiment in which NMR spin lattice relaxation rate measurements are used to quantify the relaxivities of the active ingredients of Dotarem and Magnevist. The spin lattice relaxation rate gives the average amount of time it takes the excited nucleus to relax back to the original state. Students learn by constructing molar relaxivity curves based on inversion recovery data sets that Magnevist is more relaxive than Dotarem. This experiment is suitable for any analytical chemistry laboratory with access to NMR. PMID:23929983

  8. Evaluation of the MOCAGE Chemistry Transport Model during the ICARTT/ITOP Experiment

    Science.gov (United States)

    Bousserez, N.; Attie, J. L.; Peuch, V. H.; Michou, M.; Pfister, G.; Edwards, D.; Emmons, L.; Arnold, S.; Heckel, A.; Richter, A.; Shlager, H.; Lewis A.; Avery, M.; Sachse, G.; Browell, E.; Ferrare, R.

    2007-01-01

    We evaluate the Meteo-France global chemistry transport 3D model MOCAGE (MOdele de Chimie Atmospherique a Grande Echelle) using the important set of aircraft measurements collected during the ICARRT/ITOP experiment. This experiment took place between US and Europe during summer 2004 (July 15-August 15). Four aircraft were involved in this experiment providing a wealth of chemical data in a large area including the North East of US and western Europe. The model outputs are compared to the following species of which concentration is measured by the aircraft: OH, H2O2, CO, NO, NO2, PAN, HNO3, isoprene, ethane, HCHO and O3. Moreover, to complete this evaluation at larger scale, we used also satellite data such as SCIAMACHY NO2 and MOPITT CO. Interestingly, the comprehensive dataset allowed us to evaluate separately the model representation of emissions, transport and chemical processes. Using a daily emission source of biomass burning, we obtain a very good agreement for CO while the evaluation of NO2 points out incertainties resulting from inaccurate ratio of emission factors of NOx/CO. Moreover, the chemical behavior of O3 is satisfactory as discussed in the paper.

  9. The Chemistry Experiment Skills Competition to the Innovation and Chemistry Experiment Skills of Undergraduates%实验技能大赛对大学生化学实验技能培养及创新

    Institute of Scientific and Technical Information of China (English)

    赵祥华; 周莉; 王莉敏

    2016-01-01

    围绕实验技能大赛对大学生化学实验技能培养和创新展开简单论述,对当今大学生实验技能薄弱现状作出了具体分析,从化学实验技能大赛的形式以及竞赛在实验技能培养和创新中的作用两个方面作出了全面阐述。实践证明:开展实验技能大赛有利于促进学生化学实验技能的提高、激发学生的学习兴趣并能培养学生的创新能力。%Chemistry experiment skills competition for the innovation and chemistry experiment skills of undergraduates was discussed. A concrete analysis was made on the weak present situation of college students experiment skill, and a comprehensive elaboration about the form of the chemical experiment competition and its function in the training of innovation and chemistry experiment skills of undergraduates. The practice proved that it was beneficial to university students for the improvement of their chemical experiment skills, stimulation of their interests and cultivation of their innovation ability by carrying out experiment skill competition.

  10. Cough Syncope due to ACE Inhibitor

    Directory of Open Access Journals (Sweden)

    Filiz Koc

    2015-09-01

    Full Text Available Syncope is defined as a transient loss of consciousness due to sudden temporary decline in cerebral perfusion. Cough syncope is classically seen in middle aged obese men with obstructive pulmonary disease. In patients that use Angiotensin converting enzyme (ACE inhibitors, a dry persistent cough can emerge due to the side effects of this medication. Seventy years old male patient that use ACE inhibitor for hypertension accepted to the clinic with the complaint of syncope. A bout of coughing has developed during electroencephalography recording and 10 seconds in duration of subcortical like epileptiform discharges were viewed. The ACE inhibitor the patient was receiving was replaced with calcium channel blocker and no complaint was observed during the follow up period. [Cukurova Med J 2015; 40(3.000: 619-622

  11. Results of aerosol code comparisons with releases from ACE MCCI tests

    International Nuclear Information System (INIS)

    Results of aerosol release calculations by six groups from six countries are compared with the releases from ACE MCCI Test L6. The codes used for these calculations included: SOLGASMIX-PV, SOLGASMIX Reactor 1986, CORCON.UW, VANESA 1.01, and CORCON mod2.04/VANESA 1.01. Calculations were performed with the standard VANESA 1.01 code and with modifications to the VANESA code such as the inclusion of various zirconium-silica chemical reactions. Comparisons of results from these calculations were made with Test L6 release fractions for U, Zr, Si, the fission-product elements Te, Ba, Sr, Ce, La, Mo, Ru and control materials Ag and In. Reasonable agreement was obtained between calculations and Test L6 results for the volatile elements Ag, In and Te. Calculated releases of the low volatility fission products ranged from within an order of magnitude to five orders of magnitude of Test L6 values. Releases were over and underestimated by calculations. Poorest agreements were obtained for Mo and Si. In summary: Results of this code comparison effort are useful in assessing progress on fission-product release calculations and in providing guidance with respect to databases and further model development. Conclusions and recommendations are given below. 1. Significant progress has been made by the development of various SOLGASMIX chemical equilibrium codes with extensive databases and the development of the CORCON.UW code which gives better agreement with Test L6 than the CORCON mod2.04/VANESA 1.01 codes. The SOLGASMIX calculations on Test L6 and other ACE MCCI tests have provided valuable contributions on the importance of various species in the melt chemistry and the effects of various test parameters on the release. 2. Although some possible causes for discrepancies between calculated and measured releases have been proposed in this paper, the combined efforts of specialists are needed to identify the causes of discrepancies between the calculated and measured releases for each

  12. Use of Protecting Groups in Carbohydrate Chemistry: An Advanced Organic Synthesis Experiment

    Science.gov (United States)

    Cunha, Anna C.; Pereira, Leticia O. R.; de Souza, Maria Cecília B. V.; Ferreira, Vitor F.

    1999-01-01

    A simple and inexpensive three-step reaction sequence for advanced experimental organic chemistry using D-glucosamine hydrochloride as starting material for the synthesis of 2-amino-2-deoxy-1,3,4,6-tetra-O-acetyl-b-D-glucopyranose hydrochloride is described. D-Glucosamine hydrochloride is a carbohydrate derivative isolated from crab shells. It is inexpensive and readily available from most chemical companies. This reaction sequence is appropriate for teaching undergraduate students the correct use of protecting groups. This is a major concept in organic synthesis and one of the determinant factors in the successful realization of multiple-step synthetic projects. The aim of the experiment is to protect the hydroxyl groups of D-glucosamine leaving its amino group as hydrochloride salt. The experiment deals only with protection and deprotection reactions. All products are crystalline substances. The amino group of d-glucosamine hydrochloride is protected by a condensation reaction with p-methoxybenzaldehyde to produce the Schiff's base as a mixture of a- and b-anomers. The second step involves the protection of all hydroxyl groups by esterification reaction using acetic anhydride, forming the imino-tetraacetate derivative as the b-anomer. The stereospecificity of this reaction at the anomeric center is due to the voluminous imino group at C-2. Removal of the amino protection group of this derivative is the final step, which can be accomplished by a selective acid hydrolysis affording the desired peracylated D-glucosamine hydrochloride.

  13. Zinc addition experience in BWRs under normal and hydrogen addition chemistry

    International Nuclear Information System (INIS)

    Experience at GE BWRs has shown that DZO (Depleted zinc oxide) addition is a viable method for reactor water activity reduction, piping dose rate reduction and radiation worker exposure control, even for plants injecting moderate HWC (Hydrogen water chemistry) for IGSCC (Intergranular stress corrosion crack) mitigation. It is recommended that zinc addition be practiced only with DZO and that reactor water concentrations of 5-10 ppb zinc be maintained during plant operation. Other methods for dose control such as source term reduction and decontamination are also viable but should be evaluated on a cost benefit basis. Plant data supplied from the GE BWRs in this report have been acquired from plants with varying levels of feedwater iron and cobalt input, different decontamination histories and varied operating experience, yet all have observed significant benefits from zinc addition. It is also recommended that HWC be practiced with minimal cycling and that the required level of hydrogen injection for IGSCC control be performed. (J.P.N.)

  14. Remarks on KERMA Factors in ACE files

    Science.gov (United States)

    Konno, C.; Ochiai, K.; Takakura, K.; Sato, S.

    2014-04-01

    Some neutron KERMA factors in ACE files are negative and extremely large if nuclear data libraries do not keep energy-balance. The status of neutron KERMA factors in the official ACE file of ENDF/B-VII.1 is examined. As a result, it is found out that neutron KERMA factors of nuclei more than 200 in ENDF/B-VII.1 have some problems. Effects of the inadequate KERMA factor are also investigated, which are large for neutron heat while those are small for total (neutron + gamma) heat. Users who use only neutron KERMA factors should check if the factors are adequate or not before they use the factors.

  15. Extraction and [superscript 1]H NMR Analysis of Fats from Convenience Foods: A Laboratory Experiment for Organic Chemistry

    Science.gov (United States)

    Hartel, Aaron M.; Moore, Amy C.

    2014-01-01

    The extraction and analysis of fats from convenience foods (crackers, cookies, chips, candies) has been developed as an experiment for a second-year undergraduate organic chemistry laboratory course. Students gravimetrically determine the fat content per serving and then perform a [superscript 1]H NMR analysis of the recovered fat to determine the…

  16. An Advanced Analytical Chemistry Experiment Using Gas Chromatography-Mass Spectrometry, MATLAB, and Chemometrics to Predict Biodiesel Blend Percent Composition

    Science.gov (United States)

    Pierce, Karisa M.; Schale, Stephen P.; Le, Trang M.; Larson, Joel C.

    2011-01-01

    We present a laboratory experiment for an advanced analytical chemistry course where we first focus on the chemometric technique partial least-squares (PLS) analysis applied to one-dimensional (1D) total-ion-current gas chromatography-mass spectrometry (GC-TIC) separations of biodiesel blends. Then, we focus on n-way PLS (n-PLS) applied to…

  17. [60]Fullerene Displacement from (Dihapto-Buckminster-Fullerene) Pentacarbonyl Tungsten(0): An Experiment for the Inorganic Chemistry Laboratory, Part II

    Science.gov (United States)

    Cortes-Figueroa, Jose E.; Moore-Russo, Deborah A.

    2006-01-01

    The kinetics experiments on the ligand-C[subscript 60] exchange reactions on (dihapto-[60]fullerene) pentacarbonyl tungsten(0), ([eta][superscript 2]-C[subscript 60])W(CO)[subscript 5], form an educational activity for the inorganic chemistry laboratory that promotes graphical thinking as well as the understanding of kinetics, mechanisms, and the…

  18. The Quantitative Resolution of a Mixture of Group II Metal Ions by Thermometric Titration with EDTA. An Analytical Chemistry Experiment.

    Science.gov (United States)

    Smith, Robert L.; Popham, Ronald E.

    1983-01-01

    Presents an experiment in thermometric titration used in an analytic chemistry-chemical instrumentation course, consisting of two titrations, one a mixture of calcium and magnesium, the other of calcium, magnesium, and barium ions. Provides equipment and solutions list/specifications, graphs, and discussion of results. (JM)

  19. A Simple Experiment in the Separation of a Solid-Phase Mixture and Infrared Spectroscopy for Introductory Chemistry

    Science.gov (United States)

    Szalay, Paul S.

    2008-01-01

    This experiment was developed as a means of incorporating instrumental analyses into an introductory chemistry laboratory. A two-component solid mixture of caffeine and ibuprofen is separated through a series of solution extractions and precipitation and their relative amounts measured. These compounds were chosen because the combination of…

  20. Synthesis of Hollow Gold-Silver Alloyed Nanoparticles: A "Galvanic Replacement" Experiment for Chemistry and Engineering Students

    Science.gov (United States)

    Jenkins, Samir V.; Gohman, Taylor D.; Miller, Emily K.; Chen, Jingyi

    2015-01-01

    The rapid academic and industrial development of nanotechnology has led to its implementation in laboratory teaching for undergraduate-level chemistry and engineering students. This laboratory experiment introduces the galvanic replacement reaction for synthesis of hollow metal nanoparticles and investigates the optical properties of these…

  1. Temperature and Electron Density Determination on Laser-Induced Breakdown Spectroscopy (LIBS) Plasmas: A Physical Chemistry Experiment

    Science.gov (United States)

    Najarian, Maya L.; Chinni, Rosemarie C.

    2013-01-01

    This laboratory is designed for physical chemistry students to gain experience using laser-induced breakdown spectroscopy (LIBS) in understanding plasma diagnostics. LIBS uses a high-powered laser that is focused on the sample causing a plasma to form. The emission of this plasma is then spectrally resolved and detected. Temperature and electron…

  2. Binary Solid-Liquid Phase Diagram of Phenol and t-Butanol: An Undergraduate Physical Chemistry Experiment

    Science.gov (United States)

    Xu, Xinhua; Wang, Xiaogang; Wu, Meifen

    2014-01-01

    The determination of the solid-liquid phase diagram of a binary system is always used as an experiment in the undergraduate physical chemistry laboratory courses. However, most phase diagrams investigated in the lab are simple eutectic ones, despite the fact that complex binary solid-liquid phase diagrams are more common. In this article, the…

  3. Using an Advanced Computational Laboratory Experiment to Extend and Deepen Physical Chemistry Students' Understanding of Atomic Structure

    Science.gov (United States)

    Hoffman, Gary G.

    2015-01-01

    A computational laboratory experiment is described, which involves the advanced study of an atomic system. The students use concepts and techniques typically covered in a physical chemistry course but extend those concepts and techniques to more complex situations. The students get a chance to explore the study of atomic states and perform…

  4. Sol-Gel Synthesis of a Biotemplated Inorganic Photocatalyst: A Simple Experiment for Introducing Undergraduate Students to Materials Chemistry

    Science.gov (United States)

    Boffa, Vittorio; Yue, Yuanzheng; He, Wen

    2012-01-01

    As part of a laboratory course, undergraduate students were asked to use baker's yeast cells as biotemplate in preparing TiO[subscript 2] powders and to test the photocatalytic activity of the resulting materials. This laboratory experience, selected because of the important environmental implications of soft chemistry and photocatalysis, provides…

  5. Removal of Aromatic Pollutant Surrogate from Water by Recyclable Magnetite-Activated Carbon Nanocomposite: An Experiment for General Chemistry

    Science.gov (United States)

    Furlan, Ping Y.; Melcer, Michael E.

    2014-01-01

    A general chemistry laboratory experiment using readily available chemicals is described to introduce college students to an exciting class of nanocomposite materials. In a one-step room temperature synthetic process, magnetite nanoparticles are embedded onto activated carbon matrix. The resultant nanocomposite has been shown to combine the…

  6. Neonatal ACE inhibition in rats interferes with lung development.

    OpenAIRE

    Lasaitiene, Daina; Chen, Yun; Nannmark, Ulf; Wollmer, Per; Friberg, Peter

    2004-01-01

    The renin-angiotensin system (RAS) is developmentally up-regulated and it is essential for kidney development in several species. Given the fact that the rat lung undergoes postnatal development, the mammalian lung possesses the highest angiotensin-converting enzyme (ACE) levels and ACE activity increases during the first weeks postpartum, we tested the hypothesis that ACE inhibition influences postnatal lung development. Rats were given the ACE inhibitor enalapril (10 mg kg-1) from 0 to 9 da...

  7. 农业院校《基础化学实验》教学中化学史的渗透%Introduction of Chemistry History into the Teaching of Basic Chemistry Experiment of Agricultural Universities

    Institute of Scientific and Technical Information of China (English)

    赵李霞; 付颖; 叶非

    2012-01-01

    基础化学实验课程是高等农业院校基础化学系列课程体系中的重要组成部分。在大一新生《基础化学实验》教学中渗透化学史教育,可以提高学生动手积极性,开拓学生实验思路,改善实验课堂教学效果。%In agricultural universities, basic chemistry experiment is an important part of chemistry curriculums. To freshmen of agricul- tural universities, learning basic chemistry experiment well could make good preparation for their further learning and practices. Introduction chemistry history into the teaching of basic chemistry experiment would improve teaching quality and stimulate students' learning interest.

  8. Bradykinin potentiation by angiotensin-(1-7) and ACE inhibitors correlates with ACE C- and N-domain blockade

    NARCIS (Netherlands)

    B. Tom (Beril); R. de Vries (René); P.R. Saxena (Pramod Ranjan); A.H.J. Danser (Jan)

    2001-01-01

    textabstractACE inhibitors block B(2) receptor desensitization, thereby potentiating bradykinin beyond blocking its hydrolysis. Angiotensin (Ang)-(1-7) also acts as an ACE inhibitor and, in addition, may stimulate bradykinin release via angiotensin II type 2 receptors.

  9. Developing Communities: Serving ACE through Tertiary Education

    Science.gov (United States)

    Sofo, Francesco

    2011-01-01

    Purpose: The purpose of this paper is to review the focus and practice of Adult and Community Education (ACE) as well as its conceptualization and delivery and to suggest parameters for an approach based on excellence, a balanced scorecard and performance to meet community needs. Design/methodology/approach: The review examines key aspects of the…

  10. Heavy-ion-induced production and preseparation of short-livedisotopes for chemistry experiments

    Energy Technology Data Exchange (ETDEWEB)

    Dullmann, Christoph E.; Folden III, Charles M.; Gregorich, Kenneth E.; Hoffman, Darleane C.; Leitner, Daniela; Pang, Gregory K.; Sudowe, Ralf; Zielinski, Peter M.; Nitsche, Heino

    2005-02-24

    Physical separation of short-lived isotopes produced inheavy-ion-induced fusion reactions is a powerful and well know method andoften applied in investigations of the heaviest elements, called thetransactinides (Z>=104). By extracting these isotopes from a recoilseparator, they can be made available for transport to setups locatedoutside the heavily shielded irradiation position such as chemistrysetups. This physical preseparation technique overcomes many limitationscurrently faced in the chemical investigation of transactinides. Here wedescribe the basic principle using relatively short-lived isotopes of thelighter group 4 elements zirconium (Zr) and hafnium (Hf) that are used asanalogs of the lightest transactinide element, rutherfordium (Rf, element104). The Zr and Hf isotopes were produced at the LBNL 88-Inch Cyclotronusing a cocktail of 18O and 50Ti beams and the appropriate targets.Subsequently, the isotopes were physically separated in the BerkeleyGas-filled Separator (BGS) and guided to a Recoil Transfer Chamber (RTC)to transfer them to chemistry setups. The magnetic rigidities of thereaction products in low-pressure helium gas were measured and theiridentities determined with gamma-pectroscopy. Using preseparated isotopeshas the advantages of low background and beam plasma free environment forchemistry experiments. The new possibilities that open up for chemicalinvestigations of transactinide elements are descr ibed. The method canreadily be applied to homologous elements within other groups in theperiodic table.

  11. The adsorption of amino acids and cations onto goethite: a prebiotic chemistry experiment.

    Science.gov (United States)

    Farias, Ana Paula S F; Carneiro, Cristine E A; de Batista Fonseca, Inês C; Zaia, Cássia T B V; Zaia, Dimas A M

    2016-06-01

    Few prebiotic chemistry experiments have assessed the adsorption of biomolecules by iron oxide-hydroxides. The present work investigated the effects of cations in artificial seawaters on the adsorption of Gly, α-Ala and β-Ala onto goethite, and vice versa. Goethite served to concentrate K and Mg cations from solution; these effects could have played important roles in peptide nucleoside formation. Goethite showed low adsorption of Gly and α-Ala. On the other hand, β-Ala (a non-protein amino acid) was highly adsorbed by goethite. Because Gly and α-Ala are the most common amino acids in living beings, and iron oxide-hydroxides are widespread on Earth, additional iron oxides should be studied. Increased ionic strength in artificial seawaters decreased the adsorption of amino acids by goethite. Because Na was highly abundant in the artificial seawater, it showed the highest effect on amino acid adsorption. β-Ala increased the adsorption of K and Ca by goethite, this effect could have been important for peptide synthesis. PMID:26984319

  12. Computational chemistry

    OpenAIRE

    Truhlar, Donald G.; McKoy, Vincent

    2000-01-01

    Computational chemistry has come of age. With significant strides in computer hardware and software over the last few decades, computational chemistry has achieved full partnership with theory and experiment as a tool for understanding and predicting the behavior of a broad range of chemical, physical, and biological phenomena. The Nobel Prize award to John Pople and Walter Kohn in 1998 highlighted the importance of these advances in computational chemistry. With massively parallel computers ...

  13. Field experience with advanced methods of on-line monitoring of water chemistry and corrosion degradation in nuclear power stations

    International Nuclear Information System (INIS)

    Advanced methods for on-line, in-situ water chemistry and corrosion monitoring in nuclear power stations have been developed during the past decade. The terms ''on-line'' and ''in-situ'' characterize approaches involving continuous measurement of relevant parameters in high temperature water, preferably directly in the systems and components and not in removed samples at room temperature. This paper describes the field experience to-date with such methods in terms of three examples: (1) On-line chemistry monitoring of the primary coolant during shutdown of a Type WWER-440 PWR. (2) Redox and corrosion potential measurements in final feedwater preheaters and steam generators of two large KWU PWRs over several cycles of plant operation. (3) Real-time, in-situ corrosion surveillance inside the calundia vault of a CANDU reactor. The way in which water chemistry sensors and corrosion monitoring sensors complement each other is outlined: on-line, in-situ measurement of pH, conductivity and redox potential gives information about the possible corrosivity of the environment. Electrochemical noise techniques display signals of corrosion activity under the actual environmental conditions. A common experience gained from separate use of these different types of sensors has been that new and additional information about plants and their actual process conditions is obtained. Moreover, they reveal the intimate relationship between the operational situation and its consequences for the quality of the working fluid and the corrosion behaviour of the plant materials. On this basis, the efficiency of the existing chemistry sampling and control system can be checked and corrosion degradation can be minimized. Furthermore, activity buildup in the primary circuit can be studied. Further significant advantages can be expected from an integration of these various types of sensors into a common water chemistry and corrosion surveillance system. For confirmation, a complete set of sensors

  14. Experiments in Physical Chemistry, Sixth Edition (by David P. Shoemaker, Carl W. Garland, and Joseph W. Nibler)

    Science.gov (United States)

    Feigerle, Charles S.

    1997-05-01

    McGraw-Hill: New York, 1996. xii + 778 pp. ISBN 0-07-057074-4. Experiments in Physical Chemistry has long been one of the best textbooks available for undergraduate courses in physical chemistry laboratory. The present edition follows a similar format as previous editions, consisting of (i) a series of introductory sections dealing with common aspects of all experiments, such as recording of data, report writing, data and error analysis, and the use of computer software to aide in these, (ii) 48 experiments spanning 12 fundamental areas, and (iii) a series of resource chapters providing an introduction to electronics, instruments, techniques, and procedures commonly utilized in the performance of experiments in physical chemistry. Some needed changes have been incorporated in this edition, most notably the addition of sections that recognize the increased role of computers in modern experimentation. In particular, the section on computer software has been expanded and moved ahead of the experiments. The use of word processing, spreadsheets, and symbolic mathematics programs is emphasized, with examples using some of the most popular commercial programs. Three new experiments have been added and a fourth substantially modified. Each of the 44 other experiments has undergone some review and modernization, and a much-needed section on safety issues has been added to each. A resource chapter on computer interfacing, treating data types, programming languages and interfacing has been added. Examples are given for programming RS-232 communication and analog/digital interface boards using visual basic routines. I recommend this book be given serious consideration as a text for a one- or two-semester course in physical chemistry laboratory. The approach to experimentation in physical chemistry, the experiments, and the techniques that are described can form a solid basis for such a course. My one criticism is that the text offers only a limited number of laser

  15. Carbon cycling and phytoplankton responses within highly-replicated shipboard carbonate chemistry manipulation experiments conducted around Northwest European Shelf Seas

    Science.gov (United States)

    Richier, S.; Achterberg, E. P.; Dumousseaud, C.; Poulton, A. J.; Suggett, D. J.; Tyrrell, T.; Zubkov, M. V.; Moore, C. M.

    2014-03-01

    The ongoing oceanic uptake of anthropogenic carbon dioxide (CO2) is significantly altering the carbonate chemistry of seawater, a phenomenon referred to as ocean acidification. Experimental manipulations have been increasingly used to gauge how continued ocean acidification will potentially impact marine ecosystems and their associated biogeochemical cycles in the future; however, results amongst studies, particularly when performed on natural communities, are highly variable, which in part likely reflects inconsistencies in experimental approach. To investigate the potential for identification of more generic responses and greater experimentally reproducibility, we devised and implemented a series of highly replicated (n = 8), short term (2-4 days) multi-level (≥ 4 conditions) carbonate chemistry/nutrient manipulation experiments on a range of natural microbial communities sampled in Northwest European shelf seas. Carbonate chemistry manipulations and resulting biological responses were found to be highly reproducible within individual experiments and to a lesser extent between geographically different experiments. Statistically robust reproducible physiological responses of phytoplankton to increasing pCO2, characterized by a suppression of net growth for small sized cells (< 10 μm), were observed in the majority of the experiments, irrespective of nutrient status. Remaining between-experiment variability was potentially linked to initial community structure and/or other site-specific environmental factors. Analysis of carbon cycling within the experiments revealed the expected increased sensitivity of carbonate chemistry to biological processes at higher pCO2 and hence lower buffer capacity. The results thus emphasize how biological-chemical feedbacks may be altered in the future ocean.

  16. Phytoplankton responses and associated carbon cycling during shipboard carbonate chemistry manipulation experiments conducted around Northwest European shelf seas

    Science.gov (United States)

    Richier, S.; Achterberg, E. P.; Dumousseaud, C.; Poulton, A. J.; Suggett, D. J.; Tyrrell, T.; Zubkov, M. V.; Moore, C. M.

    2014-09-01

    The ongoing oceanic uptake of anthropogenic carbon dioxide (CO2) is significantly altering the carbonate chemistry of seawater, a phenomenon referred to as ocean acidification. Experimental manipulations have been increasingly used to gauge how continued ocean acidification will potentially impact marine ecosystems and their associated biogeochemical cycles in the future; however, results amongst studies, particularly when performed on natural communities, are highly variable, which may reflect community/environment-specific responses or inconsistencies in experimental approach. To investigate the potential for identification of more generic responses and greater experimentally reproducibility, we devised and implemented a series (n = 8) of short-term (2-4 days) multi-level (≥4 conditions) carbonate chemistry/nutrient manipulation experiments on a range of natural microbial communities sampled in Northwest European shelf seas. Carbonate chemistry manipulations and resulting biological responses were found to be highly reproducible within individual experiments and to a lesser extent between geographically separated experiments. Statistically robust reproducible physiological responses of phytoplankton to increasing pCO2, characterised by a suppression of net growth for small-sized cells (<10 μm), were observed in the majority of the experiments, irrespective of natural or manipulated nutrient status. Remaining between-experiment variability was potentially linked to initial community structure and/or other site-specific environmental factors. Analysis of carbon cycling within the experiments revealed the expected increased sensitivity of carbonate chemistry to biological processes at higher pCO2 and hence lower buffer capacity. The results thus emphasise how biogeochemical feedbacks may be altered in the future ocean.

  17. AceWiki: Collaborative Ontology Management in Controlled Natural Language

    CERN Document Server

    Kuhn, Tobias

    2008-01-01

    AceWiki is a prototype that shows how a semantic wiki using controlled natural language - Attempto Controlled English (ACE) in our case - can make ontology management easy for everybody. Sentences in ACE can automatically be translated into first-order logic, OWL, or SWRL. AceWiki integrates the OWL reasoner Pellet and ensures that the ontology is always consistent. Previous results have shown that people with no background in logic are able to add formal knowledge to AceWiki without being instructed or trained in advance.

  18. AceWiki: Collaborative Ontology Management in Controlled Natural Language

    OpenAIRE

    Kuhn, T.

    2008-01-01

    AceWiki is a prototype that shows how a semantic wiki using controlled natural language - Attempto Controlled English (ACE) in our case - can make ontology management easy for everybody. Sentences in ACE can automatically be translated into first-order logic, OWL, or SWRL. AceWiki integrates the OWL reasoner Pellet and ensures that the ontology is always consistent. Previous results have shown that people with no background in logic are able to add formal knowledge to AceWiki without being in...

  19. ACE-FTS observations of pyrogenic trace species in boreal biomass burning plumes during BORTAS

    Directory of Open Access Journals (Sweden)

    K. A. Tereszchuk

    2012-12-01

    Full Text Available To further our understanding of the effects of biomass burning emissions on atmospheric composition, the Quantifying the impact of BOReal forest fires on Tropospheric oxidants over the Atlantic using Aircraft and Satellites (BORTAS campaign was conducted on 12 July to 3 August 2011 during the Boreal forest fire season in Canada. The simultaneous aerial, ground and satellite measurement campaign sought to record instances of Boreal biomass burning to measure the tropospheric volume mixing ratios (VMRs of short- and long-lived trace molecular species from biomass burning emissions. The goal was to investigate the connection between the composition and the distribution of these pyrogenic outflows and their resulting perturbation to atmospheric chemistry, with particular focus on oxidant species to determine the overall impact on the oxidizing capacity of the free troposphere.

    Measurements of pyrogenic trace species in Boreal biomass burning plumes were made by the Atmospheric Chemistry Experiment Fourier Transform Spectrometer (ACE-FTS onboard the Canadian Space Agency (CSA SCISAT-1 satellite during the BORTAS campaign. Even though most biomass burning smoke is typically confined to the boundary layer, emissions are often injected directly into the upper troposphere via fire-related convective processes, thus allowing space-borne instruments to measure these pyrogenic outflows. An extensive set of 15 molecules, CH3OH, CH4, C2H2, C2H6, C3H6O, CO, HCN, HCOOH, HNO3, H2CO, NO, NO2, OCS, O3 and PAN have been analyzed. Included in this analysis is the calculation of age-dependent sets of enhancement ratios for each of the species.

  20. porewater chemistry experiment at Mont Terri rock laboratory. Reactive transport modelling including bacterial activity

    International Nuclear Information System (INIS)

    Document available in extended abstract form only. An in-situ test in the Opalinus Clay formation, termed pore water Chemistry (PC) experiment, was run for a period of five years. It was based on the concept of diffusive equilibration whereby traced water with a composition close to that expected in the formation was continuously circulated and monitored in a packed off borehole. The main original focus was to obtain reliable data on the pH/pCO2 of the pore water, but because of unexpected microbially- induced redox reactions, the objective was then changed to elucidate the biogeochemical processes happening in the borehole and to understand their impact on pH/pCO2 and pH in the low permeability clay formation. The biologically perturbed chemical evolution of the PC experiment was simulated with reactive transport models. The aim of this modelling exercise was to develop a 'minimal-' model able to reproduce the chemical evolution of the PC experiment, i.e. the chemical evolution of solute inorganic and organic compounds (organic carbon, dissolved inorganic carbon etc...) that are coupled with each other through the simultaneous occurrence of biological transformation of solute or solid compounds, in-diffusion and out-diffusion of solute species and precipitation/dissolution of minerals (in the borehole and in the formation). An accurate description of the initial chemical conditions in the surrounding formation together with simplified kinetics rule mimicking the different phases of bacterial activities allowed reproducing the evolution of all main measured parameters (e.g. pH, TOC). Analyses from the overcoring and these simulations evidence the high buffer capacity of Opalinus clay regarding chemical perturbations due to bacterial activity. This pH buffering capacity is mainly attributed to the carbonate system as well as to the clay surfaces reactivity. Glycerol leaching from the pH-electrode might be the primary organic source responsible for

  1. Operating experience in correcting severe secondary chemistry upsets by controlling makeup water organics (TOC)

    International Nuclear Information System (INIS)

    In this paper following observations are presented: conductivity and chloride excursions in steam condensate were directly linked to makeup water quality. Data strongly suggests that the breakdown of makeup water organics was responsible for substandard condensate water quality; although the short-term effects of gross organic contamination have been documented, the longer term consequences of continuous exposure by moderate organic levels needs to be addressed; a greater understanding of the organic removal efficiency of the various water purification technologies is essential to controlling TOC contamination; and a much better understanding of makeup plant chemistry and the interrelationship of makeup water contamination and plant chemistry has proven essential to optimizing plant performance and guaranteeing the best possible steam chemistry. The role of the chemistry group as an active participant in operations has been proven at Kewaunee Nuclear Plant

  2. An overview of the Chemistry-Aerosol Mediterranean Experiment (ChArMEx)

    Science.gov (United States)

    Dulac, François

    2014-05-01

    The Chemistry-Aerosol Mediterranean Experiment (ChArMEx, http://charmex.lsce.ipsl.fr) is a French initiative of the MISTRALS meta-programme (Mediterranean Integrated Studies at Regional And Locals Scales, http://www.mistrals-home.org). It federates a great number of national and international cooperative research actions aiming at a scientific assessment of the present and future state of the atmospheric environment in the Mediterranean Basin, and of its impacts on the regional climate, air quality, and marine biogeochemistry. The target is short-lived particulate and gaseous tropospheric trace species which are the cause of poor air quality events, have two-way interactions with climate, or impact the marine biogeochemistry, in a context of strong regional anthropogenic and climatic pressures. The six ChArMEx work packages include Emissions, Chemical processes and ageing, Transport processes and air quality, Aerosol-radiation-climate interactions, Deposition, and Present and future variability and trends. For several years, efforts have been deployed in several countries to develop (i) a network of relevant stations for atmospheric chemistry at background sites on islands and continental coasts around the basin and (ii) several intensive field campaigns including the operation of surface supersites and various instrumented mobile platforms (large and ultra-light aircraft, sounding and drifting balloons, ZeroCO2 sailboat). This presentation is an attempt to provide an overview of the various experimental, remote sensing and modelling efforts produced and to highlight major findings, by referencing more detailed ChArMEx presentations given in this conference and recently published or submitted papers. During the first phase of the project experimental efforts have been mainly concentrated on the western basin. Plans for the 2nd phase of ChArMEx, more dedicated towards the eastern basin, will also be given. In particular we plan to develop monitoring activities at

  3. Experience with primary hydrazine water chemistry at WWER-440 units of Paks nuclear power plant

    International Nuclear Information System (INIS)

    1. Control measurements during application of hydrazine water chemistry have shown that, after a brief initial rise, the concentration of corrosion products stabilises at a level lower than that observed with the ammonia cycle. 2. In the case of transitional operating conditions, the rise in insoluble corrosion products is lower with hydrazine water chemistry applied than with the ammonia water chemistry. 3. Lowering of the measured values of radioactive surface contamination and of the dose rates measured in the various primary loops of course proceeds on dissimilar levels, but measured values show a distinct downward trend, both for the case of high and low initial values. 4. The amount of liquid radioactive wastes can be reduced by delaying chemical contamination. 5. Using hydrazine water chemistry also considerably reduces re-contamination through radioactive isotopes, as compared to the effects of chemical decontamination or even ammonia water chemistry. 6. Another important financial profit can be gained by hydrazine water chemistry, as it reduces the collective dose. (orig./CB)

  4. An Overview of the Lightning - Atmospheric Chemistry Aspects of the Deep Convective Clouds and Chemistry (DC3) Experiment

    Science.gov (United States)

    Pickering, K. E.; Barth, M. C.; Koshak, W.; Bucsela, E. J.; Allen, D. J.; Weinheimer, A.; Ryerson, T.; Huntrieser, H.; Bruning, E.; MacGorman, D.; Krehbiel, P.; Thomas, R.; Carey, L.

    2012-01-01

    Some of the major goals of the DC3 experiment are to determine the contribution of lightning to NO(x) in the anvils of observed thunderstorms, examine the relationship of lightning NO(x) production to flash rates and to lightning channel lengths, and estimate the relative production per flash for cloud-to-ground flashes and intracloud flashes. In addition, the effects of lightning NO(x) production on photochemistry downwind of thunderstorms is also being examined. The talk will survey the observation types that were conducted during DC3 relevant to these goals and provide an overview of the analysis and modeling techniques which are being used to achieve them. NO(x) was observed on three research aircraft during DC3 (the NCAR G-V, the NASA DC-8, and the DLR Falcon) in flights through storm anvils in three study regions (NE Colorado, Central Oklahoma to West Texas, and northern Alabama) where lightning mapping arrays (LMAs) and radar coverage were available. Initial comparisons of the aircraft NOx observations in storm anvils relative to flash rates have been conducted, which will be followed with calculations of the flux of NO(x) through the anvils, which when combined with observed flash rates can be used to estimate storm-average lightning NOx production per flash. The WRF-Chem model will be run for cloud-resolved simulations of selected observed storms during DC3. Detailed lightning information from the LMAs (flash rates and flash lengths as a function of time and vertical distributions of flash channel segments) will be input to the model along with assumptions concerning NO(x) production per CG flash and per IC flash. These assumptions will be tested through comparisons with the aircraft NOx data from anvil traverses. A specially designed retrieval method for lightning NO2 column amounts from the OMI instrument on NASA fs Aura satellite has been utilized to estimate NO2 over the region affected by selected DC3 storms. Combined with NO(x) to NO2 ratios from the

  5. Experimental study on iodine chemistry (EXSI) - Containment experiments with methyl iodide

    Energy Technology Data Exchange (ETDEWEB)

    Holm, J.; Ekberg, C. (Chalmers Univ. of Technology, Goeteborg (Sweden)); Kaerkelae, T.; Auvinen, A. (VTT, Espoo (Finland)); Glaenneskog, H. (Vattenfall Power Consultant, Goeteborg (Sweden))

    2011-05-15

    An experimental study on radiolytic decomposition of methyl iodide was conducted in co-operation between VTT and Chalmers University of Technology as a part of the NKS-R programs. In year 2008 the NROI project, a Nordic collaboration studying iodine chemistry in the containment, was started. During year 2008 (NROI-1) the radiolytic oxidation of elemental iodine was investigated and during 2009 (NROI-2), the radiolytic oxidation of organic iodine was studied. This project (NROI-3) is a continuation of the investigation of the oxidation of organic iodine. The project has been divided into two parts. 1. The aims of the first part were to investigate the effect of ozone and UV-radiation, in dry and humid conditions, on methyl iodide. 2. The second project was about gamma radiation (approx20 kGy/h) and methyl iodide in dry and humid conditions. 1. Experimental results showed that the methyl iodide concentration in the facility was reduced with increasing temperature and increasing UV-radiation intensity. Similar behaviour occurred when ozone was present in the system. Formed organic gas species during the decomposition of methyl iodide was mainly formaldehyde and methanol. The particle formation was instant and extensive when methyl iodide was exposed to ozone and/or radiation at all temperatures. The size of the formed primary particles was about 10 nm and the size of secondary particles was between 50-200 nm. From the SEM-EDX analyses of the particles, the conclusion was drawn that these were some kind of iodine oxides (I{sub xO{sub y}). However, the correct speciation of the formed particles was difficult to obtain because the particles melted and fused together under the electron beam. 2. The results from this sub-project are more inconsistent and hard to interpret. The particle formation was significant lesser than corresponding experiments when ozone/UV-radiation was used instead of gamma radiation. The transport of gaseous methyl iodide through the facility was

  6. Climatology and variability of trace gases in extratropical double-tropopause regions from MLS, HIRDLS, and ACE-FTS measurements

    Science.gov (United States)

    Schwartz, M. J.; Manney, G. L.; Hegglin, M. I.; Livesey, N. J.; Santee, M. L.; Daffer, W. H.

    2015-01-01

    Upper tropospheric and lower stratospheric measurements from the Aura Microwave Limb Sounder (MLS), the Aura High Resolution Dynamics Limb Sounder (HIRDLS), and the Atmospheric Chemistry Experiment-Fourier transform spectrometer (ACE-FTS) are used to present the first global climatological comparison of extratropical, nonpolar trace gas distributions in double-tropopause (DT) and single-tropopause (ST) regions. Stratospheric tracers, O3, HNO3, and HCl, have lower mixing ratios ˜2-8 km above the primary (lowermost) tropopause in DT than in ST regions in all seasons, with maximum Northern Hemisphere (NH) differences near 50% in winter and 30% in summer. Southern Hemisphere winter differences are somewhat smaller, but summer differences are similar in the two hemispheres. H2O in DT regions of both hemispheres shows strong negative anomalies in November through February and positive anomalies in July through October, reflecting the strong seasonal cycle in H2O near the tropical tropopause. CO and other tropospheric tracers examined have higher DT than ST values 2-7 km above the primary tropopause, with the largest differences in winter. Large DT-ST differences extend to high NH latitudes in fall and winter, with longitudinal maxima in regions associated with enhanced wave activity and subtropical jet variations. Results for O3 and HNO3 agree closely between MLS and HIRDLS, and differences from ACE-FTS are consistent with its sparse and irregular midlatitude sampling. Consistent signatures in climatological trace gas fields provide strong evidence that transport from the tropical upper troposphere into the layer between double tropopauses is an important pathway for stratosphere-troposphere exchange.

  7. Advanced Customer Oriented Development of Software (ACES

    Directory of Open Access Journals (Sweden)

    Stojan Russev

    2006-12-01

    Full Text Available Object oriented development languages and event driven programming, distributed or centralized data processing with thick or rich clients are used at present in information systems (IS development. Using of existing methodologies and methods In IS designing does not always mean reaching of needed project solution quality. In some cases it is more effective to use combination of structured and object oriented tools or new methodology, which is built according the newest information technologies. One of such methodologies is Advanced Customer Oriented Development of Software (ACES, which is oriented on IS of economic organization development and application of the newest information technologies. ACES was established by the authors at Faculty of Economic Informatics of University of Economics in Bratislava.

  8. 绿色化学与微型有机化学实验研究与实践分析%Research and Practice Analysis of Green Chemistry and Micro-organic Chemistry Experiment

    Institute of Scientific and Technical Information of China (English)

    商桂君

    2014-01-01

    This paper will starts from establishing the people's green awareness to analyzes micro-organic chemistry experiment, and proposes using the concept of green chemistry to reform the organic chemistry experiment teaching, expects to better know the chemistry experiment teaching.%本文将从树立人们的绿色化意识出发,对微型有机化学实验进行深入分析,并提出利用绿色化学的理念对有机化学实验教学进行改革具体措施,以期更好的知道化学实验教学。

  9. Linking the microscopic view of chemistry to real-life experiences: Intertextuality in a high-school science classroom

    Science.gov (United States)

    Wu, Hsin-Kai

    2003-11-01

    Chemistry learning involves establishing conceptual relationships among macroscopic, microscopic, and symbolic representations. Employing the notion of intertextuality to conceptualize these relationships, this study investigates how class members interactionally construct meanings of chemical representations by connecting them to real-life experiences and how the teachers' content knowledge shapes their ways to coconstruct intertextual links with students. Multiple sources of data were collected over 7 weeks with a participation of 25 eleventh graders, an experienced teacher, and a student teacher. An examination of classroom discourse shows that the intertextual links between the microscopic view of chemistry and students' real-life experiences could be initiated by students and instigated by the teachers. The teachers applied several discursive strategies to scaffold students building meaningful links based on their prior knowledge and experiences. Additionally, the experienced teacher with stronger content knowledge tended to present links in both dialogic and monologic discourses. Yet, the relatively limited content knowledge did not necessarily constrain the student teacher's interactions with students. The findings of this study provide a backdrop for further research to explore how chemistry is learned and taught in a class through the social constructivist lens.

  10. Carbon cycling and phytoplankton responses within highly-replicated shipboard carbonate chemistry manipulation experiments conducted around Northwest European Shelf Seas

    Directory of Open Access Journals (Sweden)

    S. Richier

    2014-03-01

    Full Text Available The ongoing oceanic uptake of anthropogenic carbon dioxide (CO2 is significantly altering the carbonate chemistry of seawater, a phenomenon referred to as ocean acidification. Experimental manipulations have been increasingly used to gauge how continued ocean acidification will potentially impact marine ecosystems and their associated biogeochemical cycles in the future; however, results amongst studies, particularly when performed on natural communities, are highly variable, which in part likely reflects inconsistencies in experimental approach. To investigate the potential for identification of more generic responses and greater experimentally reproducibility, we devised and implemented a series of highly replicated (n = 8, short term (2–4 days multi-level (≥ 4 conditions carbonate chemistry/nutrient manipulation experiments on a range of natural microbial communities sampled in Northwest European shelf seas. Carbonate chemistry manipulations and resulting biological responses were found to be highly reproducible within individual experiments and to a lesser extent between geographically different experiments. Statistically robust reproducible physiological responses of phytoplankton to increasing pCO2, characterized by a suppression of net growth for small sized cells (pCO2 and hence lower buffer capacity. The results thus emphasize how biological-chemical feedbacks may be altered in the future ocean.

  11. Exploring Atmospheric Aqueous Chemistry (and Secondary Organic Aerosol Formation) through OH Radical Oxidation Experiments, Droplet Evaporation and Chemical Modeling

    Science.gov (United States)

    Turpin, B. J.; Kirkland, J. R.; Lim, Y. B.; Ortiz-Montalvo, D. L.; Sullivan, A.; Häkkinen, S.; Schwier, A. N.; Tan, Y.; McNeill, V. F.; Collett, J. L.; Skog, K.; Keutsch, F. N.; Sareen, N.; Carlton, A. G.; Decesari, S.; Facchini, C.

    2013-12-01

    Gas phase photochemistry fragments and oxidizes organic emissions, making water-soluble organics ubiquitous in the atmosphere. My group and others have found that several water-soluble compounds react further in the aqueous phase forming low volatility products under atmospherically-relevant conditions (i.e., in clouds, fogs and wet aerosols). Thus, secondary organic aerosol can form as a result of gas followed by aqueous chemistry (aqSOA). We have used aqueous OH radical oxidation experiments coupled with product analysis and chemical modeling to validate and refine the aqueous chemistry of glyoxal, methylglyoxal, glycolaldehyde, and acetic acid. The resulting chemical model has provided insights into the differences between oxidation chemistry in clouds and in wet aerosols. Further, we conducted droplet evaporation experiments to characterize the volatility of the products. Most recently, we have conducted aqueous OH radical oxidation experiments with ambient mixtures of water-soluble gases to identify additional atmospherically-important precursors and products. Specifically, we scrubbed water-soluble gases from the ambient air in the Po Valley, Italy using four mist chambers in parallel, operating at 25-30 L min-1. Aqueous OH radical oxidation experiments and control experiments were conducted with these mixtures (total organic carbon ≈ 100 μM-C). OH radicals (3.5E-2 μM [OH] s-1) were generated by photolyzing H2O2. Precursors and products were characterized using electrospray ionization mass spectrometry (ESI-MS), ion chromatography (IC), IC-ESI-MS, and ultra high resolution Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR-MS). Chemical modeling suggests that organic acids (e.g., oxalate, pyruvate, glycolate) are major products of OH radical oxidation at cloud-relevant concentrations, whereas organic radical - radical reactions result in the formation of oligomers in wet aerosols. Products of cloud chemistry and droplet evaporation have

  12. Variability of the carbonate chemistry in a shallow, seagrass-dominated ecosystem: implications for ocean acidification experiments

    Science.gov (United States)

    Challener, Roberta; Robbins, Lisa L.; Mcclintock, James B.

    2016-01-01

    Open ocean observations have shown that increasing levels of anthropogenically derived atmospheric CO2 are causing acidification of the world's oceans. Yet little is known about coastal acidification and studies are just beginning to characterise the carbonate chemistry of shallow, nearshore zones where many ecologically and economically important organisms occur. We characterised the carbonate chemistry of seawater within an area dominated by seagrass beds (Saint Joseph Bay, Florida) to determine the extent of variation in pH and pCO2 over monthly and daily timescales. Distinct diel and seasonal fluctuations were observed at daily and monthly timescales respectively, indicating the influence of photosynthetic and respiratory processes on the local carbonate chemistry. Over the course of a year, the range in monthly values of pH (7.36-8.28), aragonite saturation state (0.65-5.63), and calculated pCO2 (195-2537 μatm) were significant. When sampled on a daily basis the range in pH (7.70-8.06), aragonite saturation state (1.86-3.85), and calculated pCO2 (379-1019 μatm) also exhibited significant range and indicated variation between timescales. The results of this study have significant implications for the design of ocean acidification experiments where nearshore species are utilised and indicate that coastal species are experiencing far greater fluctuations in carbonate chemistry than previously thought.

  13. Students’ interest and experiences in physics and chemistry related themes: Reflections based on a ROSE-survey in Finland

    Directory of Open Access Journals (Sweden)

    Jari Lavonen

    2008-01-01

    Full Text Available Interest in physics and chemistry topics and out-of-school experiences of Finnish secondary school students (n=3626, median age 15 were surveyed using the international ROSE questionnaire. Based on explorative factor analysis the scores of six out-of-school experience factors (indicating how often students had done something outside of school and eight topic factors (indicating how interested students were in learning about something were studied. The students had a lot of out-of-school experiences in simple measuring and observing and in ICT use, but they had few science and technology related hobbies and activities or experiences of camping. Several gender differences were found. Observing natural phenomena and collecting objects was the most important factor correlating with the topic factors. Factors measuring experiences of ICT use and the use of mechanical tools had the lowest correlations with the topic factors. Based on the results, the implications for science education will be discussed.

  14. PWR primary system chemistry: experience with elevated pH at Millstone Point unit 3

    International Nuclear Information System (INIS)

    This paper describes the results of using elevated pH primary system chemistry for the second cycle of operation of the Millstone Point Unit 3 PWR. A maximum lithium concentration of 3.5 ppm lithium was used, with a maximum pH of 7.4. Radiation fields were approximately 10% higher after the second cycle, compared to an increase of about 25% which was estimated for continued operation with standard pH 6.9 chemistry, which was used in the first cycle. Results of gamma spectroscopy measurements and fuel examination are discussed and future strategy is outlined. (author)

  15. 做好化学实验 发展创新能力%Using Chemistry Experiments to Cultivate Students' Innovative Ability

    Institute of Scientific and Technical Information of China (English)

    曹润红

    2011-01-01

    This paper expounds how to apply chemistry experiments to cultivate students' innovative awareness and innovative ability in chemistry teaching.%本文就笔者在化学教学中,如何利用化学实验对学生进行创新意识和创新能力的培养谈几点做法。

  16. Determining the Quantum Efficiency for Activation of an Organometallic Photoinitiator for Cationic Polymerization: An Experiment for the Physical or Inorganic Chemistry Laboratory

    Science.gov (United States)

    Hayes, David M.; Mahar, Maura; Schnabel, R. Chris; Shah, Paras; Lees, Alistair J.; Jakubek, Vladimir

    2007-01-01

    We present a new laboratory experiment on the photochemistry of organometallic [eta][superscript 5],[eta][superscript 6]-mixed-sandwich compounds, which is suitable for both the physical chemistry and inorganic chemistry laboratory. Specifically, students use 1,10-phenanthroline to trap the intermediate formed when…

  17. Effects of Small Molecule Calcium-Activated Chloride Channel Inhibitors on Structure and Function of Accessory Cholera Enterotoxin (Ace of Vibrio cholerae.

    Directory of Open Access Journals (Sweden)

    Tanaya Chatterjee

    Full Text Available Cholera pathogenesis occurs due to synergistic pro-secretory effects of several toxins, such as cholera toxin (CTX and Accessory cholera enterotoxin (Ace secreted by Vibrio cholerae strains. Ace activates chloride channels stimulating chloride/bicarbonate transport that augments fluid secretion resulting in diarrhea. These channels have been targeted for drug development. However, lesser attention has been paid to the interaction of chloride channel modulators with bacterial toxins. Here we report the modulation of the structure/function of recombinant Ace by small molecule calcium-activated chloride channel (CaCC inhibitors, namely CaCCinh-A01, digallic acid (DGA and tannic acid. Biophysical studies indicate that the unfolding (induced by urea free energy increases upon binding CaCCinh-A01 and DGA, compared to native Ace, whereas binding of tannic acid destabilizes the protein. Far-UV CD experiments revealed that the α-helical content of Ace-CaCCinh-A01 and Ace-DGA complexes increased relative to Ace. In contrast, binding to tannic acid had the opposite effect, indicating the loss of protein secondary structure. The modulation of Ace structure induced by CaCC inhibitors was also analyzed using docking and molecular dynamics (MD simulation. Functional studies, performed using mouse ileal loops and Ussing chamber experiments, corroborate biophysical data, all pointing to the fact that tannic acid destabilizes Ace, inhibiting its function, whereas DGA stabilizes the toxin with enhanced fluid accumulation in mouse ileal loop. The efficacy of tannic acid in mouse model suggests that the targeted modulation of Ace structure may be of therapeutic benefit for gastrointestinal disorders.

  18. Effects of Small Molecule Calcium-Activated Chloride Channel Inhibitors on Structure and Function of Accessory Cholera Enterotoxin (Ace) of Vibrio cholerae

    Science.gov (United States)

    Chatterjee, Tanaya; Sheikh, Irshad Ali; Chakravarty, Devlina; Chakrabarti, Pinak; Sarkar, Paramita; Saha, Tultul; Chakrabarti, Manoj K.; Hoque, Kazi Mirajul

    2015-01-01

    Cholera pathogenesis occurs due to synergistic pro-secretory effects of several toxins, such as cholera toxin (CTX) and Accessory cholera enterotoxin (Ace) secreted by Vibrio cholerae strains. Ace activates chloride channels stimulating chloride/bicarbonate transport that augments fluid secretion resulting in diarrhea. These channels have been targeted for drug development. However, lesser attention has been paid to the interaction of chloride channel modulators with bacterial toxins. Here we report the modulation of the structure/function of recombinant Ace by small molecule calcium-activated chloride channel (CaCC) inhibitors, namely CaCCinh-A01, digallic acid (DGA) and tannic acid. Biophysical studies indicate that the unfolding (induced by urea) free energy increases upon binding CaCCinh-A01 and DGA, compared to native Ace, whereas binding of tannic acid destabilizes the protein. Far-UV CD experiments revealed that the α-helical content of Ace-CaCCinh-A01 and Ace-DGA complexes increased relative to Ace. In contrast, binding to tannic acid had the opposite effect, indicating the loss of protein secondary structure. The modulation of Ace structure induced by CaCC inhibitors was also analyzed using docking and molecular dynamics (MD) simulation. Functional studies, performed using mouse ileal loops and Ussing chamber experiments, corroborate biophysical data, all pointing to the fact that tannic acid destabilizes Ace, inhibiting its function, whereas DGA stabilizes the toxin with enhanced fluid accumulation in mouse ileal loop. The efficacy of tannic acid in mouse model suggests that the targeted modulation of Ace structure may be of therapeutic benefit for gastrointestinal disorders. PMID:26540279

  19. Extraction and Quantitation of FD&C Red Dye #40 from Beverages Containing Cranberry Juice: A College-Level Analytical Chemistry Experiment

    Science.gov (United States)

    Rossi, Henry F., III; Rizzo, Jacqueline; Zimmerman, Devon C.; Usher, Karyn M.

    2012-01-01

    A chemical separation experiment can be an interesting addition to an introductory analytical chemistry laboratory course. We have developed an experiment to extract FD&C Red Dye #40 from beverages containing cranberry juice. After extraction, the dye is quantified using colorimetry. The experiment gives students hands-on experience in using solid…

  20. Teaching Reform of Applied Chemistry Experiment%应用化学实验教学改革

    Institute of Scientific and Technical Information of China (English)

    马学林; 杨威

    2015-01-01

    “应用化学实验”是高等院校应用化学专业学生必修课程之一,也是高校为化工企业输出应用型人才的地方。结合包头化工产业的发展,我校加大对应用化学实验课程教学内容改革,通过应用化学实验教学改革,实现企业、学校与学生三者共赢的局面,并收到显著成效。%Applied Chemistry Experiment "is the basis for compulsory courses to Normal College in Chemis-try, And is a place which provided application -oriented talents to chemical companies .According to the develop-ment of chemical industry in Baotou , The teaching reform of applied chemistry experiment was increased .The win-win situation of companys , colleges and students was realized through the teaching reform .

  1. Insights into aerosol formation chemistry from comprehensive gas-phase precursor measurement in the TRAPOZ chamber experiments; an overview

    Science.gov (United States)

    Carr, Timo; Wyche, Kevin; Monks, Paul S.; Camredon, Marie; Alam, Mohammed S.; Bloss, William J.; Rickard, Andrew R.

    2010-05-01

    Aerosols have a profound affect on the environment on local, regional and even global levels, with impacts including adverse health effects, (Alfarra, Paulsen et al. 2006) visibility reduction, cloud formation, direct radiative forcing (Charlson, Schwartz et al. 1992) and an important role in influencing the climate due to their contribution to important atmospheric processes (Baltensperger, Kalberer et al. 2005; Alfarra, Paulsen et al. 2006). The Total Radical Production from the OZonolysis of alkenes (TRAPOZ) project was used to study the gas phase and radical chemistry along with secondary organic aerosol (SOA) formation for a number of different alkenes and terpenes. In order to better the scientific knowledge regarding the oxidation mechanisms of terpene and alkene species along with radical and SOA formation, the experiments were conducted under varying conditions controlled and monitored by the EUropean PHOto REactor (EUPHORE) simulation chamber in Valencia, Spain. A vast number of instruments enabled a detailed examination of the chemistry within oxidation of each precursor. However the work here will focus on the results obtained from the University of Leicester Chemical Ionisation Reaction Time-of-Flight Mass Spectrometer (CIR-TOF-MS). With regard to the gas phase chemistry an analysis of the degradation of the precursor Volatile Organic Compounds (VOCs) and evolution of certain gas phase species in each experiment has been presented and discussed.

  2. Challenges in Teaching "Colloid and Surface Chemistry"--A Danish Experience

    Science.gov (United States)

    Kontogeorgis, Georgios M.; Vigild, Martin E.

    2009-01-01

    Seven years ago we were asked, as one of our first teaching duties at the Technical University of Denmark (DTU), to teach a 5 ECTS point course on "Colloid and Surface Chemistry". The topic is itself at the same time exciting and demanding, largely due to its multidisciplinary nature. Several "local" requirements posed additional challenges. The…

  3. Experiments and Simulations of Ion-Enhanced Interfacial Chemistry on Aqueous NaCl Aerosols

    Czech Academy of Sciences Publication Activity Database

    Knipping, E. M.; Lakin, M. J.; Foster, K. L.; Jungwirth, Pavel; Tobias, D. J.; Gerber, R. B.; Dabdub, D.; Finlayson-Pitts, B. J.

    2000-01-01

    Roč. 288, - (2000), s. 301-306. ISSN 0036-8075 Grant ostatní: NATO Science Program(XE) CLG-974459 Institutional research plan: CEZ:AV0Z4040901; CEZ:A54/98:Z4-040-9-ii Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 23.872, year: 2000

  4. Incorporating Course-Based Undergraduate Research Experiences into Analytical Chemistry Laboratory Curricula

    Science.gov (United States)

    Kerr, Melissa A.; Yan, Fei

    2016-01-01

    A continuous effort within an undergraduate university setting is to improve students' learning outcomes and thus improve students' attitudes about a particular field of study. This is undoubtedly relevant within a chemistry laboratory. This paper reports the results of an effort to introduce a problem-based learning strategy into the analytical…

  5. Real Science: MIT Reality Show Tracks Experiences, Frustrations of Chemistry Lab Students

    Science.gov (United States)

    Cooper, Kenneth J.

    2012-01-01

    A reality show about a college course--a chemistry class no less? That's what "ChemLab Boot Camp" is. The 14-part series of short videos is being released one episode at a time on the online learning site of the Massachusetts Institute of Technology. The novel show follows a diverse group of 14 freshmen as they struggle to master the laboratory…

  6. Sugar-Cube Science: An Economical Inquiry Experiment for High School Chemistry

    Science.gov (United States)

    Smith, Jennifer

    2010-01-01

    Many first-year chemistry students have memorized the steps of the "scientific method" and can recite them without any prompting. But when introduced to controlled, independent, and dependent variables, they hit a brick wall. Therefore, the author of this article created a lesson that allows students to determine the fastest way to dissolve a…

  7. Quantitative Ultrasound-Assisted Extraction for Trace-Metal Determination: An Experiment for Analytical Chemistry

    Science.gov (United States)

    Lavilla, Isela; Costas, Marta; Pena-Pereira, Francisco; Gil, Sandra; Bendicho, Carlos

    2011-01-01

    Ultrasound-assisted extraction (UAE) is introduced to upper-level analytical chemistry students as a simple strategy focused on sample preparation for trace-metal determination in biological tissues. Nickel extraction in seafood samples and quantification by electrothermal atomic absorption spectrometry (ETAAS) are carried out by a team of four…

  8. The Evolution of a Green Chemistry Laboratory Experiment: Greener Brominations of Stilbene

    Science.gov (United States)

    McKenzie, Lallie C.; Huffman, Lauren M.; Hutchison, James E.

    2005-01-01

    The use of green metrics to compare three bromination laboratory procedures demonstrates the effectiveness of an incremental greening process for chemistry curricula. Due to this process, the bromination of alkenes can be introduced to students through the use of a safe, effective, modern practice.

  9. Offering English-Mediated Chemistry Classes in South Korea: A Note on This Nationwide Experiment

    Science.gov (United States)

    Lee, Jae-Seung

    2010-01-01

    The importance of English as a means of communicating chemical information effectively cannot be overemphasized. Ironically, however, using English as a common language of chemistry might hinder nonnative English speakers from actively participating in major chemical communication. To address this problem, South Korea, where English is not an…

  10. Integrating Chemistry Laboratory Instrumentation into the Industrial Internet: Building, Programming, and Experimenting with an Automatic Titrator

    Science.gov (United States)

    Famularo, Nicole; Kholod, Yana; Kosenkov, Dmytro

    2016-01-01

    This project is designed to improve physical chemistry and instrumental analysis laboratory courses for undergraduate students by employing as teaching tools novel technologies in electronics and data integration using the industrial Internet. The project carried out by upper-division undergraduates is described. Students are exposed to a complete…

  11. U.S. experience with hydrogen water chemistry in boiling water reactors

    International Nuclear Information System (INIS)

    Hydrogen water chemistry in boiling water reactors is currently being adopted by many utilities in the U.S., with eleven units having completed preimplementation test programs, four units operating permanently with hydrogen water chemistry, and six other units in the process of installing permanent equipment. Intergranular stress corrosion cracking protection is required for the recirculation piping system and other regions of the BWR systems. The present paper explores progress in predicting and monitoring hydrogen water chemistry response in these areas. Testing has shown that impurities can play an important role in hydrogen water chemistry. Evaluation of their effects are also performed. Both computer modeling and in plant measurements show that each plant will respond uniquely to feedwater hydrogen addition. Thus, each plant has its own unique hydrogen requirement for recirculation system protecion. Furthermore, the modeling, and plant measurements show that different regions of the BWR respond differently to hydrogen injection. Thus, to insure protection of components other than the recirculation systems may require more (or less) hydrogen demand than indicated by the recirculation system measurements. In addition, impurities such as copper can play a significant role in establishing hydrogen demand. (Nogami, K.)

  12. AceWiki: A Natural and Expressive Semantic Wiki

    CERN Document Server

    Kuhn, Tobias

    2008-01-01

    We present AceWiki, a prototype of a new kind of semantic wiki using the controlled natural language Attempto Controlled English (ACE) for representing its content. ACE is a subset of English with a restricted grammar and a formal semantics. The use of ACE has two important advantages over existing semantic wikis. First, we can improve the usability and achieve a shallow learning curve. Second, ACE is more expressive than the formal languages of existing semantic wikis. Our evaluation shows that people who are not familiar with the formal foundations of the Semantic Web are able to deal with AceWiki after a very short learning phase and without the help of an expert.

  13. HCl and ClO profiles inside the Antarctic vortex as observed by SMILES in November 2009: comparisons with MLS and ACE-FTS instruments

    Directory of Open Access Journals (Sweden)

    T. Sugita

    2013-07-01

    Full Text Available We present vertical profiles of hydrogen chloride (HCl and chlorine monoxide (ClO as observed by the Superconducting Submillimeter-Wave Limb-Emission Sounder (SMILES inside the Antarctic vortex on 19–24 November 2009. The SMILES HCl value reveals 2.8–3.1 ppbv between 450 and 500 K levels in potential temperature (PT. The high value of HCl is highlighted since it is suggested that HCl was a main component of the total inorganic chlorine (Cly, defined as Cly ≃ HCl + ClO + chlorine nitrate (ClONO2 inside the Antarctic vortex in spring, owing to low ozone values. To confirm the quality of two SMILES Level 2 (L2 data products provided by Japan Aerospace Exploration Agency (JAXA and National Institute of Information and Communications Technology (NICT from a view point of the partitioning of Cly, comparisons are made using other satellite data, from the Aura Microwave Limb Sounder (MLS and Atmospheric Chemistry Experiment Fourier Transform Spectrometer (ACE-FTS. HCl values from the SMILES NICT L2 product agree to within 10% with the MLS HCl data between 425 and 650 K levels in PT and with the ACE-FTS HCl data between 425 and 575 K, respectively. The SMILES JAXA L2 product is 10 to 20% smaller than that from MLS (ACE-FTS between 400 (500 K and 700 K. For ClO in daytime, the difference between SMILES (JAXA and NICT and MLS was less than ±0.05 ppbv between 500 and 650 K with the ClO values less than 0.2 ppbv. ClONO2 values as measured by ACE-FTS also reveal 0.2 ppbv at 475–500 K level, resulting in the HCl/Cly ratios of 0.91–0.95. The high HCl value and HCl/Cly ratio found from the three satellite instruments agree with the past observations inside the Antarctic vortex at this time (October to November of year in the lower stratosphere.

  14. HCl and ClO profiles inside the Antarctic vortex as observed by SMILES in November 2009: comparisons with MLS and ACE-FTS instruments

    Science.gov (United States)

    Sugita, T.; Kasai, Y.; Terao, Y.; Hayashida, S.; Manney, G. L.; Daffer, W. H.; Sagawa, H.; Suzuki, M.; Shiotani, M.; Walker, K. A.; Boone, C. D.; Bernath, P. F.

    2013-11-01

    We present vertical profiles of hydrogen chloride (HCl) and chlorine monoxide (ClO) as observed by the Superconducting Submillimeter-Wave Limb-Emission Sounder (SMILES) on the International Space Station (ISS) inside the Antarctic vortex on 19-24 November 2009. The SMILES HCl value reveals 2.8-3.1 ppbv between 450 K and 500 K levels in potential temperature (PT). The high value of HCl is highlighted since it is suggested that HCl is a main component of the total inorganic chlorine (Cly), defined as Cly ≃ HCl + ClO + chlorine nitrate (ClONO2), inside the Antarctic vortex in spring, owing to low ozone values. To confirm the quality of two SMILES level 2 (L2) data products provided by the Japan Aerospace Exploration Agency (JAXA) and Japan's National Institute of Information and Communications Technology (NICT), vis-à-vis the partitioning of Cly, comparisons are made using other satellite data from the Aura Microwave Limb Sounder (MLS) and Atmospheric Chemistry Experiment Fourier Transform Spectrometer (ACE-FTS). HCl values from the SMILES NICT L2 product agree to within 10% (0.3 ppbv) with the MLS HCl data between 450 and 575 K levels in PT and with the ACE-FTS HCl data between 425 and 575 K. The SMILES JAXA L2 product is 10 to 20% (0.2-0.5 ppbv) lower than that from MLS between 400 and 700 K and from ACE-FTS between 500 and 700 K. For ClO in daytime, the difference between SMILES (JAXA and NICT) and MLS is less than ±0.05 ppbv (100 %) between 500 K and 650 K with the ClO values less than 0.2 ppbv. ClONO2 values as measured by ACE-FTS also reveal 0.2 ppbv at 475-500 K level, resulting in the HCl / Cly ratios of 0.91-0.95. The HCl / Cly ratios derived from each retrieval agree to within -5 to 8 % with regard to their averages. The high HCl values and HCl / Cly ratios observed by the three instruments in the lower stratospheric Antarctic vortex are consistent with previous observations in late Austral spring.

  15. Tissue-specific expression of transgenic secreted ACE in vasculature can restore normal kidney functions, but not blood pressure, of Ace-/- mice.

    Directory of Open Access Journals (Sweden)

    Saurabh Chattopadhyay

    Full Text Available Angiotensin-converting enzyme (ACE regulates normal blood pressure and fluid homeostasis through its action in the renin-angiotensin-system (RAS. Ace-/- mice are smaller in size, have low blood pressure and defective kidney structure and functions. All of these defects are cured by transgenic expression of somatic ACE (sACE in vascular endothelial cells of Ace-/- mice. sACE is expressed on the surface of vascular endothelial cells and undergoes a natural cleavage secretion process to generate a soluble form in the body fluids. Both the tissue-bound and the soluble forms of ACE are enzymatically active, and generate the vasoactive octapeptide Angiotensin II (Ang II with equal efficiency. To assess the relative physiological roles of the secreted and the cell-bound forms of ACE, we expressed, in the vascular endothelial cells of Ace-/- mice, the ectodomain of sACE, which corresponded to only the secreted form of ACE. Our results demonstrated that the secreted form of ACE could normalize kidney functions and RAS integrity, growth and development of Ace-/- mice, but not their blood pressure. This study clearly demonstrates that the secreted form of ACE cannot replace the tissue-bound ACE for maintaining normal blood pressure; a suitable balance between the tissue-bound and the soluble forms of ACE is essential for maintaining all physiological functions of ACE.

  16. ACE and ACTN3 genes and muscle phenotypes in nonagenarians

    OpenAIRE

    Bustamante-Ara, Natalia; Santiago Dorrego, Catalina; Verde Rello, Zoraida; Yvert, Thomas; Gómez Gallego, Félix; Rodríguez Romo, Gabriel; González Gil, Pedro; Serra-Rexach, José A.; Ruiz, Jonatan R.; Lucía Mulas, Alejandro

    2010-01-01

    We studied the association of ACE and ACTN3 polymorphisms with skeletal muscle phenotypes (i. e. upper and lower body muscular strength and functional tests) in Spanish nonagenarian subjects [n=41, 33 women, 8 men, age: 90-97 years]. Mean values of the study phenotypes were not significantly different (all P>0.05) between ACE and ACTN3 genotypes. The analyses of the combined effects between genotypes ( ACE DD & ACTN3 RR/RX vs. ACE II/ID & ACTN3 XX) did not yield any significant difference. Ou...

  17. Unraveling the Pivotal Role of Bradykinin in ACE Inhibitor Activity.

    Science.gov (United States)

    Taddei, Stefano; Bortolotto, L

    2016-10-01

    Historically, the first described effect of an angiotensin converting enzyme (ACE) inhibitor was an increased activity of bradykinin, one of the substrates of ACE. However, in the subsequent years, molecular models describing the mechanism of action of ACE inhibitors in decreasing blood pressure and cardiovascular risk have focused mostly on the renin-angiotensin system. Nonetheless, over the last 20 years, the importance of bradykinin in regulating vasodilation, natriuresis, oxidative stress, fibrinolysis, inflammation, and apoptosis has become clearer. The affinity of ACE appears to be higher for bradykinin than for angiotensin I, thereby suggesting that ACE inhibitors may be more effective inhibitors of bradykinin degradation than of angiotensin II production. Data describing the effect of ACE inhibition on bradykinin signaling support the hypothesis that the most cardioprotective benefits attributed to ACE inhibition may be due to increased bradykinin signaling rather than to decreased angiotensin II signaling, especially when high dosages of ACE inhibitors are considered. In particular, modulation of bradykinin in the endothelium appears to be a major target of ACE inhibition. These new mechanistic concepts may lead to further development of strategies enhancing the bradykinin signaling. PMID:27260014

  18. User's manual ACE/ONED (Version 1.0)

    International Nuclear Information System (INIS)

    This report explains installation of ACE/ONED code, structure of input and output, how to prepare input and introduces some sample inputs. ACE/ONED developed by KAERI is a two-group one-dimensional diffusion theory code for nuclear design and reactor simulations. The usage of ACE/ONED encompasses core follow calculation, load-following calculation, plant power control simulation, xenon oscillation simulation, control rod maneuvering, and so on. ACE/ONED programmed of FORTRAN 77 in most part can be run on almost all kinds of computer including personal computer. 4 tabs., 4 figs., 8 refs. (Author) .new

  19. Westinghouse Electric Company experiences in chemistry on-line monitoring in Eastern European nuclear power plants

    International Nuclear Information System (INIS)

    Westinghouse Electric Company has provided a number of Chemistry On-Line Monitoring (OLM) Systems to Nuclear Power Plants in Eastern Europe. Eleven systems were provided to the Temelin Nuclear Power Plant in the south of the Czech Republic. Four systems were provided to the Russian NPP at Novovoronezh. In addition, a system design was developed for primary side chemistry monitoring for units 5 and 6 of another eastern European VVER. The status of the Temelin OLM systems is discussed including updates to the Temelin designs, and the other Eastern European installations and designs are also described briefly. Some of the problems encountered and lessons learned from these projects are also discussed. (R.P.)

  20. Analytical chemistry

    International Nuclear Information System (INIS)

    This book is comprised of nineteen chapters, which describes introduction of analytical chemistry, experimental error and statistics, chemistry equilibrium and solubility, gravimetric analysis with mechanism of precipitation, range and calculation of the result, volume analysis on general principle, sedimentation method on types and titration curve, acid base balance, acid base titration curve, complex and firing reaction, introduction of chemical electro analysis, acid-base titration curve, electrode and potentiometry, electrolysis and conductometry, voltammetry and polarographic spectrophotometry, atomic spectrometry, solvent extraction, chromatograph and experiments.

  1. 物理化学实验的教学改革%The Teaching Reform in Physics And Chemistry Experiment

    Institute of Scientific and Technical Information of China (English)

    谷中明; 李建军

    2001-01-01

    It discussed the method of teaching reform and efficienc e of teaching in physics and chemistry experiment,the contents included:1.Make physics chemistry experimental pattern;2.Fill in terecords list of physics chemi stry experiment;3.Design to complete and solve an assignable experimental data;4 .Be sure to preview before the experiment;5.Re-made the ratio of experimental p rerformance.%本文详尽论述了物理化学实验教学改革的具体措施及教学效果.内容包括:1.制作"物理化学实验模板”;2.填写;3.学生独立设计完成一个指定实验的数据处理过程;4.加强实验前的预习工作;5.调整实验成绩评定的权重系数.

  2. Mortality in patients with hypertension on angiotensin-I converting enzyme (ACE)-inhibitor treatment is influenced by the ACE insertion/deletion polymorphism

    NARCIS (Netherlands)

    Bleumink, GS; Schut, Anna F.C.; Sturkenboom, MCJM; van Duijn, CM; Deckers, JW; Hofman, A; Kingma, J. Herre; Witteman, JCM; Stricker, BHC

    2005-01-01

    Background The response to angiotensin-l converting enzyme (ACE)-inhibitor therapy is highly variable. Residual ACE activity during treatment, potentially modified by the ACE insertion/deletion (I/D) polymorphism, may explain part of this variability. We studied the possible interaction between ACE-

  3. Characterization of angiotensin converting enzyme (ACE) in the testis and assessment of the in vivo effects of the ACE inhibitor perindopril

    Energy Technology Data Exchange (ETDEWEB)

    Jackson, B.; Cubela, R.B.; Sakaguchi, K.; Johnston, C.I.

    1988-07-01

    Angiotensin converting enzyme (ACE) was characterized by radioligand studies utilizing the potent ACE inhibitor 351A, a derivative of lisinopril. Ligand binding characteristics were similar for ACE derived from testis, lung, and kidney, despite known differences in structure between ACe from these sources. This observation suggests that the ACE active enzymatic site is similar in different tissues. The effect of the orally active ACE inhibitor perindopril was studied ex vivo in tissues of the rat after oral gavage. Radioligand bound to tissue ACE was reduced after perindopril treatment, in tissue homogenates of lung and kidney, but not testis. Autoradiographs of radioligand binding to tissue sections obtained ex vivo after oral perindopril showed inhibition of ACE in the aorta, lung, and kidney, but did not reveal any inhibition of ACE in the testis. ACE in small vessels of the testis was inhibited as in the aorta, while at the same time testicular ACE was unaffected. ACE in rat testis appears to have a similar enzymatic binding site to ACE from the lung and kidney. Perindopril inhibited ACE in the lung and kidney but did not affect ACE in the testis, suggesting the drug is limited in testicular penetration by the blood-testis barrier. This may explain the lack of any reports of adverse effects of ACE inhibitors on testicular function.

  4. Micro-abrasion package capture cell experiment on the trailing edge of LDEF: Impactor chemistry and whipple bumper shield efficiencies

    Science.gov (United States)

    Fitzgerald, Howard J.; Yano, Hajime

    1995-01-01

    Four of the eight available double layer microparticle capture cells, flown as the experiment A0023 on the trailing (West) face of LDEF, have been extensively studied. An investigation of the chemistry of impactors has been made using SEM/EDX techniques and the effectiveness of the capture cells as bumper shields has also been examined. Studies of these capture cells gave positive EDX results, with 53 percent of impact sites indicating the presence of some chemical residues, the predominant residue identified as being silicon in varying quantities.

  5. Treating High Blood Pressure: Is an ACE Inhibitor Drug Right for You?

    Science.gov (United States)

    ... High Blood Pressure: Is an ACE Inhibitor Drug Right for You? What are ACE inhibitors? ACE inhibitors, ... talk with your doctor about which drugs are right for you. If your blood pressure is slightly ...

  6. Seasonal variations of acetone in the upper troposphere-lower stratosphere of the northern midlatitudes as observed by ACE-FTS

    Science.gov (United States)

    Dufour, G.; Szopa, S.; Harrison, J. J.; Boone, C. D.; Bernath, P. F.

    2016-05-01

    This study reports on the climatological acetone distribution and seasonal variations in the upper troposphere and lower stratosphere of the northern midlatitudes, derived from observations by the Atmospheric Chemistry Experiment Fourier Transform Spectrometer (ACE-FTS) onboard SCISAT. The acetone profiles retrieved from 5 to ∼20 km cover the period from January 2004 to September 2010. The 1σ statistical fitting errors are typically ∼5-20% within the upper troposphere (UT), increasing in the lower stratosphere (LS) with decreasing acetone. The systematic errors range between 15% and 20%. The largest UT acetone mixing ratios (∼1200 ppt on average in July over Siberia) are observed in summer in the northern mid- and high latitudes. Mixing ratios are larger over continental regions than over the ocean. Comparisons with airborne measurements available in the literature point toward a possible underestimation in acetone retrieved from ACE-FTS. The largest differences occur primarily in winter and for the background values. This underestimation is attributed to the complexity of the spectral region used for the retrieval. The annual cycle of acetone for the 30-70°N midlatitude band shows a maximum during summer, reflecting the annual cycle of the primary terrestrial biogenic source of acetone. By comparison with ACE-FTS, the LMDz-INCA global climate-chemistry model systematically overestimates acetone mixing ratios lower than 400 ppt. This overestimation is thus generalized for the lower stratosphere, the Tropics and beyond 70°N for the upper troposphere. In contrast, in the upper troposphere of the 30-70°N region, where the acetone levels are the highest (>450 ppt on average), the model-observation differences are in the range of the observation uncertainty. However, in this region, the model fails to capture the annual cycle of acetone, culminating in July. A seasonal cycle can only be obtained by considering high biogenic emissions but this cycle is shifted

  7. Validation of ACE-FTS v2.2 measurements of HCl, HF, CCl3F and CCl2F2 using space-, balloon- and ground-based instrument observations

    Directory of Open Access Journals (Sweden)

    C. Servais

    2008-10-01

    Full Text Available Hydrogen chloride (HCl and hydrogen fluoride (HF are respectively the main chlorine and fluorine reservoirs in the Earth's stratosphere. Their buildup resulted from the intensive use of man-made halogenated source gases, in particular CFC-11 (CCl3F and CFC-12 (CCl2F2, during the second half of the 20th century. It is important to continue monitoring the evolution of these source gases and reservoirs, in support of the Montreal Protocol and also indirectly of the Kyoto Protocol. The Atmospheric Chemistry Experiment Fourier Transform Spectrometer (ACE-FTS is a space-based instrument that has been performing regular solar occultation measurements of over 30 atmospheric gases since early 2004. In this validation paper, the HCl, HF, CFC-11 and CFC-12 version 2.2 profile data products retrieved from ACE-FTS measurements are evaluated. Volume mixing ratio profiles have been compared to observations made from space by MLS and HALOE, and from stratospheric balloons by SPIRALE, FIRS-2 and Mark-IV. Partial columns derived from the ACE-FTS data were also compared to column measurements from ground-based Fourier transform instruments operated at 12 sites. ACE-FTS data recorded from March 2004 to August 2007 have been used for the comparisons. These data are representative of a variety of atmospheric and chemical situations, with sounded air masses extending from the winter vortex to summer sub-tropical conditions. Typically, the ACE-FTS products are available in the 10–50 km altitude range for HCl and HF, and in the 7–20 and 7–25 km ranges for CFC-11 and -12, respectively. For both reservoirs, comparison results indicate an agreement generally better than 5–10% above 20 km altitude, when accounting for the known offset affecting HALOE measurements of HCl and HF. Larger positive differences are however found for comparisons with single profiles from FIRS-2 and SPIRALE. For CFCs, the few coincident measurements available suggest that the differences

  8. Validation of ACE-FTS v2.2 measurements of HCl, HF, CCl3F and CCl2F2 using space-, balloon- and ground-based instrument observations

    Directory of Open Access Journals (Sweden)

    C. Tétard

    2008-02-01

    Full Text Available Hydrogen chloride (HCl and hydrogen fluoride (HF are respectively the main chlorine and fluorine reservoirs in the Earth's stratosphere. Their buildup resulted from the intensive use of man-made halogenated source gases, in particular CFC-11 (CCl3F and CFC-12 (CCl2F2, during the second half of the 20th century. It is important to continue monitoring the evolution of these source gases and reservoirs, in support of the Montreal Protocol and also indirectly of the Kyoto Protocol. The Atmospheric Chemistry Experiment Fourier Transform Spectrometer (ACE-FTS is a space-based instrument that has been performing regular solar occultation measurements of over 30 atmospheric gases since early 2004. In this validation paper, the HCl, HF, CFC-11 and CFC-12 version 2.2 profile data products retrieved from ACE-FTS measurements are evaluated. Volume mixing ratio profiles have been compared to observations made from space by MLS and HALOE, and from stratospheric balloons by SPIRALE, FIRS-2 and Mark-IV. Partial columns derived from the ACE-FTS data were also compared to column measurements from ground-based Fourier transform instruments operated at 12 sites. ACE-FTS data recorded from March 2004 to August 2007 have been used for the comparisons. These data are representative of a variety of atmospheric and chemical situations, with sounded air masses extending from the winter vortex to summer sub-tropical conditions. Typically, the ACE-FTS products are available in the 10–50 km altitude range for HCl and HF, and in the 7–20 and 7–25 km ranges for CFC-11 and CFC-12, respectively. For both reservoirs, comparison results indicate an agreement generally better than 5–10%, when accounting for the known offset affecting HALOE measurements of HCl and HF. Larger positive differences are however found for comparisons with single profiles from FIRS-2 and SPIRALE. For CFCs, the few coincident measurements available suggest that the differences probably remain

  9. Sunset-sunrise difference in solar occultation ozone measurements (SAGE II, HALOE, and ACE-FTS) and its relationship to tidal vertical winds

    Science.gov (United States)

    Sakazaki, T.; Shiotani, M.; Suzuki, M.; Kinnison, D.; Zawodny, J. M.; McHugh, M.; Walker, K. A.

    2015-01-01

    This paper contains a comprehensive investigation of the sunset-sunrise difference (SSD, i.e., the sunset-minus-sunrise value) of the ozone mixing ratio in the latitude range of 10° S-10° N. SSD values were determined from solar occultation measurements based on data obtained from the Stratospheric Aerosol and Gas Experiment (SAGE) II, the Halogen Occultation Experiment (HALOE), and the Atmospheric Chemistry Experiment-Fourier transform spectrometer (ACE-FTS). The SSD was negative at altitudes of 20-30 km (-0.1 ppmv at 25 km) and positive at 30-50 km (+0.2 ppmv at 40-45 km) for HALOE and ACE-FTS data. SAGE II data also showed a qualitatively similar result, although the SSD in the upper stratosphere was 2 times larger than those derived from the other data sets. On the basis of an analysis of data from the Superconducting Submillimeter-Wave Limb-Emission Sounder (SMILES) and a nudged chemical transport model (the specified dynamics version of the Whole Atmosphere Community Climate Model: SD-WACCM), we conclude that the SSD can be explained by diurnal variations in the ozone concentration, particularly those caused by vertical transport by the atmospheric tidal winds. All data sets showed significant seasonal variations in the SSD; the SSD in the upper stratosphere is greatest from December through February, while that in the lower stratosphere reaches a maximum twice: during the periods March-April and September-October. Based on an analysis of SD-WACCM results, we found that these seasonal variations follow those associated with the tidal vertical winds.

  10. Experience with turbulence interaction and turbulence-chemistry models at Fluent Inc.

    Science.gov (United States)

    Choudhury, D.; Kim, S. E.; Tselepidakis, D. P.; Missaghi, M.

    1995-01-01

    This viewgraph presentation discusses (1) turbulence modeling: challenges in turbulence modeling, desirable attributes of turbulence models, turbulence models in FLUENT, and examples using FLUENT; and (2) combustion modeling: turbulence-chemistry interaction and FLUENT equilibrium model. As of now, three turbulence models are provided: the conventional k-epsilon model, the renormalization group model, and the Reynolds-stress model. The renormalization group k-epsilon model has broadened the range of applicability of two-equation turbulence models. The Reynolds-stress model has proved useful for strongly anisotropic flows such as those encountered in cyclones, swirlers, and combustors. Issues remain, such as near-wall closure, with all classes of models.

  11. ACE and AGTR1 polymorphisms in elite rhythmic gymnastics.

    Science.gov (United States)

    Di Cagno, Alessandra; Sapere, Nadia; Piazza, Marina; Aquino, Giovanna; Iuliano, Enzo; Intrieri, Mariano; Calcagno, Giuseppe

    2013-02-01

    In the angiotensin-converting enzyme (ACE) gene, Alu deletion, in intron 16, is associated with higher concentrations of ACE serum activity and this may be associated with elite sprint and power performance. The Alu insertion is associated with lower ACE levels and this could lead to endurance performance. Moreover, recent studies have identified a single-nucleotide polymorphism of the angiotensin type 1 receptor gene AGTR1, which seems to be related to ACE activity. The aim of this study was to examine the involvement of the ACE and the AGTR1 gene polymorphisms in 28 Italian elite rhythmic gymnasts (age range 21 ± 7.6 years), and compare them to 23 middle level rhythmic gymnasts (age range 17 ± 10.9 years). The ACE D allele was significantly more frequent in elite athletes than in the control population (χ(2)=4.07, p=0.04). Comparisons between the middle level and elite athletes revealed significant differences (p<0.0001) for the ACE DD genotype (OR=6.48, 95% confidence interval=1.48-28.34), which was more frequent in elite athletes. There were no significant differences in the AGTR1 A/C genotype or allele distributions between the middle level and elite athletes. In conclusion, the ACE D allele genotype could be a contributing factor to high-performance rhythmic gymnastics that should be considered in athlete development and could help to identify which skills should be trained for talent promotion. PMID:23145508

  12. Virginia Tech Hosts One Of Nation's 37 ACE Fellows

    OpenAIRE

    Cox, Clara B.

    2003-01-01

    Diane Bell, professor of anthropology and director of women's studies at George Washington University and one of 37 American Council on Education (ACE) Fellows, will spend the current academic year in the provost's office at Virginia Tech, examining the globalization efforts of the university and its core curriculum as part of her ACE fellowship.

  13. CO[subscript 2] Investigations: An Open Inquiry Experiment for General Chemistry

    Science.gov (United States)

    Stout, Roland P.

    2016-01-01

    This paper presents a successful, free inquiry experiment in which students devise an experiment to measure carbon dioxide in an important chemical, biological, or environmental situation. Also discussed is rationale for adopting an open inquiry experiment and how it fits into the laboratory as a whole. Typical student projects are given, and data…

  14. Circulation and Integration of Medical Chemistry Experiment%医学化学实验的循环与整合

    Institute of Scientific and Technical Information of China (English)

    余录; 胡光强; 杜曦; 陈碧琼

    2015-01-01

    The circulation and integration of experiment are important measures to save the resources and improve teaching quality.According to the problems existing in medical chemistry experiment including too much specialties, complex branches of chemistry sciences and restricted hardware facilities, our teaching team explorated coressponding measures for circulation and integration including the adjustment of experimental hours, replanning the sequence of experimental rotation and reusing the resources, which promoted the improvement and development of experimental teaching.%实验循环与整合是节约教育资源、提高教学质量的重要举措。针对医学化学实验存在专业众多、学科分支繁杂,实验室硬件设施局限等问题,教学团队探索了相应的循环与整合方案,包括调整实验课时、重新规划实验轮序及循环利用资源等,促进了实验教学的提高和发展。

  15. The angiotensin-converting enzyme (ACE) gene insertion/ deletion dimorphism tracks with higher serum ace activities in both younger and older subjects

    International Nuclear Information System (INIS)

    The absence of a 287 base pair alu sequence in the ACE gene (D allele) is associated with higher ACE levels than its presence (I allele) in adults. We carried out a case control study of thr ACE*I/D dimorphism in relation to circulating ACE activities to evaluate associations between the two variables in adults, compared to younger (18 years or less) individuals. Genotypes of the ACE*I/D dimorphism were determined on DNA samples from a population of 164 random (unrelated) Emirtaes nationals, composed of groups: 112 subjects above 18 years of age (range=20-77), and 52 subjects of 18 years or less (range=1-18) and analyzed for putative associations with serum ACE activities. ACE*I/D genotypes of the 164 individualds were determined by assays based on polymerase chain reaction. ACE activities were determined on serum samples of these subjects bu colorimetric assays. The D allele was associared with increasd ACE values in both adult and younger individuals. Mean ACE activity levels associated with II, ID and DD genotypes, however, were 42%-61% higher in the 18 years and under group of subjects. The ACE*I/D marker accounted for 28% of the variance of the phenomenon determining ACE levels in adults, and for 30% among youngsters. The ACE*I/D dimorphism is correlated strongly with circulating ACE activities in both and young Emirati, subjects and the corresponding mean ACE activities were significantly higher among the youngsters. (author)

  16. Experience and the arts: An examination of an arts-based chemistry class

    Science.gov (United States)

    Wunsch, Patricia Ann

    Many high school students are either intimidated or unmotivated when faced with science courses taught with a traditional teaching methodology. The focus of this study was the integration of the arts, specifically the Creative Arts Laboratory (CAL) approach, into the teaching methodology and assessment of a high school chemistry class, with particular interest in what occurs from the point of view of the students and the teacher throughout the integration. Using a case study design, research questions were developed that looked at the effects of arts-integration on the students and teacher in a high school chemistry class; what strategies of arts integration were viewed positively and negatively by the students and teacher; and what role the arts may play in the formation of a new approach to the high school science curriculum. The levels of student engagement and participation were changed and thusly viewed positively by both students and teacher. Specifically, group work that allowed students to choose various arts elements to depict chemistry concepts was considered most favorably. The role of the teacher shifted from a teacher-centered design to a more student-centered environment. Classroom activities that garnered the most student engagement included peer-to-peer review through the critique process and the reinforcement of vocabulary definitions through movement activities. Negative student reviews of the integration were noted when time constraints prevented them from completing their projects to their own standards of satisfaction. However, within this study, the arts allowed many students of varying learning abilities to potentially grasp and understand scientific concepts in new and individual ways, which reinforces an inquiry-based scientific method. Further research is necessary to determine how to prepare teachers to use varying teaching methodologies including the CAL method. Moreover, high school science curricula need to be reviewed to potentially

  17. Two decades of experience with steam-water chemistry maintenance of fast breeder test reactor

    International Nuclear Information System (INIS)

    Fast Breeder Test Reactor (FBTR) at Kalpakkam is a 40 MWt, loop type, sodium cooled fast reactor. The fission heat generated in the core is extracted by primary sodium circuit and the thermal energy is transferred to non-radioactive liquid sodium in the secondary circuit which in turn, heats Once Through-type shell and tube counter current Steam Generator (OTSG) for producing super heated steam at 480 °C and 125 kg/cm2. This secondary circuit is provided to avoid the ingress of hydrogenous materials and pressure surges reaching the core in the event of SG tube leak. Corrosion related problems are very less in the sodium circuits due to the absence of electrochemical reaction. The OTSG consists of four modules each of 12.5 MWt rating. OTSG was chosen due to its higher thermal efficiency and lesser inventory of steam/water in OTSG as it reduces the severity of sodium-water reaction, in case of tube leak. From the point of view of corrosion and deposition, the chemistry specifications are more stringent for OTSG than those of drum type boilers because 100 % conversion of feed water into steam takes place in OTSG. The chemistry requirements are achieved by providing ion exchange resin based online condensate polishing to remove ionic and suspended impurities. Dissolved Oxygen and pH are maintained by all volatile treatment (AVT) using hydrazine and ammonia respectively. Being a test reactor, a dump condenser with 100 % steam dump facility with cupro-nickel tubes is available for uninterrupted reactor operation during the non-availability of turbine. Regenerative feed heating by the exhausted steam from the turbine is also available to stage heaters and deaerator. Efficient water chemistry control plays important role in minimizing corrosion related failures of steam generator tubes and ensuring steam generator tube integrity. This paper describes the operational difficulties such as premature exhaustion of CPU, impurity pick up from the system, silica excursion

  18. Organometallic Chemistry of Molybdenum.

    Science.gov (United States)

    Lucas, C. Robert; Walsh, Kelly A.

    1987-01-01

    Suggests ways to avoid some of the problems students have learning the principles of organometallic chemistry. Provides a description of an experiment used in a third-year college chemistry laboratory on molybdenum. (TW)

  19. Overview of the Chemistry-Aerosol Mediterranean Experiment/Aerosol Direct Radiative Forcing on the Mediterranean Climate (ChArMEx/ADRIMED) summer 2013 campaign

    OpenAIRE

    Mallet, Marc; Dulac, François; Formenti, Paola; Nabat, Pierre; Sclare, J.; Roberts, Gregory; Pelon, Jacques; Ancellet, Gérard; Tanré, Didier; Parol, Frédéric; A. di Sarra; Alados, L.; Arndt, J.; Auriol, Frédérique; L. Blarel

    2015-01-01

    The Chemistry-Aerosol Mediterranean Experiment (ChArMEx; http://charmex.lsce.ipsl.fr) is a collaborative research program federating international activities to investigate Mediterranean regional chemistry-climate interactions. A special observing period (SOP-1a) including intensive airborne measurements was performed in the framework of the Aerosol Direct Radiative Forcing on the Mediterranean Climate (ADRIMED) project during the Mediterranean dry season over the western and central Mediterr...

  20. Overview of the Chemistry-Aerosol Mediterranean Experiment/Aerosol Direct Radiative Forcing on the Mediterranean Climate (ChArMEx/ADRIMED) summer 2013 campaign

    OpenAIRE

    M. Mallet; Dulac, F.; Formenti, P.; P. Nabat; Sciare, J; Roberts, G; Pelon, J.; G. Ancellet; Tanré, D.; F. Parol; A. di Sarra; Alados, L.; Arndt, J; F. Auriol; Blarel, L.

    2015-01-01

    The Chemistry-Aerosol Mediterranean Experiment (ChArMEx; http://charmex.lsce.ipsl.fr) is a collaborative research program federating international activities to investigate Mediterranean regional chemistry-climate interactions. A special observing period (SOP-1a) including intensive airborne measurements was performed in the framework of the Aerosol Direct Radiative Forcing on the Mediterranean Climate (ADRIMED) project during the Mediterranean dry season ove...

  1. Overview of the Chemistry-Aerosol Mediterranean Experiment/Aerosol Direct Radiative Forcing on the Mediterranean Climate (ChArMEx/ADRIMED) summer 2013 campaign

    OpenAIRE

    Mallet, Marc; DULAC, FRANÇOIS; Formenti, Paola; Nabat, Pierre; Sclare, J.; Roberts, Gregory; Pelon, Jacques; Ancellet, Gérard; Tanré, Didier; Parol, Frédéric; A. Di Sarra; L. Alados; Arndt, J; Auriol, Frédérique; Blarel, L.

    2015-01-01

    International audience The Chemistry-Aerosol Mediterranean Experiment (ChArMEx; http://charmex.lsce.ipsl.fr) is a collaborative research program federating international activities to investigate Mediterranean regional chemistry-climate interactions. A special observing period (SOP-1a) including intensive airborne measurements was performed in the framework of the Aerosol Direct Radiative Forcing on the Mediterranean Climate (ADRIMED) project during the Mediterranean dry season over the we...

  2. Adverse Childhood Experiences and Childhood Autobiographical Memory Disturbance

    Science.gov (United States)

    Brown, David W.; Anda, Robert F.; Edwards, Valerie J.; Felitti, Vincent J.; Dube, Shanta R.; Giles, Wayne H.

    2007-01-01

    Objective: To examine relationships between childhood autobiographical memory disturbance (CAMD) and adverse childhood experiences (ACEs) which are defined as common forms of child maltreatment and related traumatic stressors. Methods: We use the ACE score (an integer count of eight different categories of ACEs) as a measure of cumulative exposure…

  3. How Much Cranberry Juice Is in Cranberry-Apple Juice? A General Chemistry Spectrophotometric Experiment

    Science.gov (United States)

    Edionwe, Etinosa; Villarreal, John R.; Smith, K. Christopher

    2011-01-01

    A laboratory experiment that spectrophotometrically determines the percent of cranberry juice in cranberry-apple juice is described. The experiment involves recording an absorption spectrum of cranberry juice to determine the wavelength of maximum absorption, generating a calibration curve, and measuring the absorbance of cranberry-apple juice.…

  4. Using Mole Ratios of Electrolytic Products of Water for Analysis of Household Vinegar: An Experiment for the Undergraduate Physical Chemistry Laboratory

    Science.gov (United States)

    Dabke, Rajeev B.; Gebeyehu, Zewdu

    2012-01-01

    A simple 3-h physical chemistry undergraduate experiment for the quantitative analysis of acetic acid in household vinegar is presented. The laboratory experiment combines titration concept with electrolysis and an application of the gas laws. A vinegar sample was placed in the cathode compartment of the electrolysis cell. Electrolysis of water…

  5. Chlorine activation in the Arctic winter of 2009/2010 analyzed by combined use of JEM/SMILES and ACE-FTS

    Science.gov (United States)

    Yuji, T.; Saitoh, N.; Sugita, T.; Kasai, Y.

    2013-12-01

    The Superconducting Submillimeter-Wave Limb-Emission Sounder (SMILES) equipped in the Japanese Experiment Module "KIBO" on board the International Space Station (ISS) had observed atmospheric minor constituents including ClO in the stratosphere and mesosphere from October 12, 2009 to April 21, 2010 with more than ten times the precision of other existing sensors due to its unprecedented high sensitivity with superconducting technology. The Atmospheric Chemistry Experiment-Fourier Transform Spectrometer (ACE-FTS), which is on board SCISAT-1, has been observing atmospheric minor constituents in the upper troposphere and stratosphere since March 11, 2004 by solar occultation technique. We have analyzed the SMILES Level 2 (L2) V2.1.5 research products and the ACE-FTS L2 V3.0 products to discuss the relationship between temperature and stratospheric minor gases related to ozone depletion and the time variation of 'Cl partitioning' in the Arctic winter of 2009/2010. The correlation between the SMILES L2r ClO concentration and temperature on 475 K and 525 K from mid-January to early February showed that the ClO concentrations were higher than 0.5 ppbv at equivalent latitudes higher than 70° and solar zenith angles lower than 96°, where the temperatures were well lower than 200 K; the ClO concentrations and the solar zenith angles had a positive correlation in the region where the ClO concentrations were higher than 0.5 ppbv. However, some data with high ClO concentration also occurred under relatively warmer conditions where PSCs were not expected to exist. The temperature histories of those data showed that they had experienced near ice frost point of ~187 K at 2-4 days before the observations, and then the temperatures drastically increased as much as 20 degrees just before the observations. We have analyzed a time-series of 'Cl partitioning' by using ClO, HOCl, and HCl observed by SMILES and HCl and ClONO2 observed by ACE-FTS inside the polar vortex in 2009/2010. HCl

  6. The Blue Bottle Reaction as a General Chemistry Experiment on Reaction Mechanisms

    Science.gov (United States)

    Engerer, Steven C.; Cook, A. Gilbert

    1999-11-01

    A kinetics/reaction mechanism experiment using the classic blue bottle reaction is described. Using the scientific method (observe, question, hypothesize, experiment, repeat) students propose and test possible reaction mechanisms for the methylene blue-catalyzed oxidation of dextrose with its dramatic color change. Students are led to discover the three-step mechanism through a series of questions. An advanced version for honors lab courses is also suggested.

  7. A Coupled Programme of Aerosol Research Within the OP3 and ACES Projects

    Science.gov (United States)

    McFiggans, G.; Aces Aerosol Teams, P A

    2008-12-01

    The oxidation of organic compounds in the troposphere plays a central role in the generation of ozone, and leads to the formation of secondary organic aerosol (SOA) and other secondary pollutants. Approximately 90% of organic material emitted globally is estimated to originate from biogenic sources, with almost half of all reactive biogenic volatile organic compounds (BVOC) being emitted from tropical and sub-tropical forests. It is becoming increasingly clear from observational studies that biogenic SOA (BSOA) is the dominant source of aerosol organic carbon concentrations in remote environments. This provides part of the motivation for the OP3 project. Ground-based aerosol measurements at the Global Atmosphere Watch (GAW) site in Danum Valley Conservation Area in OP3 were provided by a suite of instrumentation for full composition and physical property characterisation (size distribution, hygroscopicity and CCN activation). To further enhance our understanding of aerosol processes in the Borneo rainforest, additional capability was assembled within the UK NERC funded "Aerosol Coupling in the Earth System" (ACES) programme. Field component enhancements to the OP3 aerosol payload by ACES included a deployment of aerosol and precursor flux measurements within the forest canopy to characterise primary bioaerosol sources and in-canopy chemistry leading to formation of secondary aerosol components. In addition, measurements of VOCs and aerosol composition were made above an oil palm plantation to assess the impact of land-use change on aerosol processes. ACES is a coupled programme of field, chamber, mechanism development and modelling investigations aiming to reduce uncertainties in our fundamental understanding of BSOA formation and the subsequent impact on atmospheric composition. In addition to summarising aerosol field measurements within ACES / OP3, we will present an overview of the status of the ACES chamber and modelling results with the overall aim to: i

  8. Introducing Undergraduate Students to Electrochemistry: A Two-Week Discovery Chemistry Experiment

    Science.gov (United States)

    Mills, Kenneth V.; Herrick, Richard S.; Guilmette, Louise W.; Nestor, Lisa P.; Shafer, Heather; Ditzler, Mauri A.

    2008-01-01

    Within the framework of a laboratory-focused, guided-inquiry pedagogy, students discover the Nernst equation, the spontaneity of galvanic cells, concentration cells, and the use of electrochemical data to calculate equilibrium constants. The laboratory experiment we describe here is a continuation of curriculum reform and pedagogical innovation at…

  9. Synthesis of Carbon Nanotube-Inorganic Hybrid Nanocomposites: An Instructional Experiment in Nanomaterials Chemistry

    Science.gov (United States)

    de Dios, Miguel; Salgueirino, Veronica; Perez-Lorenzo, Moises; Correa-Duarte, Miguel A.

    2012-01-01

    An experiment is described to introduce advanced undergraduate students to an exciting area of nanotechnology that incorporates nanoparticles onto carbon nanotubes to produce systems that have valuable technological applications. The synthesis of such material has been easily achieved through a simple three-step procedure. Students explore…

  10. NMR Determination of Hydrogen Bond Thermodynamics in a Simple Diamide: A Physical Chemistry Experiment

    Science.gov (United States)

    Morton, Janine G.; Joe, Candice L.; Stolla, Massiel C.; Koshland, Sophia R.; Londergan, Casey H.; Schofield, Mark H.

    2015-01-01

    Variable temperature NMR spectroscopy is used to determine the ?H° and ?S° of hydrogen bond formation in a simple diamide. In this two- or three-day experiment, students synthesize N,N'-dimethylmalonamide, dimethylsuccinamide, dimethylglutaramide, or dimethyladipamide from methylamine and the corresponding diester (typically in 50% recrystallized…

  11. Instrumental Analysis of Biodiesel Content in Commercial Diesel Blends: An Experiment for Undergraduate Analytical Chemistry

    Science.gov (United States)

    Feng, Z. Vivian; Buchman, Joseph T.

    2012-01-01

    The potential of replacing petroleum fuels with renewable biofuels has drawn significant public interest. Many states have imposed biodiesel mandates or incentives to use commercial biodiesel blends. We present an inquiry-driven experiment where students are given the tasks to gather samples, develop analytical methods using various instrumental…

  12. Quantitative Investigations of Biodiesel Fuel Using Infrared Spectroscopy: An Instrumental Analysis Experiment for Undergraduate Chemistry Students

    Science.gov (United States)

    Ault, Andrew P.; Pomeroy, Robert

    2012-01-01

    Biodiesel has gained attention in recent years as a renewable fuel source due to its reduced greenhouse gas and particulate emissions, and it can be produced within the United States. A laboratory experiment designed for students in an upper-division undergraduate laboratory is described to study biodiesel production and biodiesel mixing with…

  13. The Radiative Decay of Green and Red Photoluminescent Phosphors: An Undergraduate Kinetics Experiment for Materials Chemistry

    Science.gov (United States)

    Esposti, C. Degli; Bizzocchi, L.

    2008-01-01

    This article describes a laboratory experiment that allows the students to investigate the radiative properties of the green and red emitting phosphors that are employed in commercial fluorescent lamps. Making use of a spectrofluorometer, students first record the emission spectrum of a fluorescent lamp under normal operating conditions, and then…

  14. Quenching of Tryptophan Fluorescence in Unfolded Cytochrome "c": A Biophysics Experiment for Physical Chemistry Students

    Science.gov (United States)

    Schlamadinger, Diana E.; Kats, Dina I.; Kim, Judy E.

    2010-01-01

    Laboratory experiments that focus on protein folding provide excellent opportunities for undergraduate students to learn important topics in the expanding interdisciplinary field of biophysics. Here, we describe the use of Stern-Volmer plots to determine the extent of solvent accessibility of the single tryptophan residue (trp-59) in unfolded and…

  15. Conducting food Chemistry experiments on the basis of the practical applications%以实际应用为基础开展食品化学实验

    Institute of Scientific and Technical Information of China (English)

    王可兴

    2014-01-01

    Food chemical experiments as a compulsory course play an important role in college student professional education. Food Chemistry experiments innovation is the inevitable outcome with social development. Based on the innovation of food Chemistry experiments and combined with teaching experience for many years, the view conducting food Chemistry experiments on the basis of the practical applications was point out and expected to widen the road of innovation in food Chemistry experiment courses.%食品化学实验是食品科学专业必修课程,对大学生职业化教育起重要作用。近年来,随着社会对人才培养要求的不断提高,食品化学实验课程改革已是社会发展的必然。以创新食品化学实验为起点,结合多年教学经验,提出以实际应用为基础展开食品化学实验的观点,拓宽食品化学实验课程的创新之路。

  16. Polarimetric Multiwavelength Focal Plane Arrays for ACE and CLARREO Project

    Data.gov (United States)

    National Aeronautics and Space Administration — High-performance polarimetric and nonpolarimetric sensing is crucial to upcoming NASA missions, including ACE and CLARREO and the multi-agency VIIRS NPP project....

  17. Angioedema Due to use of ACE-Inhibitor

    Directory of Open Access Journals (Sweden)

    Hulya Eyigor

    2014-03-01

    Full Text Available       Angioedema; which may be hereditary or non-hereditary, is defined as a sudden, severe, often in awkward, temporary swelling of skin, subcutaneous and mucous membranes of the face, tongue, lip, larynx, and gastrointestinal areas. Angiotensin Converting Enzyme (ACE inhibitor drugs are widely used in essential hypertension and congestive heart diseases and effective and safe drugs. Angioedema is quite rare due to the use of ACE inhibitors, the rate changes from 0.1 to 0.7% reported in the literature. The pathophysiology of angioedema induced by ACE inhibitors are not completely understood, this situation has been tought to be associated with an increased activity of bradykinin related vasodilatation, increased vascular permeability and interstitial edema. In this study, a case of 65-year-old male patient presented angioedema induced by lisinopril was presented and a very rare side effect of ACE inhibitor drugs was reviewed with the relevant literature.

  18. Introductory Chemistry: A Molar Relaxivity Experiment in the High School Classroom

    OpenAIRE

    Dawsey, Anna C.; Hathaway, Kathryn L.; Kim, Susie; Williams, Travis J.

    2013-01-01

    Dotarem and Magnevist, two clinically available magnetic resonance imaging (MRI) contrast agents, were assessed in a high school science classroom with respect to which is the better contrast agent. Magnevist, the more efficacious contrast agent, has negative side effects because its gadolinium center can escape from its ligand. However, Dotarem, though a less efficacious contrast agent, is a safer drug choice. After the experiment, students are confronted with the FDA warning on Magnevist, w...

  19. ACE View � an ontology and rule editor based on controlled English

    OpenAIRE

    Kaljurand, K

    2008-01-01

    We describe the architecture of a novel ontology and rule editor ACE View. The goal of ACE View is to simplify viewing and editing expressive and syntactically complex OWL/SWRL knowledge bases by making most of the interaction with the knowledge base happen via Attempto Controlled English (ACE). This makes ACE View radically different from current OWL/SWRL editors which are based on formal logic syntaxes and general purpose graphical user interface widgets. ACE Vie...

  20. Sorption of Sulfonamide Antibiotics to Soil Organic Sorbents: Batch Experiments with Model Compounds and Computational Chemistry

    OpenAIRE

    Schwarz, J.; S. Thiele-Bruhn; K.-U. Eckhardt; H.-R. Schulten

    2012-01-01

    Sorption of the sulfonamide antibiotics sulfanilamide, sulfadimethoxine, and sulfapyridine to model soil organic matter was investigated. Therefore, Fluka humic acid and an enzymatically reacted vanillin oligomer were used in batch experiments at pH 4.5, 6.0, and 7.5. Sorption of the amphoteric sulfonamides was nonlinear and pH dependent. At pH 4.5 and 6.0 sorption to both humic acid and oligomer increased in the order sulfanilamide < sulfapyridine < sulfadimethoxine. This was primarily attri...

  1. Orbital chemistry - Lunar surface analysis from the X-ray and gamma ray remote sensing experiments

    Science.gov (United States)

    Adler, I.; Trombka, J. I.

    1977-01-01

    The X-ray and gamma-ray lunar surface remote sensing experiments conducted by the Apollo 15 and 16 are discussed. The data indicate mare basins that are extensively basaltic and highlands of aluminum-rich anorthositic-type feldspar. An east-west asymmetry involving higher Al/Si ratios toward the east is noted; high concentrations of a KREEP-type component along the Imbrium-Procellarum edges and throughout the basin are also observed. Lunar K/Th ratios, lowest in areas of the Imbrium and higher in the surrounding mare and highlands, may lend support to the picture of the moon as a high-temperature condensate.

  2. Angiotensin-Converting Enzyme (ACE) 2 Overexpression Ameliorates Glomerular Injury in a Rat Model of Diabetic Nephropathy: A Comparison with ACE Inhibition

    OpenAIRE

    Liu, Chun Xi; Hu, Qin; Yan WANG; Zhang, Wei; Ma, Zhi Yong; Feng, Jin Bo; Wang, Rong; Wang, Xu Ping; Dong, Bo; Gao, Fei; Zhang, Ming Xiang; Zhang, Yun

    2010-01-01

    The reduced expression of angiotensin-converting enzyme (ACE) 2 in the kidneys of animal models and patients with diabetes suggests ACE2 involvement in diabetic nephrology. To explore the renoprotective effects of ACE2 overexpression, ACE inhibition (ACEI) or both on diabetic nephropathy and the potential mechanisms involved, 50 Wistar rats were randomly divided into a normal group that received an injection of sodium citrate buffer and a diabetic model group that received an injection of 60 ...

  3. Assessing Cost-Effectiveness in Obesity (ACE-Obesity): an overview of the ACE approach, economic methods and cost results

    OpenAIRE

    Swinburn Boyd; Vos Theo; Magnus Anne; Markwick Alison; Moodie Marj; Carter Rob; Haby Michele M

    2009-01-01

    Abstract Background The aim of the ACE-Obesity study was to determine the economic credentials of interventions which aim to prevent unhealthy weight gain in children and adolescents. We have reported elsewhere on the modelled effectiveness of 13 obesity prevention interventions in children. In this paper, we report on the cost results and associated methods together with the innovative approach to priority setting that underpins the ACE-Obesity study. Methods The Assessing Cost Effectiveness...

  4. Transient Changes in Shallow Groundwater Chemistry During the MSU-ZERT CO2 Injection Experiment

    Science.gov (United States)

    Zheng, L.; Apps, J. A.; Spycher, N.; Birkholzer, J. T.; Kharaka, Y. K.; Thordsen, J. J.; Kakouros, E.; Trautz, R. C.

    2009-12-01

    The Montana State University Zero Emission Research and Technology (MSU-ZERT) field experiment at Bozeman, Montana, is designed to evaluate atmospheric and near-surface monitoring and detection techniques applicable to the potential leakage of CO2 from deep storage reservoirs. However, the experiment also affords an excellent opportunity to investigate the transient changes in groundwater chemical composition in response to increasing CO2 partial pressures. Between July 9 and August 7, 2008, 300 kg/day of food-grade CO2 was injected into shallow groundwater through a horizontal perforated pipe about 2-2.3 m below the ground surface. Changes in groundwater quality were investigated through comprehensive chemical analyses of 80 water samples taken before, during and following CO2 injection from 10 shallow observation wells located 1-6 m from the injection pipe, and from two distant monitoring wells. Field and laboratory analyses suggest rapid and systematic changes in pH, alkalinity, and conductance, as well as increases in the aqueous concentrations of both major and trace element species. A principal component analysis and independent thermodynamic interpretation of the water quality analyses were conducted. Results were interpreted in conjunction with a mineralogical characterization of the shallow sediments and a review of historical records of the chemical composition of rainfall at neighboring monitoring sites. The interpretation permitted tentative identification of a complex array of adsorption/desorption, ion exchange, precipitation/dissolution, oxidation/reduction and infiltration processes that were operative during the test. Geochemical modeling was conducted using TOUGHREACT to test whether the observed water quality changes were consistent with the hypothesized processes, and very good agreement was obtained with respect to the behavior of both major and trace elements.

  5. ACE Observatory Control System - 16 years of remote intercontinental observing

    Science.gov (United States)

    Mack, Peter

    2011-03-01

    The ACE Observatory Control System has been used for remote control since 1995. The system was designed for use at isolated observatories with no-one present on the mountain-top. The software provides complete diagnostic feedback to the astronomer and is supplemented by live audio-visual. Accessories include environmental sensors (weather station, all-sky camera, constellation cameras), automated mirror covers and remote power control. This gives the astronomer the same experience as being present at the observatory. The system is installed on 30 telescopes and many of them are used for routine nightly intercontinental observations, such as Taejeon (S. Korea) to Mt. Lemmon (Arizona) and southeast USA to KPNO and CTIO. The system has fully integrated autoguider acquisition and science camera control. We describe the building blocks of the system and the accessories including automated mirror covers, weather station, all sky camera, remote power control and dome control. Future plans are presented for a fully autonomous platform-independent scheduler and robot for use on multiple telescopes.

  6. Adsorption of a Textile Dye on Commercial Activated Carbon: A Simple Experiment to Explore the Role of Surface Chemistry and Ionic Strength

    Science.gov (United States)

    Martins, Angela; Nunes, Nelson

    2015-01-01

    In this study, an adsorption experiment is proposed using commercial activated carbon as adsorbent and a textile azo dye, Mordant Blue-9, as adsorbate. The surface chemistry of the activated carbon is changed through a simple oxidation treatment and the ionic strength of the dye solution is also modified, simulating distinct conditions of water…

  7. Ion Exchange and Thin Layer Chromatographic Separation and Identification of Amino Acids in a Mixture: An Experiment for General Chemistry and Biotechnology Laboratories

    Science.gov (United States)

    Brunauer, Linda S.; Caslavka, Katelyn E.; Van Groningen, Karinne

    2014-01-01

    A multiday laboratory exercise is described that is suitable for first-year undergraduate chemistry, biochemistry, or biotechnology students. Students gain experience in performing chromatographic separations of biomolecules, in both a column and thin layer chromatography (TLC) format. Students chromatographically separate amino acids (AA) in an…

  8. Detection of Salicylic Acid in Willow Bark: An Addition to a Classic Series of Experiments in the Introductory Organic Chemistry Laboratory

    Science.gov (United States)

    Clay, Matthew D.; McLeod, Eric J.

    2012-01-01

    Salicylic acid and its derivative, acetylsalicylic acid, are often encountered in introductory organic chemistry experiments, and mention is often made that salicylic acid was originally isolated from the bark of the willow tree. This biological connection, however, is typically not further pursued, leaving students with an impression that biology…

  9. Nobel Chemistry in the Laboratory: Synthesis of a Ruthenium Catalyst for Ring-Closing Olefin Metathesis--An Experiment for the Advanced Inorganic or Organic Laboratory

    Science.gov (United States)

    Greco, George E.

    2007-01-01

    An experiment for the upper-level undergraduate laboratory is described in which students synthesize a ruthenium olefin metathesis catalyst, then use the catalyst to carry out the ring-closing metathesis of diethyl diallylmalonate. The olefin metathesis reaction was the subject of the 2005 Nobel Prize in chemistry. The catalyst chosen for this…

  10. Fine-Structure Measurements of Oxygen A Band Absorbance for Estimating the Thermodynamic Average Temperature of the Earth's Atmosphere: An Experiment in Physical and Environmental Chemistry

    Science.gov (United States)

    Myrick, M. L.; Greer, A. E.; Nieuwland, A.; Priore, R. J.; Scaffidi, J.; Andreatta, Daniele; Colavita, Paula

    2006-01-01

    The experiment describe the measures of the A band transitions of atmospheric oxygen, a rich series of rotation-electronic absorption lines falling in the deep red portion of the optical spectrum and clearly visible owing to attenuation of solar radiation. It combines pure physical chemistry with analytical and environmental science and provides a…

  11. Using a Sequence of Experiments with Turmeric Pigments from Food to Teach Extraction, Distillation, and Thin-Layer Chromatography to Introductory Organic Chemistry Students

    Science.gov (United States)

    da S. F. Fagundes, Thayssa; Dutra, Karen Danielle B.; Ribeiro, Carlos Magno R.; de A. Epifanio, Rosa^ngela; Valverde, Alessandra L.

    2016-01-01

    This experiment encourages students to use deductive reasoning skills to understand the correlation between different techniques used in a chemistry laboratory and to extract and analyze curcuminoids using natural products and processed food from a grocery store. Turmeric pigments were used to teach continuous or discontinuous extraction, vacuum…

  12. 分析化学实验仪器改进的几点探索%Some Experiences of Improving Analytical Chemistry Experiment

    Institute of Scientific and Technical Information of China (English)

    曲仕明; 高世杰; 王集会

    2012-01-01

    设计了一种可用于分析化学实验及企事业单位化验室的复合式滴定台,方便了相关人员的实验操作,并大大提高了实验台利用率;发明了一套可修复损坏的酸碱式滴定管的仪器;探索了一种解决酸碱式滴定管刻度线读数模糊不清问题的方法,方便了学生读数。通过以上改进,节省了教学成本。%A new- type burette holder was designed for analytical chemistry experiments and testing laboratories of enterprises and institutions. An instrument for repairing the damaged burettes was also invented. In addition, the unclear scale lines of burettes can be easy to read by the new method. Thus, the teaching cost was saved and the students would fell easy in a titration experiment.

  13. AngⅡ对肝星状细胞中ACE 2和Mas受体mRNA的影响

    Institute of Scientific and Technical Information of China (English)

    许小妹; 申凤俊; 贾秀艳

    2014-01-01

    Objective To investigate the efects of angiotensin converting enzyme inhibitors benazepril on angiotensin converting enzyme 2(ACE 2) and Mas receptor production of in vitro cultured hepatic stellate cells (HSC). Methods HSC-T 6 rat hepatic stelate was chosen as the main study model of experiment,Cultured HSC were randomized into control group,AngⅡgroup,benazepril group and AngⅡ+benazepril group. The expression of ACE 2 and Mas receptor in different group was measured by by RTFQ PCR.Results The ACE 2 and Mas receptor expression level of HSC in AngⅡgroup were higher than control group(P<0.05).All index of AngⅡ+benazepril group were higher than AngⅡgroup (P<0.05). Conclusion After hepatic stelate cells was activated,Benazepril can elevated the ACE 2 and Mas receptor expression level of HSC,and play an important role in anti-hepatic fibrosis.%目的:体外培养肝星状细胞(HSC),从分子生物学的角度探索其是否有ACE 2和Mas受体mRNA的表达,以及血管紧张素转换酶抑制剂(ACEI)贝那普利对二者的影响。方法大鼠肝星状细胞株(HSC-T 6)按实验计划分组处理(正常对照组、AngⅡ组、AngⅡ+贝那普利组、贝那普利组),提取总RNA,逆转录后应用RTFQ PCR的方法测量ACE 2及Mas受体 mRNA的基因水平。结果 ACE 2、Mas受体mRNA在各组中均有表达;与对照组相比,AngⅡ组中二者的表达均较高,差异有统计学意义(P<0.05);在AngⅡ+贝那普利组,二者均较AngⅡ组升高,差异有统计学意义(P<0.05)。结论 AngⅡ可使肝星状细胞激活,活化后的HSC的ACE 2、Mas受体mRNA的基因表达水平升高,从而发挥其抗肝纤维化的作用。

  14. Experimental study on iodine chemistry (EXSI) - Containment experiments with elemental iodine

    International Nuclear Information System (INIS)

    The behaviour of iodine during a severe accident has been studied in several experimental programs, ranging from the large-scale PHEBUS FP tests and intermediate-scale ThAI tests to numerous separate effect studies. Oxidation of iodine in gas phase has been one of the greatest remaining uncertainties in iodine behaviour during a severe accident. In this study the possible formation of iodine oxide aerosol due to radiolytic oxidation of gaseous iodine is experimentally tested and the reaction products are analysed. The experimental facility applied in this study is based on the sampling system built at VTT for ISTP program project CHIP conducted IRSN. The experimental facility and the measuring technology are sophisticated and unique in the area of nuclear research as well as in the field of aerosol science. The results from the experiments show an extensive particle formation when ozone and gaseous iodine react with each other. The formed particles were collected on filters, while gaseous iodine was trapped into bubbles. The particles were iodine oxides and the size of particles was approximately 100 nm. The transport of gaseous iodine through the facility decreased when both gaseous iodine and ozone were fed together into facility. Experimental study on radiolytic oxidation of iodine was conducted in co-operation between VTT and Chalmers University of Technology as a part of the NKS-R programs. (author)

  15. Experimental study on iodine chemistry (EXSI) - Containment experiments with elemental iodine

    Energy Technology Data Exchange (ETDEWEB)

    Kaerkelae, T.; Auvinen, A. (VTT Technical Research Centre of Finland (Finland)); Holm, J.; Ekberg, C. (Chalmers Univ. of Technology (Sweden)); Glaenneskog, H. (Vattenfall Power Consultant (Sweden))

    2009-10-15

    The behaviour of iodine during a severe accident has been studied in several experimental programs, ranging from the large-scale PHEBUS FP tests and intermediate-scale ThAI tests to numerous separate effect studies. Oxidation of iodine in gas phase has been one of the greatest remaining uncertainties in iodine behaviour during a severe accident. In this study the possible formation of iodine oxide aerosol due to radiolytic oxidation of gaseous iodine is experimentally tested and the reaction products are analysed. The experimental facility applied in this study is based on the sampling system built at VTT for ISTP program project CHIP conducted IRSN. The experimental facility and the measuring technology are sophisticated and unique in the area of nuclear research as well as in the field of aerosol science. The results from the experiments show an extensive particle formation when ozone and gaseous iodine react with each other. The formed particles were collected on filters, while gaseous iodine was trapped into bubbles. The particles were iodine oxides and the size of particles was approximately 100 nm. The transport of gaseous iodine through the facility decreased when both gaseous iodine and ozone were fed together into facility. Experimental study on radiolytic oxidation of iodine was conducted in co-operation between VTT and Chalmers University of Technology as a part of the NKS-R programs. (author)

  16. Experiments probing the influence of air exchange rates on secondary organic aerosols derived from indoor chemistry

    DEFF Research Database (Denmark)

    Weschler, Charles J.; Shields, H.C.

    2003-01-01

    particle size distributions. The experiments were performed in a manipulated office setting containing a constant source of d-limonene and an ozone generator that was remotely turned "on" or "off" at 6h intervals. The particle number concentrations were monitored using an optical particle counter with......Reactions between ozone and terpenes have been shown to increase the concentrations of submicron particles in indoor settings. The present study was designed to examine the influence of air exchange rates on the concentrations of these secondary organic aerosols as well as on the evolution of their...... studies, at an air exchange rate of 1.6h $+-1$/ particle number concentration in the 0.1-0.2$mu@m size-range peaked 1.2h after the ozone generator was switched on. In the ensuing 4.8h particle counts increased in successive size-ranges up to the 0.5-0.7$mu@m diameter range. At higher air exchange rates...

  17. Fission-product chemistry in severe reactor accidents: review of relevant integral experiments

    International Nuclear Information System (INIS)

    The attenuation of the radioactive fission-product emission from a severe reactor accident will depend on a combination of chemical, physical and thermal-hydraulic effects. Chemical species stabilised under the prevailing conditions will determine the extent of aerosol formation and any subsequent interaction, so defining the magnitude and physical forms of the eventual release into the environment. While several important integral tests have taken place in recent years, these experiments have tended to focus on the generation of mass-balance and aerosol-related data to test and validate materials-transport codes rather than study the impact of important chemical phenomena. This emphasis on thermal hydraulics, fuel behaviour and aerosol properties has occurred in many tests. Nevertheless, the generation and reaction of the chemical species in all of these programmes determined the transport properties of the resulting vapours and aerosols. Chemical effects have been studied in measurements somewhat subsidiary to the main aims of the tests. This work has been reviewed in detail with respect to other research programs. Specific issues remain to be addressed, and these are discussed in terms of the proposed Phebus-Fission Product programme. (author)

  18. SP.ACE: taking secondary school students' hearts and minds "up, up and away"

    Science.gov (United States)

    de Schrijver, Erik

    2005-08-01

    Secondary school students were given the opportunity to build and fly "pongsats" (small experiments weighing under 100 grams each, and packed inside a ping pong ball) on high-altitude balloons bound for 100000 feet, or 30 km: the edge of space. The need to acquire the knowledge and know-how to build successful experiments gave birth to the SP.ACE project. Over their last 3 years of secondary education, students are now learning about flight vehicles, the physical conditions in space, microcontrollers, sensors, programming, data logging, flight path analysis, and much more.

  19. Seasonal carbonate chemistry covariation with temperature, oxygen, and salinity in a fjord estuary: implications for the design of ocean acidification experiments.

    Directory of Open Access Journals (Sweden)

    Jonathan C P Reum

    Full Text Available Carbonate chemistry variability is often poorly characterized in coastal regions and patterns of covariation with other biologically important variables such as temperature, oxygen concentration, and salinity are rarely evaluated. This absence of information hampers the design and interpretation of ocean acidification experiments that aim to characterize biological responses to future pCO2 levels relative to contemporary conditions. Here, we analyzed a large carbonate chemistry data set from Puget Sound, a fjord estuary on the U.S. west coast, and included measurements from three seasons (winter, summer, and fall. pCO2 exceeded the 2008-2011 mean atmospheric level (392 µatm at all depths and seasons sampled except for the near-surface waters (< 10 m in the summer. Further, undersaturated conditions with respect to the biogenic carbonate mineral aragonite were widespread (Ωar<1. We show that pCO2 values were relatively uniform throughout the water column and across regions in winter, enriched in subsurface waters in summer, and in the fall some values exceeded 2500 µatm in near-surface waters. Carbonate chemistry covaried to differing levels with temperature and oxygen depending primarily on season and secondarily on region. Salinity, which varied little (27 to 31, was weakly correlated with carbonate chemistry. We illustrate potential high-frequency changes in carbonate chemistry, temperature, and oxygen conditions experienced simultaneously by organisms in Puget Sound that undergo diel vertical migrations under present-day conditions. We used simple calculations to estimate future pCO2 and Ωar values experienced by diel vertical migrators based on an increase in atmospheric CO2. Given the potential for non-linear interactions between pCO2 and other abiotic variables on physiological and ecological processes, our results provide a basis for identifying control conditions in ocean acidification experiments for this region, but also highlight

  20. Adverse Childhood Experiences and Hallucinations

    Science.gov (United States)

    Whitfield, C.L.; Dube, S.R.; Felitti, V.J.; Anda, R.F.

    2005-01-01

    Objective:: Little information is available about the contribution of multiple adverse childhood experiences (ACEs) to the likelihood of reporting hallucinations. We used data from the ACE study to assess this relationship. Methods:: We conducted a survey about childhood abuse and household dysfunction while growing up, with questions about health…

  1. 高分子化学开放性实验开设初探%The Polymer Chemistry Openness Experiment Start Initially Searches

    Institute of Scientific and Technical Information of China (English)

    李新娟; 徐桂清; 胡志国

    2011-01-01

    为了更好的提高学生对理论课知识的学习和掌握,我们结合自身的教学实践,在高分子化学课程开设的同时开设高分子化学实验,并将开放性实验的特点“设计性、综合性”引入到高分子化学实验教学过程中。通过设计性实验使学生成为学习的主体,主动学习,达到对高分子化学理论知识深入理解和掌握;通过增加综合探究性实验,使学生对高分子化学前沿学科领域有所了解,提高学生学科兴趣的同时,也提高了学习的主动性和科学研究能力。本文提出了初步的实验开设方案。%In order to make the students better improve and grasp the academic knowledge, combining our teaching practice, we opened the polymer chemistry experiment with the polymer chemistry being opened and introduced the characteristics of the open experiment " design, comprehensive" into polymer chemistry experiment in the teaching process. By designing experiments to make the students become the real master of learning, deep understand and master the knowledge of polymer chemistry theory; by adding the comprehensive experiment, to make the students know the frontier of polymer chemistry, and improve their academic interest, thus improve their learning initiative and scientific research capabilities, then process them to an utilized produce in this course.

  2. Aerosol Composition, Chemistry, and Source Characterization during the 2008 VOCALS Experiment

    Science.gov (United States)

    Lee, Y.; Springston, S.; Jayne, J. T.; Wang, J.; Senum, G.; Hubbe, J.; Alexander, L.; Brioude, J.; Spak, S.; Mena-Carrasco, M.; Kleinman, L. I.; Daum, P. H.

    2009-12-01

    Chemical composition of fine aerosol particles over the northern Chilean coastal waters was determined on board the US DOE G-1 aircraft during the VOCALS (VAMOS Ocean-Cloud-Atmosphere-Land Study) field experiment between October 16 and November 15, 2008. Chemical species determined included SO42-, NO3-, NH4+, and total organics (Org) using an Aerodyne Aerosol Mass Spectrometer, and SO42-, NO3-, NH4+, Na+, Cl-, CH3SO3-, Mg2+, Ca2+, and K+ using a particle-into-liquid sampler-ion chromatography technique. The results show the marine boundary layer (MBL) aerosol mass was dominated by non-sea-salt SO42- followed by Na+, Cl-, Org, NO3-, and NH4+, in decreasing importance; CH3SO3-, Ca2+, and K+ rarely exceeded their respective limits of detection. The SO42- aerosols were strongly acidic as the equivalent NH4+ to SO42- ratio was only ~0.25 on average. NaCl particles, presumably of sea-salt origin, showed chloride deficits but retained Cl- typically more than half the equivalency of Na+, and are believed to be externally mixed with the acidic sulfate aerosols. Nitrate was observed only on sea-salt particles, consistent with adsorption of HNO3 on non-acidic sea-salt aerosols, responsible partly for the Cl- deficit. Dust particles appeared to play a minor role judging from the small volume differences between that derived from the observed mass concentrations and that calculated based on particle size distributions. Because SO42- concentrations in the study domain were substantial (~0.5 - ~3 μg/m3) with a strong gradient (highest near the shore decreasing with distance from land), and the ocean-emitted dimethylsulfide and its unique oxidation product, CH3SO3-, were very low (i.e., ≤ 40 parts per trillion and power plants along coastal regions of Peru and Chile are the main sources of these SO4- aerosols. However, compared to observations, model calculations appeared to underestimate sulfate concentrations based on an existing emission inventory. An up-to-date and

  3. Effects of the Cooperative Class Experiment Teaching Method on Secondary School Students' Chemistry Achievement in Kenya's Nakuru District

    Science.gov (United States)

    Wachanga, Samuel W.; Mwangi, John Gowland

    2004-01-01

    Successful teaching and learning of chemistry depends partly on correct use of a teaching method whose activities target most learning senses. Though chemistry enhances students' learning of biology, physics and agriculture on which Kenyan industries and prosperity depend, most secondary school students in Kenya perform poorly on the subject. This…

  4. The angiotensin-converting enzyme (ACE gene family of Anopheles gambiae

    Directory of Open Access Journals (Sweden)

    Isaac R Elwyn

    2005-12-01

    Full Text Available Abstract Background Members of the M2 family of peptidases, related to mammalian angiotensin converting enzyme (ACE, play important roles in regulating a number of physiological processes. As more invertebrate genomes are sequenced, there is increasing evidence of a variety of M2 peptidase genes, even within a single species. The function of these ACE-like proteins is largely unknown. Sequencing of the A. gambiae genome has revealed a number of ACE-like genes but probable errors in the Ensembl annotation have left the number of ACE-like genes, and their structure, unclear. Results TBLASTN and sequence analysis of cDNAs revealed that the A. gambiae genome contains nine genes (AnoACE genes which code for proteins with similarity to mammalian ACE. Eight of these genes code for putative single domain enzymes similar to other insect ACEs described so far. AnoACE9, however, has several features in common with mammalian somatic ACE such as a two domain structure and a hydrophobic C terminus. Four of the AnoACE genes (2, 3, 7 and 9 were shown to be expressed at a variety of developmental stages. Expression of AnoACE3, AnoACE7 and AnoACE9 is induced by a blood meal, with AnoACE7 showing the largest (approximately 10-fold induction. Conclusion Genes coding for two-domain ACEs have arisen several times during the course of evolution suggesting a common selective advantage to having an ACE with two active-sites in tandem in a single protein. AnoACE7 belongs to a sub-group of insect ACEs which are likely to be membrane-bound and which have an unusual, conserved gene structure.

  5. Disk Chemistry*

    OpenAIRE

    Thi Wing-Fai

    2015-01-01

    The chemical species in protoplanetary disks react with each other. The chemical species control part of the thermal balance in those disks. How the chemistry proceeds in the varied conditions encountered in disks relies on detailed microscopic understanding of the reactions through experiments or theoretical studies. This chapter strives to summarize and explain in simple terms the different types of chemical reactions that can lead to complex species. The first part of the chapter deals wit...

  6. Results from the SolACES instrument onboard the International Space Station (ISS)

    Science.gov (United States)

    Schmidtke, Gerhard; Eparvier, Francis; Brunner, Raimund; Woods, Thomas; Jacobi, Christoph; Thuillier, Gerard; Nikutowski, Bernd; Erhardt, Christian

    2012-07-01

    showing the SSI variability and composition in the EUV spectral region with solar activity will be presented in further detail in another talk. Similarly it is proposed for the inter-comparison of SolACES Level 1 data with SSI data from other experiments such as SDO EVE. As a result a first proposal for a common SSI data base in close international cooperation will be presented.

  7. Fundamentals of reactor chemistry

    International Nuclear Information System (INIS)

    In the Nuclear Engineering School of JAERI, many courses are presented for the people working in and around the nuclear reactors. The curricula of the courses contain also the subject material of chemistry. With reference to the foreign curricula, a plan of educational subject material of chemistry in the Nuclear Engineering School of JAERI was considered, and the fundamental part of reactor chemistry was reviewed in this report. Since the students of the Nuclear Engineering School are not chemists, the knowledge necessary in and around the nuclear reactors was emphasized in order to familiarize the students with the reactor chemistry. The teaching experience of the fundamentals of reactor chemistry is also given. (author)

  8. ACE INHIBITORS ARE RATIONAL PHARMACOTHERAPY OF ENDOTHELIAL DYSFUNCTION

    Directory of Open Access Journals (Sweden)

    M. P. Metrova

    2008-01-01

    Full Text Available Aim. To study effects of ACE inhibitor perindopril on markers of endothelial dysfunction in therapy of patients with arterial hypertension (HT.Material and methods. 82 patients with HT, complicated by ischemic stroke were involved in the study. 30 patients with uncomplicated HT were included into control group. Antihypertensive therapy with perindopril (52 patients or amlodipine (30 patients was conducted additionally to standard neurotropic therapy in hypertensive patients with ischemic stroke. Phase-contrast microscopy and enzyme immunoassay were used for screening of endothelial dysfunction markers (blebbing, desquamated endothelial cells, membrane-liberated parts, sPECAM-1.Results. Reduction in levels of markers of endothelial dysfunction was observed among patients treated with perindopril in comparison with patients who did not receive ACE inhibitor or patients of control group. Target levels of blood pressure were reached in 96% of patients treated with perindopril. Сonclusion. ACE inhibitors in therapy patients with HT reduce endothelial dysfunction additionally to antihypertensive effect.

  9. ACE inhibition, ACE2 and angiotensin-(1-7) axis in kidney and cardiac inflammation and fibrosis.

    Science.gov (United States)

    Simões E Silva, Ana Cristina; Teixeira, Mauro Martins

    2016-05-01

    The Renin Angiotensin System (RAS) is a pivotal physiological regulator of heart and kidney homeostasis, but also plays an important role in the pathophysiology of heart and kidney diseases. Recently, new components of the RAS have been discovered, including angiotensin converting enzyme 2 (ACE2), Angiotensin(Ang)-(1-7), Mas receptor, Ang-(1-9) and Alamandine. These new components of RAS are formed by the hydrolysis of Ang I and Ang II and, in general, counteract the effects of Ang II. In experimental models of heart and renal diseases, Ang-(1-7), Ang-(1-9) and Alamandine produced vasodilation, inhibition of cell growth, anti-thrombotic, anti-inflammatory and anti-fibrotic effects. Recent pharmacological strategies have been proposed to potentiate the effects or to enhance the formation of Ang-(1-7) and Ang-(1-9), including ACE2 activators, Ang-(1-7) in hydroxypropyl β-cyclodextrin, cyclized form of Ang-(1-7) and nonpeptide synthetic Mas receptor agonists. Here, we review the role and effects of ACE2, ACE2 activators, Ang-(1-7) and synthetic Mas receptor agonists in the control of inflammation and fibrosis in cardiovascular and renal diseases and as counter-regulators of the ACE-Ang II-AT1 axis. We briefly comment on the therapeutic potential of the novel members of RAS, Ang-(1-9) and alamandine, and the interactions between classical RAS inhibitors and new players in heart and kidney diseases. PMID:26995300

  10. Parental Alcoholism, Adverse Childhood Experiences, and Later Risk of Personal Alcohol Abuse among Chinese Medical Students

    Institute of Scientific and Technical Information of China (English)

    QIN XIAO; MA-XIA DONG; JIE YAO; WEN-XIAN LI; DONG-QING YE

    2008-01-01

    Objective To determine the status of adverse childhood experiences (ACEs) and the association of multiple ACEs with both parental alcoholism and later personal alcohol abuse among Chinese medical students with a view of improving adolescent health and reducing alcohol abuse among them. Methods In this cross-sectional study, 2073 Chinese medical students completed a survey on ten categories of ACEs in Anhui province of China. The association of parental alcoholism with ACEs and personal lcohol abuse was assessed by logistic regression analyses. Results The adjusted odds ratio (OR) for each category of ACEs in the subjects whose parents (either fathers or mothers or oth) had alcohol abuse was 2 to 14 times higher than that inthose with parental alcoholism (P<0.05). Subjects with i-parental alcoholism had the highest likelihood of ACEs. Compared with the subjects without ACEs, the risk of personal alcohol abuse was increased by 2-4-folds in the subjects with ACEs, irrespective of parental alcoholism (P<0.05). The total number of ACEs (ACE score) had a graded relationship to 4 categories of personal alcohol abuse with or without parental alcoholism. The prevalence of personal alcohol abuse among the subjects with parental alcoholism was higher, which was ndependent of ACE scores. Conclusion The prevalence of ACEs is generally serious in China. Efforts should be made to prevent and treat children with ACEs and subsequently to reduce alcohol abuse and later problems.

  11. Measuring Heterogeneous Reaction Rates with ATR-FTIR Spectroscopy to Evaluate Chemical Fates in an Atmospheric Environment: A Physical Chemistry and Environmental Chemistry Laboratory Experiment

    Science.gov (United States)

    Roberts, Jason E.; Zeng, Guang; Maron, Marta K.; Mach, Mindy; Dwebi, Iman; Liu, Yong

    2016-01-01

    This paper reports an undergraduate laboratory experiment to measure heterogeneous liquid/gas reaction kinetics (ozone-oleic acid and ozone-phenothrin) using a flow reactor coupled to an attenuated total reflectance-Fourier transform infrared (ATR-FTIR) spectrometer. The experiment is specially designed for an upper-level undergraduate Physical…

  12. Comparison of CMAM simulations of carbon monoxide (CO, nitrous oxide (N2O, and methane (CH4 with observations from Odin/SMR, ACE-FTS, and Aura/MLS

    Directory of Open Access Journals (Sweden)

    B. Barret

    2009-05-01

    Full Text Available Simulations of CO, N2O and CH4 from a coupled chemistry-climate model (CMAM are compared with satellite measurements from Odin Sub-Millimeter Radiometer (Odin/SMR, Atmospheric Chemistry Experiment Fourier Transform Spectrometer (ACE-FTS, and Aura Microwave Limb Sounder (Aura/MLS. Pressure-latitude cross-sections and seasonal time series demonstrate that CMAM reproduces the observed global CO, N2O, and CH4 distributions quite well. Generally, excellent agreement with measurements is found between CO simulations and observations in the stratosphere and mesosphere. Differences between the simulations and the ACE-FTS observations are generally within 30%, and the differences between CMAM results and SMR and MLS observations are slightly larger. These differences are comparable with the difference between the instruments in the upper stratosphere and mesosphere. Comparisons of N2O show that CMAM results are usually within 15% of the measurements in the lower and middle stratosphere, and the observations are close to each other. However, the standard version of CMAM has a low N2O bias in the upper stratosphere. The CMAM CH4 distribution also reproduces the observations in the lower stratosphere, but has a similar but smaller negative bias in the upper stratosphere. The negative bias may be due to that the gravity drag is not fully resolved in the model. The simulated polar CO evolution in the Arctic and Antarctic agrees with the ACE and MLS observations. CO measurements from 2006 show evidence of enhanced descent of air from the mesosphere into the stratosphere in the Arctic after strong stratospheric sudden warmings (SSWs. CMAM also shows strong descent of air after SSWs. In the tropics, CMAM captures the annual oscillation in the lower stratosphere and the semiannual oscillations at the stratopause and mesopause seen in Aura/MLS CO and N2O observations and in Odin/SMR N2O observations. The Odin/SMR and Aura/MLS N2O observations also show a quasi

  13. Optimization of Physical Chemistry Experiment Course in Local Colleges and Universities%地方院校物理化学实验课程的优化

    Institute of Scientific and Technical Information of China (English)

    杨绳岩; 孟祥珍; 韩阗俐; 王新

    2016-01-01

    物理化学实验是我院开设的一门重要的专业基础实验,在物理化学教学中占有举足轻重的作用。物理化学实验课程的教学存在着一些根深蒂固的问题与不足,严重影响教学质量和学生能力的提高。本文从实验内容的优化、教学资源的优化、考核体系的优化及教师教学方法的优化等方面对物理化学实验课程的优化提出建设性的意见。优化后的实验课程激发了学生学习的主动性,显著提高了学生的综合素质和教师的教学效果。%Physical Chemistry Experiment is an important professional basic experiment , which plays an important role in Physical Chemistry teaching .There are some deep-rooted problems and deficiencies in the teaching of Physical Chemistry Experiment course , which seriously affects the quality of teaching and the improvement of students ’ability. Constructive suggestions for the optimization of Physical Chemistry Experiment course from the optimization of the experimental content , the optimization of teaching resources , the optimization of the examination system and the optimization of the teaching method were put forward .The optimized experiment course stimulated the initiative of the students and improved the overall quality of the students and the teaching effect .

  14. The Synthetic Strategy toward of ACE-Inhibitors

    Institute of Scientific and Technical Information of China (English)

    CHANG; ChingYao

    2001-01-01

    Angiotensin II is an important octapeptide which is responsible for the increase in blood pressure in three major mechanisms. It acts as a hormone to attack the receptor on the blood vessels, which cause strong vasoconstriction. It is also the major stimulus for release another hormone, aldolsterone, which promote the excretion of potassium ion and retention of sodium and waster. Both of the above effects increase the blood pressure. On the other hand, ACE (Angiotensin Converting Enzyme) catalyzes the hydrolysis of bradykinin that is a potent vasodilator. Therefore, the inhibitor of ACE can act as an efficient anti-hypertensive agent through multiple routes.  ……

  15. The Synthetic Strategy toward of ACE-Inhibitors

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    @@ Angiotensin II is an important octapeptide which is responsible for the increase in blood pressure in three major mechanisms. It acts as a hormone to attack the receptor on the blood vessels, which cause strong vasoconstriction. It is also the major stimulus for release another hormone, aldolsterone, which promote the excretion of potassium ion and retention of sodium and waster. Both of the above effects increase the blood pressure. On the other hand, ACE (Angiotensin Converting Enzyme) catalyzes the hydrolysis of bradykinin that is a potent vasodilator. Therefore, the inhibitor of ACE can act as an efficient anti-hypertensive agent through multiple routes.

  16. Performance Enhancement of the Automated Concrete Evaluation System (ACES)

    Energy Technology Data Exchange (ETDEWEB)

    Baumgart,C.W.; Cave,S.P.; Linder,K.E.

    2002-02-14

    The objective of this proposed research is to improve and expand the detection and analysis capabilities of the automated, concrete evaluation (ACE) system. MoDOT and Honeywell jointly developed this system. The focus of this proposed research will be on the following: Coordination of concrete imaging efforts with other states, Validation and testing of the ACE system on a broad range of concrete samples, and Identification and development of software and hardware enhancements. These enhancements will meet the needs of diverse users in the field of concrete materials, construction, and research.

  17. Performance Enhancement of the Automated Concrete Evaluation System (ACES)

    International Nuclear Information System (INIS)

    The objective of this proposed research is to improve and expand the detection and analysis capabilities of the automated, concrete evaluation (ACE) system. MoDOT and Honeywell jointly developed this system. The focus of this proposed research will be on the following: Coordination of concrete imaging efforts with other states, Validation and testing of the ACE system on a broad range of concrete samples, and Identification and development of software and hardware enhancements. These enhancements will meet the needs of diverse users in the field of concrete materials, construction, and research

  18. Bulgarian Experience with the Implementation of 235U Higher Enriched Fuel in WWER-1000 (Water Chemistry Aspects)

    International Nuclear Information System (INIS)

    Water chemistry and radiochemistry plant data from the WWER-1000 Units in NPP Kozloduy confirm that a realistic way for satisfactory implementation of 235U high enriched (up to 4.3%) fuel has been found. The main requirements are: implementation of solid neutron burnable absorbers; application of corrosion resistant fuel cladding; and the maintenance of suitable coolant water chemistry. The implementation at NPP Kozloduy is described. (author)

  19. Taxes and Corporate Financing Decisions – Evidence from the Belgian ACE Reform

    OpenAIRE

    aus dem Moore, Nils

    2014-01-01

    We contribute to the empirical literature on the debt bias of corporate income taxation through a micro-econometric evaluation of the so-called ACE corporate tax reform in Belgium based on firm-level accounting data. We interpret the tax reform that came into effect in January 2006 as an economic quasi experiment. We identify its causal impact on the leverage ratio of Belgian corporations by means of a difference-in-differences (DiD) approach, using corporations from the UK as comparison grou...

  20. Seminar教学模式在分析化学实验中的应用%Application of Seminar Teaching Pattern in Analytical Chemistry Experiment

    Institute of Scientific and Technical Information of China (English)

    葛伊莉; 郭慧

    2011-01-01

    Seminar teaching pattern was used in analytical chemistry experiment of undergraduate students.Most students participated in the course think that seminar teaching pattern can improve the quality of teaching and studying and promote the capacity of students in teaching themselves.The teaching practice shows that it is feasible for Seminar teaching pattern applied in analytical chemistry experiment.%在本科分析化学实验课中采用了Seminar教学模式进行教学探究,参与课程的大多数学生认为Seminar教学模式能明显改善教学效果并能提升学生自主学习能力,教学实践证明Seminar教学模式在分析化学实验中的运用是可行的。

  1. A Crucial Role in Fertility for the Oyster Angiotensin-Converting Enzyme Orthologue CgACE

    OpenAIRE

    Riviere, Guillaume; Fellous, Alexandre; Franco, Alban; Bernay, Benoit; Favrel, Pascal

    2011-01-01

    Angiotensin-converting enzyme (ACE) is a highly conserved metallopeptidase. In mammals, the somatic isoform governs blood pressure whereas the germinal isoform (tACE) is required for fertility. In Ecdysozoans, ACE-like enzymes are implicated in reproduction. Despite ACE orthologues being present from bacteria to humans, their function(s) remain(s) unknown in distant organisms such as Lophotrochozoans. In silico analysis of an oyster (Crassostrea gigas) EST library suggested the presence of an...

  2. Production of Vibrio cholerae accessory cholera enterotoxin (Ace) in the yeast Pichia pastoris.

    OpenAIRE

    Trucksis, M; Conn, T L; Fasano, A; Kaper, J B

    1997-01-01

    Accessory cholera enterotoxin (Ace) is a recently identified toxin of Vibrio cholerae. Preliminary studies using crude toxin extracts in animal models indicate that Ace increases transcellular ion transport, which is proposed to contribute to diarrhea in cholera. The lack of purified toxin has hindered elucidation of the mechanism of action of Ace. In this study, ace was cloned and was expressed in and secreted by the methylotrophic yeast Pichia pastoris. Secreted toxin constituted 50% of the...

  3. Safety of ACE inhibitor therapies in patients with chronic kidney disease

    NARCIS (Netherlands)

    Sidorenkov, Grigory; Navis, Gerjan

    2014-01-01

    Introduction: ACE inhibitors are first-line therapy in patients with chronic kidney disease (CKD). The main adverse effects of ACE inhibitors are hypotension, renal function impairment and hyperkalemia. Areas covered: This paper reviews evidence from clinical studies regarding adverse effects of ACE

  4. Dosing of ACE inhibitors in left ventricular dysfunction : Does current clinical dosing provide optimal benefit?

    NARCIS (Netherlands)

    Pinto, YM; van Geel, PP; Alkfaji, H; van Veldhuisen, DJ; van Gilst, WH

    1999-01-01

    In the present review, we discuss the role of clinical dosing of angiotensin converting enzyme (ACE) inhibitors in the treatment of left ventricular dysfunction. Although the precise mechanism of action of ACE inhibitors is still unresolved, the clinical efficacy of ACE inhibitors in the treatment o

  5. Cricothyroidotomy in a angiotensin-converting enzyme (ACE Inhibitor tongue´s angioedema.

    Directory of Open Access Journals (Sweden)

    Acle-Cervera L, Morales-Angulo C, García-Zornoza R, Rubio Suárez A

    2013-01-01

    Full Text Available Hereditary angioedema by inhibitors of Angiotensin Converting Enzyme(ACE is a very rare disorder. It usually affects the upper airway mucosa andproduce rapidly evolving acute exacerbations requiring urgent treatment.We repost the case of a patient being treated with ACE inhibitors and anreview of prevalence, pathophysiology and management of angioedemawith ACE inhibitors for treatment and the latest treatments.

  6. 21 CFR 862.1090 - Angiotensin converting enzyme (A.C.E.) test system.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Angiotensin converting enzyme (A.C.E.) test system... Test Systems § 862.1090 Angiotensin converting enzyme (A.C.E.) test system. (a) Identification. An angiotensin converting enzyme (A.C.E.) test system is a device intended to measure the activity of...

  7. The antiproteinuric effect of ace inhibition in renal disease

    NARCIS (Netherlands)

    Heeg, J.E.

    1992-01-01

    In 1985 some studies were published showing that angiotensin converting enzyme (ACE) inhibition not only reduced the elevated blood pressure in animals with chronic renal failure (experimentally induced by renal ablation or by induced diabetic nephropathy), but also prevented the development of glom

  8. Compliance, Persistence, and Switching Patterns for ACE Inhibitors and ARBs

    NARCIS (Netherlands)

    Vegter, S.; Nguyen, N.H.; Visser, S.T.; de Jong-van den Berg, LTW; Postma, M.J.; Boersma, C.

    2011-01-01

    Objectives: To investigate compliance, persistence, and switching patterns for angiotensin-converting enzyme (ACE) inhibitors and angiotensin receptor blockers (ARBs). Study Design: Drug-utilization analysis using a large prescription database. Methods: Prescription data for more than 50,000 inciden

  9. Applying computationally efficient schemes for biogeochemical cycles (ACES4BGC)

    Energy Technology Data Exchange (ETDEWEB)

    Vertenstein, Mariana [Univ. Corporation For Atmospheric Research, Boulder, CO (United States)

    2016-01-11

    NCAR contributed to the ACES4BGC project through software engineering work on aerosol model implementation, build system and script changes, coupler enhancements for biogeochemical tracers, improvements to the Community Land Model (CLM) code and testing infrastructure, and coordinating and integrating code changes from the various project participants.

  10. ACE: accurate correction of errors using K-mer tries

    NARCIS (Netherlands)

    Sheikhizadeh Anari, S.; Ridder, de D.

    2015-01-01

    The quality of high-throughput next-generation sequencing data significantly influences the performance and memory consumption of assembly and mapping algorithms. The most ubiquitous platform, Illumina, mainly suffers from substitution errors. We have developed a tool, ACE, based on K-mer tries to c

  11. Development of Antennas for Subsurface Radars within ACE

    DEFF Research Database (Denmark)

    Yarovoy, Alexander; Meincke, Peter; Dauvignac, Jean-Yves; Craddock, Ian; Sarri, Antonio; Huang, Yi

    The paper gives an overview of the joint activities of the ACE-2 partners in the area of antennas for surface penetrating radar. Main areas of joint research and development are discussed and main results of joint activities are presented. Special attention is given to experimental verification of...

  12. Bad chemistry

    OpenAIRE

    Petsko, Gregory A

    2004-01-01

    General chemistry courses haven't changed significantly in forty years. Because most basic chemistry students are premedical students, medical schools have enormous influence and could help us start all over again to create undergraduate chemistry education that works.

  13. Analysis of Whiskey by Dispersive Liquid-Liquid Microextraction Coupled with Gas Chromatography/Mass Spectrometry: An Upper Division Analytical Chemistry Experiment Guided by Green Chemistry

    Science.gov (United States)

    Owens, Janel E.; Zimmerman, Laura B.; Gardner, Michael A.; Lowe, Luis E.

    2016-01-01

    Analysis of whiskey samples prepared by a green microextraction technique, dispersive liquid-liquid microextraction (DLLME), before analysis by a qualitative gas chromatography-mass spectrometry (GC/MS) method, is described as a laboratory experiment for an upper division instrumental methods of analysis laboratory course. Here, aroma compounds in…

  14. Self-help Experimental Teaching Methods on Organic Chemistry Experiments%“自助式”有机化学实验教学模式初探

    Institute of Scientific and Technical Information of China (English)

    袁园; 张孝琴

    2015-01-01

    有机化学是以实验为基础的学科,通过实验能使学生掌握基本操作技能,深化理论知识与原理,培养实事求是的科学态度。针对传统有机化学实验教学中存在的问题和不足,在有机化学实验中采用“自助式”实验教学模式,通过开设自选型实验,为学生提供多种实验方案,使学生可以根据自己的的兴趣与能力选取实验内容和实验用品,开展实验室的“自助餐”,提高学生积极性,培养学生的创新思维和实践能力。%Organic chemistry is a subject which based on experiments, students can master the basic operation skills by experiments, deepening the theory knowledge and principle, to develop the scientific attitude of seeking truth from facts. Aimed at the problems existing in the traditional organic chemistry experiment teaching and the disadvantages, in the organic chemistry experiments, “self-help” experimental teaching methods were used, by means of optional experiments, to provide a variety of experimental scheme to students, so that the students can select experiment contents and experimental supplies according to their own interest and ability, setting up laboratory’s“buffet”, to improve students’ enthusiasm and to develop students’ innovative thinking and practical ability.

  15. ACE-FTS observations of pyrogenic trace species in boreal biomass burning plumes during BORTAS

    Science.gov (United States)

    Tereszchuk, K. A.; González Abad, G.; Clerbaux, C.; Hadji-Lazaro, J.; Hurtmans, D.; Coheur, P.-F.; Bernath, P. F.

    2013-05-01

    To further our understanding of the effects of biomass burning emissions on atmospheric composition, the BORTAS campaign (BOReal forest fires on Tropospheric oxidants over the Atlantic using Aircraft and Satellites) was conducted on 12 July to 3 August 2011 during the boreal forest fire season in Canada. The simultaneous aerial, ground and satellite measurement campaign sought to record instances of boreal biomass burning to measure the tropospheric volume mixing ratios (VMRs) of short- and long-lived trace molecular species from biomass burning emissions. The goal was to investigate the connection between the composition and the distribution of these pyrogenic outflows and their resulting perturbation to atmospheric chemistry, with particular focus on oxidant species to determine the overall impact on the oxidizing capacity of the free troposphere. Measurements of pyrogenic trace species in boreal biomass burning plumes were made by the Atmospheric Chemistry Experiment Fourier Transform Spectrometer (ACE-FTS) onboard the Canadian Space Agency (CSA) SCISAT-1 satellite during the BORTAS campaign. Even though biomass burning emissions are typically confined to the boundary layer, outflows are often injected into the upper troposphere by isolated convection and fire-related convective processes, thus allowing space-borne instruments to measure these pyrogenic outflows. An extensive set of 14 molecules - CH3OH, C2H2, C2H6, C3H6O, CO, HCN, HCOOH, HNO3, H2CO, NO, NO2, OCS, O3, and PAN - have been analysed. Included in this analysis is the calculation of age-dependent sets of enhancement ratios for each of the species originating from fires in North America (Canada, Alaska) and Siberia for a period of up to 7 days. Ratio values for the shorter lived primary pyrogenic species decrease over time primarily due to oxidation by the OH radical as the plume ages and values for longer lived species such as HCN and C2H6 remain relatively unchanged. Increasing negative values are

  16. Computational chemistry

    Science.gov (United States)

    Arnold, J. O.

    1987-01-01

    With the advent of supercomputers, modern computational chemistry algorithms and codes, a powerful tool was created to help fill NASA's continuing need for information on the properties of matter in hostile or unusual environments. Computational resources provided under the National Aerodynamics Simulator (NAS) program were a cornerstone for recent advancements in this field. Properties of gases, materials, and their interactions can be determined from solutions of the governing equations. In the case of gases, for example, radiative transition probabilites per particle, bond-dissociation energies, and rates of simple chemical reactions can be determined computationally as reliably as from experiment. The data are proving to be quite valuable in providing inputs to real-gas flow simulation codes used to compute aerothermodynamic loads on NASA's aeroassist orbital transfer vehicles and a host of problems related to the National Aerospace Plane Program. Although more approximate, similar solutions can be obtained for ensembles of atoms simulating small particles of materials with and without the presence of gases. Computational chemistry has application in studying catalysis, properties of polymers, all of interest to various NASA missions, including those previously mentioned. In addition to discussing these applications of computational chemistry within NASA, the governing equations and the need for supercomputers for their solution is outlined.

  17. ACE up the sleeve – are vascular patients medically optimized

    Directory of Open Access Journals (Sweden)

    AP Coveney

    2011-01-01

    Full Text Available AP Coveney, GC O’Brien, GJ FultonDepartment of Vascular Surgery, Cork University Hospital and National University of Ireland, Cork, IrelandObjective: To examine the current medical management of arteriopathic patients attending a vascular surgical service at a university teaching hospital over a 6-month period. The prescribing of antiplatelets, statins, angiotensin-converting enzyme (ACE inhibitors, or angiotensin receptor blockers and beta-blockers was specifically examined. Vascular patients are often under the care of multiple specialties, and therefore the influence of different medical specialties on the patients’ medical management was also examined.Design: Between January and June 2009, data were recorded on sequential patients with arterial disease attending the vascular surgical service. Patients’ demographics, type of arterial disease, medical consultations within the previous 12 months, and current medications were recorded.Results: The study included 180 patients with a mean age of 69 years (39–88 years. All but 4% were taking an antiplatelet or anticoagulant, predominantly aspirin. There were 86% taking a statin, 44% taking a beta-blocker, and 51% taking an ACE inhibitor. Suboptimal prescription of ACE inhibitors and beta-blockers was evident regardless of the type of medical consultations in the previous year. No specialty group differed significantly from vascular surgeons in their prescribing pattern.Conclusions: While almost all arteriopaths receive some form of antiplatelet and statin in line with clinical evidence, ACE inhibitors and beta-blockers appear to be under-prescribed in this arteriopathic population. We conclude that opportunity exists for vascular surgeons to embrace recent guidelines and lead the way in both surgical and medical optimization of arteriopathic patients through improving links with primary care physicians or taking greater responsibility themselves for the medical as well as the surgical care

  18. [Trials with ACE-inhibitors in acute myocardial infarction].

    Science.gov (United States)

    Dalla Volta, S

    1994-12-01

    In acute myocardial infarction, the results of the trials with ACE-inhibitors have not been always good, in contrast with what has been observed in chronic heart failure. The comparison of these compounds with the placebo has demonstrated lack of reduction of mortality in the study CONSENSUS II, favorable results on the survival as first endpoint and on the secondary endpoints, as reinfarction, heart failure and stroke in the studies SOLVD, AIRE, GISSI 3, ISIS 4, and uncertain (interim report) results in the Chinese study. Nevertheless, the analysis of the recruitment of the patients with acute infarction and the way these patients have been treated seem to be the most important cause of the conflicting results. ACE-inhibitors have proved no efficacy in acute myocardial infarction without signs of left ventricular failure (CONSENSUS II), have worsened the clinical picture and the mortality in patients in shock or with severe heart failure in the acute phase. On the reverse, in presence of mild to moderate left ventricular dysfunction and failure, the use of ACE-inhibitors has been followed by reduction of mortality in the early (AIRE, GISSI 3, ISIS 4), medium term (GISSI 3) and long-term follow-up (up to 4 years in the AIRE study). In parallel with the reduction of the primary endpoint, also secondary endpoints have been favorably influenced by the different ACE-inhibitors. No differences have been observed among the different class of compounds. ACE-inhibitors seem, therefore, to have a clear indication in acute myocardial infarction with mild or moderate signs and symptoms of heart failure. PMID:7634258

  19. A crucial role in fertility for the oyster angiotensin-converting enzyme orthologue CgACE.

    Science.gov (United States)

    Riviere, Guillaume; Fellous, Alexandre; Franco, Alban; Bernay, Benoit; Favrel, Pascal

    2011-01-01

    Angiotensin-converting enzyme (ACE) is a highly conserved metallopeptidase. In mammals, the somatic isoform governs blood pressure whereas the germinal isoform (tACE) is required for fertility. In Ecdysozoans, ACE-like enzymes are implicated in reproduction. Despite ACE orthologues being present from bacteria to humans, their function(s) remain(s) unknown in distant organisms such as Lophotrochozoans. In silico analysis of an oyster (Crassostrea gigas) EST library suggested the presence of an ACE orthologue in molluscs. Primer walking and 5'-RACE revealed that the 1.9 kb cDNA encodes CgACE, a 632 amino acid protein displaying a conserved single active site and a putative C-terminal transmembrane anchor, thus resembling human tACE, as supported by molecular modelling. FRET activity assays and Maldi-TOF spectrometry indicated that CgACE is a functional dipeptidyl-carboxypeptidase which is active on Angiotensin I and sensitive to ACE inhibitors and chloride ion concentration. Immunocytochemistry revealed that, as its human counterpart, recombinant CgACE is synthesised as a transmembrane enzyme. RT-qPCR, in-situ hybridization and immunohistochemistry shed light on a tissue, and development stage, specific expression pattern for CgACE, which is increased in the gonad during spermatogenesis. The use of ACE inhibitors in vivo indicates that the dipeptidase activity of CgACE is crucial for the oyster fertilization. Our study demonstrates that a transmembrane active ACE is present in the oyster Crassostrea gigas, and for the first time ascribes a functional role for ACE in Lophotrochozoans. Its biological function in reproduction is conserved from molluscs to humans, a finding of particular evolutionary interest especially since oysters represent the most important aquaculture resource worldwide. PMID:22174750

  20. A crucial role in fertility for the oyster angiotensin-converting enzyme orthologue CgACE.

    Directory of Open Access Journals (Sweden)

    Guillaume Riviere

    Full Text Available Angiotensin-converting enzyme (ACE is a highly conserved metallopeptidase. In mammals, the somatic isoform governs blood pressure whereas the germinal isoform (tACE is required for fertility. In Ecdysozoans, ACE-like enzymes are implicated in reproduction. Despite ACE orthologues being present from bacteria to humans, their function(s remain(s unknown in distant organisms such as Lophotrochozoans. In silico analysis of an oyster (Crassostrea gigas EST library suggested the presence of an ACE orthologue in molluscs. Primer walking and 5'-RACE revealed that the 1.9 kb cDNA encodes CgACE, a 632 amino acid protein displaying a conserved single active site and a putative C-terminal transmembrane anchor, thus resembling human tACE, as supported by molecular modelling. FRET activity assays and Maldi-TOF spectrometry indicated that CgACE is a functional dipeptidyl-carboxypeptidase which is active on Angiotensin I and sensitive to ACE inhibitors and chloride ion concentration. Immunocytochemistry revealed that, as its human counterpart, recombinant CgACE is synthesised as a transmembrane enzyme. RT-qPCR, in-situ hybridization and immunohistochemistry shed light on a tissue, and development stage, specific expression pattern for CgACE, which is increased in the gonad during spermatogenesis. The use of ACE inhibitors in vivo indicates that the dipeptidase activity of CgACE is crucial for the oyster fertilization. Our study demonstrates that a transmembrane active ACE is present in the oyster Crassostrea gigas, and for the first time ascribes a functional role for ACE in Lophotrochozoans. Its biological function in reproduction is conserved from molluscs to humans, a finding of particular evolutionary interest especially since oysters represent the most important aquaculture resource worldwide.

  1. 地方院校物理化学实验教学改革探讨%Teaching Reform of Physical Chemistry Experiment in Local Colleges

    Institute of Scientific and Technical Information of China (English)

    李浩; 张喜斌; 金真; 刘惠茹

    2011-01-01

    Based on the situation and characteristics of local colleges, some suggestions for the teaching reform of physical chemistry experiment were proposed, including making full use of the limited experimental resource, preparing the experiments with the assistance of the internet, reforming the contents and style of experiments, processing the experimental data with computer software as well as the cooperation between theory and experiment. By doing so, both the teaching performance in the physical chemistry experiment course and comprehensive ability of the students were greatly improved.%结合地方院校的实际情况和特点,提出了物理化学实验教学改革措施,包括充分利用有限的实验资源、利用网络资源做预习报告、改革教学内容和教学模式、利用电脑软件处理实验数据以及注意物理化学理论课和实验课的配合.通过这些改革措施有效地提高了物理化学实验教学质量和学生的综合能力.

  2. ACE INHIBITOR POSSIBILITIES IN CLINICAL PRACTICE: WHAT WE KNOW ABOUT THEM?

    Directory of Open Access Journals (Sweden)

    D. V. Nebieridze

    2010-01-01

    Full Text Available New possibilities of ACE inhibitors application on the base of international trails review are presented. Traditional therapy areas of ACE inhibitors (hypertension, heart failure are well known. However recent studies have shown that ACE inhibitors improve prognosis in patients with clinically proved atherosclerosis. This ACE inhibitor ability is a result of their high vasoprotective effect. It provides new clinical possibilities for their use for slowing a progression of diseases associated with atherosclerosis. However this property can not be extended to all ACE inhibitors. Only ramipril and perindopril have a strong evidence base.

  3. Smart tetroons for Lagrangian air-mass tracking during ACE 1

    Science.gov (United States)

    Businger, Steven; Johnson, Randy; Katzfey, Jack; Siems, Steven; Wang, Qing

    1999-05-01

    A series of "smart" tetroons was released from shipboard during the recent ACE 1 field experiment designed to monitor changes in the sulfur budget in a remote marine boundary layer (MBL) south of Tasmania, Australia. The smart tetroons were designed at NOAA Air Resources Laboratory Field Research Division to provide air parcel tracking information. The adjective smart here refers here to the fact that the buoyancy of the tetroons automatically adjusts through the action of a pump and valves when the tetroon travels vertically outside a range of pressures set prior to tetroon release. The smart tetroon design provides GPS location, barometric pressure, temperature, relative humidity, and tetroon status data via a transponder to the NCAR C-130 research aircraft flying in the vicinity of the tetroons. In this paper we will describe (1) the design and capability of the smart tetroons and their performance during the two Lagrangian experiments conducted during ACE 1, (2) the synoptic context of the Lagrangians, including the origin of the air parcels being tracked, and (3) the results of trajectory predictions derived from the National Center for Environmental Prediction (NCEP) Global Spectral Model (GSM) and Australia's Commonwealth Scientific and Industrial Research Organization (CSIRO) Division of Atmospheric Research (DAR) limited-area model.

  4. A case study of the effects of social experiences on the science identity formation of Mexican American females in high school chemistry

    Science.gov (United States)

    Beeton, Renee P.

    Mexican Americans are a rapidly growing ethnic group in the United States. However, they are noticeably absent from physical science fields. Little research has explored the experiences of Mexican American girls in high school chemistry. The theories of identity based on communities of practice and multicultural feminism framed this year-long case study of nine Mexican American girls in a high school chemistry course. This study explored the social encounters and experiences that shaped the participants' identities and how their views of themselves affected their attitudes towards high school chemistry and future science careers. Data collection included a focus group and in-depth interviews with the participants, classroom observations, and teacher interviews. Five main identities influenced the participants' potential to become a scientist: ethnic, gender, science, student, and college. Mexican ethnic identity was the overarching identity; however gender also influenced the participants' other identities. The participants were aware of ethnic gender stereotypes that might hinder them from being successful in science. Also, ethnic factors, such as citizenship and abilities to receive financial aid limited their views of themselves as chemists. Participatory science, student, and school identities were all needed in order for the participants to be potential scientists. Family expectations, authentic relationships with teachers, and personal connections were important factors in the development of these participatory identities.

  5. Mechanochemical Synthesis of Two Polymorphs of the Tetrathiafulvalene-Chloranil Charge Transfer Salt: An Experiment for Organic Chemistry

    Science.gov (United States)

    Wixtrom, Alex; Buhler, Jessica; Abdel-Fattah, Tarek

    2014-01-01

    Mechanochemical syntheses avoid or considerably reduce the use of reaction solvents, thus providing green chemistry synthetic alternatives that are both environmentally friendly and economically advantageous. The increased solid-state reactivity generated by mechanical energy imparted to the reactants by grinding or milling can offer alternative…

  6. Surface-Enhanced Resonance Raman Scattering and Visible Extinction Spectroscopy of Copper Chlorophyllin: An Upper Level Chemistry Experiment

    Science.gov (United States)

    Schnitzer, Cheryl S.; Reim, Candace Lawson; Sirois, John J.; House, Paul G.

    2010-01-01

    Advanced chemistry students are introduced to surface-enhanced resonance Raman scattering (SERRS) by studying how sodium copper chlorophyllin (CuChl) adsorbs onto silver colloids (CuChl/Ag) as a function of pH. Using both SERRS and visible extinction spectroscopy, the extent of CuChl adsorption and colloidal aggregation are monitored. Initially at…

  7. Determination of Molecular Self-Diffusion Coefficients Using Pulsed-Field-Gradient NMR: An Experiment for Undergraduate Physical Chemistry Laboratory

    Science.gov (United States)

    Harmon, Jennifer; Coffman, Cierra; Villarrial, Spring; Chabolla, Steven; Heisel, Kurt A.; Krishnan, Viswanathan V.

    2012-01-01

    NMR spectroscopy has become one of the primary tools that chemists utilize to characterize a range of chemical species in the solution phase, from small organic molecules to medium-sized proteins. A discussion of NMR spectroscopy is an essential component of physical and biophysical chemistry lecture courses, and a number of instructional…

  8. Experiences and Reflections about Teaching Atomic Structure in a Jigsaw Classroom in Lower Secondary School Chemistry Lessons

    Science.gov (United States)

    Eilks, Ingo

    2005-01-01

    The study investigates the students opinions on learning in a jigsaw classroom and enquiring on what they think about jigsaw classroom having the potential to make chemistry learning more attractive and whether it can help them to improve their communicative and social skills. The study was carried out using a lesson design for teaching an…

  9. Measurement of Henry's Law Constants Using Internal Standards: A Quantitative GC Experiment for the Instrumental Analysis or Environmental Chemistry Laboratory

    Science.gov (United States)

    Ji, Chang; Boisvert, Susanne M.; Arida, Ann-Marie C.; Day, Shannon E.

    2008-01-01

    An internal standard method applicable to undergraduate instrumental analysis or environmental chemistry laboratory has been designed and tested to determine the Henry's law constants for a series of alkyl nitriles. In this method, a mixture of the analytes and an internal standard is prepared and used to make a standard solution (organic solvent)…

  10. Synthesis and Characterization of Europium(III) and Terbium(III) Complexes: An Advanced Undergraduate Inorganic Chemistry Experiment

    Science.gov (United States)

    Swavey, Shawn

    2010-01-01

    Undergraduate laboratories rarely involve lanthanide coordination chemistry. This is unfortunate in light of the ease with which many of these complexes are made and the interesting and instructive photophysical properties they entail. The forbidden nature of the 4f transitions associated with the lanthanides is overcome by incorporation of…

  11. Chemistry in Microfluidic Channels

    Science.gov (United States)

    Chia, Matthew C.; Sweeney, Christina M.; Odom, Teri W.

    2011-01-01

    General chemistry introduces principles such as acid-base chemistry, mixing, and precipitation that are usually demonstrated in bulk solutions. In this laboratory experiment, we describe how chemical reactions can be performed in a microfluidic channel to show advanced concepts such as laminar fluid flow and controlled precipitation. Three sets of…

  12. Primary chemistry as an action lever to reduce the source term. Review of the experience at Doel 3 and 4

    International Nuclear Information System (INIS)

    Dose rate reduction is of primary concern in order to make nuclear energy part of the future energy mix. This article presents the chemistry related actions undertaken at Doel 3 and 4 units in order to reduce the source term. Doel 3 and 4 are two 3 loops 1000 MWe Pressurized Water Reactors which respectively started operating commercial in 1982 and 1985. Both units have undergone a steam generators replacement: from Inconel 600MA tubing material to Incoloy 800 in 1993 for D3 and to Inconel 690TT in 1996 for D4. Until now, very similar chemistry strategies during operation, startup and shutdown have been applied in both units. They are in good accordance with the international standards. Both units operate under a coordinated chemistry, with a target pHTave=7.2. Dissolved hydrogen concentration is maintained in the range 25-35 cc/kg STD H2O. During shutdown, oxygenation is performed at full loop by means of hydrogen peroxide injections. However, significant differences in dose rates have been observed between the two units, with higher levels in Doel 3. In an attempt to understand these differences and to define new improvements pathways to lower the dose rates, this article assesses the chemistry strategy based on the available radiochemistry data, the RCS oxide layers characterization and the measured dose rates around the primary system. Primary chemistry strategy seems to be suited to maintain low level of radiation fields at Doel 4. However, Doel 3 is characterized by a contamination mainly driven by the Co-60. Specific actions have to be undertaken to minimize dose rates at Doel 3. Regarding the high contribution of Co-60 to dose rates, zinc injection seems to be a promising mitigation technique. (author)

  13. Recent Observations of Clouds and Precipitation by the Airborne Precipitation Radar 2nd Generation in Support of the GPM and ACE Missions

    Science.gov (United States)

    Durden, Stephen L.; Tanelli, Simone; Im, Eastwood

    2012-01-01

    In this paper we illustrate the unique dataset collected during the Global Precipitation Measurement Cold-season Precipitation Experiment (GCPEx, US/Canada Jan/Feb 2012). We will focus on the significance of these observations for the development of algorithms for GPM and ACE, with particular attention to classification and retrievals of frozen and mixed phase hydrometeors.

  14. Adverse childhood experiences, gender, and HIV risk behaviors: Results from a population-based sample.

    Science.gov (United States)

    Fang, Lin; Chuang, Deng-Min; Lee, Yookyong

    2016-12-01

    Recent HIV research suggested assessing adverse childhood experiences (ACEs) as contributing factors of HIV risk behaviors. However, studies often focused on a single type of adverse experience and very few utilized population-based data. This population study examined the associations between ACE (individual and cumulative ACE score) and HIV risk behaviors. We analyzed the 2012 Behavioral Risk Factor Surveillance Survey (BRFSS) from 5 states. The sample consisted of 39,434 adults. Eight types of ACEs that included different types of child abuse and household dysfunctions before the age of 18 were measured. A cumulative score of ACEs was also computed. Logistic regression estimated of the association between ACEs and HIV risk behaviors using odds ratio (OR) with 95% confidence intervals (CIs) for males and females separately. We found that ACEs were positively associated with HIV risk behaviors overall, but the associations differed between males and females in a few instances. While the cumulative ACE score was associated with HIV risk behaviors in a stepwise manner, the pattern varied by gender. For males, the odds of HIV risk increased at a significant level as long as they experienced one ACE, whereas for females, the odds did not increase until they experienced three or more ACEs. Future research should further investigate the gender-specific associations between ACEs and HIV risk behaviors. As childhood adversities are prevalent among general population, and such experiences are associated with increased risk behaviors for HIV transmission, service providers can benefit from the principles of trauma-informed practice. PMID:27413671

  15. Complex chemistry

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Bong Gon; Kim, Jae Sang; Kim, Jin Eun; Lee, Boo Yeon

    2006-06-15

    This book introduces complex chemistry with ten chapters, which include development of complex chemistry on history coordination theory and Warner's coordination theory and new development of complex chemistry, nomenclature on complex with conception and define, chemical formula on coordination compound, symbol of stereochemistry, stereo structure and isomerism, electron structure and bond theory on complex, structure of complex like NMR and XAFS, balance and reaction on solution, an organo-metallic chemistry, biology inorganic chemistry, material chemistry of complex, design of complex and calculation chemistry.

  16. Complex chemistry

    International Nuclear Information System (INIS)

    This book introduces complex chemistry with ten chapters, which include development of complex chemistry on history coordination theory and Warner's coordination theory and new development of complex chemistry, nomenclature on complex with conception and define, chemical formula on coordination compound, symbol of stereochemistry, stereo structure and isomerism, electron structure and bond theory on complex, structure of complex like NMR and XAFS, balance and reaction on solution, an organo-metallic chemistry, biology inorganic chemistry, material chemistry of complex, design of complex and calculation chemistry.

  17. Mathematical Chemistry

    OpenAIRE

    Trinajstić, Nenad; Gutman, Ivan

    2002-01-01

    A brief description is given of the historical development of mathematics and chemistry. A path leading to the meeting of these two sciences is described. An attempt is made to define mathematical chemistry, and journals containing the term mathematical chemistry in their titles are noted. In conclusion, the statement is made that although chemistry is an experimental science aimed at preparing new compounds and materials, mathematics is very useful in chemistry, among other things, to produc...

  18. An inquiry into factors affecting the online learning experiences of A-level chemistry students studying in a blended learning course in a college in Malta and the impact of these experiences on learning identity

    OpenAIRE

    Role, Sharon Joan

    2014-01-01

    This study carried out as practitioner-research explores the new online collaborative learning experiences of a class of thirty-seven college students studying A-level chemistry in a blended learning context. It is a case-study with a multi-method interpretivist approach using observations, unsolicited meetings, VLE tracking system, students’ reflective journal, online informal discussions, questionnaires, focus groups and individual interviews. The students, used to traditional non-collabo...

  19. Extracting physical chemistry from mechanics: a new approach to investigate DNA interactions with drugs and proteins in single molecule experiments

    CERN Document Server

    Rocha, M S

    2015-01-01

    In this review we focus on the idea of establishing connections between the mechanical properties of DNAligand complexes and the physical chemistry of DNA-ligand interactions. This type of connection is interesting because it opens the possibility of performing a robust characterization of such interactions by using only one experimental technique: single molecule stretching. Furthermore, it also opens new possibilities in comparing results obtained by very different approaches, in special when comparing single molecule techniques to ensemble-averaging techniques. We start the manuscript reviewing important concepts of the DNA mechanics, from the basic mechanical properties to the Worm-Like Chain model. Next we review the basic concepts of the physical chemistry of DNA-ligand interactions, revisiting the most important models used to analyze the binding data and discussing their binding isotherms. Then, we discuss the basic features of the single molecule techniques most used to stretch the DNA-ligand complex...

  20. Beauty in chemistry

    Directory of Open Access Journals (Sweden)

    Peter Atkins

    2006-03-01

    Full Text Available Though hard going for the general reader and highly personal in its selectivity, Elegant Solutions: Ten Beautiful Experiments in Chemistry provides reflections of a thoughtful author that will delight chemists

  1. Beauty in chemistry

    OpenAIRE

    Peter Atkins

    2006-01-01

    Though hard going for the general reader and highly personal in its selectivity, Elegant Solutions: Ten Beautiful Experiments in Chemistry provides reflections of a thoughtful author that will delight chemists

  2. Parallel Signal Processing and System Simulation using aCe

    Science.gov (United States)

    Dorband, John E.; Aburdene, Maurice F.

    2003-01-01

    Recently, networked and cluster computation have become very popular for both signal processing and system simulation. A new language is ideally suited for parallel signal processing applications and system simulation since it allows the programmer to explicitly express the computations that can be performed concurrently. In addition, the new C based parallel language (ace C) for architecture-adaptive programming allows programmers to implement algorithms and system simulation applications on parallel architectures by providing them with the assurance that future parallel architectures will be able to run their applications with a minimum of modification. In this paper, we will focus on some fundamental features of ace C and present a signal processing application (FFT).

  3. Progress in Airborne Polarimeter Inter Comparison for the NASA Aerosols-Clouds-Ecosystems (ACE) Mission

    Science.gov (United States)

    Knobelspiesse, Kirk; Redemann, Jens

    2014-01-01

    The Aerosols-Clouds-Ecosystems (ACE) mission, recommended by the National Research Council's Decadal Survey, calls for a multi-angle, multi-spectral polarimeter devoted to observations of atmospheric aerosols and clouds. In preparation for ACE, NASA funds the deployment of airborne polarimeters, including the Airborne Multiangle SpectroPolarimeter Imager (AirMSPI), the Passive Aerosol and Cloud Suite (PACS) and the Research Scanning Polarimeter (RSP). These instruments have been operated together on NASA's ER-2 high altitude aircraft as part of field campaigns such as the POlarimeter DEfinition EXperiment (PODEX) (California, early 2013) and Studies of Emissions and Atmospheric Composition, Clouds and Climate Coupling by Regional Surveys (SEAC4RS, California and Texas, summer 2013). Our role in these efforts has been to serve as an assessment team performing level 1 (calibrated radiance, polarization) and level 2 (retrieved geophysical parameter) instrument intercomparisons, and to promote unified and generalized calibration, uncertainty assessment and retrieval techniques. We will present our progress in this endeavor thus far and describe upcoming research in 2015.

  4. Airborne Polarimeter Intercomparison for the NASA Aerosols-Clouds-Ecosystems (ACE) Mission

    Science.gov (United States)

    Knobelspiesse, Kirk; Redemann, Jens

    2014-01-01

    The Aerosols-Clouds-Ecosystems (ACE) mission, recommended by the National Research Council's Decadal Survey, calls for a multi-angle, multi-spectral polarimeter devoted to observations of atmospheric aerosols and clouds. In preparation for ACE, NASA funds the deployment of airborne polarimeters, including the Airborne Multi-angle SpectroPolarimeter Imager (AirMSPI), the Passive Aerosol and Cloud Suite (PACS) and the Research Scanning Polarimeter (RSP). These instruments have been operated together on NASA's ER-2 high altitude aircraft as part of field campaigns such as the POlarimeter DEfinition EXperiment (PODEX) (California, early 2013) and Studies of Emissions and Atmospheric Composition, Clouds and Climate Coupling by Regional Surveys (SEAC4RS, California and Texas, summer 2013). Our role in these efforts has been to serve as an assessment team performing level 1 (calibrated radiance, polarization) and level 2 (retrieved geophysical parameter) instrument intercomparisons, and to promote unified and generalized calibration, uncertainty assessment and retrieval techniques. We will present our progress in this endeavor thus far and describe upcoming research in 2015.

  5. Valuation of international oil companies : the RoACE era

    OpenAIRE

    Osmundsen, Petter; Asche, Frank; Mohn, Klaus

    2004-01-01

    To improve their basis for investment recommendations and decisions, stock market analysts and investors make extensive use of operational and financial indicators. For the international oil and gas industry, a predominant indicator is return on capital employed (RoACE). The rationale for using this indicator is an assumed correlation between rentability and valuation metrics. Based on panel data for 11 international oil and gas companies, we seek to establish econometric relations between ma...

  6. ACE up the sleeve - are vascular patients medically optimized?

    LENUS (Irish Health Repository)

    Coveney, A P

    2011-03-01

    To examine the current medical management of arteriopathic patients attending a vascular surgical service at a university teaching hospital over a 6-month period. The prescribing of antiplatelets, statins, angiotensin-converting enzyme (ACE) inhibitors, or angiotensin receptor blockers and beta-blockers was specifically examined. Vascular patients are often under the care of multiple specialties, and therefore the influence of different medical specialties on the patients\\' medical management was also examined.

  7. Theory of Aces: Fame by chance or merit?

    OpenAIRE

    Simkin, M. V.; Roychowdhury, V. P.

    2003-01-01

    We study empirically how fame of WWI fighter-pilot aces, measured in numbers of web pages mentioning them, is related to their achievement or merit, measured in numbers of opponent aircraft destroyed. We find that on the average fame grows exponentially with achievement; to be precise, there is a strong correlation (~0.7) between achievement and the logarithm of fame. At the same time, the number of individuals achieving a particular level of merit decreases exponentially with the magnitude o...

  8. Assertion checking environment (ACE) for formal verification of C programs

    International Nuclear Information System (INIS)

    In this paper we describe an Assertion Checking Environment (ACE) for compositional verification of programs, which are written in an industrially sponsored safe subset of C programming language called MISRA C [Guidelines for the Use of the C Language in Vehicle Based Software, 1998]. The theory is based on Hoare logic [Commun. ACM 12 (1969) 576] and the C programs are verified using static assertion checking technique. First the functional specifications of the program, captured in the form of pre- and post-conditions for each C function, are derived from the specifications. These pre- and post-conditions are then introduced as assertions (also called annotations or formal comments) in the program code. The assertions are then proved formally using ACE and theorem proving tool called Stanford Temporal Prover [The Stanford Temporal Prover User's Manual, 1998]. ACE has been developed by us and consists mainly of a translator c2spl, a GUI and some utility programs. The technique and tools developed are targeted towards verification of real-time embedded software

  9. 生化学实验中培养学生的创造性思维%Cultivating Students' Innovative Thinking in Chemistry Experiments

    Institute of Scientific and Technical Information of China (English)

    宁封耀

    2011-01-01

    Innovative thinking is a kind of psychological process in which an individual creates new matters in brains according to certain objectives and tasks. This paper throws light on how to cultivate students' innovative thinking in chemistry experiments.%创造性思维就是根据一定的目的、任务,在头脑中独立地创造出新事物的心理过程。本文论述了如何在化学实验中培养学生创造性思维。

  10. Linking systemic arterial stiffness among adolescents to adverse childhood experiences.

    Science.gov (United States)

    Klassen, Stephen A; Chirico, Daniele; O'Leary, Deborah D; Cairney, John; Wade, Terrance J

    2016-06-01

    Adverse childhood experiences (ACEs) have been linked with cardiovascular disease and early mortality among adults. Most research examines this relationship retrospectively. Examining the association between ACEs and children's cardiovascular health is required to understand the time course of this association. We examined the relationship between ACEs exposure and ECG-to-toe pulse wave velocity (PWV), a measure of systemic arterial stiffness that is strongly related to cardiovascular mortality among adults. PWV (distance/transit time; m/s) was calculated using transit times from the ECG R-wave to the pulse wave contour at the toe. Transit times were collected over 15 heartbeats and the distance from the sternal notch to the left middle toe was used. A total of 221 children (119 females) aged 10-14 years participated in data collection of PWV, hemodynamic and anthropometric variables. Parents of these children completed a modified inventory of ACEs taken from the Childhood Trust Events Survey. Multivariable regression assessed the relationship between ACEs group (<4 ACEs versus ≥4 ACEs) and PWV. Analyses yielded an ACEs group by sex interaction, with males who experienced four or more ACEs having higher PWV (p<0.01). This association was independent of hemodynamic, anthropometric and sociodemographic variables (R(2)=0.346; p<0.01). Four or more ACEs is associated with greater arterial stiffness in male children aged 10-14 years. Addressing stress and trauma exposure in childhood is an important target for public health interventions to reduce early cardiovascular risk. PMID:27107504

  11. ACE2 gene expression is up-regulated in the human failing heart

    Directory of Open Access Journals (Sweden)

    Allen Jennifer C

    2004-05-01

    Full Text Available Abstract Background ACE2 is a novel homologue of angiotensin converting enzyme (ACE. ACE2 is highly expressed in human heart and animal data suggest that ACE2 is an essential regulator of cardiac function in vivo. Since overactivity of the renin-angiotensin system contributes to the progression of heart failure, this investigation assessed changes in gene expression of ACE2, ACE, AT1 receptor and renin in the human failing heart. Methods The sensitive technique of quantitative reverse transcriptase polymerase chain reaction was used to determine the level of mRNA expression of ACE and ACE2 in human ventricular myocardium from donors with non-diseased hearts (n = 9, idiopathic dilated cardiomyopathy (IDC, n = 11 and ischemic cardiomyopathy (ICM, n = 12. Following logarithmic transformation of the data, a one-way analysis of variance was performed for each target gene followed by a Dunnett's test to compare the two disease groups IDC and ICM versus control. Results As anticipated, ACE mRNA was found to be significantly increased in the failing heart with a 3.1 and 2.4-fold up-regulation found in IDC and ICM relative to non-diseased myocardium. Expression of ACE2 mRNA was also significantly up-regulated in IDC (2.4-fold increase and ICM (1.8-fold increase versus non-diseased myocardium. No change in angiotensin AT1 receptor mRNA expression was found in failing myocardium and renin mRNA was not detected. Conclusions These data suggest that ACE2 is up-regulated in human IDC and ICM and are consistent with the hypothesis that differential regulation of this enzyme may have important functional consequences in heart failure. This strengthens the hypothesis that ACE2 may be a relevant target for the treatment of heart failure and will hopefully spur further studies to clarify the functional effects in human myocardium of ACE2 derived peptides.

  12. Assessing Cost-Effectiveness in Obesity (ACE-Obesity: an overview of the ACE approach, economic methods and cost results

    Directory of Open Access Journals (Sweden)

    Swinburn Boyd

    2009-11-01

    Full Text Available Abstract Background The aim of the ACE-Obesity study was to determine the economic credentials of interventions which aim to prevent unhealthy weight gain in children and adolescents. We have reported elsewhere on the modelled effectiveness of 13 obesity prevention interventions in children. In this paper, we report on the cost results and associated methods together with the innovative approach to priority setting that underpins the ACE-Obesity study. Methods The Assessing Cost Effectiveness (ACE approach combines technical rigour with 'due process' to facilitate evidence-based policy analysis. Technical rigour was achieved through use of standardised evaluation methods, a research team that assembles best available evidence and extensive uncertainty analysis. Cost estimates were based on pathway analysis, with resource usage estimated for the interventions and their 'current practice' comparator, as well as associated cost offsets. Due process was achieved through involvement of stakeholders, consensus decisions informed by briefing papers and 2nd stage filter analysis that captures broader factors that influence policy judgements in addition to cost-effectiveness results. The 2nd stage filters agreed by stakeholders were 'equity', 'strength of the evidence', 'feasibility of implementation', 'acceptability to stakeholders', 'sustainability' and 'potential for side-effects'. Results The intervention costs varied considerably, both in absolute terms (from cost saving [6 interventions] to in excess of AUD50m per annum and when expressed as a 'cost per child' estimate (from Conclusion The use of consistent methods enables valid comparison of potential intervention costs and cost-offsets for each of the interventions. ACE-Obesity informs policy-makers about cost-effectiveness, health impact, affordability and 2nd stage filters for important options for preventing unhealthy weight gain in children. In related articles cost-effectiveness results and

  13. Experience in performing the commissioning procedures for meeting the requirements of water chemistry at NPP With VVER

    International Nuclear Information System (INIS)

    The integrity of NPP Unit equipment and pipelines is assured by strict following the requirements of rules and regulations by the NPP personnel in the field of nuclear power engineering and other regulatory documents. But all efforts of NPP personnel are unavailing in case of violation of the requirements of design documentation during Unit commissioning. Here the surface cleanness of equipment and pipelines during mounting, the post-mounting cleaning and assurance of water chemistry quality figures during commissioning procedures are of importance. During commissioning activities at the Unit of NPP with VVER a number of procedures are performed and the important place belongs to the procedures on water chemistry coordination. Post-mounting washing of steam generators is intended for cleaning and washing the steam generator internal surfaces against corrosion products, corrosive impurities, preservative residue and mounting fouling. During circulation washing of the reactor plant primary circuit the final cleaning of the internal surfaces is performed as well as preparing for formation of the protective oxide film. During reactor plant «hot» running-in the homogeneous solid protective oxide film is formed during a long-term interaction of the primary circuit internal surfaces with the alkaline reducing medium created due to proportioning of hydrazine and potassium hydroxide into the primary water. The composition and structure of the protective oxide film, formed on the internal surfaces, is such that its safe keeping is assured during Unit further operation. (author)

  14. Enhancing the Practicum Experience for Pre-service Chemistry Teachers Through Collaborative CoRe Design with Mentor Teachers

    Science.gov (United States)

    Hume, Anne; Berry, Amanda

    2013-01-01

    This paper reports findings from an ongoing study exploring how the Content Representation (CoRe) design can be used as a tool to help chemistry student teachers begin acquiring the professional knowledge required to become expert chemistry teachers. Phase 2 of the study, reported in this paper, investigated how collaboration with school-based mentors (associate teachers) on teaching practice (practicum) might impact on this process and student teachers' development of their pedagogical content knowledge (PCK). The collaboration involved identifying and discussing pedagogical issues related to a practicum-teaching topic using a student teacher's draft CoRe as a starting point and ongoing focus for the professional dialogue. Practicum offered an opportunity for aspects of student teachers' PCK, as embodied in their draft CoRes, to be explored and expanded upon in classroom programmes with the support and input of associate teachers. The findings were influenced by different contextual factors; however, the student teachers found their CoRes to be very useful frameworks for engaging in focussed professional dialogue with their teaching mentors. They valued the expertise, currency of knowledge and mentoring of their associates and reported positively about the contribution this support made to their PCK development via the CoRe design process and the transformation of the CoRe into classroom teaching.

  15. Effect of cation exchange of major cation chemistry in the large scale redox experiment at Aespoe. Revision 1

    International Nuclear Information System (INIS)

    Geochemical modeling was used to test the hypothesis that cation exchange with fracture-lining clays during fluid mixing in the Aespoe Hard Rock Laboratory can significantly affect major element chemistry. Conservative mixing models do not adequately account for changes in Na, Ca and Mg concentrations during mixing. Mixing between relatively dilute shallow waters and more concentrated waters at depth along fracture zones was modeled using the EQ3/6 geochemical modeling package. A cation exchange model was added to the code to describe simultaneously aqueous speciation, mineral precipitation/dissolution, and equilibration between a fluid and a cation exchanger. Fluid chemistries predicted to result from mixing were compared with those monitored from boreholes intersecting the fracture zone. Modeling results suggest that less than 0.1 equivalent of a smectite exchanger per liter of groundwater is necessary to account for discrepancies between predictions from a conservative mixing model and measured Na and Ca concentrations. This quantity of exchanger equates to an effective fracture coating thickness of 20 microm or less given a fracture aperture width of 1,000 microm or less. Trends in cation ratios in the fluid cannot be used to predict trends in cation ratios on the exchanger because of the influence of ionic strength on heterovalent exchange equilibrium. It is expected that Na for Ca exchange will dominate when shallow waters such as HBHO2 are mixed with deeper waters. In contrast, Na for Mg exchange will dominate mixing between deeper waters

  16. A Study of High School Students' Performance of a Chemistry Experiment within the Virtual World of Second Life

    Science.gov (United States)

    Winkelmann, Kurt; Scott, Matthew; Wong, Deborah

    2014-01-01

    A small group of high school students performed a virtual laboratory experiment in Second Life that mimicked a real experiment in both its appearance and procedure. Lab report grades were equivalent to report grades for hands-on experiments, and the quality of students' results was similar. Results of an attitudinal survey show that students…

  17. Combinatorial chemistry

    DEFF Research Database (Denmark)

    Nielsen, John

    1994-01-01

    An overview of combinatorial chemistry is presented. Combinatorial chemistry, sometimes referred to as `irrational drug design,' involves the generation of molecular diversity. The resulting chemical library is then screened for biologically active compounds.......An overview of combinatorial chemistry is presented. Combinatorial chemistry, sometimes referred to as `irrational drug design,' involves the generation of molecular diversity. The resulting chemical library is then screened for biologically active compounds....

  18. Positronium chemistry

    CERN Document Server

    Green, James

    1964-01-01

    Positronium Chemistry focuses on the methodologies, reactions, processes, and transformations involved in positronium chemistry. The publication first offers information on positrons and positronium and experimental methods, including mesonic atoms, angular correlation measurements, annihilation spectra, and statistical errors in delayed coincidence measurements. The text then ponders on positrons in gases and solids. The manuscript takes a look at the theoretical chemistry of positronium and positronium chemistry in gases. Topics include quenching, annihilation spectrum, delayed coincidence

  19. Elevated ACE activity is not associated with asthma, COPD, and COPD co-morbidity

    DEFF Research Database (Denmark)

    Lee, Julie; Nordestgaard, Børge G; Dahl, Morten

    2009-01-01

    .4-1.2). The results were similar upon adjustment for sex, age, smoking status, body mass index, total cholesterol, and ACE inhibitor/angiotensin II type 1 receptor blocker use. These data suggest that lifelong genetically elevated ACE activity is not a major risk factor for asthma or COPD, or for ischemic heart......The angiotensin-converting enzyme (ACE) gene is a potential candidate gene for risk of asthma, COPD, and COPD co-morbidity. In 9034 Danish adults, we determined whether individuals homozygous or heterozygous for the ACE D allele are at greater risk of asthma, COPD, or COPD co-morbidity compared...... with ACE II homozygous individuals. In the general population, serum ACE activity increased with the number of D alleles (Kruskal-Wallis ANOVA: II vs. ID, p

  20. Effect of pretreatment on enzymatic hydrolysis of bovine collagen and formation of ACE-inhibitory peptides

    DEFF Research Database (Denmark)

    Zhang, Yuhao; Olsen, Karsten; Grossi, Alberto Blak;

    2013-01-01

    Bovine collagen was pre-treated (boiled or high pressure (HP)-treated) and then hydrolysed by 6 proteases. The degree of hydrolysis (DH) and the angiotensin-converting enzyme (ACE)-inhibitory activity of hydrolysates were measured. All enzymes used were able to partly degrade collagen and release...... ACEinhibitory peptides. The highest ACE-inhibitory activity was obtained with Alcalase. Pretreatment significantly influenced the DH and ACE-inhibition. For most enzymes, boiling for 5 min resulted in a significantly higher DH and ACE-inhibitory activity. With Alcalase and collagenase, hydrolysis and release of...... ACE-inhibitory peptides occurred without any pretreatment, but HP-treatment significantly improved the DH and ACE-inhibitory activity. HP did not markedly affect the hydrolysis with the other enzymes. The major peptides obtained with Alcalase were identified; all were released from the triple helix...

  1. Design and Practice of the Chemistry Opened Experiment in Secondary Vocational School%中职化学开放实验的设计与实践

    Institute of Scientific and Technical Information of China (English)

    唐秋萍; 韦小杰

    2012-01-01

    By applying the open educational idea, the method of adequately excavating teaching resource and designing the practical and exploring open experiments based on neutralization reaction were introduced in process of secondary vocational school chemistry and experimental teaching. It discussed the organization and implementation ways of the chemistry open experiment.%以开放教育新理念为指导思想,酸碱中和反应为基础,介绍了在中等职业学校化学与实验课程教学中,充分发掘现有教学资源,开设以实用性和探究性为主的酸碱滴定分析开放性实验课题的设计方法,讨论了在中等职业学校化学实验教学中开放性实验的组织和实施策略。

  2. 化学实验在教学中的六个作用%A Brief Analysis of Functions of Chemistry Experiments in Teaching

    Institute of Scientific and Technical Information of China (English)

    欧瑞强

    2011-01-01

    在化学教学中,实验是必不可缺的教学手段。充分运用实验,可以激发学生的学习兴趣、培养学生的观察能力、锻炼学生的思维、培养创新意识和动手探究能力、提升环保意识。因此,实验在化学教学中起到非常重要作用。%In chemistry teaching, doing experiments is an indispensable teaching method. Doing experiments can motivate students' learning interest, cultivate their observing ability, train their thinking, cultivate their innovative awareness and operating ability,

  3. Construindo o conhecimento através de projetos de trabalho: uma experiência no curso de química da universidade estadual de Santa Cruz Building knowledge through work projects: an experiment in the chemistry course of the state university os Santa Cruz in Bahia

    Directory of Open Access Journals (Sweden)

    Edson José Wartha

    2008-01-01

    Full Text Available In this work, we describe a pedagogical experiment using work projects in chemistry undergraduate programs in general chemistry and inorganic chemistry courses making learning more dynamic and consolidating the link between students and the external community. We highlight as fundamental outcomes the improvement in the learning process and, above all, the active participation of the students in investigation and problem-solving activities.

  4. The Pharmacogenetic Footprint of ACE Inhibition: A Population-Based Metabolomics Study.

    Science.gov (United States)

    Altmaier, Elisabeth; Menni, Cristina; Heier, Margit; Meisinger, Christa; Thorand, Barbara; Quell, Jan; Kobl, Michael; Römisch-Margl, Werner; Valdes, Ana M; Mangino, Massimo; Waldenberger, Melanie; Strauch, Konstantin; Illig, Thomas; Adamski, Jerzy; Spector, Tim; Gieger, Christian; Suhre, Karsten; Kastenmüller, Gabi

    2016-01-01

    Angiotensin-I-converting enzyme (ACE) inhibitors are an important class of antihypertensives whose action on the human organism is still not fully understood. Although it is known that ACE especially cleaves COOH-terminal dipeptides from active polypeptides, the whole range of substrates and products is still unknown. When analyzing the action of ACE inhibitors, effects of genetic variation on metabolism need to be considered since genetic variance in the ACE gene locus was found to be associated with ACE-concentration in blood as well as with changes in the metabolic profiles of a general population. To investigate the interactions between genetic variance at the ACE-locus and the influence of ACE-therapy on the metabolic status we analyzed 517 metabolites in 1,361 participants from the KORA F4 study. We replicated our results in 1,964 individuals from TwinsUK. We observed differences in the concentration of five dipeptides and three ratios of di- and oligopeptides between ACE inhibitor users and non-users that were genotype dependent. Such changes in the concentration affected major homozygotes, and to a lesser extent heterozygotes, while minor homozygotes showed no or only small changes in the metabolite status. Two of these resulting dipeptides, namely aspartylphenylalanine and phenylalanylserine, showed significant associations with blood pressure which qualifies them-and perhaps also the other dipeptides-as readouts of ACE-activity. Since so far ACE activity measurement is substrate specific due to the usage of only one oligopeptide, taking several dipeptides as potential products of ACE into account may provide a broader picture of the ACE activity. PMID:27120469

  5. The Pharmacogenetic Footprint of ACE Inhibition: A Population-Based Metabolomics Study

    Science.gov (United States)

    Altmaier, Elisabeth; Menni, Cristina; Heier, Margit; Meisinger, Christa; Thorand, Barbara; Quell, Jan; Kobl, Michael; Römisch-Margl, Werner; Valdes, Ana M.; Mangino, Massimo; Waldenberger, Melanie; Strauch, Konstantin; Illig, Thomas; Adamski, Jerzy; Spector, Tim; Gieger, Christian; Suhre, Karsten; Kastenmüller, Gabi

    2016-01-01

    Angiotensin-I-converting enzyme (ACE) inhibitors are an important class of antihypertensives whose action on the human organism is still not fully understood. Although it is known that ACE especially cleaves COOH-terminal dipeptides from active polypeptides, the whole range of substrates and products is still unknown. When analyzing the action of ACE inhibitors, effects of genetic variation on metabolism need to be considered since genetic variance in the ACE gene locus was found to be associated with ACE-concentration in blood as well as with changes in the metabolic profiles of a general population. To investigate the interactions between genetic variance at the ACE-locus and the influence of ACE-therapy on the metabolic status we analyzed 517 metabolites in 1,361 participants from the KORA F4 study. We replicated our results in 1,964 individuals from TwinsUK. We observed differences in the concentration of five dipeptides and three ratios of di- and oligopeptides between ACE inhibitor users and non-users that were genotype dependent. Such changes in the concentration affected major homozygotes, and to a lesser extent heterozygotes, while minor homozygotes showed no or only small changes in the metabolite status. Two of these resulting dipeptides, namely aspartylphenylalanine and phenylalanylserine, showed significant associations with blood pressure which qualifies them—and perhaps also the other dipeptides—as readouts of ACE-activity. Since so far ACE activity measurement is substrate specific due to the usage of only one oligopeptide, taking several dipeptides as potential products of ACE into account may provide a broader picture of the ACE activity. PMID:27120469

  6. Independent Metalloregulation of Ace1 and Mac1 in Saccharomyces cerevisiae

    OpenAIRE

    Keller, Greg; Bird, Amanda; Winge, Dennis R.

    2005-01-01

    Ace1 and Mac1 undergo reciprocal copper metalloregulation in yeast cells. Mac1 is functional as a transcriptional activator in copper-deficient cells, whereas Ace1 is a transcriptional activator in copper-replete cells. Cells undergoing a transition from copper-deficient to copper-sufficient conditions through a switch in the growth medium show a rapid inactivation of Mac1 and a corresponding rise in Ace1 activation. Cells analyzed after the transition show a massive accumulation of cellular ...

  7. Extension of the ACE solar panels is tested in SAEF-II

    Science.gov (United States)

    1997-01-01

    Extension of the solar panels is tested on the Advanced Composition Explorer (ACE) spacecraft in KSC's Spacecraft Assembly and Encapsulation Facility-II (SAEF-II). Scheduled for launch on a Delta II rocket from Cape Canaveral Air Station on Aug. 25, ACE will study low-energy particles of solar origin and high-energy galactic particles. The collecting power of instruments aboard ACE is 10 to 1,000 times greater than anything previously flown to collect similar data by NASA.

  8. The angiotensin-converting enzyme (ACE) gene family of Anopheles gambiae.

    OpenAIRE

    Isaac R Elwyn; Lee Alison J; Smith Judith A; Burnham Susan; Shirras Alan D

    2005-01-01

    Abstract Background Members of the M2 family of peptidases, related to mammalian angiotensin converting enzyme (ACE), play important roles in regulating a number of physiological processes. As more invertebrate genomes are sequenced, there is increasing evidence of a variety of M2 peptidase genes, even within a single species. The function of these ACE-like proteins is largely unknown. Sequencing of the A. gambiae genome has revealed a number of ACE-like genes but probable errors in the Ensem...

  9. Secoisolariciresinol Diglucoside (SDG) Isolated from Flaxseed, an Alternative to ACE Inhibitors in the Treatment of Hypertension

    OpenAIRE

    Prasad, Kailash

    2013-01-01

    Secoisolariciresionol diglucoside (SDG) is a plant lignan isolated from flaxseed and is phytoestrogen. SDG is a potent and long-acting hypotensive agent. Plant phytoestrogens have inhibitory effects on angiotensin-converting enzyme (ACE). The hypotensive effects of SDG, a phytoestrogen, may be mediated through inhibition of ACE. The objective of this study was to investigate if SDG-induced hypotension is mediated through inhibition of ACE. The Sprague Dawley male rats were anesthetized and tr...

  10. Overview of ACE-Asia Spring 2001 Investigations on Aerosol Radiative Effects and Related Aerosol Properties

    Science.gov (United States)

    Russell, Philip B.; Valero, F. P. J.; Flatau, P. J.; Bergin, M.; Holben, B.; Nakajima, T.; Pilewskie, P.; Bergstrom, R.; Hipskind, R. Stephen (Technical Monitor)

    2001-01-01

    A primary, ACE-Asia objective was to quantify the interactions between aerosols and radiation in the Asia-Pacific region. Toward this end, radiometric and related aerosol measurements were made from ocean, land, air and space platforms. Models that predict aerosol fields guided the measurements and are helping integrate and interpret results. Companion overview's survey these measurement and modeling components. Here we illustrate how these components were combined to determine aerosol radiative. impacts and their relation to aerosol properties. Because clouds can obscure or change aerosol direct radiative effects, aircraft and ship sorties to measure these effects depended on predicting and finding cloud-free areas and times with interesting aerosols present. Pre-experiment satellite cloud climatologies, pre-flight aerosol and cloud forecasts, and in-flight guidance from satellite imagery all helped achieve this. Assessments of aerosol regional radiative impacts benefit from the spatiotemporal coverage of satellites, provided satellite-retrieved aerosol properties are accurate. Therefore, ACE-Asia included satellite retrieval tests, as part of many comparisons to judge the consistency (closure) among, diverse measurements. Early results include: (1) Solar spectrally resolved and broadband irradiances and optical depth measurements from the C-130 aircraft and at Kosan, Korea yielded aerosol radiative forcing efficiencies, permitting comparisons between efficiencies of ACE-Asia and INDOEX aerosols, and between dust and "pollution" aerosols. Detailed results will be presented in separate papers. (2) Based on measurements of wavelength dependent aerosol optical depth (AOD) and single scattering albedo the estimated 24-h a average aerosol radiative forcing efficiency at the surface for photosynthetically active radiation (400 - 700 nm) in Yulin, China is approx. 30 W sq m per AOD(500 nm). (3) The R/V Brown cruise from Honolulu to Sea of Japan sampled an aerosol optical

  11. Educational experiences in Chemistry with Adult and Youth: incursions at science, work and ideology and its curriculums implications

    Directory of Open Access Journals (Sweden)

    Alceu Júnior Paz da Silva

    2015-11-01

    Full Text Available The contemporary setting of huge unemployment and precarization of work has brought to Adult and Youth Education courses an imaginary that secondary education is fundamental for professional qualification and achievement of (better jobs. The objective of this work is to problematize the Chemistry curriculum according to young and adults interests in order to qualify them to the world of work. For that purpose, we adopted some contributions of Gramsci’s Marxist social theory as methodological and theoretical tools to investigate hegemonic aspects in which the curriculum is immersed. By analyzing the curriculum as a space of struggle for social hegemony, we conclude that is promising to explore the historical approach of the chemical knowledge as a mediator element of counter-hegemonic educational practices.

  12. Different in vivo functions of the two catalytic domains of angiotensin converting enzyme (ACE)

    OpenAIRE

    Bernstein, Kenneth E.; Shen, Xiao Z.; Gonzalez-Villalobos, Romer A.; Billet, Sandrine; Okwan-Duodu, Derick; Ong, Frank S.; Fuchs, Sebastien

    2010-01-01

    Angiotensin converting enzyme (ACE) can cleave angiotensin I, bradykinin, neurotensin and many other peptide substrates in vitro. In part, this is due to the structure of ACE, a protein composed of two independent catalytic domains. Until very recently, little was known regarding the specific in vivo role of each ACE domain, and they were commonly regarded as equivalent. This is not true, as shown by mouse models with a genetic inactivation of either the ACE N- or C-domains. In vivo, most ang...

  13. Processo químico industrial de extração de óleo vegetal: um experimento de química geral Chemical industrial process of vegetable oil extraction: an experiment for teaching general chemistry

    Directory of Open Access Journals (Sweden)

    José Francisco Vianna

    1999-09-01

    Full Text Available In this study we describe an experimental procedure based on a chemical industrial process of soya-bean oil extraction applied in general chemistry for undergraduate students. The experiment was planned according to the Science, Technology and Society (STS approach to teach basic chemical concepts and provide grounding in the management of environmental care. The use of real life chemistry problems seems to salient the relevance of chemistry to our students and enhances their motivation to learn both the practical and theoretical components of the discipline.

  14. Hydrogen cyanide in the upper troposphere: GEM-AQ simulation and comparison with ACE-FTS observations

    Directory of Open Access Journals (Sweden)

    A. Lupu

    2009-01-01

    Full Text Available We investigate the spatial and temporal distribution of hydrogen cyanide (HCN in the upper troposphere through numerical simulations and comparison with observations from a space-based instrument. To perform the simulations, we used the Global Environmental Multiscale Air Quality model (GEM-AQ, which is based on the three-dimensional global multiscale model developed by the Meteorological Service of Canada for operational weather forecasting. The model was run for the period 2004–2006 on a 1.5°×1.5° global grid with 28 hybrid vertical levels from the surface up to 10 hPa. Objective analysis data from the Canadian Meteorological Centre were used to update the meteorological fields every 24 h. Fire emission fluxes of gas species were generated by using year-specific inventories of carbon emissions with 8-day temporal resolution from the Global Fire Emission Database (GFED version 2. The model output is compared with HCN profiles measured by the Atmospheric Chemistry Experiment Fourier Transform Spectrometer (ACE-FTS instrument onboard the Canadian SCISAT-1 satellite. High values of up to a few ppbv are observed in the tropics in the Southern Hemisphere; the enhancement in HCN volume mixing ratios in the upper troposphere is most prominent in October. Low upper-tropospheric mixing ratios of less than 100 pptv are mostly recorded at middle and high latitudes in the Southern Hemisphere in May–July. Mixing ratios in Northern Hemisphere peak in the boreal summer. The amplitude of the seasonal variation is less pronounced than in the Southern Hemisphere. Our model results show that in the upper troposphere GEM-AQ performs well globally for all seasons, except at Northern high and middle latitudes in summer, where the model has a large negative bias, and in the tropics in winter and spring, where it exhibits large positive bias. This may reflect inaccurate emissions or possible inaccuracies in the emission profile. The model is able to explain

  15. Hydrogen cyanide in the upper troposphere: GEM-AQ simulation and comparison with ACE-FTS observations

    Directory of Open Access Journals (Sweden)

    A. Lupu

    2009-07-01

    Full Text Available We investigate the spatial and temporal distribution of hydrogen cyanide (HCN in the upper troposphere through numerical simulations and comparison with observations from a space-based instrument. To perform the simulations, we used the Global Environmental Multiscale Air Quality model (GEM-AQ, which is based on the three-dimensional global multiscale model developed by the Meteorological Service of Canada for operational weather forecasting. The model was run for the period 2004–2006 on a 1.5°×1.5° global grid with 28 hybrid vertical levels from the surface up to 10 hPa. Objective analysis data from the Canadian Meteorological Centre were used to update the meteorological fields every 24 h. Fire emission fluxes of gas species were generated by using year-specific inventories of carbon emissions with 8-day temporal resolution from the Global Fire Emission Database (GFED version 2. The model output is compared with HCN profiles measured by the Atmospheric Chemistry Experiment Fourier Transform Spectrometer (ACE-FTS instrument onboard the Canadian SCISAT-1 satellite. High values of up to a few ppbv are observed in the tropics in the Southern Hemisphere; the enhancement in HCN volume mixing ratios in the upper troposphere is most prominent in October. Low upper-tropospheric mixing ratios of less than 100 pptv are mostly recorded at middle and high latitudes in the Southern Hemisphere in May–July. Mixing ratios in Northern Hemisphere peak in the boreal summer. The amplitude of the seasonal variation is less pronounced than in the Southern Hemisphere. The comparison with the satellite data shows that in the upper troposphere GEM-AQ performs well globally for all seasons, except at northern high and middle latitudes in summer, where the model has a large negative bias, and in the tropics in winter and spring, where it exhibits large positive bias. This may reflect inaccurate emissions or possible inaccuracies in the emission profile. The model

  16. The effect of a computer-based, spectrometer tutorial on chemistry students' learning in a UV/vis spectroscopy laboratory experiment

    Science.gov (United States)

    Wood, Nathan Brent

    It is common for fairly sophisticated instruments to be used in undergraduate, general chemistry, laboratory courses. Typically, these instruments are treated as incidental to the experiment: students are given extensive operating instructions, but told little or nothing about how they work, because understanding the instruments themselves is not an objective of the course. The implicit assumption is that chemical principles can be deduced simply from accurate data. However, cognitive load theory (Sweller, 1988, 2005) predicts it would be more difficult for students with limited prior knowledge to make sense of their data if they do not know how measurements made with the instruments are actually derived from their physical sample. Therefore, treating laboratory instruments as incidental may actually make it more difficult for students to learn the chemical concepts that underlie the data they collect. This experimental study was intended to determine whether a multimedia tutorial, designed to help students understand how a UV/vis spectrophotometer works, brings about any changes in performance on a laboratory experiment about food dye solutions. Working in pairs, 750 students were randomly assigned to receive either the tutorial (treatment) or an alternative task (comparison) as an introduction to an experiment that was a regular part of an undergraduate, general chemistry, laboratory course. Students' responses to all laboratory questions were collected and scored. The amount of time students spent on each laboratory task was collected as well. On average, treatment students completed many of the laboratory tasks significantly more quickly than comparison students. Treatment students typically also provided more concise responses to many of the laboratory questions. Unfortunately, no differences were found in scores on laboratory questions. Therefore, while there is evidence the tutorial helped students learn more efficiently, evidence could not be found that

  17. Peer Mentoring in the General Chemistry and Organic Chemistry Laboratories: The Pinacol Rearrangement--An Exercise in NMR and IR Spectroscopy for General Chemistry and Organic Chemistry Laboratories

    Science.gov (United States)

    Arrington, Caleb A.; Hill, Jameica B.; Radfar, Ramin; Whisnant, David M.; Bass, Charles G.

    2008-01-01

    This article describes a discovery experiment for general chemistry and organic chemistry labs. Although the pinacol rearrangement has been employed in undergraduate organic laboratories before, in this application organic chemistry students act as mentors to students of general chemistry. Students work together using distillation--a new technique…

  18. Quantitative analysis chemistry

    International Nuclear Information System (INIS)

    This book is about quantitative analysis chemistry. It is divided into ten chapters, which deal with the basic conception of material with the meaning of analysis chemistry and SI units, chemical equilibrium, basic preparation for quantitative analysis, introduction of volumetric analysis, acid-base titration of outline and experiment examples, chelate titration, oxidation-reduction titration with introduction, titration curve, and diazotization titration, precipitation titration, electrometric titration and quantitative analysis.

  19. Some Experiences to Improve Organic Chemistry Experimental Teaching%提高有机化学实验教学效果的几点体会

    Institute of Scientific and Technical Information of China (English)

    廖小建; 徐石海

    2012-01-01

    Taking into account the specific circumstance and the existing problem in organic chemistry experiments,the experimental teaching method was reformed,the experimental teaching content was updated,triage training and bilingual education to the students were launched,online teaching resource library was built.The basic operation training was strengthened and innovation capability was developed,organic chemistry experimental teaching was improved.%针对我校在有机化学实验教学中的具体情况和存在的一些问题,我们改革实验教学方法,更新实验教学内容,对学生进行分流培养和双语教学,建设网络教学资源库,在加强基本操作训练的同时培学生的创新能力,提高有机化学实验教学效果.

  20. Development of Online Emulation Physical Chemistry Virtual Experiment System%在线仿真物理化学虚拟实验系统的开发

    Institute of Scientific and Technical Information of China (English)

    熊焰; 姚俊

    2012-01-01

    随着网络应用技术的不断发展,化学实验室的网络化程度越来越高,使在线仿真虚拟实验成为了可能。在新的网络化条件下,为了全方位提高物理化学实验的教学质量,华东理工大学化学实验中心开发了在线仿真物理化学虚拟实验系统,应用在实验前预习、实验中帮助、实验后测试等各个环节,取得了较好的教学效果。%Along with the development of internet technology, chemistry tabs are widely spread by the network system and virtual labs are becoming possible now. The article introduces the development of online emulation physical chemistry virtual experiment system, which improves education quality from three activities: preparation before lesson, supervision in lesson and test after lesson.

  1. Crocodile Chemistry. [CD-ROM].

    Science.gov (United States)

    1999

    This high school chemistry resource is an on-screen chemistry lab. In the program, students can experiment with a huge range of chemicals, choosing the form, quantity and concentrations. Dangerous or difficult experiments can be investigated safely and easily. A vast range of equipment can be set up, and complex simulations can be put together and…

  2. 有机化学实验绿色化教学改革与实践%Reform and Practice on Greening Teaching of Organic Chemistry Experiments

    Institute of Scientific and Technical Information of China (English)

    宋明芝; 范传刚; 解胜利; 李红

    2012-01-01

    The greening methods of organic chemistry experiments are reformed and explored in the paper,such as reasonably selecting experiments items,conducting combination or multi-step synthesis of experiments introducing advanced synthesis methods,the use of micro and semi-micro experiment,employing the new experimental technique of microwave and ultrasonic,making multimedia course ware and developing virtual labs,and reasonably collecting "three wastes",by which to train the students' consciousness of environmental protection and sustainable development.%文章主要通过合理选择实验内容、设计连续化和系列化实验、采用微量及半微量实验、利用微波、超声波等新的实验技术、制作多媒体教学课件开发网上虚拟实验室、合理收集及排放三废等方法对有机化学实验进行了绿色化的改革与探索,培养学生的环境保护和可持续发展意识。

  3. DNA methylation analysis of the angiotensin converting enzyme (ACE gene in major depression.

    Directory of Open Access Journals (Sweden)

    Peter Zill

    Full Text Available BACKGROUND: The angiotensin converting enzyme (ACE has been repeatedly discussed as susceptibility factor for major depression (MD and the bi-directional relation between MD and cardiovascular disorders (CVD. In this context, functional polymorphisms of the ACE gene have been linked to depression, to antidepressant treatment response, to ACE serum concentrations, as well as to hypertension, myocardial infarction and CVD risk markers. The mostly investigated ACE Ins/Del polymorphism accounts for ~40%-50% of the ACE serum concentration variance, the remaining half is probably determined by other genetic, environmental or epigenetic factors, but these are poorly understood. MATERIALS AND METHODS: The main aim of the present study was the analysis of the DNA methylation pattern in the regulatory region of the ACE gene in peripheral leukocytes of 81 MD patients and 81 healthy controls. RESULTS: We detected intensive DNA methylation within a recently described, functional important region of the ACE gene promoter including hypermethylation in depressed patients (p = 0.008 and a significant inverse correlation between the ACE serum concentration and ACE promoter methylation frequency in the total sample (p = 0.02. Furthermore, a significant inverse correlation between the concentrations of the inflammatory CVD risk markers ICAM-1, E-selectin and P-selectin and the degree of ACE promoter methylation in MD patients could be demonstrated (p = 0.01 - 0.04. CONCLUSION: The results of the present study suggest that aberrations in ACE promoter DNA methylation may be an underlying cause of MD and probably a common pathogenic factor for the bi-directional relationship between MD and cardiovascular disorders.

  4. CTD and Water Chemistry data of the Eastern Pacific Redox Experiment of May - June 2000 (NODC Accession 0000833)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The Eastern Pacific Redox Experiment (EPREX) took place 24 May to 28 June 2000 on the R/V Roger Revelle. The first station was at the Hawaii Ocean Time Series...

  5. Operating experience with water chemistry in the No. 2 unit of Fukushima-Daini nuclear power plant

    International Nuclear Information System (INIS)

    The No. 2 Unit of Fukushima - Daini Nuclear Power plant was commercially operated for 17,337 effective full power hours as its first and second fuel cycles. Its basic design concept incorporated two features: the first was the application of procedures for reducing shutdown dose rate based on the Japanese Improvement and Standardization Program and, secondly, low crud generation to minimize radioactive waste by careful material selection for the primary system. As a result of suppressing crud concentration in the feed water, the water chemistry of the reactor was characterized by low iron and high nickel concentrations, and low 60Co and high 58Co radioactivities in the reactor water, which resulted in a low shutdown dose rate determined mainly by 58Co depositing on the primary piping. For example, average dose rate around the primary piping just after reactor shutdown was about 70 mR/h after the first fuel cycle and 60 mR/h after the second. The dose rate decrease came about mainly from decay of 58Co depositing on the piping inner surface. (author)

  6. An ABWR water chemistry control design concept for low radiation exposure and the operating experience at the first ABWR

    International Nuclear Information System (INIS)

    No. 6 and 7 units of the Kashiwazaki-Kariwa Nuclear Power Station are the first advanced boiling water reactors (ABWR). Unit No. 6 (K6) started commercial operation in November 1996 and unit No. 7 (K7), which is identical to unit 6, began operation in July 1997. Both of them have now finished three cycles of operation. In the design stage of the ABWR, specifications for material selection were based on a detailed review of corrosion product mass balance from the standpoint of radiation source reduction. Improved cobalt specifications were applied to the stainless steel of the feed water heater tube and corrosion resistant steel was used in the turbine system. K6 and K7 adopted different water chemistry controls to reduce the dose rate during plant operation. K6 used extremely low iron crud control in the feed water and K7 used improved Ni/Fe control. As the result of these challenges, both of them attained the design target of less than 0.36 mSv/year radiation exposure. (authors)

  7. Meteorological observations in support of a hill cap cloud experiment

    Energy Technology Data Exchange (ETDEWEB)

    Nielsen, Morten

    1998-06-01

    Humid air flows form a hill cap cloud over the Agana mountain ridge in the north-east of Tenerife. The HILLCLOUD project utilised this cloud formation to investigate the chemical and physical properties of cloud aerosols by land based observations. The project was part of the second Aerosol characterisation Experiment (ACE-2) of the International Global Atmospheric chemistry project (IGAC). The present report describes meteorological observations in support of the hill cap cloud experiment. Time-series of wind speed, wind direction, temperature and humidity were collected at ground-based meteorological stations during a period starting one year in advance of the main campaign. A series of radiosonde detecting the upstream stability and wind profile were launched during the main campaign. (au) 5 tabs., 32 ills., 6 refs.

  8. Uncertainty quantification for accident management using ACE surrogates

    International Nuclear Information System (INIS)

    The alternating conditional expectation (ACE) regression method is used to generate RELAP5 surrogates which are then used to determine the distribution of the peak clad temperature (PCT) during the loss of feedwater accident coupled with a subsequent initiation of the feed and bleed (F and B) operation in the Zion-1 nuclear power plant. The construction of the surrogates assumes conditional independence relations among key reactor parameters. The choice of parameters to model is based on the macroscopic balance statements governing the behavior of the reactor. The peak clad temperature is calculated based on the independent variables that are known to be important in determining the success of the F and B operation. The relationship between these independent variables and the plant parameters such as coolant pressure and temperature is represented by surrogates that are constructed based on 45 RELAP5 cases. The time-dependent PCT for different values of F and B parameters is calculated by sampling the independent variables from their probability distributions and propagating the information through two layers of surrogates. The results of our analysis show that the ACE surrogates are able to satisfactorily reproduce the behavior of the plant parameters even though a quasi-static assumption is primarily used in their construction. The PCT is found to be lower in cases where the F and B operation is initiated, compared to the case without F and B, regardless of the F and B parameters used. (authors)

  9. ACE: A distributed system to manage large data archives

    Science.gov (United States)

    Daily, Mike I.; Allen, Frank W.

    1993-01-01

    Competitive pressures in the oil and gas industry are requiring a much tighter integration of technical data into E and P business processes. The development of new systems to accommodate this business need must comprehend the significant numbers of large, complex data objects which the industry generates. The life cycle of the data objects is a four phase progression from data acquisition, to data processing, through data interpretation, and ending finally with data archival. In order to implement a cost effect system which provides an efficient conversion from data to information and allows effective use of this information, an organization must consider the technical data management requirements in all four phases. A set of technical issues which may differ in each phase must be addressed to insure an overall successful development strategy. The technical issues include standardized data formats and media for data acquisition, data management during processing, plus networks, applications software, and GUI's for interpretation of the processed data. Mass storage hardware and software is required to provide cost effective storage and retrieval during the latter three stages as well as long term archival. Mobil Oil Corporation's Exploration and Producing Technical Center (MEPTEC) has addressed the technical and cost issues of designing, building, and implementing an Advanced Computing Environment (ACE) to support the petroleum E and P function, which is critical to the corporation's continued success. Mobile views ACE as a cost effective solution which can give Mobile a competitive edge as well as a viable technical solution.

  10. Signatures of interchange reconnection: STEREO, ACE and Hinode observations combined

    Directory of Open Access Journals (Sweden)

    D. Baker

    2009-10-01

    Full Text Available Combining STEREO, ACE and Hinode observations has presented an opportunity to follow a filament eruption and coronal mass ejection (CME on 17 October 2007 from an active region (AR inside a coronal hole (CH into the heliosphere. This particular combination of "open" and closed magnetic topologies provides an ideal scenario for interchange reconnection to take place. With Hinode and STEREO data we were able to identify the emergence time and type of structure seen in the in-situ data four days later. On the 21st, ACE observed in-situ the passage of an ICME with "open" magnetic topology. The magnetic field configuration of the source, a mature AR located inside an equatorial CH, has important implications for the solar and interplanetary signatures of the eruption. We interpret the formation of an "anemone" structure of the erupting AR and the passage in-situ of the ICME being disconnected at one leg, as manifested by uni-directional suprathermal electron flux in the ICME, to be a direct result of interchange reconnection between closed loops of the CME originating from the AR and "open" field lines of the surrounding CH.

  11. Signatures of Interchange Reconnection: STEREO, ACE and Hinode Observations Combined

    CERN Document Server

    Baker, D; Van Driel-Gesztelyi, L; Demoulin, P; Harra, L K; Lavraud, B; Davies, J A; Optiz, A; Luhmann, J G; Sauvaud, J A; Galvin, A B

    2009-01-01

    Combining STEREO, ACE and Hinode observations has presented an opportunity to follow a filament eruption and coronal mass ejection (CME) on the 17th of October 2007 from an active region (AR) inside a coronal hole (CH) into the heliosphere. This particular combination of `open' and closed magnetic topologies provides an ideal scenario for interchange reconnection to take place. With Hinode and STEREO data we were able to identify the emergence time and type of structure seen in the in-situ data four days later. On the 21st, ACE observed in-situ the passage of an ICME with `open' magnetic topology. The magnetic field configuration of the source, a mature AR located inside an equatorial CH, has important implications for the solar and interplanetary signatures of the eruption. We interpret the formation of an `anemone' structure of the erupting AR and the passage in-situ of the ICME being disconnected at one leg, as manifested by uni-directional suprathermal electron flux in the ICME, to be a direct result of i...

  12. Social Chemistry

    OpenAIRE

    Lichtfouse, Eric; Schwarzbauer, Jan; Robert, Didier

    2012-01-01

    International audience This article is both an essay to propose social chemistry as a new scientific discipline, and a preface of the book Environmental Chemistry for a Sustainable World. Environmental chemistry is a fast emerging discipline aiming at the understanding the fate of pollutants in ecosystems and at designing novel processes that are safe for ecosystems. Past pollution should be cleaned, future pollution should be predicted and avoided (Lichtfouse et al., 2005a). Such advices ...

  13. Bioinorganic Chemistry

    OpenAIRE

    Bertini, Ivano; Gray, Harry B.; Lippard, Stephen J.; Valentine, Joan Selverstone

    1994-01-01

    This book covers material that could be included in a one-quarter or one-semester course in bioinorganic chemistry for graduate students and advanced undergraduate students in chemistry or biochemistry. We believe that such a course should provide students with the background required to follow the research literature in the field. The topics were chosen to represent those areas of bioinorganic chemistry that are mature enough for textbook presentation. Although each chapter presents material...

  14. First multi-year occultation observations of CO2 in the MLT by ACE satellite: observations and analysis using the extended CMAM

    Directory of Open Access Journals (Sweden)

    P. F. Bernath

    2009-05-01

    Full Text Available This paper presents the first multi-year global set of observations of CO2 in the mesosphere and lower thermosphere (MLT obtained by the ACE-FTS instrument on SCISAT-I, a small Canadian satellite launched in 2003. The observations use the solar occultation technique and document the fall-off in the mixing ratio of CO2 in the MLT region. The beginning of the fall-off of the CO2, or "knee" occurs at about 78 km and lies higher than in the CRISTA measurements (~70 km but lower than in the SABER 1.06 (~82 km and much lower than in rocket measurements. We also present the measurements of CO obtained concurrently which provide important constraints for analysis. We have compared the ACE measurements with simulations of the CO2 and CO distributions in the vertically extended version of the Canadian Middle Atmosphere Model (CMAM. Applying standard chemistry we find that we cannot get agreement between the model and ACE CO2 observations although the CO observations are adequately reproduced. There appears to be about a 10 km offset compared to the observed ACE CO2, with the model knee occurring too high. In analysing the disagreement, we have investigated the variation of several parameters of interest, photolysis rates, formation rate for CO2, and the impact of uncertainty in eddy diffusion, in order to explore parameter space for this problem. Our conclusions are that there must be a loss process for CO2, about 2–4 times faster than photolysis that will sequester the carbon in some form other than CO and we have speculated on the role of meteoritic dust as a possible candidate. In addition, from this study we have highlighted a possible important role for vertical eddy diffusion in 3-D models in determining the distribution of candidate species in the mesosphere which requires further study.

  15. Study on introducing system management thought into college chemistry experiment teaching%系统管理思维导入大学化学实验教学的研究

    Institute of Scientific and Technical Information of China (English)

    金晓艳; 张宏; 蒋雪月

    2011-01-01

    大学化学实验在实验教学体系中具有重要的地位,但传统化学实验教学中缺少系统管理的思维。将系统管理思维引入大学化学实验教学,从时间和空间维度思考,将化学实验涉及的教学团队予以系统化、教学资源进行信息化与系统化、构建学生学习共同体,并将之构建成以学生为中心的育人系统,可以取得理想的教学与育人效果。%The college chemistry experiment has an important position in the whole chemistry teaching system. It should be noted that the system management thought is scarce during the traditional chemistry experiment teaching. It is the key to introduce the system management thought into cortege chemistry experiment teaching for obtaining the ideal teaching and educating the person effects. The thought include the systematization of teaching group concerning chemistry experiment from the angle of time and spatial dimensions, the informatization teaching resources, the construction of students' learning community and buih the educating - person system centering on students.

  16. Technetium chemistry

    International Nuclear Information System (INIS)

    Technetium chemistry is a young and developing field. Despite the limited knowledge of its chemistry, technetium is the workhorse for nuclear medicine. Technetium is also a significant environmental concern because it is formed as a byproduct of nuclear weapons production and fission-power generators. Development of new technetium radio-pharmaceuticals and effective environmental control depends strongly upon knowledge of basic technetium chemistry. The authors performed research into the basic coordination and organometallic chemistry of technetium and used this knowledge to address nuclear medicine and environmental applications. This is the final report of a three-year Laboratory-Directed Research and Development (LDRD) project at the Los Alamos National Laboratory (LANL)

  17. Adverse childhood experiences and premature all-cause mortality.

    Science.gov (United States)

    Kelly-Irving, Michelle; Lepage, Benoit; Dedieu, Dominique; Bartley, Mel; Blane, David; Grosclaude, Pascale; Lang, Thierry; Delpierre, Cyrille

    2013-09-01

    Events causing stress responses during sensitive periods of rapid neurological development in childhood may be early determinants of all-cause premature mortality. Using a British birth cohort study of individuals born in 1958, the relationship between adverse childhood experiences (ACE) and mortality≤50 year was examined for men (n=7,816) and women (n=7,405) separately. ACE were measured using prospectively collected reports from parents and the school: no adversities (70%); one adversity (22%), two or more adversities (8%). A Cox regression model was carried out controlling for early life variables and for characteristics at 23 years. In men the risk of death was 57% higher among those who had experienced 2+ ACE compared to those with none (HR 1.57, 95% CI 1.13, 2.18, p=0.007). In women, a graded relationship was observed between ACE and mortality, the risk increasing as ACE accumulated. Women with one ACE had a 66% increased risk of death (HR 1.66, 95% CI 1.19, 2.33, p=0.003) and those with ≥2 ACE had an 80% increased risk (HR 1.80, 95% CI 1.10, 2.95, p=0.020) versus those with no ACE. Given the small impact of adult life style factors on the association between ACE and premature mortality, biological embedding during sensitive periods in early development is a plausible explanatory mechanism. PMID:23887883

  18. Tailored-therapy of ACE-inhibitors in Coronary Artery Disease: Pharmacogenetic Profiling of Treatment Benefit

    NARCIS (Netherlands)

    J.J. Brugts (Jasper)

    2010-01-01

    textabstractTo optimally treat patients, and to develop ways to guide ACE-inhibitor treatment, it remains essential to identify those patients most likely to benefit from therapy. New research to elucidate such heterogeneity is necessary. If feasible, guided-therapy of ACE-inhibitors will have a lar

  19. Modeling the QSAR of ACE-Inhibitory Peptides with ANN and Its Applied Illustration

    Directory of Open Access Journals (Sweden)

    Ronghai He

    2012-01-01

    Full Text Available A quantitative structure-activity relationship (QSAR model of angiotensin-converting enzyme- (ACE- inhibitory peptides was built with an artificial neural network (ANN approach based on structural or activity data of 58 dipeptides (including peptide activity, hydrophilic amino acids content, three-dimensional shape, size, and electrical parameters, the overall correlation coefficient of the predicted versus actual data points is =0.928, and the model was applied in ACE-inhibitory peptides preparation from defatted wheat germ protein (DWGP. According to the QSAR model, the C-terminal of the peptide was found to have principal importance on ACE-inhibitory activity, that is, if the C-terminal is hydrophobic amino acid, the peptide's ACE-inhibitory activity will be high, and proteins which contain abundant hydrophobic amino acids are suitable to produce ACE-inhibitory peptides. According to the model, DWGP is a good protein material to produce ACE-inhibitory peptides because it contains 42.84% of hydrophobic amino acids, and structural information analysis from the QSAR model showed that proteases of Alcalase and Neutrase were suitable candidates for ACE-inhibitory peptides preparation from DWGP. Considering higher DH and similar ACE-inhibitory activity of hydrolysate compared with Neutrase, Alcalase was finally selected through experimental study.

  20. ACE2 is augmented in dystrophic skeletal muscle and plays a role in decreasing associated fibrosis.

    Directory of Open Access Journals (Sweden)

    Cecilia Riquelme

    Full Text Available Duchenne muscular dystrophy (DMD is the most common inherited neuromuscular disease and is characterized by absence of the cytoskeletal protein dystrophin, muscle wasting, and fibrosis. We previously demonstrated that systemic infusion or oral administration of angiotensin-(1-7 (Ang-(1-7, a peptide with opposing effects to angiotensin II, normalized skeletal muscle architecture, decreased local fibrosis, and improved muscle function in mdx mice, a dystrophic model for DMD. In this study, we investigated the presence, activity, and localization of ACE2, the enzyme responsible for Ang-(1-7 production, in wild type (wt and mdx skeletal muscle and in a model of induced chronic damage in wt mice. All dystrophic muscles studied showed higher ACE2 activity than wt muscle. Immunolocalization studies indicated that ACE2 was localized mainly at the sarcolemma and, to a lesser extent, associated with interstitial cells. Similar results were observed in the model of chronic damage in the tibialis anterior (TA muscle. Furthermore, we evaluated the effect of ACE2 overexpression in mdx TA muscle using an adenovirus containing human ACE2 sequence and showed that expression of ACE2 reduced the fibrosis associated with TA dystrophic muscles. Moreover, we observed fewer inflammatory cells infiltrating the mdx muscle. Finally, mdx gastrocnemius muscles from mice infused with Ang-(1-7, which decreases fibrosis, contain less ACE2 associated with the muscle. This is the first evidence supporting ACE2 as an important therapeutic target to improve the dystrophic skeletal muscle phenotype.

  1. Does angiotensin (1-7) contribute to the anti-proteinuric effect of ACE-inhibitors

    NARCIS (Netherlands)

    van der Wouden, Els A; Henning, Robert H; Deelman, Leo E; Roks, Anton J M; Boomsma, Frans; de Zeeuw, Dick

    2005-01-01

    Angiotensin-converting enzyme inhibitors (ACE-I) reduce proteinuria and protect the kidney in proteinuric renal disease. During ACE-I therapy, circulating levels of angiotensin (1-7) [Ang (1-7)] are increased. As cardiac and renal protective effects of Ang (1-7) have been reported, we questioned whe

  2. Formative Evaluation of ACES Program: Findings from Surveys and Interviews Year One, Grades 11 and 12

    Science.gov (United States)

    Wolanin, Natalie; Modarresi, Shahpar

    2015-01-01

    The Office of Shared Accountability (OSA) in Montgomery County (Maryland) Public Schools (MCPS) is conducting a multiyear evaluation of the Achieving Collegiate Excellence and Success (ACES) program. The ACES program is a collaboration between MCPS, Montgomery College (MC), and the Universities at Shady Grove (USG) to create a seamless pathway…

  3. 77 FR 20835 - National Customs Automation Program (NCAP) Test Concerning Automated Commercial Environment (ACE...

    Science.gov (United States)

    2012-04-06

    ... Portal Accounts and Subsequent Revision Notices: 67 FR 21800 (May 1, 2002); 70 FR 5199 (February 1, 2005); 69 FR 5360 and 69 FR 5362 (February 4, 2004); 69 FR 54302 (September 8, 2004). ACE System of Records Notice: 71 FR 3109 (January 19, 2006). Terms/Conditions for Access to the ACE Portal and...

  4. Angiotensin I-Converting Enzyme (ACE Inhibitory Activity and ACE Inhibitory Peptides of Salmon (Salmo salar Protein Hydrolysates Obtained by Human and Porcine Gastrointestinal Enzymes

    Directory of Open Access Journals (Sweden)

    Małgorzata Darewicz

    2014-08-01

    Full Text Available The objectives of the present study were two-fold: first, to detect whether salmon protein fractions possess angiotensin I-converting enzyme (ACE inhibitory properties and whether salmon proteins can release ACE inhibitory peptides during a sequential in vitro hydrolysis (with commercial porcine enzymes and ex vivo digestion (with human gastrointestinal enzymes. Secondly, to evaluate the ACE inhibitory activity of generated hydrolysates. A two-step ex vivo and in vitro model digestion was performed to simulate the human digestion process. Salmon proteins were degraded more efficiently by porcine enzymes than by human gastrointestinal juices and sarcoplasmic proteins were digested/hydrolyzed more easily than myofibrillar proteins. The ex vivo digested myofibrillar and sarcoplasmic duodenal samples showed IC50 values (concentration required to decrease the ACE activity by 50% of 1.06 and 2.16 mg/mL, respectively. The in vitro hydrolyzed myofibrillar and sarcoplasmic samples showed IC50 values of 0.91 and 1.04 mg/mL, respectively. Based on the results of in silico studies, it was possible to identify 9 peptides of the ex vivo hydrolysates and 7 peptides of the in vitro hydrolysates of salmon proteins of 11 selected peptides. In both types of salmon hydrolysates, ACE-inhibitory peptides IW, IY, TVY and VW were identified. In the in vitro salmon protein hydrolysates an ACE-inhibitory peptides VPW and VY were also detected, while ACE-inhibitory peptides ALPHA, IVY and IWHHT were identified in the hydrolysates generated with ex vivo digestion. In our studies, we documented ACE inhibitory in vitro effects of salmon protein hydrolysates obtained by human and as well as porcine gastrointestinal enzymes.

  5. 高职化学实验网络辅助学习平台的设计与开发%Chemistry Experiment Network Assisted Learning Platform Design and Development

    Institute of Scientific and Technical Information of China (English)

    郑小斌

    2012-01-01

      化学是一门重视实践的学科,理论知识只有在实际的实验操作中才能掌握得更牢。然而由于学校各方条件的限制,化学实验操作课程往往难以按科学的标准实施。信息技术的蓬勃发展为缓解学校和学生对化学实验教学的需求提供了有利条件。本文针对目前我国高职化学实验教学过程中普遍存在的问题,设计开发了基于交互仿真智能性化学实验课件、网络型化学实验课件等多媒体学习资源来辅助学生的化学实验学习。%  Chemistry is a practical subject, theory of knowledge only in the actual experiment in order to grasp bet er. However, due to the school all the conditions, chemical experiment course are often dif icult to press scientific standards implementation. The rapid development of information technology to al eviate the school and students in chemistry experiment teaching needs to provide favorable conditions. This article in view of the present our country higher vocational chemistry experiment teaching the universal existence question, is designed and developed based on interactive simulation intel igent chemistry experiment courseware, network chemistry experiment courseware of multimedia learning resources to assist students in chemistry learning.

  6. FTIR Determination of Pollutants in Automobile Exhaust: An Environmental Chemistry Experiment Comparing Cold-Start and Warm-Engine Conditions

    Science.gov (United States)

    Medhurst, Laura L.

    2005-01-01

    An experiment developed from the Advanced Integrated Environmental Laboratory illustrates the differences in automobile exhaust before and after the engine is warmed, using gas-phase Fourier transform infrared spectroscopy (FTIR). The apparatus consists of an Avatar 360 FTIR spectrometer from Nicolet fitted with a variable path length gas cell,…

  7. Experimenting with Synthesis and Analysis of Cationic Gemini Surfactants in a Second-Semester General Chemistry Laboratory

    Science.gov (United States)

    Anzovino, Mary E.; Greenberg, Andrew E.; Moore, John W.

    2015-01-01

    A laboratory experiment is described in which students synthesize a variety of cationic gemini surfactants and analyze their efficacy as fabric softeners. Students perform a simple organic synthesis reaction and two analytical tests (one qualitative and one quantitative), and use the class data to assess the synthesized products. The experiment…

  8. Measuring the Density of a Sugar Solution: A General Chemistry Experiment Using a Student-Prepared Unknown

    Science.gov (United States)

    Peterson, Karen I.

    2008-01-01

    The experiment developed in this article addresses the concept of equipment calibration for reducing systematic error. It also suggests simple student-prepared sucrose solutions for which accurate densities are known, but not readily available to students. Densities are measured with simple glassware that has been calibrated using the density of…

  9. Using Artificial Soil and Dry-Column Flash Chromatography to Simulate Organic Substance Leaching Process: A Colorful Environmental Chemistry Experiment

    Science.gov (United States)

    de Avellar, Isa G. J.; Cotta, Tais A. P. G.; Neder, Amarilis de V. Finageiv

    2012-01-01

    Soil is an important and complex environmental compartment and soil contamination contributes to the pollution of aquifers and other water basins. A simple and low-cost experiment is described in which the mobility of three organic compounds in an artificial soil is examined using dry-column flash chromatography. The compounds were applied on top…

  10. Hydrolysis Studies and Quantitative Determination of Aluminum Ions Using [superscript 27]Al NMR: An Undergraduate Analytical Chemistry Experiment

    Science.gov (United States)

    Curtin, Maria A.; Ingalls, Laura R.; Campbell, Andrew; James-Pederson, Magdalena

    2008-01-01

    This article describes a novel experiment focused on metal ion hydrolysis and the equilibria related to metal ions in aqueous systems. Using [superscript 27]Al NMR, the students become familiar with NMR spectroscopy as a quantitative analytical tool for the determination of aluminum by preparing a standard calibration curve using standard aluminum…

  11. Headspace GC-MS Analysis of Halogenated Volatile Organic Compounds in Aqueous Samples: An Experiment for General Chemistry Laboratory

    Science.gov (United States)

    Keller, John W.; Fabbri, Cindy E.

    2012-01-01

    Analysis of halogenated volatile organic compounds (HVOCs) by GC-MS demonstrates the use of instrumentation in the environmental analysis of pollutant molecules and enhances student understanding of stable isotopes in nature. In this experiment, students separated and identified several HVOCs that have been implicated as industrial groundwater…

  12. Does the Angiotensin-converting enzyme (ACE gene insertion/deletion polymorphism modify the response to ACE inhibitor therapy? – A systematic review

    Directory of Open Access Journals (Sweden)

    Perna Annalisa

    2005-10-01

    Full Text Available Abstract Background Pharmacogenetic testing to individualize ACE inhibitor therapy remains controversial. We conducted a systematic review to assess the effect modification of the insertion/deletion (I/D polymorphism of the ACE gene on any outcome in patients treated with ACE inhibitors for cardiovascular and/or renal disease. Methods Our systematic review involved searching six electronic databases, then contacting the investigators (and pharmaceutical industry representatives responsible for the creation of these databases. Two reviewers independently selected relevant randomized, placebo-controlled trials and abstracted from each study details on characteristics and quality. Results Eleven studies met our inclusion criteria. Despite repeated efforts to contact authors, only four of the eleven studies provided sufficient data to quantify the effect modification by genotypes. We observed a trend towards better response to ACE inhibitors in Caucasian DD carriers compared to II carriers, in terms of blood pressure, proteinuria, glomerular filtration rate, ACE activity and progression to end-stage renal failure. Pooling of the results was inappropriate, due to heterogeneity in ethnicity, clinical domains and outcomes. Conclusion Lack of sufficient genetic data from the reviewed studies precluded drawing any convincing conclusions. Better reporting of genetic data are needed to confirm our preliminary observations concerning better response to ACE inhibitors among Caucasian DD carriers as compared to II carriers.

  13. Performance of the University of Denver Low Turbulence, Airborne Aerosol Inlet in ACE-Asia

    Science.gov (United States)

    Lafleur, B.; Wilson, J. C.; Seebaugh, W. R.; Gesler, D.; Hilbert, H.; Mullen, J.; Reeves, J. M.

    2002-12-01

    The University of Denver Low Turbulence Inlet (DULTI) was flown on the NCAR C-130 in ACE-Asia. This inlet delivered large sample flows at velocities of a few meters per second at the exit of the inlet. This flow was slowed from the true air speed of the aircraft (100 to 150 m/s) to a few meters per second in a short diffuser with porous walls. The flow in the diffusing section was laminar. The automatic control system kept the inlet operating at near isokinetic intake velocities and in laminar flow for nearly all the flight time. The DULTI permits super micron particles to be sampled and delivered with high efficiency to the interior of the aircraft where they can be measured or collected. Because most of the air entering the inlet is removed through the porous medium, the sample flow experiences inertial enhancements. Because these enhancements occur in laminar flow, they are calculable using FLUENT. Enhancement factors are defined as the ratio of the number of particles of a given size per unit mass of air in the sample to the number of particles of that size per unit mass of air in the ambient. Experimenters divide measured mixing ratios of the aerosol by the enhancement factor to get the ambient mixing ratio of the particles. The diffuser used in ACE-Asia differed from that used in PELTI (2000), TexAQS2000 (2000) and ITCT (2002). In this poster, the flow parameters measured in the inlet in flight are compared with those calculated from FLUENT. And enhancement factors are presented for flight conditions. The enhancement factors are found to depend upon the Stokes number of particles in the entrance to the inlet and the ratio of the mass flow rate of air removed by suction to the mass flow rate delivered as sample.

  14. Isolation of an angiotensin converting enzyme (ACE) inhibitor from Olea europea and Olea lancea

    DEFF Research Database (Denmark)

    Hansen, K; Adsersen, A.; Brøgger Christensen, S.;

    1996-01-01

    The aqueous extract of the leaves of Olea europea and Olea lancea both inhibited Angiotensin Converting Enzyme (ACE) in vitro. A bioassay-directed fractionation resulted in the isolation of a strong ACE-inhibitor namely the secoiridoid 2-(3,4-dihydroxyphenyl)ethyl 4-formyl-3-(2-oxoethyl)-4E...... have not been described previously in the literature as inhibitors of ACE. Oleacin showed a low toxicity in the brine shrimp (Artemia salina) lethality test (LC50(24 h) = 969 ppm).......-hexenoate (oleacin)(IC50 = 26 myM). Five secoiridoid glucosides (oleuropein, ligstroside, excelsioside, oleoside 11-methyl ester, oleoside) isolated from Oleaceous plants showed no significant ACE-inhibition whereas, after enzymatic hydrolysis, the ACE-inhibition at 0.33 mg/ml was between 64% to 95%. Secoiridoids...

  15. Angiotensin-I-Converting Enzyme (ACE Inhibitors from Marine Resources: Prospects in the Pharmaceutical Industry

    Directory of Open Access Journals (Sweden)

    Isuru Wijesekara

    2010-03-01

    Full Text Available Hypertension or high blood pressure is one of the major independent risk factors for cardiovascular diseases. Angiotensin-I-converting enzyme (EC 3.4.15.1; ACE plays an important physiological role in regulation of blood pressure by converting angiotensin I to angiotensin II, a potent vasoconstrictor. Therefore, the inhibition of ACE activity is a major target in the prevention of hypertension. Recently, the search for natural ACE inhibitors as alternatives to synthetic drugs is of great interest to prevent several side effects and a number of novel compounds such as bioactive peptides, chitooligosaccharide derivatives (COS and phlorotannins have been derived from marine organisms as potential ACE inhibitors. These inhibitory derivatives can be developed as nutraceuticals and pharmaceuticals with potential to prevent hypertension. Hence, the aim of this review is to discuss the marine-derived ACE inhibitors and their future prospects as novel therapeutic drug candidates for treat hypertension.

  16. Effects of ACE2 deficiency on physical performance and physiological adaptations of cardiac and skeletal muscle to exercise.

    Science.gov (United States)

    Motta-Santos, Daisy; Dos Santos, Robson Augusto Souza; Oliveira, Marilene; Qadri, Fatimunnisa; Poglitsch, Marko; Mosienko, Valentina; Kappes Becker, Lenice; Campagnole-Santos, Maria Jose; M Penninger, Joseph; Alenina, Natalia; Bader, Michael

    2016-07-01

    The renin-angiotensin system (RAS) is related to physiological adaptations induced by exercise. Angiotensin-converting enzyme (ACE) 2 is a major regulator of the RAS in tissues, as it metabolizes angiotensin (Ang) II to Ang-(1-7). The aim of this study was to determine the effects of ACE2 deficiency on physical performance and physiological adaptations induced by voluntary running. Physical performance, body composition and plasma angiotensin levels, as well as tissue morphology and gene expression of RAS components in the left ventricle (LV) and skeletal muscle (gastrocnemius), were evaluated in ACE2-deficient (ACE2(-/y)) and wild-type (ACE2(+/y)) mice after 6 weeks of voluntary wheel running. ACE2(-/y) mice run less than ACE2(+/y) mice (19±4.7 vs. 26±12.6 revolutions per day × 100, Pmuscle mass (76.6±1.6%) after 6 weeks of voluntary running compared with the sedentary control group (fat mass: 18.3±2.1%; muscle mass: 72.7±2.2). However, no change in body composition was observed in ACE2(-/y) mice after exercise. Heart and skeletal muscle hypertrophy was observed only in trained ACE2(+/y) mice. Besides a small decrease in Ang I in ACE2(-/y) mice, plasma levels of angiotensin peptides remained unchanged by exercise or ACE2 deficiency. In the LV of trained animals, AT2 gene expression was higher in ACE2(+/y) compared with ACE2(-/y) mice. ACE2 deficiency leads to an increase in AT1 gene expression in skeletal muscle. ACE expression in soleus was increased in all exercised groups. ACE2 deficiency affects physical performance and impairs cardiac and skeletal muscle adaptations to exercise. PMID:27053009

  17. ACE2-mediated reduction of oxidative stress in the central nervous system is associated with improvement of autonomic function.

    Directory of Open Access Journals (Sweden)

    Huijing Xia

    Full Text Available Oxidative stress in the central nervous system mediates the increase in sympathetic tone that precedes the development of hypertension. We hypothesized that by transforming Angiotensin-II (AngII into Ang-(1-7, ACE2 might reduce AngII-mediated oxidative stress in the brain and prevent autonomic dysfunction. To test this hypothesis, a relationship between ACE2 and oxidative stress was first confirmed in a mouse neuroblastoma cell line (Neuro2A cells treated with AngII and infected with Ad-hACE2. ACE2 overexpression resulted in a reduction of reactive oxygen species (ROS formation. In vivo, ACE2 knockout (ACE2(-/y mice and non-transgenic (NT littermates were infused with AngII (10 days and infected with Ad-hACE2 in the paraventricular nucleus (PVN. Baseline blood pressure (BP, AngII and brain ROS levels were not different between young mice (12 weeks. However, cardiac sympathetic tone, brain NADPH oxidase and SOD activities were significantly increased in ACE2(-/y. Post infusion, plasma and brain AngII levels were also significantly higher in ACE2(-/y, although BP was similarly increased in both genotypes. ROS formation in the PVN and RVLM was significantly higher in ACE2(-/y mice following AngII infusion. Similar phenotypes, i.e. increased oxidative stress, exacerbated dysautonomia and hypertension, were also observed on baseline in mature ACE2(-/y mice (48 weeks. ACE2 gene therapy to the PVN reduced AngII-mediated increase in NADPH oxidase activity and normalized cardiac dysautonomia in ACE2(-/y mice. Altogether, these data indicate that ACE2 gene deletion promotes age-dependent oxidative stress, autonomic dysfunction and hypertension, while PVN-targeted ACE2 gene therapy decreases ROS formation via NADPH oxidase inhibition and improves autonomic function. Accordingly, ACE2 could represent a new target for the treatment of hypertension-associated dysautonomia and oxidative stress.

  18. Water-Shale interactions in bench-top and high pressure/high temperature autoclave experiments: Identifying geochemical reaction controlling flow back water chemistry

    Science.gov (United States)

    Mickler, P. J.; Lu, J.; Nicot, J.

    2013-12-01

    An important side effect of hydraulic fracturing (HF) in shale gas wells is the production of saline flow-back water. This water often contains total dissolved soil (TDS) concentrations greater than 100,000 ppm which requires expensive treatment and disposal of the produced water. Possible origins of the high TDS content include: 1. Mixing of fresh HF-fluids with highly saline pore fluids in the targeted shale. 2. Migration and mixing of saline brines by newly-formed fractures into the HF-water from neighboring formations. 3. Water rock interactions between the targeted shale and HF-water that include mineral dissolution, pyrite oxidation buffered by carbonate dissolution and cation exchange in newly hydrated clay minerals.. These possibilities are not mutually exclusive and all may be operating to alter flow-back water chemistry. This study will examine geochemical reactions between a productive Gulf Coast shale and manufactured HF-waters using sealed bench top experiments and high temperature/high pressure autoclave experiments. The samples of the shale were collected from core material housed at The Bureau of Economic Geology collected from two wells. The manufactured HF-waters were produced by mixing NaCl, KCl and CaCl2 salts with De-ionized water at approximately 0, 2000 and 20,000 ppm. During experiments, elements that show large increases in aqueous concentrations are Na, Cl, Ca and SO4. Simultaneous increases in Na and Cl, coupled with high Cl/Br ratios, suggest halite dissolution rather than pore space brine is responsible for Na and Cl concentrations. Simultaneous increase in Ca and SO4 suggest anhydrite dissolution. (SEM imaging shows that anhydrite crystals are usually embedded with the framework mineral grains, rather than precipitated in pores during sample drying, which suggests mineral source of Ca and SO4, possibly for Na and Cl as well). Pyrite oxidation and calcium carbonate dissolution were not significant due to no decrease in pH and no

  19. ACE I/D genotype, adiposity, and blood pressure in children

    Directory of Open Access Journals (Sweden)

    Rothschild Max

    2009-03-01

    Full Text Available Abstract Background Angiotensin converting enzyme (ACE is a possible candidate gene that may influence both body fatness and blood pressure. Although several genetic studies have been conducted in adults, relatively few studies have examined the contribution of potential candidate genes, and specifically ACE I/D, on adiposity and BP phenotypes in childhood. Such studies may prove insightful for the development of the obesity-hypertension phenotype early in life. The purpose of this study was to examine differences in body fatness and resting blood pressure (BP by ACE I/D genotype, and determine if the association between adiposity and BP varies by ACE I/D genotype in children. Methods 152 children (75 girls, 77 boys were assessed for body composition (% body fat using dual energy x-ray absorbtiometry and resting BP according to American Heart Association recommendations. Buccal cell samples were genotyped using newly developed PCR-RFLP tests for two SNPs (rs4341 and rs4343 in complete linkage disequilibrium with the ACE I/D polymorphism. Partial correlations were computed to assess the ociations between % body fat and BP in the total sample and by genotype. ANCOVA was used to examine differences in resting BP by ACE I/D genotype and fatness groups. Results Approximately 39% of youth were overfat based on % body fat (>30% fat in girls, 25% fat in boys. Body mass, body mass index, and fat-free mass were significantly higher in the ACE D-carriers compared to the II group (p Conclusion ACE D-carriers are heavier than ACE II children; however, BP did not differ by ACE I/D genotype but was adversely influenced in the overfat D-carriers. Further studies are warranted to investigate the genetics of fatness and BP phenotypes in children.

  20. Good chemistry

    OpenAIRE

    Petsko, Gregory A

    2004-01-01

    The subject matter in chemistry courses reflects almost nothing of the issues that chemists are interested in. It is important to formulate a set of topics - and a Medical College Admissions Test reflecting them - that would leave chemistry departments no choice but to change their teaching.