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Sample records for catalytic adsorptive stripping

  1. Quantitative Analysis of Trace Chromium in Blood Samples. Combination of the Advanced Oxidation Process with Catalytic Adsorptive Stripping Voltammetry

    OpenAIRE

    Yong, Li; Armstrong, Kristie C.; Dansby-Sparks, Royce N.; Carrington, Nathan A.; Chambers, James Q.; Xue, Zi-Ling

    2006-01-01

    A new method for pretreating blood samples for trace Cr analysis is described. The Advanced Oxidation Process (AOP with H2O2 and 5.5-W irradiation for 60 min) is used to remove biological/organic species for subsequent analysis. Prior to the AOP pretreatment, acid (HNO3) is used at pH 3.0 to inhibit the enzyme catalase in the blood samples. Catalytic Adsorptive Stripping Voltammetry (CAdSV) at a bismuth film electrode (BiFE) gives Cr concentration of 6.0 ± 0.3 ppb in the blood samples. This c...

  2. Tritium stripping by a catalytic exchange stripper

    International Nuclear Information System (INIS)

    A catalytic exchange process for stripping elemental tritium from gas streams has been demonstrated. The process uses a catalyzed isotopic exchange reaction between tritium in the gas phase and protium or deuterium in the solid phase on alumina. The reaction is catalyzed by platinum deposited on the alumina. The process has been tested with both tritium and deuterium. Decontamination factors (ration of inlet and outlet tritium concentrations) as high as 1000 have been achieved, depending on inlet concentration. The test results and some demonstrated applications are presented

  3. Microscopic and electrochemical characterization of lead film electrode applied in adsorptive stripping analysis

    International Nuclear Information System (INIS)

    Lead film electrodes (PbFEs) deposited in situ on glassy carbon or carbon paste supports have recently found application in adsorptive stripping voltammetric determination of inorganic ions and organic substances. In this work, the PbFE, prepared in ammonia buffer solutions, was investigated using scanning electron microscopy, atomic force microscopy and various voltammetric techniques. The microscopic images of the lead films deposited on the glassy carbon substrate showed a considerable variability in microstructure and compactness of the deposited layer depending on the selected experimental conditions, such as the concentration of Pb(II) species, the nucleation and deposition potential, and the time applied. The catalytic adsorptive systems of cobalt and nickel in a solution containing 0.1 ammonia buffer, 2.5 x 10-5 M nioxime and 0.25 M NaNO2 were employed to investigate the electrochemical characteristics and utility of the in situ prepared lead films. The optimal parameters, i.e. the lead concentration in the solution, the procedure of film removal, and the time and potential of lead nucleation and film deposition for the adsorptive determination of metal traces, were selected, resulting in the very good reproducibility (RSD = 4.2% for 35 scans) of recorded signals. The voltammetric utility of the lead film electrode was compared to that of glassy carbon, mercury film and bismuth film electrodes, and was subsequently evaluated as superior.

  4. Adsorptive Stripping Voltammetry of Environmental Indicators: Determination of Zinc in Algae

    Science.gov (United States)

    Collado-Sanchez, C.; Hernandez-Brito, J. J.; Perez-Pena, J.; Torres-Padron, M. E.; Gelado-Caballero, M. D.

    2005-01-01

    A method for sample preparation and for the determination of average zinc content in algae using adsorptive stripping voltammetry are described. The students gain important didactic advantages through metal determination in environmental matrices, which include carrying out clean protocols for sampling and handling, and digesting samples using…

  5. Square wave adsorptive stripping voltammetry of nickel and cobalt at wall-jet electrodes in continuous flow

    OpenAIRE

    Brett, Christopher M. A.; Garcia, M. Beatriz Quinaz; Lima, José L.F.C.

    1996-01-01

    Square wave adsorptive stripping voltammetry (SWAdSV) of nickel and cobalt at wall-jet electrodes in a continuous flow system has been evaluated. Characteristics and advantages relative to differential pulse adsorptive stripping voltammetry (DPAdSV) in continuous flow systems are explored. Under optimized experimental conditions, sensitivity is approximately a factor of ten higher than DPAdSV, and one-nanomolar detection limits are achieved. Solution deoxygenation is unnecessary and sample th...

  6. Modifying the catalytic and adsorption properties of metals and oxides

    Science.gov (United States)

    Yagodovskii, V. D.

    2015-11-01

    A new approach to interpreting the effect of promoters (inhibitors) of nonmetals and metals added to a host metal (catalyst) is considered. Theoretical calculations are based on a model of an actual two-dimensional electron gas and adsorbate particles. An equation is derived for the isotherm of induced adsorption on metals and semiconductors with respect to small fillings of θ ~ 0.1-0.15. The applicability of this equation is verified experimentally for metals (Ag, Pd, Cu, Fe, and Ni), graphitized ash, and semiconductor oxides Ta2O5, ZnO, and Ni. The applicability of the theoretical model of promotion is verified by the hydrogenation reaction of CO on ultradispersed nickel powder. The use of plasmachemical surface treatments of metals and oxides, accompanied by an increase in activity and variation in selectivity, are investigated based on the dehydrocyclization reactions of n-hexane and the dehydrogenation and dehydration of alcohols. It is established that such treatments for metals (Pt, Cu, Ni, and Co) raise their activity due to the growth of the number of active centers upon an increase in the activation energy. Applying XPES and XRD methods to metallic catalysts, it is shown that the rise in activity is associated with a change in their surface states (variation in the structural characteristics of metal particles and localization of certain forms of carbon in catalytically active centers). It is shown that plasmachemical treatments also alter their surface composition, surface activity, and raise their activity when used with complex phosphate oxides of the NASICON type. It is shown by the example of conversion of butanol-2 that abrupt variations in selectivity (prevalence of dehydration over dehydrogenation and vice versa) occur, depending on the type of plasma. It is concluded that plasmachemical treatments of metals and ZnO and NiO alter the isosteric heats and entropies of adsorption of isopropanol.

  7. Cathodic adsorptive stripping voltammetric determination of uranium with potassium hydrogen phthalate.

    Science.gov (United States)

    Farghaly, O A; Ghandour, M A

    1999-06-01

    The adsorption properties of dioxouranium (II)-Phathalate complexes onto hanging mercury drop electrode are exploited in developing a highly sensitive and selective stripping voltammetric procedure for the determination of uranium (VI). The reduction current of adsorbed complex ions of U(VI) was measured by both linear sweep (LSCSV) and differential pulse cathodic stripping voltammetry (DPCSV), preceded by a period of preconcentration onto the electrode surface. As low as 2x10(-9) mol dm(-3) (0.5 mug/l) and 2x10(-8) mol dm(-3) (4.8 mug/l) with accumulation time 240 and 120 s using DPCSV and LSCSV, respectively, have been determined successfully. The relative standard deviation of 2.2% at the 5 ppm level was obtained. The interferences of some metal ions and anions were studied. The application of this method was tested in the determination of uranium in superphosphate fertilizer. PMID:18967571

  8. Electrochemistry and analytical determination of lysergic acid diethylamide (LSD) via adsorptive stripping voltammetry.

    Science.gov (United States)

    Merli, Daniele; Zamboni, Daniele; Protti, Stefano; Pesavento, Maria; Profumo, Antonella

    2014-12-01

    Lysergic acid diethylamide (LSD) is hardly detectable and quantifiable in biological samples because of its low active dose. Although several analytical tests are available, routine analysis of this drug is rarely performed. In this article, we report a simple and accurate method for the determination of LSD, based on adsorptive stripping voltammetry in DMF/tetrabutylammonium perchlorate, with a linear range of 1-90 ng L(-1) for deposition times of 50s. LOD of 1.4 ng L(-1) and LOQ of 4.3 ng L(-1) were found. The method can be also applied to biological samples after a simple extraction with 1-chlorobutane.

  9. Determination of Lamotrigine in Pharmaceutical Preparations by Adsorptive Stripping Voltammetry Using Screen Printed Electrodes

    OpenAIRE

    M. Julia Arcos-Martínez; M. Encarnación Burgoa Calvo; Olga Domínguez-Renedo

    2008-01-01

    This paper describes a procedure that has been optimized for the determination of lamotrigine by Differential Pulse Adsorptive Stripping Voltammetry (DPAdSV) using carbon screen-printed electrodes (CSPE) and mercury coated carbon screen-printed electrodes. Selection of the experimental parameters was made using experimental design methodology. The detection limit found was 5.0 x 10-6 M and 2.0 x 10-6 M for the non modified and Hg modified CSPE, respectively. In terms of reproducibility, the p...

  10. Determination of copper in whole blood by differential pulse adsorptive stripping voltammetry

    Directory of Open Access Journals (Sweden)

    Tarik Attar

    2014-02-01

    Full Text Available A selective and sensitive method for determination of copper in blood by adsorptive differential pulse cathodic stripping voltammetry is presented. The method is based on adsorptive accumulation of the complexes of Cu (II ions with benzenesulfonyl hydrazide onto hanging mercury drop electrode (HMDE, followed by the reduction of the adsorbed species by differential pulse cathodic stripping voltammetry. The effect of various parameters such as supporting electrolyte, concentration of benzenesulfonyl hydrazide, accumulation potential, accumulation time and stirring rate on the selectivity and sensitivity were studied. The optimum conditions for determination of copper include perchloric acid 0.03 M, concentration of benzenesulfonyl hydrazide 7.5×10-5 M, the accumulation potential of -350 mV (vs. Ag/AgCl, the accumulation time of 50 s, and the scan rate of 50 mV s-1. Under optimized conditions, linear calibration curves were established for the concentration of Cu (II in the range of 0.62-275 ng mL-1, with detection limit of 0.186 ng mL-1 for Cu (II. The procedure was successfully applied to the determination of copper ion in whole blood samples.

  11. Theoretical and experimental study of redox processes combined with adsorption phenomena under conditions of square-wave voltammetry

    OpenAIRE

    Gulaboski, Rubin

    2001-01-01

    Theoretical models of four electrode reactions coupled with adsorption phenomena under conditions of square-wave voltammetry are developed: simple surface redox reaction, surface catalytic reaction, cathodic stripping reaction of I order, and cathodic stripping reaction of II order.

  12. Aged nano-structured platinum based catalyst: effect of chemical treatment on adsorption and catalytic activity.

    Science.gov (United States)

    Shim, Wang Geun; Nahm, Seung Won; Park, Hyuk Ryeol; Yun, Hyung Sun; Seo, Seong Gyu; Kim, Sang Chai

    2011-02-01

    To examine the effect of chemical treatment on the adsorption and catalytic activity of nanostructured platinum based catalyst, the aged commercial Pt/AC catalyst was pretreated with sulfuric acid (H2SO4) and a cleaning agent (Hexane). Several reliable methods such as nitrogen adsorption, X-ray powder diffraction (XRD), scanning electron microscopy (SEM) and inductively coupled plasma (ICP) were employed to characterize the aged Pt/AC catalyst and its chemically pretreated Pt/AC catalysts. The catalytic and adsorption activities of nano-structured heterogeneous Pt/AC catalyst were investigated on the basis of toluene oxidation and adsorption isotherm data. In addition, the adsorption isotherms of toluene were used to calculate the adsorption energy distribution functions for the parent catalyst and its pre-treated nano-structured Pt/AC catalysts. It was found that sulfuric acid aqueous treatment can enhance the catalytic performance of aged Pt/AC catalyst toward catalytic oxidation of toluene. It was also shown that a comparative analysis of the energy distribution functions for nano-structured Pt/AC catalysts as well as the pore size distribution provides valuable information about their structural and energetic heterogeneity.

  13. Determination of Lamotrigine in Pharmaceutical Preparations by Adsorptive Stripping Voltammetry Using Screen Printed Electrodes

    Directory of Open Access Journals (Sweden)

    M. Julia Arcos-Martínez

    2008-07-01

    Full Text Available This paper describes a procedure that has been optimized for the determination of lamotrigine by Differential Pulse Adsorptive Stripping Voltammetry (DPAdSV using carbon screen-printed electrodes (CSPE and mercury coated carbon screen-printed electrodes. Selection of the experimental parameters was made using experimental design methodology. The detection limit found was 5.0 x 10-6 M and 2.0 x 10-6 M for the non modified and Hg modified CSPE, respectively. In terms of reproducibility, the precision of the above mentioned methods was calculated in %RSD values at 9.83% for CSPE and 2.73% for Hg-CSPE. The Hg-coated CSPEs developed in this work were successfully applied in the determination of lamotrigine in pharmaceutical preparations.

  14. Determination of Sudan I in drinks containing Sunset yellow by adsorptive stripping voltammetry.

    Science.gov (United States)

    Gómez, Marisol; Arancibia, Verónica; Aliaga, Margarita; Núñez, Claudia; Rojas-Romo, Carlos

    2016-12-01

    An efficient, fast and sensitive method for the determination of Sudan I (SI) in drinks containing Sunset yellow (Sy) is developed and validated using an adsorptive stripping voltammetric procedure. Sy is currently added to a large number of foods; however during their synthesis SI may be produced. The determination is based on adsorption of Sy and SI onto HMDE and later reduction of the azo group at -0.71 and -0.82V, respectively. Using the best set of the experimental conditions (pH 12.3; Eads: -0.40V) for the determination of SI in Sy, a linear response for SI in the concentration range 0.5-27.2μgL(-1) was found, with a detection limit of 1.5μgL(-1) in a tads of only 30s. The method was applied to the determination of SI in commercial drinks with satisfactory results. The presence of SI was confirmed by mass spectrometry. PMID:27374598

  15. Speciation study of aluminium in beverages by Competitive Ligand Exchange-Adsorptive Stripping Voltammetry.

    Science.gov (United States)

    Magnier, A; Fekete, V; Van Loco, J; Bolle, F; Elskens, M

    2014-05-01

    Competitive Ligand Exchange-Adsorptive Stripping Voltammetry (CLE-AdSV) was used for determining the speciation of aluminium in commonly consumed beverages (water, tea, infusion, coffee, orange juice, tomato juice, beer and red wine). Aluminium determination involves the adsorption of Al-complexes with the ligand cupferron onto a hanging mercury drop electrode. All samples were studied at pH 6.5 with an accumulation step at -0.60 V (all potential values in the paper are given versus the Ag/AgCl, [KCl]=3 M reference electrode) during 60 s, and a final cupferron concentration of 4 × 10(-4)M. These conditions were used to establish (i) the concentration of electro-labile aluminium, (ii) the range of ligand concentrations and (iii) the conditional stability constants of beverage samples using titration procedures. The results based on Ruzic plots were compared to computer simulation with Visual MINTEQ. This comparison suggests that labile monomeric Al-forms and soluble organic complexes of low molecular weight can be quantified by the CLE-AdSV procedure. Overall the relative uncertainties on the determination of the electro-active Al fraction and the complexing parameters, i.e., concentration and conditional stability constant of natural ligands in the samples, are less than 15%. Thanks to these results, information on Al bioavailability in beverages was collected and discussed. This study also illustrates the value of computer simulations when complex, time-consuming voltammetric techniques are applied.

  16. Degradation of paracetamol by catalytic wet air oxidation and sequential adsorption - Catalytic wet air oxidation on activated carbons

    Energy Technology Data Exchange (ETDEWEB)

    Quesada-Penate, I. [Universite de Toulouse, INPT, UPS, Laboratoire de Genie Chimique, 4, Allee Emile Monso, F-31432 Toulouse (France); CNRS, Laboratoire de Genie Chimique, F-31432 Toulouse (France); Julcour-Lebigue, C., E-mail: carine.julcour@ensiacet.fr [Universite de Toulouse, INPT, UPS, Laboratoire de Genie Chimique, 4, Allee Emile Monso, F-31432 Toulouse (France); CNRS, Laboratoire de Genie Chimique, F-31432 Toulouse (France); Jauregui-Haza, U.J. [Instituto Superior de Tecnologias y Ciencias Aplicadas, Ave. Salvador Allende y Luaces, Habana (Cuba); Wilhelm, A.M.; Delmas, H. [Universite de Toulouse, INPT, UPS, Laboratoire de Genie Chimique, 4, Allee Emile Monso, F-31432 Toulouse (France); CNRS, Laboratoire de Genie Chimique, F-31432 Toulouse (France)

    2012-06-30

    Highlights: Black-Right-Pointing-Pointer Three activated carbons (AC) compared as adsorbents and oxidation catalysts. Black-Right-Pointing-Pointer Similar evolution for catalytic and adsorptive properties of AC over reuses. Black-Right-Pointing-Pointer Acidic and mesoporous AC to be preferred, despite lower initial efficiency. Black-Right-Pointing-Pointer Oxidative degradation of paracetamol improves biodegradability. Black-Right-Pointing-Pointer Convenient hybrid adsorption-regenerative oxidation process for continuous treatment. - Abstract: The concern about the fate of pharmaceutical products has raised owing to the increasing contamination of rivers, lakes and groundwater. The aim of this paper is to evaluate two different processes for paracetamol removal. The catalytic wet air oxidation (CWAO) of paracetamol on activated carbon was investigated both as a water treatment technique using an autoclave reactor and as a regenerative treatment of the carbon after adsorption in a sequential fixed bed process. Three activated carbons (ACs) from different source materials were used as catalysts: two microporous basic ACs (S23 and C1) and a meso- and micro-porous acidic one (L27). During the first CWAO experiment the adsorption capacity and catalytic performance of fresh S23 and C1 were higher than those of fresh L27 despite its higher surface area. This situation changed after AC reuse, as finally L27 gave the best results after five CWAO cycles. Respirometry tests with activated sludge revealed that in the studied conditions the use of CWAO enhanced the aerobic biodegradability of the effluent. In the ADOX process L27 also showed better oxidation performances and regeneration efficiency. This different ageing was examined through AC physico-chemical properties.

  17. Study on the adsorptive catalytic voltammetry of aloe-emodin at a carbon paste electrode

    Institute of Scientific and Technical Information of China (English)

    LI; Ju'nan; GAO; Peng; LI; Xiangling; YAN; Zhihong; MAO; Xu

    2005-01-01

    A new catalytic voltammetric method for the determination of anthraqunone medicines at a carbon paste electrode (CPE) was described for the first time. The mechanism of the catalytic reaction was investigated by using linear sweep voltammetry, cyclic voltammetry, constant potential electrolysis and so on. The experiment results indicate that aloe-emodin was efficiently accumulated at a CPE by adsorption. In the following potential scan, aloe-emodin was reduced to homologous anthrahydroquinone compound, then the compound was immediately oxidized to aloe-emodin by the dissolved oxygen, and the aloe-emodin was again reduced at the CPE. As a result, a cyclic catalytic reaction was established. But a reversible redox reaction of aloe-emodin can only be observed at a mercury electrode, no catalytic reaction occurs there. A sensitive catalytic voltammetric peak of aloe-emodin was obtained at about -0.60 V (vs. SCE) in 0.56 mol/L NH3-NH4Cl buffer (pH 8.9). The proposed method was applied to the determination of aloe-emodin in the Radix Rhei with satisfactory results. The determination results were in good agreement with reference values obtained by the HPLC. The adsorptive catalytic voltammetry for the determination of organic compound at CPE, chemically modified electrode and other solid electrodes could be significant in the studies on pharmacology, pharmacodynamics, toxicity of medicine, clinical medicine and biochemistry.

  18. Ammonia stripping, activated carbon adsorption and anaerobic biological oxidation as process combination for the treatment of oil shale wastewater.

    Science.gov (United States)

    Alexandre, Verônica M F; do Nascimento, Felipe V; Cammarota, Magali C

    2016-10-01

    Anaerobic biodegradability of oil shale wastewater was investigated after the following pretreatment sequence: ammonia stripping and activated carbon adsorption. Anaerobic biological treatment of oil shale wastewater is technically feasible after stripping at pH 11 for reducing the N-NH3 concentration, adsorption with 5 g/L of activated carbon in order to reduce recalcitrance and pH adjustment with CO2 so that the sulphate concentration in the medium remains low. After this pretreatment sequence, it was possible to submit the wastewater without dilution to an anaerobic treatment with 62.7% soluble chemical oxygen demand removal and specific methane production of 233.2 mL CH4STP/g CODremoved.

  19. Ammonia stripping, activated carbon adsorption and anaerobic biological oxidation as process combination for the treatment of oil shale wastewater.

    Science.gov (United States)

    Alexandre, Verônica M F; do Nascimento, Felipe V; Cammarota, Magali C

    2016-10-01

    Anaerobic biodegradability of oil shale wastewater was investigated after the following pretreatment sequence: ammonia stripping and activated carbon adsorption. Anaerobic biological treatment of oil shale wastewater is technically feasible after stripping at pH 11 for reducing the N-NH3 concentration, adsorption with 5 g/L of activated carbon in order to reduce recalcitrance and pH adjustment with CO2 so that the sulphate concentration in the medium remains low. After this pretreatment sequence, it was possible to submit the wastewater without dilution to an anaerobic treatment with 62.7% soluble chemical oxygen demand removal and specific methane production of 233.2 mL CH4STP/g CODremoved. PMID:27003628

  20. Adsorptive Stripping Voltammetric Determination of Hydroquinone using an Electrochemically Pretreated Glassy Carbon Electrode

    Directory of Open Access Journals (Sweden)

    Abdul Niaz1,

    2008-12-01

    Full Text Available A simple and efficient adsorptive stripping voltammetric (AdSV method was developed for the determination of hydroquinone at an electrochemically pretreated glassy carbon (GC electrode in waste water. Various parameters such as solvent system, accumulation potential, accumulation time and scan rate were optimized. The electrochemically pretreated GC electrode showed good response towards hydroquinone determination by using AdSV. Under the optimized conditions the peak current showed good linear relationship with the hydroquinone concentration in the range of 0.5-4.0mg L-1 and 5-30mg L-1. The 60/40 methanol/water composition was found to be the best solvent system and 0.05mol L-1 H2SO4 was found as useful supporting electrolyte concentration. The accumulation time was 60 s and the detection limit was 50µg L-1. The developed method was successfully applied for the determination of hydroquinone in polymeric industrial discharge samples waste photographic developer solution and cream sample without any significant effect of surface fouling.

  1. Adsorptive stripping voltammetric assay of phenazopyridine hydrochloride in biological fluids and pharmaceutical preparations.

    Science.gov (United States)

    Sabry, S M

    1999-08-23

    A sensitive method for the measurement of phenazopyridine hydrochloride (PAP) by differential pulse polarography (DPP) based on adsorptive stripping technique, using a hanging mercury drop electrode (HMDE) is described. The voltammetric peak is obtained at -0.760 V, which corresponds to the reduction of the azo group in Britton-Robinson buffer. The redox behaviour is reversible. Optimum conditions were found to be: accumulation potential -50 mV (vs. Ag/AgCl), accumulation time 60 s, scan rate 5 mV s(-1), pulse amplitude -100 mV and supporting electrolyte Britton-Robinson buffer (0.04 M, pH=11). The relative standard deviation (at 20 ng ml(-1) level) was +/-0.6% for six measurements. The calculated detection limit was 0.0299 ng ml(-1) with a 60-s accumulation time. The applicability of such a method was evaluated through the assay of PAP in human plasma and urine samples after a simple extraction procedure and in pharmaceutical preparation. The mean recovery was 97+/-2 (100 ng ml(-1) plasma). PMID:18967703

  2. Adsorptive stripping voltammetric determination of netilmicin in the presence of formaldehyde.

    Science.gov (United States)

    Sun, Nan; Mo, Weimin; Hu, Baoxiang; Shen, Zhenlu

    2006-05-01

    A linear sweep adsorptive stripping voltammetric method for the determination of netilmicin in the presence of formaldehyde has been proposed for the first time. In the presence of 3.0 x 10(-3) g ml(-1) formaldehyde, netilmicin exhibits a sensitive cathodic peak at -1.30 V (vs. the saturated calomel electrode, SCE) in a medium of Britton-Robinson buffer (pH 8.7) with a scan rate of 100 mV s(-1) after a preconcentration period of 120 s at -1.10 V (vs. SCE). The peak current showed a linear dependence on the netilmicin concentration over the range 4.2 x 10(-9)-1.0 x 10(-7) g ml(-1). The achieved limits of detection and quantitation were 1.0 x 10(-10) and 3.3 x 10(-10) g ml(-1) netilmicin, respectively. It was deduced from the experiments that the amine-aldehyde condensation product formed between netilmicin and formaldehyde is mainly responsible for the appearance of the peak. The electrochemical behavior of netilmicin in the presence of formaldehyde has been studied. The method was applied to the direct determination of netilmicin in injectable formulations and spiked human urine and serum samples.

  3. Adsorption and catalytic combustion of ARB on CuO-Fe2O3

    Institute of Scientific and Technical Information of China (English)

    WU Rongcheng; QU Jiuhui; HE Hong; YU Yunbo

    2003-01-01

    CuO-Fe2O3 composite material with strong magnetism and a large surfacearea is prepared by the co-precipitate method. Its adsorption properties towards Acid Red B (ARB) and the regeneration by catalytic combustion of organic compounds have been studied. The results show that the prepared CuO-Fe2O3 composite is an excellent adsorbent for ARB adsorption at acid condition. The presence of Cl- has no effect on ARB adsorption. But the can inhibit ARB adsorption. After being recovered by the magnetic separation method, the adsorbent can be regenerated by catalytic oxidation of absorbate at 300℃ in air atmosphere. The combustion reactions of ARB in the presence or absence of CuO-Fe2O3 are studied by in situ diffuse reflection FTIR. The results indicate that, in the presence of CuO-Fe2O3, the degradation temperature is significantly lowered by the catalysis of CuO-Fe2O3, and ARB can be oxidized completely without volatile organic compound by-product; in comparison, in the absence of CuO-Fe2O3, the temperature needed for oxidation of ARB is higher and the reaction is incomplete with some N-containingharmful compounds produced. The reusability of CuO-Fe2O3 is also studied in successive seven adsorption-regeneration cycles.

  4. Determination of tryptamine in foods using square wave adsorptive stripping voltammetry.

    Science.gov (United States)

    Costa, Daniel J E; Martínez, Ana M; Ribeiro, Williame F; Bichinho, Kátia M; Di Nezio, María Susana; Pistonesi, Marcelo F; Araujo, Mario C U

    2016-07-01

    Tryptamine, a biogenic amine, is an indole derivative with an electrophilic substituent at the C3 position of the pyrrole ring of the indole moiety. The electrochemical oxidation of tryptamine was investigated using glassy carbon electrode (GCE), and focusing on trace level determination in food products by square wave adsorptive stripping voltammetry (SWAdSV). The electrochemical responses of tryptamine were evaluated using differing voltammetric techniques over a wide pH range, a quasi-reversible electron-transfer to redox system represented by coupled peaks P1-P3, and an irreversible reaction for peak P2 were demonstrated. The proton and electron counts associated with the oxidation reactions were estimated. The nature of the mass transfer process was predominantly diffusion-limited for the oxidation process of P1, the most selective and sensitive analytical response (acetate buffer solution pH 5.3), being used for the development of SWAdSV method, under optimum conditions. The excellent response allowed the development of an electroanalytical method with a linear response range of from 4.7-54.5)×10(-)(8)molL(-1), low detection limit (0.8×10(-)(9)molL(-)(1)), and quantification limit (2.7×10(-9)molL(-1)), and acceptable levels of repeatability (3.6%), and reproducibility (3.8%). Tryptamine content was determined in bananas, tomatoes, cheese (mozzarella and gorgonzola), and cold meats (chicken sausage and pepperoni sausage), yielding recoveries above 90%, with excellent analytical performance using simple and low cost instrumentation. PMID:27154658

  5. Lignite utilisation for binding of radionuclides and uranium determination by adsorptive stripping chronopotentiometry

    International Nuclear Information System (INIS)

    on amalgam work electrode with the value of accumulation potential +200 mV (vs. Ag/AgCl). The work includes optimisation of the accumulation and regeneration time, the regeneration potential, the pH value of supporting electrolyte and concentration of used complexing agent (cupferron). The interference impacts of selected cations on uranium determination by means of adsorptive stripping chronopotentiometry (AdSC) have been also studied. The method is linear within the range of up to 50 μg dm-3, relative standard deviation for 10 μg dm-3 of uranium is 5.2 % (n=10, accumulation time 60 s). Experimentally, the value of limit of detection was determined for uranium (1.2 μg dm-3) as well as the value of limit of quantification (3.6 μg dm-3). Using AdSC, the content of uranium was successfully determined in the sample of natural mineral water with high content of salts. The newly designed electrochemical method of determining uranium was validated by means of ICP- MS analysis and spectrophotometric determination of uranium with arsenazo III. The AdSC method may be used for uranium monitoring in waters and after potential further optimisation of sample pre-treatment also in sediments and in soil. (author)

  6. Effect of citrate on Aspergillus niger phytase adsorption and catalytic activity in soil

    Science.gov (United States)

    Mezeli, Malika; Menezes-Blackburn, Daniel; Zhang, Hao; Giles, Courtney; George, Timothy; Shand, Charlie; Lumsdon, David; Cooper, Patricia; Wendler, Renate; Brown, Lawrie; Stutter, Marc; Blackwell, Martin; Darch, Tegan; Wearing, Catherine; Haygarth, Philip

    2015-04-01

    Current developments in cropping systems that promote mobilisation of phytate in agricultural soils, by exploiting plant-root exudation of phytase and organic acids, offer potential for developments in sustainable phosphorus use. However, phytase adsorption to soil particles and phytate complexion has been shown to inhibit phytate dephosphorylation, thereby inhibiting plant P uptake, increasing the risk of this pool contributing to diffuse pollution and reducing the potential benefits of biotechnologies and management strategies aimed to utilise this abundant reserve of 'legacy' phosphorus. Citrate has been seen to increase phytase catalytic efficiency towards complexed forms of phytate, but the mechanisms by which citrate promotes phytase remains poorly understood. In this study, we evaluated phytase (from Aspergillus niger) inactivation, and change in catalytic properties upon addition to soil and the effect citrate had on adsorption of phytase and hydrolysis towards free, precipitated and adsorbed phytate. A Langmuir model was fitted to phytase adsorption isotherms showing a maximum adsorption of 0.23 nKat g-1 (19 mg protein g-1) and affinity constant of 435 nKat gˉ1 (8.5 mg protein g-1 ), demonstrating that phytase from A.niger showed a relatively low affinity for our test soil (Tayport). Phytases were partially inhibited upon adsorption and the specific activity was of 40.44 nKat mgˉ1 protein for the free enzyme and 25.35 nKat mgˉ1 protein when immobilised. The kinetics of adsorption detailed that most of the adsorption occurred within the first 20 min upon addition to soil. Citrate had no effect on the rate or total amount of phytase adsorption or loss of activity, within the studied citrate concentrations (0-4mM). Free phytases in soil solution and phytase immobilised on soil particles showed optimum activity (>80%) at pH 4.5-5.5. Immobilised phytase showed greater loss of activity at pH levels over 5.5 and lower activities at the secondary peak at pH 2

  7. Some problems in adsorption and calorimetric studies of the steps of catalytic processes

    Institute of Scientific and Technical Information of China (English)

    Victor E. Ostrovskii

    2004-01-01

    Principal side factors as well as technical and procedural peculiarities capable of distorting the results of measurements of adsorbed and desorbed amounts, of falsifying the nature of the processes proceeding in the systems under study, and of promoting artifacts in calorimetric and other studies of gas chemisorption on powders are considered. Modified techniques and procedures allowing the elimination of sources of side phenomena and artifacts and freeing traditional glass static adsorption apparatuses and experimental procedures from undesirable factors and peculiarities are proposed.Some available chemisorption and calorimetric data representing artifacts and also some data that are not artifacts but,due to imperfections of chemisorption techniques, show up as artifacts are presented and discussed. Several applications of the improved techniques and procedures to calorimetric and adsorption studies of the steps of catalytic processes proceeding on the basis of natural gas and of products of its processing are presented and discussed.

  8. Session 6: Water depollution from aniline and phenol by air oxidation and adsorptive-catalytic oxidation in liquid phase

    Energy Technology Data Exchange (ETDEWEB)

    Dobrynkin, N.M.; Batygina, M.V.; Noskov, A.S. [Boreskov Institute of Catalysis of Siberian Branch of Russian Academy of Sciences, Pr. Ak. Lavrentieva (Russian Federation)

    2004-07-01

    This paper is devoted to development of carbon catalysts and application of catalytic wet air oxidation for deep cleaning of polluted waters. The described catalysts and method are solving the problem of development environmentally reliable method for fluids treatment and allow carrying out the adsorption of pollutants on carbon CAPM (catalytically active porous material) with following regeneration of the CAPM without the loss of adsorptive qualities. The experiments have shown a principal capability simultaneously to use carbon CAPM as adsorbent and either as catalyst, or as a catalyst support for oxidation of aniline and phenol in water solutions. (authors)

  9. Catalytic Hollow-Fiber Membranes Prepared Using Layer-by-Layer Adsorption of Polyelectrolytes and Metal Nanoparticles

    OpenAIRE

    Ouyang, Lu; Dotzauer, David M.; Hogg, Seth R.; Macanas, Jorge; Lahitte, Jean-Francois; Bruening, Merlin L.

    2010-01-01

    Immobilization of metal nanoparticles in hollow fiber membranes via alternating adsorption of polyelectrolytes and negatively charged Au nanoparticles yields catalytic reactors with high surface areas. SEM images show that this technique deposits a high density of unaggregated metal nanoparticles both on the surfaces and in the pores of the hollow fibers. Catalytic reduction of 4-nitrophenol with NaBH4, which can be easily monitored by UV-Vis spectrophotometry, demonstrates that the nanopar...

  10. Strip biosensor for amplified detection of nerve growth factor-beta based on a molecular translator and catalytic DNA circuit.

    Science.gov (United States)

    Liu, Jun; Lai, Ting; Mu, Kejie; Zhou, Zheng

    2014-10-01

    We have demonstrated a new visual detection approach based on a molecular translator and a catalytic DNA circuit for the detection of nerve growth factor-beta (NGF-β). In this assay, a molecular translator based on the binding-induced DNA strand-displacement reaction was employed to convert the input protein to an output DNA signal. The molecular translator is composed of a target recognition element and a signal output element. Target recognition is achieved by the binding of the anti-NGF-β antibody to the target protein. Polyclonal anti-NGF-β antibody is conjugated to DNA1 and DNA2. The antibody conjugated DNA1 is initially hybridized to DNA3 to form a stable DNA1/DNA3 duplex. In the presence of NGF-β, the binding of the same target protein brings DNA1 and DNA2 into close proximity, resulting in an increase in their local effective concentration. This process triggers the strand-displacement reaction between DNA2 and DNA3 and releases the output DNA3. The released DNA3 is further amplified by a catalytic DNA circuit. The product of the catalytic DNA circuit is detected by a strip biosensor. This proposed assay has high sensitivity and selectivity with a dynamic response ranging from 10 fM to 10 pM, and its detection limit is 10 fM of NGF-β. This work provides a sensitive, enzyme-free, and universal strategy for the detection of other proteins. PMID:25068151

  11. From Electronic Structure to Catalytic Activity: A Single Descriptor for Adsorption and Reactivity on Transition-Metal Carbides

    DEFF Research Database (Denmark)

    Vojvodic, A.; Hellman, Anders; Ruberto, C.;

    2009-01-01

    Adsorption and catalytic properties of the polar (111) surface of transition-metal carbides (TMC's) are investigated by density-functional theory. Atomic and molecular adsorption are rationalized with the concerted-coupling model, in which two types of TMC surface resonances (SR's) play key roles....... The transition-metal derived SR is found to be a single measurable descriptor for the adsorption processes, implying that the Bronsted-Evans-Polanyi relation and scaling relations apply. This gives a picture with implications for ligand and vacancy effects and which has a potential for a broad screening...

  12. From electronic structure to catalytic activity: A single descriptor for adsorption and reactivity on transition-metal carbides

    CERN Document Server

    Vojvodic, Aleksandra; Ruberto, Carlo; Lundqvist, Bengt I

    2009-01-01

    Adsorption and catalytic properties of the polar (111) surface of transition-metal carbides (TMC's) are investigated by density-functional theory. Atomic and molecular adsorption are rationalized with the concerted-coupling model, in which two types of TMC surface resonances (SR's) play key roles. The transition-metal derived SR is found to be a single measurable descriptor for the adsorption processes, implying that the Br{\\o}nsted-Evans-Polanyi relation and scaling relations apply. This gives a picture with implications for ligand and vacancy effects and which has a potential for a broad screening procedure for heterogeneous catalysts.

  13. Electrochemical behavior of folic acid at calixarene based chemically modified electrodes and its determination by adsorptive stripping voltammetry

    Energy Technology Data Exchange (ETDEWEB)

    Vaze, Vishwanath D. [Department of Chemistry, University of Mumbai, Vidyanagari, Santacruz (East), Mumbai 400098 (India); Srivastava, Ashwini K. [Department of Chemistry, University of Mumbai, Vidyanagari, Santacruz (East), Mumbai 400098 (India)], E-mail: aksrivastava@chem.mu.ac.in

    2007-12-31

    Voltammetric behavior of folic acid at plain carbon paste electrode and electrode modified with calixarenes has been studied. Two peaks for irreversible oxidation were observed. Out of the three calixarenes chosen for modification of the electrodes, p-tert-butyl-calix[6]arene modified electrode (CME-6) was found to have better sensitivity for folic acid. Chronocoulometric and differential pulse voltammetric studies reveal that folic acid can assemble at CME-6 to form a monolayer whose electron transfer rate is 0.00273 s{sup -1} with 2-electron/2-proton transfer for the peak at +0.71 V against SCE. An adsorption equilibrium constant of 5 x 10{sup 3} l/mol for maximum surface coverage of 2.89 x 10{sup -10} mol/cm{sup 2} was obtained. The current is found to be rectilinear with concentration by differential pulse voltammetry. However, linearity in the lower range of concentration 8.79 x 10{sup -12} M to 1.93 x 10{sup -9} M with correlation coefficient of 0.9920 was achieved by adsorptive stripping voltammetry. The limit of detection obtained was found to be 1.24 x 10{sup -12} M. This method was used for the determination of folic acid in a variety of samples, viz. serum, asparagus, spinach, oranges and multivitamin preparations.

  14. A square-wave adsorptive stripping voltammetric method for the determination of Amaranth, a food additive dye.

    Science.gov (United States)

    Alghamdi, Ahmad H

    2005-01-01

    Square-wave adsorptive stripping voltammetric (AdSV) determinations of trace concentrations of the azo coloring agent Amaranth are described. The analytical methodology used was based on the adsorptive preconcentration of the dye on the hanging mercury drop electrode, followed by initiation of a negative sweep. In a pH 10 carbonate supporting electrolyte, Amaranth gave a well-defined and sensitive AdSV peak at -518 mV. The electroanalytical determination of this azo dye was found to be optimal in carbonate buffer (pH 10) under the following experimental conditions: accumulation time, 120 s; accumulation potential, 0.0 V; scan rate, 600 mV/s; pulse amplitude, 90 mV; and frequency, 50 Hz. Under these optimized conditions the AdSV peak current was proportional over the concentration range 1 x 10(-8)-1.1 x 10(-7) mol/L (r = 0.999) with a detection limit of 1.7 x 10(-9) mol/L (1.03 ppb). This analytical approach possessed enhanced sensitivity, compared with conventional liquid chromatography or spectrophotometry and it was simple and fast. The precision of the method, expressed as the relative standard deviation, was 0.23%, whereas the accuracy, expressed as the mean recovery, was 104%. Possible interferences by several substances usually present as food additive azo dyes (E110, E102), gelatin, natural and artificial sweeteners, preservatives, and antioxidants were also investigated. The developed electroanalyticals method was applied to the determination of Amaranth in soft drink samples, and the results were compared with those obtained by a reference spectrophotometric method. Statistical analysis (paired t-test) of these data showed that the results of the 2 methods compared favorably.

  15. Solar UV-assisted sample preparation of river water for ultra-trace determination of uranium by adsorptive stripping voltammetry

    International Nuclear Information System (INIS)

    The article describes how solar ultraviolet-A radiation can be used to digest samples as needed for voltammetric ultratrace determination of uranium(VI) in river water. We applied adsorptive stripping voltammetry (AdSV) using chloranilic acid as the complexing agent. Samples from the river Warnow in Rostock (Germany) were pretreated with either soft solar UV or wit artificial hard UV from a 30-W source emitting 254-nm light. Samples were irradiated for 12 h, and both methods yielded the same results. We were able to detect around 1 μg.L-1 of uranium(VI) in a sample of river water that also contained dissolved organic carbon at a higher mg.L-1 levels. No AdSV signal was obtained for U(VI) without any UV pre-treatment. Pseudo-polarographic experiments confirmed the dramatic effect of both digestion techniques the the AdSV response. The new method is recommended for use in mobile ultratrace voltammetry of heavy metals for most kinds of natural water samples including tap, spring, ground, sea, and river waters. The direct use of solar radiation for sample pre-treatment represents a sustainable technique for sample preparation that does not consume large quantities of chemicals or energy. (author)

  16. Adsorptive stripping voltammetric determination of nitroimidazole derivative on multiwalled carbon nanotube modified electrodes: influence of size and functionalization of nanotubes

    Energy Technology Data Exchange (ETDEWEB)

    Jara-Ulloa, Paola; Canete-Rosales, Paulina; Nunez-Vergara, Luis J; Squella, Juan A., E-mail: asquella@ciq.uchile.c [University of Chile, Santiago (Chile). Chemical and Pharmaceutical Sciences Faculty. Bioelectrochemistry Lab.

    2011-07-01

    1-Methyl-4-nitro-2-bromine methylimidazole (4-NimMeBr), was electrochemically reduced on mercury, glassy carbon and multiwalled carbon nanotubes (MWCNT) modified electrodes. 4-NimMeBr was adsorbed on the MWCNT modified electrode thus permitting the implementation of an adsorptive stripping voltammetric (ASV) method. We have used 4-NimMeBr as a prototype electroactive nitro compound to study the effect of both the size of the nanotubes and its functionalization by oxidation. The oxidized MWCNT forms better dispersions than the non-oxidized, producing electrode surface with higher density of MWCNT as was determined by electrochemical mapping using scanning electrochemical microscopy (SECM). Under the optimized conditions, the peak current was proportional to the concentration of 4-NimMeBr in the range of 10{sup -6} mol L{sup -1} to 10{sup -4} mol L{sup -1} with detection and quantification limits of 4.41 x 10{sup -6} mol L{sup -1} and 6.21 x 10{sup -6} mol L{sup -1}, respectively. The sensibility of bare electrode was 0.01 {mu}A per mmol L{sup -1}, which was lower than the value of 5.34 and 6.97 mA per mmol L{sup -1} obtained using short and large oxidized MWCNT, respectively. (author)

  17. Determination of Xanthine in the Presence of Hypoxanthine by Adsorptive Stripping Voltammetry at the Mercury Film Electrode

    Science.gov (United States)

    Farias, Percio Augusto Mardini; Castro, Arnaldo Aguiar

    2014-01-01

    A stripping method for the determination of xanthine in the presence of hypoxanthine at the submicromolar concentration levels is described. The method is based on controlled adsorptive accumulation at the thin-film mercury electrode followed by a fast linear scan voltammetric measurement of the surface species. Optimum experimental conditions were found to be the use of 1.0 × 10−3 mol L−1 NaOH solution as supporting electrolyte, an accumulation potential of 0.00 V for xanthine and −0.50 V for hypoxanthine–copper, and a linear scan rate of 200 mV second−1. The response of xanthine is linear over the concentration ranges of 20–140 ppb. For an accumulation time of 30 minutes, the detection limit was found to be 36 ppt (2.3 × 10−10 mol L−1). Adequate conditions for measuring the xanthine in the presence of hypoxanthine, copper and other metals, uric acid, and other nitrogenated bases were also investigated. The utility of the method is demonstrated by the presence of xanthine associated with hypoxanthine, uric acid, nitrogenated bases, ATP, and ssDNA. PMID:24940040

  18. Adsorption of acetanilide herbicides on soil and its components II. Adsorption and catalytic hydrolysis of diethatyl-ethyl on saturated Na+-, K+-, Ca2+-, and Mg2+-montmorillonite

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    Adsorption and catalytic hydrolysis of the herbicidediethatyl-ethyl [N-chloroacetyl-N-(2,6-diethylphenyl)glycine ethyl ester] on homoionic Na+-, K+-, Ca2+-, and Mg2+-montmorillonite clays were investigated in water solution. The Freundlich adsorption coefficient, Kf, got from isotherms on clay followed the order of Na+ K+ > Mg2+ Ca2+. Analysis of FT-IR spectra of diethatyl-ethyl adsorbed on clay suggests probable bonding at the carboxyl and amide carbonyl groups of the herbicide. The rate of herbicide hydrolysis in homoionic clay suspensions followed the same order as that for adsorption, indicating that adsorption may have preceded and thus caused hydrolysis. Preliminary product identification showed that hydrolysis occurred via nucleophilic substitution at the carboxyl carbon, causing the cleavage of the ester bond and formation of diethatyl and its dechlorinated derivative, and at the amide carbon, yielding an ethyl ester derivative and its acid.These pathways also suggest that hydrolysis of diethatyl-ethyl was catalyzed by adsorption on the clay surface.

  19. Adsorptive and stripping behavior of methylene blue at gold electrodes in the presence of cationic gemini surfactants

    Energy Technology Data Exchange (ETDEWEB)

    Li, Jiangwen; Zhao, Faqiong; Zhao, Jia; Zeng, Baizhao [Wuhan University, Wuhan (China). Department of Chemistry

    2005-10-10

    The adsorptive and stripping behavior of methylene blue (i.e. methylene blue chloride, MB) at a gold electrode has been studied with voltammetry, alternating current impedance spectra (ACIS) and quartz crystal microbalance (QCM). MB exhibits a pair of cyclic voltammetry peaks at about -0.3 V (versus SCE) in 0.05 M pH 6.9 phosphate buffer solutions. In the presence of cationic gemini surfactants such as C{sub 16}H{sub 33}N(CH{sub 3}){sub 2}-C{sub 4}H{sub 8}-N(CH{sub 3}){sub 2}C{sub 16}H{sub 33}Br{sub 2} (C{sub 16}-C{sub 4}-C{sub 16}), C{sub 16}H{sub 33}N(CH{sub 3}){sub 2}-C{sub 4}H{sub 7}OH-N(CH{sub 3}){sub 2}C{sub 16}H{sub 33}Br{sub 2} (C{sub 16}-C{sub 4}OH-C{sub 16}), C{sub 16}H{sub 33}N(CH{sub 3}){sub 2}-CH{sub 2}-C{sub 6}H{sub 4}-CH{sub 2}-N(CH{sub 3}){sub 2}C{sub 16}H{sub 33}Br{sub 2} (C{sub 16}-ph-C{sub 16}) and C{sub 16}H{sub 33}N(CH{sub 3}){sub 2}-C{sub 12}H{sub 24}-N(CH{sub 3}){sub 2}C{sub 16}H{sub 33}Br{sub 2} (C{sub 16}-C{sub 12}-C{sub 16}), the anodic peak grows rapidly and moves in positive direction, but the cathodic peak gradually decreases, due to the association adsorption and electrostatic interaction of the geminis with MB and its reduced product (i.e. leuko methylene blue, LMB). With the aid of geminis the adsorption amount of MB increases under open-circuit, but the impedance of the mixed adsorption film to Fe(CN){sub 6}{sup 3-/4-} almost keeps unchanged, compared with either bare gold electrodes or MB film, while the adsorption film of geminis exhibits greater impedance. This probably is due to the electron medium action of MB in the film. Gemini surfactants with same alkyl-chain (i.e. -(CH{sub 2}){sub 15}CH{sub 3}) but different molecular structure, exhibit different influence. The enhancing action of geminis studied follows such order as: C{sub 16}-ph-C{sub 16} > C{sub 16}-C{sub 4}-C{sub 16} > C{sub 16}-C{sub 4}OH-C{sub 16} > C{sub 16}-C{sub 12}-C{sub 16}. The change of peak potential was ascribed to the interaction between MB and surfactants

  20. Adsorptive and stripping behavior of methylene blue at gold electrodes in the presence of cationic gemini surfactants

    Energy Technology Data Exchange (ETDEWEB)

    Li Jiangwen [Department of Chemistry, Wuhan University, Wuhan 430072 (China); Zhao Faqiong [Department of Chemistry, Wuhan University, Wuhan 430072 (China); Zhao Jia [Department of Chemistry, Wuhan University, Wuhan 430072 (China); Zeng Baizhao [Department of Chemistry, Wuhan University, Wuhan 430072 (China)]. E-mail: zengbz@chem.whu.edu.cn

    2005-10-10

    The adsorptive and stripping behavior of methylene blue (i.e. methylene blue chloride, MB) at a gold electrode has been studied with voltammetry, alternating current impedance spectra (ACIS) and quartz crystal microbalance (QCM). MB exhibits a pair of cyclic voltammetry peaks at about -0.3 V (versus SCE) in 0.05 M pH 6.9 phosphate buffer solutions. In the presence of cationic gemini surfactants such as C{sub 16}H{sub 33}N(CH{sub 3}){sub 2}-C{sub 4}H{sub 8}-N(CH{sub 3}){sub 2}C{sub 16}H{sub 33}Br{sub 2} (C{sub 16}-C{sub 4}-C{sub 16}), C{sub 16}H{sub 33}N(CH{sub 3}){sub 2}-C{sub 4}H{sub 7}OH-N(CH{sub 3}){sub 2}C{sub 16}H{sub 33}Br{sub 2} (C{sub 16}-C{sub 4}OH-C{sub 16}), C{sub 16}H{sub 33}N(CH{sub 3}){sub 2}-CH{sub 2}-C{sub 6}H{sub 4}-CH{sub 2}-N(CH{sub 3}){sub 2}C{sub 16}H{sub 33}Br{sub 2} (C{sub 16}-ph-C{sub 16}) and C{sub 16}H{sub 33}N(CH{sub 3}){sub 2}-C{sub 12}H{sub 24}-N(CH{sub 3}){sub 2}C{sub 16}H{sub 33}Br{sub 2} (C{sub 16}-C{sub 12}-C{sub 16}), the anodic peak grows rapidly and moves in positive direction, but the cathodic peak gradually decreases, due to the association adsorption and electrostatic interaction of the geminis with MB and its reduced product (i.e. leuko methylene blue, LMB). With the aid of geminis the adsorption amount of MB increases under open-circuit, but the impedance of the mixed adsorption film to Fe(CN){sub 6} {sup 3-/4-} almost keeps unchanged, compared with either bare gold electrodes or MB film, while the adsorption film of geminis exhibits greater impedance. This probably is due to the electron medium action of MB in the film. Gemini surfactants with same alkyl-chain (i.e. -(CH{sub 2}){sub 15}CH{sub 3}) but different molecular structure, exhibit different influence. The enhancing action of geminis studied follows such order as: C{sub 16}-ph-C{sub 16} > C{sub 16}-C{sub 4}-C{sub 16} > C{sub 16}-C{sub 4}OH-C{sub 16} > C{sub 16}-C{sub 12}-C{sub 16}. The change of peak potential was ascribed to the interaction between MB and

  1. In situ infrared study of adsorbed species during catalytic oxidation and carbon dioxide adsorption

    Science.gov (United States)

    Khatri, Rajesh A.

    2005-11-01

    Hydrogen is considered to be the fuel of the next century. Hydrogen can be produced by either water splitting using the solar or nuclear energy or by catalytic cracking and reforming of the fossil fuels. The water splitting process using solar energy and photovoltaics is a clean way to produce hydrogen, but it suffers from very low efficiency. A promising scheme to produce H 2 from natural gas involves following steps: (i) partial oxidation and reforming of natural gas to syngas, (ii) water-gas shift reaction to convert CO in the syngas to additional H2, (iii) separation of the H2 from CO2, and (iv) CO2 sequestration. The requirements for the above scheme are (i) a highly active coke resistant catalyst for generation of syngas by direct partial oxidation, (ii) a highly active sulfur tolerant catalyst for the water-gas shift reaction, and (iii) a low cost sorbent with high CO2 adsorption capacity for CO2 sequestration. This dissertation will address the mechanisms of partial oxidation, CO2 adsorption, and water-gas shift catalysis using in situ IR spectroscopy coupled with mass spectrometry (MS). The results from these studies will lead to a better understanding of the reaction mechanism and design of both the catalyst and sorbent for production of hydrogen with zero emissions. Partial oxidation of methane is studied over Rh/Al2O 3 catalyst to elucidate the reaction mechanism for synthesis gas formation. The product lead-lag relationship observed with in situ IR and MS results revealed that syngas is produced via a two-step reforming mechanism: the first step involving total oxidation of CH4 to CO2 and H 2O and the second step involving the reforming of unconverted methane with CO2 and H2O to form syngas. Furthermore, the Rh on the catalyst surface remains predominantly in the partially oxidized state (Rhdelta+ and Rh0). For the water-gas shift reaction, addition of Re to the Ni/CeO2 catalyst enhanced the water gas shift activity by a factor of three. The activity

  2. Adsorption-parallel catalytic waves of cinnamic acid in hydrogen peroxide-tetra-n-butylammonium bromide-acetate system

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    The mechanism of the adsorption-parallel catalytic wave of cinnamic acid (C6H5-CH == CH-COOH) in acetate buffer (pH = 4.0)-H2O2-tetra-n-butylammonium bromide (Bu4N.Br) solution was studied by the linear-sweep polarography, cyclic voltammetry and digital simulation approach. Experimental results indicate that the reduction mechanism of cinnamic acid is ECdimE'process, in which the C == C double bond of cinnamic acid first undergoes 1e, 1H+ reduction to produce an intermediate free radical C6H5-C.H-CH2-COOH(E'), then the further reduction of the free radical in 1e,1H+ addition (E') occurs simultaneously with a dimerization reaction between two free radicals (Cdim). Bu4N.Br enhances the polarographic current of cinnamic acid and shifts the peak potential to positive direction. The enhancement action of Bu4N.Br is due to the adsorption of cinnamic acid induced by Bu4N+ species. In addition, H2O2 causes the parallel catalytic wave of cinnamic acid. The mechanism of the catalytic wave is EC'process because H2O2 oxidizes the free radical of cinnamic acid to regenerate the original C == C bond(C'), preventing both the further reduction and the dimerization of the free radicals. The apparent rate constant kf of the oxidation reaction is 1.35×102 mol.L-1.s-1. A new class of catalytic waves for organic compounds, the adsorption-parallel catalytic waves upon the dual enhancement action of both the surfactant and oxidant, has been presented.

  3. Determination of Sb(III) using an ex-situ bismuth screen-printed carbon electrode by adsorptive stripping voltammetry.

    Science.gov (United States)

    Rojas-Romo, Carlos; Serrano, Núria; Ariño, Cristina; Arancibia, Verónica; Díaz-Cruz, José Manuel; Esteban, Miquel

    2016-08-01

    The determination of Sb(III) on an ex-situ bismuth screen-printed carbon electrode (ex-situ BiSPCE) by means of adsorptive stripping voltammetry (AdSV) using quercetin-5'-sulfonic acid as chelating agent was optimized. The effect of different experimental parameters such pH, ligand concentration (CQSA), accumulation potential (Eacc) and accumulation time (tacc) were studied to obtain a wide linear range, the highest sensitivity and the lowest detection limit. Ex-situ BiSPCE was analytically compared with a sputtered bismuth screen-printed electrode (BispSPE) under optimal conditions. The obtained analytical parameters suggest that ex-situ BiSPCE behaves much better than BispSPE and the first was selected for this study. Optimal parameters were pH=4.6; CQSA=10.0 to 20.0×10(-6)molL(-1); Eacc=-0.5V and tacc=60s. Peak area is proportional to Sb(III) concentration up to 100.0μgL(-1) (tacc 60s) and 45.0μgL(-1) (tacc 120s) range, with detection limits of 1.2μgL(-)(1) (tacc 60s) and 0.8μgL(-1) (tacc 120s). The relative standard deviation for a Sb(III) solution (20.0μgL(-1)) was 3.9% for ten successive assays. Thus, the effect of various interfering metal ions was studied and the methodology was validated using a spiked groundwater reference material with very satisfactory results. PMID:27216652

  4. Adsorption-parallel catalytic waves of cinnamic acid in hydrogen peroxide-tetra-n-butylammonium bromide-acetate system

    Institute of Scientific and Technical Information of China (English)

    亢晓峰; 过玮; 赵川; 宋俊峰

    2000-01-01

    The mechanism of the adsorption-parallel catalytic wave of cinnamic acid (C6H5—CH = CH—COOH) in acetate buffer (pH = 4.0)-H2O2-tetra-n-butylammonium bromide (Bu4N · Br) solution was studied by the linear-sweep polarography, cyclic voltammetry and digital simulation approach. Experimental results indicate that the reduction mechanism of cinnamic acid is ECdimE’ process, in which the C = C double bond of cinnamic acid first undergoes 1 e, 1H+ reduction to produce an intermediate free radical C6H5—CH—CH2—COOH(E), then the further reduction of the free radical in 1e,1H+ addition (E’) occurs simultaneously with a dimerization reaction between two free radicals (Cdim). Bu4N · Br enhances the polarographic current of cinnamic acid and shifts the peak potential to positive direction. The enhancement action of Bu4N · Br is due to the adsorption of cinnamic acid induced by Bu4N+ species. In addition, H2O2 causes the parallel catalytic wave of cinnamic acid. The mechanism of the catalytic wave is EC’ proce

  5. Ultra-sensitive quantification of sub-nanomolar levels of tin by adsorptive stripping voltammetry by using N-nitroso-N-phenylhydroxylamine as a selective chelating agent

    International Nuclear Information System (INIS)

    In present paper, a simple and sensitive adsorptive stripping voltammetry method was developed for detection of Sn by using N-Nitroso-N-Phenylhydroxylamine (Cupferron) as a selective complexing agent. The influence of ph and the nature of supporting electrolytes, concentration of ligand, preconcentration time and applied potential on were investigated. The detection limits were 0.12 ng/ml. The method has been applied for the determination of tin in human blood, edible oil and water samples with the satisfactory results. (author)

  6. Co-Adsorption of CO in NO-CO Reaction on a Metal Catalytic Surface Studied by Computer Simulation

    Institute of Scientific and Technical Information of China (English)

    Waqar Ahmad

    2009-01-01

    The effect of co-adsorption of CO molecules in the NO-CO reaction on a metal catalytic surface like Pt(001) is studied by applying the Langmuir-Hinshelwood mechanism using the Monte Carlo simulations.The system is investigated by two approaches of NO adsorption;dissociatively at two empty surface sites and molecularly at a single vacant site. The elementary steps are the same as those in the conventional Ziff-Gulari-Barshad model.With the additional reaction step of co-adsorption,the sustained production of CO2 is obtained,which has never been seen on a square lattice without introducing additional parameters.The most interesting result is the elimination of continuous second order phase transition,i.e.the production of CO2 starts as soon as the partial pressure of CO departs from zero,which is in accordance with the experimental observations,The effect of co-adsorption probability on the phase diagrams has also been studied.

  7. Nanomolar detection of rutin based on adsorptive stripping analysis at single-sided heated graphite cylindrical electrodes with direct current heating

    Energy Technology Data Exchange (ETDEWEB)

    Wu, Shao-Hua; Sun, Jian-Jun; Zhang, De-Feng; Lin, Zhi-Bin; Nie, Fa-Hui; Qiu, He-Yuan; Chen, Guo-Nan [Key Laboratory of Analysis and Detection Technology for Food Safety, Ministry of Education, College of Chemistry and Chemical Engineering, Fuzhou University, 523 Gong Ye Road, Fuzhou 350002 (China)

    2008-09-20

    A single-sided heated graphite cylindrical electrode (ss-HGCE) was designed. Compared to previous alternative current (AC) heating, much simpler and cheaper direct current (DC) heating supplier was adopted for the first time to perform adsorptive accumulation of rutin at ss-HGCE at elevated electrode temperature. This offers great promise for low cost, miniaturization and high compatibility with portability. The square wave voltammetry (SWV) stripping peak current was enhanced with increasing the electrode temperature only during preconcentration step. This enhancement was contributed to the forced thermal convection induced by heating the electrode rather than the bulk solution, which is able to improve mass transfer and facilitate adsorption hence enhance stripping response. A detection limit of 1.0 x 10{sup -9} M (S/N = 3) could be obtained at an electrode temperature of 48 C during 5 min accumulation, one magnitude lower than that at 28 C (room temperature). This is the lowest value at carbon-based electrodes for rutin determination as we know. Such novel method was also successfully used to determine rutin in pharmaceutical tablets. (author)

  8. Kinetic and equilibrium studies for the adsorption process of cadmium(II) and copper(II) onto Pseudomonas aeruginosa using square wave anodic stripping voltammetry method

    International Nuclear Information System (INIS)

    A novel method for the simultaneous determination of cadmium(II) and copper(II) during the adsorption process onto Pseudomonas aeruginosa was developed. The concentration of the free metal ions was successfully detected by square wave anodic stripping voltammetry (SWASV) on the mercaptoethane sulfonate (MES) modified gold electrode, while the P. aeruginosa was efficiently avoided approaching to the electrode surface by the MES monolayer. And the anodic stripping peaks of Cd2+ and Cu2+ appear at -0.13 and 0.34 V respectively, at the concentration range of 5-50 μM, the peak currents of SWASV present linear relationships with the concentrations of cadmium and copper respectively. As the determination of Cd2+ and Cu2+ was in real time and without pretreatment, the kinetic characteristics of the adsorption process were studied and all the corresponding regression parameters were obtained by fitting the electrochemical experimental data to the pseudo-second-order kinetic model. Moreover, Langmuir and Freundlich models well described the biosorption isotherms. And there were some differences in the amount of metal ion adsorbed at equilibrium (qe) and other kinetics parameters when the two ions coexisted were compared with the unaccompanied condition, which were also discussed in this paper. The proposed electrode system provides excellent platform for the simultaneous determination of trace metals in complex biosorption process.

  9. LabVIEW-based sequential-injection analysis system for the determination of trace metals by square-wave anodic and adsorptive stripping voltammetry on mercury-film electrodes

    OpenAIRE

    Anastasios Economou; Anastasios Voulgaropoulos

    2003-01-01

    The development of a dedicated automated sequential-injection analysis apparatus for anodic stripping voltammetry (ASV) and adsorptive stripping voltammetry (AdSV) is reported. The instrument comprised a peristaltic pump, a multiposition selector valve and a home-made potentiostat and used a mercury-film electrode as the working electrodes in a thin-layer electrochemical detector. Programming of the experimental sequence was performed in LabVIEW 5.1. The sequence of operations included format...

  10. Simultaneous Removal of NOx and Mercury in Low Temperature Selective Catalytic and Adsorptive Reactor

    Energy Technology Data Exchange (ETDEWEB)

    Neville G. Pinto; Panagiotis G. Smirniotis

    2006-03-31

    The results of a 18-month investigation to advance the development of a novel Low Temperature Selective Catalytic and Adsorptive Reactor (LTSCAR), for the simultaneous removal of NO{sub x} and mercury (elemental and oxidized) from flue gases in a single unit operation located downstream of the particulate collectors, are reported. In the proposed LTSCAR, NO{sub x} removal is in a traditional SCR mode but at low temperature, and, uniquely, using carbon monoxide as a reductant. The concomitant capture of mercury in the unit is achieved through the incorporation of a novel chelating adsorbent. As conceptualized, the LTSCAR will be located downstream of the particulate collectors (flue gas temperature 140-160 C) and will be similar in structure to a conventional SCR. That is, it will have 3-4 beds that are loaded with catalyst and adsorbent allowing staged replacement of catalyst and adsorbent as required. Various Mn/TiO{sub 2} SCR catalysts were synthesized and evaluated for their ability to reduce NO at low temperature using CO as the reductant. It has been shown that with a suitably tailored catalyst more than 65% NO conversion with 100% N{sub 2} selectivity can be achieved, even at a high space velocity (SV) of 50,000 h-1 and in the presence of 2 v% H{sub 2}O. Three adsorbents for oxidized mercury were developed in this project with thermal stability in the required range. Based on detailed evaluations of their characteristics, the mercaptopropyltrimethoxysilane (MPTS) adsorbent was found to be most promising for the capture of oxidized mercury. This adsorbent has been shown to be thermally stable to 200 C. Fixed-bed evaluations in the targeted temperature range demonstrated effective removal of oxidized mercury from simulated flue gas at very high capacity ({approx}>58 mg Hg/g adsorbent). Extension of the capability of the adsorbent to elemental mercury capture was pursued with two independent approaches: incorporation of a novel nano-layer on the surface of the

  11. CATALYTIC AND ADSORPTION PROPERTIES OF Al- AND Ti-MCM-41 SYNTHESIZED AT ROOM TEMPERATURE

    OpenAIRE

    Silva, Tiago N.; Lopes, José Madeira; Ribeiro, Fernando Ramôa; Carrott, Manuela Ribeiro; Galacho, Cristina; Sousa, Maria José; Carrott, Peter

    2002-01-01

    Aluminosilicate and titanosilicate MCM-41 were synthesized using a room temperature method. A preliminary catalytic evaluation was performed in the promotion of the 1-butene double bond isomerization, which was successful in probing differences in the acidity of the samples prepared.

  12. METHANOL REMOVAL FROM METHANOL-WATER MIXTURE USING ACTIVATED SLUDGE, AIR STRIPPING AND ADSORPTION PROCESS: COMPARATIVE STUDY

    Directory of Open Access Journals (Sweden)

    SALAM K. AL-DAWERY

    2015-12-01

    Full Text Available An experimental research has been carried out in order to examine the removal of methanol from methanol-water mixtures using three different methods; activated sludge; activated carbon and air stripping. The results showed that the methanol was totally consumed by the bacteria as quickly as the feed entered the activated sludge vessel. Air stripping process has a limited ability for removing of methanol due to strong intermolecular forces between methanol and water; however, the results showed that the percentage of methanol removed using air pressure at 0.5 bar was higher than that of using air pressure of 0.25 bar. Removal of methanol from the mixture with a methanol content of 5% using activated carbon was not successful due to the limited capacity of the of the activated carbon. Thus, the activated sludge process can be considered as the most suitable process for the treatment of methanol-water mixtures.

  13. The selective catalytic reduction (SCR) of NO with NH3 at vanadium oxide catalysts: Adsorption, diffusion, reaction

    International Nuclear Information System (INIS)

    The selective catalytic reduction (SCR) of NOx with NH3 over vanadium based metal-oxide (VOx) catalysts has been proven to be one of the most effective NOx reduction processes. Even though it is widely used in commercial applications details of the reaction mechanism are still under debate. Experiments show that adsorption, diffusion, and reactions with NO and (de)hydrogenation processes at the VOx surface contribute elementary steps. These processes are examined in theoretical studies employing density-functional theory together with gradient corrected functionals. The VOx substrate is modeled by clusters cut out from the ideal V2O5(010) surface where peripheral oxygen bonds are saturated by hydrogen. Apart from the perfect oxide surface also differently reduced surfaces are considered by introducing oxygen vacancies. NH3 is found to interact only weakly with the perfect V2O5(010) surface. In the presence of OH groups (Broensted acid sites) NH3 can form a surface NH4+ species. NH3 can also interact with the surface near oxygen vacancies, adsorbing at vanadium centers of lower coordination (Lewis acid sites). In contrast, NO interacts much more weakly with the surface. Further, simultaneous NO, NH3 adsorption and SCR reaction scenarios at Broensted and Lewis acid sites are examined. They result in different reaction paths and intermediates as will be discussed in detail.

  14. Adsorptive removal of lead and cadmium ions using Cross -linked CMC Schiff base: Isotherm, Kinetics and Catalytic Activity

    Directory of Open Access Journals (Sweden)

    P. Moganavally

    2016-03-01

    Full Text Available Water plays a vital role to human and other living organisms. Due to the effluent coming from chemical industries, the industrial activity, contamination of ground water level is goes on increasing nowadays. Therefore, there is a need to develop technologies that can remove toxic pollutants in wastewater. Hence the cross linked Carboxymethyl chitosan(CMC/ 2,3-dimethoxy Benzaldehyde Schiff base complex has been synthesized and characterized by using FT-IR and SEM analysis. All these results revealed that cross linked Schiff base has formed with high adsorption capacity. The prepared effective adsorbent used for the removal of heavy metals like lead (II and cadmium (II ions from aqueous solution and the adsorption data follow the Freundlich model, which follows pseudo first order kinetics. Effect of various parameters like solution pH, adsorbent dose and contact time for the removal of heavy metals has been studied. The synthesized sample undergoes catalytic oxidation process significantly at 24 hrs. The results showed that cross linked Schiff base is an effective, eco-friendly, low-cost adsorbent.

  15. Adsorption and catalytic hydrolysis of carbaryl and atrazine on pig manure-derived biochars: Impact of structural properties of biochars

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Peng, E-mail: phevos1983@yahoo.com.cn [MOE Key Laboratory of Pollution Processes and Environmental Criteria, College of Environmental Science and Engineering, Nankai University, Tianjin 300071 (China); Sun, Hongwen, E-mail: sunhongwen@nankai.edu.cn [MOE Key Laboratory of Pollution Processes and Environmental Criteria, College of Environmental Science and Engineering, Nankai University, Tianjin 300071 (China); Yu, Li [MOE Key Laboratory of Pollution Processes and Environmental Criteria, College of Environmental Science and Engineering, Nankai University, Tianjin 300071 (China); Sun, Tieheng [Institute of Applied Ecology, Chinese Academy of Sciences, Shenyang 110016 (China)

    2013-01-15

    Highlights: ► High ash content biochar can increase solution pH and released metal ions. ► Ash in biochar can combine pesticide through specific interactions. ► Composition and structure of biochar is favor for the hydrolysis of pesticides. -- Abstract: Biochars were produced from pig manure to elucidate the influence of biochars with high ash contents on the fate of pesticides. Adsorption and catalytic hydrolysis of carbaryl and atrazine on original biochars and deashed biochars were investigated. The two pesticides were substantially adsorbed by the biochars, with organic carbon normalized sorption coefficient (K{sub oc}) values of 10{sup 2.65}–10{sup 3.66} L/kg for carbaryl and 10{sup 1.90}–10{sup 3.57} L/kg for atrazine at C{sub e} of 0.5 mg/L. Hydrophobic effect alone could not explain the sorption, and several other processes including pore-filling and π–π electron donor–acceptor interactions were involved in pesticide adsorption. Adsorption increased greatly on the deashed biochar, indicating that some organic sorption sites in the original biochars were blocked or difficult to access due to their interactions with inorganic moiety. The pesticides were found to hydrolyze faster in the presence of biochars, and in the presence of biochar pyrolyzed at 700 °C, carbaryl and atrazine were decomposed by 71.8% and 27.9% in 12 h, respectively. The elevated solution pH was the main reason for the enhanced hydrolysis; however both the mineral surface and dissolved metal ions released from the biochars were confirmed to catalyze the hydrolysis.

  16. Adsorption and catalytic hydrolysis of carbaryl and atrazine on pig manure-derived biochars: Impact of structural properties of biochars

    International Nuclear Information System (INIS)

    Highlights: ► High ash content biochar can increase solution pH and released metal ions. ► Ash in biochar can combine pesticide through specific interactions. ► Composition and structure of biochar is favor for the hydrolysis of pesticides. -- Abstract: Biochars were produced from pig manure to elucidate the influence of biochars with high ash contents on the fate of pesticides. Adsorption and catalytic hydrolysis of carbaryl and atrazine on original biochars and deashed biochars were investigated. The two pesticides were substantially adsorbed by the biochars, with organic carbon normalized sorption coefficient (Koc) values of 102.65–103.66 L/kg for carbaryl and 101.90–103.57 L/kg for atrazine at Ce of 0.5 mg/L. Hydrophobic effect alone could not explain the sorption, and several other processes including pore-filling and π–π electron donor–acceptor interactions were involved in pesticide adsorption. Adsorption increased greatly on the deashed biochar, indicating that some organic sorption sites in the original biochars were blocked or difficult to access due to their interactions with inorganic moiety. The pesticides were found to hydrolyze faster in the presence of biochars, and in the presence of biochar pyrolyzed at 700 °C, carbaryl and atrazine were decomposed by 71.8% and 27.9% in 12 h, respectively. The elevated solution pH was the main reason for the enhanced hydrolysis; however both the mineral surface and dissolved metal ions released from the biochars were confirmed to catalyze the hydrolysis

  17. Adsorption, Separation, and Catalytic Properties of Densified Metal-Organic Frameworks

    Energy Technology Data Exchange (ETDEWEB)

    Nandasiri, Manjula I.; Jambovane, Sachin R.; McGrail, B. Peter; Schaef, Herbert T.; Nune, Satish K.

    2016-03-15

    Metal-organic frameworks (MOFs) are one of the widely investigated materials of 21st century due to their unique properties such as structural tailorability, controlled porosity and crystallinity. These exceptional properties make them promising candidates for various applications including gas adsorption and storage, separation, and catalysis. However, commercial applications of MOFs produced by conventional methods including solvothermal or hydrothermal synthesis are rather limited or restricted because they often produce fine powders. The use of MOF powders for industrial applications often results in pressure drop problems similar to the case with Zeolites. To realize these materials for practical applications, densification of MOFs is routinely employed to form pellets, extrudates or beads to improve the overall density, volumetric adsorption, mechanical and thermal properties. However, the improvements come with some drawbacks such as reduction in overall porosity, surface area, and gravimetric adsorption capacity. Thus, optimizing the properties of densified MOF’s by tuning the packing density is very crucial for realizing these materials for industrial applications. In this review, various methods of densification of MOFs, their properties, and applications are discussed.

  18. Polyvinylpyrrolidone adsorption effects on the morphologies of synthesized platinum particles and its catalytic activity

    Energy Technology Data Exchange (ETDEWEB)

    Ooi, Mahayatun Dayana Johan [Nano - Optoelectronic Research and Technology Laboratory, School of Physics, Universiti Sains Malaysia, 11800, Minden, Pulau Pinang (Malaysia); Aziz, Azlan Abdul [Nano - Optoelectronic Research and Technology Laboratory, School of Physics, Universiti Sains Malaysia, 11800, Minden, Pulau Pinang (Malaysia); Nanobiotechnology Research and Innovation (NanoBRI), INFORMM, Universiti Sains Malaysia, 11800, Minden, Pulau Pinang (Malaysia)

    2015-04-24

    Flower-like Platinum micro-structures were synthesized from different concentration of the PVP using solvothermal method. At 5.0×10{sup −3} mmol of PVP, well-defined flower-like pattern consists of triangular petals radiating from the centre were produced whereas larger flower network developed at higher PVP concentration. High degree of crystallinity was obtained upon each increment of PVP. The well defined flower like pattern synthesized using 5.0×10{sup −3} mmol PVP exhibit the highest catalytic activity and stability towards electro-oxidation of formic acid.

  19. Polyvinylpyrrolidone adsorption effects on the morphologies of synthesized platinum particles and its catalytic activity

    Science.gov (United States)

    Ooi, Mahayatun Dayana Johan; Aziz, Azlan Abdul

    2015-04-01

    Flower-like Platinum micro-structures were synthesized from different concentration of the PVP using solvothermal method. At 5.0×10-3 mmol of PVP, well-defined flower-like pattern consists of triangular petals radiating from the centre were produced whereas larger flower network developed at higher PVP concentration. High degree of crystallinity was obtained upon each increment of PVP. The well defined flower like pattern synthesized using 5.0×10-3 mmol PVP exhibit the highest catalytic activity and stability towards electro-oxidation of formic acid.

  20. Ultrasensitive multiplexed immunoassay with electrochemical stripping analysis of silver nanoparticles catalytically deposited by gold nanoparticles and enzymatic reaction.

    Science.gov (United States)

    Lai, Guosong; Yan, Feng; Wu, Jie; Leng, Chuan; Ju, Huangxian

    2011-04-01

    A novel ultrasensitive multiplexed immunoassay method was developed by combining alkaline phosphatase (ALP)-labeled antibody functionalized gold nanoparticles (ALP-Ab/Au NPs) and enzyme-Au NP catalyzed deposition of silver nanoparticles at a disposable immunosensor array. The immunosensor array was prepared by covalently immobilizing capture antibodies on chitosan modified screen-printed carbon electrodes. After sandwich-type immunoreactions, the ALP-Ab/Au NPs were captured on an immunosensor surface to catalyze the hydrolysis of 3-indoxyl phosphate, which produced an indoxyl intermediate to reduce Ag(+). The silver deposition process was catalyzed by both ALP and Au NPs, which amplified the detection signal. The deposited silver was then measured by anodic stripping analysis in KCl solution. Using human and mouse IgG as model analytes, this multiplexed immunoassay method showed wide linear ranges over 4 orders of magnitude with the detection limits down to 4.8 and 6.1 pg/mL, respectively. Acceptable assay results for practical samples could be obtained. The newly designed strategy avoided cross talk and the need of deoxygenation for the electrochemical immunoassay and, thus, provided a promising potential in clinical applications.

  1. INVESTIGATION OF AMMONIA ADSORPTION ON FLY ASH DUE TO INSTALLATION OF SELECTIVE CATALYTIC REDUCTION SYSTEMS

    Energy Technology Data Exchange (ETDEWEB)

    G.F. Brendel; J.E. Bonetti; R.F. Rathbone; R.N. Frey Jr.

    2000-11-01

    This report summarizes an investigation of the potential impacts associated with the utilization of selective catalytic reduction (SCR) systems at coal-fired power plants. The study was sponsored by the U.S. Department of Energy Emission Control By-Products Consortium, Dominion Generation, the University of Kentucky Center for Applied Energy Research and GAI Consultants, Inc. SCR systems are effective in reducing nitrogen oxides (NOx) emissions as required by the Clean Air Act (CAA) Amendments. However, there may be potential consequences associated with ammonia contamination of stack emissions and combustion by-products from these systems. Costs for air quality, landfill and pond environmental compliance may increase significantly and the marketability of ash may be seriously reduced, which, in turn, may also lead to increased disposal costs. The potential impacts to air, surface water, groundwater, ash disposal, ash utilization, health and safety, and environmental compliance can not be easily quantified based on the information presently available. The investigation included: (1) a review of information and data available from published and unpublished sources; (2) baseline ash characterization testing of ash samples produced from several central Appalachian high-volatile bituminous coals from plants that do not currently employ SCR systems in order to characterize the ash prior to ammonia exposure; (3) an investigation of ammonia release from fly ash, including leaching and thermal studies; and (4) an evaluation of the potential impacts on plant equipment, air quality, water quality, ash disposal operations, and ash marketing.

  2. Modification of carbon screen-printed electrodes by adsorption of chemically synthesized Bi nanoparticles for the voltammetric stripping detection of Zn(II), Cd(II) and Pb(II).

    Science.gov (United States)

    Rico, Ma Angeles Granado; Olivares-Marín, Mara; Gil, Eduardo Pinilla

    2009-12-15

    A simple procedure for the chemical synthesis of bismuth nanoparticles and subsequent adsorption on commercial screen-printed carbon electrodes offer reliable quantitation of trace zinc, cadmium and lead by anodic stripping square-wave voltammetry in nondeareated water samples. The influence of two hydrodynamic configurations (convective cell and flow cell) and the effect of various experimental variables upon the stripping signals at the bismuth-coated sensor are explored. The square-wave peak current signal is linear over the low ng mL(-1) range (120 s deposition), with detections limits ranging from 0.9 to 4.9 ng mL(-1) and good precision. Applicability to waste water certified reference material and drinking water samples is demonstrated. The attractive behaviour of the new disposable Bi nanoparticles modified carbon strip electrodes, coupled with the negligible toxicity of bismuth, hold great promise for decentralized heavy metal testing in environmental and industrial effluents waters.

  3. Determination of oleuropein using multiwalled carbon nanotube modified glassy carbon electrode by adsorptive stripping square wave voltammetry.

    Science.gov (United States)

    Cittan, Mustafa; Koçak, Süleyman; Çelik, Ali; Dost, Kenan

    2016-10-01

    A multi-walled carbon nanotube modified glassy carbon electrode was used to prepare an electrochemical sensing platform for the determination of oleuropein. Results showed that, the accumulation of oleuropein on the prepared electrode takes place with the adsorption process. Electrochemical behavior of oleuropein was studied by using cyclic voltammetry. Compared to the bare GCE, the oxidation peak current of oleuropein increased about 340 times at MWCNT/GCE. Voltammetric determination of oleuropein on the surface of prepared electrode was studied using square wave voltammetry where the oxidation peak current of oleuropein was measured as an analytical signal. A calibration curve of oleuropein was performed between 0.01 and 0.70µM and a good linearity was obtained with a correlation coefficient of 0.9984. Detection and quantification limits of the method were obtained as 2.73 and 9.09nM, respectively. In addition, intra-day and inter-day precision studies indicated that the voltammetric method was sufficiently repeatable. Finally, the proposed electrochemical sensor was successfully applied to the determination of oleuropein in an olive leaf extract. Microwave-assisted extraction of oleuropein had good recovery values between 92% and 98%. The results obtained with the proposed electrochemical sensor were compared with liquid chromatography-tandem mass spectrometry (LC-MS/MS) analysis. PMID:27474292

  4. A novel method for oxidative desulfurization of liquid hydrocarbon fuels based on catalytic oxidation using molecular oxygen coupled with selective adsorption

    Energy Technology Data Exchange (ETDEWEB)

    Ma, Xiaoliang; Song, Chunshan [Clean Fuels and Catalysis Program, The Energy Institute, Department of Energy and Geo-Environmental Engineering, The Pennsylvania State University, 209 Academic Projects Building, University Park, PA 16802 (United States); Zhou, Anning [Clean Fuels and Catalysis Program, The Energy Institute, Department of Energy and Geo-Environmental Engineering, The Pennsylvania State University, 209 Academic Projects Building, University Park, PA 16802 (United States); Department of Chemistry and Chemical Engineering, Xian University of Science and Technology, Xian 710054 (China)

    2007-05-30

    The present study explored a novel oxidative desulfurization (ODS) method of liquid hydrocarbon fuels, which combines a catalytic oxidation step of the sulfur compounds directly in the presence of molecular oxygen and an adsorption step of the oxidation-treated fuel over activated carbon. The ODS of a model jet fuel and a real jet fuel (JP-8) was conducted in a batch system at ambient conditions. It was found that the oxidation in the presence of molecular oxygen with Fe(III) salts was able to convert the thiophenic compounds in the fuel to the corresponding sulfone and/or sulfoxide compounds at 25 C. The oxidation reactivity of the sulfur compounds decreases in the order of 2-methylbenzothiophene > 5-methylbenzothiophene > benzothiophene >> dibenzothiophene. The alkyl benzothiophenes with more alkyl substituents have higher oxidation reactivity. In real JP-8 fuel, 2,3-dimethylbenzothiophene was found to be the most refractory sulfur compound to be oxidized. The catalytic oxidation of the sulfur compounds to form the corresponding sulfones and/or sulfoxides improved significantly the adsorptivity of the sulfur compounds on activated carbon, because the activated carbon has higher adsorptive affinity for the sulfones and sulfoxides than thiophenic compounds due to the higher polarity of the former. The remarkable advantages of the developed ODS method are that the ODS can be run in the presence of O{sub 2} at ambient condition without using peroxides and aqueous solvent and thus without involving the biphasic oil-aqueous-solution system. (author)

  5. Stripping voltammetry of flavonoids

    International Nuclear Information System (INIS)

    The electrochemical behavior of the flavonoids hesperidin, quercetin, naringin, rutin, catechin, epicatechin and caffeic acid at the mercury electrode (HMDE, DME) and at a glassy carbon electrode has been studied by differential pulse polarography. Determination of flavonoids can be achieved either by direct reduction of the carbonyl group in the gamma-pyron ring, indirectly by cathodic stripping voltammetry via the formation of different flavonoid-mercury complexes at the mercury electrode surface and by adsorptive stripping voltammetry via the direct oxidation of aromatic o-dihydroxy groups. The advantage of stripping voltammetry is higher sensitivity and due to the possibility of higher sample dilution less influence of matrix effects. The application by cathodic stripping voltammetry to the determination of hesperidin in orange juice, hesperidin and rutin in helopyrin(R) tablets, a phytopharmaceutical preparation, naringin in grapefruit juice is demonstrated. Also the application by adsorptive stripping voltammetry at a glassy carbon electrode to the determination of quercetin in blood and sinupret, a phytopharmaceutical preparation and catechin in beer is demonstrated. Both methods are suitable for the determination of low flavonoid concentrations down to the ppb concentration range. (author)

  6. Catalytic Role Of Palladium And Relative Reactivity Of Substituted Chlorines During Adsorption And Treatment Of PCBs On Reactive Activated Carbon

    Science.gov (United States)

    The adsorption-mediated dechlorination of polychlorinated biphenyls (PCBs) is a unique feature of reactive activated cabon (RAC). Here, we address the RAC system, containing a tunable amount of Fe as a primary electron donor coupled with Pd as an electrochemical catalyst to pote...

  7. H2 damage of ferroelectric Pb(Zr,Ti)O3 thin-film capacitors—The role of catalytic and adsorptive activity of the top electrode

    Science.gov (United States)

    Shimamoto, Y.; Kushida-Abdelghafar, K.; Miki, H.; Fujisaki, Y.

    1997-06-01

    Large-scale integrated fabrication in a H2 containing atmosphere, for example, during the passivation process, can cause serious damage in metal/Pb(Zr,Ti)O3/metal capacitors (i.e., Pt/PZT/Pt capacitors). To reveal the cause of the H2 damage, we investigated the behavior of hysteresis curves and the leakage current of capacitors with a top electrode of Pt, Pd, Au, or Ag. Capacitors with a top electrode of Au or Ag are more resistant to the H2 annealing damage than those of Pt or Pd. We found that the H2 damage was strongly affected by the catalytic activity and adsorptive properties of the top electrode when exposed to H2.

  8. Determination of adsorptive and catalytic properties of copper, silver and iron contain titanium-pillared bentonite for the removal bisphenol A from aqueous solution

    Science.gov (United States)

    Tomul, Fatma; Turgut Basoglu, Funda; Canbay, Hale

    2016-01-01

    Ti-pillared bentonite, Cu, Ag and Fe modified Ti-pillared bentonite and Cu/Ti- and Fe/Ti-mixed pillared bentonite were synthesized using different titanium sources by direct synthesis or by modification after synthesis. The effects of synthesis conditions on the surface characteristics, pore structure and acidity of the pillared bentonites were investigated by SEM-EDS, XPS, XRD, N2-adsorption/desorption and FTIR analyses before and after ammonia adsorption. The results of EDS, XPS and XRD analysis confirmed that titanium, copper, silver and iron were incorporated into the bentonite structure. In the XRD patterns, the formation of delaminated structure reflecting the non-parallel distribution of the bentonite layers by pillaring with Ti, Cu/Ti and Fe/Ti-pillars was observed. XPS spectra indicated the presence of TiO2, CuO, Ag and Ag2O and Fe2O3 species depending on the source of active metals in the synthesized samples. In the FTIR spectra, an increase in the Bronsted/Lewis peak intensity was observed with the loading of copper and iron, whereas a decrease in Lewis and Bronsted acidities was observed with incorporation of silver. Adsorption studies indicated that the adsorption capacity of the sample synthesized using titanium (IV) propoxide and incorporating iron to the structure by ion exchange (Fe-PTi-PILC) were higher than those in other samples. The adsorption of BPA (bisphenol A) by all tested samples was found to fit the Langmuir isotherm. In the catalytic wet peroxide oxidation (CWPO) over PTi-PILC (prepared by titanium (IV) propoxide), Fe-PTi-PILC and Cu-PTi-PILC (prepared by copper impregnated Ti-pillared bentonite) samples, BPA values close to complete conversion were achieved within 30 min at 25 °C, pH 4 and 5 g/L mcat. CWPO results showed that increasement of pH causes a decrease the rate of oxidation. On the other hand, by the time catalyst and BPA concentration is increased, the rate of oxidation is increased as well.

  9. Thermal desorption study of catalytic systems. Communication 20. Adsorption of water vapors on the calcium aluminate components of catalysts

    Energy Technology Data Exchange (ETDEWEB)

    Nissenbaum, V.D.; Danyushevskii, V.Y.; Golosman, E.Z.; Rubinstein, A.M.; Yakerson, V.I.

    1985-05-01

    Ca aluminates are used as a component of catalysts of gas-phase processes, some of which take place with the participation of water. Nickel calcium aluminate catalysts are thus used for hydrogenation of CO and CO/sub 2/ to CH/sub 4/ and water; zinc calcium aluminate catalysts are used for sulfur purification of process gases, where water is liberated during sulfiding of ZnO; and copper zinc calcium aluminate catalysts are used in low-temperature conversion of CO with water vapor. It is also known that Ca aluminates undergo various transformations in aqueous media with the formation of Ca hydroaluminates. This paper discusses the adsorption of water from the gas phase on calcium aluminate systems, which was investigated by the thermal desorption method. Samples of varying phase composition, different CaO/Al/sub 2/O/sub 3/ ratios, and specific surface areas were also studied and are reported on here.

  10. Toluene removal by sequential adsorption-plasma catalytic process: Effects of Ag and Mn impregnation sequence on Ag-Mn/γ-Al2O3.

    Science.gov (United States)

    Qin, Caihong; Huang, Xuemin; Dang, Xiaoqing; Huang, Jiayu; Teng, Jingjing; Kang, Zhongli

    2016-11-01

    A series of Ag-Mn/γ-Al2O3 were prepared under different Ag/Mn impregnation sequence and tested in the sequential adsorption-plasma catalytic removal of toluene. When Mn was impregnated first, the resulting catalyst, Ag-Mn(F)/γ-Al2O3, had longer breakthrough time, gave less emission of toluene, had higher CO2 selectivity, and had better carbon balance and COx yield compared to catalysts prepared via other impregnation sequences. After 120 min of NTP treatment, the carbon balance of Ag-Mn(F)/γ-Al2O3 was 91%, with 87% as COx contributions. A Brunauer-Emmett-Teller (BET) analysis and X-ray photoelectron spectroscopy (XPS) results show that, the impregnation sequence impacts the BET surface area and the ratio and existing state of Ag on the surface of the catalysts. The longer breakthrough time when using Ag-Mn(F)/γ-Al2O3 as catalyst is attributed to the large amount of Ag(+) on the surface. Ag(+) is a new active site for toluene adsorption. When Ag was impregnated first (Ag(F)-Mn/γ-Al2O3) or Ag and Mn co-impregnated (Ag-Mn-C/γ-Al2O3), the predominant specie was Ag(+). Both Ag(0) and Ag(+) species were detected on Ag-Mn(F)/γ-Al2O3. Ag(0) cooperation with MnOx may promote the migration of surface active oxygen. This would facilitate the oxidation of adsorbed toluene with CC bond already weakened by Ag(+) and would result in higher CO2 selectivity and better carbon balance as seen in the Ag-Mn(F)/γ-Al2O3 system. PMID:27494312

  11. Integrated Removal of NOx with Carbon Monoxide as Reductant, and Capture of Mercury in a Low Temperature Selective Catalytic and Adsorptive Reactor

    Energy Technology Data Exchange (ETDEWEB)

    Neville Pinto; Panagiotis Smirniotis; Stephen Thiel

    2010-08-31

    Coal will likely continue to be a dominant component of power generation in the foreseeable future. This project addresses the issue of environmental compliance for two important pollutants: NO{sub x} and mercury. Integration of emission control units is in principle possible through a Low Temperature Selective Catalytic and Adsorptive Reactor (LTSCAR) in which NO{sub x} removal is achieved in a traditional SCR mode but at low temperature, and, uniquely, using carbon monoxide as a reductant. The capture of mercury is integrated into the same process unit. Such an arrangement would reduce mercury removal costs significantly, and provide improved control for the ultimate disposal of mercury. The work completed in this project demonstrates that the use of CO as a reductant in LTSCR is technically feasible using supported manganese oxide catalysts, that the simultaneous warm-gas capture of elemental and oxidized mercury is technically feasible using both nanostructured chelating adsorbents and ceria-titania-based materials, and that integrated removal of mercury and NO{sub x} is technically feasible using ceria-titania-based materials.

  12. Lanthanide Metal-Organic Frameworks with Six-Coordinated Ln(III) Ions and Free Functional Organic Sites for Adsorptions and Extensive Catalytic Activities

    Science.gov (United States)

    Zhu, Yu; Zhu, Min; Xia, Li; Wu, Yunlong; Hua, Hui; Xie, Jimin

    2016-07-01

    Three chelating-amino-functionalized lanthanide metal-organic frameworks, Y-DDQ, Dy-DDQ and Eu-DDQ, were synthesized with a flexible dicarboxylate ligand based on quinoxaline (H2DDQ = N, N‧-dibenzoic acid-2,3-diaminoquinoxaline). The three-dimensional framework is constructed by the H2DDQ linkers connecting the zigzag ladders, showing a net of sra topology. In the structures, one kind of Ln(III) ions metal centers are six-coordinated and thus can potentially behave as open metal sites (OMSs), while the free chelating amino groups can act as free functional organic sites (FOSs). The N2 and Ar adsorption behaviors indicate that these Ln-DDQ exhibits stable microporous frameworks with high surface area after remove of the solvents. Owing to presence of OMSs and FOSs, these MOFs show good ability of CO2, dyes captures and Lewis acid catalyst for cyanosilylation reaction. In view of the existing FOSs in the framework, Pd NPs were immobilized onto the MOFs through graft interactions between free chelating amino groups and metal ions precursor using postsynthetic modification. The well dispersed Pd@Ln-DDQs exhibit efficient and recyclable catalytic reduction of 4-nitrophenol to 4-aminophenol, and they can also act as an excellent catalyst for Suzuki-Miyaura cross-coupling reactions with the exposed Pd NPs.

  13. Modification of the adsorption and catalytic properties of micro-and mesoporous materials by reactions with organometallic complexes

    Institute of Scientific and Technical Information of China (English)

    LEFEBVRE; Frédéric; PUTAJ; Piotr; BASSET; Jean-Marie

    2010-01-01

    This review describes the work of two laboratories in the field of the modification of micro-and mesoporous molecular sieves through reactions with organometallic complexes.The modification of zeolites can occur inside the pore channels or on the external surface,depending on the size of the organometallic complex.When the modification occurs on the external surface,it results in a decrease of the pore entrance,which will lead in turn to a modification of the sorption properties of the zeolite,by decreasing the rate of the adsorption(mainly by a kinetic control).Such a material can be also used in catalysis,because the external acid sites,which are responsible for side-reactions,have been removed upon grafting.When small organometallic complexes are used,they can fill the channels and cages of the zeolite and react with internal hydroxyl groups.Due to the high acidity of zeolites,the reaction occurs very easily(for example at-100℃ on faujasite),in contrast to what is observed on the external surface,therefore leading to high metal loadings.In that case,the modification of the sorption properties will be mainly related to a thermodynamic control.The resulting materials can be useful in catalysis,by combining the activity of the organometallic complex and properties(for example shape-selectivity) of the zeolite.Modification of mesoporous molecular sieves occurs always in the pores and results in altering of the sorption properties of the solid,by changing the interaction type between the sorbent and the sorbate.For example the sorption isotherm of alkanes is changed from type II to type III according to the IUPAC nomenclature.

  14. A solid paraffin-based carbon paste electrode modified with 2-aminothiazole organofunctionalized silica for differential pulse adsorptive stripping analysis of nickel in ethanol fuel

    Energy Technology Data Exchange (ETDEWEB)

    Takeuchi, Regina M. [Departamento de Quimica Analitica, Instituto de Quimica, UNESP, CP 355, 14801-970 Araraquara, SP (Brazil)]. E-mail: takeuchi@iq.unesp.br; Santos, Andre L. [Departamento de Quimica Analitica, Instituto de Quimica, UNESP, CP 355, 14801-970 Araraquara, SP (Brazil); Padilha, Pedro M. [Departamento de Quimica e Bioquimica-IB/UNESP, CP 510, 18618-000 Botucatu, SP (Brazil); Stradiotto, Nelson R. [Departamento de Quimica Analitica, Instituto de Quimica, UNESP, CP 355, 14801-970 Araraquara, SP (Brazil)

    2007-02-19

    A solid paraffin-based carbon paste electrode modified with 2-aminothiazole organofunctionalized silica (SiAt-SPCPE) was applied to Ni{sup 2+} determination in commercial ethanol fuel samples. The proposed method comprised four steps: (1) Ni{sup 2+} preconcentration at open circuit potential directly in the ethanol fuel sample, (2) transference of the electrode to an electrochemical cell containing DMG, (3) differential pulse voltammogram registering and (4) surface regeneration by polishing the electrode. The proposed method combines the high Ni{sup 2+} adsorption capacity presented by 2-aminothiazole organofunctionalized silica with the electrochemical properties of the Ni(DMG){sub 2} complex, whose electrochemical reduction provides the analytical signal. All experimental parameters involved in the proposed method were optimized. Using a preconcentration time of 20 min, it was obtained a linear range from 7.5 x 10{sup -9} to 1.0 x 10{sup -6} mol L{sup -1} with detection limit of 2.0 x 10{sup -9} mol L{sup -1}. Recovery values between 96.5 and 102.4% were obtained for commercial samples spiked with 1.0 {mu}mol L{sup -1} Ni{sup 2+} and the developed electrode was totally stable in ethanolic solutions. The contents of Ni{sup 2+} found in the commercial samples using the proposed method were compared to those obtained by graphite furnace atomic absorption spectroscopy by using the F- and t-test. Neither the F- nor t-values exceeded the critical values at 95% confidence level, confirming that there are not statistical differences between the results obtained by both methods. These results indicate that the developed electrode can be successfully employed to reliable Ni{sup 2+} determination in commercial ethanol fuel samples without any sample pretreatment or dilution step.

  15. Microcalorimetric Study of the Catalytic Properties of SBA-15 Modified with Cu or Fe for Adsorption/Oxidation of methyl mercaptane

    Directory of Open Access Journals (Sweden)

    Liliana Giraldo

    2014-01-01

    Full Text Available SBA-15 modified with Cu or Fe was used for adsorption/oxidation of methyl mercapthane in the vapour phase. These solids were synthesized from SBA-15 using the template method with a non-ionic surfactant and impregnating the SBA-15 with Cu and Fe. The solids were characterized by using XRD, FTIR and isotherms of adsorption in N2. An increase in the surface area, pore volume and mesoporosity of the SBA-15 with each metal was observed. Adsorption microcalorimetry is an effective method to measure thermal effects generated during the decomposition of methyl mercapthane.

  16. Lateral flow strip assay

    Science.gov (United States)

    Miles, Robin R.; Benett, William J.; Coleman, Matthew A.; Pearson, Francesca S.; Nasarabadi, Shanavaz L.

    2011-03-08

    A lateral flow strip assay apparatus comprising a housing; a lateral flow strip in the housing, the lateral flow strip having a receiving portion; a sample collection unit; and a reagent reservoir. Saliva and/or buccal cells are collected from an individual using the sample collection unit. The sample collection unit is immersed in the reagent reservoir. The tip of the lateral flow strip is immersed in the reservoir and the reagent/sample mixture wicks up into the lateral flow strip to perform the assay.

  17. A comparative DFT study of adsorption and catalytic performance of Au nanoparticles at anatase and brookite TiO 2 surfaces

    Science.gov (United States)

    Li, Wei-Kun; Chu, Li-Na; Gong, Xue-Qing; Lu, Guanzhong

    2011-08-01

    We have compared the adsorption properties of small Au n ( n = 1-8) nanoparticles on the defect-free (stoichiometric) and defective (partially reduced) brookite TiO 2(210) and anatase TiO 2(101) surfaces using density functional theory calculations. The interaction between Au atoms and anatase TiO 2(101) was determined to be quite weak and small Au n particles grown at defects (O vacancies) prefer extended 2D structures. By contrast, dispersion and 3D configurations appear to be favored at brookite TiO 2(210) for Au n nanoparticles due to their strong interaction. Calculations of CO oxidation at Au n ( n = 6-8) particles supported at defective brookite TiO 2(210) show that occurrence of protruding low-coordinated Au atoms is essential for favorable CO adsorption and subsequent reaction with O 2. In particular, the configuration of the Au n nanoparticles can determine the energetics in the formation of active Au atoms, and their mobility also affects the reaction between CO and O 2 (or O).

  18. Anatomy comic strips.

    Science.gov (United States)

    Park, Jin Seo; Kim, Dae Hyun; Chung, Min Suk

    2011-01-01

    Comics are powerful visual messages that convey immediate visceral meaning in ways that conventional texts often cannot. This article's authors created comic strips to teach anatomy more interestingly and effectively. Four-frame comic strips were conceptualized from a set of anatomy-related humorous stories gathered from the authors' collective imagination. The comics were drawn on paper and then recreated with digital graphics software. More than 500 comic strips have been drawn and labeled in Korean language, and some of them have been translated into English. All comic strips can be viewed on the Department of Anatomy homepage at the Ajou University School of Medicine, Suwon, Republic of Korea. The comic strips were written and drawn by experienced anatomists, and responses from viewers have generally been favorable. These anatomy comic strips, designed to help students learn the complexities of anatomy in a straightforward and humorous way, are expected to be improved further by the authors and other interested anatomists. PMID:21634024

  19. ALICE silicon strip module

    CERN Multimedia

    Maximilien Brice

    2006-01-01

    This small silicon detector strip will be inserted into the inner tracking system (ITS) on the ALICE detector at CERN. This detector relies on state-of-the-art particle tracking techniques. These double-sided silicon strip modules have been designed to be as lightweight and delicate as possible as the ITS will eventually contain five square metres of these devices.

  20. Anatomy Comic Strips

    Science.gov (United States)

    Park, Jin Seo; Kim, Dae Hyun; Chung, Min Suk

    2011-01-01

    Comics are powerful visual messages that convey immediate visceral meaning in ways that conventional texts often cannot. This article's authors created comic strips to teach anatomy more interestingly and effectively. Four-frame comic strips were conceptualized from a set of anatomy-related humorous stories gathered from the authors' collective…

  1. Science Comic Strips

    Science.gov (United States)

    Kim, Dae Hyun; Jang, Hae Gwon; Shin, Dong Sun; Kim, Sun-Ja; Yoo, Chang Young; Chung, Min Suk

    2012-01-01

    Science comic strips entitled Dr. Scifun were planned to promote science jobs and studies among professionals (scientists, graduate and undergraduate students) and children. To this end, the authors collected intriguing science stories as the basis of scenarios, and drew four-cut comic strips, first on paper and subsequently as computer files.…

  2. Surface structure of crystalline and amorphous chromia catalysts for the selective catalytic reduction of nitric oxide. 2. Diffuse reflectance FTIR study of thermal treatment and oxygen adsorption

    Energy Technology Data Exchange (ETDEWEB)

    Schraml-Marth, M.; Wokaun, A. (Univ. of Bayreuth (Germany)); Curry-Hyde, H.E.; Baiker, A. (Swiss Federal Inst. of Tech., Zuerich (Switzerland))

    1992-02-01

    The activation of crystalline and amorphous chromia surfaces by thermal pretreatment in argon and oxygen adsorption at 473 K has been studied by diffuse reflectance FTIR and Raman spectroscopy. The formation of coordinatively unsaturated chromium sites during thermal activation is monitored by observing the evolution of Cr{double bond}O stretching absorptions both in the fundamental and overtone regions of the FTIR spectrum. On {alpha}-Cr{sub 2}O{sub 3}, labile surface oxygen species are largely removed at 498 K, whereas on the amorphous chromia surface, labile oxygen is more tightly bound. As a consequence, coordinatively unsaturated chromium sites are generated on amorphous chromia to a lesser extent than on {alpha}-Cr{sub 2}O{sub 3}. Upon high-temperature oxygen treatment, O{sub 2} is dissociatively adsorbed. Coordinatively unsaturated sites are occupied by the added oxygen, as manifested by an increase in the number of Cr{double bond}O oscillators. Fine structure in the Cr{double bond}O absorptions of the amorphous chromia is observed for the first time, and is tentatively assigned to various types of surface sites. Raman spectroscopic characterization of the amorphous chromia surface reveals laser-induced dehydration and creation of coordinatively unsaturated surface Cr{double bond}O sites, accompanied by progressive crystallization of the amorphous substrate. Differences between crystalline and amorphous chromia with respect to their SCR activity are correlated with the higher density of labile oxygen species available on the surface of amorphous chromia under SCR reaction conditions (423-473 K).

  3. Fabrication of chitosan-magnetite nanocomposite strip for chromium removal

    Science.gov (United States)

    Sureshkumar, Vaishnavi; Kiruba Daniel, S. C. G.; Ruckmani, K.; Sivakumar, M.

    2016-02-01

    Environmental pollution caused by heavy metals is a serious threat. In the present work, removal of chromium was carried out using chitosan-magnetite nanocomposite strip. Magnetite nanoparticles (Fe3O4) were synthesized using chemical co-precipitation method at 80 °C. The nanoparticles were characterized using UV-visible spectroscopy, fourier transform infrared spectroscopy, X-ray diffraction spectrometer, atomic force microscope, dynamic light scattering and vibrating sample magnetometer, which confirm the size, shape, crystalline nature and magnetic behaviour of nanoparticles. Atomic force microscope revealed that the particle size was 15-30 nm and spherical in shape. The magnetite nanoparticles were mixed with chitosan solution to form hybrid nanocomposite. Chitosan strip was casted with and without nanoparticle. The affinity of hybrid nanocomposite for chromium was studied using K2Cr2O7 (potassium dichromate) solution as the heavy metal solution containing Cr(VI) ions. Adsorption tests were carried out using chitosan strip and hybrid nanocomposite strip at different time intervals. Amount of chromium adsorbed by chitosan strip and chitosan-magnetite nanocomposite strip from aqueous solution was evaluated using UV-visible spectroscopy. The results confirm that the heavy metal removal efficiency of chitosan-magnetite nanocomposite strip is 92.33 %, which is higher when compared to chitosan strip, which is 29.39 %.

  4. Optimization of operating condition for process of catalytic oxidative adsorption desulfurization of coking diesel%焦化柴油催化氧化吸附脱硫工艺条件优化

    Institute of Scientific and Technical Information of China (English)

    张华军; 闫锋; 廖克俭; 兰艳

    2011-01-01

    以磷钼酸季铵盐为催化剂,三氟乙酸为氧化剂,糠醛为萃取剂,采用催化氧化-萃取吸附组合工艺对焦化柴油进行脱硫处理.结果表明,在反应温度为60℃,氧化剂用量(V(氧化剂)/V(焦化柴油))为0.2,催化剂用量(m(催化剂)/V(焦化柴油))为8 g/L,反应时间为60 min,萃取剂用量(V(萃取剂)/V(焦化柴油))为1.0,萃取时间为30 min的最佳工艺条件下,焦化柴油的硫质量分数可从1.05×10-3下降为42×10-6.%The deep desulfurization of coking diesel was investigated by catalytic oxidation -extraction- adsorption combination process with quaternary ammonium phosphomolybdate as catalyst,trifluoroacetic acid as oxidant, furfural as extractant.The results showed that under the optimal condition of reaction temperature of 60 ℃, volume ratio of oxidant to coking diesel of 0.2, catalyst mass concentration in coking diesel of 8 g/L, reaction time of 60 min,volume ratio of extractant to coking diesel of 1.0 and extraction time of 30 min, the mass fraction of sulfur in coking diesel could decrease from 1.05 × 10-3 to 42 × 10-6

  5. micro strip gas chamber

    CERN Multimedia

    1998-01-01

    About 16 000 Micro Strip Gas Chambers like this one will be used in the CMS tracking detector. They will measure the tracks of charged particles to a hundredth of a millimetre precision in the region near the collision point where the density of particles is very high. Each chamber is filled with a gas mixture of argon and dimethyl ether. Charged particles passing through ionise the gas, knocking out electrons which are collected on the aluminium strips visible under the microscope. Such detectors are being used in radiography. They give higher resolution imaging and reduce the required dose of radiation.

  6. Research progress of adsorption/activation and catalytic hydrogenation of CO2%CO2吸附活化及催化加氢制低碳烯烃的研究进展

    Institute of Scientific and Technical Information of China (English)

    李静; 邓廷云; 杨林; 曹建新

    2013-01-01

    随着工业化的发展,CO2的排放与日俱增,给环境带来了不可忽视的严重后果.同时,石油资源日渐匮乏,使得以石油为原料制低碳烯烃的工业面临严峻的挑战.利用CO2制低碳烯烃是缓解环境与资源双重压力的有效途径之一.本文综述了CO2催化加氢制低碳烯烃的热力学分析,CO2在过渡金属单晶和氧化物表面的吸附活化机理以及CO2催化加氢制低碳烯烃催化剂的研究进展.分析比较了包括单金属催化剂、双金属催化剂和复合催化剂在内的CO2制低碳烯烃催化剂的优缺点.提出了催化反应过程中存在催化剂难以兼顾选择性和转化率的技术难题,并指出了今后的主要研究方向是加强催化反应机理和催化剂制备、改性技术的研究.%Growing emission of CO2 has brought serious consequences to the environment. At the same time, fossil energy is depleting, which challenges oil-based low carbon olefins industry. Using CO2 to produce carbon olefins is one of effective ways to alleviate the dual pressure of environment and resource. Thermodynamic analysis of CO2 hydrogenation to light olefins, adsorption/activation mechanism of CO2 on single crystal and oxides of transition metal and research progress of catalyst for hydrogenation of carbon dioxide to light alkenes are reviewed. The advantages and disadvantages of catalysts for CO2 hydrogenation, including single metal catalysts, bimetallic catalysts and the composite catalyst are analyzed. The problem of catalyst is how to balance selectivity and conversion rate. The future research directions of catalyst are mechanism of catalytic reaction, and catalyst preparation and modification.

  7. ALICE Silicon Strip Detector

    CERN Multimedia

    Nooren, G

    2013-01-01

    The Silicon Strip Detector (SSD) constitutes the two outermost layers of the Inner Tracking System (ITS) of the ALICE Experiment. The SSD plays a crucial role in the tracking of the particles produced in the collisions connecting the tracks from the external detectors (Time Projection Chamber) to the ITS. The SSD also contributes to the particle identification through the measurement of their energy loss.

  8. Enhancement of CO2 Adsorption and Catalytic Properties by Fe-Doping of [Ga2(OH)2(L)] (H4L = Biphenyl-3,3',5,5'-tetracarboxylic Acid), MFM-300(Ga2).

    Science.gov (United States)

    Krap, Cristina P; Newby, Ruth; Dhakshinamoorthy, Amarajothi; García, Hermenegildo; Cebula, Izabela; Easun, Timothy L; Savage, Mathew; Eyley, Jennifer E; Gao, Shan; Blake, Alexander J; Lewis, William; Beton, Peter H; Warren, Mark R; Allan, David R; Frogley, Mark D; Tang, Chiu C; Cinque, Gianfelice; Yang, Sihai; Schröder, Martin

    2016-02-01

    Metal-organic frameworks (MOFs) are usually synthesized using a single type of metal ion, and MOFs containing mixtures of different metal ions are of great interest and represent a methodology to enhance and tune materials properties. We report the synthesis of [Ga2(OH)2(L)] (H4L = biphenyl-3,3',5,5'-tetracarboxylic acid), designated as MFM-300(Ga2), (MFM = Manchester Framework Material replacing NOTT designation), by solvothermal reaction of Ga(NO3)3 and H4L in a mixture of DMF, THF, and water containing HCl for 3 days. MFM-300(Ga2) crystallizes in the tetragonal space group I4122, a = b = 15.0174(7) Å and c = 11.9111(11) Å and is isostructural with the Al(III) analogue MFM-300(Al2) with pores decorated with -OH groups bridging Ga(III) centers. The isostructural Fe-doped material [Ga(1.87)Fe(0.13)(OH)2(L)], MFM-300(Ga(1.87)Fe(0.13)), can be prepared under similar conditions to MFM-300(Ga2) via reaction of a homogeneous mixture of Fe(NO3)3 and Ga(NO3)3 with biphenyl-3,3',5,5'-tetracarboxylic acid. An Fe(III)-based material [Fe3O(1.5)(OH)(HL)(L)(0.5)(H2O)(3.5)], MFM-310(Fe), was synthesized with Fe(NO3)3 and the same ligand via hydrothermal methods. [MFM-310(Fe)] crystallizes in the orthorhombic space group Pmn21 with a = 10.560(4) Å, b = 19.451(8) Å, and c = 11.773(5) Å and incorporates μ3-oxo-centered trinuclear iron cluster nodes connected by ligands to give a 3D nonporous framework that has a different structure to the MFM-300 series. Thus, Fe-doping can be used to monitor the effects of the heteroatom center within a parent Ga(III) framework without the requirement of synthesizing the isostructural Fe(III) analogue [Fe2(OH)2(L)], MFM-300(Fe2), which we have thus far been unable to prepare. Fe-doping of MFM-300(Ga2) affords positive effects on gas adsorption capacities, particularly for CO2 adsorption, whereby MFM-300(Ga(1.87)Fe(0.13)) shows a 49% enhancement of CO2 adsorption capacity in comparison to the homometallic parent material. We thus report

  9. Research progress of novel adsorption processes in water purification:A review

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    As an effective, efficient, and economic approach for water purification, adsorbents and adsorption processes have been widely studied and applied in different aspects for a long time. In the recent years, a lot of novel adsorption processes have been developed for enhancing the efficiency of removing the organic and inorganic contaminants from water. This article reviews some new adsorbents and advanced adsorption methods that specialize in their compositions, structures, functions, and characteristics used in water treatment. The review emphasizes adsorption/catalytic oxidation process, adsorption/catalytic reduction process, adsorption coupled with redox process, biomimetic sorbent and its sorption behaviors of POPs, and modified adsorbents and their water purification efficiency.

  10. 75 FR 62101 - Stainless Steel Sheet and Strip in Coils From the Republic of Korea: Final Results of Expedited...

    Science.gov (United States)

    2010-10-07

    ...-Year (``Sunset'') Reviews, 75 FR 30777 (June 2, 2010). The Department received a notice of intent to... substrate with a honeycomb structure for use in automotive catalytic converters. The steel contains, by... automotive catalytic converters is also excluded from the scope of the order. This stainless steel strip...

  11. Spray Rolling Aluminum Strip

    Energy Technology Data Exchange (ETDEWEB)

    Lavernia, E.J.; Delplanque, J-P; McHugh, K.M.

    2006-05-10

    Spray forming is a competitive low-cost alternative to ingot metallurgy for manufacturing ferrous and non-ferrous alloy shapes. It produces materials with a reduced number of processing steps, while maintaining materials properties, with the possibility of near-net-shape manufacturing. However, there are several hurdles to large-scale commercial adoption of spray forming: 1) ensuring strip is consistently flat, 2) eliminating porosity, particularly at the deposit/substrate interface, and 3) improving material yield. Through this program, a new strip/sheet casting process, termed spray rolling, has been developed, which is an innovative manufacturing technique to produce aluminum net-shape products. Spray rolling combines the benefits of twin-roll casting and conventional spray forming, showing a promising potential to overcome the above hurdles associated with spray forming. Spray rolling requires less energy and generates less scrap than conventional processes and, consequently, enables the development of materials with lower environmental impacts in both processing and final products. Spray Rolling was developed as a collaborative project between the University of California-Davis, the Colorado School of Mines, the Idaho National Engineering and Environmental Laboratory, and an industry team. The following objectives of this project were achieved: (1) Demonstration of the feasibility of the spray rolling process at the bench-scale level and evaluation of the materials properties of spray rolled aluminum strip alloys; and (2) Demonstration of 2X scalability of the process and documentation of technical hurdles to further scale up and initiate technology transfer to industry for eventual commercialization of the process.

  12. Study of heterogeneous catalytic processes over cobalt, molybdenum and cobalt-molybdenum catalysts supported on alumina by temperature-programmed desorption and temperature-programmed reaction. 1. Adsorption of hydrozen

    International Nuclear Information System (INIS)

    Hydrogen adsorption on reduced, sulphidized and reoxidized specimens of molybdenum-and cobalt-molybdenum-containing catalysts applied on aluminium oxide has been studied by the method of thermal desorption (TD). Comparison of TD spectra of hydrogen and data of X-ray phase analysis of the specimens and mass-spectrometric analysis of the products desorbed from the surface of catalysts after their successive reduction sulphidizing, carbonizing and reoxidation permitted a correlation between various forms of hydrogen adsorption and certain centres on the surface of the catalysts. 12 refs., 2 figs

  13. Strip shape control capability of hot wide strip rolling mills

    Institute of Scientific and Technical Information of China (English)

    Renzhong Wang; Quan Yang; Anrui He; Jian Shao; Haitao Bian

    2008-01-01

    The elasticity deformation of rolls was analyzed by means of two-dimensional f'mite element method (FEM) with vari-able thickness. Three typical mills were used as objects for analysis. A thorough study was done on the control capabilities of these mills on the strip shape. Then the strip shape control capabilities of the three mills was compared synthetically.

  14. Complex zero strip decreasing operators

    OpenAIRE

    Cardon, David A.

    2013-01-01

    In this paper we study the effect of linear differential operators coming from the Laguerre-Polya class that act on functions in the extended Laguerre-Polya class with zeros in a horizontal strip in the complex plane. These operator decrease the size of the strip containing the zeros.

  15. Modified strip saturation model for a cracked piezoelectric strip

    OpenAIRE

    R.R. Bhargava; A. Setia

    2008-01-01

    Purpose: The investigations aim to propose a model for arresting an electrical opening of a crack which weakensa narrow, poled and infinite piezoelectric strip. The edges of the strip are subjected to uniform, constant anti-planestresses and in-plane electrical displacements.Design/methodology/approach: The loads applied at the edges of the strip open the crack in a self-similar fashion.Consequently at each tip of the crack a saturation zone protrudes. To stop the crack from further opening t...

  16. ATLAS Strip Upgrade

    CERN Document Server

    Bernabeu, J; The ATLAS collaboration

    2012-01-01

    A phased upgrade of the Large Hadron Collider (LHC) at CERN is planned. The last upgrade phase (HL-LHC) is currently foreseen in 2022-2023. It aims to increase the integrated luminosity to about ten times the original LHC design luminosity. To cope with the harsh conditions in terms of particle rates and radiation dose expected during HL-LHC operation, the ATLAS collaboration is developing technologies for a complete tracker replacement. This new detector will need to provide extreme radiation hardness and a high granularity, within the tight constraints imposed by the existing detectors and their services. An all-silicon high granularity tracking detector is proposed. An international R&D collaboration is working on the strip layers for this new tracker. A number of large area prototype planar detectors produced on p-type wafers have been designed and fabricated for use at HL-LHC. These prototype detectors and miniature test detectors have been irradiated to a set of fluences matched to HL-LHC expectatio...

  17. ATLAS Strip Upgrade

    CERN Document Server

    Bernabeu, J; The ATLAS collaboration

    2012-01-01

    A phased upgrade of the Large Hadron Collider (LHC) at CERN is planned. The last upgrade phase (HL-LHC) is currently foreseen in 2022-2023. It aims to increase the integrated luminosity to about ten times the original LHC design luminosity. To cope with the harsh conditions in terms of particle rates and radiation dose expected during HL-LHC operation, the ATLAS collaboration is developing technologies for a complete tracker replacement. This new detector will need to provide extreme radiation hardness and a high granularity, within the tight constraints imposed by the existing detectors and their services. An all-silicon high-granularity tracking detector is proposed. An international R&D collaboration is working on the strip layers for this new tracker. A number of large area prototype planar detectors produced on p-type wafers have been designed and fabricated for use at HL-LHC. These prototype detectors and miniature test detectors have been irradiated to a set of fluences matched to HL-LHC expectatio...

  18. Strip casting of stainless steels

    OpenAIRE

    Raabe, D.

    1997-01-01

    FLAT PRODUCTS OF STAINLESS STEELS ARE CONVENTIONALLY MANUFACTURED BY CONTINUOUS CASTING, HOT ROLLING, HOT BAND ANNEALING, PICKLING, COLD ROLLING AND RECRYSTALLISATION. IN THE LAST YEARS STRIP CASTING HAS INCREASINGLY ATTRACTED ATTENTION. IT OFFERS THREE IMPROVEMENTS IN COMPARISON TO THE CONVENTIONAL METHOD.1.) IT ALLOWS TO CAST STEEL SHEETS WITH THE SAME THICKNESS AND WIDTH AS THOSE PRODUCED BY HOT ROLLING. THIS MEANS THAT THE HOT ROLLING PROCESSIS BYPASSED. 2.) THE STRIP CAST STEEL REVEALS A...

  19. Air Stripping Designs and Reactive Water Purification Processes for the Lunar Surface

    Science.gov (United States)

    Boul, Peter J.; Lange, Kevin; Conger, Bruce; Anderson, Molly

    2010-01-01

    Air stripping designs are considered to reduce the presence of volatile organic compounds in the purified water. Components of the wastewater streams are ranked by Henry's Law Constant and the suitability of air stripping in the purification of wastewater in terms of component removal is evaluated. Distillation processes are modeled in tandem with air stripping to demonstrate the potential effectiveness and utility of these methods in recycling wastewater on the Moon. Scaling factors for distillation and air stripping columns are presented to account for the difference in the lunar gravitation environment. Commercially available distillation and air stripping units which are considered suitable for Exploration Life Support are presented. The advantages to the various designs are summarized with respect to water purity levels, power consumption, and processing rates. An evaluation of reactive distillation and air stripping is presented with regards to the reduction of volatile organic compounds in the contaminated water and air. Among the methods presented, an architecture is presented for the evaluation of the simultaneous oxidation of organics in air and water. These and other designs are presented in light of potential improvements in power consumptions and air and water purities for architectures which include catalytic activity integrated into the water processor. In particular, catalytic oxidation of organics may be useful as a tool to remove contaminants that more traditional distillation and/or air stripping columns may not remove. A review of the current leading edge at the commercial level and at the research frontier in catalytically active materials is presented. Themes and directions from the engineering developments in catalyst design are presented conceptually in light of developments in the nanoscale chemistry of a variety of catalyst materials.

  20. Heterogeneous Catalytic Ozonization of Sulfosalicylic Acid

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    This paper describes the potential of heterogeneous catalytic ozonization of sulfo-salicylic acid (SSal). It was found that catalytic ozonization in the presence of Mn-Zr-O (a modified manganese dioxide supported on silica gel) had significantly enhanced the removal rate (72%) of total organic carbon (TOC) compared with that of ozonization alone (19%). The efficient removal rate of TOC was probably due to increasing the adsorption ability of catalyst and accelerating decomposition of ozone to produce more powerful oxidants than ozone.

  1. Chemically modified flexible strips as electrochemical biosensors.

    Science.gov (United States)

    Thota, Raju; Ganesh, V

    2014-09-21

    A flexible and disposable strip sensor for non-enzymatic glucose detection is demonstrated in this work. The strips are prepared by using chemical modification processes followed by a simple electroless deposition of copper. Essentially, polyester overhead projector (OHP) transparent films are modified with a monolayer of 3-aminopropyltrimethoxysilane (APTMS) and polyaniline (PANI) conducting polymer. Later, nanostructured copper is deposited onto this modified film. Scanning electron microscope (SEM) and X-ray diffraction (XRD) studies are used for the structural, morphological and crystallinity characterization of the modified films. Electrochemical techniques, namely cyclic voltammetry (CV) and chronoamperometry (CA), are employed for the non-enzymatic detection of glucose. These studies clearly reveal the formation of homogeneous, close-packed spherical Cu particles converged into uniform film that exhibits a good catalytic activity towards the oxidation of glucose. The Cu/PANI/APTMS/OHP sensor displays a remarkable enhancement in the oxidation current density, a very high sensitivity value of 2.8456 mA cm(-2) per mM, and a linear concentration range from 100 μM to 6.5 mM associated with glucose detection. Detection limit is estimated to be 5 μM and the response time of the sensor is determined to be less than 5 s. For comparison, similar studies are performed without PANI, namely Cu/APTMS/OHP films for glucose detection. In this case, a sensitivity value of 2.4457 mA cm(-2) per mM and a linear concentration range of 100 μM-3 mM are estimated. The higher performance characteristics observed in the case of Cu/PANI/APTMS/OHP are attributed to the synergistic effects of the conducting polymer acting as an electron facilitator and the nanostructured Cu films. These disposable, flexible and low-cost strip sensors have also been applied to the detection of glucose in clinical blood serum samples and the results obtained agree very well with the actual glucose

  2. An assay for measurement of protein adsorption to glass vials.

    Science.gov (United States)

    Varmette, Elizabeth; Strony, Brianne; Haines, Daniel; Redkar, Rajendra

    2010-01-01

    Protein adsorption to primary packaging is one of the problems faced by biopharmaceutical drug companies. An assay was developed to quantify loss of proteins to glass vial surfaces. The assay involves the labeling of protein with a fluorescent dye, incubation of the labeled protein with the vial surface, elution of the adsorbed protein using a stripping buffer, and determination of fluorescence of the adsorbed protein using a fluorometer. The assay is simple to set up, accurate, sensitive, and flexible. The assay can be modified for indirect measurement of protein adsorption and offers an attractive alternative for researchers to quantify protein adsorption to glass vials and syringes. PMID:21502031

  3. Adsorption Rate Models for Multicomponent Adsorption Systems

    Institute of Scientific and Technical Information of China (English)

    姚春才

    2004-01-01

    Three adsorption rate models are derived for multicomponent adsorption systems under either pore diffusion or surface diffusion control. The linear driving force (LDF) model is obtained by assuming a parabolic intraparticle concentration profile. Models I and Ⅱ are obtained from the parabolic concentration layer approximation. Examples are presented to demonstrate the usage and accuracy of these models. It is shown that Model I is suitable for batch adsorption calculations and Model Ⅱ provides a good approximation in fixed-bed adsorption processes while the LDF model should not be used in batch adsorption and may be considered acceptable in fixed-bed adsorption where the parameter Ti is relatively large.

  4. Intrabeam stripping in H- Linacs

    CERN Document Server

    Lebedev, V; Ostigy, J -F; Alexandrov, A; Shishlo, A

    2012-01-01

    A beam loss in the superconducting part of the SNS linac has been observed during its commissioning and operation. Although the loss does not prevent the SNS high power operation, it results in an almost uniform irradiation of linac components and increased radiation levels in the tunnel. Multi-particle tracking could neither account for the magnitude of the observed loss nor its dependence on machine parameters. It was recently found that the loss is consistent with the intrabeam particle collisions resulting in stripping of H- ions. The paper describes experimental observations and corresponding analytical estimates of the intrabeam stripping.

  5. Adsorption characteristics of siloxanes in landfill gas by the adsorption equilibrium test

    Energy Technology Data Exchange (ETDEWEB)

    Nam, Sangchul; Namkoong, Wan [Department of Environmental Engineering, Konkuk University, Hwayang-Dong, Gwangjin-Gu, Seoul 143-701 (Korea, Republic of); Kang, Jeong-Hee; Park, Jin-Kyu [Department of Environmental Engineering, Anyang University, Anyang 5-Dong, Manan-Gu, Anyang-Si, Gyeonggi-Do 430-714 (Korea, Republic of); Lee, Namhoon, E-mail: nhlee@anyang.ac.kr [Department of Environmental Engineering, Anyang University, Anyang 5-Dong, Manan-Gu, Anyang-Si, Gyeonggi-Do 430-714 (Korea, Republic of)

    2013-10-15

    Highlights: • Equilibrium test was attempted to evaluate adsorption characteristics of siloxane. • L2 had higher removal efficiency in carbon compared to noncarbon adsorbents. • Total adsorption capacity of siloxane was 300 mg/g by coal activated carbon. • Adsorption characteristics rely on size of siloxane molecule and adsorbent pore. • Conversion of siloxane was caused by adsorption of noncarbon adsorbents. - Abstract: Due to the increase in energy cost by constantly high oil prices and the obligation to reduce greenhouse effect gases, landfill gas is frequently used as an alternative energy source for producing heat and electricity. Most of landfill gas utility facilities, however, are experiencing problems controlling siloxanes from landfill gas as their catalytic oxidizers are becoming fouled by silicon dioxide dust. To evaluate adsorption characteristics of siloxanes, an adsorption equilibrium test was conducted and parameters in the Freundlich and Langmuir isotherms were analyzed. Coconut activated carbon (CA1), coal activated carbon (CA2), impregnated activated carbon (CA3), silicagel (NCA1), and activated alumina (NCA2) were used for the adsorption of the mixed siloxane which contained hexamethyldisiloxane (L2), octamethylcyclotetrasiloxane (D4), and decamethylcyclopentasiloxane (D5). L2 had higher removal efficiency in noncarbon adsorbents compared to carbon adsorbents. The application of Langmuir and Freundlich adsorption isotherm demonstrated that coconut based CA1 and CA3 provided higher adsorption capacity on L2. And CA2 and NCA1 provided higher adsorption capacity on D4 and D5. Based on the experimental results, L2, D4, and D5 were converted by adsorption and desorption in noncarbon adsorbents. Adsorption affinity of siloxane is considered to be affect by the pore size distribution of the adsorbents and by the molecular size of each siloxane.

  6. Adsorption and wetting.

    NARCIS (Netherlands)

    Schlangen, L.J.M.

    1995-01-01

    Adsorption and wetting are related phenomena. In order to improve knowledge of both and their relations, experiments, thermodynamics and a theoretical interpretation have been connected, starring n-alkanes.Starting from the Gibbs adsorption equation thermodynamic relations between vapour adsorption

  7. Modified strip saturation model for a cracked piezoelectric strip

    Directory of Open Access Journals (Sweden)

    R.R. Bhargava

    2008-03-01

    Full Text Available Purpose: The investigations aim to propose a model for arresting an electrical opening of a crack which weakensa narrow, poled and infinite piezoelectric strip. The edges of the strip are subjected to uniform, constant anti-planestresses and in-plane electrical displacements.Design/methodology/approach: The loads applied at the edges of the strip open the crack in a self-similar fashion.Consequently at each tip of the crack a saturation zone protrudes. To stop the crack from further opening the rims ofdeveloped saturation zones are subjected to normal, cohesive linearly varying saturation limit electric displacement. Theedges of the strip are subjected to anti-plane deformation and in-plane electrical displacement. Fourier integral transformmethod employed reduces the problem to the solution of a Fredholm integral equation of second kind.Findings: The electrical displacement, stress intensity factor, the saturation zone length, crack opening displacementand crack growth rate have been calculated. The results obtained presented graphically, analysed and concluded.Research limitations/implications: The ceramic used for strip is being assumed to be electrically morebrittle. The investigations are carried at this level in the present paper. Also the small scale electrical yielding isconsidered. Consequently the developed saturation zone is proposed to lie in a line segment ahead of crack.Practical implications: Piezoelectric ceramics being widely used as transducers. Their wide utility hasprompted to study many attires of such ceramic and one such attire is fracture mechanics of these ceramics.Originality/value: The paper gives an assessment of the electrical load necessary to arrest the electrical crack opening.The investigations are useful to smart material design technology where sensors and actuators are manufactured.

  8. Electrodynamics on the Moebius Strip

    OpenAIRE

    Pauschenwein, Gernot,

    2004-01-01

    In this diploma work electrostatics and -dynamics of two dimensional structures are examined. Mathematica is used for visualisation and packages for Mathematica have been programmed which use subroutines written in C to improve numerical calculations. The well known Moebius Strip is used as an example structure throughout the work.

  9. Adsorption characteristics of siloxanes in landfill gas by the adsorption equilibrium test.

    Science.gov (United States)

    Nam, Sangchul; Namkoong, Wan; Kang, Jeong-Hee; Park, Jin-Kyu; Lee, Namhoon

    2013-10-01

    Due to the increase in energy cost by constantly high oil prices and the obligation to reduce greenhouse effect gases, landfill gas is frequently used as an alternative energy source for producing heat and electricity. Most of landfill gas utility facilities, however, are experiencing problems controlling siloxanes from landfill gas as their catalytic oxidizers are becoming fouled by silicon dioxide dust. To evaluate adsorption characteristics of siloxanes, an adsorption equilibrium test was conducted and parameters in the Freundlich and Langmuir isotherms were analyzed. Coconut activated carbon (CA1), coal activated carbon (CA2), impregnated activated carbon (CA3), silicagel (NCA1), and activated alumina (NCA2) were used for the adsorption of the mixed siloxane which contained hexamethyldisiloxane (L2), octamethylcyclotetrasiloxane (D4), and decamethylcyclopentasiloxane (D5). L2 had higher removal efficiency in noncarbon adsorbents compared to carbon adsorbents. The application of Langmuir and Freundlich adsorption isotherm demonstrated that coconut based CA1 and CA3 provided higher adsorption capacity on L2. And CA2 and NCA1 provided higher adsorption capacity on D4 and D5. Based on the experimental results, L2, D4, and D5 were converted by adsorption and desorption in noncarbon adsorbents. Adsorption affinity of siloxane is considered to be affect by the pore size distribution of the adsorbents and by the molecular size of each siloxane. PMID:23684695

  10. Using Comic Strips in Language Classes

    Science.gov (United States)

    Csabay, Noémi

    2006-01-01

    The author believes that using comic strips in language-learning classes has three main benefits. First, comic strips motivate younger learners. Second, they provide a context and logically connected sentences to help language learning. Third, their visual information is helpful for comprehension. The author argues that comic strips can be used in…

  11. Fast variation method for elastic strip calculation.

    Science.gov (United States)

    Biryukov, Sergey V

    2002-05-01

    A new, fast, variation method (FVM) for determining an elastic strip response to stresses arbitrarily distributed on the flat side of the strip is proposed. The remaining surface of the strip may have an arbitrary form, and it is free of stresses. The FVM, as well as the well-known finite element method (FEM), starts with the variational principle. However, it does not use the meshing of the strip. A comparison of FVM results with the exact analytical solution in the special case of shear stresses and a rectangular strip demonstrates an excellent agreement.

  12. Triangular buckling patterns of twisted inextensible strips

    CERN Document Server

    Korte, A P; van der Heijden, G H M

    2010-01-01

    When twisting a strip of paper or acetate under high longitudinal tension, one observes, at some critical load, a buckling of the strip into a regular triangular pattern. Very similar triangular facets have recently been observed in solutions to a new set of geometrically-exact equations describing the equilibrium shape of thin inextensible elastic strips. Here we formulate a modified boundary-value problem for these equations and construct post-buckling solutions in good agreement with the observed pattern in twisted strips. We also study the force-extension and moment-twist behaviour of these strips by varying the mode number n of triangular facets.

  13. Antenna structure with distributed strip

    Science.gov (United States)

    Rodenbeck, Christopher T.

    2008-03-18

    An antenna comprises electrical conductors arranged to form a radiating element including a folded line configuration and a distributed strip configuration, where the radiating element is in proximity to a ground conductor. The folded line and the distributed strip can be electrically interconnected and substantially coplanar. The ground conductor can be spaced from, and coplanar to, the radiating element, or can alternatively lie in a plane set at an angle to the radiating element. Embodiments of the antenna include conductor patterns formed on a printed wiring board, having a ground plane, spacedly adjacent to and coplanar with the radiating element. Other embodiments of the antenna comprise a ground plane and radiating element on opposed sides of a printed wiring board. Other embodiments of the antenna comprise conductors that can be arranged as free standing "foils". Other embodiments include antennas that are encapsulated into a package containing the antenna.

  14. Adsorption and wetting.

    OpenAIRE

    Schlangen, L.J.M.

    1995-01-01

    Adsorption and wetting are related phenomena. In order to improve knowledge of both and their relations, experiments, thermodynamics and a theoretical interpretation have been connected, starring n-alkanes.Starting from the Gibbs adsorption equation thermodynamic relations between vapour adsorption and wetting are derived. The surface pressure of a film, formed by vapour adsorption on a solid surface, is calculated by integrating the vapour adsorption isotherm. The surface pressure at the sat...

  15. Stripping ethanol from ethanol-blended fuels for use in NO.sub.x SCR

    Science.gov (United States)

    Kass, Michael Delos; Graves, Ronald Lee; Storey, John Morse Elliot; Lewis, Sr., Samuel Arthur; Sluder, Charles Scott; Thomas, John Foster

    2007-08-21

    A method to use diesel fuel alchohol micro emulsions (E-diesel) to provide a source of reductant to lower NO.sub.x emissions using selective catalytic reduction. Ethanol is stripped from the micro emulsion and entered into the exhaust gasses upstream of the reducing catalyst. The method allows diesel (and other lean-burn) engines to meet new, lower emission standards without having to carry separate fuel and reductant tanks.

  16. Alkali cation specific adsorption onto fcc(111) transition metal electrodes.

    Science.gov (United States)

    Mills, J N; McCrum, I T; Janik, M J

    2014-07-21

    The presence of alkali cations in electrolyte solutions is known to impact the rate of electrocatalytic reactions, though the mechanism of such impact is not conclusively determined. We use density functional theory (DFT) to examine the specific adsorption of alkali cations to fcc(111) electrode surfaces, as specific adsorption may block catalyst sites or otherwise impact surface catalytic chemistry. Solvation of the cation-metal surface structure was investigated using explicit water models. Computed equilibrium potentials for alkali cation adsorption suggest that alkali and alkaline earth cations will specifically adsorb onto Pt(111) and Pd(111) surfaces in the potential range of hydrogen oxidation and hydrogen evolution catalysis in alkaline solutions.

  17. Dynamic Underground Stripping Demonstration Project

    International Nuclear Information System (INIS)

    LLNL is collaborating with the UC Berkeley College of Engineering to develop and demonstrate a system of thermal remediation and underground imaging techniques for use in rapid cleanup of localized underground spills. Called ''Dynamic Stripping'' to reflect the rapid and controllable nature of the process, it will combine steam injection, direct electrical heating, and tomographic geophysical imaging in a cleanup of the LLNL gasoline spill. In the first 8 months of the project, a Clean Site engineering test was conducted to prove the field application of the techniques before moving to the contaminated site in FY 92

  18. Method of stripping metals from organic solvents

    Science.gov (United States)

    Todd, Terry A.; Law, Jack D.; Herbst, R. Scott; Romanovskiy, Valeriy N.; Smirnov, Igor V.; Babain, Vasily A.; Esimantovski, Vyatcheslav M.

    2009-02-24

    A new method to strip metals from organic solvents in a manner that allows for the recycle of the stripping agent. The method utilizes carbonate solutions of organic amines with complexants, in low concentrations, to strip metals from organic solvents. The method allows for the distillation and reuse of organic amines. The concentrated metal/complexant fraction from distillation is more amenable to immobilization than solutions resulting from current practice.

  19. Quantifiable Lateral Flow Assay Test Strips

    Science.gov (United States)

    2003-01-01

    As easy to read as a home pregnancy test, three Quantifiable Lateral Flow Assay (QLFA) strips used to test water for E. coli show different results. The brightly glowing control line on the far right of each strip indicates that all three tests ran successfully. But the glowing test line on the middle left and bottom strips reveal their samples were contaminated with E. coli bacteria at two different concentrations. The color intensity correlates with concentration of contamination.

  20. Studies of Heterogeneous Hydrothermal Stripping from Iron-loaded Naphthenic Acid-Alcohol-Kerosen

    Institute of Scientific and Technical Information of China (English)

    王兴尧; 康晓红; 谢慧琴; 卢立柱

    2003-01-01

    The technique of hydrothermal stripping from mixed aqueous-organic systems is a promising method for synthesizing oxide ceramic powders for high-performance applications. Some factors influencing heterogeneous hydrothermal stripping with water from iron-loaded organic phase of naphthenic acid-isooctyl alcohol-kerosene, such as initial concentrations of iron and naphthenic acid, concentration of Fe2O3 "seed", temperature and time, were investigated. Based on the experimental results, the rate equation was established. Nano-ferric oxide powders were obtained by the technique of hydrothermal stripping from the iron-loaded organic phase. The results suggest that the heterogeneous hydrothermal stripping proceeds in 3 steps: adsorption of naphthenic acid dimers and naphthenic complex of iron onto the surface of "seed", hydrolysis of adsorbed complex of iron, and condensation of hydrolyzed complex. The process activation energy is 115 kJ/mol and the heterogeneous hydrothermal stripping is controlled by a chemical reaction(the hydrolysis of naphthenic complex of iron).

  1. Solidification Structure of Low Carbon Steel Strips with Different Phosphorus Contents Produced by Strip Casting

    Institute of Scientific and Technical Information of China (English)

    Na LI; Zhenyu LIU; Yiqing QIU; Zhaosen LIN; Xianghua LIU; Guodong WANG

    2006-01-01

    In the present paper, low carbon steel strips with different phosphorus contents were produced using a twin roll strip casting process. The solidification structure was studied and its features were analyzed in detail. It was found that the strips possessed a fine microstructure compared with the mould cast steels. With increasing phosphorus content more ferrite has been formed with finer grains.

  2. Catalytic distillation structure

    Science.gov (United States)

    Smith, Jr., Lawrence A.

    1984-01-01

    Catalytic distillation structure for use in reaction distillation columns, a providing reaction sites and distillation structure and consisting of a catalyst component and a resilient component intimately associated therewith. The resilient component has at least about 70 volume % open space and being present with the catalyst component in an amount such that the catalytic distillation structure consist of at least 10 volume % open space.

  3. Catalytic combustor for hydrogen

    Energy Technology Data Exchange (ETDEWEB)

    Mercea, J.; Grecu, E.; Fodor, T.; Kreibik, S.

    1982-01-01

    The performance of catalytic combustors for hydrogen using platinum-supported catalysts is described. Catalytic plates of different sizes were constructed using fibrous and ceramic supports. The temperature distribution as well as the reaction efficiency as a function of the fuel input rate was determined, and a comparison between the performances of different plates is discussed.

  4. Hardy inequalities in strips on ruled surfaces

    Directory of Open Access Journals (Sweden)

    2006-01-01

    Full Text Available We consider the Dirichlet Laplacian in infinite two-dimensional strips defined as uniform tubular neighbourhoods of curves on ruled surfaces. We show that the negative Gauss curvature of the ambient surface gives rise to a Hardy inequality and we use this to prove certain stability of spectrum in the case of asymptotically straight strips about mildly perturbed geodesics.

  5. 33 CFR 157.128 - Stripping system.

    Science.gov (United States)

    2010-07-01

    ... 33 Navigation and Navigable Waters 2 2010-07-01 2010-07-01 false Stripping system. 157.128 Section... Crude Oil Washing (COW) System on Tank Vessels Design, Equipment, and Installation § 157.128 Stripping system. (a) Each tank vessel having a COW system under § 157.10(e), § 157.10a(a)(2), or §...

  6. Water problems in Gaza Strip,Palestine

    Institute of Scientific and Technical Information of China (English)

    Ismail ALGHALBAN

    2001-01-01

    The only source for water in Gaza strip, southern Palestine, is the groundwater aquifer. The Pliocene - Pleistocene aquifer has two serious problems: quantity and quality. This study is an attempt to identify the problems and to suggest solutions for water problems in Gaza strip. In addition, some rules for rehabilitation of the aquifers were suggested.

  7. Smooth muscle strips for intestinal tissue engineering.

    Directory of Open Access Journals (Sweden)

    Christopher M Walthers

    Full Text Available Functionally contracting smooth muscle is an essential part of the engineered intestine that has not been replicated in vitro. The purpose of this study is to produce contracting smooth muscle in culture by maintaining the native smooth muscle organization. We employed intact smooth muscle strips and compared them to dissociated smooth muscle cells in culture for 14 days. Cells isolated by enzymatic digestion quickly lost maturity markers for smooth muscle cells and contained few enteric neural and glial cells. Cultured smooth muscle strips exhibited periodic contraction and maintained neural and glial markers. Smooth muscle strips cultured for 14 days also exhibited regular fluctuation of intracellular calcium, whereas cultured smooth muscle cells did not. After implantation in omentum for 14 days on polycaprolactone scaffolds, smooth muscle strip constructs expressed high levels of smooth muscle maturity markers as well as enteric neural and glial cells. Intact smooth muscle strips may be a useful component for engineered intestinal smooth muscle.

  8. Ultrasonic examination of JBK-75 strip material

    International Nuclear Information System (INIS)

    An ultrasonic inspection system was assembled to inspect the JBK-75 stainless steel sheath material (for the Large Coil Project) for the Westinghouse-Airco superconducting magnet program. The mechanical system provided for handling the 180-kg (400-lb) coils of strip material [1.6 mm thick by 78 mm wide by 90 to 120 m long (0.064 by 3.07 in. by 300 to 400 ft)], feeding the strip through the ultrasonic inspection and cleaning stations, and respooling the coils. We inspected 54 coils of strip for both longitudinal and laminar flaws. Simulated flaws were used to calibrate both inspections. Saw-cut notches [0.28 mm deep (0.011 in., about 17% of the strip thickness)] were used to calibrate the longitudinal flaw inspections; 1.59-mm-diam (0.063-in.) flat-bottom holes drilled halfway through a calibration strip were used to calibrate the laminar flaw tests

  9. Removal of Xylene fromWaste Air Stream Using Catalytic Ozonation Process

    Directory of Open Access Journals (Sweden)

    H Mokarami

    2010-10-01

    Full Text Available "n "n "nBackgrounds and Objectives: Volatile organic compounds (VOCs are one of the common groups of contaminants encountered in the industrial activities, emitted through air stream into the atmosphere. To prevent the human and environmental health from the adverse effects of VOCs, air streams containing VOCs need to be treated before discharging to environment. This study was aimed at investigating the catalytic ozonation process for removing xylene from a contaminated air stream."nMaterials and Methods: In the present work, a bench scale experimental setup was constructed and used for catalytic ozonation of xylene. The performance of catalytic ozonation process was compared with that of single adsorption and ozonation in removal of several concentration of xylene under the similar experimental conditions."nResults: The results indicated that the efficiency of catalytic ozonation was higher than that of single adsorption and ozonation in removal of xylene. The emerging time and elimination capacity of xylene for inlet concentration of 300 ppm was 1.4 and 5.8 times of those in adsorption system. The activated carbon acted as catalyst in the presence of ozone and thus attaining the synergistic effect for xylene degradation."nConclusion: catalytic ozonation process is an efficient technique the treatment of air streams containing high concentrations of xylene. The adsorption systems can also be simply retrofitted to catalytic ozonation process and thereby improving their performance for treating VOCs.

  10. Study on Synthesis and Catalytic Performance of Hierarchical Zeolite

    Institute of Scientific and Technical Information of China (English)

    Zhang Lingling; Li Fengyan; ZhaoTianbo; Sun Guida

    2007-01-01

    A kind of hierarchical zeolite catalyst was synthesized by hydrothermal method.X-ray diffraction (XRD)and nitrogen adsorption-desorption method were used to study the phase and aperture structure of the prepared catalyst.Infrared(IR)spectra of pyridine adsorbed on the sample showed that the hierarchical zeolite really had much more Bronsted and Lewis acidic sites than the HZSM-5 zeolite.The catalytic cracking of large hydrocarbon molecules showed that the hierarchical zeolite had a higher catalytic activity than the HZSM-5 zeolite.

  11. Interfacial adsorption of insulin - Conformational changes and reversibility of adsorption

    NARCIS (Netherlands)

    Mollmann, SH; Jorgensen, L; Bukrinsky, JT; Elofsson, U; Norde, W; Frokjaer, S

    2006-01-01

    The adsorption of human insulin to Teflon particles was studied with respect to conformational changes and the reversibility of adsorption was examined by total internal reflection fluorescence (TIRF). Adsorption isotherms for the adsorption of human insulin indicated high affinity adsorption, even

  12. Interfacial adsorption of insulin. Conformational changes and reversibility of adsorption

    NARCIS (Netherlands)

    Mollmann, S.H.; Bukrinsky, J.T.; Elofsson, U.; Norde, W.; Frokjaer, S.

    2006-01-01

    The adsorption of human insulin to Teflon particles was studied with respect to conformational changes and the reversibility of adsorption was examined by total internal reflection fluorescence (TIRF). Adsorption isotherms for the adsorption of human insulin indicated high affinity adsorption, even

  13. A Strip Cell in Pyroelectric Devices

    Science.gov (United States)

    Siao, An-Shen; Chao, Ching-Kong; Hsiao, Chun-Ching

    2016-01-01

    The pyroelectric effect affords the opportunity to convert temporal temperature fluctuations into usable electrical energy in order to develop abundantly available waste heat. A strip pyroelectric cell, used to enhance temperature variation rates by lateral temperature gradients and to reduce cell capacitance to further promote the induced voltage, is described as a means of improving pyroelectric energy transformation. A precision dicing saw was successfully applied in fabricating the pyroelectric cell with a strip form. The strip pyroelectric cell with a high-narrow cross section is able to greatly absorb thermal energy via the side walls of the strips, thereby inducing lateral temperature gradients and increasing temperature variation rates in a thicker pyroelectric cell. Both simulation and experimentation show that the strip pyroelectric cell improves the electrical outputs of pyroelectric cells and enhances the efficiency of pyroelectric harvesters. The strip-type pyroelectric cell has a larger temperature variation when compared to the trenched electrode and the original type, by about 1.9 and 2.4 times, respectively. The measured electrical output of the strip type demonstrates a conspicuous increase in stored energy as compared to the trenched electrode and the original type, by of about 15.6 and 19.8 times, respectively. PMID:26999134

  14. Transfusion and blood donation in comic strips.

    Science.gov (United States)

    Lefrère, Jean-Jacques; Danic, Bruno

    2013-07-01

    The representation of blood transfusion and donation of blood in the comic strip has never been studied. The comic strip, which is a relatively recent art, emerged in the 19th century before becoming a mass medium during the 20th century. We have sought, by calling on collectors and using the resources of Internet, comic strips devoted, wholly or in part, to the themes of transfusion and blood donation. We present some of them here in chronologic order, indicating the title, country of origin, year of publication, and names of authors. The theme of the superhero using transfusion to transmit his virtues or his powers is repeated throughout the 20th century in North American comic strips. More recently, comic strips have been conceived from the outset with a promotional aim. They perpetuate positive images and are directed toward a young readership, wielding humor to reduce the fear of venipuncture. Few comic strips denounce the abuse of the commercialization of products derived from the human body. The image of transfusion and blood donation given by the comic strips is not to be underestimated because their readership is primarily children, some of whom will become blood donors. Furthermore, if some readers are transfused during their lives, the impact of a memory more or less conscious of these childhood readings may resurface, both in hopes and in fears.

  15. Saving Energy Through Advanced Power Strips (Poster)

    Energy Technology Data Exchange (ETDEWEB)

    Christensen, D.

    2013-10-01

    Advanced Power Strips (APS) look just like ordinary power strips, except that they have built-in features that are designed to reduce the amount of energy used by many consumer electronics. There are several different types of APSs on the market, but they all operate on the same basic principle of shutting off the supply power to devices that are not in use. By replacing your standard power strip with an APS, you can signifcantly cut the amount of electricity used by your home office and entertainment center devices, and save money on your electric bill. This illustration summarizes the different options.

  16. Instabilities and Solitons in Minimal Strips.

    Science.gov (United States)

    Machon, Thomas; Alexander, Gareth P; Goldstein, Raymond E; Pesci, Adriana I

    2016-07-01

    We show that highly twisted minimal strips can undergo a nonsingular transition, unlike the singular transitions seen in the Möbius strip and the catenoid. If the strip is nonorientable, this transition is topologically frustrated, and the resulting surface contains a helicoidal defect. Through a controlled analytic approximation, the system can be mapped onto a scalar ϕ^{4} theory on a nonorientable line bundle over the circle, where the defect becomes a topologically protected kink soliton or domain wall, thus establishing their existence in minimal surfaces. Demonstrations with soap films confirm these results and show how the position of the defect can be controlled through boundary deformation. PMID:27419593

  17. THE DEVELOPMENT OF FCC STRIPPING TECHNOLOGY

    Institute of Scientific and Technical Information of China (English)

    ZHANGZhen-qian

    2003-01-01

    This article briefly describes the major patents domestic and the abroad,and the current situation and achievements of FCC stripping technology in China.The develping trend of FCC stripping technology is presented,including further developments of FCC stripper to improve unit performance,combination of the stripper and pre-stripper within disengager to from a complete high-efficiency FCC stripping system.In addition to high efficiency,simple structure and easiness of installation and maintenance for a new FCC stripper are all of consideration.

  18. Catalytic distillation process

    Science.gov (United States)

    Smith, Jr., Lawrence A.

    1982-01-01

    A method for conducting chemical reactions and fractionation of the reaction mixture comprising feeding reactants to a distillation column reactor into a feed zone and concurrently contacting the reactants with a fixed bed catalytic packing to concurrently carry out the reaction and fractionate the reaction mixture. For example, a method for preparing methyl tertiary butyl ether in high purity from a mixed feed stream of isobutene and normal butene comprising feeding the mixed feed stream to a distillation column reactor into a feed zone at the lower end of a distillation reaction zone, and methanol into the upper end of said distillation reaction zone, which is packed with a properly supported cationic ion exchange resin, contacting the C.sub.4 feed and methanol with the catalytic distillation packing to react methanol and isobutene, and concurrently fractionating the ether from the column below the catalytic zone and removing normal butene overhead above the catalytic zone.

  19. Catalytic Functions of Standards

    NARCIS (Netherlands)

    K. Blind (Knut)

    2009-01-01

    textabstractThe three different areas and the examples have illustrated several catalytic functions of standards for innovation. First, the standardisation process reduces the time to market of inventions, research results and innovative technologies. Second, standards themselves promote the diffusi

  20. Inapproximability of maximal strip recovery

    CERN Document Server

    Jiang, Minghui

    2009-01-01

    In comparative genomic, the first step of sequence analysis is usually to decompose two or more genomes into syntenic blocks that are segments of homologous chromosomes. For the reliable recovery of syntenic blocks, noise and ambiguities in the genomic maps need to be removed first. Maximal Strip Recovery (MSR) is an optimization problem proposed by Zheng, Zhu, and Sankoff for reliably recovering syntenic blocks from genomic maps in the midst of noise and ambiguities. Given $d$ genomic maps as sequences of gene markers, the objective of \\msr{d} is to find $d$ subsequences, one subsequence of each genomic map, such that the total length of syntenic blocks in these subsequences is maximized. For any constant $d \\ge 2$, a polynomial-time 2d-approximation for \\msr{d} was previously known. In this paper, we show that for any $d \\ge 2$, \\msr{d} is APX-hard, even for the most basic version of the problem in which all gene markers are distinct and appear in positive orientation in each genomic map. Moreover, we provi...

  1. A video strip chart program

    International Nuclear Information System (INIS)

    A strip chart recorder has been utilized for trend analysis of the Oak Ridge National Laboratory EN tandem since 1987. At the EN, the author could not afford the nice eight channel thermal pen recorder that was used at the 25 URC. He had to suffice with two channel fiber tip or capillary pen type recorders retrieved from salvage and maintained with parts from other salvaged recorders. After cycling through several machines that eventually became completely unserviceable, a search for a new thermal recorder was begun. As much as he hates to write computer code, he decided to try his hand at getting an old data acquisition unit, that had been retrieved several years ago from salvage, to meet his needs. A BASIC language compiler was used because time was not available to learn a more advanced language. While attempting to increase acquisition and scroll speed on the 6 MHz 80286 that the code was first developed on, it became apparent that scrolling only the first small portion of the screen at high speed and then averaging that region and histogramming the average provided both the speed necessary for capturing fairly short duration events, and a trend record without use of back scrolling and disk storage routines. This turned out to be quite sufficient

  2. Dynamic underground stripping demonstration project

    International Nuclear Information System (INIS)

    LLNL is collaborating with the UC Berkeley College of Engineering to develop and demonstrate a system of thermal remediation techniques for rapid cleanup of localized underground spills. Called dynamic stripping to reflect the rapid and controllable nature of the process, it will combine steam injection, direct electrical heating, and tomographic geophysical imaging in a cleanup of the LLNL gasoline spill. In the first eight months of the project, a Clean Site engineering test was conducted to prove the field application of the techniques. Tests then began on the contaminated site in FY 1992. This report describes the work at the Clean Site, including design and performance criteria, test results, interpretations, and conclusions. We fielded 'a wide range of new designs and techniques, some successful and some not. In this document, we focus on results and performance, lessons learned, and design and operational changes recommended for work at the contaminated site. Each section focuses on a different aspect of the work and can be considered a self-contained contribution

  3. Catalytic ignition of light hydrocarbons

    Institute of Scientific and Technical Information of China (English)

    K. L. Hohn; C.-C. Huang; C. Cao

    2009-01-01

    Catalytic ignition refers to phenomenon where sufficient energy is released from a catalytic reaction to maintain further reaction without additional extemai heating. This phenomenon is important in the development of catalytic combustion and catalytic partial oxidation processes, both of which have received extensive attention in recent years. In addition, catalytic ignition studies provide experimental data which can be used to test theoretical hydrocarbon oxidation models. For these reasons, catalytic ignition has been frequently studied. This review summarizes the experimental methods used to study catalytic ignition of light hydrocarbons and describes the experimental and theoretical results obtained related to catalytic ignition. The role of catalyst metal, fuel and fuel concentration, and catalyst state in catalytic ignition are examined, and some conclusions are drawn on the mechanism of catalytic ignition.

  4. Disposable amperometric glucose sensor electrode with enzyme-immobilized nitrocellulose strip.

    Science.gov (United States)

    Cui, G; Yoo, J H; Woo, B W; Kim, S S; Cha, G S; Nam, H

    2001-07-01

    Electrochemical properties of screen-printed carbon paste electrodes (CPEs) with a glucose oxidase-immobilized and hexamineruthenium (III) chloride ([Ru(NH(3))(6)](3+)) containing nitrocellulose (NC) strip were examined. The NC strip (2x8 mm) placed on the CPEs printed on polyester (PE) film is tightly sealed using another PE film on the top with open edges on both sides. Samples containing macromolecules and particles (e.g. proteins and blood cells) are applied at one edge of the NC strip and reach the detection area, chromatographically separating small molecules (e.g. glucose, ascorbate, acetaminophen, and uric acid) of analytical interests. Since sample volumes and the amount of catalytic reagents (mediator and glucose oxidase) are precisely predefined by the dimension and pore size (8 mum) of the NC strip, the sensor-to-sensor reproducibility and accuracy of analysis are greatly improved. The use of [Ru(NH(3))(6)](3+) mediator, which exhibits characteristic substantially lowers the applied potential (0.0 V vs Ag/AgCl) for glucose determination and eliminates the interference from other oxidizable species, providing improved analytical results. PMID:18968332

  5. Reactive Distillation and Air Stripping Processes for Water Recycling and Trace Contaminant Control

    Science.gov (United States)

    Boul, Peter J.; Lange, Kevin E.; Conger, Bruce; Anderson, Molly

    2009-01-01

    Reactive distillation designs are considered to reduce the presence of volatile organic compounds in the purified water. Reactive distillation integrates a reactor with a distillation column. A review of the literature in this field has revealed a variety of functional reactive columns in industry. Wastewater may be purified by a combination of a reactor and a distiller (e.g., the EWRS or VPCAR concepts) or, in principle, through a design which integrates the reactor with the distiller. A review of the literature in reactive distillation has identified some different designs in such combinations of reactor and distiller. An evaluation of reactive distillation and reactive air stripping is presented with regards to the reduction of volatile organic compounds in the contaminated water and air. Among the methods presented, an architecture is presented for the evaluation of the simultaneous oxidation of organics in air and water. These and other designs are presented in light of potential improvements in power consumptions and air and water purities for architectures which include catalytic activity integrated into the water processor. In particular, catalytic oxidation of organics may be useful as a tool to remove contaminants that more traditional distillation and/or air stripping columns may not remove. A review of the current leading edge at the commercial level and at the research frontier in catalytically active materials is presented. Themes and directions from the engineering developments in catalyst design are presented conceptually in light of developments in the nanoscale chemistry of a variety of catalyst materials.

  6. Fabrication of MMC Strip by CRB Process

    Science.gov (United States)

    Jamaati, Roohollah; Toroghinejad, Mohammad Reza

    2012-06-01

    In this study, Al/Al2O3 composite strips were produced by the cold roll bonding (CRB) process. Microhardness, tensile strength, and elongation of composite strips were investigated as a result of changes in thickness reduction, quantity of alumina particles, and the production method used. It was found that higher values of reduction and quantities of alumina improved microhardness and tensile strength but decreased elongation. Furthermore, as-received strips exhibited the highest values for microhardness and tensile strength but the lowest for elongation. In contrast, post-rolling annealed strips recorded the lowest values for microhardness and tensile strength but the highest for elongation. Finally, it was found that pre-rolling annealing was the best method for producing this composite via the CRB process.

  7. Ram Pressure Stripping: The Long Goodbye

    Science.gov (United States)

    Tonnesen, Stephanie; Lu, Yu; Benson, Andrew; Peter, Annika; Boylan-Kolchin, Michael; Wetzel, Andrew R.; Weisz, Daniel R.

    2016-01-01

    What turns off star formation in satellite galaxies? Ram pressure stripping, the removal of a galaxy's gas through direct interaction with the gas halo in which it orbits, is an attractive quenching mechanism, particularly in the Milky Way halo where the radial distribution of quenching is dramatic. However, many implementations of this process in semi-analytic models result in overly-rapid gas removal when compared with observations. We use high resolution hydrodynamical simulations run with Enzo to parameterize the stripping of disk and halo gas from an orbiting satellite galaxy for use in the semi-analytic modeling code Galacticus. We find that using the instantaneous ram pressure overestimates the amount of gas that is stripped, and present a physically-motivated module for including ram pressure stripping in semi-analytic models that uses the integral of the ram pressure experienced by a satellite galaxy. We will compare our results to observations of the Milky Way satellites.

  8. Potential profile in a conducting polymer strip

    DEFF Research Database (Denmark)

    Bay, Lasse; West, Keld; Vlachopoulos, Nikolaos;

    2002-01-01

    Many conjugated polymers show an appreciable difference in volume between their oxidized and reduced forms. This property can be utilized in soft electrochemically driven actuators, "artificial muscles". Several geometries have been proposed for the conversion of the volume expansion into useful...... mechanical work. In a particularly simple geometry, the length change of polymer strips is exploited. The polymer strips are connected to the driving circuit at the end of the strip that is attached to the support of the device. The other end of the strip is connected to the load. The advantage of this set......-up is simplicity and that the maximum force generated in the polymer can be transferred directly to the load. There is, however, an inherent problem in this design that will be examined in this paper. If the potential of the reduced state is below that for oxygen reduction, only a finite length of the free...

  9. Performance of a Novel Hydrophobic Mesoporous Material for High Temperature Catalytic Oxidation of Naphthalene

    Directory of Open Access Journals (Sweden)

    Guotao Zhao

    2014-01-01

    Full Text Available A high surface area, hydrophobic mesoporous material, MFS, has been successfully synthesized by a hydrothermal synthesis method using a perfluorinated surfactant, SURFLON S-386, as the single template. N2 adsorption and TEM were employed to characterize the pore structure and morphology of MFS. Static water adsorption test indicates that the hydrophobicity of MFS is significantly higher than that of MCM-41. XPS and Py-GC/MS analysis confirmed the existence of perfluoroalkyl groups in MFS which led to its high hydrophobicity. MFS was used as a support for CuO in experiments of catalytic combustion of naphthalene, where it showed a significant advantage over MCM-41 and ZSM-5. SEM was helpful in understanding why CuO-MFS performed so well in the catalytic combustion of naphthalene. Experimental results indicated that MFS was a suitable support for catalytic combustion of large molecular organic compounds, especially for some high temperature catalytic reactions when water vapor was present.

  10. Determination of mobile form contents of Zn, Cd, Pb and Cu in soil extracts by combined stripping voltammetry

    Energy Technology Data Exchange (ETDEWEB)

    Nedeltcheva, T. [Department of Analytical Chemistry, University of Chemical Technology and Metallurgy, 8 Kl. Ohridsi Blvd., 1756 Sofia (Bulgaria)]. E-mail: nedel@uctm.edu; Atanassova, M. [Department of Analytical Chemistry, University of Chemical Technology and Metallurgy, 8 Kl. Ohridsi Blvd., 1756 Sofia (Bulgaria); Dimitrov, J. [N. Pushkarov Institute of Soil Science and Agroecology, 7 Shosse Bankya St., 1080 Sofia (Bulgaria); Stanislavova, L. [N. Pushkarov Institute of Soil Science and Agroecology, 7 Shosse Bankya St., 1080 Sofia (Bulgaria)

    2005-01-10

    The amount of mobile forms of Zn, Pb, Cd and Cu in extracts obtained by treating soil samples with ammonium nitrate were determined by an appropriate combination of anodic and cathodic stripping voltammetry with hanging mercury drop electrode. Every analysis required three mercury drops: on the first one, zinc was determined; on the second, cadmium and lead; on the third, copper was determined. Zinc, lead and cadmium were determined by conventional differential-pulse anodic stripping voltammetry. For copper determination, adsorptive differential-pulse cathodic stripping voltammetry with amalgamation using chloride ions as a complexing agent was applied. The standard deviation of the results was from 1 to 10% depending on the metal content in the sample. Voltammetric results were in good agreement with the AAS analysis. No microwave digestion of soil extracts was necessary.

  11. Si strip detector with integrated coupling capacitors

    Energy Technology Data Exchange (ETDEWEB)

    Caccia, M.; Evensen, L.; Hansen, T.E.; Horisberger, R.; Hubbeling, L.; Peisert, A.; Tuuva, T.; Weilhammer, P.; Zalewska, A.

    1987-10-01

    A silicon microstrip detector with capacitive coupling of the diode strips to the metallization and with individual polysilicon resistors to each diode has been developed. The detector was tested in a minimum ionizing particle beam showing a performance similar to conventional strip detectors and a spatial resolution of 3.5 ..mu..m. Capacitive coupling allows the decoupling of the leakage current from the input to the charge sensitive preamplifier especially in the case of LSI electronics.

  12. Speed Control and Coiling Temperature Control of Strip

    Institute of Scientific and Technical Information of China (English)

    CAI Xiao-hui; ZHANG Dian-hua; WANG Guo-dong; LIU Xiang-hua; FAN Lei

    2004-01-01

    Considering the strip speed during controlled laminar cooling on Baosteel 1580 hot strip mill in China, the influence of strip speed fluctuation on coiling temperature control for the tail and "neck" of the strip was analyzed. The optimization strategies were put forward and proved effective in operation.

  13. Excess Production Capacity Squeezes Profits of Brass Strip Enterprises

    Institute of Scientific and Technical Information of China (English)

    2012-01-01

    <正>Between 2003 and 2006,under the backdrop of rapid growth of domestic demand for brass strip and soaring copper price,brass strip manufacturers made a fortune.And brass strip manufacturers mushroomed in Zhejiang,Anhui and Jiangsu.Large brass strip manufacturers

  14. Process development of thin strip steel casting

    Energy Technology Data Exchange (ETDEWEB)

    Sussman, R.C.; Williams, R.S.

    1990-12-01

    An important new frontier is being opened in steel processing with the emergence of thin strip casting. Casting steel directly to thin strip has enormous benefits in energy savings by potentially eliminating the need for hot reduction in a hot strip mill. This has been the driving force for numerous current research efforts into the direct strip casting of steel. The US Department of Energy initiated a program to evaluate the development of thin strip casting in the steel industry. In earlier phases of this program, planar flow casting on an experimental caster was studied by a team of engineers from Westinghouse Electric corporation and Armco Inc. A subsequent research program was designed as a fundamental and developmental study of both planar and melt overflow casting processes. This study was arranged as several separate and distinct tasks which were often completed by different teams of researchers. An early task was to design and build a water model to study fluid flow through different designs of planar flow casting nozzles. Another important task was mathematically modeling of melt overflow casting process. A mathematical solidification model for the formation of the strip in the melt overflow process was written. A study of the material and conditioning of casting substrates was made on the small wheel caster using the melt overflow casting process. This report discusses work on the development of thin steel casting.

  15. Structure sensitivity in adsorption

    DEFF Research Database (Denmark)

    Hammer, Bjørk; Nielsen, Ole Holm; Nørskov, Jens Kehlet

    1997-01-01

    The structure sensitivity of CO adsorption on different flat, stepped, kinked and reconstructed Pt surfaces is studied using large-scale density-functional calculations. We find an extremely strong structure sensitivity in the adsorption energy with variations up to 1 eV (or 100%) from one...

  16. A Simple Adsorption Experiment

    Science.gov (United States)

    Guirado, Gonzalo; Ayllon, Jose A.

    2011-01-01

    The study of adsorption phenomenon is one of the most relevant and traditional physical chemistry experiments performed by chemistry undergraduate students in laboratory courses. In this article, we describe an easy, inexpensive, and straightforward way to experimentally determine adsorption isotherms using pieces of filter paper as the adsorbent…

  17. CHARACTERIZATION AND ADSORPTION PROPERTIES OF POROUS CARBON NANOFIBER GRANULES

    Institute of Scientific and Technical Information of China (English)

    Jiuling Chen; Qinghai Chen; Yongdan Li

    2006-01-01

    The properties of the porous granules produced by agglomeration of catalytically grown carbon nanofibers were investigated in this work. The single pellet crushing strength of the granules is high, e.g., 1.6-2.5 MPa. They have adsorption at 298 K of benzene or phenol on the granules is much lower than that on activated carbon and depends not only on the specific surface area of the carbon material but also on the sewing structure of the granules and the morphology of the carbon nanofibers. Treatment in dilute nitric acid appreciably reduces such adsorption.

  18. Catalytic coherence transformations

    Science.gov (United States)

    Bu, Kaifeng; Singh, Uttam; Wu, Junde

    2016-04-01

    Catalytic coherence transformations allow the otherwise impossible state transformations using only incoherent operations with the aid of an auxiliary system with finite coherence that is not being consumed in any way. Here we find the necessary and sufficient conditions for the deterministic and stochastic catalytic coherence transformations between a pair of pure quantum states. In particular, we show that the simultaneous decrease of a family of Rényi entropies of the diagonal parts of the states under consideration is a necessary and sufficient condition for the deterministic catalytic coherence transformations. Similarly, for stochastic catalytic coherence transformations we find the necessary and sufficient conditions for achieving a higher optimal probability of conversion. We thus completely characterize the coherence transformations among pure quantum states under incoherent operations. We give numerous examples to elaborate our results. We also explore the possibility of the same system acting as a catalyst for itself and find that indeed self-catalysis is possible. Further, for the cases where no catalytic coherence transformation is possible we provide entanglement-assisted coherence transformations and find the necessary and sufficient conditions for such transformations.

  19. Novel photoresist stripping technology using steam-water mixture*

    Institute of Scientific and Technical Information of China (English)

    Wang Lei; Hui Yu; Gao Chaoqun; Jing Yupeng

    2011-01-01

    A novel wet vapor photoresist stripping technology is developed as an alternative to dry plasma ashing and wet stripping. Experiments using this technology to strip hard baked SU-8 photoresist, aurum and chromium film are carried out. Then the images of stripping results are shown and the mechanism is analyzed and discussed.The most striking result of this experiment is that the spraying mixture of steam and water droplets can strip photoresist and even metal film with ease.

  20. Catalytic Polymer Multilayer Shell Motors for Separation of Organics.

    Science.gov (United States)

    Lin, Zhihua; Wu, Zhiguang; Lin, Xiankun; He, Qiang

    2016-01-26

    A catalytic polymer multilayer shell motor has been developed, which effects fast motion-based separation of charged organics in water. The shell motors are fabricated by sputtering platinum onto the exposed surface of silica templates embedded in Parafilm, followed by layer-by-layer assembly of polyelectrolyte multilayers to the templates. The catalytic shell motors display high bubble propulsion with speeds of up to 260 μm s(-1) (13 body lengths per second). Moreover, the polyelectrolyte multilayers assembled at high pH (pH>9.0) adsorb approximately 89% of dye molecules from water, owing to the electrostatic interaction between the positively charged polymers and the anionic dye molecules, and subsequently release them at neutral pH in a microfluidic device. The efficient propulsion coupled with the effective adsorption behavior of the catalytic shell motors in a microfluidic device results in accelerated separation of organics in water and thus holds considerable promise for water analysis.

  1. Catalytic activity of cerium-doped Ru/Al2O3 during ozonation of dimethyl phthalate

    Institute of Scientific and Technical Information of China (English)

    Yunrui ZHOU; Wanpeng ZHU; Xun CHEN

    2008-01-01

    In this paper, factors influencing the mineraliza-tion of dimethyl phthalate (DMP) during catalytic ozona-tion with a cerium-doped Ru/Al2O3 catalyst were studied. The catalytic contribution was calculated through the results of a companrison experiment. It showed that doping cerium significantly enhanced catalytic activity. The total organic carbon (TOC) removal over the doped catalyst at 100 rain reached 75.1%, 61.3% using Ru/Al2O3 catalyst and only 14.0% using ozone alone. Catalytic activity reached the maximum when 0.2% of ruthenium and 1.0% of cerium'were simultaneously loaded onto Al2O3 support. Results of experiments on oxidation by ozone alone, adsorption of the catalyst, Ce ion's and heterogeneous catalytic ozonation confirmed that the contribution of het-erogeneous catalytic ozonation was about 50%, which showed the obvious effect of Ru-Ce/Al2O3 on catalytic activity.

  2. Removal of semivolatiles from soils by steam stripping. 1. A local equilibrium model

    International Nuclear Information System (INIS)

    A mathematical model for the in-situ steam stripping of volatile and semivolatile organics from contaminated vadose zone soils at hazardous waste sites is developed. A single steam injection well is modeled. The model assumes that the pneumatic permeability of the soil is spatially constant and isotropic, that the adsorption isotherm of the contaminant is linear, and that the local equilibrium approximation is adequate. The model is used to explore the streamlines and transit times of the injected steam as well as the effects of injection well depth and contaminant distribution on the time required for remediation

  3. Depletive stripping chronopotentiometry : a major step forward in electrochemical stripping techniques for metal ion speciation analysis

    NARCIS (Netherlands)

    Town, R.M.; Leeuwen, van H.P.

    2004-01-01

    A comparative evaluation of the utility of the various modes of stripping chronopotentiometry (SCP) for trace metal speciation analysis is presented in the broad context of stripping voltammetric techniques. The remarkable fundamental advantages of depletive SCP at scanned deposition potential (SSCP

  4. Effect of Load Distribution on Strip Crown in Hot Strip Rolling

    Institute of Scientific and Technical Information of China (English)

    Hongshuang DI; Jianzhong XU; Dianyao GONG; Xianghua LIU; Guodong WANG; Xiaoming HE; Liying BA

    2004-01-01

    In order to establish precision model, a software to calculate the strip crown of four-high hot rolling mill was developed by using affecting function method according to the strip crown calculation theory. The effect of work roll diameter, unit width rolling load, roll bending force, work roll crown, initial strip crown and reduction, etc, on load distribution effect rate was simulated by using the software. The results show that the load distribution effect rate increases with the increase of strip width, work roll diameter, unit width rolling load, roll bending force, work roll crown, initial strip crown and reduction. Based on the simulation results, base value of load distribution effect rate and fitting coefficients of six power polynomial of load distribution effect rate modification coefficient were determined considering all of the above parameters. A simplified mathematical model for calculating load distribution effect rate was established.

  5. Development of floating strip micromegas detectors

    Energy Technology Data Exchange (ETDEWEB)

    Bortfeldt, Jonathan

    2014-04-28

    Micromegas are high-rate capable, high-resolution micro-pattern gaseous detectors. Square meter sized resistive strip Micromegas are foreseen as replacement of the currently used precision tracking detectors in the Small Wheel, which is part of the forward region of the ATLAS muon spectrometer. The replacement is necessary to ensure tracking and triggering performance of the muon spectrometer after the luminosity increase of the Large Hadron Collider beyond its design value of 10{sup 34} cm{sup -2}s{sup -1} around 2020. In this thesis a novel discharge tolerant floating strip Micromegas detector is presented and described. By individually powering copper anode strips, the effects of a discharge are confined to a small region of the detector. This reduces the impact of discharges on the efficiency by three orders of magnitude, compared to a standard Micromegas. The physics of the detector is studied and discussed in detail. Several detectors are developed: A 6.4 x 6.4 cm{sup 2} floating strip Micromegas with exchangeable SMD capacitors and resistors allows for an optimization of the floating strip principle. The discharge behavior is investigated on this device in depth. The microscopic structure of discharges is quantitatively explained by a detailed detector simulation. A 48 x 50 cm{sup 2} floating strip Micromegas is studied in high energy pion beams. Its homogeneity with respect to pulse height, efficiency and spatial resolution is investigated. The good performance in high-rate background environments is demonstrated in cosmic muon tracking measurements with a 6.4 x 6.4 cm{sup 2} floating strip Micromegas under lateral irradiation with 550 kHz 20 MeV proton beams. A floating strip Micromegas doublet with low material budget is developed for ion tracking without limitations from multiple scattering in imaging applications during medical ion therapy. Highly efficient tracking of 20 MeV protons at particle rates of 550 kHz is possible. The reconstruction of the

  6. Area specific stripping factors for AGS. A method for extracting stripping factors from survey data

    Energy Technology Data Exchange (ETDEWEB)

    Aage, H.K.; Korsbech, U. [Technical Univ. of Denmark (Denmark)

    2006-04-15

    In order to use Airborne Gamma-ray Spectrometry (AGS) for contamination mapping, for source search etc. one must to be able to eliminate the contribution to the spectra from natural radioactivity. This in general is done by a stripping technique. The parameters for performing a stripping have until recently been measured by recording gamma spectra at special calibration sites (pads). This may be cumbersome and the parameters may not be correct when used at low gamma energies for environmental spectra. During 2000-2001 DTU tested with success a new technique for Carborne Gamma-ray Spectrometry (CGS) where the spectra from the surveyed area (or from a similar area) were used for calculating the stripping parameters. It was possible to calculate usable stripping ratios for a number of low energy windows - and weak source signals not detectable by other means were discovered with the ASS technique. In this report it is shown that the ASS technique also works for AGS data, and it has been used for recent Danish AGS tests with point sources. (Check of calibration of AGS parameters.) By using the ASS technique with the Boden data (Barents Rescue) an exercise source was detected that has not been detected by any of the teams during the exercise. The ASS technique therefore seems to be better for search for radiation anomalies than any other method known presently. The experiences also tell that although the stripping can be performed correctly at any altitude there is a variation of the stripping parameters with altitude that has not yet been quite understood. However, even with the oddly variations the stripping worked as expected. It was also observed that one might calculate a single common set of usable stripping factors for all altitudes from the entire data set i.e. some average a, b and c values. When those stripping factors were used the stripping technique still worked well. (au)

  7. Competitive Protein Adsorption - Multilayer Adsorption and Surface Induced Protein Aggregation

    DEFF Research Database (Denmark)

    Holmberg, Maria; Hou, Xiaolin

    2009-01-01

    In this study, competitive adsorption of albumin and IgG (immunoglobulin G) from human serum solutions and protein mixtures onto polymer surfaces is studied by means of radioactive labeling. By using two different radiolabels (125I and 131I), albumin and IgG adsorption to polymer surfaces...... is monitored simultaneously and the influence from the presence of other human serum proteins on albumin and IgG adsorption, as well as their mutual influence during adsorption processes, is investigated. Exploring protein adsorption by combining analysis of competitive adsorption from complex solutions...... of high concentration with investigation of single protein adsorption and interdependent adsorption between two specific proteins enables us to map protein adsorption sequences during competitive protein adsorption. Our study shows that proteins can adsorb in a multilayer fashion onto the polymer surfaces...

  8. Superconducting nano-strip particle detectors

    Science.gov (United States)

    Cristiano, R.; Ejrnaes, M.; Casaburi, A.; Zen, N.; Ohkubo, M.

    2015-12-01

    We review progress in the development and applications of superconducting nano-strip particle detectors. Particle detectors based on superconducting nano-strips stem from the parent devices developed for single photon detection (SSPD) and share with them ultra-fast response times (sub-nanosecond) and the ability to operate at a relatively high temperature (2-5 K) compared with other cryogenic detectors. SSPDs have been used in the detection of electrons, neutral and charged ions, and biological macromolecules; nevertheless, the development of superconducting nano-strip particle detectors has mainly been driven by their use in time-of-flight mass spectrometers (TOF-MSs) where the goal of 100% efficiency at large mass values can be achieved. Special emphasis will be given to this case, reporting on the great progress which has been achieved and which permits us to overcome the limitations of existing mass spectrometers represented by low detection efficiency at large masses and charge/mass ambiguity. Furthermore, such progress could represent a breakthrough in the field. In this review article we will introduce the device concept and detection principle, stressing the peculiarities of the nano-strip particle detector as well as its similarities with photon detectors. The development of parallel strip configuration is introduced and extensively discussed, since it has contributed to the significant progress of TOF-MS applications.

  9. Beam stripping extraction from the VINCY cyclotron

    Directory of Open Access Journals (Sweden)

    Ristić-Đurović Jasna L.

    2006-01-01

    Full Text Available The extraction system of a cyclotron guides an ion beam from a spiral acceleration orbit, through an extraction trajectory, into a high energy transport line. The two methods commonly used to direct an ion into the extraction path are deflection, by the electric field of an electrostatic deflector, and ion stripping, by a thin carbon foil. Compared to the electrostatic deflector system, the stripping extraction provides a fast and easy change of the extracted ion energy and is easier to manufacture operate, and maintain. However, the extraction trajectory and dynamics of an ion beam after stripping are highly dependant on the ion energy and specific charge. Thus, when a multipurpose machine such as the VINCY Cyclotron is concerned, it is far from easy to deliver a variety of ion beams into the same high energy transport line and at the same time preserve a reasonable compactness of the extraction system. The front side stripping extraction system of the VINCY Cyclotron provides high (~70 MeV and mid (~30 MeV energy protons, as well as a number of heavy ions in broad energy ranges. The back side stripping extraction system extracts low energy protons (~18 MeV and enables their simultaneous use with high energy protons at the front side of the machine.

  10. Tests of Cathode Strip Chamber Prototypes

    CERN Document Server

    Bonushkin, Yuri; Chrisman, David; Durkin, S; Ferguson, Thomas; Giacomelli, Paolo; Gorn, William; Hauser, Jay; Hirschfelder, J; Hoftiezer, John; Hoorani, Hafeez R; Kisselev, Oleg; Klem, Daniel; Korytov, Andrey; Layter, John G; Lennous, Paul; Ling, Ta-Yung; Matthey, Christina; Medved, Serguei; Minor, C; Mitselmakher, Guenakh; Müller, Thomas; Otwinowski, Stanislaw; Preston, L; Prokofiev, O E; Rush, Chuck J; Schenk, P; Sedykh, Yu; Smirnov, Igor; Soulimov, V; Vaniachine, A; Vercelli, T; Wuest, Craig R; Zeng, Ji-Yang; von Goeler, Eberhard

    1997-01-01

    We report on the results of testing two six-layer 0.6 x 0.6 cm^2 cathode strip chamber ( CSC) prototypes in a muon beam at CERN. The prototypes were designed to simulate sections of the end-cap muon system of the Compact Muon Solenoid ( CMS) detector which will be installed at the Large Hadron Collider ( LHC). We measured the spatial and time resolutions of each chamber for different gains, different orientations with respect to the beam direction and different strength magnetic fields. The single-layer spatial resolution of a prototype with a strip pitch of 15.88 mm ranged from 78 micron to 468 micron, depending on whether the particle passed between two cathode strips or through the center of a strip; its six-layer resolution was found to be 44 micron. The single-layer spatial resolution of a prototype with a strip pitch of 6.35 mm ranged from 54 to 66 micron; its six-layer resolution w as found to be 23 micron. The efficiency for collecting an anode wire signal from one of six layers within a 20 ns time wi...

  11. Effects of carrier and Mn loading on supported manganese oxide catalysts for catalytic combustion of methane

    Institute of Scientific and Technical Information of China (English)

    Jinyan Hu; Wei Chu; Limin Shi

    2008-01-01

    Supported manganese oxide catalysts were prepared by incipient wetness impregnation method for methane cat-alytic combustion, and effects of the support (Al2O3, SiO2 and TiO2) and Mn loading were investigated. These catalysts were characterized with N2 adsorption, X-ray diffraction, X-ray photoelectron spectroscopy and temperature-programmed reduction techniques. Methane conversion varied in a large range depending on supports or Mn loading. Al2O3 supported 15% Mn cata-lyst exhibited better activity toward methane catalytic oxidation. The manganese state and oxygen species played an important role in the catalytic performance.

  12. Effect of Initial Crown on Shape of Hot Rolled Strip

    Institute of Scientific and Technical Information of China (English)

    HU Yu; GONG Dian-yao; JIANG Zheng-yi; XU Jian-zhong; ZHANG Dian-hua; LIU Xiang-hua

    2009-01-01

    Based on the influence coefficient method, the effect of entry strip crown on the shape of hot rolled strip was analyzed using the software of roll elastic deformation simulation. According to the practical condition of a domestic hot roiled strip plant, the unit strip crown change from the first stand to the last stand was calculated when the entry crown of hot strip varies. The calculated result shows that the entry strip crown does not significantly affect the target strip crown at the exit of the last finishing stand in respect to a fixed strip shape control reference (such as bending force). The calculation was analyzed, and the research is helpful in modeling strip shape setup and shape control.

  13. Catalytic Conversion of Biofuels

    DEFF Research Database (Denmark)

    Jørgensen, Betina

    This thesis describes the catalytic conversion of bioethanol into higher value chemicals. The motivation has been the unavoidable coming depletion of the fossil resources. The thesis is focused on two ways of utilising ethanol; the steam reforming of ethanol to form hydrogen and the partial oxida...

  14. Catalytic Phosphination and Arsination

    Institute of Scientific and Technical Information of China (English)

    Kwong Fuk Yee; Chan Kin Shing

    2004-01-01

    The catalytic, user-friendly phosphination and arsination of aryl halides and triflates by triphenylphosphine and triphenylarsine using palladium catalysts have provided a facile synthesis of functionalized aryl phosphines and arsines in neutral media. Modification of the cynaoarisne yielded optically active N, As ligands which will be screened in various asymmetric catalysis.

  15. Catalytic efficiency of designed catalytic proteins.

    Science.gov (United States)

    Korendovych, Ivan V; DeGrado, William F

    2014-08-01

    The de novo design of catalysts that mimic the affinity and specificity of natural enzymes remains one of the Holy Grails of chemistry. Despite decades of concerted effort we are still unable to design catalysts as efficient as enzymes. Here we critically evaluate approaches to (re)design of novel catalytic function in proteins using two test cases: Kemp elimination and ester hydrolysis. We show that the degree of success thus far has been modest when the rate enhancements seen for the designed proteins are compared with the rate enhancements by small molecule catalysts in solvents with properties similar to the active site. Nevertheless, there are reasons for optimism: the design methods are ever improving and the resulting catalyst can be efficiently improved using directed evolution.

  16. Hybrid adsorptive membrane reactor

    Science.gov (United States)

    Tsotsis, Theodore T.; Sahimi, Muhammad; Fayyaz-Najafi, Babak; Harale, Aadesh; Park, Byoung-Gi; Liu, Paul K. T.

    2011-03-01

    A hybrid adsorbent-membrane reactor in which the chemical reaction, membrane separation, and product adsorption are coupled. Also disclosed are a dual-reactor apparatus and a process using the reactor or the apparatus.

  17. Hybrid adsorptive membrane reactor

    Science.gov (United States)

    Tsotsis, Theodore T. (Inventor); Sahimi, Muhammad (Inventor); Fayyaz-Najafi, Babak (Inventor); Harale, Aadesh (Inventor); Park, Byoung-Gi (Inventor); Liu, Paul K. T. (Inventor)

    2011-01-01

    A hybrid adsorbent-membrane reactor in which the chemical reaction, membrane separation, and product adsorption are coupled. Also disclosed are a dual-reactor apparatus and a process using the reactor or the apparatus.

  18. Ram pressure stripping of tilted galaxies

    CERN Document Server

    Jachym, P; Palous, J; Combes, F

    2009-01-01

    Ram pressure stripping of galaxies in clusters can yield gas deficient disks. Previous numerical simulations based on various approaches suggested that, except for near edge-on disk orientations, the amount of stripping depends very little on the inclination angle. Following our previous study of face-on stripping, we extend the set of parameters with the disk tilt angle and explore in detail the effects of the ram pressure on the interstellar content (ISM) of tilted galaxies that orbit in various environments of clusters, with compact or extended distributions of the intra-cluster medium (ICM). We further study how results of numerical simulations could be estimated analytically. A grid of numerical simulations with varying parameters is produced using the tree/SPH code GADGET with a modified method for calculating the ISM-ICM interaction. These SPH calculations extend the set of existing results obtained from different codes using various numerical techniques. The simulations confirm the general trend of le...

  19. Analysis of 'Coma strip' galaxy redshift catalog

    International Nuclear Information System (INIS)

    We present results of the analysis of a galaxy redshift catalog made at the 6-m telescope by Karachentsev and Kopylov (1990. Mon. Not. R. astr. Soc., 243, 390). The catalog covers a long narrow strip on the sky (10 arcmin by 630) and lists 283 galaxies up to limiting blue magnitude mB = 17.6. The strip goes through the core of Coma cluster and this is called the 'Coma strip' catalog. The catalog is almost two times deeper than the CfA redshift survey and creates the possibility of studying the galaxy distribution on scales of 100-250 Mpc. Due to the small number of galaxies in the catalog, we were able to estimate only very general and stable parameters of the distribution. (author)

  20. Adsorption behaviour of bulgur.

    Science.gov (United States)

    Erbaş, Mustafa; Aykın, Elif; Arslan, Sultan; Durak, Atike N

    2016-03-15

    The aim of this research was to determine the adsorption behaviour of bulgur. Three different particle sizes (2dry matter and 4.96-16.57, respectively. Constant k was between 0.85 and 0.93, and GAB equation was determined to fit very well for bulgur adsorption, because of %E values lower than 10%. Bulgur must be stored below 70% relative humidity and with less than 10 g water per 100 g of dry mater. PMID:26575716

  1. Spray forming lead strip. Final report

    Energy Technology Data Exchange (ETDEWEB)

    McHugh, K.

    1996-04-10

    A cooperative research project was conducted between the Idaho National Engineering Laboratory (INEL) and Johnson Controls, Inc. (JCI) to adapt the INEL spray forming process to produce near-net-shape lead alloy strip. The emphasis of the work was to spray form lead strip samples at INEL, using a variety of spray conditions, for characterization at JCI. An existing glove box apparatus was modified at INEL to spray form lead. The main spray forming components were housed inside the glove box. They included a spray nozzle, tundish (crucible), substrate assembly, gas heater and furnaces to heat the nozzle and tundish. To spray form metal strip, liquid metal was pressure-fed at a controlled rate through a series of circular orifices that span the width of the nozzle. There the metal contacted high velocity, high temperature inert gas (nitrogen) which atomized the molten material into fine droplets, entrained the droplets in a directed flow, and deposited them onto glass plates that were swept through the spray plume to form strip samples. In-flight convection cooling of the droplets followed by conduction and convection cooling at the substrate resulted in rapid solidification of the deposit. During operation, the inside of the glove box was purged with an inert gas to limit the effects of in-flight oxidation of the particles and spray-formed strips, as well as to protect personnel from exposure to airborne lead particulate. Remote controls were used to start/stop the spray and control the speed and position of the substrate. In addition, substrate samples were loaded into the substrate translator manually using the gloved side ports of the box. In this way, the glove box remained closed during a series of spray trials, and was opened only when loading the crucible with a lead charge or when removing lead strip samples for shipment to JCI.

  2. Spray Rolling Aluminum Strip for Transportation Applications

    Energy Technology Data Exchange (ETDEWEB)

    Kevin M. McHugh; Y. Lin; Y. Zhou; E. J. Lavernia; J.-P. Delplanque; S. B. Johnson

    2005-02-01

    Spray rolling is a novel strip casting technology in which molten aluminum alloy is atomized and deposited into the roll gap of mill rolls to produce aluminum strip. A combined experimental/modeling approach has been followed in developing this technology with active participation from industry. The feasibility of this technology has been demonstrated at the laboratory scale and it is currently being scaled-up. This paper provides an overview of the process and compares the microstructure and properties of spray-rolled 2124 aluminum alloy with commercial ingot-processed material

  3. Lubrication in strip cold rolling process

    Institute of Scientific and Technical Information of China (English)

    Jianlin Sun; Yonglin Kang; Tianguo Xiao; Jianze Wang

    2004-01-01

    A lubrication model was developed for explaining how to form an oil film in the deformation zone, predicting the film thickness and determining the characteristics of lubrication in the strip rolling process, combined with the knowledge of hydrodythicknesses in the strip cold rolling. Results from the experiment and calculation show that the oil film forming in hydrodynamic lubrication is up to the bit angle and a higher rolling speed or a higher rolling oil viscosity. The mechanism of mechanical entrainment always affects the film thickness that increases with the rolling oil viscosity increasing or the reduction rate decreasing in rolling.

  4. Test strip and method for its use

    International Nuclear Information System (INIS)

    A test strip device is described which is useful in performing binding assays involving antigens, antibodies, hormones, vitamins, metabolites or pharmacological agents. The device is capable of application to analytical methods in which a set of sequential test reactions is involved and in which a minute sample size may be used. This test strip is particularly useful in radioimmunoassays. The use of the device is illustrated in radioimmunoassays for 1) thyroxine in serum, 2) the triiodothyronine binding capacity of serum and 3) folic acid and its analogues in serum. (U.K.)

  5. slice of LEP beamtube with getter strip

    CERN Multimedia

    1989-01-01

    A section of the LEP beam pipe. This is the chamber in which LEP's counter-rotating electron and positron beams travel. It is made of lead-clad aluminium. The beams circulate in the oval cross-section part of the chamber. In the rectangular cross-section part, LEP's innovative getter-strip vacuum pump is installed. After heating to purify the surface of the getter, the strip acts like molecular sticky tape, trapping any stray molecules left behind after the accelerator's traditional vacuum pumps have done their job.

  6. Multi-twist optical Mobius strips

    CERN Document Server

    Freund, Isaac

    2009-01-01

    Circularly polarized Gauss-Laguerre GL(0,0) and GL(0,1) laser beams that cross at their waists at a small angle are shown to generate a quasi-paraxial field that contains an axial line of circular polarization, a C line, surrounded by polarization ellipses whose major and minor axes generate multi-twist Mobius strips with twist numbers that increase with distance from the C point. These Mobius strips are interpreted in terms of Berry's phase for parallel transport of the ellipse axes around the C point.

  7. Asset Stripping in a Mature Market Economy

    DEFF Research Database (Denmark)

    Klarskov Jeppesen, Kim; Møller, Ulrik Gorm

    2011-01-01

    indicates that asset stripping may take place in mature market economies to the extent that perpetrators are able to circumvent the corporate governance system by giving lawyers, public accountants and banks incentives to act less critically towards dubious business transactions. Research limitations...... is to analyse why the asset-stripping schemes occurred in a mature market economy with a strong corporate governance system and a low level of corruption. Design/methodology/approach – The research is conducted as a longitudinal single case study based on documentary research. Findings – The Danish case...

  8. Voltammetric characteristics of miconazole and its cathodic stripping voltammetric determination

    Directory of Open Access Journals (Sweden)

    PEREIRA FRANCISCO C.

    2002-01-01

    Full Text Available Miconazole is reduced at mercury electrode above pH 6 involving organometallic compound formation, responsible for an anomalous polarographic behavior. The electrodic process presents a large contribution of the adsorption effects. The drug can be determined by cathodic stripping voltammetry from 8.0 x 10-8 to 1, 5 x 10-6 molL-1 in Britton-Robinson buffer pH 8.0, when pre-accumulated for 30s at an accumulation potential of 0V. A relative standard deviation of 3.8% was obtained for ten measurements of 1.0 x 10-7 molL-1 miconazole in B-R buffer pH 8.0 and a limit detection of 1, 7 x 10-8 molL-1 was determined using 60s of deposition time and scan rate of 100 mVs-1. The proposed method is simple, precise and it was applied successfully for the determination of the miconazole in pure form and in commercial formulations, showing mean recoveries of 99.7-98.4%.

  9. Catalytic thermal barrier coatings

    Science.gov (United States)

    Kulkarni, Anand A.; Campbell, Christian X.; Subramanian, Ramesh

    2009-06-02

    A catalyst element (30) for high temperature applications such as a gas turbine engine. The catalyst element includes a metal substrate such as a tube (32) having a layer of ceramic thermal barrier coating material (34) disposed on the substrate for thermally insulating the metal substrate from a high temperature fuel/air mixture. The ceramic thermal barrier coating material is formed of a crystal structure populated with base elements but with selected sites of the crystal structure being populated by substitute ions selected to allow the ceramic thermal barrier coating material to catalytically react the fuel-air mixture at a higher rate than would the base compound without the ionic substitutions. Precious metal crystallites may be disposed within the crystal structure to allow the ceramic thermal barrier coating material to catalytically react the fuel-air mixture at a lower light-off temperature than would the ceramic thermal barrier coating material without the precious metal crystallites.

  10. The CMS silicon strip tracker modules production

    CERN Document Server

    Giorgi, M

    2006-01-01

    To complete the construction of the CMS silicon strip tracker, about 16,000 silicon microstrip detector modules will be required. In order to guarantee the uniform quality of the produced modules and to be able to match the deadlines requested by the CMS collaboration, a semi-industrialized organization has been developed, and the different components are being presented here.

  11. Anodic Stripping Voltammetry: An Instrumental Analysis Experiment.

    Science.gov (United States)

    Wang, Joseph

    1983-01-01

    Describes an experiment designed to acquaint students with the theory and applications of anodic stripping voltammetry (ASV) as well as such ASV problems as contamination associated with trace analysis. The experimental procedure, instrumentation, and materials discussed are designed to minimize cost and keep procedures as simple as possible. (JM)

  12. Basic Principles of Anodic Stripping Voltammetry (ASV)

    OpenAIRE

    2012-01-01

    In this interactive exercise, the basic principles of Anodic Stripping Voltammetry are shown. Each step of the voltammetric process is described using simulated animations. This activity illustrates what takes place in the voltammetric cell when this technique is applied to the determination of cadmium as well as to the simultaneous determination of copper and cadmium.

  13. Improved lower bound for online strip packing

    NARCIS (Netherlands)

    Harren, Rolf; Kern, Walter

    2015-01-01

    We study the online strip packing problem and derive an improved lower bound of ρ ≥ 2.589... for the competitive ratio of this problem. The construction is based on modified “Brown-Baker-Katseff sequences” (Brown et al. in Acta Inform. 18:207–225, 1982) using only two types of rectangles. In additio

  14. Nonlinear optical model for strip plasmonic waveguides

    DEFF Research Database (Denmark)

    Lysenko, Oleg; Bache, Morten; Lavrinenko, Andrei

    2016-01-01

    This paper presents a theoretical model of nonlinear optical properties for strip plasmonic waveguides. The particular waveguides geometry that we investigate contains a gold core, adhesion layers, and silicon dioxide cladding. It is shown that the third-order susceptibility of the gold core sign...

  15. Nanoscale Test Strips for Multiplexed Blood Analysis

    Science.gov (United States)

    Chan, Eugene

    2015-01-01

    A critical component of the DNA Medicine Institute's Reusable Handheld Electrolyte and Lab Technology for Humans (rHEALTH) sensor are nanoscale test strips, or nanostrips, that enable multiplexed blood analysis. Nanostrips are conceptually similar to the standard urinalysis test strip, but the strips are shrunk down a billionfold to the microscale. Each nanostrip can have several sensor pads that fluoresce in response to different targets in a sample. The strips carry identification tags that permit differentiation of a specific panel from hundreds of other nanostrip panels during a single measurement session. In Phase I of the project, the company fabricated, tested, and demonstrated functional parathyroid hormone and vitamin D nanostrips for bone metabolism, and thrombin aptamer and immunoglobulin G antibody nanostrips. In Phase II, numerous nanostrips were developed to address key space flight-based medical needs: assessment of bone metabolism, immune response, cardiac status, liver metabolism, and lipid profiles. This unique approach holds genuine promise for space-based portable biodiagnostics and for point-of-care (POC) health monitoring and diagnostics here on Earth.

  16. Topics in Chemical Instrumentation: CII. Automated Anodic Stripping Voltammetry.

    Science.gov (United States)

    Stock, John T.; Ewing, Galen W., Ed.

    1980-01-01

    Presents details of anodic stripping analysis (ASV) in college chemistry laboratory experiments. Provides block diagrams of the analyzer system, circuitry and power supplies of the automated stripping analyzer, and instructions for implementing microcomputer control of the ASV. (CS)

  17. Comparative evaluation of scanned stripping techniques: SSCP vs. SSV

    NARCIS (Netherlands)

    Town, R.M.; Leeuwen, van H.P.

    2006-01-01

    The characteristic features of scanned deposition potential curves constructed from stripping chronopotentiometry (SSCP) and various modes of stripping voltammetry (SSV) are critically evaluated. The strengths and weaknesses of each method for identification of metal ion speciation features and susc

  18. A catalytic cracking process

    Energy Technology Data Exchange (ETDEWEB)

    Degnan, T.F.; Helton, T.E.

    1995-07-20

    Heavy oils are subjected to catalytic cracking in the absence of added hydrogen using a catalyst containing a zeolite having the structure of ZSM-12 and a large-pore crystalline zeolite having a Constraint Index less than about 1. The process is able to effect a bulk conversion of the oil at the same time yielding a higher octane gasoline and increased light olefin content. (author)

  19. Refuges, flower strips, biodiversity and agronomic interest.

    Science.gov (United States)

    Roy, Grégory; Wateau, Karine; Legrand, Mickaël; Oste, Sandrine

    2008-01-01

    Several arthropods are natural predators of pests, and they are able to reduce and control their population development. FREDON Nord Pas-de-Calais (Federation Regionate de Defense contre les Organismes Nuisibles = Regional Federation for Pest Control) has begun for a long time to form farmers to the recognition of beneficial arthropods and to show them their usefulness. These beneficial insects or arachnids are present everywhere, in orchards and even in fields which are areas relatively poor in biodiversity. Adults feed in the flower strips instead larvae and some adults feed on preys such as aphids or caterpillars. Most of the time, beneficial insects can regulate pest but sometimes, in agricultural area, they can't make it early enough and efficiently. Their action begin too late and there biodiversity and number are too low. It's possible to enhance their action by manipulating the ecological infrastructures, like sewing flower strips or installing refuges. Flower strips increase the density of natural enemies and make them be present earlier in the field in order to control pests. Refuges permit beneficial's to spend winter on the spot. So they're able to be active and to grow in number earlier. From 2004 to 2007, on the one hand, FREDON Nord Pas-de-Calais has developed a research program. Its purpose was to inventory practices and also tools and means available and to judge the advisability of using such or such beneficial refuge in orchards. On the second hand, it studied the impact in orchard of refuges on population of beneficial's and the difference there were between manufactured refuges and homemade refuges. Interesting prospects were obtained with some of them. Otherwise, since 2003, FREDON has studied flower strips influence on beneficial population and their impact on pest control. In cabbage fields, results of trials have shown that flower strips lead to a reduction of aphid number under acceptable economic level, up to 50 meters from flower strips

  20. Dual Strip-Excited Dielectric Resonator Antenna with Parasitic Strips for Radiation Pattern Reconfigurability

    Directory of Open Access Journals (Sweden)

    M. Kamran Saleem

    2014-01-01

    Full Text Available A novel pattern reconfigurable antenna concept utilizing rectangular dielectric resonator antenna (DRA placed over dielectric substrate backed by a ground plane is presented. A dual strip excitation scheme is utilized and both excitation strips are connected together by means of a 50 Ω microstrip feed network placed over the substrate. The four vertical metallic parasitic strips are placed at corner of DRA each having a corresponding ground pad to provide a short/open circuit between the parasitic strip and antenna ground plane, through which a shift of 90° in antenna radiation pattern in elevation plane is achieved. A fractional bandwidth of approximately 40% at center frequency of 1.6 GHz is achieved. The DRA peak realized gain in whole frequency band of operation is found to be above 4 dB. The antenna configuration along with simulation and measured results are presented.

  1. Calculation and Analysis of Temperature Distribution in Hot Rolling Strip

    OpenAIRE

    Kaixiang Peng

    2013-01-01

    Modern steel grades require constant and reproducible production conditions both in the hot strip mill and in the cooling section to achieve constant material properties along the entire strip length and from strip to strip. Calculation of the temperature in final rolling process always utilizes factors such as the work piece's inner organizational structure, plastic deformation, and it's variations of properties and so on, also as well as the physical parameters such as gauge, shape, etc. In...

  2. Study on the Carbon-Methanation and Catalytic Activity of Ru/AC for Ammonia Synthesis

    Institute of Scientific and Technical Information of China (English)

    祝一锋; 李小年; 季德春; 刘化章

    2004-01-01

    The effects of promoters K, Ba, Sm on the resistance to carbon-methanation and catalytic activity of ruthenium supported on active carbon (Ru/AC) for ammonia synthesis have been studied by means of TG-DTG (thermalgravity-differential thermalgravity), temperature-programmed desorption, and activity test. Promoters Ba,K, and Sm increased the activity of Ru/AC catalysts for ammonia synthesis significantly. Much higher activity can be reached for Ru/AC catalyst with bi- or tri-promoters. Indeed, the triply promoted catalyst showed the highest activity, coupled to a surprisingly high resistance to methanation. The ability of resistance of promoter to methanation of Ru/AC catalyst is dependent on the adsorption intensity of hydrogen. The strong adsorption of hydrogen would enhance methanation and impact the adsorption of nitrogen, which results in the decrease of catalytic activity.

  3. Site-Specific Scaling Relations for Hydrocarbon Adsorption on Hexagonal Transition Metal Surfaces

    Energy Technology Data Exchange (ETDEWEB)

    Montemore, Matthew M.; Medlin, James W.

    2013-10-03

    Screening a large number of surfaces for their catalytic performance remains a challenge, leading to the need for simple models to predict adsorption properties. To facilitate rapid prediction of hydrocarbon adsorption energies, scaling relations that allow for calculation of the adsorption energy of any intermediate attached to any symmetric site on any hexagonal metal surface through a carbon atom were developed. For input, these relations require only simple electronic properties of the surface and of the gas-phase reactant molecules. Determining adsorption energies consists of up to four steps: (i) calculating the adsorption energy of methyl in the top site using density functional theory or by simple relations based on the electronic structure of the surface; (ii) using modified versions of classical scaling relations to scale between methyl in the top site and C₁ species with more metal-surface bonds (i.e., C, CH, CH₂) in sites that complete adsorbate tetravalency; (iii) using gas-phase bond energies to predict adsorption energies of longer hydrocarbons (i.e., CR, CR₂, CR₃); and (iv) expressing energetic changes upon translation of hydrocarbons to various sites in terms of the number of agostic interactions and the change in the number of carbon-metal bonds. Combining all of these relations allows accurate scaling over a wide range of adsorbates and surfaces, resulting in efficient screening of catalytic surfaces and a clear elucidation of adsorption trends. The relations are used to explain trends in methane reforming, hydrocarbon chain growth, and propane dehydrogenation.

  4. Resolution Studies on Silicon Strip Sensors with fine Pitch

    CERN Document Server

    Haensel, S; Dolezal, Z; Dragicevic, M; Drasal, Z; Friedl, M; Hrubec, Josef; Irmler, C; Kiesenhofer, W; Krammer, M; Kvasnicka, P

    2009-01-01

    In June 2008 single-sided silicon strip sensors with 50~$\\mu$m readout pitch were tested in a pion beam at the SPS at CERN. The purpose of the test was to evaluate characteristic detector properties by varying the strip width and the number of intermediate strips. The experimental setup and first results for the spatial resolution are described.

  5. 21 CFR 880.2200 - Liquid crystal forehead temperature strip.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Liquid crystal forehead temperature strip. 880... Personal Use Monitoring Devices § 880.2200 Liquid crystal forehead temperature strip. (a) Identification. A liquid crystal forehead temperature strip is a device applied to the forehead that is used to...

  6. Effect of Water Vapour on the Acidity of ZSM-5Zeolite Used for Catalytic Cracking of Naphtha to Manufacture Ethylene and Propylene

    Institute of Scientific and Technical Information of China (English)

    Ma Guangwei; Xiao Jingxian; ZhangHuining; Xie Zaiku

    2008-01-01

    The change in acidity of the ZSM-5 zeolite was investigated after it was treated with water vapour,and its capability on ammonia adsorption was also studied after having adsorbed water vapour.The effect of water vapour on products distribution was studied during catalytic cracking of naphtha,the changes in the adsorption ability and catalytic performance of the ZSM-5 zeolite was investigated after the catalyst was loaded with phosphorus species.These results all indicated that water vapour could reduce the acid strength and acid density of ZSM-5 zeolite and affect the capability of ZSM-5 on adsorption of gases,therefore the activated energy contributed by the ZSM-5 zeolite to the catalytic cracking reaction would be low to prevent the feedstock from deepened catalytic cracking and coke formation.

  7. Regenerative adsorption distillation system

    KAUST Repository

    Ng, Kim Choon

    2013-12-26

    There is provided a regenerative adsorption distillation system comprising a train of distillation effects in fluid communication with each other. The train of distillation effects comprises at least one intermediate effect between the first and last distillation effects of the train, each effect comprising a vessel and a condensing tube for flow of a fluid therein. The system further comprises a pair of adsorption-desorption beds in vapour communication with the last effect and at least one intermediate effect, wherein the beds contain an adsorbent that adsorbs vapour from the last effect and transmits desorbed vapour into at least one of the intermediate effect.

  8. Combining an Optical Resonance Biosensor with Enzyme Activity Kinetics to Understand Protein Adsorption and Denaturation

    Science.gov (United States)

    Wilson, Kerry A.; Finch, Craig A.; Anderson, Phillip; Vollmer, Frank; Hickman, James J.

    2014-01-01

    Understanding protein adsorption and resultant conformation changes on modified and unmodified silicon dioxide surfaces is a subject of keen interest in biosensors, microfluidic systems and for medical diagnostics. However, it has been proven difficult to investigate the kinetics of the adsorption process on these surfaces as well as understand the topic of the denaturation of proteins and its effect on enzyme activity. A highly sensitive optical whispering gallery mode (WGM) resonator was used to study a catalytic enzyme’s adsorption processes on different silane modified glass substrates (plain glass control, DETA, 13F, and SiPEG). The WGM sensor was able to obtain high resolution kinetic data of glucose oxidase (GO) adsorption with sensitivity of adsorption better than that possible with SPR. The kinetic data, in combination with a functional assay of the enzyme activity, was used to test hypotheses on adsorption mechanisms. By fitting numerical models to the WGM sensograms for protein adsorption, and by confirming numerical predictions of enzyme activity in a separate assay, we were able to identify mechanisms for GO adsorption on different alkylsilanes and infer information about the adsorption of protein on nanostructured surfaces. PMID:25453976

  9. MnO2/CeO2 for catalytic ultrasonic degradation of methyl orange.

    Science.gov (United States)

    Zhao, He; Zhang, Guangming; Zhang, Quanling

    2014-05-01

    Catalytic ultrasonic degradation of aqueous methyl orange was studied in this paper. Heterogeneous catalyst MnO2/CeO2 was prepared by impregnation of manganese oxide on cerium oxide. Morphology and specific surface area of MnO2/CeO2 catalyst were characterized and its composition was determined. Results showed big differences between fresh and used catalyst. The removal efficiency of methyl orange by MnO2/CeO2 catalytic ultrasonic process was investigated. Results showed that ultrasonic process could remove 3.5% of methyl orange while catalytic ultrasonic process could remove 85% of methyl orange in 10 min. The effects of free radical scavengers were studied to determine the role of hydroxyl free radical in catalytic ultrasonic process. Results showed that methyl orange degradation efficiency declined after adding free radical scavengers, illustrating that hydroxyl free radical played an important role in degrading methyl orange. Theoretic analysis showed that the resonance size of cavitation bubbles was comparable with the size of catalyst particles. Thus, catalyst particles might act as cavitation nucleus and enhance ultrasonic cavitation effects. Measurement of H2O2 concentration in catalytic ultrasonic process confirmed this hypothesis. Effects of pre-adsorption on catalytic ultrasonic process were examined. Pre-adsorption significantly improved methyl orange removal. The potential explanation was that methyl orange molecules adsorbed on catalysts could enter cavitation bubbles and undergo stronger cavitation. PMID:24369902

  10. Removal performance and mechanism of ibuprofen from water by catalytic ozonation using sludge-corncob activated carbon as catalyst.

    Science.gov (United States)

    Wang, Hongjuan; Zhang, Liqiu; Qi, Fei; Wang, Xue; Li, Lu; Feng, Li

    2014-09-01

    To discover the catalytic activity of sludge-corncob activated carbon in catalytic ozonation of Ibuprofen, the performance of sludge-corncob activated carbon and three selected commercial activated carbons as catalysts in catalytic ozonation was investigated. The observation indicates the degradation rate of Ibuprofen increases significantly in the presence of sludge-corncob activated carbon and the catalytic activity of sludge-corncob activated carbon is much higher than that of the other three commercial activated carbons. Ibuprofen's removal rate follows pseudo-first order kinetics model well. It is also found that the adsorption removal of Ibuprofen by sludge-corncob activated carbon is less than 30% after 40 min. And the removal efficiency of Ibuprofen in the hybrid ozone/sludge-corncob activated carbon system is higher than the sum of sludge-corncob activated carbon adsorption and ozonation alone, which is a supportive evidence for catalytic reaction. In addition, the results of radical scavenger experiments demonstrate that catalytic ozonation of Ibuprofen by sludge-corncob activated carbon follows a hydroxyl radical reaction pathway. During ozonation of Ibuprofen in the presence of activated carbon, ozone could be catalytically decomposed to form hydrogen peroxide, which can promote the formation of hydroxyl radical. The maximum amount of hydrogen peroxide occurs in the presence of sludge-corncob activated carbon, which can explain why sludge-corncob activated carbon has the best catalytic activity among four different activated carbons.

  11. Microflora cultivable from minocycline strips placed in persisting periodontal pockets

    OpenAIRE

    Leung, WK; Jin, L; Yau, JYY; Q. Sun; Corbet, EF

    2005-01-01

    The microflora that develops on minocycline strips, used as an adjunct in non-surgical periodontal therapy was studied. Minocycline (1.4 mg in polycaprolactone vehicle) and control strips were applied into all residual pockets (PD ≥ 5 mm, ≥2 pockets/subject) of patients with chronic periodontitis 1 month after a course of non-surgical periodontal therapy. Strips were inserted and retained for 3 days, changed to new strips for 3 more days and then removed. Strips were recovered from 14 (eight ...

  12. Shape Setup System for 1700 Hot Strip Mill

    Institute of Scientific and Technical Information of China (English)

    GUO Zhong-feng; XU Jian-zhong; LI Chang-sheng; LIU Xiang-hua

    2007-01-01

    Shape setup (SSU) system is the core technology for hot strip mill (HSM). A precise SSU system was used to improve the strip quality for HSM. The function of SSU, setup, and feedback was introduced. The main mathematical models of roll gap profile and longitudinal strain difference are set up. Strip profile allocation strategy was researched according to the SSU system of a domestic 1 700 mm HSM. The SSU system was put into practical use and the measurement results showed that strip flatness variation and strip profile variation could be controlled in target scope.

  13. Mechanics of Thin Strip Steering in Hot Rolling

    Science.gov (United States)

    Jiang, Zhengyi; Tieu, Kiet A.

    2004-06-01

    The hot rolling of thin strip can result in several problems in hot rolling, for instance, the control of strip steering, strip shape and flatness and surface roughness etc. Therefore, the hot rolling of thin strip brings out a requirement of innovative technologies such as the extended control of shape and flatness, steering control and reduction of load by roll gap lubrication. In this paper, the authors focus on the analysis of thin strip snaking movement, as well as solve the related problems such as the shape and flatness due to a larger reduction applied when the strip is thinner. A finite element method was used to simulate this nonsymmetricity rolling considering the non-uniform reduction along the strip width. The calculated spread is compared with the measured values obtained from the rolling mill in laboratory and the friction effect is also discussed.

  14. Antenna with distributed strip and integrated electronic components

    Science.gov (United States)

    Rodenbeck, Christopher T.; Payne, Jason A.; Ottesen, Cory W.

    2008-08-05

    An antenna comprises electrical conductors arranged to form a radiating element including a folded line configuration and a distributed strip configuration, where the radiating element can be in proximity to a ground conductor and/or arranged as a dipole. Embodiments of the antenna include conductor patterns formed on a printed wiring board, having a ground plane, spacedly adjacent to and coplanar with the radiating element. An antenna can comprise a distributed strip patterned on a printed wiring board, integrated with electronic components mounted on top of or below the distributed strip, and substantially within the extents of the distributed strip. Mounting of electronic components on top of or below the distributed strip has little effect on the performance of the antenna, and allows for realizing the combination of the antenna and integrated components in a compact form. An embodiment of the invention comprises an antenna including a distributed strip, integrated with a battery mounted on the distributed strip.

  15. The STAR Silicon Strip Detector (SSD)

    CERN Document Server

    Arnold, L; Bonnet, D; Boucham, A; Bouvier, S; Castillo, J; Coffin, J P; Drancourt, C; Erazmus, B; Gaudichet, L; Germain, M; Gojak, C; Grabski, J; Guilloux, G; Guedon, M; Hippolyte, B; Janik, M; Kisiel, A; Kuhn, C; Lakehal-Ayat, L; Lefèvre, F; Le Moal, C; Leszczynski, P; Lutz, Jean Robert; Maliszewski, A; Martin, L; Milletto, T; Pawlak, T; Peryt, W; Pluta, J; Przewlocki, M; Radomski, S; Ravel, O; Renard, C; Renault, G; Rigalleau, L M; Roy, C; Roy, D; Suire, C; Szarwas, P; Tarchini, A

    2003-01-01

    The STAR Silicon Strip Detector (SSD) completes the three layers of the Silicon Vertex Tracker (SVT) to make an inner tracking system located inside the Time Projection Chamber (TPC). This additional fourth layer provides two dimensional hit position and energy loss measurements for charged particles, improving the extrapolation of TPC tracks through SVT hits. To match the high multiplicity of central Au+Au collisions at RHIC the double sided silicon strip technology was chosen which makes the SSD a half million channels detector. Dedicated electronics have been designed for both readout and control. Also a novel technique of bonding, the Tape Automated Bonding (TAB), was used to fullfill the large number of bounds to be done. All aspects of the SSD are shortly described here and test performances of produced detection modules as well as simulated results on hit reconstruction are given.

  16. Electron capture by highly stripped ions

    International Nuclear Information System (INIS)

    This review describes theories of electron capture suitable for the description of rearrangement collisions between atomic hydrogen and completely stripped projectiles with charge greater than unity. The region of impact velocity considered lies between 0.05 and 3 au, which is of technological importance in fusion power devices. The semiclassical, impact parameter formalism is discussed and the use of atomic expansions at medium impact velocity is described. Experimental results for both completely and partially stripped projectiles are reviewed. The use of a molecular basis at low energy, and the role of pseudocrossings peculiar to the two centre Coulomb interaction are described. Finally, purely classical techniques, in which the electron wavefunction is represented by an ensemble of Kepler orbits are considered. The review was completed in February 1981. (author)

  17. The extent of the stop coannihilation strip

    Energy Technology Data Exchange (ETDEWEB)

    Ellis, John [King' s College London, Theoretical Particle Physics and Cosmology Group, Department of Physics, London (United Kingdom); CERN, Theory Division, Geneva 23 (Switzerland); Olive, Keith A. [University of Minnesota, School of Physics and Astronomy, Minneapolis, MN (United States); University of Minnesota, William I. Fine Theoretical Physics Institute, School of Physics and Astronomy, Minneapolis, MN (United States); Zheng, Jiaming [University of Minnesota, School of Physics and Astronomy, Minneapolis, MN (United States)

    2014-07-15

    Many supersymmetric models such as the constrained minimal supersymmetric extension of the Standard Model (CMSSM) feature a strip in parameter space where the lightest neutralino χ is identified as the lightest supersymmetric particle, the lighter stop squark t{sub 1} is the next-to-lightest supersymmetric particle (NLSP), and the relic χ cold darkmatter density is brought into the range allowed by astrophysics and cosmology by coannihilation with the lighter stop squark t{sub 1} NLSP. We calculate the stop coannihilation strip in the CMSSM, incorporating Sommerfeld enhancement effects, and we explore the relevant phenomenological constraints and phenomenological signatures. In particular, we show that the t{sub 1} may weigh several TeV, and its lifetime may be in the nanosecond range, features that are more general than the specific CMSSM scenarios that we study in this paper. (orig.)

  18. Operation of a Batch Stripping Distillation Column

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    A stripping batch distillation column is preferred when the amount of the light component in the feed is small and the products are to be recovered at high purity. The operation modes of a batch stripping are believed to be the same as those of a rectifier. However, the control system of a stripper is different. In this paper, we explore three different control methods with Hysys (Hyprotech Ltd. 1997) for a batch stripper. The main difference is the control scheme for reboiler liquid level: (a) controlled by reflux flow; (b) controlled by reboiler heat duty; (c) controlled by bottom product flow. The main characteristics of operating a batch stripper with different control scheme are presented in this paper. Guidelines are provided for the startup of a batch stripper, the effects of somecontrol tuning parameters on the column performance are discussed.

  19. Frequency dependent magnetization of superconductor strip

    Energy Technology Data Exchange (ETDEWEB)

    Thakur, Kailash Prasad [Landcare Research, Palmerston North (New Zealand); Raj, Ashish [Computer Science in Radiology, Weill Medical College, Cornell University, NY (United States); Brandt, Ernst Helmut [Max-Planck-Institut fuer Metallforschung, POB 800665, D-70506 Stuttgart (Germany); Sastry, Pamidi V P S S, E-mail: thakurk@landcareresearch.co.nz, E-mail: asr2004@med.cornell.edu, E-mail: ehb@mf.mpg.de, E-mail: pamidi@caps.fsu.edu [Center for Advanced Power Systems, Florida State University, Tallahassee, FL 32310 (United States)

    2011-04-15

    The frequency dependence of magnetic ac loss of thin superconductor strip subjected to an ac magnetic field perpendicular to the surface of the strip is investigated by incorporating a flux creep model into the critical state model of Brandt and Indenbom. It is found that the reduced ac loss exhibits a maximum value at a frequency f{sub m}, which is a rapidly varying function of the applied ac magnetic field. At low magnetic field, f{sub m} becomes zero, and ac loss decreases with frequency as a power law ({approx}f{sup -2/n}). Whereas at high magnetic field f{sub m} becomes infinite and ac loss increases with frequency, still following the power law ({approx}f{sup 1/n}). The analytical results are substantiated with experimental data and the results of a 2D finite element simulation.

  20. Stage- vs. Channel-strip Metaphor

    DEFF Research Database (Denmark)

    Gelineck, Steven; Korsgaard, Dannie Michael; Büchert, Morten

    2015-01-01

    This study compares the stage metaphor and the channel strip metaphor in terms of performance. Traditionally, music mixing consoles employ a channels strip control metaphor for adjusting parameters such as volume and panning of each track. An alternative control metaphor, the so-called stage...... metaphor lets the user adjust volume and panning by positioning tracks relative to a virtual listening position. In this study test participants are given the task to adjust volume and panning of one channel (in mixes consisting of three channels) in order to replicate a series of simple pre-rendered mixes....... They do this using (1) a small physical mixing controller and (2) using an iPad app, which implements a simple stage metaphor interface. We measure how accurately they are able to replicate mixes in terms of volume and panning and how fast they are at doing so. Results reveal that performance...

  1. PRESUPPOSITIONS AND IMPLICATURES IN COMIC STRIPS

    Directory of Open Access Journals (Sweden)

    Ienneke Indra Dewi

    2008-05-01

    Full Text Available Article aimed to find out the role of presuppositions, implicatures, as well as to see the maxims violated or flouted in the comic strips i.e. to whether there is a miscommunication among the characters in the comic strips. Data were taken from the three comics, those are Peanuts, Andy, and Tintin, and were analysed based on the pattern that the sender made a presupposition before transferring information and the receiver would try to get the implied message. The results show that presuppositions and implicatures are much influenced by the background knowledge. The more the speaker and hearer know each other’s background, the better presuppositions and implicatures they make and finally, the less miscommunication occurred.

  2. Strip-till seeder for sugar beets

    Directory of Open Access Journals (Sweden)

    Peter Schulze Lammers

    2014-06-01

    Full Text Available Strip-till save costs by reducing tillage on the area of sugar beet rows only. The seeding system is characterized by a deep loosening of soil with a tine combined with a share and by following tools generating fine-grained soil as seed bed. In cooperation with the Kverneland company group Soest/Germany a strip tiller combined with precision seeder was designed and tested in field experiments. Tilling and seeding was performed in one path on fields with straw and mustard mulch. Even the plant development was slower as compared to conventional sawn sugar beets the yield was on equivalent level. Further field experiments are planned to attest constant yield, cost and energy efficiency of the seeding system.

  3. Coiling Temperature Control in Hot Strip Mill

    Science.gov (United States)

    Imanari, Hiroyuki; Fujiyama, Hiroaki

    Coiling temperature is one of the most significant factors in products of hot strip mill to determine material properties such as strength, toughness of steel, so it is very important to achieve accurate coiling temperature control (CTC). Usually there are a few pyrometers on the run out table in hot strip mill, therefore temperature model and its adapting system have large influences on the accuracy of CTC. Also unscheduled change of rolling speed has a bad effect to keep coiling temperature as its target. Newly developed CTC system is able to get very accurate coiling temperature against uncertain factors and disturbances by adopting easily identified temperature model, learning method and dynamic set up function. The features of the CTC system are discussed with actual data, and the effectiveness of the system is shown by actual control results.

  4. Development of Silicon Multi-strip Detector

    Institute of Scientific and Technical Information of China (English)

    TanJilian; JinGenming; WangHongwei; YuanXiaohua; DuanLiming; LiSonglin; LuZiwei; XuHushan; NingBaojun; TianDayu; WangWei; ZhangLu

    2003-01-01

    Position sensitive detector is very important for nuclear physics experiment. There several techniques can be used to fabricate position sensitive detector, for example, Si-surface barrier method, diffusion method, ion implantation and planar process etc. Among all the techniques mentioned above planar process is the best one. We have developed batch of position sensitive detector -- silicon multi-strip detector by using planar process.

  5. Transparent Helium in Stripped Envelope Supernovae

    OpenAIRE

    Piro, Anthony L.; Morozova, Viktoriya S.

    2014-01-01

    Using simple arguments based on photometric light curves and velocity evolution, we propose that some stripped envelope supernovae (SNe) show signs that a significant fraction of their helium is effectively transparent. The main pieces of evidence are the relatively low velocities with little velocity evolution, as are expected deep inside an exploding star, along with temperatures that are too low to ionize helium. This means that the helium should not contribute to the shaping of the main S...

  6. Hot Strip Laminar Cooling Control Model

    Institute of Scientific and Technical Information of China (English)

    WANG Jun; WANG Guo-dong; LIU Xiang-hua

    2004-01-01

    The control model of laminar cooling system for hot strip, including air-cooling model, water-cooling model, temperature distribution model along thickness direction, feedforward control model, feedback control model and self-learning model, was introduced. PID arithmetic and Smith predictor controller were applied to feedback control. The sample of model parameter classification was given. The calculation process was shown by flow chart. The model has been proved to be simple, effective and of high precision.

  7. Mastering Interproximal Stripping: With Innovations in Slenderization

    OpenAIRE

    Sharma, Narendra Shriram; Shrivastav, Sunita S; Hazarey, Pushpa V

    2012-01-01

    ABSTRACT Crowding and irregularity remain a consistent problem for children. Management of space problems continues to play an important role in a dental practice. It also represents an area of major interaction between the primary provider and the specialists. Proximal stripping is routinely carried out to avoid extraction in borderline cases where space discrepancy is less and in cases where there is a discrepancy between the mesio- distal width of maxillary and mandibular teeth to satisfy ...

  8. Multitwist optical Möbius strips.

    Science.gov (United States)

    Freund, Isaac

    2010-01-15

    Circularly polarized Gauss-Laguerre GL00 and GL01 laser beams that cross at their waists at a small angle are shown to generate a quasi-paraxial field that contains a line of circular polarization, a C line, surrounded by polarization ellipses whose major and minor axes generate multitwist Möbius strips with twist numbers that increase with the distance from the C point.

  9. Process Simulation Analysis of HF Stripping

    OpenAIRE

    Thaer A. Abdulla

    2013-01-01

       HYSYS process simulator is used for the analysis of existing HF stripping column in LAB plant (Arab Detergent Company, Baiji-Iraq). Simulated column performance and profiles curves are constructed. The variables considered are the thermodynamic model option, bottom temperature, feed temperature, and column profiles for the temperature, vapor flow rate, liquid flow rate and composition. The five thermodynamic models options used (Margules, UNIQUAC, van laar, Antoine, and Zudkevitch-Joffee),...

  10. Self-recovering superconducting strip detectors

    International Nuclear Information System (INIS)

    Using a 1.8 μm wide superconducting strip made of granular tungsten, we have observed self-recovering pulses when the detector is irradiated with a 55Fe 6 keV X-rays source. For low values of the bias current (i.e. Ibb=1.5K) the superconducting state is recovered in 10--50 ns giving voltage pulses across the strip of few hundred μv in amplitude. At high bias currents the detector did not self-recover and a constant counting efficiency has measured at different operating temperatures. There are good indications that this high counting rate can be extended to all the reduced bias currents where the detector is able to reset itself after every switch. The current threshold between collapsing and propagating switches and the time evolution of the voltage pulses can be described using a thermal propagation model developed in previous works. The ability of detectors to automatically recover the superconducting state in a short period of time after sensing a particle is encouraging in the feasibility study of fast superconducting microvertex detectors and also confirm the potential application of superconducting strips as high fast resolution X-rays detectors

  11. Multiple Electron Stripping of Heavy Ion Beams

    International Nuclear Information System (INIS)

    One approach being explored as a route to practical fusion energy uses heavy ion beams focused on an indirect drive target. Such beams will lose electrons while passing through background gas in the target chamber, and therefore it is necessary to assess the rate at which the charge state of the incident beam evolves on the way to the target. Accelerators designed primarily for nuclear physics or high energy physics experiments utilize ion sources that generate highly stripped ions in order to achieve high energies economically. As a result, accelerators capable of producing heavy ion beams of 10 to 40 Mev/amu with charge state 1 currently do not exist. Hence, the stripping cross-sections used to model the performance of heavy ion fusion driver beams have, up to now, been based upon theoretical calculations. We have investigated experimentally the stripping of 3.4 Mev/amu Kr 7+ and Xe +11 in N2; 10.2 MeV/amu Ar +6 in He, N2, Ar and Xe; 19 MeV/amu Ar +8 in He, N2, Ar and Xe; 30 MeV He 1 + in He, N2, Ar and Xe; and 38 MeV/amu N +6 in He, N2, Ar and Xe. The results of these measurements are compared with the theoretical calculations to assess their applicability over a wide range of parameters

  12. High-Rate Capable Floating Strip Micromegas

    CERN Document Server

    Bortfeldt, Jonathan; Biebel, Otmar; Danger, Helge; Flierl, Bernhard; Hertenberger, Ralf; Lösel, Philipp; Moll, Samuel; Parodi, Katia; Rinaldi, Ilaria; Ruschke, Alexander; Zibell, André

    2015-01-01

    We report on the optimization of discharge insensitive floating strip Micromegas (MICRO-MEsh GASeous) detectors, fit for use in high-energy muon spectrometers. The suitability of these detectors for particle tracking is shown in high-background environments and at very high particle fluxes up to 60MHz/cm$^2$. Measurement and simulation of the microscopic discharge behavior have demonstrated the excellent discharge tolerance. A floating strip Micromegas with an active area of 48cm$\\times$50cm with 1920 copper anode strips exhibits in 120GeV pion beams a spatial resolution of 50$\\mu$m at detection efficiencies above 95%. Pulse height, spatial resolution and detection efficiency are homogeneous over the detector. Reconstruction of particle track inclination in a single detector plane is discussed, optimum angular resolutions below $5^\\circ$ are observed. Systematic deviations of this $\\mu$TPC-method are fully understood. The reconstruction capabilities for minimum ionizing muons are investigated in a 6.4cm$\\time...

  13. Novel Catalytic Membrane Reactors

    Energy Technology Data Exchange (ETDEWEB)

    Stuart Nemser, PhD

    2010-10-01

    There are many industrial catalytic organic reversible reactions with amines or alcohols that have water as one of the products. Many of these reactions are homogeneously catalyzed. In all cases removal of water facilitates the reaction and produces more of the desired chemical product. By shifting the reaction to right we produce more chemical product with little or no additional capital investment. Many of these reactions can also relate to bioprocesses. Given the large number of water-organic compound separations achievable and the ability of the Compact Membrane Systems, Inc. (CMS) perfluoro membranes to withstand these harsh operating conditions, this is an ideal demonstration system for the water-of-reaction removal using a membrane reactor. Enhanced reaction synthesis is consistent with the DOE objective to lower the energy intensity of U.S. industry 25% by 2017 in accord with the Energy Policy Act of 2005 and to improve the United States manufacturing competitiveness. The objective of this program is to develop the platform technology for enhancing homogeneous catalytic chemical syntheses.

  14. Solar efficiency of a photo catalytic nonwoven: dye removal applications

    Energy Technology Data Exchange (ETDEWEB)

    Guillard, C.; Disdier, J.; Herrmann, J. M.; Monnet, C.; Dussaud, J.; Malato, S.; Blanco, J.

    2003-07-01

    A specially designed titania photo catalyst was prepared by coating Ahlstrom non-woven paper, used as a flexible photo catalytic support, with Millennium anatase PC50 and PC500 at different mass coatings. Several types of reactants were treated: formetanate (pesticide), Remazole (azo-dye), Amaranth (azo-dye) and Methylene Blue (model dye). Supported catalysts installed in a new solar photo reactor (STEP) were compared to the well-known CPCs working with slurries (0.5 g/L) of the same catalysts. Efficiency of both photo catalytic system was very similar for formetanate removal but not for dye degradation, for which the CPC was more efficient. Solar UV light adsorption by dyes is proposed as the reason for these results. (Author) 12 refs.

  15. KINETIC ANALYSIS OF THE CATALYTIC DECOMPOSITION OF HYDRAZINE

    Directory of Open Access Journals (Sweden)

    J.E. de MEDEIROS

    1998-06-01

    Full Text Available The bond-order conservation method was used to study the catalytic decomposition of N2H4. Variation in the activation energy, E, of the most relevant steps was calculated as a function of the enthalpy of adsorption of N, QN, between 0 and 1250 kJmol-1. Results suggest that below QN = 520 kJmol-1 the catalytic decomposition of N2H4 produces mostly N2 and H2. Above QN = 520 kJmol-1, NH3 and N2 are the main products. Near QN = 520 kJmol-1 N2, H2 and NH3 are obtained, in agreement with experimental results on different metals.

  16. Synthesis, characterization and catalytic activity of chromium substituted cobalt ferrospinels

    International Nuclear Information System (INIS)

    Chromium substituted cobalt ferrospinels were prepared by soft citrate gel method. The synthesized material was characterized by various physico-chemical methods. All the samples showed a single-phase cubic structure. Lattice constant varies from 8.389 to 8.323 A. Transmission electron microscopic study indicated the nanostructure of the catalysts while homogenous grain distribution was presented by scanning electron microscopic studies. The catalytic activity of the samples was investigated towards acetylation of phenols. The presence of active centers on the surface of the material was confirmed through pyridine adsorption studies. The surface acidity of the catalyst is responsible for better catalytic performance. The material was found to serve as a promising catalyst for acylation and benzoylation of phenols under solvent free condition. These catalysts are ∼100% selective towards o-acylation of phenols, a promising reaction for perfumery intermediates. The catalysts were seen to be reusable without any further treatment. Catalytic activities of cobalt, chromium and iron oxides were also investigated for comparison. The cobalt ferrospinel was found to have better catalytic activity as compared to the Cr-substituted ferrospinels and the pure oxides. Cobalt ferrite catalyst offers high yields in a short reaction time under solvent-free conditions.

  17. Synthesis, characterization and catalytic activity of chromium substituted cobalt ferrospinels

    Energy Technology Data Exchange (ETDEWEB)

    Hankare, P.P., E-mail: p_hankarep@rediffmail.com [Department of Chemistry, Shivaji University, Kolhapur, Maharashtra, 416 004 (India); Sankpal, U.B., E-mail: sankpalumesh@gmail.com [Department of Chemistry, Shivaji University, Kolhapur, Maharashtra, 416 004 (India); Patil, R.P. [Department of Chemistry, Shivaji University, Kolhapur, Maharashtra, 416 004 (India); Lokhande, P.D. [Department of Chemistry, University of Pune, Pune, Maharashtra, 411 007 (India); Sasikala, R. [Chemistry Division, Bhabha Atomic Research Centre, Trombay, Mumbai 400 085 (India)

    2011-02-15

    Chromium substituted cobalt ferrospinels were prepared by soft citrate gel method. The synthesized material was characterized by various physico-chemical methods. All the samples showed a single-phase cubic structure. Lattice constant varies from 8.389 to 8.323 A. Transmission electron microscopic study indicated the nanostructure of the catalysts while homogenous grain distribution was presented by scanning electron microscopic studies. The catalytic activity of the samples was investigated towards acetylation of phenols. The presence of active centers on the surface of the material was confirmed through pyridine adsorption studies. The surface acidity of the catalyst is responsible for better catalytic performance. The material was found to serve as a promising catalyst for acylation and benzoylation of phenols under solvent free condition. These catalysts are {approx}100% selective towards o-acylation of phenols, a promising reaction for perfumery intermediates. The catalysts were seen to be reusable without any further treatment. Catalytic activities of cobalt, chromium and iron oxides were also investigated for comparison. The cobalt ferrospinel was found to have better catalytic activity as compared to the Cr-substituted ferrospinels and the pure oxides. Cobalt ferrite catalyst offers high yields in a short reaction time under solvent-free conditions.

  18. Single-species reactions on a random catalytic chain

    Energy Technology Data Exchange (ETDEWEB)

    Oshanin, G [Laboratoire de Physique Theorique des Liquides, Universite Paris 6, 4 Place Jussieu, 75252 Paris (France); Burlatsky, S F [United Technologies Research Center, United Technologies Corporation, 411 Silver Lane, 129-21 East Hartford, CT (United States)

    2002-11-29

    We present an exact solution for a catalytically activated annihilation A+A {yields} 0 reaction taking place on a one-dimensional chain in which some segments (placed at random, with mean concentration p) possess special, catalytic properties. An annihilation reaction takes place as soon as any two A particles land from the reservoir onto two vacant sites at the extremities of the catalytic segment, or when any A particle lands onto a vacant site on a catalytic segment while the site at the other extremity of this segment is already occupied by another A particle. We find that the disorder-average pressure P{sup (quen)} per site of such a chain is given by P{sup (quen)} P{sup (Lan)} + {beta}{sup -1}F, where P{sup (Lan)}={beta}{sup -1} ln(1+z) is the Langmuir adsorption pressure, (z being the activity and {beta}{sup -1} the temperature), while {beta}{sup -1}F is the reaction-induced contribution, which can be expressed, under appropriate change of notation, as the Lyapunov exponent for the product of 2x2 random matrices, obtained exactly by Derrida and Hilhorst (1983 J. Phys. A: Math. Gen. 16 2641). Explicit asymptotic formulae for the particle mean density and the compressibility are also presented. (letter to the editor)

  19. Hydrotalcite-supported Pd-Cu catalyst for nitrate adsorption and reduction from water

    Institute of Scientific and Technical Information of China (English)

    WANG Ying; QU Jiuhui; LIU Huijuan; WU Rongcheng

    2006-01-01

    Hydrotalcite-supported Pd-Cu catalyst for nitrate adsorption and catalytic reduction from water is prepared by co-impregnation method and characterized by surface area (BET), X-ray diffraction (XRD), scanning electron microscope (SEM), transmission electron microscope (TEM) and X-ray photoelectron spectrum (XPS). The performance of adsorption and hydrogenation of nitrate was evaluated and compared with Al2O3, TiO2, and HZSM-supported Pd-Cu catalysts. The experimental results demonstrated that hydrotalcite-supported Pd-Cu catalyst exhibited a high surface area (185.3 m2/g) and mesopore structure (average pore diameter of 52.2 (A)). The active metal clusters were homogeneously dispersed on the support, and the size of the most was less than 10 nm. Excellent adsorption for nitrate resulted from that nitrate ions were forced to enter the interlayer space when the calcined hydrotalcite regenerated layer structure in nitrate solution. The adsorption isotherm could be well described by the Langmuir model. The comparison between the adsorption and catalytic hydrogenation for nitrate using hydrogen indicated that nitrate reduction on hydrotalcite-supported Pd-Cu catalysts was a consecutive and dynamic adsorption and catalytic hydrogenation process. Compared with the Al2O3, TiO2, and HZSM- supported catalysts, hydrotalcite-supported Pd-Cu catalyst possessed higher catalytic activity and selectivity. The analysis on the dissolving of metals in the solution demonstrated that there was hydrolyzation on the surface of the hydrotalcite-supported Pd-Cu catalyst. However, the concentrations of dissolved metals in the solution were lower than the standard executed in China. The activity of the hydrotalcite-supported Pd-Cu catalyst for nitrate reduction kept steady after repeated use.

  20. Carbonaceous materials for adsorptive refrigerators

    Science.gov (United States)

    Buczek, B.; Wolak, E.

    2012-06-01

    Carbon monoliths prepared from hard coal precursors were obtained. The porous structure of the monoliths was evaluated on the basis of nitrogen adsorption — desorption equilibrium data. The investigated monoliths have a well-developed microporous structure with significant specific surface area (S BET ). Equilibrium studies of methanol vapour adsorption were used to characterize the methanol adsorptive capacity that was determined using a volumetric method. The heat of wetting by methanol was determined in order to estimate the energetic effects of the adsorption process. The results of the investigations show that all monoliths exhibit high adsorption capacity and high heat of wetting with methanol.

  1. Catalytic converter applications for two stroke, spark-ignited marine engines

    Energy Technology Data Exchange (ETDEWEB)

    Fujimoto, Hiroaki; Isogawa, Atsushi; Matsumoto, Naoto

    1995-12-31

    When catalytic converters are used for cleansing of exhaust gas from two-stroke marine engines, new issues must be brought up in combination with prior technology. Therefore, a study was made of V6, 2600cc engine having a large volume of hydrocarbon emissions with respect to three issues: (1) To what degree seawater effects catalytic converter performance and possible countermeasures; (2) Effects attained on cleansing level and catalyst temperature; (3) Finding abatement levels for catalyst deterioration and exhaust emission output in the marine mode. It was found that physical adsorption was a significant factor in catalytic degradation resulting from direct contact with seawater. The cleansing levels obtained when a marine engine is equipped with a catalyst converter were found by clarifying the extent of effects of catalyst volume, performance and temperature. The reduction obtained in exhaust emission allowing for a deterioration factor, is shown in a catalytic converter heated to the maximum temperature of 960 C.

  2. High activity in catalytic cracking of large molecules over micro-mesoporous silicoaluminophosphate with controlled morphology

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    A novel micro-mesoporous silicoaluminophosphate(MUS-5) with controlled morphology has been first synthesized in a two-step route.The physical properties of the silicoaluminophosphate were characterized using XRD,SEM,TEM,nitrogen adsorption-desorption and NH3-TPD techniques.When the pH value of the solution system was varied in the range from 2.0 to 5.0,three different morphologies of silicoaluminophosphate including chain-like,flower-like and barrel-like morphology were obtained.Catalytic tests showed that the silicoaluminophosphate exhibited higher catalytic activity compared with the conventional microporous SAPO-5 under the same conditions for catalytic cracking of 1,3,5-triisopropylbenzene heavy aromatics.The remarkable catalytic reactivity was mainly attributed to the presence of the hierarchical porosity in the silicoaluminophosphate catalyst.

  3. Differential pulse anodic stripping voltammetry for detection of As (III) by Chitosan-Fe(OH)3 modified glassy carbon electrode: A new approach towards speciation of arsenic.

    Science.gov (United States)

    Saha, Suparna; Sarkar, Priyabrata

    2016-09-01

    An efficient electrochemical sensor for As(III) was developed based on adsorption of arsenic on a specially modified electrodes at some applied potential and subsequent i) stripping at a fixed potential by anodic stripping voltammetry ii) analysis by generating surface plasmon resonance (SPR). The working glassy carbon electrode was modified by Chitosan-Fe(OH)3 composite and a reducing agent L-cysteine. The composite enhanced adsorption of As(III) and subsequent reduction to As(O) moieties and measurement by anodic stripping. The surface property of modified electrode was characterized by SEM, AFM, FTIR, XPS and electrochemistry was analyzed by impedance spectroscopy (EIS). Surface Plasmon resonance (SPR) was also employed to investigate the As(III) binding capability of polymer matrix. Several optimum voltammetric parameters e.g supporting electrolyte; 0.1M acetate buffer (pH 5.2) deposition potential, -0.9V; deposition time, 100s were established for anodic stripping voltammetry (ASV). A linear correlation was obtained in the range of 2-100ppb for ASV (R(2) 0.974) with limit of detection 0.072ppb. A variety of common coexistent ions such as Mn, Zn, Pb, Cu, Cd in water samples showed no interferences on the As (III) determination. The method was applied successfully to real samples collected from arsenic affected areas of West Bengal, India. PMID:27343601

  4. Nonmetallic inclusions in SUS304 strip produced by twin-roll strip casting

    Institute of Scientific and Technical Information of China (English)

    Fuxiang Huang; Jiongming Zhang; Xinhua Wang; Yuan Fang; Yan Yu

    2008-01-01

    The shape, type, content, and dimension of nonmetallic inclusions in SUS304 strip produced by twin-roll strip casting were studied using scanning electron microscopy (SEM). The results show that the inclusions are mainly spherical Al2O3 and com- plex oxides composed of MnO, Al2O3., and SiO2. The percentage of fine oxides smaller than 3 μm reaches up to 51.8%. The theoreti- cal calculations show that fine oxides have precipitated during solidification. Therefore, it is concluded that during twin-roll strip casting, because of high cooling rate, the size of inclusions precipitated during solidification decreases, and the amount increases.

  5. Effect of boron on hot strips of low carbon steel produced by compact strip production

    Institute of Scientific and Technical Information of China (English)

    Hao Yu; Yonglin Kang

    2008-01-01

    The effect of boron on hot strips of low carbon steel produced by compact strip production (CSP) to reduce the strength to a certain degree was investigated, which is quite different from that of high-strength low alloy steel. The mechanical properties and microstructural evolution of the hot strip were studied using optical microscopy and tensile tests. By means of an electrolytic disso- lution technique and Thermo-Cal calculation, the precipitates containing boron were analyzed and detected. From the electron back- scattered diffraction analysis, it can be deciphered whether the microstructure has recrystallized or not. Furthermore, the effect of boron segregation on the recrystallization or non-recrystallization conditions can be distinguished. The segregation behavior of boron was investigated in boron-containing steel. The nonequilibrium segregation of boron during processing was discussed on the basis of the forming complexes with vacancies that migrate to the boundaries prior to annihilation, which was confirmed by the subsequent cold rolling with annealing experiments.

  6. HYDROGEN TRANSFER IN CATALYTIC CRACKING

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    Hydrogen transfer is an important secondary reaction of catalytic cracking reactions, which affects product yield distribution and product quality. It is an exothermic reaction with low activation energy around 43.3 kJ/mol. Catalyst properties and operation parameters in catalytic cracking greatly influence the hydrogen transfer reaction. Satisfactory results are expected through careful selection of proper catalysts and operation conditions.

  7. Bifunctional catalytic electrode

    Science.gov (United States)

    Cisar, Alan (Inventor); Murphy, Oliver J. (Inventor); Clarke, Eric (Inventor)

    2005-01-01

    The present invention relates to an oxygen electrode for a unitized regenerative hydrogen-oxygen fuel cell and the unitized regenerative fuel cell having the oxygen electrode. The oxygen electrode contains components electrocatalytically active for the evolution of oxygen from water and the reduction of oxygen to water, and has a structure that supports the flow of both water and gases between the catalytically active surface and a flow field or electrode chamber for bulk flow of the fluids. The electrode has an electrocatalyst layer and a diffusion backing layer interspersed with hydrophilic and hydrophobic regions. The diffusion backing layer consists of a metal core having gas diffusion structures bonded to the metal core.

  8. Catalytic quantum error correction

    CERN Document Server

    Brun, T; Hsieh, M H; Brun, Todd; Devetak, Igor; Hsieh, Min-Hsiu

    2006-01-01

    We develop the theory of entanglement-assisted quantum error correcting (EAQEC) codes, a generalization of the stabilizer formalism to the setting in which the sender and receiver have access to pre-shared entanglement. Conventional stabilizer codes are equivalent to dual-containing symplectic codes. In contrast, EAQEC codes do not require the dual-containing condition, which greatly simplifies their construction. We show how any quaternary classical code can be made into a EAQEC code. In particular, efficient modern codes, like LDPC codes, which attain the Shannon capacity, can be made into EAQEC codes attaining the hashing bound. In a quantum computation setting, EAQEC codes give rise to catalytic quantum codes which maintain a region of inherited noiseless qubits. We also give an alternative construction of EAQEC codes by making classical entanglement assisted codes coherent.

  9. Entropically favored adsorption of cellulosic molecules onto carbon materials through hydrophobic functionalities.

    Science.gov (United States)

    Yabushita, Mizuho; Kobayashi, Hirokazu; Hasegawa, Jun-Ya; Hara, Kenji; Fukuoka, Atsushi

    2014-05-01

    Carbon-based materials have attracted interest as high-performance catalysts for the aqueous-phase conversion of cellulose. The adsorption of β-glucans plays a crucial role in the catalytic performance of carbons, although the primary driving force and details of the adsorption process remain unclear. This study demonstrates that adsorption occurs at hydrophobic sites on the carbon surface and that hydrophilic groups are not involved. Analysis of adsorption temperature dependence also reveals that the entropy change associated with adsorption is positive. Our results indicate that adsorption occurs by entropically driven hydrophobic interactions in addition to CH-π hydrogen bonding. These same CH-π hydrogen bonds are also confirmed by DFT calculations. The adsorption of β-glucans on carbons is significantly stronger than the affinity between β-glucans. The adsorption equilibrium constants of β-glucans on carbons increase exponentially with increasing degrees of polymerization, which supports the theory of strong interactions between the carbon and the long β-glucans found in cellulose.

  10. Catalytic Combustion of Gasified Waste

    Energy Technology Data Exchange (ETDEWEB)

    Kusar, Henrik

    2003-09-01

    This thesis concerns catalytic combustion for gas turbine application using a low heating-value (LHV) gas, derived from gasified waste. The main research in catalytic combustion focuses on methane as fuel, but an increasing interest is directed towards catalytic combustion of LHV fuels. This thesis shows that it is possible to catalytically combust a LHV gas and to oxidize fuel-bound nitrogen (NH{sub 3}) directly into N{sub 2} without forming NO{sub x} The first part of the thesis gives a background to the system. It defines waste, shortly describes gasification and more thoroughly catalytic combustion. The second part of the present thesis, paper I, concerns the development and testing of potential catalysts for catalytic combustion of LHV gases. The objective of this work was to investigate the possibility to use a stable metal oxide instead of noble metals as ignition catalyst and at the same time reduce the formation of NO{sub x} In paper II pilot-scale tests were carried out to prove the potential of catalytic combustion using real gasified waste and to compare with the results obtained in laboratory scale using a synthetic gas simulating gasified waste. In paper III, selective catalytic oxidation for decreasing the NO{sub x} formation from fuel-bound nitrogen was examined using two different approaches: fuel-lean and fuel-rich conditions. Finally, the last part of the thesis deals with deactivation of catalysts. The various deactivation processes which may affect high-temperature catalytic combustion are reviewed in paper IV. In paper V the poisoning effect of low amounts of sulfur was studied; various metal oxides as well as supported palladium and platinum catalysts were used as catalysts for combustion of a synthetic gas. In conclusion, with the results obtained in this thesis it would be possible to compose a working catalytic system for gas turbine application using a LHV gas.

  11. Performance of an activated carbon made from waste palm shell in simultaneous adsorption of SO_x and NO_x of flue gas at low temperature

    Institute of Scientific and Technical Information of China (English)

    S.; SUMATHI; S.; BHATIA; K.T.; LEE; A.; R.; MOHAMED

    2009-01-01

    This study examined the individual and simultaneous adsorption of SOx (SO2) and NOx (NO-NO2) on activated carbon prepared from waste palm shell. The adsorption process was examined in a fixed bed reactor at low temperatures (100―300℃). For individual adsorption without any catalytic activation, SOx showed good adsorption whereas NOx was very much poor. In the simultaneous adsorption of SOx and NOx, SOx showed greater adsorption affinity than NOx. For palm shell activated carbon (PSAC) impregnated with metal catalyst (Ni and Ce) the concentration adsorbed profile showed that the amount of SOx adsorbed decreased regularly, while the amount of the adsorbed NOx increased irregularly. The properties of the pure and impregnated PSAC were analyzed by BET, SEM and EDX. These investiga-tions indicated that PSAC impregnated with metal catalyst is the determining factor in the adsorption of SOx and NOx simultaneously.

  12. Performance of an activated carbon made from waste palm shell in simultaneous adsorption of SOx and NOx of flue gas at low temperature

    Institute of Scientific and Technical Information of China (English)

    S.SUMATHI; S.BHATIA; K.T.LEE; A.R.MOHAMED

    2009-01-01

    This study examined the individual and simultaneous adsorption of SOx (SO2) and NOx (NO-NO2) on activated carbon prepared from waste palm shell. The adsorption process was examined in a fixed bed reactor at low temperatures (100-300℃). For individual adsorption without any catalytic activation, SOx showed good adsorption whereas NOx was very much poor. In the simultaneous adsorption of SOx and NOx, SOx showed greater adsorption affinity than NOx. For palm shell activated carbon (PSAC) im-pregnated with metal catalyst (Ni and Ce) the concentration adsorbed profile showed that the amount of SOx adsorbed decreased regularly, while the amount of the adsorbed NOx increased irregularly. The properties of the pure and impregnated PSAC were analyzed by BET, SEM and EDX. These investiga-tions indicated that PSAC impregnated with metal catalyst is the determining factor in the adsorption of SOxand NOx simultaneously.

  13. Catalytic hot gas cleaning of gasification gas

    Energy Technology Data Exchange (ETDEWEB)

    Simell, P. [VTT Energy, Espoo (Finland). Energy Production Technologies

    1997-12-31

    The aim of this work was to study the catalytic cleaning of gasification gas from tars and ammonia. In addition, factors influencing catalytic activity in industrial applications were studied, as well as the effects of different operation conditions and limits. Also the catalytic reactions of tar and ammonia with gasification gas components were studied. The activities of different catalyst materials were measured with laboratory-scale reactors fed by slip streams taken from updraft and fluid bed gasifiers. Carbonate rocks and nickel catalysts proved to be active tar decomposing catalysts. Ammonia decomposition was in turn facilitated by nickel catalysts and iron materials like iron sinter and iron dolomite. Temperatures over 850 deg C were required at 2000{sup -1} space velocity at ambient pressure to achieve almost complete conversions. During catalytic reactions H{sub 2} and CO were formed and H{sub 2}O was consumed in addition to decomposing hydrocarbons and ammonia. Equilibrium gas composition was almost achieved with nickel catalysts at 900 deg C. No deactivation by H{sub 2}S or carbon took place in these conditions. Catalyst blocking by particulates was avoided by using a monolith type of catalyst. The apparent first order kinetic parameters were determined for the most active materials. The activities of dolomite, nickel catalyst and reference materials were measured in different gas atmospheres using laboratory apparatus. This consisted of nitrogen carrier, toluene as tar model compound, ammonia and one of the components H{sub 2}, H{sub 2}O, CO, CO{sub 2}, CO{sub 2}+H{sub 2}O or CO+CO{sub 2}. Also synthetic gasification gas was used. With the dolomite and nickel catalyst the highest toluene decomposition rates were measured with CO{sub 2} and H{sub 2}O. In gasification gas, however, the rate was retarded due to inhibition by reaction products (CO, H{sub 2}, CO{sub 2}). Tar decomposition over dolomite was modelled by benzene reactions with CO{sub 2}, H

  14. Unsteady catalytic processes and sorption-catalytic technologies

    International Nuclear Information System (INIS)

    Catalytic processes that occur under conditions of the targeted unsteady state of the catalyst are considered. The highest efficiency of catalytic processes was found to be ensured by a controlled combination of thermal non-stationarity and unsteady composition of the catalyst surface. The processes based on this principle are analysed, in particular, catalytic selective reduction of nitrogen oxides, deep oxidation of volatile organic impurities, production of sulfur by the Claus process and by hydrogen sulfide decomposition, oxidation of sulfur dioxide, methane steam reforming and anaerobic combustion, selective oxidation of hydrocarbons, etc.

  15. Unsteady catalytic processes and sorption-catalytic technologies

    Energy Technology Data Exchange (ETDEWEB)

    Zagoruiko, A N [G.K. Boreskov Institute of Catalysis, Siberian Branch of the Russian Academy of Sciences, Novosibirsk (Russian Federation)

    2007-07-31

    Catalytic processes that occur under conditions of the targeted unsteady state of the catalyst are considered. The highest efficiency of catalytic processes was found to be ensured by a controlled combination of thermal non-stationarity and unsteady composition of the catalyst surface. The processes based on this principle are analysed, in particular, catalytic selective reduction of nitrogen oxides, deep oxidation of volatile organic impurities, production of sulfur by the Claus process and by hydrogen sulfide decomposition, oxidation of sulfur dioxide, methane steam reforming and anaerobic combustion, selective oxidation of hydrocarbons, etc.

  16. Uranium stripping from tributyl phosphate by urea solutions

    Science.gov (United States)

    Skripchenko, S. Yu.; Titova, S. M.; Smirnov, A. L.; Rychkov, V. N.

    2016-09-01

    The process of uranium stripping from tri-n-butyl phosphate in kerosene by urea solutions was investigated at the volume ratio of the organic and aqueous phases of (1-10) : 1 in the temperature range of 20-60 °C. The stripping of uranium from a loaded organic phase increased with increasing urea content in the solution and with increasing temperature. Maximum recovery of uranium from tributyl phosphate was obtained using a solution that contained 8-12 mol/l of urea. The application of a urea solution for uranium stripping resulted in the strip product solution containing 200-240 g/L of uranium. The process of uranium stripping by dilute nitric acid was also investigated. Results of uranium stripping by the two methods are compared and discussed.

  17. Development of a cathode strip chamber for minimum ionizing particles

    International Nuclear Information System (INIS)

    A cathode strip chamber (CSC) capable of measuring position information for minimum ionizing particles (MIPS) has been developed. The chamber operates in the proportional or limited proportional region, where the avalanche on the anode wire is localised to a small region around the anode wire. The position of the avalanche can be obtained by the pulse heights induced on the cathode strips which run perpendicular to direction of the anode wire. The pulse height induced on the cathode strips is proportional directly to the strip width and inversely to the distance between the strip centre to the avalanche location. Thus by measuring the pulse heights on at least three cathode strips for every event, one can reconstruct the centroid that would give the location of the avalanche on the anode

  18. A consistent reaction scheme for the selective catalytic reduction of nitrogen oxides with ammonia

    DEFF Research Database (Denmark)

    Janssens, Ton V.W.; Falsig, Hanne; Lundegaard, Lars Fahl;

    2015-01-01

    For the first time, the standard and fast selective catalytic reduction of NO by NH3 are described in a complete catalytic cycle, that is able to produce the correct stoichiometry, while only allowing adsorption and desorption of stable molecules. The standard SCR reaction is a coupling of the ac......For the first time, the standard and fast selective catalytic reduction of NO by NH3 are described in a complete catalytic cycle, that is able to produce the correct stoichiometry, while only allowing adsorption and desorption of stable molecules. The standard SCR reaction is a coupling...... of the activation of NO by O2 with the fast SCR reaction, enabled by the release of NO2. According to the scheme, the SCR reaction can be divided in an oxidation of the catalyst by NO + O2 and a reduction by NO + NH3; these steps together constitute a complete catalytic cycle. Furthermore both NO and NH3...... spectroscopy (FTIR). A consequence of the reaction scheme is that all intermediates in fast SCR are also part of the standard SCR cycle. The calculated activation energy by density functional theory (DFT) indicates that the oxidation of an NO molecule by O2 to a bidentate nitrate ligand is rate determining...

  19. Intelligent Control on Hot Strip Coiling Temperature

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    A new intelligent control scheme for hot strip coiling temperature is presented. In this scheme, the prediction model of finishing temperature and the presetting model of main cooling zone are establish based on BP neural network, the feed-forward open-loop control model of main cooling zone is constructed based on T-S fuzzy neural network, a new improved structure of T-S fuzzy neural network is developed, and the feedback close-loop control model of precision cooling zone is obtained based on fuzzy control. The effectiveness of the proposed scheme has been demonstrated by computer simulation with a satisfactory result.

  20. Power and control in gay strip clubs.

    Science.gov (United States)

    DeMarco, Joseph R G

    2007-01-01

    The gay strip club is a place in which more than displays of male beauty take place. The mix of customers, performers, liquor, and nudity results in fascinating dynamics. Of interest in this article are the power relationships and issues of control played out both among and between strippers and customers. Based on extensive participant observation conducted in eight cities and numerous bars/clubs and including more than 150 in-depth interviews, this article concerns just one aspect of the world of male strippers who perform for men. PMID:18019071

  1. Fluorocarbon stripping of low beta heavy ions

    International Nuclear Information System (INIS)

    Equilibrium charge state distributions were measured for Kr, Xe, Ho and Pb ions at energies from 25 to 160 keV/amu passing through a high molecular weight fluorocarbon vapor, as well as air and carbon foil strippers. Measured charge state distributions are given which show that the fluorocarbon distributions are intermediate between those of air and foil strippers, becoming closer to foil values as velocity is decreased. At all energies substantial asymmetry in the fluorocarbon distributions towards higher charge states were observed. These favorable distributions, coupled with very high beam handling capability, low maintenance and indefinite lifetime clearly indicate the value of fluorocarbon stripping for many accelerator applications. 5 refs

  2. Collision physics with highly stripped slow ions

    International Nuclear Information System (INIS)

    A review about recent studies with highly stripped heavy ions is given. Its scope is limited to mainly inner shell processes and slow collisions compared to the Bohr velocity of electrons in these shells. The processes discussed are: population of excited states by electron capture in asymmetric collision systems; electron capture and excitation in symmetric collisions with an emphasis on the impact parameter dependence of K- to L-shell and K- to K-shell vacancy transfer; the interference structure in the quasimolecular X-rays from slow hydrogen-like ion-atom collisions which is used for direct spectroscopy of quasimolecular energies. (Auth.)

  3. Time domain non linear strip theory for ship motions

    OpenAIRE

    Fan, Y.T.; Wilson, P. A.

    2004-01-01

    A new implementation of strip theory is proposed based on the strip theory by Salvesen, et al. [1] and early work by Westlake and Wilson [2]. Compared with traditional strip theory, the main difference is that the calculation is carried out in the time domain. This makes it possible to cope with relatively large-amplitude motions and non-constant forward speed problems. At each time step, the exact underwater sections are extracted; the velocity potential is required to satisfyt...

  4. Adsorption and coupling of 4-aminophenol on Pt(111) surfaces

    Science.gov (United States)

    Otero-Irurueta, G.; Martínez, J. I.; Bueno, R. A.; Palomares, F. J.; Salavagione, H. J.; Singh, M. K.; Méndez, J.; Ellis, G. J.; López, M. F.; Martín-Gago, J. A.

    2016-04-01

    We have deposited 4-aminophenol on Pt(111) surfaces in ultra-high vacuum and studied the strength of its adsorption through a combination of STM, LEED, XPS and ab initio calculations. Although an ordered (2√3 × 2√3)R30° phase appears, we have observed that molecule-substrate interaction dominates the adsorption geometry and properties of the system. At RT the high catalytic activity of Pt induces aminophenol to lose the H atom from the hydroxyl group, and a proportion of the molecules lose the complete hydroxyl group. After annealing above 420 K, all deposited aminophenol molecules have lost the OH moiety and some hydrogen atoms from the amino groups. At this temperature, short single-molecule oligomer chains can be observed. These chains are the product of a new reaction that proceeds via the coupling of radical species that is favored by surface diffusion.

  5. Strip type radiation detector and method of making same

    International Nuclear Information System (INIS)

    An improved strip detector and a method for making such a detector are described. A high resistivity N conduction semiconductor body has electrode strips formed thereon by diffusion. The strips are formed so as to be covered by an oxide layer at the surface point of the PN junction and in which the opposite side of the semiconductor body then has a substantial amount of material etched away to form a thin semiconductor upon which strip electrodes which are perpendicular to the electrodes on the first side are then placed

  6. Strip type radiation detector and method of making same

    International Nuclear Information System (INIS)

    An improved strip detector and a method for making such a detector in which a high resistivity N conduction semiconductor body has electrode strips formed thereon by diffusion is described. The strips are formed so as to be covered by an oxide layer at the surface point of the PN junction and in which the opposite side of the semiconductor body then has a substantial amount of material etched away to form a thin semiconductor upon which strip electrodes which are perpendicular to the electrodes on the first side are then placed

  7. Three-Dimensional Model for Strip Hot Rolling

    Institute of Scientific and Technical Information of China (English)

    ZHANG Guo-min; XIAO Hong; WANG Chun-hua

    2006-01-01

    A three-dimensional model for strip hot rolling was developed, in which the plastic deformation of strip, the thermal crown of rolls, roll deflection and flattening were calculated by rigid-plastic finite element method, finite difference method, influential function method and elastic finite element method respectively. The roll wear was taken into consideration. The model can provide detailed information such as rolling pressure distribution, contact pressure distribution between backup rolls and work rolls, deflection and flattening of work rolls, lateral distribution of strip thickness, and lateral distribution of front and back tensions. The finish rolling on a 1 450 mm hot strip mill was simulated.

  8. Catalytic production of biodiesel

    Energy Technology Data Exchange (ETDEWEB)

    Theilgaard Madsen, A.

    2011-07-01

    The focus of this thesis is the catalytic production of diesel from biomass, especially emphasising catalytic conversion of waste vegetable oils and fats. In chapter 1 an introduction to biofuels and a review on different catalytic methods for diesel production from biomass is given. Two of these methods have been used industrially for a number of years already, namely the transesterification (and esterification) of oils and fats with methanol to form fatty acid methyl esters (FAME), and the hydrodeoxygenation (HDO) of fats and oils to form straight-chain alkanes. Other possible routes to diesel include upgrading and deoxygenation of pyrolysis oils or aqueous sludge wastes, condensations and reductions of sugars in aqueous phase (aqueous-phase reforming, APR) for monofunctional hydrocarbons, and gasification of any type of biomass followed by Fischer-Tropsch-synthesis for alkane biofuels. These methods have not yet been industrialised, but may be more promising due to the larger abundance of their potential feedstocks, especially waste feedstocks. Chapter 2 deals with formation of FAME from waste fats and oils. A range of acidic catalysts were tested in a model fat mixture of methanol, lauric acid and trioctanoin. Sulphonic acid-functionalised ionic liquids showed extremely fast convertion of lauric acid to methyl laurate, and trioctanoate was converted to methyl octanoate within 24 h. A catalyst based on a sulphonated carbon-matrix made by pyrolysing (or carbonising) carbohydrates, so-called sulphonated pyrolysed sucrose (SPS), was optimised further. No systematic dependency on pyrolysis and sulphonation conditions could be obtained, however, with respect to esterification activity, but high activity was obtained in the model fat mixture. SPS impregnated on opel-cell Al{sub 2}O{sub 3} and microporous SiO{sub 2} (ISPS) was much less active in the esterification than the original SPS powder due to low loading and thereby low number of strongly acidic sites on the

  9. Effect of Alkali Treatment on the Structure and Catalytic Properties of ZSM-5 Zeolite

    Institute of Scientific and Technical Information of China (English)

    Zi Yun LI; Xin SUN; Qiang XIAO; Shou He XIANG

    2005-01-01

    Catalytic properties of ZSM-5 zeolite samples pretreated with NaOH solution have been investigated. The samples are characterized by XRD, SEM, chemical analysis, and N2 adsorption.The results indicate that mesopores are created in ZSM-5 crystals under alkali treatment without change the microporous structure and acidic strength of the zeolite, but the crystallinity is greatly decreased under severe treatment. IR indicates that the concentration of silanol is greatly enriched by alkali treatment. The etherification activities of ZSM-5 zeolites are greatly increased by alkali-treatment. The noticeably improved catalytic activity of treated samples is ascribed to the formation of mesopores and greatly enriched silanol group.

  10. Stripped elliptical galaxies as probes of ICM physics: I. Tails, wakes, and flow patterns in and around stripped ellipticals

    CERN Document Server

    Roediger, E; Nulsen, P E J; Forman, W R; Machacek, M; Randall, S; Jones, C; Churazov, E; Kokotanekova, R

    2014-01-01

    (abridged) Elliptical cluster galaxies are successively stripped of their gaseous atmospheres due to their motion through the ICM. The stripped galactic gas forms a 'tail' in the galaxy's wake. Deep X-ray observations reveal the fine-structure of the gas tail and of the interface between galactic gas and ICM. This fine-structure depends on dynamic conditions (galaxy potential, initial gas contents, orbit in the host cluster), stripping stage (early infall, pre-/post-pericenter passage), and on the still ill-constrained ICM plasma properties (thermal conductivity, viscosity, magnetic field structure). In a series of papers, we aim at disentangling dynamic and plasma effects in order to use observed stripped ellipticals as probes of the ICM plasma properties. This first paper determines flow phases and flow patterns of successive gas stripping by means of hydrodynamical simulations. During quasi-steady stripping, the flow of ICM around the remnant atmosphere is similar to the flow around solid bodies, including...

  11. Copper adsorption in tropical oxisols

    Directory of Open Access Journals (Sweden)

    Silveira Maria Lucia Azevedo

    2003-01-01

    Full Text Available Cu adsorption, at concentrations between 0 to 800 mg L-1, was evaluated in surface and subsurface samples of three Brazilian soils: a heavy clayey-textured Rhodic Hapludalf (RH, a heavy clayey-textured Anionic ''Rhodic'' Acrudox (RA and a medium-textured Anionic ''Xanthic'' Acrudox (XA. After adsorption, two consecutive extractions were performed to the samples which received 100 mg L-1 copper. Surface samples adsorbed higher amounts of Cu than the subsurface, and exhibited lower Cu removed after the extractions, reinforcing the influence of the organic matter in the reactions. Cu adsorption was significant in the subsurface horizons of the Oxisols, despite the positive balance of charge, demonstrating the existence of mechanisms for specific adsorption, mainly related to the predominance of iron and aluminum oxides in the mineral fractions. In these samples, Cu was easily removed from the adsorption sites. RH demonstrated a higher capacity for the Cu adsorption in both horizons.

  12. Catalytic hydrolysis for the degradation of organophosphorus pesticides in water

    International Nuclear Information System (INIS)

    The kinetic studies of catalytic hydrolysis revealed that the concentration of two kinds of organophosphorus pesticides (omethoate and methidathion) in solution apparently decays according to the second order reaction. It was found that the rate constant value was highest at strong acidic conditions and it continued to decrease as the pH of the solution was increased. At basic conditions the rate constant value decreased to minimum. Manganese dioxide under acidic conditions converted into Mn/sup 2+/ ions and then these ions in water form hexaaquomanganese (II) ion. This hexaaquomanganese (II ion then adsorbed itself on the S or O atom of the organophosphorus compound and thus weakens the bond between P-S. This reaction facilitated the attack of H/sub 2/O or OH/sup -/ ion and thus enhanced the efficiency of hydrolysis. It was studied that methidathion hydrolyzed more efficiently than omethoate The rate constants of catalytic hydrolysis were increased with increasing the amount of MnO/sub 2/. It was found that the pesticides had undergone adsorption on catalyst in the first few minutes and there was the rapid drop of total phosphorus concentration. The decrease of total phosphorus adsorption with increasing pH was also observed. After the addition of alkaline earth metal cations (Ca/sup 2+/ and Mg/sup 2+/) along with magnesium, the enhancement in the efficiency of hydrolysis at near neutral conditions occurred. (author)

  13. Reversibility of substrate adsorption for the cellulases Cel7A, Cel6A and Cel7B from H. jecorina

    DEFF Research Database (Denmark)

    Pellegrini, Vanessa de Oliveira Arnoldi; Lei, Nina; Kysaram, Madhuri;

    2014-01-01

    Adsorption of cellulases on the cellulose surface is an integral part of the catalytic mechanism, and a detailed description of the adsorption process is therefore required for a fundamental understanding of this industrially important class of enzymes. However, the mode of adsorption has proven...... cellobiohydrolases (Cel7A and Cel6A) and one endoglucanase (Cel7B) on four types of pure cellulose substrates. Specifically, we monitored dilution-induced release of adsorbed enzyme in samples that had previously been brought to a steady state (constant concentration of free enzyme). In simple dilution experiments...

  14. Adsorption design for wastewater treatment

    Energy Technology Data Exchange (ETDEWEB)

    Cooney, D.O.

    1998-12-31

    Understand the premier method for removing organic contaminants from water. Straight forward explanations and illustrations allow this overview to fill a dual purpose: study manual and design guide. The book discusses basic properties of activated carbons; explains the kinetics of adsorption processes; describes the design of both fixed-bed and batch process adsorption systems; contains useful knowledge that can be extended to other applications of adsorption, including drinking water treatment; and includes many illustrated examples and practice exercises.

  15. Adsorption of polyhydroxyl based surfactants

    OpenAIRE

    Matsson, Maria

    2005-01-01

    Adsorption on solid surfaces from solution is a fundamental property of a surfactant. It might even be the most important aspect of surfactant behavior, since it influences many applications, such as cleaning, detergency, dispersion, separation, flotation, and lubrication. Consequently, fundamental investigations of surfactant adsorption are relevant to many areas. The main aim of this thesis has been to elucidate the adsorption properties, primarily on the solid/water interface, of a particu...

  16. Liquid crystal elastomer strips as soft crawlers

    Science.gov (United States)

    DeSimone, Antonio; Gidoni, Paolo; Noselli, Giovanni

    2015-11-01

    In this paper, we speculate on a possible application of Liquid Crystal Elastomers to the field of soft robotics. In particular, we study a concept for limbless locomotion that is amenable to miniaturisation. For this purpose, we formulate and solve the evolution equations for a strip of nematic elastomer, subject to directional frictional interactions with a flat solid substrate, and cyclically actuated by a spatially uniform, time-periodic stimulus (e.g., temperature change). The presence of frictional forces that are sensitive to the direction of sliding transforms reciprocal, 'breathing-like' deformations into directed forward motion. We derive formulas quantifying this motion in the case of distributed friction, by solving a differential inclusion for the displacement field. The simpler case of concentrated frictional interactions at the two ends of the strip is also solved, in order to provide a benchmark to compare the continuously distributed case with a finite-dimensional benchmark. We also provide explicit formulas for the axial force along the crawler body.

  17. TRANSPARENT HELIUM IN STRIPPED ENVELOPE SUPERNOVAE

    International Nuclear Information System (INIS)

    Using simple arguments based on photometric light curves and velocity evolution, we propose that some stripped envelope supernovae (SNe) show signs that a significant fraction of their helium is effectively transparent. The main pieces of evidence are the relatively low velocities with little velocity evolution, as are expected deep inside an exploding star, along with temperatures that are too low to ionize helium. This means that the helium should not contribute to the shaping of the main SN light curve, and thus the total helium mass may be difficult to measure from simple light curve modeling. Conversely, such modeling may be more useful for constraining the mass of the carbon/oxygen core of the SN progenitor. Other stripped envelope SNe show higher velocities and larger velocity gradients, which require an additional opacity source (perhaps the mixing of heavier elements or radioactive nickel) to prevent the helium from being transparent. We discuss ways in which similar analysis can provide insights into the differences and similarities between SNe Ib and Ic, which will lead to a better understanding of their respective formation mechanisms

  18. Transparent Helium in Stripped Envelope Supernovae

    CERN Document Server

    Piro, Anthony L

    2014-01-01

    The light curves and velocity evolution of core-collapse supernovae (SNe) provide important clues to help constrain their progenitors. This may be especially important for stripped envelope SNe (Type Ib, Ic, and IIb), which have been elusive in providing direct connections with the massive stars that give rise to these explosions. Using simple arguments based on photometric light curves, we propose that many of these stripped envelope SNe show evidence that a significant fraction their helium is effectively transparent during the majority of their light curve evolution. This means that the helium should not contribute to the shaping of the main SN light curve and thus the total helium mass may be difficult to constrain from simple light curve modeling. Conversely, such modeling may be more useful for constraining the mass of the carbon/oxygen core of the SN progenitor. We discuss ways in which similar analysis can provide insights into the differences and similarities between SNe Ib and Ic, which will help le...

  19. Therapeutic surfactant-stripped frozen micelles

    Science.gov (United States)

    Zhang, Yumiao; Song, Wentao; Geng, Jumin; Chitgupi, Upendra; Unsal, Hande; Federizon, Jasmin; Rzayev, Javid; Sukumaran, Dinesh K.; Alexandridis, Paschalis; Lovell, Jonathan F.

    2016-05-01

    Injectable hydrophobic drugs are typically dissolved in surfactants and non-aqueous solvents which can induce negative side-effects. Alternatives like `top-down' fine milling of excipient-free injectable drug suspensions are not yet clinically viable and `bottom-up' self-assembled delivery systems usually substitute one solubilizing excipient for another, bringing new issues to consider. Here, we show that Pluronic (Poloxamer) block copolymers are amenable to low-temperature processing to strip away all free and loosely bound surfactant, leaving behind concentrated, kinetically frozen drug micelles containing minimal solubilizing excipient. This approach was validated for phylloquinone, cyclosporine, testosterone undecanoate, cabazitaxel and seven other bioactive molecules, achieving sizes between 45 and 160 nm and drug to solubilizer molar ratios 2-3 orders of magnitude higher than current formulations. Hypertonic saline or co-loaded cargo was found to prevent aggregation in some cases. Use of surfactant-stripped micelles avoided potential risks associated with other injectable formulations. Mechanistic insights are elucidated and therapeutic dose responses are demonstrated.

  20. Catalytic cracking of lignites

    Energy Technology Data Exchange (ETDEWEB)

    Seitz, M.; Nowak, S.; Naegler, T.; Zimmermann, J. [Hochschule Merseburg (Germany); Welscher, J.; Schwieger, W. [Erlangen-Nuernberg Univ. (Germany); Hahn, T. [Halle-Wittenberg Univ., Halle (Germany)

    2013-11-01

    A most important factor for the chemical industry is the availability of cheap raw materials. As the oil price of crude oil is rising alternative feedstocks like coal are coming into focus. This work, the catalytic cracking of lignite is part of the alliance ibi (innovative Braunkohlenintegration) to use lignite as a raw material to produce chemicals. With this new one step process without an input of external hydrogen, mostly propylene, butenes and aromatics and char are formed. The product yield depends on manifold process parameters. The use of acid catalysts (zeolites like MFI) shows the highest amount of the desired products. Hydrogen rich lignites with a molar H/C ratio of > 1 are to be favoured. Due to primary cracking and secondary reactions the ratio between catalyst and lignite, temperature and residence time are the most important parameter to control the product distribution. Experiments at 500 C in a discontinuous rotary kiln reactor show yields up to 32 wt-% of hydrocarbons per lignite (maf - moisture and ash free) and 43 wt-% char, which can be gasified. Particularly, the yields of propylene and butenes as main products can be enhanced four times to about 8 wt-% by the use of catalysts while the tar yield decreases. In order to develop this innovative process catalyst systems fixed on beads were developed for an easy separation and regeneration of the used catalyst from the formed char. (orig.)

  1. Catalytic Membrane Sensors

    Energy Technology Data Exchange (ETDEWEB)

    Boyle, T.J.; Brinker, C.J.; Gardner, T.J.; Hughes, R.C.; Sault, A.G.

    1998-12-01

    The proposed "catalytic membrane sensor" (CMS) was developed to generate a device which would selectively identify a specific reagent in a complex mixture of gases. This was to be accomplished by modifying an existing Hz sensor with a series of thin films. Through selectively sieving the desired component from a complex mixture and identifying it by decomposing it into Hz (and other by-products), a Hz sensor could then be used to detect the presence of the select component. The proposed "sandwich-type" modifications involved the deposition of a catalyst layered between two size selective sol-gel layers on a Pd/Ni resistive Hz sensor. The role of the catalyst was to convert organic materials to Hz and organic by-products. The role of the membraneo was to impart both chemical specificity by molecukir sieving of the analyte and converted product streams, as well as controlling access to the underlying Pd/Ni sensor. Ultimately, an array of these CMS elements encompassing different catalysts and membranes were to be developed which would enable improved selectivity and specificity from a compiex mixture of organic gases via pattern recognition methodologies. We have successfully generated a CMS device by a series of spin-coat deposited methods; however, it was determined that the high temperature required to activate the catalyst, destroys the sensor.

  2. Catalytic gasification of biomass

    Science.gov (United States)

    Robertus, R. J.; Mudge, L. K.; Sealock, L. J., Jr.; Mitchell, D. H.; Weber, S. L.

    1981-12-01

    Methane and methanol synthesis gas can be produced by steam gasification of biomass in the presence of appropriate catalysts. This concept is to use catalysts in a fluidized bed reactor which is heated indirectly. The objective is to determine the technical and economic feasibility of the concept. Technically the concept has been demonstrated on a 50 lb per hr scale. Potential advantages over conventional processes include: no oxygen plant is needed, little tar is produced so gas and water treatment are simplified, and yields and efficiencies are greater than obtained by conventional gasification. Economic studies for a plant processing 2000 T/per day dry wood show that the cost of methanol from wood by catalytic gasification is competitive with the current price of methanol. Similar studies show the cost of methane from wood is competitive with projected future costs of synthetic natural gas. When the plant capacity is decreased to 200 T per day dry wood, neither product is very attractive in today's market.

  3. Stream Surface Strip Element Method and Simulation of Three-Dimensional Deformation of Continuous Hot Rolled Strip

    Institute of Scientific and Technical Information of China (English)

    LIU Hong-min; WANG Ying-rui

    2004-01-01

    A new method, the stream surface strip element method, for simulating the three-dimensional deformation of plate and strip rolling process was proposed. The rolling deformation zone was divided into a number of stream surface (curved surface) strip elements along metal flow traces, and the stream surface strip elements were mapped into the corresponding plane strip elements for analysis and computation. The longitudinal distributions of the lateral displacement and the altitudinal displacement of metal were respectively constructed to be a quartic curve and a quadratic curve, of which the lateral distributions were expressed as the third-power spline function, and the altitudinal distributions were fitted in the quadratic curve. From the flow theory of plastic mechanics, the mathematical models of the three-dimensional deformations and stresses of the deformation zone were constructed. Compared with the streamline strip element method proposed by the first author of this paper, the stream surface strip element method takes into account the uneven distributions of stresses and deformations along altitudinal direction, and realizes the precise three-dimensional analysis and computation. The simulation example of continuous hot rolled strip indicates that the method and the model accord with facts and provide a new reliable engineering-computation method for the three-dimensional mechanics simulation of plate and strip rolling process.

  4. Adsorption and collective paramagnetism

    CERN Document Server

    Selwood, Pierce W

    1962-01-01

    Adsorption and Collective Paramagnetism describes a novel method for studying chemisorption. The method is based on the change in the number of unpaired electrons in the adsorbent as chemisorption occurs. The method is applicable to almost all adsorbates, but it is restricted to ferromagnetic adsorbents such as nickel, which may be obtained in the form of very small particles, that is to say, to ferromagnetic adsorbents with a high specific surface. While almost all the data used illustratively have been published elsewhere this is the first complete review of the subject. The book is addresse

  5. Immigration process in catalytic medium

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    The longtime behavior of the immigration process associated with a catalytic super-Brownian motion is studied. A large number law is proved in dimension d≤3 and a central limit theorem is proved for dimension d=3.

  6. Immigration process in catalytic medium

    Institute of Scientific and Technical Information of China (English)

    洪文明; 王梓坤

    2000-01-01

    The longtime behavior of the immigration process associated with a catalytic super-Brown-ian motion is studied. A large number law is proved in dimension d≤3 and a central limit theorem is proved for dimension d = 3.

  7. Catalytic glycerol steam reforming for hydrogen production

    Energy Technology Data Exchange (ETDEWEB)

    Dan, Monica, E-mail: monica.dan@itim-cj.ro; Mihet, Maria, E-mail: maria.mihet@itim-cj.ro; Lazar, Mihaela D., E-mail: diana.lazar@itim-cj.ro [National Institute for Research and Development of Isotopic and Molecular Technologies, 67-103 Donat Street, 400293 Cluj Napoca (Romania)

    2015-12-23

    Hydrogen production from glycerol by steam reforming combine two major advantages: (i) using glycerol as raw material add value to this by product of bio-diesel production which is obtained in large quantities around the world and have a very limited utilization now, and (ii) by implication of water molecules in the reaction the efficiency of hydrogen generation is increased as each mol of glycerol produces 7 mol of H{sub 2}. In this work we present the results obtained in the process of steam reforming of glycerol on Ni/Al{sub 2}O{sub 3}. The catalyst was prepared by wet impregnation method and characterized through different methods: N{sub 2} adsorption-desorption, XRD, TPR. The catalytic study was performed in a stainless steel tubular reactor at atmospheric pressure by varying the reaction conditions: steam/carbon ratio (1-9), gas flow (35 ml/min -133 ml/min), temperature (450-650°C). The gaseous fraction of the reaction products contain: H{sub 2}, CH{sub 4}, CO, CO{sub 2}. The optimum reaction conditions as resulted from this study are: temperature 550°C, Gly:H{sub 2}O ratio 9:1 and Ar flow 133 ml/min. In these conditions the glycerol conversion to gaseous products was 43% and the hydrogen yield was 30%.

  8. Catalytic glycerol steam reforming for hydrogen production

    Science.gov (United States)

    Dan, Monica; Mihet, Maria; Lazar, Mihaela D.

    2015-12-01

    Hydrogen production from glycerol by steam reforming combine two major advantages: (i) using glycerol as raw material add value to this by product of bio-diesel production which is obtained in large quantities around the world and have a very limited utilization now, and (ii) by implication of water molecules in the reaction the efficiency of hydrogen generation is increased as each mol of glycerol produces 7 mol of H2. In this work we present the results obtained in the process of steam reforming of glycerol on Ni/Al2O3. The catalyst was prepared by wet impregnation method and characterized through different methods: N2 adsorption-desorption, XRD, TPR. The catalytic study was performed in a stainless steel tubular reactor at atmospheric pressure by varying the reaction conditions: steam/carbon ratio (1-9), gas flow (35 ml/min -133 ml/min), temperature (450-650°C). The gaseous fraction of the reaction products contain: H2, CH4, CO, CO2. The optimum reaction conditions as resulted from this study are: temperature 550°C, Gly:H2O ratio 9:1 and Ar flow 133 ml/min. In these conditions the glycerol conversion to gaseous products was 43% and the hydrogen yield was 30%.

  9. Status Quo of China’s Aluminum Sheet & Strip Industry

    Institute of Scientific and Technical Information of China (English)

    2013-01-01

    <正>Aluminum sheet & strip products are one of the major product varieties in the aluminum processing industry, they also provide indis-pensable basic materials for the development of national economy. In recent years, driven by rapid economic growth, China’s investment in aluminum sheet & strip industry continued to

  10. COMPUTER PROCESSING OF MULTISPECTRAL SCANNER DATA OVER COAL STRIP MINES

    Science.gov (United States)

    There is little doubt that remote sensing techniques can be effectively applied to the task of monitoring coal strip mine progress and reclamation work. Aircraft multispectral scanner data acquired over six coal strip mines in the states of Wyoming, Montana, Colorado, and Arizona...

  11. Micro-strip sensors based on CVD Diamond

    CERN Document Server

    Adam, W; Bergonzo, P; Bertuccio, G; Bogani, F; Borchi, E; Brambilla, A; Bruzzi, Mara; Colledani, C; Conway, J; D'Angelo, P; Dabrowski, W; Delpierre, P A; Deneuville, A; Dulinski, W; van Eijk, B; Fallou, A; Fizzotti, F; Foulon, F; Friedl, M; Gan, K K; Gheeraert, E; Hallewell, G D; Han, S; Hartjes, F G; Hrubec, Josef; Husson, D; Kagan, H; Kania, D R; Kaplon, J; Kass, R; Koeth, T W; Krammer, Manfred; Lo Giudice, A; Lü, R; MacLynne, L; Manfredotti, C; Meier, D; Mishina, M; Moroni, L; Oh, A; Pan, L S; Pernicka, Manfred; Peitz, A; Perera, L P; Pirollo, S; Procario, M; Riester, J L; Roe, S; Rousseau, L; Rudge, A; Russ, J; Sala, S; Sampietro, M; Schnetzer, S R; Sciortino, S; Stelzer, H; Stone, R; Suter, B; Tapper, R J; Tesarek, R J; Trischuk, W; Tromson, D; Vittone, E; Walsh, A M; Wedenig, R; Weilhammer, Peter; Wetstein, M; White, C; Zeuner, W; Zoeller, M M

    2000-01-01

    In this article we present the performance of recent chemical vapour deposition (CVD) diamond micro-strip sensors in beam tests. In addition we present the first comparison of a CVD diamond micro-strip sensor before and after proton irradiation.

  12. Micro-strip sensors based on CVD diamond

    Energy Technology Data Exchange (ETDEWEB)

    Adam, W.; Berdermann, E.; Bergonzo, P.; Bertuccio, G.; Bogani, F.; Borchi, E.; Brambilla, A.; Bruzzi, M.; Colledani, C.; Conway, J.; D' Angelo, P.; Dabrowski, W.; Delpierre, P.; Deneuville, A.; Dulinski, W.; Eijk, B. van; Fallou, A.; Fizzotti, F.; Foulon, F.; Friedl, M.; Gan, K.K.; Gheeraert, E.; Hallewell, G.; Han, S.; Hartjes, F.; Hrubec, J.; Husson, D.; Kagan, H.; Kania, D.; Kaplon, J.; Kass, R.; Koeth, T.; Krammer, M.; Logiudice, A.; Lu, R.; Mac Lynne, L.; Manfredotti, C.; Meier, D. E-mail: dirk.meier@cern.ch; Mishina, M.; Moroni, L.; Oh, A.; Pan, L.S.; Pernicka, M.; Peitz, A.; Perera, L.; Pirollo, S.; Procario, M.; Riester, J.L.; Roe, S.; Rousseau, L.; Rudge, A.; Russ, J.; Sala, S.; Sampietro, M.; Schnetzer, S.; Sciortino, S.; Stelzer, H.; Stone, R.; Suter, B.; Tapper, R.J.; Tesarek, R.; Trischuk, W.; Tromson, D.; Vittone, E.; Walsh, A.M.; Wedenig, R.; Weilhammer, P.; Wetstein, M.; White, C.; Zeuner, W.; Zoeller, M

    2000-10-11

    In this article we present the performance of recent chemical vapour deposition (CVD) diamond micro-strip sensors in beam tests. In addition, we present the first comparison of a CVD diamond micro-strip sensor before and after proton irradiation.

  13. Micro-strip sensors based on CVD diamond

    International Nuclear Information System (INIS)

    In this article we present the performance of recent chemical vapour deposition (CVD) diamond micro-strip sensors in beam tests. In addition, we present the first comparison of a CVD diamond micro-strip sensor before and after proton irradiation

  14. Photomask technique for fabricating high purity germanium strip detectors

    International Nuclear Information System (INIS)

    A new technology for germanium strip detectors has been developed. This technique uses a photomask process which needs no growing and etching and allows all kinds of segmented electrodes. Typically we have obtained 1.2 keV FWHM on the 122 keV line of 57Co and a X-Y detector having 20 strips in each side. (orig.)

  15. Magnetic domain-wall dynamics in wide permalloy strips

    Science.gov (United States)

    Estévez, Virginia; Laurson, Lasse

    2016-02-01

    Domain walls in soft permalloy strips may exhibit various equilibrium micromagnetic structures depending on the width and thickness of the strip, ranging from the well-known transverse and vortex walls in narrow and thin strips to double and triple vortex walls recently reported in wider strips [V. Estévez and L. Laurson, Phys. Rev. B 91, 054407 (2015), 10.1103/PhysRevB.91.054407]. Here, we analyze the field driven dynamics of such domain walls in permalloy strips of widths from 240 nm up to 6 μ m , using the known equilibrium domain wall structures as initial configurations. Our micromagnetic simulations show that the domain wall dynamics in wide strips is very complex, and depends strongly on the geometry of the system, as well as on the magnitude of the driving field. We discuss in detail the rich variety of the dynamical behaviors found, including dynamic transitions between different domain wall structures, periodic dynamics of a vortex core close to the strip edge, transitions towards simpler domain wall structures of the multi-vortex domain walls controlled by vortex polarity, and the fact that for some combinations of the strip geometry and the driving field the system cannot support a compact domain wall.

  16. Using Comic Strips as a Book Report Alternative

    Science.gov (United States)

    Reading Teacher, 2012

    2012-01-01

    Comic strips are great to share with parents, younger students, and peers. This article presents an activity where students use a six-paneled comic strip to summarize a story. This activity allows for multiple interpretations and enhances comprehension by drawing attention to story elements.

  17. Young tourists visiting strip clubs and paying for sex

    DEFF Research Database (Denmark)

    Hesse, Morten; Tutenges, Sébastien

    2011-01-01

    Little is known about young adults’ use of strip clubs and prostitution during their holidays abroad. This study examined this issue with a sample of 1125 Danish tourists between the ages of 16 and 34, and sought data about the frequency with which they paid for sex and attended strip clubs while...

  18. Emission reduction by multipurpose buffer strips on arable fields.

    Science.gov (United States)

    Sloots, K; van der Vlies, A W

    2007-01-01

    In the area managed by Hollandse Delta, agriculture is under great pressure and the social awareness of the agricultural sector is increasing steadily. In recent years, a stand-still has been observed in water quality, in terms of agrochemicals, and concentrations even exceed the standard. To improve the waterquality a multi-purpose Field Margin Regulation was drafted for the Hoeksche Waard island in 2005. The regulation prescribes a crop-free strip, 3.5 m wide, alongside wet drainage ditches. The strip must be sown with mixtures of grasses, flowers or herbs. No crop protection chemicals or fertilizer may be used on the strips. A total length of approximately 200 km of buffer strip has now been laid. Besides reducing emissions, the buffer strips also stimulate natural pest control methods and encourage local tourism. Finally, the strips should lead to an improvement in the farmers' image. The regulation has proved to be successful. The buffer strips boosted both local tourism and the image of the agricultural sector. Above all, the strips provided a natural shield for emission to surface water, which will lead to an improvement of the water quality and raise the farmers' awareness of water quality and the environment. PMID:17711002

  19. Catalytic Polymer Multilayer Shell Motors for Separation of Organics.

    Science.gov (United States)

    Lin, Zhihua; Wu, Zhiguang; Lin, Xiankun; He, Qiang

    2016-01-26

    A catalytic polymer multilayer shell motor has been developed, which effects fast motion-based separation of charged organics in water. The shell motors are fabricated by sputtering platinum onto the exposed surface of silica templates embedded in Parafilm, followed by layer-by-layer assembly of polyelectrolyte multilayers to the templates. The catalytic shell motors display high bubble propulsion with speeds of up to 260 μm s(-1) (13 body lengths per second). Moreover, the polyelectrolyte multilayers assembled at high pH (pH>9.0) adsorb approximately 89% of dye molecules from water, owing to the electrostatic interaction between the positively charged polymers and the anionic dye molecules, and subsequently release them at neutral pH in a microfluidic device. The efficient propulsion coupled with the effective adsorption behavior of the catalytic shell motors in a microfluidic device results in accelerated separation of organics in water and thus holds considerable promise for water analysis. PMID:26632275

  20. Liquid-Phase Adsorption Fundamentals.

    Science.gov (United States)

    Cooney, David O.

    1987-01-01

    Describes an experiment developed and used in the unit operations laboratory course at the University of Wyoming. Involves the liquid-phase adsorption of an organic compound from aqueous solution on activated carbon, and is relevant to adsorption processes in general. (TW)

  1. Evaluation of anatomy comic strips for further production and applications.

    Science.gov (United States)

    Shin, Dong Sun; Kim, Dae Hyun; Park, Jin Seo; Jang, Hae Gwon; Chung, Min Suk

    2013-09-01

    The corresponding author of the study has been sketching comic strips to explain anatomy in a humorous manner. All the anatomy comic strips, including those in Korean (650 episodes) and English (451 episodes), can be viewed on the homepage (http://anatomy.co.kr). Such comic strips were created with the aim of assisting medical students. However, their impact was unknown, and therefore, we surveyed the students' responses. We noted that anatomy grades were better in the students who read the comic strips. The comics helped the trainees chat with individuals with and without a medical background. The authors also considered comments on the problems with the comic strips and attempted to find solutions. The episodes are being currently used and further produced for educational purposes. To support this effort, the readers' valuable opinions will be continuously collected and assessed.

  2. Re-reddening on Strip Surface After Water Cooling

    Institute of Scientific and Technical Information of China (English)

    ZHI Ying; LIU Xiang-hua; WANG Guo-dong

    2007-01-01

    After water cooling, there is a big temperature difference between the center and the surface of strip,which leads to the heat transfer from the center to the surface, and the surface temperature can rise in a short time. The finite element method was used to simulate the phenomena of re-reddening on the surface of strip and to analyze the temperature field of hot rolled strip during laminar cooling, and the periodical variation curve of the cooling rate was obtained during water cooling and subsequent re-reddening. The results show that the critical line of the cooling rate is at 1/3 of the half-thickness from the strip surface. The regression model of the relation of rereddening temperature, time, and distance from the surface was obtained in the re-reddening region. Re-reddening regularity on the surface of strip under the condition of different thickness and cooling rate was also studied.

  3. Nonattacking Queens in a Rectangular Strip

    CERN Document Server

    Chaiken, Seth; Zaslavsky, Thomas; 10.1007/s00026-011-0068-7

    2011-01-01

    The function that counts the number of ways to place nonattacking identical chess or fairy chess pieces in a rectangular strip of fixed height and variable width, as a function of the width, is a piecewise polynomial which is eventually a polynomial and whose behavior can be described in some detail. We deduce this by converting the problem to one of counting lattice points outside an affinographic hyperplane arrangement, which Forge and Zaslavsky solved by means of weighted integral gain graphs. We extend their work by developing both generating functions and a detailed analysis of deletion and contraction for weighted integral gain graphs. For chess pieces we find the asymptotic probability that a random configuration is nonattacking, and we obtain exact counts of nonattacking configurations of small numbers of queens, bishops, knights, and nightriders.

  4. Bismuth electrodes, an alternative in stripping voltammetry

    International Nuclear Information System (INIS)

    The heavy metals are known as highly toxic contaminants, the processes carried out in industry contribute that finally they remain dispersed in effluents and sewage, doing part of the food chain. The importance of controlling the levels of these heavy metals has become an international policy, so it has generated interest in developing new analytical methodologies for its determination [1, 2, 3, 4]. The stripping voltammetry has been considered as a family of electro-sensitive analytical techniques useful for the determination of trace levels of many metals in environmental, clinical and industrial samples [3, 4]. This work presents an overview of these bismuth-based electrodes which were introduced around 2000, which have interesting characteristics for detection of heavy metals and which represent an alternative to mercury electrodes

  5. Digital autoradiography using silicon strip detectors

    Energy Technology Data Exchange (ETDEWEB)

    Overdick, M.

    1998-05-01

    Spatially resolving radiation detection systems operating in real time can be used to acquire autoradiographic images. An overview over alternatives to traditional autoradiography is given and the special features of these filmless methods are discussed. On this basis the design of a system for digital autoradiography using silicon strip detectors is presented. Special emphasis is put on the physical background of the detection process in the semiconductor and on the self-triggering read-out technique. The practical performance of the system is analyzed with respect to energy and spatial resolution. This analysis is complemented by case studies from cell biology (especially electrophoresis), botany and mineralogy. Also the results from a time-resolved autoradiographic experiment are presented. (orig.) 80 refs.

  6. Cataract surgery after Descemet stripping endothelial keratoplasty

    Directory of Open Access Journals (Sweden)

    Sunita Chaurasia

    2012-01-01

    Full Text Available Management of endothelial dysfunction in phakic patients is sometimes a dilemma for corneal surgeons. Phakic patients with visually significant cataract and endothelial dysfunction are preferably managed by performing combined cataract surgery with endothelial keratoplasty. However, combined surgery may be deferred in eyes with early incipient cataract, younger age and where anterior chamber is poorly visualized. As cataract formation may be accelerated after endothelial keratoplasty, these eyes may need cataract surgery subsequently. Surgical intervention in eyes with endothelial keratoplasty is of concern as this may affect the graft adversely and threaten graft survival. In this report, we describe the intraoperative surgical details and postoperative clinical course of a patient who underwent phacoemulsification with intraocular lens implantation after Descemet stripping automated endothelial keratoplasty (DSAEK.

  7. Bismuth electrodes, an alternative in stripping voltammetry

    Science.gov (United States)

    Barón-Jaimez, J.; Joya, M. R.; Barba-Ortega, J.

    2013-11-01

    The heavy metals are known as highly toxic contaminants, the processes carried out in industry contribute that finally they remain dispersed in effluents and sewage, doing part of the food chain. The importance of controlling the levels of these heavy metals has become an international policy, so it has generated interest in developing new analytical methodologies for its determination [1, 2, 3, 4]. The stripping voltammetry has been considered as a family of electro-sensitive analytical techniques useful for the determination of trace levels of many metals in environmental, clinical and industrial samples [3, 4]. This work presents an overview of these bismuth-based electrodes which were introduced around 2000, which have interesting characteristics for detection of heavy metals and which represent an alternative to mercury electrodes.

  8. [Obstetrical handbook in comic strip form].

    Science.gov (United States)

    1998-04-01

    An obstetric handbook was created in comic strip form in cooperation with the Ministry of Health in the region of Segou, Mali, for training of traditional midwives living far from community health centers. The drawings illustrate pregnancies at risk that the midwife should be able to identify in order to advise women to stay near the health facility before onset of labor. Drawings indicate pregnancies that are at risk because of the following: small stature, limping as a result of polio or sciatic paralysis, high parity, prior cesarean delivery, heart disease, overly large uterus, or prior stillbirth. Serious complications requiring referral to a health service are also illustrated and include severe anemia, genital bleeding, and signs of toxemia and edema. The midwife should accompany the woman during transport.

  9. Enhanced fluoride adsorption by nano crystalline γ-alumina: adsorption kinetics, isotherm modeling and thermodynamic studies

    Science.gov (United States)

    Chinnakoti, Prathibha; Chunduri, Avinash L. A.; Vankayala, Ranganayakulu K.; Patnaik, Sandeep; Kamisetti, Venkataramaniah

    2016-06-01

    Nano materials in particular nano oxides with enhanced surface area and an excellent catalytic surface serve as potential adsorbents for defluoridation of water. In the present study nano γ-alumina was synthesized through a simple and low cost, surfactant assisted solution combustion method. As synthesized material was characterized by XRD and FESEM for its phase, size and morphological characteristics. Surface properties have been investigated by BET method. Nano γ-alumina was further used for a detailed adsorption study to remove fluoride from water. Batches of experiments were performed at various experimental conditions such as solution pH, adsorbent dose, initial fluoride concentration and contact time to test the defluoridation ability of γ-alumina. Fluoride Adsorption by nano sized γ-alumina was rapid and reached equilibrium within two hours. The adsorption worked well at pH 4.0, where ˜96 % of fluoride was found to be adsorbed on adsorbent. It was possible to reduce fluoride levels to as low as 0.3 mg/L (within the safe limit of WHO: ≤1.5 mg/L) from an initial fluoride levels of 10 mg/L. This could be achieved using a very small quantity, 1 g/L of γ-alumina at pH 4 within 1 h of contact time. Defluoridation capacity of nano γ-alumina was further investigated by fitting the equilibrium data to various isotherm as well as kinetic models. The present study revealed that γ-alumina could be an efficient adsorbent for treating fluoride contaminated water.

  10. Streptococcus pneumoniae carriage in the Gaza strip.

    Directory of Open Access Journals (Sweden)

    Gili Regev-Yochay

    Full Text Available BACKGROUND: Pneumococcal infections cause major morbidity and mortality in developing countries. We report the epidemiology of S. pneumoniae carriage in a developing region, the Gaza strip, and evaluate the theoretical coverage of carriage strains by pneumococcal conjugate vaccines (PCVs. METHODOLOGY: In 2009 we conducted a cross-sectional survey of S. pneumoniae carriage in healthy children and their parents, living throughout the Gaza strip. Data were collected and nasopharyngeal swabs were obtained. Antibiotic susceptibilities were determined by Vitek-2 and serotypes by the Quellung reaction. PRINCIPAL FINDINGS: S. pneumoniae carriage was detected in 189/379 (50% of children and 30/376 (8% of parents. Carriage prevalence was highest in children <6 months of age (63%. Significant predictors for child carriage were number of household members and DCC attendance. The proportion of pediatric and adults isolates with serotypes included in PCV7 were 32% and 20% respectively, and 46% and 33% in PCV13 respectively. The most prominent non-vaccine serotypes (NVT were 35B, 15B/C and 23B. Penicillin-nonsusceptible strains were carried by 70% of carriers, penicillin-resistant strains (PRSP by 13% and Multi-drug-resistant (MDR by 30%. Of all PRSP isolates 54% belonged to serotypes included in PCV7 and 71% in the PCV13. Similarly, 59% and 73% of MDR-SP isolates, would theoretically be covered by PCV7 and PCV13, respectively. CONCLUSIONS: This study demonstrates that, PCV13-included strains were carried by 46% and 33% of pediatric and adult subjects respectively. In the absence of definitive data regarding the virulence of the NVT strains, it is difficult to predict the effect of PCVs on IPD in this region.

  11. Application of WLS strips for position determination in Strip PET tomograph based on plastic scintillators

    CERN Document Server

    Smyrski, J; Bednarski, T; Białas, P; Czerwiński, E; Kapłon, Ł; Kochanowski, A; Korcyl, G; Kowal, J; Kowalski, P; Kozik, T; Krzemień, W; Molenda, M; Niedźwiecki, Sz; Pałka, M; Pawlik, M; Raczyński, L; Rudy, Z; Salabura, P; Sharma, N G; Silarski, M; Słomski, A; Strzelecki, A; Wiślicki, W; Zieliński, M; Zoń, N

    2013-01-01

    A method of determination of a gamma quantum absorption point in a plastic scintillator block using a matrix of wavelength-shifting (WLS) strips is proposed. Application of this method for improvement of position resolution in newly proposed PET detectors based on plastic scintillators is presented. The method enables to reduce parallax errors in reconstruction of images which occurs in the presently used Positron Emission Tomography scanners.

  12. Low concentration volatile organic pollutants removal in combined adsorber-desorber-catalytic reactor system

    Directory of Open Access Journals (Sweden)

    Arsenijević Zorana

    2008-01-01

    Full Text Available The removal of volatile organic compounds (VOCs from numerous emission sources is of crucial importance due to more rigorous demands on air quality. Different technologies can be used to treat the VOCs from effluent gases: absorption, physical adsorption, open flame combustion, thermal and catalytic incineration. Their appropriateness for the specific process depends on several factors such as efficiency, energy consumption, secondary pollution, capital investments etc. The distinctive features of the catalytic combustion are high efficiency and selectivity toward be­nign products, low energy consumption and absence of secondary polluti­on. The supported noble catalysts are widely used for catalytic incineration due to their low ignition temperatures and high thermal and chemical stability. In our combined system adsorption and desorption are applied in the spouted bed with draft tube (SBDT unit. The annular zone, loaded with sorbent, was divided in adsorption and desorption section. Draft tube enabled sorbent recirculation between sections. Combustion of desorbed gases to CO2 and water vapor are realized in additive catalytic reactor. This integrated device provided low concentrations VOCs removal with reduced energy consumption. Experiments were conducted on a pilot unit of 220 m3/h nominal capacity. The sorbent was activated carbon, type K81/B - Trayal Corporation, Krusevac. A sphere shaped commercial Pt/Al2O3 catalyst with "egg-shell" macro-distribution was used for the investigation of xylene deep oxidation. Within this paper the investigations of removal of xylene vapors, a typical pollutant in production of liquid pesticides, in combined adsorber/desorber/catalytic reactor system is presented.

  13. Mesoporous Phosphate Heterostructures: Synthesis and Application on Adsorption and Catalysis

    Science.gov (United States)

    Moreno-Tost, Ramón; Jiménez-Jiménez, José; Infantes-Molina, Antonia; Cavalcante, Celio L.; Azevedo, Diana C. S.; Soriano, María Dolores; López Nieto, José Manuel; Jiménez-López, Antonio; Rodríguez-Castellón, Enrique

    Porous phosphate heterostructures (PPHs) are solids formed by a layered metal(IV) phosphate expanded with silica galleries obtained by combining the two main strategies for obtaining mesoporous materials [pillared layered structures (PLS') and MCM-41]. The different synthetic pathways for obtaining mesoporous phosphate structures with silica galleries with Zr- or Ti-doped silica, the study of their structural, textural and acid properties, its functionalisation with different organic substances such as propionitrile, 3-aminopropyl triethoxysilane, (3-mercaptopropyl)trimethoxysilane, vinyltrimethoxysilane, phenyltriethoxysilane and 3-(triethoxysilyl)propionitrile are discussed. The preparation of metal-supported catalysts and their application in gas separation, adsorption and catalysis are reviewed. Specifically, the use of Cu- and Fe-exchanged PPH for the adsorption of benzothiophene and the separation of propane/propene is the main application as adsorbent. The hydrotreating of aromatic hydrocarbons using ruthenium-impregnated catalysts via hydrogenation and hydrogenolysis/hydrocracking for the production of clean diesel fuels, the selective catalytic reduction of NO from stationary and mobile sources by using Cu-PPH with 1, 3 and 7 wt% of Cu and the selective oxidation of hydrogen sulphide to sulphur with vanadium-containing PPH are the three catalytic reactions of environmental interest studied.

  14. New Concept of Cultivation Using Limited Strip-Tillage with Strip Shallow Irrigation

    Directory of Open Access Journals (Sweden)

    Yazid Ismi Intara

    2014-04-01

    Full Text Available Normal 0 false false false IN X-NONE X-NONE Dry land is one of land resources which potentially used for food crop cultivation, especially in the areas which have light to medium technical obstacles. The development of technology to improve soil quality in marginal lands to be productive lands is still widely open for agricultural development in Indonesia. Rooting medium quality can be improved by changing soil tillage method and observing the proper crop irrigation technology. It can be the solution for crop cultivation in clay loam soil. This study aimed to obtain water movement model in a minimally-tilled clay soil with strip shallow irrigation. The concept is limited soil-tillage with strip shallow irrigation method, water supply technique, and crop water requirement. Method used in this study includes developing water movement model (software development in a minimally-tilled clay soil with subsurface irrigation. In the final stages, research also conducted water movement analysis testing apparatus in the laboratory, field validation of the subsurface irrigation performance, and cultivation technique testing to chili pepper growth (Capsicum annuumL.. The development of water movement simulation on a limited strip-tillage with subsurface irrigation uses the concept to quantify the amount of water in the soil. The analysis of movement pattern was demonstrated on contour patterns. It showed that the wetting process can reach depth zone – 5 cm to the rooting zone. It was an important discovery on the development of minimum stripe tillage soil with subsurface irrigation. Specifically, it can be concluded that: the result of fitting by eyes to diffusivity graphic and water content obtained the required parameter values for soil physical properties. It was then simulated on horizontal water movement model on a minimum strip-tillage with strip shallow irrigation /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Table Normal"; mso

  15. Experimental study on dynamic gas adsorption

    Institute of Scientific and Technical Information of China (English)

    Qin Yueping; Wang Yaru; Yang Xiaobin; Liu Wei; Luo Wei

    2012-01-01

    In order to predict the actual adsorption amount as gas adsorption reaches the equilibrium,this research designed a dynamic gas adsorption experiment under constant temperature and pressure,and also studied the isopiestic adsorption characteristics of coal samples with same quality but different sizes.Through the experiment,the study found the adsorption-time changing relationships under different pressures of four different size samples.After regression analysis,we obtained the functional relationship between adsorption and time.According to this,the research resulted in the actual adsorption amount when gas adsorption reaches the equilibrium.In addition,the current study obtained the relationship between adsorption and pressure as well as the effect of the coal size to the adsorption rate.These results have great theoretical and practical significance for the prediction of gas amount in coal seam and gas adsorption process.

  16. Pore Structure and Catalytic Performance of Steam-Dealuminated ZSM-5/Y Composite Zeolites

    Institute of Scientific and Technical Information of China (English)

    GuoJintao; ShenBaojian; ChenHonglin

    2005-01-01

    For investigating the effect of dealumination on the pore structure and catalytic performance, ZSM-5/Y composite zeolites synthesized in situ from NaY gel were dealuminated by steaming at different temperatures. XRD (X-ray diffraction) characterization indicates that the relative crystallinity of the composite zeolites decreases with the increase in Si/Al ratio after steaming. N2 adsorption-desorption suggests that more mesopores are formed while the BET(Brunauer, Emmett and Teller) specific surface area and the micropore specific surface area decrease as the temperature of steaming rises. Daqing heavy oil was used as feedstock to test the catalytic cracking activity of ZSM-5/Y composite zeolites. The experimental results of the catalytic cracking performance reveal that the distribution of products differs due to the different conditions of hydrothermal treatment. Further hydrothermal treatment leads to an increase in the yield of light oil, and a decrease in the yield of gas products and coke.

  17. Effect of hierarchical porosity and phosphorus modification on the catalytic properties of zeolite Y

    Science.gov (United States)

    Li, Wenlin; Zheng, Jinyu; Luo, Yibin; Da, Zhijian

    2016-09-01

    The zeolite Y is considered as a leading catalyst for FCC industry. The acidity and porosity modification play important roles in determining the final catalytic properties of zeolite Y. The alkaline treatment of zeolite Y by dealumination and alkaline treatment with NaOH and NaOH&TBPH was investigated. The zeolites were characterized by X-ray diffraction, low-temperature adsorption of nitrogen, transmission electron microscope, NMR, NH3-TPD and IR study of acidity. Accordingly, the hierarchical porosity and acidity property were discussed systematically. Finally, the catalytic performance of the zeolites Y was evaluated in the cracking of 1,3,5-TIPB. It was found that desilication with NaOH&TBPH ensured the more uniform intracrystalline mesoporosity with higher microporosity, while preserving higher B/L ratio and moderate Brønsted acidities resulting in catalysts with the most appropriated acidity and then with better catalytic performance.

  18. Catalytic property of TiO2/PS complex nanoparticles prepared via a novel TSM

    Indian Academy of Sciences (India)

    Bitao Su; Xiaohong Zhang; Zhanying Ma; Peng Fei; Jiaxing Sun; Ziqiang Lei

    2010-12-01

    With an average size of 7 nm and good catalytic property under the natural light, TiO2/PS complex nanoparticles were successfully prepared through a novel two-step method (TSM) from TiCl4, used as both the catalyst for polymerization of styrene and Ti source, and styrene monomer and characterized by TG-DTA, XRD, IR, TEM and UV-Vis techniques. Its catalytic property was evaluated by the decolourization and degradation of dye MB solution under the natural light. From its TEM, the particles with an average size of 7 nm were observed without the separation of TiO2 and PS phases, i.e., TiO2/PS was hybrid material in nanosize scale. IR spectrum of TiO2/PS showed increase of unsaturated degree and growth of the group C=O on the chain of PS and Ti–O–C coordination bond between TiO2 and PS. The nanosize of the TiO2/PS complex particles and the conjugated structure and polar groups of PS were advantageous to good adsorptive property and strong interaction of PS and TiO2. And they brought multi-functions of inorganic and organic materials in the single material. Catalytic experiments indicated that the complex nanoparticles could catalytically degrade dye MB solution in 10 min under the natural light while P25 basically showed adsorptive property for MB molecules under the same conditions.

  19. Enhanced catalytic oxidation ability of ternary layered double hydroxides for organic pollutants degradation.

    Science.gov (United States)

    Fahel, Jean; Kim, Sanghoon; Durand, Pierrick; André, Erwan; Carteret, Cédric

    2016-05-10

    Co(2+) and Cu(2+) substituted MgAl layered double hydroxides with an M(2+)/M(3+) atomic ratio of 2.0 were synthesized by a co-precipitation method and fully characterized using various techniques including powder X-ray diffraction, ICP-AES analysis, FT-IR, DR UV-Vis spectroscopy, N2 adsorption-desorption and transmission electron microscopy. The materials revealed a good crystallinity with no phase impurity and successful substitution of cobalt and copper ions in the framework of binary LDH with the target ratio of metals in the sheet. The adsorption characteristics (kinetic and isotherm) and the catalytic oxidation of organic pollutants, methylene blue (cationic dye) and orange II (anionic) were carried out to investigate a potential use of LDH materials as catalysts. In particular, Co3Cu1Al2 LDH exhibited an excellent catalytic activity towards catalytic dye degradation, especially for orange II with good stability and reusability over several times. Furthermore, this LDH material showed good catalytic performance for several chlorophenol compounds, suggesting its practical application in wastewater treatment. Therefore, layered double hydroxides substituted with Co(2+) and Cu(2+) could be promising candidates in various applications, such as the abatement of organic pollutants. PMID:27097543

  20. Adsorption of Atenolol on Kaolinite

    Directory of Open Access Journals (Sweden)

    Yingmo Hu

    2015-01-01

    Full Text Available In this study the adsorption of atenolol (AT, a β-blocker, on kaolinite, a clay mineral of low surface charge, was investigated under varying initial AT concentration, equilibrium time, solution pH, ionic strength, and temperature conditions. The results showed that the amounts of AT uptake by kaolinite were close to its cation exchange capacity value and the AT adsorption was almost instantaneous, suggesting a surface adsorption. The adsorption was exothermic and the free energy of adsorption was small negative, indicating physical adsorption. The increase in ionic strength of the solution drastically reduced AT uptake on kaolinite. A significant reduction in AT uptake was found at solution pH below 5 or above 10. The FTIR results showed band shifting and disappearance for NH bending vibration and benzene ring skeletal vibration at 3360 and 1515 cm−1 and band splitting at 1412 and 1240 cm−1 attributed to C–N valence vibration coupled with NH bending vibrations and alkyl aryl ether linkage, suggesting the participation of NH, –O–, and benzene ring for AT adsorption on kaolinite.

  1. Adsorption Desalination: A Novel Method

    KAUST Repository

    Ng, Kim Choon

    2010-11-15

    The search for potable water for quenching global thirst remains a pressing concern throughout many regions of the world. The demand for new and sustainable sources and the associated technologies for producing fresh water are intrinsically linked to the solving of potable water availability and hitherto, innovative and energy efficient desalination methods seems to be the practical solutions. Quenching global thirst by adsorption desalination is a practical and inexpensive method of desalinating the saline and brackish water to produce fresh water for agriculture irrigation, industrial, and building applications. This chapter provides a general overview of the adsorption fundamentals in terms of adsorption isotherms, kinetics, and heat of adsorption. It is then being more focused on the principles of thermally driven adsorption desalination methods. The recent developments of adsorption desalination plants and the effect of operating conditions on the system performance in terms of specific daily water production and performance ratio are presented. Design of a large commercial adsorption desalination plant is also discussed herein.

  2. Thickness dependence of fracture behaviour in a superconducting strip

    International Nuclear Information System (INIS)

    When subjected to a magnetic field, a superconducting strip will undergo an electromagnetic body force induced by flux pinning. The magnitude of the body force is dependent on the critical current density. It is well known that the critical current density in the strip will decrease with increasing thickness. In addition, the mechanical behaviour of the strip will also be affected by the thickness of the strip. Thus, the strip thickness has an influence on both the electromagnetic and mechanical behaviours. In this paper, we analyse the fracture behaviour by considering the competition of electromagnetic and mechanical behaviours. In order to study the central crack problem of a superconducting strip with different thicknesses, we replace the electromagnetic body force with the total surface force. Using a Fourier transform method, the boundary value problem is reduced to a singular integral equation. By solving the singular integral equation, we obtain the stress intensity factors for two different crack lengths during field descent. The results show that the stress intensity factor is not a monotonic function of the thickness and that two competing factors dominate in different field regions. It is necessary to obtain the optimized thickness by considering both the superconductivity and mechanical behaviour in the superconducting strip. (paper)

  3. Catalytic distillation water recovery subsystem

    Science.gov (United States)

    Budininkas, P.; Rasouli, F.

    1985-01-01

    An integrated engineering breadboard subsystem for the recovery of potable water from untreated urine based on the vapor phase catalytic ammonia removal was designed, fabricated and tested. Unlike other evaporative methods, this process catalytically oxidizes ammonia and volatile hydrocarbons vaporizing with water to innocuous products; therefore, no pretreatment of urine is required. Since the subsystem is fabricated from commercially available components, its volume, weight and power requirements are not optimized; however, it is suitable for zero-g operation. The testing program consists of parametric tests, one month of daily tests and a continuous test of 168 hours duration. The recovered water is clear, odorless, low in ammonia and organic carbon, and requires only an adjustment of its pH to meet potable water standards. The obtained data indicate that the vapor phase catalytic ammonia removal process, if further developed, would also be competitive with other water recovery systems in weight, volume and power requirements.

  4. Engineering reactors for catalytic reactions

    Indian Academy of Sciences (India)

    Vivek V Ranade

    2014-03-01

    Catalytic reactions are ubiquitous in chemical and allied industries. A homogeneous or heterogeneous catalyst which provides an alternative route of reaction with lower activation energy and better control on selectivity can make substantial impact on process viability and economics. Extensive studies have been conducted to establish sound basis for design and engineering of reactors for practising such catalytic reactions and for realizing improvements in reactor performance. In this article, application of recent (and not so recent) developments in engineering reactors for catalytic reactions is discussed. Some examples where performance enhancement was realized by catalyst design, appropriate choice of reactor, better injection and dispersion strategies and recent advances in process intensification/ multifunctional reactors are discussed to illustrate the approach.

  5. Catalytic activity of Au nanoparticles

    DEFF Research Database (Denmark)

    Larsen, Britt Hvolbæk; Janssens, Ton V.W.; Clausen, Bjerne;

    2007-01-01

    Au is usually viewed as an inert metal, but surprisingly it has been found that Au nanoparticles less than 3–5 nm in diameter are catalytically active for several chemical reactions. We discuss the origin of this effect, focusing on the way in which the chemical activity of Au may change with par......Au is usually viewed as an inert metal, but surprisingly it has been found that Au nanoparticles less than 3–5 nm in diameter are catalytically active for several chemical reactions. We discuss the origin of this effect, focusing on the way in which the chemical activity of Au may change...... with particle size. We find that the fraction of low-coordinated Au atoms scales approximately with the catalytic activity, suggesting that atoms on the corners and edges of Au nanoparticles are the active sites. This effect is explained using density functional calculations....

  6. The water crisis in the gaza strip: prospects for resolution.

    Science.gov (United States)

    Weinthal, E; Vengosh, A; Marei, A; Kloppmann, W

    2005-01-01

    Israel and the Palestinian Authority share the southern Mediterranean coastal aquifer. Long-term overexploitation in the Gaza Strip has resulted in a decreasing water table, accompanied by the degradation of its water quality. Due to high levels of salinity and nitrate and boron pollution, most of the ground water is inadequate for both domestic and agricultural consumption. The rapid rate of population growth in the Gaza Strip and dependence upon ground water as a single water source present a serious challenge for future political stability and economic development. Here, we integrate the results of geochemical studies and numerical modeling to postulate different management scenarios for joint management between Israel and the Palestinian Authority. The chemical and isotopic data show that most of the salinity phenomena in the Gaza Strip are derived from the natural flow of saline ground water from Israel toward the Gaza Strip. As a result, the southern coastal aquifer does not resemble a classic "upstream-downstream" dispute because Israel's pumping of the saline ground water reduces the salinization rates of ground water in the Gaza Strip. Simulation of different pumping scenarios using a monolayer, hydrodynamic, two-dimensional model (MARTHE) confirms the hypothesis that increasing pumping along the Gaza Strip border combined with a moderate reduction of pumping within the Gaza Strip would improve ground water quality within the Gaza Strip. We find that pumping the saline ground water for a source of reverse-osmosis desalination and then supplying the desalinated water to the Gaza Strip should be an essential component of a future joint management strategy between Israel and the Palestinian Authority.

  7. tudy on Hydrolysis of Methyl Acetate in a Catalytic Distillation Column

    Institute of Scientific and Technical Information of China (English)

    王成习

    2001-01-01

    A nonequilibrium stage model was used to simulate countercurrent multicomponent catalytic distillation processes for methyl acetate hydrolysis. Computations of stage eiliciencies or height equivalent to a theoretical plate (HETP) were entirely avoided by this model. The consistency of simulated results and experimental data in conversions and concentration of each component along a column indicates that the model predicts the actual process well. The influences of operating parameters on hydrolytic conversions, such as feed molar ratios, feed locations, feed and reflux rates, heights of reactive and stripping sections, were analyzed adequately by simulating calcuiations. A good operating mode was then obtained, which is helpful to the development of a new process.

  8. Reaction Current Phenomenon in Bifunctional Catalytic Metal-Semiconductor Nanostructures

    Science.gov (United States)

    Hashemian, Mohammad Amin

    Energy transfer processes accompany every elementary step of catalytic chemical processes on material surface including molecular adsorption and dissociation on atoms, interactions between intermediates, and desorption of reaction products from the catalyst surface. Therefore, detailed understanding of these processes on the molecular level is of great fundamental and practical interest in energy-related applications of nanomaterials. Two main mechanisms of energy transfer from adsorbed particles to a surface are known: (i) adiabatic via excitation of quantized lattice vibrations (phonons) and (ii) non-adiabatic via electronic excitations (electron/hole pairs). Electronic excitations play a key role in nanocatalysis, and it was recently shown that they can be efficiently detected and studied using Schottky-type catalytic nanostructures in the form of measureable electrical currents (chemicurrents) in an external electrical circuit. These nanostructures typically contain an electrically continuous nanocathode layers made of a catalytic metal deposited on a semiconductor substrate. The goal of this research is to study the direct observations of hot electron currents (chemicurrents) in catalytic Schottky structures, using a continuous mesh-like Pt nanofilm grown onto a mesoporous TiO2 substrate. Such devices showed qualitatively different and more diverse signal properties, compared to the earlier devices using smooth substrates, which could only be explained on the basis of bifunctionality. In particular, it was necessary to suggest that different stages of the reaction are occurring on both phases of the catalytic structure. Analysis of the signal behavior also led to discovery of a formerly unknown (very slow) mode of the oxyhydrogen reaction on the Pt/TiO2(por) system occurring at room temperature. This slow mode was producing surprisingly large stationary chemicurrents in the range 10--50 microA/cm2. Results of the chemicurrent measurements for the bifunctional

  9. Carbon nanomaterials for gas adsorption

    CERN Document Server

    Terranova, Maria Letizia

    2012-01-01

    Research in adsorption of gases by carbon nanomaterials has experienced considerable growth in recent years, with increasing interest for practical applications. Many research groups are now producing or using such materials for gas adsorption, storage, purification, and sensing. This book provides a selected overview of some of the most interesting scientific results regarding the outstanding properties of carbon nanomaterials for gas adsorption and of interest both for basic research and technological applications. Topics receiving special attention in this book include storage of H, purific

  10. A Study of Pt4+-Adsorption and Its Reduction by Bacillus Megaterium D01

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    The properties of Pt4+-adsorption and its reduction by Bacillus megaterium D01 were studied by means of ICP,anode-stripping voltammetry,TEM,IR and XPS.The results of ICP analyses showed that the Pt4+-adsorptive efficiency of the strain D01 was as high as 94.3% under the conditions of 100 mg Pt4+/L,1 g biomass/L,pH 3.5 and at 30 ℃ for 24 h.Moreover,it was confirmed from anode stripping voltammetry that the strain D01 possessed a strong reducibility.The TEM analysis indicated that the strain D01 was able to adsorb and reduce Pt4+ to Pt0,small particles.The XPS result further supported the reduction of Pt4+ to Pt2+,followed by the further recuction to Pt0.The IR spectrum implied that D01 biomass adsorption of Pt4+ may result in the complexation of the C=O bond to the Pt species.

  11. Improvement of Prediction Method for Strip Coiling Temperature

    Institute of Scientific and Technical Information of China (English)

    YU Qing-bo; WANG Zhao-dong; WANG Zhe-ying; LIU Xiang-hua; WANG Guo-dong

    2003-01-01

    In order to improve the control precision of strip coiling temperature for hot strip mill, the BP neural network was combined with mathematical model to calculate convective heat-transfer coefficient of laminar flow cooling. The off-line calculated results indicate that the standard deviation of coiling temperature prediction is reduced by 22.84 % with the convective heat-transfer coefficient calculated by BP neural network. The prospects of this method for on-line application are bright. This method is more helpful to increasing the control precision of coiling temperature for hot strip steel.

  12. New technology for the production of magnesium strips and sheets

    Directory of Open Access Journals (Sweden)

    R. Kawalla

    2008-07-01

    Full Text Available A new production technology for magnesium strip, based on twin-roll-casting and strip rolling was developed in Freiberg Germany. By means of this economic method it is possible to produce strips in deep drawing quality with good forming properties in order to satisfy the request for low cost Mg sheets in the automotive and electronic industry. Both, coils as single sheets, were manufactured and rolled to a thickness of 1mm(0,5 mm. The technology of the new process and the properties of the twin-roll-casted material and the final sheets are presented.

  13. Water Modeling of Twin-Roll Strip Casting

    Institute of Scientific and Technical Information of China (English)

    WANG Bo; ZHANG Jie-yu; FAN Jun-fei; ZHAO Shun-li; FANG Yuan; AN Sheng-li

    2006-01-01

    Twin-roll strip casting is regarded as a prospective technology of near net shape continuous casting. The fluid flow field and level fluctuation in the pool have a strong influence not only on composition and temperature homogeneity of pool, but also on the strip quality. A 1∶1 water model of a twin-roll strip caster was set up based on the criteria of Froude number and Reynold number similarity. The level fluctuation was measured. The influence of pool depth, casting speed and feeding system configuration on level fluctuation in the pool was studied. The experimental results provided a basis for the optimization of feeding system and process parameters.

  14. Element Tracking Strategies for Hot Strip Laminar Cooling Control

    Institute of Scientific and Technical Information of China (English)

    HAN Bin; ZHANG Zhong-ping; LIU Xiang-hua; WANG Guo-dong

    2005-01-01

    Feedforward control is the core to control function in the cooling process of hot strip. One of the most important tasks in feedforward control is to determine the arrival time of the strip at various locations on the runout table for effective control. Based on the principles of element tracking and tracking strategies for variable rolling speed and constant rolling speed, a simple diagonal tracking method for an existing hot strip mill was proposed and tested. The test results show that the proposed strategies are effective for improving tracking control.

  15. Understanding the Optimal Adsorption Energies for Catalyst Screening in Heterogeneous Catalysis

    OpenAIRE

    Yang, Bo; Burch, Robbie; Hardacre, Christopher; Headdock, Gareth; Hu, P

    2014-01-01

    The fundamental understanding of the activity in heterogeneous catalysis has long been the major subject in chemistry. This paper shows the development of a two-step model to understand this activity. Using the theory of chemical potential kinetics with Bronsted-Evans-Polanyi relations, the general adsorption energy window is determined from volcano curves, using which the best catalysts can be searched. Significant insights into the reasons for catalytic activity are obtained.

  16. [Selective catalytic oxidation of H2S over supported Fe catalysts on CeO2-intercalated laponite clay].

    Science.gov (United States)

    Sun, Chao; Zhang, Xin; Hao, Zheng-Ping; Dou, Guang-Yu; Sun, Chun-Bao

    2014-05-01

    A series of Fe/CeO2-intercalated clay catalysts were synthesized successfully, the physicochemical properties of the catalysts were characterized by XRD, BET, XRF, TG, FT-IR, O2-TPD, H2-TPR and XPS methods. The catalytic performances for selective catalytic oxidation of H2S were further investigated, all catalysts exhibited high catalytic activities. Among them 5% Fe/Ce-Lap presented the best activity at 180 degreeC and the maximum sulfur yield was up to 96% due to the interaction between iron and cerium, which improved the redox ability of Fe3+ . Moreover, the strong oxygen adsorption capacity and the well dispersion of iron species improved the catalytic performance efficiently.

  17. How surface reparation prevents catalytic oxidation of carbon monoxide on atomic gold at defective magnesium oxide surfaces.

    Science.gov (United States)

    Töpfer, Kai; Tremblay, Jean Christophe

    2016-07-21

    In this contribution, we study using first principles the co-adsorption and catalytic behaviors of CO and O2 on a single gold atom deposited at defective magnesium oxide surfaces. Using cluster models and point charge embedding within a density functional theory framework, we simulate the CO oxidation reaction for Au1 on differently charged oxygen vacancies of MgO(001) to rationalize its experimentally observed lack of catalytic activity. Our results show that: (1) co-adsorption is weakly supported at F(0) and F(2+) defects but not at F(1+) sites, (2) electron redistribution from the F(0) vacancy via the Au1 cluster to the adsorbed molecular oxygen weakens the O2 bond, as required for a sustainable catalytic cycle, (3) a metastable carbonate intermediate can form on defects of the F(0) type, (4) only a small activation barrier exists for the highly favorable dissociation of CO2 from F(0), and (5) the moderate adsorption energy of the gold atom on the F(0) defect cannot prevent insertion of molecular oxygen inside the defect. Due to the lack of protection of the color centers, the surface becomes invariably repaired by the surrounding oxygen and the catalytic cycle is irreversibly broken in the first oxidation step. PMID:27345190

  18. Anodic stripping voltammetry of technetium alkaline media

    International Nuclear Information System (INIS)

    A method of direct determination of technetium in 0.1 M NaOH by anodic stripping voltametry at glassy carbon electrode has been elaborated. The peak height of anodic TcO2(OH)2 dissolution was found to be linearly dependent on preconcentration time, and the concentration of technetium in the range 5.0 * 10-8 -6 M. The detection limit for the Tc determination by ASV technique under study was found to be 5.0 * 10-8 M with standard deviation 5-7% (p2(OH)2 anodic dissolution peak current. Addition of 1.0* 10-6 M U(UI) to the sample solution was found to shift the peak of the TcO2(OH)2 100 mV towards negative direction and disturb the linearity of the calibration curve. Therefore; for a successful application of the developed ASV technique for Tc determination in the alkaline media, uranium should be removed from the analyte before determination

  19. Profile of a science comic strip author

    CERN Multimedia

    Anaïs Schaeffer

    2014-01-01

    After studying visual arts, Lison Bernet worked as a lock keeper, waitress, grape picker, farm labourer and chef before finally returning to her first love: drawing. Today a scientific illustrator, Lison is the author of the cartoon strip "La BD du LHC", which she draws every month for LHC France (by CNRS/IN2P3 and CEA/Irfu, see here).   © Lison Bernet. Lison’s career path might seem somewhat chaotic, but it is a reflection of the artist herself: original and passionate. “I never do anything by half measures. When I got into cooking for example [Lison took a chef training course for adults], I became completely wrapped up in it. I even went as far as cooking roasts during my lunch hour, just for practice…” says Lison. On completing the course, Lison got a job as a chef on a canal boat. And it was then that she got the drawing bug again. “I started keeping an illustrated travel diary,” she says. &ldquo...

  20. An improved rolled strip pulse forming line

    Science.gov (United States)

    Li, Song; Qian, Bao-Liang; Yang, Han-Wu; Gao, Jing-Ming; Liu, Zhao-Xi

    2013-06-01

    The rolled strip pulse forming line (RSPFL) has advantages of compactness, portability, and long pulse achievability which could well meet the requirements of industrial application of the pulse power technology. In this paper, an improved RSPFL with an additional insulator between the grounded conductors is investigated numerically and experimentally. Results demonstrate that the jitter on the flat-top of the output voltage waveform is reduced to 3.8% due to the improved structure. Theoretical analysis shows that the electromagnetic coupling between the conductors of the RSPFL strongly influences the output voltage waveform. Therefore, the new structure was designed to minimize the detrimental effect of the electromagnetic coupling. Simulation results show that the electromagnetic coupling can be efficiently reduced in the improved RSPFL. Experimental results illustrate that the improved RSPFL, with dimensions and weight of Φ 290 × 250 mm and 16 kg, when used as a simple pulse forming line, could generate a well shaped quasi-square pulse with output power of hundreds of MW and pulse duration of 250 ns. Importantly, the improved RSPFL was successfully used as a Blumlein pulse forming line, and a 10.8 kV, 260 ns quasi-square pulse was obtained on a 2 Ω dummy load. Experiments show reasonable agreement with numerical analysis.

  1. Study of highly stripped ionic spectroscopy

    International Nuclear Information System (INIS)

    The soft X-ray emission spectra from very highly stripped ions of the medium-Z elements of 22T, 26Fe, 28Ni, 29Cu, 30Zn and 32Ge, and the high-Z elements of 72Hf, 73Ta, 74W and 75Re have been observed in laser-produced plasmas generated by focusing a Nd-glass laser beam onto the surface of the plane solid targets at the 'Xing Guang' laser facility. The spectra in the range of 3.6∼300 angstrom were recorded by using four flat crystal spectrographs with different 2d spacing and a 1-m grazing incidence grating spectrometer, respectively. Several hundred lines from Na-like through H-like ions of six medium-Z elements and from Co-like and Ni-like ions of four high-Z elements were identified and classified on the basis of a comparison between the measured wavelengths and intensities with the predicted values which were calculated by Hartree-Fock-Relativistic method with configuration interaction and the multiconfiguration Dirac-Fock-Relativistic method with configuration interaction and the multiconfiguration Dirac-Fock method. The quasi-continuum bands in Cu-like through Ge-like ions of Hf, Ta, W and Re were analyzed by unresolved spin-orbit-split array model

  2. Surface-integral formalism of deuteron stripping

    CERN Document Server

    Mukhamedzhanov, A M; Bertulani, C A; Kadyrov, A S

    2014-01-01

    The purpose of this paper is to develop an alternative theory of deuteron stripping to resonance states based on the surface integral formalism of Kadyrov et al. [Ann. Phys. 324, 1516 (2009)] and continuum-discretized coupled channels (CDCC). First we demonstrate how the surface integral formalism works in the three-body model and then we consider a more realistic problem in which a composite structure of target nuclei is taken via optical potentials. We explore different choices of channel wave functions and transition operators and show that a conventional CDCC volume matrix element can be written in terms of a surface-integral matrix element, which is peripheral, and an auxiliary matrix element, which determines the contribution of the nuclear interior over the variable $r_{nA}$. This auxiliary matrix element appears due to the inconsistency in treating of the $n-A$ potential: this potential should be real in the final state to support bound states or resonance scattering and complex in the initial state t...

  3. The progenitors of stripped-envelope supernovae

    Science.gov (United States)

    Elias-Rosa, N.

    2013-05-01

    The type Ib/c SNe are those explosions which come from massive star populations, but lack hydrogen and helium. These have been proposed to originate in the explosions of massive Wolf-Rayet stars, and we should easily be able to detect the very luminous, young progenitors if they exist. However, there has not been any detection of progenitors so far. I present the study of two extinguished Type Ic SNe 2003jg and 2004cc. In both cases there is no clear evidence of a direct detection of their progenitors in deep pre-explosion images. Upper limits derived by inserting artificial stars of known brightness at random positions around the progenitor positions (M_v>-8.8 and M_v>-9 magnitudes for the progenitors of SN 2003jg and SN 2004cc, respectively) are brighter than those expected for a massive WC (Wolf-Rayet, carbon-rich) or WO (Wolf-Rayet, oxygen-rich) (e.g., approximately between -3 and -6 in the LMC). Therefore, this is perhaps further evidence that the most massive stars may give rise to black-holes forming SNe, or it is an undetected, compact massive star hidden by a thick dust lane. However the extinction toward these SNe is currently one of the largest known. Even if these results do not directly reveal the nature of the type Ic SN progenitors, they can help to characterize the dusty environment which surrounded the progenitor of the stripped-envelope CC-SNe.

  4. Semiautomatic reconstruction of strip-shredded documents

    Science.gov (United States)

    De Smet, Patrick; De Bock, Johan; Philips, Wilfried

    2005-03-01

    Until recently, the forensic or investigative reconstruction of shredded documents has always been dismissed as an important but unsolvable problem. Manual reassembly of the physical remnants can always be considered, but for large amounts of shreds this problem can quickly become an intangible task that requires vast amounts of time and/or personnel. In this paper we propose and discuss several image processing techniques that can be used to enable the reconstruction of strip-shredded documents stored within a database of digital images. The technical content of this paper mainly revolves around the use of feature based matching and grouping methods for classifying the initial database of shreds, and the subsequent procedure for computing more accurate pairing results for the obtained classes of shreds. Additionally, we discuss the actual reassembly of the different shreds on top of a common image canvas. We illustrate our algorithms with example matching and reconstruction results obtained for a real shred database containing various types of shredded document pages. Finally, we briefly discuss the impact of our findings on secure document management strategies and the possibilities for applying the proposed techniques within the context of forensic investigation.

  5. The ALICE silicon strip detector system

    CERN Document Server

    Kuijer, P

    2000-01-01

    ALICE (A Large Ion Collider Experiment) is an experiment at the Large Hadron Collider (LHC) optimized for the study of heavy-ion collisions at a centre-of-mass energy of 5.5 TeV per nucleon. The detector consists essentially of two main components: the central part, composed of detectors mainly devoted to the study of hadronic signals and dielectrons, and the forward muon spectrometer devoted to the study of quarkonia behaviour in dense matter. The central part, which covers +-45 deg. (|eta|<0.9) over the full azimuth, is embedded in a large magnet with a weak solenoidal field. Outside of the Inner Tracking System (ITS), there are a cylindrical TPC and a large area PID array of time-of-flight (TOF) counters. In addition, there are two small-area single-arm detectors: an electromagnetic calorimeter (Photon Spectrometer, PHOS) and an array of RICH counters optimized for high-momentum inclusive particle identification (HMPID). This article describes the silicon strip detector system used in the outer layers o...

  6. Potential Theory of Multicomponent Adsorption

    DEFF Research Database (Denmark)

    Shapiro, Alexander; Stenby, Erling Halfdan

    1998-01-01

    We developed a theory of multicomponent adsorption on the basis of the potential concept originally suggested by Polanyi. The mixture is considered as a heterogeneous substance segregated in the external field emitted by the adsorbent. The same standard equation of state, with no additional fitting...... parameters, is used for the segregated and for the bulk phases. With this approach, few parameters are needed to correlate pure component adsorption isotherms. These parameters may be used to predict adsorption equilibria of multicomponent mixtures without additional adjustment. A connection between...... the potential theory and the spreading pressure concept is established, and problems of the theory consistency are studied. Numerical algorithms are suggested for evaluation of the segregated state of the mixture in the potential field of adsorption forces. Comparison with experimental data shows good agreement...

  7. Prediction of Pure Component Adsorption Equilibria Using an Adsorption Isotherm Equation Based on Vacancy Solution Theory

    DEFF Research Database (Denmark)

    Marcussen, Lis; Aasberg-Petersen, K.; Krøll, Annette Elisabeth

    2000-01-01

    An adsorption isotherm equation for nonideal pure component adsorption based on vacancy solution theory and the Non-Random-Two-Liquid (NRTL) equation is found to be useful for predicting pure component adsorption equilibria at a variety of conditions. The isotherm equation is evaluated successfully...... adsorption systems, spreading pressure and isosteric heat of adsorption are also calculated....

  8. Non-Oriented Fe-Si Thin Strip Produced from Grain Oriented Fe-Si Strip by CSR

    Institute of Scientific and Technical Information of China (English)

    YE He-zhou; QI Ke-min; GAO Xiu-hua; QIU Chun-lin; LIU En

    2004-01-01

    The grain oriented silicon strip was rolled by cross shear rolling (CSR) and then annealed to manufacture non-oriented thin silicon strip of high quality. The recrystallization of rolled grain-oriented silicon steel into non-oriented silicon steel was studied. For this purpose, CSR is better than conventional rolling, and the higher the mismatched speed rate is, the better the properties of the non-oriented thin silicon strip are. The optimum annealing schedule is heating at 1 000 ℃ for 1 h in pure hydrogen atmosphere added with H2S of 0.001 0 %.

  9. Molecular adsorption on graphene

    Science.gov (United States)

    Kong, Lingmei; Enders, Axel; Rahman, Talat S.; Dowben, Peter A.

    2014-11-01

    Current studies addressing the engineering of charge carrier concentration and the electronic band gap in epitaxial graphene using molecular adsorbates are reviewed. The focus here is on interactions between the graphene surface and the adsorbed molecules, including small gas molecules (H2O, H2, O2, CO, NO2, NO, and NH3), aromatic, and non-aromatic molecules (F4-TCNQ, PTCDA, TPA, Na-NH2, An-CH3, An-Br, Poly (ethylene imine) (PEI), and diazonium salts), and various biomolecules such as peptides, DNA fragments, and other derivatives. This is followed by a discussion on graphene-based gas sensor concepts. In reviewing the studies of the effects of molecular adsorption on graphene, it is evident that the strong manipulation of graphene’s electronic structure, including p- and n-doping, is not only possible with molecular adsorbates, but that this approach appears to be superior compared to these exploiting edge effects, local defects, or strain. However, graphene-based gas sensors, albeit feasible because huge adsorbate-induced variations in the relative conductivity are possible, generally suffer from the lack of chemical selectivity.

  10. Protein Adsorption in Three Dimensions

    OpenAIRE

    Vogler, Erwin A.

    2011-01-01

    Recent experimental and theoretical work clarifying the physical chemistry of blood-protein adsorption from aqueous-buffer solution to various kinds of surfaces is reviewed and interpreted within the context of biomaterial applications, especially toward development of cardiovascular biomaterials. The importance of this subject in biomaterials surface science is emphasized by reducing the “protein-adsorption problem” to three core questions that require quantitative answer. An overview of the...

  11. Amphiphile Adsorption on Rigid Polyelectrolytes

    OpenAIRE

    Kuhn, Paulo S.; Levin, Yan; Barbosa, Marcia C.; Ravazzolo, Ana Paula

    2007-01-01

    A theory is presented which quantitatively accounts for the cooperative adsorption of cationic surfactants to anionic polyelectrolytes. For high salt concentration we find that the critical adsorption concentration (CAC) is a bilinear function of the polyion monomer and salt concentrations, with the coefficients dependent only on the type of surfactant used. The results presented in the paper might be useful for designing more efficient gene delivery systems.

  12. Unique reactivity of Fe nanoparticles-defective graphene composites toward NH x (x = 0, 1, 2, 3) adsorption: A first-principles study

    KAUST Repository

    Liu, Xin

    2012-01-01

    We investigated the electronic structure of Fe nanoparticle-graphene composites and the impact of the interfacial interaction on NH x (x = 0, 1, 2, 3) adsorption by first-principles based calculations. We found that Fe 13 nanoparticles can be stabilized by the sp 2 dangling bonds on single vacancy graphene substrate with a binding energy up to -7.07 eV. This interaction not only deformed the carbon atoms around the defect and gave rise to the stability of the Fe nanoparticle against sintering, but also had significant impact on the adsorption of NH x that is related to the catalytic performance of these composites in NH 3 decomposition. Doping of the single vacancy graphene with N or B can finely tune the adsorption of NH x. Further analysis revealed that the calculated adsorption energies of NH x on these composites correlated well with the shift of the average d-band center of the Fe nanoparticles and they were around the peak of the activity-adsorption energy curve for NH 3 decomposition catalysts, especially when doped with B. The optimal adsorption of NH x on Fe nanoparticles deposited on boron-doped defective graphene suggests the possible high stability and superior catalytic performance of these composites in the low-temperature catalytic decomposition of NH 3. This journal is © 2012 the Owner Societies.

  13. Catalytic properties of niobium compounds

    International Nuclear Information System (INIS)

    The catalytic activity and selectivity of niobium compounds including oxides, salts, organometallic compounds and others are outlined. The application of these compounds as catalysts to diversified reactions is reported. The nature and action of niobium catalysts are characteristic and sometimes anomalous, suggesting the necessity of basic research and the potential use as catalysts for important processes in the chemical industry. (Author)

  14. Simple, chemoselective, catalytic olefin isomerization.

    Science.gov (United States)

    Crossley, Steven W M; Barabé, Francis; Shenvi, Ryan A

    2014-12-01

    Catalytic amounts of Co(Sal(tBu,tBu))Cl and organosilane irreversibly isomerize terminal alkenes by one position. The same catalysts effect cycloisomerization of dienes and retrocycloisomerization of strained rings. Strong Lewis bases like amines and imidazoles, and labile functionalities like epoxides, are tolerated.

  15. Acrylamide content and color development in fried potato strips

    DEFF Research Database (Denmark)

    Pedreschi, F.; Kaack, K.; Granby, Kit

    2006-01-01

    and 45 min; 90 degrees C for 3 and 10 min); (iii) immersed in a citric acid solution of 10 g/L for an hour; (iv) immersed in a sodium pyrophosphate solution of 10 g/L for an hour. Acrylamide content and color was determined in the potato strips after frying. Immersed strips in water for 120 min showed...... (13 5, 327 and 564 mu m acrylamide/kg for 150, 170 and 190 degrees C, respectively). Potato strip immersion in citric acid solution of 10 g/L reduced much more the acrylamide formation after frying than the strip immersion in sodium pyrophosphate solution of 10 g/L (53% vs. 17%, respectively, average...

  16. Results of Laboratory Testing of Advanced Power Strips: Preprint

    Energy Technology Data Exchange (ETDEWEB)

    Earle, L.; Sparn, B.

    2012-08-01

    This paper describes the results of a laboratory investigation to evaluate the technical performance of advanced power strip (APS) devices when subjected to a range of home entertainment center and home office usage scenarios.

  17. SIMULATION OF THE TWIN ROLL STAINLESS STRIP CASTING PROCESS

    Institute of Scientific and Technical Information of China (English)

    Y.C. Miao; X.M. Zhang; G.D. Wang; H.S. Di; X.H. Liu

    2001-01-01

    The position of the solidification completed temperature of twin roll stainless strip casting process is very important to the quality of the casting strip. In order to control this position, the solidification completed temperature should be known at first.The present paper first simulated dendritic microsegregation under conditions of twin roll stainless strip casting, and got the relationship between the temperature and solid fraction of the mush zone. The temperatures such as ZDT (equal to the solidification completed temperature) and LIT (liquid impenetrable temperature), et al., also were obtained. Then by using the turbulent model, the flow and thermal fields of the pool of the twin roll stainless strip casting, and the speed and temperature fields of different casting speeds were given and also explained. The results are coincident with the experimental result. Combined with the results of these two simulations. the appropriated casting speed was found.

  18. Flow and heat transfer in compact offset strip fin surfaces

    Institute of Scientific and Technical Information of China (English)

    Junqi DONG; Jiangping CHEN; Zhijiu CHEN

    2008-01-01

    Experimental studies of air-side heat transfer and pressure drop characteristics of offset strip fins and flat tube heat exchangers were performed. A series of tests were conducted for 9 heat exchangers with different fin space, fin height, fin strip length and flow length, at a constant tube-side water flow rate of 2.5 m3/h. The char-acteristics of the heat transfer and pressure drop of differ-ent fin space, fin height and fin length were analyzed and compared. The curves of the heat transfer coefficients vs. The pumping power per unit frontal area were then plot-ted. Moreover, the enhanced heat transfer mechanism of offset strip fins was analyzed using field synergy theory. The results showed that fin length and flow length have more obviously effect on the thermal hydraulic character-istics of offset strip fins.

  19. Digital simulation of anodic stripping voltammetry from thin film electrodes

    International Nuclear Information System (INIS)

    The anodic stripping voltammetry (ASV) is routinely applied to control of Cu(II) in heavy water in the primary cooling loop of the Nuclear Power Reactor. The anodic stripping voltammetry (ASV) is a very well-known technique in electroanalytical chemistry. However, due to the complexity of the phenomena, it is practised with the fundamentals of empiric considerations. A geometric model for the anodic stripping voltammetry (ASV) from thin film electrodes which can be calculated by explicit digital simulation method is proposed as a possibility of solving the electrochemically reversible, cuasi-reversible and irreversible reactions under linear potential scan and multiple potential scans. (Until now the analytical mathematical method was applied to reversible reactions). All the results are compared with analytical solutions and experimental results and it permits to conclude that the anodic stripping voltammetry (ASV) can be studied with the simplicity and potentialities of explicit digital simulation methods. (M.E.L.)

  20. Slow-plasmon resonant nano-strip antennas

    DEFF Research Database (Denmark)

    Søndergaard, Thomas; Beermann, Jonas; Boltasseva, Alexandra;

    2008-01-01

    Resonant scattering by gold nanostrip antennas due to constructive interference of counterpropagating slow surface plasmon polaritons SPPs is analyzed, including the quasistatic limit of ultrasmall antennas, and experimentally demonstrated. The phase of slow SPP reflection by strip ends is found...

  1. Data acquisition software for the CMS strip tracker

    CERN Document Server

    Bainbridge, R; Bel, S; Cole, J; Cripps, N; Delaere, C; Jesus, A C A; Drouhin, F; Fulcher, J; Giassi, A; Gill, K; Giordano, D; Gross, L; Hahn, K; Mersi, S; Mirabito, L; Nikolic, M; Radicci, V; Tkaczyk, S; Wingham, M

    2008-01-01

    The CMS silicon strip tracker, providing a sensitive area of approximately 200 m2 and comprising 10 million readout channels, has recently been completed at the tracker integration facility at CERN. The strip tracker community is currently working to develop and integrate the online and offline software frameworks, known as XDAQ and CMSSW respectively, for the purposes of data acquisition and detector commissioning and monitoring. Recent developments have seen the integration of many new services and tools within the online data acquisition system, such as event building, online distributed analysis, an online monitoring framework, and data storage management. We review the various software components that comprise the strip tracker data acquisition system, the software architectures used for stand-alone and global data-taking modes. Our experiences in commissioning and operating one of the largest ever silicon micro-strip tracking systems are also reviewed.

  2. Method for measuring the heavy stripped ion abundances of plasma

    International Nuclear Information System (INIS)

    A description is given of a system which uses a velocity filter and an energy filter in tandem to analyze the abundances and energy spreads of highly stripped ions. The system can also serve as a plasma diagnostic. (Auth.)

  3. Electroplating and stripping copper on molybdenum and niobium

    Science.gov (United States)

    Power, J. L.

    1978-01-01

    Molybdenum and niobium are often electroplated and subsequently stripped of copper. Since general standard plating techniques produce poor quality coatings, general procedures have been optimized and specified to give good results.

  4. Nanoscale Test Strips for Multiplexed Blood Analysis Project

    Data.gov (United States)

    National Aeronautics and Space Administration — The goal of our nanoscale test strips, or nanostrips, is to provide rapid, low-cost, powerful multiplexed analyses in a diminutive form so that whole body health...

  5. ADSORPTION OF POLYCHLORINATED BIPHENYLS BY SOILS

    OpenAIRE

    Mihaela Preda; Radu Lăcătuşu; Dumitru Marian Motelică; Nicoleta Vrînceanu; Veronica Tănase

    2010-01-01

    The behavior of polychlorinated biphenyls (PCBs) in soil is determined by several factors including adsorption, mobility and degradation. Adsorption, directly or indirectly, influences the other factors. Adsorption process is generally evaluated by using adsorption isotherms representing the relationship between the quantity of substance adsorbed per unit weight and concentration of the substance in solution at equilibrium. They allow determination of the adsorption constant, which is directl...

  6. Adsorption refrigeration technology theory and application

    CERN Document Server

    Wang, Ruzhu; Wu, Jingyi

    2014-01-01

    Gives readers a detailed understanding of adsorption refrigeration technology, with a focus on practical applications and environmental concerns Systematically covering the technology of adsorption refrigeration, this book provides readers with a technical understanding of the topic as well as detailed information on the state-of-the-art from leading researchers in the field. Introducing readers to background on the development of adsorption refrigeration, the authors also cover the development of adsorbents, various thermodynamic theories, the design of adsorption systems and adsorption refri

  7. Modeling of Experimental Adsorption Isotherm Data

    OpenAIRE

    Xunjun Chen

    2015-01-01

    Adsorption is considered to be one of the most effective technologies widely used in global environmental protection areas. Modeling of experimental adsorption isotherm data is an essential way for predicting the mechanisms of adsorption, which will lead to an improvement in the area of adsorption science. In this paper, we employed three isotherm models, namely: Langmuir, Freundlich, and Dubinin-Radushkevich to correlate four sets of experimental adsorption isotherm data, which were obtained...

  8. Ram Pressure Stripping in Groups: Comparing Theory and Observations

    OpenAIRE

    Hester, J. A.

    2006-01-01

    Ram pressure stripping may be the dominant mechanisms driving the evolution of galaxy colors in groups and clusters. In this paper, an analytic model of ram pressure stripping is confronted with observations of galaxy colors and star formation rates in groups using a group catalog drawn from the Sloan Digital Sky Survey. An observed increase in the fraction of galaxies residing on the red sequence, the red fraction, with both increasing group mass, $M_{gr}$, and decreasing satellite luminosit...

  9. Rigorous LiDAR Strip Adjustment with Triangulated Aerial Imagery

    OpenAIRE

    Zhang, Y. J.; Xiong, X. D.; Hu, X Y

    2013-01-01

    This paper proposes a POS aided LiDAR strip adjustment method. Firstly, aero-triangulation of the simultaneously obtained aerial images is conducted with a few photogrammetry-specific ground control points. Secondly, LiDAR intensity images are generated from the reflectance signals of laser foot points, and conjugate points are automatically matched between the LiDAR intensity image and the aero-triangulated aerial image. Control points used in LiDAR strip adjustment are derived from...

  10. Continuous extrusion and rolling forming technology of copper strip manufacture

    OpenAIRE

    Yun Xinbing; Zhou Mo; Tian Tian; Zhao Ying

    2015-01-01

    Continuous extrusion and rolling technology was proposed as a new strip production technology. It finished hot rolling process using the waste heat of the continuous extrusion forming. The continuous extrusion and rolling forming process was simulated by DEFORM-3DT software. The influence of extrusion wheel velocity and strip size on the continuous extrusion and rolling forming process was analyzed. The experiment was carried out according to optimized results of numerical simulation, the mic...

  11. The diagonal strip system in the Macro experiment

    Science.gov (United States)

    Devicenzi, M.; Lipari, P.; Martellotti, G.; Pellizzoni, G.

    1988-11-01

    The Macro scintillation counter modular system with streamer tubes and track-etch detectors is presented, and the characteristics, manufacturing, and assembling of its pick-up strips are described. The strips are composed of thin conducting plates 31 mm long, spaced 2.6 mm apart, and bonded on a 1 mm polyvinyl chloride (PVC) ribbon with a grounded metal surface on the other side of the ribbon. The manufacturing is done by bonding the aluminum elements on the PVC ribbon.

  12. PECULIAR FEATURES PERTAINING TO STRIP FORMATION FROM BAR

    Directory of Open Access Journals (Sweden)

    G. N. Zdor

    2010-01-01

    Full Text Available The paper describes results of calculations and presents experimental substantiation of the dependence of a strip width being rolled out of a 10-mm diameter bar on its final thickness. It has been shown that the formation technology of thin steel strips out of a round bar makes it possible without any difficulties to obtain rolled products with the given cross-section dimensions due to proper selection of single drafting.

  13. PECULIAR FEATURES PERTAINING TO STRIP FORMATION FROM BAR

    OpenAIRE

    G. N. Zdor; L. A. Isaevich; S. V. Ivanitsky

    2010-01-01

    The paper describes results of calculations and presents experimental substantiation of the dependence of a strip width being rolled out of a 10-mm diameter bar on its final thickness. It has been shown that the formation technology of thin steel strips out of a round bar makes it possible without any difficulties to obtain rolled products with the given cross-section dimensions due to proper selection of single drafting.

  14. Adsorption behaviors of thiophene, benzene, and cyclohexene on FAU zeolites: Comparison of CeY obtained by liquid-, and solid-state ion exchange

    Science.gov (United States)

    Qin, Yucai; Mo, Zhousheng; Yu, Wenguang; Dong, Shiwei; Duan, Linhai; Gao, Xionghou; Song, Lijuan

    2014-02-01

    Cerium containing Y zeolites were prepared by liquid- (L-CeY) and solid- (S-CeY) state ion exchange from NaY and HY, respectively. The structural and textural properties were characterized by XRD and N2 adsorption, and acidity properties were characterized by NH3 temperature-programmed desorption (NH3-TPD) and in situ FTIR spectrum of chemisorbed pyridine (in situ Py-FTIR). Furthermore, the single component adsorption and multi-component competitive adsorption behavior of thiophene, benzene and cyclohexene on those zeolites have also been studied by using vapor adsorption isotherms, solution adsorption breakthrough curves, thermogravimetry and derivative thermogravimetry (TG/DTG), frequency response (FR) and in situ FTIR techniques. The results indicate that the primary adsorption mode of benzene is simply micropore filling process, but the nature of effect of aromatics on selective adsorption of thiophene is competitive adsorption. The strong chemical adsorptions and protonization reactions of thiophene and cyclohexene occur upon the Brönsted acid sites of the HY and L-CeY zeolites, and the preferable acid catalytic protonization reactions of olefins hinder the further adsorption of sulfur compounds.

  15. Tuning the Reactivity of Ultrathin Oxides: NO Adsorption on Monolayer FeO(111).

    Science.gov (United States)

    Merte, Lindsay R; Heard, Christopher J; Zhang, Feng; Choi, Juhee; Shipilin, Mikhail; Gustafson, Johan; Weaver, Jason F; Grönbeck, Henrik; Lundgren, Edvin

    2016-08-01

    Ultrathin metal oxides exhibit unique chemical properties and show promise for applications in heterogeneous catalysis. Monolayer FeO films supported on metal surfaces show large differences in reactivity depending on the metal substrate, potentially enabling tuning of the catalytic properties of these materials. Nitric oxide (NO) adsorption is facile on silver-supported FeO, whereas a similar film grown on platinum is inert to NO under similar conditions. Ab initio calculations link this substrate-dependent behavior to steric hindrance caused by substrate-induced rumpling of the FeO surface, which is stronger for the platinum-supported film. Calculations show that the size of the activation barrier to adsorption caused by the rumpling is dictated by the strength of the metal-oxide interaction, offering a straightforward method for tailoring the adsorption properties of ultrathin films. PMID:27346455

  16. Development of a thin steel strip casting process. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Williams, R.S.

    1994-04-01

    This is a comprehensive effort to develop direct strip casting to the point where a pilot scale program for casting carbon steel strip could be initiated. All important aspects of the technology were being investigated, however the program was terminated early due to a change in the business strategy of the primary contractor, Armco Inc. (focus to be directed at specialty steels, not low carbon steel). At termination, the project was on target on all milestones and under budget. Major part was casting of strip at the experiment casting facility. A new caster, capable of producing direct cast strip of up to 12 in. wide in heats of 1000 and 3000 lb, was used. A total of 81 1000-1200 lb heats were cast as well as one test heat of 3000 lb. Most produced strip of from 0.016 to 0.085 in. thick. Process reliability was excellent for short casting times; quality was generally poor from modern hot strip mill standards, but the practices necessary for good surface quality were identified.

  17. Effects of γ-irradiation and ageing on surface and catalytic properties of nano-sized Cu O/Mg O system

    International Nuclear Information System (INIS)

    0.2 Cu O/Mg O system prepared by impregnation method was calcined at 350 and 450 C. The effects of γ-rays (0.2-1.6 MGy) on its structure, surface and catalytic properties were investigated by using XRD, N2-adsorption at -196 C and catalytic conversion of isopropanol at 150-275 C using a flow technique. The results revealed that the investigated solids consisted of nano-sized Mg O as a major phase besides Cu O and trace amount of Cu2O. γ-Irradiation of the solids investigated exerted measurable changes in their surface and catalytic properties dependent on the calcination temperature and dose of irradiation. The catalysts investigated acted as active dehydrogenation solids. The five years-ageing of different solids showed limited changes of their surface and catalytic properties indicating a good catalytic stability of the irradiated prepared solids. (Author)

  18. Effects of {gamma}-irradiation and ageing on surface and catalytic properties of nano-sized Cu O/Mg O system

    Energy Technology Data Exchange (ETDEWEB)

    El-Molla, S. A. [Ain Shams University, Faculty of Education, Chemistry Deparment, Roxy, Heliopolis, 11757 Cairo (Egypt); Ismail, S. A.; Ibrahim, M. M., E-mail: saharelmolla@yahoo.com [National Center for Radiation Research and Technology, Nasr City, P.O. Box 29, 11731 Cairo (Egypt)

    2011-07-01

    0.2 Cu O/Mg O system prepared by impregnation method was calcined at 350 and 450 C. The effects of {gamma}-rays (0.2-1.6 MGy) on its structure, surface and catalytic properties were investigated by using XRD, N{sub 2}-adsorption at -196 C and catalytic conversion of isopropanol at 150-275 C using a flow technique. The results revealed that the investigated solids consisted of nano-sized Mg O as a major phase besides Cu O and trace amount of Cu{sub 2}O. {gamma}-Irradiation of the solids investigated exerted measurable changes in their surface and catalytic properties dependent on the calcination temperature and dose of irradiation. The catalysts investigated acted as active dehydrogenation solids. The five years-ageing of different solids showed limited changes of their surface and catalytic properties indicating a good catalytic stability of the irradiated prepared solids. (Author)

  19. Catalytic activity trends of CO oxidation – A DFT study

    DEFF Research Database (Denmark)

    Jiang, Tao

    There are two goals of this thesis, the first one is to understand the reactivity of noble metal nanoparticles for CO oxidation reaction. The second goal is to gain understanding to the second derivative (Hessian matrix) of the potential energy surfaces (PES) of adsorption systems, especially its...... eigenmodes and eigenvalues, and improving algorithms for geometry optimization in electronic structure calculations. The catalytic activity of gold nanoparticles has received wide attention since the discovery of their activity on CO oxidation by Professor Haruta in 1987. By using density functional theory...... oxidation by molecular O2 occurs via a different reaction pathway, which instead involves a meta-stable intermediate CO-O2. However, although the two oxidizing agents used proceeded via different reaction pathways on different active sites, the apparent overall activation barriers obtained from both theory...

  20. Mechanism for enhanced degradation of clofibric acid in aqueous by catalytic ozonation over MnOx/SBA-15.

    Science.gov (United States)

    Sun, Qiangqiang; Wang, Yu; Li, Laisheng; Bing, Jishuai; Wang, Yingxin; Yan, Huihua

    2015-04-01

    Comparative experiments were conducted to investigate the catalytic ability of MnO(x)/SBA-15 for the ozonation of clofibric acid (CA) and its reaction mechanism. Compared with ozonation alone, the degradation of CA was barely enhanced, while the removal of TOC was significantly improved by catalytic ozonation (O3/MnO(x)/SBA-15). Adsorption of CA and its intermediates by MnO(x)/SBA-15 was proved unimportant in O3/MnO(x)/SBA-15 due to the insignificant adsorption of CA and little TOC variation after ceasing ozone in stopped-flow experiment. The more remarkably inhibition effect of sodium bisulfite (NaHSO3) on the removal of TOC in catalytic ozonation than in ozonation alone elucidated that MnO(x)/SBA-15 facilitated the generation of hydroxyl radicals (OH), which was further verified by electron spin-resonance spectroscopy (ESR). Highly dispersed MnO(x) on SBA-15 were believed to be the main active component in MnO(x)/SBA-15. Some intermediates were indentified and different degradation routes of CA were proposed in both ozonation alone and catalytic ozonation. The amounts of small molecular carboxylic acids (i.e., formic acid (FA), acetic acid (AA) and oxalic acid (OA)) generated in catalytic ozonation were lower than in ozonation alone, resulting from the generation of more OH.

  1. Size-dependent catalytic kinetics and dynamics of Pd nanocubes: a single-particle study.

    Science.gov (United States)

    Chen, Tao; Zhang, Yuwei; Xu, Weilin

    2016-08-10

    Due to the well-known significant effect of the size on the catalytic activity of nanocatalysts, here we use single-molecule fluorescence microscopy to study the size-dependent catalytic kinetics and dynamics of individual Pd nanocubes. A series of size-dependent catalytic properties were revealed in both product formation and product desorption processes. It was found that, due to the different adsorption mechanisms of substrate molecules on Pd nanocubes, H2 adsorption is independent of the size of Pd nanocubes, while the large flat resazurin molecules show stronger adsorption on larger sized Pd nanocubes. Apparently, the Pd nanocubes can be divided into three types: when the size of the Pd nanocube is small, substrate binding can prohibit product desorption and product desorption prefers the direct pathway; when the size is in an appropriate range, the product desorption process could be independent of substrate binding and shows no selectivity between two parallel desorption pathways; if the size is large enough, substrate binding can promote product desorption and product desorption prefers the indirect pathway. We also observed the surface-restructuring-induced dynamic heterogeneity of individual Pd nanocubes in both product formation and desorption processes with timescales of about tens to one hundred seconds. The activity fluctuation of individual Pd nanocubes was found to be mainly due to the spontaneous surface-restructuring rather than the catalysis. Furthermore, we estimated the size-dependent activation energies and time scales of spontaneous dynamic surface restructuring, which are fundamental to heterogeneous catalysis. The work presented here reveals new insight into nanocatalysis and exemplifies the advantages of the single-molecule approach in probing the catalytic properties of nanocatalysts. PMID:27465438

  2. Microstructure and Eutectic Carbide Morphology of the High Speed Steel Strips Produced by Twin Roll Strip Casting Process

    Institute of Scientific and Technical Information of China (English)

    Hongshuang DI; Xiaoming ZHANG; Guodong WANG; Xianghua LIU

    2003-01-01

    The M2 high-speed steel strip was produced by using the laboratory scale twin roll strip caster. The microstructureand eutectic carbide morphology of thus produced products were observed and analyzed, and the comparison ofthose with conventional products was carried out. The effects of the processing parameters such as the meltingtemperature, the pouring temperature, rolling speed and separating force on the microstructure and eutectic carbidemorphology and their distribution were analyzed. The spheroidizing process of the strips in the annealing process wasinvestigated. The relations between the growth and spheroidizing of the eutectic carbide and the annealing technologywere obtained, and the mechanism of the twin roll strip casting process improving the eutectic carbide spheroidizingwas discussed. The theoretical instruction for determining the subsequent treatment process was provided.

  3. DuraFoil{sup TM} ICR-a new material for catalytic converter substrates

    Energy Technology Data Exchange (ETDEWEB)

    Sukonnik, I.M.; Chang, S.; Jha, B. [Texas Instruments, Inc., Attleboro, MA (United States)

    1997-12-31

    A new type of FeCrAl material for catalytic converter substrate applications, DuraFoil{sup TM} ICR, has been developed by solid state bonding of strip layers of steel and aluminum. Such clad material is further rolled to intermediate gauge and then subjected to a thermal in situ reaction to form a solid solution material. Such monolithic material is subsequently thermomechanically processed to foil gauges. The combination of roll bonding followed by thermo-mechanical processing to produce FeCrAl foil for metallic catalytic converter substrate offers many metallurgical and economic advantages over conventional ingot metallurgy practice. The fact that thermal diffusion was performed at the intermediate gauge prior to reaching the final foil thickness gives material properties for use in the wider design range of catalytic converters. In its simplest form, the requirements for a catalytic converter substrate (foil material) are dictated by four major factors: oxidation resistance; shape stability; formability (applicable ductility); and compatibility with typical substrate processing technologies such as brazing and washcoating. To this end, the microstructures, mechanical properties, chemical homogeneity, surface chemistry and morphology of two DuraFoil{sup TM} new grades foil materials, i.e., ICR-H (hard) and ICR-F (soft), were characterized. This study has shown those superior properties, desirable formability can be achieved from diffusion-made material. (orig.)

  4. Analysis of heterogeneous oxygen exchange and fuel oxidation on the catalytic surface of perovskite membranes

    KAUST Repository

    Hong, Jongsup

    2013-10-01

    The catalytic kinetics of oxygen surface exchange and fuel oxidation for a perovskite membrane is investigated in terms of the thermodynamic state in the immediate vicinity of or on the membrane surface. Perovskite membranes have been shown to exhibit both oxygen perm-selectivity and catalytic activity for hydrocarbon conversion. A fundamental description of their catalytic surface reactions is needed. In this study, we infer the kinetic parameters for heterogeneous oxygen surface exchange and catalytic fuel conversion reactions, based on permeation rate measurements and a spatially resolved physical model that incorporates detailed chemical kinetics and transport in the gas-phase. The conservation equations for surface and bulk species are coupled with those of the gas-phase species through the species production rates from surface reactions. It is shown that oxygen surface exchange is limited by dissociative/associative adsorption/desorption of oxygen molecules onto/from the membrane surface. On the sweep side, while the catalytic conversion of methane to methyl radical governs the overall surface reactions at high temperature, carbon monoxide oxidation on the membrane surface is dominant at low temperature. Given the sweep side conditions considered in ITM reactor experiments, gas-phase reactions also play an important role, indicating the significance of investigating both homogeneous and heterogeneous chemistry and their coupling when examining the results. We show that the local thermodynamic state at the membrane surface should be considered when constructing and examining models of oxygen permeation and heterogeneous chemistry. © 2013 Elsevier B.V.

  5. Preparation of birnessite-supported pt nanoparticles and their application in catalytic oxidation of formaldehyde.

    Science.gov (United States)

    Liu, Linlin; Tian, Hua; He, Junhui; Wang, Donghui; Yang, Qiaowen

    2012-01-01

    Flaky and nanospherical birnessite and birnessite-supported Pt catalysts were successfully prepared and characterized by means of Xray diffraction (XRD), transmission electron microscopy (TEM), energy dispersive spectroscopy (EDS) and N2 adsorption-desorption. Effects of the birnessite morphology and Pt reduction method on the catalytic activity for the complete oxidation of formaldehyde (HCHO) were investigated. It was found that flaky birnessite exhibited higher catalytic activity than nanospherical birnessite. The promoting effect of Pt on the birnessite catalyst indicated that the reduction method of the Pt precursor greatly influenced the catalytic performance. Flaky birnessite-supported Pt nanoparticles reduced by KBH4 showed the highest catalytic activity and could completely oxidize HCHO into CO2 and H20 at 50 degreesC, whereas the sample reduced using H2-plasma showed lower activity for HCHO oxidation. The differences in catalytic activity of these materials were jointly attributed to the effects of pore structure, surface active sites exposed to HCHO and the dispersion of Pt nanoparticles.

  6. Stripping voltammetric determination of palladium, platinum and rhodium in freshwater and sediment samples from South African water resources.

    Science.gov (United States)

    van der Horst, C; Silwana, B; Iwuoha, E; Somerset, V

    2012-01-01

    Stripping voltammetry as technique has proved to be very useful in the analysis of heavy and other metal ions due to its excellent detection limits and its sensitivity in the presence of different metal species or interfering ions. Recent assessments of aquatic samples have shown increased levels of platinum group metals (PGMs) in aquatic ecosystems, caused by automobile exhaust emissions and mining activities. The development of an analytical sensor for the detection and characterisation of PGMs were investigated, since there is an ongoing need to find new sensing materials with suitable recognition elements that can respond selectively and reversibly to specific metal ions in environmental samples. The work reported shows the successful application of another mercury-free sensor electrode for the determination of platinum group metals in environmental samples. The work reported in this study entails the use of a glassy carbon electrode modified with a bismuth film for the determination of platinum (Pt(2+)), palladium (Pd(2+)) or rhodium (Rh(2+)) by means of adsorptive cathodic stripping voltammetry. Optimised experimental conditions included composition of the supporting electrolyte, complexing agent concentration, deposition potential, deposition time and instrumental voltammetry parameters for Pt(2+), Pd(2+) and Rh(2+) determination. Adsorptive differential pulse stripping voltammetric measurements for PGMs were performed in the presence of dimethylglyoxime (DMG) as complexing agent. The glassy carbon bismuth film electrode (GC/BiFE) employed in this study exhibit good and reproducible sensor characteristics. Application of GC/BiFE sensor exhibited well-defined peaks and highly linear behaviour for the stripping analysis of the PGMs in the concentration range between 0 and 3.5 μg/L. The detection limit of Pd, Pt and Rh was found to be 0.12 μg/L, 0.04 μg/L and 0.23 μg/L, respectively for the deposition times of 90 s (Pd) and 150 s (for both Pt and Rh). Good

  7. Understanding the Adsorption Interface of Polyelectrolyte Coating on Redox Active Nanoparticles Using Soft Particle Electrokinetics and Its Biological Activity

    Science.gov (United States)

    2015-01-01

    The application of cerium oxide nanoparticles (CNPs) for therapeutic purposes requires a stable dispersion of nanoparticles in a biological environment. The objective of this study is to tailor the properties of polyelectrolyte coated CNPs as a function of molecular weight to achieve a stable and catalytic active dispersion. The coating of CNPs with polyacrylic acid (PAA) has increased the dispersion stability of CNPs and enhanced the catalytic ability. The stability of PAA coating was analyzed using the change in the Gibbs free energy computed by the Langmuir adsorption model. The adsorption isotherms were determined using soft particle electrokinetics which overcomes the challenges presented by other techniques. The change in Gibbs free energy was highest for CNPs coated with PAA of 250 kg/mol indicating the most stable coating. The change in free energy for PAA of 100 kg/mol coated CNPs was 85% lower than the PAA of 250 kg/mol coated CNPs. This significant difference is caused by the strong adsorption of PAA of 100 kg/mol on CNPs. Catalytic activity of PAA-CNPs is assessed by the catalase enzymatic mimetic activity of nanoparticles. The catalase activity was higher for PAA coated CNPs as compared to bare CNPs which indicated preferential adsorption of hydrogen peroxide induced by coating. This indicates that the catalase activity is also affected by the structure of the coating layer. PMID:24673655

  8. Microstructure evolution of eutectic Al-Cu strips by high-speed twin-roll strip casting process

    Science.gov (United States)

    Sahoo, Seshadev; Ghosh, Sudipto

    2015-10-01

    In the present investigation, microstructural evolutions of functionally graded eutectic Al-Cu strips prepared by high-speed twin-roll strip caster at different casting speeds and liquid melt superheats were studied. The as-cast sample was subjected to scanning electron microscope to study the evolution of microstructure of the strip at different casting speeds and liquid melt superheats. At different casting speeds, non-equilibrium eutectic structure observed on the Al-Cu eutectic strip consists of lamellar as well as wavy structure with a distinct boundary. The lamellar microstructure consists of alternating layers of well-bonded α-Al phase and θ-Al2Cu phase. The globular flowery structure within the eutectic matrix was observed on the strip at different liquid melt superheats. The microhardness of the as-cast strip was studied by Vickers hardness tester, and it was found that hardness value increases with increasing casting speed and decreases with increasing liquid melt superheat.

  9. Control Strategies of Asymmetric Strip Shape in Six-High Cold Rolling Mill%Control Strategies of Asymmetric Strip Shape in Six-High Cold Rolling Mill

    Institute of Scientific and Technical Information of China (English)

    ZHANG Yun; YANG Quan; WANG Xiao-chen

    2011-01-01

    It is a complicated problem for cold-rolled strip to improve asymmetric strip shape in strip production. A roll system and strip coupled model of six-high cold rolling mill was established with finite element method to estimate the effect of intermediate roll shifting, tilting, symmetric and asymmetric bending technologies on strip profile. To reduce asymmetric defects of strip shape as much as possible, some control strategies were proposed, including tilting and asymmetric bending of intermediate roll and work roll. The combinations of these three control strategies can effectively eliminate asymmetric strip shape defects. Finally, the closed-loop control model of asymmetric flat- ness at the last stand was given, and the flatness control system with the function of asymmetric strip shape control was also designed for cold tandem mill.

  10. Enzymatically catalytic deposition of gold nanoparticles by glucose oxidase-functionalized gold nanoprobe for ultrasensitive electrochemical immunoassay.

    Science.gov (United States)

    Cheng, Hui; Lai, Guosong; Fu, Li; Zhang, Haili; Yu, Aimin

    2015-09-15

    A novel ultrasensitive immunoassay method was developed by combination of the enzymatically catalytic gold deposition with the prepared gold nanoprobe and the gold stripping analysis at an electrochemical chip based immunosensor. The immunosensor was constructed through covalently immobilizing capture antibody at a carbon nanotube (CNT) modified screen-printed carbon electrode. The gold nanoprobe was prepared by loading signal antibody and high-content glucose oxidase (GOD) on the nanocarrier of gold nanorod (Au NR). After sandwich immunoreaction, the GOD-Au NR nanoprobe could be quantitatively captured onto the immunosensor surface and then induce the deposition of gold nanoparticles (Au NPs) via the enzymatically catalytic reaction. Based on the electrochemical stripping analysis of the Au NR nanocarriers and the enzymatically produced Au NPs, sensitive electrochemical signal was obtained for the immunoassay. Both the GOD-induced deposition of Au NPs by the nanoprobe and the sensitive electrochemical stripping analysis on the CNTs based sensing surface greatly amplified the signal response, leading to the ultrahigh sensitivity of this method. Using carcinoembryonic antigen as a model analyte, excellent analytical performance including a wide linear range from 0.01 to 100 ng/mL and a detection limit down to 4.2 pg/mL was obtained. In addition, this immunosensor showed high specificity and satisfactory reproducibility, stability and reliability. The relatively positive detection potential excluded the conventional interference from dissolved oxygen. Thus this electrochemical chip based immunosensing method provided great potentials for practical applications. PMID:25932794

  11. A biological oil adsorption filter

    Energy Technology Data Exchange (ETDEWEB)

    Pasila, A. [University of Helsinki (Finland). Dept. of Agricultural Engineering and Household Technology

    2005-12-01

    A new oil adsorption method called adsorption filtration (AF) has been developed. It is a technology where by oil residues can be cleaned from water by running it through a simple filter made from freeze treated, dried, milled and then fragmented plant material. By choosing suitable plants and fragmentation sizes it is possible to produce filters, which pass water but adsorb oil. The aim of this study was to investigate the possibilities of manufacturing oil adsorbing filter materials from reed canary grass (Phalaris arundinacea), flax (Linum usitatissimum L.) or hemp fibre (Cannabis sativa L.). The oil (80 ml) was mixed with de-ionised water (200 ml) and this mixture was filtered through 10 or 20 g adsorption filters. Fine spring harvested hemp fibre (diameter less than 1 mm) and reed canary grass fragments adsorb 2-4 g of oil per gram of adsorption material compared to 1-3 g of water. Adsorption filtration is thus a novel way of gathering spilled oil in shallow coastal waters before the oil reaches the shore. (author)

  12. THE COORDINATION ADSORPTION OF AMINES ON CARBOXYL RESIN IN Cu2+ FORM FROM NON-AQUEOUS MEDIUM AND DESORPTION WITH ANHYDROUS ELUANT

    Institute of Scientific and Technical Information of China (English)

    Jia-zheng Li; Zuo-qing Shi; Yun-ge Fan

    2002-01-01

    The adsorption of aniline, N-methylaniline and N,N-dimethylaniline onto carboxyl resin in Cu2+ form from water,ethanol and n-hexane have been studied. The results show that the adsorption affinities from n-hexane are higher than that from water, and nearly zero from ethanol. The separation factors for the adsorption of these three amines from mixed solution were also examined. The results of continuous column operations show that the breakthrough capacity of aniline from nhexane reaches 90 mg/g dry resin in Cu2+ form, and the amines adsorbed can be stripped with anhydrous ethanol effectively.Adsorption onto carboxyl resin in Cu2+ form from non-aqueous medium and desorption with anhydrous eluant can overcome the run-off of Cu2+ from the resin, and would show potential advantages in the separation of some water-insoluble natural products.

  13. Highly Selective Synthesis of Catalytically Active Monodisperse Rhodium Nanocubes

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Y.; Grass, M.E.; Kuhn, J.N.; Tao, F.; Habas, S.E.; Huang, W.; Yang, P.; Somorjai, G.A.

    2009-02-21

    Synthesis of monodisperse and shape-controlled colloidal inorganic nanocrystals (NCs) is of increasing scientific interest and technological significance. Recently, shape control of Pt, Pd, Ag, Au, and Rh NCs has been obtained by tuning growth kinetics in various solution-phase approaches, including modified polyol methods, seeded growth by polyol reduction, thermolysis of organometallics, and micelle techniques. Control of reduction kinetics of the noble metal precursors and regulation of the relative growth rates of low-index planes (i.e. {l_brace}100{r_brace} and {l_brace}111{r_brace}) via selective adsorption of selected chemical species are two keys for achieving shape modification of noble metal NCs. One application for noble metal NCs of well-defined shape is in understanding how NC faceting (determines which crystallographic planes are exposed) affects catalytic performance. Rh NCs are used in many catalytic reactions, including hydrogenation, hydroformylation, hydrocarbonylation, and combustion reactions. Shape manipulation of Rh NCs may be important in understanding how faceting on the nanoscale affects catalytic properties, but such control is challenging and there are fewer reports on the shape control of Rh NCs compared to other noble metals. Xia and coworkers obtained Rh multipods exhibiting interesting surface plasmonic properties by a polyol approach. The Somorjai and Tilley groups synthesized crystalline Rh multipods, cubes, horns and cuboctahedra, via polyol seeded growth. Son and colleagues prepared catalytically active monodisperse oleylamine-capped tetrahedral Rh NCs for the hydrogenation of arenes via an organometallic route. More recently, the Somorjai group synthesized sizetunable monodisperse Rh NCs using a one-step polyol technique. In this Communication, we report the highly selective synthesis of catalytically active, monodisperse Rh nanocubes of < 10 nm by a seedless polyol method. In this approach, Br{sup -} ions from trimethyl

  14. Catalytic Fast Pyrolysis: A Review

    Directory of Open Access Journals (Sweden)

    Theodore Dickerson

    2013-01-01

    Full Text Available Catalytic pyrolysis is a promising thermochemical conversion route for lignocellulosic biomass that produces chemicals and fuels compatible with current, petrochemical infrastructure. Catalytic modifications to pyrolysis bio-oils are geared towards the elimination and substitution of oxygen and oxygen-containing functionalities in addition to increasing the hydrogen to carbon ratio of the final products. Recent progress has focused on both hydrodeoxygenation and hydrogenation of bio-oil using a variety of metal catalysts and the production of aromatics from bio-oil using cracking zeolites. Research is currently focused on developing multi-functional catalysts used in situ that benefit from the advantages of both hydrodeoxygenation and zeolite cracking. Development of robust, highly selective catalysts will help achieve the goal of producing drop-in fuels and petrochemical commodities from wood and other lignocellulosic biomass streams. The current paper will examine these developments by means of a review of existing literature.

  15. Combined catalytic converter and afterburner

    Energy Technology Data Exchange (ETDEWEB)

    Ma, T.T.-H.

    1994-11-30

    This patent describes the combined use of a catalytic converter and afterburner. An afterburner chamber and a catalyst matrix are disposed in series within a casing. A combustible premixed charge is ignited in the afterburner chamber before it enters the catalyst matrix. This invention overcomes the problem encountered in previous designs of some of the premixed charge passing unreacted through the device unless a very long afterburner chamber is used. (UK)

  16. Deep desulfurization of diesel fuels by catalytic oxidation

    Institute of Scientific and Technical Information of China (English)

    YU Guoxian; CHEN Hui; LU Shanxiang; ZHU Zhongnan

    2007-01-01

    Reaction feed was prepared by dissolving dibenzothiophene (DBT),which was selected as a model organosulfur compound in diesel fuels,in n-octane.The oxidant was a 30 wt-% aqueous solution of hydrogen peroxide.Catalytic performance of the activated carbons with saturation adsorption of DBT was investigated in the presence of formic acid.In addition,the effects of activated carbon dosage,formic acid concentration,initial concentration of hydrogen peroxide,initial concentration of DBT and reaction temperature on the oxidation of DBT were investigated.Experimental results indicated that performic acid and the hydroxyl radicals produced are coupled to oxidize DBT with a conversion ratio of 100%.Catalytic performance of the combination of activated carbon and formic acid is higher than that ofouly formic acid.The concentration of formic acid,activated carbon dosage,initial concentration of hydrogen peroxide and reaction temperature affect the oxidative removal of DBT.The higher the initial concentration of DBT in the n-octane solution,the more difficult the deep desulfurization by oxidation is.

  17. Catalytically active single-atom niobium in graphitic layers.

    Science.gov (United States)

    Zhang, Xuefeng; Guo, Junjie; Guan, Pengfei; Liu, Chunjing; Huang, Hao; Xue, Fanghong; Dong, Xinglong; Pennycook, Stephen J; Chisholm, Matthew F

    2013-01-01

    Carbides of groups IV through VI (Ti, V and Cr groups) have long been proposed as substitutes for noble metal-based electrocatalysts in polymer electrolyte fuel cells. However, their catalytic activity has been extremely limited because of the low density and stability of catalytically active sites. Here we report the excellent performance of a niobium-carbon structure for catalysing the cathodic oxygen reduction reaction. A large number of single niobium atoms and ultra small clusters trapped in graphitic layers are directly identified using state-of-the-art aberration-corrected scanning transmission electron microscopy. This structure not only enhances the overall conductivity for accelerating the exchange of ions and electrons, but it suppresses the chemical/thermal coarsening of the active particles. Experimental results coupled with theory calculations reveal that the single niobium atoms incorporated within the graphitic layers produce a redistribution of d-band electrons and become surprisingly active for O2 adsorption and dissociation, and also exhibit high stability. PMID:23715283

  18. Catalytic wet air oxidation of chlorophenols over supported ruthenium catalysts

    Energy Technology Data Exchange (ETDEWEB)

    Li Ning [Institut de recherches sur la catalyse et l' environnement de Lyon (IRCELYON), UMR 5256, CNRS/Universite Claude Bernard Lyon 1, 2 Avenue Albert Einstein, 69626 Villeurbanne Cedex (France); Descorme, Claude [Institut de recherches sur la catalyse et l' environnement de Lyon (IRCELYON), UMR 5256, CNRS/Universite Claude Bernard Lyon 1, 2 Avenue Albert Einstein, 69626 Villeurbanne Cedex (France)]. E-mail: claude.descorme@catalyse.cnrs.fr; Besson, Michele [Institut de recherches sur la catalyse et l' environnement de Lyon (IRCELYON), UMR 5256, CNRS/Universite Claude Bernard Lyon 1, 2 Avenue Albert Einstein, 69626 Villeurbanne Cedex (France)

    2007-07-31

    A series of noble metal (Pt, Pd, Ru) loaded zirconia catalysts were evaluated in the catalytic wet air oxidation (CWAO) of mono-chlorophenols (2-CP, 3-CP, 4-CP) under relatively mild reaction conditions. Among the investigated noble metals, Ru appeared to be the best to promote the CWAO of CPs as far as incipient-wetness impregnation was used to prepare all the catalysts. The position of the chlorine substitution on the aromatic ring was also shown to have a significant effect on the CP reactivity in the CWAO over 3 wt.% Ru/ZrO{sub 2}. 2-CP was relatively easier to degradate compared to 3-CP and 4-CP. One reason could be the higher adsorption of 2-CP on the catalyst surface. Further investigations suggested that 3 wt.% Ru/ZrO{sub 2} is a very efficient catalyst in the CWAO of 2-CP as far as high 2-CP conversion and TOC abatement could still be reached at even lower temperature (393 K) and lower total pressure (3 MPa). Additionally, the conversion of 2-CP was demonstrated to increase with the initial pH of the 2-CP solution. The dechlorination reaction is promoted at higher pH. In all cases, the adsorption of the reactants and the reaction intermediates was shown to play a major role. All parameters that would control the molecule speciation in solution or the catalyst surface properties would have a key effect.

  19. Thermodynamics of catalytic nanoparticle morphology

    Science.gov (United States)

    Zwolak, Michael; Sharma, Renu; Lin, Pin Ann

    Metallic nanoparticles are an important class of industrial catalysts. The variability of their properties and the environment in which they act, from their chemical nature & surface modification to their dispersion and support, allows their performance to be optimized for many chemical processes useful in, e.g., energy applications and other areas. Their large surface area to volume ratio, as well as varying sizes and faceting, in particular, makes them an efficient source for catalytically active sites. These characteristics of nanoparticles - i.e., their morphology - can often display intriguing behavior as a catalytic process progresses. We develop a thermodynamic model of nanoparticle morphology, one that captures the competition of surface energy with other interactions, to predict structural changes during catalytic processes. Comparing the model to environmental transmission electron microscope images of nickel nanoparticles during carbon nanotube (and other product) growth demonstrates that nickel deformation in response to the nanotube growth is due to a favorable interaction with carbon. Moreover, this deformation is halted due to insufficient volume of the particles. We will discuss the factors that influence morphology and also how the model can be used to extract interaction strengths from experimental observations.

  20. Effects of Calcination Temperature on the Acidity and Catalytic Performances of HZSM-5 Zeolite Catalysts for the Catalytic Cracking of n-Butane

    Institute of Scientific and Technical Information of China (English)

    Jiangyin Lu; Zhen Zhao; Chunming Xu; Aijun Duan; Pu Zhang

    2005-01-01

    The acidic modulations of a series of HZSM-5 catalysts were successfully made by calcination at different treatment temperatures, i.e. 500, 600, 650, 700 and 800 ℃, respectively. The results indicated that the total acid amounts, their density and the amount of B-type acid of HZSM-5 catalysts rapidly decreased, while the amounts of L-type acid had almost no change and thus the ratio of L/B was obviously enhanced with the increase of calcination temperature (excluding 800 ℃). The catalytic performances of modified HZSM-5 catalysts for the cracking of n-butane were also investigated. The main properties of these catalysts were characterized by means of XRD, N2 adsorption at low temperature, NH3-TPD, FTIR of pyridine adsorption and BET surface area measurements. The results showed that HZSM-5 zeolite pretreated at 800 ℃ had very low catalytic activity for n-butane cracking. In the calcination temperature range of 500-700 ℃, the total selectivity to olefins, propylene and butene were increased with the increase of calcination temperature, while, the selectivity for arene decreased with the calcination temperature.The HZSM-5 zeolite calcined at 700 ℃ produced light olefins with high yield, at the reaction temperature of 650 ℃ the yields of total olefins and ethylene were 52.8% and 29.4%, respectively. Besides, the more important role is that high calcination temperature treatment improved the duration stability of HZSM-5zeolites. The effect of calcination temperature on the physico-chemical properties and catalytic performance of HZSM-5 for cracking of n-butane was explored. It was found that the calcination temperature had large effects on the surface area, crystallinity and acid properties of HZSM-5 catalyst, which further affected the catalytic performance for n-butane cracking.

  1. Host receptors for bacteriophage adsorption.

    Science.gov (United States)

    Bertozzi Silva, Juliano; Storms, Zachary; Sauvageau, Dominic

    2016-02-01

    The adsorption of bacteriophages (phages) onto host cells is, in all but a few rare cases, a sine qua non condition for the onset of the infection process. Understanding the mechanisms involved and the factors affecting it is, thus, crucial for the investigation of host-phage interactions. This review provides a survey of the phage host receptors involved in recognition and adsorption and their interactions during attachment. Comprehension of the whole infection process, starting with the adsorption step, can enable and accelerate our understanding of phage ecology and the development of phage-based technologies. To assist in this effort, we have established an open-access resource--the Phage Receptor Database (PhReD)--to serve as a repository for information on known and newly identified phage receptors. PMID:26755501

  2. [Catalytic ozonation by ceramic honeycomb for the degradation of oxalic acid in aqueous solution].

    Science.gov (United States)

    Zhao, Lei; Sun, Zhi-Zhong; Ma, Jun

    2007-11-01

    Comparative experiments for the degradation of oxalic acid in aqueous solution were carried out in the three processes of ozonation alone, ceramic honeycomb-catalyzed ozonation and ceramic honeycomb adsorption. The results show that the degradation rates of oxalic acid in the ceramic honeycomb-catalyzed ozonation, ozonation alone and ceramic honeycomb adsorption systems are 37.6%, 2.2% and 0.4%, and the presence of ceramic honeycomb catalyst significantly improves the degradation rate of oxalic acid compared to the results from non-catalytic ozonation and adsorption. With the addition of tert-butanol, the degradation rates of oxalic acid in catalytic ozonation system decrease by 24.1%, 29.0% and 30.1%, respectively, at the concentration of 5, 10 and 15 mg x L(-1). This phenomenon indicates that ceramic honeycomb-catalyzed ozonation for the degradation of oxalic acid in aqueous solution follows the mechanism of *OH oxidation, namely the heterogeneous surface of catalyst enhances the initiation of *OH. The results of TOC analysis demonstrate that the process of ceramic honeycomb-catalyzed ozonation can achieve the complete mineralization level without the formation of intermediary degradation products. The experimental results suggest that the reaction temperature has positive relationship with the degradation rate of oxalic acid. The degradation rates of oxalic acid in the ceramic honeycomb-catalyzed ozonation system are 16.4%, 37.6%, 61.3% and 68.2%, at the respective reaction temperature of 10, 20, 30 and 40 degrees C.

  3. Substrate-mediated enhanced activity of Ru nanoparticles in catalytic hydrogenation of benzene

    KAUST Repository

    Liu, Xin

    2012-01-01

    The impact of carbon substrate-Ru nanoparticle interactions on benzene and hydrogen adsorption that is directly related to the performance in catalytic hydrogenation of benzene has been investigated by first-principles based calculations. The stability of Ru 13 nanoparticles is enhanced by the defective graphene substrate due to the hybridization between the dsp states of the Ru 13 particle with the sp 2 dangling bonds at the defect sites. The local curvature formed at the interface will also raise the Ru atomic diffusion barrier, and prohibit the particle sintering. The strong interfacial interaction results in the shift of averaged d-band center of the deposited Ru nanoparticle, from -1.41 eV for a freestanding Ru 13 particle, to -1.17 eV for the Ru/Graphene composites, and to -1.54 eV on mesocellular foam carbon. Accordingly, the adsorption energies of benzene are increased from -2.53 eV for the Ru/mesocellular foam carbon composites, to -2.62 eV on freestanding Ru 13 particles, to -2.74 eV on Ru/graphene composites. A similar change in hydrogen adsorption is also observed, and all these can be correlated to the shift of the d-band center of the nanoparticle. Thus, Ru nanoparticles graphene composites are expected to exhibit both high stability and superior catalytic performance in hydrogenation of arenes. © 2012 The Royal Society of Chemistry.

  4. Stripped Elliptical Galaxies as Probes of ICM Physics: I. Tails, Wakes, and Flow Patterns in and Around Stripped Ellipticals

    Science.gov (United States)

    Roediger, E.; Kraft, R. P.; Nulsen, P. E. J.; Forman, W. R.; Machacek, M.; Randall, S.; Jones, C.; Churazov, E.; Kokotanekova, R.

    2015-06-01

    Elliptical cluster galaxies are progressively stripped of their atmospheres due to their motion through the intracluster medium (ICM). Deep X-ray observations reveal the fine-structure of the galaxy’s remnant atmosphere and its gas tail and wake. This fine-structure depends on dynamic conditions (galaxy potential, initial gas contents, orbit through the host cluster), orbital stage (early infall, pre-/post-pericenter passage), and ICM plasma properties (thermal conductivity, viscosity, magnetic field structure). We aim to disentangle dynamic and plasma effects in order to use stripped ellipticals as probes of ICM plasma properties. This first paper of a series investigates the hydrodynamics of progressive gas stripping by means of inviscid hydrodynamical simulations. We distinguish a long-lasting initial relaxation phase and a quasi-steady stripping phase. During quasi-steady stripping, the ICM flow around the remnant atmosphere resembles the flow around solid bodies, including a “deadwater” region in the near wake. Gas is stripped from the remnant atmosphere predominantly at its sides via Kelvin-Helmholtz instabilities. The downstream atmosphere is largely shielded from the ICM wind and thus shaped into a tail. Observationally, both this “remnant tail” and the stripped gas in the wake can appear as a “tail”, but only in the wake can galactic gas mix with the ambient ICM. While the qualitative results are generic, the simulations presented here are tailored to the Virgo elliptical galaxy M89 (NGC 4552) for the most direct comparison to observations. Papers II and III of this series describe the effect of viscosity and compare to Chandra and XMM-Newton observations, respectively.

  5. Characterization and Calibration of Large Area Resistive Strip Micromegas Detectors

    CERN Document Server

    Losel, Philipp Jonathan; The ATLAS collaboration

    2015-01-01

    Resisitve strip Micromegas detectors behave discharge tolerant. They have been tested extensively as smaller detectors of about 10 x 10 cm$^2$ in size and they work reliably at high rates of 100\\,kHz/cm$^2$ and above. Tracking resolutions well below 100\\,$\\mu$m have been observed for 100 GeV muons and pions. Micromegas detectors are meanwhile proposed as large area muon precision trackers of 2-3\\,m$^2$ in size. To investigate possible differences between small and large detectors, a 1\\,m$^2$ detector with 2048 resistive strips at a pitch of 450 $\\mu$m was studied in the LMU Cosmic Ray Facility (CRF) using two 4 $\\times$ 2.2 m$^2$ large Monitored Drift Tube (MDT) chambers for cosmic muon reference tracking. Segmentation of the resistive strip anode plane in 57.6\\,mm x 95\\,mm large areas has been realized by the readout of 128 strips with one APV25 chip each and by 11 95\\,mm broad trigger scintillators placed along the readout strips.\\\\ This allows for mapping of homogenity in pulse height and efficiency, deter...

  6. Characterization and Calibration of Large Area Resistive Strip Micromegas Detectors

    CERN Document Server

    Losel, Philipp Jonathan; The ATLAS collaboration

    2015-01-01

    Resistive strip Micromegas detectors are discharge tolerant. They have been tested extensively as small detectors of about 10 x 10 cm$^2$ in size and they work reliably at high rates of 100 kHz/cm$^2$ and above. Tracking resolution well below 100 $\\mu$m has been observed for 100 GeV muons and pions. Micromegas detectors are meanwhile proposed as large area muon precision trackers of 2-3 m$^2$ in size. To investigate possible differences between small and large detectors, a 1 m$^2$ detector with 2048 resistive strips at a pitch of 450 $\\mu$m was studied in the LMU Cosmic Ray Measurement Facility (CRMF) using two 4 $\\times$ 2.2 m$^2$ large Monitored Drift Tube (MDT) chambers for cosmic muon reference tracking. A segmentation of the resistive strip anode plane in 57.6 mm x 93 mm large areas has been realized by the readout of 128 strips with one APV25 chip each and by eleven 93 mm broad trigger scintillators placed along the readout strips. This allows for mapping of homogeneity in pulse height and efficiency, d...

  7. Prototype indicator strip for tank ammunition. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Bates, B.; Griest, W.

    1993-10-31

    Combustible nitrocellulose ordnance casings offer advantages of: light weight, low cost, low detectability, and quick cycling of rounds by immediate disposal. However, mechanical strength is degraded with time by the action of humidity and nitroester diffusion through the casing to adhesives. The primary development effort of this study is a means to detect nitroester migration to the crucial skive joint which binds an assortment of warhead choices to propellant casings. This work has developed a prototype colorimetric indicator strip which, when applied in a field environment, produces a purple tint proportional to casing nitroester concentration, and inversely proportional to remaining adhesive joint strength. This work addressed the three steps in indicator strip use: (1) A suggested protocol for indicator strip preparation was developed. Various coatings, support reagents, and backings were examined resulting in a choice of polyethylene tape coating over separate AB- and C-impregnated cellulose punches. Various methods of punch creation and impregnation were tried resulting in stirred aqueous solutions and suspensions of AB and C, respectively. (2) Suggested protocols for indicator strip application to lab backings and field casings were developed. After chemical stripper was applied to the alumina-polyurethane paint on casings, C and AB punches were stacked and double-tape sealed. (3) A means for indicator strip monitoring was developed. From known time of indicator reaction, casing humidity, and indicator color, a means for field concentration determination was determined. Lab time-lapse photography was used to calibrate the indicator at a single level of humidity.

  8. VTT's micron-scale silicon rib+strip waveguide platform

    Science.gov (United States)

    Aalto, Timo; Harjanne, Mikko; Cherchi, Matteo

    2016-05-01

    Silicon rib waveguides enable single-mode (SM) operation even with the combination of multi-micron core dimensions and high refractive index contrast. In such large waveguides the optical mode field is almost completely confined inside the Si core, which leads to small propagation losses and small polarization dependency. The unique SM condition of the rib waveguide also enables the use of an ultra-wide wavelength range, for example from 1.2 to <1.7 μm, without sacrificing either SM operation or low propagation loss. This makes micron-scale Si waveguides particularly well-suited for spectroscopy and extensive wavelength division multiplexing. However, rib waveguides require large bending radii, which lead to large circuit sizes. There are two solutions for this. So-called Euler bends in Si strip waveguides enable low-loss bends down to 1 μm bending radius with less than 0.1 dB/90° loss for both polarizations. Another alternative is a total-internal reflection mirror that can have loss as low as 0.1 dB for both polarizations in either strip or rib waveguides. The excitation of higher order modes in large strip waveguides is avoided by using adiabatic rib-strip converters and low-loss components. With rib and strip waveguides it is possible to reach a unique combination of low loss, extremely small footprint, small polarization dependency, ultra-wide bandwidth and tolerance to high optical powers.

  9. Calculation and Analysis of Temperature Distribution in Hot Rolling Strip

    Directory of Open Access Journals (Sweden)

    Kaixiang Peng

    2013-07-01

    Full Text Available Modern steel grades require constant and reproducible production conditions both in the hot strip mill and in the cooling section to achieve constant material properties along the entire strip length and from strip to strip. Calculation of the temperature in final rolling process always utilizes factors such as the work piece's inner organizational structure, plastic deformation, and it's variations of properties and so on, also as well as the physical parameters such as gauge, shape, etc. In this paper, a finite element model is constructed for the temperature field in a rolling process. The temperature field of strip steel is modeled with a 3-D finite element analysis (FEA structure, simultaneously considering the distribution of the work roll temperature. Then the distribution of field is simulated numerically. From the model, the temperature contours can be obtained by analysis of the temperature distribution of contact area. At the same time, the distribution of temperature in any position at any time can be acquired. These efforts provide the reliable parameters for the later finishing temperature and shape control.  

  10. Monomer Adsorption-Desorption Processes

    Institute of Scientific and Technical Information of China (English)

    KE Jian-Hong; LIN Zhen-Quan; CHEN Xiao-Shuang

    2009-01-01

    We propose an adsorption-desorption model for a deposit growth system, in which the adsorption and desorption of particles coexist. By means of the generalized rate equation we investigate the cluster (island) size distribution in the dynamic equilibrium state. The results show that the evolution behaviour of the system depends crucially on the details of the rate kernels. The cluster size distribution can take the ecale-frse power-law form in some cases, while it grows exponentially with size in other cases.

  11. Theoretical insight of adsorption cooling

    KAUST Repository

    Chakraborty, Anutosh

    2011-06-03

    This letter proposes and presents a thermodynamic formulation to calculate the energetic performances of an adsorption cooler as a function of pore widths and volumes of solid adsorbents. The simulated results in terms of the coefficient of performance are validated with experimental data. It is found from the present analysis that the performance of an adsorption cooling device is influenced mainly by the physical characteristics of solid adsorbents, and the characteristics energy between the adsorbent-adsorbate systems. The present study confirms that there exists a special type of silicagel having optimal physical characteristics that allows us to obtain the best performance.

  12. Kinetics of nitrate adsorption and reduction by nano-scale zero valent iron (NZVI): Effect of ionic strength and initial pH

    DEFF Research Database (Denmark)

    Kim, Do-Gun; Hwang, Yuhoon; Shin, Hang-Sik;

    2016-01-01

    Kinetic models for pollutants reduction by Nano-scale Zero Valent Iron (NZVI) were tested in this study to gain a better understanding and description of the reaction. Adsorption kinetic models and a heterogeneous catalytic reaction kinetic equation were proposed for nitrate removal and for ammon...

  13. Study on Hexagon-enveloping Leaf-stripping Mechanism for Corn Stalk

    Institute of Scientific and Technical Information of China (English)

    Li Li-qiao; Li Chao; Li Dong-hong; Wang Mo; Yu Ke-qiang; Yang Xing; Zhang Quan-chao; Wang De-fu; He Yuan

    2015-01-01

    In order to deeply study the leaf-stripping principle for corn stalk, the hexagon-enveloping leaf-stripping experimental device was designed. To achieve higher leaf-stripping percent and provide important references for the separation equipment for corn stalk, it is necessary to find out the laws of leaf-stripping of such mechanism and to select the main influencing factors of separation performance from a number of factors. Through the study on hexagon-enveloping leaf-stripping mechanism for corn stalks, the leaf-stripping principle of such mechanism was more clear, and the optimization of structural and kinematic parameters achieved by the experiment whose influencing factors were the four selected ones (feeding speed, rotary speed of leaf-stripping roll, clearance and included angle between two leaf-stripping plates) could be directly applied to the development of efficient rind-pith or leaf-stripping separation for corn stalks.

  14. In-situ stripping of H{sub 2}S in gasoil hydrodesulphurization - reactor design considerations

    Energy Technology Data Exchange (ETDEWEB)

    Nava, J.A.O.; Krishna, R. [Amsterdam Univ., Dept. of Chemical Engineering, Amsterdam (Netherlands)

    2004-02-01

    In order to meet future diesel specifications the sulphur content of diesel would need to be reduced to below 50 ppm. This requirement would require improved reactor configurations. In this study we examine the benefits of counter-current contacting of gas oil with H{sub 2}, over conventional co-current contacting in a trickle bed hydrodesulphurization (HDS) reactor. In counter-current contacting, we achieve in-situ stripping of H{sub 2}S from the liquid phase; this is beneficial to the HDS kinetics. A comparison simulation study shows that counter-current contacting would require about 20% lower catalyst load than co-current contacting. However, counter-current contacting of gas and liquid phases in conventionally used HDS catalysts, of 1.5 mm sizes, is not possible due to flooding limitations. The catalysts need to be housed in special wire gauze envelopes as in the catalytic bales or KATAPAK-S configurations. A preliminary hardware design of a counter-current HDS reactor using catalytic bales was carried out in order to determine the technical feasibility. Using a realistic sulphur containing feedstock, the target of 50 ppm S content of desulphurized oil could be met in a reactor of reasonable dimensions. The study also underlines the need for accurate modelling of thermal effects during desulphurization. Our study also shows that interphase mass transfer is unlikely to be a limiting factor and there is a need to develop improved reactor configurations allowing for increased catalyst loading, at the expense of gas-liquid interfacial area. (Author)

  15. Adsorption of Organics from Domestic Water Supplies.

    Science.gov (United States)

    McGuire, Michael J.; Suffet, Irwin H.

    1978-01-01

    This article discusses the current state of the art of organics removal by adsorption. Various theoretical explanations of the adsorption process are given, along with practical results from laboratory, pilot-scale, and full-scale applications. (CS)

  16. Phosphorus Removal From Milkhouse Wastewater and Barnyard Runoff With Fly ash Amendments in Vegetative Filter Strips

    Science.gov (United States)

    Giri, S.; Richards, B. K.; Geohring, L. D.; Steenhuis, T. S.

    2005-12-01

    Vegetative filter strips (VFS) are commonly used to reduce agricultural pollutants such as phosphorus (P) present in milkhouse wastewater and barnyard runoff. Although VFS can sometimes efficiently remove P, water flow and P sorption in a VFS used for treating milkhouse wastewater and barnyard runoff were found to be erratic due to preferential flow and reduced soil infiltration capacity. Several possible amendments were tested for P immobilization potential in the laboratory, including wollastonite (calcium metasilicate) and fly ash from a coal-fired power plant. Fly ash demonstrated superior P immobilization potential, with a Langmuir adsorption isotherm capacity of 10 mg g.-1. Fly ash was placed in the wastewater holding tank and in flow channels of an actual VFS, resulting in reduction of test well water ortho-P to ug L-1 (ppb) levels. Fly ash was shown to act in three ways: P adsorption, precipitation of P as Apatite, and co-precipitation of P during hydrolysis of Fe and Al. However, during summer P concentrations in observation wells was observed to be much higher than the influent wastewater in the VFS, particularly near the preferential flow path. Measurements of dissolved organic carbon (DOC), iron and total phosphorus indicate enhanced microbial activities during summer. As a result, anaerobic biodegradation of organic matter plays a great role in releasing P, Fe and Mn from adsorbed sites. It is believed that certain components of DOC (such as hydrophilic, hydrophobic and neutrals) are formed during anaerobic biodegradation of organic matter present in water and the VFS. These DOC components may interact with iron, aluminum, manganese, calcium etc. present in soil resulting in the concomitant release of elements together with adsorbed P. A practical management approach to reducing P during summer may involve relocating the preferred wastewater flowpaths in the VFS, as well as fresh applications of fly ash to the new flowpaths in order to avoid the

  17. First-principles study toward CO adsorption on Au/Ni surface alloys.

    Science.gov (United States)

    Huang, Yu Cheng; Du, Jin Yan; Zhou, Tao; Wang, Su Fan

    2012-12-01

    The introduction of a second metal, gold, into a nickel matrix can effectively improve the catalytic performance and thermal stability of the catalysts toward steam reforming of methane. To investigate the effect of Au on the adsorption properties and electronic structure of the Ni(111) surface, we chose CO as a probe molecule and examined CO adsorption on various Au/Ni surfaces. It was revealed that Au addition weakened the absorbate-substrate interactions on the Ni(111) surface. With increasing gold concentration, the binding energy declines further. The variation of the binding energies has been interpreted by exploring the electronic structure of surface nickel atoms. The effect of gold can be quantitatively characterized by the slopes of the fitting equations between the binding energy and the number of gold atoms surrounding the adsorption site. Our results show that the binding energy at top sites can be approximately estimated by counting the number of surrounding gold atoms. On one specific surface, the relative magnitude of the binding energy can be simply judged by the distance between gold and the geometrical center of the adsorption site. This empirical rule holds true for C, H, and O adsorption on the Au/Ni surface. It may be applicable to a system in which a doped atom of larger atomic size is incorporated into the host metal surface by forming a surface alloy. PMID:23047643

  18. Adsorption of SO2 onto oxidized and heat-treated activated carbon fibers (ACFS)

    Science.gov (United States)

    Daley, M.A.; Mangun, C.L.; DeBarr, J.A.; Riha, S.; Lizzio, A.A.; Donnals, G.L.; Economy, J.

    1997-01-01

    A series of activated carbon fibers (ACFs) and heat-treated oxidized ACFs prepared from phenolic fiber precursors have been studied to elucidate the role of pore size, pore surface chemistry and pore volume for the adsorption of SO2 and its catalytic conversion to H2SO4. For untreated ACFs, the initial rate of SO2 adsorption from flue gas was shown to be inversely related to pore size. At longer times, the amount of SO2 adsorbed from flue gas was dependent on both the pore size and pore volume. Oxidation of the ACFs, using an aqueous oxidant, decreased their adsorption capacity for SO2 from flue gas due to a decrease in pore volume and repulsion of the SO2 from acidic surface groups. If these samples were heat-treated to desorb the oxygen containing function groups, the amount of SO2 adsorption increased. This increase in adsorption capacity was directly correlated to the amount of CO2 evolved during heat-treatment of the oxidized ACFs. The amount of SO2 adsorbed for these samples was related to the pore size, pore surface chemistry and pore volume. This analysis is explained in more detail in this paper. ?? 1997 Elsevier Science Ltd. All rights reserved.

  19. Heterogeneous photocatalysis of methylene blue over titanate nanotubes: effect of adsorption.

    Science.gov (United States)

    Xiong, Lin; Sun, Weiling; Yang, Ye; Chen, Cheng; Ni, Jinren

    2011-04-01

    Titanate nanotubes were synthesized with hydrothermal reaction using TiO(2) and NaOH as the precursors and subsequent calcination at 400°C for 2h. The products were characterized with SEM and XRD. Adsorption and photocatalysis of methylene blue over titanate nanotubes and TiO(2) were investigated. The results indicated that titanate nanotubes exhibited a better photocatalytic degradation of methylene blue in a simultaneous adsorption and photodegradation system than that in equilibrium adsorption followed by a photodegradation system, whereas TiO(2) showed no significant differences in photocatalytic activity in the two systems. The methylene blue overall removal efficiency over TNTs in the first system even exceeded that over TiO(2). The different catalytic performances of titanate nanotubes in the two systems were tentatively attributed to different effects of adsorption of methylene blue, i.e., the promoting effect in the former and the inhibition effect in the latter. Decantation experiments showed that the titanate nanotube photocatalyst could be easily separated from the reaction medium by sedimentation. Thus titanate nanotubes with high sedimentation rates and concurrent adsorption represent a new catalyst system with a strong potential for commercial applications.

  20. Adsorption of HMF from water/DMSO solutions onto hydrophobic zeolites: experiment and simulation.

    Science.gov (United States)

    Xiong, Ruichang; León, Marta; Nikolakis, Vladimiros; Sandler, Stanley I; Vlachos, Dionisios G

    2014-01-01

    The adsorption of 5-hydroxymethylfurfural (HMF), DMSO, and water from binary and ternary mixtures in hydrophobic silicalite-1 and dealuminated Y (DAY) zeolites at ambient conditions was studied by experiments and molecular modeling. HMF and DMSO adsorption isotherms were measured and compared to those calculated using a combination of grand canonical Monte Carlo and expanded ensemble (GCMC-EE) simulations. A method based on GCMC-EE simulations for dilute solutions combined with the Redlich-Kister (RK) expansion (GCMC-EE-RK) is introduced to calculate the isotherms over a wide range of concentrations. The simulations, using literature force fields, are in reasonable agreement with experimental data. In HMF/water binary mixtures, large-pore hydrophobic zeolites are much more effective for HMF adsorption but less selective because large pores allow water adsorption because of H2 O-HMF attraction. In ternary HMF/DMSO/water mixtures, HMF loading decreases with increasing DMSO fraction, rendering the separation of HMF from water/DMSO mixtures by adsorption difficult. The ratio of the energetic interaction in the zeolite to the solvation free energy is a key factor in controlling separation from liquid mixtures. Overall, our findings could have an impact on the separation and catalytic conversion of HMF and the rational design of nanoporous adsorbents for liquid-phase separations in biomass processing. PMID:24106213

  1. Analytical possibilities of microelectrode use for stripping voltammetry

    Energy Technology Data Exchange (ETDEWEB)

    Matysik, F.M. (Leipzig Univ. (Germany). Dept. of Chemistry); Glaeser, P. (Leipzig Univ. (Germany). Dept. of Chemistry); Werner, G. (Leipzig Univ. (Germany). Dept. of Chemistry)

    1994-07-01

    The analytical utility of microelectrodes for stripping voltammetry is discussed from several points of view. The application of microelectrodes for microanalysis is demonstrated using a novel capillary flow injection system. Heavy metals at [mu]g l[sup -1] concentrations have been determined in [mu]l-samples. The influence of electrode size and convection during the deposition period of anodic stripping voltammetry on the reproducibility of trace metal determination was studied for various types of electrodes. In the case of mercury film microelectrodes, the precision can be improved if the accumulation of the analyte is performed under quiescent conditions. Practical examples of stripping voltammetry with microelectrodes such as copper determination in whisky and trace metal measurements in drinking water are given. (orig.)

  2. Development, prototyping and characterization of double sided silicon strip detectors

    Science.gov (United States)

    Topkar, Anita; Singh, Arvind; Aggarwal, Bharti; Kumar, Amit; Kumar, Arvind; Murali Krishna, L. V.; Das, D.

    2016-10-01

    Double sided DC-coupled silicon strip detectors with geometry of 65 mm×65 mm have been developed in India for nuclear physics experiments. The detectors have 64 P+ strips on the front side and 64 N+ strips on the backside with a pitch of 0.9 mm. These detectors were fabricated using a twelve mask layer process involving double sided wafer processing technology. Semiconductor process and device simulations were carried out in order to theoretically estimate the impact of important design and process parameters on the breakdown voltage of detectors. The performance of the first lot of prototype detectors has been studied using static characterization tests and using an alpha source. The characterization results demonstrate that the detectors have low leakage currents and good uniformity over the detector area of about 40 cm2. Overview of the detector design, fabrication process, simulation results and initial characterization results of the detectors are presented in this paper.

  3. Fast image retargeting based on strip dividing and resizing

    Institute of Scientific and Technical Information of China (English)

    Shungang Hua; Honglei Wei; Tieming Su

    2014-01-01

    Based on image strip dividing, an effective and fast image retargeting algorithm is proposed for resizing images. First, we construct the image energy map using gradient magnitude of the pixels and calculate the accumulated energy of each column, dividing the image into several strips by integrating similar energy columns. The reduced amount of dimension is decided in inverse proportion to the average energy for each strip. Then we retar-get the image combining scaling with cropping in terms of each strip’s reduced ratio. Experiment results show that the proposed algorithm is capable of implementing fast image retargeting and preserving both the local structures and the global visual effect of the image.

  4. Performance studies of the CMS Strip Tracker before installation

    CERN Document Server

    Adam, Wolfgang; Dragicevic, Marko; Friedl, Markus; Fruhwirth, R; Hansel, S; Hrubec, Josef; Krammer, Manfred; Oberegger, Margit; Pernicka, Manfred; Schmid, Siegfried; Stark, Roland; Steininger, Helmut; Uhl, Dieter; Waltenberger, Wolfgang; Widl, Edmund; Van Mechelen, Pierre; Cardaci, Marco; Beaumont, Willem; de Langhe, Eric; de Wolf, Eddi A; Delmeire, Evelyne; Hashemi, Majid; Bouhali, Othmane; Charaf, Otman; Clerbaux, Barbara; Dewulf, Jean-Paul; Elgammal, Sherif; Hammad, Gregory Habib; de Lentdecker, Gilles; Marage, Pierre Edouard; Vander Velde, Catherine; Vanlaer, Pascal; Wickens, John; Adler, Volker; Devroede, Olivier; De Weirdt, Stijn; D'Hondt, Jorgen; Goorens, Robert; Heyninck, Jan; Maes, Joris; Mozer, Matthias Ulrich; Tavernier, Stefaan; Van Lancker, Luc; Van Mulders, Petra; Villella, Ilaria; Wastiels, C; Bonnet, Jean-Luc; Bruno, Giacomo; De Callatay, Bernard; Florins, Benoit; Giammanco, Andrea; Gregoire, Ghislain; Keutgen, Thomas; Kcira, Dorian; Lemaitre, Vincent; Michotte, Daniel; Militaru, Otilia; Piotrzkowski, Krzysztof; Quertermont, L; Roberfroid, Vincent; Rouby, Xavier; Teyssier, Daniel; Daubie, Evelyne; Anttila, Erkki; Czellar, Sandor; Engstrom, Pauli; Harkonen, J; Karimaki, V; Kostesmaa, J; Kuronen, Auli; Lampen, Tapio; Linden, Tomas; Luukka, Panja-Riina; Maenpaa, T; Michal, Sebastien; Tuominen, Eija; Tuominiemi, Jorma; Ageron, Michel; Baulieu, Guillaume; Bonnevaux, Alain; Boudoul, Gaelle; Chabanat, Eric; Chabert, Eric Christian; Chierici, Roberto; Contardo, Didier; Della Negra, Rodolphe; Dupasquier, Thierry; Gelin, Georges; Giraud, Noël; Guillot, Gérard; Estre, Nicolas; Haroutunian, Roger; Lumb, Nicholas; Perries, Stephane; Schirra, Florent; Trocme, Benjamin; Vanzetto, Sylvain; Agram, Jean-Laurent; Blaes, Reiner; Drouhin, Frédéric; Ernenwein, Jean-Pierre; Fontaine, Jean-Charles; Berst, Jean-Daniel; Brom, Jean-Marie; Didierjean, Francois; Goerlach, Ulrich; Graehling, Philippe; Gross, Laurent; Hosselet, J; Juillot, Pierre; Lounis, Abdenour; Maazouzi, Chaker; Olivetto, Christian; Strub, Roger; Van Hove, Pierre; Anagnostou, Georgios; Brauer, Richard; Esser, Hans; Feld, Lutz; Karpinski, Waclaw; Klein, Katja; Kukulies, Christoph; Olzem, Jan; Ostapchuk, Andrey; Pandoulas, Demetrios; Pierschel, Gerhard; Raupach, Frank; Schael, Stefan; Schwering, Georg; Sprenger, Daniel; Thomas, Maarten; Weber, Markus; Wittmer, Bruno; Wlochal, Michael; Beissel, Franz; Bock, E; Flugge, G; Gillissen, C; Hermanns, Thomas; Heydhausen, Dirk; Jahn, Dieter; Kaussen, Gordon; Linn, Alexander; Perchalla, Lars; Poettgens, Michael; Pooth, Oliver; Stahl, Achim; Zoeller, Marc Henning; Buhmann, Peter; Butz, Erik; Flucke, Gero; Hamdorf, Richard Helmut; Hauk, Johannes; Klanner, Robert; Pein, Uwe; Schleper, Peter; Steinbruck, G; Blum, P; De Boer, Wim; Dierlamm, Alexander; Dirkes, Guido; Fahrer, Manuel; Frey, Martin; Furgeri, Alexander; Hartmann, Frank; Heier, Stefan; Hoffmann, Karl-Heinz; Kaminski, Jochen; Ledermann, Bernhard; Liamsuwan, Thiansin; Muller, S; Muller, Th; Schilling, Frank-Peter; Simonis, Hans-Jürgen; Steck, Pia; Zhukov, Valery; Cariola, P; De Robertis, Giuseppe; Ferorelli, Raffaele; Fiore, Luigi; Preda, M; Sala, Giuliano; Silvestris, Lucia; Tempesta, Paolo; Zito, Giuseppe; Creanza, Donato; De Filippis, Nicola; De Palma, Mauro; Giordano, Domenico; Maggi, Giorgio; Manna, Norman; My, Salvatore; Selvaggi, Giovanna; Albergo, Sebastiano; Chiorboli, Massimiliano; Costa, Salvatore; Galanti, Mario; Giudice, Nunzio; Guardone, Nunzio; Noto, Francesco; Potenza, Renato; Saizu, Mirela Angela; Sparti, V; Sutera, Concetta; Tricomi, Alessia; Tuve, Cristina; Brianzi, Mirko; Civinini, Carlo; Maletta, Fernando; Manolescu, Florentina; Meschini, Marco; Paoletti, Simone; Sguazzoni, Giacomo; Broccolo, B; Ciulli, Vitaliano; D'Alessandro, Raffaello; Focardi, Ettore; Frosali, Simone; Genta, Chiara; Landi, Gregorio; Lenzi, Piergiulio; Macchiolo, Anna; Magini, Nicolo; Parrini, Giuliano; Scarlini, Enrico; Cerati, Giuseppe Benedetto; Azzi, Patrizia; Bacchetta, Nicola; Candelori, Andrea; Dorigo, Tommaso; Kaminsky, A; Karaevski, S; Khomenkov, Volodymyr; Reznikov, Sergey; Tessaro, Mario; Bisello, Dario; De Mattia, Marco; Giubilato, Piero; Loreti, Maurizio; Mattiazzo, Serena; Nigro, Massimo; Paccagnella, Alessandro; Pantano, Devis; Pozzobon, Nicola; Tosi, Mia; Bilei, Gian Mario; Checcucci, Bruno; Fano, Livio; Servoli, Leonello; Ambroglini, Filippo; Babucci, Ezio; Benedetti, Daniele; Biasini, Maurizio; Caponeri, Benedetta; Covarelli, Roberto; Giorgi, Marco; Lariccia, Paolo; Mantovani, Giancarlo; Marcantonini, Marta; Postolache, Vasile; Santocchia, Attilio; Spiga, Daniele; Bagliesi, Giuseppe; Balestri, Gabriele; Berretta, Luca; Bianucci, S; Boccali, Tommaso; Bosi, Filippo; Bracci, Fabrizio; Castaldi, Rino; Ceccanti, Marco; Cecchi, Roberto; Cerri, Claudio; Cucoanes, Andi Sebastian; Dell'Orso, Roberto; Dobur, Didar; Dutta, Suchandra; Giassi, Alessandro; Giusti, Simone; Kartashov, Dmitry; Kraan, Aafke; Lomtadze, Teimuraz; Lungu, George-Adrian; Magazzu, Guido; Mammini, Paolo; Mariani, Filippo; Martinelli, Giovanni; Moggi, Andrea; Palla, Fabrizio; Palmonari, Francesco; Petragnani, Giulio; Profeti, Alessandro; Raffaelli, Fabrizio; Rizzi, Domenico; Sanguinetti, Giulio; Sarkar, Subir; Sentenac, Daniel; Serban, Alin Titus; Slav, Adrian; Soldani, A; Spagnolo, Paolo; Tenchini, Roberto; Tolaini, Sergio; Venturi, Andrea; Verdini, Piero Giorgio; Vos, Marcel; Zaccarelli, Luciano; Avanzini, Carlo; Basti, Andrea; Benucci, Leonardo; Bocci, Andrea; Cazzola, Ugo; Fiori, Francesco; Linari, Stefano; Massa, Maurizio; Messineo, Alberto; Segneri, Gabriele; Tonelli, Guido; Azzurri, Paolo; Bernardini, Jacopo; Borrello, Laura; Calzolari, Federico; Foa, Lorenzo; Gennai, Simone; Ligabue, Franco; Petrucciani, Giovanni; Rizzi, Andrea; Yang, Zong-Chang; Benotto, Franco; Demaria, Natale; Dumitrache, Floarea; Farano, R; Borgia, Maria Assunta; Castello, Roberto; Costa, Marco; Migliore, Ernesto; Romero, Alessandra; Abbaneo, Duccio; Abbas, M; Ahmed, Ijaz; Akhtar, I; Albert, Eric; Bloch, Christoph; Breuker, Horst; Butt, Shahid Aleem; Buchmuller, Oliver; Cattai, Ariella; Delaere, Christophe; Delattre, Michel; Edera, Laura Maria; Engstrom, Pauli; Eppard, Michael; Gateau, Maryline; Gill, Karl; Giolo-Nicollerat, Anne-Sylvie; Grabit, Robert; Honma, Alan; Huhtinen, Mika; Kloukinas, Kostas; Kortesmaa, Jarmo; Kottelat, Luc-Joseph; Kuronen, Auli; Leonardo, Nuno; Ljuslin, Christer; Mannelli, Marcello; Masetti, Lorenzo; Marchioro, Alessandro; Mersi, Stefano; Michal, Sebastien; Mirabito, Laurent; Muffat-Joly, Jeannine; Onnela, Antti; Paillard, Christian; Pal, Imre; Pernot, Jean-Francois; Petagna, Paolo; Petit, Patrick; Piccut, C; Pioppi, Michele; Postema, Hans; Ranieri, Riccardo; Ricci, Daniel; Rolandi, Gigi; Ronga, Frederic Jean; Sigaud, Christophe; Syed, A; Siegrist, Patrice; Tropea, Paola; Troska, Jan; Tsirou, Andromachi; Vander Donckt, Muriel; Vasey, François; Alagoz, Enver; Amsler, Claude; Chiochia, Vincenzo; Regenfus, Christian; Robmann, Peter; Rochet, Jacky; Rommerskirchen, Tanja; Schmidt, Alexander; Steiner, Stefan; Wilke, Lotte; Church, Ivan; Cole, Joanne; Coughlan, John A; Gay, Arnaud; Taghavi, S; Tomalin, Ian R; Bainbridge, Robert; Cripps, Nicholas; Fulcher, Jonathan; Hall, Geoffrey; Noy, Matthew; Pesaresi, Mark; Radicci, Valeria; Raymond, David Mark; Sharp, Peter; Stoye, Markus; Wingham, Matthew; Zorba, Osman; Goitom, Israel; Hobson, Peter R; Reid, Ivan; Teodorescu, Liliana; Hanson, Gail; Jeng, Geng-Yuan; Liu, Haidong; Pasztor, Gabriella; Satpathy, Asish; Stringer, Robert; Mangano, Boris; Affolder, K; Affolder, T; Allen, Andrea; Barge, Derek; Burke, Samuel; Callahan, D; Campagnari, Claudio; Crook, A; D'Alfonso, Mariarosaria; Dietch, J; Garberson, Jeffrey; Hale, David; Incandela, H; Incandela, Joe; Jaditz, Stephen; Kalavase, Puneeth; Kreyer, Steven Lawrence; Kyre, Susanne; Lamb, James; Mc Guinness, C; Mills, C; Nguyen, Harold; Nikolic, Milan; Lowette, Steven; Rebassoo, Finn; Ribnik, Jacob; Richman, Jeffrey; Rubinstein, Noah; Sanhueza, S; Shah, Yousaf Syed; Simms, L; Staszak, D; Stoner, J; Stuart, David; Swain, Sanjay Kumar; Vlimant, Jean-Roch; White, Dean; Ulmer, Keith; Wagner, Stephen Robert; Bagby, Linda; Bhat, Pushpalatha C; Burkett, Kevin; Cihangir, Selcuk; Gutsche, Oliver; Jensen, Hans; Johnson, Mark; Luzhetskiy, Nikolay; Mason, David; Miao, Ting; Moccia, Stefano; Noeding, Carsten; Ronzhin, Anatoly; Skup, Ewa; Spalding, William J; Spiegel, Leonard; Tkaczyk, Slawek; Yumiceva, Francisco; Zatserklyaniy, Andriy; Zerev, E; Anghel, Ioana Maria; Bazterra, Victor Eduardo; Gerber, Cecilia Elena; Khalatian, S; Shabalina, Elizaveta; Baringer, Philip; Bean, Alice; Chen, Jie; Hinchey, Carl Louis; Martin, Christophe; Moulik, Tania; Robinson, Richard; Gritsan, Andrei; Lae, Chung Khim; Tran, Nhan Viet; Everaerts, Pieter; Hahn, Kristan Allan; Harris, Philip; Nahn, Steve; Rudolph, Matthew; Sung, Kevin; Betchart, Burton; Demina, Regina; Gotra, Yury; Korjenevski, Sergey; Miner, Daniel Carl; Orbaker, Douglas; Christofek, Leonard; Hooper, Ryan; Landsberg, Greg; Nguyen, Duong; Narain, Meenakshi; Speer, Thomas; Tsang, Ka Vang

    2009-01-01

    In March 2007 the assembly of the Silicon Strip Tracker was completed at the Tracker Integration Facility at CERN. Nearly 15% of the detector was instrumented using cables, fiber optics, power supplies, and electronics intended for the operation at the LHC. A local chiller was used to circulate the coolant for low temperature operation. In order to understand the efficiency and alignment of the strip tracker modules, a cosmic ray trigger was implemented. From March through July 4.5 million triggers were recorded. This period, referred to as the Sector Test, provided practical experience with the operation of the Tracker, especially safety, data acquisition, power, and cooling systems. This paper describes the performance of the strip system during the Sector Test, which consisted of five distinct periods defined by the coolant temperature. Significant emphasis is placed on comparisons between the data and results from Monte Carlo studies.

  5. Performance studies of the CMS Strip Tracker before installation

    Energy Technology Data Exchange (ETDEWEB)

    Adam, W.; et al.

    2009-06-01

    In March 2007 the assembly of the Silicon Strip Tracker was completed at the Tracker Integration Facility at CERN. Nearly 15% of the detector was instrumented using cables, fiber optics, power supplies, and electronics intended for the operation at the LHC. A local chiller was used to circulate the coolant for low temperature operation. In order to understand the efficiency and alignment of the strip tracker modules, a cosmic ray trigger was implemented. From March through July 4.5 million triggers were recorded. This period, referred to as the Sector Test, provided practical experience with the operation of the Tracker, especially safety, data acquisition, power, and cooling systems. This paper describes the performance of the strip system during the Sector Test, which consisted of five distinct periods defined by the coolant temperature. Significant emphasis is placed on comparisons between the data and results from Monte Carlo studies.

  6. Nonlinear Vibration Analysis of Moving Strip with Inertial Boundary Condition

    Directory of Open Access Journals (Sweden)

    Chong-yi Gao

    2015-01-01

    Full Text Available According to the movement mechanism of strip and rollers in tandem mill, the strip between two stands was simplified to axially moving Euler beam and the rollers were simplified to the inertial component on the fixed axis rotation, namely, inertial boundary. Nonlinear vibration mechanical model of Euler beam with inertial boundary conditions was established. The transverse and longitudinal motion equations were derived based on Hamilton’s principle. Kantorovich averaging method was employed to discretize the motion equations and the inertial boundary equations, and the solutions were obtained using the modified iteration method. Depending on numerical calculation, the amplitude-frequency responses of Euler beam were determined. The axial velocity, tension, and rotational inertia have strong influences on the vibration characteristics. The results would provide an important theoretical reference to control and analyze the vertical vibration of moving strip in continuous rolling process.

  7. ADSORPTION MALACHITE GREEN ON NATURAL ZEOLITE

    Directory of Open Access Journals (Sweden)

    Eko Ariyanto

    2012-02-01

    Full Text Available A natural zeolite was employed as adsorbent for reducing of malachite green from aqueous solution. A batch system was applied to study the adsorption of malachite green in single system on natural zeolite. The adsorption studies indicate that malachite green in single component system follows the second-order kinetics and the adsorption is diffusion process with two stages for malachite green. Malachite green adsorption isotherm follows the Langmuir model.

  8. Distillation and Air Stripping Designs for the Lunar Surface

    Science.gov (United States)

    Boul, Peter J.; Lange, Kevin E.; Conger, Bruce; Anderson, Molly

    2009-01-01

    Air stripping and distillation are two different gravity-based methods, which may be applied to the purification of wastewater on the lunar base. These gravity-based solutions to water processing are robust physical separation techniques, which may be advantageous to many other techniques for their simplicity in design and operation. The two techniques can be used in conjunction with each other to obtain high purity water. The components and feed compositions for modeling waste water streams are presented in conjunction with the Aspen property system for traditional stage distillation models and air stripping models. While the individual components for each of the waste streams will vary naturally within certain bounds, an analog model for waste water processing is suggested based on typical concentration ranges for these components. Target purity levels for the for recycled water are determined for each individual component based on NASA s required maximum contaminant levels for potable water Distillation processes are modeled separately and in tandem with air stripping to demonstrate the potential effectiveness and utility of these methods in recycling wastewater on the Moon. Optimum parameters such as reflux ratio, feed stage location, and processing rates are determined with respect to the power consumption of the process. Multistage distillation is evaluated for components in wastewater to determine the minimum number of stages necessary for each of 65 components in humidity condensate and urine wastewater mixed streams. Components of the wastewater streams are ranked by Henry s Law Constant and the suitability of air stripping in the purification of wastewater in terms of component removal is evaluated. Scaling factors for distillation and air stripping columns are presented to account for the difference in the lunar gravitation environment. Commercially available distillation and air stripping units which are considered suitable for Exploration Life Support

  9. Silicon strip detector qualification for the CMS experiment

    International Nuclear Information System (INIS)

    To provide the best spatial resolution for the particle trajectory reconstruction and a very fast readout, the inner tracking system of CMS is build up of silicon detectors with a pixel tracker in the center surrounded by a strip tracker. The silicon strip tracker consists of so-called modules representing the smallest detection unit of the tracking device. These modules are mounted on higher-level structures called shells in the tracker inner barrel (TIB), rods in the tracker outer barrel (TOB), disks in the tracker inner disks (TID) and petals in the tracker end caps (TEC). The performance of the participating two shells of the TIB, four rods of the TOB and two petals of the TEC (representing about 1% of the final strip tracker) could be studied in different magnetic fields over a period of approximately two month using cosmic muon signals. The last test before inserting the tracker in the CMS experiment was the Tracker Slice Test performed in spring/summer 2007 at the Tracker Integration Facility (TIF) at CERN after installing all subdetectors in the tracker support tube. Approximately 25% of the strip tracker +z side was powered and read out using a cosmic ray trigger built up of scintillation counters. In total, about 5 million muon events were recorded under various operating conditions. These events together with results from commissioning runs were used to study the detector response like cluster charges, signal-to-noise ratios and single strip noise behaviour as well as to identify faulty channels which turned out to be in the order of a few per mille. The performance of the silicon strip tracker during these different construction stages is discussed in this thesis with a special emphasis on the tracker end caps. (orig.)

  10. A visual strip sensor for determination of iron

    International Nuclear Information System (INIS)

    Highlights: • A visual strip sensor for on-site detection of iron has been developed and made. • The sensor is easy to synthesize, portable and recyclable with shelf life >1 year. • Visual detection limit for iron using the present sensor is 50 ng mL−1. • Visual strip sensor was applied to ground water and fruit juices. - Abstract: A visual strip has been developed for sensing iron in different aqueous samples like natural water and fruit juices. The sensor has been synthesized by UV-radiation induced graft polymerization of acrylamide monomer in microporous poly(propylene) base. For physical immobilization of iron selective reagent, the in situ polymerization of acrylamide has been carried out in the presence of 1,10-phenanthroline. The loaded strip on interaction with Fe(II) in aqueous solution turned into orange red color and the intensity of the color was found to be directly proportional to the amount of Fe(II) in the aqueous sample. The minimal sensor response with naked eye was found for 50 ng mL−1 of Fe in 15 min of interaction. However, as low as 20 ng mL−1 Fe could be quantified using a spectrophotometer. The detection limit calculated using the 3s/S criteria, where ‘s’ is the standard deviation of the absorbance of blank reagent loaded strip and ‘S’ is the slope of the linear calibration plot, was 1.0 ng mL−1. The strip was applied to measure Fe in a variety of samples such as ground water and fruit juices

  11. A visual strip sensor for determination of iron

    Energy Technology Data Exchange (ETDEWEB)

    Kumar, Sanjukta A., E-mail: sanjuktaak301@gmail.com [Analytical Chemistry Division, BARC, Trombay, Mumbai 400085 (India); Thakur, Neha; Parab, Harshala J.; Pandey, Shailaja P. [Analytical Chemistry Division, BARC, Trombay, Mumbai 400085 (India); Shinde, Rakesh N.; Pandey, Ashok K. [Radiochemistry Division, BARC, Trombay, Mumbai 400085 (India); Kumar, Sangita D.; Reddy, A.V.R. [Analytical Chemistry Division, BARC, Trombay, Mumbai 400085 (India)

    2014-12-03

    Highlights: • A visual strip sensor for on-site detection of iron has been developed and made. • The sensor is easy to synthesize, portable and recyclable with shelf life >1 year. • Visual detection limit for iron using the present sensor is 50 ng mL{sup −1}. • Visual strip sensor was applied to ground water and fruit juices. - Abstract: A visual strip has been developed for sensing iron in different aqueous samples like natural water and fruit juices. The sensor has been synthesized by UV-radiation induced graft polymerization of acrylamide monomer in microporous poly(propylene) base. For physical immobilization of iron selective reagent, the in situ polymerization of acrylamide has been carried out in the presence of 1,10-phenanthroline. The loaded strip on interaction with Fe(II) in aqueous solution turned into orange red color and the intensity of the color was found to be directly proportional to the amount of Fe(II) in the aqueous sample. The minimal sensor response with naked eye was found for 50 ng mL{sup −1} of Fe in 15 min of interaction. However, as low as 20 ng mL{sup −1} Fe could be quantified using a spectrophotometer. The detection limit calculated using the 3s/S criteria, where ‘s’ is the standard deviation of the absorbance of blank reagent loaded strip and ‘S’ is the slope of the linear calibration plot, was 1.0 ng mL{sup −1}. The strip was applied to measure Fe in a variety of samples such as ground water and fruit juices.

  12. Experimental evidence that wildflower strips increase pollinator visits to crops.

    Science.gov (United States)

    Feltham, Hannah; Park, Kirsty; Minderman, Jeroen; Goulson, Dave

    2015-08-01

    Wild bees provide a free and potentially diverse ecosystem service to farmers growing pollination-dependent crops. While many crops benefit from insect pollination, soft fruit crops, including strawberries are highly dependent on this ecosystem service to produce viable fruit. However, as a result of intensive farming practices and declining pollinator populations, farmers are increasingly turning to commercially reared bees to ensure that crops are adequately pollinated throughout the season. Wildflower strips are a commonly used measure aimed at the conservation of wild pollinators. It has been suggested that commercial crops may also benefit from the presence of noncrop flowers; however, the efficacy and economic benefits of sowing flower strips for crops remain relatively unstudied. In a study system that utilizes both wild and commercial pollinators, we test whether wildflower strips increase the number of visits to adjacent commercial strawberry crops by pollinating insects. We quantified this by experimentally sowing wildflower strips approximately 20 meters away from the crop and recording the number of pollinator visits to crops with, and without, flower strips. Between June and August 2013, we walked 292 crop transects at six farms in Scotland, recording a total of 2826 pollinators. On average, the frequency of pollinator visits was 25% higher for crops with adjacent flower strips compared to those without, with a combination of wild and commercial bumblebees (Bombus spp.) accounting for 67% of all pollinators observed. This effect was independent of other confounding effects, such as the number of flowers on the crop, date, and temperature. Synthesis and applications. This study provides evidence that soft fruit farmers can increase the number of pollinators that visit their crops by sowing inexpensive flower seed mixes nearby. By investing in this management option, farmers have the potential to increase and sustain pollinator populations over time

  13. Silicon strip detector qualification for the CMS experiment

    Energy Technology Data Exchange (ETDEWEB)

    Kaussen, Gordon

    2008-10-06

    To provide the best spatial resolution for the particle trajectory reconstruction and a very fast readout, the inner tracking system of CMS is build up of silicon detectors with a pixel tracker in the center surrounded by a strip tracker. The silicon strip tracker consists of so-called modules representing the smallest detection unit of the tracking device. These modules are mounted on higher-level structures called shells in the tracker inner barrel (TIB), rods in the tracker outer barrel (TOB), disks in the tracker inner disks (TID) and petals in the tracker end caps (TEC). The performance of the participating two shells of the TIB, four rods of the TOB and two petals of the TEC (representing about 1% of the final strip tracker) could be studied in different magnetic fields over a period of approximately two month using cosmic muon signals. The last test before inserting the tracker in the CMS experiment was the Tracker Slice Test performed in spring/summer 2007 at the Tracker Integration Facility (TIF) at CERN after installing all subdetectors in the tracker support tube. Approximately 25% of the strip tracker +z side was powered and read out using a cosmic ray trigger built up of scintillation counters. In total, about 5 million muon events were recorded under various operating conditions. These events together with results from commissioning runs were used to study the detector response like cluster charges, signal-to-noise ratios and single strip noise behaviour as well as to identify faulty channels which turned out to be in the order of a few per mille. The performance of the silicon strip tracker during these different construction stages is discussed in this thesis with a special emphasis on the tracker end caps. (orig.)

  14. Study on increasing calculation precision and convergence speed of streamline strip element method

    Institute of Scientific and Technical Information of China (English)

    彭艳; 刘宏民

    2004-01-01

    The calculation precision and convergence speed of streamline strip element method are increased by using the method whose initial value of the exit lateral displacement is determined with strip element variation method, and the accurate tension lateral distribution model is adopted based on the original third power spline function streamline strip element method. The basic theory of the strip element method is developed. The calculated results by the improved streamline strip element method and the original streamline strip element method are compared with the measured results, showing that the calculated results of the improved method are in good agreement with the measured results.

  15. Adsorption theory for polydisperse polymers.

    NARCIS (Netherlands)

    Roefs, S.P.F.M.; Scheutjens, J.M.H.M.; Leermakers, F.A.M.

    1994-01-01

    Most polymers are polydisperse. We extend the self-consistent field polymer adsorption theory due to Scheutjens and Fleer to account for an arbitrary polymer molecular weight distribution with a cutoff chain length Nmax. In this paper, the treatment is restricted to homopolymers. For this case a ver

  16. Adsorption of Levofloxacin to Goethite

    NARCIS (Netherlands)

    Qin, Xiaopeng; Liu, Fei; Zhao, Long; Hou, Hong; Wang, Guangcai; Li, Fasheng; Weng, Liping

    2016-01-01

    Batch experiments were conducted to investigate the adsorption of a widely used fluoroquinolone antibiotic levofloxacin (LEV) to goethite and effects of nitrate, sulfate, small organic acids, and humic acid (HA). The concentrations of LEV and small organic acids in single systems or mixtures were

  17. Scaling Laws of Polyelectrolyte Adsorption

    OpenAIRE

    Borukhov, I.; Andelman, D.; Orland, H.

    1997-01-01

    Adsorption of charged polymers (polyelectrolytes) from a semi-dilute solution to a charged surface is investigated theoretically. We obtain simple scaling laws for (i) the amount of polymer adsorbed to the surface, Gamma, and (ii) the width of the adsorbed layer D, as function of the fractional charge per monomer p and the salt concentration c_b. For strongly charged polyelectrolytes (p

  18. Beam test of CSES silicon strip detector module

    CERN Document Server

    Zhang, Da-Li; Wang, Huan-Yu; Li, Xin-Qiao; Xu, Yan-Bing; An, heng-Hua; Yu, Xiao-xia; Wang, Hui; Shi, Feng; Wang, Ping; Zhao, Xiao-Yun

    2016-01-01

    The silicon-strip tracker of China Seismo-Electromagnetic Satellite (CSES) consists of two double-sided silicon strip detectors (DSSD). It provides the tracking information of incident particles. The low-noise analog ASIC VA140 was used for signal readout of DSSD. A beam test of the DSSD module was performed in the Beijing test beam Facility of the Beijing Electron Positron Collider (BEPC) using proton beam of 400~800MeV/c. Results on pedestal analysis, RMSE noise, gain correction and reconstruction of incident position of DSSD module are presented.

  19. Development of thermochromic strips as a water pasteurization indicator

    Institute of Scientific and Technical Information of China (English)

    Ishtiaq A. Qazi; M. Ali Awan; M. Anwar Baig

    2003-01-01

    Boiling of water, for purification, commonly practiced in the world, has many problems associated with it like danger of scalding,scaling in the vessels, removal of useful minerals and blandness of taste etc. Water can be made safe for drinking simply by heating at 65℃ for 6 minutes. A colour indicating strip was developed which changes colour from red to purple at 67℃. Use of this strip can help in pasteurizing water without the above problems and with considerable energy saving.

  20. A plane mirror experiment inspired by a comic strip

    Science.gov (United States)

    Lúcio Prados Ribeiro, Jair

    2016-01-01

    A comic strip about a plane mirror was used in a high school optics test, and it was perceived that a large portion of the students believed that the mirror should be larger than the object so the virtual image could be entirely visible. Inspired on the comic strip, an experimental demonstration with flat mirrors was developed, in order to readdress this topic learning. Students were encouraged to create their own investigation of the phenomenon with a simple instrumental apparatus and also suggest different experimental approaches.

  1. In-well vapor stripping drilling and characterization work plan

    International Nuclear Information System (INIS)

    This work plan provides the information necessary for drilling, sampling, and hydrologic testing of wells to be completed in support of a demonstration of the in-well vapor stripping system. The in-well vapor stripping system is a remediation technology designed to preferentially extract volatile organic compounds (VOCs) from contaminated groundwater by converting them to a vapor phase. Air-lift pumping is used to lift and aerate groundwater within the well. The volatiles escaping the aerated water are drawn off by a slight vacuum and treated at the surface while the water is allowed to infiltrate the vadose zone back to the watertable

  2. Ultra-stripped supernovae and double neutron star systems

    CERN Document Server

    Tauris, Thomas

    2015-01-01

    The evolution of close-orbit progenitor binaries of double neutron star (DNS) systems leads to supernova (SN) explosions of ultra-stripped stars. The amount of SN ejecta mass is very limited from such, more or less, naked metal cores with envelope masses of only 0.01-0.2 Msun. The combination of little SN ejecta mass and the associated possibility of small NS kicks is quite important for the characteristics of the resulting DNS systems left behind. Here, we discuss theoretical predictions for DNS systems, based on Case BB Roche-lobe overflow prior to ultra-stripped SNe, and briefly compare with observations.

  3. Application of Adaptive Threading Technique to Hot Strip Mill

    Institute of Scientific and Technical Information of China (English)

    DING Jing-guo; HU Xian-lei; JIAO Jing-min; SHE Guang-fu; LIU Xiang-hua

    2008-01-01

    Thickness deviation of hot strip rolling needs to be strictly controlled in the computer system.An adaptive threading technique was researched,in which the measured data from threaded stands were used to predict thickness and material hardness errors,to modify the setup for the remaining unthreaded stands.After the adaptive threading model was used online on the hot strip mill of the Panzhihua Iron and Steel Group Co Ltd,the thickness deviation was decreased obviously.The hit rate of thickness control of different steel grades increases.

  4. Optical Möbius strips and twisted ribbon cloaks.

    Science.gov (United States)

    Freund, Isaac

    2014-02-15

    Optical Möbius strips that surround points of circular polarization, C points, in a generic three-dimensional optical field are cloaked by lines of twisted ribbons attached to the C points. When cloaking occurs, the observable signed twist index that counts the number of half-twists (one or three), and also measures the handedness (right or left), of a generic Möbius strip is determined by the twisted ribbon cloaks. Although some cloaks can be detached, they can never all be removed.

  5. Kinetics of heterogeneous catalytic reactions

    CERN Document Server

    Boudart, Michel

    2014-01-01

    This book is a critical account of the principles of the kinetics of heterogeneous catalytic reactions in the light of recent developments in surface science and catalysis science. Originally published in 1984. The Princeton Legacy Library uses the latest print-on-demand technology to again make available previously out-of-print books from the distinguished backlist of Princeton University Press. These paperback editions preserve the original texts of these important books while presenting them in durable paperback editions. The goal of the Princeton Legacy Library is to vastly increase acc

  6. Molecular catalytic coal liquid conversion

    Energy Technology Data Exchange (ETDEWEB)

    Stock, L.M.; Yang, Shiyong [Univ. of Chicago, IL (United States)

    1995-12-31

    This research, which is relevant to the development of new catalytic systems for the improvement of the quality of coal liquids by the addition of dihydrogen, is divided into two tasks. Task 1 centers on the activation of dihydrogen by molecular basic reagents such as hydroxide ion to convert it into a reactive adduct (OH{center_dot}H{sub 2}){sup {minus}} that can reduce organic molecules. Such species should be robust withstanding severe conditions and chemical poisons. Task 2 is focused on an entirely different approach that exploits molecular catalysts, derived from organometallic compounds that are capable of reducing monocyclic aromatic compounds under very mild conditions. Accomplishments and conclusions are discussed.

  7. Computational Introduction of Catalytic Activity into Proteins.

    Science.gov (United States)

    Bertolani, Steve J; Carlin, Dylan Alexander; Siegel, Justin B

    2016-01-01

    Recently, there have been several successful cases of introducing catalytic activity into proteins. One method that has been used successfully to achieve this is the theozyme placement and enzyme design algorithms implemented in Rosetta Molecular Modeling Suite. Here, we illustrate how to use this software to recapitulate the placement of catalytic residues and ligand into a protein using a theozyme, protein scaffold, and catalytic constraints as input. PMID:27094294

  8. Estimating the temperature of a catalytic converter

    Energy Technology Data Exchange (ETDEWEB)

    Ma, T.T.-H.

    1994-11-02

    A method is described for estimating the temperature in a catalytic converter used in the exhaust system of an internal combustion engine. Pressure sensors monitor the flow resistance across the catalytic converter to provide an indication of the temperature inside. This feedback system allows heating devices to be switched off and thus avoid overheating, while maintaining the catalytic converter's efficiency by assuring that it does not operate below its light off temperature. (UK)

  9. Estimating the temperature of a catalytic converter

    Energy Technology Data Exchange (ETDEWEB)

    Ma, T.T.-H.

    1994-11-02

    A method of estimating the temperature of a catalytic converter used in the exhaust system of an internal combustion engine is described. Heated exhaust gas oxygen (HEGO) sensors are placed upstream and downstream of the catalytic converter. The temperature of the catalytic converter shortly after start-up is measured by monitoring the resistance of the HEGO sensor's heating element. The downstream sensor is used for mixture control and to double check results of the upstream sensor. (UK)

  10. Some Aspects of the Catalytic Organic Synthesis

    Institute of Scientific and Technical Information of China (English)

    Anil; K.Saikia

    2007-01-01

    1 Results Catalytic reactions are gaining importance due to its low cost, operational simplicity, high efficiency and selectivity. It is also getting much attention in green synthesis. Many useful organic reactions, including the acylation of alcohols and aldehydes, carbon-carbon, carbon-nitrogen, carbon-sulfur bond forming and oxidation reactions are carried out by catalyst. We are exploring the catalytic acylation of alcohols and aldehydes in a simple and efficient manner. Catalytic activation of unr...

  11. Adsorption behavior of bisphenol-A and diethyl phthalate onto bubble surface in nonfoaming adsorptive bubble separation

    OpenAIRE

    Maruyama, Hideo; Seki, Hideshi; Matsukawa, Yasuhiro; Suzuki, Akira; INOUE, Norio

    2008-01-01

    To clarify adsorption equilibrium relationship at liquid-atmosphere interface, adsorption behavior of bisphenol-A (BPA) and diethyl phthalate (DEP) onto bubble surface was studied by using nonfoaming adsorptive bubble separation (NFBS) technique. The adsorption isotherm of BPA and DEP were obtained experimentally. The experimental results showed that adsorption equilibrium of BPA and DEP on bubble surface followed Langmuir's adsorption isotherm. Two adsorption parameters, the adsorption equil...

  12. Nanostructured Catalytic Reactors for Air Purification Project

    Data.gov (United States)

    National Aeronautics and Space Administration — This SBIR Phase I project proposes the development of lightweight compact nanostructured catalytic reactors for air purification from toxic gaseous organic...

  13. Nanostructured Catalytic Reactors for Air Purification Project

    Data.gov (United States)

    National Aeronautics and Space Administration — This SBIR Phase II project proposes the development of lightweight compact nanostructured catalytic reactors for air purification from toxic gaseous organic...

  14. Direct electron transfer type disposable sensor strip for glucose sensing employing an engineered FAD glucose dehydrogenase.

    Science.gov (United States)

    Yamashita, Yuki; Ferri, Stefano; Huynh, Mai Linh; Shimizu, Hitomi; Yamaoka, Hideaki; Sode, Koji

    2013-02-01

    The FAD-dependent glucose dehydrogenase (FADGDH) from Burkholderia cepacia has several attractive features for glucose sensing. However, expanding the application of this enzyme requires improvement of its substrate specificity, especially decreasing its high activity toward maltose. A three-dimensional structural model of the FADGDH catalytic subunit was generated by homology modeling. By comparing the predicted active site with that of glucose oxidase, the two amino acid residues serine 326 and serine 365 were targeted for site-directed mutagenesis. The single mutations that produced the highest glucose specificity were combined, leading to the creation of the S326Q/S365Y double mutant, which was virtually nonreactive to maltose while retaining high glucose dehydrogenase activity. The engineered FADGDH was used to develop a direct electron transfer-type, disposable glucose sensor strip by immobilizing the enzyme complex onto a carbon screen-printed electrode. While the electrode employing wild-type FADGDH provided dangerously flawed results in the presence of maltose, the sensor employing our engineered FADGDH showed a clear glucose concentration-dependent response that was not affected by the presence of maltose. PMID:23273282

  15. Direct analysis of palladium in active pharmaceutical ingredients by anodic stripping voltammetry.

    Science.gov (United States)

    Rosolina, Samuel M; Chambers, James Q; Xue, Zi-Ling

    2016-03-31

    Anodic stripping voltammetry, a classical electroanalytical method has been optimized to analyze trace Pd(II) in active pharmaceutical ingredient matrices. The electroanalytical approach with an unmodified glassy carbon electrode was performed in both aqueous and 95% DMSO/5% water (95/5 DMSO/H2O) solutions, without pretreatment such as acid digestion or dry ashing to remove the organics. Limits of detection (LODs) in the presence of caffeine and ketoprofen were determined to be 11 and 9.6 μg g(-1), with a relative standard deviation (RSD) of 5.7% and 2.3%, respectively. This method is simple, highly reproducible, sensitive, and robust. The instrumentation has the potential to be portable and the obviation of sample pretreatment makes it an ideal approach for determining lost catalytic metals in pharmaceutical-related industries. Furthermore, the simultaneous detection of Pd(II) with Cd(II) and Pb(II) in the low μg L(-1) range indicates that this system is capable of simultaneous multi-analyte analysis in a variety of matrices. PMID:26965326

  16. Dual-nanomaterial based electrode for voltammetric stripping of trace Fe(II) in coastal waters.

    Science.gov (United States)

    Lin, Mingyue; Pan, Dawei; Zhu, Yun; Hu, Xueping; Han, Haitao; Wang, ChenChen

    2016-07-01

    In this work, a dual-nanomaterial based electrode was established for selective and sensitive detection of trace Fe(II) in the presence of complexing agent (2,2'-bipyridyl). Titanium carbide nanoparticles (TiCNPs) were used as the growth-template for the formation of three-dimensional platinum nanoflowers (PtNFs) due to their unique cubic structures. Nafion was employed as the conducting matrix to help TiCNPs better attached onto the surface of the electrode and slow down the crystal rate of PtNFs during electrodeposition, which resulted in flower structure and more active surface of PtNFs. Taking advantage of synergistic effects of TiCNPs and Nafion as well as the catalytic amplifying effect of PtNFs, the excellent anodic signal responses for the voltammetric stripping determination of Fe(II) were obtained. The linear range of Fe(II) on this dual-nanomaterial based electrode was from 1nmolL(-1) to 6μmolL(-1) with the lowest detectable concentration of 0.1nmolL(-1) and a detection limit of 0.03nmolL(-1). Additionally, the effect of several experimental parameters, such as concentration and pH value of buffer solution, concentration of modifier and ligand, deposition potential and time of electrochemical determination, and scan rate were studied for analytical applications. The fabricated sensor had been successfully applied for the sensitive determination of trace Fe(II) in coastal waters.

  17. Direct analysis of palladium in active pharmaceutical ingredients by anodic stripping voltammetry.

    Science.gov (United States)

    Rosolina, Samuel M; Chambers, James Q; Xue, Zi-Ling

    2016-03-31

    Anodic stripping voltammetry, a classical electroanalytical method has been optimized to analyze trace Pd(II) in active pharmaceutical ingredient matrices. The electroanalytical approach with an unmodified glassy carbon electrode was performed in both aqueous and 95% DMSO/5% water (95/5 DMSO/H2O) solutions, without pretreatment such as acid digestion or dry ashing to remove the organics. Limits of detection (LODs) in the presence of caffeine and ketoprofen were determined to be 11 and 9.6 μg g(-1), with a relative standard deviation (RSD) of 5.7% and 2.3%, respectively. This method is simple, highly reproducible, sensitive, and robust. The instrumentation has the potential to be portable and the obviation of sample pretreatment makes it an ideal approach for determining lost catalytic metals in pharmaceutical-related industries. Furthermore, the simultaneous detection of Pd(II) with Cd(II) and Pb(II) in the low μg L(-1) range indicates that this system is capable of simultaneous multi-analyte analysis in a variety of matrices.

  18. Palladium catalysts supported on novel CexY1-xO washcoats for toluene catalytic combustion

    Institute of Scientific and Technical Information of China (English)

    JIN Lingyun; HE Mai; LU Jiqing; LUO Mengfei; GAO Libiao; HE Jun

    2008-01-01

    Novel CexY1-xO washcoats adhered on the cordierite honeycomb, used as supports for Pd catalysts, were prepared by an impregnation method. It was found that the CexY1-xO washcoats had better adhesion and higher adsorption efficiency of H2PdCl4, and the optimal component of the washcoat was Ce0.8Y0.2O. Model reaction of catalytic combustion of toluene was chosen to evaluate the performance of the developed Pd/CexY1-xO/substrate catalysts. The results showed that the catalytic performance of the Pd/CexY1-xO/substrate catalysts depended on the component of the washcoats, with the Pd/Ce0.8Y0.2O/ substrate catalyst giving the best catalytic activity and thermal stability.

  19. The chemical and catalytic properties of nanocrystalline metal oxides prepared through modified sol-gel synthesis

    Science.gov (United States)

    Carnes, Corrie Leigh

    The goal of this research was to synthesize, characterize and study the chemical properties of nanocrystalline metal oxides. Nanocrystalline (NC) ZnO, CuO, NiO, Al2O3, and the binary Al2O 3/MgO and ZnO/CuO were prepared through modified sol gel methods. These NC metal oxides were studied in comparison to the commercial (CM) metal oxides. The samples were characterized by XRD, TGA, FTIR, BET, and TEM. The NC samples were all accompanied by a significant increase in surface area and decrease in crystallite size. Several chemical reactions were studied to compare the NC samples to the CM samples. One of the reactions involved a high temperature reaction between carbon tetrachloride and the oxide to form carbon dioxide and the corresponding metal chloride. A similar high temperature reaction was conducted between the metal oxide and hydrogen sulfide to form water and the corresponding metal sulfide. A room temperature gas phase adsorption was studied where SO2 was adsorbed onto the oxide. A liquid phase adsorption conducted at room temperature was the destructive adsorption of paraoxon (a toxic insecticide). In all reactions the NC samples exhibited greater activity, destroying or adsorbing a larger amount of the toxins compared to the CM samples. To better study surface area effects catalytic reactions were also studied. The catalysis of methanol was studied over the nanocrystalline ZnO, CuO, NiO, and ZnO/CuO samples in comparison to their commercial counterparts. In most cases the NC samples proved to be more active catalysts, having higher percent conversions and turnover numbers. A second catalytic reaction was also studied, this reaction was investigated to look at the support effects. The catalysis of cyclopropane to propane was studied over Pt and Co catalysts. These catalysts were supported onto NC and CM alumina by impregnation. By observing differences in the catalytic behavior, support effects have become apparent.

  20. Interactions Between Surface Reactions and Gas-phase Reactions in Catalytic Combustion and Their Influence on Ignition of HCCI Engine

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    The catalytic combustion of methane in a microchannel whose surface was coated with platinum(Pt)catalyst was studied by numerical-simulation. The effects of gas-phase reactions on the whole catalytic combustion process were analyzed at a high inlet pressure. A sensitivity analysis of the detailed mechanisms of the surface reaction of methane on Pt revealed that the most sensitive reactions affecting the heterogeneous ignition are oxygen adsorption/desorption and methane adsorption, and the most sensitive reactions affecting the homogeneous ignition are OH and H2O adsorption/desorption. The combustion process of the homogeneous charge compression ignition(HCCI) engine whose piston face was coated with Pt catalyst was simulated. The effects of catalysis and the most sensitive reactions on the ignition timing and the concentration of the main intermediate species during the HCCI engine combustion are discussed. The results show that the ignition timing of the HCCI engine can be increased by catalysis, and the most sensitive reactions affecting the ignition timing of the HCCI engine are OH and H2O adsorption/desorption.

  1. Adsorption of hydrogen sulfide on montmorillonites modified with iron.

    Science.gov (United States)

    Nguyen-Thanh, Danh; Block, Karin; Bandosz, Teresa J

    2005-04-01

    Sodium-rich montmorillonite was modified with iron in order to introduce active centers for hydrogen sulfide adsorption. In the first modification, interlayer sodium cations were exchanged with iron. In another modification, iron oxocations were introduced to the clay surface. The most elaborated modification was based on doping of iron within the interlayer space of aluminum-pillared clay. The modified clay samples were tested as hydrogen sulfide adsorbents. Iron-doped samples showed a significant improvement in the capacity for H2S removal, despite of a noticeable decrease in microporosity compared to the initial pillared clay. The smallest capacity was obtained for the clay modified with iron oxocations. Variations in adsorption capacity are likely due to differences in the chemistry of iron species, degree of their dispersion on the surface, and accessibility of small pores for H2S molecule. The results suggest that on the surface of iron-modified clay hydrogen sulfide reacts with Fe(+3) forming sulfides or it is catalytically oxidized to SO2 on iron (hydro)oxides. Subsequent oxidation may lead to sulfate formation.

  2. Catalytic peptide hydrolysis by mineral surface: Implications for prebiotic chemistry

    Science.gov (United States)

    Marshall-Bowman, Karina; Ohara, Shohei; Sverjensky, Dimitri A.; Hazen, Robert M.; Cleaves, H. James

    2010-10-01

    The abiotic polymerization of amino acids may have been important for the origin of life, as peptides may have been components of the first self-replicating systems. Though amino acid concentrations in the primitive oceans may have been too dilute for significant oligomerization to occur, mineral surface adsorption may have provided a concentration mechanism. As unactivated amino acid polymerization is thermodynamically unfavorable and kinetically slow in aqueous solution, we studied mainly the reverse reaction of polymer degradation to measure the impact of mineral surface catalysis on peptide bonds. Aqueous glycine (G), diglycine (GG), diketopiperazine (DKP), and triglycine (GGG) were reacted with minerals (calcite, hematite, montmorillonite, pyrite, rutile, or amorphous silica) in the presence of 0.05 M, pH 8.1, KHCO 3 buffer and 0.1 M NaCl as background electrolyte in a thermostatted oven at 25, 50 or 70 °C. Below 70 °C, reaction kinetics were too sluggish to detect catalytic activity over amenable laboratory time-scales. Minerals were not found to have measurable effects on the degradation or elongation of G, GG or DKP at 70 °C in solution. At 70 °C pyrite was the most catalytic mineral with detectible effects on the degradation of GGG, although several others also displayed catalytic behavior. GGG degraded ˜1.5-4 times faster in the presence of pyrite than in control reactions, depending on the ratio of solution concentration to mineral surface area. The rate of pyrite catalysis of GGG hydrolysis was found to be saturable, suggesting the presence of discrete catalytic sites on the mineral surface. The mineral-catalyzed degradation of GGG appears to occur via a GGG → DKP + G mechanism, rather than via GGG → GG + G, as in solution-phase reactions. These results are compatible with many previous findings and suggest that minerals may have assisted in peptide synthesis in certain geological settings, specifically by speeding the approach to equilibrium

  3. Heats of adsorption for charcoal nitrogen systems

    Energy Technology Data Exchange (ETDEWEB)

    Prasad, M.; Akkimaradi, B.S.; Rastogi, S.C. [ISRO Satellite Centre, Bangalore (India). Thermal Systems Group; Rao, R.R. [Government College for Boys, Kolar, Karnataka (India); Srinivasan, K. [Indian Institute of Science, Bangalore (India). Dept. of Mechanical Engineering

    1999-07-01

    This paper develops an empirical equation for correlation of the loading dependence of the heat of adsorption for two samples of activated charcoal-nitrogen systems. Details are given of the use of isotherm data, the evaluation of the heat of adsorption using the Clausius-Clapeyron equation, the plotting of primary adsorption data, and the plotting of the heat of adsorption as a function of the loading of the two samples. The need to consider the heat of adsorption property when designing a system in which a gaseous medium is adsorbed by a solid sorbent is discussed. (UK)

  4. Adsorption from solutions of non-electrolytes

    CERN Document Server

    Kipling, J J

    1965-01-01

    Adsorption from Solutions of Non-Electrolytes provides a general discussion of the subject, which has so far been given little or no attention in current textbooks of physical chemistry. A general view of the subject is particularly needed at a time when we wish to see how far it will be possible to use theories of solutions to explain the phenomena of adsorption. The book opens with an introductory chapter on the types of interface, aspects of adsorption from solution, types of adsorption, and classification of systems. This is followed by separate chapters on experimental methods, adsorption

  5. Catalytic reforming feed characterisation technique

    Energy Technology Data Exchange (ETDEWEB)

    Larraz Mora, R.; Arvelo Alvarez, R. [Univ. of La Laguna, Chemical Engineering Dept., La Laguna (Spain)

    2002-09-01

    The catalytic reforming of naphtha is one of the major refinery processes, designed to increase the octane number of naphtha or to produce aromatics. The naphtha used as catalytic reformer feedstock usually contains a mixture of paraffins, naphthenes, and aromatics in the carbon number range C{sub 6} to C{sub 10}. The detailed chemical composition of the feed is necessary to predict the aromatics and hydrogen production as well as the operation severity. The analysis of feed naphtha is usually reported in terms of its ASTM distillation curve and API or specific gravity. Since reforming reactions are described in terms of lumped chemical species (paraffins, naphthenes and aromatics), a feed characterisation technique should be useful in order to predict reforming operating conditions and detect feed quality changes. Unfortunately online analyzer applications as cromatography or recently introduced naphtha NMR [1] are scarce in most of refineries. This work proposes an algorithmic characterisation method focusing on its main steps description. The method could help on the subjects previously described, finally a calculation example is shown. (orig.)

  6. Catalytic conversion of light alkanes

    Energy Technology Data Exchange (ETDEWEB)

    Lyons, J.E.

    1992-06-30

    The second Quarterly Report of 1992 on the Catalytic Conversion of Light Alkanes reviews the work done between April 1, 1992 and June 31, 1992 on the Cooperative Agreement. The mission of this work is to devise a new catalyst which can be used in a simple economic process to convert the light alkanes in natural gas to oxygenate products that can either be used as clean-burning, high octane liquid fuels, as fuel components or as precursors to liquid hydrocarbon uwspomdon fuel. During the past quarter we have continued to design, prepare, characterize and test novel catalysts for the mild selective reaction of light hydrocarbons with air or oxygen to produce alcohols directly. These catalysts are designed to form active metal oxo (MO) species and to be uniquely active for the homolytic cleavage of the carbon-hydrogen bonds in light alkanes producing intermediates which can form alcohols. We continue to investigate three molecular environments for the active catalytic species that we are trying to generate: electron-deficient macrocycles (PHASE I), polyoxometallates (PHASE II), and regular oxidic lattices including zeolites and related structures as well as other molecular surface structures having metal oxo groups (PHASE I).

  7. An improved d-band model of the catalytic activity of magnetic transition metal surfaces

    CERN Document Server

    Bhattacharjee, Satadeep; Lee, S C

    2016-01-01

    The d-band center model of Hammer and N{\\o}rskov is widely used in understanding and predicting catalytic activity on transition metal (TM) surfaces. Here, we demonstrate that this model is inadequate for capturing the complete catalytic activity of the magnetically polarized TM surfaces and propose its generalization. We validate the generalized model through comparison of adsorption energies of the NH$_3$ molecule on the surfaces of 3d TMs (V, Cr, Mn, Fe, Co, Ni, Cu and Zn) determined with spin-polarized density functional theory (DFT)-based methods with the predictions of our model. Compared to the conventional d-band model, where the nature of the metal-adsorbate interaction is entirely determined through the energy and the occupation of the d-band center, we emphasize that for the surfaces with high spin polarization, the metal-adsorbate system can be stabilized through a competition of the spin-dependent metal-adsorbate interactions.

  8. Effect of preparation conditions on physicochemical, surface and catalytic properties of cobalt ferrite prepared by coprecipitation

    Energy Technology Data Exchange (ETDEWEB)

    El-Shobaky, G.A., E-mail: elshobaky@yahoo.co [Physical Chemistry Department, National Research Center, Dokki, Cairo (Egypt); Turky, A.M.; Mostafa, N.Y.; Mohamed, S.K. [Chemistry Department, Faculty of Science, Suez Canal University, Ismailia 41522 (Egypt)

    2010-03-18

    Cobalt ferrite nanoparticles were prepared via thermal treatment of cobalt-iron mixed hydroxides at 400-600 {sup o}C. The mixed hydroxides were coprecipitated from their nitrates solutions using NaOH as precipitating agent. The effects of pH and temperature of coprecipitation and calcination temperature on the physicochemical, surface and catalytic properties of the prepared ferrites were studied. The prepared systems were characterized using TG, DTG, DTA, chemical analysis, atomic absorption spectroscopy (AAS), X-ray diffraction (XRD), energy dispersive X-ray (EDX) as well as surface and texture properties based on nitrogen adsorption-desorption isotherms. The prepared cobalt ferrites were found to be mesoporous materials that have crystallite size ranges between 8 and 45 nm. The surface and catalytic properties of the produced ferrite phase were strongly dependent on coprecipitation conditions of the mixed hydroxides and on their calcination temperature.

  9. Synthesis,Characterization and Catalytic Properties of Mesoporous HPMo/SiO2 Composite

    Institute of Scientific and Technical Information of China (English)

    YAN Xuemin; YAN Jiabao; MEI Ping; LEI Jiaheng

    2008-01-01

    A novel mesoporous HPMo/SiO2 composite was synthesized by the sol-gel method with triblock copolymer EO20PO70EO20 as template.The properties of the product were characterized by X-ray diffraction,transmission electron microscopy,N2 adsorption-desorption isotherms,Fourier transform infrared spectrometer and inductively-coupled plasma analysis.The experimental results show that the product has a very ordered hexagonal mesostructure,and the HPMo is immobilized into the framework of silica.The final mesoporous composite shows excellent stability in polar solvents.Results of catalytic tests indicate that the composite is an effective catalyst for oxidation of dibenzothiophen,and there are few activity losses even after the third cycle of uses.The high catalytic activity and good insolubility make it a promising catalyst in oxidative desulfurization process.

  10. Room Temperature Synthesis and Catalytic Properties of Surfactant-Modified Ag Nanoparticles

    Directory of Open Access Journals (Sweden)

    Weihua Li

    2012-01-01

    Full Text Available Well-dispersed Ag nanoparticles with size of 20–30 nm were synthesized in water at room temperature with a self-made novel imidazoline Gemini surfactant quaternary ammonium salt of di (2-heptadecyl-1-formyl aminoethyl imidazoline hexanediamine. Transmission electron microscopy, X-ray powder diffraction, ultraviolet-visible absorption spectra, and Fourier transform infrared ray were used to characterize the Ag nanoparticles. Results showed that the micellized aggregation of imidazoline Gemini surfactant in water, the growth of Ag initial particles, and the interaction (adsorption and coordination between surfactant and Ag+/Ag nanoparticles took place simultaneously to form the well-dispersed Ag nanoparticles. Catalytic results show that the surface-modified Ag product was an active metal catalyst for methyl orange reduction reaction due to the effective adsorption between Ag nanoparticles and methyl orange molecules, which was of promising application in environmental protection.

  11. Adsorption of Phosphate on Variable Charge Soils

    Institute of Scientific and Technical Information of China (English)

    HUGUO-SONG; ZHUZU-XIANG; 等

    1992-01-01

    The study about the adsorption of phosphate on four variable charge soils and some minerals revealed that two stage adsorption appeared in the adsorption isothems of phosphate on 4 soils and there was a maximum adsorption on Al-oxide-typed surfaces between pH 3.5 to pH 5.5 as suspension pH changed from 2 to 9,but the adsorption amount of phosphate decreased continually as pH rose on Fe-oxide typed surfaces.The adsorption amount of phosphate and the maximum phosphate adsorption pH decreased in the order of yellow-red soil> lateritic red soil> red soil> paddy soil,which was coincided with the content order of amorphous Al oxide.The removement of organic matter and Fe oxide made the maximum phosphate adsorption pH rise from 4.0 to 5.0 and 4.5,respectively.The desorption curves with pH of four soils showed that phosphate desorbed least at pH 5.Generally the desorption was contrary to the adsorption with pH changing.There was a good accordance between adsorption or desorption and the concentration of Al in the suspension.The possible mechanisms of phosphate adsorption are discussed.

  12. Phosphate adsorption on lanthanum loaded biochar.

    Science.gov (United States)

    Wang, Zhanghong; Shen, Dekui; Shen, Fei; Li, Tianyu

    2016-05-01

    To attain a low-cost and high-efficient phosphate adsorbent, lanthanum (La) loaded biochar (La-BC) prepared by a chemical precipitation method was developed. La-BC and its pristine biochar (CK-BC) were comparatively characterized using zeta potential, BET surface area, scanning electron microscopy/energy dispersive spectrometer (SEM-EDS), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS) and Fourier transform infrared spectroscopy (FT-IR). The adsorption ability and the mechanisms during adsorption process for the La-BC samples were also investigated. La loaded on the surface of biochar can be termed as La-composites (such as LaOOH, LaONO3 and La(OH)3), leading to the decrease of negative charge and surface area of biochar. La-BC exhibited the high adsorption capacity to phosphate compared to CK-BC. Adsorption isotherm and adsorption kinetic studies showed that the Langmuir isotherm and second order model could well describe the adsorption process of La-BC, indicating that the adsorption was dominated by a homogeneous and chemical process. The calculated maximum adsorption capacity was as high as 46.37 mg g(-1) (computed in P). Thermodynamic analysis revealed that the adsorption was spontaneous and endothermic. SEM, XRD, XPS and FT-IR analysis suggested that the multi-adsorption mechanisms including precipitation, ligand exchange and complexation interactions can be evidenced during the phosphate adsorption process by La-composites in La-BC. PMID:26871732

  13. The microwave adsorption behavior and microwave-assisted heteroatoms doping of graphene-based nano-carbon materials

    OpenAIRE

    Tang, Pei; Hu, Gang; Gao, Yongjun; Li, Wenjing; Yao, Siyu; Liu, Zongyuan; Ma, Ding

    2014-01-01

    Microwave-assisted heating method is used to treat graphite oxide (GO), pyrolytic graphene oxide (PGO) and hydrogen-reduced pyrolytic graphene oxide (HPGO). Pure or doped graphene are prepared in the time of minutes and a thermal deoxygenization reduction mechanism is proposed to understand their microwave adsorption behaviors. These carbon materials are excellent catalysts in the reduction of nitrobenzene. The defects are believed to play an important role in the catalytic performance.

  14. Catalytic ozonation of bisphenol A in aqueous solution using Mn-Ce/HZSM-5 as catalyst.

    Science.gov (United States)

    Liu, Yanfang; Zhao, Junna; Li, Zaixing; Li, Guixia; Li, Wei; Gao, Xiang

    2015-01-01

    Mixed manganese and cerium oxide supported on HZSM-5 were synthesized and used as heterogeneous catalysts for ozonation of bisphenol A (BPA) in aqueous solution. The prepared catalysts of Mn-Ce/HZSM-5 were characterized by X-ray diffraction, scanning electron microscopy and Fourier transform-infrared spectroscopy. The results indicated that Mn-Ce/HZSM-5 exhibits extraordinary catalytic activity for the degradation of BPA. Removal of 89.3% of BPA and 90.4% of total organic carbon (TOC) was achieved in 30 min, compared to non-catalytic ozonation, where only 50.5% BPA and 28.1% TOC removal were reached under the same conditions. Adsorption of BPA on HZSM-5 support and Mn-Ce/HZSM-5 catalysts was negligible. The strong inhibition of BPA removal by tert-butyl alcohol indicated that the attack of hydroxyl radicals was responsible for the improvement of catalytic ozonation. It was observed that at neutral pH, which is near the point of zero charge of the catalyst, the catalytic activity reached its maximum. Increasing the amount of Mn-Ce/HZSM-5 catalyst until it exceeded 3 g/L did not show a strong effect on BPA removal. The catalysts showed high stability and reusability.

  15. Catalytic decomposition of low level ozone with gold nanoparticles supported on activated carbon

    Institute of Scientific and Technical Information of China (English)

    Pengyi ZHANG; Bo ZHANG; Rui SHI

    2009-01-01

    Highly dispersed gold nanoparticles were supported on coal-based activated carbon (AC) by a sol immobilization method and were used to investigate their catalytic activity for low-level ozone decomposition at ambient temperature. Nitrogen adsorption-desorption,scanning electron microscope (SEM), and X-ray photo-electron spectroscopy (XPS) were used to characterize the catalysts before and after ozone decomposition. The results showed that the supported gold nanoparticles prepared with microwave heating were much smaller and more uniformly dispersed on the activated carbon than those prepared with traditional conduction heating, exhibiting higher catalytic activity for ozone decomposition. The pH values of gold precursor solution significantly influenced the catalytic activity of supported gold for ozone decomposition, and the best pH value was 8. In the case of space velocity of 120000 h-1, inlet ozone concentration of 50mg/m3, and relative humidity of 45%, the Au/AC catalyst maintained the ozone removal ratio at 90.7% after 2500 min. After being used for ozone decomposition, the surface carbon of the catalyst was partly oxidized and the oxygen content increased accordingly, while its specific surface area and pore volume only decreased a little.Ozone was mainly catalytically decomposed by the gold nanoparticles supported on the activated carbon.

  16. Catalytic performance of hierarchical H-ZSM-5/MCM-41 for methanol dehydration to dimethyl ether

    Institute of Scientific and Technical Information of China (English)

    Yu; Sang; Hongxiao; Liu; Shichao; He; Hansheng; Li; Qingze; Jiao; Qin; Wu; Kening; Sun

    2013-01-01

    Micro-mesoporous composite molecular sieves H-ZSM-5/MCM-41 were prepared by the hydrothermal technique with alkali-treated H-ZSM-5zeolite as the source and characterized by scanning electron microscopy,transmission electron microscopy,energy dispersive spectroscopy,X-ray diffraction,N2 adsorption-desorption measurement and NH3 temperature-programmed desorption.The catalytic performances for the methanol dehydration to dimethyl ether over H-ZSM-5/MCM-41 were evaluated.Among these catalysts,H-ZSM-5/MCM-41 prepared with NaOH dosage (nNa/nSi) varying from 0.4 to 0.47 presented excellent catalytic activity with more than 80%methanol conversion and 100%dimethyl ether selectivity in a wide temperature range of 170—300℃,and H-ZSM-5/MCM-41 prepared with nNa/nSi=0.47 showed constant methanol conversion of about 88.7%,100% dimethyl ether selectivity and excellent lifetime at 220℃.The excellent catalytic performances were due to the highly active and uniform acidic sites and the hierarchical porosity in the micro-mesoporous composite molecular sieves.The catalytic mechanism of H-ZSM-5/MCM-41 for the methanol dehydration to dimethyl ether process was also discussed.

  17. Development of the photo catalytic materials for the purification and deodorization of hazardous wastes

    International Nuclear Information System (INIS)

    A hazardous material treatment system utilizing photochemical reaction is a new technology which does not produce any secondary pollutants after dissolving treatment because it is activated by solar photo energy. Photo catalysis reaction apparatus using photo catalytic reaction of TiO2 was fabricated and installed to food waste treatment system for removing bad smell during treatment of food waste. Evolved gas was analysed by gas chromatograph and active carbon fiber sheet and yarn were used as adsorption media for photo catalysis in order to increase the effectiveness of filter system. (author)

  18. Catalytic oxidation of 4-tert-butyltoluene over Ti-MCM-41

    Institute of Scientific and Technical Information of China (English)

    Wei Hua Yu; Chun Hui Zhou; Xiang Sheng Xu; Zhong Hua Ge

    2007-01-01

    The surface-grafted titanium MCM-41 materials were prepared by anchoring titanocene onto the inner walls of MCM-41. The materials were characterized by powder X-ray diffraction (XRD), N2 adsorption-desorption isotherm and diffuse reflectance UV-visible (UV-vis) spectroscopies. The catalytic properties of Ti-MCM-41 were tested in oxidation of 4-tert-butyltoluene with tert-butylhydroperoxide (TBHP) in liquid phase. MCM-41 with loading 4.8 mol% Ti gave the maximal conversions of 23.6% of 4-tert-butyltoluene with a complete selectivity to 4-tert-butylbenzaldehyde.

  19. Preparation, characterization, and catalytic performance of Ta-HMS mesoporous molecular sieve

    Science.gov (United States)

    Li, Xuefeng; Zhang, Like; Gao, Huanxin; Chen, Qingling

    2016-08-01

    Various Ta-HMS (hexagonal mesoporous silica) samples with different Ta content were hydrothermally prepared and characterized by XRD, N2-adsorption, ICP-AES, FTIR, and UV-Vis spectroscopy. The catalytic performance of the samples was also evaluated in the epoxidation of cyclohexene with cumene hydroperoxide as oxidant. The regularity of mesoporous structure decreases while more extraframe Ta ions are formed with increasing the Ta content. Ta-HMS with Ta/Si ratio of 0.015 shows the highest conversion and selectivity in the studied epoxidation reaction. The catalyst can be used for three times without significant activity loss.

  20. Adsorption of amitraz on the clay

    Directory of Open Access Journals (Sweden)

    Jale Gülen

    2013-01-01

    Full Text Available Amitraz (AZ that is used as acaridies was tried to extract with a clay. The experimental data were modelled as using Langmuir and Freundlich isotherms. The adsorption data fit well with Langmuir isotherm that indicated the AZ adsorption is homogeneous and monolayer. The monolayer adsorption capacity was found to be 35.02 mg/g at 20 ºC temperature. Effect of the phases contact time, the initial solution pH and the initial pesticide concentration were investigated from the point of adsorption equilibrium and yield. The adsorption kinetics were investigated by applying pseudo first order, pseudo second order and intra particle diffusion laws. Adsorption of AZ was found to be best fitted by the pseudo second order model. The intra particle diffusion also plays an important role in adsorption phenomenon.

  1. Adsorption modeling for macroscopic contaminant dispersal analysis

    Energy Technology Data Exchange (ETDEWEB)

    Axley, J.W.

    1990-05-01

    Two families of macroscopic adsorption models are formulated, based on fundamental principles of adsorption science and technology, that may be used for macroscopic (such as whole-building) contaminant dispersal analysis. The first family of adsorption models - the Equilibrium Adsorption (EA) Models - are based upon the simple requirement of equilibrium between adsorbent and room air. The second family - the Boundary Layer Diffusion Controlled Adsorption (BLDC) Models - add to the equilibrium requirement a boundary layer model for diffusion of the adsorbate from the room air to the adsorbent surface. Two members of each of these families are explicitly discussed, one based on the linear adsorption isotherm model and the other on the Langmuir model. The linear variants of each family are applied to model the adsorption dynamics of formaldehyde in gypsum wall board and compared to measured data.

  2. Fibrinogen adsorption on blocked surface of albumin

    DEFF Research Database (Denmark)

    Holmberg, Maria; Hou, Xiaolin

    2011-01-01

    We have investigated the adsorption of albumin and fibrinogen onto PET (polyethylene terephthalate) and glass surfaces and how pre-adsorption of albumin onto these surfaces can affect the adsorption of later added fibrinogen. For materials and devices being exposed to blood, adsorption...... of fibrinogen is often a non-wanted event, since fibrinogen is part of the clotting cascade and unspecific adsorption of fibrinogen can have an influence on the activation of platelets. Albumin is often used as blocking agent for avoiding unspecific protein adsorption onto surfaces in devices designed to handle...... energies, the adsorption of both albumin and fibrinogen has been monitored simultaneously on the same sample. Information about topography and coverage of adsorbed protein layers has been obtained using AFM (Atomic Force Microscopy) analysis in liquid. Our studies show that albumin adsorbs in a multilayer...

  3. MUST: A silicon strip detector array for radioactive beam experiments

    CERN Document Server

    Blumenfeld, Y; Sauvestre, J E; Maréchal, F; Ottini, S; Alamanos, N; Barbier, A; Beaumel, D; Bonnereau, B; Charlet, D; Clavelin, J F; Courtat, P; Delbourgo-Salvador, P; Douet, R; Engrand, M; Ethvignot, T; Gillibert, A; Khan, E; Lapoux, V; Lagoyannis, A; Lavergne, L; Lebon, S; Lelong, P; Lesage, A; Le Ven, V; Lhenry, I; Martin, J M; Musumarra, A; Pita, S; Petizon, L; Pollacco, E; Pouthas, J; Richard, A; Rougier, D; Santonocito, D; Scarpaci, J A; Sida, J L; Soulet, C; Stutzmann, J S; Suomijärvi, T; Szmigiel, M; Volkov, P; Voltolini, G

    1999-01-01

    A new and innovative array, MUST, based on silicon strip technology and dedicated to the study of reactions induced by radioactive beams on light particles is described. The detector consists of 8 silicon strip - Si(Li) telescopes used to identify recoiling light charged particles through time of flight, energy loss and energy measurements and to determine precisely their scattering angle through X, Y position measurements. Each 60x60 mm sup 2 double sided silicon strip detector with 60 vertical and 60 horizontal strips yields an X-Y position resolution of 1 mm, an energy resolution of 50 keV, a time resolution of around 1 ns and a 500 keV energy threshold for protons. The backing Si(Li) detectors stop protons up to 25 MeV with a resolution of approximately 50 keV. CsI crystals read out by photo-diodes which stop protons up to 70 MeV are added to the telescopes for applications where higher energy particles need to be detected. The dedicated electronics in VXIbus standard allow us to house the 968 logic and a...

  4. Magnetic stray fields of periodically arranged Co-Crmicro strips

    NARCIS (Netherlands)

    Lintelo, te J.G.T.

    1993-01-01

    Research was carried out on magnetic stray fields of Co-Cr micro strips. This investigation was motivated by the search for increasing bit density and miniaturisation in magnetic data storage and magnetic sensor devices. In these devices the magnetisation is patterned, i.e. by writing bits or etchin

  5. Consideration of Factors Affecting Strip Effluent PH and Sodium Content

    Energy Technology Data Exchange (ETDEWEB)

    Peters, T. [Savannah River Site (SRS), Aiken, SC (United States)

    2015-07-29

    A number of factors were investigated to determine possible reasons for why the Strip Effluent (SE) can sometimes have higher than expected pH values and/or sodium content, both of which have prescribed limits. All of the factors likely have some impact on the pH values and Na content.

  6. 12 CFR 204.132 - Treatment of loan strip participations.

    Science.gov (United States)

    2010-01-01

    ... selling the loan or participation in effect must buy back the loan or participation at the maturity of the... 12 Banks and Banking 2 2010-01-01 2010-01-01 false Treatment of loan strip participations. 204.132... RESERVE REQUIREMENTS OF DEPOSITORY INSTITUTIONS (REGULATION D) Interpretations § 204.132 Treatment of...

  7. Results of Laboratory Testing of Advanced Power Strips

    Energy Technology Data Exchange (ETDEWEB)

    Earle, L. [National Renewable Energy Lab. (NREL), Golden, CO (United States); Sparn, B. [National Renewable Energy Lab. (NREL), Golden, CO (United States)

    2012-08-01

    Presented at the ACEEE Summer Study on Energy Efficiency in Buildings on August 12-17, 2012, this presentation reports on laboratory tests of 20 currently available advanced power strip products, which reduce wasteful electricity use of miscellaneous electric loads in buildings.

  8. Integrated Strip Foundation Systems for Small Residential Buildings

    DEFF Research Database (Denmark)

    Rasmussen, Torben Valdbjørn

    2010-01-01

    A prefabricated lightweight element was designed for a strip foundation that was used on site as the bases of two small residential buildings, in this case single-family houses; one was built with a double-brick exterior wall separated by mineral fiber insulation and the other was built with a wood...

  9. Penaeus monodon nucleopolyhedrovirus detection using an immunochromatographic strip test.

    Science.gov (United States)

    Wangman, Pradit; Longyant, Siwaporn; Chaivisuthangkura, Parin; Sridulyakul, Pattarin; Rukpratanporn, Sombat; Sithigorngul, Paisarn

    2012-08-01

    An immunochromatographic strip test is described for detection of the polyhedrin protein of Penaeus monodon nucleopolyhedrovirus (PemoNPV). The test employs one monoclonal antibody (MAb MBV5) conjugated to colloidal gold to bind to polyhedrin protein and a 1:1:1 mixture of 3 other MAbs (MBV8, 14 and 21) to capture colloidal-gold MAb-protein complexes at a test (T) line on the nitrocellulose strip. A downstream control (C) line of goat anti-mouse immunoglobulin G (GAM) antibody is used to capture excess free colloidal-gold conjugated MBV5 to validate test performance. Heating of homogenates of PemoNPV-infected P. monodon postlarvae prepared in PBS for 30min was necessary to maximize T line color intensity, and homogenates of infected postlarvae could still be scored as PemoNPV-positive when diluted 1:64. A strip test result was obtained within 15min of sample application, and although about 200-fold lower than a one-step PCR test for PemoNPV, its detection sensitivity was comparable to a dot blot. Due to its simplicity not reliant on sophisticated equipment or specialized skills, the strip test could be adopted to screen easily for PemoNPV infections at shrimp hatcheries and farms. PMID:22580094

  10. Deceleration of highly stripped ions by the Heidelberg postaccelerator

    International Nuclear Information System (INIS)

    The Heidelberg MP-tandem has been used to produce highly stripped ions of Ssup(14,15,16+), Ni20+ and Br23+ which subsequently were decelerated to 0.15 MeV/amu for atomic physics experiments by the rf-postaccelerator. (orig.)

  11. Reactive strip method for mixing and reaction in two dimensions

    CERN Document Server

    Bandopadhyay, Aditya; Méheust, Yves

    2016-01-01

    A numerical method to efficiently solve for mixing and reaction of scalars in a two-dimensional flow field at large P\\'eclet numbers but otherwise arbitrary Damk\\"ohler numbers is reported. We consider a strip of one reactant in a pool of another reactant, both of which are advected with the known velocity field. We first establish that the system evolution for such a system under certain conditions is described by a locally one-dimensional reaction-diffusion problem. The approximation of a locally one-dimensional dynamics is true for cases where the strip thickness is smaller than the local radius of curvature and also when the strip thickness is smaller than the distance between adjacent strips. We first demonstrate the method for the transport of a conservative scalar under a linear shear flow, point vortex and a chaotic sine flow. We then proceed to consider the situation with a simple bimolecular reaction between two reactants to yield a single product. The methodology presented herewith essentially gene...

  12. Microstructure changes of IF steels during hot strip rolling

    International Nuclear Information System (INIS)

    The hot deformation behavior of three interstitial free (IF) steels containing Ti and/or Nb under strip or plate rolling was investigated by means of multi-pass torsion tests. All the tests were carried out at a strain rate of 2 s-1. Three types of strip rolling schedules (they differed only with respect to the number and total strain of finishing passes) and one type of plate rolling were employed. Under strip rolling conditions the effects of total finishing pass strain and first finishing pass temperature was investigated. The plate rolling schedule was used in order to determine the three critical hot deformation temperature, i.e. Tnr, Ar3 and Arl. The results indicate that , under strip rolling conditions, static recrystallization is responsible for the high degree of inter pass softening in the early passes of rolling. During the final passes, dynamic recrystallization occurs to a degree that depends on the composition of the steel, the total finishing strain and the temperature. (author)

  13. Off-line Simulation of PFC for Hot Rolling Strip

    Institute of Scientific and Technical Information of China (English)

    Xiangwei KONG; Hezhou YE; Jianzhong XU; Guodong WANG; Liying BA; Xiaoming HE

    2003-01-01

    In order to improve the quality of the strip for the hot continuous rolling, the high accuracy set-up control must be applied toproduction. In the paper, we analyze the PFC (profile and flatness control) system and simulate the set-up process. Calculationresults are in agreement to the actual measurements. It is the basis on the developing model.

  14. Upconversion fluorescent strip sensor for rapid determination of Vibrio anguillarum

    Science.gov (United States)

    Zhao, Peng; Wu, Yuanyuan; Zhu, Yihua; Yang, Xiaoling; Jiang, Xin; Xiao, Jingfan; Zhang, Yuanxing; Li, Chunzhong

    2014-03-01

    Here, we report a simple and ultrasensitive upconversion fluorescent strip sensor based on NaYF4:Yb,Er nanoparticles (NPs) and the lateral flow immunochromatographic assay (LFIA). Carboxyl-modified β-NaYF4:Yb,Er NPs were successfully synthesized by a facile one-pot solvothermal approach, upon further coupling with monoclonal antibody, the resultant UCNPs-antibody conjugates probes were used in LFIA and served as signal vehicles for the fluorescent reporters. V. anguillarum was used as a model analyte to demonstrate the use of this strip sensor. The limit of the detection for the fluorescent strip was determined as 102 CFU mL-1, which is 100 times lower than those displayed by enzyme-linked immunosorbent assays, while the time needed for the detection was only 15 min. Furthermore, no cross-reaction with other eight pathogens was found, indicating the good specificity of the strip. This developed LFIA would offer the potential as a useful tool for the quantification of pathogens analysis in the future.

  15. Development of a Calibration Strip for Immunochromatographic Assay Detection Systems.

    Science.gov (United States)

    Gao, Yue-Ming; Wei, Jian-Chong; Mak, Peng-Un; Vai, Mang-I; Du, Min; Pun, Sio-Hang

    2016-01-01

    With many benefits and applications, immunochromatographic (ICG) assay detection systems have been reported on a great deal. However, the existing research mainly focuses on increasing the dynamic detection range or application fields. Calibration of the detection system, which has a great influence on the detection accuracy, has not been addressed properly. In this context, this work develops a calibration strip for ICG assay photoelectric detection systems. An image of the test strip is captured by an image acquisition device, followed by performing a fuzzy c-means (FCM) clustering algorithm and maximin-distance algorithm for image segmentation. Additionally, experiments are conducted to find the best characteristic quantity. By analyzing the linear coefficient, an average value of hue (H) at 14 min is chosen as the characteristic quantity and the empirical formula between H and optical density (OD) value is established. Therefore, H, saturation (S), and value (V) are calculated by a number of selected OD values. Then, H, S, and V values are transferred to the RGB color space and a high-resolution printer is used to print the strip images on cellulose nitrate membranes. Finally, verification of the printed calibration strips is conducted by analyzing the linear correlation between OD and the spectral reflectance, which shows a good linear correlation (R² = 98.78%). PMID:27367694

  16. State selective electron capture by highly stripped ions from atoms

    International Nuclear Information System (INIS)

    An experimental study on final-state distribution in one-electron capture from slow fully-stripped and hydrogen-like projectile ions from H and He atoms is discussed. After a short review of the available results, state-selectiveness of the process is interpreted using the Landau-Zener model

  17. Evaluation of an automated urine chemistry reagent-strip analyzer.

    Science.gov (United States)

    Lott, J A; Johnson, W R; Luke, K E

    1995-01-01

    We evaluated the Miles Inc., Clinitek Atlas Automated Urine Chemistry Analyzer for 11 tests: bilirubin, color, glucose, ketones, leukocyte esterase, nitrite, occult blood, pH, protein, specific gravity, and urobilinogen. The instrument uses a roll of reagent strips affixed to a clear plastic support; urine specimens are automatically pipetted onto these strips. The instrument measures the pads' color using reflectance colorimetry. Specific gravity is measured using a fiberoptic refractive index method. Four hospitals participated in the evaluation, and tests were performed only on fresh urine samples. We found the instrument easy to use; it has walk-away capability with up to 40-specimen loading capacity plus spaces for STATs, calibrators and controls. We found good comparability with chemical tests and other nonreagent strip procedures, as well as good agreement with the Miles Inc. Clinitek 200+ urine chemistry analyzer and visual reading of the Miles Inc. Multistix Reagent Strips. The Clinitek Atlas is rugged and reliable, and is suitable for a high-volume urinalysis laboratory.

  18. INSECTICIDE CONCENTRATIONS IN AIR AFTER APPLICATION OF PEST CONTROL STRIPS

    Science.gov (United States)

    Contamination of air in homes due to spraying of pesticides is of concern to the public. A pest control strip which kills creeping and crawling insects by contact is one method of reducing the amount of insecticide in the air. Several different insecticides are now available in t...

  19. Ammonia removal from landfill leachate by air stripping and absorption.

    Science.gov (United States)

    Ferraz, Fernanda M; Povinelli, Jurandyr; Vieira, Eny Maria

    2013-01-01

    An old landfill leachate was pre-treated in a pilot-scale aerated packed tower operated in batch mode for total ammoniacal nitrogen (TAN) removal. The stripped ammonia was recovered with a 0.4 mol L(-1) H2SO4 solution, deionized water and tap water. Ca(OH)2 (95% purity) or commercial hydrated lime was added to the raw leachate to adjust its pH to 11, causing removal of colour (82%) and heavy metals (70-90% for Zn, Fe and Mn). The 0.4 molL(-1) H2SO4 solution was able to neutralize 80% of the stripped ammonia removed from 12 L of leachate. The effectiveness of the neutralization of ammonia with deionized water was 75%. Treating 100 L of leachate, the air stripping tower removed 88% of TAN after 72 h of aeration, and 87% of the stripped ammonia was recovered in two 31 L pilot-scale absorption units filled with 20 L of tap water. PMID:24350487

  20. Stripping chronopotentiometry for metal ion speciation analysis at a microelectrode

    NARCIS (Netherlands)

    Leeuwen, van H.P.; Town, R.

    2002-01-01

    The features of metal ion speciation determination by stripping chronopotentiometry (SCP) at a microelectrode are examined and compared with those of DP-SV. SCP measurements are essentially of a steady-state nature under experimentally achievable conditions and correspond to practically complete dep