WorldWideScience

Sample records for on-line chemical studies

  1. On-line chemical composition analyzer development

    Energy Technology Data Exchange (ETDEWEB)

    Roberts, M.J.; Garrison, A.A.; Muly, E.C.; Moore, C.F.

    1992-02-01

    The energy consumed in distillation processes in the United States represents nearly three percent of the total national energy consumption. If effective control of distillation columns can be accomplished, it has been estimated that it would result in a reduction in the national energy consumption of 0.3%. Real-time control based on mixture composition could achieve these savings. However, the major distillation processes represent diverse applications and at present there does not exist a proven on-line chemical composition sensor technology which can be used to control these diverse processes in real-time. This report presents a summary of the findings of the second phase of a three phase effort undertaken to develop an on-line real-time measurement and control system utilizing Raman spectroscopy. A prototype instrument system has been constructed utilizing a Perkin Elmer 1700 Spectrometer, a diode pumped YAG laser, two three axis positioning systems, a process sample cell land a personal computer. This system has been successfully tested using industrially supplied process samples to establish its performance. Also, continued application development was undertaken during this Phase of the program using both the spontaneous Raman and Surface-enhanced Raman modes of operation. The study was performed for the US Department of Energy, Office of Industrial Technologies, whose mission is to conduct cost-shared R D for new high-risk, high-payoff industrial energy conservation technologies. Although this document contains references to individual manufacturers and their products, the opinions expressed on the products reported do not necessarily reflect the position of the Department of Energy.

  2. An experimental study of the feasibility of substituting Chemical Abstracts on-line for the printed copy in a medium-sized medical library.

    Science.gov (United States)

    Baldinger, E L; Nakeff-Plaat, J P; Cummings, M S

    1981-04-01

    The reference staff of the Washington University School of Medicine Library, in an attempt to consider an alternative way of providing the information contained in the printed Chemical Abstracts, designed a study to examine whether the on-line version of Chemical Abstracts could be substituted for the hard copy. For a thirteen-week period, all patrons using the printed index were offered a free computer search of Chemical Abstracts in exchange for evaluating the searches. Only 39.6% of those offered a free search chose to do so. Of these patrons, 62% still planned to refer to the abstracts later, which are only available in the printed index. The hypothesis that the on-line version could be substituted for the printed index was not confirmed.

  3. Using an On-Line Tool To Investigate Chemical Engineering Seniors' Concept of the Design Process.

    Science.gov (United States)

    Streveler, Ruth A.; Miller, Ronald L.; Boyd, Thomas M.

    In this study, multidimensional scaling (MDS) was used to measure how 23 chemical engineering seniors categorized key design terms at the beginning and end of a capstone design course. An on-line method was developed to collect the MDS data. The results suggest that some important design concepts were not well understood, even at the end of the…

  4. Process Analytical Technology and On-Line Spectroscopic Measurements of Chemical Meat Quality

    DEFF Research Database (Denmark)

    Sørensen, Klavs Martin

    This thesis deals with process analytical technology and how it can be implemented in the meat industry through on-line grading of chemical meat quality. The focus will be on two applications, namely the rapid quality control of fat quality and the development of a method for on-line detection of...... quality, but also with environmental issues such as energy and water use and animal welfare. Future research into the technologies will ultimately allow broad on-line screening of biomarkers, leading to on-line metabolomics......This thesis deals with process analytical technology and how it can be implemented in the meat industry through on-line grading of chemical meat quality. The focus will be on two applications, namely the rapid quality control of fat quality and the development of a method for on-line detection...... of boar taint. The chemical makeup of fat has a large effect on meat cut quality. Fat quality has traditionally been determined by methylation of a tissue sample followed by chromatography on a GC-MS system, elucidating the composition of the individual fatty acids. As this procedure typically takes far...

  5. Process Analytical Technology and On-Line Spectroscopic Measurements of Chemical Meat Quality

    DEFF Research Database (Denmark)

    Sørensen, Klavs Martin

    This thesis deals with process analytical technology and how it can be implemented in the meat industry through on-line grading of chemical meat quality. The focus will be on two applications, namely the rapid quality control of fat quality and the development of a method for on-line detection...... of boar taint. The chemical makeup of fat has a large effect on meat cut quality. Fat quality has traditionally been determined by methylation of a tissue sample followed by chromatography on a GC-MS system, elucidating the composition of the individual fatty acids. As this procedure typically takes far...... on surgical castration will be in effect starting 2018. With the ban, the risk of meat products with the malodorous taint reaching the consumer is highly increased, and thus, detection of boar taint is a necessity. No current on-line detection system is available; the only alternative is chemical extraction...

  6. A New On-Line Resource for Psycholinguistic Studies

    Science.gov (United States)

    Szekely, Anna; Jacobsen, Thomas; D'Amico, Simona; Devescovi, Antonella; Andonoa, Elena; Herron, Daniel; Lu, Ching Ching; Pechmann, Thomas; Pleh, Csaba; Wicha, Nicole; Federmeier, Kara; Gerdjikova, Irina; Gutierrez, Gabriel; Hung, Daisy, Hsu, Jeanne; Iyer, Gowri; Kohnert, Kathryn; Mehotcheva, Teodora; Orozco-Figueroa, Araceli; Tzeng, Angela; Tzeng, Ovid; Arevalo, Analia; Vargha, Andras; Butler, Andrew C.; Buffington, Robert; Bates, Elizabeth

    2004-01-01

    Picture naming is a widely used technique in psycholinguistic studies. Here, we describe new on-line resources that our project has compiled and made available to researchers on the world wide web at http://crl.ucsd.edu/~aszekely/ipnp/. The website provides access to a wide range of picture stimuli and related norms in seven languages. Picture…

  7. On-line coating of glass with tin oxide by atmospheric pressure chemical vapor deposition.

    Energy Technology Data Exchange (ETDEWEB)

    Allendorf, Mark D.; Sopko, J.F. (PPF Industries, Pittsburgh, PA); Houf, William G.; Chae, Yong Kee; McDaniel, Anthony H.; Li, M. (PPF Industries, Pittsburgh, PA); McCamy, J.W. (PPF Industries, Pittsburgh, PA)

    2006-11-01

    Atmospheric pressure chemical vapor deposition (APCVD) of tin oxide is a very important manufacturing technique used in the production of low-emissivity glass. It is also the primary method used to provide wear-resistant coatings on glass containers. The complexity of these systems, which involve chemical reactions in both the gas phase and on the deposition surface, as well as complex fluid dynamics, makes process optimization and design of new coating reactors a very difficult task. In 2001 the U.S. Dept. of Energy Industrial Technologies Program Glass Industry of the Future Team funded a project to address the need for more accurate data concerning the tin oxide APCVD process. This report presents a case study of on-line APCVD using organometallic precursors, which are the primary reactants used in industrial coating processes. Research staff at Sandia National Laboratories in Livermore, CA, and the PPG Industries Glass Technology Center in Pittsburgh, PA collaborated to produce this work. In this report, we describe a detailed investigation of the factors controlling the growth of tin oxide films. The report begins with a discussion of the basic elements of the deposition chemistry, including gas-phase thermochemistry of tin species and mechanisms of chemical reactions involved in the decomposition of tin precursors. These results provide the basis for experimental investigations in which tin oxide growth rates were measured as a function of all major process variables. The experiments focused on growth from monobutyltintrichloride (MBTC) since this is one of the two primary precursors used industrially. There are almost no reliable growth-rate data available for this precursor. Robust models describing the growth rate as a function of these variables are derived from modeling of these data. Finally, the results are used to conduct computational fluid dynamic simulations of both pilot- and full-scale coating reactors. As a result, general conclusions are

  8. On-line chemical composition analyzer development. Phase 2, Final report

    Energy Technology Data Exchange (ETDEWEB)

    Roberts, M.J.; Garrison, A.A.; Muly, E.C.; Moore, C.F.

    1992-02-01

    The energy consumed in distillation processes in the United States represents nearly three percent of the total national energy consumption. If effective control of distillation columns can be accomplished, it has been estimated that it would result in a reduction in the national energy consumption of 0.3%. Real-time control based on mixture composition could achieve these savings. However, the major distillation processes represent diverse applications and at present there does not exist a proven on-line chemical composition sensor technology which can be used to control these diverse processes in real-time. This report presents a summary of the findings of the second phase of a three phase effort undertaken to develop an on-line real-time measurement and control system utilizing Raman spectroscopy. A prototype instrument system has been constructed utilizing a Perkin Elmer 1700 Spectrometer, a diode pumped YAG laser, two three axis positioning systems, a process sample cell land a personal computer. This system has been successfully tested using industrially supplied process samples to establish its performance. Also, continued application development was undertaken during this Phase of the program using both the spontaneous Raman and Surface-enhanced Raman modes of operation. The study was performed for the US Department of Energy, Office of Industrial Technologies, whose mission is to conduct cost-shared R&D for new high-risk, high-payoff industrial energy conservation technologies. Although this document contains references to individual manufacturers and their products, the opinions expressed on the products reported do not necessarily reflect the position of the Department of Energy.

  9. Chemical investigations of isotope separation on line target units for carbon and nitrogen beams

    CERN Document Server

    Franberg, H; Gäggeler, H W; Köster, U

    2006-01-01

    Radioactive ion beams (RIBs) are of significant interest in a number of applications. Isotope separation on line (ISOL) facilities provide RIB with high beam intensities and good beam quality. An atom that is produced within the ISOL target will first diffuse out from the target material. During the effusion towards the transfer line and into the ion source the many contacts with the surrounding surfaces may cause unacceptable delays in the transport and, hence, losses of the shorter-lived isotopes. We performed systematic chemical investigations of adsorption in a temperature and concentration regime relevant for ISOL targets and ion source units, with regard to CO/sub x/ and NOmaterials are potential construction materials for the above-mentioned areas. Off-line and on-line tests have been performed using a gas thermochromatography setup with radioactive tracers. The experiments were performed at the production of tracers for atmospheric chemistry (PROTRAC) facility at the Paul Schener Institute in Villigen...

  10. On-line Dynamic Model Correction Based Fault Diagnosis in Chemical Processes

    Institute of Scientific and Technical Information of China (English)

    田文德; 孙素莉

    2007-01-01

    A novel fault detection and diagnosis method was proposed,using dynamic simulation to monitor chemical process and identify faults when large tracking deviations occur.It aims at parameter failures,and the parameters are updated via on-line correction.As it can predict the trend of process and determine the existence of malfunctions simultaneously,this method does not need to design problem-specific observer to estimate unmeasured state variables.Application of the proposed method is presented on one water tank and one aromatization reactor,and the results are compared with those from the traditional method.

  11. An on-line method in studying music parsing.

    Science.gov (United States)

    Berent, I; Perfetti, C A

    1993-03-01

    Listening to music entails the construction of a mental representation based on partial and ambiguous information. This study examines an experimental method that reflects such parsing decisions on-line by detecting the cognitive load resulting from temporary parsing failures. The method investigated was a divided attention paradigm in which listening to music was the primary task and click detection was a concurrent secondary task. It was hypothesized that increasing the complexity of the primary task by introducing an unprepared chromatic modulation results in an increase in response latencies to a click presented immediately after the modulatory shift. The support of this prediction by musicians' data provides evidence for the sensitivity of the paradigm. The failure of non-musicians to reflect the expected load is attributed to their attention-allocation strategy. These results are discussed in terms of their implications on the view of the musical parser as deterministic.

  12. A novel inlet system for on-line chemical analysis of semi-volatile submicron particulate matter

    Directory of Open Access Journals (Sweden)

    P. Eichler

    2014-09-01

    Full Text Available We herein present the concept of a novel modular inlet system that allows using gas-phase analyzers for on-line chemical characterization of semi-volatile submicron particles. The "chemical analysis of aerosol on-line" (CHARON inlet consists of a gas-phase denuder for stripping off gas-phase analytes, an aerodynamic lens for particle enrichment in the sampling flow and a thermo-desorption unit for particle volatilization prior to chemical analysis. We coupled the CHARON inlet to a proton-transfer-reaction time-of-flight mass spectrometer (PTR-ToF-MS which quantitatively detects most organic analytes and ammonia. The combined set-up measures submicron organic and ammonium nitrate/sulfate particles online. Two proof-of-principle studies were carried out for demonstrating the analytical power of the new set-up in analyzing primarily emitted and secondarily generated particles. Oxygenated organics and their partitioning between the gas and the particulate phase were observed from the reaction of limonene with ozone. Abundant quasi-molecular ions of organic particulate constituents were observed when submicron particles were sampled from diluted mainstream cigarette smoke.

  13. Recent studies to improve release properties from thick isotope separator on-line fission targets

    CERN Document Server

    Lau, C; Verney, D; Bajeat, O; Ibrahim, F; Clapier, F; Cottereau, E; Donzaud, C; Ducourtieux, M; Essabaa, S; Guillemaud-Müller, D; Hosni, F; Lefort, H; Le Blanc, F; Müller, A C

    2003-01-01

    In the framework of the PARRNe program (Production d'Atomes Radioactifs Riches en Neutrons) of IPN Orsay, various techniques are currently used to characterize the release properties of elements of interest from a UC//X target. On-line studies have been carried out with two plasma ion sources: a Nier-Bernas and a hot plasma ISOLDE- type (the ISOLDE collaboration kindly supplied us a MK5 ion source for these studies). In parallel, the analysis of the chemical and structure properties of some UC//X samples as function of heating conditions has been carried out. Such data are essential to determine optimal conditions for the production of isotopes by the isotope separator on-line (ISOL) technique. First results are presented here for Kr and Ag. Investigations for other kinds of fission targets are planned.

  14. The Cryo-Thermochromatographic Separator (CTS) A new rapid separation and alpha-detection system for on-line chemical studies of highly volatile osmium and hassium (Z=108) tetroxides

    CERN Document Server

    Kirbach, U W; Gregorich, K E; Lee, D M; Ninov, V; Omtvedt, J P; Patin, J B; Seward, N K; Strellis, D A; Sudowe, R; Türler, A; Wilk, P A; Zielinski, P M; Hoffman, D C; Nitsche, H

    2002-01-01

    The Cryo-Thermochromatographic Separator (CTS) was designed and constructed for rapid, continuous on-line separation and simultaneous detection of highly volatile compounds of short-lived alpha-decaying isotopes of osmium and hassium (Hs, Z=108). A flowing carrier gas containing the volatile species is passed through a channel formed by two facing rows of 32 alpha-particle detectors, cooled to form a temperature gradient extending from 247 K at the channel entrance down to 176 K at the exit. The volatile species adsorb onto the SiO sub 2 -coated detector surfaces at a characteristic deposition temperature and are identified by their observed alpha-decay energies. The CTS was tested on-line with OsO sub 4 prepared from sup 1 sup 6 sup 9 sup - sup 1 sup 7 sup 3 Os isotopes produced in sup 1 sup 1 sup 8 sup , sup 1 sup 2 sup 0 Sn( sup 5 sup 6 Fe, 3,4,5n) reactions. An adsorption enthalpy for OsO sub 4 of -40.2+-1.5 kJ/mol on SiO sub 2 was deduced by comparing the measured deposition distribution with Monte Carlo...

  15. On-Line Adaptive Radiation Therapy: Feasibility and Clinical Study

    Directory of Open Access Journals (Sweden)

    Taoran Li

    2010-01-01

    Full Text Available The purpose of this paper is to evaluate the feasibility and clinical dosimetric benefit of an on-line, that is, with the patient in the treatment position, Adaptive Radiation Therapy (ART system for prostate cancer treatment based on daily cone-beam CT imaging and fast volumetric reoptimization of treatment plans. A fast intensity-modulated radiotherapy (IMRT plan reoptimization algorithm is implemented and evaluated with clinical cases. The quality of these adapted plans is compared to the corresponding new plans generated by an experienced planner using a commercial treatment planning system and also evaluated by an in-house developed tool estimating achievable dose-volume histograms (DVHs based on a database of existing treatment plans. In addition, a clinical implementation scheme for ART is designed and evaluated using clinical cases for its dosimetric qualities and efficiency.

  16. On-line monitoring of chemical reactions by using bench-top nuclear magnetic resonance spectroscopy.

    Science.gov (United States)

    Danieli, E; Perlo, J; Duchateau, A L L; Verzijl, G K M; Litvinov, V M; Blümich, B; Casanova, F

    2014-10-06

    Real-time nuclear magnetic resonance (NMR) spectroscopy measurements carried out with a bench-top system installed next to the reactor inside the fume hood of the chemistry laboratory are presented. To test the system for on-line monitoring, a transfer hydrogenation reaction was studied by continuously pumping the reaction mixture from the reactor to the magnet and back in a closed loop. In addition to improving the time resolution provided by standard sampling methods, the use of such a flow setup eliminates the need for sample preparation. Owing to the progress in terms of field homogeneity and sensitivity now available with compact NMR spectrometers, small molecules dissolved at concentrations on the order of 1 mmol L(-1) can be characterized in single-scan measurements with 1 Hz resolution. Owing to the reduced field strength of compact low-field systems compared to that of conventional high-field magnets, the overlap in the spectrum of different NMR signals is a typical situation. The data processing required to obtain concentrations in the presence of signal overlap are discussed in detail, methods such as plain integration and line-fitting approaches are compared, and the accuracy of each method is determined. The kinetic rates measured for different catalytic concentrations show good agreement with those obtained with gas chromatography as a reference analytical method. Finally, as the measurements are performed under continuous flow conditions, the experimental setup and the flow parameters are optimized to maximize time resolution and signal-to-noise ratio.

  17. Use of the Riccatti Equation On-Line for Adaptively Controlling a CSTR Chemical Reactor.

    OpenAIRE

    Edwards, J B; Mohd Noor, S.B.

    1995-01-01

    An idealised nonlinear model of an isothermal continuous stirred-tank reactor (CSTR) is analysed and simulated for optimal control based on the continuous on-line recomputation of a Riccati Controller as proposed by Banks (1). The controller and resulting behaviour are derived analytically and confirmed to be optimal by derivation also via Dynamic Programming. For comparison purposes, the behaviour of the same model under linear proportional control (with feedforward compensation)is derived a...

  18. Operational on-line coupled chemical weather forecasts for Europe with WRF/Chem

    Science.gov (United States)

    Hirtl, Marcus; Mantovani, Simone; Krüger, Bernd C.; Flandorfer, Claudia; Langer, Matthias

    2014-05-01

    Air quality is a key element for the well-being and quality of life of European citizens. Air pollution measurements and modeling tools are essential for the assessment of air quality according to EU legislation. The responsibilities of ZAMG as the national weather service of Austria include the support of the federal states and the public in questions connected to the protection of the environment in the frame of advisory and counseling services as well as expert opinions. ZAMG conducts daily Air-Quality forecasts using the on-line coupled model WRF/Chem. Meteorology is simulated simultaneously with the emissions, turbulent mixing, transport, transformation, and fate of trace gases and aerosols. The emphasis of the application is on predicting pollutants over Austria. Two domains are used for the simulations: the mother domain covers Europe with a resolution of 12 km, the inner domain includes the alpine region with a horizontal resolution of 4 km; 45 model levels are used in the vertical direction. The model runs 2 times per day for a period of 72 hours and is initialized with ECMWF forecasts. On-line coupled models allow considering two-way interactions between different atmospheric processes including chemistry (both gases and aerosols), clouds, radiation, boundary layer, emissions, meteorology and climate. In the operational set-up direct-, indirect and semi-direct effects between meteorology and air chemistry are enabled. The model is running on the HPCF (High Performance Computing Facility) of the ZAMG. In the current set-up 1248 CPUs are used. As the simulations need a big amount of computing resources, a method to safe I/O-time was implemented. Every MPI task writes all its output into the shared memory filesystem of the compute nodes. Once the WRF/Chem integration is finished, all split NetCDF-files are merged and saved on the global file system. The merge-routine is based on parallel-NetCDF. With this method the model runs about 30% faster on the SGI

  19. Micro flow reactor chips with integrated luminescent chemosensors for spatially resolved on-line chemical reaction monitoring.

    Science.gov (United States)

    Gitlin, Leonid; Hoera, Christian; Meier, Robert J; Nagl, Stefan; Belder, Detlev

    2013-10-21

    Real-time chemical reaction monitoring in microfluidic environments is demonstrated using luminescent chemical sensors integrated in PDMS/glass-based microscale reactors. A fabrication procedure is presented that allows for straightforward integration of thin polymer layers with optical sensing functionality in microchannels of glass-PDMS chips of only 150 μm width and of 10 to 35 μm height. Sensor layers consisting of polystyrene and an oxygen-sensitive platinum porphyrin probe with film thicknesses of about 0.5 to 4 μm were generated by combining spin coating and abrasion techniques. Optimal coating procedures were developed and evaluated. The chip-integrated sensor layers were calibrated and investigated with respect to stability, reproducibility and response times. These microchips allowed observation of dissolved oxygen concentration in the range of 0 to over 40 mg L(-1) with a detection limit of 368 μg L(-1). The sensor layers were then used for observation of a model reaction, the oxidation of sulphite to sulphate in a microfluidic chemical reactor and could observe sulphite concentrations of less than 200 μM. Real-time on-line monitoring of this chemical reaction was realized at a fluorescence microscope setup with 405 nm LED excitation and CCD camera detection.

  20. On-line Meteorology-Chemistry/Aerosols Modelling and Integration for Risk Assessment: Case Studies

    Science.gov (United States)

    Bostanbekov, Kairat; Mahura, Alexander; Nuterman, Roman; Nurseitov, Daniyar; Zakarin, Edige; Baklanov, Alexander

    2016-04-01

    On regional level, and especially in areas with potential diverse sources of industrial pollutants, the risk assessment of impact on environment and population is critically important. During normal operations, the risk is minimal. However, during accidental situations, the risk is increased due to releases of harmful pollutants into different environments such as water, soil, and atmosphere where it is following processes of continuous transformation and transport. In this study, the Enviro-HIRLAM (Environment High Resolution Limited Area Model) was adapted and employed for assessment of scenarios with accidental and continuous emissions of sulphur dioxide (SO2) for selected case studies during January of 2010. The following scenarios were considered: (i) control reference run; (ii) accidental release (due to short-term 1 day fire at oil storage facility) occurred at city of Atyrau (Kazakhstan) near the northern part of the Caspian Sea; and (iii) doubling of original continuous emissions from three locations of metallurgical enterprises on the Kola Peninsula (Russia). The implemented aerosol microphysics module M7 uses 5 types - sulphates, sea salt, dust, black and organic carbon; as well as distributed in 7 size modes. Removal processes of aerosols include gravitational settling and wet deposition. As the Enviro-HIRLAM model is the on-line integrated model, both meteorological and chemical processes are simultaneously modelled at each time step. The modelled spatio-temporal variations for meteorological and chemical patterns are analyzed for both European and Kazakhstan regions domains. The results of evaluation of sulphur dioxide concentration and deposition on main populated cities, selected regions, countries are presented employing GIS tools. As outcome, the results of Enviro-HIRLAM modelling for accidental release near the Caspian Sea are integrated into the RANDOM (Risk Assessment of Nature Detriment due to Oil spill Migration) system.

  1. Electrospray micromixer chip for on-line derivatization and kinetic studies.

    Science.gov (United States)

    Abonnenc, Mélanie; Dayon, Loïc; Perruche, Brice; Lion, Niels; Girault, Hubert H

    2008-05-01

    An electrospray microchip for mass spectrometry comprising an integrated passive mixer to carry out on-chip chemical derivatizations is described. The microchip fabricated using UV-photoablation is composed of two microchannels linked together by a liquid junction. Downstream of this liquid junction, a mixing unit made of parallel oblique grooves is integrated to the microchannel in order to create flow perturbations. Several mixer designs are evaluated. The mixer efficiency is investigated both by fluorescence study and mass spectrometric monitoring of the tagging reaction of cysteinyl peptides with 1,4-benzoquinone. The comparisons with a microchip without a mixing unit and a kinetic model are used to assess the efficiency of the mixer showing tagging kinetics close to that of bulk reactions in an ideally mixed reactor. As an ultimate application, the electrospray micromixer is implemented in a LC-MS workflow. On-line derivatization of albumin tryptic peptides after a reversed-phase separation and counting of their cysteines drastically enhance the protein identification.

  2. Treatment of hepatic encephalopathy by on-line hemodiafiltration: a case series study

    Directory of Open Access Journals (Sweden)

    Sugiyama Mitsugi

    2010-05-01

    Full Text Available Abstract Background It is thought that a good survival rate of patients with acute liver failure can be achieved by establishing an artificial liver support system that reliably compensates liver function until the liver regenerates or a patient undergoes transplantation. We introduced a new artificial liver support system, on-line hemodiafiltration, in patients with acute liver failure. Methods This case series study was conducted from May 2001 to October 2008 at the medical intensive care unit of a tertiary care academic medical center. Seventeen consecutive patients who admitted to our hospital presenting with acute liver failure were treated with artificial liver support including daily on-line hemodiafiltration and plasma exchange. Results After 4.9 ± 0.7 (mean ± SD on-line hemodiafiltration sessions, 16 of 17 (94.1% patients completely recovered from hepatic encephalopathy and maintained consciousness for 16.4 ± 3.4 (7-55 days until discontinuation of artificial liver support (a total of 14.4 ± 2.6 [6-47] on-line hemodiafiltration sessions. Significant correlation was observed between the degree of encephalopathy and number of sessions of on-line HDF required for recovery of consciousness. Of the 16 patients who recovered consciousness, 7 fully recovered and returned to society with no cognitive sequelae, 3 died of complications of acute liver failure except brain edema, and the remaining 6 were candidates for liver transplantation; 2 of them received living-related liver transplantation but 4 died without transplantation after discontinuation of therapy. Conclusions On-line hemodiafiltration was effective in patients with acute liver failure, and consciousness was maintained for the duration of artificial liver support, even in those in whom it was considered that hepatic function was completely abolished.

  3. Chemical Industry Bandwidth Study

    Energy Technology Data Exchange (ETDEWEB)

    none,

    2006-12-01

    The Chemical Bandwidth Study provides a snapshot of potentially recoverable energy losses during chemical manufacturing. The advantage of this study is the use of "exergy" analysis as a tool for pinpointing inefficiencies.

  4. On-line derivatization gas chromatography with furan chemical ionization tandem mass spectrometry for screening of amphetamines in urine.

    Science.gov (United States)

    Tzing, Shin-Hwa; Ghule, Anil; Liu, Jen-Yu; Ling, Yong-Chien

    2006-12-22

    A simple alternative method with minimal sample pretreatment is investigated for screening of amphetamines in small volume (using only 20 microL) of urine sample. The method is sensitive and selective. The method uses gas chromatography (GC) direct sample introduction (DSI) for on-line derivatization (acylation) of amphetamines to improve sensitivity. Furan as chemical ionization (CI) reagent in conjunction with tandem mass spectrometry (MS/MS) is used to improve selectivity. Low background with sharp protonated molecular ion peaks of analytes is the evidence of improvement in sensitivity and selectivity. Blank urine samples spiked with known amounts of amphetamine, methamphetamine, 3,4-methylenedioxyamphetamine, 3,4-methylenedioxymethamphetamine and 3,4-methylenedioxyethylamphetamine is analyzed. Selected ion monitoring of the characteristic product ions (m/z 119+136+150+163) using furan CI-MS/MS in positive ion mode is used for quantification. Limits of detection (LOD) between 0.4 and 1.0 ng mL(-1) and limits of quantitation (LOQ) between 1.0 and 2.0 ng mL(-1) are established. Linear response over the range of 1-1000 ng mL(-1) (r(2)>0.997) is observed for all analytes, except for methamphetamine (2.0-1000 ng mL(-1)). Good accuracy between 86 and 113% and precision ranging from 4 to 18% is obtained. The method is also tested on real samples of urine from suspected drug abusers. This method could be used for screening and determination of amphetamines in urine samples, however needs additional work for full validation.

  5. Identification of Variables and Factors Impacting Consumer Behavior in On-line Shopping in India: An Empirical Study

    Science.gov (United States)

    Chhikara, Sudesh

    On-line shopping is a recent phenomenon in the field of E-Business and is definitely going to be the future of shopping in the world. Most of the companies are running their on-line portals to sell their products/services. Though online shopping is very common outside India, its growth in Indian Market, which is a large and strategic consumer market, is still not in line with the global market. The potential growth of on-line shopping has triggered the idea of conducting a study on on-line shopping in India. The present research paper has used exploratory study to depict and highlight the various categories of factors and variables impacting the behavior of consumers towards on-line shopping in India. The data was collected through in-depth interviews on a sample of 41 respondents from Delhi, Mumbai, Chennai and Bangalore. The results of the study show that on-line shopping in India is basically impacted by five categories of factors like demographics factor, Psychographics factor, Online shopping feature and policies, Technological factor, Security factor. The results of the study are used to present a comprehensive model of on-line shopping which could be further used by the researchers and practitioners for conducting future studies in the similar area. A brief operational definition of all the factors and variables impacting on-line shopping in India is also described. And finally practical implications of the study are also elucidated.

  6. Feasibility study of on-line digital X-ray imaging for irradiated fuel rods

    Energy Technology Data Exchange (ETDEWEB)

    Parthoens, Y.; Gys, A. [Reactor Material Research Department, SCK-CEN, Mol (Belgium); Smolders, V. [Industrial Engineer Department, Katholieke Hogeschool Kempen, Geel (Belgium)

    2003-07-01

    At the Reactor Material Research Department of the Belgian Nuclear Research Centre SCK-CEN Xray imaging of the internal parts of irradiated fuel rods is done on silver-halide films using a 420 kV X-ray source. The replacement of the films by an on-line digital X-ray imaging system implies several advantages. Images can be evaluated instantly and source parameters can be optimized more easily. Time consuming film development is superfluous. The images can digitally be enhanced, processed, reported and archived. Within this work the feasibility of four commercial on-line digital X-ray imaging systems were studied for post-irradiation examination on fuel rods in a hot cell environment. The criteria to evaluate the systems were image quality, integration in the existing hot cell infrastructure, durability and cost price. For the evaluation and comparison of the image quality a simulation fuel rod was fabricated. Three systems suffered from lack of sensitivity, contrast and/or resolution. Only the CsI-scintillator coupled to a CCD-camera with image intensifier gave a sufficient image quality. On the other hand the image intensifiers' dimensions are difficult to integrate in the existing hot cell infrastructure. Also the durability of intensifier screens is questionable as they are susceptible to image burn. Smaller image intensifiers easier to integrate are commercial available nowadays.

  7. Asymmetrical flow field-flow fractionation with on-line detection for drug transfer studies: a feasibility study

    DEFF Research Database (Denmark)

    Hinna, A.; Steiniger, F.; Hupfeld, S.

    2014-01-01

    Knowledge about drug retention within colloidal carriers is of uppermost importance particularly if drug targeting is anticipated. The aim of the present study was to evaluate asymmetrical flow field-flow fractionation (AF4) with on-line UV/VIS drug quantification for its suitability to determine...... both release and transfer of drug from liposomal carriers to a model acceptor phase consisting of large liposomes. The hydrophobic porphyrin 5,10,15,20-tetrakis(4-hydroxyphenyl)21H,23H-porphine (p-THPP), a fluorescent dye with an absorbance maximum in the visible range and structural similarity...... channel geometries. Drug quantification by on-line absorbance measurements was established by comprehensive evaluation of the size-dependent turbidity contribution in on-line UV/VIS detection and by comparison with off-line results obtained for the respective dye-loaded donor formulations (dissolved...

  8. GEM-AQ/EC, an on-line global multi-scale chemical weather modelling system: model development and evaluation of global aerosol climatology

    Directory of Open Access Journals (Sweden)

    S. L. Gong

    2012-09-01

    Full Text Available A global air quality modeling system GEM-AQ/EC was developed by implementing tropospheric chemistry and aerosol processes on-line into the Global Environmental Multiscale weather prediction model – GEM. Due to the multi-scale features of the GEM, the integrated model, GEM-AQ/EC, is able to investigate chemical weather at scales from global to urban domains. The current chemical mechanism is comprised of 50 gas-phase species, 116 chemical and 19 photolysis reactions, and is complemented by a sectional aerosol module CAM (The Canadian Aerosol Module with 5 aerosols types: sulphate, black carbon, organic carbon, sea-salt and soil dust. Monthly emission inventories of black carbon and organic carbon from boreal and temperate vegetation fires were assembled using the most reliable areas burned datasets by countries, from statistical databases and derived from remote sensing products of 1995–2004. The model was run for ten years from from 1995–2004 with re-analyzed meteorology on a global uniform 1° × 1° horizontal resolution domain and 28 hybrid levels extending up to 10 hPa. The simulating results were compared with various observations including surface network around the globe and satellite data. Regional features of global aerosols are reasonably captured including emission, surface concentrations and aerosol optical depth. For various types of aerosols, satisfactory correlations were achieved between modeled and observed with some degree of systematic bias possibly due to large uncertainties in the emissions used in this study. A global distribution of natural aerosol contributions to the total aerosols is obtained and compared with observations.

  9. GEM-AQ/EC, an on-line global multiscale chemical weather modelling system: model development and evaluations of global aerosol climatology

    Directory of Open Access Journals (Sweden)

    S. L. Gong

    2012-04-01

    Full Text Available A global air quality modeling system GEM-AQ/EC was developed by implementing tropospheric chemistry and aerosol processes on-line into the Global Environmental Multiscale weather prediction model – GEM. Due to the multi-scale features of the GEM, the integrated model, GEM-AQ/EC, is able to investigate chemical weather at scales from global to urban domains. The current chemical mechanism is comprised of 50 gas-phase species, 116 chemical and 19 photolysis reactions, and is complemented by a sectional aerosol module CAM (The Canadian Aerosol Module with 5 aerosols types: sulphate, black carbon, organic carbon, sea-salt and soil dust. Monthly emission inventories of black carbon and organic carbon from boreal and temperate vegetation fires were assembled using the most reliable areas burned datasets by countries, from statistical databases and derived from remote sensing products of 1995–2004. The model was run for ten years from from 1995–2004 with re-analyzed meteorology on a global uniform 1 × 1° horizontal resolution domain and 28 hybrid levels extending up to 10 hPa. The simulating results were compared with various observations including surface network around the globe and satellite data. Regional features of global aerosols are reasonably captured including emission, surface concentrations and aerosol optical depth. For various types of aerosols, satisfactory correlations were achieved between modeled and observed with some degree of systematic bias possibly due to large uncertainties in the emissions used in this study. A global distribution of natural aerosol contributions to the total aerosols is obtained and compared with observations.

  10. High School Open On-Line Courses (HOOC): A Case Study from Italy

    Science.gov (United States)

    Canessa, Enrique; Pisani, Armando

    2013-01-01

    The first implementation of complete high school, open on-line courses (HOOC) aiming to support the training and basic scientific knowledge of young students from the Liceo Ginnasio Dante Alighieri in Gorizia, Italy, is discussed. Using the open source and automated recording system openEyA, HOOC give a student the opportunity to watch on-line, at…

  11. Study on biomass catalytic pyrolysis for production of bio-gasoline by on-line FTIR

    Institute of Scientific and Technical Information of China (English)

    Chang Bo Lu; Jian Zhong Yao; Wei Gang Lin; Wen Li Song

    2007-01-01

    The pyrolysis of biomass is a promising way for production of bio-gasoline if the stability and quality problems of the bio-crudeoil can be solved by catalytic cracking and reforming. In this paper, an on-line infrared spectrum was used to study the characteristics of catalytic pyrolysis with the following preliminary results. The removal of C=O of organic acid is more difficult than that of aldehydes and ketones. HUSY/γ-Al2O3 and REY/γ-Al2O3 catalysts exhibited better deoxygenating activities while HZSM-5/γ-Al2O3 catalyst exhibited preferred selectivities for production of iso-alkanes and aromatics. Finally, possible mechanisms of biomass catalytic pyrolysis are discussed as well.

  12. In-beam PET imaging for on-line adaptive proton therapy: an initial phantom study

    Science.gov (United States)

    Shao, Yiping; Sun, Xishan; Lou, Kai; Zhu, Xiaorong R.; Mirkovic, Dragon; Poenisch, Falk; Grosshans, David

    2014-07-01

    We developed and investigated a positron emission tomography (PET) system for use with on-line (both in-beam and intra-fraction) image-guided adaptive proton therapy applications. The PET has dual rotating depth-of-interaction measurable detector panels by using solid-state photomultiplier (SSPM) arrays and LYSO scintillators. It has a 44 mm diameter trans-axial and 30 mm axial field-of-view (FOV). A 38 mm diameter polymethyl methacrylate phantom was placed inside the FOV. Both PET and phantom axes were aligned with a collimated 179.2 MeV beam. Each beam delivered ˜50 spills (0.5 s spill and 1.5 s inter-spill time, 3.8 Gy at Bragg peak). Data from each beam were acquired with detectors at a given angle. Nine datasets for nine beams with detectors at nine different angles over 180° were acquired for full-tomographic imaging. Each dataset included data both during and 5 min after irradiations. The positron activity-range was measured from the PET image reconstructed from all nine datasets and compared to the results from simulated images. A 22Na disc-source was also imaged after each beam to monitor the PET system's performance. PET performed well except for slight shifts of energy photo-peak positions (PET with high sensitivity and uniform resolution. Sub-mm activity-ranges were achieved with minimal 6 s acquisition time and three spill irradiations. These results indicate the feasibility of PET for intra-fraction beam-range verification. Further studies are needed to develop and apply a novel clinical PET system for on-line image-guided adaptive proton therapy.

  13. The Study on On-line Scheduling Algorithm of Imprecise Computation under Transient Overload

    Institute of Scientific and Technical Information of China (English)

    WEIZhenhua; HONGBingrong; QIAOYongqiang; CAIZesu; PENGJunjie

    2003-01-01

    Transient overload always occurs in realtime computer system. An on-line scheduling algorithm of imprecise computation is proposed in this paper to deal with it. This algorithm can be sure of getting acceptable computation result under the condition of overload, and at the same time it can improve the computation precision as much as possible. The system model of imprecise computation and the on-line imprecise computation algorithm are elaborated. And the algorithm is proved correct by simulation.

  14. On-line sensor monitoring for chemical contaminant attenuation during UV/H2O2 advanced oxidation process.

    Science.gov (United States)

    Yu, Hye-Weon; Anumol, Tarun; Park, Minkyu; Pepper, Ian; Scheideler, Jens; Snyder, Shane A

    2015-09-15

    A combination of surrogate parameters and indicator compounds were measured to predict the removal efficiency of trace organic compounds (TOrCs) using low pressure (LP)-UV/H2O2 advanced oxidation process (AOP), engaged with online sensor-based monitoring system. Thirty-nine TOrCs were evaluated in two distinct secondary wastewater effluents in terms of estimated photochemical reactivity, as a function of the rate constants of UV direct photolysis (kUV) and hydroxyl radical (OH) oxidation (kOH). The selected eighteen TOrCs were classified into three groups that served as indicator compounds: Group 1 for photo-susceptible TOrCs but with minor degradation by OH oxidation (diclofenac, fluoxetine, iohexol, iopamidol, iopromide, simazine and sulfamethoxazole); Group 2 for TOrCs susceptible to both direct photolysis and OH oxidation (benzotriazole, diphenhydramine, ibuprofen, naproxen and sucralose); and Group 3 for photo-resistant TOrCs showing dominant degradation by OH oxidation (atenolol, carbamazepine, DEET, gemfibrozil, primidone and trimethoprim). The results indicate that TOC (optical-based measurement), UVA254 or UVT254 (UV absorbance or transmittance at 254 nm), and total fluorescence can all be used as suitable on-line organic surrogate parameters to predict the attenuation of TOrCs. Furthermore, the automated real-time monitoring via on-line surrogate sensors and equipped with the developed degradation profiles between sensor response and a group of TOrCs removal can provide a diagnostic tool for process control during advanced treatment of reclaimed waters.

  15. GEM-AQ, an on-line global multiscale chemical weather system: model description and evaluation of gas phase chemistry processes

    Directory of Open Access Journals (Sweden)

    J. W. Kaminski

    2007-10-01

    Full Text Available Tropospheric chemistry and air quality processes were implemented on-line in the Global Environmental Multiscale model. The integrated model, GEM-AQ, has been developed as a platform to investigate chemical weather at scales from global to urban. The model was exercised for five years (2001–2005 to evaluate its ability to simulate seasonal variations and regional distributions of trace gases such as ozone, nitrogen dioxide and carbon monoxide on the global scale. The model results presented are compared with observations from satellites, aircraft measurement campaigns and balloon sondes.

  16. Determination and characterization of phytochelatins by liquid chromatography coupled with on line chemical vapour generation and atomic fluorescence spectrometric detection.

    Science.gov (United States)

    Bramanti, Emilia; Toncelli, Daniel; Morelli, Elisabetta; Lampugnani, Leonardo; Zamboni, Roberto; Miller, Keith E; Zemetra, Joseph; D'Ulivo, Alessandro

    2006-11-10

    Liquid chromatography (LC) coupled on line with UV/visible diode array detector (DAD) and cold vapour generation atomic fluorescence spectrometry (CVGAFS) has been developed for the speciation, determination and characterization of phytochelatins (PCs). The method is based on a bidimensional approach, e.g. on the analysis of synthetic PC solutions (apo-PCs and Cd(2+)-complexed PCs) (i) by size exclusion chromatography coupled to UV diode array detector (SEC-DAD); (ii) by the derivatization of PC -SH groups in SEC fractions by p-hydroxymercurybenzoate (PHMB) and the indirect detection of PC-PHMB complexes by reversed phase liquid chromatography coupled to atomic fluorescence detector (RPLC-CVGAFS). MALDI-TOF/MS (matrix assisted laser desorption ionization time of flight mass spectrometry) analysis of underivatized synthetic PC samples was performed in order have a qualitative information of their composition. Quantitative analysis of synthetic PC solutions has been performed on the basis of peak area of PC-PHMB complexes of the mercury specific chromatogram and calibration curve of standard solution of glutathione (GSH) complexed to PHMB (GS-PHMB). The limit of quantitation (LOQ) in terms of GS-PHMB complex was 90 nM (CV 5%) with an injection volume of 35 microL, corresponding to 3.2 pmol (0.97 ng) of GSH. The method has been applied to analysis of extracts of cell cultures from Phaeodactylum tricornutum grown in Cd-containing nutrient solutions, analysed by SEC-DAD-CVGAFS and RPLC-DAD-CVGAFS.

  17. A Phenomenological Study of Gifted Adolescents and Their Engagement with One On-Line Learning System

    Science.gov (United States)

    Swicord, Barbara

    2010-01-01

    Little research exists on the nature of the interactions between gifted students and the use of technology. Furthermore, no research has investigated the phenomenon of gifted adolescents using one internet-based program, the Renzulli Learning System (RLS). Renzulli Learning is an on-line educational profile with a matching database that provides…

  18. Study Progress of On-line Monitoring Device for Uranium and Plutonium by XRF

    Institute of Scientific and Technical Information of China (English)

    2011-01-01

    An X-ray fluorescence spectrometer was designed and set up, which was used to determine uranium and plutonium on-line in reprocessing process stream. Uranium in aqueous and organic phase, plutonium in aqueous were measured by using the device,

  19. The role of attitudinal factors in mathematical on-line assessments: a study of undergraduate STEM students

    CERN Document Server

    Acosta-Gonzaga, Elizabeth

    2016-01-01

    This study explores student attitudes to the use of substantive on-line assessments that require mathematical answers. Our goal is to learn what are the important aspects in a design of more effective e-assessments that support learning of mathematical subjects in a higher education setting. To that end we analyse the effects of a variety of attitudinal factors towards such assessments amongst a cross-section of 1st year students in an English University. These students were all previously exposed to on-line assessments containing substantial mathematical work, including testing of and feedback on the algebraic structure of their answers. They were provided with detailed online feedback, and we therefore specifically examine the effect of formative feedback on the usage of educational technology. Our results suggest that students find on-line feedback more enjoyable and useful than traditional feedback. 'Attitude' and 'Enjoyment' are the two most important factors influencing their usage intention. Our result...

  20. Multilingual Searching in Digital Archives: A Case Study of Mahatma Gandhi University On-line Theses Archive

    OpenAIRE

    Jasimudeen, S.; Maghesh Rajan, M.; T. V. Suresh Kumar

    2012-01-01

    The Paper examines the multilingual search capabilities of Mahatma Gandhi University on-line theses archive using the first Digital Library solution with capabilities for information retrieval from full texts in Indian languages. The study finds that the multilingual search features of the Mahatma Gandhi University archive helps the user with more relevant hits than in any similar systems used in India.

  1. On-line updating of a distributed flow routing model - River Vistula case study

    Science.gov (United States)

    Karamuz, Emilia; Romanowicz, Renata; Napiorkowski, Jaroslaw

    2015-04-01

    This paper presents an application of methods of on-line updating in the River Vistula flow forecasting system. All flow-routing codes make simplifying assumptions and consider only a reduced set of the processes known to occur during a flood. Hence, all models are subject to a degree of structural error that is typically compensated for by calibration of the friction parameters. Calibrated parameter values are not, therefore, physically realistic, as in estimating them we also make allowance for a number of distinctly non-physical effects, such as model structural error and any energy losses or flow processes which occur at sub-grid scales. Calibrated model parameters are therefore area-effective, scale-dependent values which are not drawn from the same underlying statistical distribution as the equivalent at-a-point parameter of the same name. The aim of this paper is the derivation of real-time updated, on-line flow forecasts at certain strategic locations along the river, over a specified time horizon into the future, based on information on the behaviour of the flood wave upstream and available on-line measurements at a site. Depending on the length of the river reach and the slope of the river bed, a realistic forecast lead time, obtained in this manner, may range from hours to days. The information upstream can include observations of river levels and/or rainfall measurements. The proposed forecasting system will integrate distributed modelling, acting as a spatial interpolator with lumped parameter Stochastic Transfer Function models. Daily stage data from gauging stations are typically available at sites 10-60 km apart and test only the average routing performance of hydraulic models and not their ability to produce spatial predictions. Application of a distributed flow routing model makes it possible to interpolate forecasts both in time and space. This work was partly supported by the project "Stochastic flood forecasting system (The River Vistula reach

  2. Study on an On-line Measurement System of Corrosion Rate by Linear Polarization Resistance

    Energy Technology Data Exchange (ETDEWEB)

    Moon, Jeon Soo; Lee, Jae Kun; Lee, Jae Bong; Park, Pyl Yang [Korea Electric Power Research Institute, Daejeon (Korea, Republic of)

    2012-04-15

    The linear polarization resistance method is one of the widely used techniques for the corrosion rate monitoring in the water circulating systems of plants. The measurement is simple and rapid, so that a continuous on-line monitoring is possible without any shutdown of plants. A 2-electrode polarization corrosion rate measurement system was installed in a laboratory using a data acquisition board and PC. The signal processing parameters were optimized for the accurate corrosion rate measurement, and the polarization resistance was compensated with the solution resistance measured by the high frequency sine wave signal of an output channel. The precision of corrosion rate data was greatly improved by removing the initial noise signals on measuring the polarization resistance.

  3. Determination of Se in biological samples by axial view inductively coupled plasma optical emission spectrometry after digestion with aqua regia and on-line chemical vapor generation

    Energy Technology Data Exchange (ETDEWEB)

    Santos, Eder Jose dos [Instituto de Tecnologia do Parana (TECPAR), 81350-010 Curitiba, PR (Brazil)], E-mail: eder@tecpar.br; Herrmann, Amanda Beatriz; Kulik de Caires, Suzete [Instituto de Tecnologia do Parana (TECPAR), 81350-010 Curitiba, PR (Brazil); Azzolin Frescura, Vera Lucia; Curtius, Adilson Jose [Departamento de Quimica, Universidade Federal de Santa Catarina (UFSC), 880400-900 Florianopolis, SC (Brazil)

    2009-06-15

    A simple and fast method for the determination of Se in biological samples, including food, by axial view inductively coupled plasma optical emission spectrometry using on-line chemical vapor generation (CVG-ICP OES) is proposed. The concentrations of HCl and NaBH{sub 4}, used in the chemical vapor generation were optimized by factorial analysis. Six certified materials (non-fat milk powder, lobster hepatopancreas, human hair, whole egg powder, oyster tissue, and lyophilised pig kidney) were treated with 10 mL of aqua regia in a microwave system under reflux for 15 min followed by additional 15 min in an ultrasonic bath. The solutions were transferred to a 100 mL volumetric flask and the final volume was made up with water. The Se was determined directly in these solutions by CVG-ICP OES, using the analytical line at 196.026 nm. Calibration against aqueous standards in 10% v/v aqua regia in the concentration range of 0.5-10.0 {mu}g L{sup -} {sup 1} Se(IV) was used for the analysis. The quantification limit, considering a 0.5 g sample weight in a final volume of 100 mL{sup -} {sup 1} was 0.10 {mu}g g{sup -} {sup 1}. The obtained concentration values were in agreement with the total certified concentrations, according to the t-test for a 95% confidence level.

  4. Hemodiafiltration using pre-dilutional on-line citrate dialysate: A new technique for regional citrate anticoagulation: A feasibility study

    Directory of Open Access Journals (Sweden)

    Radhouane Bousselmi

    2015-01-01

    Full Text Available A prospective, observational, feasibility study was carried out on four patients with end-stage renal failure undergoing bicarbonate hemodialysis to study the feasibility of an on-line hemodiafiltration technique using a citrate dialysate with pre-dilutional infusion of citrate as a technique for regional citrate anticoagulation. All patients had contraindication to systemic heparin anticoagulation. The dialysis technique consisted of an on-line hemodiafiltration with a citrate dialysate without calcium using a Fresenius 4008S dialysis machine and Fresenius Polysulfone F60 dialyzers. The infusion solution was procured directly from the dialysate and was infused into the arterial line. To avoid the risk of hypocalcemia, calcium gluconate was infused to the venous return line. The study was carried out in two stages. During the first stage, the citrate infusion rate was 80 mL/min and the calcium infusion rate was 9 mmol/h. At the second stage, the rates were 100 mL/min and 11 mmol/h, respectively. The primary endpoint of this study was the incidence of thrombosis in the extracorporeal blood circuit and/or the dialyzer. A total of 78 sessions were conducted. All the sessions were well tolerated clinically and there were no major incidents in any of the four patients. At the first stage of the study, there were five incidences of small clots in the venous blood chamber, an incidence of extracorporeal blood circuit thrombosis of 12.5%. At the second stage of the study, no cases of extracorporeal blood circuit or dialyzer thrombosis were noted. Hemodiafiltration with on-line citrate dialysate infusion to the arterial line is safe and allows an effective regional anticoagulation of the extracorporeal blood circuit without the need for systemic anticoagulation.

  5. Experimental Study on an On-Line Measurement of High Temperature Circulating Ash Flux in a Circulating Fluidized Bed Boiler

    Institute of Scientific and Technical Information of China (English)

    Lu Xiaofeng; Li Yourong

    2001-01-01

    A new kind of measuring method that may be used to measure high temperature circulating solid particles flux in a circulating fluidized bed boiler is studied in this paper. The measuring method is founded on the principle of thermal equilibrium. A series of cold tests and hot tests were carried to optimize the structure and collocation of water-cooling tubes and showed that the method had the advantage of simple, accurate, reliable and good applicability for on-line usage in a circulating fluidized bed boiler.

  6. Combining Teletherapy and On-line Language Exercises in the Treatment of Chronic Aphasia: An Outcome Study

    Directory of Open Access Journals (Sweden)

    Richard D. Steele

    2015-01-01

    Full Text Available We report a 12-week outcome study in which nine persons with long-term chronic aphasia received individual and group speech-language teletherapy services, and also used on-line language exercises to practice from home between therapy sessions.  Participants were assessed at study initiation and completion using the Western Aphasia Battery, a portion of the Communicative Effectiveness Index, ASHA National Outcome Measurement System, and RIC Communication Confidence Rating Scale for Aphasia; additionally participants were polled regarding satisfaction at discharge.  Pre-treatment and post-treatment means were calculated and compared, and matched t-tests were used to determine significance of improvements following treatment, with patterns of independent on-line activity analyzed.  Analysis of scores shows that means improved on most measures following treatment, generally significantly: the WAB AQ improved +3.5 (p = .057; the CETI Overall (of items administered — +17.8 (p = .01, and CCRSA Overall — + 10.4 (p = .0004.  Independent work increased with time, and user satisfaction following participation was high.

  7. Study on on-line processing of the chaos laser radar using FPGA

    OpenAIRE

    2005-01-01

    Today, a car industry puts effort into making intelligent car to realize a safe and comfortable car society. As one of the sensing technology, laser radar is widely studied as in-car radar. The received signal in the laser radar becomes to be buried in noise with increasing distance. When the long distance is measured, it needs a high power laser, or the repetitive process that uses multiplication and integration. Therefore, a new type of the chaos laser radar has been studied. This laser rad...

  8. Electrochemistry-on-chip for on-line conversions in drug metabolism studies

    NARCIS (Netherlands)

    Odijk, Mathieu; Baumann, A.; Olthuis, Wouter; van den Berg, Albert; Karst, U.

    2010-01-01

    We have designed an integrated 3-electrode electrochemical cell on-chip with high analyte conversion rates for use in drug metabolism studies. The electrochemical cell contains platinum working and counter electrodes and an iridium oxide pseudo-reference electrode. The pseudo-reference electrode has

  9. A case study of students' experiences in an on-line college physics course

    Science.gov (United States)

    Ozen, Kadriye

    Online courses are a new paradigm in education. Many universities have adopted these courses to provide instruction to a diverse population. There were numerous issues that were addressed when delivering online courses. However, there were not many case studies conducted to take into account the students' reactions and perceptions of online learning. A qualitative case study was designed to bring out the details from the viewpoint of the students by using multiple sources of data. Both qualitative and quantitative data were collected in the fall of 1999. Data sources included surveys, email messages between the students and the instructor, interviews and field notes from observations and informal meetings. Qualitative data were analyzed using grounded theory principles. Content analysis was applied to find out the type of email interaction between the students and the instructor. One Sample t-test was applied to find out the difference between successful students and less successful students. Fifteen students who enrolled in an introductory College Physics course at the large midwestern university participated in this study. This study focused on the students' experiences with an online course as taught via the Internet. To attain deeper understanding of student learning experiences with the course, the study looked at the elements of how students respond to the instructional system delivering the materials online, the learning environments created online by the instructor, the learning materials provided online or offline, the nature of interactions, sources of motivation, advantages and issues associated with online learning and technology-mediated learning. The findings indicated that the online learning puts a high premium on the students becoming independent learners. Therefore, the students needed to have a specific study guideline that provides direction on how to approach the subject and physics problems including some highlights pertaining to the subject

  10. An on-line modelling study of the direct effect of atmospheric aerosols over Europe

    Energy Technology Data Exchange (ETDEWEB)

    Palacios, L.; Baro, R.; Jimenez-Guerrero, P.

    2015-07-01

    Atmospheric aerosols affect human health, ecosystems, materials, visibility and Earths climate. Those effects are studied in this present work and depend mainly on the aerosol optical properties and how they influence the Earths radiation budget. Such properties can be divided on direct and semi-direct effect, produced by the scattering and absorption of radiation; and indirect effect, which influences the aerosols-cloud interactions. The aim of this work is to assess the direct effect through the study of the mean temperature; the radiation that reaches the Earths surface and at the top of the atmosphere; and the interaction of these meteorological variables with particulate matter (PM10). Results indicate decreases in temperature and radiation that reaches the Earth's surface, together with increases in the outgoing radiation at top of the atmosphere, and changes in the particulate matter, thus proving a colder climate due to the direct effect of atmospheric aerosols. (Author)

  11. An on-line modelling study of the direct effect of atmospheric aerosols over Europe

    Energy Technology Data Exchange (ETDEWEB)

    Palacios, L.; Baro, R.; Jimenez-Guerrero, P.

    2015-07-01

    Atmospheric aerosols affect human health, ecosystems, materials, visibility and Earth’s climate. Those effects are studied in this present work and depend mainly on the aerosol optical properties and how they influence the Earth’s radiation budget. Such properties can be divided on direct and semi-direct effect, produced by the scattering and absorption of radiation; and indirect effect, which influences the aerosols-cloud interactions. The aim of this work is to assess the direct effect through the study of the mean temperature; the radiation that reaches the Earth’s surface and at the top of the atmosphere; and the interaction of these meteorological variables with particulate matter (PM10). Results indicate decreases in temperature and radiation that reaches the Earth's surface, together with increases in the outgoing radiation at top of the atmosphere, and changes in the particulate matter, thus proving a colder climate due to the direct effect of atmospheric aerosols. (Author)

  12. Study on On-line Trace Analysis Technique for SG Tube Leakage Monitoring

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Seban; Park, Jongsuk; Kim, Seungil; Jo, Youngsoo; Kang, Dukwon [HaJI Co. Ltd., Radiation Eng. Center, Shihung (Korea, Republic of)

    2014-05-15

    NPPs steam generator leakage monitoring method is mainly adopted in the world. Since this method is using nuclear fission product of certain radionuclides ({sup 16}N, {sup 3}H, Xe, etc.), it is only available when the reactor power is more than 20%. Therefore, it requires alternative techniques of real-time leakage monitoring under a variety of operation conditions such as start-up, abnormal environment of NPPs, etc. Boron which exists mostly nonionic particle state has been weakly ionized, revealing the lowest anionic tendency in aqueous phase (SO{sub 4}{sup 2-}>Cl{sup -}>F{sup -}>SiO{sub 2}{sup -}>HBO{sub 3}{sup -}). In general, B has been titrated with a NaOH solution into a new compound forming a strong alkaline anion after being dissociated with addition of a polyhydric alcohol. And that has been also measured amplified conductivity that reacting directly polyhydric alcohol by conductivity detector. GE (General Electric Company) has applied monitoring equipment of ultrapure water production by using mannitol reagent as polyhydric alcohol, which is detected less than 20 ppb of boron in the semiconductor company. However, the separation of boron among the secondary water system has been regarded as a critical issue because it contains a lot of impurities and particulate materials which are N{sub 2}H{sub 4}, NH{sub 3}, ETA and component of the iron in the system. This study is a follow-up study concerning the separation of boron peak presented at the 2013 Korean Nuclear Society. This study indicates the possibility of analysis of trace-level boron. The study investigated the separation of boron peak with anion through 3-steps mode. In previous studies, the problem of peaks overlap has been solved through the rinse process completely removing the interfering ions presented on the line. The combination of mannitol and MSA was dissociated from the strong compound between boron and a chelating type resin in the CB column. In particular, the CB column will be able to

  13. Anticipation Models for On-Line Control in Steel Industry: Methodologies and Case Study

    Science.gov (United States)

    Briano, Enrico; Caballini, Claudia; Revetria, Roberto; Testa, Alessandro; De Leo, Marco; Belgrano, Franco; Bertolotto, Alessandro

    2010-11-01

    , the Authors present the conclusions of this work, with a particular attention to the savings that the simulation can bring to this real system, explaining the results of the case study to which it was applied, and the possible future developments of this research are discussed. This model can anyway be applied to other realities than the one exemplified in this paper.

  14. Production of chemically reactive radioactive ion beams through on-line separation; Production de faisceaux d'ions radioactifs chimiquement reactifs par separation en ligne

    Energy Technology Data Exchange (ETDEWEB)

    Joinet, A

    2003-10-01

    The ISOL (isotope separation on line) allows the production of secondary radioactive ion beams through spallation or fragmentation or fission reactions that take place in a thick target bombarded by a high intensity primary beam. The challenge is to increase the intensity and purity of the radioactive beam. The optimization of the system target/source requires the right choice of material for the target by taking into account the stability of the material, its reactivity and the ionization method used. The target is an essential part of the system because radioactive elements are generated in it and are released more or less quickly. Tests have been made in order to select the best fitted material for the release of S, Se, Te, Ge and Sn. Materials tested as target filling are: ZrO{sub 2}, Nb, Ti, V,TiO{sub 2}, CeO{sub x}, ThO{sub 2}, C, ZrC{sub 4} and VC). Other molecules such as: COSe, COS, SeS, COTe, GeS, SiS, SnS have been studied to ease the extraction of recoil nuclei (Se, S, Te, Ge and Sn) produced inside the target.

  15. Lattice location and thermal stability of implanted nickel in silicon studied by on-line emission channeling

    CERN Document Server

    Silva, Daniel José; Correia, Joaõ Guilherme; Pereira, Lino Miguel da Costa; Amorim, Lígia Marina; da Silva, Manuel Ribeiro; David-Bosne, Eric; Araújo, João Pedro

    2013-01-01

    We have studied the lattice location of implanted nickel in silicon, for different doping types (n, n$^{+}$ and p$^{+}$). By means of on-line emission channeling, $^{65}$Ni was identified on three different sites of the diamond lattice: ideal substitutional sites, displaced bond-center towards substitutional sites (near-BC) and displaced tetrahedral interstitial towards anti-bonding sites (near-T). We suggest that the large majority of the observed lattice sites are not related to the isolated form of Ni but rather to its trapping into vacancy-related defects produced during the implantation. While near-BC sites are prominent after annealing up to 300-500°C, near-T sites are preferred after 500-600°C anneals. Long-range diffusion starts at 600-700°C. We show evidence of Ni diffusion towards the surface and its further trapping on near-T sites at the R$_p$/2 region, providing a clear picture of the microscopic mechanism of Ni gettering by vacancy-type defects. The high thermal stability of near-BC sites in ...

  16. Production of neutron deficient rare isotope beams at IGISOL; on-line and off-line studies

    Energy Technology Data Exchange (ETDEWEB)

    Huikari, J. E-mail: jussi.huikari@phys.jyu.fi; Dendooven, P.; Jokinen, A.; Nieminen, A.; Penttilae, H.; Peraejaervi, K.; Popov, A.; Rinta-Antila, S.; Aeystoe, J

    2004-08-01

    This article reports on recent on-line yield measurements employing the light-ion and heavy-ion reaction-based ion guide systems and new results on {alpha}-recoil ion transport properties in ion guides with and without electric fields. In addition, the presently used ion guide designs for fusion evaporation reactions are introduced. The present study investigated different schemes for ion extraction from the gas cell. The addition of an extra ring electrode between the traditional skimmer electrode and the exit hole led to transmission independent of the primary beam intensity as opposed to strong intensity dependence observed earlier with the plain skimmer only. Furthermore, the mass resolving power of the IGISOL mass separator was increased to 1100 as compared to 250 with the skimmer system when using the RF-sextupole for the extraction from the heavy-ion ion guide. As a new method, the possibility to increase the ion guide efficiency by injecting electrons into the stopping volume is introduced. The efficiency of the electron emitter ion guide was a factor of ten higher in off-line conditions. Also, the influence of the buffer gas purity on the ion survival is discussed.

  17. The Eurisol report. A feasibility study for a European isotope-separation-on-line radioactive ion beam facility

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2003-12-01

    The Eurisol project aims at a preliminary design study of the next-generation European isotope separation on-line (ISOL) radioactive ion beam (RIB) facility. In this document, the scientific case of high-intensity RIBs using the ISOL method is first summarised, more details being given in appendix A. It includes: 1) the study of atomic nuclei under extreme and so-far unexplored conditions of composition (i.e. as a function of the numbers of protons and neutrons, or the so-called isospin), rotational angular velocity (or spin), density and temperature, 2) the investigation of the nucleosynthesis of heavy elements in the Universe, an important part of nuclear astrophysics, 3) a study of the properties of the fundamental interactions which govern the properties of the universe, and in particular of the violation of some of their symmetries, 4) potential applications of RIBs in solid-state physics and in nuclear medicine, for example, where completely new fields could be opened up by the availability of high-intensity RIBs produced by the ISOL method. The proposed Eurisol facility is then presented, with particular emphasis on its main components: the driver accelerator, the target/ion-source assembly, the mass-selection system and post-accelerator, and the required scientific instrumentation. Special details of these components are given in appendices B to E, respectively. The estimates of the costs of the Eurisol, construction and running costs, have been performed in as much details as is presently possible. The total capital cost (installation manpower cost included) of the project is estimated to be of the order of 630 million Euros within 20%. In general, experience has shown that operational costs per annum for large accelerator facilities are about 10% of the capital cost. (A.C.)

  18. Efficacy comparison between simple mixed-dilution and simple mid-dilution on-line hemodiafiltration techniques: a crossover study.

    Science.gov (United States)

    Susantitaphong, Paweena; Tiranathanagul, Khajohn; Katavetin, Pisut; Hanwiwatwong, Orawadee; Wittayalertpanya, Supeecha; Praditpornsilpa, Kearkiat; Tungsanga, Kriang; Eiam-Ong, Somchai

    2012-12-01

    Mid-dilution and mixed-dilution on-line hemodiafiltration (OL-HDF) techniques are innovated to overcome the limitations of two standard techniques including predilution and postdilution. Unfortunately, the head-to-head comparisons between these two novel techniques in the same study are still limited. Moreover, the original mid-dilution and mixed-dilution OL-HDF need special dialyzers and special machines. In the present study, simple mid-dilution and simple mixed-dilution OL-HDF were settled with the aim for clinical use in general hemodialysis (HD) centers. The efficacies of uremic toxins removal between both modalities were measured and compared. This prospective randomized crossover study was conducted on 12 stable HD patients undergoing simple mixed-dilution and simple mid-dilution OL-HDF techniques. HD prescriptions were similar in both techniques. The dialysis efficacies were determined by calculating small- (urea, creatinine, and phosphate) and middle-molecule (beta-2 microglobulin [β2M]) removal. Moreover, potential complications such as high transmembrane pressure (TMP) and protein loss were also observed. Simple mixed-dilution OL-HDF provided significantly greater clearances of urea, creatinine, and β2M when compared with the simple mid-dilution OL-HDF techniques. Phosphate clearances in both techniques were comparable. In addition, TMP and dialysate albumin loss were not different. There were no intradialytic complications in both techniques. Simple mixed-dilution OL-HDF could provide greater efficacy for small- and middle-molecule clearances and acceptable potential risks, while phosphate removal is comparable.

  19. On-line computerized diagnosis of pain-related disability and psychological status of TMD patients: a pilot study.

    Science.gov (United States)

    Yap, A U; Tan, K B; Hoe, J K; Yap, R H; Jaffar, J

    2001-01-01

    Temporomandibular disorders (TMD) is a collective term embracing a number of clinical problems, which involve the masticatory musculature, the temporomandibular joint or both. Virtually all theories dealing with the aetiology and treatment of TMD have recognized the importance of psychological factors. This paper reports the development of a computerized on-line program (NUS TMD v1.1) for the diagnosis of pain-related disability and psychological status of TMD patients based on Axis II of the research diagnostic criteria (RDC)/TMD (Dworkin, S.F. & LeResche, L. 1992. Journal of Craniomandibular Disorders: Facial Oral Pain, 6, 301), which was developed to redress the lack of diagnostic criteria in TMD research. Methods adopted by RDC/TMD for use in assessing Axis II status include a seven-item questionnaire for grading chronic pain severity, the Symptom Checklist 90 Revised (SCL-90-R) and a jaw disability checklist. A pilot study, based on 37 new TMD patient records, was conducted to study the pain-related disability and psychological status of TMD patients using this newly developed program. The mean age of the predominantly Chinese population (86.5%) was 32.19 years (range 20-72 years) with a sex distribution of 24 females and 13 males. Most patients (78%) had low disability, with 12 patients having low intensity and 17 patients having high intensity pain. Approximately 73% of the sample population were moderately or severely depressed. Patients that were moderately and severely depressed had significantly higher scores for limitation related to mandibular functioning than normal patients. The three most frequent jaw disabilities were: eating hard foods (84%), yawning (78%) and chewing (65%).

  20. Short Feasibility Study on Using the Post Office Telex Network for On-Line Computer Information Retrieval.

    Science.gov (United States)

    O'Sullivan, D. F.; Hall, F. J.

    In 1972 there were 33,000 Telex installations in the United Kingdom with 240,000 predicted by 1983. The feasibility of using these Telex systems for on-line accession of computer based information systems was investigated in this report. Comparisons between the Telex system and the Teletypewriter or Teleprinter system now in use reveal that the…

  1. On-line HPLC Analysis System for Metabolism and Inhibition Studies in Precision-Cut Liver Slices

    NARCIS (Netherlands)

    van Midwoud, Paul M.; Janssen, Joost; Merema, M.T.; de Graaf, Inge A. M.; Groothuis, Geny M. M.; Verpoorte, Elisabeth

    2011-01-01

    A novel approach for on-line monitoring of drug metabolism in continuously perifused, precision-cut liver slices (PCLS) in a microfluidic system has been developed using high-performance liquid chromatography with UV detection (HPLC-UV). In this approach, PCLS are incubated in a microfluidic device

  2. Production of neutron deficient rare isotope beams at IGISOL; on-line and off-line studies

    NARCIS (Netherlands)

    Huikari, J; Dendooven, P; Jokinen, A; Nieminen, A; Penttila, H; Perajarvi, K; Popov, A; Rinta-Antila, S; Aysto, J

    2004-01-01

    This article reports on recent on-line yield measurements employing the light-ion and heavy-ion reaction-based ion guide systems and new results on a-recoil ion transport properties in ion guides with and without electric fields. In addition, the presently used ion guide designs for fusion evaporati

  3. An atmospheric pressure chemical ionization-ion-trap mass spectrometer for the on-line analysis of volatile compounds in foods: a tool for linking aroma release to aroma perception.

    Science.gov (United States)

    Le Quéré, Jean-Luc; Gierczynski, Isabelle; Sémon, Etienne

    2014-09-01

    An atmospheric pressure chemical ionization ion-trap mass spectrometer was set up for the on-line analysis of aroma compounds. This instrument, which has been successfully employed for some years in several in vitro and in vivo flavour release studies, is described for the first time in detail. The ion source was fashioned from polyether ether ketone and operated at ambient pressure and temperature making use of a discharge corona pin facing coaxially the capillary ion entrance of the ion-trap mass spectrometer. Linear dynamic ranges (LDR), limits of detection (LOD) and other analytical characteristics have been re-evaluated. LDRs and LODs have been found fully compatible with the concentrations of aroma compounds commonly found in foods. Thus, detection limits have been found in the low ppt range for common flavouring aroma compounds (for example 5.3 ppt (0.82 ppbV) for ethyl hexanoate and 4.8 ppt (1.0 ppbV) for 2,5-dimethylpyrazine). This makes the instrument applicable for in vitro and in vivo aroma release investigations. The use of dynamic sensory techniques such as the temporal dominance of sensations (TDS) method conducted simultaneously with in vivo aroma release measurements allowed to get some new insights in the link between flavour release and flavour perception.

  4. Effect of rare earth ions on transition temperature in perovskite materials by on-line ultrasonic studies

    Directory of Open Access Journals (Sweden)

    Sundararaman Sankarrajan

    2012-08-01

    Full Text Available On-line measurements of ultrasonic longitudinal velocity, shear velocity and longitudinal attenuation were carried out on R1-xSr xMnO3 perovskites (R = La, Pr, Nd and Sm for different compositions of Sr, at a fundamental frequency of 5 MHz over wide range of temperatures using the through-transmission method. The observed maxima/minima in velocities and attenuation have been discussed with decrease in ionic radii and composition. As a decrease in the ionic radii of rare earth elements leads to a decrease in transition temperature (Tc, the results that are observed show that measurement is one of the best tools to explore the structural/phase transition on-line velocity in perovskite manganese materials as a function of the ionic radii of rare earth elements.

  5. On line clinical reasoning assessment with Script Concordance test in urology: results of a French pilot study

    Directory of Open Access Journals (Sweden)

    Hellot Marie-France

    2006-08-01

    Full Text Available Abstract Background The Script Concordance test (SC test is an assessment tool that measures the capacity to solve ill-defined problems, that is, reasoning in a context of uncertainty. This study assesses the feasibility, reliability and validity of the SC test made available on the Web to French urologists. Methods A 97 items SC test was developed based on major educational objectives of French urology training programmes. A secure Web site was created with two sequential modules: a The first one for the reference panel to elaborate the scoring system; b The second for candidates with different levels of experience in urology: Board certified urologists, chief-residents, residents, medical students. All participants were recruited on a voluntary basis. Statistical analysis included descriptive statistics of the participants' scores and factorial analysis of variance (ANOVA to study differences between groups' means. Reliability was evaluated with Cronbach's alpha coefficient. Results The on line SC test has been operational since June 2004. Twenty-six faculty members constituted the reference panel. During the following 10 months, 207 participants took the test online (124 urologists, 29 chief-residents, 38 residents, 16 students. No technical problem was encountered. Forty-five percent of the participants completed the test partially only. Differences between the means scores for the 4 groups were statistically significant (P = 0.0123. The Bonferroni post-hoc correction indicated that significant differences were present between students and chief-residents, between students and urologists. There were no differences between chief-residents and urologists. Reliability coefficient was 0.734 for the total group of participants. Conclusion Feasibility of Web-based SC test was proved successful by the large number of participants who participated in a few months. This Web site has permitted to quickly confirm reliability of the SC test and develop

  6. Study of on-line analysis using energy dispersive X-ray fluorescence spectrometry for controlling lanthanum and neodymium extraction

    Energy Technology Data Exchange (ETDEWEB)

    Wenli, Li; Ascenzo, G.D`; Curini, R. [Department of Chemistry, University of Rome `La Sapienza`, Rome (Italy); Gasparini, G.M.; Casarci, M.; Mattia, B.; Traverso, D.M.; Bellisario, F. [ENEA, CRE Casaccia INN-NUMA (Italy)

    1998-05-04

    Many rare-earth extraction processes require frequent control over separation process quality. Ideally, an analysis method for this type should be simple, rapid and reliable. Energy dispersive X-ray fluorescence (EDXRF) spectrometry, due to its relative simplicity of instrumentation, speed of analysis, and non-destructive nature, is well suited to this on-line analysis application. In particular, since the radioisotope energy dispersive XRF method eliminates the need to transport samples to a laboratory which houses the X-ray spectrometry, it is most commonly used for on-line analysis of extraction systems. The present paper describes an attempt to type the radioisotope source {sup 241}Am XRF on-line analysis arrangement coupled with a personal computer for controlling a lanthanum and neodymium separation process. From the HpGe detector (high-purity germanium) response, a continuous spectral signal is observed during loading of the feed samples. The separation process using countercurrent extraction consists of a 16-stage laboratory mixer-settler, a switching valve, and a pumping system. The performance of this control system is illustrated by extracting La, Nd acidic solutions with 100% tributyl phosphate

  7. A study of the growth for the microalga Chlorella vulgaris by photo-bio-calorimetry and other on-line and off-line techniques

    NARCIS (Netherlands)

    Patino, R.; Janssen, M.G.J.; Stockar, von U.

    2007-01-01

    Calorimetry and other on-line techniques are used for the first time as complement to the traditional off-line methods in order to follow the growth of the green Chlorella vulgaris microalgae. A 2-L photo-bio-reactor was adapted from a commercial calorimeter used previously to study heterotrophic mi

  8. A study of the growth for the microalga Chlorella vulgaris by photo-bio-calorimetry and other on-line and off-line techniques

    NARCIS (Netherlands)

    Patino, R.; Janssen, M.G.J.; Stockar, von U.

    2007-01-01

    Calorimetry and other on-line techniques are used for the first time as complement to the traditional off-line methods in order to follow the growth of the green Chlorella vulgaris microalgae. A 2-L photo-bio-reactor was adapted from a commercial calorimeter used previously to study heterotrophic

  9. Design and development of a miniaturised total chemical analysis system for on-line lactate and glucose monitoring in biological samples

    NARCIS (Netherlands)

    Dempsey, Eithne; Diamond, Dermot; Smyth, Malcolm R.; Urban, Gerald; Jobst, Gerhard; Moser, Isabella; Verpoorte, Elisabeth M.J.; Manz, Andreas; Widmer, H. Michael; Rabenstein, Kai; Freaney, Rosemarie

    1997-01-01

    A miniaturised Total chemical Analysis System (μTAS) for glucose and lactate measurement in biological samples constructed based on an integrated microdialysis sampling and detection system. The complete system incorporates a microdialysis probe for intravascular monitoring in an ex vivo mini-shunt

  10. The 1-way on-line coupled model system MECO(n) - Part 4: Chemical evaluation (based on MESSy v2.52)

    Science.gov (United States)

    Mertens, Mariano; Kerkweg, Astrid; Jöckel, Patrick; Tost, Holger; Hofmann, Christiane

    2016-10-01

    For the first time, a simulation incorporating tropospheric and stratospheric chemistry using the newly developed MECO(n) model system is performed. MECO(n) is short for MESSy-fied ECHAM and COSMO models nested n times. It features an online coupling of the COSMO-CLM model, equipped with the Modular Earth Submodel System (MESSy) interface (called COSMO/MESSy), with the global atmospheric chemistry model ECHAM5/MESSy for Atmospheric Chemistry (EMAC). This online coupling allows a consistent model chain with respect to chemical and meteorological boundary conditions from the global scale down to the regional kilometre scale. A MECO(2) simulation incorporating one regional instance over Europe with 50 km resolution and one instance over Germany with 12 km resolution is conducted for the evaluation of MECO(n) with respect to tropospheric gas-phase chemistry. The main goal of this evaluation is to ensure that the chemistry-related MESSy submodels and the online coupling with respect to the chemistry are correctly implemented. This evaluation is a prerequisite for the further usage of MECO(n) in atmospheric chemistry-related studies. Results of EMAC and the two COSMO/MESSy instances are compared with satellite, ground-based and aircraft in situ observations, focusing on ozone, carbon monoxide and nitrogen dioxide. Further, the methane lifetimes in EMAC and the two COSMO/MESSy instances are analysed in view of the tropospheric oxidation capacity. From this evaluation, we conclude that the chemistry-related submodels and the online coupling with respect to the chemistry are correctly implemented. In comparison with observations, both EMAC and COSMO/MESSy show strengths and weaknesses. Especially in comparison to aircraft in situ observations, COSMO/MESSy shows very promising results. However, the amplitude of the diurnal cycle of ground-level ozone measurements is underestimated. Most of the differences between COSMO/MESSy and EMAC can be attributed to differences in the

  11. STUDY ON THE GASEOUS PRODUCTS OF HIGH TEMPERATURE PYROLYSIS OF ACRYLONITRILE POLYMERS BY ON-LINE FTIR METHOD

    Institute of Scientific and Technical Information of China (English)

    ZHAO Genxiang; CHEN Bangjie

    1987-01-01

    The gaseous products of high temperature pyrolysis (300℃ to 960℃) of acrylonitrile polymers were measured continuously under nitrogen atnosphere by on-line Fourier Transform Infrared Spectroscopic method (FTIR). From the variations of characteristic peaks it was found that the nitrogen of macromolecules evolved were mainly in the form of hydrogen cyanide and ammonia. During the pyrolysis amorphous carbonaceous element was formed, and crosslinked to form network structure. Three kinds of samples were used for comparison. The experimental results show that the gaseous products of volatile small molecules were HCN, NH3, CH4, C2H6 and cyanide. CO and CO2 were also formed when copolymers of PAN were thermally pyrolyzed.

  12. On-line study of growth kinetics of single hyphae of Aspergillus oryzae in a flow-through cell

    DEFF Research Database (Denmark)

    Christiansen, Torben; Spohr, Anders Bendsen; Nielsen, Jens Bredal

    1999-01-01

    the outgrowth of a hyphal element from a single spore using a Monte Carlo simulation technique. The simulations shows that the observed kinetics for the individual hyphae result in an experimentally verified growth pattern with exponential growth in both total hyphal length and number of tips. (C) 1999 John......Using image analysis the growth kinetics of the single hyphae of the filamentous fungus Aspergillus oryzae has been determined on-line in a flow-through cell at different glucose concentrations in the range from 26 mg L-1 to 20 g L-1. The tip extension rate of the individual hyphae can be described...... branching occurs, it is observed that the tip extension rate decreases temporarily. The number of branches formed on a hypha is proportional to the length of the hypha that exceeds a certain minimum length required to support the growth of a new branch. The observed kinetics has been used to simulate...

  13. Study for on-line system to identify inadvertent control rod drops in PWR reactors using ex-core detector and thermocouple measures

    Energy Technology Data Exchange (ETDEWEB)

    Souza, Thiago J.; Medeiros, Jose A.C.C.; Goncalves, Alessandro C., E-mail: tsouza@nuclear.ufrj.br, E-mail: canedo@lmp.ufrj.br, E-mail: alessandro@nuclear.ufrj.br [Coordenacao dos Programas de Pos-Graduacao em Engenharia (COPPE/UFRJ), Rio de Janeiro, RJ (Brazil). Programa de Engenharia Nuclear

    2015-07-01

    Accidental control rod drops event in PWR reactors leads to an unsafe operating condition. It is important to quickly identify the rod to minimize undesirable effects in such a scenario. In this event, there is a distortion in the power distribution and temperature in the reactor core. The goal of this study is to develop an on-line model to identify the inadvertent control rod dropped in PWR reactor. The proposed model is based on physical correlations and pattern recognition of ex-core detector responses and thermocouples measures. The results of the study demonstrated the feasibility of an on-line system, contributing to safer operation conditions and preventing undesirable effects, as its shutdown. (author)

  14. On line chemical analyzers for high purity steam and water, applied to steam power plants; Analizadores quimicos en linea para agua y vapor de alta pureza, aplicados a centrales termoelectricas

    Energy Technology Data Exchange (ETDEWEB)

    Diaz Perez, Ruth [Instituto de Investigaciones Electricas, Cuernavaca (Mexico)

    1989-12-31

    This article presents a general overview of the advances in the subject of on line analyzers of chemical parameters for high purity water and steam and specifies which ones are commercially available. Also are mentioned besides, the criteria nowadays applied for the selection of the sites for sample grabbing and the analysis that is necessary to perform in each point, depending on the power plant type and the treatment administered (phosphates-Ph coordinated or AVT treatment). [Espanol] El articulo presenta un panorama general de los avances que en materia de analizadores de parametros quimicos en linea para agua y vapor de alta pureza, y especifica cuales estan disponibles en forma comercial. Se citan, ademas los criterios que se aplican actualmente para seleccionar los puntos de toma de muestra y los analisis que es necesario efectuar en cada punto, dependiendo del tipo de central y del tratamiento que se le administre (fosfatos-pH coordinado o tratamiento AVT).

  15. On-line preferential solvation studies of polymers by coupled chromatographic-Fourier transform infrared spectroscopic flow-cell technique.

    Science.gov (United States)

    Malanin, M; Eichhorn, K-J; Lederer, A; Treppe, P; Adam, G; Fischer, D; Voigt, D

    2009-12-18

    Qualitative and quantitative comparison between liquid chromatography (LC) and LC coupled with Fourier transform infrared spectroscopy (LC-FTIR) to evaluate preferential solvation phenomenon of polymers in a mixed solvent has been performed. These studies show that LC-FTIR technique leads to detailed structural information without the requirement for determination of additional parameters for quantitative analysis except calibration. Appropriate experimental conditions for preferential solvation study have been established by variation of polymer concentration, molar mass and eluent content.

  16. On-line combination of high performance liquid chromatography with comprehensive two-dimensional gas chromatography-triple quadrupole mass spectrometry: a proof of principle study.

    Science.gov (United States)

    Zoccali, Mariosimone; Tranchida, Peter Quinto; Mondello, Luigi

    2015-02-03

    The present contribution is focused on the on-line combination of high performance liquid chromatography (HPLC), cryogenically modulated comprehensive two-dimensional gas chromatography (GC × GC), and triple quadrupole mass spectrometry (QqQ MS), generating a very powerful unified separation-science tool. The instrument can be used in seven different combinations ranging from one-dimensional HPLC with a photodiode array detector to on-line LC × GC × GC/QqQ MS. The main focus of the present research is directed to the LC-GC × GC/QqQ MS configuration, with its analytical potential shown in a proof-of-principle study involving a very complex sample, namely, coal tar. Specifically, a normal-phase LC process enabled the separation of three classes of coal tar compounds: (1) nonaromatic hydrocarbons; (2) unsaturated compounds (with and without S); (3) oxygenated constituents. The HPLC fractions were transferred to the GC × GC instrument via a syringe-based interface mounted on an autosampler. Each fraction was subjected to a specific programmed temperature vaporizer GC × GC/QqQ MS untargeted or targeted analysis. For example, the coal tar S-containing compounds were pinpointed through multiple-reaction-monitoring analysis, while full-scan information was attained for the oxygenated constituents.

  17. Size characterization of airborne SiO{sub 2} nanoparticles with on-line and off-line measurement techniques: an interlaboratory comparison study

    Energy Technology Data Exchange (ETDEWEB)

    Motzkus, C., E-mail: charles.motzkus@lne.fr; Mace, T.; Gaie-Levrel, F.; Ducourtieux, S.; Delvallee, A. [Laboratoire National de Metrologie et d' Essais (LNE) (France); Dirscherl, K. [Danish Fundamental Metrology (DFM) (Denmark); Hodoroaba, V.-D. [BAM Federal Institute for Materials Research and Testing (Germany); Popov, I. [The Hebrew University of Jerusalem, Unit for Nanocharacterization (Israel); Popov, O.; Kuselman, I. [National Physical Laboratory of Israel (INPL) (Israel); Takahata, K.; Ehara, K. [National Institute of Advanced Industrial Science and Technology (AIST), National Metrology Institute of Japan (NMIJ) (Japan); Ausset, P.; Maille, M. [Universite Paris-Est Creteil et Universite Paris-Diderot, Laboratoire Interuniversitaire des Systemes Atmospheriques (LISA), UMR CNRS 7583 (France); Michielsen, N.; Bondiguel, S.; Gensdarmes, F. [Institut de Radioprotection et de Surete Nucleaire (IRSN), PSN-RES, SCA, LPMA (France); Morawska, L.; Johnson, G. R.; Faghihi, E. M. [Queensland University of Technology (QUT), International Laboratory for Air Quality and Health (ILAQH) (Australia); and others

    2013-10-15

    Results of an interlaboratory comparison on size characterization of SiO{sub 2} airborne nanoparticles using on-line and off-line measurement techniques are discussed. This study was performed in the framework of Technical Working Area (TWA) 34-'Properties of Nanoparticle Populations' of the Versailles Project on Advanced Materials and Standards (VAMAS) in the project no. 3 'Techniques for characterizing size distribution of airborne nanoparticles'. Two types of nano-aerosols, consisting of (1) one population of nanoparticles with a mean diameter between 30.3 and 39.0 nm and (2) two populations of non-agglomerated nanoparticles with mean diameters between, respectively, 36.2-46.6 nm and 80.2-89.8 nm, were generated for characterization measurements. Scanning mobility particle size spectrometers (SMPS) were used for on-line measurements of size distributions of the produced nano-aerosols. Transmission electron microscopy, scanning electron microscopy, and atomic force microscopy were used as off-line measurement techniques for nanoparticles characterization. Samples were deposited on appropriate supports such as grids, filters, and mica plates by electrostatic precipitation and a filtration technique using SMPS controlled generation upstream. The results of the main size distribution parameters (mean and mode diameters), obtained from several laboratories, were compared based on metrological approaches including metrological traceability, calibration, and evaluation of the measurement uncertainty. Internationally harmonized measurement procedures for airborne SiO{sub 2} nanoparticles characterization are proposed.

  18. Influence of age and sex on line bisection: a study of normal performance with implications for visuospatial neglect.

    Science.gov (United States)

    Varnava, Alice; Halligan, Peter W

    2007-11-01

    Line bisection is an established clinical task used to diagnose visuospatial neglect. To date, few studies have considered the extent to which age and sex as background variables contribute to bisection performance. Both variables affect the neural substrates underlying cognitive processes and hence the behavioural performance of bisection. The purpose of this study was to examine the effects of age and sex on normal bisection performance, using three different line lengths to elucidate the influence of these potential contributing factors. Seventy men and 70 women, divided equally into seven age-cohorts between 14 and 80 years, bisected lines. Results indicated clear age- and sex-related differences both in the magnitude and direction of bisection deviations across the three line lengths. Differences are discussed in terms of neural changes across the adult lifespan including hemispheric differences and hormonally mediated changes.

  19. Exploring Content Management Issues in Air Force On-Line Communities of Practice: A Multiple Case Study Approach

    Science.gov (United States)

    2006-05-31

    CoPs will come with an automated content management system . The default setting on the content management system for content review on the... content management system , the APQC found “conducting a content audit was strongly correlated with every category of improved performance in content...the CoPs. Finally, a researcher could perform a more in-depth study to determine if a commercially available content management system would be

  20. On-Line Change Monitoring with Transformed Multi-Spectral Time Series, a Study Case in Tropical Forest

    Science.gov (United States)

    Lu, Meng; Hamunyela, Eliakim

    2016-10-01

    In recent years, the methods for detecting structural changes in time series have been adapted for forest disturbance monitoring using satellite data. The BFAST (Breaks For Additive Season and Trend) Monitor framework, which detects forest cover disturbances from satellite image time series based on empirical fluctuation tests, is particularly used for near real-time deforestation monitoring, and it has been shown to be robust in detecting forest disturbances. Typically, a vegetation index that is transformed from spectral bands into feature space (e.g. normalised difference vegetation index (NDVI)) is used as input for BFAST Monitor. However, using a vegetation index for deforestation monitoring is a major limitation because it is difficult to separate deforestation from multiple seasonality effects, noise, and other forest disturbance. In this study, we address such limitation by exploiting the multi-spectral band of satellite data. To demonstrate our approach, we carried out a case study in a deciduous tropical forest in Bolivia, South America. We reduce the dimensionality from spectral bands, space and time with projective methods particularly the Principal Component Analysis (PCA), resulting in a new index that is more suitable for change monitoring. Our results show significantly improved temporal delay in deforestation detection. With our approach, we achieved a median temporal lag of 6 observations, which was significantly shorter than the temporal lags from conventional approaches (14 to 21 observations).

  1. Preliminary study of a new gamma imager for on-line proton range monitoring during proton radiotherapy

    Science.gov (United States)

    Bennati, P.; Dasu, A.; Colarieti-Tosti, M.; Lönn, G.; Larsson, D.; Fabbri, A.; Galasso, M.; Cinti, M. N.; Pellegrini, R.; Pani, R.

    2017-05-01

    We designed and tested new concept imaging devices, based on a thin scintillating crystal, aimed at the online monitoring of the range of protons in tissue during proton radiotherapy. The proposed crystal can guarantee better spatial resolution and lower sensitivity with respect to a thicker one, at the cost of a coarser energy resolution. Two different samples of thin crystals were coupled to a position sensitive photo multiplier tube read out by 64 independent channels electronics. The detector was equipped with a knife-edge Lead collimator that defined a reasonable field of view of about 10 cm in the target. Geant4 Monte Carlo simulations were used to optimize the design of the experimental setup and assess the accuracy of the results. Experimental measurements were carried out at the Skandion Clinic, the recently opened proton beam facility in Uppsala, Sweden. PMMA and water phantoms studies were performed with a first prototype based on a round 6.0 mm thick Cry019 crystal and with a second detector based on a thinner 5 × 5 cm2, 2.0 mm thick LFS crystal. Phantoms were irradiated with mono-energetic proton beams whose energy was in the range between 110 and 160 MeV. According with the simulations and the experimental data, the detector based on LFS crystal seems able to identify the peak of prompt-gamma radiation and its results are in fair agreement with the expected shift of the proton range as a function of energy. The count rate remains one of the most critical limitations of our system, which was able to cope with only about 20% of the clinical dose rate. Nevertheless, we are confident that our study might provide the basis for developing a new full-functional system.

  2. Experimental study on the push-broom infrared imaging system based on line-plane-switching fiber bundle

    Science.gov (United States)

    Yan, Xingtao; Li, Fu; Ma, Xiaolong; Lv, Juan; He, Yinghong; Zhao, Yiyi; Bu, Fan

    2016-10-01

    The use of line-plane-switching infrared fiber bundle to achieve wide field of view push-broom infrared imaging has been studied with experiment. In this technology, the linear array end of the imaging fiber bundle is used as a long-linear array infrared detector, and the plane array end of the bundle is coupled by a mature small scale Infrared Focal Plane Array (IRFPA). It can evade the difficulty of getting the long-linear array infrared detector directly, and has a signally significance to the development of internal infrared imaging technology. Based on the introduction of the composition, working principle of this novel infrared optical system, the system principle-demonstrating experiment has been accomplished. The line-plane-switching fiber bundle used in this experiment is 64×9 format plane array and 192×3 format linear array. It is made from chalcogenide glass fibers, possessing core (As40S59.5Se0.5) of 45 μm, cladding (As40S60) of 5 μm, and error of 1% in diameter. Perfect imaging results prove that this novel technology is feasibility and superiority. The analysis of the experiment makes a foundation for the subsequent further verification experiments.

  3. Analysis of drug-protein binding using on-line immunoextraction and high-performance affinity microcolumns: Studies with normal and glycated human serum albumin.

    Science.gov (United States)

    Matsuda, Ryan; Jobe, Donald; Beyersdorf, Jared; Hage, David S

    2015-10-16

    A method combining on-line immunoextraction microcolumns with high-performance affinity chromatography (HPAC) was developed and tested for use in examining drug-protein interactions with normal or modified proteins. Normal human serum albumin (HSA) and glycated HSA were used as model proteins for this work. High-performance immunoextraction microcolumns with sizes of 1.0-2.0 cm × 2.1mm i.d. and containing anti-HSA polyclonal antibodies were developed and tested for their ability to bind normal HSA or glycated HSA. These microcolumns were able to extract up to 82-93% for either type of protein at 0.05-0.10 mL/min and had a binding capacity of 0.34-0.42 nmol HSA for a 1.0 cm × 2.1mm i.d. microcolumn. The immunoextraction microcolumns and their adsorbed proteins were tested for use in various approaches for drug binding studies. Frontal analysis was used with the adsorbed HSA/glycated HSA to measure the overall affinities of these proteins for the drugs warfarin and gliclazide, giving comparable values to those obtained previously using similar protein preparations that had been covalently immobilized within HPAC columns. Zonal elution competition studies with gliclazide were next performed to examine the specific interactions of this drug at Sudlow sites I and II of the adsorbed proteins. These results were also comparable to those noted in prior work with covalently immobilized samples of normal HSA or glycated HSA. These experiments indicated that drug-protein binding studies can be carried out by using on-line immunoextraction microcolumns with HPAC. The same method could be used in the future with clinical samples and other drugs or proteins of interest in pharmaceutical studies or biomedical research.

  4. Quantitative Determination of ABT-925 in Human Plasma by On-Line SPE and LC-MS/MS: Validation and Sample Analysis in Phase II Studies

    Directory of Open Access Journals (Sweden)

    Katty Wan

    2010-05-01

    Full Text Available A fully automated 96-well On-Line Solid Phase Extraction (SPE followed by High Performance Liquid Chromatography (HPLC-Tandem Mass Spectrometric (MS/MS method for the determination of ABT-925 (2-{3-[4-(2-tert-Butyl-6-trifluoromethyl-pyrimidin-4-yl-piperazin-1-yl-propyl-sulfanyl}-3H-pyrimidin-4-one fumarate in human plasma was developed, validated and utilized in Phase II clinical studies. 50 µL of plasma sample was fortified with internal standard (IS, d8-ABT-925 and extracted on-line with Cohesive Turbo Flow Cyclone P HTLC column. The chromatographic separation was performed on Aquasil C18 (3 μm 50 × 3 mm HPLC column with a mobile phase consisting of 50/50/0.1 (v/v/v ACN/H2O/formic acid. The mass spectrometric measurement was conducted under positive ion mode using multiple reaction monitoring (MRM of m/z 457.4 → 329.4 for analyte and m/z 465.5 → 337.5 for IS.The peak area ratio (analyte/IS was used to quantitate ABT-925. A dynamic range of 0.0102 μg/mL to 5.24 μg/mL was established after the validation. The validated method was then used for two Phase II studies. To demonstrate the method reproducibility, approximately 10% of the incurred samples from one study were repeated in singlet. The repeated values were compared to the initial values. All repeated values agreed within ±15% of the mean values.

  5. Quantitative Determination of ABT-925 in Human Plasma by On-Line SPE and LC-MS/MS: Validation and Sample Analysis in Phase II Studies.

    Science.gov (United States)

    Wan, Katty; Rieser, Matthew; El-Shourbagy, Tawakol

    2010-05-04

    A fully automated 96-well On-Line Solid Phase Extraction (SPE) followed by High Performance Liquid Chromatography (HPLC)-Tandem Mass Spectrometric (MS/MS) method for the determination of ABT-925 (2-{3-[4-(2-tert-Butyl-6-trifluoromethyl-pyrimidin-4-yl)-piperazin-1-yl)-propyl-sulfanyl}-3H-pyrimidin-4-one fumarate) in human plasma was developed, validated and utilized in Phase II clinical studies. 50 µL of plasma sample was fortified with internal standard (IS, d8-ABT-925) and extracted on-line with Cohesive Turbo Flow Cyclone P HTLC column. The chromatographic separation was performed on Aquasil C18 (3 μm 50 × 3 mm) HPLC column with a mobile phase consisting of 50/50/0.1 (v/v/v) ACN/H₂O/formic acid. The mass spectrometric measurement was conducted under positive ion mode using multiple reaction monitoring (MRM) of m/z 457.4 → 329.4 for analyte and m/z 465.5 → 337.5 for IS.The peak area ratio (analyte/IS) was used to quantitate ABT-925. A dynamic range of 0.0102 μg/mL to 5.24 μg/mL was established after the validation. The validated method was then used for two Phase II studies. To demonstrate the method reproducibility, approximately 10% of the incurred samples from one study were repeated in singlet. The repeated values were compared to the initial values. All repeated values agreed within ±15% of the mean values.

  6. Using eye-tracking to study the on-line processing of case-marking information among intermediate L2 learners of German

    Science.gov (United States)

    Jackson, Carrie N.; Dussias, Paola E.; Hristova, Adelina

    2012-01-01

    This study uses eye-tracking to examine the processing of case-marking information in ambiguous subject- and object-first wh-questions in German. The position of the lexical verb was also manipulated via verb tense to investigate whether verb location influences how intermediate L2 learners process L2 sentences. Results show that intermediate L2 German learners were sensitive to case-marking information, exhibiting longer processing times on subject-first than object-first sentences, regardless of verb location. German native speakers exhibited the opposite word order preference, with longer processing times on object-first than subject-first sentences, replicating previous findings. These results are discussed in light of current L2 processing research, highlighting how methodological constraints influence researchers’ abilities to measure the on-line processing of morphosyntactic information among intermediate L2 learners. PMID:23493761

  7. Formación on line On line learning

    Directory of Open Access Journals (Sweden)

    O. Grau-Perejoan

    2008-09-01

    Full Text Available La formación on line es una modalidad de enseñanza a distancia basada en las nuevas tecnologías. En este artículo se pretende hacer una introducción a base de describir a grandes rasgos sus características principales: asincronía, no presencialidad, comunicación escrita, función del profesor on line, así como los retos, los riesgos, las ventajas y los inconvenientes que plantea. Se exponen las diferencias entre la formación on line y la formación presencial, de manera que los docentes puedan adaptar de la mejor manera posible sus propuestas formativas a la modalidad on line. Se introduce el importantísimo papel de la planificación y de la fase de diseño y, finalmente, se repasan conceptos útiles para comprender mejor el mundo de la formación on line como son los conceptos entorno virtual de aprendizaje (EVA o Blended Learning (B-Learning.On line learning is a type of distance education based on new technologies. This article's aim is to introduce its main characteristics -asynchrony, non-presentiality, written communication, e-teacher role- as well as its challenges, risks, advantages and limitations. Differences between on line learning and face-to-face learning are presented in order to enable educational professionals to adapt their courses to the on line methodology. Planning and designing are introduced as key phases and, finally, useful concepts such as Virtual Learning Environment (VLE or Blended Learning (B-Learning are reviewed in order to achieve a better understanding of the on line learning field.

  8. Chemical biology approaches for studying posttranslational modifications.

    Science.gov (United States)

    Yang, Aerin; Cho, Kyukwang; Park, Hee-Sung

    2017-09-13

    Posttranslational modification (PTM) is a key mechanism for regulating diverse protein functions, and thus critically affects many essential biological processes. Critical for systematic study of the effects of PTMs is the ability to obtain recombinant proteins with defined and homogenous modifications. To this end, various synthetic and chemical biology approaches, including genetic code expansion and protein chemical modification methods, have been developed. These methods have proven effective for generating site-specific authentic modifications or structural mimics, and have demonstrated their value for in vitro and in vivo functional studies of diverse PTMs. This review will discuss recent advances in chemical biology strategies and their application to various PTM studies.

  9. Hyphenating size-exclusion chromatography with electrospray mass spectrometry; using on-line liquid-liquid extraction to study the lipid composition of lipoprotein particles.

    Science.gov (United States)

    Osei, Michael; Griffin, Julian L; Koulman, Albert

    2015-11-15

    Lipoproteins belong to the most commonly measured clinical biochemical parameters. Lipidomics is an orthogonal approach and aims to profile the individual lipid molecules that jointly form the lipoprotein particles. However, in the first step of the extraction of lipid molecules from serum, an organic solvent is used leading to dissociation of the lipoproteins. Thus far it has been impossible to combine lipidomics and lipoprotein analysis in one analytical system. Human plasma was diluted in phosphate-buffered saline (PBS) and injected onto a Superose 6 PC 3.2 column with PBS as a mobile phase to separate lipoproteins. The eluent was led to a Syrris FLLEX module, which also received CHCl3 /MeOH (3:1). The two phases were mixed and subsequently separated using a Teflon membrane in an especially designed pressurized flow chamber. The organic phase was led to a standard electrospray source of an Orbitrap mass spectrometer. Size-exclusion chromatography (SEC) has been commonly applied to separate lipoproteins and is considered a practical alternative to ultracentrifugation. Through the on-line liquid-liquid extraction method it becomes possible to obtained detailed mass spectra of lipids across different lipoprotein fractions. The extracted ion chromatograms of specific lipid signals showed their distribution against the size of lipoprotein particles. The application of on-line liquid-liquid extraction allows for the continuous electrospray-based mass spectral analysis of SEC eluent, providing the detailed lipid composition of lipoprotein particles separated by size. This approach provides new possibilities for the study of the biochemistry of lipoproteins. © 2015 The Authors. Rapid Communications in Mass Spectrometry Published by John Wiley & Sons Ltd.

  10. Texts On-Line.

    Science.gov (United States)

    Thomas, Jean-Jacques

    1993-01-01

    Maintains that the study of signs is divided between those scholars who use the Saussurian binary sign (semiology) and those who prefer the Peirce tripartite sign (semiotics). Concludes that neither the Saussurian nor Peircian analysis methods can produce a semiotic interpretation based on a hierarchy of the text's various components. (CFR)

  11. Texts On-Line.

    Science.gov (United States)

    Thomas, Jean-Jacques

    1993-01-01

    Maintains that the study of signs is divided between those scholars who use the Saussurian binary sign (semiology) and those who prefer the Peirce tripartite sign (semiotics). Concludes that neither the Saussurian nor Peircian analysis methods can produce a semiotic interpretation based on a hierarchy of the text's various components. (CFR)

  12. Influence of visualization on consumption during on-line shopping

    OpenAIRE

    Hictaler, Urška

    2013-01-01

    This diploma work studies the influence of visualization on consumption during on-line shopping. The first part of the thesis starts with key areas of visualization, consumption and on-line shopping. Visualization, areas of use, human perception and ways of product presentation in on-line shops are defined discussed first. Next, consumption, consumers and factors that influence their decisions and satisfaction are defined. The last topic in the first part of the thesis discusses on-line shopp...

  13. On-Line Learning: One Way to Bring People Together

    Science.gov (United States)

    Goff-Kfouri, Carol Ann

    2006-01-01

    The purpose of this study was to demonstrate the benefits of on-line learning for adult learners and to further demystify three common misconceptions concerning on-line learning: students certainly do receive support from their on-line professors, the professor is pro-active rather than passive, and students may be more motivated to learn than in…

  14. Development of the helium-jet fed on-line mass separator RAMA and its application to studies of T/sub z/ = -2 nuclei

    Energy Technology Data Exchange (ETDEWEB)

    Moltz, D.M.

    1979-10-01

    The study of nuclei far from beta stability is hampered greatly when the nuclide of interest decays in a manner identical to that of a nuclide produced in greater yield in the same bombardment. One solution to this problem is through the use of an on-line mass separator. Development of the Berkelely helium-jet fed on-line mass separator RAMA is discussed as applied to studies of the A = 4n, T/sub z/ = -2 nuclides. RAMA (Recoil Atom Mass Analyzer) has typical efficiencies of 0.1% for approx. 75 elements with melting points less than or equal to 2000/sup 0/C. This efficiency permits decay studies to be readily performed on nuclei with production cross sections greater than or equal to 500 ..mu..b for ..gamma..-ray spectroscopy and greater than or equal to 1 ..mu..b for discrete energy charged particle spectroscopy. The mass range on the normalized RAMA focal plane is +- 10%. The quoted efficiency is for a mass resolution of M/..delta..M approx. 300. RAMA has been used to observe two members of the A = 4n, T/sub z/ = -2 series of beta-delayed proton emitters, /sup 20/Mg and /sup 24/Si. Observation of beta-delayed protons from a mass-separated sample of /sup 20/Mg(t/sub 1/2/ approx. 95 ms) establishes the mass-excess of the lowest T = 2 (0/sup +/) state in /sup 20/Na (13.42 +- .05 MeV), thereby completing the mass twenty isospin quintet. A similar measurement of the decay of /sup 24/Si (t/sub 1/2/ approx. 100 ms) establishes the mass-excess of the lowest T = 2 (0/sup +/) state in /sup 24/Al (5.903 +- 0.009 MeV). The mass 24 isospin quintet is incomplete because the mass of /sup 24/Si remains unknown. In both cases, excellent agreement is obtained using only the quadratic form of the isobaric multiplet mass equation (IMME). 79 references.

  15. Educational On-Line Gaming Propensity

    DEFF Research Database (Denmark)

    Sudzina, Frantisek; Razmerita, Liana; Kirchner, Kathrin

    2014-01-01

    Educational on-line games are promising for new generations of students who are grown up digital. Th e new generations of students are technology savvy and spend lots of time on the web and on social networks. Based on an exploratory study, this article investigates the factors that infl uence...... students’ willingness to participate in serious games for teaching/learning. Th is study investigates the relationship between students’ behavior on Facebook, Facebook games, and their attitude toward educational on-line games. Th e results of the study reveal that the early adopters of educational games...

  16. Cyclic pentapeptide analogs based on endomorphin-2 structure: cyclization studies using liquid chromatography combined with on-line mass spectrometry and tandem mass spectrometry.

    Science.gov (United States)

    Piekielna, Justyna; Kluczyk, Alicja; Perlikowska, Renata; Janecka, Anna

    2014-05-01

    The cyclization of linear analogs based on endomorphin-2 structure, Tyr/Dmt-d-Lys-Phe-Phe-Asp-NH2 and Tyr/Dmt-d-Cys-Phe-Phe-Cys-NH2 (where Dmt=2',6'-dimethyltyrosine), resulting in obtaining lactam or disulfide derivatives, was studied using liquid chromatography combined with on-line mass spectrometry (LC-MS) and tandem mass spectrometry (LC-MS/MS). In case of cyclization via an amide bond, the formation of the cyclic monomers, cyclic but not linear dimers and even traces of cyclic trimers was observed. Disulfide bridge containing peptides was obtained by the solid-phase synthesis of the linear sequences, followed by either in-solution or on-resin cyclization. In case of the in-solution cyclization, the expected cyclic monomers were the only products. When oxidation of the cysteine residues was performed when the peptides were still on the resin, cyclic monomer and two cyclodimers, parallel and antiparallel, were found. Digestion of the isolated cyclodimers with α-chymotrypsin allowed for their unambiguous identification. The comparison of the cyclic monomer/dimer ratios for analogs with Tyr versus Dmt in position 1 revealed that the presence of the exocyclic Dmt favored formation of the cyclic monomer, most likely due to the increased steric bulk of this amino acid side-chain as compared with Tyr.

  17. Development of an on-line source-tagged model for sulfate, nitrate and ammonium: A modeling study for highly polluted periods in Shanghai, China.

    Science.gov (United States)

    Wu, Jian-Bin; Wang, Zifa; Wang, Qian; Li, Jie; Xu, Jianming; Chen, HuanSheng; Ge, Baozhu; Zhou, Guangqiang; Chang, Luyu

    2017-02-01

    An on-line source-tagged model coupled with an air quality model (Nested Air Quality Prediction Model System, NAQPMS) was applied to estimate source contributions of primary and secondary sulfate, nitrate and ammonium (SNA) during a representative winter period in Shanghai. This source-tagged model system could simultaneously track spatial and temporal sources of SNA, which were apportioned to their respective primary precursors in a simulation run. The results indicate that in the study period, local emissions in Shanghai accounted for over 20% of SNA contributions and that Jiangsu and Shandong were the two major non-local sources. In particular, non-local emissions had higher contributions during recorded pollution periods. This suggests that the transportation of pollutants plays a key role in air pollution in Shanghai. The temporal contributions show that the emissions from the "current day" (emission contribution from the current day during which the model was simulating) contributed 60%-70% of the sulfate and ammonium concentrations but only 10%-20% of the nitrate concentration, while the previous days' contributions increased during the recorded pollution periods. Emissions that were released within three days contributed over 85% averagely for SNA in January 2013. To evaluate the source-tagged model system, the results were compared by sensitivity analysis (emission perturbation of -30%) and backward trajectory analysis. The consistency of the comparison results indicated that the source-tagged model system can track sources of SNA with reasonable accuracy.

  18. On-line, real time monitoring of exhaled trace gases by SIFT-MS in the perioperative setting: a feasibility study.

    Science.gov (United States)

    Boshier, Piers R; Cushnir, Julia R; Mistry, Vikash; Knaggs, Alison; Španěl, Patrik; Smith, David; Hanna, George B

    2011-08-21

    A study is described of the first on line, real time analyses of the exhaled breath of five anaesthetized patients during the complete perioperative periods of laparoscopic surgery. These breath analyses were achieved using a selected ion flow tube, SIFT-MS, instrument, located in the operating theatre at an acceptable distance from the operating table, and coupled to the endotracheal tube in the ventilation circuit via a 5 metre long capillary tube. Thus, inhalation/exhalation breathing cycles, set to be at a frequency of 10 per minute, were sampled continuously for water vapour, the metabolites acetone and isoprene and the propofol used to induce anaesthesia for each operating period that ranged from 20 min (shortest) to 80 min (longest). Whilst there was some loss of water vapour along the long sampling line, the concentrations of the other trace compounds were not diminished. The breath acetone was essentially at a constant level for each patient, but increased somewhat over the longest operating period due to the onset of lipolysis. Most interesting is the clear increase of breath isoprene following abdomen inflation with carbon dioxide. The vapour of the intravenously injected propofol was detected in the exhaled breath and remained essentially constant during the perioperative period. These analyses were performed totally non-invasively and the data were immediately and constantly available to the anaesthetist and surgeon. Exploitation of this development could influence decision making and potentially improve patient safety within the perioperative setting.

  19. On line routing per mobile phone

    DEFF Research Database (Denmark)

    Bieding, Thomas; Görtz, Simon; Klose, Andreas

    2009-01-01

    . Additionally it is of utmost importance that the employed communication system is suitable integrated with the firm’s enterprise application system and business processes. On basis of a case study, we describe in this paper a system that is cheap and easy to implement due to the use of simple mobile phones......On-line routing is concerned with building vehicle routes in an ongoing fashion in such a way that customer requests arriving dynamically in time are efficiently and effectively served. An indispensable prerequisite for applying on-line routing methods is mobile communication technology...

  20. How and When Accentuation Influences Temporally Selective Attention and Subsequent Semantic Processing during On-Line Spoken Language Comprehension: An ERP Study

    Science.gov (United States)

    Li, Xiao-qing; Ren, Gui-qin

    2012-01-01

    An event-related brain potentials (ERP) experiment was carried out to investigate how and when accentuation influences temporally selective attention and subsequent semantic processing during on-line spoken language comprehension, and how the effect of accentuation on attention allocation and semantic processing changed with the degree of…

  1. CERN Video News on line

    CERN Multimedia

    2003-01-01

    The latest CERN video news is on line. In this issue : an interview with the Director General and reports on the new home for the DELPHI barrel and the CERN firemen's spectacular training programme. There's also a vintage video news clip from 1954. See: www.cern.ch/video or Bulletin web page

  2. Studying chemical reactivity in a virtual environment.

    Science.gov (United States)

    Haag, Moritz P; Reiher, Markus

    2014-01-01

    Chemical reactivity of a set of reactants is determined by its potential (electronic) energy (hyper)surface. The high dimensionality of this surface renders it difficult to efficiently explore reactivity in a large reactive system. Exhaustive sampling techniques and search algorithms are not straightforward to employ as it is not clear which explored path will eventually produce the minimum energy path of a reaction passing through a transition structure. Here, the chemist's intuition would be of invaluable help, but it cannot be easily exploited because (1) no intuitive and direct tool for the scientist to manipulate molecular structures is currently available and because (2) quantum chemical calculations are inherently expensive in terms of computational effort. In this work, we elaborate on how the chemist can be reintroduced into the exploratory process within a virtual environment that provides immediate feedback and intuitive tools to manipulate a reactive system. We work out in detail how this immersion should take place. We provide an analysis of modern semi-empirical methods which already today are candidates for the interactive study of chemical reactivity. Implications of manual structure manipulations for their physical meaning and chemical relevance are carefully analysed in order to provide sound theoretical foundations for the interpretation of the interactive reactivity exploration.

  3. On-line study of flavonoids of Trollius chinensis Bunge binding to DNA with ethidium bromide using a novel combination of chromatographic, mass spectrometric and fluorescence techniques.

    Science.gov (United States)

    Song, Zhiling; Wang, Hong; Ren, Biao; Zhang, Baobao; Hashi, Yuki; Chen, Shizhong

    2013-03-22

    The study of the interaction between drugs and DNA is an important way to understand the role of drug molecules. A novel online analytical method for this purpose combining high-performance liquid chromatography-diode array detector-electrospray ionization-ion-trap time-of-flight mass spectrometry (HPLC-DAD-ESI-IT-TOF-MS(n)) and DNA-ethidium bromide detection with a fluorescence detector (DNA-EB-FLD) was firstly developed, which could rapidly identify the chemical constituents and obtain the profile related to DNA binding activity. This method has been applied for a precise or probable identification of the chemical constituents by ultraviolet (UV) absorption and MS(n) data analysis, while the DNA binding profile has been characterized by directly measuring the fluorescence intensity of compound-DNA-EB. Using this method, Trollius chinensis Bunge was studied and 18 constituents were identified by MS(n) data; six of them (4'-methoxy-2″-O-(2‴-methylbutyryl)vitexin,2″-O-(3‴-methoxycaffeoyl)vitexin) and 4'-methoxy-2″-O-(2‴-methylbutyryl)orientin,acacetin-7-O-rutinoside,quercetin-3-O-xylosylglucoside,quercetin-3-O-arabinosylglucoside) were identified for the first time in T. chinensis Bunge, and 16 constituents accounted for its activity of binding to DNA. The established (HPLC-DAD-ESI-IT-TOF-MS(n) DNA-EB-FLD) system has proved to offer a useful strategy for correlating the chemical profile with the binding to DNA activities of the components without their isolation and purification, and may be used for multicomponent analysis of active substances in other herbs.

  4. 全新在线滴定技术的研究与应用%Study and Application of a New On-Line Titration Technique

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    A new on-line titration method and device based on a new technique-continuous flow titration is described. By the meansofelectronically controlled switching of a solenoid valve, the main component of the system, the equivalent point of the titration is easilydetermined. Several kinds of mixing tools were examined, whereby a self-made mixing chamber with minimum volume gave best re-sults and was therefore used in the device. The error of the titration is within 0.2% and the relative standard deviation (RSD) isbe-low 1.2%. The results show no difference compared with a commercial device, meanwhile the new on-line titration system is cheaperand fully automated and thus easy to hand and less solvent consumption.

  5. On-line Monitoring of Epoxy Resin Exposed to Acid Solution

    Institute of Scientific and Technical Information of China (English)

    Yuyan LIU; M.Kubouchi; H.Sembokuya; K.Tsuda; T.Tomiyama

    2006-01-01

    In this study, a new on-line health monitoring technology for the determination of the penetration of environment solution into epoxy resin was pursued. A corrosion sensor including plastic optical fiber and pH indicator was fabricated. The color-change layer of this sensor appeared after immersion in sulfuric acid solution, which could be examined by using optical fiber and spectrophotometer. The results showed that the penetration of sulfuric acid was detected by adding bromophenol blue (BPB) in the corrosion sensor. This system could be applied to on-line health monitoring of chemical equipment structures.

  6. The interaction of lexical tone, intonation and semantic context in on-line spoken word recognition: an ERP study on Cantonese Chinese.

    Science.gov (United States)

    Kung, Carmen; Chwilla, Dorothee J; Schriefers, Herbert

    2014-01-01

    In two ERP experiments, we investigate the on-line interplay of lexical tone, intonation and semantic context during spoken word recognition in Cantonese Chinese. Experiment 1 shows that lexical tone and intonation interact immediately. Words with a low lexical tone at the end of questions (with a rising question intonation) lead to a processing conflict. This is reflected in a low accuracy in lexical identification and in a P600 effect compared to the same words at the end of a statement. Experiment 2 shows that a strongly biasing semantic context leads to much better lexical-identification performance for words with a low tone at the end of questions and to a disappearance of the P600 effect. These results support the claim that semantic context plays a major role in disentangling the tonal information from the intonational information, and thus, in resolving the on-line conflict between intonation and tone. However, the ERP data indicate that the introduction of a semantic context does not entirely eliminate on-line processing problems for words at the end of questions. This is revealed by the presence of an N400 effect for words with a low lexical tone and for words with a high-mid lexical tone at the end of questions. The ERP data thus show that, while semantic context helps in the eventual lexical identification, it makes the deviation of the contextually expected lexical tone from the actual acoustic signal more salient. © 2013 Published by Elsevier Ltd.

  7. Clean Air OnLine

    Energy Technology Data Exchange (ETDEWEB)

    Finney, D. [Environment Canada, Gatineau, PQ (Canada). Air Pollution Prevention Directorate

    2004-04-07

    This presentation describes Clean Air OnLine, a multi-tiered website dedicated to providing Canadians with information on air quality. The website is under development to support action to reduce air emissions, demonstrate the links between air emissions and environmental impacts, and enhance the understanding of sustainable community development issues such as health, energy, and urban sprawl. Partners in the Clean Air OnLine (CAOL) initiative include Environment Canada and the Clean Air Partnership which includes the Greater Toronto Area pilot project. The audience for CAOL includes municipal decision makers, local decision makers, community leaders, and the general public. The project provides Canadians with air pollution contextual information on pollution sources, pollutants, and related issues. It also provides information on health, environmental and economic impacts and the interrelationships with climate change issues and energy use. tabs., figs.

  8. On-line moisture analysis

    CERN Document Server

    Cutmore, N G

    2002-01-01

    Measurement of the moisture content of iron ore has become a key issue for controlling moisture additions for dust suppression. In most cases moisture content is still determined by manual or automatic sampling of the ore stream, followed by conventional laboratory analysis by oven drying. Although this procedure enables the moisture content to be routinely monitored, it is too slow for control purposes. This has generated renewed interest in on-line techniques for the accurate and rapid measurement of moisture in iron ore on conveyors. Microwave transmission techniques have emerged over the past 40 years as the dominant technology for on-line measurement of moisture in bulk materials, including iron ores. Alternative technologies have their limitations. Infra-red analysers are used in a variety of process industries, but rely on the measurement of absorption by moisture in a very thin surface layer. Consequently such probes may be compromised by particle size effects and biased presentation of the bulk mater...

  9. Study of chemical and radiation induced carcinogenesis

    Energy Technology Data Exchange (ETDEWEB)

    Chmura, A.

    1995-11-01

    The study of chemical and radiation induced carcinogenesis has up to now based many of its results on the detection of genetic aberrations using the fluorescent in situ hybridization (FISH) technique. FISH is time consuming and this tends to hinder its use for looking at large numbers of samples. We are currently developing new technological advances which will increase the speed, clarity and functionality of the FISH technique. These advances include multi-labeled probes, amplification techniques, and separation techniques.

  10. Theoretical studies of chemical reaction dynamics

    Energy Technology Data Exchange (ETDEWEB)

    Schatz, G.C. [Argonne National Laboratory, IL (United States)

    1993-12-01

    This collaborative program with the Theoretical Chemistry Group at Argonne involves theoretical studies of gas phase chemical reactions and related energy transfer and photodissociation processes. Many of the reactions studied are of direct relevance to combustion; others are selected they provide important examples of special dynamical processes, or are of relevance to experimental measurements. Both classical trajectory and quantum reactive scattering methods are used for these studies, and the types of information determined range from thermal rate constants to state to state differential cross sections.

  11. Kinetic studies of elementary chemical reactions

    Energy Technology Data Exchange (ETDEWEB)

    Durant, J.L. Jr. [Sandia National Laboratories, Livermore, CA (United States)

    1993-12-01

    This program concerning kinetic studies of elementary chemical reactions is presently focussed on understanding reactions of NH{sub x} species. To reach this goal, the author is pursuing experimental studies of reaction rate coefficients and product branching fractions as well as using electronic structure calculations to calculate transition state properties and reaction rate calculations to relate these properties to predicted kinetic behavior. The synergy existing between the experimental and theoretical studies allow one to gain a deeper insight into more complex elementary reactions.

  12. Educational On-Line Gaming Propensity

    DEFF Research Database (Denmark)

    Sudzina, Frantisek; Razmerita, Liana; Kirchner, Kathrin

    2014-01-01

    Educational on-line games are promising for new generations of students who are grown up digital. Th e new generations of students are technology savvy and spend lots of time on the web and on social networks. Based on an exploratory study, this article investigates the factors that infl uence...... students’ willingness to participate in serious games for teaching/learning. Th is study investigates the relationship between students’ behavior on Facebook, Facebook games, and their attitude toward educational on-line games. Th e results of the study reveal that the early adopters of educational games...... are likely to be students, who are young, have only a few Facebook connections, who currently play Facebook game(s). Furthermore, the study emphasizes that there may be differences between students coming from various countries....

  13. PHENIX on-line systems

    Energy Technology Data Exchange (ETDEWEB)

    Adler, S.S.; Allen, M.; Alley, G.; Amirikas, R.; Arai, Y.; Awes, T.C.; Barish, K.N.; Barta, F.; Batsouli, S.; Belikov, S.; Bennett, M.J.; Bobrek, M.; Boissevain, J.G.; Boose, S.; Britton, C.; Britton, L.; Bryan, W.L.; Cafferty, M.M.; Carey, T.A.; Chang, W.C.; Chi, C.Y.; Chiu, M.; Cianciolo, V.; Cole, B.A.; Constantin, P.; Cook, K.C.; Cunitz, H.; Desmond, E.J.; Ebisu, K.; Efremenko, Y.V.; El Chenawi, K.; Emery, M.S.; Engo, D.; Ericson, N.; Fields, D.E.; Frank, S.; Frantz, J.E.; Franz, A.; Frawley, A.D.; Fried, J.; Gannon, J.; Gee, T.F.; Gentry, R.; Giannotti, P.; Gustafsson, H.-A.; Haggerty, J.S.; Hahn, S.; Halliwell, J.; Hamagaki, H.; Hansen, A.G.; Hara, H.; Harder, J.; He, X.; Heistermann, F.; Hemmick, T.K.; Hibino, M.; Hill, J.C. E-mail: jhill@iastate.edu; Homma, K.; Jacak, B.V.; Jagadish, U.; Jia, J.; Kajihara, F.; Kametani, S.; Kamyshkov, Y.; Kandasamy, A.; Kang, J.H.; Kapustinsky, J.; Katou, K.; Kelley, M.A.; Kelly, S.; Kikuchi, J.; Kim, S.Y.; Kim, Y.G.; Kistenev, E.; Kotchetkov, D.; Kurita, K.; Lajoie, J.G.; Lenz, M.; Lenz, W.; Li, X.H.; Lin, S.; Liu, M.X.; Markacs, S.; Matathias, F.; Matsumoto, T.; Mead, J.; Mischke, R.E.; Mishra, G.C.; Moore, A.; Muniruzzamann, M.; Musrock, M.; Nagle, J.L.; Nandi, B.K.; Newby, J.; Nystrand, J.; O' Brien, E.; O' Connor, P.; Ohnishi, H.; Oskarsson, A.; Osterman, L.; Oyama, K.; Paffrath, L.; Pancake, C.E.; Pantuev, V.S.; Petridis, A.N.; Pisani, R.P.; Plagge, T.; Plasil, F.; Purschke, M.L.; Rankowitz, S.; Rao, R.; Rau, M.; Read, K.F.; Ryu, S.S.; Sakaguchi, T.; Sato, H.D.; Seto, R.; Shiina, T.; Silvermyr, D.; Simon-Gillo, J.; Simpson, M.; Sippach, W.; Skank, H.D.; Skutnik, S.; Sleege, G.A.; Smith, G.D.; Smith, M.; Stankus, P.W.; Steinberg, P.; Sugitate, T.; Sullivan, J.P.; Taketani, A.; Tamai, M.; Tanaka, Y.; Thomas, W.D.; Todd, R.; Toldo, F.; Turner, G.; Ushiroda, T.; Velkovska, J.; Hecke, H.W. van; Lith, M. van; Villatte, L.; Achen, W. von; Walker, J.W.; Wang, H.Q.; White, S.N.; Wintenberg, A.L.; Witzig, C.; Wood, L.[and others

    2003-03-01

    The PHENIX On-Line system takes signals from the Front End Modules (FEM) on each detector subsystem for the purpose of generating events for physics analysis. Processing of event data begins when the Data Collection Modules (DCM) receive data via fiber-optic links from the FEMs. The DCMs format and zero suppress the data and generate data packets. These packets go to the Event Builders (EvB) that assemble the events in final form. The Level-1 trigger (LVL1) generates a decision for each beam crossing and eliminates uninteresting events. The FEMs carry out all detector processing of the data so that it is delivered to the DCMs using a standard format. The FEMs also provide buffering for LVL1 trigger processing and DCM data collection. This is carried out using an architecture that is pipelined and deadtimeless. All of this is controlled by the Master Timing System (MTS) that distributes the RHIC clocks. A Level-2 trigger (LVL2) gives additional discrimination. A description of the components and operation of the PHENIX On-Line system is given and the solution to a number of electronic infrastructure problems are discussed.

  14. On-line Mass Spectrometric Study of Heavy-Ion Induced Reactions at Energies up to 86 MeV/amu

    CERN Multimedia

    2002-01-01

    The aim of the experiment was to measure isotopic distributions of Li, Na, K, Rb, Cs and Fr as reaction fragments in heavy ion collisions. In order to get an overall view of the new energy range for heavy ions available from the SC, different energies and projectile-target combinations had to be studied. The data taking status is now finished. |1|2C and |1|8O beams were used in bombarding |1|2C, |9|3Nb, |1|8|1Ta and |2|3|8U in order to look at target fragmentation, projectile fragmentation and evaporative residues of spallation processes. The experimental apparatus is composed of three parts: \\item a)~A target-oven-ionizer assembly where selective thermal diffusion and selective surface ionization takes place in order to obtain a chemical separation of the reaction products. \\item b)~The mass spectrometer where the different-mass fragments are selected. \\item c)~An electrostatic ion beam line through which the fragments are transported to a low-background area where the detector (an electron multiplier) is lo...

  15. On-Line and Off-Line Assessment of Metacognition

    Science.gov (United States)

    Saraç, Seda; Karakelle, Sema

    2012-01-01

    The study investigates the interrelationships between different on-line and off-line measures for assessing metacognition. The participants were 47 fifth grade elementary students. Metacognition was assessed through two off-line and two on-line measures. The off-line measures consisted of a teacher rating scale and a self-report questionnaire. The…

  16. Sistema de Optimización en Línea y Diagnosis de Fallos para Procesos Químicos An On-line Optimization and Fault Diagnosis System for Chemical Processes

    Directory of Open Access Journals (Sweden)

    Ignacio Yélamos

    2007-01-01

    Full Text Available En este artículo, la técnica Evolución en Tiempo Real (ETR es aplicada a la optimización en línea de una columna de destilación multicomponente. Un Sistema de Diagnóstico de Fallos (SDF dentro de un módulo de supervisión es responsable de la gestión de cualquier incidencia (fallos o perturbaciones que ocurra en la planta, consiguiéndose un funcionamiento en línea más robusto. La implementación de este módulo supervisado (ETRS se ha llevado a cabo usando Matlab® y el simulador comercial Hysys®, aprovechando las posibilidades de comunicación existentes entre ambos. Se tratan diferentes incidencias, involucrando diferentes fuentes y tipos de perturbaciones. Los resultados de la ETRS son comparados con los que se obtuvieron mediante la Optimización en Tiempo Real clásica.In this paper, the Real Time Evolution technique (RTE is applied to the on-line optimization of a multi-component distillation column. A Fault Diagnosis System (FDS implemented within a supervisory module is responsible for handling incidences (faults or disturbances occurring in the plant, achieving more robust on-line performance. The implementation of the supervised scheme (SRTE has been performed using Matlab® and the commercial simulation software Hysys®, taking advantage of their communication capabilities. Different possible plant incidences are considered involving different sources and types of disturbances. Results of SRTE are compared with those obtained using the standard Real Time Optimization approach.

  17. On-line speciation of inorganic and methyl mercury in waters and fish tissues using polyaniline micro-column and flow injection-chemical vapour generation-inductively coupled plasma mass spectrometry (FI-CVG-ICPMS).

    Science.gov (United States)

    Krishna, M V Balarama; Chandrasekaran, K; Karunasagar, D

    2010-04-15

    A simple and efficient method for the determination of ultra-trace amounts of inorganic mercury (iHg) and methylmercury (MeHg) in waters and fish tissues was developed using a micro-column filled with polyaniline (PANI) coupled online to flow injection-chemical vapour generation-inductively coupled plasma mass spectrometry (FI-CVG-ICPMS) system. Preliminary studies indicated that inorganic and methyl mercury species could be separated on PANI column in two different speciation approaches. At pH extraction of the mercury species from biological samples, was used directly to separate MeHg from iHg in the fish tissues (tuna fish ERM-CE 463, ERM-CE 464 and IAEA-350) by PANI column using speciation procedure 1. The determined values were in good agreement with certified values. Under optimal conditions, the limits of detection (LODs) were 2.52 pg and 3.24 pg for iHg and MeHg (as Hg) respectively. The developed method was applied successfully to the direct determination of iHg and MeHg in various waters (tap water, lake water, ground water and sea-water) and the recoveries for the spiked samples were in the range of 96-102% for both the Hg species.

  18. On-Line Synthesis and Analysis by Mass Spectrometry

    Science.gov (United States)

    Bain, Ryan M.; Pulliam, Christopher J.; Raab, Shannon A.; Cooks, R. Graham

    2015-01-01

    In this laboratory experiment, students learn how to use ESI to accelerate chemical synthesis and to couple it with on-line mass spectrometry for structural analysis. The Hantzsch synthesis of symmetric 1,4-dihydropyridines is a classic example of a one-pot reaction in which multiple intermediates can serve to indicate the progress of the reaction…

  19. On-Line Synthesis and Analysis by Mass Spectrometry

    Science.gov (United States)

    Bain, Ryan M.; Pulliam, Christopher J.; Raab, Shannon A.; Cooks, R. Graham

    2015-01-01

    In this laboratory experiment, students learn how to use ESI to accelerate chemical synthesis and to couple it with on-line mass spectrometry for structural analysis. The Hantzsch synthesis of symmetric 1,4-dihydropyridines is a classic example of a one-pot reaction in which multiple intermediates can serve to indicate the progress of the reaction…

  20. 40 CFR 792.135 - Physical and chemical characterization studies.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 31 2010-07-01 2010-07-01 true Physical and chemical characterization... A Study § 792.135 Physical and chemical characterization studies. (a) All provisions of the GLPs shall apply to physical and chemical characterization studies designed to determine...

  1. Regulation of Blood Glucose Concentration in Type 1 Diabetics Using Single Order Sliding Mode Control Combined with Fuzzy On-line Tunable Gain, a Simulation Study.

    Science.gov (United States)

    Dinani, Soudabeh Taghian; Zekri, Maryam; Kamali, Marzieh

    2015-01-01

    Diabetes is considered as a global affecting disease with an increasing contribution to both mortality rate and cost damage in the society. Therefore, tight control of blood glucose levels has gained significant attention over the decades. This paper proposes a method for blood glucose level regulation in type 1 diabetics. The control strategy is based on combining the fuzzy logic theory and single order sliding mode control (SOSMC) to improve the properties of sliding mode control method and to alleviate its drawbacks. The aim of the proposed controller that is called SOSMC combined with fuzzy on-line tunable gain is to tune the gain of the controller adaptively. This merit causes a less amount of control effort, which is the rate of insulin delivered to the patient body. As a result, this method can decline the risk of hypoglycemia, a lethal phenomenon in regulating blood glucose level in diabetics caused by a low blood glucose level. Moreover, it attenuates the chattering observed in SOSMC significantly. It is worth noting that in this approach, a mathematical model called minimal model is applied instead of the intravenously infused insulin-blood glucose dynamics. The simulation results demonstrate a good performance of the proposed controller in meal disturbance rejection and robustness against parameter changes. In addition, this method is compared to fuzzy high-order sliding mode control (FHOSMC) and the superiority of the new method compared to FHOSMC is shown in the results.

  2. Study of On-line Real Time Measurement Technology of Absorbent Powder%吸收药在线实时计量技术研究

    Institute of Scientific and Technical Information of China (English)

    吕飞; 刘宏英

    2012-01-01

    On-line real time measurement of absorbent powder is the premise of realizing continuation and automation of the gunpowder manufacture process. According to the prpperty of absorbent pulp, this paper selected microwave concentration meter and electromagnetic flow meter, expounded their functions and working principlesi measured the concentration and flow rate of absorbent pulp more than once. In addition, the pulps pure weight was calculated by PLC system. The results showed that the property of this measurement system is good and the measuring error is small, which can meet the need of continuation and automation of the gunpowder manufacture process.%吸收药在线实时计量是实现火药制造工艺连续化、自动化的前提.根据吸收药浆料的特性,选择了微波浓度仪和电磁流量计,分别对它们的性能和工作原理进行了阐述,多次测量了吸收药浆料的浓度和流量,并且利用PLC系统计算了浆料的绝干量.结果表明,该计量系统性能好,测量误差小,能够满足火药制造工艺连续化、自动化的需要.

  3. Quantum chemical studies of estrogenic compounds

    Science.gov (United States)

    Quantum chemical methods are potent tools to provide information on the chemical structure and electronic properties of organic molecules. Modern computational chemistry methods have provided a great deal of insight into the binding of estrogenic compounds to estrogenic receptors (ER), an important ...

  4. Algorithms for semi on-line multiprocessor scheduling problems

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    In the classical multiprocessor scheduling problems, it is assumed that the problems are considered in off-line or on-line environment. But in practice, problems are often not really off-line or on-line but somehow in between. This means that, with respect to the on-line problem, some further information about the tasks is available, which allows the improvement of the performance of the best possible algorithms. Problems of this class are called semi on-line ones. The authors studied two semi on-line multiprocessor scheduling problems, in which, the total processing time of all tasks is known in advance, or all processing times lie in a given interval. They proposed approximation algorithms for minimizing the makespan and analyzed their performance guarantee. The algorithms improve the known results for 3 or more processor cases in the literature.

  5. Charge variants characterization of a monoclonal antibody by ion exchange chromatography coupled on-line to native mass spectrometry: Case study after a long-term storage at +5°C.

    Science.gov (United States)

    Leblanc, Y; Ramon, C; Bihoreau, N; Chevreux, G

    2017-03-24

    Numerous putative post-translational modifications may induce variations of monoclonal antibodies charge distribution that can potentially affect their biological activity. The characterization and the monitoring of these charge variants are critical quality requirements to ensure stability and process consistency. Charge variants are usually characterized by preparative ion exchange chromatography, collection of fractions and subsequent reverse-phase liquid chromatography with mass spectrometry analysis. While this process can be automatized by on-line two-dimensional chromatography, it remains often complex and time consuming. For this reason, a straightforward on-line charge variant analysis method is highly desirable and analytical laboratories are actively pursuing efforts to overcome this challenge. In this study, a mixed mode ion exchange chromatographic method using volatile salts and coupled on-line to native mass spectrometry was developed in association with a middle-up approach for a detailed characterization of monoclonal antibodies charge variants. An aged monoclonal antibody, presenting a complex charge variant profile was successfully investigated by this methodology as a case study. Results demonstrate that deamidation of the heavy chain was the major degradation pathway after long-term storage at 5°C while oxidation was rather low. The method was also very useful to identify all the clipped forms of the antibody. Copyright © 2017 LFB Biotechnologies. Published by Elsevier B.V. All rights reserved.

  6. System chemical biology studies of endocrine disruptors

    DEFF Research Database (Denmark)

    Taboureau, Olivier; Oprea, Tudor I.

    Endocrine disrupting chemicals (EDCs) alter hormonal balance and other physiological systems through inappropriate developmental or adult exposure, perturbing the reproductive function of further generations. While disruption of key receptors (e.g., estrogen, androgen, and thyroid) at the ligand...

  7. A photometric study of chemically peculiar stars with the STEREO satellites. I. Magnetic chemically peculiar stars

    CERN Document Server

    Wraight, K T; Netopil, M; Paunzen, E; Rode-Paunzen, M; Bewsher, D; Norton, A J; White, G J

    2011-01-01

    About 10% of upper main sequence stars are characterised by the presence of chemical peculiarities, often found together with a structured magnetic field. The atmospheres of most of those chemically peculiar stars present surface spots, leading to photometric variability caused by rotational modulation. The study of the light curves of those stars therefore, permits a precise measurement of their rotational period, which is important to study stellar evolution and to plan further detailed observations. We analysed the light curves of 1028 chemically peculiar stars obtained with the STEREO spacecraft. We present here the results obtained for the 337 magnetic chemically peculiar stars in our sample. Thanks to the cadence and stability of the photometry, STEREO data are perfectly suitable to study variability signals with a periodicity typical of magnetic chemically peculiar stars. Using a matched filter algorithm and then two different period searching algorithms, we compiled a list of 82 magnetic chemically pe...

  8. Directions for Future Research in On-line Distance Education

    OpenAIRE

    Alaa SADIK

    2015-01-01

    Although institutions have invested much in developing on-line environments or using already established commercial platforms, only few studies have been conducted to investigate the effectiveness of on-line courses based on empirical data (Jung and Rha, 2000). A review of the literature conducted in this study showed that most of online learning studies investigated the effectiveness of Web-based interaction or Internet conferencing on learning, not the entire learning environment. Even in t...

  9. Electron transport studies of chemical nanostructures

    Science.gov (United States)

    Liang, Wenjie

    2005-11-01

    In this thesis, I present electron transport studies of chemical nanostructures: single-walled carbon nanotubes (SWNTs) and single molecules. In chemical nanostructures, coulomb blockade and electronic energy level quantization dominate electron transport properties. High order correlated transport processes also play an important role in those nanostructures that are strongly coupled to electrodes. The electron transport spectra of SWNTs are investigated as a function of coupling strength of nanotube-electrode contacts. Measurements of nanotube devices at different coupling regimes showed distinct transport phenomena, including coulomb charging and electron level quantization, the experimental determination of all Hartree-Fock parameters that govern the electronic structure of metallic nanotubes and the demonstration of Fabry-Perot resonators based on the interference of electron waves. The presence of defects is important in low dimensional materials, for instance 1D SWNTs. A scanned gate microscopy (SGM) is used to locate defect center on SWNTs and study electron resonant scattering by defects. The reflection coefficient at the peak of a scattering resonance is determined to be ˜0.5 at room temperature. An intra-tube quantum-dot device formed by two defects was demonstrated by low-temperature transport measurements. Transport investigation of semiconducting SWNTs transistors shows large hysteresis effect upon gate voltage sweeping, which came from local charge redistribution around semiconducting SWNTs. A nonvolatile charge storage memory operating at room temperature was realized. Single molecule transistors incorporating different molecule (divanadium molecule [(N,N',N ″-trimethyl-1,4,7-triazacyclononane)2V2(CN) 4(mu-C4N4)], ferrocene and nickelocene) molecule, were achieved utilizing electromigration-induced break junction technique. Transport spectrum of divanadium molecules showed strange Kondo resonance where individual divanadium molecule serves as

  10. 40 CFR 160.135 - Physical and chemical characterization studies.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 23 2010-07-01 2010-07-01 false Physical and chemical characterization... and chemical characterization studies. (a) All provisions of the GLP standards shall apply to physical... physical and chemical characteristics of a test, control, or reference substance: § 160.31 (c), (d), and...

  11. On-line tribochemical strengthening of gear surface

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    It has been found that under favorable friction conditions some antiwear elements inlubricating additives can permeate into subsurface of metal which can strengthens the friction sur-faces and improves anti-wear capacity of frication pairs. It is in many ways similar to chemical heattreatment. A new concept, technology of on-line strengthening, was logically put forward. Based oncurrent gear surface treatment technology, the on-line strengthen of gear surface is proposed. Itsdesign method is established. Based on it, the on-line strengthen of gear is achieved on CL-100gear test machine. A new method is put forward for strengthen treatment of gear surface. Andthree kinds of surface film were suggested.

  12. On-line Autonomous Learning Based on Leamerg Expectation

    Institute of Scientific and Technical Information of China (English)

    李利娜

    2008-01-01

    On-line autonomous learning of College English is one of the important reforms in colleges recently.This paper aims to explore the changes of teachers'role in the new on-line setting.The article first reviews the theoretical study of learner autonomy,then makes a practical investigation into the attitude and expectation learners have on teachers through a self-designed questionnaire,and explores that teachers should make an adjustment to their role orientation and changes their roles into motivators,evaluators and resources supphers in the new on-line setting.

  13. Experimental study of chemical concentration variation of ASP flooding

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    A physical modeling system of long slim tube was established. Several pressure measuring and sampling points were laid out at different positions along the tube. Through real-time measurements of pressures and chemical concentrations at different points, the mass transfer and chemical concentration of ASP flooding in porous media are studied. The concentration of chemicals declines gradually during the fluid flow from the inlet to the outlet of the model. The concentration increases in the front edge of the slug faster than the concentration decreases in the rear edge of the slug. The concentration variation of the chemicals is an asymmetrical and offset process. The order of motion velocities of the chemicals from fast to slow is polymer, alkali and surfactant. The motion lag and comprehensive diffusion are strong in the vicinity of the inlet, the motion velocities of the chemicals are high, the difference of flow velocities among the three chemicals is significant and the chromatographic separation of the chemicals is obvious. In the area near the outlet, the comprehensive diffusion and motion lag become weak, the concentrations of the chemicals decrease, the motion velocities of the chemicals are slow, the difference among the motion velocities of the chemicals becomes small, the chromatographic separation is not obvious, the adsorption and retention of chemicals gradually increase as the chemical slug moves further along the tube, the adsorption and retention of polymer is the most serious.

  14. A spectroelectrochemical and chemical study on oxidation of hydroxycinnamic acids in aprotic medium

    Energy Technology Data Exchange (ETDEWEB)

    Petrucci, Rita [Dipartimento di Ingegneria Chimica M.M.P.M., Universita di Roma ' La Sapienza' , via del Castro Laurenziano 7, I-00161 Rome (Italy)]. E-mail: rita.petrucci@uniroma1.it; Astolfi, Paola [Dipartimento di Scienze dei Materiali e della Terra, Universita Politecnica delle Marche, via Brecce Bianche, I-60131 Ancona (Italy); Greci, Lucedio [Dipartimento di Scienze dei Materiali e della Terra, Universita Politecnica delle Marche, via Brecce Bianche, I-60131 Ancona (Italy); Firuzi, Omidreza [Dipartimento di Farmacologia delle Sostanze Naturali e Fisiologia Generale, Universita di Roma ' La Sapienza' , p.le Aldo Moro 5, I-00185 Rome (Italy); Saso, Luciano [Dipartimento di Farmacologia delle Sostanze Naturali e Fisiologia Generale, Universita di Roma ' La Sapienza' , p.le Aldo Moro 5, I-00185 Rome (Italy); Marrosu, Giancarlo [Dipartimento di Ingegneria Chimica M.M.P.M., Universita di Roma ' La Sapienza' , via del Castro Laurenziano 7, I-00161 Rome (Italy)

    2007-02-01

    Electrochemical and chemical oxidation of hydroxycinnamic acids (HCAs) was studied to investigate the mechanisms occurring in their antioxidant activities in a protons poor medium. Electrolyses and chemical reactions were followed on-line by monitoring the UV-spectral changes with time; final solutions were analysed by HPLC-MS. Anodic oxidation of mono- and di-HCAs, studied by cyclic voltammetry and controlled potential electrolyses, occurs via a reversible one-step two-electrons process, yielding the corresponding stable phenoxonium cation. A cyclization product was also proposed, as supported by ESR studies. Chemical oxidation with lead dioxide leads to different oxidation products according to the starting substrate. Di-HCAs like chlorogenic and rosmarinic acids and the ethyl ester of caffeic acid gave the corresponding neutral o-quinones, while mono-HCAs like cumaric, ferulic and sinapinic acids yielded the corresponding unstable neutral phenoxyl radical, as supported by the formation of dimerization products evidenced by HPLC-MS. In the case of caffeic acid, traces of the dimerization product suggest that the neutral phenoxyl radical may competitively undergo dimerization or decomposition of the neutral quinone. Chemical oxidation of HCAs was also followed by ESR spectroscopy: the di-HCAs radical anions were generated and detected, whereas among the mono-HCAs only the phenoxyl radical of the sinapinic acid was recorded.

  15. Study of Endocrine Disrupting Chemicals in Environment

    Directory of Open Access Journals (Sweden)

    Zoltán Juvancz

    2008-06-01

    Full Text Available Endocrine disrupting chemicals (EDC cause more and more seriousenvironmental pollutions. The EDCs show only ng-μg/l concentration level in theenvironment, therefore their determinations require multistep sample preparationprocesses and highly sophisticated instrumentation. This paper discuss the EDC effects,and show examples for determination of such compounds.

  16. SOME QUANTUM CHEMICAL STUDY ON THE STRUCTURAL ...

    African Journals Online (AJOL)

    Preferred Customer

    Formula. Formula weight. (gmol-1) ... Quantum chemical calculations (Density Functional Theory, B3LYP/6-31G (d)) were used to purposed the ... correlation functional [B3LYP/6-31G(d)]) calculations were done by using Gaussian 03 program ...

  17. Are on-line currencies virtual banknotes?

    OpenAIRE

    Stephen F. Quinn; William Roberds

    2003-01-01

    The history of money is marked by innovations that have expanded the role of "inside money"-money created by the private sector. For instance, the past few years have seen the development of several types of on-line payment arrangements, some of which have been dubbed "on-line currencies." ; This article examines the likely success or failure of on-line currencies by means of a historical analogy. The discussion compares the introduction of on-line currencies to the debut of the bearer bankno...

  18. Chemical approaches to studying stem cell biology

    Institute of Scientific and Technical Information of China (English)

    Wenlin Li; Kai Jiang; Wanguo Wei; Yan Shi; Sheng Ding

    2013-01-01

    Stem cells,including both pluripotent stem cells and multipotent somatic stem cells,hold great potential for interrogating the mechanisms of tissue development,homeostasis and pathology,and for treating numerous devastating diseases.Establishment of in vitro platforms to faithfully maintain and precisely manipulate stem cell fates is essential to understand the basic mechanisms of stem cell biology,and to translate stem cells into regenerative medicine.Chemical approaches have recently provided a number of small molecules that can be used to control cell selfrenewal,lineage differentiation,reprogramming and regeneration.These chemical modulators have been proven to be versatile tools for probing stem cell biology and manipulating cell fates toward desired outcomes.Ultimately,this strategy is promising to be a new frontier for drug development aimed at endogenous stem cell modulation.

  19. From User Comments to On-line Conversations

    OpenAIRE

    Wang, Chunyan; Ye, Mao; Huberman, Bernardo A.

    2012-01-01

    We present an analysis of user conversations in on-line social media and their evolution over time. We propose a dynamic model that accurately predicts the growth dynamics and structural properties of conversation threads. The model successfully reconciles the differing observations that have been reported in existing studies. By separating artificial factors from user behaviors, we show that there are actually underlying rules in common for on-line conversations in different social media web...

  20. Physical-chemical studies of transuranium elements

    Energy Technology Data Exchange (ETDEWEB)

    Peterson, J.R.

    1991-01-01

    Major advances in our continuing program to determine, interpret, and correlate the basic chemical and physical properties of the transuranium elements are summarized. Research topics include: Molar enthalpies of formation of BaCmO{sub 3} and BaCfO{sub 3}; luminescence of europium oxychloride at various pressures; and anti-stokes luminescence of selected actinide (III) compounds. 42 refs., 4 figs., 2 tabs.

  1. On line routing per mobile phone

    DEFF Research Database (Denmark)

    Bieding, Thomas; Görtz, Simon; Klose, Andreas

    2009-01-01

    On-line routing is concerned with building vehicle routes in an ongoing fashion in such a way that customer requests arriving dynamically in time are efficiently and effectively served. An indispensable prerequisite for applying on-line routing methods is mobile communication technology. Addition...

  2. Application of on Line Chemical Analysis Instrument in Thermal Power Plant%在线化学分析仪表在火力发电企业中的应用

    Institute of Scientific and Technical Information of China (English)

    孙连开

    2016-01-01

    在线化学分析仪表在火力发电厂中具有举足轻重的地位,直接关系到热力系统安全、稳定、长周期、高效率运行,火力发电厂主要配置的仪表有浊度仪、PH表、钠表、硅表、电导率表、氧表、酸碱浓度计、氧化还原电位(ORP)表、磷酸根表、余氯表等,这些仪表的合理配置、及时投用、准确测量将给热力系统的高效运行带来意想不到的效果,不仅可以保证锅炉给水水质的安全,同时可以减少锅炉换热面的结垢及磨损,减少爆管次数,提高企业供热及发电效率,上述仪表的投用及准确监测还可以保证给汽轮发电机提供优质的蒸汽,避免因蒸汽污染而造成汽轮发电机叶片结垢甚至受损,给火力供热发电企业带来巨大损失。%Online chemical analysis instrument in thermal power plant has a pivotal position, directly related to the thermodynamic system security, stability, long period, high efifciency operation of thermal power plant is the main conifguration of the instrument are the turbidity, pH, sodium, silicon, conductivity, oxygen and acid and alkali concentration, oxidation reduction potential (ORP), phosphate, residual chlorine, the instrument is reasonable configuration, timely investment, accurate measurement for thermal system and efficient operation of an unexpected effect, not only can ensure the boiler feed water quality safety and also can reduce boiler heat surface fouling and wear, reducing the blast tube times. High heating enterprises and power generation efifciency, the instrument of investment and accurate monitoring can also ensure the provision of high quality steam to the steam turbine generator and avoid due to steam pollution caused by turbine generator blade scaling or even damaged, thermal heating power generation enterprises to bring huge losses.

  3. Studies on Chemical Constituents From Artabotrys Hainanensis

    Institute of Scientific and Technical Information of China (English)

    CHEN Guangying; SONG Xiao-Ping; HAN Chang-ri

    2004-01-01

    Artabotrys Hainanensis R.E. Fries are plants of the Annonaccac family artabotrys genus,which includes an estimated 100 types of plants distributed mainly in the tropical zone and the subtropics areas. Four types of the plants are discovered in our country, two of which, A.Hongkongensis Hance and A. hexapetalus (Linn. F.) Bhandari, in Guangdong Province, and the other two, A. Pilosus and A. Hainanensis R.E. Fries, in Hainan Province. The latter are widely distributed in Hainan Island with very rich reserves. They have long been used among the ordinary people as medicinal plants with antipyretic, antidotal, antiphlogistic and analgesic effects and are often used for malaria. Scholars from home and abroad have paid much attention to the plants of the Annonaccac family for their containing anti-tumor activities, and after early or late research of the chemical constituents of the root, stem (derm), leaf and fruit of many types of plants of Artabotrys genus, more than 40 compounds including alkaloid, flavone and terpenoid have been isolated and obtained. Artabotrys Hainanensis R.E. Fries are Hainan endemic plants and there has been no report on the research of their chemical constituents and biological activities so far. In order to find new constituents of pharmacologic activity, we have researched the chemical constituents of the leaf and stem.The crude drugs were collected from Hainan Jianfeng Mountain and were identified as Artabotrys Hainanensis R.E. Fries of the Annonaccac family artabotrys genus. Its sample specimen is now kept in Chemistry Department of Hainan Normal University.After isolation and identification of constituent, six compounds were isolated from the leaf of Artabotrys Hainanensis R.E. Fries and elucidated as β -sitosterol (Ⅰ), catechin (Ⅱ), mangiferin (Ⅲ),(Ⅳ), (Ⅴ), (Ⅵ). All the compounds were obtained from this plant for the first time. Compounds Ⅱ, Ⅲ,Ⅳ, Ⅴ and Ⅵ were obtained from the genus of Artabotrys for the first time.

  4. System chemical biology studies of endocrine disruptors

    DEFF Research Database (Denmark)

    Taboureau, Olivier; Oprea, Tudor I.

    Endocrine disrupting chemicals (EDCs) alter hormonal balance and other physiological systems through inappropriate developmental or adult exposure, perturbing the reproductive function of further generations. While disruption of key receptors (e.g., estrogen, androgen, and thyroid) at the ligand...... binding domain (LBD) has been associated with EDCs, a significant number of EDCs do not appear to influence the LBDs of these receptors. Therefore, we evaluated the potential biological effects of EDCs in humans with the aim to rationalize the etiology of certain disorders associated with the reproductive...

  5. Polyketide stereocontrol: a study in chemical biology

    Science.gov (United States)

    2017-01-01

    The biosynthesis of reduced polyketides in bacteria by modular polyketide synthases (PKSs) proceeds with exquisite stereocontrol. As the stereochemistry is intimately linked to the strong bioactivity of these molecules, the origins of stereochemical control are of significant interest in attempts to create derivatives of these compounds by genetic engineering. In this review, we discuss the current state of knowledge regarding this key aspect of the biosynthetic pathways. Given that much of this information has been obtained using chemical biology tools, work in this area serves as a showcase for the power of this approach to provide answers to fundamental biological questions.

  6. Prediction of XRF analyzers error for elements on-line assaying using Kalman Filter

    Institute of Scientific and Technical Information of China (English)

    Nakhaei F; Sam A; Mosavi MR; Nakhaei A

    2012-01-01

    Determination of chemical elements assay plays an important role in mineral processing operations.This factor is used to control process accuracy,recovery calculation and plant profitability.The new assaying methods including chemical methods,X-ray fluorescence and atomic absorption spectrometry are advanced and accurate.However,in some applications,such as on-line assaying process,high accuracy is required.In this paper,an algorithm based on Kalman Filter is presented to predict on-line XRF errors.This research has been carried out on the basis of based the industrial real data collection for evaluating the performance of the presented algorithm.The measurements and analysis for this study were conducted at the Sarcheshmeh Copper Concentrator Plant located in Iran.The quality of the obtained results was very satisfied; so that the RMS errors of prediction obtained for Cu and Mo grade assaying errors in rougher feed were less than 0.039 and 0.002 and in final flotation concentration less than 0.58 and 0.074,respectively.The results indicate that the mentioned method is quite accurate to reduce the on-line XRF errors measurement.

  7. Determination of anions with an on-line capillary electrophoresis method; Anionien on-line maeaeritys kapillaarielektroforeesilla - MPKT 10

    Energy Technology Data Exchange (ETDEWEB)

    Siren, H.; Saerme, T.; Kotiaho, T.; Hiissa, T.; Savolahti, P.; Komppa, V. [VTT Chemical Technology, Espoo (Finland)

    1998-12-31

    The aim of the study was to set-up an on-line capillary electrophoresis method for determination of anions in process waters of pulp and paper industry with exporting the results to the process control system of the mill. The quantification is important, since it will give information about the possible causes of precipitation. In recent years, the capillary electrophoresis (CE) due to its high separation efficiency has been shown as a method to take into consideration when analyzing chemical species ranging from small inorganic anions to different macromolecules. Many compounds are not easily detected in their native state, why analysis methods must be developed to improve their detection. Especially, small inorganic and organic anions which do not have chromophores are not sensitive enough for direct-UV detection. In such analyses the anions are mostly detected with indirect-UV technique. Capillary electrophoresis instruments are used to analyze samples in off-line, which seldom represent the situation in process. Therefore, on-line instrument technology with autoanalyzing settings will be needed in quality control. The development of a fully automatic capillary electrophoresis system is underway in co-operation with KCL (The Finnish Pulp and Paper Research Institute). In our research, we have first concentrated on the determination of sulphate in waters of paper industry. The method used for detection of sulphate is based on indirect-UV detection with CE, where the background electrolyte (BGE) is an absorbing mixture of secondary amines. The whole procedure for quantification of sulphate is performed within 15 minutes, after which a new sample is analyzed automatically. The only sample pretreatment is filtration, which is necessary before analysis. The concentrations of sulphate in process waters tested were between 300 and 800 ppm. Our tests show that a simultaneous determination of chloride, sulphate, nitrate, nitrite, sulphite, carbonate and oxalate is also

  8. Purity, adulteration and price of drugs bought on-line versus off-line in the Netherlands.

    Science.gov (United States)

    van der Gouwe, Daan; Brunt, Tibor M; van Laar, Margriet; van der Pol, Peggy

    2017-04-01

    On-line drug markets flourish and consumers have high expectations of on-line quality and drug value. The aim of this study was to (i) describe on-line drug purchases and (ii) compare on-line with off-line purchased drugs regarding purity, adulteration and price. Comparison of laboratory analyses of 32 663 drug consumer samples (stimulants and hallucinogens) purchased between January 2013 and January 2016, 928 of which were bought on-line. The Netherlands. Primary outcome measures were (i) the percentage of samples purchased on-line and (ii) the chemical purity of powders (or dosage per tablet); adulteration; and the price per gram, blotter or tablet of drugs bought on-line compared with drugs bought off-line. The proportion of drug samples purchased on-line increased from 1.4% in 2013 to 4.1% in 2015. The frequency varied widely, from a maximum of 6% for controlled, traditional substances [ecstasy tablets, 3,4-methylenedioxy-methamphetamine (MDMA) powder, amphetamine powder, cocaine powder, 4-bromo-2,5-dimethoxyphenethylamine (2C-B) and lysergic acid diethylamide (LSD)] to more than a third for new psychoactive substances (NPS) [4-fluoroamphetamine (4-FA), 5/6-(2-aminopropyl)benzofuran (5/6-APB) and methoxetamine (MXE)]. There were no large differences in drug purity, yet small but statistically significant differences were found for 4-FA (on-line 59% versus off-line 52% purity for 4-FA on average, P = 0.001), MDMA powders (45 versus 61% purity for MDMA, P = 0.02), 2C-B tablets (21 versus 10 mg 2C-B/tablet dosage, P = 0.49) and ecstasy tablets (131 versus 121 mg MDMA/tablet dosage, P = 0.05). The proportion of adulterated samples purchased on-line and off-line did not differ, except for 4-FA powder, being less adulterated on-line (χ(2)  = 8.3; P Addiction.

  9. Linguistic Affordances of Korean-English Tandem Learning: A Case Study of Korean-English On-Line Chat Pair Interaction

    Science.gov (United States)

    Cheon, Heesok

    2012-01-01

    In an attempt to explore an environment for language learning that tandem learning via real-time chat affords to foreign language learners and how language learners respond to those affordances, this study examined learner interaction in online Korean-English Tandem Learning with focus on how tandem learners engaged in peer assistance and how they…

  10. The Role of Explicit Information in Instructed SLA: An On-Line Study with Processing Instruction and German Accusative Case Inflections

    Science.gov (United States)

    Culman, Hillah; Henry, Nicholas; VanPatten, Bill

    2009-01-01

    The present study reports the findings of an experiment on the effects of explicit information on the learning of German case markings. Fifty-nine learners of first- and second-year German received computer-based processing instruction on German accusative case marking and word order. These learners were divided into two groups: one received…

  11. Using Eye-Tracking to Study the On-Line Processing of Case-Marking Information among Intermediate L2 Learners of German

    Science.gov (United States)

    Jackson, Carrie N.; Dussias, Paola E.; Hristova, Adelina

    2012-01-01

    This study uses eye-tracking to examine the processing of case-marking information in ambiguous subject- and object-first wh-questions in German. The position of the lexical verb was also manipulated via verb tense to investigate whether verb location influences how intermediate L2 learners process L2 sentences. Results show that intermediate L2…

  12. Development of an on-line aqueous particle sensor to study the performance of inclusions in a 12 tonne, delta shaped full scale water model tundish

    Science.gov (United States)

    Chakraborty, Abhishek

    Detection of particulate matter thinly dispersed in a fluid medium with the aid of the difference in electrical conductivity between the pure fluid and the particles has been practiced at least since the last 50 to 60 years. The first such instruments were employed to measure cell counts in samples of biological fluid. Following a detailed study of the physics and principles operating within the device, called the Electric Sensing Zone (ESZ) principle, a new device called the Liquid Metal Cleanliness Analyzer (LiMCA) was invented which could measure and count particles of inclusions in molten metal. It provided a fast and fairly accurate tool to make online measurement of the quality of steel during refining and casting operations. On similar lines of development as the LiMCA, a water analogue of the device called, the Aqueous Particle Sensor (APS) was developed for physical modeling experiments of metal refining operations involving water models. The APS can detect and measure simulated particles of inclusions added to the working fluid (water). The present study involves the designing, building and final application of a new and improved APS in water modeling experiments to study inclusion behavior in a tundish operation. The custom built instrument shows superior performance and applicability in experiments involving physical modeling of metal refining operations, compared to its commercial counterparts. In addition to higher accuracy and range of operating parameters, its capability to take real-time experimental data for extended periods of time helps to reduce the total number of experiments required to reach a result, and makes it suitable for analyzing temporal changes occurring in unsteady systems. With the modern impetus on the quality of the final product of metallurgical operations, the new APS can prove to be an indispensable research tool to study and put forward innovative design and parametric changes in industrially practised metallurgical

  13. THE STUDY OF CHEMICAL COMPOSITION FOR ANIMAL FATS DURING STORAGE

    OpenAIRE

    Flavia Pop; Cornel Laslo

    2009-01-01

    In this article the chemical composition for 3 types of animal fats (pork fat, beef tallow and buffalo tallow), following the variation of saturated and unsaturated fatty acids proportion during freezing storage was studied. Determination of chemical composition of animal fats is important in establishing organoleptic and physico-chemical parameters, the variation of them in time, nature and proportion of fatty acids conferring specific characteristics to them. For pork fat was determined the...

  14. Linking NASA Environmental Data with a National Public Health Cohort Study and a CDC On-Line System to Enhance Public Health Decision Making

    Science.gov (United States)

    Al-Hamdan, Mohammad; Crosson, William; Economou, Sigrid; Estes, Maurice, Jr.; Estes, Sue; Hemmings, Sarah; Kent, Shia; Puckett, Mark; Quattrochi, Dale; Wade, Gina; McClure, Leslie

    2012-01-01

    The overall goal of this study is to address issues of environmental health and enhance public health decision making by utilizing NASA remotely-sensed data and products. This study is a collaboration between NASA Marshall Space Flight Center, Universities Space Research Association (USRA), the University of Alabama at Birmingham (UAB) School of Public Health and the Centers for Disease Control and Prevention (CDC) National Center for Public Health Informatics. The objectives of this study are to develop high-quality spatial data sets of environmental variables, link these with public health data from a national cohort study, and deliver the linked data sets and associated analyses to local, state and federal end-user groups. Three daily environmental data sets were developed for the conterminous U.S. on different spatial resolutions for the period 2003-2008: (1) spatial surfaces of estimated fine particulate matter (PM2.5) exposures on a 10-km grid utilizing the US Environmental Protection Agency (EPA) ground observations and NASA s MODerate-resolution Imaging Spectroradiometer (MODIS) data; (2) a 1-km grid of Land Surface Temperature (LST) using MODIS data; and (3) a 12-km grid of daily Solar Insolation (SI) and maximum and minimum air temperature using the North American Land Data Assimilation System (NLDAS) forcing data. These environmental datasets were linked with public health data from the UAB REasons for Geographic and Racial Differences in Stroke (REGARDS) national cohort study to determine whether exposures to these environmental risk factors are related to cognitive decline and other health outcomes. These environmental national datasets will also be made available to public health professionals, researchers and the general public via the CDC Wide-ranging Online Data for Epidemiologic Research (WONDER) system, where they can be aggregated to the county, state or regional level as per users need and downloaded in tabular, graphical, and map formats. The

  15. [Studies on chemical constituents of Saussurea laniceps].

    Science.gov (United States)

    Dawa, Zhuo-Ma; Zhou, Yan; Bai, Yang; Gesang, Suo-Lang; Xie, Ping; Ding, Li-Sheng

    2008-05-01

    To investigate the chemical constituents of Saussurea laniceps. The ethanol extract of S. laniceps was separated by means of silica gel chromatography. The compounds isolated from the plant were identified by their spectral evidence. Fifteen compounds were isolated and identified as beta-stiosterol (1), umbelliferone (2), 4-hydroxyacetophenone (3), scopoletin (4), isoscopoletin (5), xuelianlactone (6), methyl 3-(2', 4'-dihydroxyphenyl) propanoate (7), apigenin (8), neoechinulin A (9), daucosterol (10), scopolin (11), xuelianlactone 8-O-beta-D-glcuoside (12), apigenin 7-glcuoside (13), apigenin 7-lutinoside (14) and syringin (15). Compounds 5-15 were isolated from S. laniceps, and among them, 7 and 9 were isolated from genus Saussurea for the first time.

  16. [Studies on chemical compounds of Chlorella sorokiniana].

    Science.gov (United States)

    Zhang, Ling; Liu, Ping-huai; Wu, Jiao-na; Yang, Guo-fu; Suo, Yang-yang; Luo, Ning; Chen, Chen

    2015-04-01

    Chemical constituents of Chlorella sorokiniana were isolated and purified by repeated column chromatographies, over silicagel and Sephadex LH-20. Their structures were identified on the basis of physicochemical properties and spectroscopic data analysis. Five compounds were obtained from the petroleum ether extract of Chlorella sorokiniana, and their structures were identified as (22E, 24R)-5alpha, 3beta-epidioxiergosta-6, 22-dien-3beta-ol(1),(24S)-ergosta-7-en-3beta-ol(2), loliolide(3), stigmasta-7,22-dien-3beta,5alpha,6alpha-triol(4), and 3beta-hydroxy-5alpha,6alpha-epoxy-7-megastigmen-9-one(5). The main liposoluble fractions from Chlorella sorokiniana maiuly contain fatty acids, alkyl acids and olefine acids. Components 1-5 were isolated from the genus Chlorella for the first time.

  17. Nová publikace "Exploring regional sustainable development issues. Using the case study approach in higher education" dostupná on-line.

    Directory of Open Access Journals (Sweden)

    Jiří Dlouhý

    2015-06-01

    Full Text Available S tématem udržitelného rozvoje na regionální (a globální úrovni souvisí nedávno publikovaná kniha "Exploring regional sustainable development issues. Using the case study approach in higher education" editorů Andrew Bartona a Jany Dlouhé. Jsou zde rekapitulována teoretická východiska pro užití případových studií ve výuce (především na vysokoškolské úrovni, kde představují vhodnou formupředstavení kvalitativních metod výzkumu a jejich využití praxi; obsahuje dále celkem sedm případových studií udržitelného rozvoje, které byly použity jako otevřené vzdělávací zdroje v mezinárodních programech výuky (především v programu ISPoS a EVS. Plný text knihy je dostupný zde. Vznik publikace byl podpořen z projektu MOSUR a projektů TAČR Omega "Metodika tvorby a využití tzv. Open Educational Resources (TD020400" a "Studium a podpora procesů participativní tvorby regionálních strategií UR (TD020120".

  18. Nová publikace "Exploring regional sustainable development issues. Using the case study approach in higher education" dostupná on-line.

    Directory of Open Access Journals (Sweden)

    Jiří Dlouhý

    2015-06-01

    Full Text Available S tématem udržitelného rozvoje na regionální (a globální úrovni souvisí nedávno publikovaná kniha "Exploring regional sustainable development issues. Using the case study approach in higher education" editorů Andrew Bartona a Jany Dlouhé. Jsou zde rekapitulována teoretická východiska pro užití případových studií ve výuce (především na vysokoškolské úrovni, kde představují vhodnou formupředstavení kvalitativních metod výzkumu a jejich využití praxi; obsahuje dále celkem sedm případových studií udržitelného rozvoje, které byly použity jako otevřené vzdělávací zdroje v mezinárodních programech výuky (především v programu ISPoS a EVS. Plný text knihy je dostupný zde. Vznik publikace byl podpořen z projektu MOSUR a projektů TAČR Omega "Metodika tvorby a využití tzv. Open Educational Resources (TD020400" a "Studium a podpora procesů participativní tvorby regionálních strategií UR (TD020120".

  19. Collaborative on-line teaching

    DEFF Research Database (Denmark)

    Levinsen, Karin

    2007-01-01

      It is often stressed that the pedagogic models and approaches of Collaborative Online Learning support learners' shared knowledge building within collaborating groups of learners, the individual construction of knowledge as well as the formation of an ongoing learning Community of Practice...... exclude students from participating in the learning Community of Practice. Conclusively, the case study identifies slowly emerging tendencies that may be detected and observed at earlier stages, thus pointing to areas requiring awareness in online learning environments....

  20. Collaborative on-line teaching

    DEFF Research Database (Denmark)

    Levinsen, Karin

    2007-01-01

      It is often stressed that the pedagogic models and approaches of Collaborative Online Learning support learners' shared knowledge building within collaborating groups of learners, the individual construction of knowledge as well as the formation of an ongoing learning Community of Practice...... exclude students from participating in the learning Community of Practice. Conclusively, the case study identifies slowly emerging tendencies that may be detected and observed at earlier stages, thus pointing to areas requiring awareness in online learning environments....

  1. On-line extractive separation in flow injection analysis based on polymer inclusion membranes: a study on membrane stability and approaches for improving membrane permeability.

    Science.gov (United States)

    Zhang, Lujia L; Cattrall, Robert W; Ashokkumar, Muthupandian; Kolev, Spas D

    2012-08-15

    The effect of temperature on the sensitivity and sampling rate is studied for a flow injection analysis (FIA) system that uses a membrane separation cell fitted with a polymer inclusion membrane (PIM) for the determination of Zn(II). A temperature of 50 °C for the flowing donor and acceptor solutions and the membrane separation cell improves the sensitivity and the sampling rate relative to 20 °C up to 10-fold and 2-fold, respectively. Studies on the stability of the PIM are reported that show a limited loss of the membrane liquid phase into the aqueous phases used in the FIA system but this has exhibited a negligible effect on the amount of Zn(II) transported across the membrane. Most importantly, the extent of leaching of the PIM components is shown to depend on the nature of the aqueous phase with the membrane eventually reaching a stable composition. It is also shown that the application of ultrasound to the membrane separation cell leads to a slight increase in sensitivity without affecting the long term membrane stability.

  2. Feasibility Study of Using High-Temperature Raman Spectroscopy for On-Line Monitoring and Product Control of the Glass Vitrification Process

    Energy Technology Data Exchange (ETDEWEB)

    Windisch, C.F. Jr.; Piepel, G.F.; Li, H.; Elliott, M.L.; Su, Y.

    1999-01-04

    A pulse-gating Raman spectroscopy setup was developed in this project. The setup was capable of performing in-situ high-temperature Raman measurements for glasses at temperatures as high as 1412 C. In the literature, high-temperature Raman measurements have only been performed on thin films of glass to minimize black-body radiation effects. The pulse-gating Raman setup allows making high-temperature measurements for bulk melts while effectively minimizing black-body radiation effects. A good correlation was found between certain Raman characteristic parameters and glass melt temperature for sodium silicate glasses measured in this project. Comparisons were made between the high-temperature Raman data from this study and literature data. The results suggest that an optimization of the pulse-gating Raman setup is necessary to further improve data quality (i.e., to obtain data with a higher signal-to-noise ratio). An W confocal Raman microspectrometer with continuous wave laser excitation using a 325 nm excitation line was evaluated selectively using a transparent silicate glass ad a deep-colored high-level waste glass in a bulk quantity. The data were successfully collected at temperatures as high as approximately 1500 C. The results demonstrated that the UV excitation line can be used for high-temperature Raman measurements of molten glasses without black-body radiation interference from the melt for both transparent and deep-color glasses. Further studies are needed to select the best laser system that can be used to develop high-temperature Raman glass databases.

  3. Study on BOTDR technology-based OPGW on-line monitoring%基于BOTDR技术的OPGW在线监测研究

    Institute of Scientific and Technical Information of China (English)

    李永倩; 翟丽娜; 赵丽娟; 宋士刚

    2013-01-01

    For ensuring the secure operation of power system communications,real-time monitoring of the running state of the OPtical fiber composite overhead Ground Wire (OPGW)is necessary.This paper presents a method on the basis of the Bril-louin Optical Time Domain Reflectometry (BOTDR)technology,in which real-time monitoring is performed on the OPGW temperature and strain.Then,it calibrates the temperature and strain coefficients of G.652 optical fiber in OPGW.On the ba-sis of the experimental results,it studies the temperature and strain distribution of OPGW in field operation and analyzes the faults brought about by temperature and strain using the differential method and the relative value method.The results indicate that the BOTDR-based online monitoring system can realize real-time measurement of distributed temperature and strain and fault location for OPGW.%为保证电力系统通信的安全运行,实时监测 OPGW(光纤复合架空地线)的运行状态,提出了基于 BOTDR(布里渊光时域反射)技术对 OPGW线路温度和应变实时监测的方法。采用加温加压的方法,对 OPGW纤芯 G.652光纤的温度和应变系数进行了标定,基于实验结论,对现场运行的 OPGW线路温度和应变的分布进行了研究。同时采用差值法和相对值法分别对温度和应变引起的故障进行了分析,分析结果表明,该系统能实现 OPGW分布式温度和应变的实时测量和故障点定位。

  4. Chemical Physics: A Subject for Study at University?

    Science.gov (United States)

    Dunmur, D. A.

    1982-01-01

    Traces development of chemical physics as a distinct discipline and reviews its position as a subject for study in United Kingdom universities. Reports results of a survey of chemical physics courses and graduates (1975-1980), including employment data on these graduates. (Author/JN)

  5. On-line generalized Steiner problem

    Energy Technology Data Exchange (ETDEWEB)

    Awerbuch, B.; Azar, Y.; Bartal, Y. [Tel Aviv Univ. (Israel)

    1996-12-31

    The Generalized Steiner Problem (GSP) is defined as follows. We are given a graph with non-negative weights and a set of pairs of vertices. The algorithm has to construct minimum weight subgraph such that the two nodes of each pair are connected by a path. We consider the on-line generalized Steiner problem, in which pairs of vertices arrive on-line and are needed to be connected immediately. We give a simple O(log{sup 2} n) competitive deterministic on-line algorithm. The previous best online algorithm (by Westbrook and Yan) was O({radical}n log n) competitive. We also consider the network connectivity leasing problem which is a generalization of the GSP. Here edges of the graph can be either bought or leased for different costs. We provide simple randomized O(log{sup 2} n) competitive algorithm based on the on-line generalized Steiner problem result.

  6. The war against on-line piracy

    OpenAIRE

    Harris, Julian

    2011-01-01

    A summary by Julian Harris, Deputy General Editor Amicus Curiae, of US attempts to control what it identifies as rogue Internet sites engaged in on-line piracy and opposition to such legislative moves.

  7. Clinical case studies in mental health by means of the on-line discussion Estudios de casos clínicos en salud mental mediante discusión en-linea Estudos de casos clínicos em saúde mental por meio de discussão on-line

    Directory of Open Access Journals (Sweden)

    Edilaine Cristina da Silva

    2008-06-01

    Full Text Available This descriptive and exploratory study with a qualitative design aimed to describe and analyze discussions in online chats about mental disorders in a psychiatric nursing course as part of an undergraduate nursing program. The sample consisted of 32 undergraduate students who attended the course. Data analysis showed that the discussions through online chat sessions permeated the acquisition of knowledge, procedures, attitudes and values and promoted students' active participation. The results reaffirm the discussions' importance for students' learning and showed the potential of technology resources, such as real-time communication tools, to support and improve teaching possibilities in psychiatric nursing.Estudio descriptivo y exploratorio con enfoque cualitativo con el objetivo de describir y analizar discusiones en-línea sobre casos clínicos, como parte de la disciplina de Enfermería Psiquiátrica. La muestra formada por 32 alumnos que cursaban la asignatura. El análisis de los datos mostró que las discusiones a través de las conversaciones en-linea favorecieron el aprendizaje, procedimientos, actitudes y valores; promoviendo la participación activa de los estudiantes. Los resultados fundamentan la riqueza en la discusión, para el aprendizaje del estudiante, así como evidencian la potencialidad para el uso de herramientas tecnológicas, como las de comunicación en tiempo real, para apoyar e incrementar las posibilidades educativas en enfermería psiquiátrica.Estudo descritivo e exploratório, com abordagem qualitativa, cujo objetivo foi descrever e analisar discussões de casos clínicos on-line na disciplina de Enfermagem Psiquiátrica do Curso de Graduação em Enfermagem. A amostra constituiu-se de 32 acadêmicos de enfermagem que cursavam a disciplina. A análise dos dados evidenciou que as discussões, através do bate-papo, permearam a aprendizagem de conhecimentos, procedimentos, atitudes e valores e promoveram a participa

  8. On-Line Acquisitions by LOLITA

    Directory of Open Access Journals (Sweden)

    Frances G. Spigai

    1970-12-01

    Full Text Available The on-line acquisition program (LOLITA in use at the Oregon State University Library is described in terms of development costs, equipment requirements, and overall design philosophy. In particular, the record format and content of records in the on-order file, and the on-line processing of these records (input, search, correction, output using a cathode ray tube display terminal are detailed.

  9. ACSEPP On-Line Electronic Payment Protocol

    Institute of Scientific and Technical Information of China (English)

    WANG Shao-bin; ZHU Xian; HONG Fan

    2004-01-01

    With analyzing the existing on-line electronic payment protocols, this paper presents a new on-line electronic payment protocol named ACSEPP: Anonymous, Convenient and Secure Electronic Payment Protocol.Its aim is to design a practical electronic payment protocol which is both secure and convenient.Without using PKI_CA frame, it realized the anonymity of consumer and merchant, the convenient of handling, the low cost of maintenance and the security.

  10. Fenton-Driven Chemical Regeneration of MTBE-Spent Granular Activated Carbon -- A Pilot Study

    Science.gov (United States)

    MTBE-spent granular activated carbon (GAC) underwent 3 adsorption/oxidation cycles. Pilot-scale columns were intermittently placed on-line at a ground water pump and treat facility, saturated with MTBE, and regenerated with H2O2 under different chemical, physical, and operational...

  11. Robust on-line monitoring of biogas processes; Robusta maettekniker on-line foer optimerad biogasproduktion

    Energy Technology Data Exchange (ETDEWEB)

    Nordberg, Aake; Hansson, Mikael; Kanerot, Mija; Krozer, Anatol; Loefving, Bjoern; Sahlin, Eskil

    2010-03-15

    Although demand for biomethane in Sweden is higher than ever, many Swedish codigestion plants are presently operated below their designed capacity. Efforts must be taken to increase the loading rate and guarantee stable operation and high availability of the plants. There are currently no commercial systems for on-line monitoring, and due to the characteristics of the material, including corrosion and tearing, robust applications have to be developed. The objective of this project was to identify and study different monitoring technologies with potential for on-line monitoring of both substrate mixtures and anaerobic digester content. Based on the prerequisites and demands at Boraas Energi och Miljoe AB's (BEMAB, the municipal energy and waste utility in the city of Boraas, Sweden) biogas plant, the extent of the problems, measurement variables and possible ways of managing these issues have been identified and prioritized. The substrate mixtures in question have a high viscosity and are inhomogeneous with variation in composition, which calls for further homogenization, dilution and filtration to achieve high precision in the necessary analyses. Studies of using different mixers and mills showed that the particle size (800 mum) needed for on-line COD measurement could not be achieved. The problem of homogenization can be avoided if indirect measurement methods are used. Laboratory tests with NIR (near-infra red spectroscopy) showed that VS can be predicted (R2=0,78) in the interval of 2-9% VS. Furthermore, impedance can give a measurement of soluble components. However, impedance is not sensitive enough to give a good measurement of total TS. Microwave technology was installed at the production plant and showed a faster response to changes in TS than the existing TS-sensor. However, due to technical problems, the evaluation only could be done during a limited period of ten days. BEMAB will continue the measurements and evaluation of the instrument. The

  12. Extended Functional Groups (EFG: An Efficient Set for Chemical Characterization and Structure-Activity Relationship Studies of Chemical Compounds

    Directory of Open Access Journals (Sweden)

    Elena S. Salmina

    2015-12-01

    Full Text Available The article describes a classification system termed “extended functional groups” (EFG, which are an extension of a set previously used by the CheckMol software, that covers in addition heterocyclic compound classes and periodic table groups. The functional groups are defined as SMARTS patterns and are available as part of the ToxAlerts tool (http://ochem.eu/alerts of the On-line CHEmical database and Modeling (OCHEM environment platform. The article describes the motivation and the main ideas behind this extension and demonstrates that EFG can be efficiently used to develop and interpret structure-activity relationship models.

  13. Chromatographic on-line detection of bioactives in food

    Directory of Open Access Journals (Sweden)

    Remmelt Van der Werf

    2013-08-01

    Full Text Available ABSTRACTFindings were focused on the anti-oxidative activity of numerous fruits and vegetables by means of an on-line HPLC radical scavenging detection method. The reactant used was the ABTS•+ green radical cation. The system has been optimized in terms of reactor design, and chemical reactions kinetics. It has been qualified to classify molecules in order of their increasing activity to scavenge exogenous radicals. It may be used as a powerful high resolution screening tool to investigate the radical scavenging activities of natural plants. Bioassays consisting in cellular in vitro antioxidant assay using pancreatic β-cells have been used to confirm the bioactivity of the selected micronutrients. This study demonstrated that it is possible to screen at the molecular level, the bioactivity of numerous natural samples and to point out the richness of the local biodiversity in terms of natural resource of functional food ingredients usable for their potential benefits for consumer’s health, wellbeing and wellaging.Key words: HPLC radical scavenging detection method, bioactivity of natural samples

  14. Feasibility and effectiveness of chemical bile duct embolization for chemical hepatectomy:a preliminary study

    Institute of Scientific and Technical Information of China (English)

    Fu-Yu Li; Ning Li; Li-Sheng Jiang; Jing-Qiu Cheng; Nan-Sheng Cheng; Xing-Wu Wu; Sheng He

    2006-01-01

    BACKGROUND: The high operative risk of hepatectomy for specially located intrahepatic stones is still a problem to be solved. This study was undertaken to investigate the feasibility and effectiveness of chemical bile duct embolization for chemical hepatectomy. METHODS: Oxybenzene or absolute ethanol plus N-butyl-cyanoacrylate was employed for embolization. The feasibility, effectiveness and mechanism of chemical hepatectomy were preliminarily analyzed histologically or by Fas, TIMP-1, TGF-β1, and collagenⅠ. RESULTS:Oxybenzene plus cyanonacrylate can preferably destroy and embolize the intrahepatic biliary duct, leading to the disappearance of hepatocytes in the periphery of embolized lobe and the achievement of effective chemical hepatectomy. The expressions of Fas, TIMP-1 and TGF-β1 in oxybenzene embolism group (88.90±38.10, 619.43± 183.42, 185.22±70.39) and ethanol embolism group (72.39± 29.51, 407.55±134.74, 163.56±51.75) were higher than those of biliary duct-ligated group (26.31±12.07, 195.31±107.67, 74.84±40.73) (P CONCLUSION: The effect of chemical hepatectomy may be achieved by chemical bile duct embolization.

  15. Chemical - Elwha River Dam Removal Study

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This study examines the ecosystem response of the Elwha River to the removal of the Elwha River dams. We will measure the following attributes of ecosystem response:...

  16. Quantum-chemical studies on porphyrins, fullerenes and carbon nanostructures

    CERN Document Server

    Loboda, Oleksandr

    2014-01-01

    ​This book presents theoretical studies of electronic structure, optical and spectroscopic properties of a number of compounds. It presents new, faster calculation methods for applications in quantum-chemical theory of electronic structures.

  17. Study on New Approaches for extended chemical management and REACH

    DEFF Research Database (Denmark)

    Lee, Jihyun

    2014-01-01

    For several decades, the use of chemicals has been rapidly increasing and widely spread in our daily life. To cope with this trend, the paradigm of chemical management system has changed: from hazard criteria which is based on their intrinsic hazardous properties, to the actual risk of chemicals...... which is based on both the hazard of the substance and the possible exposure level of human to the substance, and from single substance-oriented to multiple chemical (e.g. mixture toxicity)–oriented management system (EC, 2012; Moeller and Biwer, 2014). This study aims to examine the limitations...... of existing chemical regulations in view of protecting vulnerable populations from “excessive total risk” and to explore the possibilities for improvement. Firstly, the completeness of the REACH exposure scenario was reviewed with the finding that the current scenario does not take into account territorial...

  18. On-line laser spectroscopy with thermal atomic beams

    CERN Document Server

    Thibault, C; De Saint-Simon, M; Duong, H T; Guimbal, P; Huber, G; Jacquinot, P; Juncar, P; Klapisch, Robert; Liberman, S; Pesnelle, A; Pillet, P; Pinard, J; Serre, J M; Touchard, F; Vialle, J L

    1981-01-01

    On-line high resolution laser spectroscopy experiments have been performed in which the light from a CW tunable dye laser interacts at right angles with a thermal atomic beam. /sup 76-98/Rb, /sup 118-145 /Cs and /sup 208-213/Fr have been studied using the ionic beam delivered by the ISOLDE on-line mass separator at CERN while /sup 30-31/Na and /sup 38-47/K have been studied by setting the apparatus directly on-line with the PS 20 GeV proton beam. The principle of the method is briefly explained and some results concerning nuclear structure are given. The hyperfine structure, spins and isotope shifts of the alkali isotopes and isomers are measured. (8 refs).

  19. The User-friendly On-Line Diffusion Chamber

    CERN Document Server

    Aviles Acosta, Jaime

    2015-01-01

    The On-Line Diffusion Chamber is a stand-alone apparatus built to carry out short-live radiotracer diffusion studies. The availability of the on-demand production of isotopes in the ISOLDE facility, and the design of the apparatus to streamline the implantation process, annealing treatment, ion gun ablation with a tape transport system, and radiation intensity measurement with a Ge gamma detector all in the same apparatus, gives the On-Line Diffusion Chamber a unique ability to studies with short-lived radioisotopes or isomer states that are not possible in any other facility in the world.

  20. Formación on line

    Directory of Open Access Journals (Sweden)

    O. Grau-Perejoan

    Full Text Available La formación on line es una modalidad de enseñanza a distancia basada en las nuevas tecnologías. En este artículo se pretende hacer una introducción a base de describir a grandes rasgos sus características principales: asincronía, no presencialidad, comunicación escrita, función del profesor on line, así como los retos, los riesgos, las ventajas y los inconvenientes que plantea. Se exponen las diferencias entre la formación on line y la formación presencial, de manera que los docentes puedan adaptar de la mejor manera posible sus propuestas formativas a la modalidad on line. Se introduce el importantísimo papel de la planificación y de la fase de diseño y, finalmente, se repasan conceptos útiles para comprender mejor el mundo de la formación on line como son los conceptos entorno virtual de aprendizaje (EVA o Blended Learning (B-Learning.

  1. CHEMICALS

    CERN Document Server

    Medical Service

    2002-01-01

    It is reminded that all persons who use chemicals must inform CERN's Chemistry Service (TIS-GS-GC) and the CERN Medical Service (TIS-ME). Information concerning their toxicity or other hazards as well as the necessary individual and collective protection measures will be provided by these two services. Users must be in possession of a material safety data sheet (MSDS) for each chemical used. These can be obtained by one of several means : the manufacturer of the chemical (legally obliged to supply an MSDS for each chemical delivered) ; CERN's Chemistry Service of the General Safety Group of TIS ; for chemicals and gases available in the CERN Stores the MSDS has been made available via EDH either in pdf format or else via a link to the supplier's web site. Training courses in chemical safety are available for registration via HR-TD. CERN Medical Service : TIS-ME :73186 or service.medical@cern.ch Chemistry Service : TIS-GS-GC : 78546

  2. Study on scattering properties of tissues with hyperosmotic chemical agents

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    Optical properties of biological tissue are variable due to the changes of micro-structures and scattering constituents after hyperosmotic chemical agents permeates into tissue. The changes of optical properties of biological tissue are due to the refractive indices matching between the scatterers with high refractive index and the ground substances, which reduce scattering of tissue. The main reasons are that permeated semipermeable chemical agents with higher refractive index than the ground substances of tissuemakes the refractive index of ground substances of tissue higher by the enhancement of the permeated concentration. We studied on the collimated transmittance changes of light penetrating biological tissue after the hyperosmotic chemical agents administrates with different concentration.

  3. On-Line Voltage Stability Assessment based on PMU Measurements

    DEFF Research Database (Denmark)

    Garcia-Valle, Rodrigo; P. Da Silva, Luiz C.; Nielsen, Arne Hejde

    2009-01-01

    through statistic analysis. During the off-line analysis, a memory of high-risk situations following a pre-defined voltage stability criterion is obtained. Thereafter, basic statistics analyses are applied resulting in the definition of voltage regions. During on-line operation, voltage magnitudes......This paper presents a method for on-line monitoring of risk voltage collapse based on synchronised phasor measurement. As there is no room for intensive computation and analysis in real-time, the method is based on the combination of off-line computation and on-line monitoring, which are correlated...... of critical buses obtained by phasor measurements are monitored in relation to the risk regions. Comprehensive studies demonstrate that the proposed method could assist operators to avoid voltage collapse events, by taking preventive or emergency actions....

  4. Study of Intelligent Secure Chemical Inventory Management System

    Science.gov (United States)

    Shukran, Mohd Afizi Mohd; Naim Abdullah, Muhammad; Nazri Ismail, Mohd; Maskat, Kamaruzaman; Isa, Mohd Rizal Mohd; Shahfee Ishak, Muhammad; Adib Khairuddin, Muhamad

    2017-08-01

    Chemical inventory management system has been experiencing a new revolution from traditional inventory system which is manual to an automated inventory management system. In this paper, some review of the classic and modern approaches to chemical inventory management system has been discussed. This paper also describe about both type of inventory management. After a comparative analysis of the traditional method and automated method, it can be said that both methods have some distinctive characteristics. Moreover, the automated inventory management method has higher accuracy of calculation because the calculations are handled by software, eliminating possible errors and saving time. The automated inventory system also allows users and administrators to track the availability, location and consumption of chemicals. The study of this paper can provide forceful review analysis support for the chemical inventory management related research.

  5. Developing an On-Line Interactive Health Psychology Module

    Science.gov (United States)

    Upton, Dominic; Cooper, Carol

    2006-01-01

    On-line teaching material in health psychology was developed which ensured a range of students could access appropriate material for their course and level of study. This material has been developed around the concept of smaller "content chunks" which can be combined into whole units of learning (topics), and ultimately, a module. On the basis of…

  6. Cutaneous chemical burns in children - a comparative study.

    Science.gov (United States)

    Hardwicke, Joseph; Bechar, Janak; Bella, Husam; Moiemen, Naiem

    2013-12-01

    Exposure to chemicals is an unusual causation of cutaneous burns in children. The aim of this study is to look at childhood chemical burns and compare this to adult chemical burns from the same population. A total of 2054 patients were referred to the pediatric burns unit during the study period. This included 24 cutaneous chemical burns, equating to an incidence of 1.1%. Over half of the injuries occurred in the domestic setting. The mean total body surface area (TBSA) affected was 1.9%. When compared to a cohort of adult patients from the same population with cutaneous chemical burns, the TBSA affected was identical (1.9%) but distribution favored the buttock and perineum in children, rather than the distal lower limb in adults. Children presented earlier, had lower rates of surgical intervention and had a shorter length of stay in hospital (p Chemical burns in children are rare, but are becoming more common in our region. It is important to be aware of the characteristic distribution, etiology and need to identify children at risk of child protection issues.

  7. A chemical EOR benchmark study of different reservoir simulators

    Science.gov (United States)

    Goudarzi, Ali; Delshad, Mojdeh; Sepehrnoori, Kamy

    2016-09-01

    chemical design for field-scale studies using commercial simulators. The benchmark tests illustrate the potential of commercial simulators for chemical flooding projects and provide a comprehensive table of strengths and limitations of each simulator for a given chemical EOR process. Mechanistic simulations of chemical EOR processes will provide predictive capability and can aid in optimization of the field injection projects. The objective of this paper is not to compare the computational efficiency and solution algorithms; it only focuses on the process modeling comparison.

  8. ON-LINE DOCUMENTS CONTENT MANAGEMENT

    Directory of Open Access Journals (Sweden)

    VASILESCU RAMONA VIOLETA

    2010-05-01

    Full Text Available This paper outlines the steps and technologies used in developing an on-line application server with many desktop clients, and with high power processing for a wide range of input documents to obtain searchable documents on the highest portability standards, PDF and PDF /A.

  9. Radiation chemical study on benzaldehyde-chlorobenzene system. A novel radiation chemical route for benzophenone formation

    Energy Technology Data Exchange (ETDEWEB)

    Sife-Eldeen, Kh.A. [National Center for Radiation Research and Technology, Nasr City, Cairo (Egypt)

    2009-07-01

    The effects of reactants molar ratio, absorbed dose, and absorbed dose rate were studied on benzaldehyde-chlorobenzene system. Irradiation products were identified by GC/MS analysis and their quantities were determined by GC analysis. Study of the reactants molar ratio effect indicates important aspects of the radiation chemistry of this system. It was observed that the yields of the major products increase as absorbed dose increase. On the other hand, these yields decrease as dose rate increases. Which reflects that the major products are formed via inter-spur reactions i.e. in the bulk of the medium. The mechanisms of the formation of the products were suggested. Benzophenone is one of the main products of this system. Therefore, this study gives a spot of light on a novel radiation chemical route for benzophenone formation. The radiation chemical yield (G-value) of benzophenone was determined at different dose rates. (orig.)

  10. [The development of acetylene on-line monitoring technology based on laser absorption spectrum].

    Science.gov (United States)

    He, Ying; Zhang, Yu-jun; Kan, Rui-feng; Xia, Hui; Wang, Min; Cui, Xiao-juan; Chen, Jiu-ying; Chen, Dong; Liu, Wen-qing; Liu, Jian-guo

    2008-10-01

    As one of the materials in organic chemical industry, acetylene has been used in many aspects of chemical industry. But acetylene is a very dangerous inflammable and explosive gas, so it needs in-situ monitoring during industrial storage and production. Tunable diode laser absorption spectroscopy (TDLAS) technology has been widely used in atmospheric trace gases detection, because it has a lot of advantageous characteristics, such as high sensitivity, good selectivity, and rapid time response. The distribution characteristics of absorption lines of acetylene in near infrared band were studied, and then the system designing scheme of acetylene on-line monitoring based on near infrared tunable diode laser absorption spectroscopy technology was discussed in detail. Moreover, the system of experiment measurement was set up and the method of signal detection and the algorithm of concentration inversion were studied. In addition, the sample cell with a path length of 10 cm, and the acetylene of different known concentrations were measured. As a result, the detection limit obtained reached 1.46 cm3 x m(-3). Finally the dynamic detection experiment was carried out, and the measurement result is stable and reliable, so the design of the system is practicable through experiment analysis. On-line acetylene leakage monitoring system was developed based on the experiment, and it is suitable for giving a leakage alarm of acetylene during its storage, transportation and use.

  11. A novel microwave sensor to determine particulate blend composition on-line.

    Science.gov (United States)

    Austin, John; Gupta, Anshu; McDonnell, Ryan; Reklaitis, Gintaras V; Harris, Michael T

    2014-03-28

    Due to the ease with which particulate blends tend to segregate, blend uniformity and chemical composition are two critical control parameters in nearly all solids manufacturing industries. The prevailing wisdom has been that microwave sensors are not capable of or sensitive enough to measure the relative concentrations of components in a blend. Consequently, it is common to turn to near infrared sensing to determine material composition on-line. In this study, a novel microwave sensor was designed and utilized to determine, separately, the concentrations of different components in a blend of microcrystalline cellulose, acetaminophen, and water. This custom microwave sensor was shown to have comparable accuracy to a commercial NIR probe for both chemical composition and moisture content determination. Copyright © 2014 Elsevier B.V. All rights reserved.

  12. Chemical properties and morphology of Marine Aerosol in the Mediterranean atmosphere: a mesocosm study

    Science.gov (United States)

    D'Anna, Barbara; Sellegri, Karine; Charrière, Bruno; Sempéré, Richard; Mas, Sébastien; Marchand, Nicolas; George, Christian; Même, Aurèlie; R'mili, Badr; Delmont, Anne; Schwier, Allison; Rose, Clémence; Colomb, Aurèlie; Pey, Jorge; Langley Dewitt, Helen

    2014-05-01

    The Mediterranean Sea is a special marine environment characterized by low biological activity and high anthropogenic pressure. It is often difficult to discriminate the contribution of Primary Sea Salt Aerosol formed at the sea surface from background level of the aerosol. An alternative tool to study the sea-air exchanges in a controlled environment is provided by the mesocosms, which represent an important link between field studies and laboratory experiments. The sea-air transfer of particles and gases was investigated in relation to water chemical composition and biological activity during a mesocosm experiment within the SAM project (Sources of marine Aerosol in the Mediterranean) at the Oceanographic and Marine Station STARESO in Western Corsica (May 2013). Three 2 m mesocosms were filled with screened (treatments: one was left unchanged as control and two were enriched by addition of nitrates and phosphates respecting Redfield ratio (N:P = 16). The evolution of the three systems was followed for 20 days. The set of sensors in each mesocosm was allowed to monitor, at high frequency (every 10 min), the water temperature, conductivity, pH, incident light, fluorescence of chlorophyll a and dissolved oxygen concentration. The mesocosm seawaters were daily sampled for chemical (colored dissolved organic matter, particulate matter and related polar compounds, transparent polysaccharides and nutrients concentration) and biological (chlorophyll a, virus, phytoplankton and zooplankton) analyses. Both dissolved and gaseous VOCs were also analyzed. In addition, few liters of seawater from each mesocosm were daily and immediately collected and transferred to a bubble-bursting apparatus to simulate nascent sea spray aerosol. On-line chemical analysis of the sub-micrometer fraction was performed by a TOF-AMS (Aerodyne). Off-line analysis included TEM-EDX for morphology and size distribution studies and a hybrid quadrupole-orbitrap mass spectrometer (Thermo Fischer) for

  13. Chemiluminescence determination of cefotaxime sodium with flow-injection analysis of cerium (IV)-rhodamine 6G system and its application to the binding study of cefotaxime sodium to protein with on-line microdialysis sampling

    Science.gov (United States)

    Chen, Dinglong; Wang, Huiying; Zhang, Zhujun; Ci, Lijie; Zhang, Xuehong

    2011-01-01

    A simple, sensitive and rapid flow-injection chemiluminescence (CL) method has been developed for the determination of cefotaxime sodium based on the chemiluminescence reaction of cefotaxime sodium with ceric sulfate and rhodamine 6G in nitric acid solution. The concentration of cefotaxime sodium was proportional with the CL intensity in the range of 4 × 10 -8 - 8 × 10 -6 mol L -1. The detection limit (signal-to-noise ratio = 3) was 1 × 10 -8 mol L -1. Coupled to the technique of on-line microdialysis sampling, this method was successfully applied to study cefotaxime sodium-protein interaction. The drug and protein were mixed in different molar ratios in Ringer's solution, pH 7.4, and incubated at 37 °C in a water bath. The microdialysis probe was utilized to sample the mixed solution at a perfusion rate of 5 μL min -1 and the recovery of cefotaxime sodium under experimental condition was 16.2%. The data obtained by the present Microdialysis-Flow Injection Analysis-CL method was analyzed with the Scatchard analysis and Klotz plot. The estimated association constant ( K) and the number of the binding sites ( n) on one of BSA molecule were 5.94 × 10 4 M -1 and 1.29 (Klotz equation), respectively.

  14. On-Line NDE for Advanced Reactor Designs

    Science.gov (United States)

    Nakagawa, N.; Inanc, F.; Thompson, R. B.; Junker, W. R.; Ruddy, F. H.; Beatty, J. M.; Arlia, N. G.

    2003-03-01

    This expository paper introduces the concept of on-line sensor methodologies for monitoring the integrity of components in next generation power systems, and explains general benefits of the approach, while describing early conceptual developments of suitable NDE methodologies. The paper first explains the philosophy behind this approach (i.e. the design-for-inspectability concept). Specifically, we describe where and how decades of accumulated knowledge and experience in nuclear power system maintenance are utilized in Generation IV power system designs, as the designs are being actively developed, in order to advance their safety and economy. Second, we explain that Generation IV reactor design features call for the replacement of the current outage-based maintenance by on-line inspection and monitoring. Third, the model-based approach toward design and performance optimization of on-line sensor systems, using electromagnetic, ultrasonic, and radiation detectors, will be explained. Fourth, general types of NDE inspections that are considered amenable to on-line health monitoring will be listed. Fifth, we will describe specific modeling developments to be used for radiography, EMAT UT, and EC detector design studies.

  15. New Trends in on-line Marketing

    OpenAIRE

    Palkovič, Lukáš

    2011-01-01

    This bachelor thesis deals with new trend of internet marketing, it focuses especially on viral marketing. The theoretical part charasterizes the process of viral campaigns, furthermore deals with the components and aspects of on-line environment. Another separated chapter presents social networks, their place in viral marketing and at last but not least the viral video making process. The practical part contains different analyses of specific viral campaigns. The next and equally the last pa...

  16. Connecting to On-line Data

    Science.gov (United States)

    Eichhorn, G.; Astrophysics Datacenter Executive Committee (ADEC)

    2004-05-01

    The Astrophysics Datacenter Executive Committee (ADEC) is coordinating the development of a system to facilitate the linking to on-line data. This system has three components: 1. Unique dataset identifiers. 2. A verification system for identifiers. 3. Permanent links to on-line data sets. 1. The ADEC has agreed on a naming scheme for data sets that allows for the unique identification of any data set. The ADEC data centers will clearly mark their data with these identifiers to allow the generation of links to these data. 2. Each data center has a utility that can check whether a data set identifier is a valid identifier at that center. A central verifier allows third parties access to these individual verifiers through a single portal. 3. The central verifier also provides permanent links to data sets through a central link forwarding system. This makes it possible to move data sets between data centers while maintaining the permanent links. The ADEC plans to first use this system to implement the linking from the literature to on-line data in a collaboration with the AAS and the University of Chicago Press for the AAS journals.

  17. Chemical studies on hot springs in Ehime Prefecture

    Energy Technology Data Exchange (ETDEWEB)

    Mitarai, K. (Ehime Prefecture Research Institute of Public Health, Japan)

    1971-12-01

    One hundred and twenty-seven hot springs in Ehime Prefecture, which are primarily located in the Dogo area, were studied. The waters were subjected to chemical analysis and the springs were surveyed in-situ for hydrogen ion concentration, total soluble component, temperature, and F ion concentration. About 80% of the springs were slightly alkaline and the major soluble component was NaHCO/sub 3/ or NaCl. Fifty percent of the springs contained more than 2 ppm of F ion. The chemical components were closely related to area geology.

  18. [Studies on chemical constituents of leaves of Cassia angustifolia].

    Science.gov (United States)

    He, Wen-fei; Lu, Jin-cai; Yu, Xiao-min; Ding, You-mei

    2007-09-01

    To study the chemical constituents of the leaves of Cassia angustifolia Vahl. Solvents extraction and various chromatographic methods were applied to separate and purify its constituents. The structures were elucidated on the basis of chemical evidence and spectral analysis. Six compounds were obtained and identified as cholesterol (I), kampferol-3-rutinoside (II), calyxanthone (III), 3-methoxy-4-hydroxy-benzoic acid (IV), p-dimethylaminobenzaldehyde (V), 3,4-dihydroxybenzoic acid (VI). Six compounds ( I -VI) are obtained from this plant for the first time.

  19. Chemical Reactivity Theory Study of Advanced Glycation Endproduct Inhibitors.

    Science.gov (United States)

    Frau, Juan; Glossman-Mitnik, Daniel

    2017-02-02

    Several compounds with the known ability to perform as inhibitors of advanced glycation endproducts (AGE) have been studied with Density Functional Theory (DFT) through the use of anumberofdensityfunctionalswhoseaccuracyhasbeentestedacrossabroadspectrumofdatabases in Chemistry and Physics. The chemical reactivity descriptors for these systems have been calculated through Conceptual DFT in an attempt to relate their intrinsic chemical reactivity with the ability to inhibit the action of glycating carbonyl compounds on amino acids and proteins. This knowledge could be useful in the design and development of new drugs which can be potential medicines for diabetes and Alzheimer's disease.

  20. [Scanning electron microscope study of chemically disinfected endodontic files].

    Science.gov (United States)

    Navarro, G; Mateos, M; Navarro, J L; Canalda, C

    1991-01-01

    Forty stainless steel endodontic files were observed at scanning electron microscopy after being subjected to ten disinfection cycles of 10 minutes each one, immersed in different chemical disinfectants. Corrosion was not observed on the surface of the files in circumstances that this study was made.

  1. Comparative Studies of Physico-chemical Properties of Some ...

    African Journals Online (AJOL)

    Akorede

    ABSTRACT: The aim of this study was to evaluate some physico-chemical properties of four major general purpose ... In the year 2006 alone, four cases of such collapses .... (ASTM, 1986). The percentage SiO2 was calculated using. Eqn (11).

  2. Preliminary study of chemical compositional data from Amazon ceramics

    Energy Technology Data Exchange (ETDEWEB)

    Toyota, Rosimeiri G.; Munita, Casimiro S.; Luz, Fabio A. [Instituto de Pesquisas Energeticas e Nucleares (IPEN), Sao Paulo, SP (Brazil)]. E-mail: rosimeiritoy@yahoo.com.br; Neves, Eduardo G. [Museu de Arqueologia e Etnolgia, Sao Paulo, SP (Brazil)]. E-mail: egneves@usp.br; Oliveira, Paulo M.S. [Sao Paulo Univ., SP (Brazil). Escola Politecnica. Inst. de Matematica e Estatistica]. E-mail: poliver@usp.br

    2005-07-01

    Eighty seven ceramic samples from Acutuba, Lago Grande and Osvaldo archaeological sites located in the confluence of the rivers Negro and Solimoes were submitted to chemical analysis using instrumental neutron activation analysis to determine As, Ba, Ce, Co, Cr, Cs, Eu, Fe, Hf, K, La, Lu, Rb, Na, Nd, Sb, Sc, Sm, Ta, Tb, Th, Yb, Zn, and U. The database were studied using the Mahalanobis distance, and discriminant analysis. The results showed that the ceramics of each site differ from each other in chemical composition and that they form three different groups. Chemical classification of the ceramics suggests that vessels were made locally, as only ceramics from the same area show homogeneity of data. (author)

  3. Studying chemical reactions in biological systems with MBN Explorer

    DEFF Research Database (Denmark)

    Sushko, Gennady B.; Solov'yov, Ilia A.; Verkhovtsev, Alexey V.

    2016-01-01

    The concept of molecular mechanics force field has been widely accepted nowadays for studying various processes in biomolecular systems. In this paper, we suggest a modification for the standard CHARMM force field that permits simulations of systems with dynamically changing molecular topologies....... for studying processes where rupture of chemical bonds plays an essential role, e.g., in irradiation- or collision-induced damage, and also in transformation and fragmentation processes involving biomolecular systems....

  4. On-line solid-phase extraction coupled with high-performance liquid chromatography and tandem mass spectrometry (SPE-HPLC-MS-MS) for quantification of bromazepam in human plasma: an automated method for bioequivalence studies.

    Science.gov (United States)

    Gonçalves, José Carlos Saraiva; Monteiro, Tânia Maria; Neves, Claúdia Silvana de Miranda; Gram, Karla Regina da Silva; Volpato, Nádia Maria; Silva, Vivian A; Caminha, Ricardo; Gonçalves, Maria do Rocio Bencke; Santos, Fábio Monteiro Dos; Silveira, Gabriel Estolano da; Noël, François

    2005-10-01

    A validated method for on-line solid-phase extraction coupled with high-performance liquid chromatography tandem mass spectrometry (SPE-HPLC-MS-MS) is described for the quantification of bromazepam in human plasma. The method involves a dilution of 300 muL of plasma with 100 muL of carbamazepine (2.5 ng/mL), used as internal standard, vortex-mixing, centrifugation, and injection of 100 muL of the supernate. The analytes were ionized using positive electrospray mass spectrometry then detected by multiple reaction monitoring (MRM). The m/z transitions 316-->182 (bromazepam) and 237-->194 (carbamazepine) were used for quantification. The calibration curve was linear from 1 ng/mL (limit of quantification) to 200 ng/mL. The retention times of bromazepam and carbamazepine were 2.6 and 3.2 minutes, respectively. The intraday and interday precisions were 3.43%-15.45% and 5.2%-17%, respectively. The intraday and interday accuracy was 94.00%-103.94%. This new automated method has been successfully applied in a bioequivalence study of 2 tablet formulations of 6 mg bromazepam: Lexotan(R) from Produtos Roche Químicos e Farmacêuticos SA, Rio de Janeiro, Brazil (reference) and test formulation from Laboratórios Biosintética Ltda, São Paulo, Brazil. Because the 90% CI of geometric mean ratios between reference and test were completely included in the 80%-125% interval, the 2 formulations were considered bioequivalent. The comparison of different experimental conditions for establishing a dissolution profile in vitro along with our bioavailability data further allowed us to propose rationally based experimental conditions for a dissolution test of bromazepam tablets, actually lacking a pharmacopeial monograph.

  5. On-line Ramsey Numbers for Paths and Stars

    Directory of Open Access Journals (Sweden)

    Jaroslaw Grytczuk

    2008-08-01

    Full Text Available We study on-line version of size-Ramsey numbers of graphs defined via a game played between Builder and Painter: in one round Builder joins two vertices by an edge and Painter paints it red or blue. The goal of Builder is to force Painter to create a monochromatic copy of a fixed graph H in as few rounds as possible. The minimum number of rounds (assuming both players play perfectly is the on-line Ramsey number r(H of the graph H. We determine exact values of r(H for a few short paths and obtain a general upper bound r(Pn ≤ 4n-7. We also study asymmetric version of this parameter when one of the target graphs is a star Sn with n edges. We prove that r(Sn,H≤n ·e(H when H is any tree, cycle or clique.

  6. Total on-line purchasing system (TOPS)

    Energy Technology Data Exchange (ETDEWEB)

    Collins, N.

    1995-11-01

    The Information Management Division (IMD) at LLNL is developing a new purchasing system for the Procurement Department. The first major development of this new system is called, {open_quotes}Total On-Line Purchasing System{close_quotes} (TOPS). TOPS will help speed up the requisitioning process by having requisitions electronically entered by requesters and electronically sent to buyers to be put on Purchase Orders. The new purchasing system will use Electronic Commerce (EC)/Electronic Data Interchange (EDI), to help increase transaction flows for shipping notices, RFQs, Quotes, Purchase Orders, and Invoices. ANSI X.12 is the EDI standard that this new EC will use.

  7. Interlocuções e saberes docentes em interações on-line: um estudo de caso com professores de matemática Teachers' interlocution and knowledge in online interactions: a case study with mathematics teachers

    Directory of Open Access Journals (Sweden)

    Marcelo A. Bairral

    2013-04-01

    Full Text Available Integrando matemática, educação, comunicação, TIC e ciência cognitiva, este artigo é resultado de um projeto de pesquisa em Educação Matemática que, através de estudos empíricos, tem como objetivo analisar situações cognitivas e condições pedagógicas que favoreçam a aprendizagem em ambientes virtuais. O enquadramento teórico da investigação é baseado em estudos sobre aprendizagem matemática que combinam a comunicação e o pensamento, bem como as interações e as interlocuções. Aqui analisamos reflexões on-line entre os professores de Matemática dentro de um ambiente chamado Virtual Math Teams (VMT, colaborando para resolver um problema de geometria do táxi. Ilustramos diferentes tipos de interlocução (informativa, negociativa, avaliativa e interpretativa, bem como domínios de conhecimentos (epistemologia, didática e mediação identificados com o conhecimento profissional dos professores. Nossos resultados indicam que interlocuções interpretativas e negociativas têm maior potencial para aprimorar o pensamento matemático dos interlocutores. O estudo também destaca que, por meio da identificação e da análise de propriedades de interlocução, os pesquisadores podem obter insights sobre o conhecimento profissional dos professores.Integrating mathematics, education, communication, ICT, and cognitive science, this study is the result of a research program in mathematics education that aims to analyze cognitive situations and pedagogic conditions, through empirical studies, that favor learning in virtual environments. The theoretical framework of the investigation is based on studies of mathematics learning that combine communication and thought as well as interactions and interlocutions. In this article, we analyze interactions among mathematics teachers who interact online within an environment, called Virtual Math Teams (VMT, collaborating to solve a problem in taxicab geometry. We illustrate different

  8. Communicating serum chemical concentrations to study participants: follow up survey

    Directory of Open Access Journals (Sweden)

    Louis Germaine M

    2010-05-01

    Full Text Available Abstract Background A considerable literature now supports the importance of effective communication with study participants, including how best to develop communication plans focusing on the uncertainty of health risks associated with particular environmental exposures. Strategies for communicating individual concentrations of environmental chemicals in human biological samples in the absence of clearly established safe or hazardous levels have been discussed from a conceptual basis and to a lesser extent from an empirical basis. We designed and evaluated an empirically based communication strategy for women of reproductive age who previously participated in a prospective study focusing on persistent environmental chemicals and reproductive outcomes. Methods A cohort of women followed from preconception through pregnancy or up to 12 menstrual cycles without pregnancy was given their individual serum concentrations for lead, dichloro-2,2-bisp-chlorophenyl ethylene, and select polychlorinated biphenyl congeners. Two versions of standardized letters were prepared depending upon women's exposure status, which was characterized as low or high. Letters included an introduction, individual concentrations, population reference values and guidance for minimizing future exposures. Participants were actively monitored for any questions or concerns following receipt of letters. Results Ninety-eight women were sent letters informing them of their individual concentrations to select study chemicals. None of the 89 (91% participating women irrespective of exposure status contacted the research team with questions or concerns about communicated exposures despite an invitation to do so. Conclusions Our findings suggest that study participants can be informed about their individual serum concentrations without generating unnecessary concern.

  9. Quantum-chemical studies of metal oxides for photoelectrochemical applications

    Science.gov (United States)

    Persson, P.; Bergström, R.; Ojamäe, L.; Lunell, S.

    A review of recent research, as well as new results, are presented on transition metal oxide clusters, surfaces, and crystals. Quantum-chemical calculations of clusters of first row transition metal oxides have been made to evaluate the accuracy of ab initio and density functional calculations. Adsorbates on metal oxide surfaces have been studied with both ab initio and semi-empirical methods, and results are presented for the bonding and electronic interactions of large organic adsorbates, e.g. aromatic molecules, on Ti02 and ZnO. Defects and intercalation, notably of H, Li, and Na in Ti02 have been investigated theoretically. Comparisons with experiments are made throughout to validate the calculations. Finally, the role of quantum-chemical calculations in the study of metal oxide based photoelectrochemical devices, such as dyesensitized solar cells and electrochromic displays. is discussed.

  10. On-line and Mobil Learning Activities

    Science.gov (United States)

    Ackerman, S. A.; Whittaker, T. M.; Jasmin, T.; Mooney, M. E.

    2012-12-01

    Introductory college-level science courses for non-majors are critical gateways to imparting not only discipline-specific information, but also the basics of the scientific method and how science influences society. They are also indispensable for student success to degree. On-line, web-based homework (whether on computers or mobile devices) is a rapidly growing use of the Internet and is becoming a major component of instruction in science, replacing delayed feedback from a few major exams. Web delivery and grading of traditional textbook-type questions is equally effective as having students write them out for hand grading, as measured by student performance on conceptual and problem solving exams. During this presentation we will demonstrate some of the interactive on-line activities used to teach concepts and how scientists approach problem solving, and how these activities have impacted student learning. Evaluation of the activities, including formative and summative, will be discussed and provide evidence that these interactive activities significantly enhance understanding of introductory meteorological concepts in a college-level science course. More advanced interactive activities are also used in our courses for department majors, some of these will be discussed and demonstrated. Bring your mobile devices to play along! Here is an example on teaching contouring: http://profhorn.aos.wisc.edu/wxwise/contour/index.html

  11. Study of interfacial phenomena for bio/chemical sensing applications

    Science.gov (United States)

    Min, Hwall

    This work presents the fundamental study of biological and chemical interfacial phenomena and (bio)chemical sensing applications using high frequency resonator arrays. To realize a versatile (bio)chemical sensing system for the fundamental study as well as their practical applications, the following three distinct components were studied and developed: i) detection platforms with high sensitivity, ii) novel innovative sensing materials with high selectivity, iii) analytical model for data interpretation. 8-pixel micromachined quartz crystal resonator (muQCR) arrays with a fundamental resonance frequency of 60 ¡V 90 MHz have been used to provide a reliable detection platform with high sensitivity. Room temperature ionic liquid (RTIL) has been explored and integrated into the sensing system as a smart chemical sensing material. The use of nanoporous gold (np-Au) enables the combination of the resonator and surface-enhanced Raman spectroscopy for both quantitative and qualitative measurement. A statistical model for the characterization of resonator behavior to study the protein adsorption kinetics is developed by random sequential adsorption (RSA) approach with the integration of an effective surface depletion theory. The investigation of the adsorption kinetics of blood proteins is reported as the fundamental study of biological phenomena using the proposed sensing system. The aim of this work is to study different aspects of protein adsorption and kinetics of adsorption process with blood proteins on different surfaces. We specifically focus on surface depletion effect in conjunction with the RSA model to explain the observed adsorption isotherm characteristics. A number of case studies on protein adsorption conducted using the proposed sensing system has been discussed. Effort is specifically made to understand adsorption kinetics, and the effect of surface on the adsorption process as well as the properties of the adsorbed protein layer. The second half of the

  12. Chemical elements in invertebrate orders for environmental quality studies

    Energy Technology Data Exchange (ETDEWEB)

    Magalhaes, Marcelo R.L.; Franca, Elvis J.; Paiva, Jose D.S.; Hazin, Clovis A., E-mail: marcelo_rlm@hotmail.com, E-mail: ejfranca@cnen.gov.br, E-mail: dan-paiva@hotmail.com, E-mail: chazin@cnen.gov.br [Centro Regional de Ciencias Nucleares do Nordeste (CRCN-NE/CNEN-PE), Recife, PE (Brazil); Fonseca, Felipe Y.; Fernandes, Elisabete A. de Nadai; Bacchi, Marcio A., E-mail: felipe-yamada@hotmail.com, E-mail: lis@cena.usp.br, E-mail: mabacchi@cena.usp.br [Centro de Energia Nuclear na Agricultura (CENA/USP), Piracicaba, SP (Brazil)

    2013-07-01

    Among the biomonitors of environmental quality, there is a lack of studies on using invertebrates to evaluate quantitatively chemical elements in ecosystems. This group of animals is quite numerous, widely distributed and adaptable to the most diverse environmental conditions. These features are very useful for the environmental quality assessment, as well as the several occurring insect-plant interactions performing essential functions in ecosystems. The objective of this work is to study the variability of chemical composition of invertebrate orders for using in environmental quality monitoring studies. Instrumental neutron activation analysis - INAA was applied to determine some nutrients and trace elements in invertebrate samples. Sampling by pitfall traps was carried out in riverine ecosystems from the urban area from the Piracicaba Municipality, State of Sao Paulo, Brazil. Invertebrate and reference material samples were irradiated in the nuclear research reactor IEA-R1, Instituto de Pesquisas Energeticas e Nucleares - IPEN/CNEN. Fragments of a Ni-Cr alloy were irradiated for monitoring the thermal neutron flux. Hymenoptera order was considered the most representative according to the total number of sampled species (about 60%). Significant amounts of Ba, Br, Fe and Sc were found in invertebrates of the order Opiliones. Potassium, rubidium and zinc were highly accumulated in species from Blattodea order, indicating a consistent pattern of accumulation for this invertebrate order. Taking into account the abundance of Hymenoptera order, the chemical composition of its species was significant different at the 95% confidence level for Br and Na in the sampled locals. (author)

  13. On-line Measuring Method for Shell Chamber Volume

    Institute of Scientific and Technical Information of China (English)

    ZHANG Li-zhong; WANG De-min; JIANG Tao; CAO Guo-hua; WANG Qi

    2005-01-01

    Using the ideal gas state equation, an on-line measuring method for the shell chamber volume is studied in this paper. After analyzing how various measurement parameters affect the measurement accuracy, the system parameters are optimized in this method. Because the shape and volume of the tested items are similar, the method of using "tamping" to raise the accuracy and speed of the measurement is put forward. Based on the work above, a prototype of the testing instrument for shell chamber volume was developed, automatically testing and controlling. Compared with the method of "water weight", this method is more accurate, quicker and more automotive, so it is adaptable for the use of on-line detection.

  14. On-line Dynamic Security Assessment in Power Systems

    DEFF Research Database (Denmark)

    Weckesser, Johannes Tilman Gabriel

    tools may no longer be feasible, since they are generally based on extensive off-line studies. A core component of an efficient on-line dynamic security assessment is a fast and reliable contingency screening. As part of this thesis a contingency screening method is developed and its performance......The thesis concerns the development of tools and methods for on-line dynamic security assessment (DSA). In a future power system with low-dependence or even independence of fossil fuels, generation will be based to a large extent on noncontrollable renewable energy sources (RES), such as wind...... and solar radiation. Moreover, ongoing research suggests that demand response will be introduced to maintain power balance between generation and consumption at all times. Due to these changes the operating point of the power system will be less predictable and today’s stability and security assessment...

  15. Fractal groups: Emergent dynamics in on-line learning communities

    Directory of Open Access Journals (Sweden)

    Junia de Carvalho Fidelis Braga

    Full Text Available Drawing on complexity theory, this work discusses the complex dynamics and emergent patterns of on-line learning communities based on a doctoral study in the area of Applied Linguistics. The analysis will center on the interlocutions of fifty students who interacted in small groups without the teacher's direct intervention, in an undergraduate course offered by the School of Languages and Literature at the Federal University of Minas Gerais. By analyzing the data, I demonstrate that out of the interactions among the peers of autonomous on-line learning communities arise opportunities for the construction of shared meaning, distributed leadership, as well as other dynamics. I also demonstrate the fractal nature of these communities. Moreover, I discuss how these findings shed light on the creation and development of course designs for large groups.

  16. Escapist Motives for Playing On-Line Games

    DEFF Research Database (Denmark)

    Sudzina, Frantisek; Razmerita, Liana

    , Harteveld and Mayer’s framework (2009) of escapist motives, which identifies four main motives for playing on-line games: mundane breaking, stress relieving, pleasure seeking, and imagination conjuring. In the paper, we report preliminary findings from an exploratory questionnaire survey. Besides importance...... of escapist motives for playing Facebook and other on-line games, we investigate how they are linked to demographic data such as: age, gender, place of origin, along with other social interactions patterns and social network usage behavior, current gaming status and an estimate of gaming time. According......Social games have become popular along with the tremendous growth of social networking sites, esp. Facebook. There is a gap in literature on what motivates people to play Facebook games. This paper studies social games usage behavior of students. We focus on escapist reasons, based on Warmelink...

  17. The chemical shock tube as a tool for studying high-temperature chemical kinetics

    Science.gov (United States)

    Brabbs, Theodore A.

    1986-01-01

    Although the combustion of hydrocarbons is our primary source of energy today, the chemical reactions, or pathway, by which even the simplest hydro-carbon reacts with atmospheric oxygen to form CO2 and water may not always be known. Furthermore, even when the reaction pathway is known, the reaction rates are always under discussion. The shock tube has been an important and unique tool for building a data base of reaction rates important in the combustion of hydrocarbon fuels. The ability of a shock wave to bring the gas sample to reaction conditions rapidly and homogeneously makes shock-tube studies of reaction kinetics extremely attractive. In addition to the control and uniformity of reaction conditions achieved with shock-wave methods, shock compression can produce gas temperatures far in excess of those in conventional reactors. Argon can be heated to well over 10 000 K, and temperatures around 5000 K are easily obtained with conventional shock-tube techniques. Experiments have proven the validity of shock-wave theory; thus, reaction temperatures and pressures can be calculated from a measurement of the incident shock velocity. A description is given of the chemical shock tube and auxiliary equipment and of two examples of kinetic experiments conducted in a shock tube.

  18. Internet Teaching By Style: Profiling the On-line Professor

    Directory of Open Access Journals (Sweden)

    Sharon Strand

    2000-01-01

    Full Text Available The goal of this article is to offer the results of a pilot study which examined the personality type and teaching style preferences of faculty who elected to teach an on-line course. The article will present a description of personality assessments, including the Myers-Briggs Type Indicator (MBTI and Anthony Gregorc's Transaction Ability Inventory used to determine teaching tendencies and styles. In addition, a structured written questionnaire developed by the researchers was used to assess teacher satisfaction with worldwide web-based instruction. Utilizing the results of these psychological assessments, a preliminary analysis of the personal characteristics of college professors who chose to teach on line will be presented. This pilot study found that some preferred teaching styles may be more compatible with the dynamics of distance learning formats. By determining successful teaching styles for on-line courses, we can develop more effective faculty development programs to assist others in successfully transitioning into the cyber-teaching and learning environment.

  19. NATO Advanced Study Institute on Advances in Chemical Reaction Dynamics

    CERN Document Server

    Capellos, Christos

    1986-01-01

    This book contains the formal lectures and contributed papers presented at the NATO Advanced Study Institute on. the Advances in Chemical Reaction Dynamics. The meeting convened at the city of Iraklion, Crete, Greece on 25 August 1985 and continued to 7 September 1985. The material presented describes the fundamental and recent advances in experimental and theoretical aspects of, reaction dynamics. A large section is devoted to electronically excited states, ionic species, and free radicals, relevant to chemical sys­ tems. In addition recent advances in gas phase polymerization, formation of clusters, and energy release processes in energetic materials were presented. Selected papers deal with topics such as the dynamics of electric field effects in low polar solutions, high electric field perturbations and relaxation of dipole equilibria, correlation in picosecond/laser pulse scattering, and applications to fast reaction dynamics. Picosecond transient Raman spectroscopy which has been used for the elucidati...

  20. [Studies on the chemical constituents of Rumex crispus].

    Science.gov (United States)

    Fan, Ji-ping; Zhang, Zhen-liang

    2009-12-01

    To study the chemical constituents of Rumex crispus. Compounds were isolated and purified repeatedly by silica gel, Sephadex gel and ODS C18 column chromatographies, and structure identifications of compounds were carried out by physical, chemical methods and spectral data. Fifteen compounds were obtained from the petroleum ether and ethyl acetate fractions of R. crispus, and were identified as beta-sitosterol(1), hexadecanoic acid(2), hexadecanoic-2,3-dihydroxy propyleste(3), chrysophanol(4), physcion(5), emodin(6), chrysophanol-8-O-beta-D-glucopyranoside(7), physcion-8-O-beta-D-glucopyranoside(8), emodin-8O-beta-D-glucopyranoside(9), gallic acid(10), (+)-catechin(11), kaempferol(12), quercetin(13), kaempferol-3-O-alpha-L-rhamnopyranoside(14), quercetin-3-O-alpha-L-rhamnopyranoside(15). Compounds 3,8-12,14 and 15 are obtained from R. crispus for the first time.

  1. Chemical Approaches to Studying Labile Amino Acid Phosphorylation.

    Science.gov (United States)

    Marmelstein, Alan M; Moreno, Javier; Fiedler, Dorothea

    2017-04-01

    Phosphorylation of serine, threonine, and tyrosine residues is the archetypal posttranslational modification of proteins. While phosphorylation of these residues has become standard textbook knowledge, phosphorylation of other amino acid side chains is underappreciated and minimally characterized by comparison. This disparity is rooted in the relative instability of these chemically distinct amino acid side chain moieties, namely phosphoramidates, acyl phosphates, thiophosphates, and phosphoanhydrides. In the case of the O-phosphorylated amino acids, synthetic constructs were critical to assessing their stability and developing tools for their study. As the chemical biology community has become more aware of these alternative phosphorylation sites, methodology has been developed for the synthesis of well-characterized standards and close mimics of these phosphorylated amino acids as well. In this article, we review the synthetic chemistry that is a prerequisite to progress in this field.

  2. Spectroscopic and quantum chemical calculation study on 2-ethoxythiazole molecule

    Science.gov (United States)

    Avcı, Davut; Dede, Bülent; Bahçeli, Semiha; Varkal, Döndü

    2017-06-01

    In this study, the 2-ethoxythiazole molecule (C5H7NSO) which is a member of the five-membered heterocyles with one nitrogen atom group has been investigated by using the experimental UV-vis (in three different solvents) and FT-IR spectral results as well as some magnetic properties. Furthermore, the calculated molecular geometric parameters, vibrational wavenumbers, HOMO-LUMO energies, 1H and 13C NMR chemical shift values and natural bond orbitals (NBO) of the title molecule have been calculated at the B3LYP and HSEH1PBE levels of theory with the 6-311++G(d,p) basis set. The spectral results obtained from the quantum chemical calculations are in good agreement with the experimental results.

  3. Workers' perception of chemical risks: a focus group study.

    Science.gov (United States)

    Hambach, Ramona; Mairiaux, Philippe; François, Guido; Braeckman, Lutgart; Balsat, Alain; Van Hal, Guido; Vandoorne, Chantal; Van Royen, Paul; van Sprundel, Marc

    2011-02-01

    Workers' perceptions with respect to health and safety at work are rarely taken into account when considering the development of prevention programs. The aim of this study was to explore workers' perceptions of chemical risks at the workplace, in order to investigate the prerequisites for a workplace health program. A qualitative study was conducted involving seven focus groups of 5-10 participants (blue-collar workers) each. All groups were homogeneous in terms of sex, work status, language, and company membership. Results showed that several factors have an important influence on workers' perception of chemical risks. Workers assess risks by means of both sensory and empirical diagnosis and are concerned about the long-term health consequences. They perceive the threat of chemical risks as high. Despite this, they are resigned to accepting the risks. Existing formal sources of information are rarely consulted because they are judged to be difficult to understand and not user friendly. Instead, workers tend to obtain information from informal sources. Communication problems with and lack of trust in prevention advisers and hierarchy are frequently mentioned. Workers feel that their specific knowledge of their working conditions and their proposals for practical, cost-effective solutions to improve health and safety at the workplace are insufficiently taken into account. The use of focus groups yielded a useful insight into workers' perceptions of chemical risks. Our findings suggest that training programs for prevention advisers should include topics such as understanding of workers' perceptions, usefulness of a participatory approach, and communication and education skills. © 2010 Society for Risk Analysis.

  4. Review of trigger and on-line processors at SLAC

    Energy Technology Data Exchange (ETDEWEB)

    Lankford, A.J.

    1984-07-01

    The role of trigger and on-line processors in reducing data rates to manageable proportions in e/sup +/e/sup -/ physics experiments is defined not by high physics or background rates, but by the large event sizes of the general-purpose detectors employed. The rate of e/sup +/e/sup -/ annihilation is low, and backgrounds are not high; yet the number of physics processes which can be studied is vast and varied. This paper begins by briefly describing the role of trigger processors in the e/sup +/e/sup -/ context. The usual flow of the trigger decision process is illustrated with selected examples of SLAC trigger processing. The features are mentioned of triggering at the SLC and the trigger processing plans of the two SLC detectors: The Mark II and the SLD. The most common on-line processors at SLAC, the BADC, the SLAC Scanner Processor, the SLAC FASTBUS Controller, and the VAX CAMAC Channel, are discussed. Uses of the 168/E, 3081/E, and FASTBUS VAX processors are mentioned. The manner in which these processors are interfaced and the function they serve on line is described. Finally, the accelerator control system for the SLC is outlined. This paper is a survey in nature, and hence, relies heavily upon references to previous publications for detailed description of work mentioned here. 27 references, 9 figures, 1 table.

  5. Quantum Chemical Study on Reaction of Acetaldehyde with Hydroxyl Radical

    Institute of Scientific and Technical Information of China (English)

    LI,Ming(李明); ZHANG,Jin-Sheng(张金生); SHEN,Wei(申伟); MENG,Qing-Xi(孟庆喜)

    2004-01-01

    The reaction of acetaldehyde with hydroxyl radical was studied by means of quantum chemical methods. The geometries for all the stationary points on the potential energy surfaces were optimized fully, respectively, at the G3MP2, G3, and MP2/6-311++G(d,p) levels. Single-point energies of all the species were calculated at the QCISD/6-311 + +G(d,p) level. The mechanism of the reaction studied was confirmed. The predicted product is acetyl radical that is in agreement with the experiment.

  6. Aprender a innovar: una experiencia on line

    Directory of Open Access Journals (Sweden)

    Joaquín MORENO MARCHAL

    2014-11-01

    Full Text Available La creatividad y la innovación se han convertido en recursos clave en la denominada sociedad del conocimiento, que bien podría ser también llamada sociedad de la innovación. Pero innovar es una actividad compleja, que integra la aplicación de múltiples capacidades, el pensamiento divergente y convergente, la gestión de equipos humanos, la comunicación. Ahora bien, a innovar se puede, y se debe, aprender. Aprender a innovar es un reto y también una obligación para el conjunto del sistema educativo en todos sus niveles. Partiendo de estas consideraciones este trabajo expone una experiencia de aprendizaje de la creatividad y de la innovación a través de un curso totalmente on line basado en la plataforma MOODLE, en el marco del Programa de Formación Permanente de la Universidad de Cádiz. Se presenta un modelo del proceso de innovación, denominado CREALAB, de elaboración propia. Este modelo se ha utilizado como base del proceso de aprendizaje de la creatividad y de la innovación y en el diseño del curso, está organizado en torno a actividades y tiene un carácter iterativo y realimentado. Se presentan además el conjunto del diseño metodológico y los resultados obtenidos en las dos ediciones celebradas hasta el momento. El diseño del curso totalmente on line y los resultados alcanzados permiten estimar un alto potencial de aplicación, tanto a nivel personal como a nivel organizacional.

  7. Chemical functionalization of graphene via aryne cycloaddition: a theoretical study.

    Science.gov (United States)

    Zhao, Jing-xiang; Wang, Hong-xia; Gao, Bo; Wang, Xiao-guang; Cai, Qing-hai; Wang, Xuan-zhang

    2012-06-01

    Chemical functionalization of graphene provides a promising route to improve its solubility in water and organic solvents as well as modify its electronic properties, thus significantly expanding its potential applications. In this article, by using density functional theory (DFT) methods, we have studied the effects of the chemical functionalization of graphenes via aryne cycloaddition on its properties. We found that the adsorption of an isolated aryne group on the graphene sheet is very weak with the adsorption energy of -0.204 eV, even though two new single C-C interactions are formed between the aryne group and the graphene. However, the interaction of graphene with the aryne group can be greatly strengthened by (i) substituting the H-atoms in aryne group with F-, Cl-, -NO(2) (electron-withdrawing capability), or CH(3)-group (electron-donating capability), and (ii) increasing the coverage of the adsorbed aryne groups on the graphene sheet. As expected, the strongest bonding is found on the graphene edges, in which the adsorbed aryne groups prefer to be far away from each other. Interestingly, chemical functionalization with aryne groups leads to an opening of the band gap of graphene, which is dependent on the coverage of the adsorbed aryne groups. The present work provides an insight into the modifications of graphene with aryne groups in experiment.

  8. Relative influence of chemical and non-chemical stressors on invertebrate communities: a case study in the Danube River.

    Science.gov (United States)

    Rico, Andreu; Van den Brink, Paul J; Leitner, Patrick; Graf, Wolfram; Focks, Andreas

    2016-11-15

    A key challenge for the ecological risk assessment of chemicals has been to evaluate the relative contribution of chemical pollution to the variability observed in biological communities, as well as to identify multiple stressor groups. In this study we evaluated the toxic pressure exerted by >200 contaminants to benthic macroinvertebrates in the Danube River using the Toxic Unit approach. Furthermore, we evaluated correlations between several stressors (chemical and non-chemical) and biological indices commonly used for the ecological status assessment of aquatic ecosystems. We also performed several variation partitioning analyses to evaluate the relative contribution of contaminants and other abiotic parameters (i.e. habitat characteristics, hydromorphological alterations, water quality parameters) to the structural and biological trait variation of the invertebrate community. The results of this study show that most biological indices significantly correlate to parameters related to habitat and physico-chemical conditions, but showed limited correlation with the calculated toxic pressure. The calculated toxic pressure, however, showed little variation between sampling sites, which complicates the identification of pollution-induced effects. The results of this study show that the variation in the structure and trait composition of the invertebrate community are mainly explained by habitat and water quality parameters, whereas hydromorphological alterations play a less important role. Among the water quality parameters, physico-chemical parameters such as suspended solids, nutrients or dissolved oxygen explained a larger part of the variation in the invertebrate community as compared to metals or organic contaminants. Significant correlations exist between some physico-chemical measurements (e.g. nutrients) and some chemical classes (i.e. pharmaceuticals, chemicals related to human presence) which constitute important multiple stressor groups. This study

  9. [Study on the chemical constituents in Pouzolzia zeylanica].

    Science.gov (United States)

    Fu, Ming; Niu, You-Ya; Yu, Juan; Kong, Qing-Tong

    2012-11-01

    To study the chemical constituents of Pouzolzia zeylanica. Many chromatography means were used in separation and purification, and the structures of all compounds were identified by the means of spectroscopic analysis and physicochemical properties. 14 compounds were elucidated as: beta-sitosterol (1), daucosterol (2), oleanolic acid (3), epicatechin (4), alpha-amyrin (5), eugenyl-beta-rutinoside (6), 2alpha, 3alpha, 19alpha-trihydroxyurs-12-en-28-oic (7), scopolin (8), scutellarein-7-O-alpha-L-rhamnoside (9), scopoletin (10), quercetin (11), quercetin-3-O-beta-D-glucoside (12), apigenin (13), 2alpha-hydroxyursolic acid (14). All compounds are obtained from this plant for the first time.

  10. Studies on the Chemical Constituents and Bioactivities of Tripterygium Wilfordii

    Institute of Scientific and Technical Information of China (English)

    LI; YuanChao

    2001-01-01

    Tripterygium wilfordii Hook (TW) is a medicinal plant distributed widely in southern china. This plant was recently found to possess anti-inflammatory, antitumor and immunosuppressive activities. Some preparation of the plant root has been used for the treatment of rheumatoid arthritis, systemic acne rosacea, nephritis and some skin diseases. Chemical studies on this plant and its preparation have shown they contain a large number of sesquiterpenoid, diterpenoids, triterpenoids and alkaloids in which some diterpene triepoxy lactones such as triptolide and triptonide etc are considered as mainly active compounds.  ……

  11. Studies on the Chemical Constituents and Bioactivities of Tripterygium Wilfordii

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    @@ Tripterygium wilfordii Hook (TW) is a medicinal plant distributed widely in southern china. This plant was recently found to possess anti-inflammatory, antitumor and immunosuppressive activities. Some preparation of the plant root has been used for the treatment of rheumatoid arthritis, systemic acne rosacea, nephritis and some skin diseases. Chemical studies on this plant and its preparation have shown they contain a large number of sesquiterpenoid, diterpenoids, triterpenoids and alkaloids in which some diterpene triepoxy lactones such as triptolide and triptonide etc are considered as mainly active compounds.

  12. Solid-State NMR Studies of Chemically Lithiated CFx

    Science.gov (United States)

    Leifer, N. D.; Johnson, V. S.; Ben-Ari, R.; Gan, H.; Lehnes, J. M.; Guo, R.; Lu, W.; Muffoletto, B. C.; Reddy, T.; Stallworth, P. E.; Greenbaum, S. G.

    2010-01-01

    Three types of fluorinated carbon, all in their original form and upon sequential chemical lithiations via n-butyllithium, were investigated by 13C and 19F solid-state NMR methods. The three starting CFx materials [where x = 1 (nominally)] were fiber based, graphite based, and petroleum coke based. The aim of the current study was to identify, at the atomic/molecular structural level, factors that might account for differences in electrochemical performance among the different kinds of CFx. Differences were noted in the covalent F character among the starting compounds and in the details of LiF production among the lithiated samples. PMID:20676233

  13. Matrix isolation as a tool for studying interstellar chemical reactions

    Science.gov (United States)

    Ball, David W.; Ortman, Bryan J.; Hauge, Robert H.; Margrave, John L.

    1989-01-01

    Since the identification of the OH radical as an interstellar species, over 50 molecular species were identified as interstellar denizens. While identification of new species appears straightforward, an explanation for their mechanisms of formation is not. Most astronomers concede that large bodies like interstellar dust grains are necessary for adsorption of molecules and their energies of reactions, but many of the mechanistic steps are unknown and speculative. It is proposed that data from matrix isolation experiments involving the reactions of refractory materials (especially C, Si, and Fe atoms and clusters) with small molecules (mainly H2, H2O, CO, CO2) are particularly applicable to explaining mechanistic details of likely interstellar chemical reactions. In many cases, matrix isolation techniques are the sole method of studying such reactions; also in many cases, complexations and bond rearrangements yield molecules never before observed. The study of these reactions thus provides a logical basis for the mechanisms of interstellar reactions. A list of reactions is presented that would simulate interstellar chemical reactions. These reactions were studied using FTIR-matrix isolation techniques.

  14. A Distributed System for Learning Programming On-Line

    Science.gov (United States)

    Verdu, Elena; Regueras, Luisa M.; Verdu, Maria J.; Leal, Jose P.; de Castro, Juan P.; Queiros, Ricardo

    2012-01-01

    Several Web-based on-line judges or on-line programming trainers have been developed in order to allow students to train their programming skills. However, their pedagogical functionalities in the learning of programming have not been clearly defined. EduJudge is a project which aims to integrate the "UVA On-line Judge", an existing…

  15. 基于DSP和小波变换的电压暂态扰动在线监测方法研究%Study of voltage transient disturbance on-line detection based on DSP and wavelet transform

    Institute of Scientific and Technical Information of China (English)

    王飞; 黄细霞; 张兵; 骆秀江

    2015-01-01

    A voltage disturbance detection device based on DSP2812 is designed in this paper. A method of transient voltage disturbance detection based on DSP and wavelet transform is studied. The system takes a Hall sensor and the parallel A/D con⁃verter chip as its acquisition circuit,and a kind of digital signal processing chip TMS320F2812 as its core information process⁃ing unit,by which the design of DSP and its peripheral circuit are achieved. The discrete wavelet transform(DWT)is adopted to detect transient voltage disturbance on line and realize wavelet algorithm in DSP. Software modules including the main pro⁃gram module,A/D module,interrupt module,communication module and so on were designed. Its simulation experiment was performed in Matlab to choose suitable wavelet functions and to locate disturbance position by utilizing DB4 wavelet in Matlab. The signal generator is used to produce the signal including transient voltage disturbance. The power acquisition and real⁃time analysis of transient voltage disturbance can be realized simultaneously by the strong operation ability of DSP and the effective DWT algorithm. The contrast test shows that the system has high precision,high data processing speed and perfect capability for real⁃time detection of transient voltage disturbance.%设计了一款基于DSP2812的电压暂态扰动在线检测装置,研究了基于DSP和小波变换的电压暂态扰动在线检测方法。该装置通过霍尔传感器和模数转换芯片采集电信号,以高性能数字信号处理芯片TMS320F2812为核心信息处理单元,完成了DSP及其外围电路设计。采用小波变换在线检测电压暂态扰动,并在DSP中实现了小波算法,软件还包括主程序模块、A/D采集模块、中断模块、上位机处理模块和通讯模块等设计。实验首先在Matlab中进行了仿真实验,选取合适的小波函数,利用Matlab中的DB4小波对扰动进行定位;然后再利用信号发生

  16. Comparación del aprendizaje en internet con la clase convencional en estudiantes de medicina, en Argentina Comparative study between learning on line and traditional lectures for medical students in Argentina

    Directory of Open Access Journals (Sweden)

    Bogdan Mihai Popescu

    2005-12-01

    students of the Northeastern National University of Argentina. The first survey was a questionnaire of 20 items about DT. The students were then randomized to two groups: one assigned to traditional lecture, and another assigned to an online Forum about DT. The students were not aware of the study’s purpose. The same guidelines were provided to both groups. Duration of the lecture was 2 hours. The group working online was connected at the same time to the Web forum for 48h. 70 hours after the lecture and the on line exposure all students repeated the initial questionnaire. Results: 107 students were included (13 were excluded because they didn’t complete one of the questionnaires. The average performance of the lecture’s group was 8.30+/-2.48 points before, and 9.76+/- 2.17 after the educational intervention. In the Web program group it was 8.39 +/- 2.14 points initially, and 9.76 +/- 2.8 after. The p was >0.10 comparing the lectures and the internet groups. Conclusion: Learning a therapeutic subject by Argentinean students was equally as effective with Web based learning as with traditional lectures.

  17. Vibrational spectroscopic studies of Isoleucine by quantum chemical calculations.

    Science.gov (United States)

    Moorthi, P P; Gunasekaran, S; Ramkumaar, G R

    2014-04-24

    In this work, we reported a combined experimental and theoretical study on molecular structure, vibrational spectra and NBO analysis of Isoleucine (2-Amino-3-methylpentanoic acid). The optimized molecular structure, vibrational frequencies, corresponding vibrational assignments, thermodynamics properties, NBO analyses, NMR chemical shifts and ultraviolet-visible spectral interpretation of Isoleucine have been studied by performing MP2 and DFT/cc-pVDZ level of theory. The FTIR, FT-Raman spectra were recorded in the region 4000-400 cm(-1) and 3500-50 cm(-1) respectively. The UV-visible absorption spectra of the compound were recorded in the range of 200-800 nm. Computational calculations at MP2 and B3LYP level with basis set of cc-pVDZ is employed in complete assignments of Isoleucine molecule on the basis of the potential energy distribution (PED) of the vibrational modes, calculated using VEDA-4 program. The calculated wavenumbers are compared with the experimental values. The difference between the observed and calculated wavenumber values of most of the fundamentals is very small. (13)C and (1)H nuclear magnetic resonance chemical shifts of the molecule were calculated using the gauge independent atomic orbital (GIAO) method and compared with experimental results. The formation of hydrogen bond was investigated in terms of the charge density by the NBO calculations. Based on the UV spectra and TD-DFT calculations, the electronic structure and the assignments of the absorption bands were carried out. Besides, molecular electrostatic potential (MEP) were investigated using theoretical calculations.

  18. Chemical reaction and dust formation studies in laboratory hydrocarbon plasmas.

    Science.gov (United States)

    Hippler, Rainer; Majumdar, Abhijit; Thejaswini, H. C.

    Plasma chemical reaction studies with relevance to, e.g., Titan's atmosphere have been per-formed in various laboratory plasmas [1,2]. Chemical reactions in a dielectric barrier discharge at medium pressure of 250-300 mbar have been studied in CH4 /N2 and CH4 /Ar gas mixtures by means of mass spectrometry. The main reaction scheme is production of H2 by fragmenta-tion of CH4 , but also production of larger hydrocarbons like Cn Hm with n up to 10 including formation of different functional CN groups is observed. [1] A. Majumdar and R. Hippler, Development of dielectric barrier discharge plasma processing apparatus for mass spectrometry and thin film deposition, Rev. Sci. Instrum. 78, 075103 (2007) [2] H.T. Do, G. Thieme, M. Frühlich, H. Kersten, and R. Hippler, Ion Molecule and Dust Particle Formation in Ar/CH4 , Ar/C2 H2 and Ar/C3 H6 Radio-frequency Plasmas, Contrib. Plasma Phys. 45, No. 5-6, 378-384 (2005)

  19. On-line Vis-Nir sensor determination of soil variations of sodium, potassium and magnesium

    Science.gov (United States)

    Tekin, Y.; Tumsavaş, Z.; Ulusoy, Y.; Mouazen, A. M.

    2016-08-01

    Among proximal measurement methods, visible and near infrared (Vis-Nir) spectroscopy probably has the greatest potential for determining the physico-chemical properties of different natural resources, including soils. This study was conducted to determine the sodium, potassium and magnesium variations in a 10. Ha field located in Karacabey district (Bursa Province, Turkey) using an on-line Vis-Nir sensor. A total of 92 soil samples were collected from the field. The performance and accuracy of the Na, K and Mg calibration models was evaluated in cross-validation and independent validation. Three categories of maps were developed: 1) reference laboratory analyses maps based on 92 points 2) Full-data point maps based on all 6486 on-line points Vis-Nir predicted in 2013 and 3) full- data point maps based on all 2496 on-line points Vis-Nir predicted in 2015. Results showed that the prediction performance in the validation set was successful, with average R2 values of 0.82 for Na, 0.70 for K, and 0.79 for Mg, average root mean square error of prediction (RMSEP) values of 0.02% (Na), 0.20% (K), and 1.32% (Mg) and average residual prediction deviation (RPD) values of 2.13 (Na), 0.97 (K), and 2.20 (Mg). On-line field measurement was also proven to be successful with validation results showing average R2 values of 0.78 (Na), 0.64 (K), and 0.60 (Mg), average RMSEP values of 0.04% (Na), 0.13% (K), and 2.19% (Mg) and average RPD values of 1.57 (Na) 1.68 (K) and 1.56 (Mg). Based on 3297 points, maps of Na, K and Mg were produced after N, P, K and organic fertilizer applications, and these maps were then compared to the corresponding maps from the previous year. The comparison showed a variation in soil properties that was attributed to the variable rate of fertilization implemented in the preceding year.

  20. On-Line Impact Load Identification

    Directory of Open Access Journals (Sweden)

    Krzysztof Sekuła

    2013-01-01

    Full Text Available The so-called Adaptive Impact Absorption (AIA is a research area of safety engineering devoted to problems of shock absorption in various unpredictable scenarios of collisions. It makes use of smart technologies (systems equipped with sensors, controllable dissipaters and specialised tools for signal processing. Examples of engineering applications for AIA systems are protective road barriers, automotive bumpers or adaptive landing gears. One of the most challenging problems for AIA systems is on-line identification of impact loads, which is crucial for introducing the optimum real-time strategy of adaptive impact absorption. This paper presents the concept of an impactometer and develops the methodology able to perform real-time impact load identification. Considered dynamic excitation is generated by a mass M1 impacting with initial velocity V0. An analytical formulation of the problem, supported with numerical simulations and experimental verifications is presented. Two identification algorithms based on measured response of the impacted structure are proposed and discussed. Finally, a concept of the AIA device utilizing the idea of impactometer is briefly presented.

  1. SOL: INNOVACIÓN ON-LINE

    Directory of Open Access Journals (Sweden)

    Rubén Faúndez

    2007-11-01

    Full Text Available Las aplicaciones de simulación tienden a ser cada vez más cercanas a usuarios e industrias. Sin embargo, muchas de ellas no poseen ni la capacidad ni el conocimiento como para desarrollar internamente sus modelos de simulación. Por este motivo, y como una forma de apoyar la toma de decisiones basándose en modelos de simulación, se presenta la plataforma SOL (Simulación On Line. La metodología completa de trabajo, así como la interacción entre SOL, Empresa y Asesor, son presentadas. Su base de datos, los niveles de usuarios, sus funcionalidades, y la creación automatizada de información grafica y visual, también son explicadas. En el caso de aplicación, el uso de SOL para apoyar la toma de decisiones en una operación de movimiento de material, permite a los tomadores de decisión acceder a análisis robustos basados en información extraída de los modelos de simulación. SOL, al almacenar información, funcionar vía web, generar análisis automatizados y crear visualizaciones, permite cumplir con las expectativas de los usuarios respecto a una solución integral en simulación.

  2. On-line neutron beam monitoring of the Finnish BNCT facility

    Science.gov (United States)

    Tanner, Vesa; Auterinen, Iiro; Helin, Jori; Kosunen, Antti; Savolainen, Sauli

    1999-02-01

    A Boron Neutron Capture Therapy (BNCT) facility has been built at the FiR 1 research reactor of VTT Chemical Technology in Espoo, Finland. The facility is currently undergoing dosimetry characterisation and neutron beam operation research for clinical trials. The healthy tissue tolerance study, which was carried out in the new facility during spring 1998, demonstrated the reliability and user-friendliness of the new on-line beam monitoring system designed and constructed for BNCT by VTT Chemical Technology. The epithermal neutron beam is monitored at a bismuth gamma shield after an aluminiumfluoride-aluminium moderator. The detectors are three pulse mode U 235-fission chambers for epithermal neutron fluence rate and one current mode ionisation chamber for gamma dose rate. By using different detector sensitivities the beam intensity can be measured over a wide range of reactor power levels (0.001-250 kW). The detector signals are monitored on-line with a virtual instrumentation (LabView) based PC-program, which records and displays the actual count rates and total counts of the detectors in the beam. Also reactor in-core power instrumentation and control rod positions can be monitored via another LabView application. The main purpose of the monitoring system is to provide a dosimetric link to the dose in a patient during the treatment, as the fission chamber count rates have been calibrated to the induced thermal neutron fluence rate and to the absorbed dose rate at reference conditions in a tissue substitute phantom.

  3. Combined spectroscopic and quantum chemical studies of ezetimibe

    Science.gov (United States)

    Prajapati, Preeti; Pandey, Jaya; Shimpi, Manishkumar R.; Srivastava, Anubha; Tandon, Poonam; Velaga, Sitaram P.; Sinha, Kirti

    2016-12-01

    Ezetimibe (EZT) is a hypocholesterolemic agent used for the treatment of elevated blood cholesterol levels as it lowers the blood cholesterol by blocking the absorption of cholesterol in intestine. Study aims to combine experimental and computational methods to provide insights into the structural and vibrational spectroscopic properties of EZT which is important for explaining drug substance physical and biological properties. Computational study on molecular properties of ezetimibe is presented using density functional theory (DFT) with B3LYP functional and 6-311++G(d,p) basis set. A detailed vibrational assignment has been done for the observed IR and Raman spectra of EZT. In addition to the conformational study, hydrogen bonding and molecular docking studies have been also performed. For conformational studies, the double well potential energy curves have been plotted for the rotation around the six flexible bonds of the molecule. UV absorption spectrum was examined in methanol solvent and compared with calculated one in solvent environment (IEF-PCM) using TD-DFT/6-31G basis set. HOMO-LUMO energy gap of both the conformers have also been calculated in order to predict its chemical reactivity and stability. The stability of the molecule was also examined by means of natural bond analysis (NBO) analysis. To account for the chemical reactivity and site selectivity of the molecules, molecular electrostatic potential (MEPS) map has been plotted. The combination of experimental and calculated results provide an insight into the structural and vibrational spectroscopic properties of EZT. In order to give an insight for the biological activity of EZT, molecular docking of EZT with protein NPC1L1 has been done.

  4. On-line determination of anions in pulp mills by capillary electrophoresis (CE); Tehdasoloissa tapahtuva anionien kapillaarielektroforeettinen on-line maeaeritys ja sen hyoedyntaeminen prosessivalvonnassa - MPKY 02

    Energy Technology Data Exchange (ETDEWEB)

    Kokkonen, R.; Holmberg, M.; Vainikka, V. [Finnish Pulp and Paper Research Institute, Espoo (Finland)

    1998-12-31

    The aim of the study was to set-up a process control system for on-line measurement of certain anions. Typical anions which forms precipitates in pulp and paper mills are oxalate, carbonate and sulphate. Thus it is important to develop a continuous process analyzing system to control concentration levels of this anions. For the preliminary tests of continuous determinations of chloride and sulphate anions in tap water a simple on-line system was build in KCL (The Finnish Pulp and Paper Research Institute) and connected to a capillary electroforesis apparatus. In the preliminary tests a chromate buffer (ph = 7.6) was used. Separation of chloride and sulphate was excellent but the stability of buffer was not good enough and it was usable only for few hours. After experimental studies VTT developed a stable capillary electrophoresis method based on mixed amine buffer and this was selected for an on-line method for determination of anions in process waters of the pulp and paper industry. In the preliminary on-line test (r = 20) repeatabilities of migration times of sulphate and chloride with the chromate buffer were < 5 % (RSD) and peak heights < 15 % (RSD). With the mixed amine buffer repeatabilities were better. The preliminary tests showed that it is possible to connect a capillary electrophoresis system to on-line measurements. For the moment no commercial on-line CE apparatus is available. (orig.)

  5. Corrosion study in the chemical air separation (MOLTOX trademark ) process

    Energy Technology Data Exchange (ETDEWEB)

    Kang, Doohee; Wong, Kai P.; Archer, R.A.; Cassano, A.A.

    1988-12-01

    This report presents the results of studies aimed at solving the corrosion problems encountered during operation of the MOLTOX{trademark} pilot plant. These studies concentrated on the screening of commercial and developmental alloys under conditions simulating operation conditions in this high temperature molten salt process. Process economic studies were preformed in parallel with the laboratory testing to ensure that an economically feasible solution would be achieved. In addition to the above DOE co-funded studies, Air Products and Chemicals pursued proprietary studies aimed at developing a less corrosive salt mixture which would potentially allow the use of chemurgically available alloys such as stainless steels throughout the system. These studies will not be reported here; however, the results of corrosion tests in the new less corrosive salt mixtures are reported. Because our own studies on salt chemistry impacts heavily on the overall process and thereby has an influence on the experimental work conducted under this contract, some of the studies discussed here were impacted by our own proprietary data. Therefore, the reasons behind some of the experiments presented herein will not be explained because that information is proprietary to Air Products. 14 refs., 42 figs., 21 tabs.

  6. Enhancing Learner Autonomy in an On-line Editing Programme

    Directory of Open Access Journals (Sweden)

    Hebe Wong

    2011-09-01

    Full Text Available Little (1999 argues that in formal educational contexts, “the basis of learner autonomy is acceptance of responsibility for one’s own learning” (p.11. An autonomous learner takes responsibility for various aspects of learning (Benson & Voller, 1997; Holec, 1981. This study examines how learner autonomy opportunities were provided at various stages of writing in an on-line editing programme for a group of electronic engineering students and how the students took charge of their language learning when receiving feedback on their technical writing. The impact on their own learning effectiveness of the decisions students made is also discussed.

  7. Robust Control Methods for On-Line Statistical Learning

    Directory of Open Access Journals (Sweden)

    Capobianco Enrico

    2001-01-01

    Full Text Available The issue of controlling that data processing in an experiment results not affected by the presence of outliers is relevant for statistical control and learning studies. Learning schemes should thus be tested for their capacity of handling outliers in the observed training set so to achieve reliable estimates with respect to the crucial bias and variance aspects. We describe possible ways of endowing neural networks with statistically robust properties by defining feasible error criteria. It is convenient to cast neural nets in state space representations and apply both Kalman filter and stochastic approximation procedures in order to suggest statistically robustified solutions for on-line learning.

  8. [Studies on the chemical constituents from Inula cappa (II)].

    Science.gov (United States)

    Guo, Qi-lei; Yang, Jun-shan; Liu, Jian-xun

    2007-01-01

    To study the chemical constituents of the root of Inula cappa. The compounds were isolated and purified by recrystallization and chromatography with silica gel column and Sephadex LH-20 column. Their structures were identified by physico-chemical properties and spectral analysis. Seven compounds were isolated as scopolin (I), octacosanoic acid (II), tritriacontane (III), (2S,3S,4R,8E)-2-[(2'R)-2'-hydroxydocosanosylamino]-octadecane-1,3,4-triol(IV),(2S,3S,4R,8E)-2-[(2'R)-2'-hydroxytricosanosylamino]-octadecane-1,3,4-triol(V), (2S,3S,4R,8E)-2-[(2'R)-2'-hydroxytetracosanosylamino]-octadecane-1,3,4-triol(VI), (2S,3S,4R,8E)-2-[(2'R)-2'-hydroxypentacosanosylamino]-octadecane-1,3,4-triol(VIII), (2S,3S,4R,8E)-2-[(2'R)-2'-hydroxyhexacosanosylamino]-octadecane-1,3,4-triol(VIII). All compounds were isolated from Inula cappa for the first time.

  9. Sensitivity study of SMILES-2 for chemical species

    Science.gov (United States)

    Suzuki, Makoto; Manago, Naohiro; Ozeki, Hiroyuki; Ochiai, Satoshi; Baron, Philippe

    2015-10-01

    Sensitivity studies of temperature and chemical species (Observed by ISS/JEM/SMILES: O3, HCl, ClO, HO2, BrO, HNO3, CH3CN, and Not observed by SMILES: Temperature, H2O, N2O, NO2, NO, CH3Cl, CO, H2CO, OH and O-atom) was carried out for the SMILES-2 proposal, a sub-mm and THz observation of limb emission from space over the spectral region from 400 GHz to 2.5 THz. Tentative but optimal candidate of frequency bands to cover these species was selected with 3 SIS (Superconductor-Insulator-Superconductor) mixers; SIS-1 (485-489 GHz + 523-527 GHz), SIS-2 (623-627 GHz + 648-652 GHz), SIS-3 (557 GHz + 576.3 GHz) and 2 HEB (Hot Electron Bolometer); HEB-1 (1.8 THz OH) and HEB-2 (2.06 THz O-atom). Temperature can be retrieved with 1 K precision and 1 km vertical resolution from 15 to 120 km. Other chemical species also showed very high single scan precision (random error) comparable to statistical standard error of previous satellite measurements.

  10. Diuretic Properties and Chemical Constituent Studies on Stauntonia brachyanthera

    Directory of Open Access Journals (Sweden)

    Xuan Li Liu

    2015-01-01

    Full Text Available The pharmacological evaluation demonstrated that the extracts from the stem of S. brachyanthera could significantly increase the outputs of urine of rats compared to those of furosemide treated group, and the effect could last for a longer period of time. The best effect appeared in the first two hours, which scientifically confirmed the diuretic effect of the plant. The comparative pharmacognosy study showed that the characters of the crude drugs of the stem of S. brachyanthera were similar to those of Akebia caulis. Further systemic work on its chemical constituents by chromatographic methods and NMR elucidations led to the isolation of 10 triterpenoids, 6 flavonoids, 4 lignanoids, and 3 phenylethanoid glycosides, whose structural types were much similar to those of A. quinata. Among them, 7 compounds were firstly reported in the genus of Stauntonia and calceolarioside B was the common characteristic constituent in both plants. From the similar pharmacognosy characters, pharmacological effects, and chemical constituents, it could be concluded that S. brachyanthera have a great possibility to be a succedaneum of Akebia caulis, whose supply is extremely short in recent years.

  11. Studies on high chemical reactivity of nano-NaH

    Institute of Scientific and Technical Information of China (English)

    FAN Yinheng; ZOU Yunling; JIN Dan; WU Qiang; LIU Tong; XU Jie

    2007-01-01

    A comparison between the initial reaction rates of nanometric and commercial Nail has been studied in four test reactions: 1) hydrogenolysis of chlorobenzene; 2) selec-tive reduction of cinnamaldehyde to cinnamyl alcohol; 3)metallation of dimethyl sulfoxide; and 4) catalytic hydroge-nation ofolefins. The experimental results indicate that when Nail is used as a chemical reagent in the first three reactions,the initial reaction rates of nano-NaH is 230, 120 and 110 times higher than those of the commercial ones respectively,and it is in agreement with the difference in specific surface areas between these two forms of Nail. When Nail is used as a catalyst component together with Cp2TiCl2 in the fourth reaction, catalyst with nano-NaH gives extremely high activity in the hydrogenation of olefins, while the one with commercial Nail gives no activity at all even ifa large amount of the commercial Nail is used to make the total surface area equivalent to that of nano-NaH. Thus, it is evident that although large specific surface area is important for nano-Nail to be used as a catalyst component, high surface energy with surface defects seems to be more important. The largespecific surface and the activated surface of nano-NaH withhigh surface energy should be the main factors for thei rextremely high chemical reactivity, while whether the former or the latter one plays a leading role depends on the type of reactions involved.

  12. Study on On-line Retailer's Return Policy in B2C Mode%B2C模式下的在线零售商退货策略研究

    Institute of Scientific and Technical Information of China (English)

    翟春娟; 李勇建

    2011-01-01

    retailer, respectively.Subsequently, these three models were compared with each other.The analysis results show that the profit of online retailers and of the whole supply chain varies with these three return strategies.The cooperative return strategy has the highest profit for the whole supply chain. The higher the utilization rate of the returns, the more benefits companies can garner with an effective return strategy. The demand quality in Model 1 is twice that in Model 2. The retail price in Model 1 is lower than that in Model 3. This means that the retail price is lower when manufacturer and on - line retailer cooperate to collect returned goods. Furthermore, the decision on return strategy relies on the utilization rate of returns and the profit from the returns.Practical implications are drawn from the findings of this study. Supply chain professionals dealing with the return policy can use the findings of this study as a reference to improve their reverse logistics practices.%近年来,随着电子商务的飞速发展,消费者退货问题日益突出.在一个由制造商和在线零售商组成的供应链中,以在线零售商为研究主体,讨论了三种退货处理策略,即合作型退货策略、在电子市场进行二次销售的退货策略以及返还制造商的退货策略.通过考察这三种策略中,在线零售商的最优利润以及供应链总利润等变量的变化情况,为在线零售商选择合适的退货处理策略提供依据.研究结果表明:不同的退货策略下,在线零售商以及整个供应链的所得的利润存在差异;退货利用率越高,在线零售商从退货处理中得到的利润越高,也越有利于降低退货带来的损失;而在线零售商的退货处理模式的选择则依赖于退货利用率以及从退货中得到的利润.最后,数值算例也有力地支持了文中提出的结论和性质.

  13. Quantum chemical study on asymmetric catalysis reduction of imine

    Institute of Scientific and Technical Information of China (English)

    LI; Ming; (李明); TIAN; Anmin; (田安民)

    2003-01-01

    The quantum chemical method is employed to study the enantioselective reduction of imine with borane catalyzed by chiral oxazaborolidine. All the structures are optimized completely at the B3LYP/6-31G(d) level. The catalysis property of oxazaborolidine is notable. The reduction goes mainly through the formations of the catalyst-borane adduct, the catalyst-borane-imine adduct, and the catalyst-amidoborane adduct and the dissociation of the catalyst-amidoborane adduct with the regeneration of the catalyst. The controlling step for the reduction is the dissociation of the catalyst-amidoborane adduct. The main reduced product predicted theoretically is (R )-sec- ondary amine, which is in agreement with the experiment.

  14. [Studies on chemical constituents in seeds of Cicer arietinum].

    Science.gov (United States)

    Tan, Yong-xia; Sun, Yu-hua; Chen, Ruo-yun

    2007-08-01

    To study the chemical constituents in seeds of Cicer arietinum, so that to find bioactive natural products. Dried and sprouted seeds of C. arietinum were extracted with ethanol of various concentrations respectively, then isolated and purified by silica gel, macroreticular resin D 101, Sephadex LH -20 gel column chromatography, and structures of compounds were identified by spectral analysis. Nine compounds have been isolated and identified: 3-hydroxy-olean-12-ene (1), biochanin A-7-O-beta-D-glucoside (2), cerebroside (3), 1-ethyl-alpha-L-galactoside (4), uridine (5), adenosine (6), trytophan (7), biochanin A (8), fomononetin (9). Compounds 1, 3, 4, 6, 7 were isolated from genus Cicer for the first time.

  15. Quantum Chemical Study on the Corrosion Inhibition of Some Oxadiazoles

    Directory of Open Access Journals (Sweden)

    Hong Ju

    2015-01-01

    Full Text Available Quantum chemical calculations based on DFT method were performed on three nitrogen-bearing heterocyclic compounds used as corrosion inhibitors for the mild steel in acid media to determine the relationship between the molecular structure of inhibitors and inhibition efficiency. The structural parameters, such as energy and distribution of highest occupied molecular orbital (HOMO and lowest unoccupied molecular orbital (LUMO, the charge distribution of the studied inhibitors, the absolute electronegativity (χ values, and the fraction of electrons (ΔN transfer from inhibitors to mild steel were also calculated and correlated with inhibition efficiencies. The results showed that the inhibition efficiency of inhibitors increased with the increase in energy of HOMO and decrease in energy gap of frontier molecular orbital, and the areas containing N and O atoms are most possible sites for bonding the steel surface by donating electrons to the mild steel.

  16. Study of physical chemical characteristics of a shungite

    OpenAIRE

    Maira Kazankapova; A. Bekzhanova; Sergey Efremov; Mikhail Nauryzbayev

    2012-01-01

    The physico-chemical characteristics of shungite from the field of Kazakhstan ("Bakyrchik") and Russia ("Zazhegino") was studied by elemental analysis, IR- spectroscopy and electron microscopy. The content of carbon in the schungite field "Zazhegino" is 28,0-31,0 %,  in the field "Bakyrchik" - 15,0-19,0 %, in schungite concentrate  "Bakyrchik" is 40,0 ± 2,0 %.  IR-spectroscopic analysis have been shown that carboxyl groups appear in addition to the concentrate of polycyclic hydrocarbons conta...

  17. Chemical treatment of zinc surface and its corrosion inhibition studies

    Indian Academy of Sciences (India)

    S K Rajappa; T V Venkatesha; B M Praveen

    2008-02-01

    The surface treatment of zinc and its corrosion inhibition was studied using a product (BTSC) formed in the reaction between benzaldehyde and thiosemicarbozide. The corrosion behaviour of chemically treated zinc surface was investigated in aqueous chloride–sulphate medium using galvanostatic polarization technique. Zinc samples treated in BTSC solution exhibited good corrosion resistance. The measured electrochemical data indicated a basic modification of the cathode reaction during corrosion of treated zinc. The corrosion protection may be explained on the basis of adsorption and formation of BTSC film on zinc surface. The film was binding strongly to the metal surface through nitrogen and sulphur atoms of the product. The formation of film on the zinc surface was established by surface analysis techniques such as scanning electron microscopy (SEM–EDS) and Fourier transform infrared spectroscopy (FTIR).

  18. ALTERNATIVE AND ENHANCED CHEMICAL CLEANING: CORROSION STUDIES RESULTS: FY2010

    Energy Technology Data Exchange (ETDEWEB)

    Wiersma, B.

    2010-09-29

    Due to the need to close High Level Waste storage tanks, chemical cleaning methods are needed for the removal of sludge heel materials remaining at the completion of mechanical tank cleaning efforts. Oxalic acid is considered the preferred cleaning reagent for heel dissolution of iron-based sludge. However, the large quantity of chemical reagents added to the tank farm from oxalic acid based cleaning has significant downstream impacts. Optimization of the oxalic acid cleaning process can potentially reduce the downstream impacts from chemical cleaning. To optimize oxalic acid usage, a detailed understanding of the chemistry of oxalic acid based sludge dissolution is required. Additionally, other acidic systems may be required for specific waste components that have low solubility in oxalic acid, and as a means to reduce oxalic acid usage in general. Electrochemical corrosion studies were conducted with 1 wt. % oxalic acid at mineral acid concentrations above and below the optimal conditions for this oxalic acid concentration. Testing environments included pure reagents, pure iron and aluminum phases, and sludge simulants. Mineral acid concentrations greater than 0.2 M and temperatures greater than 50 C result in unacceptably high corrosion rates. Results showed that manageable corrosion rates of carbon steel can be achieved at dilute mineral acid concentrations (i.e. less than 0.2 M) and low temperatures based on the contact times involved. Therefore, it is recommended that future dissolution and corrosion testing be performed with a dilute mineral acid and a less concentrated oxalic acid (e.g., 0.5 wt.%) that still promotes optimal dissolution. This recommendation requires the processing of greater water volumes than those for the baseline process during heel dissolution, but allows for minimization of oxalic acid additions. The following conclusions can be drawn from the test results: (1) In both nitric and sulfuric acid based reagents, the low temperature and

  19. Increased Cortical Thickness in Professional On-Line Gamers

    Science.gov (United States)

    Hyun, Gi Jung; Shin, Yong Wook; Kim, Bung-Nyun; Cheong, Jae Hoon; Jin, Seong Nam

    2013-01-01

    Objective The bulk of recent studies have tested whether video games change the brain in terms of activity and cortical volume. However, such studies are limited by several factors including cross-sectional comparisons, co-morbidity, and short-term follow-up periods. In the present study, we hypothesized that cognitive flexibility and the volume of brain cortex would be correlated with the career length of on-line pro-gamers. Methods High-resolution magnetic resonance scans were acquired in twenty-three pro-gamers recruited from StarCraft pro-game teams. We measured cortical thickness in each individual using FreeSurfer and the cortical thickness was correlated with the career length and the performance of the pro-gamers. Results Career length was positively correlated with cortical thickness in three brain regions: right superior frontal gyrus, right superior parietal gyrus, and right precentral gyrus. Additionally, increased cortical thickness in the prefrontal cortex was correlated with winning rates of the pro-game league. Increased cortical thickness in the prefrontal and parietal cortices was also associated with higher performance of Wisconsin Card Sorting Test. Conclusion Our results suggest that in individuals without pathologic conditions, regular, long-term playing of on-line games is associated with volume changes in the prefrontal and parietal cortices, which are associated with cognitive flexibility. PMID:24474988

  20. Increased cortical thickness in professional on-line gamers.

    Science.gov (United States)

    Hyun, Gi Jung; Shin, Yong Wook; Kim, Bung-Nyun; Cheong, Jae Hoon; Jin, Seong Nam; Han, Doug Hyun

    2013-12-01

    The bulk of recent studies have tested whether video games change the brain in terms of activity and cortical volume. However, such studies are limited by several factors including cross-sectional comparisons, co-morbidity, and short-term follow-up periods. In the present study, we hypothesized that cognitive flexibility and the volume of brain cortex would be correlated with the career length of on-line pro-gamers. High-resolution magnetic resonance scans were acquired in twenty-three pro-gamers recruited from StarCraft pro-game teams. We measured cortical thickness in each individual using FreeSurfer and the cortical thickness was correlated with the career length and the performance of the pro-gamers. CAREER LENGTH WAS POSITIVELY CORRELATED WITH CORTICAL THICKNESS IN THREE BRAIN REGIONS: right superior frontal gyrus, right superior parietal gyrus, and right precentral gyrus. Additionally, increased cortical thickness in the prefrontal cortex was correlated with winning rates of the pro-game league. Increased cortical thickness in the prefrontal and parietal cortices was also associated with higher performance of Wisconsin Card Sorting Test. Our results suggest that in individuals without pathologic conditions, regular, long-term playing of on-line games is associated with volume changes in the prefrontal and parietal cortices, which are associated with cognitive flexibility.

  1. [Study of quantum-pharmacological chemical characteristics of quercetin].

    Science.gov (United States)

    Zahorodnyĭ, M I

    2007-01-01

    It was established in the previous studies that quercetin prevented the development and caused faster regression of ulcers, petechia and anabroses in rats, which were induced by diclofenac taking. In the group of patients taking diclofenac together with quercetin, the ulcers and dyspeptic events were less found. The application of quercetin normalizes the function and metabolism of cartilage tissue of rabbits with an experimental osteoarthrosis and in patients with osteoartrosis. Quantum-chemical properties of molecule quercetin were studied using the methods of molecular mechanics MM+ and ab initio 6-31G*, and also semiempirical method. The following indices were investigated: distance between atoms (A), the distribution of electronic density of only external valency electrons, distribution of electrostatic potential; common energy of the exertion of molecule (kkal/mmol); binding energy (kkal/mmol); electron energy (kkal/mmol); energy of nucleus-nucleus interaction (kkal/mmol); formation heat (kkal/mmol); atomic charge (eB); value of the dipole moment of molecule (D); localization and energy of highest occupied orbital (HOMO) and the lowest unoccupied (LUMO) molecular orbital (eB) of quercetin miolecule; the value of absolute rigidity of chemical structure of bioflavonoid. It was shown, that bioflavonoid quercetin belongs to mild reagents, has nucleophilic properties, can react with alkaline, unsaturated and aromatic compounds,. Polar substitutes in the quercetine molecule influence on the distribution of superficial valency electrons and localization of HOMO and LUMO. The energy value of quercetin LUMO enables us to refer quercetine to the reducing agent and it is illustrated by antioxidant properties of this medicine.

  2. Radiation and quantum chemical studies of chalcone derivatives.

    Science.gov (United States)

    Gaikwad, P; Priyadarsini, K I; Naumov, S; Rao, B S M

    2010-08-05

    The reactions of oxidizing radicals ((*)OH, Br(2)(*-), and SO(4)(*-)) with -OH-, -CH(3)-, or -NH(2)-substituted indole chalcones and hydroxy benzenoid chalcones were studied by radiation and quantum chemical methods. The (*)OH radical was found to react by addition at diffusion-controlled rates (k = 1.1-1.7 x 10(10) dm(3) mol(-1) s(-1)), but Br(2)(*-) radical reacted by 2 orders of magnitude lower. Quantum chemical calculations at the B3LYP/6-31+G(d,p) level of theory have shown that the (C2-OH)(*), (C11-OH)(*), and (C10-OH)(*) adducts of the indole chalcones and the (C7-OH)(*) and (C8-OH)(*) adducts of the hydroxy benzenoid chalcones are more stable with DeltaH = -39 to -28 kcal mol(-1) and DeltaG = -32 to -19 kcal mol(-1). This suggests that (*)OH addition to the alpha,beta-unsaturated bond is a major reaction channel in both types of chalcones and is barrierless. The stability and lack of dehydration of the (*)OH adducts arise from two factors: strong frontier orbital interaction due to the low energy gap between interacting orbitals and the negligible Coulombic repulsion due to small absolute values of Mulliken charges. The transient absorption spectrum measured in the (*)OH radical reaction with all the indole chalcone derivatives exhibited a maximum at 390 nm, which is in excellent agreement with the computed value (394 nm). The formation of three phenolic products under steady-state radiolysis is in line with the three stable (*)OH adducts predicted by theory. Independent of the substituent, identical spectra (lambda(max) = 330-360 and approximately 580 nm) were obtained on one-electron oxidation of the three indole chalcones. MO calculations predict the deprotonation from the -NH group is more efficient than from the substituent due to the larger electron density on the N1 atom forming the chalcone indolyl radical. Its reduction potential was determined to be 0.56 V from the ABTS(*-)/ABTS(2-) couple. In benzenoid chalcones, the (*)OH adduct spectrum is

  3. The Leuven isotope separator on-line laser ion source

    CERN Document Server

    Kudryavtsev, Y; Franchoo, S; Huyse, M; Gentens, J; Kruglov, K; Müller, W F; Prasad, N V S; Raabe, R; Reusen, I; Van den Bergh, P; Van Duppen, P; Van Roosbroeck, J; Vermeeren, L; Weissman, L

    2002-01-01

    An element-selective laser ion source has been used to produce beams of exotic radioactive nuclei and to study their decay properties. The operational principle of the ion source is based on selective resonant laser ionization of nuclear reaction products thermalized and neutralized in a noble gas at high pressure. The ion source has been installed at the Leuven Isotope Separator On-Line (LISOL), which is coupled on-line to the cyclotron accelerator at Louvain-la-Neuve. sup 5 sup 4 sup , sup 5 sup 5 Ni and sup 5 sup 4 sup , sup 5 sup 5 Co isotopes were produced in light-ion-induced fusion reactions. Exotic nickel, cobalt and copper nuclei were produced in proton-induced fission of sup 2 sup 3 sup 8 U. The b decay of the sup 6 sup 8 sup - sup 7 sup 4 Ni, sup 6 sup 7 sup - sup 7 sup 0 Co, sup 7 sup 0 sup - sup 7 sup 5 Cu and sup 1 sup 1 sup 0 sup - sup 1 sup 1 sup 4 Rh isotopes has been studied by means of beta-gamma and gamma-gamma spectroscopy. Recently, the laser ion source has been used to produce neutron-d...

  4. Studies of Trace Gas Chemical Cycles Using Observations, Inverse Methods and Global Chemical Transport Models

    Science.gov (United States)

    Prinn, Ronald G.

    2001-01-01

    For interpreting observational data, and in particular for use in inverse methods, accurate and realistic chemical transport models are essential. Toward this end we have, in recent years, helped develop and utilize a number of three-dimensional models including the Model for Atmospheric Transport and Chemistry (MATCH).

  5. Combination Method of Principal Component Analysis and Support Vector Machine for On-line Process Monitoring and Fault Diagnosis

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    On-line monitoring and fault diagnosis of chemical process is extremely important for operation safety and product quality. Principal component analysis (PCA) has been widely used in multivariate statistical process monitoring for its ability to reduce processes dimensions. PCA and other statistical techniques, however, have difficulties in differentiating faults correctly in complex chemical process.Support vector machine (SVM) is a novel approach based on statistical learning theory, which has emerged for feature identification and classification. In this paper, an integrated method is applied for process monitoring and fault diagnosis, which combines PCA for fault feature extraction and multiple SVMs for identification of different fault sources. This approach is verified and illustrated on the Tennessee Eastman benchmark process as a case study.Results show that the proposed PCA-SVMs method has good diagnosis capability and overall diagnosis correctness rate.

  6. A chemical study of the photodissociation region NGC 7023

    Science.gov (United States)

    Fuente, A.; Martin-Pintado, J.; Cernicharo, J.; Bachiller, R.

    1993-09-01

    To investigate the effects of the UV radiation on the chemistry of nitrogenated molecules in molecular clouds, we have carried out an observational study of the photodissociation region (PDR) associated with the reflection nebula NGC 7023. We mapped a region of 3' × 3' over the PDR in millimeter transitions of 12CO, 13CO, C18O, HCO+, HCN, HNC and N2H+. Spectra of CS, CN and C2H and of the rarer isotopic species H13CO+, H13CN, and HN13C, were also obtained at selected positions. We find evidences of selective photodissociation in the estimated 13CO/C15O ratio. Furthermore, all molecular abundances, except those of CN and perhaps C2H, decrease towards the star, and significant gradients in the values of some molecular abundance ratios (the HNC/HCN ratio decreases by a factor of 5, the N2H+/HCO+ ratio decreases by a factor of 12, the CN/HCN ratio increases by a factor of 8 and the (CN+HCN+HNC)/NH3 ratio increases by a factor of 30 towards the star position) reveal the existence of important chemical changes in this direction. Chemical equilibrium model calculations have been also carried out in order to interpret the observed behavior. Our results show that the variations found in molecular abundances cannot be explained by the kinetic temperature and/or the hydrogen density gradients measured in this region. The observed behavior is well explained by the influence of the stellar UV radiation on the chemistry of the molecular gas if the emission arises in a region at a visual extinction between 6 and 10 mag from the star. Molecular destruction in this region (Aυ ˜ 6 mag) is due mainly to reactions with H+, C, H, C+, O, and to electronic recombination. The CN/HCN ratio is suggested as a tracer of enhanced UV fields.

  7. Study on the effect of on line cleaning of the methanol synthesis system%甲醇合成系统在线清蜡效果的研究

    Institute of Scientific and Technical Information of China (English)

    张标

    2015-01-01

    石蜡作为甲醇合成反应的副产物严重影响了甲醇的产量以及生产装置的运行,究其成因是相当复杂的,那么如何彻底的去除石蜡成为当前化工生产领域研究的首要问题。以天然气为原料制甲醇在生产过程中产生石蜡混合物的原因以及合成系统结蜡后对装置造成的危害为基础,以石蜡混合物的特性尤其是熔点特性为依据探讨甲醇生产装置合成系统进行在线除蜡的方法和步骤,着重分析清蜡温度及温度的维持时间对于清蜡效果所产生的不同影响。%Paraffin wax as a byproduct of the methanol synthesis reaction has seriously affected the production and operation of methanol production plant,study its causes are complex,then how to completely remove become the most important issue in the field of chemical production and research , Based on the reason of producing paraffin mixture in the process of natural gas as raw material to produce methanol and the harm caused by the system after the wax,with the characteristics of paraffin wax especially melting characteristic as the basis to explore the methods and steps of how methanol synthesis system do running paraffin wax removal,emphatically analyzes the paraffin wax cleaning effect produced by different paraffin temperature and its duration.

  8. Key Technique of Austenitic Stainless Steel on-line Solution Treatment

    Institute of Scientific and Technical Information of China (English)

    LI Sheng-li; LI Wei-juan; LIU Shuang; LI Ying; ZHAO Fei

    2004-01-01

    Generally the methods of solution treatment of austenitic stainless steel are bifurcated on-line solution and off-line solution . For a founded enterprise, it is necessary to find out how to get across alterations and search a measure of on -line solution disposal with less investment and higher efficiency. By studying and analysingin laboratory, several key points and the methods settle them are presented, which offers a new route to realize austenitic stainless steel on-line solution. By reducing the cost greatly, it makes the enterprise larger benefits.

  9. The Iron Blast Furnace: A Study in Chemical Thermodynamics.

    Science.gov (United States)

    Treptow, Richard S.; Jean, Luckner

    1998-01-01

    Discusses the furnace from a chemical thermodynamics perspective. Examines the enthalpy, entropy, and free energy change for each reaction of importance. These properties are interpreted on the molecular level then used to deduce the conditions necessary for each reaction to occur in its intended direction. Chemical kinetics is also discussed.…

  10. Sustainability Indicators for Chemical Processes: III. Biodiesel Case Study

    Science.gov (United States)

    The chemical industry is one of the most important business sectors, not only economically, but also societally; as it allows humanity to attain higher standards and quality of life. Simultaneously, chemical products and processes can be the origin of potential human health and ...

  11. Material Development Study for a Hazardous Chemical Protective Clothing Outfit

    Science.gov (United States)

    1980-08-01

    chemicals was technical grade or better (>90%) and were used without further purification. Specialty chemicals including formuations such as agri- cultural...polycarbon- ate. Teflon yarn is available for sewing seams. Bonding patches over the seams would be required to cover holes left from sewing. Because

  12. The Iron Blast Furnace: A Study in Chemical Thermodynamics.

    Science.gov (United States)

    Treptow, Richard S.; Jean, Luckner

    1998-01-01

    Discusses the furnace from a chemical thermodynamics perspective. Examines the enthalpy, entropy, and free energy change for each reaction of importance. These properties are interpreted on the molecular level then used to deduce the conditions necessary for each reaction to occur in its intended direction. Chemical kinetics is also discussed.…

  13. Study on Edge Extraction Methods for Image-based Icing On-line Monitoring on Overhead Transmission Lines%输电线路覆冰图像边缘提取方法研究

    Institute of Scientific and Technical Information of China (English)

    王小朋; 胡建林; 吴彬

    2008-01-01

    A new method of measuring the icing thickness of transmission lines on-line is proposed in this paper. In this method, the pictures of transmission lines which are photoed by the camera on the iron tower are processed immediately to extract the edges of the transmission line conductor and transmission line insulators. The icing thickness can be gained by comparing the edges of the iced transmission line and the uniced one. Two icing image edge extraction methods are described in detail, that is, a method based on the combination of the wavelet transform and the floating threshold method and a method based on the combination of the optimal threshold method and the mathematical morphology transform. The icing images from the artificial climatic chamber and transmission lines are used to test the methods above. The results show that the method based on the wavelet transform and the floating threshold method does well in the extraction of relatively smooth edges, such as glaze icing on conductor and icing on the insulator;meanwhile, the method based on the optimal threshold method and the mathematical morphology transform does well in the edge extraction of icing on the conductor, especially the opaque rime icing on the conductor with complicated edges.

  14. Alternative Enhanced Chemical Cleaning Basic Studies Results FY09

    Energy Technology Data Exchange (ETDEWEB)

    Hay, M.; King, W.

    2010-05-05

    Due to the need to close waste storage tanks, chemical cleaning methods are needed for the effective removal of the heels. Oxalic acid is the preferred cleaning reagent for sludge heel dissolution, particularly for iron-based sludge, due to the strong complexing strength of the oxalate. However, the large quantity of oxalate added to the tank farm from oxalic acid based chemical cleaning has significant downstream impacts. Optimization of the oxalic acid cleaning process can potentially reduce the downstream impacts from chemical cleaning. To optimize oxalic acid usage, a detailed understanding of the chemistry of oxalic acid based sludge dissolution is required. Additionally, other acid systems may be required for specific waste components with low solubility in oxalic acid and as a means to reduce oxalic acid usage in general. Solubility tests were conducted using non-radioactive, pure metal phases known to be the primary phases present in High Level Waste sludge. The metal phases studied included the aluminum phases gibbsite and boehmite and the iron phases magnetite and hematite. Hematite and boehmite are expected to be the most difficult iron and aluminum phases to dissolve. These mineral phases have been identified in both SRS and Hanford High Level Waste sludge. Acids evaluated for dissolution included oxalic, nitric, and sulfuric acids. The results of the solubility tests indicate that oxalic and sulfuric acids are more effective for the dissolution of the primary sludge phases. For boehmite, elevated temperature will be required to promote effective phase dissolution in the acids studied. Literature reviews, thermodynamic modeling, and experimental results have all confirmed that pH control using a supplemental proton source (additional acid) is critical for minimization of oxalic acid usage during the dissolution of hematite. These results emphasize the importance of pH control in optimizing hematite dissolution in oxalic acid and may explain the somewhat

  15. Chemical and biological warfare: General studies. (Latest citations from the NTIS bibliographic database). Published Search

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1996-10-01

    The bibliography contains citations concerning federally sponsored and conducted studies into chemical and biological warfare operations and planning. These studies cover areas not addressed in other parts of this series. The topics include production and storage of agents, delivery techniques, training, military and civil defense, general planning studies, psychological reactions to chemical warfare, evaluations of materials exposed to chemical agents, and studies on banning or limiting chemical warfare. Other published searches in this series on chemical warfare cover detection and warning, defoliants, protection, and biological studies, including chemistry and toxicology. (Contains 50-250 citations and includes a subject term index and title list.) (Copyright NERAC, Inc. 1995)

  16. Chemical and biological warfare: General studies. (Latest citations from the NTIS bibliographic database). Published Search

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1997-11-01

    The bibliography contains citations concerning federally sponsored and conducted studies into chemical and biological warfare operations and planning. These studies cover areas not addressed in other parts of this series. The topics include production and storage of agents, delivery techniques, training, military and civil defense, general planning studies, psychological reactions to chemical warfare, evaluations of materials exposed to chemical agents, and studies on banning or limiting chemical warfare. Other published searches in this series on chemical warfare cover detection and warning, defoliants, protection, and biological studies, including chemistry and toxicology.(Contains 50-250 citations and includes a subject term index and title list.) (Copyright NERAC, Inc. 1995)

  17. DOE-EPRI On-Line Monitoring Implementation Guidelines

    Energy Technology Data Exchange (ETDEWEB)

    E. Davis, R. Bickford

    2003-01-02

    Industry and EPRI experience at several plants has shown on-line monitoring to be very effective in identifying out-of-calibration instrument channels or indications of equipment-degradation problems. The EPRI implementation project for on-line monitoring has demonstrated the feasability of on-line monitoring at several participating nuclear plants. The results have been very enouraging, and substantial progress is anticipated in the coming years.

  18. NATO Advanced Study Institute on Chemical Transport in Melasomatic Processes

    CERN Document Server

    1987-01-01

    As indicated on the title page, this book is an outgrowth of the NATO Advanced Study Institute (ASI) on Chemical Transport in Metasomatic Processes, which was held in Greece, June 3-16, 1985. The ASI consisted of five days of invited lectures, poster sessions, and discussion at the Club Poseidon near Loutraki, Corinthia, followed by a two-day field trip in Corinthia and Attica. The second week of the ASI consisted of an excursion aboard M/S Zeus, M/Y Dimitrios II, and the M/S Irini to four of the Cycladic Islands to visit, study, and sample outstanding exposures of metasomatic activity on Syros, Siphnos, Seriphos, and Naxos. Nine­ teen invited lectures and 10 session chairmen/discussion leaders participated in the ASI, which was attended by a total of 92 professional scientists and graduate stu­ dents from 15 countries. Seventeen of the invited lectures and the Field Excursion Guide are included in this volume, together with 10 papers and six abstracts representing contributed poster sessions. Although more...

  19. Quantum chemical studies of photochromic properties of benzoxazine compound

    Energy Technology Data Exchange (ETDEWEB)

    Toliautas, Stepas, E-mail: stepas.toliautas@ff.stud.vu.lt [Department of Theoretical Physics, Vilnius University, Sauletekio 9-III, LT-10222 Vilnius (Lithuania); Sulskus, Juozas, E-mail: juozas.sulskus@ff.vu.lt [Department of Theoretical Physics, Vilnius University, Sauletekio 9-III, LT-10222 Vilnius (Lithuania); Valkunas, Leonas, E-mail: leonas.valkunas@ff.vu.lt [Department of Theoretical Physics, Vilnius University, Sauletekio 9-III, LT-10222 Vilnius (Lithuania); Institute of Physics, Center for Physical Sciences and Technology, Savanoriu 231, LT-02300 Vilnius (Lithuania); Vengris, Mikas, E-mail: mikas.vengris@ff.vu.lt [Department of Quantum Electronics, Vilnius University, Sauletekio 9-III, LT-10222 Vilnius (Lithuania)

    2012-08-24

    Highlights: Black-Right-Pointing-Pointer Photochromic indolo-benzoxazine compound is studied. Black-Right-Pointing-Pointer Advanced LC-TDDFT and GMC-QDPT methods are used for excited state calculations. Black-Right-Pointing-Pointer Oxazine ring opens upon UV light excitation. Black-Right-Pointing-Pointer Fragments of the compound assume structures similar to the ions of separate molecules. Black-Right-Pointing-Pointer Multiple pathways of the photo-induced reaction are expected. -- Abstract: Molecular electronic structure of ground and excited states of a photochromic indolo[2,1-b][1,3]benzoxazine compound incorporating closed-ring system, which opens upon UV light excitation, was studied using various quantum chemical methods. Three local minima of the ground electronic state potential energy surface and related transition states were identified along the path of rotation of 4-nitrophenol group. Additionally, three local minima of the excited electronic states were located. The evaluated transition energy barriers between local ground-state minima nearest to the initial structure of the investigated molecule are less than 2 k{sub B}T, making open structures likely to revert to the initial structure by thermalization. Results obtained using ab initio GMC-QDPT method were explored and compared to the widely used TD-DFT and semi-empiric ZINDO methods.

  20. Chemical studies of single-walled carbon nanotubes

    CERN Document Server

    Xu, C

    2001-01-01

    WCl sub 6 has also been introduced into arc-vapourised SWNTs. Chapter 6 gives the details for all the experimental work of the thesis. of H sub 2 have also been studied. Chapter four describes the various processes used to purify arc-vapourised SWNTs on a laboratory scale. Two potentially scalable processes have also been studied. Both acid and gas oxidants have been used to purify SWNTs grown in the CVD method. The chemical resistance of CVD SWNTs (48 h of conc. HNO sub 3 treatment) has been shown for the first time. Various assembly behaviours of purified SWNTs, including loop and spiral structures, straight long bundles or somewhat aligned structures, are also described. Chapter five presents the filling of arc-vapourised SWNTs with LnX sub n (X = Cl, Br and I, n = 2 or 3) using the capallarity method at high temperature (570-910 deg C). The first example of a polycrystalline structure within SWNTs filled with a single material (SmCl sub 3) has been provided. Fullerenes within SWNTs in the SWNT samples ext...

  1. Quantum chemical studies on the reactivity of oxazole derivatives

    Science.gov (United States)

    Hosseinzadeh, Behzad; Eskandari, Khalil; Zarandi, Maryam; Asli, Reza

    2016-11-01

    The quantum chemical study of the reactivity of a series of oxazole derivatives substituted at 2, 4, and 5 positions was performed using B3LYP/6-311++G( d, p) and MP2/6-311++G( d, p) levels of theory. Different substituents have been applied to cover a wide range of electronic effects. On the basis of Fukui functions, oxazole derivatives in the gas phase are found to be suitable nucleophilic sites. For the most of studied substituents, it was observed that the calculated Fukui function f k - values at the N-position are small in case of electron-withdrawing substituents, resulting a preferred N-position for hard reactions. In contrast, large f k - values in case of electron-donating groups show a preferred N-position for soft reactions. These two local reactivity descriptors predicted the reactivity of the electron-rich oxazoles sequence to be 2-substituted oxazoles > 5-substituted oxazoles > 4-substituted oxazoles, where due to resonance effect, the reactivity toward electrophilic attack at the pyridine nitrogen atom is enhanced by electron donor substituents.

  2. Dimensional Description of On-line Wear Debris Images for Wear Characterization

    Institute of Scientific and Technical Information of China (English)

    WU Tonghai; PENG Yeping; DU Ying; WANG Junqun

    2014-01-01

    As one of the most wear monitoring indicator, dimensional feature of individual particles has been studied mostly focusing on off-line analytical ferrograph. Recent development in on-line wear monitoring with wear debris images shows that merely wear debris concentration has been extracted from on-line ferrograph images. It remains a bottleneck of obtaining the dimension of on-line particles due to the low resolution, high contamination and particle’s chain pattern of an on-line image sample. In this work, statistical dimension of wear debris in on-line ferrograph images is investigated. A two-step procedure is proposed as follows. First, an on-line ferrograph image is decomposed into four component images with different frequencies. By doing this, the size of each component image is reduced by one fourth, which will increase the efficiency of subsequent processing. The low-frequency image is used for extracting the area of wear debris, and the high-frequency image is adopted for extracting contour. Second, a statistical equivalent circle dimension is constructed by equaling the overall wear debris in the image into equivalent circles referring to the extracted total area and premeter of overall wear debris. The equivalent circle dimension, reflecting the statistical dimension of larger wear debris in an on-line image, is verified by manual measurement. Consequently, two preliminary applications are carried out in gasoline engine bench tests of durability and running-in. Evidently, the equivalent circle dimension, together with the previously developed concentration index, index of particle coverage area (IPCA), show good performances in characterizing engine wear conditions. The proposed dimensional indicator provides a new statistical feature of on-line wear particles for on-line wear monitoring. The new dimensional feature conveys profound information about wear severity.

  3. Poss On-line (Personalisation of Self-Service Solutions across On-line platforms)

    DEFF Research Database (Denmark)

    Nielsen, Janni; Nielsen, Lene; Jespersen, Mikkel

    2005-01-01

    The project on Personalisation of Self-service Solutions across On-line Platforms (POSS ON-LINE) focuses on users, clients, and self-service solutions. It is based on the understanding that clients and users are different and have different goals, and that self-service takes place in different co...... at the process of development. However, we lack methods to predict user behaviour without having to deal with huge amounts of data and data from both quantitative data as well as life world observations are required....... the client and the user. The system gathers data about the user, which enables the client to push information to the user. Personalisation enables graphic user interface design that is personalised and relevant to the individual user and invites the user to get access to information with less strain....... Personalisation of self-service solutions is promising and IT companies are experiencing an increase in the clients' demands. At the same time the development of solutions moves within a shorter and shorter time span. Hence the process of innovations is paced and there is an increasing need of new ways of looking...

  4. Optical fiber sensor for an on-line monitoring of epoxy resin/amine reaction

    Science.gov (United States)

    Fouchal, F.; Knight, J. A. G.; Garrington, N.; Cope, B.

    2002-05-01

    An optical fiber sensor is described; it permits a rapid determination of the state of chemical reaction in epoxy resin diglycidyl ether of bisphenol A (DGEBA), and Triethylenetetramine stoichiometric reaction. Mid infrared Fourier transform technique was used to analyze the mixture via a pair of embedded optical fibers connected to an FTIR spectrometer, which operates in the region 4000-700 cm-1 of the electromagnetic waves. An accurate monitoring of the concentration changes over time of epoxy, amine and hydroxyl groups gave a good estimate of extent of reaction and description of physical state of the produced matrix. The chemical group peaks 1130 cm-1 and 3300-3400 cm-1 where used to follow the disappearance of the epoxy, and the amine respectively, while the peak 2970 cm-1 was used as reference peak. A review of a number of other techniques used to study the curing of epoxy resins together with on-line monitoring methods applied in processing thermoset resin is referred to.

  5. A Correlation of Raman and Single and Multiple Layer Graphene Conductivity As Detected With A Cryogenic Multiprobe AFM With On-line Raman, NSOM and Other SPM Modalities

    Science.gov (United States)

    Lewis, Aaron; Zinoviev, Oleg; Komissar, Anatoly; Maayan, Eran; Lewis, David

    2015-03-01

    It is a challenge to study 2D materials, such as Graphene, MoS2, WeSe2, etc. at temperatures down to 10°K when considering the wide variety of physical phenomena that must be applied for a full picture of the functionality of these materials. This involves questions of structure, nanometric photoconductivity, electrical properties, thermal properties, near-field optical in the apertured & scattering modes, Kelvin probe, and Raman. These phenomena are common not only to 2D materials but also to carbon nanotubes and related nanomaterials. This presentation will describe the instrumental development of such a multiprobe cryogenic system that allows for state of the art on-line optical measurements and will also include a review of the probe developments that permit such multifunctional multiprobe operation with on-line full optical access. This system has a completely free optical axis from above and below not obscured by electrical or other probes that have been developed for multiprobe operation. This permits on-line Raman and Tip Enhanced NanoRaman Scattering. With such a system we have investigated graphene and HfO2 using multiprobe electrical, Kelvin probe, NSOM and on-line Raman. The results have yielded new insights into chemical changes correlated to electrical conductivity.

  6. Study and interpretation of the chemical characteristics of natural water

    Science.gov (United States)

    Hem, John David

    1985-01-01

    The chemical composition of natural water is derived from many different sources of solutes, including gases and aerosols from the atmosphere, weathering and erosion of rocks and soil, solution or precipitation reactions occurring below the land surface, and cultural effects resulting from human activities. Broad interrelationships among these processes and their effects can be discerned by application of principles of chemical thermodynamics. Some of the processes of solution or precipitation of minerals can be closely evaluated by means of principles of chemical equilibrium, including the law of mass action and the Nernst equation. Other processes are irreversible and require consideration of reaction mechanisms and rates. The chemical composition of the crustal rocks of the Earth and the composition of the ocean and the atmosphere are significant in evaluating sources of solutes in natural freshwater.

  7. USI/Chemplex/Quantum Chemical Co. Outfall Study, 1987

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — Sediment samples collected in 1987 from the Quantum Chemical Corporation outfall on the Upper Mississippi River detected 14 polycyclic aromatic hydrocarbons (PAH's)....

  8. Periodic quantum chemical studies on anhydrous and hydrated acid clinoptilolite.

    Science.gov (United States)

    Valdiviés Cruz, Karell; Lam, Anabel; Zicovich-Wilson, Claudio M

    2014-08-07

    Periodic quantum chemistry methods as implemented in the crystal09 code were considered to study acid clinoptilolite (HEU framework type), both anhydrous and hydrated. The most probable location of acid sites and water molecules together with other structural details has been the object of particular attention. Calculations were performed at hybrid and pristine DFT levels of theory with a VDZP quality basis set in order to compare performances. It arises that PBE0 provides the best agreement with experimental data as concerns structural features and the most stable Al distribution in the framework. The role of the water molecule distribution in the stability of the systems, the most probable structure that they induce in the material, and their eventual influence on further chemical modification processes, such as dealumination, are discussed in detail. Results show that, apart from the usually considered interactions of water molecules with the zeolite framework, that is, a H-bond with Brönsted acid sites and coordination with framework Al as Lewis ones, it is necessary to consider cooperation of other weaker effects so as to fully understand the hydration effect in this kind of materials.

  9. Forcing an entire bifurcation diagram: Case studies in chemical oscillators

    Science.gov (United States)

    Kevrekidis, I. G.; Aris, R.; Schmidt, L. D.

    1986-12-01

    We study the finite amplitude periodic forcing of chemical oscillators. In particular, we examine systems that, when autonomous, (i.e. for zero forcing amplitude) exhibit a single stable oscillation. Using one of the system parameters as a forcing variable by varying it periodically, we show through extensive numerical work how the bifurcation diagram of the autonomous system with respect to this parameter affects the qualitative response of the full forced system. As the forcing variable oscillates around its midpoint, its instantaneous values may cross points (such as Hopf bifurcation poiints) of the autonomous bifurcation diagram so that the characterization of the system as a simple forced oscillator is no longer valid. Such a neighboring Hopf bifurcation of the unforced system is found to set the scene for the interaction of resonance horns and the loss of tori in the full forced system as the amplitude of the forcing grows. Our test case presented here is the Continuous Stirred Tank Reactor (CSTR) with periodically forced coolant temperature.

  10. Studies on the Chemical Constituents from Marine Bryozoan Cryptosula pallasiana

    Directory of Open Access Journals (Sweden)

    Xiang-Rong Tian

    2015-06-01

    Full Text Available The aim of this study was to investigate the chemical constituents of marine bryozoan Cryptosula pallasiana inhabiting Huang Island of China. Three aromatic compounds, p-methylsulfonylmethyl-phenol (1, p-hydroxybenzaldehyde (4 and methylparaben (5, nine alkaloids, 7-bromoquinolin-4(1H-one (2, 7-bromo-2,4(1H,3H-quinazolinedione (3, benzamide (6, phenylacetamide (7, 4(3H-quinazolinone (8, thymine (9, uracil (10, hypoxanthine (11 and tryptophan (12, together with two glycerol derivatives, glycerol (13 and monoheneicosanoin (14, were isolated for the first time from this marine bryozoan. Among the isolates, compounds 1 and 2 were new natural products, and their spectral traits were reported for the first time. The structures of the two compounds were elucidated by extensive spectroscopic analyses, including HR-ESI-MS, EI-MS, 1D- and 2D-NMR techniques. The isolated compounds 1–3 were evaluated for their cytotoxicity against HL-60 human myeloid leukemia cell line. The results showed that bromated alkaloid (3 appeared strong cytotoxicity against HL-60 cells with IC 50 value of 11.87 µg/mL, while compounds 1 and 2 were inactivity.

  11. Study of physical chemical characteristics of a shungite

    Directory of Open Access Journals (Sweden)

    Maira Kazankapova

    2012-05-01

    Full Text Available The physico-chemical characteristics of shungite from the field of Kazakhstan ("Bakyrchik" and Russia ("Zazhegino" was studied by elemental analysis, IR- spectroscopy and electron microscopy. The content of carbon in the schungite field "Zazhegino" is 28,0-31,0 %,  in the field "Bakyrchik" - 15,0-19,0 %, in schungite concentrate  "Bakyrchik" is 40,0 ± 2,0 %.  IR-spectroscopic analysis have been shown that carboxyl groups appear in addition to the concentrate of polycyclic hydrocarbons containing methylene groups. Analysis of electron microscopy have been shown that as a result of enrichment by carbon, shungite can get a more developed surface structure and porosity.

  12. Rodent-repellent studies. III. Advanced studies in the evaluation of chemical repellents

    Science.gov (United States)

    Bellack, E.; DeWitt, J.B.

    1949-01-01

    In order to bridge the gap between preliminary screening of chemicals for potential rodent repellency and the application ofthese compounds to paper cartons, more advanced studies in the evaluation ofpromising materials have been carried out. These studies have resulted in: (1) a modification of the food acceptance technique which eliminates doubtful compounds and also provides a closer analogy to the ultimate goal, and (2) a method for rapidly testing chemicals incorporated in paper. When the results of these latter tests are expressed as a function of time, it can be shown that a distinct correlation exists between the deterrency exhibited by treated paper and the repellency of treated food.

  13. On Chemical Modeling an Alchemical Process: The Use of Combined Chemical Methods in a Historical Study

    Science.gov (United States)

    Rodygin, Mikhail Yu.; Rodygin, Irene V.

    1997-08-01

    Laboratory work is an important component of a course in the History of Chemistry and Alchemy, though it can only be illustrative and not comprehensive. The course should exercise both the cognitive and research abilities of an university student. Therefore methods of modeling are of prime importance at this stage of instruction. Modeling can be both a priori and experimental. The experiment can use the alchemist's materials, or it can reproduce the procedure with modern reagents. A good example for the use of this method is a recipe for the preparation of the Philosopher's Stone attributed to Lullius and cited by J. Ripley in Liber Duodecium Portarum. Thus, the Ripley's recipe is not only considered to be the first indication of the existence of acetone, but it may also indicate the formation of acetyl acetone and its derivatives. Thus, as far as the history of alchemy is concerned, the use of an experimental model not only allows us to solve a number of specific problems such as recipe interpretation and product identification, but it allows also to probe the essence of alchemical work. The combination of empirical and speculative modelings leads to the interaction of the exact methods of chemistry with the broad historico-chemical generalizations, thus introducing some additional dimensions to the definition of historico-chemical practice.

  14. A Study on Physical Dispersion and Chemical Modification of Graphene

    Energy Technology Data Exchange (ETDEWEB)

    Yim, Eun-Chae; Kim, Seong-Jun [Chonnam National University, Gwangju (Korea, Republic of)

    2015-12-15

    Graphene has a wide spectrum on its application field due to various and excellent physical properties. However, it is very difficult to apply that graphene exists as lump or fold condition in general organic solvents. Besides, graphene was difficult to maintain as uniform condition due to chemical inert and distributions with various size and shapes. Therefore, this study was focused to study dispersion and modifying methods of aggregated graphene. The dispersion methods contain as follow: i) physical milling using glass bead, ii) co-treatment of glass bead and ultrasonic waves, iii) dispersion in organic solvents, iv) modifying with dry-ice. Milling using glass bead with size 2.5 mm was effective to be size decrease of 36.4% in comparison with control group. Mixed treatment of glass bead (size 2.5 mm) and ultrasonic waves (225W, 10 min) showed relative size decrease of 76%, suggesting that the size decrease depends on the size of glass bead, intensity of ultrasonic waves and treatment time. Solvents of Ethyl acetate (EA) and Isoprophyl alcohol (IPA) were used in order to improve dispersion by modifying surface of graphene. IPA of them showed a favorable dispersion with more -CO functional groups in the FT-IR analysis. On the other hand, the oxygen content of graphene surface modified by dry-ice was highly increased from 0.8 to 4.9%. From the results, it was decided that the favorable dispersion state for a long time was obtained under the condition of -CO functional group increase in IPA solvent.

  15. Modelling of pulverized coal boilers: review and validation of on-line simulation techniques

    Energy Technology Data Exchange (ETDEWEB)

    Diez, L.I.; Cortes, C.; Campo, A. [University of Zaragoza, Zaragoza (Spain). Centro de Investigacion de Recursos y Consumos Energeticos (CIRCE)

    2005-07-01

    Thermal modelling of large pulverized fuel utility boilers has reached a very remarkable development, through the application of CFD techniques and other advanced mathematical methods. However, due to the computational requirements, on-line monitoring and simulation tools still rely on lumped models and semiempirical approaches, which are often strongly simplified and not well connected with sound theoretical basis. This paper reviews on-line modelling techniques, aiming at the improvement of their capabilities, by means of the revision and modification of conventional lumped models and the integration of off-line CFD predictions. The paper illustrates the coherence of monitoring calculations as well as the validation of the on-line thermal simulator, starting from real operation data from a case-study unit. The outcome is that it is possible to significantly improve the accuracy of on-line calculations provided by conventional models, taking into account the singularities of large combustion systems and coupling offline CFD predictions for selected scenarios.

  16. Using a strengths model to build an on-line nursing education program.

    Science.gov (United States)

    Wieck, K Lynn; Alfred, Danita; Haas, Barbara K; Yarbrough, Susan

    2014-01-01

    The on-line environment is the new frontier for academia struggling to define its place in the evolving economy. A concern is how to engage students who maximize their on-line experience and graduate in a timely manner. A strengths model was used as the basis for development of an on-line doctoral nursing program. Upon entering the program, students were given a strengths assessment that focused both students and faculty on the positive attributes students were bringing to their doctoral studies. A positive feedback methodology using on-line discussions in each course was used to support the identified strengths. The optimal picture of a successful entering doctoral student appears to be a person whose top five strengths are learner, achiever, input, connectedness and responsibility. A strengths model promotes a positive learning environment and supports a teacher-learner dynamic where faculty members are encouraged to focus on the students' strengths rather than their challenges.

  17. ON-LINE PREEMPTIVE SCHEDULING ON UNIFORM MACHINES

    Institute of Scientific and Technical Information of China (English)

    ZHANG Yuzhong; WANG Shouyang; Bo Chen; ZHANG Shuxia

    2001-01-01

    We address the problem of preemptively schedule on-line jobs on arbitrary muniformly related machines with the objective of minimizing the schedule length. We provide the first on-line algorithm for this general problem, and show that the algorithm being the speeds of the m machines.

  18. From Off-line to On-line Handwriting Recognition

    NARCIS (Netherlands)

    Lallican, P.; Viard-Gaudin, C.; Knerr, S.

    2004-01-01

    On-line handwriting includes more information on time order of the writing signal and on the dynamics of the writing process than off-line handwriting. Therefore, on-line recognition systems achieve higher recognition rates. This can be concluded from results reported in the literature, and has been

  19. On-line characterization of a hybridoma cell culture process.

    Science.gov (United States)

    Zhou, W; Hu, W S

    1994-06-20

    The on-line determination of the physiological state of a cell culture process requires reliable on-line measurements of various parameters and calculations of specific rates from these measurements. The cell concentration of a hybridoma culture was estimated on-line by measuring optical density (OD) with a laser turbidity probe. The oxygen uptake rate (OUR) was determined by monitoring dynamically dissolved oxygen concentration profiles and closing oxygen balances in the culture. The base addition for neutralizing lactate produced by cells was also monitored on-line via a balance. Using OD and OUR measurements, the specific growth and specific oxygen consumption rates were determined on-line. By combining predetermined stoichiometric relationships among oxygen and glucose consumption and lactate production, the specific glucose consumption and lactate production rates were also calculated on-line. Using these on-line measurements and calculations, the hybridoma culture process was characterized on-line by identifying the physiological states. They will also facilitate the implementation of nutrient feeding strategies for fed-batch and perfusion cultures. (c) 1994 John Wiley & Sons, Inc.

  20. On-line optimal control of greenhouse crop cultivation.

    NARCIS (Netherlands)

    Straten, van G.

    1996-01-01

    Thus far, optimal control has primarily been investigated for seasonal crop growth optimization. On-line aspects have received much less attention. The decomposition between long term strategies and on-line control, however, is not trivial. Appreciable losses occur when set-points generated by seaso

  1. On-line optimal control of greenhouse crop cultivation.

    NARCIS (Netherlands)

    Straten, van G.

    1996-01-01

    Thus far, optimal control has primarily been investigated for seasonal crop growth optimization. On-line aspects have received much less attention. The decomposition between long term strategies and on-line control, however, is not trivial. Appreciable losses occur when set-points generated by seaso

  2. Preferred Methods of Learning for Nursing Students in an On-Line Degree Program.

    Science.gov (United States)

    Hampton, Debra; Pearce, Patricia F; Moser, Debra K

    Investigators have demonstrated that on-line courses result in effective learning outcomes, but limited information has been published related to preferred teaching strategies. Delivery of on-line courses requires various teaching methods to facilitate interaction between students, content, and technology. The purposes of this study were to understand student teaching/learning preferences in on-line courses to include (a) differences in preferred teaching/learning methods for on-line nursing students across generations and (b) which teaching strategies students found to be most engaging and effective. Participants were recruited from 2 accredited, private school nursing programs (N=944) that admit students from across the United States and deliver courses on-line. Participants provided implied consent, and 217 (23%) students completed the on-line survey. Thirty-two percent of the students were from the Baby Boomer generation (1946-1964), 48% from Generation X (1965-1980), and 20% from the Millennial Generation (born after 1980). The preferred teaching/learning methods for students were videos or narrated PowerPoint presentations, followed by synchronous Adobe Connect educations sessions, assigned journal article reading, and e-mail dialog with the instructor. The top 2 methods identified by participants as the most energizing/engaging and most effective for learning were videos or narrated PowerPoint presentations and case studies. The teaching/learning method least preferred by participants and that was the least energizing/engaging was group collaborative projects with other students; the method that was the least effective for learning was wikis. Baby Boomers and Generation X participants had a significantly greater preference for discussion board (Plearning (Pteaching/learning methods for on-line students. Faculty need to incorporate various teaching methodologies within on-line courses to include both synchronous and asynchronous activities and interactive and

  3. On-line separation of refractory hafnium and tantalum isotopes at the ISOCELE separator

    CERN Document Server

    Liang, C F; Obert, J; Paris, P; Putaux, J C

    1981-01-01

    By chemical evaporation technique, neutron deficient hafnium nuclei have been on-line separated at the ISOCELE facility, from the isobar rare-earth elements, in the metal-fluoride HfF/sub 3//sup +/ ion form. Half-lives of /sup 162-165/Hf have been measured. Similarly, tantalum has been selectively separated on the TaF/sub 4//sup +/ form. (4 refs) .

  4. PROFILES AND PREFERENCES OF ON-LINE MILLENIAL SHOPPERS IN BULGARIA

    Directory of Open Access Journals (Sweden)

    Patricia R. Loubeau

    2014-05-01

    Full Text Available This research seeks to develop a better understanding of the factors affecting on-line purchasing behavior among Generation Y (Gen Y consumers in Bulgaria. Also called millenials and born between the mid-1970s and late 1990s, this generation is especially active on-line and will be a dominant influence shaping e-commerce. An empirical study was conducted based on a written survey of a sample consisting of 367 high school and university students in Bulgaria. The most important reason why Bulgarian young people shop on-line is the pursuit of unique products not locally available, followed by convenience and better pricing, and their favorite category of internet purchases is “Apparel and Accessories.” Bulgarian millennials are using the internet to shop for trendy fashion and to obtain a variety of brands that are unavailable locally. Like other regions of the world, concern about financial transactions security is a major barrier limiting the willingness to shop on-line in Bulgaria. Unlike other markets where on-line music purchases are growing, high levels of digital piracy in Bulgaria strongly discourage Bulgarian students from purchasing music on-line. One limitation of this study arises because of its reliance on a convenience sample of students from medium sized cities in Southern Bulgaria. Further research employing stratified random sampling across Bulgaria is needed to assess whether the findings are broadly generalizable for the Gen Y population.

  5. Chemical bonding in TiSb(2) and VSb(2): a quantum chemical and experimental study.

    Science.gov (United States)

    Armbrüster, Marc; Schnelle, Walter; Schwarz, Ulrich; Grin, Yuri

    2007-08-06

    The chemical bonding in the isostructural intermetallic compounds TiSb2 and VSb2, crystallizing in the CuAl2 type, was investigated by means of quantum chemical calculations, particularly the electron localization function (ELF), as well as by Raman spectroscopy, Hall effect and conductivity measurements on oriented single crystals, and high-pressure X-ray powder diffraction. The homogeneity ranges of the compounds were determined by powder X-ray diffraction, WDXS, and DSC measurements. TiSb2 exhibits no significant homogeneity range, while VSb2 shows a small homogeneity range of approximately 0.3 at. %. According to the ELF calculations, the Sb atoms form dumbbells via a two-center two-electron bond, while the T atoms (T = Ti, V) build up chains along the crystallographic c-axis. Both building units are connected by covalent T-Sb-T three-center bonds, thus forming a three-dimensional network. The strength of the bonds involving Sb was determined by fitting a force constant model to the vibrational mode frequencies observed by polarized Raman measurements on oriented single crystals. The resulting bond order of the Sb2 dumbbells is 1, while the strength of the three-center bonds resembles a bond order of 1.5. The weak pressure dependence of the c/a ratio confirms the slightly different bonding picture in TiSb2 compared to that in CuAl2. Electrical transport measurements show the presence of free charge carriers, as well as a metal-like temperature dependence of the electrical resistivity.

  6. Experimental study on effect of on-line emitter on head loss in drip irrigation laterals%滴头插入对滴灌毛管水头损失影响试验研究

    Institute of Scientific and Technical Information of China (English)

    仇振杰; 朱德兰; 张林

    2013-01-01

    For hydraulic design of drip irrigation lateral to be improved,the minor head loss caused from on-line emitters in drip irrigation laterals was explored experimentally.Based on the experimental results,the minor head loss coefficient (ξ) and the ratio of the minor head loss over the frictional head loss,hj/hf,were correlated to Reynolds number and emitter spacing for different types of emitter.It was shown that hj/hf is considerably dependent on type of emitter and emitter spacing.At the same emitter spacing,hj/hf caused from on-line labyrinth channel emitters is greater than that from pressure compensating emitters; for the same type of emitters,however,hj/hf is inversely proportional to emit ter spacing.Importantly,all the hj/hf values are larger than those specified in the Technical Standard of Micro-Irrigation Project (SL-103-95).According to the standard,the minor head loss is about (0.1-0.2) % of the total frictional head loss ; obviously the total head loss will be underestimated by this.Further,the minor head loss coefficient (ξ) are related to the type of emitter,Reynolds number and emitter spacing.For labyrinth channel emitters the coefficient is higher than 0.6 ; however,for compensating pressure emitters,it is ranged in 0.3-0.5.The coefficient increases with decreasing emitter spacing,and declines with increasing Reynolds number.An empirical formula for the coefficient was proposed by regression.%为了提高滴灌毛管水力设计精度,通过试验研究了因滴头插入引起的毛管局部水头损失,根据试验现象分析了毛管局部水头损失占沿程水头损失比例hj/hf、毛管局部水头损失系数(ξ),与滴头类型、滴头间距以及雷诺数之间的关系.结果表明:对于不同的滴头和滴头间距,毛管局部水头损失占沿程水头损失比例hj/hf差别较大.在相同间距下,迷宫流道滴头插入导致的hj/hf要大于压力补偿式滴头;对于同一类型滴头,滴头间距越小,局部

  7. Laser studies of chemical reaction and collision processes

    Energy Technology Data Exchange (ETDEWEB)

    Flynn, G. [Columbia Univ., New York, NY (United States)

    1993-12-01

    This work has concentrated on several interrelated projects in the area of laser photochemistry and photophysics which impinge on a variety of questions in combustion chemistry and general chemical kinetics. Infrared diode laser probes of the quenching of molecules with {open_quotes}chemically significant{close_quotes} amounts of energy in which the energy transferred to the quencher has, for the first time, been separated into its vibrational, rotational, and translational components. Probes of quantum state distributions and velocity profiles for atomic fragments produced in photodissociation reactions have been explored for iodine chloride.

  8. EXPERIMENTAL STUDY OF CHEMICAL CHOLECYSTECTOMY: OBSERVATION OF PATHOLOGICAL CHANGES

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    Objective: TO verify through animal experiment the validity of chemical cholecystectomy . Methods: The experimental objects seven healthy juvenile pigs,hardener was infused into the gallbladder,after infusion the samples were collected by pathoiogical examination , according to the different duration under anesthestize. Reslts:The mucous destructive and digestive process remained with one week, the inflammatory reacton in two weeks,the chronic inflatoy reaction compained a a great deal of granu lation tissue and scar formation occurred in 4th-8th week,10 weeks latter,the inflmmatory reaction reduced ,and scar tissue formed. Conclusion: Chemical cholecystectomy is safe and reliable in clinical.

  9. EXPERIMENTAL STUDY OF CHEMICAL CHOLECYSTECTOMY OF PATHOLOGIC OBSERVATION

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    Objective:To verify through animal experiment the validity of chemical cholecystectomy.Mothods:The expermental objects seven healthy juvenile pigs,hardener was infused into the gallbladder,after infusion the sapmles were collected by pathological examination,according to the different duration under anesthestize.Results:The mucous destructive and digestive process remained with one week,the inflammatory reaction in two weeks,the chronic inflammatory reaction compained a great deal of granulation tissue and scar formation occurred in 4th-8th week,10 weeks latter,the inflammatory reaction reduced,and scar tissue formed.Conlusion:Chemical cholecystecomy is safe and reliable in clinic.

  10. [Study on chemical constituents from flowers of Ailanthus altissima].

    Science.gov (United States)

    Lou, Ke-Qin; Tang, Wen-Zhao; Wang, Xiao-Jing

    2012-10-01

    To isolate and identify the chemical constituents from the flowers of Ailanthus altissima. Macroporous adsorptive resins (DM130), Silica gel, Sephadex LH-20, ODS were employed for the isolation and purification of chemical constituents. The structures were identified on the basis of spectral data and physicochemical examination. Eight compounds were isolated and identified as follows: brevifolin (1), brevifolin carboxylic acid (2), methyl brevifolin carboxylate (3), ellagic acid (4), diethyl-2,2',3,3',4,4'- hexahydroxybiphenyl-6,6'-dicarboxylate (5), rutin (6), gallic acid (7), ethyl gallate (8). Compounds 1 -5 are isolated from this genus for the first time.

  11. The Effects of Pre-Task, On-Line, and Both Pre-Task and On-Line Planning on Fluency, Complexity, and Accuracy--The Case of Iranian EFL Learners' Written Production

    Science.gov (United States)

    Piri, Faramarz; Barati, Hossein; Ketabi, Saeed

    2012-01-01

    Previous studies on the effect of planning on language production have revealed that planning does have a positive effect on language performance in terms of fluency, complexity, and accuracy. The present study was an attempt to investigate the effects of pre-task, on-line, and both pre-task and on-line planning on fluency, accuracy, and…

  12. Remote Automatic Material On-Line Sensor

    Energy Technology Data Exchange (ETDEWEB)

    Magnuson, Erik

    2005-12-20

    Low cost NMR sensor for measuring moisture content of forest products. The Department of Energy (DOE) Industries of the Future (IOF) program seeks development and implementation of technologies that make industry more efficient--in particular, more energy-efficient. Quantum Magnetics, Inc. (QM), a wholly-owned subsidiary of GE Security, received an award under the program to investigate roles for low-cost Nuclear Magnetic Resonance (NMR) technology in furtherance of these goals. Most NMR systems are designed for high-resolution spectroscopy applications. These systems use intense magnetic fields produced by superconducting magnets that drive price and operating cost to levels beyond industry tolerance. At low magnetic fields, achievable at low cost, one loses the ability to obtain spectroscopic information. However, measuring the time constants associated with the NMR signal, called NMR relaxometry, gives indications of chemical and physical states of interest to process control and optimization. It was the purpose of this effort to investigate the technical and economic feasibility of using such low-field, low-cost NMR to monitor parameters enabling greater process efficiencies. The primary target industry identified in the Cooperative Development Agreement was the wood industry, where the moisture content of wood is a key process parameter from the time the cut tree enters a mill until the time it is delivered as pieces of lumber. Extracting the moisture is energy consuming, and improvements in drying efficiency stand to reduce costs and emissions substantially. QM designed and developed a new, low-cost NMR instrument suitable for inspecting lumber up to 3 inches by 12 inches in cross section, and other materials of similar size. Low cost is achieved via an inexpensive, permanent magnet and low-cost NMR spectrometer electronics. Laboratory testing demonstrated that the NMR system is capable of accurate ({+-} 0.5%) measurements of the moisture content of wood for

  13. ECHMERIT: A new on-line global mercury-chemistry model

    Science.gov (United States)

    Jung, G.; Hedgecock, I. M.; Pirrone, N.

    2009-04-01

    Mercury is a volatile metal, that is of concern because when deposited and transformed to methylmercury accumulates within the food-web. Due to the long lifetime of elemental mercury, which is the dominant fraction of mercury species in the atmosphere, mercury is prone to long-range transport and therefore distributed over the globe, transported and hence deposited even in regions far from anthropogenic emission sources. Mercury is released to the atmosphere from a variety of natural and anthropogenic sources, in elementary and oxidised forms, and as particulate mercury. It is then transported, but also transformed chemically in the gaseous phase, as well as in aqueous phase within cloud and rain droplets. Mercury (particularly its oxidised forms) is removed from the atmosphere though wet and dry deposition processes, a large fraction of deposited mercury is, after chemical or biological reduction, re-emitted to the atmosphere as elementary mercury. To investigate mercury chemistry and transport processes on the global scale, the new, global model ECHMERIT has been developed. ECHMERIT simulates meteorology, transport, deposition, photolysis and chemistry on-line. The general circulation model on which ECHMERIT is based is ECHAM5. Sophisticated chemical modules have been implemented, including gas phase chemistry based on the CBM-Z chemistry mechanism, as well as aqueous phase chemistry, both of which have been adapted to include Hg chemistry and Hg species gas-droplet mass transfer. ECHMERIT uses the fast-J photolysis routine. State-of-the-art procedures simulating wet and dry deposition and emissions were adapted and included in the model as well. An overview of the model structure, development, validation and sensitivity studies is presented.

  14. [Studies on chemical constitutents in roots of Jasminum sambac].

    Science.gov (United States)

    Zhang, Zheng-fu; Bian, Bao-lin; Yang, Jian; Tian, Xiu-feng

    2004-03-01

    To isolate and identify the chemical constitutents in roots of Jasminum sambac. The compounds were isolated by means of chromatography and the structures were identified on the basis of physical and spectral data. Dotriacontanoic acid, dotriacontanol, oleanolic acid, daucosterol and hesperidin were elucidated. All compounds were found in this plant for the first time.

  15. Study on Web-based Equipment On-line Fault Diagnosis System%一种基于网络的设备在线故障诊断系统研究

    Institute of Scientific and Technical Information of China (English)

    咸龙新; 田枫

    2012-01-01

    针对生产过程中设备参数时变、非稳态特点,提出了基于网络的故障诊断系统结构,用于设备的远程监测与故障诊断。设计了TE过程与模拟电路故障实验,结果表明应用该结构对设备进行监控可以提高设备故障诊断的准确率,降低系统维修成本,提高生产效率。针对快速性问题,采用提升小波与递推最小二乘支持向量机相混合的快速故障诊断方法;通过快速算法训练最小二乘支持向量机分类器,节省了存储空间和运算时间,增加了诊断模型的适应性。根据设计要求设计了工业故障诊断研究实验平台,并在此平台上对提出的方法进行了验证。该应用平台采用C/S,B/S的混合模式,集成Matlab,力控等专业软件系统,并采用OPC,ODBC,数据库技术实现了故障诊断系统的基本功能。%In allusion to the characteristic of time-varying, non-stationary, an architecture of on-line fault diagnosis system was presented for remote equipment monitoring and defalut diagnosing. This system is applied to the fault diagnosis of Tennessee Eastman (TE) model and analog circuit. The result indicates the application of the presented algorithms to monitor the equipment can lead to a considerable reduction in the number of false alarms and maintenance cost, and production yeild increse. A combined fault diagnosis method based on lifting wavelet and recursive least squares support vector machine of LW-RLSSVM is proposed to realize fast fault diagnosis for complex industrial processes. Data are denoised by lifting wavelet transform in real time, then least squares support vector machine classifier is trained by real-time algorithm. According to the request, an industry platform with the function of fault diagnosis is established. This platform adopts the modes of mixing of Client/Server(C/S) and Browser/Sever (B/S). This platform is established with integration of some special

  16. An experimental study on on-line fouling fluidized-removing of sewage heat exchanger%污水换热器流态化在线防、除垢实验

    Institute of Scientific and Technical Information of China (English)

    王勇; 杨启容; 吴荣华; 陈霄

    2015-01-01

    采用污水源热泵供暖空调是节能减排的有效途径,但换热器结垢问题尚未得到有效解决.本文将固液流态化除垢技术应用到污水源热泵换热器的防、除垢中,并设计了一套污水换热器流态化除垢系统.该系统以沙粒作为除垢颗粒,通过理论分析和实验验证相结合的方法,研究了固液流态化除垢的最佳流速、除垢能力、强化换热效果及减少磨损的最佳工作参数.实验结果表明;当换热管内污水流速达到0.87m/s时,直径2~3mm沙粒可流化,沙粒循环回收率达到 95%,实现了污水换热器在线清洗;沙粒对壁面的碰撞力可有效去除换热管壁的软垢及铁锈,除垢效果明显;该除垢系统持续运行24h后,污水换热器传热系数提高了25.6%;沙粒体积分数为4%,流速为扬动流速,是减少磨损和保证除垢效率的最佳工作参数.%Using sewage source heat pump to heat and ventilate for building is an effective way of energy saving and emission reduction. However,fouling of heat exchanger remains an urgent and unresolved issue. In order to solve this problem,the solid-liquid fouling fluidized-removing technology was applied for fouling prevention and removing of sewage heat exchanger. A set of fouling removing system using sand as fouling removing particles was established in this paper. Combined theory analysis with experimental validation,the optimal flow rate,the heat transfer enhancement effect,the optimal technological parameters of anti-attrition and the fouling removing ability of fouling fluidized-removing were discussed. The experimental results showed that the sand grains with the diameter of 2—3mm could be fluidized if the flow rate of the sewage reached 0.87m/s.The recycling efficiency of the sand grains was almost 95%. The on-line cleaning was realized. The fouling fluidized-removing technology could effectively remove soft dirt and rust of sewage heat exchanger. The heat transfer coefficient

  17. Review of Worcestershire On-line Fabric Type Series website

    Directory of Open Access Journals (Sweden)

    Beverley Nenk

    2003-06-01

    Full Text Available The study of archaeological ceramics is advanced through the creation and development of regional and national pottery type-series, which contain samples of each type of pottery identified from a particular area or region. Pottery researchers working in any period, from prehistoric to post-medieval, require access to such type-series, and to their associated data, in order to be able to advance the identification of all types of pottery, not only those types produced in the local area, but those produced in surrounding regions, as well as those imported from abroad. The publication of such type-series, as well as their accessibility to researchers, is essential if the information they contain is to be disseminated. The development of the Worcestershire On-Line Fabric Type Series is the first stage in a remarkable project designed to make the complete fabric and form type series for Worcestershire ceramics accessible on the internet. As part of the Historic Environment Record for Worcestershire, formerly the Sites and Monuments Record, it is designed to improve access to finds and environmental data, with the aim of encouraging and facilitating research. Funded by Worcestershire County Council as part of its commitment to e-government, it is being developed by Worcestershire County Council Archaeology Service with OxfordArchDigital. It is one of a proposed series of on-line specialist resources (to include, for example, clay pipes, environmental archaeology, flint tools, historic buildings, which are also designed to stand alone as research tools. The ceramics website is the first part of Pottery in Perspective, a web-based project to provide information on the pottery used and made in Worcestershire from prehistory to c. 1900AD.

  18. Research of On-line Analytical Method of Trace Oxygen and Water in Argon

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    Metal sodium has an active chemical quality. When it is used as a coolant in a fast neutron reactor, it must be protected by a cover gas argon for safety operation of the reactor. But oxygen and water in argon can produce chemical reaction with sodium. Then sodium hydroxide, sodium oxide and hydrogen can be produced. This will be harmful to the safety operation of reactor. The purpose of controlling a level of impurity in the cover gas is for controlling a level of impurity in sodium. The research is to find an on-line determining method and a sampling system to monitor

  19. Quantum chemical studies of trace gas adsorption on ice nanoparticles

    Science.gov (United States)

    Schrems, Otto; Ignatov, Stanislav K.; Gadzhiev, Oleg B.; Masunov, Artem E.

    2013-04-01

    We have investigated the interaction of atmospheric trace gases with crystalline water ice particles of nanoscale size by modern quantum chemical methods. Small ice particles which can be formed in different altitudes play an important role in chemistry and physics of the Earth atmosphere. Knowledge about the uptake and incorporation of atmospheric trace gases in ice particles as well as their interactions with water molecules is very important for the understanding of processes at the air/ice interface. The interaction of the atmospheric trace gases with atmospheric ice nanoparticles is also an important issue for the development of modern physicochemical models. Usually, the interactions between trace gases and small particles considered theoretically apply small-size model complexes or the surface models representing only fragments of the ideal surface. Ice particles consisting of 48, 72, 216 and 270 water molecules with a distorted structure of hexagonal water ice Ih were studied using the new SCC-DFTBA method combining well the advantages of the DFT theory and semiempirical methods of quantum chemistry. The largest clusters correspond to the minimal nanoparticle size which are considered to be crystalline as determined experimentally. The clusters up to (H2O)72 were studied at the B3LYP/6-31++G(d,p) and B3LYP/6-311++G(2d,2p) levels. The larger clusters were studied using DFTBA and DFTB+ methods. Several adsorption complexes for the (H2O)270 water ice cluster were optimized at the RI-BLYP/6-31+G(d) theory level to verify the DFTB+ results. Trace gas molecules were coordinated on different sites of the nanoparticles corresponding to different ice Ih crystal planes: (0001), (10-10), (11-20). As atmospheric trace gases we have chosen CO, CO2, HCO*, HCOH*, HCHO, HCOOH and (HCO)2. which are the possible products and intermediates of the UV photolysis of organic molecules such as HCHCHO adsorbed on the ice surface. The structures of the corresponding coordination

  20. On-line Classical Guitar Course: Blogs for Music Education

    OpenAIRE

    José Luis Navarro; Gilles Lavigne; G. Guadalupe Martínez Salgado

    2009-01-01

    This article introduces an on-line course constructed by means of a blog. The tool was the main goal of a research project titled “Develop, Implementation and evaluation of a Hybrid Course Face to face-On Line for Teaching the Beginning to Play the Classical Guitar”. This work was a three steep project in which it was implemented, applied and evaluated. The on-line course was intended to prepare the students to learn the basic principles to start in classical music with the guitar. The result...

  1. Understanding on-line community: the affordances of virtual space

    Directory of Open Access Journals (Sweden)

    Karen Ruhleder

    2002-01-01

    Full Text Available Increasing numbers of on-line venues for learning are emerging as virtual communities become more accessible and commonplace. This paper looks at one particular virtual community, an on-line degree programme at the University of Illinois, Urbana-Champaign, which offers an M.S. in Library and Information Science (called LEEP. It draws on a framework presented by Mynatt, et al. (1998, which provides a lens for talking about on-line community as a set of affordances. This framework is applied to illustrate the interactions, artefacts, and expectations that shape this community.

  2. Factors associated with chemical burns in Zhejiang province, China: An epidemiological study

    Directory of Open Access Journals (Sweden)

    Jiang Rui M

    2011-09-01

    Full Text Available Abstract Background Work-related burns are common among occupational injuries. Zhejiang Province is an industrial area with a high incidence of chemical burns. We aimed to survey epidemiological features of chemical burns in Zhejiang province to determine associated factors and acquire data for developing a strategy to prevent and treat chemical burns. Methods Questionnaires were developed, reviewed and validated by experts, and sent to 25 hospitals in Zhejiang province to prospectively collect data of 492 chemical burn patients admitted during one year from Sept. 1, 2008 to Aug. 31, 2009. Questions included victims' characteristics and general condition, injury location, causes of accident, causative chemicals, total body surface area burn, concomitant injuries, employee safety training, and awareness level of protective measures. Surveys were completed for each of burn patients by burn department personnel who interviewed the hospitalized patients. Results In this study, 417 victims (87.61% got chemical burn at work, of which 355 victims (74.58% worked in private or individual enterprises. Most frequent chemicals involved were hydrofluoric acid and sulfuric acid. Main causes of chemical injury accidents were inappropriate operation of equipment or handling of chemicals and absence of or failure to use effective individual protection. Conclusions Most chemical burns are preventable occupational injuries that can be attributed to inappropriate operation of equipment or handling of chemicals, lack of employee awareness about appropriate action and lack of effective protective equipment and training. Emphasis on safety education and protection for workers may help protect workers and prevent chemical burns.

  3. Accelerating Wave Function Convergence in Interactive Quantum Chemical Reactivity Studies

    CERN Document Server

    Mühlbach, Adrian H; Reiher, Markus

    2015-01-01

    The inherently high computational cost of iterative self-consistent-field (SCF) methods proves to be a critical issue delaying visual and haptic feedback in real-time quantum chemistry. In this work, we introduce two schemes for SCF acceleration. They provide a guess for the initial density matrix of the SCF procedure generated by extrapolation techniques. SCF optimizations then converge in fewer iterations, which decreases the execution time of the SCF optimization procedure. To benchmark the proposed propagation schemes, we developed a test bed for performing quantum chemical calculations on sequences of molecular structures mimicking real-time quantum chemical explorations. Explorations of a set of six model reactions employing the semi-empirical methods PM6 and DFTB3 in this testing environment showed that the proposed propagation schemes achieved speedups of up to thirty percent as a consequence of a reduced number of SCF iterations.

  4. Models of chemical biosignatures - a vibrational spectroscopic study

    Science.gov (United States)

    Bödeker, B.; Böttger, U.; Hübers, H.-W.; deVera, J.-P.; Fox, S.; Strasdeit, H.

    2013-09-01

    Investigating possible biosignatures is of central interest in the search for the oldest traces of terrestrial life. Possible biosignatures are: (i) physical structures, such as fossilized single-celled or colonyforming microorganisms; (ii) biomolecules and their altered residues (chemical biosignatures); (iii) altered element, isotope and mineral compositions in former microbial habitats and related effects caused by metabolic activity [1]. New insights in this field of research are also important in the search for life on other planets and moons, especially Mars. However, abiotically formed organic compounds are widely distributed in the universe. Therefore, in future Mars missions, it will be essential to know whether organic molecules are actually of biological origin. Here, we describe the syntheses and spectroscopic (Raman and infrared) properties of artificial chemical biosignatures that might help answering this question.

  5. [Studies on chemical constituents from bark of Morus nigra].

    Science.gov (United States)

    Wang, Lei; Wang, Hong-Qing; Chen, Ruo-Yun

    2007-12-01

    To investigate the chemical constituents in the barks of Morus nigra. The nine compounds were isolated and purified by column chromatography over silica gel, LH -20 and preparative HPLC and their structures were identified by various spectroscopic methods. The nine compounds were isolated and identified as olcancolic acid , apigenin, cyclocommunol, morusin, cyclomorusin, kuwanon C, daucosterol, ursolic acid, 63-sitosterol. Olcancolic acid, apingenin, cyclocommunol, morusin, cyclomorusin, kuwanon C, daucosterol were firstly isolated from the M. nigra.

  6. Chemical and pharmacological studies of the plants from genus Celastrus.

    Science.gov (United States)

    Su, Xiao-Hui; Zhang, Man-Li; Zhan, Wen-Hong; Huo, Chang-Hong; Shi, Qing-Wen; Gu, Yu-Cheng; Kiyota, Hiromasa

    2009-02-01

    The plants of genus Celastrus, distributed in Asia, have been used as natural insecticides and folk medicines to treat fever, chill, joint pain, edema, rheumatoid arthritis, and bacterial infection in China for a long time. This contribution reviews the chemical constituents, isolated from the plants in genus Celastrus in the past few decades, and their biological activities. The compounds listed are sesquiterpenes (beta-agarofurans), diterpenes, triterpenes, alkaloids, and flavonoids.

  7. [Studies on the chemical constituents of Dendrobium loddigesii rolfe].

    Science.gov (United States)

    Li, M F; Hirata, Y; Xu, G J; Niwa, M; Wu, H M

    1991-01-01

    According to IR, UV, MS and NMR spectra of the compounds isolated from the fresh stem of Dendrobium loddigesii Rolfe (a Chinese medicine), 3 constituents were identified. They are shihunidine, shihunine and dendrophenol (4,4'- dihydroxy-3,3',5-trimethoxybibenzyl). Chemical reactions showed that shihunidine was derived from shihunine during isolation. Shihunidine and shihunine were shown to be inhibitors of Na+, K+-ATPase of the rat kidney.

  8. Chemical Arsenal for the Study of O-GlcNAc

    Directory of Open Access Journals (Sweden)

    Eun J. Kim

    2011-02-01

    Full Text Available The concepts of both protein glycosylation and cellular signaling have been influenced by O-linked-β-N-acetylglucosamine (O-GlcNAc modification (O-GlcNAcylation on the hydroxyl group of serine or threonine residues. Unlike conventional protein glycosylation, O-GlcNAcylation is localized in the nucleocytoplasm and its cycling is a dynamic process that operates in a highly regulated manner in response to various cellular stimuli. These characteristics render O-GlcNAcylation similar to phosphorylation, which has long been considered a major regulatory mechanism in cellular processes. Various efficient chemical approaches and novel mass spectrometric (MS techniques have uncovered numerous O-GlcNAcylated proteins that are involved in the regulation of many important cellular events. These discoveries imply that O-GlcNAcylation is another major regulator of cellular signaling. However, in contrast to phosphorylation, which is regulated by hundreds of kinases and phosphatases, dynamic O-GlcNAc cycling is catalyzed by only two enzymes: uridine diphospho-N-acetyl-glucosamine:polypeptide β-N-acetylglucosaminyl transferase (OGT and β-D-N-acetylglucosaminidase (OGA. Many useful chemical tools have recently been used to greatly expand our understanding of the extensive crosstalk between O-GlcNAcylation and phosphorylation and hence of cellular signaling. This review article describes the various useful chemical tools that have been developed and discusses the considerable advances made in the O-GlcNAc field.

  9. Quantifying the uncertainties of chemical evolution studies. II. Stellar yields

    CERN Document Server

    Romano, D; Tosi, M; Matteucci, F

    2010-01-01

    This is the second paper of a series which aims at quantifying the uncertainties in chemical evolution model predictions related to the underlying model assumptions. Specifically, it deals with the uncertainties due to the choice of the stellar yields. We adopt a widely used model for the chemical evolution of the Galaxy and test the effects of changing the stellar nucleosynthesis prescriptions on the predicted evolution of several chemical species. We find that, except for a handful of elements whose nucleosynthesis in stars is well understood by now, large uncertainties still affect the model predictions. This is especially true for the majority of the iron-peak elements, but also for much more abundant species such as carbon and nitrogen. The main causes of the mismatch we find among the outputs of different models assuming different stellar yields and among model predictions and observations are: (i) the adopted location of the mass cut in models of type II supernova explosions; (ii) the adopted strength ...

  10. Properties of on-line social systems

    Science.gov (United States)

    Grabowski, A.; Kruszewska, N.; Kosiński, R. A.

    2008-11-01

    We study properties of five different social systems: (i) internet society of friends consisting of over 106 people, (ii) social network consisting of 3 × 104 individuals, who interact in a large virtual world of Massive Multiplayer Online Role Playing Games (MMORPGs), (iii) over 106 users of music community website, (iv) over 5 × 106 users of gamers community server and (v) over 0.25 × 106 users of books admirer website. Individuals included in large social network form an Internet community and organize themselves in groups of different sizes. The destiny of those systems, as well as the method of creating of new connections, are different, however we found that the properties of these networks are very similar. We have found that the network components size distribution follow the power-law scaling form. In all five systems we have found interesting scaling laws concerning human dynamics. Our research has shown how long people are interested in a single task, how much time they devote to it and how fast they are making friends. It is surprising that the time evolution of an individual connectivity is very similar in each system.

  11. Bandwidth Study on Energy Use and Potential Energy Saving Opportunities in U.S. Chemical Manufacturing

    Energy Technology Data Exchange (ETDEWEB)

    Sabine Brueske, Caroline Kramer, Aaron Fisher

    2015-06-01

    Energy bandwidth studies of U.S. manufacturing sectors can serve as foundational references in framing the range (or bandwidth) of potential energy savings opportunities. This bandwidth study examines energy consumption and potential energy savings opportunities in U.S. chemical manufacturing. The study relies on multiple sources to estimate the energy used in the production of 74 individual chemicals, representing 57% of sector-wide energy consumption. Energy savings opportunities for individual chemicals and for 15 subsectors of chemicals manufacturing are based on technologies currently in use or under development; these potential savings are then extrapolated to estimate sector-wide energy savings opportunity.

  12. On-Line Trajectory Retargeting for Alternate Landing Sites Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Barron Associates, Inc. proposes to develop a novel on-line trajectory optimization approach for Reusable Launch Vehicles (RLVs) under failure scenarios, targeting...

  13. ON-LINE SCHEDULING WITH REJECTION ON IDENTICAL PARALLEL MACHINES

    Institute of Scientific and Technical Information of China (English)

    Cuixia MIAO; Yuzhong ZHANG

    2006-01-01

    In this paper, we consider the on-line scheduling of unit time jobs with rejection on m identical parallel machines. The objective is to minimize the total completion time of the accepted jobs plus the total penalty of the rejected jobs. We give an on-line algorithm for the problem with competitive ratio 1/2(2 + √3) ≈ 1.86602.

  14. An On-line Ferrograph for Monitoring Machine Wear

    Institute of Scientific and Technical Information of China (English)

    L(U) Xiao-jun; JING Min-qing; XIE You-bai

    2005-01-01

    In order to improve an on-line ferrograph, this paper simulates a three dimensional magnetic field distribution of an electromagnet, builds a sinking motion model of a wear particle, and investigates the motion law of wear particles under two different conditions. Both numeric results and experimental results show that the on-line ferrograph is capable of monitoring machine wear conditions by measuring the concentration and size distribution of wear particles in lubricating oil.

  15. Incorporating transgenerational testing and epigenetic mechanisms into chemical testing and risk assessment: A survey of transgenerational responses in environmental chemical studies

    Science.gov (United States)

    A number of environmental chemicals have been shown to alter markers of epigenetic change. Some published multi-generation rodent studies have identified effects on F2 and greater generations after chemical exposures solely to F0 dams, but were not focused on chemical safety. We ...

  16. ALTERNATIVE AND ENHANCED CHEMICAL CLEANING: BASIC STUDIES RESULTS FY2010

    Energy Technology Data Exchange (ETDEWEB)

    King, W.; Hay, M.

    2011-01-24

    In an effort to develop and optimize chemical cleaning methods for the removal of sludge heels from High Level Waste tanks, solubility tests have been conducted using nonradioactive, pure metal phases. The metal phases studied included the aluminum phase gibbsite and the iron phases hematite, maghemite, goethite, lepidocrocite, magnetite, and wustite. Many of these mineral phases have been identified in radioactive, High Level Waste sludge at the Savannah River and Hanford Sites. Acids evaluated for dissolution included oxalic, nitric, and sulfuric acids and a variety of other complexing organic acids. The results of the solubility tests indicate that mixtures of oxalic acid with either nitric or sulfuric acid are the most effective cleaning solutions for the dissolution of the primary metal phases in sludge waste. Based on the results, optimized conditions for hematite dissolution in oxalic acid were selected using nitric or sulfuric acid as a supplemental proton source. Electrochemical corrosion studies were also conducted (reported separately; Wiersma, 2010) with oxalic/mineral acid mixtures to evaluate the effects of these solutions on waste tank integrity. The following specific conclusions can be drawn from the test results: (1) Oxalic acid was shown to be superior to all of the other organic acids evaluated in promoting the dissolution of the primary sludge phases. (2) All iron phases showed similar solubility trends in oxalic acid versus pH, with hematite exhibiting the lowest solubility and the slowest dissolution. (3) Greater than 90% hematite dissolution occurred in oxalic/nitric acid mixtures within one week for two hematite sources and within three weeks for a third hematite sample with a larger average particle size. This dissolution rate appears acceptable for waste tank cleaning applications. (4) Stoichiometric dissolution of iron phases in oxalic acid (based on the oxalate concentration) and the formation of the preferred 1:1 Fe to oxalate complex

  17. ALTERNATIVE AND ENHANCED CHEMICAL CLEANING: BASIC STUDIES RESULTS FY2010

    Energy Technology Data Exchange (ETDEWEB)

    King, W.; Hay, M.

    2011-01-24

    In an effort to develop and optimize chemical cleaning methods for the removal of sludge heels from High Level Waste tanks, solubility tests have been conducted using nonradioactive, pure metal phases. The metal phases studied included the aluminum phase gibbsite and the iron phases hematite, maghemite, goethite, lepidocrocite, magnetite, and wustite. Many of these mineral phases have been identified in radioactive, High Level Waste sludge at the Savannah River and Hanford Sites. Acids evaluated for dissolution included oxalic, nitric, and sulfuric acids and a variety of other complexing organic acids. The results of the solubility tests indicate that mixtures of oxalic acid with either nitric or sulfuric acid are the most effective cleaning solutions for the dissolution of the primary metal phases in sludge waste. Based on the results, optimized conditions for hematite dissolution in oxalic acid were selected using nitric or sulfuric acid as a supplemental proton source. Electrochemical corrosion studies were also conducted (reported separately; Wiersma, 2010) with oxalic/mineral acid mixtures to evaluate the effects of these solutions on waste tank integrity. The following specific conclusions can be drawn from the test results: (1) Oxalic acid was shown to be superior to all of the other organic acids evaluated in promoting the dissolution of the primary sludge phases. (2) All iron phases showed similar solubility trends in oxalic acid versus pH, with hematite exhibiting the lowest solubility and the slowest dissolution. (3) Greater than 90% hematite dissolution occurred in oxalic/nitric acid mixtures within one week for two hematite sources and within three weeks for a third hematite sample with a larger average particle size. This dissolution rate appears acceptable for waste tank cleaning applications. (4) Stoichiometric dissolution of iron phases in oxalic acid (based on the oxalate concentration) and the formation of the preferred 1:1 Fe to oxalate complex

  18. A Rapid Compression Expansion Machine (RCEM) for studying chemical kinetics: Experimental principle and first applications

    CERN Document Server

    Werler, Marc; Maas, Ulrich

    2016-01-01

    A novel extension of a rapid compression machine (RCM), namely a Rapid Compression Expansion Machine (RCEM), is described and its use for studying chemical kinetics is demonstrated. Like conventional RCMs, the RCEM quickly compresses a fuel/air mixture by pushing a piston into a cylinder; the resulting high temperatures and pressures initiate chemical reactions. In addition, the machine can rapidly expand the compressed gas in a controlled way by pulling the piston outwards again. This freezes chemical activity after a pre-defined reaction duration, and therefore allows a convenient probe sampling and ex-situ gas analysis of stable species. The RCEM therefore is a promising instrument for studying chemical kinetics, including also partially reacted fuel/air mixtures. The setup of the RCEM, its experimental characteristics and its use for studying chemical reactions are outlined in detail. To allow comparisons of RCEM results with predictions of chemical reaction mechanisms, a simple numerical model of the RCE...

  19. On the study of nonlinear dynamics of complex chemical reaction systems

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    With ever-increasing attentions being paid to complex systems such as the life system, soft matter, and nano-systems, theoretical studies of non-equilibrium nonlinear problems involved in chemical dynamics are now of general interest. In this mini-review, we mainly give a brief introduction to some frontier topics in this field, namely, nonlinear state-state dynamics, nonlinear chemical dynamics on complex networks, and nonlinear dynamics in mesoscopic chemical reaction systems. Deep study of these topics will make great contribution to discovering new laws of chemical dynamics, to exploring new control methods of complex chemical processes, to figuring out the very roles of chemical processes in the life system, and to crosslinking the scientific study of chemistry, physics and biology.

  20. Collagen-curcumin interaction - A physico-chemical study

    Indian Academy of Sciences (India)

    N Nishad Fathima; R Saranya Devi; K B Rekha; Aruna Dhathathreyan

    2009-07-01

    Curcumin is a widely used therapeutic agent with a wide spectrum of biological and physiological applications like wound healing and interacts with the skin protein, collagen. This work reports the effect of curcumin on various physico-chemical properties of collagen. The results suggest that significant changes in viscosity and surface tension occur on collagen interacting with curcumin. Secondary structure analysis using circular dichroism shows that curcumin does not alter the triple helical structure of collagen. Increasing concentration of curcumin resulted in aggregation of the protein. Further, curcumin imparts high level of thermal stability to collagen with shrinkage temperature of collagen increasing from 60 to 90°C.

  1. An Experimental Study on Electro Chemical Machining of Microelectrode

    Institute of Scientific and Technical Information of China (English)

    ZHANG Liao-yuan; LIU Yao

    2006-01-01

    Puts forward a new method in machining microelectrode by electro chemical machining (ECM) and plastic deformed theory. Theprocedure of this method is to machine the microelectrode according to the basic rule of ECM theory at first. Then, with the change of ECM machining parameters, one of the microelectrode ends is exerted by a load. As a result, the elastic and plastic deformation is produced at the machining section and the microelectrode diameter is reduced.It has been proved that the proposed method can determine the optimum machining parameters to machine the microelectrode of Cu.

  2. Physico-Chemical Study of Barium (II) Dipivaloylmethanate Nature

    OpenAIRE

    Fedotova, N.; Igumenov, I.; Mamatyuk, V.; Sidorenko, G.

    1995-01-01

    A physico-chemical research of bis-(dipivaloylmethanato)baryum(II) (Ba(thd)2) has been carried out from the point of its use in CVD process as a precursor (thermal stability, immunity to external effects and etc.). The optimal conditions for synthesis, purification and storage have been found. It has been shown, that the sublimated product presents a mixture of several modifications with the main phase of a composition Ba4(th)8. At a lowered pressure the sublimated product is preserved withou...

  3. Structural studies of chemical constituents of Thithonia Tagetiflora Desv (Asteraceae)

    DEFF Research Database (Denmark)

    Ngoc Huynh, Vinh; Nguyen Thi Hoai, Thu; Phi Phung Nguyen, Kim

    2013-01-01

    Tithonia tagetiflora Desv. (Asteraceae) is a widespread plant in Vietnam, and the species of Tithonia are known as plants containing many biologically active compounds. However, T. tagetiflora's chemical composition remains mostly unknown. Therefore, we now report the structural elucidation of tw......)-roseoside (4), and one glutinane type triterpene, epi-glutinol (5), from the leaves of T. tagetiflora. Their structures are established by 1D and 2D NMR spectroscopy, as well as ESI-MS analysis and comparison with literature data...

  4. El aprendizaje on-line: oportunidades y retos en instituciones politécnicas Apprenticeship Students Learning On-line: Opportunities and Challenges for Polytechnic Institutions

    Directory of Open Access Journals (Sweden)

    Martha Burkle

    2011-10-01

    challenges and opportunities of delivering on-line and virtual content to apprentices in a Polytechnic institution. Due to the current financial recession, apprentices are going back to academia in order to update their skills, but these potential students are not willing to leave their workplace or their personal lives behind to study. In this context on-line delivery represents an opportunity to provide access to content without leaving the work environment. However, in order to be successful in providing on-line materials for apprentices, polytechnics around the world are facing two challenges: How to transform hands-on Learning skills to online Learning material, and how to provide a rich-engaging environment for this group of learners. But not only the learner expectations should be taken when designing on-line learning. Instructors play also a crucial role in this endeavor, as Web 2.0 technologies offer the instructor an entirely new role in teaching: that of a facilitator. In order to analyze apprenticeship students’ on-line learning, 57 on-line surveys were distributed among a group of students registered for on-line apprenticeship programs. The paper presents research findings and a comparison of these with a what the literature states regarding the new generation of learners and their use of technologies, and the behavior (learning preferences, learning styles, use of IT presented by the research sample. Innovative opportunities for learning at the workplace (such as recommendations and future areas of research are suggested.

  5. Non-allergic cutaneous reactions in airborne chemical sensitivity--a population based study.

    Science.gov (United States)

    Berg, Nikolaj Drimer; Linneberg, Allan; Thyssen, Jacob Pontoppidan; Dirksen, Asger; Elberling, Jesper

    2011-06-01

    Multiple chemical sensitivity (MCS) is characterised by adverse effects due to exposure to low levels of chemical substances. The aetiology is unknown, but chemical related respiratory symptoms have been found associated with positive patch test. The purpose of this study was to investigate the relationship between cutaneous reactions from patch testing and self-reported severity of chemical sensitivity to common airborne chemicals. A total of 3460 individuals participating in a general health examination, Health 2006, were patch tested with allergens from the European standard series and screened for chemical sensitivity with a standardised questionnaire dividing the participants into four severity groups of chemical sensitivity. Both allergic and non-allergic cutaneous reactions--defined as irritative, follicular, or doubtful allergic reactions--were analysed in relationship with severity of chemical sensitivity. Associations were controlled for the possible confounding effects of sex, age, asthma, eczema, atopic dermatitis, psychological and social factors, and smoking habits. In unadjusted analyses we found associations between allergic and non-allergic cutaneous reactions on patch testing and the two most severe groups of self-reported sensitivity to airborne chemicals. When adjusting for confounding, associations were weakened, and only non-allergic cutaneous reactions were significantly associated with individuals most severely affected by inhalation of airborne chemicals (odds ratio = 2.5, p = 0.006). Our results suggest that individuals with self-reported chemical sensitivity show increased non-allergic cutaneous reactions based on day 2 readings of patch tests.

  6. Studies on modelling of bubble driven flows in chemical reactors

    Energy Technology Data Exchange (ETDEWEB)

    Grevskott, Sverre

    1997-12-31

    Multiphase reactors are widely used in the process industry, especially in the petrochemical industry. They very often are characterized by very good thermal control and high heat transfer coefficients against heating and cooling surfaces. This thesis first reviews recent advances in bubble column modelling, focusing on the fundamental flow equations, drag forces, transversal forces and added mass forces. The mathematical equations for the bubble column reactor are developed, using an Eulerian description for the continuous and dispersed phase in tensor notation. Conservation equations for mass, momentum, energy and chemical species are given, and the k-{epsilon} and Rice-Geary models for turbulence are described. The different algebraic solvers used in the model are described, as are relaxation procedures. Simulation results are presented and compared with experimental values. Attention is focused on the modelling of void fractions and gas velocities in the column. The energy conservation equation has been included in the bubble column model in order to model temperature distributions in a heated reactor. The conservation equation of chemical species has been included to simulate absorption of CO{sub 2}. Simulated axial and radial mass fraction profiles for CO{sub 2} in the gas phase are compared with measured values. Simulations of the dynamic behaviour of the column are also presented. 189 refs., 124 figs., 1 tab.

  7. On-line I-/Te- separation for the AMS analysis of 125I

    Science.gov (United States)

    Charles, C. R. J.; Cornett, R. J.; Zhao, X.-L.; Litherland, A. E.; Kieser, W. E.

    2015-10-01

    The isobar separator for anions (ISA) was used together with a 3 MV tandem accelerator mass spectrometer (AMS) to demonstrate the real time (on-line) separation of Te- from I-. Following the ion source mass spectrometry and major retardation to tens of eV, the ISA uses a radiofrequency quadrupole (RFQ) ion guide to confine and direct I- and associated Te- isobar anions through a gas-reaction cell, where chemical reactions occur at eV energies with the electronegative gas NO2. Anions are subsequently reaccelerated out of the ISA to near original ion source extraction energies for AMS analysis. At 5 mTorr NO2 in the ISA gas-reaction cell, 125Te- was observed to be attenuated by a factor of ∼107 as compared to 127I- that did not experience significant (107 relative to 37Cl- under the same ISA-AMS conditions. The preferential destruction of Te- (and S-) at eV energies in the ISA is likely due to a larger favorable destruction cross-section with NO2. This study is the first demonstration of I-Te anion separation for AMS, and makes possible the use of 125I, free of the contaminant 125Te isobar after suitable sample purification, for future 129I/125I carrier-free analyses of natural samples at ultra-low trace levels.

  8. Synthesis and quantum chemical studies of metalloorganics for electro-optical studies

    Science.gov (United States)

    Deepthi, S.; Jha, A.; Kumar, Ch. Ravi Shankar

    2017-07-01

    The dynamic nature of molecular materials are functional due to their nonlinear optical properties. Nonlinearity arising due to intermolecular interactions as self assembling phenomena between organic and metallic nanoparticles is of interest. The insight of this phenomena is attributed both by experimental and quantum chemical studies. Vibration studies performed by FTIR reveal intermolecular bonding forming metalloorganic POMZ with PAA and zinc oxide. These wave numbers were in agreement with theoretical studies performed by Gaussian 03v software package with B3LYP/6-31G basis set. Nonlinear optical properties such as energy difference, dipole moment, electronegativity, electrophylicity index and polarizability were attributed for electrical and optical properties of the material.

  9. CH 1 Introduction to Chemistry. Study Guide to Minicourse I - 13 Chemical Reaction Principles.

    Science.gov (United States)

    Schlenker, Richard

    Provided is a study guide for an introductory minicourse to the principles of chemical reactions. This written text is designed to accompany a series of audio tapes and 35mm slides which the student studies at his own pace. The course presents chemical kinetics, reaction mechanisms, reaction rates, and equilibrium. (SL)

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

    Science.gov (United States)

    Abraham, Nithin Susan; Abulencia, James Patrick

    2011-01-01

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

  11. [Study of chemical constituents in active parts of Mentha spicata III].

    Science.gov (United States)

    Chen, Guang-Tong; Gao, Hui-Yuan; Zheng, Jian; Wu, Bin; Yang, Xiao-Ke; Wu, Li-Jun

    2006-04-01

    To study the chemical constituents of Mentha spicata. The chemical constituents were isolated by silica gel column chromatography, and identified by physical and chemical characters and spectroscopic analysis. Compounds I - V were obtained and their structures were elucidated as protocatechuic aldehyde (I), protocatechuic acid (II), chrysoeriol (III), 5, 6-dihydroxy-7, 8, 3', 4'-tetramethoxyflavone (IV), nodifloretin (V). Compound I and II were first isolated from the genus Mentha. Compound Ill, IV and V were isolated from M. spicata for the first time.

  12. Modeling a multivariable reactor and on-line model predictive control.

    Science.gov (United States)

    Yu, D W; Yu, D L

    2005-10-01

    A nonlinear first principle model is developed for a laboratory-scaled multivariable chemical reactor rig in this paper and the on-line model predictive control (MPC) is implemented to the rig. The reactor has three variables-temperature, pH, and dissolved oxygen with nonlinear dynamics-and is therefore used as a pilot system for the biochemical industry. A nonlinear discrete-time model is derived for each of the three output variables and their model parameters are estimated from the real data using an adaptive optimization method. The developed model is used in a nonlinear MPC scheme. An accurate multistep-ahead prediction is obtained for MPC, where the extended Kalman filter is used to estimate system unknown states. The on-line control is implemented and a satisfactory tracking performance is achieved. The MPC is compared with three decentralized PID controllers and the advantage of the nonlinear MPC over the PID is clearly shown.

  13. MultiProbe Electrical Measurements of Carbon Nanotubes With On-line Raman Scattering

    Science.gov (United States)

    Yablon, Dalia; Yeshua, Talia; Lehmann, Christian; Reich, Stephanie; Strain, Kristin; Campbell, Eleano

    2014-03-01

    A multiprobe scanning probe microscope (SPM) system has been used to perform multiprobe electrical measurement of carbon nanotubes. In this system two probes can be used across an isolated carbon nanotube. A variety of probes have been developed that are compatible with multiprobe operation. These include probes for writing single single walled carbon nanotubes which have a high degree of alignment and this is demonstrated with on-line Raman. The interconnection of the multiprobe system with the Raman System will be described in detail. The combination has the potential to cross the fabrication/measurement gap that will allow for both production and nanocharacterization of such single molecule carbon nanotube molecular devices both with chemically sensitive Raman measurements (with and without plasmonic enhancement) and with on-line electrical transport on isolated carbon nanotubes.

  14. The on-line low temperature nuclear orientation facility NICOLE

    Science.gov (United States)

    Ohtsubo, T.; Roccia, S.; Stone, N. J.; Stone, J. R.; Gaulard, C.; Köster, U.; Nikolov, J.; Simpson, G. S.; Veskovic, M.

    2017-04-01

    We review major experiments and results obtained by the on-line low temperature nuclear orientation method at the NICOLE facility at ISOLDE, CERN since the year 2000 and highlight their general physical impact. This versatile facility, providing a large degree of controlled nuclear polarization, was used for a long-standing study of magnetic moments at shell closures in the region Z = 28, N = 28–50 but also for dedicated studies in the deformed region around A ∼ 180. Another physics program was conducted to test symmetry in the weak sector and constrain weak coupling beyond V–A. Those two programs were supported by careful measurements of the involved solid state physics parameters to attain the full sensitivity of the technique and provide interesting interdisciplinary results. Future plans for this facility include the challenging idea of measuring the beta–gamma–neutron angular distributions from polarized beta delayed neutron emitters, further test of fundamental symmetries and obtaining nuclear structure data used in medical applications. The facility will also continue to contribute to both the nuclear structure and fundamental symmetry test programs.

  15. Using on-line altered auditory feedback treating Parkinsonian speech

    Science.gov (United States)

    Wang, Emily; Verhagen, Leo; de Vries, Meinou H.

    2005-09-01

    Patients with advanced Parkinson's disease tend to have dysarthric speech that is hesitant, accelerated, and repetitive, and that is often resistant to behavior speech therapy. In this pilot study, the speech disturbances were treated using on-line altered feedbacks (AF) provided by SpeechEasy (SE), an in-the-ear device registered with the FDA for use in humans to treat chronic stuttering. Eight PD patients participated in the study. All had moderate to severe speech disturbances. In addition, two patients had moderate recurring stuttering at the onset of PD after long remission since adolescence, two had bilateral STN DBS, and two bilateral pallidal DBS. An effective combination of delayed auditory feedback and frequency-altered feedback was selected for each subject and provided via SE worn in one ear. All subjects produced speech samples (structured-monologue and reading) under three conditions: baseline, with SE without, and with feedbacks. The speech samples were randomly presented and rated for speech intelligibility goodness using UPDRS-III item 18 and the speaking rate. The results indicted that SpeechEasy is well tolerated and AF can improve speech intelligibility in spontaneous speech. Further investigational use of this device for treating speech disorders in PD is warranted [Work partially supported by Janus Dev. Group, Inc.].

  16. Physico-chemical study of barium (II) dipivaloylmethanate nature

    Energy Technology Data Exchange (ETDEWEB)

    Fedotova, N.E. [Rossijskaya Akademiya Nauk, Novosibirsk (Russian Federation). Inst. of Inorganic Chemistry; Igumenov, I.K. [Rossijskaya Akademiya Nauk, Novosibirsk (Russian Federation). Inst. of Inorganic Chemistry; Mamatyuk, V.I. [Rossijskaya Akademiya Nauk, Novosibirsk (Russian Federation). Inst. of Inorganic Chemistry; Sidorenko, G.V. [Rossijskaya Akademiya Nauk, Novosibirsk (Russian Federation). Inst. of Inorganic Chemistry

    1995-06-01

    A physico-chemical research of bis-(dipivaloylmethanato)barium(II) (Ba(thd){sub 2}) has been carried out from the point of its use in CVD processes as a precursor (thermal stability, immunity to external effects and etc.). The optimal conditions for synthesis, purification and storage have been found. It has been shown, that the sublimated product presents a mixture of several modifications with the main phase of a composition Ba{sub 4}(thd){sub 8}. At a lowered pressure the sublimated product is preserved without decomposition for a long time. In the air it is a monomer of a composition Ba(thd){sub 2}*2H{sub 2}O, decomposing in the course of time with forming a free ligand or a diketone (C{sub 8}H{sub 21}O{sub 2}) depending on the way of purification of the initial compound. (orig.).

  17. TREATMENT TANK CORROSION STUDIES FOR THE ENHANCED CHEMICAL CLEANING PROCESS

    Energy Technology Data Exchange (ETDEWEB)

    Wiersma, B.

    2011-08-24

    Radioactive waste is stored in high level waste tanks on the Savannah River Site (SRS). Savannah River Remediation (SRR) is aggressively seeking to close the non-compliant Type I and II waste tanks. The removal of sludge (i.e., metal oxide) heels from the tank is the final stage in the waste removal process. The Enhanced Chemical Cleaning (ECC) process is being developed and investigated by SRR to aid in Savannah River Site (SRS) High-Level Waste (HLW) as an option for sludge heel removal. Corrosion rate data for carbon steel exposed to the ECC treatment tank environment was obtained to evaluate the degree of corrosion that occurs. These tests were also designed to determine the effect of various environmental variables such as temperature, agitation and sludge slurry type on the corrosion behavior of carbon steel. Coupon tests were performed to estimate the corrosion rate during the ECC process, as well as determine any susceptibility to localized corrosion. Electrochemical studies were performed to develop a better understanding of the corrosion mechanism. The tests were performed in 1 wt.% and 2.5 wt.% oxalic acid with HM and PUREX sludge simulants. The following results and conclusions were made based on this testing: (1) In 1 wt.% oxalic acid with a sludge simulant, carbon steel corroded at a rate of less than 25 mpy within the temperature and agitation levels of the test. No susceptibility to localized corrosion was observed. (2) In 2.5 wt.% oxalic acid with a sludge simulant, the carbon steel corrosion rates ranged between 15 and 88 mpy. The most severe corrosion was observed at 75 C in the HM/2.5 wt.% oxalic acid simulant. Pitting and general corrosion increased with the agitation level at this condition. No pitting and lower general corrosion rates were observed with the PUREX/2.5 wt.% oxalic acid simulant. The electrochemical and coupon tests both indicated that carbon steel is more susceptible to localized corrosion in the HM/oxalic acid environment than

  18. TREATMENT TANK CORROSION STUDIES FOR THE ENHANCED CHEMICAL CLEANING PROCESS

    Energy Technology Data Exchange (ETDEWEB)

    Wiersma, B.

    2011-08-24

    Radioactive waste is stored in high level waste tanks on the Savannah River Site (SRS). Savannah River Remediation (SRR) is aggressively seeking to close the non-compliant Type I and II waste tanks. The removal of sludge (i.e., metal oxide) heels from the tank is the final stage in the waste removal process. The Enhanced Chemical Cleaning (ECC) process is being developed and investigated by SRR to aid in Savannah River Site (SRS) High-Level Waste (HLW) as an option for sludge heel removal. Corrosion rate data for carbon steel exposed to the ECC treatment tank environment was obtained to evaluate the degree of corrosion that occurs. These tests were also designed to determine the effect of various environmental variables such as temperature, agitation and sludge slurry type on the corrosion behavior of carbon steel. Coupon tests were performed to estimate the corrosion rate during the ECC process, as well as determine any susceptibility to localized corrosion. Electrochemical studies were performed to develop a better understanding of the corrosion mechanism. The tests were performed in 1 wt.% and 2.5 wt.% oxalic acid with HM and PUREX sludge simulants. The following results and conclusions were made based on this testing: (1) In 1 wt.% oxalic acid with a sludge simulant, carbon steel corroded at a rate of less than 25 mpy within the temperature and agitation levels of the test. No susceptibility to localized corrosion was observed. (2) In 2.5 wt.% oxalic acid with a sludge simulant, the carbon steel corrosion rates ranged between 15 and 88 mpy. The most severe corrosion was observed at 75 C in the HM/2.5 wt.% oxalic acid simulant. Pitting and general corrosion increased with the agitation level at this condition. No pitting and lower general corrosion rates were observed with the PUREX/2.5 wt.% oxalic acid simulant. The electrochemical and coupon tests both indicated that carbon steel is more susceptible to localized corrosion in the HM/oxalic acid environment than

  19. Quantum chemical studies on structural, vibrational, nonlinear optical properties and chemical reactivity of indigo carmine dye

    Science.gov (United States)

    El-Mansy, M. A. M.

    2017-08-01

    Structural and vibrational spectroscopic studies were performed on indigo carmine (IC) isomers using FT-IR spectral analysis along with DFT/B3LYP method utilizing Gaussian 09 software. GaussView 5 program has been employed to perform a detailed interpretation of vibrational spectra. Simulation of infrared spectra has led to an excellent overall agreement with the observed spectral patterns. Mulliken population analyses on atomic charges, MEP, HOMO-LUMO, NLO, first order hyperpolarizability and thermodynamic properties have been examined by (DFT/B3LYP) method with the SDD basis set level. Density of state spectra (DOS) were calculated using GaussSum 3 at the same level of theory. Molecular modeling approved that DOS Spectra are the most significant tools for differentiating between two IC isomers so far. Moreover, The IC isomers (cis-isomer) have shown an extended applicability for manufacturing both NLO and photovoltaic devices such as solar cells.

  20. Sport Management Taught On-Line: A Discussion

    Directory of Open Access Journals (Sweden)

    William F. Stier Jr

    2009-01-01

    Full Text Available An introduction to the world of on-line courses (distance education/learning is presented. In addition, the world of on-line learning, as it pertains to sport management, is examined within the framework of (a pedagogy, (b finances,(c assessment, and (d choosing to transition from the traditional classroom to on-line learning. Pertinent points relative to each of the four categories are presented from the literature. In an effort to stimulate thought and discussion to the subject of on-line learning for sport management programs/courses the authors provide their reactions to the literature points by presenting their comments/reactions from a sport management perspective. Sport management professors and administrators are encouraged to critically examine the feasibility of such on-line courses (distance education/learning within their own curricula while maintaining an appropriate framework revolving around sound theoretical instructional strategies, methods as well as appropriate use of instructional tools, including but not limited to, computersand the WWW.

  1. Development of on-line laser power monitoring system

    Science.gov (United States)

    Ding, Chien-Fang; Lee, Meng-Shiou; Li, Kuan-Ming

    2016-03-01

    Since the laser was invented, laser has been applied in many fields such as material processing, communication, measurement, biomedical engineering, defense industries and etc. Laser power is an important parameter in laser material processing, i.e. laser cutting, and laser drilling. However, the laser power is easily affected by the environment temperature, we tend to monitor the laser power status, ensuring there is an effective material processing. Besides, the response time of current laser power meters is too long, they cannot measure laser power accurately in a short time. To be more precisely, we can know the status of laser power and help us to achieve an effective material processing at the same time. To monitor the laser power, this study utilize a CMOS (Complementary metal-oxide-semiconductor) camera to develop an on-line laser power monitoring system. The CMOS camera captures images of incident laser beam after it is split and attenuated by beam splitter and neutral density filter. By comparing the average brightness of the beam spots and measurement results from laser power meter, laser power can be estimated. Under continuous measuring mode, the average measuring error is about 3%, and the response time is at least 3.6 second shorter than thermopile power meters; under trigger measuring mode which enables the CMOS camera to synchronize with intermittent laser output, the average measuring error is less than 3%, and the shortest response time is 20 millisecond.

  2. AMADEUS on-line trigger and filtering methods

    Energy Technology Data Exchange (ETDEWEB)

    Neff, M. [Erlangen Centre for Astroparticle Physics (ECAP), Friedrich-Alexander-Universitaet Erlangen-Nuernberg, Physikalisches Institut, Erwin-Rommel-Strasse 1, D-91058 Erlangen (Germany)], E-mail: max.neff@physik.uni-erlangen.de; Anton, G.; Graf, K.; Hoessl, J.; Katz, U.; Lahmann, R.; Richardt, C. [Erlangen Centre for Astroparticle Physics (ECAP), Friedrich-Alexander-Universitaet Erlangen-Nuernberg, Physikalisches Institut, Erwin-Rommel-Strasse 1, D-91058 Erlangen (Germany)

    2009-06-01

    AMADEUS is a system designed to investigate the method of acoustic particle detection for high energy neutrinos and the acoustic environment in the deep sea as part of the ANTARES neutrino telescope. In this context, six local clusters of six acoustic sensors each were integrated into the ANTARES infrastructure. The first three clusters have been taking data since December 2007 and the second three since the completion of ANTARES in May 2008. In the paper, the methods used for the on-line triggering and filtering of the data acquired with the AMADEUS set-up are described. On-shore, a dedicated computer-cluster is used to control the off-shore DAQ hardware, to process and store the acoustic data arriving from the sensors. On this cluster different data filtering schemes and triggers are implemented. Transient signals are selected by a variable threshold, which is self-adjusting to the changing conditions of the deep sea. For bipolar pulses-the characteristic acoustic signature of a neutrino-a pattern recognition is used based on cross-correlating the output of the sensors with a pre-defined bipolar pulse. To study the characteristics of the ambient noise in the deep sea an amount of unfiltered data is stored in regular intervals.

  3. Effect of increased convective clearance by on-line hemodiafiltration on all cause and cardiovascular mortality in chronic hemodialysis patients – the Dutch CONvective TRAnsport STudy (CONTRAST: rationale and design of a randomised controlled trial [ISRCTN38365125

    Directory of Open Access Journals (Sweden)

    Nubé Menso J

    2005-05-01

    Full Text Available Abstract Background The high incidence of cardiovascular disease in patients with end stage renal disease (ESRD is related to the accumulation of uremic toxins in the middle and large-middle molecular weight range. As online hemodiafiltration (HDF removes these molecules more effectively than standard hemodialysis (HD, it has been suggested that online HDF improves survival and cardiovascular outcome. Thus far, no conclusive data of HDF on target organ damage and cardiovascular morbidity and mortality are available. Therefore, the CONvective TRAnsport STudy (CONTRAST has been initiated. Methods CONTRAST is a Dutch multi-center randomised controlled trial. In this trial, approximately 800 chronic hemodialysis patients will be randomised between online HDF and low-flux HD, and followed for three years. The primary endpoint is all cause mortality. The main secondary outcome variables are fatal and non-fatal cardiovascular events. Conclusion The study is designed to provide conclusive evidence whether online HDF leads to a lower mortality and less cardiovascular events as compared to standard HD.

  4. On-Line Sentence Processing in Swedish: Cross-Linguistic Developmental Comparisons with French

    Science.gov (United States)

    Kail, Michele; Kihlstedt, Maria; Bonnet, Philippe

    2012-01-01

    This study examined on-line processing of Swedish sentences in a grammaticality-judgement experiment within the framework of the Competition Model. Three age groups from 6 to 11 and an adult group were asked to detect grammatical violations as quickly as possible. Three factors concerning cue cost were studied: violation position (early vs. late),…

  5. Development of On-Line Spectroscopic pH Monitoring for Nuclear Fuel Reprocessing Plants: Weak Acid Schemes

    Energy Technology Data Exchange (ETDEWEB)

    Casella, Amanda J.; Hylden, Laura R.; Campbell, Emily L.; Levitskaia, Tatiana G.; Peterson, James M.; Smith, Frances N.; Bryan, Samuel A.

    2015-05-19

    Knowledge of real-time solution properties and composition is a necessity for any spent nuclear fuel reprocessing method. Metal-ligand speciation in aqueous solutions derived from the dissolved commercial spent fuel is highly dependent upon the acid concentration/pH, which influences extraction efficiency and the resulting speciation in the organic phase. Spectroscopic process monitoring capabilities, incorporated in a counter current centrifugal contactor bank, provide a pathway for on-line real-time measurement of solution pH. The spectroscopic techniques are process-friendly and can be easily configured for on-line applications, while classic potentiometric pH measurements require frequent calibration/maintenance and have poor long-term stability in aggressive chemical and radiation environments. Our research is focused on developing a general method for on-line determination of pH of aqueous solutions through chemometric analysis of Raman spectra. Interpretive quantitative models have been developed and validated under the range of chemical composition and pH using a lactic acid/lactate buffer system. The developed model was applied to spectra obtained on-line during solvent extractions performed in a centrifugal contactor bank. The model predicted the pH within 11% for pH > 2, thus demonstrating that this technique could provide the capability of monitoring pH on-line in applications such as nuclear fuel reprocessing.

  6. [Multifrequency vestibular study after vestibular neurotomy and chemical labyrinthectomy].

    Science.gov (United States)

    Morel, N; Dumas, G; Righini, C; Karkas, A; Hitter, A; Schmerber, S

    2008-06-01

    Vestibular neurotomy (VN) and chemical labyrinthectomy (CL) are the two most common techniques of vestibular deafferention to treat patients with intractable vertigo. A long-term evaluation of vestibular function has been performed with a variety of vestibular tests to find out whether there persisted any residual vestibular function after each technique. We called in all patients who have been treated for the last 10 years and have no known vestibular disease in the non treated ear. Low frequencies were analyzed with caloric tests, medium frequencies with the head-shaking test and head-impulse test, and high frequencies with the skull vibration test. The otolithic function was explored with the subjective vertical visual analysis and otolithic myogenic evoked potentials. Nine patients treated with VN and 12 with CL presented to our department. We were thus able to compare VN and CL patients with a group of 10 normal patients and another group of nine patients that had had a translabyrinthine approach for an acoustic neuroma. We found out that vestibular responses did persist in seven out of nine (78 %) patients after VN and 11 out of 12 (92 %) patients after CL. On the other hand, no vestibular response was detected following resection of vestibular schwannoma through a translabyrinthine approach. We came to the conclusion that the two latter techniques, unlike vestibulocochlear nerve section via the translabyrinthine approach, are only incomplete methods of vestibular deafferention.

  7. Interfacial studies of chemical-vapor-infiltrated ceramic matrix composites

    Energy Technology Data Exchange (ETDEWEB)

    Brennan, J.J. (United Technologies Research Center, East Hartford, CT (USA))

    1990-06-15

    The objective of this program was to investigate the fiber-matrix interfacial chemistry in chemical-vapor-infiltrated SiC matrix composites utilizing NICALON SiC and Nextel 400 mullite fibers and how this interface influences composite properties such as strength, toughness and environmental stability. The SiC matrix was deposited using three different reactants: methyldichlorosilane, methyltrichlorosilane and dimethyldichlorosilane. It was found that by varying the reactant gas flow rates, the ratio of carrier gas to reactant gas, the type of carrier gas (hydrogen or argon), the flushing gas used in the reactor prior to deposition (hydrogen or argon) or the type of silane reactant gas used, the composition of the deposited SiC could be varied from very silicon rich (75 at.%) to carbon rich (60%) to almost pure carbon. Stoichiometric SiC was found to bond very strongly to both NICALON and Nextel fibers, resulting in a weak and brittle composite. A thin carbon interfacial layer deposited either deliberately by the decomposition of methane or inadvertently by the introduction of argon into the reactor prior to silane flow resulted in a weakly bonded fiber-matrix interface and strong and tough composites. However, composites with this type of interface were not oxidatively stable. Preliminary results point ot the use of a carbon-rich SiC (mixture of carbon plus SiC) interfacial zone to achieve a relatively weak, crack-deflecting fiber-matrix bond but also exhibiting oxidative stability. (orig.).

  8. Study of Aerosol Chemical Composition Based on Aerosol Optical Properties

    Science.gov (United States)

    Berry, Austin; Aryal, Rudra

    2015-03-01

    We investigated the variation of aerosol absorption optical properties obtained from the CIMEL Sun-Photometer measurements over three years (2012-2014) at three AERONET sites GSFC; MD Science_Center and Tudor Hill, Bermuda. These sites were chosen based on the availability of data and locations that can receive different types of aerosols from land and ocean. These absorption properties, mainly the aerosol absorption angstrom exponent, were analyzed to examine the corresponding aerosol chemical composition. We observed that the retrieved absorption angstrom exponents over the two sites, GSFC and MD Science Center, are near 1 (the theoretical value for black carbon) and with low single scattering albedo values during summer seasons indicating presence of black carbon. Strong variability of aerosol absorption properties were observed over Tudor Hill and will be analyzed based on the air mass embedded from ocean side and land side. We will also present the seasonal variability of these properties based on long-range air mass sources at these three sites. Brent Holben, NASA GSFC, AERONET, Jon Rodriguez.

  9. Use of terrestrial field studies in the derivation of bioaccumulation potential of chemicals

    NARCIS (Netherlands)

    Brink, van den N.W.; Arblaster, J.A.; Bowman, S.R.; Conder, J.M.; Elliott, J.E.; Johnson, M.S.; Muir, D.C.G.; Natal-da-Luz, Tiago; Rattner, B.A.; Sample, B.E.; Shore, R.F.

    2016-01-01

    Field-based studies are an essential component of research addressing the behavior of organic chemicals, and a unique line of evidence that can be used to assess bioaccumulation potential in chemical registration programs and aid in development of associated laboratory and modeling efforts. To ai

  10. Use of terrestrial field studies in the derivation of bioaccumulation potential of chemicals

    NARCIS (Netherlands)

    Brink, van den N.W.; Arblaster, J.A.; Bowman, S.R.; Conder, J.M.; Elliott, J.E.; Johnson, M.S.; Muir, D.C.G.; Natal-da-Luz, Tiago; Rattner, B.A.; Sample, B.E.; Shore, R.F.

    2016-01-01

    Field-based studies are an essential component of research addressing the behavior of organic chemicals, and a unique line of evidence that can be used to assess bioaccumulation potential in chemical registration programs and aid in development of associated laboratory and modeling efforts. To

  11. [Advances in studies on chemical constituents and biological activities of Desmodium species].

    Science.gov (United States)

    Liu, Chao; Wu, Ying; Zhang, Qian-Jun; Kang, Wen-Yi; Zhang, Long; Zhou, Qing-Di

    2013-12-01

    The chemical constituents isolated from Desmodium species (Leguminosae) included terpenoids, flavonoids, steroids, alkaloids compounds. Modem pharmacological studies have showed that the Desmodium species have antioxidant, antibacterial, anti-inflammatory, hepatoprotective, diuretic, antipyretic, analgesic and choleretic activity. This article mainly has reviewed the research advances of chemical constituents and biological activities of Desmodium species since 2003.

  12. Immunotoxic effects of chemicals: A matrix for occupational and environmental epidemiological studies.

    NARCIS (Netherlands)

    Veraldi, Angela; Costantini, Adele Seniori; Bolejack, Vanessa; Miligi, Lucia; Vineis, Paolo; Loveren, Henk van

    2006-01-01

    BACKGROUND: Many biological and chemical agents have the capacity to alter the way the immune system functions in human and animals. This study evaluates the immunotoxicity of 20 substances used widely in work environments. METHODS: A systematic literature search on the immunotoxicity of 20 chemical

  13. Research on the Influence of Perceived Risk in Consumer On-line Purchasing Decision

    Science.gov (United States)

    Hong, Zhao; Yi, Li

    Perceived risk is an important factor that affects consumer's on-line shopping purchasing decision, through the perceived theories the consumer can know clearly which step owns higher risk in the whole shopping process, then learn how to prevent it, this process also strengthen the consumer confidence, thus lowering to know that the risk adjudicate to the feeling, so the essay has important and realistic meaning for further expand the electronic commerce. At first, investigate, collect, tidy up, analyze the questionnaire information, and thus get the primary data. Finally try to find out the influence of perceived risk to each stage of purchasing decision during consumer on-line shopping process with data and personal analytical. The paper is a complement to the local and existing perceived theories. The result of the study manifests that, the order of main perceived risks which felt by consumer during on-line shopping process are as follow: financial risk, the performance risk and service risk.

  14. DSSTOX NATIONAL TOXICOLOGY PROGRAM BIOASSAY ON-LINE DATABASE STRUCTURE-INDEX LOCATOR FILE: SDF FILE AND DOCUMENTATION

    Science.gov (United States)

    NTPBSI: National Toxicology Program Bioassay On-line Database Structure-Index Locator File. Database contains the results collected on approxiately 300 toxicity studies from shorter duration test and from genetic toxicity studies, both in vitro and in vivo tests.

  15. Study of Online Detection Blast Furnace Temperature Sensor Based on Lining Thickness%基于炉衬厚度的高炉炉温在线检测传感器

    Institute of Scientific and Technical Information of China (English)

    王月明; 孙采鹰; 董大明; 贾华

    2015-01-01

    This paper described the background of the blast furnace temperature online measurement applications and analyzed the study progress of existing blast furnace temperature measurements, then proposed two blast furnace temperature online meas-urement sensor models based on the thickness of lining, which provided a new solution for the blast furnace temperature measure-ments.The sensor model of blast furnace temperature online detection enriched blast furnace expert system database, correctly ad-justed control parameters of blast furnace, maintained blast furnace temperature in the best condition, ensured anterograde smooth working of blast furnace conditions, and increased the life of the blast furnace.%介绍了高炉测温的应用背景,分析现有高炉炉温测量研究情况,提出了两种基于炉衬厚度的高炉炉温在线检测传感器模型,为高炉炉内温度测量提供一种新的解决方案。基于炉衬厚度的高炉炉温在线检测传感器模型能够充实和丰富高炉专家系统数据库规则制定中的参数,可以指导高炉工长及时正确地调节高炉控制参数,把炉温保持在最佳状态,保证炉况平稳顺行,以延长高炉寿命。

  16. On-line Payment System Survey – eCash

    Directory of Open Access Journals (Sweden)

    Marius Popa

    2009-12-01

    Full Text Available The paper presents the main aspects regarding an on-line payment system. Some characteristics of such system are presented and an existing system is analyzed. On its fundamental sense, the electronic commerce is a concept that represents the purchase and sale process or exchange of products, services, information, using o computer network, inclusively the Internet. In the most part of the cases, the electronic commerce imply on-line payments that lead to creation of some kinds of electronic money and some specific payment systems. There are described the some electronic payment mechanisms and the architecture and the functions of the on-line payment system E-Cash are depicted.

  17. A Hybrid On-line Verification Method of Relay Setting

    Science.gov (United States)

    Gao, Wangyuan; Chen, Qing; Si, Ji; Huang, Xin

    2017-05-01

    Along with the rapid development of the power industry, grid structure gets more sophisticated. The validity and rationality of protective relaying are vital to the security of power systems. To increase the security of power systems, it is essential to verify the setting values of relays online. Traditional verification methods mainly include the comparison of protection range and the comparison of calculated setting value. To realize on-line verification, the verifying speed is the key. The verifying result of comparing protection range is accurate, but the computation burden is heavy, and the verifying speed is slow. Comparing calculated setting value is much faster, but the verifying result is conservative and inaccurate. Taking the overcurrent protection as example, this paper analyses the advantages and disadvantages of the two traditional methods above, and proposes a hybrid method of on-line verification which synthesizes the advantages of the two traditional methods. This hybrid method can meet the requirements of accurate on-line verification.

  18. Strengthening weak ties through on-line gaming

    DEFF Research Database (Denmark)

    Sudzina, Frantisek; Razmerita, Liana Virginia; Kirchner, Kathrin

    On-line gaming became widespread in the last couple of years. The aim of the research presented in the paper is to figure out to what extent does game playing helps to strengthen weak ties and what additional factors influence this process. The approach is rather exploratory – some factors...... are grounded in theory, some are new. These factors are age, gender, place of origin, number of their Facebook connections (friends in Facebook terminology), the amount of time they are on Facebook, the amount of time they keep the Facebook site open, the amount of time they play on-line games, and the reasons...... for starting to play on-line games. Regarding the latter, we chose to focus only on escapist reasons....

  19. PROFILES AND PREFERENCES OF ON-LINE MILLENIAL SHOPPERS IN BULGARIA

    OpenAIRE

    Loubeau, Patricia R.; Robert Jantzen; Elitsa Alexander

    2014-01-01

    This research seeks to develop a better understanding of the factors affecting on-line purchasing behavior among Generation Y (Gen Y) consumers in Bulgaria. Also called millenials and born between the mid-1970s and late 1990s, this generation is especially active on-line and will be a dominant influence shaping e-commerce. An empirical study was conducted based on a written survey of a sample consisting of 367 high school and university students in Bulgaria. The most important reason why Bulg...

  20. 利用 PGNAA 系统对铝土矿石进行在线检测的可行性研究%Feasibility study for on-line analysis of bauxite using a PGNAA system

    Institute of Scientific and Technical Information of China (English)

    宋青锋; 龚亚林; 张伟; 赵龙; 尚庆敏; 谢福生

    2015-01-01

    利用一款基于瞬发γ中子活化原理设计的主要针对皮带散状物料元素进行在线检测的工业仪器,研究这款仪器用于测量铝土矿组成分析的可行性,实验主要进行了两组样品中 Ca、Si、Al、Fe、Ti 五种元素的测试,其中一组样品由高纯氧化物组成,一组样品由铝土矿和高纯氧化物组成,测量结果表明, CaO、SiO2、Al2 O3、Fe2 O3、TiO2的测量精度分别为±0.23%、±0.18%、±0.35%、±0.14%、±0.08%,能够满足原料自动配比及入厂原料质量控制的要求。%An industrial prompt-gamma neutron activation analysis(PGNAA)system,designed for the real-time elemental analysis of bulk materiel on a conveyor belt,has been studied to examine the feasibility of using such a system for bauxite composition analysis.Experiments were conducted to measure Ca Si Fe Al in two simple,one simple is comprised of pure oxide,and the other simple is comprised of bauxite and pure oxide.The static accuracy are ± 0.23% (CaO),± 0.18% (SiO2 ),± 0.35% (Al2 O3 ),± 0.14% (Fe2 O3 ), ±0.08%(TiO2 ).The instrument can meet the requirements of automatic mixing system of row material and quality controlling after entering factory.

  1. On-Line pre-concentration of Cr(III) and Mn(II) in FI-FAAS: A critical study involving interference effects and analytical use of an immobilized 8-hydroxyquinoline minicolumn

    Energy Technology Data Exchange (ETDEWEB)

    Bruhn, C.G.; Pino, F.E.; Campos, V.H. [Depto. de Analisis Instrumental, Facultad de Farmacia, Universidad de Concepcion, P.O. Box 237, Concepcion (Chile); Nobrega, J.A. [Departamento de Quimica, Universidade Federal de Sao Carlos, Caixa Postal 676, 13565-905, Sao Carlos, SP (Brazil)

    2002-09-01

    A flow injection system with a pre-concentration minicolumn based on a chelating resin was coupled to a flame atomic absorption spectrometer. The focus of this work was the investigation of interference effects and the analytical applicability of the azo-immobilized 8-hydroxyquinoline on controlled-pore glass for the determination of Cr and Mn in mussel and non-fat milk powder. All studied concomitants affected the retention of Cr(III). These effects are probably related to the formation of hydroxo-complexes at the optimum pH range 9.0-10. The positive effect caused by Ca(II) was exploited to increase the retention of Cr(III) species and to improve the slope by 70%. The interferences on Mn(II) retention were less severe. The quantification of Cr and Mn was performed by standard additions. The proposed methodology was validated by analysis of three certified reference materials of mussels (Cr and Mn) and non-fat milk powder (Mn) with a mean relative percent error of <6.5% and mean relative standard deviation of <13%. Chromium and Mn were determined in typical Chilean mussels samples, and Mn was determined in non-fat milk powder samples. Results agreed at the 95% confidence level with those obtained by electrothermal atomic absorption spectrometry (ETAAS) using graphite furnace atomization. The method detection limits for a 30 s pre-concentration time were 0.9 and 1.1 {mu}g L{sup -1} for Mn, and 2.2 and 2.5 {mu}g L{sup -1} for Cr in acid digested solutions of mussel and non-fat milk, respectively. The methodology is simple, fast (sampling frequency 60-72 h{sup -1}), reliable, of low cost, and can be applied to the determination of traces of Cr ({>=}0.18 {mu}g g{sup -1}) and Mn ({>=}0.6 {mu}g g{sup -1}) in mussel samples, and Mn ({>=}0.37 {mu}g g{sup -1}) in non-fat milk powder. (orig.)

  2. Single-collision studies of energy transfer and chemical reaction

    Energy Technology Data Exchange (ETDEWEB)

    Valentini, J.J. [Columbia Univ., New York, NY (United States)

    1993-12-01

    The research focus in this group is state-to-state dynamics of reaction and energy transfer in collisions of free radicals such as H, OH, and CH{sub 3} with H{sub 2}, alkanes, alcohols and other hydrogen-containing molecules. The motivation for the work is the desire to provide a detailed understanding of the chemical dynamics of prototype reactions that are important in the production and utilization of energy sources, most importantly in combustion. The work is primarily experimental, but with an important and growing theoretical/computational component. The focus of this research program is now on reactions in which at least one of the reactants and one of the products is polyatomic. The objective is to determine how the high dimensionality of the reactants and products differentiates such reactions from atom + diatom reactions of the same kinematics and energetics. The experiments use highly time-resolved laser spectroscopic methods to prepare reactant states and analyze the states of the products on a single-collision time scale. The primary spectroscopic tool for product state analysis is coherent anti-Stokes Raman scattering (CARS) spectroscopy. CARS is used because of its generality and because the extraction of quantum state populations from CARS spectra is straightforward. The combination of the generality and easy analysis of CARS makes possible absolute cross section measurements (both state-to-state and total), a particularly valuable capability for characterizing reactive and inelastic collisions. Reactant free radicals are produced by laser photolysis of appropriate precursors. For reactant vibrational excitation stimulated Raman techniques are being developed and implemented.

  3. Electrical and magnetoresistivity studies in chemical solution deposited La

    Energy Technology Data Exchange (ETDEWEB)

    Angappane, S.; Murugaraj, P.; Sethupathi, K.; Rangarajan, G.; Sastry, V. S.; Chakkaravarthi, A. Arul; Ramasamy, P.

    2001-06-01

    High quality magnetoresistive La{sub (1{minus}x)}Ca{sub x}MnO{sub 3} thin films have been prepared by the chemical solution deposition technique. A solution of propionate precursors of lanthanum, calcium, and manganese in propionic acid was used for this purpose. Films of varying compositions (x varying from 0.1 to 0.4) were spin coated on to LaAlO{sub 3}(100) and SrTiO{sub 3}(100) substrates at room temperature and pyrolyzed in the temperature range 600{endash}850{degree}C. For fixed compositions, annealing at higher temperatures shifts the insulator{endash}metal transition temperature (T{sub I{endash}M}) to higher values accompanied by a reduction in the resistivity values. The T{sub I{endash}M} variation for different x values was found to be less pronounced in the compositions x=0.2, 0.3, and 0.4. Typical T{sub I{endash}M} values of 283 K and 290 K were obtained for La{sub 0.7}Ca{sub 0.3}MnO{sub 3} coated on LaAlO{sub 3} and SrTiO{sub 3} substrates, respectively, when annealed at 850{degree}C. The substrate effect was found to be more pronounced for the x value 0.1 which showed two peaks (one at 271 K and another at 122 K) in the {rho}-T curve. The roles of substrate mismatch, composition variation, and annealing temperatures are discussed. {copyright} 2001 American Institute of Physics.

  4. Undisclosed chemicals--implications for risk assessment: a case study from the mining industry.

    Science.gov (United States)

    Singh, Khareen; Oates, Christopher; Plant, Jane; Voulvoulis, Nikolaos

    2014-07-01

    Many of the chemicals used in industry can be hazardous to human health and the environment, and some formulations can have undisclosed ingredients and hazards, increasing the uncertainty of the risks posed by their use. The need for a better understanding of the extent of undisclosed information in chemicals arose from collecting data on the hazards and exposures of chemicals used in typical mining operations (copper, platinum and coal). Four main categories of undisclosed chemicals were defined (incomplete disclosure; chemicals with unspecific identities; relative quantities of ingredients not stated; and trade secret ingredients) by reviewing material safety data sheet (MSDS) omissions in previous studies. A significant number of chemicals (20% of 957 different chemicals) across the three sites had a range of undisclosed information, with majority of the chemicals (39%) having unspecific identities. The majority of undisclosed information was found in commercially available motor oils followed by cleaning products and mechanical maintenance products, as opposed to reagents critical to the main mining processes. All three types of chemicals had trade secrets, unspecific chemical identities and incomplete disclosures. These types of undisclosed information pose a hindrance to a full understanding of the hazards, which is made worse when combined with additional MSDS omissions such as acute toxicity endpoints (LD50) and/or acute aquatic toxicity endpoints (LC50), as well as inadequate hazard classifications of ingredients. The communication of the hazard information in the MSDSs varied according to the chemical type, the manufacturer and the regulations governing the MSDSs. Undisclosed information can undermine occupational health protection, compromise the safety of workers in industry, hinder risk assessment procedures and cause uncertainty about future health. It comes down to the duty of care that industries have towards their employees. With a wide range of

  5. Chemical and quantitive study of hepatotoxins from fresh water ...

    African Journals Online (AJOL)

    Aghomotsegin

    2015-07-22

    Jul 22, 2015 ... Recently, studies on the classification and characterization of ... of Saudi Arabia. In this study we isolated and ..... city for Science and Technology, General directorate of research .... Spirulina platensis in axenic cultures. Bull.

  6. Why do People Stop Playing On-Line Games?

    DEFF Research Database (Denmark)

    Sudzina, Frantisek; Razmerita, Liana

    2012-01-01

    The recent initial public offering of shares of Zynga, probably the most important on-line game provider, drew interest of potential investors but also of general public to their business model. What the most interested people learned so far is that if Zynga had not changed their accounting...... practice, they would be in red numbers for several months already. This is most likely caused by people stopping to play their games. This paper provides an estimate of what proportion of people, who played on-line games, already stopped playing them. Additionally, it analyzed the reasons why people...

  7. On-Line Generation of 3D-Waves

    DEFF Research Database (Denmark)

    Frigaard, Peter

    1992-01-01

    The paper describes the technique of filtering white noise for on-line generation of 3D-waves on a small computer in the laboratory. The wave generation package is implemented and tested in the 3D-wave basin at the University of Aalborg.......The paper describes the technique of filtering white noise for on-line generation of 3D-waves on a small computer in the laboratory. The wave generation package is implemented and tested in the 3D-wave basin at the University of Aalborg....

  8. On-line measurement of heat of combustion

    Science.gov (United States)

    Chaturvedi, S. K.; Chegini, H.

    1988-01-01

    An experimental method for an on-line measurement of heat of combustion of a gaseous hydrocarbon fuel mixture of unknown composition is developed. It involves combustion of a test gas with a known quantity of air to achieve a predetermined oxygen concentration level in the combustion products. This is accomplished by a feedback controller which maintains the gas volumetric flow rate at a level consistent with the desired oxygen concentration in the products. The heat of combustion is determined from a known correlation with the gas volumetric flow rate. An on-line microcomputer accesses the gas volumetric flow data, and displays the heat of combustion values at desired time intervals.

  9. 5th Computer Science On-line Conference

    CERN Document Server

    Senkerik, Roman; Oplatkova, Zuzana; Silhavy, Petr; Prokopova, Zdenka

    2016-01-01

    This volume is based on the research papers presented in the 5th Computer Science On-line Conference. The volume Artificial Intelligence Perspectives in Intelligent Systems presents modern trends and methods to real-world problems, and in particular, exploratory research that describes novel approaches in the field of artificial intelligence. New algorithms in a variety of fields are also presented. The Computer Science On-line Conference (CSOC 2016) is intended to provide an international forum for discussions on the latest research results in all areas related to Computer Science. The addressed topics are the theoretical aspects and applications of Computer Science, Artificial Intelligences, Cybernetics, Automation Control Theory and Software Engineering.

  10. Trace analysis of anions in organic matrices by ion chromatography coupled with a novel reversed-phase column for on-line sample pretreatment

    Institute of Scientific and Technical Information of China (English)

    Ying Ying Zhong; Wen Fang Zhou; Xue Ling Zeng; Ming Li Ye; Yan Zhu

    2011-01-01

    An ion chromatography (IC) system coupled with on-line column-switching technique was used to determine anions of μg/g levels in organic chemicals of analytical reagent grade. A novel polystyrene-divinylbenzene-carbon nanotube (PS-DVB-CNT) stationary phase was utilized for matrix elimination. A calibration study was conducted by preparing and analyzing eight concentrations (between 10 and 5000 μg/L) of eight standards in deionized water. The linearity was between 0.9978 and 1. And the detection limits ranged from 1.54 μg/L to 10.02 μg/L. A spiking study was performed on two representative organic chemicals. The recoveries were between 84.3% and 119.6%.

  11. Worldwide On-line Distance Learning University Astronomy

    Science.gov (United States)

    Eyres, S. P. S.; Hassall, B. J. M.; Butchart, I.; Bromage, G. E.

    2006-08-01

    The University of Central Lancashire operates a suite of distance learning courses in Astronomy, available both on-line and via CD-ROM. The courses are available worldwide, and emphasise flexibility of study. To this end students can study anything from a single module (1/6^th of a full year at degree level) all the way up to an entire degree entirely by distance learning. Study rates vary from one to four modules each year, and students can move on to Level 2 modules (equivalent to second year level in a UK degree) before completing the full set of Level 1 modules. Over 1000 awards have been made to date. The core syllabus is Astronomy and Cosmology at Level 1, alongside skills in literature research, using computers, and basic observing. We also offer a basic history of European astronomy. At Level 2 we look at the astrophysics of the Sun, the stars, and galaxies including the Milky Way. By Level 3 students are expected to engage in a large individual project, and a collaborative investigation with other students, alongside high-level courses in cosmology, relativity, extreme states of matter and the origins of the elements, life and astronomical objects. While many students are retired people looking to exercise their brains, keen amateur amateurs or professionals with disposable incomes, and significant fraction are teachers seeking to improve their subject knowledge or high school students gaining an edge in the UK University entrance competition. Via our involvement with SALT we offer our courses to members of previously disadvantaged communities. This leads to an incredibly diverse and lively student body.

  12. Chemical Risk Evaluation: A Case Study in an Automotive Air Conditioner Production Facility

    Directory of Open Access Journals (Sweden)

    Tengku Hanidza T.I.

    2010-01-01

    Full Text Available There has been limited knowledge on worker’s exposure to chemicals used in the automotive industries. The purpose of this study is to assess chemical risk and to determine the adequacy of the existing control measures to reduce chemical exposure. A cross sectional survey was conducted in a factory involving installation and servicing of automotive air conditioner units. Qualitative exposure assessment was carried out following the Malaysian Chemical Health Risk Assessment Manual (CHRA. There were 180 employees, 156 workers worked in the production line, which constitutes six work units Tube fin pressed, Brazing, Welding, Final assembly, Piping and Kit II. From the chemical risk evaluation for each work unit, 26 chemical compounds were used. Most of the chemicals were irritants (eye and skin and some were asphyxiants and sensitizers. Based on the work assignment, 93 out of 180 (51.67% of the workers were exposed to chemicals. The highest numbers of workers exposed to chemicals were from the Brazing section (22.22% while the Final Assembly section was the lowest (1.67%. Health survey among the workers showed occurrence of eye irritation, skin irritation, and respiratory irritation, symptoms usually associated with chemical exposure. Using a risk rating matrix, several work process were identified as having ‘significant risk’. For these areas, the workers are at risk of adverse health effects since chemical exposure is not adequately controlled. This study recommends corrective actions be taken in order to control the level of exposure and to provide a safe work environment for workers.

  13. On-line professional staff development: an evaluation study

    NARCIS (Netherlands)

    Vries, de Linda; Naidu, Som; Jegede, Olugbemiro; Collis, Betty

    1995-01-01

    This paper reports the design, implementation, and evaluation of a teleseminar on instructional design (ID) and computer-mediated communication (CMC) for the purposes of staff development at The University of Southern Queensland, Toowoomba, Australia. Participation was open to any staff with an invo

  14. On-line student feedback: a pilot study

    Directory of Open Access Journals (Sweden)

    Liz Barnett

    2001-12-01

    Full Text Available Student feedback on courses has been a standard feature of university life for several years, with a substantial research backing to it (see, for example, reviews by Marsh, 1987; Marsh and Dunkin, 1992. Most feedback systems endeavour to serve more than one purpose, with student feedback forming part of the evidence used by: • individual teachers to improve teaching • heads of departments to monitor and guide individual teachers, especially part-time teachers; • course leaders for course development; • senior managers to make decisions on probation and promotion related to teaching performance; consider changes to the wider learning environment; help with the marketing of programmes; • external agencies to assess quality of provision

  15. On-Line Processing of Tense and Temporality in Agrammatic Aphasia

    Science.gov (United States)

    Faroqi-Shah, Yasmeen; Dickey, Michael Walsh

    2009-01-01

    Agrammatic aphasic individuals exhibit marked production deficits for tense morphology. This paper presents three experiments examining whether a group of English-speaking agrammatic individuals (n = 10) exhibit parallel deficits in their comprehension of tense. Results from two comprehension experiments (on-line grammaticality judgment studies)…

  16. Evidence for priming across intervening sentences during on-line sentence comprehension

    NARCIS (Netherlands)

    Tooley, K.M.; Swaab, T.Y.; Boudewyn, M.A.; Zirnstein, M.; Traxler, M.J.

    2014-01-01

    Three experiments investigated factors contributing to syntactic priming during on-line comprehension. In all of the experiments, a prime sentence containing a reduced relative clause was presented prior to a target sentence that contained the same structure. Previous studies have shown that people

  17. Model for on-line moisture-content control during solid-state fermentation

    NARCIS (Netherlands)

    Nagel, F.J.J.I.; Tramper, J.; Bakker, M.S.N.; Rinzema, A.

    2001-01-01

    In this study we describe a model that estimates the extracellular (nonfungal) and overall water contents of wheat grains during solid-state fermentation (SSF) with Aspergillus oryzae, using on-line measurements of oxygen, carbon dioxide, and water vapor in the gas phase. The model uses elemental ba

  18. Optimization of antibody immobilization for on-line or off-line immunoaffinity chromatography

    DEFF Research Database (Denmark)

    Beyer, Natascha Helena; Schou, Christian; Højrup, Peter

    2009-01-01

    . A systematic study was conducted to determine the most versatile antibody immobilization method for use in on-line and off-line IA chromatography applications using commonly accessible immobilization methods. Four chemistries were examined using polyclonal and monoclonal antibodies and antibody fragments. We...

  19. Antioxidants in Raspberry: On-line analysis links antioxidant activity to a diversity of individual metabolites

    NARCIS (Netherlands)

    Beekwilder, M.J.; Jonker, H.H.; Hall, R.D.; Meer, van der I.M.; Vos, de C.H.

    2005-01-01

    The presence of antioxidant compounds can be considered as a quality parameter for edible fruit. In this paper, we studied the antioxidant compounds in raspberry (Rubus idaeus) fruits by high-performance liquid chromatography (HPLC) coupled to an on-line postcolumn antioxidant detection system. Both

  20. The On-Line Yes/No Test as a Placement Tool

    Science.gov (United States)

    Harrington, Michael; Carey, Michael

    2009-01-01

    This study evaluates the concurrent validity of an on-line Yes/No test of recognition vocabulary as a placement tool at an Australian English language school. Newly entering students (n = 88) completed a Yes/No test, which measured accuracy and speed of response, and a school placement battery consisting of grammar, writing, speaking and listening…

  1. On-line monitoring of the crystallization process: relationship between crystal size and electrical impedance spectra

    Science.gov (United States)

    Zhao, Yanlin; Yao, Jun; Wang, Mi

    2016-07-01

    On-line monitoring of crystal size in the crystallization process is crucial to many pharmaceutical and fine-chemical industrial applications. In this paper, a novel method is proposed for the on-line monitoring of the cooling crystallization process of L-glutamic acid (LGA) using electrical impedance spectroscopy (EIS). The EIS method can be used to monitor the growth of crystal particles relying on the presence of an electrical double layer on the charged particle surface and the polarization of double layer under the excitation of alternating electrical field. The electrical impedance spectra and crystal size were measured on-line simultaneously by an impedance analyzer and focused beam reflectance measurement (FBRM), respectively. The impedance spectra were analyzed using the equivalent circuit model and the equivalent circuit elements in the model can be obtained by fitting the experimental data. Two equivalent circuit elements, including capacitance (C 2) and resistance (R 2) from the dielectric polarization of the LGA solution and crystal particle/solution interface, are in relation with the crystal size. The mathematical relationship between the crystal size and the equivalent circuit elements can be obtained by a non-linear fitting method. The function can be used to predict the change of crystal size during the crystallization process.

  2. On-Line Learning and the Implications for School Design

    Science.gov (United States)

    Stack, Greg

    2011-01-01

    "Disrupting Class," published in 2008, is the story of how disruptive innovation, innovation that changes the business model organizations, will fundamentally change the American school system. The book's most startling prediction is that half of all high school classes will be on-line by 2019. In considering these predictions, the author began to…

  3. On-line multidimensional separation systems for peptide analysis

    NARCIS (Netherlands)

    Stroink, T.

    2005-01-01

    Today, there is an increasing interest in selective and sensitive analysis of proteins and peptides with a relatively high speed. The first chapter of this thesis describes several strategies for the on-line multidimensional analysis of peptides and proteins in biological samples. This overview of t

  4. On-line probabilistic classification with particle filters

    DEFF Research Database (Denmark)

    Højen-Sørensen, Pedro; de Freitas, N.; Fog, Torben L.

    2000-01-01

    We apply particle filters to the problem of on-line classification with possibly overlapping classes. This allows us to compute the probabilities of class membership as the classes evolve. Although we adopt neural network classifiers, the work can be extended to any other parametric classification...

  5. Personal Assistant for onLine Services: Addressing human factors

    NARCIS (Netherlands)

    Lindenberg, J.; Nagata, S.F.; Neerincx, M.A.

    2003-01-01

    The Personal Assistant for onLine Services (PALS) project aims at substantially improving the user experience of mobile internet services. It focuses on a generic solution: a personal assistant, which attunes the interaction to the momentary user needs and use context (e.g. adjusting the

  6. Efficiently Building On-line Tools for Distributed Heterogeneous Environments

    Directory of Open Access Journals (Sweden)

    Günther Rackl

    2002-01-01

    Full Text Available Software development is getting more and more complex, especially within distributed middleware-based environments. A major drawback during the overall software development process is the lack of on-line tools, i.e. tools applied as soon as there is a running prototype of an application. The MIMO MIddleware MOnitor provides a solution to this problem by implementing a framework for an efficient development of on-line tools. This paper presents a methodology for developing on-line tools with MIMO. As an example scenario, we choose a distributed medical image reconstruction application, which represents a test case with high performance requirements. Our distributed, CORBA-based application is instrumented for being observed with MIMO and related tools. Additionally, load balancing mechanisms are integrated for further performance improvements. As a result, we obtain an integrated tool environment for observing and steering the image reconstruction application. By using our rapid tool development process, the integration of on-line tools shows to be very convenient and enables an efficient tool deployment.

  7. Why do People Stop playing On-Line Games?

    DEFF Research Database (Denmark)

    Sudzina, Frantisek; Razmerita, Liana

    2012-01-01

    The recent initial public offering of shares of Zynga, probably the most important on-line game provider, drew interest of potential investors but also of general public to their business model. What the most interested people learned so far is that if Zynga had not changed their accounting...

  8. On-line fuzzy logic control of tube bending

    Science.gov (United States)

    Lieh, Junghsen; Li, Wei Jie

    2005-11-01

    This paper describes the simulation and on-line fuzzy logic control of tube bending. By combining elasticity and plasticity theories, a conventional model was developed. The results from simulation were compared with those obtained from testing. The experimental data reveal that there exists certain level of uncertainty and nonlinearity in tube bending, and its variation could be significant. To overcome this, a on-line fuzzy logic controller with self-tuning capabilities was designed. The advantages of this on-line system are (1) its computational requirement is simple in comparison with more algorithmic-based controllers, and (2) the system does not need prior knowledge of material characteristics. The device includes an AC motor, a servo controller, a forming mechanism, a 3D optical sensor, and a microprocessor. This automated bending machine adopts primary and secondary errors between the actual response and desired output to conduct on-line rule reasoning. Results from testing show that the spring back angle can be effectively compensated by the self- tuning fuzzy system in a real-time fashion.

  9. The dynamics of on-line principal component analysis

    NARCIS (Netherlands)

    Biehl, M.; Schlösser, E.

    1998-01-01

    The learning dynamics of an on-line algorithm for principal component analysis is described exactly in the thermodynamic limit by means of coupled ordinary differential equations for a set of order parameters. It is demonstrated that learning is delayed significantly because existing symmetries amon

  10. On-Line Learning and the Implications for School Design

    Science.gov (United States)

    Stack, Greg

    2011-01-01

    "Disrupting Class," published in 2008, is the story of how disruptive innovation, innovation that changes the business model organizations, will fundamentally change the American school system. The book's most startling prediction is that half of all high school classes will be on-line by 2019. In considering these predictions, the author began to…

  11. Specialization processes in on-line unsupervised learning

    NARCIS (Netherlands)

    Biehl, M.; Freking, A.; Reents, G.; Schlösser, E.

    1998-01-01

    From the recent analysis of supervised learning by on-line gradient descent in multilayered neural networks it is known that the necessary process of student specialization can be delayed significantly. We demonstrate that this phenomenon also occurs in various models of unsupervised learning. A sol

  12. On-line sample treatment - Capillary gas chromatography

    NARCIS (Netherlands)

    Goosens, EC; de Jong, D; de Jong, GJ; Brinkman, UAT

    1998-01-01

    Sample pretreatment is often the bottleneck of a trace level analytical procedure. In order to increase performance, increasing attention is therefore being devoted to combining sample pretreatment on-line with the separation technique that has to be used. In the present review, a variety of procedu

  13. ADAPTIVE CONTEXT PROCESSING IN ON-LINE HANDWRITTEN CHARACTER RECOGNITION

    NARCIS (Netherlands)

    Iwayama, N.; Ishigaki, K.

    2004-01-01

    We propose a new approach to context processing in on-line handwritten character recognition (OLCR). Based on the observation that writers often repeat the strings that they input, we take the approach of adaptive context processing. (ACP). In ACP, the strings input by a writer are automatically

  14. The Lesson Observation On-Line (Evidence Portfolio) Platform

    Science.gov (United States)

    Cooper, David G.

    2015-01-01

    At a time when teacher training is being moved to school-based programmes it is important to engage in a research-informed dialogue about creating more distinctive, and cost-effective 21st century models of teacher training. Three years ago I began feasibility field testing the Lesson Observation On-line (Evidence Portfolio) Platform [LOOP]…

  15. On-line EM algorithm for the normalized gaussian network.

    Science.gov (United States)

    Sato, M; Ishii, S

    2000-02-01

    A normalized gaussian network (NGnet) (Moody & Darken, 1989) is a network of local linear regression units. The model softly partitions the input space by normalized gaussian functions, and each local unit linearly approximates the output within the partition. In this article, we propose a new on-line EMalgorithm for the NGnet, which is derived from the batch EMalgorithm (Xu, Jordan, &Hinton 1995), by introducing a discount factor. We show that the on-line EM algorithm is equivalent to the batch EM algorithm if a specific scheduling of the discount factor is employed. In addition, we show that the on-line EM algorithm can be considered as a stochastic approximation method to find the maximum likelihood estimator. A new regularization method is proposed in order to deal with a singular input distribution. In order to manage dynamic environments, where the input-output distribution of data changes over time, unit manipulation mechanisms such as unit production, unit deletion, and unit division are also introduced based on probabilistic interpretation. Experimental results show that our approach is suitable for function approximation problems in dynamic environments. We also apply our on-line EM algorithm to robot dynamics problems and compare our algorithm with the mixtures-of-experts family.

  16. Investigating on-line pornography at the University of Johannesburg

    Directory of Open Access Journals (Sweden)

    P. Laughton

    2008-01-01

    Full Text Available The on-line user of today has access to a vast collection of information resources. In addition, the developments in Internet and Web technologies have made it even easier for surfers to anonymously get access to on-line pornography. The purpose of this research was to investigate the extent to which access to on-line pornography at the University of Johannesburg can be managed. For the empirical part of this research 1037 questionnaires were proportionally distributed to and completed by students on all five campuses of the university. The questionnaire consisted of four sections: biographical information; university computer facility usage; university acceptable use policy; and personal experience with university computer facilities. The gender distribution for the sample was almost even, with a total of 49,4% male participants and 50,6% female, with the largest grouping of respondents (61,6% aged between 19 years and 21 years. Of the respondents, 36,7% indicated that exposure to unsolicited pornography did not bother them. When asked to what extent students should have access to pornography, 60,5% stated 'None' while 32,6% believed that 'Restricted' access should be granted for research purposes and 6,9% believed that students should be granted 'Total' access to pornography. Results from the research will be used to manage access to on-line resources at the University of Johannesburg better.

  17. Investigating on-line pornography at the University of Johannesburg

    Directory of Open Access Journals (Sweden)

    P. Laughton

    2007-12-01

    Full Text Available The on-line user of today has access to a vast collection of information resources. In addition, the developments in Internet and Web technologies have made it even easier for surfers to anonymously get access to on-line pornography. The purpose of this research was to investigate the extent to which access to on-line pornography at the University of Johannesburg can be managed. For the empirical part of this research 1037 questionnaires were proportionally distributed to and completed by students on all five campuses of the university. The questionnaire consisted of four sections: biographical information; university computer facility usage; university acceptable use policy; and personal experience with university computer facilities. The gender distribution for the sample was almost even, with total of 49,4% male participants and 50,6% female, with the largest grouping of respondents(61,6% aged between 19 years and 21 years. Of the respondents, 36,7% indicated that exposure to unsolicited pornography did not bother them. When asked to what extent students should have access to pornography, 60,5% stated 'None' while 32,6% believed that 'Restricted' access should be granted for research purposes and 6,9% believed that students should be granted 'Total' access to pornography. Results from the research will be used to manage access to on-line resources at the University of Johannesburg better.

  18. Why do People Stop Playing On-Line Games?

    DEFF Research Database (Denmark)

    Sudzina, Frantisek; Razmerita, Liana

    2012-01-01

    The recent initial public offering of shares of Zynga, probably the most important on-line game provider, drew interest of potential investors but also of general public to their business model. What the most interested people learned so far is that if Zynga had not changed their accounting...

  19. On-line survivable routing in WDM networks

    NARCIS (Netherlands)

    Beshir, A.A.; Kuipers, F.A.; Van Mieghem, P.F.A.; Orda, A.

    2009-01-01

    In WDM networks, survivable routing and wavelength assignment (SRWA) involves assigning link-disjoint primary and backup lightpaths. In the on-line SRWA problem, a sequence of requests arrive and each request is either accepted or rejected based only on the input sequence seen so far. For special

  20. On-line Survivable Routing in WDM Networks

    NARCIS (Netherlands)

    Beshir, A.A.; Kuipers, F.A.; Van Mieghem, P.; Orda, A.

    In WDM networks, survivable routing and wavelength assignment (SRWA) involves assigning link-disjoint primary and backup lightpaths. In the on-line SRWA problem, a sequence of requests arrive and each request is either accepted or rejected based only on the input sequence seen so far. For special

  1. A study of the chemical composition of peat humic acids by adsorption liquid chromatography

    Energy Technology Data Exchange (ETDEWEB)

    Platonov, V.V.; Proskuryakov, V.A.; Surasinkha, S.; Platonova, M.V.; Taran, N.A. [Lev Tolstoi State Pedagogical University, Tula (Russian Federation)

    1998-12-01

    The chemical composition of peat humic acids was studied in detail by IR and UV spectroscopy, elemental, emission spectral X-ray fluorescence, and structural-group analyses, cryoscopy, and capillary gas chromatography.

  2. DS-OPTIMAL DESIGNS FOR STUDYING COMBINATIONS OF CHEMICALS USING MULTIPLE FIXED-RATIO RAY EXPERIMENTS

    Science.gov (United States)

    ABSTRACT Detecting and characterizing interactions among chemicals is an important environmental issue. Traditional factorial designs become infeasible as the number of compounds under study increases. Ray designs, which reduce the amount of experimental effort, can be...

  3. Non-allergic cutaneous reactions in airborne chemical sensitivity--a population based study

    DEFF Research Database (Denmark)

    Berg, Nikolaj Drimer; Linneberg, Allan; Thyssen, Jacob Pontoppidan;

    2011-01-01

    Multiple chemical sensitivity (MCS) is characterised by adverse effects due to exposure to low levels of chemical substances. The aetiology is unknown, but chemical related respiratory symptoms have been found associated with positive patch test. The purpose of this study was to investigate...... the relationship between cutaneous reactions from patch testing and self-reported severity of chemical sensitivity to common airborne chemicals. A total of 3460 individuals participating in a general health examination, Health 2006, were patch tested with allergens from the European standard series and screened...... sensitivity. Associations were controlled for the possible confounding effects of sex, age, asthma, eczema, atopic dermatitis, psychological and social factors, and smoking habits. In unadjusted analyses we found associations between allergic and non-allergic cutaneous reactions on patch testing and the two...

  4. Problem-based learning in an on-line biotechnology course

    Science.gov (United States)

    Cheaney, James Daniel

    Problem-based learning (PBL) is a pedagogical tool that uses a "real world" problem or situation as a context for learning. PBL encourages student development of critical thinking skills, a high professional competency, problem-solving ability, knowledge acquisition, the ability to work productively as a team member and make decisions in unfamiliar situations, and the acquisition of skills that support self-directed life-long learning, metacognition, and adaptation to change. However, little research has focused on the use of PBL in on-line "virtual" classes. We conducted two studies exploring the use of PBL in an on-line biotechnology course. In the first study, ethical, legal, social, and human issues were used as a motivation for learning about DNA testing technologies, applications, and bioethical issues. In the second study, we combined PBL pedagogy with a rich multimedia environment of streaming video interviews, physical artifacts, and extensive links to articles and databases to create a multidimensional immersive PBL environment called "Robert's World". In "Robert's World", a man is determining whether to undergo a pre-symptomatic DNA test for an untreatable, incurable, fatal genetic disease for which he has a family history. In both studies, design and implementation issues of the on-line PBL environment are discussed, as are differences between on-line PBL and face-to-face PBL. Both studies provide evidence to suggest that PBL stimulates higher-order learning in students. However, in both studies, student performance on an exam testing acquisition of lower-order factual learning was lower for PBL students than for students who learned the same material through a traditional lecture-based approach. Possible reasons for this lower level of performance are explored. Student feedback expressed engagement with the issues and material covered, with reservations about some aspects of the PBL format, such as the lack of flexibility provided in cooperative

  5. IOOS Data Portals and Uniform On-line Browse Capabilities

    Science.gov (United States)

    Howard, M.; Currier, R. D.; Kobara, S.; Gayanilo, F.

    2015-12-01

    The Gulf of Mexico Coastal Ocean Observing System Regional Association (GCOOS-RA) is one of eleven Regional Associations organized under the NOAA-led U.S. Integrated Ocean Observing System (IOOS) Program Office. Each of the RAs operate standards-based regional data portals designed to aggregate near real-time and historical observed data and modeled outputs from distributed providers and to offer these and derived products in standardized ways to a diverse set of users. The RA's portals are based on the IOOS Data and Communications Plan which describes the functional elements needed for an interoperable system. One of these elements is called "Uniform On-line Browse" which is an informational service designed primarily to visualize the inventory of a portal. An on-line browse service supports the end user's need to discover what parameters are available, to learn the spatial and temporal extend of the holdings, and to examine the character of the data (e.g, variability, gappiness, etc). These pieces of information help the end user decide if the data are fit for his/her purpose and to construct valid data requests. Note that on-line browse is a distinctly different activity than data analysis because it seeks to yield knowledge about the inventory and not about what the data mean. "Uniform" on-line browse is a service that takes advantage of the standardization of the data portal's data access points. Most portals represent station locations on a map. This is a view of the data inventory but these plots are rarely generated by pulling data through the standards-based services offered to the end users but through methods only available to the portal programmers. This work will present results of Uniform On-line browse tools developed within GCOOS-RA and their applicability to other RA portals.

  6. Mentoring Narratives ON-LINE:Teaching the Principalship

    Directory of Open Access Journals (Sweden)

    Allison I. Griffith

    2002-05-01

    Full Text Available The need to develop new models for preparation of school administrators has been a prominent concern in educational discourse in the last decade. Having been criticized for the inadequate preparation of the school leadership cadre, academic departments responsible for training future school administrators have had to revisit their approaches and to reframe their teaching philosophies to ensure the readiness of their graduates for the challenges and complexities of school leadership. This article reports on the new model of principals' training that has been used in York University's Principals' Qualification Program (PQP from the late 1990s onward. One component of the program brings traditional case methodology into a computer-mediated/on-line environment. The on-line cases are narratives from the everyday lives of the Ontario school administrators who serve as mentors in the on-line environment. Situating our discussion within the context of the rapidly changing educational landscape of Ontario, we focus on the PQP model to explore experientially generated case narratives as one method for teaching and learning the work of the local school administrator. We focus particularly on the teaching and learning embedded in computer-mediated or on-line case narratives used in training teachers for school leadership. We argue that the complexities of school leadership—the social, cultural, relational, ethical and moral context of school leadership—can be taught effectively through the reflective processes of on-line case narratives. We seek to contribute to the ongoing dialogue on the potential of new pedagogies and new technologies to help prepare the competent and responsible leaders for tomorrow's schools.

  7. Theoretical studies of the dynamics of chemical reactions

    Energy Technology Data Exchange (ETDEWEB)

    Wagner, A.F. [Argonne National Laboratory, IL (United States)

    1993-12-01

    Recent research effort has focussed on several reactions pertinent to combustion. The formation of the formyl radical from atomic hydrogen and carbon monoxide, recombination of alkyl radicals and halo-alkyl radicals with halogen atoms, and the thermal dissociation of hydrogen cyanide and acetylene have been studied by modeling. In addition, the inelastic collisions of NCO with helium have been investigated.

  8. Theoretical Studies in Chemical Kinetics - Annual Report, 1970.

    Science.gov (United States)

    Karplus, Martin

    1970-10-01

    The research performed includes (a) Alkali-Halide, Alkali-Halide (MX, M’X’) Exchange Reactions; (b) Inversion Problem; (c) Quantum Mechanics of Scattering Processes, (d) Transition State Analysis of Classical Trajectories, (e) Differential Cross Sections from Classical Trajectories; and (f) Other Studies.

  9. Chemical Study of the Essential Oil of Mutisia Friesiana

    Directory of Open Access Journals (Sweden)

    J. De la Fuente

    2000-03-01

    Full Text Available The composition of essential oil of Mutisia friesiana (Asteracae was studied. The oil is a complex system in which 127 compounds were identified. The major components are monoterpenes: b-phellandrene, (Z-β-ocimene, α and β-pinene and sabinene.

  10. Using chemical approaches to study selenoproteins - focus on thioredoxin reductases

    OpenAIRE

    Hondal, Robert J.

    2009-01-01

    The study of selenocysteine-containing proteins is difficult due to the problems associated with the heterologous production of these proteins. These problems are due to the intricate recoding mechanism used by cells to translate the UGA codon as a sense codon for selenocysteine. The process is further complicated by the fact that eukaryotes and prokaryotes have different UGA recoding machineries.

  11. study of phytoplanktonin relation to physico- chemical properties of a ...

    African Journals Online (AJOL)

    (Babatunde et al., 2014), without phytoplankton, the diversity and abundance of aquatic life ... (mussels, oysters, scallops and clams), and small fish. These animals provide ... Studies on phytoplankton algae of Lotic effluents environment and fresh water in ... influence of physicochemical parameter of water on phytoplankton ...

  12. Caring On-Line: On-Line Empathy, Self-Disclosure, Emotional Expression, and Nurturing.

    Science.gov (United States)

    Burford, Vicki Niemants; Gross, Daniel D.

    The purpose of this study was to analyze, categorize, and critique actual responses to expressed student confusion and frustration with online courses. Samplings of actual student messages from two courses were used to frame instructor responses, as well as a focus group survey of current college students. The focus of the study was the…

  13. Physico-Chemical Studies of the Pvc K+ - Selective Membrane

    Directory of Open Access Journals (Sweden)

    Ana COROIAN

    2002-12-01

    Full Text Available A plasticized ion-selective membrane based on PVC matrix which tricrezylphosphate (TCP and containing K+ - ionophores (dibenzo-18-crown-6 and decyl-18-crown-6 was used to obtain a potentiometric potassium sensor. The potassium selective membranes were characterized in terms of their electrochemical and physical properties, surface morphology and structural parameters. The a.c. impedance, UV/VIS analysis of the membranes was also studied.

  14. Preliminary Problem Definition Study on Munitions-Related Chemicals.

    Science.gov (United States)

    1979-04-01

    literature; how- S ever, Sander et al. (1975a, b) studied the effect of N-nitrosomorpholine in a series of experiments with cress plants (Lepidiwu sativum...Adenomas by Amines or Ureas Plus Nitrite and by N-Nitroso Compounds: Effect of Ascorbate, Gallic Acid, Thiocyanate, and Caffine ," j. Nat’l Cancer instit...Washington, D.C. Garber, K. (1970), "Air Pollution by Heavy-Metal-Containing Dusts. Effects on Plants ." LandAirt, Forsch, Sonderh., 25, 59-68

  15. Single Particle Analysis by Combined Chemical Imaging to Study Episodic Air Pollution Events in Vienna

    Science.gov (United States)

    Ofner, Johannes; Eitenberger, Elisabeth; Friedbacher, Gernot; Brenner, Florian; Hutter, Herbert; Schauer, Gerhard; Kistler, Magdalena; Greilinger, Marion; Lohninger, Hans; Lendl, Bernhard; Kasper-Giebl, Anne

    2017-04-01

    The aerosol composition of a city like Vienna is characterized by a complex interaction of local emissions and atmospheric input on a regional and continental scale. The identification of major aerosol constituents for basic source appointment and air quality issues needs a high analytical effort. Exceptional episodic air pollution events strongly change the typical aerosol composition of a city like Vienna on a time-scale of few hours to several days. Analyzing the chemistry of particulate matter from these events is often hampered by the sampling time and related sample amount necessary to apply the full range of bulk analytical methods needed for chemical characterization. Additionally, morphological and single particle features are hardly accessible. Chemical Imaging evolved to a powerful tool for image-based chemical analysis of complex samples. As a complementary technique to bulk analytical methods, chemical imaging can address a new access to study air pollution events by obtaining major aerosol constituents with single particle features at high temporal resolutions and small sample volumes. The analysis of the chemical imaging datasets is assisted by multivariate statistics with the benefit of image-based chemical structure determination for direct aerosol source appointment. A novel approach in chemical imaging is combined chemical imaging or so-called multisensor hyperspectral imaging, involving elemental imaging (electron microscopy-based energy dispersive X-ray imaging), vibrational imaging (Raman micro-spectroscopy) and mass spectrometric imaging (Time-of-Flight Secondary Ion Mass Spectrometry) with subsequent combined multivariate analytics. Combined chemical imaging of precipitated aerosol particles will be demonstrated by the following examples of air pollution events in Vienna: Exceptional episodic events like the transformation of Saharan dust by the impact of the city of Vienna will be discussed and compared to samples obtained at a high alpine

  16. Astronomy On-Line Programme Enters "hot Week"

    Science.gov (United States)

    1996-11-01

    World's Biggest Astronomy WWW-Event Attracts Thousands of Students The Astronomy On-line Programme (See ESO Press Release 09/96 of 18 June 1996) began officially on 1 October and is now about to enter its most intense phase, known as the Hot Week . On 18 - 22 November, an estimated 4000 astronomy-interested, mostly young people in Europe and on four other continents will get together during five days in what - not unexpected - has become the world's biggest astronomy event ever organised on the World Wide Web. This carefully structured Programme is carried out in collaboration between the European Association for Astronomy Education (EAAE), the European Southern Observatory and the European Commission, under the auspices of the Fourth European Week for Scientific and Technological Culture. The Programme has already had a most visible impact on the school education of natural sciences in various countries; for instance, the Internet-connection of schools has been advanced in some, in order to allow groups to participate. There have been numerous contacts among the groups across the borders and there are clear signs that many Astronomy On-line participants have progressed to use the impressive possibilities of the Web in an efficient and structured way. There has been a lively media interest in Astronomy On-line all over Europe and it is expected to increase during the next week. The current status of Astronomy On-line It is obvious that the pilot function of the Astronomy On-line Programme in the use of the Web has been very effective and that the associated dissemination of astronomical knowledge has been successful. At this time, more than 650 groups have registered with Astronomy On-line. Most come from 31 different European countries and a few dozen groups are located in North and South America as well as in Asia and Australia. Together they have experienced the steady build-up of Astronomy On-line over the past weeks, by means of numerous contributions from a

  17. Empirical Force Fields for Mechanistic Studies of Chemical Reactions in Proteins.

    Science.gov (United States)

    Das, A K; Meuwly, M

    2016-01-01

    Following chemical reactions in atomistic detail is one of the most challenging aspects of current computational approaches to chemistry. In this chapter the application of adiabatic reactive MD (ARMD) and its multistate version (MS-ARMD) are discussed. Both methods allow to study bond-breaking and bond-forming processes in chemical and biological processes. Particular emphasis is put on practical aspects for applying the methods to investigate the dynamics of chemical reactions. The chapter closes with an outlook of possible generalizations of the methods discussed.

  18. An Investigative Study of Safety Management Practices in Chemical-Related Industries

    Science.gov (United States)

    Lewers, Sarah Grace

    Industrial chemicals are a major part of the United States economic growth and impact every product that we use in everyday life. Some of the major products produced by chemical-related industries are plastics, textiles, petroleum, paper and important metals. Governmental regulations like those created by the Occupational Safety and Health Organization (OSHA), Environmental Protection Agency (EPA) and the U.S. Chemical Safety and Hazard Investigation Board are vital to a chemical-related industries' safety management. Contributing to and helping to drive economic growth, the enforcement of proper safety practices is a necessity. This study was conducted to investigate and assess various safety management practices in selected chemical-related industries. The research design involved the use of a questionnaire/survey method in which a random sample of participants completed a questionnaire related to the variables of interest. Random sampling helps to ensure the generalizability of the survey results. The target population consisted of a subset of employees currently working for plants, businesses and organizations in chemical-related industries. To collect the data, surveys were given to employees in various positions at chemical-related industries such as basic chemicals, specialty chemicals, agricultural chemicals, pharmaceuticals and consumer products. A set of criteria was created to establish the qualification to be recognized as a chemical-related industry. The questionnaire/survey was reviewed by the Institutional Review Board at NC A&T State University to meet necessary regulation guidelines for research involving human subjects. The results showed that 60.22% or more than half of the respondents have worked with their company and organization for over thirty years providing the ability to see the progression of chemical-related industry safety management practices over time. Over eighty percent (80.66%) or 146 respondents agreed that their company or

  19. Physico-chemical studies for strontium sulfate radiation dosimeter

    Directory of Open Access Journals (Sweden)

    M.A.H. Rushdi

    2015-04-01

    Full Text Available Anhydrous strontium sulfate (SrSO4 has shown a promise candidate as a dosimeter for low dose applications producing unique EPR signals with γ-rays which it has a linear response relationship (r2 = 0.999 in the range of 1–100 Gy. The present study extended to evaluate the properties of strontium sulfate dosimeter in intermediate dose range of technology applications. It was observed that the intensity of the EPR signal at g = 2.01081 increases with a 3rd polynomial function in the range of 0.10–15 kGy. In addition, the radical (SO4− provides a stable signal with a good reproducibility (0.107%. Other physics characteristic including the collision of mass stopping power dependence of the system and the effect of atomic number in different energy regions were investigated. The uncertainty budget for high doses has obtained from the measurement with value of 3.57% at 2σ confidence level.

  20. Chemical Biology Studies on Molecular Diversity of Annonaceous Acetogenins

    Institute of Scientific and Technical Information of China (English)

    Yao Zhu-Jun

    2004-01-01

    Annonaceous acetogenins, isolated from the Annonaceae plants, have been attracting worldwide attention in recent years due to their biological activities, especially as growth inhibitors of certain tumor ceils [ 1 ]. They have been shown to function by blocking complex I in mitochondria [2] as well as ubiquinone-linked NADPH oxidase in the cells of specific tumor cell lines, including some multidrug-resistant ones [3]. These features make these acetogenins excellent leads for the new antitumor agents. In our previous work, the compounds 1a to 1d (Figure 1), which relies on structure simplification while maintaining all essential functionalities of the acetogenins, was in vitro tested against several human solid tumor cell lines and showed interesting cell selectivity [4]. All four analogues show remarkable activity against the HCT-8 and HT-29 cell lines, while compound 1c was found the best [4bi. In order to further investigate the effects of key structural features, a convergent parallel fragments assembly strategy was developed [4e]. In addition, the biological relevancies of typical annonaceous acetogenin mimetics were also studied [4f].

  1. CERN HR receives award for on-line recruitment and communication

    CERN Multimedia

    Joannah Caborn Wengler

    2012-01-01

    In a survey of 21,000 European students, CERN ranked 15th, ahead of giants like Microsoft and Nestlé, for the quality of its on-line "talent communication", that is how it uses the Internet to attract job applicants. HR now boasts a new virtual award, certifying its on-line savvy.   The "virtual" award given to HR. How did you get your job at CERN? Via the CERN HR website, or Facebook, or Twitter? Or were you headhunted on LinkedIn? Particularly if you’re from the younger generation, chances are that you used some form of on-line recruitment. In this case you will have used one of the best recruitment tools in Europe, according to the 2012 OTaC (Online Talent Communication) study, carried out by a research institute named Potentialpark. It surveyed over 21,000 students, asking them to rate employers’ use of seven different channels of communication about jobs and careers, from HR websites and on-line application systems to the...

  2. Engaging Students On-Line:Does Gender Matter in Adoption of Learning Material Design?

    Directory of Open Access Journals (Sweden)

    Norziani Dahalan

    2013-12-01

    Full Text Available Education is reforming with the birth of the internet. Learning is not solely based on classroom basis but also through on-line. The revolution of Internet has transformed teaching via face-to-face into virtual teaching. The expansion of teaching deliveries suggests that we need interactive mechanism to accommodate course material for on-line students. However, creating on-line materials requires the conception of on-line instructional design. A suitable online material design will allow learners to engage with learning. Learners will have opportunities to develop their own understanding. In addition, suitable learning material will strengthen learner’s knowledge construction from their short-term memory to long-term memory. The purpose of this paper is to discover the learning material design approach based on gender by evaluating lecturer’s adoption of online material design using Keller’s ARCS model. The sample consisting of 30 lecturers from distance education learning reveals that gender differs in their adoption of learning material design specifically on getting attention of the student. The result also shows that relevance and satisfaction contribute to gender differences in learning material adoption. Limitations of the study and practical implications of these findings discussed.

  3. Comparing the Hierarchy of Keywords in On-Line News Portals

    Science.gov (United States)

    Tibély, Gergely; Sousa-Rodrigues, David; Pollner, Péter; Palla, Gergely

    2016-01-01

    Hierarchical organization is prevalent in networks representing a wide range of systems in nature and society. An important example is given by the tag hierarchies extracted from large on-line data repositories such as scientific publication archives, file sharing portals, blogs, on-line news portals, etc. The tagging of the stored objects with informative keywords in such repositories has become very common, and in most cases the tags on a given item are free words chosen by the authors independently. Therefore, the relations among keywords appearing in an on-line data repository are unknown in general. However, in most cases the topics and concepts described by these keywords are forming a latent hierarchy, with the more general topics and categories at the top, and more specialized ones at the bottom. There are several algorithms available for deducing this hierarchy from the statistical features of the keywords. In the present work we apply a recent, co-occurrence-based tag hierarchy extraction method to sets of keywords obtained from four different on-line news portals. The resulting hierarchies show substantial differences not just in the topics rendered as important (being at the top of the hierarchy) or of less interest (categorized low in the hierarchy), but also in the underlying network structure. This reveals discrepancies between the plausible keyword association frameworks in the studied news portals. PMID:27802319

  4. Comparing the Hierarchy of Keywords in On-Line News Portals.

    Science.gov (United States)

    Tibély, Gergely; Sousa-Rodrigues, David; Pollner, Péter; Palla, Gergely

    2016-01-01

    Hierarchical organization is prevalent in networks representing a wide range of systems in nature and society. An important example is given by the tag hierarchies extracted from large on-line data repositories such as scientific publication archives, file sharing portals, blogs, on-line news portals, etc. The tagging of the stored objects with informative keywords in such repositories has become very common, and in most cases the tags on a given item are free words chosen by the authors independently. Therefore, the relations among keywords appearing in an on-line data repository are unknown in general. However, in most cases the topics and concepts described by these keywords are forming a latent hierarchy, with the more general topics and categories at the top, and more specialized ones at the bottom. There are several algorithms available for deducing this hierarchy from the statistical features of the keywords. In the present work we apply a recent, co-occurrence-based tag hierarchy extraction method to sets of keywords obtained from four different on-line news portals. The resulting hierarchies show substantial differences not just in the topics rendered as important (being at the top of the hierarchy) or of less interest (categorized low in the hierarchy), but also in the underlying network structure. This reveals discrepancies between the plausible keyword association frameworks in the studied news portals.

  5. Distributed Fiber Optic Sensor for On-Line Monitoring of Coal Gasifier Refractory Health

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Anbo [Center for Photonics Technology, Blacksburgh, VA (United States); Yu, Zhihao [Center for Photonics Technology, Blacksburgh, VA (United States)

    2015-11-30

    This report summarizes technical progress on the program “Distributed Fiber Optic Sensor for On-Line Monitoring of Coal Gasifier Refractory Health,” funded by the National Energy Technology Laboratory of the U.S. Department of Energy, and performed by the Center for Photonics Technology of the Bradley Department of Electrical and Computer Engineering at Virginia Tech. The scope of work entails analyses of traveling grating generation technologies in an optical fiber, as well as the interrogation of the gratings to infer a distributed temperature along the fiber, for the purpose of developing a real-time refractory health condition monitoring technology for coal gasifiers. During the project period, which is from 2011-2015, three different sensing principles were studied, including four-wave mixing (FWM), coherent optical time-domain reflectometer (C-OTDR) and Brillouin optical time-domain analysis (BOTDA). By comparing the three methods, the BOTDA was selected for further development into a complete bench-top sensing system for the proposed high-temperature sensing application. Based on the input from Eastman Chemical, the industrial collaborator on this project, a cylindrical furnace was designed and constructed to simulate typical gasifier refractory temperature conditions in the laboratory, and verify the sensor’s capability to fully monitor refractory conditions on the back-side at temperatures up to 1000°C. In the later stages of the project, the sensing system was tested in the simulated environment for its sensing performance and high-temperature survivability. Through theoretical analyses and experimental research on the different factors affecting the sensor performance, a sensor field deployment strategy was proposed for possible future sensor field implementations.

  6. A small-scale air-cathode microbial fuel cell for on-line monitoring of water quality.

    Science.gov (United States)

    Di Lorenzo, Mirella; Thomson, Alexander R; Schneider, Kenneth; Cameron, Petra J; Ieropoulos, Ioannis

    2014-12-15

    The heavy use of chemicals for agricultural, industrial and domestic purposes has increased the risk of freshwater contamination worldwide. Consequently, the demand for efficient new analytical tools for on-line and on-site water quality monitoring has become particularly urgent. In this study, a small-scale single chamber air-cathode microbial fuel cell (SCMFC), fabricated by rapid prototyping layer-by-layer 3D printing, was tested as a biosensor for continuous water quality monitoring. When acetate was fed as the rate-limiting substrate, the SCMFC acted as a sensor for chemical oxygen demand (COD) in water. The linear detection range was 3-164 ppm, with a sensitivity of 0.05 μA mM(-1) cm(-2) with respect to the anode total surface area. The response time was as fast as 2.8 min. At saturating acetate concentrations (COD>164 ppm), the miniature SCMFC could rapidly detect the presence of cadmium in water with high sensitivity (0.2 μg l(-1) cm(-2)) and a lower detection limit of only 1 μg l(-1). The biosensor dynamic range was 1-25 μg l(-1). Within this range of concentrations, cadmium affected only temporarily the electroactive biofilm at the anode. When the SCMFCs were again fed with fresh wastewater and no pollutant, the initial steady-state current was recovered within 12 min.

  7. IVO, a device for In situ Volatilization and On-line detection of products from heavy ion reactions

    CERN Document Server

    Duellmann, C E; Eichler, R; Gäggeler, H W; Jost, D T; Piguet, D; Türler, A

    2002-01-01

    A new gaschromatographic separation system to rapidly isolate heavy ion reaction products in the form of highly volatile species is described. Reaction products recoiling from the target are stopped in a gas volume and converted in situ to volatile species, which are swept by the carrier gas to a chromatography column. Species that are volatile under the given conditions pass through the column. In a cluster chamber, which is directly attached to the exit of the column, the isolated volatile species are chemically adsorbed to the surface of aerosol particles and transported to an on-line detection system. The whole set-up was tested using short-lived osmium (Os) and mercury (Hg) nuclides produced in heavy ion reactions to model future chemical studies with hassium (Hs, Z=108) and element 112. By varying the temperature of the isothermal section of the chromatography column between room temperature and -80 deg. C, yield measurements of given species can be conducted, yielding information about the volatility o...

  8. The role of mathematical modelling in chemical and food engineering studies

    OpenAIRE

    Brandão, Teresa R. S.; Silva, Cristina L. M.

    2003-01-01

    The role of mathematical modelling in chemical and food engineering studies is briefly and consistently presented. The main goal was to give a short global overview of the relevant aspects involved in modelling processes. Food engineering problems are generally highlighted. It must be emphasised that the following matter should not be analysed in a narrow perspective. The mathematical modelling field, in chemical and food engineering subjects, is very wide and this paper just presents the ...

  9. Consumer products as sources of chemical exposures to children: case study of triclosan.

    Science.gov (United States)

    Ginsberg, Gary L; Balk, Sophie J

    2016-04-01

    Consumer products are often overlooked as sources of children's exposures to toxic chemicals. Various regulatory bodies have developed lists of chemicals of concern that can be found in products contacted by children. However, this information has not been summarized for health practitioners. This review organizes such chemicals and products into four categories, with the antibacterial agent triclosan used to illustrate the potential risks to children from a common ingredient in consumer products. Biomonitoring, house dust, indoor air, and product testing document children's exposures to a wide variety of chemicals. An increasing number of epidemiology studies have shown associations between these exposures and health effects in children. Triclosan is an example of a chemical contained in high contact products (e.g., soaps, lotions, and toothpaste) not necessarily designed for children. Triclosan exposure in children has been associated with increased responsiveness to airway allergens, with it also capable of endocrine disruption. However, the utility and necessity of this chemical in consumer products has not been demonstrated in most cases. Triclosan and the other examples provided show that a changing marketplace with little regulatory oversight of chemical uses can lead to unanticipated exposures and potential health risks to children.

  10. On-line corrosion monitoring in district heating systems

    DEFF Research Database (Denmark)

    Richter, Sonja; Thorarinsdottir, R.I.; Hilbert, Lisbeth Rischel

    2004-01-01

    complicates the chemistry of the environment. Hydrogen sulphide is present in geothermal systems and can be formed as a by-product of sulphate-reducing-bacteria (SRB). The application of electrochemical methods makes on-line monitoring possible. These methods include: Linear Polarization Resistance (LPR......), Electrochemical Noise (EN) and Zero Resistance Ammetry (ZRA). Electrochemical Resistance (ER) has also been used to measure corrosion. The method traditionally only measures corrosion off-line but with newly developed high-sensitive ER technique developed by MetriCorr in Denmark, on-line monitoring is possible......Traditionally corrosion monitoring in district heating systems has been performed offline via weight loss coupons. These measurements give information about the past and not the present situation and require long exposure time (weeks or months). The good quality of district heating medium makes...

  11. On-Line Metrology with Conoscopic Holography: Beyond Triangulation

    Science.gov (United States)

    Álvarez, Ignacio; Enguita, Jose M.; Frade, María; Marina, Jorge; Ojea, Guillermo

    2009-01-01

    On-line non-contact surface inspection with high precision is still an open problem. Laser triangulation techniques are the most common solution for this kind of systems, but there exist fundamental limitations to their applicability when high precisions, long standoffs or large apertures are needed, and when there are difficult operating conditions. Other methods are, in general, not applicable in hostile environments or inadequate for on-line measurement. In this paper we review the latest research in Conoscopic Holography, an interferometric technique that has been applied successfully in this kind of applications, ranging from submicrometric roughness measurements, to long standoff sensors for surface defect detection in steel at high temperatures. PMID:22399984

  12. On-line Corrosion Monitoring in District Heating Systems

    DEFF Research Database (Denmark)

    Richter, Sonja; Thorarinsdottir, R.I.; Hilbert, Lisbeth Rischel

    2005-01-01

    The corrosion control in district heating systems is today performed primarily with control of the water quality. The corrosion rate is kept low by assuring low dissolved oxygen concentration, high pH and low conductivity. Corrosion failures can occur, e.g. as a result of unknown oxygen ingress......, precipitation of deposits or crevices. The authors describe methods used for on-line monitoring of corrosion, cover the complications and the main results of a Nordic project....

  13. On-Line and Back at S.F.U.

    Directory of Open Access Journals (Sweden)

    M. Sanderson

    1973-06-01

    Full Text Available Simon Fraser University library began operation with an automated circulation system. After deliberation, it mounted the first phase of a two-phase online circulation system. A radically revised loan pol·icy caused the system design and assumptions to be called into question. A cheaper, simpler, and more effective off-line system eventually replaced the on-line system. The systems, fiscal, and administrative implications of this decision are reviewed.

  14. Two Types of Designs for On-Line Circulation Systems

    Directory of Open Access Journals (Sweden)

    Rob McGee

    1972-09-01

    Full Text Available On-line circulation systems divide into two types. One type contains records only for charged or otherwise absent items. The other contains a file of records for all titles or volumes in the library collection, regardless of their circulation status. This paper traces differences between the two types, examining different kinds of files and terminals, transaction evidence, the quality of bibliographic data, querying, and the possibility of functions outside circulation. Aspects of both operational and potential systems are considered.

  15. Differential Electronic Nose in On-Line Dynamic Measurements

    Directory of Open Access Journals (Sweden)

    Osowski S.

    2014-12-01

    Full Text Available The paper presents application of differential electronic nose in the dynamic (on-line volatile measurement. First we compare the classical nose employing only one sensor array and its extension in the differential form containing two sensor arrays working in differential mode. We show that differential nose performs better at changing environmental conditions, especially the temperature, and well performs in the dynamic mode of operation. We show its application in recognition of different brands of tobacco

  16. On-line phase space measurement with kicker excitation

    Science.gov (United States)

    Dietrich, J.; Maier, R.; Mohos, I.

    1998-12-01

    A new method for on-line phase space measurements with kicker excitation at COSY was developed. The position data were measured using the analog output of two beam position monitors (BPMs) and directly monitored on a digital storage oscilloscope with an external clock (bunch-synchronous sampling). Nonlinear behavior of the proton beam was visible as well as were resonance islands. Typical measurements are presented.

  17. The new on-line Czech Food Composition Database.

    Science.gov (United States)

    Machackova, Marie; Holasova, Marie; Maskova, Eva

    2013-10-01

    The new on-line Czech Food Composition Database (FCDB) was launched on http://www.czfcdb.cz in December 2010 as a main freely available channel for dissemination of Czech food composition data. The application is based on a complied FCDB documented according to the EuroFIR standardised procedure for full value documentation and indexing of foods by the LanguaL™ Thesaurus. A content management system was implemented for administration of the website and performing data export (comma-separated values or EuroFIR XML transport package formats) by a compiler. Reference/s are provided for each published value with linking to available freely accessible on-line sources of data (e.g. full texts, EuroFIR Document Repository, on-line national FCDBs). LanguaL™ codes are displayed within each food record as searchable keywords of the database. A photo (or a photo gallery) is used as a visual descriptor of a food item. The application is searchable on foods, components, food groups, alphabet and a multi-field advanced search. Copyright © 2013 Elsevier Ltd. All rights reserved.

  18. DEVELOPMENT OF AN ON-LINE COAL WASHABILITY ANALYZER

    Energy Technology Data Exchange (ETDEWEB)

    J.D. Miller; C.L. Lin; G.H. Luttrell; G.T. Adel; Barbara Marin

    2001-06-26

    Washability analysis is the basis for nearly all coal preparation plant separations. Unfortunately, there are no on- line techniques for determining this most fundamental of all coal cleaning information. In light of recent successes at the University of Utah, it now appears possible to determine coal washability on-line through the use of x-ray computed tomography (CT) analysis. The successful development of such a device is critical to the establishment of process control and automated coal blending systems. In this regard, Virginia Tech, Terra Tek Inc., and U.S. coal producers have joined with the University of Utah and to undertake the development of an X-ray CT-based on- line coal washability analyzer with financial assistance from DOE. Each project participant brought special expertise to the project in order to create a new dimension in coal cleaning technology. The project involves development of appropriate software and extensive testing/evaluation of well-characterized coal samples from operating coal preparation plants. Data collected to date suggest that this new technology is capable of serving as a universal analyzer that can not only provide washability analysis, but also particle size distribution analysis, ash analysis, and perhaps pyritic sulfur analysis.

  19. DEVELOPMENT OF AN ON-LINE COAL WASHABILITY ANALYZER

    Energy Technology Data Exchange (ETDEWEB)

    J.D. Miller

    1999-09-30

    Washability analysis is the basis for nearly all coal preparation plant separations. Unfortunately, there are no on-line techniques for determining this most fundamental of all coal cleaning information. In light of recent successes at the University of Utah, it now appears possible to determine coal washability on-line through the use of x-ray computed tomography (CT) analysis. The successful development of such a device is critical to the establishment of process control and automated coal blending systems. In this regard, Virginia Tech, Terra Tek Inc., and several eastern coal companies have joined with the University of Utah and agreed to undertake the development of a x-ray CT-based on-line coal washability analyzer with financial assistance from DOE. The three-year project will cost $594,571, of which 33% ($194,575) will be cost-shared by the participants. The project involves development of appropriate software and extensive testing/evaluation of well-characterized coal samples from operating coal preparation plants. Each project participant brings special expertise to the project which is expected to create a new dimension in coal cleaning technology. Finally, it should be noted that the analyzer may prove to be a universal analyzer capable of providing not only washability analysis, but also particle size distribution analysis, ash analysis and perhaps pyritic sulfur analysis.

  20. Designing effective on-line continuing medical education.

    Science.gov (United States)

    Zimitat, Craig

    2001-03-01

    The Internet, and new information and communication technologies available through the Internet, provides medical educators with an opportunity to develop unique on-line learning environments with real potential to improve physicians' knowledge and effect change in their clinical practice. There are approximately 100 websites offering on-line CME courses in the USA alone. However, few of these CME courses appear to be based on sound educational principles or CME research and may have little chance of achieving the broader goals of CME. The majority of these courses closely resemble their traditional counterparts (e.g. paper-based books are now electronic books) and appear to be mere substitutions for old-technology CME resources. Whilst some CME providers add unique features of the Internet to enrich their websites, they do not employ strategies to optimize the learning opportunities afforded by this new technology. The adoption of adult learning principles, reflective practice and problem-based approaches can be used as a foundation for sound CME course design. In addition, knowledge of Internet technology and the learning opportunities it affords, together with strategies to maintain participation and new assessment paradigms, are all needed for developing online CME. We argue for an evidence-based and strategic approach to the development of on-line CME courses designed to enhance physician learning and facilitate change in clinical behaviour.

  1. A note on on-line Ramsey numbers for quadrilaterals

    Directory of Open Access Journals (Sweden)

    Joanna Cyman

    2014-01-01

    Full Text Available We consider on-line Ramsey numbers defined by a game played between two players, Builder and Painter. In each round Builder draws an the edge and Painter colors it either red or blue, as it appears. Builder's goal is to force Painter to create a monochromatic copy of a fixed graph \\(H\\ in as few rounds as possible. The minimum number of rounds (assuming both players play perfectly is the on-line Ramsey number \\(\\widetilde{r}(H\\ of the graph \\(H\\. An asymmetric version of the on-line Ramsey numbers \\(\\widetilde{r}(G,H\\ is defined accordingly. In 2005, Kurek and Ruciński computed \\(\\widetilde{r}(C_3\\. In this paper, we compute \\(\\widetilde{r}(C_4,C_k\\ for \\(3 \\le k \\le 7\\. Most of the results are based on computer algorithms but we obtain the exact value \\(\\widetilde{r}(C_4\\ and do so without the help of computer algorithms.

  2. An Informatics Approach to Evaluating Combined Chemical Exposures from Consumer Products: A Case Study of Asthma-Associated Chemicals and Potential Endocrine Disruptors.

    Science.gov (United States)

    Gabb, Henry A; Blake, Catherine

    2016-08-01

    Simultaneous or sequential exposure to multiple environmental stressors can affect chemical toxicity. Cumulative risk assessments consider multiple stressors but it is impractical to test every chemical combination to which people are exposed. New methods are needed to prioritize chemical combinations based on their prevalence and possible health impacts. We introduce an informatics approach that uses publicly available data to identify chemicals that co-occur in consumer products, which account for a significant proportion of overall chemical load. Fifty-five asthma-associated and endocrine disrupting chemicals (target chemicals) were selected. A database of 38,975 distinct consumer products and 32,231 distinct ingredient names was created from online sources, and PubChem and the Unified Medical Language System were used to resolve synonymous ingredient names. Synonymous ingredient names are different names for the same chemical (e.g., vitamin E and tocopherol). Nearly one-third of the products (11,688 products, 30%) contained ≥ 1 target chemical and 5,229 products (13%) contained > 1. Of the 55 target chemicals, 31 (56%) appear in ≥ 1 product and 19 (35%) appear under more than one name. The most frequent three-way chemical combination (2-phenoxyethanol, methyl paraben, and ethyl paraben) appears in 1,059 products. Further work is needed to assess combined chemical exposures related to the use of multiple products. The informatics approach increased the number of products considered in a traditional analysis by two orders of magnitude, but missing/incomplete product labels can limit the effectiveness of this approach. Such an approach must resolve synonymy to ensure that chemicals of interest are not missed. Commonly occurring chemical combinations can be used to prioritize cumulative toxicology risk assessments. Gabb HA, Blake C. 2016. An informatics approach to evaluating combined chemical exposures from consumer products: a case study of asthma

  3. An Informatics Approach to Evaluating Combined Chemical Exposures from Consumer Products: A Case Study of Asthma-Associated Chemicals and Potential Endocrine Disruptors

    Science.gov (United States)

    Gabb, Henry A.; Blake, Catherine

    2016-01-01

    exposures from consumer products: a case study of asthma-associated chemicals and potential endocrine disruptors. Environ Health Perspect 124:1155–1165; http://dx.doi.org/10.1289/ehp.1510529 PMID:26955064

  4. A photometric study of chemically peculiar stars with the STEREO satellites. II. Non-magnetic chemically peculiar stars

    CERN Document Server

    Paunzen, E; Fossati, L; Netopil, M; White, G J; Bewsher, D

    2012-01-01

    We have analysed the photometric data obtained with the STEREO spacecraft for 558 non-magnetic chemically peculiar (CP) stars to search for rotational and pulsational variability. Applying the Lomb-Scargle and the phase dispersion minimisation methods, we have detected photometric variability for 44 objects from which 35 were previously unknown. The new objects are all bright stars on the Ecliptic Plane (magnitude range 4.7 < V < 11.7) and will therefore be of great interest to studies of stellar structure and evolution. In particular, several show multiple signals consistent with hybrid delta Scuti and gamma Doradus pulsation, with different periodicities allowing very different regions of the stellar interior to be studied. There are two subgroups of stars in our sample: the cool metallic line Am (CP1) and the hot HgMn (CP3) stars. These objects fall well inside the classical instability strip where delta Scuti, gamma Doradus and slowly pulsating B-type stars are located. We also expect to find period...

  5. A Study of the Impact of the on the Accuracy of On-Line Raw Structure of Item Bank Item Attribute Identification%题库结构对原始题在线属性标定准确性之影响研究

    Institute of Scientific and Technical Information of China (English)

    汪文义; 丁树良

    2012-01-01

    目前已有研究证明可达阵在认知诊断测验编制中起重要作用,但迄今为止并没有引起普遍注意。本文主要讨论当题库缺少可达阵对应的某些项目类,对原始题的属性向量在线标定的准确性的影响。本文对含6个属性的独立型结构进行了模拟试验,结果显示:如果题库不充要,原始题的属性标定准确性受到影响,题库中非可达阵中项目对标定有一定的弥补作用。间接印证了可达阵在认知诊断题库起到非常重要的作用。%Cognitive Diagnostic Assessment is based on the incidence Q-matrix (Tatsuoka, 2009). The entries of Q-matrix indicate which skills and knowledge are involved in the solution of each item. In real situations, no matter whether the items have or have not been identified attributes before its construction, it will cost a lot of money, require more efforts to identify attributes through specialists according to the special procedure and yet can' t completely assume the correctness due to the subjectivity. On-line item attributes iden- tification as a new field and study of the impact of item bank hasn' t been found in the literature. So this study is concerned with the impact of item bank on on-line item attributes identification in cognitive diagnostic computerized adaptive testing ( CD-CAT), especially when the item bank doesn' t include the whole reachability matrix. The study describes the impact of knowledge states' equivalent classes on the item attributes vectors ' equivalent classes. Some of those are called the discriminating item attribute vector when the item attribute vectors' equivalent classes only include one item attribute vector; the others are called indiscriminate item attribute vector. Moreover, the study introduces the Marginal Maximum Likelihood Estimation (MMLE) for on-line item attribute identification, which integrates the uncertainty of estimate knowledge states in the procedure

  6. Blaptica dubia as sentinels for exposure to chemical warfare agents - a pilot study.

    Science.gov (United States)

    Worek, Franz; Seeger, Thomas; Neumaier, Katharina; Wille, Timo; Thiermann, Horst

    2016-11-16

    The increased interest of terrorist groups in toxic chemicals and chemical warfare agents presents a continuing threat to our societies. Early warning and detection is a key component for effective countermeasures against such deadly agents. Presently available and near term solutions have a number of major drawbacks, e.g. lack of automated, remote warning and detection of primarily low volatile chemical warfare agents. An alternative approach is the use of animals as sentinels for exposure to toxic chemicals. To overcome disadvantages of vertebrates the present pilot study was initiated to investigate the suitability of South American cockroaches (Blaptica dubia) as warning system for exposure to chemical warfare nerve and blister agents. Initial in vitro experiments with nerve agents showed an increasing inhibitory potency in the order tabun - cyclosarin - sarin - soman - VX of cockroach cholinesterase. Exposure of cockroaches to chemical warfare agents resulted in clearly visible and reproducible reactions, the onset being dependent on the agent and dose. With nerve agents the onset was related to the volatility of the agents. The blister agent lewisite induced signs largely comparable to those of nerve agents while sulfur mustard exposed animals exhibited a different sequence of events. In conclusion, this first pilot study indicates that Blaptica dubia could serve as a warning system to exposure of chemical warfare agents. A cockroach-based system will not detect or identify a particular chemical warfare agent but could trigger further actions, e.g. specific detection and increased protective status. By designing appropriate boxes with (IR) motion sensors and remote control (IR) camera automated off-site warning systems could be realized.

  7. Using Physiologically-Based Pharmacokinetic Models to Incorporate Chemical and Non-Chemical Stressors into Cumulative Risk Assessment: A Case Study of Pesticide Exposures

    Directory of Open Access Journals (Sweden)

    Jonathan I. Levy

    2012-05-01

    Full Text Available Cumulative risk assessment has been proposed as an approach to evaluate the health risks associated with simultaneous exposure to multiple chemical and non-chemical stressors. Physiologically based pharmacokinetic/pharmacodynamic (PBPK/PD models can allow for the inclusion and evaluation of multiple stressors, including non-chemical stressors, but studies have not leveraged PBPK/PD models to jointly consider these disparate exposures in a cumulative risk context. In this study, we focused on exposures to organophosphate (OP pesticides for children in urban low-income environments, where these children would be simultaneously exposed to other pesticides (including pyrethroids and non-chemical stressors that may modify the effects of these exposures (including diet. We developed a methodological framework to evaluate chemical and non-chemical stressor impacts on OPs, utilizing an existing PBPK/PD model for chlorpyrifos. We evaluated population-specific stressors that would influence OP doses or acetylcholinesterase (AChE inhibition, the relevant PD outcome. We incorporated the impact of simultaneous exposure to pyrethroids and dietary factors on OP dose through the compartments of metabolism and PD outcome within the PBPK model, and simulated combinations of stressors across multiple exposure ranges and potential body weights. Our analyses demonstrated that both chemical and non-chemical stressors can influence the health implications of OP exposures, with up to 5-fold variability in AChE inhibition across combinations of stressor values for a given OP dose. We demonstrate an approach for modeling OP risks in the presence of other population-specific environmental stressors, providing insight about co-exposures and variability factors that most impact OP health risks and contribute to children’s cumulative health risk from pesticides. More generally, this framework can be used to inform cumulative risk assessment for any compound impacted by

  8. A new chemical scheme to study carbon-rich exoplanet atmospheres

    CERN Document Server

    Venot, Olivia; Agúndez, Marcelino; Decin, Leen; Bounaceur, Roda

    2015-01-01

    Atmospheres with a high C/O ratio are expected to contain an important quantity of hydrocarbons, including heavy molecules (with more than 2 carbon atoms). To study correctly these C-rich atmospheres, a chemical scheme adapted to this composition is necessary. We have implemented a chemical scheme that can describe the kinetics of species with up to 6 carbon atoms. This chemical scheme has been developed with specialists of combustion and validated through experiments on a wide range of T and P. This chemical network is available on the online database KIDA. We have created a grid of 12 models to explore different thermal profiles and C/O ratios. For each of them, we have compared the chemical composition determined with a C0-C2 chemical scheme (species with up to 2 carbon atoms) and with the C0-C6 scheme. We found no difference in the results obtained with the two schemes when photolyses are not included in the model, whatever the temperature of the atmosphere. In contrast, when there is photochemistry, diff...

  9. Occupational exposure to chemicals and fetal growth: the Generation R Study.

    NARCIS (Netherlands)

    Snijder, C.A.; Roeleveld, N.; Velde, E. te; Steegers, E.A.P.; Raat, H.; Hofman, A.; Jaddoe, V.W.; Burdorf, A.

    2012-01-01

    BACKGROUND: Developmental diseases, such as birth defects, growth restriction and preterm delivery, account for >25% of infant mortality and morbidity. Several studies have shown that exposure to chemicals during pregnancy is associated with adverse birth outcomes. The aim of this study was to

  10. Occupational exposure to chemicals and fetal growth: The Generation R Study

    NARCIS (Netherlands)

    C.A. Snijder (Claudia); N. Roeleveld (Nel); E.R. te Velde (Egbert); E.A.P. Steegers (Eric); H. Raat (Hein); A. Hofman (Albert); V.W.V. Jaddoe (Vincent); A. Burdorf (Alex)

    2012-01-01

    textabstractBackground Developmental diseases, such as birth defects, growth restriction and preterm delivery, account for >25 of infant mortality and morbidity. Several studies have shown that exposure to chemicals during pregnancy is associated with adverse birth outcomes. The aim of this study

  11. IR study on surface chemical properties of catalytic grown carbon nanotubes and nanofibers

    Institute of Scientific and Technical Information of China (English)

    Li-hua TENG; Tian-di TANG

    2008-01-01

    In this study, the surface chemical properties of carbon nanotubes (CNTs) and carbon nanofibers (CNFs) grown by catalytic decomposition of methane on nickel and cobalt based catalysts were studied by DRIFT (Diffuse Reflectance Infrared Fourier Transform) and transmission Infrared (IR) spectroscopy. The results show that the surface exists not only carbon-hydrogen groups, but also carboxyl, ketene or quinone (carbonyl) oxygen-containing groups. These functional groups were formed in the process of the material growth, which result in large amount of chemical defect sites on the walls.

  12. Physico-chemical studies of radiation effects in cells: Final report

    Energy Technology Data Exchange (ETDEWEB)

    Powers, E.L.

    1987-03-01

    The career of Dr. E.L. Powers, a pioneer in the development of radiobiology, is reviewed. His initial research involved the effects of radiation and certain chemicals on Paramecium, associated ultrastructural studies on protozoan cells, responses of Rickettsia and bacteriophage to irradiation, and the development of techniques for studying bacterial spores. These efforts established the basic radiation biology of the spore and its importance in understanding the effects of free radicals, oxygen, and water. His recent research extended work on the dry spore to the very wet spore and to other selected chemical systems in aqueous suspension. 126 refs., 2 figs.

  13. Chemical compatibility study of Cooley L18KU, Herculite, and Elephant Mat with Hanford tank waste

    Energy Technology Data Exchange (ETDEWEB)

    Mercado, J.E.

    1998-06-23

    An independent chemical compatibility review of various wrapping and absorbent/padding materials was conducted to evaluate resistance to chemicals and constituents present in liquid waste from the Hanford underground tanks. These materials will be used to wrap long-length contaminated equipment when such equipment is removed from the tanks and prepared for transportation and subsequent disposal or storage. The materials studied were Cooley L18KU, Herculite, and Elephant Mat. The study concludes that these materials are appropriate for use in this application.

  14. A Refreshable, On-line Cache for HST Data Retrieval

    Science.gov (United States)

    Fraquelli, Dorothy A.; Ellis, Tracy A.; Ridgaway, Michael; DPAS Team

    2016-01-01

    We discuss upgrades to the HST Data Processing System, with an emphasis on the changes Hubble Space Telescope (HST) Archive users will experience. In particular, data are now held on-line (in a cache) removing the need to reprocess the data every time they are requested from the Archive. OTFR (on the fly reprocessing) has been replaced by a reprocessing system, which runs in the background. Data in the cache are automatically placed in the reprocessing queue when updated calibration reference files are received or when an improved calibration algorithm is installed. Data in the on-line cache are expected to be the most up to date version. These changes were phased in throughout 2015 for all active instruments.The on-line cache was populated instrument by instrument over the course of 2015. As data were placed in the cache, the flag that triggers OTFR was reset so that OTFR no longer runs on these data. "Hybrid" requests to the Archive are handled transparently, with data not yet in the cache provided via OTFR and the remaining data provided from the cache. Users do not need to make separate requests.Users of the MAST Portal will be able to download data from the cache immediately. For data not in the cache, the Portal will send the user to the standard "Retrieval Options Page," allowing the user to direct the Archive to process and deliver the data.The classic MAST Search and Retrieval interface has the same look and feel as previously. Minor changes, unrelated to the cache, have been made to the format of the Retrieval Options Page.

  15. On-line learning algorithms for locally recurrent neural networks.

    Science.gov (United States)

    Campolucci, P; Uncini, A; Piazza, F; Rao, B D

    1999-01-01

    This paper focuses on on-line learning procedures for locally recurrent neural networks with emphasis on multilayer perceptron (MLP) with infinite impulse response (IIR) synapses and its variations which include generalized output and activation feedback multilayer networks (MLN's). We propose a new gradient-based procedure called recursive backpropagation (RBP) whose on-line version, causal recursive backpropagation (CRBP), presents some advantages with respect to the other on-line training methods. The new CRBP algorithm includes as particular cases backpropagation (BP), temporal backpropagation (TBP), backpropagation for sequences (BPS), Back-Tsoi algorithm among others, thereby providing a unifying view on gradient calculation techniques for recurrent networks with local feedback. The only learning method that has been proposed for locally recurrent networks with no architectural restriction is the one by Back and Tsoi. The proposed algorithm has better stability and higher speed of convergence with respect to the Back-Tsoi algorithm, which is supported by the theoretical development and confirmed by simulations. The computational complexity of the CRBP is comparable with that of the Back-Tsoi algorithm, e.g., less that a factor of 1.5 for usual architectures and parameter settings. The superior performance of the new algorithm, however, easily justifies this small increase in computational burden. In addition, the general paradigms of truncated BPTT and RTRL are applied to networks with local feedback and compared with the new CRBP method. The simulations show that CRBP exhibits similar performances and the detailed analysis of complexity reveals that CRBP is much simpler and easier to implement, e.g., CRBP is local in space and in time while RTRL is not local in space.

  16. On-line yields obtained with the ISOLDE RILIS

    Energy Technology Data Exchange (ETDEWEB)

    Koester, U. E-mail: ulli.koster@cern.ch; Fedoseyev, V.N.; Andreyev, A.N.; Bergmann, U.C.; Catherall, R.; Cederkaell, J.; Dietrich, M.; De Witte, H.; Fedorov, D.V.; Fraile, L.; Franchoo, S.; Fynbo, H.; Georg, U.; Giles, T.; Gorska, M.; Hannawald, M.; Huyse, M.; Joinet, A.; Jonsson, O.C.; Kratz, K.L.; Kruglov, K.; Lau, Ch.; Lettry, J.; Mishin, V.I.; Oinonen, M.; Partes, K.; Peraejaervi, K.; Pfeiffer, B.; Ravn, H.L.; Seliverstov, M.D.; Thirolf, P.; Van de Vel, K.; Van Duppen, P.; Van Roosbroeck, J.; Weissman, L

    2003-05-01

    The ISOLDE resonance ionization laser ion source (RILIS) allows to ionize efficiently and selectively many metallic elements. In recent yield surveys and on-line experiments with the ISOLDE RILIS we observed {sup 23-34}Mg, {sup 26-34}Al, {sup 98-132}Cd, {sup 149}Tb, {sup 155-177}Yb, {sup 179-200}Tl, {sup 183-215}Pb and {sup 188-218}Bi. The obtained yields are presented together with measured release parameters which allow to extrapolate the release efficiency towards more exotic (short-lived) nuclides of the same elements.

  17. Integrated sensor array for on-line monitoring micro bioreactors

    NARCIS (Netherlands)

    Krommenhoek, Erik Eduard

    2007-01-01

    In this thesis the development of a microbioreactor array with integrated sensoss suitable for on-line screening of micro organisms is described. Therefore, an array of 2 micro bioreactors compatible with the 96-well microtiterplate format has been made and tested. The developed system was shown to 

  18. TELCAL: The On-line Calibration Software for ALMA

    Science.gov (United States)

    Broguière, D.; Lucas, R.; Pardo, J.; Roche, J.-C.

    2011-07-01

    The ALMA on-line calibration regroups all the operations needed to maintain the ALMA interferometer optimally tuned to successfully execute the planned observations. The results of the calibrations are used in quasi-real time by the ALMA Control System. Since the first ALMA antennas were put into operation in 2009, TELCAL has been used for all the basic calibration operations and is still being improved following the project advancement. We describe here the calibrations done by TELCAL, its relationships with the other ALMA software subsystems and, briefly, the architecture of the software based on CORBA.

  19. Molecularly imprinted polymers for on-line extraction techniques.

    Science.gov (United States)

    Moein, Mohammad M; Abdel-Rehim, Mohamed

    2015-01-01

    Recent years have seen an increasing interest in the use of molecularly imprinted polymers (MIPs) as a sorbent for different extraction methods and this is due to its high selectivity. The MIP is designed to show specificity for the analyte of interest. Moreover, MIPs show physical robustness, resistance to high temperatures and pressures, and stability in the presence of acids, bases and a wide range of organic solvents. In the present article, various novel sample preparation techniques which MIPs applied as sorbent and on-line connected with analytical instruments were highlighted and discussed. The future aspects of MIPs as well were described.

  20. On-line Adaptive Radiation Treatment of Prostate Cancer

    Science.gov (United States)

    2008-01-01

    volume (GTV), mandible, rainstem, parotids , and lymph nodes. Another physician repeated he contouring on all planning and on-line images...computed entation. Note the consistency of delineation of gross olume; light blue, nodes; purple, parotid glands; green,k com ostregicomp urs on e...0.9 1.0 Mandible D S C in de x Patient # 1 2 3 4 5 6 7 0.5 0.6 0.7 0.8 0.9 1.0 Left Parotid D S C in de x Patient # Fig. 6. Dice similarity

  1. Adaptive calibration method with on-line growing complexity

    Directory of Open Access Journals (Sweden)

    Šika Z.

    2011-12-01

    Full Text Available This paper describes a modified variant of a kinematical calibration algorithm. In the beginning, a brief review of the calibration algorithm and its simple modification are described. As the described calibration modification uses some ideas used by the Lolimot algorithm, the algorithm is described and explained. Main topic of this paper is a description of a synthesis of the Lolimot-based calibration that leads to an adaptive algorithm with an on-line growing complexity. The paper contains a comparison of simple examples results and a discussion. A note about future research topics is also included.

  2. On-line Measurements of Settling Charateristics in Activated Sludge

    DEFF Research Database (Denmark)

    Rasmussen, Michael R.; Larsen, Torben

    1997-01-01

    An on-line settling column for measuring the dynamic variations of settling velocity of activated sludge has been developed. The settling column is automatic and self-cleansing insuring continuous and reliable measurements. The settling column was tested on sludge from a batch reactor where sucrose...... was added as an impulse to activated sludge. The continuous measurement of settling velocity revealed a highly dynamic response after the sucrose was added. The result were verified with simultaneous measurement of the initial settling rate. A 200 hour experiment showed variations in settling velocity...

  3. Lower Bounds and Semi On-line Multiprocessor Scheduling

    Directory of Open Access Journals (Sweden)

    T.C. Edwin Cheng

    2003-10-01

    Full Text Available We are given a set of identical machines and a sequence of jobs from which we know the sum of the job weights in advance. The jobs have to be assigned on-line to one of the machines and the objective is to minimize the makespan. An algorithm with performance ratio 1.6 and a lower bound of 1.5 is presented. This improves recent results by Azar and Regev who published an algorithm with performance ratio 1.625 for the less general problem that the optimal makespan is known in advance.

  4. On-line Monitoring and Active Control for Transformer Noise

    Science.gov (United States)

    Liang, Jiabi; Zhao, Tong; Tian, Chun; Wang, Xia; He, Zhenhua; Duan, Lunfeng

    This paper introduces the system for on-line monitoring and active noise control towards the transformer noise based on LabVIEW and the hardware equipment including the hardware and software. For the hardware part, it is mainly focused on the composition and the role of hardware devices, as well as the mounting location in the active noise control experiment. And the software part introduces the software flow chats, the measurement and analysis module for the sound pressure level including A, B, C weighting methods, the 1/n octave spectrum and the power spectrum, active noise control module and noise data access module.

  5. Efficient and Secure Comparison for On-Line Auctions

    DEFF Research Database (Denmark)

    Damgård, Ivan Bjerre; Krøigaard, Mikkel; Geisler, Martin Joakim

    2007-01-01

    We propose a protocol for secure comparison of integers based on homomorphic encryption. We also propose a homomorphic encryption scheme that can be used in our protocol and makes it more efficient than previous solutions. Our protocol is well-suited for application in on-line auctions, both...... with respect to functionality and performance. It minimizes the amount of information bidders need to send, and for comparison of 16 bit numbers with security based on 1024 bit RSA (executed by two parties), our implementation takes 0.28 seconds including all computation and communication. Using precomputation...

  6. On-line matrix addition for detecting aerosol particles

    Institute of Scientific and Technical Information of China (English)

    ZHOU; Liuzhu; ZHU; Yuan; GUO; Xiaoyong; ZHAO; Wenwu; ZHENG; Haiyang; Gu; Xuejun; FANG; Li; ZHANG; Weijun

    2006-01-01

    Single aerosol particles were measured by matrix-assisted laser desorption/ionization (MALDI) with an aerosol time-of-flight mass spectrometer (ATOFMS). The inlet to the ATOFMS was coupled with an evaporation/condensation flow cell that allowed matrix addition by condensation onto the particles. The coated particles entered the ion source through three-stage differentially pumped capillary inlet and were then ionized by a focused 266 nm Nd:YAG laser. The mass spectra and aerodynamic size of the single particles can be obtained simultaneously. The on-line matrix addition technique makes it possible to identify biological aerosols in real-time.

  7. The Design of Partial Discharge On-Line Monitoring System for XLPE Power Cable

    OpenAIRE

    Chen Rui-Long; Qian Yong; Ye Hai-Feng; Sheng Ge-Hao; Jiang Xiu-Chen

    2013-01-01

    Partial discharge detection is an important means to assess the situation of XLPE power cable’s insulation. This study has developed an on-line monitoring system which applies to the medium voltage XLPE cable on partial discharge, described its working principle, components of hardware, software designing and program implementation in details. Through monitoring the partial discharge signal in grounding lines of the XLPE cable’s shield, the system integrated assess the situation of XLPE cable...

  8. On-line chemical cleaning of pipelines; Limpieza quimica de ductos en linea

    Energy Technology Data Exchange (ETDEWEB)

    Cross, Michael Brent [Brenntag Stinnes Logistics, Muelheim/Ruhr (Germany)

    2003-07-01

    The concern of efficiency and maintenance in the pipeline industry, due to fluids and sediments, has led the development of new methods of cleaning. Some methods of cleaning are described in this work with their advantages and disadvantages.

  9. Dispositif de détection en régime transitoire. Etude de la distribution des temps de séjour et application à la distillation simulée en ligne Transient-Flow Detection Device. Study of Residence-Time Distribution and Application to Simulated on-Line Distillation

    Directory of Open Access Journals (Sweden)

    Besson N.

    2006-11-01

    Full Text Available Cet article décrit une technique très simple à mettre en oeuvre et qui permet la détection de phénomènes transitoires. Le système proposé est un détecteur à ionisation de flamme, permettant la détection continue d'un signal proportionnel à la concentration des réactifs. Différentes utilisations de cet appareillage sont proposées : - étude de la distribution des temps de séjour d'un réacteur lit fluidisé; - déclenchement de l'analyse de distillation simulée en ligne au maximum de concentration des effluents, avec par ailleurs, la proposition d'une méthode d'étalonnage interne permettant de s'affranchir des problèmes de non-reproductibilité en chromatographie. This article describes a very simple technique to implement for detecting transient phenomena. The system proposed is a flameionization detector for the continuous detection of a signal proportional to the concentration of reactants. Different uses of this device are proposed: (1 studying the residence-time distribution of a fluidized-bed reactor; (2 triggering the analysis of simulated on-line distillation at maximum effluent concentration, including, moreover, the proposal of an internal calibration method for getting around problems of nonreproducibility in chromatography.

  10. A qualitative study of high school students' pre- and post instructional conceptions in chemical bonding

    Science.gov (United States)

    Wang, Renhong

    This study investigated high school students' understanding of chemical bonding prior to and after formal chemistry instruction. Two sets of clinical interviews were conducted prior to and after formal instructions on the topic of chemical bonding using a teacher-as-researcher protocol. Twenty-two students enrolled in a New York Regents Chemistry course were interviewed. Six students participated in the pilot study and the other sixteen were involved in the full study. Oral and pictorial data from the interviews were collected and analyzed in two parts; first, the students' conceptual understanding of chemical bonding including common themes, ideas and misconceptions were identified; second, profiles of each student were made to determine conceptual changes due to formal instruction. The findings showed that students were not familiar with the basic components and structure of atoms, especially the electrostatic properties of the sub-atomic particles. Inter-particle distance, rather than the electrostatic forces between particles, was believed to be the determining cause of the state of matter of a substance. The role of repulsive and attractive electrostatic forces in chemical bonding was not recognized. Students were unable to accurately describe the underlying scientific concepts for all types of chemical bonding and revealed a number of misconceptions, which were resistant to change by instruction. Specific areas of difficulty included the accurate descriptions of ionic bonding, covalent bonding and hydrogen bonding. Further, almost all the students could not use electrostatic forces to explain three states of water and phase changes and most students were unable to describe the energy that was released or absorbed due to bond formation or breaking. Student difficulties stemmed from a lack of understanding of some of the underlying, fundamental chemistry, such as the basic atomic structure, the particulate nature of mater and the role of electrostatic forces in

  11. Developing an EEG based On-line Closed-loop Lapse Detection and Mitigation System

    Directory of Open Access Journals (Sweden)

    Yu-Te eWang

    2014-10-01

    Full Text Available In America, sixty percent of adults reported that they have driven a motor vehicle while feeling drowsy, and at least 15-20% of fatal car accidents are fatigue-related. This study translates previous laboratory-oriented neurophysiological research to design, develop, and test an On-line Closed-loop Lapse Detection and Mitigation (OCLDM System featuring a mobile wireless dry-sensor EEG headgear and a cell-phone based real-time EEG processing platform. Eleven subjects participated in an event-related lane-keeping task, in which they were instructed to manipulate a randomly deviated, fixed-speed cruising car on a 4-lane highway. This was simulated in a 1st person view with an 8-screen and 8-projector immersive virtual-realty environment. When the subjects experienced lapses or failed to respond to events during the experiment, auditory feedback was delivered to rectify the performance decrements. However, the arousing auditory signals were not always effective. The EEG spectra exhibited statistically significant differences between effective and ineffective arousing signals, suggesting that EEG spectra could be used as a countermeasure of the efficacy of arousing signals. In this on-line pilot study, the proposed OCLDM System was able to continuously detect EEG signatures of fatigue, deliver arousing feedback to subjects suffering momentary cognitive lapses, and assess the efficacy of the feedback in near real-time to rectify cognitive lapses. The on-line testing results of the OCLDM System validated the efficacy of the arousing signals in improving subjects' response times to the subsequent lane-departure events. This study may lead to a practical on-line lapse detection and mitigation system in real-world environments.

  12. Research of on-line detection system for power capacitor

    Science.gov (United States)

    Yao, Junda; Qian, Zheng; Yu, Hao; Xia, Jiuyun

    2016-01-01

    The hidden danger exists in the power capacitor of power system due to long-time operation under the environment of high voltage. Thus, it is possible to induce serious fault, and the on-line detection system is urgently required. In this paper, two methods of the on-line detection system are compared in order to realize the better real-time condition detection. The first method is based on the STM microprocessor with an internal 12 bit A/D converter, which converts analog signals which is arrived from the sample circuit into digital signals, and then the FFT algorithm is used to accomplish the measurement of the voltage and current values of the capacitor. The second method is based on the special electric energy metering IC, which can obtain RMS (Root Mean Square) of voltage and current by processing the sampled data of the voltage and current, and store RMS of voltage and current in its certain registers. The operating condition of the capacitor can be obtained after getting the values of voltage and current. By comparing the measuring results of two methods, the second method could achieve a higher measurement accuracy and more simple construction.

  13. Polar On-Line Acquisition Relay and Transmission System (POLARATS)

    Energy Technology Data Exchange (ETDEWEB)

    Yuracko, K.

    2004-07-15

    POLARATS (Polar On-Line Acquisition Relay And Transmission System) is being developed by YAHSGS LLC (YAHSGS) and Oak Ridge National Laboratory (ORNL) to provide remote, unattended monitoring of environmental parameters under harsh environmental conditions. In particular, instrumental design and engineering is oriented towards protection of human health in the Arctic, and with the additional goal of advancing Arctic education and research. POLARATS will obtain and transmit environmental data from hardened monitoring devices deployed in locations important to understanding atmospheric and aquatic pollutant migration as it is biomagnified in Arctic food chains. An Internet- and personal computer (PC)-based educational module will provide real time sensor data, on-line educational content, and will be integrated with workbooks and textbooks for use in middle and high school science programs. The educational elements of POLARATS include an Internet-based educational module that will instruct students in the use of the data and how those data fit into changing Arctic environments and food chains. POLARATS will: (1) Enable students, members of the community, and scientific researchers to monitor local environmental conditions in real time over the Internet; and (2) Provide additional educational benefits through integration with middle- and high-school science curricula. Information will be relayed from POLARATS devices to classrooms and libraries along with custom-designed POLARATS teaching materials that will be integrated into existing curricula to enhance the educational benefits realized from the information obtained.

  14. On-line estimation of concentration parameters in fermentation processes

    Institute of Scientific and Technical Information of China (English)

    XIONG Zhi-hua; HUANG Guo-hong; SHAO Hui-he

    2005-01-01

    It has long been thought that bioprocess, with their inherent measurement difficulties and complex dynamics, posed almost insurmountable problems to engineers. A novel software sensor is proposed to make more effective use of those measurements that are already available, which enable improvement in fermentation process control. The proposed method is based on mixtures of Gaussian processes (GP) with expectation maximization (EM) algorithm employed for parameter estimation of mixture of models. The mixture model can alleviate computational complexity of GP and also accord with changes of operating condition in fermentation processes, i.e., it would certainly be able to examine what types of process-knowledge would be most relevant for local models' specific operating points of the process and then combine them into a global one. Demonstrated by on-line estimate of yeast concentration in fermentation industry as an example, it is shown that soft sensor based state estimation is a powerful technique for both enhancing automatic control performance of biological systems and implementing on-line monitoring and optimization.

  15. On-line structure-lossless digital mammogram image compression

    Science.gov (United States)

    Wang, Jun; Huang, H. K.

    1996-04-01

    This paper proposes a novel on-line structure lossless compression method for digital mammograms during the film digitization process. The structure-lossless compression segments the breast and the background, compresses the former with a predictive lossless coding method and discards the latter. This compression scheme is carried out during the film digitization process and no additional time is required for the compression. Digital mammograms are compressed on-the-fly while they are created. During digitization, lines of scanned data are first acquired into a small temporary buffer in the scanner, then they are transferred to a large image buffer in an acquisition computer which is connected to the scanner. The compression process, running concurrently with the digitization process in the acquisition computer, constantly checks the image buffer and compresses any newly arrived data. Since compression is faster than digitization, data compression is completed as soon as digitization is finished. On-line compression during digitization does not increase overall digitizing time. Additionally, it reduces the mammogram image size by a factor of 3 to 9 with no loss of information. This algorithm has been implemented in a film digitizer. Statistics were obtained based on digitizing 46 mammograms at four sampling distances from 50 to 200 microns.

  16. On-Line Core Thermal-Hydraulic Model Improvement

    Energy Technology Data Exchange (ETDEWEB)

    In, Wang Kee; Chun, Tae Hyun; Oh, Dong Seok; Shin, Chang Hwan; Hwang, Dae Hyun; Seo, Kyung Won

    2007-02-15

    The objective of this project is to implement a fast-running 4-channel based code CETOP-D in an advanced reactor core protection calculator system(RCOPS). The part required for the on-line calculation of DNBR were extracted from the source of the CETOP-D code based on analysis of the CETOP-D code. The CETOP-D code was revised to maintain the input and output variables which are the same as in CPC DNBR module. Since the DNBR module performs a complex calculation, it is divided into sub-modules per major calculation step. The functional design requirements for the DNBR module is documented and the values of the database(DB) constants were decided. This project also developed a Fortran module(BEST) of the RCOPS Fortran Simulator and a computer code RCOPS-SDNBR to independently calculate DNBR. A test was also conducted to verify the functional design and DB of thermal-hydraulic model which is necessary to calculate the DNBR on-line in RCOPS. The DNBR margin is expected to increase by 2%-3% once the CETOP-D code is used to calculate the RCOPS DNBR. It should be noted that the final DNBR margin improvement could be determined in the future based on overall uncertainty analysis of the RCOPS.

  17. Precise On-line Position Measurement for Particle Therapy

    CERN Document Server

    Actis, O; König, S

    2014-01-01

    An on-line beam position monitoring and regular beam stability tests are of utmost importance for the Quality Assurance (QA) of the patient treatment at any particle therapy facility. The Gantry${0.5 mm}2$ at the Paul Scherrer Institute uses a strip ionization chamber for the on-line beam position verification. The design of the strip chamber placed in the beam in front of the patient allows for a small beam penumbra in order to achieve a high-quality lateral beam delivery. The detector granularity and the low noise allow the reconstruction of the signals offered by Gantry${0.5 mm}2$ with a precision of about 0.1 mm. The frond-end electronics and the whole data processing sequence have been optimized for minimizing the dead time between the beam applications to about 2 ms: the charge collection is performed in about 1 ms, read-out takes place in 100 $\\mu$s while data verification and logging are completed in less than 1 ms. The sub-millimeter precision of the lateral reconstruction allows the dose inhomogenei...

  18. Fully On-line Introductory Physics with a Lab

    Science.gov (United States)

    Schatz, Michael

    We describe the development and implementation of a college-level introductory physics (mechanics) course and laboratory that is suited for both on-campus and on-line environments. The course emphasizes a ``Your World is Your Lab'' approach whereby students first examine and capture on video (using cellphones) motion in their immediate surroundings, and then use free, open-source software both to extract data from the video and to apply physics principles to build models that describe, predict, and visualize the observations. Each student reports findings by creating a video lab report and posting it online; these video lab reports are then distributed to the rest of the class for peer review. In this talk, we will discuss the student and instructor experiences in courses offered to three distinct audiences in different venues: (1) a Massively Open On-line Course (MOOC) for off-campus participants, (2) a flipped/blended course for on-campus students, and, most recently, (3) a fully-online course for off-campus students.

  19. On-Line Method and Apparatus for Coordinated Mobility and Manipulation of Mobile Robots

    Science.gov (United States)

    Seraji, Homayoun (Inventor)

    1996-01-01

    A simple and computationally efficient approach is disclosed for on-line coordinated control of mobile robots consisting of a manipulator arm mounted on a mobile base. The effect of base mobility on the end-effector manipulability index is discussed. The base mobility and arm manipulation degrees-of-freedom are treated equally as the joints of a kinematically redundant composite robot. The redundancy introduced by the mobile base is exploited to satisfy a set of user-defined additional tasks during the end-effector motion. A simple on-line control scheme is proposed which allows the user to assign weighting factors to individual degrees-of-mobility and degrees-of-manipulation, as well as to each task specification. The computational efficiency of the control algorithm makes it particularly suitable for real-time implementations. Four case studies are discussed in detail to demonstrate the application of the coordinated control scheme to various mobile robots.

  20. On-line least squares support vector machine algorithm in gas prediction

    Institute of Scientific and Technical Information of China (English)

    ZHAO Xiao-hu; WANG Gang; ZHAO Ke-ke; TAN De-jian

    2009-01-01

    Traditional coal mine safety prediction methods are off-line and do not have dynamic prediction functions. The Support Vector Machine (SVM) is a new machine learning algorithm that has excellent properties. The least squares support vector machine (LS-SVM) algorithm is an improved algorithm of SVM. But the common LS-SVM algorithm, used directly in safety predictions, has some problems. We have first studied gas prediction problems and the basic theory of LS-SVM. Given these problems, we have investigated the affect of the time factor about safety prediction and present an on-line prediction algorithm, based on LS-SVM. Finally, given our observed data, we used the on-line algorithm to predict gas emissions and used other related algorithm to com- pare its performance. The simulation results have verified the validity of the new algorithm.