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Sample records for chloride monolithic column

  1. Preparation and characterization of poly-(methacrylatoethyl trimethylammonium chloride-co-vinylbenzyl chloride-co-ethylene dimethacrylate monolith

    Directory of Open Access Journals (Sweden)

    Eko Malis

    2015-05-01

    Full Text Available A polymer monolithic column, poly-(methacrylatoethyltrimethylammonium chloride-co-vinylbenzyl chloride-co-ethylene dimethacrylate or poly-(MATE-co-VBC-co-EDMA was successfully prepared in the current study by one-step thermally initiated in situ polymerization, confined in a steel tubing of 0.5 mm i.d. and 1/16” o.d. The monoliths were prepared from methacrylatoethyltrimethylammonium chloride (MATE and vinylbenzyl chloride (VBC as monomer and ethylene dimethacrylate (EDMA as crosslinker using a binary porogen system of 1-propanol and 1,4-butanediol. The inner wall of steel tubing was pretreated with 3-methacryloxypropyl-trimethoxysilane (MAPS. In order to obtain monolith with adequate column efficiency and low flow resistance, some parameters such as total monomer concentration (%T and crosslinker concentration (%C were optimized. The morphology of this monolith was assessed by scanning electron microscopy (SEM. The properties of the monolithic column, such as permeability, binding capacity, and pore size distribution were also characterized in detail. From the results of the characterization of all monolith variation, monolith with %T 30 %C 50 and %T 35 %C 50 give the best characteristic. These monoliths have high permeability, adequate molecular recognition sites (represented with binding capacity value of over 20 mg/mL, and have over 80% flow through pores in their pore structure contribute to low flow resistance. The resulted monolithic columns have promising potential for dual mode liquid chromatography. MATE may contribute for anion-exchange while VBC may responsible for reversed-phase liquid chromatography.

  2. A novel ionic liquid monolithic column and its separation properties in capillary electrochromatography

    International Nuclear Information System (INIS)

    Highlights: ► ILs as functional monomer for capillary monolithic column. ► Separation of alkylbenzenes, thiourea analogues, and amino acids. ► The column generate a stable reversed EOF from pH 2.0 to 12.0. ► The column efficiency of 147,000 plates m−1 was obtained for thiourea. - Abstract: A novel ionic liquid (IL) monolithic capillary column was successfully prepared by thermal free radical copolymerization of IL (1-vinyl-3-octylimidazolium chloride, ViOcIm+Cl−) together with lauryl methacrylate (LMA) as the binary functional monomers and ethylene dimethacrylate (EDMA) as the cross-linker in binary porogen. The proportion of monomers, porogens and cross-linker in the polymerization mixture was optimized in detail. The resulting IL-monolithic column could not only generate a stable reversed electroosmotic flow (EOF) in a wide pH range (2.0–12.0), but also effectively eliminate the wall adsorption of the basic analytes. The obtained IL-monolithic columns were examined by scanning electron microscopy (SEM) and Fourier transform infrared (FT-IR). These results indicated that the IL-monolithic capillary column possessed good pore properties, mechanical stability and permeability. The column performance was also evaluated by separating different kinds of compounds, such as alkylbenzenes, thiourea and its analogues, and amino acids. The lowest plate height of ∼6.8 μm was obtained, which corresponded to column efficiency (theoretical plates, N) of ∼147,000 plates m−1 for thiourea. ILs, as a new type of functional monomer, present a promising option in the fabrication of the organic polymer-based monolithic columns in CEC.

  3. Preparation of imprinted monolithic column under molecular crowding conditions

    Institute of Scientific and Technical Information of China (English)

    Xiao Xia Li; Xin Liu; Li Hong Bai; Hong Quan Duan; Yan Ping Huang; Zhao Sheng Liu

    2011-01-01

    Molecular crowding is a new concept to obtain molecularly imprinted polymers (MIPs) with greater capacity and selectivity. In this work, molecular crowding agent was firstly applied to the preparation of MIPs monolithic column. A new polymerization system based on molecular crowding surrounding was developed to prepare enrofloxacin-imprinted monolith, which was composed of polystyrene and tetrahydrofuran. The result showed that the monolithic MIPs under molecular crowding conditions presented good molecular recognition for enrofloxacin with an imprinting factor of 3.03.

  4. Chromatographic Properties of Silica-Based Monolithic HPLC Columns

    OpenAIRE

    Smith, Jennifer Houston

    2002-01-01

    Silica-based monolithic HPLC columns contain a novel chromatographic support in which the traditional particulate packing has been replaced with a single, continuous network (monolith) of porous silica. The main advantage of such a network is decreased backpressure due to macropores (2 μm) throughout the network. This allows high flow rates, and hence fast analyses that are unattainable with traditional particulate columns. The Chromolith SpeedROD⠢ (EM Science, Gibbstown NJ) is a commercia...

  5. Purification of large plasmids with methacrylate monolithic columns.

    Science.gov (United States)

    Krajnc, Nika Lendero; Smrekar, Franci; Cerne, Jasmina; Raspor, Peter; Modic, Martina; Krgovic, Danijela; Strancar, Ales; Podgornik, Ales

    2009-08-01

    The rapid evolution of gene therapy and DNA vaccines results in an increasing interest in producing large quantities of pharmaceutical grade plasmid DNA. Most current clinical trials involve plasmids of 10 kb or smaller in size, however, future requirements for multigene vectors including extensive control regions may require the production of larger plasmids, e. g., 20 kb and bigger. The objective of this study was to examine certain process conditions for purification of large plasmids with the size of up to 93 kb. Since there is a lack of knowledge about production and purification of bigger plasmid DNA, cell lysis and storage conditions were investigated. The impact of chromatographic system and methacrylate monolithic column on the degradation of plasmid molecules under nonbinding conditions at different flow rates was studied. Furthermore, capacity measurements varying salt concentration in loading buffer were performed and the capacities up to 13 mg of plasmid per mL of the monolithic column were obtained. The capacity flow independence in the range from 130 to 370 cm/h was observed. Using high resolution monolithic column the separation of linear and supercoiled isoforms of large plasmids was obtained. Last but not least, since the baseline separation of RNA and pDNA was achieved, the one step purification on larger CIM DEAE 8 mL tube monolithic column was performed and the fractions were analyzed by CIM analytical monolithic columns. PMID:19598166

  6. Cyclodextrin-Functionalized Monolithic Capillary Columns: Preparation and Chiral Applications.

    Science.gov (United States)

    Adly, Frady G; Antwi, Nana Yaa; Ghanem, Ashraf

    2016-02-01

    In this review, the recently reported approaches for the preparation of cyclodextrin-functionalized capillary monolithic columns are highlighted, with few applications in chiral separations using capillary liquid chromatography (CLC) and capillary electrochromatography (CEC). Chirality 28:97-109, 2016. © 2015 Wiley Periodicals, Inc.

  7. Rapid Preparation of Monolithic Columns for Capillary Electrochromatography Separation

    Institute of Scientific and Technical Information of China (English)

    Wen Jun GONG; Yi Jun ZHANG; Yu Ping ZHANG; Seong Ho CHOI

    2006-01-01

    Fritless packed silica gel columns were prepared using sol-gel technology. The part of a75 μm i.d. capillary was filled with a mixture of methacryloxypropyltrimethoxysilane, toluene and hydrochloric acid. Four different photoinitiators such as benzoin methyl ether, Irgacure 819,Irgacure 1700 and irgacure 1800 were added in the presence or absence of sodium dodecyl sulfate during the polymerization process. The above eight solutions were irradiated at 365 nm about5-10 min to prepare the porous monolithic sol-gel columns by a one-step process.

  8. Fast preparation of photopolymerized monolithic columns for capillary electrochromatography

    Institute of Scientific and Technical Information of China (English)

    GONG Wen-jun; XU Guang-ri; ZHANG Yi-jun; ZHANG Yu-ping; CHOI Seong-ho; LEE Kwang-pill

    2008-01-01

    Photopolymerized sol-gel(PSG) columns were prepared using methacryloxypropyltrimethoxysilane as the monomer,toluene as the porogen and hydrochloric acid as the catalyst. Four different photoinitiators such as benzoin methyl ether, Irgacure 819,lrgacure 1700 and Irgacure 1800 were comparatively used in the reaction solution in the presence and absence of sodium dodecylsulfate. The above eight solutions were respectively irradiated at 365 um for 5-10 min in each capillary (75 μm inside diameter) toprepare the porous monolithic sol-gel column by a one-step, in situ, process. The chromatographic behavior of the eight PSGcolumns were comparatively studied, all of which exhibit reversed-phase character. Using these columns, several neutral compounds,namely thiourea, benzene, toluene, ethyl benzene, biphenyl and naphthalene can be separated from mixtures with a largest columnefficiency of 74 470 plate/column for thiourea. Addition of sodium dodecyl sulfate in the polymerization process has a significantinfluence on the morphology and migration time.

  9. Fiber-based monolithic columns for liquid chromatography.

    Science.gov (United States)

    Ladisch, Michael; Zhang, Leyu

    2016-10-01

    Fiber-based monoliths for use in liquid chromatographic separations are defined by columns packed with aligned fibers, woven matrices, or contiguous fiber structures capable of achieving rapid separations of proteins, macromolecules, and low molecular weight components. A common denominator and motivating driver for this approach, first initiated 25 years ago, was reducing the cost of bioseparations in a manner that also reduced residence time of retained components while achieving a high ratio of mass to momentum transfer. This type of medium, when packed into a liquid chromatography column, minimized the fraction of stagnant liquid and resulted in a constant plate height for non-adsorbing species. The uncoupling of dispersion from eluent flow rate enabled the surface chemistry of the stationary phase to be considered separately from fluid transport phenomena and pointed to new ways to apply chemistry for the engineering of rapid bioseparations. This paper addresses developments and current research on fiber-based monoliths and explains how the various forms of this type of chromatographic stationary phase have potential to provide new tools for analytical and preparative scale separations. The different stationary phases are discussed, and a model that captures the observed constant plate height as a function of mobile phase velocity is reviewed. Methods that enable hydrodynamically stable fiber columns to be packed and operated over a range of mobile phase flow rates, together with the development of new fiber chemistries, are shown to provide columns that extend the versatility of liquid chromatography using monoliths, particularly at the preparative scale. Graphical Abstract Schematic representation of a sample mixture being separated by a rolled-stationary phase column, resulting separated peaks shown in the chromatogram. PMID:27553948

  10. Monolithic molecularly imprinted polymeric capillary columns for isolation of aflatoxins.

    Science.gov (United States)

    Szumski, Michał; Grzywiński, Damian; Prus, Wojciech; Buszewski, Bogusław

    2014-10-17

    Monolithic molecularly imprinted polymers extraction columns have been prepared in fused-silica capillaries by UV or thermal polymerization in a two-step process. First, a poly-(trimethylolpropane trimethacrylate) (polyTRIM) core monolith was synthesized either by UV or thermal polymerization. Then it was grafted with the mixture of methacrylic acid (MAA) as a functional monomer, ethylene dimethacrylate (EDMA) as a cross-linking agent, 5,7-dimethoxycoumarin (DMC) as an aflatoxin-mimicking template, toluene as a porogen solvent and 2,2-azobis-(2-methylpropionitrile) (AIBN) as an initiator of the polymerization reaction. Different thermal condition of the photografting and different concentrations of the grafting mixture were tested during polymerization. The extraction capillary columns were evaluated in the terms of their hydrodynamic and chromatographic properties. Retention coefficients for aflatoxin B1 and DMC were used for assessment of the selectivity and imprinting factor. The obtained results indicate that the temperature of photografting and concentration of the grafting mixture are key parameters that determine the quality of the prepared MIPs. From the MIP columns characterized by the highest permeability the column of the highest imprinting factor was applied for isolation of aflatoxins B1, B2, G1 and G2 from the model aqueous sample followed by on-line chromatographic separation. The process was performed using a micro-MISPE-microLC-LIF system of a novel design, which allowed for detection of the eluates from the sample preparation part as well as from the chromatographic separation.

  11. Monolithic molecularly imprinted polymeric capillary columns for isolation of aflatoxins.

    Science.gov (United States)

    Szumski, Michał; Grzywiński, Damian; Prus, Wojciech; Buszewski, Bogusław

    2014-10-17

    Monolithic molecularly imprinted polymers extraction columns have been prepared in fused-silica capillaries by UV or thermal polymerization in a two-step process. First, a poly-(trimethylolpropane trimethacrylate) (polyTRIM) core monolith was synthesized either by UV or thermal polymerization. Then it was grafted with the mixture of methacrylic acid (MAA) as a functional monomer, ethylene dimethacrylate (EDMA) as a cross-linking agent, 5,7-dimethoxycoumarin (DMC) as an aflatoxin-mimicking template, toluene as a porogen solvent and 2,2-azobis-(2-methylpropionitrile) (AIBN) as an initiator of the polymerization reaction. Different thermal condition of the photografting and different concentrations of the grafting mixture were tested during polymerization. The extraction capillary columns were evaluated in the terms of their hydrodynamic and chromatographic properties. Retention coefficients for aflatoxin B1 and DMC were used for assessment of the selectivity and imprinting factor. The obtained results indicate that the temperature of photografting and concentration of the grafting mixture are key parameters that determine the quality of the prepared MIPs. From the MIP columns characterized by the highest permeability the column of the highest imprinting factor was applied for isolation of aflatoxins B1, B2, G1 and G2 from the model aqueous sample followed by on-line chromatographic separation. The process was performed using a micro-MISPE-microLC-LIF system of a novel design, which allowed for detection of the eluates from the sample preparation part as well as from the chromatographic separation. PMID:25218633

  12. Recent Progress in Monolithic Silica Columns for High-Speed and High-Selectivity Separations

    Science.gov (United States)

    Ikegami, Tohru; Tanaka, Nobuo

    2016-06-01

    Monolithic silica columns have greater (through-pore size)/(skeleton size) ratios than particulate columns and fixed support structures in a column for chemical modification, resulting in high-efficiency columns and stationary phases. This review looks at how the size range of monolithic silica columns has been expanded, how high-efficiency monolithic silica columns have been realized, and how various methods of silica surface functionalization, leading to selective stationary phases, have been developed on monolithic silica supports, and provides information on the current status of these columns. Also discussed are the practical aspects of monolithic silica columns, including how their versatility can be improved by the preparation of small-sized structural features (sub-micron) and columns (1 mm ID or smaller) and by optimizing reaction conditions for in situ chemical modification with various restrictions, with an emphasis on recent research results for both topics.

  13. A hybrid FIA/HPLC system incorporating monolithic column chromatography

    Energy Technology Data Exchange (ETDEWEB)

    Adcock, Jacqui L. [School of Life and Environmental Sciences, Deakin University, Geelong, Victoria 3217 (Australia); Francis, Paul S. [School of Life and Environmental Sciences, Deakin University, Geelong, Victoria 3217 (Australia)], E-mail: psf@deakin.edu.au; Agg, Kent M. [School of Life and Environmental Sciences, Deakin University, Geelong, Victoria 3217 (Australia); Marshall, Graham D. [GlobalFIA, Fox Island, WA 98333 (United States); Barnett, Neil W. [School of Life and Environmental Sciences, Deakin University, Geelong, Victoria 3217 (Australia)

    2007-09-26

    We have combined the generation of solvent gradients using milliGAT pumps, chromatographic separations with monolithic columns and chemiluminescence detection in an instrument manifold that approaches the automation and separation efficiency of HPLC, whilst maintaining the positive attributes of flow injection analysis (FIA), such as manifold versatility, speed of analysis and portability. As preliminary demonstrations of this hybrid FIA/HPLC system, we have determined six opiate alkaloids (morphine, pseudomorphine, codeine, oripavine, ethylmorphine and thebaine) and four biogenic amines (vanilmandelic acid, serotonin, 5-hydroxyindole-3-acetic acid and homovanillic acid) in human urine, using tris(2,2'-bipyridyl)ruthenium(III) and acidic potassium permanganate chemiluminescence detection.

  14. A hybrid FIA/HPLC system incorporating monolithic column chromatography

    International Nuclear Information System (INIS)

    We have combined the generation of solvent gradients using milliGAT pumps, chromatographic separations with monolithic columns and chemiluminescence detection in an instrument manifold that approaches the automation and separation efficiency of HPLC, whilst maintaining the positive attributes of flow injection analysis (FIA), such as manifold versatility, speed of analysis and portability. As preliminary demonstrations of this hybrid FIA/HPLC system, we have determined six opiate alkaloids (morphine, pseudomorphine, codeine, oripavine, ethylmorphine and thebaine) and four biogenic amines (vanilmandelic acid, serotonin, 5-hydroxyindole-3-acetic acid and homovanillic acid) in human urine, using tris(2,2'-bipyridyl)ruthenium(III) and acidic potassium permanganate chemiluminescence detection

  15. Integration of monolithic frit into the particulate capillary (IMFPC) column in shotgun proteome analysis.

    Science.gov (United States)

    Wang, Fangjun; Dong, Jing; Ye, Mingliang; Wu, Ren'an; Zou, Hanfa

    2009-10-12

    Capillary column plays an important role in nano-flow liquid chromatography coupled with tandem mass spectrometry for dealing with the high dynamic range and complexity of protein samples in shotgun proteome analysis. In this study, the integrated monolithic frit into the particulate capillary (IMFPC) column was prepared. By comparing the prepared IMFPC column with conventionally fritless capillary column, smaller size of packing materials could be easily packed into the capillary to achieve higher average peak capacity and proteome coverage. As the monolithic emitter was integrated onto this type of column, the void volume between packing particles and electrospray emitter was eliminated and the electrospray quality was improved. The prepared IMFPC column was applied to proteome analysis of mouse liver extracts, and it was observed that the number of identified proteins and peptides increased 14.9 and 12.9% as well as the peak capacity increased 11.6% by using IMFPC column over conventionally fritless capillary column. PMID:19786199

  16. Monolithic column incorporated with lanthanide metal-organic framework for capillary electrochromatography.

    Science.gov (United States)

    Zhang, Li-Shun; Du, Pei-Yao; Gu, Wen; Zhao, Qing-Li; Huang, Yan-Ping; Liu, Zhao-Sheng

    2016-08-26

    A new lanthanide metal-organic frameworks NKU-1 have successfully incorporated into poly (BMA-co-EDMA) monolith and evaluated by capillary electrochromatography (CEC). Lanthanide metal-organic frameworks [Eu2(ABTC)1.5(H2O)3(DMA)] (NKU-1) were synthesized by self-assembly of Eu(III) ions and 3,3',5,5'-azo benzene tetracarboxylic acid ligands have been fabricated into poly(BMA-co-EDMA) monoliths. 1-Butyl-3-methylimidazolium tetrafluoroborate and N,N-dimethylformamide were developed as binary porogen obtaining homogeneous dispersibility for NKU-1 and high permeability for monolithic column. The successful incorporation of NKU-1 into poly(BMA-co-EDMA) was confirmed and characterized by FT-IR spectra, scanning electron microscopy, X-ray diffraction, energy dispersive spectrometer area scanning, and transmission electron microscopy. Separation ability of the NKU-1-poly (BMA-co-EDMA) monoliths was demonstrated by separating four groups of analytes in CEC, including alkylbenzenes, polycyclic aromatic hydrocarbon, aniline series and naphthyl substitutes. Compared with bare monolithic (column efficiency of 100,000plates/m), the NKU-1-poly (BMA-co-EDMA) monoliths have displayed greater column efficiency (maximum 210,000plates/m) and higher permeability, as well as less peak tailing. The results showed that the NKU-1-poly (BMA-co-EDMA) monoliths are promising stationary phases for CEC separations. PMID:27432788

  17. Monolithic liquid-chromatography columns for protein analysisprotein digest separation and integrated systems

    NARCIS (Netherlands)

    van de Meent, M.H.M.

    2010-01-01

    The objectives of the research described in this thesis are to evaluate the applicability of both silica-based and polymeric monolithic columns for protein analysis. The first part describes investigations into the effects of column length and stationary-phase chemistry on the separation of protein

  18. Separation of human immunoglobulin G subclasses on a protein A monolith column

    OpenAIRE

    Leblebici, P.; Leblebici, M.E.; Ferreira-da-Silva, F.; A.E. Rodrigues; Pais, L.S.

    2014-01-01

    Monolithic columns have attracted significant attention for the purification of large biomolecules. In thepresent study, a step gradient elution method was evaluated for the separation of human immunoglobulinG (hIgG) into its subclasses on CIM (convective interaction media) r-protein A (recombinant protein A)monolithic column. hIgG was loaded onto the column and bound protein was eluted with a pH gra-dient. The subclass content of the eluted fractions was analyzed by enzyme-linked immunosorbe...

  19. Preparation of a biomimetic polyphosphorylcholine monolithic column for immobilized artificial membrane chromatography.

    Science.gov (United States)

    Zhao, XiangLong; Chen, WeiJia; Zhou, ZhengYin; Wang, QiQin; Liu, ZhengHua; Moaddel, Ruin; Jiang, ZhengJin

    2015-08-14

    The present work aims to prepare a novel phosphatidylcholine functionalized monolithic stationary phase by in situ co-polymerization of 12-methacryloyl dodecylphosphocholine (MDPC) and ethylene dimethacrylate (EDMA) for immobilized artificial membrane chromatography. Scanning electron microscopy, energy dispersive X-ray spectroscopy, FT-IR spectroscopy, pore size distribution analysis, ζ-potential analysis and micro-HPLC were used to evaluate the monolithic structure and physicochemical properties. Satisfactory morphology, high mechanical stability, good permeability and chromatographic performance were obtained on the optimized monolithic columns. A typical reverse-phase retention mechanism was observed over a wide range of organic solvent content (acetonitrilecolumn (IAM.PC.DD2) and poly(MDPC-co-EDMA) monolith. This novel poly(MDPC-co-EDMA) monolith exhibited good potential for studying the drug-membrane interaction.

  20. Recent Advances and Uses of Monolithic Columns for the Analysis of Residues and Contaminants in Food

    Directory of Open Access Journals (Sweden)

    Mónica Díaz-Bao

    2015-02-01

    Full Text Available Monolithic columns are gaining interest as excellent substitutes to conventional particle-packed columns. These columns show higher permeability and lower flow resistance than conventional liquid chromatography columns, providing high-throughput performance, resolution and separation in short run times. Monoliths possess also great potential for the clean-up and preparation of complex mixtures. In situ polymerization inside appropriate supports allows the development of several microextraction formats, such as in-tube solid-phase and pipette tip-based extractions. These techniques using porous monoliths offer several advantages, including miniaturization and on-line coupling with analytical instruments. Additionally, monoliths are ideal support media for imprinting template-specific sites, resulting in the so-called molecularly-imprinted monoliths, with ultra-high selectivity. In this review, time-saving LC columns and preparative applications applied to the analysis of residues and contaminants in food in 2010–2014 are described, focusing on recent improvements in design and with emphasis in automated on-line systems and innovative materials and formats.

  1. Robust naphthyl methacrylate monolithic column for high performance liquid chromatography of a wide range of solutes.

    Science.gov (United States)

    Jonnada, Murthy; El Rassi, Ziad

    2015-08-28

    An organic monolithic column based on the co-polymerization of 2-naphthyl methacrylate (NAPM) as the functional monomer and trimethylolpropane trimethacrylate (TRIM) as the crosslinker was introduced for high performance reversed-phase liquid chromatography (RPC). The co-polymerization was performed in situ in a stainless steel column of 4.6mm i.d. in the presence of a ternary porogen consisting of 1-dodecanol and cyclohexanol. This monolithic column (referred to as naphthyl methacrylate monolithic column or NMM column) showed high mechanical stability at relatively high mobile phase flow velocity indicating that the column has excellent hydrodynamic characteristics. To characterize the NMM column, different probe molecules including alkyl benzenes, and aniline, benzene, toluene and phenol derivatives were chromatographed on the column and the results in terms of k, selectivity and plate counts were compared to those obtained on an octadecyl silica (ODS) column in order to assess the presence of π-π and hydrophobic interactions on the NMM column under otherwise the same elution conditions. The NMM column offered additional π-π interactions with aromatic molecules in addition to hydrophobic interactions under RPC elution conditions. Run-to-run and column-to-column reproducibility of solute k values were evaluated, and percent relative standard deviation of column using shallow (30min at 1.0mL/min), steep (10min at 1.0mL/min) and ultra steep (1min at 3.0mL/min) linear gradient elution at increasing ACN concentration in the mobile phase using a 10cm×4.6mm i.d. column in case of shallow and steep linear gradients and a 3cm×4.6mm i.d. column for ultra steep linear gradient.

  2. Preparation of Monolithic Column and Its Application in p-CEC

    Institute of Scientific and Technical Information of China (English)

    Jun Jiao YANG; Kai ZHANG; Ru Yu GAO; Yu Kui ZHANG; Chao YAN

    2004-01-01

    A novel monolithic stationary phase having long alkyl chain ligands was introduced and evaluated in pressurized-capillary electrochromatography of small neutral and charged compounds.The monolithic column was prepared by the in situ copolymerization of ethylene dimethacrylate,1-hexadecene,allyl alcohol and 2-acrylamido-2-methyl-1-propanesulfonic acid in a quaternary porogenic solvent mixture consisting of 1,4-butanediol,cyclohexanol,dodecanol and water.

  3. Recent advances in the preparation and application of monolithic capillary columns in separation science.

    Science.gov (United States)

    Hong, Tingting; Yang, Xi; Xu, Yujing; Ji, Yibing

    2016-08-10

    Novel column technologies involving various materials and efficient reactions have been investigated for the fabrication of monolithic capillary columns in the field of analytical chemistry. In addition to the development of these miniaturized systems, a variety of microscale separation applications have achieved noteworthy results, providing a stepping stone for new types of chromatographic columns with improved efficiency and selectivity. Three novel strategies for the preparation of capillary monoliths, including ionic liquid-based approaches, nanoparticle-based approaches and "click chemistry", are highlighted in this review. Furthermore, we present the employment of state-of-the-art capillary monolithic stationary phases for enantioseparation, solid-phase microextraction, mixed-mode separation and immobilized enzyme reactors. The review concludes with recommendations for future studies and improvements in this field of research. PMID:27282747

  4. A monolithically fabricated gas chromatography separation column with an integrated high sensitivity thermal conductivity detector

    International Nuclear Information System (INIS)

    The monolithic integration of a high sensitivity detector with a gas chromatography (GC) separation column creates many potential advantages over the discrete components of a traditional chromatography system. In miniaturized high-speed GC systems, component interconnections can cause crucial errors and loss of fidelity during detection and analysis. A monolithically integrated device would eliminate the need to create helium-tight interconnections, which are bulky and labor intensive. Additionally, batch fabrication of integrated devices that no longer require expensive and fragile detectors can decrease the cost of micro GC systems through economies of scale. We present the design, fabrication and operation of a monolithic GC separation column and detector. Our device is able to separate nitrogen, methane and carbon dioxide within 30 s. This method of device integration could be applied to the existing wealth of column geometries and chemistries designed for specialized applications.

  5. Novel preparation of monolithic imprinted columns for electrochromatographic separation by photopolymerization

    Institute of Scientific and Technical Information of China (English)

    Yu Ping Zhang; Guo Qiang Zuo; Wen Jun Gong; Yue E. Deng; Quan Ming Li

    2007-01-01

    A monolithic molecularly imprinted polymer with specific recognition ability for 4-hydroxybenzoic acid (4-HBA) was prepared by in situ photopolymerization, using methacrylic acid (MAA) as a functional monomer, ethylene glycol dimethacrylate (EDMA) as a cross-linking agent, toluene and isooctane as porogenic solvents and Irgacure 1800 as an initiator.Baseline separation of isomers of hydroxybenzoic acid was achieved in less than 8 min on this monolithic column using 4-HBA as template, but not on the blank polymer.Furthermore, some neutral compounds could also be baseline-separated on the imprinted polymer column in the mode of pressure-driven capillary electrochromatography.

  6. Monolithic liquid-chromatography columns for protein analysisprotein digest separation and integrated systems

    OpenAIRE

    van de Meent, M. H. M.

    2010-01-01

    The objectives of the research described in this thesis are to evaluate the applicability of both silica-based and polymeric monolithic columns for protein analysis. The first part describes investigations into the effects of column length and stationary-phase chemistry on the separation of protein digests. The second part is devoted to the development of LC based integrated systems for the separation and identification of protein mixtures.

  7. Ionic liquid-based zwitterionic organic polymer monolithic column for capillary hydrophilic interaction chromatography.

    Science.gov (United States)

    Wang, Tingting; Chen, Yihui; Ma, Junfeng; Zhang, Xiaodan; Zhang, Lihua; Zhang, Yukui

    2015-08-21

    In the current study, a novel ionic liquid-based zwitterionic organic polymer monolithic column was developed by copolymerizing 1-vinyl-3-(butyl-4-sulfonate) imidazolium, acrylamide and N,N'-methylenebisacrylamide in a quaternary porogenic solvent consisting of formamide, dimethyl sulphoxide, polyethylene glycol 8000 and polyethylene glycol 10,000 for capillary hydrophilic interaction chromatography. The monolithic stationary phase was optimized by adjusting the amount of monomer in the polymerization solution along with the composition of porogenic solvent. The optimized monolith exhibited excellent selectivity and favorable retention for nucleosides and benzoic acid derivatives. The primary factors affecting the separation efficiency of the monolithic column (including acetonitrile content, pH, and buffer salt concentration in the mobile phase) have been thoroughly evaluated. Excellent reproducibility of the retention times for five nucleosides was achieved, with relative standard deviations of run-to-run (n = 3), column-to-column (n = 3) and batch-to-batch (n = 3) in the range of 0.18-0.48%, 2.33-4.20% and 3.07-6.50%, respectively.

  8. Application of monolithic affinity HPLC column for rapid determination of malt glycoproteins

    OpenAIRE

    Benkovská, D. (Dagmar); Flodrová, D. (Dana); Bobálová, J. (Janette)

    2013-01-01

    The aim of this study was to optimize separation and enrichment of barley malt glycoproteins on a monolithic ConA affinity HPLC column. ConA-bound proteins were separated on SDS-PAGE and identified using MALDI-TOF/TOF MS after chymotryptic digestion. Our proteomic analysis allowed successful determination of several putative malt glycoproteins.

  9. Capillary Electrochromatography of Molecularly Imprinted Monolithic Column Using p-Hydroxybenzoic Acid as Templates

    Institute of Scientific and Technical Information of China (English)

    Zhao Sheng LIU; Yan Li XU; Chao YAN; Ru Yu GAO

    2004-01-01

    Molecularly imprinted polymers using p-hydroxybenzoic acid as templates was synthesized by an in situ polymerization reaction and rendered capillary monolithic column was used in capillary electrochromatographic mode. Good molecular recognition was achieved forphydroxybenzoic acid and good resolution of isomers can be realized.

  10. ZIC-HILIC monolithic capillary column coupled with MALDI-MS: A tool for glycan analysis

    OpenAIRE

    Šesták, J. (Jozef); Křenková, J. (Jana); Moravcová, D. (Dana); Planeta, J. (Josef); Kahle, V. (Vladislav)

    2014-01-01

    In this contribution, we report analysis of glycans enzymatically released from bovine ribonuclease B (RNase B) and human immunoglobulin G (hIgG) combining glycan separation using the synthesized zwitterionic silica-based monolithic capillary column and off-line MALDI-MS detection.

  11. Evaluation of the clenbuterol imprinted monolithic column prepared by reversible addition-fragmentation chain transfer polymerization

    Institute of Scientific and Technical Information of China (English)

    Mamat Turson; Xiao Lei Zhuang; Hui Na Liu; Ping Jiang; Xiang Chao Dong

    2009-01-01

    To make more homogenous organic monolithic structure,reversible addition-fragmentation chain transfer(RAFT)process was employed in the synthesis of the clenbuterol imprinted polymer.In the synthesis,the influence of synthetic conditions on the polymer structure and separation efficiency was studied.The result demonstrated that the imprinted columns prepared with RAFT process have higher column efficiency and selectivity than the columns prepared with conventional polymerization in the present study,which may result from the higher surface area,smaller pore size and the narrower globule size distribution in their structures.The result indicated that RAFT polymerization provided better conditions for the clenbuterol imprinted monolithic polymer preparation.

  12. Multilayer chitosan-based open tubular capillary anion exchange column with integrated monolithic capillary suppressor

    International Nuclear Information System (INIS)

    Highlights: ► Uses a multilayer chitosan–glutaraldehyde coating as anion exchanger. ► Uses a methacrylate-acrylic acid polymer monolith as suppressor. ► Demonstrates first integral suppressor open tubular anion chromatography. - Abstract: We describe a multilayered open tubular anion exchange column fabricated by alternately pumping solutions of chitosan and glutaraldehyde. The column is terminated in an integrally bonded monolithic suppressor cast around a mandrel of a tungsten wire, composed of an acrylic acid (AA)–ethylene dimethacrylate (EDMA) monolith that is made with sufficient porogen for the monolith to function as a membrane. For a 4.5 m long 75 μm bore column coated with 24 successive layers of the condensation polymer (estimated to contain ∼72 molecular layers) and coupled to 1 cm length of a suppressor fabricated with 55–60% AA, effective separation of several common anions (F−, Cl−, NO2−, Br−, NO3−, average number of theoretical plates ∼12,000) and adequate suppression of 1 mM KOH used as eluent was observed at a flow rate of 800 nL min−1 to obtain sub-picomol detection limits at an operating pressure of ∼1 bar. The separation is not time efficient but the system can be meritorious in unique niche applications where a small form factor is desired and liquid volume and power consumption are more important than separation speed.

  13. Hexavalent chromium removal performance of anionic functionalized monolithic polymers: column adsorption, regeneration and modelling.

    Science.gov (United States)

    Barlik, Necla; Keskinler, Bülent; Kocakerim, M Muhtar

    2016-01-01

    Anionic functionalized monolithic macro-porous polymers were used for the removal of hexavalent chromium(VI) anions from aqueous solution in column experiments. At a flux of 1.0 cm min and 30 mg Cr(VI) L(-1) feed concentration, breakthrough capacity and apparent capacity were 0.066 g Cr(VI) g(-1) anionic monolith and 0.144 g Cr(VI) g(-1) anionic monolith, respectively. The degree of column utilization was found to lie in the range 41-46%. Two kinetic models, theoretical and Thomas models, were applied to experimental data to predict the breakthrough curves and to determine the characteristic parameters of the column useful for process design. The simulation of the whole breakthrough curve was effective with the models. At a flux of 1.0 cm min and 30 mg Cr(VI) L(-1) feed concentration, the dispersion coefficient and adsorption equilibrium constant (K) were 3.14 × 10(-7) m s(-1) and 3,840, respectively. Also, Thomas model parameters k1 (rate constant of adsorption) and qm (equilibrium solid-phase concentration of sorbed solute) were 1.08 × 10(-3) L mg(-1) min(-1) and 0.124 g g(-1), respectively. After reaching equilibrium adsorption capacity, the monoliths were regenerated using 1 N HCl and were subsequently re-tested. It was found that the regeneration efficiency reduced from 98% after second usage to 97% after the third usage. PMID:27003067

  14. Recent Research and Development of Monolithic Column in Ion Chromatography%整体柱离子色谱的研究进展

    Institute of Scientific and Technical Information of China (English)

    陈倩; 于泓

    2011-01-01

    Monolithic columns have been employed in low pressure, fast and high efficient separation, for their many excellent characteristics. When applied to ion chromatography field, monolithic columns can achieve more effective analysis than traditional columns. Therefore, the method of ion chromatography based on monolithic columns attracts increasing interests. In this paper, the sorts of ion chromatography, classification of monolithic stationary phases, preparation ways of monolithic columns, performances and features of monolithic columns were introduced. The application of conventional monolithic columns in ion chromatography and the utilization of capillary monolithic columns in capillary ion chromatography were summarized according to the different assortments and properties of monolithic columns and ion chromatography, which included silica-based monolithic stationary phase and organic polymer-based monolithic stationary phase. The development of ion chromatography based on monolithic columns in the future was reviewed and prospected.%该文介绍了离子色谱的分类,整体柱的分类、制备及特点,并以此为依据归纳总结了常规整体柱在离子色谱中的应用和毛细管整体柱在毛细管离子色谱中的应用,其中包括硅胶基质整体柱和聚合物基质整体柱,评述并展望了整体柱离子色谱的发展前景.

  15. Separation of human immunoglobulin G subclasses on a protein A monolith column.

    Science.gov (United States)

    Leblebici, Pelin; Leblebici, M Enis; Ferreira-da-Silva, Frederico; Rodrigues, Alírio E; Pais, Luís S

    2014-07-01

    Monolithic columns have attracted significant attention for the purification of large biomolecules. In the present study, a step gradient elution method was evaluated for the separation of human immunoglobulin G (hIgG) into its subclasses on CIM (convective interaction media) r-protein A (recombinant protein A) monolithic column. hIgG was loaded onto the column and bound protein was eluted with a pH gradient. The subclass content of the eluted fractions was analyzed by enzyme-linked immunosorbent assay (ELISA). Results showed that separation of IgG3 from the other three subclasses can be successfully achieved with high selectivity (100%) and throughput on monolithic media. It was also revealed that enriched fractions of IgG1 and IgG2 could be obtained from purified hIgG in a 28min long chromatographic run. Three fractions with high IgG1 content (89.1%, 94.3% and 88.8%) were recovered. Furthermore, IgG2 was enriched to 64% successfully. A rapid step gradient elution scheme without any additives in buffers was proven to obtain enriched preparations of the two important subclasses with high throughput. The separation time can be reduced even more by increasing the flow rate without any loss in selectivity, which will be beneficial in industrial scale applications. PMID:24907548

  16. A fast way to make a monolithic column for a high pressure electroosmotic pump.

    Science.gov (United States)

    Wang, Rong; Zhang, Feifang; Yang, Bingcheng; Liang, Xinmiao

    2010-01-01

    A simple way was proposed to make a monolithic column for a high pressure electroosmotic pump (EOP). It is in-situ synthesized inside the silica capillary from potassium silicate solution and no frit is required. Compared with common approaches to make columns for EOP, the present method is robust and fast (<4 h). For pure water, a stand-alone EOP operated at 15 kV applied voltage is capable of generating a flow rate of 3.1 microL/min and a maximum static pressure of approximately 5.4 MPa. PMID:20702950

  17. Effect of polyethylene glycol on pore structure and separation efficiency of silica-based monolithic capillary columns.

    Science.gov (United States)

    Hara, Takeshi; Desmet, Gert; Baron, Gino V; Minakuchi, Hiroyoshi; Eeltink, Sebastiaan

    2016-04-15

    Monolithic silica materials (first unclad monolith rods, then monolithic capillary columns) were prepared using various amounts of polyethylene glycols (PEGs) with different molecular weight (MW). The monolith rods were used to examine the mesoporosity by argon physisorption technique, and the macroporosity by mercury intrusion porosimetry. Subsequently, silica-based monolithic capillary columns with an inner diameter of 100 μm were produced using the same preparation conditions as used for the rods. The results obtained with the monolith rods showed the following important findings: (1) it is feasible to fabricate monolithic silica rods possessing macropore size of 0.5-1.4 μm by tuning the amount of PEGs (independently of the MW), whereas the macropore volume and the mesoporosity remain similar. (2) the smallest macropore size (0.5 μm) rod prepared with PEG having a MW=20,000g/mol provided a narrower macropore size distribution than with PEG with MW=10,000g/mol. The monolithic capillary columns produced with the different PEG type showed similar retention factors for hexylbenzene (k=2.3-2.4) and similar t0-based column permeability (Kv0=2.3-2.4×10(-14)m(2)) in 20:80% (v/v) water:methanol, as expected from the results obtained with the monolith rods. The column prepared with PEG of MW=20,000g/mol gave a plate height of H=4.0 μm for hexylbenzene at an optimal linear velocity of u0=2.6mm/s in 20:80% (v/v) water containing 0.1% formic acid:acetonitrile. To the best of our knowledge, this is the lowest plate height ever recorded for a monolithic column. Comparing the kinetic performance at 30MPa shows that the best monolithic silica column obtained in the present study performs better than the second-generation monolithic silica columns developed up till now in the practically most relevant range of plate numbers (N≤40,000). In this range, the performance is now similar to that of 2.7 μm core-shell particle columns. PMID:26976349

  18. Prediction of the Service Life of a Reinforced Concrete Column under Chloride Environment

    OpenAIRE

    Mohammad K. Alkam; Maha Alqam

    2015-01-01

    In the present investigation, service life of a reinforced concrete column exposed to chloride environment has been predicted. This study has been based on numerical simulation of chloride ion diffusion in a concrete column during its anticipated life span. The simulation process has included the concrete cover replacement whenever chloride ion concentration has reached the critical threshold value at the reinforcement surface. Repair scheduling of the concrete column under consideration has ...

  19. Monolithic stationary phases with incorporated fumed silica nanoparticles. Part II. Polymethacrylate-based monolithic column with "covalently" incorporated modified octadecyl fumed silica nanoparticles for reversed-phase chromatography.

    Science.gov (United States)

    Aydoğan, Cemil; El Rassi, Ziad

    2016-05-01

    This study is concerned with the incorporation of surface modified fumed silica nanoparticles (FSNPs) into polymethacrylate based monolithic columns for use in reversed phase chromatography (RPC) of small solutes and proteins. First, FSNPs were modified with 3-(trimethoxysilyl)propylmethacrylate (TMSPM) to yield the "hybrid" methacryloyl fumed silica nanoparticle (MFSNP) monomer. The resulting MFSNP was then mixed with glyceryl monomethacrylate (GMM) and ethylene dimethacrylate (EDMA) in a binary porogenic solvent composed of cyclohexanol and dodecanol, and the in situ copolymerization of MFSNP, GMM and EDMA was performed in a stainless steel column of 4.6 mm i.d. The silanol groups of the hybrid monolith thus obtained were grafted with octadecyl ligands by perfusing the hybrid monolithic column with a solution of 4% w/v of dimethyloctadecylchlorosilane (DODCS) in toluene while the column was maintained at 110°C for 6h (in a heated HPLC oven). One of the originalities of this study was to demonstrate MFSNP as a novel derivatized "hybrid monomer" in making RPC monolithic columns with surface bound octadecyl ligands. In this respect, the RPC behavior of the monolithic column with "covalently" incorporated FNSPs having surface grafted octadecyl ligands was evaluated with alkylbenzenes, aniline derivatives and phenolic compounds. The results showed that the hybrid poly(GMA-EDMA-MFSNP) having surface bound octadecyl ligands exhibited hydrophobic interactions under reversed phase elution conditions. Furthermore, six standard proteins were baseline separated on the column using a 10min linear gradient elution at increasing ACN concentration in the mobile phase at a flow rate of 1.0mL/min using a 10 cm×4.6mm i.d. column. The relative standard deviations (RSDs) for the retention times of the tested solutes were lower than 2.1% and 2.4% under isocratic elution and gradient elution conditions, respectively.

  20. Monolithic stationary phases with incorporated fumed silica nanoparticles. Part I. Polymethacrylate-based monolithic column with incorporated bare fumed silica nanoparticles for hydrophilic interaction liquid chromatography.

    Science.gov (United States)

    Aydoğan, Cemil; El Rassi, Ziad

    2016-05-01

    Fumed silica nanoparticles (FSNPs), were incorporated for the first time into a polymethacrylate monolithic column containing glyceryl monomethacrylate (GMM) and ethylene dimethacrylate (EDMA) in order to develop a new monolithic column for hydrophilic interaction high performance liquid chromatography (HILIC). When compared to poly(GMM-EDMA) monolithic column without FSNPs, the same monolithic column with incorporated FSNPs yielded important effects on HILIC separations. The effects of monomers and FSNPs content of the polymerization mixture on the performance of the monolithic column were examined in details, and the optimized stationary phase was investigated over a wide range of mobile phase composition with polar acidic, weakly basic and neutral analytes including hydroxy benzoic acids, nucleotides, nucleosides, dimethylformamide, formamide and thiourea. The retention of these analytes was mainly controlled by hydrophilic interactions with the FSNPs and electrostatic repulsion from the negatively charged silica surface in the case of hydroxy benzoic acids and nucleotides. The electrostatic repulsion was minimized by decreasing the pH of the aqueous component of the mobile phase, which in turn enhanced the retention of acidic solutes. Nucleotides were best separated using step gradient elution at decreasing pH as well as ACN concentration in the mobile phase. Improved peak shape and faster analysis of nucleosides were attained by a fast linear gradient elution with a shallow decrease in the ACN content of the ACN-rich mobile phase. The run-to-run and column-to-column reproducibility were satisfactory. The percent relative standard deviations (%RSDs) for the retention times of tested solutes were lower than 2.5% under isocratic conditions and lower than 3.5 under gradient conditions.

  1. Fast HPLC for quality control of Harpagophytum procumbens by using a monolithic silica column: method transfer from conventional particle-based silica column.

    Science.gov (United States)

    Schmidt, Alexander H

    2005-05-01

    The applicability of a monolithic C18-bonded silica column for the rapid HPLC separation of ingredients in medicinal plants and their phytopharmaceutical preparations has been evaluated in the author's laboratory. In this presentation, an existing method for the determination of the iridoid glycoside harpagoside in Harpagophytum procumbens (Devil's Claw) was successfully transferred from a conventional particle-based C18 silica column to a monolithic silica column. The very high porosity of the stationary phase allows chromatography with a much lower backpressure than on conventional columns. Therefore, the flow rate could be easily increased from 0.8 mL/min (particle-based column) to 5 mL/min (monolithic column) and the run-time reduced from 30 to 5 min (that is a reduction about 85% !), without losing any chromatographic resolution of the compound of interest. The amount of harpagoside was measured with the original method on a conventional particle-based silica column and on the adapted method on a monolithic silica column. The statistical mean t-test showed no significant differences of the variances and the means indicating that the fast HPLC method is an acceptable alternative. The shorter analysis time makes the method very valuable for commercial quality control of Harpagophytum extracts and its pharmaceutical preparations. PMID:15909544

  2. Control of selectivity via nanochemistry: monolithic capillary column containing hydroxyapatite nanoparticles for separation of proteins and enrichment of phosphopeptides.

    Science.gov (United States)

    Krenkova, Jana; Lacher, Nathan A; Svec, Frantisek

    2010-10-01

    New monolithic capillary columns with embedded commercial hydroxyapatite nanoparticles have been developed and used for protein separation and selective enrichment of phosphopeptides. The rod-shaped hydroxyapatite nanoparticles were incorporated into the poly(2-hydroxyethyl methacrylate-co-ethylene dimethacrylate) monolith by simply admixing them in the polymerization mixture followed by in situ polymerization. The effect of percentages of monomers and hydroxyapatite nanoparticles in the polymerization mixture on the performance of the monolithic column was explored in detail. We found that the loading capacity of the monolith is on par with other hydroxyapatite separation media. However, the speed at which these columns can be used is higher due to the fast mass transport. The function of the monolithic columns was demonstrated with the separations of a model mixture of proteins including ovalbumin, myoglobin, lysozyme, and cytochrome c as well as a monoclonal antibody and its aggregates with protein A. Selective enrichment and MALDI/MS characterization of phosphopeptides fished-out from complex peptide mixtures of ovalbumin, α-casein, and β-casein digests were also achieved using the hydroxyapatite monolith.

  3. Measurement of the eddy diffusion term in chromatographic columns. I. Application to the first generation of 4.6mm I.D. monolithic columns.

    Science.gov (United States)

    Gritti, Fabrice; Guiochon, Georges

    2011-08-01

    The corrected heights equivalent to a theoretical plate (HETP) of three 4.6mm I.D. monolithic Onyx-C(18) columns (Onyx, Phenomenex, Torrance, CA) of different lengths (2.5, 5, and 10 cm) are reported for retained (toluene, naphthalene) and non-retained (uracil, caffeine) small molecules. The moments of the peak profiles were measured according to the accurate numerical integration method. Correction for the extra-column contributions was systematically applied. The peak parking method was used in order to measure the bulk diffusion coefficients of the sample molecules, their longitudinal diffusion terms, and the eddy diffusion term of the three monolithic columns. The experimental results demonstrate that the maximum efficiency was 60,000 plates/m for retained compounds. The column length has a large impact on the plate height of non-retained species. These observations were unambiguously explained by a large trans-column eddy diffusion term in the van Deemter HETP equation. This large trans-rod eddy diffusion term is due to the combination of a large trans-rod velocity bias (≃3%), a small radial dispersion coefficient in silica monolithic columns, and a poorly designed distribution and collection of the sample streamlets at the inlet and outlet of the monolithic rod. Improving the performance of large I.D. monolithic columns will require (1) a detailed knowledge of the actual flow distribution across and along these monolithic rod and (2) the design of appropriate inlet and outlet distributors designed to minimize the nefarious impact of the radial flow heterogeneity on band broadening. PMID:21733524

  4. Controlled ultraviolet (UV) photoinitiated fabrication of monolithic porous layer open tubular (monoPLOT) capillary columns for chromatographic applications

    OpenAIRE

    Collins, David; Nesterenko, Ekaterina; Brabazon, Dermot; Paull, Brett

    2012-01-01

    An automated column fabrication technique that is based on a ultraviolet (UV) light-emitting diode (LED) array oven, and provides precisely controlled "in-capillary" ultraviolet (UV) initiated polymerization at 365 nm, is presented for the production of open tubular monolithic porous polymer layer capillary (monoPLOT) columns of varying length, inner diameter (ID), and porous layer thickness. The developed approach allows the preparation of columns of varying length, because of an automated c...

  5. [Ion-pair chromatography-indirect ultraviolet detection for determination of tetraethyl ammonium using a monolithic column and a packed column].

    Science.gov (United States)

    Zou, Chunmiao; Zhang, Xiaodong; Yu, Hong; Guan, Chao; Wang, Miaoyu

    2015-07-01

    Two methods were developed for the determination of tetraethyl ammonium by ion-pair chromatography-indirect ultraviolet detection using a monolithic column and a packed column with ionic liquid as additive in mobile phase. Chromatographic separations were performed on a monolithic column and a packed column both on reversed phase using imidazolium ionic liquid aqueous solution-ion-pair reagent-organic solvent as mobile phase. The effects of the background ultraviolet absorption reagent, detection wavelength, ion-pair reagent, organic solvent, column temperature and flow rate on the determination of tetraethyl ammonium were investigated. The difference between the two chromatographic columns was compared and the retention rules were discussed. Under the optimized chromatographic conditions, for tetraethyl ammonium on monolithic column and packed column, the retention times were 2.40 and 3.02 min; the detection limits (S/N=3), 0.04 and 0.07 mg/L; the RSDs (n = 5) for peak areas, 0.16% and 0.11%; and the RSDs (n=5) for retention times, 0.02% and 0.01%, respectively. The two methods have been successfully applied to the determination of tetraethyl ammonium ionic liquids synthesized by laboratory. The recoveries of the tetraethyl ammonium after spiking were 98.2% and 99.1%, respectively. The two methods can meet the requirements for the quantitative analysis of tetraethyl ammonium.

  6. DATA QUALITY OBJECTIVES SUMMARY REPORT FOR THE 105K EAST BASIN ION EXCHANGE COLUMN MONOLITH

    Energy Technology Data Exchange (ETDEWEB)

    JOCHEN, R.M.

    2007-02-07

    The 105-K East (KE) Basin Ion Exchange Column (IXC) cells, lead caves, and the surrounding vault are to be removed as necessary components in implementing ''Hanford Federal Facility Agreement and Consert Order'' (Ecology et al. 2003) milestone M-034-32 (Complete Removal of the K East Basin Structure). The IXCs consist of six units located in the KE Basin, three in operating positions in cells and three stored in a lead cave. Methods to remove the IXCs from the KE Basin were evaluated in KBC-28343, ''Disposal of K East Basin Ion Exchange Column Evaluation''. The method selected for removal was grouting of the six IXCs into a single monolith for disposal at the Environmental Restoration Disposal Facility (ERDF). Grout will be added to the IXC cells, IXC lead caves containing spent IXCs, and in the spaces between to immobilize the contaminants, provide self-shielding, minimize void space, and provide a structurally stable waste form. The waste to be offered for disposal is the encapsulated monolith defined by the exterior surfaces of the vault and the lower surface of the underlying slab. This document presents a summary of the data quality objective (DQO) process establishing the decisions and data required to support decision-making activities for disposition of the IXC monolith. The DQO process is completed in accordance with the seven-step planning process described in EPA QA/G-4, ''Guidance for the Data Quality Objectives Process'', which is used to clarify and study objectives; define the appropriate type, quantity, and quality of data; and support defensible decision-making. The DQO process involves the following steps: (1) state the problem; (2) identify the decision; (3) identify the inputs to the decision; (4) define the boundaries of the study; (5) develop a decision rule (DR); (6) specify tolerable limits on decision errors; and (7) optimize the design for obtaining data.

  7. Mass transfer kinetic mechanism in monolithic columns and application to the characterization of new research monolithic samples with different average pore sizes.

    Science.gov (United States)

    Gritti, Fabrice; Guiochon, Georges

    2009-06-01

    A general reduced HETP (height equivalent to a theoretical plate) equation is proposed that accounts for the mass transfer of a wide range of molecular weight compounds in monolithic columns. The detailed derivatization of each one of the individual and independent mass transfer contributions (longitudinal diffusion, eddy dispersion, film mass transfer resistance, and trans-skeleton mass transfer resistance) is discussed. The reduced HETPs of a series of small molecules (phenol, toluene, acenaphthene, and amylbenzene) and of a larger molecule, insulin, were measured on three research grade monolithic columns (M150, M225, M350) having different average pore size (approximately 150, 225, and 350 A, respectively) but the same dimension (100 mm x 4.6 mm). The first and second central moments of 2 muL samples were measured and corrected for the extra-column contributions. The h data were fitted to the new HETP equation in order to identify which contribution controls the band broadening in monolithic columns. The contribution of the B-term was found to be negligible compared to that of the A-term, even at very low reduced velocities (numass transfer across the column. Experimental chromatograms exhibited variable degrees of systematic peak fronting, depending on the column studied. The heterogeneity of the distribution of eluent velocities from the column center to its wall (average 5%) is the source of this peak fronting. At high reduced velocities (nu>5), the C-term of the monolithic columns is controlled by film mass transfer resistance between the eluent circulating in the large throughpores and the eluent stagnant inside the thin porous skeleton. The experimental Sherwood number measured on the monolith columns increases from 0.05 to 0.22 while the adsorption energy increases by nearly 6 kJ/mol. Stronger adsorption leads to an increase in the value of the estimated film mass transfer coefficient when a first order film mass transfer rate is assumed (j proportional

  8. Green approach using monolithic column for simultaneous determination of coformulated drugs.

    Science.gov (United States)

    Yehia, Ali M; Mohamed, Heba M

    2016-06-01

    Green chemistry and sustainability is now entirely encompassed across the majority of pharmaceutical companies and research labs. Researchers' attention is careworn toward implementing the green analytical chemistry principles for more eco-friendly analytical methodologies. Solvents play a dominant role in determining the greenness of the analytical procedure. Using safer solvents, the greenness profile of the methodology could be increased remarkably. In this context, a green chromatographic method has been developed and validated for the simultaneous determination of phenylephrine, paracetamol, and guaifenesin in their ternary pharmaceutical mixture. The chromatographic separation was carried out using monolithic column and green solvents as mobile phase. The use of monolithic column allows efficient separation protocols at higher flow rates, which results in short time of analysis. Two-factor three-level experimental design was used to optimize the chromatographic conditions. The greenness profile of the proposed methodology was assessed using eco-scale as a green metrics and was found to be an excellent green method with regard to the usage and production of hazardous chemicals and solvents, energy consumption, and amount of produced waste. The proposed method improved the environmental impact without compromising the analytical performance criteria and could be used as a safer alternate for the routine analysis of the studied drugs.

  9. Green approach using monolithic column for simultaneous determination of coformulated drugs.

    Science.gov (United States)

    Yehia, Ali M; Mohamed, Heba M

    2016-06-01

    Green chemistry and sustainability is now entirely encompassed across the majority of pharmaceutical companies and research labs. Researchers' attention is careworn toward implementing the green analytical chemistry principles for more eco-friendly analytical methodologies. Solvents play a dominant role in determining the greenness of the analytical procedure. Using safer solvents, the greenness profile of the methodology could be increased remarkably. In this context, a green chromatographic method has been developed and validated for the simultaneous determination of phenylephrine, paracetamol, and guaifenesin in their ternary pharmaceutical mixture. The chromatographic separation was carried out using monolithic column and green solvents as mobile phase. The use of monolithic column allows efficient separation protocols at higher flow rates, which results in short time of analysis. Two-factor three-level experimental design was used to optimize the chromatographic conditions. The greenness profile of the proposed methodology was assessed using eco-scale as a green metrics and was found to be an excellent green method with regard to the usage and production of hazardous chemicals and solvents, energy consumption, and amount of produced waste. The proposed method improved the environmental impact without compromising the analytical performance criteria and could be used as a safer alternate for the routine analysis of the studied drugs. PMID:27062581

  10. Determination of tetracyclines in food samples by molecularly imprinted monolithic column coupling with high performance liquid chromatography.

    Science.gov (United States)

    Sun, Xiangli; He, Xiwen; Zhang, Yukui; Chen, Langxing

    2009-08-15

    A novel solid phase extraction (SPE) method for determination of tetracyclines (TCs) in milk and honey samples by molecularly imprinted monolithic column was developed. Using tetracycline (TC) as the template, methacrylic acid (MAA) as the functional monomer, ethylene glycol dimethacrylate (EGDMA) as the cross-linker, methanol as the solvent, cyclohexanol and dodecanol as the mixed porogenic solvents, a TC imprinted monolithic column was prepared by in situ molecular imprinting technique for the first time, and the optimal synthesis conditions and the selectivity of TC imprinted monolithic column were investigated. The interfering substances in food samples and TCs can be separated successfully on imprinted column. Molecularly imprinted solid phase extraction (MISPE) coupling with C18 column was used to determinate the TCs in milk and honey. The recoveries of this method for six tetracyclines antibiotics such as tetracycline (TC), oxytetracycline (OTC), minocycline (MINO), chlortetracycline (CTC), metacycline (MTC) and doxycycline (DTC) were investigated, and high recoveries of 73.3-90.6% from milk samples and 62.6-82.3% from honey samples were obtained. A method for determination of TCs at low concentration level in milk and honey samples was successfully developed by using the monolithic column as the precolumn for solid phase extraction of six TCs compounds. PMID:19576466

  11. Selection of column dimensions and gradient conditions to maximize the peak-production rate in comprehensive off-line two-dimensional liquid chromatography using monolithic columns

    NARCIS (Netherlands)

    S. Eeltink; S. Dolman; G. Vivo-Truyols; P. Schoenmakers; R. Swart; M. Ursem; G. Desmet

    2010-01-01

    The peak-production rate (peak capacity per unit time) in comprehensive off-line two-dimensional liquid chromatography (LC/x/LC) was optimized for the separation of peptides using poly(styrene-co-divinylbenzene) monolithic columns in the reversed-phase (RP) mode. A first-dimension (D-1) separation w

  12. Determination of phthalate esters in physiological saline solution by monolithic silica spin column extraction method%Determination of phthalate esters in physiological saline solution by monolithic silica spin column extraction method

    Institute of Scientific and Technical Information of China (English)

    Lu Lu; Yuki Hashi; Zhi-Hua Wang; Yuan Ma; Jin- Ming Lin

    2011-01-01

    Monolithic silica spin column extraction (MonoSpin-SPE) was developed as a simple, sensitive, and eco-friendly pretreatment method which combined with ultra-fast liquid chromatography-mass spectrometry (UFLC-MS) to determine the levels of six phthalate es

  13. Preparation, characterization and application of molecularly imprinted monolithic column for hesperetin.

    Science.gov (United States)

    Shao, Huikai; Zhao, Lingguo; Chen, Jian; Zhou, Haitao; Huang, Shuting; Li, Kang

    2015-01-01

    The molecularly imprinted solid-phase extraction (MISPE) monolithic column coupled with high-performance liquid chromatography (HPLC) was firstly developed for the extraction of hesperetin in the flesh of Citrus reticulata cv. Chachiensis, which is a traditional Chinese medicine (TCM). The molecularly imprinted polymers (MIPs) have been prepared by a thermal polymerization method using hesperetin as the template, acrylamide (AM) as functional monomer and ethylene glycol dimethacrylamide (EGDMA) as cross-linker in the mixed porogen of methanol, toluene and dodecanol. The prepared MIPs were characterized in detail by SEM and FTIR. The results confirmed the uniform and open structure of network skeleton with large flow-through pores. The influence of synthesis conditions on the specific recognition properties of hesperetin MIPs were also investigated systematically. The results showed that high adsorption capacity and good selectivity of MIPs were achieved when using non-imprinted polymer monolith (NIP) and structure similarly compound rutin as references. Furthermore, several parameters of the MISPE method have been optimized, and then it was successfully applied to the extraction of hesperetin from the flesh of Citrus reticulata cv. Chachiensis. Good gathering and impurity removing ability of prepared MIP were demonstrated. The MISPE method was proven to be a potentially competitive technique for separation and cleanup of hesperetin in complex TCM with satisfied recovery (90.8 ± 3.2%) and good precision (RSD = 6.48%). PMID:25910048

  14. Laser Scanning of a Monolithic Column during Processing in Middle Egypt

    Science.gov (United States)

    Ajioka, O.; Hori, Y.

    2011-09-01

    From ancient quarries around Akoris in Middle Egypt, which belong to the Ptolemaic and Roman periods, the stone blocks could be carried to the working area located in the outside of the city. Those blocks included a giant monolithic column measured approximately 14m in length, which had been cracked for reasons unknown and must have contributed to disuse of monolith. The first deal is a comparison of plans drawn by the point clouds by laser scanning with those coming from plane-tabling, which had been one of popular methods for measuring in the last century. This part shows how the laser scanning technology is useful in far better measuring and documentation of the site. The second discuss is about a detailed assessment of the procedure of processing through the observation of chisel marks and the detail analysis about the 3 dimensional data. In the result, we are succeed to show the restoration of the procedure of the proceedings using guidelines and a wooden curve since we concentrate attention on the point of abstracting the centre line and shaving the surface into the round shape.

  15. Behavior of short silica monolithic columns in high pressure gas chromatography.

    Science.gov (United States)

    Maniquet, Adrien; Bruyer, Nicolas; Raffin, Guy; Baco-Antoniali, Franck; Demesmay, Claire; Dugas, Vincent; Randon, Jérôme

    2016-08-19

    In order to analyze light hydrocarbons mixtures with silica monolithic columns, a conventional gas chromatograph was modified to work with carrier gas pressure as high as 60bar. To understand hydrodynamic flow and retention with short columns (less than 30cm), special attention was required due to the temperature difference between the oven area and the FID detector which contain a significant length of the column. Efficiency and selectivity using various carrier gases (helium, nitrogen and carbon dioxide) at different inlet pressure for different oven temperature were studied. Carrier gas nature was a very significant parameter: on one side, linked to adsorption mechanism for gases like nitrogen and carbon dioxide onto the stationary phase modifying retention and selectivity, on the other side in relation to the minimum theoretical plate height which was as low as 15μm (66 000 platem(-1)) using carbon dioxide as carrier gas. The chromatographic system was then used to separate methane, ethane, ethylene, acetylene, propane, cyclopropane, and butane in less than 30s. PMID:27432790

  16. DATA QUALITY OBJECTIVE SUMMARY REPORT FOR THE 105 K EAST ION EXCHANGE COLUMN MONOLITH

    Energy Technology Data Exchange (ETDEWEB)

    JOCHEN, R.M.

    2007-08-02

    The 105-K East (KE) Basin Ion Exchange Column (IXC) cells, lead caves, and the surrounding vault are to be removed as necessary components in implementing ''Hanford Federal Facility Agreement and Consent Order'' (Ecology et al. 2003) milestone M-034-32 (Complete Removal of the K East Basin Structure). The IXCs consist of six units located in the KE Basin, three in operating positions in cells and three stored in a lead cave. Methods to remove the IXCs from the KE Basin were evaluated in KBC-28343, ''Disposal of K East Basin Ion Exchange Column Evaluation''. The method selected for removal was grouting the six IXCs into a single monolith for disposal at the Environmental Restoration Disposal Facility (ERDF). Grout will be added to the IXC cells, IXC lead caves containing spent IXCs, and in the spaces between the lead cave walls and metal skin, to immobilize the contaminants, provide self-shielding, minimize void space, and provide a structurally stable waste form. The waste to be offered for disposal is the encapsulated monolith defined by the exterior surfaces of the vault and the lower surface of the underlying slab. This document presents summary of the data quality objective (DQO) process establishing the decisions and data required to support decision-making activities for the disposition of the IXC monolith. The DQO process is completed in accordance with the seven-step planning process described in EPA QA/G-4, ''Guidance for the Data Quality Objectives Process'', which is used to clarify and study objectives; define the appropriate type, quantity, and quality of data; and support defensible decision-making. The DQO process involves the following steps: (1) state the problem; (2) identify the decision; (3) identify the inputs to the decision; (4) define the boundaries of the study; (5) develop a decision rule (DR); (6) specify tolerable limits on decision errors; and (7) optimize the design for

  17. Rapid determination of amino acids in biological samples using a monolithic silica column.

    Science.gov (United States)

    Song, Yanting; Funatsu, Takashi; Tsunoda, Makoto

    2012-05-01

    A high-performance liquid chromatography method in which fluorescence detection is used for the simultaneous determination of 21 amino acids is proposed. Amino acids were derivatized with 4-fluoro-7-nitro-2,1,3-benzoxadiazole (NBD-F) and then separated on a monolithic silica column (MonoClad C18-HS, 150 mm×3 mm i.d.). A mixture of 25 mM citrate buffer containing 25 mM sodium perchlorate (pH 5.5) and acetonitrile was used as the mobile phase. We found that the most significant factor in the separation was temperature, and a linear temperature gradient from 30 to 49°C was used to control the column temperature. The limits of detection and quantification for all amino acids ranged from 3.2 to 57.2 fmol and 10.8 to 191 fmol, respectively. The calibration curves for the NBD-amino acid had good linearity within the range of 40 fmol to 40 pmol when 6-aminocaproic acid was used as an internal standard. Using only conventional instruments, the 21 amino acids could be analyzed within 10 min. This method was found to be suitable for the quantification of the contents of amino acids in mouse plasma and adrenal gland samples.

  18. Separation of proteins by cation-exchange sequential injection chromatography using a polymeric monolithic column.

    Science.gov (United States)

    Masini, Jorge Cesar

    2016-02-01

    Since sequential injection chromatography (SIC) emerged in 2003, it has been used for separation of small molecules in diverse samples, but separations of high molar mass compounds such as proteins have not yet been described. In the present work a poly(glycidyl methacrylate-co-ethylene dimethacrylate) (GMA-co-EDMA) monolithic column was prepared by free radical polymerization inside a 2.1-mm-i.d. activated fused silica-lined stainless steel tubing and modified with iminodiacetic acid (IDA). The column was prepared from a mixture of 24% GMA, 16% EDMA, 20% cyclohexanol, and 40% 1-dodecanol (all% as w/w) containing 1% of azobisisobutyronitrile (AIBN) (in relation to monomers). Polymerization was done at 60 °C for 24 h. The polymer was modified with 1.0 M IDA (in 2 M Na2CO3, pH 10.5) at 80 °C for 16 h. Separation of myoglobin, ribonuclease A, cytochrome C, and lysozyme was achieved at pH 7.0 (20 mM KH2PO4/K2HPO4) using a salt gradient (NaCl). Myoglobin was not retained, and the other proteins were separated by a gradient of NaCl created inside the holding coil (4 m of 0.8-mm-i.d. PTFE tubing) by sequential aspiration of 750 and 700 μL of 0.2 and 0.1 M NaCl, respectively. As the flow was reversed toward the column (5 μL s(-1)) the interdispersion of these solutions created a reproducible gradient which separated the proteins in 10 min, with the following order of retention: ribonuclease A < cytochrome C < lysozyme. The elution order was consistent with a cation-exchange mechanism as the retention increased with the isoelectric points.

  19. Preparation and evaluation of poly(alkyl methacrylate-co-methacrylic acid-co-ethylene dimethacrylate) monolithic columns for separating polar small molecules by capillary liquid chromatography

    Energy Technology Data Exchange (ETDEWEB)

    Lin, Shu-Ling; Wu, Yu-Ru; Lin, Tzuen-Yeuan; Fuh, Ming-Ren, E-mail: msfuh@scu.edu.tw

    2015-04-29

    Highlights: • Methacrylic acid (MAA) was used to increase hydrophilicity of polymeric monoliths. • Fast separation of phenol derivatives was achieved in 5 min using MAA-incorporated column. • Separations of aflatoxins and phenicol antibiotics were achieved using MAA-incorporated column. - Abstract: In this study, methacrylic acid (MAA) was incorporated with alkyl methacrylates to increase the hydrophilicity of the synthesized ethylene dimethacrylate-based (EDMA-based) monoliths for separating polar small molecules by capillary LC analysis. Different alkyl methacrylate–MAA ratios were investigated to prepare a series of 30% alkyl methacrylate–MAA–EDMA monoliths in fused-silica capillaries (250-μm i.d.). The porosity, permeability, and column efficiency of the synthesized MAA-incorporated monolithic columns were characterized. A mixture of phenol derivatives is employed to evaluate the applicability of using the prepared monolithic columns for separating small molecules. Fast separation of six phenol derivatives was achieved in 5 min with gradient elution using the selected poly(lauryl methacrylate-co-MAA-co-EDMA) monolithic column. In addition, the effect of acetonitrile content in mobile phase on retention factor and plate height as well as the plate height-flow velocity curves were also investigated to further examine the performance of the selected poly(lauryl methacrylate-co-MAA-co-EDMA) monolithic column. Moreover, the applicability of prepared polymer-based monolithic column for potential food safety applications was also demonstrated by analyzing five aflatoxins and three phenicol antibiotics using the selected poly(lauryl methacrylate-co-MAA-co-EDMA) monolithic column.

  20. Analysis of drugs in plasma samples from schizophrenic patients by column-switching liquid chromatography-tandem mass spectrometry with organic-inorganic hybrid cyanopropyl monolithic column.

    Science.gov (United States)

    Domingues, Diego Soares; Souza, Israel Donizeti de; Queiroz, Maria Eugênia Costa

    2015-07-01

    This study reports on the development of a rapid, selective, and sensitive column-switching liquid chromatography-tandem mass spectrometry (LC-MS/MS) method to analyze sixteen drugs (antidepressants, anticonvulsants, anxiolytics, and antipsychotics) in plasma samples from schizophrenic patients. The developed organic-inorganic hybrid monolithic column with cyanopropyl groups was used for the first dimension of the column-switching arrangement. This arrangement enabled online pre-concentration of the drugs (monolithic column) and their subsequent analytical separation on an XSelect SCH C18 column. The drugs were detected on a triple quadrupole tandem mass spectrometer (multiple reactions monitoring mode) with an electrospray ionization source in the positive ion mode. The developed method afforded adequate linearity for the sixteen target drugs; the coefficients of determination (R(2)) lay above 0.9932, the interassay precision had coefficients of variation lower than 6.5%, and the relative standard error values of the accuracy ranged from -14.0 to 11.8%. The lower limits of quantification in plasma samples ranged from 63 to 1250pgmL(-1). The developed method successfully analyzed the target drugs in plasma samples from schizophrenic patients for therapeutic drug monitoring (TDM).

  1. Rapid determination of Papaver somniferum alkaloids in process streams using monolithic column high-performance liquid chromatography with chemiluminescence detection

    International Nuclear Information System (INIS)

    We have combined high-performance liquid chromatography (HPLC) separations using a monolithic column with acidic potassium permanganate and tris(2,2'-bipyridyl)ruthenium(II) chemiluminescence detection in a rapid and highly sensitive method to monitor the process of extracting opiate alkaloids from Papaver somniferum. Due to the high flow rates allowed with the monolithic column and the inherent selectivity of the chemiluminescence reactions, the four predominant alkaloids - morphine, codeine, oripavine and thebaine - were determined in less than 2 min. The results obtained with numerous process samples compared favourable with those of the standard HPLC methodology. Limits of detection were 1 x 10-10 M, 5 x 10-10 M, 5 x 10-10 M and 1 x 10-9 M, for morphine, codeine, oripavine and thebaine, respectively

  2. Analysis of Aflatoxin B1 in Iranian Foods Using HPLC and a Monolithic Column and Estimation of its Dietary Intake

    OpenAIRE

    Yazdanpanah, Hassan; Zarghi, Afshin; Shafaati, Ali Reza; FOROUTAN, SEYED MOHSEN; Aboul-Fathi, Farshid; Khoddam, Arash; Nazari, Firoozeh; Shaki, Fatemeh

    2013-01-01

    A high performance liquid chromatographic method was developed for determination of aflatoxin B1 (AFB1) in foods using a monolithic column with sample clean up on an immunoaffinity column. The method was validated for analysis of AFB1 in rice, bread, puffed corn snack, wheat flour and peanut samples. The average recoveries for AFB1 in different foods ranged from 94.4 to 102.5% with the coefficient of variation lower than 10% for all foods. Limit of detection was 0.01 ng/g. A survey of AFB1 wa...

  3. Ultrafast UPLC-ESI-MS and HPLC with monolithic column for determination of principal flavor compounds in vanilla pods.

    Science.gov (United States)

    Sharma, Upendra K; Sharma, Nandini; Sinha, Arun K; Kumar, Neeraj; Gupta, Ajai P

    2009-10-01

    In this study, two novel chromatographic methods based on monolithic column high-performance liquid chromatography (HPLC) and ultra-performance liquid chromatography (UPLC) were developed for the ultrafast determination of principal flavor compounds namely vanillin, vanillic acid, p-hydroxybenzoic acid, and p-hydroxybenzaldehyde in ethanolic extracts of Vanilla planifolia pods. Good separation was achieved within 2.5 min using Chromolith RP18e column (100 mm x 4.6 mm) for HPLC and Acquity BEH C-18 (100 mm x 2.1 mm, 1.7 microm) column for UPLC. Both methods were compared in terms of total analysis time, mobile phase consumption, sensitivity, and validation parameters like precision, accuracy, LOD, and LOQ. Further, system suitability test data including resolution, capacity factor, theoretical plates, and tailing factor was determined for both the methods by ten replicate injections. Monolithic column based HPLC gave better results for most of the selected parameters while UPLC was found to be more eco-friendly with low mobile phase consumption and better sensitivity. Both methods may be used conveniently for the high throughput analysis of large number of samples in comparison to traditional particulate column.

  4. 3D printed titanium micro-bore columns containing polymer monoliths for reversed-phase liquid chromatography.

    Science.gov (United States)

    Gupta, Vipul; Talebi, Mohammad; Deverell, Jeremy; Sandron, Sara; Nesterenko, Pavel N; Heery, Brendan; Thompson, Fletcher; Beirne, Stephen; Wallace, Gordon G; Paull, Brett

    2016-03-01

    The potential of 3D selective laser melting (SLM) technology to produce compact, temperature and pressure stable titanium alloy chromatographic columns is explored. A micro bore channel (0.9 mm I.D. × 600 mm long) was produced within a 5 × 30 × 30 mm titanium alloy (Ti-6Al-4V) cuboid, in form of a double handed spiral. A poly(butyl methacrylate-co-ethyleneglycoldimethacrylate) (BuMA-co-EDMA) monolithic stationary phase was thermally polymerised within the channel for application in reversed-phase high-performance liquid chromatography. The prepared monolithic column was applied to the liquid chromatographic separation of intact proteins and peptides. Peak capacities of 69-76 (for 6-8 proteins respectively) were observed during isothermal separation of proteins at 44 °C which were further increased to 73-77 using a thermal step gradient with programmed temperature from 60 °C to 35 °C using an in-house built direct-contact heater/cooler platform based upon matching sized Peltier thermoelectric modules. Rapid temperature gradients were possible due to direct-contact between the planar metal column and the Peltier module, and the high thermal conductivity of the titanium column as compared to a similar stainless steel printed column. The separation of peptides released from a digestion of E.coli was also achieved in less than 35 min with ca. 40 distinguishable peaks at 210 nm.

  5. 3D printed titanium micro-bore columns containing polymer monoliths for reversed-phase liquid chromatography.

    Science.gov (United States)

    Gupta, Vipul; Talebi, Mohammad; Deverell, Jeremy; Sandron, Sara; Nesterenko, Pavel N; Heery, Brendan; Thompson, Fletcher; Beirne, Stephen; Wallace, Gordon G; Paull, Brett

    2016-03-01

    The potential of 3D selective laser melting (SLM) technology to produce compact, temperature and pressure stable titanium alloy chromatographic columns is explored. A micro bore channel (0.9 mm I.D. × 600 mm long) was produced within a 5 × 30 × 30 mm titanium alloy (Ti-6Al-4V) cuboid, in form of a double handed spiral. A poly(butyl methacrylate-co-ethyleneglycoldimethacrylate) (BuMA-co-EDMA) monolithic stationary phase was thermally polymerised within the channel for application in reversed-phase high-performance liquid chromatography. The prepared monolithic column was applied to the liquid chromatographic separation of intact proteins and peptides. Peak capacities of 69-76 (for 6-8 proteins respectively) were observed during isothermal separation of proteins at 44 °C which were further increased to 73-77 using a thermal step gradient with programmed temperature from 60 °C to 35 °C using an in-house built direct-contact heater/cooler platform based upon matching sized Peltier thermoelectric modules. Rapid temperature gradients were possible due to direct-contact between the planar metal column and the Peltier module, and the high thermal conductivity of the titanium column as compared to a similar stainless steel printed column. The separation of peptides released from a digestion of E.coli was also achieved in less than 35 min with ca. 40 distinguishable peaks at 210 nm. PMID:26873472

  6. Preparation of quaternary amine monolithic column for strong anion-exchange chromatography and its application to the separation of Enterovirus 71.

    Science.gov (United States)

    Gu, Huimin; Yin, Dezhong; Ren, Jie; Zhang, Baoliang; Zhang, Qiuyu

    2016-10-15

    Large size virion is unable to diffuse into pores of conventional porous chromatography particles. Therefore, separation of virion by conventional column-packing materials is not quite efficient. To solve this problem, a monolithic column with large convective pores and quaternary amine groups was prepared and was applied to separate Enterovirus 71 (EV71, ≈5700-6000kDa). Cross-section, pore structure, hydrodynamic performance, adsorption property and dynamic binding capacity of prepared monolithic column were determined. Double-pore structures, macropore at 2472nm and mesopore at 5-60nm, were formed. The porosity was up to 63.3%, which enable higher permeability and lower back pressure of the monolithic column than commercial UNO™ Q1 column. Based on the breakthrough curves, the loading capacity of bovine serum albumin was calculated to be 42.0mg per column. In addition, prepared quaternary amine monolithic column was proved to be suitable for the separation of protein mixture by strong anion-exchange chromatography. As a practical application, prepared monolith column presents excellent performance to the separation of EV71 from virus-proteins mixture.

  7. Facile preparation of SiO2/TiO2 composite monolithic capillary column and its application in enrichment of phosphopeptides.

    Science.gov (United States)

    Wang, Shao-Ting; Wang, Meng-Ya; Su, Xin; Yuan, Bi-Feng; Feng, Yu-Qi

    2012-09-18

    A novel SiO(2)/TiO(2) composite monolithic capillary column was prepared by sol-gel technology and successfully applied to enrich phosphopeptides as a metal oxide affinity chromatography (MOAC) material. For the monolith preparation, tetramethoxysilane (TMOS) and tetrabutoxytitanium (TBOT) were used as silica and titania source, respectively, and glycerol was introduced to attenuate the activity of titanium precursor, which provided a mild synthetic condition. The prepared monolith was characterized by energy dispersive X-ray spectroscopy (EDX) and X-ray diffraction (XRD). The results revealed an approximate 1/2 molar ratio of titanium to silica as well as an atom-scale homogeneity in the framework. The scanning electron microscopy (SEM) results demonstrated an excellent anchorage between the column and the inner capillary wall, and nitrogen adsorption-desorption experiments showed a bimodal porosity with a narrow mesopore distribution around 3.6 nm. The prepared monolith was then applied for selective enrichment of phosphopeptides from the digestion mixture of phosphoproteins and bovine serum albumin (BSA) as well as human blood serum, nonfat milk, and egg white using an in-tube solid phase microextraction (SPME) system. Our results showed that SiO(2)/TiO(2) composite monolithic capillary column could efficiently enrich the phosphopeptides from complex matrixes. To the best of our knowledge, this is the first attempt for preparing the silica-metal composite monolithic capillary column, which offers the promising application of the monolith on phosphoproteomics study. PMID:22900475

  8. High-performance liquid chromatography separation of unsaturated organic compounds by a monolithic silica column embedded with silver nanoparticles.

    Science.gov (United States)

    Zhu, Yang; Morisato, Kei; Hasegawa, George; Moitra, Nirmalya; Kiyomura, Tsutomu; Kurata, Hiroki; Kanamori, Kazuyoshi; Nakanishi, Kazuki

    2015-08-01

    The optimization of a porous structure to ensure good separation performances is always a significant issue in high-performance liquid chromatography column design. Recently we reported the homogeneous embedment of Ag nanoparticles in periodic mesoporous silica monolith and the application of such Ag nanoparticles embedded silica monolith for the high-performance liquid chromatography separation of polyaromatic hydrocarbons. However, the separation performance remains to be improved and the retention mechanism as compared with the Ag ion high-performance liquid chromatography technique still needs to be clarified. In this research, Ag nanoparticles were introduced into a macro/mesoporous silica monolith with optimized pore parameters for high-performance liquid chromatography separations. Baseline separation of benzene, naphthalene, anthracene, and pyrene was achieved with the theoretical plate number for analyte naphthalene as 36,000 m(-1). Its separation function was further extended to cis/trans isomers of aromatic compounds where cis/trans stilbenes were chosen as a benchmark. Good separation of cis/trans-stilbene with separation factor as 7 and theoretical plate number as 76,000 m(-1) for cis-stilbene was obtained. The trans isomer, however, is retained more strongly, which contradicts the long- established retention rule of Ag ion chromatography. Such behavior of Ag nanoparticles embedded in a silica column can be attributed to the differences in the molecular geometric configuration of cis/trans stilbenes.

  9. Fast determination of prominent carotenoids in tomato fruits by CEC using methacrylate ester-based monolithic columns.

    Science.gov (United States)

    Adalid, Ana Maria; Herrero-Martínez, José Manuel; Roselló, Salvador; Maquieira, Angel; Nuez, Fernando

    2007-11-01

    In this study, the major carotenoids (beta-carotene and lycopene) present in tomato fruits were analyzed by CEC with a methacrylate ester-based monolithic column. The effects of the porogenic solvent ratio, and the hydrophobicity of bulk monomer employed were examined on carotenoids separations. A fast separation of these analytes was achieved in less than 5.0 min in a mobile phase containing 35% THF, 30% ACN, 30% methanol, and 5% of a 5 mM Tris aqueous buffer, pH 8, with lauryl methacrylate-based monoliths. The CEC method was evaluated in terms of detection limit and reproducibility (retention time, area, and column preparation) with values below 1.6 microg/mL and 7.2%, respectively. The proposed procedure was successfully applied to the determination of both carotenoids in fruits of several tomato-related species and its usefulness to analyze large series of samples for nutritional quality screening trials in tomato breeding programs is demonstrated. To our knowledge, this is the first work that exploits the powerful and user-friendly monolithic technology for quality breeding and germplasm evaluation program purposes. PMID:17960534

  10. Determination of nutrients in the presence of high chloride concentrations by column-switching ion chromatography.

    Science.gov (United States)

    Bruno, P; Caselli, M; de Gennaro, G; De Tommaso, B; Lastella, G; Mastrolitti, S

    2003-06-27

    Determination of inorganic anions in waters of high salinity is one of the most difficult task in analytical chemistry. A simple column-switching method, based on an original chromatographic set-up, for the determination of nutrients (nitrate, nitrite and phosphate) in chloride rich aqueous matrices is presented. A pre-separation system (made of two in line pre-columns, Dionex AG9-HC 4 mm) connected to an analytical column (Dionex AS9-HC 4 mm) by a four way pneumatic valve, allows chloride to be eluted off into the waste and nutrients to be separated and detected by a conductimeter and/or a UV spectrophotometer. Neither chemical pre-treatment nor sample dilution are required; sample matrices presenting a large range of chloride concentrations can be investigated. Moreover by using this technology, automation for routine analysis, low analysis time and low costs can be achieved. LODs of 100, 300, 1000 microg/l for nitrate, nitrite and phosphate, respectively, have been obtained by spiking a synthetic sea water sample containing 20,000 mg/l of chloride and 3000 mg/l of sulphate. Analyte calibration curves of analytes are linear (r>0.99) in the range between the LODs and 60 mg/l. This method was applied to nutrients determination in sea water samples collected near a river outlet. PMID:12899303

  11. Application of a low impedance contactless conductometric detector for the determination of inorganic cations in capillary monolithic column chromatography.

    Science.gov (United States)

    Shen, Dazhong; Li, Dongdong; Yang, Xiuwen; Zhu, Yan; Dong, Jianfeng; Kang, Qi

    2011-03-15

    Poly(glycidyl methacrylate) cation exchange monolithic column was prepared in fused-silica capillaries of 320 μm i.d. by thermally initiated radical polymerization and utilized in capillary ion chromatography. With 15 mM methanesulfonic acid as the mobile phase, the separations of a mixture of inorganic cations (Li(+), Na(+), NH(4)(+), K(+)) was tested by using a capacitively coupled contactless conductivity detector (C(4)D) and a low impedance C(4)D (LIC(4)D). The LIC(4)D is the series combination of a C(4)D and a quartz crystal resonator. At the resonant frequency of the series combination, the capacitor impedance from capillary wall was offset by the inductance impedance from the quartz crystal resonator. A minimum impedance was obtained in the impedance-frequency curve of the combination. The responses of the C(4)D and LIC(4)D were analyzed based on an equivalent circuit model. It was shown that the sensitivity of the C(4)D to the change in analyte concentration is rather poor due to the high ratio of the impedance from the capillary wall capacitor to the solution impedance. The LIC(4)D has the similar sensitivity as a contact conductivity detector but a much smaller cell volume. The on-column detection model was realized by LiC(4)D without preparation of optical detection window in monolithic column.

  12. Rapid and simultaneous determination of imidazolium and pyridinium ionic liquid cations by ion-pair chromatography using a monolithic column

    Institute of Scientific and Technical Information of China (English)

    Xu Huang; Hong Yu; Ying Jie Dong

    2012-01-01

    A method for rapid and simultaneous determination of imidazolium and pyridinium ionic liquid cations by ion-pair chromatography with ultraviolet detection was developed.Chromatographic separations were performed on a reversed-phase silica-based monolithic column using 1-heptanesulfonic acid sodium-acetonitrile as mobile phase.The effects of ion-pair reagent and acetonitrile concentration on retention of the cations were investigated.The retention times of the cations accord with carbon number rule.The method has been successfully applied to the determination of four ionic liquids synthesized by organic chemistry laboratory.

  13. FIXED BED COLUMN STUDY FOR THE REMOVAL OF CHLORIDE FROM RAW WATER

    OpenAIRE

    D. Allwin*, S. Mathan Kumar, R. Muthu Uthayan

    2016-01-01

    The responsible for increase in freshwater demand is due to rapid growth of population, industrialization and modern agriculture practices. The aim of the study tends to carry out a column study for the removal of chloride from raw water. Raw water is natural water found in environment such as rainwater, groundwater and water from bodies like lakes and rivers. Water samples were collected from Valliar River, AVM Canal and Periyakulam Pond from kanyakumari district. Soil used for the study is ...

  14. Preparation of an aptamer based organic-inorganic hybrid monolithic column with gold nanoparticles as an intermediary for the enrichment of proteins.

    Science.gov (United States)

    Zhao, Jin-Cheng; Zhu, Qing-Yun; Zhao, Ling-Yu; Lian, Hong-Zhen; Chen, Hong-Yuan

    2016-08-01

    A novel strategy for the preparation of an aptamer based organic-inorganic hybrid affinity monolithic column was developed successfully using gold nanoparticles (GNPs) as an intermediary for a sandwich structure to realize the functional modification of the surface of the monolithic matrix. This monolithic matrix was facilely pre-synthesized via one-step co-condensation. Due to the high surface-to-volume ratio of GNPs and the large specific surface area of the hybrid matrix, the average coverage density of aptamers on the hybrid monolith reached 342 pmol μL(-1). With the combination of an aptamer based hybrid affinity monolithic column and enzymatic chromogenic assay, the quantitation and detection limits of thrombin were as low as 5 nM and 2 nM, respectively. These results indicated that the GNPs attached monolith provided a novel technique to immobilize aptamers on an organic-inorganic hybrid monolith and it could be used to achieve highly selective recognition and determination of trace proteins. PMID:27307035

  15. Improvement of separation efficiencies of anion-exchange chromatography using monolithic silica capillary columns modified with polyacrylates and polymethacrylates containing tertiary amino or quaternary ammonium groups.

    Science.gov (United States)

    Watanabe, Yuta; Ikegami, Tohru; Horie, Kanta; Hara, Takeshi; Jaafar, Jafariah; Tanaka, Nobuo

    2009-10-30

    Anion-exchange (AEX) columns were prepared by on-column polymerization of acrylates and methacrylates containing tertiary amino or quaternary ammonium groups on monolithic silica in a fused silica capillary modified with anchor groups. The columns provided a plate height (H) of less than 10 microm at optimum linear velocity (u) with keeping their high permeability (K=9-12 x 10(-14) m2). Among seven kinds of AEX columns, a monolithic silica column modified with poly(2-hydroxy-3-(4-methylpiperazin-1-yl)propyl methacrylates) (HMPMA) showed larger retentions and better selectivities for nucleotides and inorganic anions than the others. The HMPMA column of 410 mm length produced 42,000-55,000 theoretical plates (N) at a linear velocity of 0.97 mm/s with a backpressure of 3.8 MPa. The same column could be employed for a fast separation of inorganic anions in 1.8 min at a linear velocity of 5.3 mm/s with a backpressure of 20 MPa. In terms of van Deemter plot and separation impedance, the HMPMA column showed higher performance than a conventional particle-packed AEX column. The HMPMA column showed good recovery of a protein, trypsin inhibitor, and it was applied to the separation of proteins and tryptic digest of bovine serum albumin (BSA) in a gradient elution, to provide better separation compared to a conventional particle-packed AEX column. PMID:19683243

  16. Monoliths in Bioprocess Technology

    Directory of Open Access Journals (Sweden)

    Vignesh Rajamanickam

    2015-04-01

    Full Text Available Monolithic columns are a special type of chromatography column, which can be used for the purification of different biomolecules. They have become popular due to their high mass transfer properties and short purification times. Several articles have already discussed monolith manufacturing, as well as monolith characteristics. In contrast, this review focuses on the applied aspect of monoliths and discusses the most relevant biomolecules that can be successfully purified by them. We describe success stories for viruses, nucleic acids and proteins and compare them to conventional purification methods. Furthermore, the advantages of monolithic columns over particle-based resins, as well as the limitations of monoliths are discussed. With a compilation of commercially available monolithic columns, this review aims at serving as a ‘yellow pages’ for bioprocess engineers who face the challenge of purifying a certain biomolecule using monoliths.

  17. Online micro-solid-phase extraction based on boronate affinity monolithic column coupled with high-performance liquid chromatography for the determination of monoamine neurotransmitters in human urine.

    Science.gov (United States)

    Yang, Xiaoting; Hu, Yufei; Li, Gongke

    2014-05-16

    Quantification of monoamine neurotransmitters is very important in diagnosing and monitoring of patients with neurological disorders. We developed an online analytical method to selectively determine urinary monoamine neurotransmitters, which coupled the boronate affinity monolithic column micro-solid-phase extraction with high-performance liquid chromatography (HPLC). The boronate affinity monolithic column was prepared by in situ polymerization of vinylphenylboronic acid (VPBA) and N,N'-methylenebisacrylamide (MBAA) in a stainless capillary column. The prepared monolithic column showed good permeability, high extraction selectivity and capacity. The column-to-column reproducibility was satisfactory and the enrichment factors were 17-243 for four monoamine neurotransmitters. Parameters that influence the online extraction efficiency, including pH of sample solution, flow rate of extraction and desorption, extraction volume and desorption volume were investigated. Under the optimized conditions, the developed method exhibited low limit of detection (0.06-0.80μg/L), good linearity (with R(2) between 0.9979 and 0.9993). The recoveries in urine samples were 81.0-105.5% for four monoamine neurotransmitters with intra- and inter-day RSDs of 2.1-8.2% and 3.7-10.6%, respectively. The online analytical method was sensitive, accurate, selective, reliable and applicable to analysis of trace monoamine neurotransmitters in human urine sample.

  18. Silica-based monolithic column with evaporative light scattering detector for HPLC analysis of bacosides and apigenin in Bacopa monnieri.

    Science.gov (United States)

    Bhandari, Pamita; Kumar, Neeraj; Singh, Bikram; Singh, Virendra; Kaur, Inderjeet

    2009-08-01

    A high performance liquid chromatographic method using a silica-based monolithic column coupled with evaporative light scattering detector (HPLC-ELSD) was developed and validated for simultaneous quantification of bacosides (bacoside A, bacopaside I, bacoside A(3), bacopaside II, bacopaside X, bacopasaponin C) and apigenin in Bacopa monnieri. The chromatographic resolution was achieved on a Chromolith RP-18 (100x4.6 mm) column with acetonitrile/water (30:70) as mobile phase in isocratic elution at a flow rate of 0.7 mL/min. The drift tube temperature of the ELSD was set to 95 degrees C, and the nitrogen flow rate was 2.0 SLM (standard liter per minute). The calibration curves revealed a good linear relationship (r(2) > 0.9988) within the test ranges. The detection limits (S/N = 3) and the quantification limits (S/N = 10) for the compounds were in the range of 0.54-6.06 and 1.61-18.78 microg/mL, respectively. Satisfactory average recovery was observed in the range of 95.8-99.0%. The method showed good reproducibility for the quantification of these compounds in B. monnieri with intra- and inter-day precision of less than 0.69 and 0.67%, respectively. The validated method was successfully applied to quantify analytes in nine accessions of B. monnieri and thus provides a new basis for overall quality assessment of B. monnieri.

  19. High performance liquid chromatographic determination of aflatoxins in chilli, peanut and rice using silica based monolithic column.

    Science.gov (United States)

    Khayoon, Wejdan Shakir; Saad, Bahruddin; Lee, Tien Ping; Salleh, Baharuddin

    2012-07-15

    A simple and rapid high performance liquid chromatographic with fluorescence detection method for the determination of the aflatoxin B1, B2, G1 and G2 in peanuts, rice and chilli was developed. The sample was extracted using acetonitrile:water (90:10, v/v%) and then purified by using ISOLUTE® multimode solid phase extraction. After the pre-column derivatisation, the analytes were separated within 3.7 min using Chromolith® performance RP-18e (100-4.6mm) monolithic column. To assess the possible effects of endogenous components in the food items, matrix-matched calibration was used for the quantification and validation. The recoveries of aflatoxins that were spiked into food samples were 86.38-104.5% and RSDs were aflatoxins in peanut (9), rice (5) and chilli (10) samples. Liquid chromatography-tandem mass spectrometry analysis using triple quadruple analyser and operated in the multiple reaction monitoring modes on the contaminated samples was performed for confirmation. PMID:25683424

  20. Molecularly imprinted coated graphene oxide solid-phase extraction monolithic capillary column for selective extraction and sensitive determination of phloxine B in coffee bean

    Energy Technology Data Exchange (ETDEWEB)

    Zhai, Haiyun, E-mail: zhaihaiyun@126.com [College of Pharmacy, Guangdong Pharmaceutical University, Guangzhou 510006 (China); Su, Zihao [College of Pharmacy, Guangdong Pharmaceutical University, Guangzhou 510006 (China); Chen, Zuanguang, E-mail: chenzg@mail.sysu.edu.cn [School of Pharmaceutical Science, Sun Yat-sen University, Guangzhou 510006 (China); Liu, Zhenping; Yuan, Kaisong; Huang, Lu [College of Pharmacy, Guangdong Pharmaceutical University, Guangzhou 510006 (China)

    2015-03-20

    Highlights: • A new GO-MISPE monolithic capillary column was prepared. • The column showed ability of impurities removal and excellent selectivity. • Phloxine B existed in real sample was enriched more than 90 times. • The GO-MISPE column presented good recovery and high stability. • The method was prospered to analyze phloxine B and LOD achieved 0.3 ng g{sup −1}. - Abstract: A method was developed to sensitively determine phloxine B in coffee bean by molecularly imprinted polymers (MIPs) coated graphene oxide (GO) solid-phase extraction (GO-MISPE) coupled with high-performance liquid chromatography and laser-induced fluorescence detection (HPLC–LIF). The GO-MISPE capillary monolithic column was prepared by water-bath in situ polymerization, using GO as supporting material, phloxine B, methacrylic acid (MAA), and ethylene dimethacrylate (EDMA) as template, functional monomer, and cross-linker, respectively. The properties of the homemade GO-MISPE capillary monolithic column, including capacity and specificity, were investigated under optimized conditions. The GO-MIPs were characterized by scanning electron microscopy (SEM) and Fourier transform-infrared spectroscopy (FT-IR). The mean recoveries of phloxine B in coffee bean ranged from 89.5% to 91.4% and the intra-day and inter-day relative standard deviation (RSD) values all ranged from 3.6% to 4.7%. Good linearity was obtained over 0.001–2.0 μg mL{sup −1} (r = 0.9995) with the detection limit (S/N = 3) of 0.075 ng mL{sup −1}. Under the selected conditions, enrichment factors of over 90-fold were obtained and extraction on the monolithic column effectively cleaned up the coffee bean matrix. The results demonstrated that the proposed GO-MISPE HPLC–LIF method can be applied to sensitively determine phloxine B in coffee bean.

  1. Molecularly imprinted coated graphene oxide solid-phase extraction monolithic capillary column for selective extraction and sensitive determination of phloxine B in coffee bean

    International Nuclear Information System (INIS)

    Highlights: • A new GO-MISPE monolithic capillary column was prepared. • The column showed ability of impurities removal and excellent selectivity. • Phloxine B existed in real sample was enriched more than 90 times. • The GO-MISPE column presented good recovery and high stability. • The method was prospered to analyze phloxine B and LOD achieved 0.3 ng g−1. - Abstract: A method was developed to sensitively determine phloxine B in coffee bean by molecularly imprinted polymers (MIPs) coated graphene oxide (GO) solid-phase extraction (GO-MISPE) coupled with high-performance liquid chromatography and laser-induced fluorescence detection (HPLC–LIF). The GO-MISPE capillary monolithic column was prepared by water-bath in situ polymerization, using GO as supporting material, phloxine B, methacrylic acid (MAA), and ethylene dimethacrylate (EDMA) as template, functional monomer, and cross-linker, respectively. The properties of the homemade GO-MISPE capillary monolithic column, including capacity and specificity, were investigated under optimized conditions. The GO-MIPs were characterized by scanning electron microscopy (SEM) and Fourier transform-infrared spectroscopy (FT-IR). The mean recoveries of phloxine B in coffee bean ranged from 89.5% to 91.4% and the intra-day and inter-day relative standard deviation (RSD) values all ranged from 3.6% to 4.7%. Good linearity was obtained over 0.001–2.0 μg mL−1 (r = 0.9995) with the detection limit (S/N = 3) of 0.075 ng mL−1. Under the selected conditions, enrichment factors of over 90-fold were obtained and extraction on the monolithic column effectively cleaned up the coffee bean matrix. The results demonstrated that the proposed GO-MISPE HPLC–LIF method can be applied to sensitively determine phloxine B in coffee bean

  2. Preparation of a poly(3'-azido-3'-deoxythymidine-co-propargyl methacrylate-co-pentaerythritol triacrylate) monolithic column by in situ polymerization and a click reaction for capillary liquid chromatography of small molecules and proteins.

    Science.gov (United States)

    Lin, Zian; Yu, Ruifang; Hu, Wenli; Zheng, Jiangnan; Tong, Ping; Zhao, Hongzhi; Cai, Zongwei

    2015-07-01

    Combining free radical polymerization with click chemistry via a copper-mediated azide/alkyne cycloaddition (CuAAC) reaction in a "one-pot" process, a facile approach was developed for the preparation of a poly(3'-azido-3'-deoxythymidine-co-propargyl methacrylate-co-pentaerythritol triacrylate) (AZT-co-PMA-co-PETA) monolithic column. The resulting poly(AZT-co-PMA-co-PETA) monolith showed a relatively homogeneous monolithic structure, good permeability and mechanical stability. Different ratios of monomers and porogens were used for optimizing the properties of a monolithic column. A series of alkylbenzenes, amides, anilines, and benzoic acids were used to evaluate the chromatographic properties of the polymer monolith in terms of hydrophobic, hydrophilic and cation-exchange interactions, and the results showed that the poly(AZT-co-PMA-co-PETA) monolith exhibited more flexible adjustment in chromatographic selectivity than that of the parent poly(PMA-co-PETA) and AZT-modified poly(PMA-co-PETA) monoliths. Column efficiencies for toluene, DMF, and formamide with 35,000-48,000 theoretical plates per m could be obtained at a linear velocity of 0.17 mm s(-1). The run-to-run, column-to-column, and batch-to-batch repeatabilities of the retention factors were less than 4.2%. In addition, the proposed monolith was also applied to efficient separation of sulfonamides, nucleobases and nucleosides, anesthetics and proteins for demonstrating its potential.

  3. Monolithic spin column: a new extraction device for analysis of drugs in urine and serum by GC/MS and HPLC/MS.

    Science.gov (United States)

    Namera, Akira; Nagao, Masakata; Nakamoto, Akihiro; Miyazaki, Shota; Saito, Takeshi

    2011-01-01

    A monolithic spin column was developed for the extraction of analytes from biological materials. This column was constructed by packing a monolithic silica disk into a spin column. Sample loading, washing, and elution of the target drugs were accomplished simply by centrifugation of the column. Opiates and benzodiazepines are abused throughout the world. Identification and quantification of these drugs is very important to solve crimes or the cause of death. Three opiates (morphine, codeine, and dihydrocodeine) were extracted from urine and serum by using the column. After conversion to trimethylsilyl derivatives of the opiates by vigorous mixing with the derivatizing reagent, the solution was subjected to GC/MS. A linear curve was observed for opiates from 10 to 2500 ng/mL in urine and 5 to 1200 ng/mL in serum, respectively (correlation coefficient > 0.996). For benzodiazepines, the hydroxyl metabolites of triazolam and etizolam were extracted from urine using the column, and the eluate was directly analyzed by HPLC/MS without evaporation. The LOD values were at the ppb level, with RSD values lower than 15%. The proposed methods were successfully applied to clinical and forensic cases, and good agreement of results was obtained compared to conventional methods. PMID:21797004

  4. Separation of intact proteins on γ-ray-induced polymethacrylate monolithic columns: A highly permeable stationary phase with high peak capacity for capillary high-performance liquid chromatography with high-resolution mass spectrometry.

    Science.gov (United States)

    Simone, Patrizia; Pierri, Giuseppe; Foglia, Patrizia; Gasparrini, Francesca; Mazzoccanti, Giulia; Capriotti, Anna Laura; Ursini, Ornella; Ciogli, Alessia; Laganà, Aldo

    2016-01-01

    Polymethacrylate-based monolithic capillary columns, prepared by γ-radiation-induced polymerization, were used to optimize the experimental conditions (nature of the organic modifiers, the content of trifluoroacetic acid and the column temperature) in the separation of nine standard proteins with different hydrophobicities and a wide range of molecular weights. Because of the excellent permeability of the monolithic columns, an ion-pair reversed-phase capillary liquid chromatography with high-resolution mass spectrometry method has been developed by coupling the column directly to the mass spectrometer without a flow-split and using a standard electrospray interface. Additionally, the high working flow and concomitant high efficiency of these columns allowed us to employ a longer column (up to 50 cm) and achieve a peak capacity value superior to 1000. This work is motivated by the need to develop new materials for high-resolution chromatographic separation that combine chemical stability at elevated temperatures (up to 75°C) and a broad pH range, with a high peak capacity value. The advantage of the γ-ray-induced monolithic column lies in the batch-to-batch reproducibility and long-term high-temperature stability. Their proven high loading capacity, recovery, good selectivity and high permeability, moreover, compared well with that of a commercially available poly(styrene-divinylbenzene) monolithic column, which confirms that such monolithic supports might facilitate analysis in proteomics.

  5. Determination of Sudan dyes in chili pepper powder by online solid-phase extraction with a butyl methacrylate monolithic column coupled to liquid chromatography with tandem mass spectrometry.

    Science.gov (United States)

    Liu, Yao; Wang, Man-Man; Ai, Lian-Feng; Zhang, Chang-Kun; Li, Xin; Wang, Xue-Sheng

    2014-07-01

    A poly(butyl methacrylate-co-ethylene dimethacrylate) monolithic column was fabricated and used as a novel sorbent for online solid-phase extraction coupled to liquid chromatography with tandem mass spectrometry for the simultaneous determination of Sudan I-IV in chili pepper powder. The prepared columns were characterized by scanning electron microscopy, nitrogen adsorption-desorption, and pressure drop measurements. Online solid-phase extraction was performed on the synthesized monolithic column using 10 mM ammonium acetate solution as the loading solution with the aid of an online cleanup chromatography system. The desorption of Sudan I-IV was achieved with acetonitrile as the eluting solution at the flow rate of 0.5 mL/min. The extracted analytes were subsequently eluted into a C18 analytical column for chromatographic separation using a mixture of 10% acetonitrile/90% formic acid (0.5%) solution as the mobile phase. Under the optimized conditions, the developed method had linear range of 1.0-50 μg/kg, a detection limit of 0.3 μg/kg, and a quantification limit of 1.0 μg/kg for each analyte. The intraday and interday recoveries of Sudan I-IV in chili pepper powder samples ranged from 94.8 to 100.9% and 94.9 to 99.4%, respectively. The intraday and interday precision were between 3.37-7.01% and 5.01-7.68%, respectively. PMID:24723310

  6. Chip-based molecularly imprinted monolithic capillary array columns coated GO/SiO2 for selective extraction and sensitive determination of rhodamine B in chili powder.

    Science.gov (United States)

    Zhai, Haiyun; Huang, Lu; Chen, Zuanguang; Su, Zihao; Yuan, Kaisong; Liang, Guohuan; Pan, Yufang

    2017-01-01

    A novel solid-phase extraction chip embedded with array columns of molecularly imprinted polymer-coated silanized graphene oxide (GO/SiO2-MISPE) was established to detect trace rhodamine B (RB) in chili powder. GO/SiO2-MISPE monolithic columns for RB detection were prepared by optimizing the supporting substrate, template, and polymerizing monomer under mild water bath conditions. Adsorption capacity and specificity, which are critical properties for the application of the GO/SiO2-MISPE monolithic column, were investigated. GO/SiO2-MIP was examined by scanning electron microscopy (SEM) and Fourier transform-infrared spectroscopy. The recovery and the intraday and interday relative standard deviations for RB ranged from 83.7% to 88.4% and 2.5% to 4.0% and the enrichment factors were higher than 110-fold. The chip-based array columns effectively eliminated impurities in chili powder, indicating that the chip-based GO/SiO2-MISPE method was reliable for RB detection in food samples using high-performance liquid chromatography. Accordingly, this method has direct applications for monitoring potentially harmful dyes in processed food. PMID:27507523

  7. Evaluation of glycidyl methacrylate-based monolith functionalized with weak anion exchange moiety inside 0.5 mm i.d. column for liquid chromatographic separation of DNA

    Directory of Open Access Journals (Sweden)

    Aprilia Nur Tasfiyati

    2016-03-01

    Full Text Available In this study, the organic polymer monolith was developed as a weak anion exchanger column in high performance liquid chromatography for DNA separation. Methacrylate-based monolithic column was prepared in microbore silicosteel column (100 × 0.5 mm i.d. by in-situ polymerization reaction using glycidyl methacrylate as monomer; ethylene dimethacrylate as crosslinker; 1-propanol, 1,4-butanediol, and water as porogenic solvents, with the presence of initiator α,α′-azobisisobutyronitrile (AIBN. The monolith matrix was modified with diethylamine to create weak anion exchanger via ring opening reaction of epoxy groups. The morphology of the monolithic column was studied by SEM. The properties of the monolithic column, such as permeability, mechanical stability, binding capacity and pore size distribution, were characterized in detail. From the results of the characterization, monoliths poly-(GMA-co-EDMA with total monomer percentage (%T 40 and crosslinker percentage (%C 25 was found to be the ideal composition of monomer and crosslinker. It has good mechanical stability and high permeability, adequate molecular recognition sites (represented with binding capacity value of 36 mg ml−1, and has relatively equal proportion of flow-through pore and mesopores (37.2% and 41.1% respectively. Poly-(GMA-co-EDMA with %T 40 and %C 25 can successfully separate oligo(dT12–18 and 50 bp DNA ladder with good resolution.

  8. Monolithic poly (SPE-co-BVPE) capillary columns as a novel hydrophilic interaction liquid chromatography stationary phase for the separation of polar analytes.

    Science.gov (United States)

    Foo, Hsiao Ching; Heaton, James; Smith, Norman W; Stanley, Shawn

    2012-10-15

    A novel hydrophilic interaction liquid chromatography (HILIC) stationary phase was prepared by the co-polymerisation of zwitterionic N,N'-dimethyl-N-methacryloxyethyl-N-(3-sulfopropyl) ammonium betaine (SPE) and the crosslinker 1,2-bis(p-vinylphenyl) ethane (BVPE) in the presence of the porogens, toluene and methanol. Monolithic columns were produced by carrying out the α,α'-azoisobutyronitrile (AIBN) initiated reaction for 1, 2, 4, 8 and 12 h inside a 200 μm i.d. fused silica capillary at 75°C (water bath). The optimum polymerisation time was shown to be 2 h, as this resulted in good porosity, due to enlarged flow-channels and the presence of a higher proportion of mesopores provided a relatively larger surface area than the other columns. The chromatographic properties of the optimised poly (SPE-co-BVPE) monolithic column were evaluated with test mixtures containing both basic and neutral compounds in the HILIC gradient separation mode. This produced relatively sharp peaks (average peak width at half height=0.1 min) with average asymmetry factors of 1.4 and baseline resolution was obtained for all the compounds. Using the isocratic separation of the test mixture, the number of theoretical plates (N) per metre calculated was between 26,888 and 35,930 by using average values obtained for triplicate injections of the compounds thiourea, toluene and acrylamide.

  9. Comprehensive profiling of ribonucleosides modification by affinity zirconium oxide-silica composite monolithic column online solid-phase microextraction - Mass spectrometry analysis.

    Science.gov (United States)

    Jiang, Han-Peng; Chu, Jie-Mei; Lan, Meng-Dan; Liu, Ping; Yang, Na; Zheng, Fang; Yuan, Bi-Feng; Feng, Yu-Qi

    2016-09-01

    More than 140 modified ribonucleosides have been identified in RNA. Determination of endogenous modified ribonucleosides in biological fluids may serve as non-invasive disease diagnostic strategy. However, detection of the modified ribonucleosides in biological fluids is challenging, especially for the low abundant modified ribonucleosides due to the serious matrix interferences of biological fluids. Here, we developed a facile preparation strategy and successfully synthesized zirconium oxide-silica (ZrO2/SiO2) composite capillary monolithic column that exhibited excellent performance for the selective enrichment of cis-diol-containing compounds. Compared with the boronate-based affinity monolith, the ZrO2/SiO2 monolith showed ∼2 orders of magnitude higher extraction capacity and can be used under physiological pH (pH 6.5-7.5). Using the prepared ZrO2/SiO2 composite monolith as the trapping column and reversed-phase C18 column as the analytical column, we further established an online solid-phase microextraction (SPME) in combination with liquid chromatography-mass spectrometry (online SPME-LC-MS/MS) analysis for the comprehensive profiling of ribonucleosides modification in human urine. Our results showed that 68 cis-diol-containing ribosylated compounds were identified in human urine, which is, to the best of our knowledge, the highest numbers of cis-diol-containing compounds were determined in a single analysis. It is worth noting that four modified ribonucleosides were discovered in the human urine for the first time. In addition, the quantification results from the pooled urine samples showed that compared to healthy controls, the contents of sixteen ribose conjugates in the urine of gastric cancer, eleven in esophagus cancer and seven in lymphoma increased more than two folds. Among these ribose conjugates, four ribose conjugates increased more than two folds in both gastric cancer and esophagus cancer; three ribose conjugates increased more than two

  10. A fluorous porous polymer monolith photo-patterned chromatographic column for the separation of a flourous/fluorescently labeled peptide within a microchip.

    Science.gov (United States)

    Xu, Zhenpo; Oleschuk, Richard D

    2014-02-01

    A fluorous porous polymer stationary phase is photo-patterned within a glass microfluidic chip to conduct CEC. During free radical-initiated polymerization, extraneous polymer forms and contributes to excessive microfluidic channel clogging. Nitrobenzene is explored as free radical quencher to limit clogging by minimizing extraneous polymer formation and a number of initiator to quencher ratios are explored with a 0.5:1 quencher (nitrobenzene): initiator (benzoin methyl ether) molar ratio shown to be optimal. The microchip patterned with a fluorous monolith was used to carry out the electrochromatographic analysis of a mixture containing fluorescent and fluorous labeling products. The fluorous monolithic column shows fluorous selectivity for compounds labeled with perfluoromethylene tags and a custom peptide is synthesized that possesses functional groups that can be both fluorescently and fluorously labeled. MALDI MS was used to identify the labeled fragments and microchip based electrochromatography was used to analyze the resulting labeling mixture. This is the first report to our knowledge that uses fluorous porous polymer monolith within a microchip to separate analytes using fluorous-fluorous interactions. PMID:24170603

  11. C18 silica packed capillary columns with monolithic frits prepared with UV light emitting diode: usefulness in nano-liquid chromatography and capillary electrochromatography.

    Science.gov (United States)

    D'Orazio, Giovanni; Fanali, Salvatore

    2012-04-01

    In this paper the potential of fused silica capillaries packed with RP18 silica particles entrapped with monolithic frits using both nano-liquid chromatography (nano-LC) and capillary electrochromatography (CEC) was investigated. Frits were prepared after removing a short part of the polyimide layer on the capillary wall and irradiating the polymerization mixture with an UV-light emitter diode (LED) at 370 nm. The capillary, was rotated during the polymerization procedure in order to obtain a homogeneous monolith. The distance of the LED from the capillary and the exposure time to UV light were studied in order to obtain frits with good porosity and high robustness. A mixture containing five alkylbenzenes was selected as sample and analyzed by both nano-LC and CEC. The standard mixture was baseline separated with good efficiency in the range 78,000-93,000 and 99,000-113,000 plates/m in nano-LC and CEC, respectively. The columns resulted to be very robust and the prepared monolithic frits allowed working with backpressure as high as 400 bar (nano-LC). In addition high voltages were applied in CEC (25-30 kV) without bubbles formation in absence of pressure assistance during runs. PMID:22189300

  12. Semi-micro reversed-phase liquid chromatography for the separation of alkyl benzenes and proteins exploiting methacrylate- and polystyrene-based monolithic columns.

    Science.gov (United States)

    Masini, Jorge Cesar

    2016-05-01

    Monolithic columns were synthesized inside 1.02 mm internal diameter fused-silica lined stainless-steel tubing. Styrene and butyl, hexyl, lauryl, and glycidyl methacrylates were the functional monomers. Ethylene glycol dimethacrylate and divinylbenzene were the crosslinkers. The glycidyl methacrylate polymer was modified with gold nanoparticles and dodecanethiol (C12 ). The separation of alkylbenzenes was investigated by isocratic elution in 60:40 v/v acetonitrile/water. The columns based on polystyrene-co-divinylbenzene and poly(glycidyl methacrylate)-co-ethylene glycol dimethacrylate modified with dodecanethiol did not provide any separation of alkyl benzenes. The poly(hexyl methacrylate)-co-ethylene glycol dimethacrylate and poly(lauryl methacrylate)-co-ethylene glycol dimethacrylate columns separated the alkyl benzenes with plate heights between 30 and 60 μm (50 μL min(-1) and 60°C). Similar efficiency was achieved in the poly(butyl methacrylate)-co-ethylene glycol dimethacrylate column, but only at 10 μL min(-1) (0.22 mm s(-1) ). Backpressures varied from 0.38 MPa in the hexyl methacrylate to 13.4 MPa in lauryl methacrylate columns (50 μL min(-1) and 60°C). Separation of proteins was achieved in all columns with different efficiencies. At 100 μL min(-1) and 60°C, the lauryl methacrylate columns provided the best separation, but their low permeability prevented high flow rates. Flow rates up to 500 μL min(-1) were possible in the styrene, butyl and hexyl methacrylate columns.

  13. Monolithic metal-organic framework MIL-53(Al)-polymethacrylate composite column for the reversed-phase capillary liquid chromatography separation of small aromatics.

    Science.gov (United States)

    Yusuf, Kareem; Badjah-Hadj-Ahmed, Ahmed Yacine; Aqel, Ahmad; ALOthman, Zeid Abdullah

    2016-03-01

    A monolithic capillary column containing a composite of metal-organic framework MIL-53(Al) incorporated into hexyl methacrylate-co-ethylene dimethacrylate was prepared to enhance the separation of mixtures of small aromatic compounds by using capillary liquid chromatography. The addition of 10 mg/mL MIL-53(Al) microparticles increased the micropore content in the monolithic matrix and increased the Brunauer-Emmett-Teller surface area from 26.92 to 85.12 m(2) /g. The presence of 1,4-benzenedicarboxylate moieties within the structure of MIL-53(Al) as an organic linker greatly influenced the separation of aromatic mixtures through π-π interactions. High-resolution separation was obtained for a series of alkylbenzenes (with resolution factors in the range 0.96-1.75) in less than 8 min, with 14 710 plates/m efficiency for propylbenzene, using a binary polar mobile phase of water/acetonitrile in isocratic mode. A reversed-phase separation mechanism was indicated by the increased retention factor and resolution as the water percentage in the mobile phase increased. A stability study on the composite column showed excellent mechanical stability under various conditions. The higher resolution and faster separation observed at increased temperature indicated an exothermic separation, whereas the negative values for the free energy change of transfer indicated a spontaneous process.

  14. Radical-mediated step-growth: Preparation of hybrid polymer monolithic columns with fine control of nanostructural and chromatographic characteristics.

    Science.gov (United States)

    Alves, Filipa; Nischang, Ivo

    2015-09-18

    The currently most successful type of porous polymer monoliths utilized in chromatography is prepared by free-radical cross-linking (co)polymerization in porogenic solvents and a single-step molding process. Though such types of materials are well-recognized in the scientific community, they suffer from their multi-scale heterogeneity originating from the nanoscale through to their microscale and ultimately limited performance on their macroscale. This is in particular true when estimating their performance under equilibrium (i.e. isocratic) elution conditions for retained compounds. In this contribution, we study a new concept in the preparation of porous monolithic hybrid materials based on polyhedral oligomeric vinylsilsesquioxanes which undergo radical mediated step-growth cross-linking with thiol-linkers. Fundamental characterization of this new entry of materials is performed via a variety of characterization approaches including infrared and Raman spectroscopies, thermogravimetric analysis, gel fraction, dry-state surface area analysis, and visualization of the capillary-scale porous structure by scanning electron microscopy. This characterization identifies that a rational choice of experimental conditions in monolith preparation leads to destined and desirable materials' properties, in particular with experimentally accessible near-ideal nanoscale network structures. With the obtained structural informations at hand, we finally evidence the monoliths' tailored chromatographic performance by isocratic elution experiments of structurally similar small molecules under reversed-phase type of chromatographic conditions. This validates the fundamental origin for an improved performance of these types of monolithic materials under solvated conditions that has its foundation established in the creation of near-ideal nanoscale networks of material. This identified ideality is manifested in an enhanced and almost retention-insensitive performance in liquid

  15. [Determination of five avermectins in bovine liver by on-line solid-phase extraction with hydrophobic monolithic column coupled with high performance liquid chromatography-tandem mass spectrometry].

    Science.gov (United States)

    Li, Xin; Zhang, Yaoqin; Ai, Lianfeng; Wang, Xuesheng; Wang, Manman; Xu, Houjun; Hao, Yulan

    2015-06-01

    A method based on on-line solid-phase extraction (SPE) with hydrophobic monolithic column coupled with high performance liquid chromatography-tandem mass spectrometry was developed for the simultaneous determination of five avermectins in bovine liver. A poly(butyl methacrylate-co-ethylene dimethacrylate) monolithic column was used as the sorbent. The parameters influenced on on-line SPE and separation process such as the loading mobile phase, the eluting flow rate and the solvent for the separation were investigated in detail. Blank samples, spiked samples, matrix effect and recovery experiments were investigated to evaluate the extraction efficiency and potential interfering compounds originating from the matrix. Under the optimized conditions, the method showed a linear range of 1-100 µg/L and the quantification limit of 5 µg/kg for each analyte. The presented method gave recoveries of 77.4%-98.4%. The relative standard deviations of intra-day and inter-day were 4.46%-8.03% and 4.79%-8.68%, respectively. Moreover, no significant changes were found in the extraction performance after more than 400 usages on one monolithic column, and even on the monoliths with various batches. The feasibility of the developed poly (butyl methacrylate-coethylene dimethacrylate) monolithic column based on the on-line SPE method for the determination of avermectins was further demonstrated by the analysis of real samples.

  16. Preparation and Characterization of a Polymeric Monolithic Column for Use in High-Performance Liquid Chromatography (HPLC)

    Science.gov (United States)

    Bindis, Michael P.; Bretz, Stacey Lowery; Danielson, Neil D.

    2011-01-01

    The high-performance liquid chromatography (HPLC) experiment, most often done in the undergraduate analytical instrumentation laboratory course, generally illustrates reversed-phase chromatography using a commercial C[subscript]18 silica column. To avoid the expense of periodic column replacement and introduce a choice of columns with different…

  17. Monolithic silica spin column extraction and simultaneous derivatization of amphetamines and 3,4-methylenedioxyamphetamines in human urine for gas chromatographic-mass spectrometric detection

    Energy Technology Data Exchange (ETDEWEB)

    Nakamoto, Akihiro [Scientific Investigation Laboratory, Hiroshima Prefectural Police Headquarters, Kohnan 2-26-3, Naka-ku, Hiroshima 730-0825 (Japan); Nishida, Manami [Hiroshima University Technical Center, Kasumi 1-2-3, Minami-ku, Hiroshima 734-8551 (Japan); Saito, Takeshi [Department of Emergency and Critical Care Medicine, Tokai University School of Medicine, Shimokasuya 143, Isehara, Kanagawa 259-1143 (Japan); Kishiyama, Izumi; Miyazaki, Shota [GL Sciences Inc., Sayamagahara 237-2, Iruma, Saitama 358-0032 (Japan); Murakami, Katsunori [Scientific Investigation Laboratory, Hiroshima Prefectural Police Headquarters, Kohnan 2-26-3, Naka-ku, Hiroshima 730-0825 (Japan); Nagao, Masataka [Department of Forensic Medicine, Graduate School of Biomedical Sciences, Hiroshima University, Kasumi 1-2-3, Minami-ku, Hiroshima 734-8551 (Japan); Namura, Akira, E-mail: namera@hiroshima-u.ac.jp [Department of Forensic Medicine, Graduate School of Biomedical Sciences, Hiroshima University, Kasumi 1-2-3, Minami-ku, Hiroshima 734-8551 (Japan)

    2010-02-19

    A simple, sensitive, and specific method with gas chromatography-mass spectrometry was developed for simultaneous extraction and derivatization of amphetamines (APs) and 3,4-methylenedioxyamphetamines (MDAs) in human urine by using a monolithic silica spin column. All the procedures, such as sample loading, washing, and elution were performed by centrifugation. APs and MDAs in urine were adsorbed on the monolithic silica and derivatized with propyl chloroformate in the column. Methamphetamine-d{sub 5} was used as an internal standard. The linear ranges were 0.01-5.0 {mu}g mL{sup -1} for methamphetamine (MA) and 3,4-methylenedioxymethamphetamine (MDMA) and 0.02-5.0 {mu}g mL{sup -1} for amphetamine (AP) and 3,4-methylenedioxyamphetamine (MDA) (coefficient of correlation {>=}0.995). The recovery of APs and MDAs in urine was 84-94%, and the relative standard deviation of the intra- and interday reproducibility for urine samples containing 0.1, 1.0, and 4.0 {mu}g mL{sup -1} of APs and MDAs ranged from 1.4% to 13.6%. The lowest detection limit (signal-to-noise ratio {>=} 3) in urine was 5 ng mL{sup -1} for MA and MDMA and 10 ng mL{sup -1} for AP and MDA. The proposed method can be used to perform simultaneous extraction and derivatization on spin columns that have been loaded with a small quantity of solvent by using centrifugation.

  18. Purification of monoclonal antibodies, IgG1, from cell culture supernatant by use of metal chelate convective interaction media monolithic columns.

    Science.gov (United States)

    Rajak, Poonam; Vijayalakshmi, M A; Jayaprakash, N S

    2012-12-01

    Monoclonal antibodies (MAbs) have diverse applications in diagnostics and therapeutics. The recent advancement in hybridoma technology for large-scale production of MAbs in bioreactors demands rapid and efficient purification methods. Conventional affinity purification systems have drawbacks of low flow rates and denaturation of antibodies owing to harsh elution conditions. Here, we attempted purification of MAbs by use of a high-throughput metal-chelate methacrylate monolithic system. Monolithic macroporous convective interaction media-iminodiacetate (CIM-IDA) disks immobilized with four different metal ions (Cu²⁺, Ni²⁺, Zn²⁺ and Co²⁺) were used and evaluated for purification of anti-human serum albumin IgG1 mouse MAbs from cell culture supernatant after precipitation with 50% ammonium sulfate. Elution with 10 mM imidazole in the equilibration buffer (25 mM MMA = MOPS (Morpholino propane sulfonic acid) + MES (Morpholino ethane sulfonic acid) + Acetate + 0.5 M NaCl, pH 7.4) resulted in a purification of 25.7 ± 2.9-fold and 32.5 ± 2.6-fold in experiments done using Zn²⁺ and Co²⁺ metal ions, respectively. The highest recovery of 85.4 ± 1.0% was obtained with a CIM-IDA-Zn(II) column. SDS-PAGE, ELISA and immuno-blot showed that the antibodies recovered were pure, with high antigen-binding efficiency. Thus, metal chelate CIM monoliths could be a potential alternative to conventional systems for fast and efficient purification of MAbs from the complex cell culture supernatant.

  19. Multi-component quantitation of loratadine, pseudoephedrine and paracetamol in plasma and pharmaceutical formulations with liquid chromatography-tandem mass spectrometry utilizing a monolithic column

    Directory of Open Access Journals (Sweden)

    Kamran Abro

    2012-01-01

    Full Text Available The purpose of this study was to develop a rapid, simple and sensitive quantitation method for pseudoephedrine (PSE, paracetamol (PAR and loratadine (LOR in plasma and pharmaceuticals using liquid chromatography-tandem mass spectrometry with a monolithic column. Separation was achieved using a gradient composition of methanol-0.1% formic acid at a flow rate of 1.0 mL min-1. Mass spectral transitions were recorded in SRM mode. System validation was evaluated for precision, specificity and linearity. Limit of detection for pseudoephedrine, paracetamol, and loratadine were determined to be 3.14, 1.86 and 1.44 ng mL-1, respectively, allowing easy determination in plasma with % recovery of 93.12 to 101.56%.

  20. A hybrid fluorous monolithic capillary column with integrated nanoelectrospray ionization emitter for determination of perfluoroalkyl acids by nano-liquid chromatography-nanoelectrospray ionization-mass spectrometry/mass spectrometry.

    Science.gov (United States)

    Zhang, Haiyang; Ou, Junjie; Wei, Yinmao; Wang, Hongwei; Liu, Zhongshan; Zou, Hanfa

    2016-04-01

    A hybrid fluorous monolithic column was simply prepared via photo-initiated free radical polymerization of an acrylopropyl polyhedral oligomeric silsesquioxane (acryl-POSS) and a perfluorous monomer (2,2,3,3,4,4,5,5,6,6,7,7-dodecafluoroheptyl acrylate) in UV-transparent fused-silica capillaries within 5min. The physical characterization of hybrid fluorous monolith, including scanning electron microscopy (SEM), Fourier transform infrared (FT-IR) spectroscopy, mercury intrusion porosimetry (MIP) and nitrogen adsorption/desorption measurement was performed. Chromatographic performance was also evaluated by capillary liquid chromatography (cLC). Due to the fluorous-fluorous interaction between fluorous monolith and analytes, fluorobenzenes could well be separated, and the column efficiencies reached 86,600-92,500plates/m at the velocity of 0.87mm/s for alkylbenzenes and 51,900-76,000plates/m at the velocity of 1.10mm/s for fluorobenzenes. Meanwhile, an approach to integrate nanoelectrospray ionization (ESI) emitter with hybrid fluorous monolithic column was developed for quantitative determination of perfluoroalkyl acids by nanoHPLC-ESI-MS/MS. The integration design could minimize extracolumn volume, thus excluding undesirable peak broadening and improving separation performance.

  1. Macroporous polymer monoliths as second dimension columns in comprehensive two-dimensional gas chromatography: a feasibility study

    NARCIS (Netherlands)

    D. Peroni; R.J. Vonk; W. van Egmond; H.-G. Janssen

    2012-01-01

    When the typical column combinations are used, comprehensive two-dimensional gas chromatography (GC × GC) suffers from the impossibility to operate both dimensions at their optimum carrier gas velocities at the same time. This as a result of the flow mismatch caused by the different dimensions of th

  2. Comparison of Stability-Indicating LC Methods Using Light Scattering and Photodiode Array Detection with Monolithic Column for Determination of Quinapril and Hydrochlorothiazide.

    Science.gov (United States)

    de Diego, Marta; Godoy, Ricardo; Mennickent, Sigrid; Vergara, Carola; Charnock, Henry; Hernández, Camilo

    2016-09-01

    Rapid stability-indicating LC methods for simultaneous analysis of quinapril and hydrochlorothiazide were developed, validated and compared using evaporative light scattering detection (ELSD) and diode array detection (DAD). For the separation of quinapril, hydrochlorothiazide and its major degradation products, a monolithic column was used and the analytes were eluted within 7 min, applying gradient mobile phase in both methods. Quinapril was subjected to hydrolytic, oxidative, thermal, humidity and photolytic stress conditions. Degradation products were well resolved from main peaks and from each other, proving the stability-indicating power of the methods. The response with DAD was linear and the response with ELSD was fitted to a power function, for quinapril and hydrochlorothiazide concentrations of 20-160 and 12.5-100 µg mL(-1), respectively. DAD method achieved better precision than ELSD method, the LOQ of DAD was lower and the accuracy of the methods was similar. Quinapril degrade by hydrolysis and thermal stress, showing the formation of quinaprilat and quinapril diketopiperazine as degradants, which were identified by MS-MS. The methods were successfully applied to quantify quinapril and hydrochlorothiazide in commercial tablets. LC-DAD and LC-ELSD methods are suitable to assess the stability and routine analysis of quinapril and hydrochlorothiazide in pharmaceutical industry. PMID:27165572

  3. Selective microemulsion liquid chromatography analysis of dopamine receptor antagonist LE300 and its N-methyl metabolite in mouse sera by using a monolithic silica column.

    Science.gov (United States)

    Al-Majed, Abdulrhman A; Hefnawy, Mohamed M; Mohammed, Mostafa S; Attia, Sabry M; Lehmann, Jochen

    2015-05-01

    A highly selective, sensitive, and rapid microemulsion liquid chromatography (MELC) method was developed and validated for the simultaneous determination of a novel type of dopamine receptor antagonist LE300 and its N-methyl metabolite in mouse sera. LE300, its N-methyl metabolite, and pindolol (an internal standard) were detected using excitation and emission wavelengths of 275 and 340 nm, respectively. HPLC analysis by using a monolithic column was performed by directly injecting the sample after appropriate dilution with the microemulsion mobile phase. The chromatographic behaviour of these compounds was studied to demonstrate their chromatographic efficiency, retention, and peak symmetry. The MELC method was validated for its specificity, linearity, accuracy, precision, robustness and stability. An experimental design was used during validation to evaluate method robustness. The calibration curves in serum showed excellent linearity (r=0.997) over concentrations ranging from 10 to 400 ngmL(-1) for LE300 and 15 to 500 ngmL(-1) for its N-methyl metabolite. The mean relative standard deviation (RSD) of the results of inter- and intra-day precision and accuracy of LE300 and its N-methyl metabolite were ≤5%. The overall recoveries of LE300 and its N-methyl metabolite from mouse sera were in the range 97.9-101.5% with %RSD ranging from 0.98% to 3.63%, which were in line with ICH guidelines. The assay was successfully applied in a pharmacokinetic study.

  4. Separation and determination of coumarins in Fructus cnidii extracts by pressurized capillary electrochromatography using a packed column with a monolithic outlet frit.

    Science.gov (United States)

    Chen, Danxia; Wang, Jiajing; Jiang, Yunyun; Zhou, Tingting; Fan, Guorong; Wu, Yutian

    2009-12-01

    The pressurized capillary electrochromatography (pCEC) was utilized for the separation and determination of coumarins in Fructus cnidii extracts from 12 different regions. After a thorough study of analytical parameters such as acetonitrile content of the mobile phase, the concentration and pH of the buffer, and the applied voltage, a methodology was proposed to separate and determine six coumarins of F. cnidii extracts in less than 15 min. The experiments were performed in an in-house packed column with a monolithic outlet frit under the optimal conditions: pH 4.0 ammonium acetate buffer at 10 mM containing 50% acetonitrile at -6kV applied voltage. The calibration curves were linear in the range of 10.0-100.0 microg/mL for bergapten, 20.0-200.0 microg/mL for imperatorin, 5.0-400.0 microg/mL for osthole, 10.0-100.0 microg/mL for 2'-acetylangelicin, 10.0-200.0 microg/mL for oroselone, and 10.0-200.0 microg/mL for O-acetylcolumbianetin. The correlation coefficients were between 0.9967 and 0.9995. With this pCEC system, fingerprints of F. cnidii extracts were preliminarily established to distinguish three types of coumarins by characteristic peaks, and the quality of various sources of raw materials was evaluated by determining the contents of six coumarins. PMID:19608371

  5. 基于整体柱的超灵敏表面增强拉曼检测%Ultra Sensitive Surface-Enhanced Raman Scattering Detection Based on Monolithic Column

    Institute of Scientific and Technical Information of China (English)

    李青青; 杜一平; 唐慧容; 汪宣; 陈贵平; 王文明

    2012-01-01

    A novel Surface-Enhanced Raman Scattering (SERS) detection method based on monolithic column which is commonly used in High Performance Liquid Chromatography (HPLC) was developed in the present study. The probe molecules were mixed with silver colloid before spread onto the monolithic column surface. In this study, SERS signals of Rhodamine 6G (R6G) at a concentration as low as 10-18 mol/L and p-aminothiophenol (PATP) at a concentration as low as 10-16 mol/L could be obtained through the use of monolithic column material. Atomic Force Microscope (AFM) and Scanning Electron Microscopy (SEM) were utilized to characterize the silver colloid and the monolithic column. It suggested that the surface morphology and the pore size do effectively assist the silver colloid in generating "hot spots".%本文提出了一种全新的基于整体柱材料的SERS检测方法.通过将探针分子和银溶胶混合后滴加在整体柱上,我们可以得到浓度低至10-18 mol/L的罗丹明6G (R6G)及10-16 mol/L的对巯基苯胺(PATP)的SERS信号.利用原子力显微镜(AFM)和扫描电镜(SEM)对银溶胶及整体柱材料进行了表征.通过实验结果可以初步推测,整体柱材料的表面形态和孔结构可以促进银溶胶产生“热点”.

  6. Separation of N-derivatized di- and tri-peptide stereoisomers by micro-liquid chromatography using a quinidine-based monolithic column - Analysis of l-carnosine in dietary supplements.

    Science.gov (United States)

    Wang, Qiqin; Sánchez-López, Elena; Han, Hai; Wu, Huihui; Zhu, Peijie; Crommen, Jacques; Marina, Maria Luisa; Jiang, Zhengjin

    2016-01-01

    In the present study, a new analytical methodology was developed enabling the enantiomeric determination of N-derivatized di- and tri-peptides in dietary supplements using chiral micro-LC on a monolithic column consisting of poly(O-9-[2-(methacryloyloxy)-ethylcarbamoyl]-10,11-dihydroquinidine-co-2-hydroxyethyl methacrylate-co-ethylene dimethacrylate) (poly(MQD-co-HEMA-co-EDMA)). After optimization of the mobile phase conditions, a baseline resolution of the stereoisomers of 24 out of 53 N-derivatized di- and tri-peptides was obtained. 3,5-Dinitrobenzoyl- and 3,5-dichlorobenzoyl-peptide stereoisomers were separated with exceptionally high selectivity and resolution. The monolithic column was then applied to the quantitative analysis of l-carnosine and its enantiomeric impurity in three different commercial dietary supplements. Method validation demonstrated satisfactory results in terms of linearity, precision, selectivity, accuracy and limits of detection and quantification. The determined amounts of l-carnosine in commercial formulations were in agreement with the labeled content for all analyzed samples, and the enantiomeric impurity was found to be below the limit of detection (LOD), showing the potential of the poly(MQD-co-HEMA-co-EDMA) monolithic column as a reliable tool for the quality control of l-carnosine in dietary supplements by micro-LC.

  7. Separation of N-derivatized di- and tri-peptide stereoisomers by micro-liquid chromatography using a quinidine-based monolithic column - Analysis of l-carnosine in dietary supplements.

    Science.gov (United States)

    Wang, Qiqin; Sánchez-López, Elena; Han, Hai; Wu, Huihui; Zhu, Peijie; Crommen, Jacques; Marina, Maria Luisa; Jiang, Zhengjin

    2016-01-01

    In the present study, a new analytical methodology was developed enabling the enantiomeric determination of N-derivatized di- and tri-peptides in dietary supplements using chiral micro-LC on a monolithic column consisting of poly(O-9-[2-(methacryloyloxy)-ethylcarbamoyl]-10,11-dihydroquinidine-co-2-hydroxyethyl methacrylate-co-ethylene dimethacrylate) (poly(MQD-co-HEMA-co-EDMA)). After optimization of the mobile phase conditions, a baseline resolution of the stereoisomers of 24 out of 53 N-derivatized di- and tri-peptides was obtained. 3,5-Dinitrobenzoyl- and 3,5-dichlorobenzoyl-peptide stereoisomers were separated with exceptionally high selectivity and resolution. The monolithic column was then applied to the quantitative analysis of l-carnosine and its enantiomeric impurity in three different commercial dietary supplements. Method validation demonstrated satisfactory results in terms of linearity, precision, selectivity, accuracy and limits of detection and quantification. The determined amounts of l-carnosine in commercial formulations were in agreement with the labeled content for all analyzed samples, and the enantiomeric impurity was found to be below the limit of detection (LOD), showing the potential of the poly(MQD-co-HEMA-co-EDMA) monolithic column as a reliable tool for the quality control of l-carnosine in dietary supplements by micro-LC. PMID:26410182

  8. 丙烯胺-β-环糊精电色谱整体柱的性能评价及应用%Evaluation and application of allylamine-β-cyclodextrin chiral monolithic column for capillary electrochromatography

    Institute of Scientific and Technical Information of China (English)

    李英杰; 王立娜; 吕仁江; 吴婧; 丁莉; 张福祥

    2012-01-01

    以丙烯胺-β-环糊精(Allylamine-β-CD)为功能单体,采用一步键合法制备毛细管电色谱手性整体柱,并考察了整体柱的制备条件.在毛细管电色谱(CEC)模式下,以苯丙氨酸为对象,考察了整体柱的分离能力,同时考察缓冲溶液pH,柱温,分离电压对拆分的影响.苯丙氨酸的拆分达到了基线分离,并在优化条件下,应用整体柱对盐酸去甲苯福林和愈创甘油醚对映体进行拆分,均达到基线分离.同时,以硫脲为电渗流标记物,测得整体柱的理论塔板数达87488板/m,并且可持续使用16 h,可间歇使用3个月以上,仍具有良好的柱效.%β-cyclodextrin chiral monolithic capillary electrochromatographic column was prepared by one-step reaction with allylamine-β-cyclodextrin as a functional monomer. In capillary electrochromatography ( CEC) mode, the as-prepared monolithic column was evaluated by separating DL-Phenylalanine. The influences of buffer pH value, temperature and voltage on separation were investigated. Under the optimal CEC conditions, norfenefrine hydrochloride and guaifenesin have reached baseline separation. At the same time, theoretical plate number of the column was more than 87 488 plates/m with thiourea as an electricity seepage marker. The monolithic column was used for continuous 16 h and intermittent 3 months with keeping good column efficiency.

  9. Green synthesis of polymer monoliths incorporated with carbon nanotubes in room temperature ionic liquid and deep eutectic solvents.

    Science.gov (United States)

    Zhang, Li-Shun; Gao, Shu-Ping; Huang, Yan-Ping; Liu, Zhao-Sheng

    2016-07-01

    In this work, an efficient method to prepare polymer monoliths with incorporated carbon nanotubes in a mixture of room temperature ionic liquid and deep eutectic solvents was developed. With assistance of the binary green solvent, 1-butyl-3-methylimidazolium tetrafluoroborate and choline chloride/ethylene glycol, single-walled carbon nanotubes were dispersed successfully in pre-polymerization mixture without need of oxidative cutting of carbon nanotubes, which may allow depletion of the emission of volatile organic compounds into environment. The novel single-walled carbon nanotubes monolith was evaluated by capillary electrochromatography. Compared with the monolith made without single-walled carbon nanotubes, the monolith with the incorporation of single-walled carbon nanotubes exhibited high column efficiency (251,000plates/m) in the chromatographic separation. The morphology of the monolith can be tuned by the composition of mixture of ionic liquids and deep eutectic solvents to afford good column permeability and excellent separation ability for small molecules of alkyl phenones and alkyl benzenes. The results demonstrated that the method is a green strategy for the fabrication of multifunctional polymer monoliths. PMID:27154683

  10. Evaluation of interactions between metal ions and nonionic surfactants in high-concentration HCl using low-pressure high-performance liquid chromatography with low-flow-resistance polystyrene-based monolithic column.

    Science.gov (United States)

    Hirano, Tomohiko; Kitagawa, Shinya; Ohtani, Hajime; Kinoshita, Takehiko; Ishigaki, Yuzo; Shibata, Nobuyuki; Nii, Susumu

    2013-10-01

    A method for evaluating the interactions between metal ions and nonionic surfactants in aqueous solutions containing high-concentration HCl, using gas pressure-driven low-pressure high-performance liquid chromatography (LP-HPLC) as a highly acid-resistant HPLC system, was developed. To construct the LP-HPLC for this purpose, poly(styrene-co-divinylbenzene)-based low-flow-resistance monolithic columns tolerant to highly acidic conditions were prepared using low-conversion thermal polymerization. Thermal polymerization at 65 °C for 1.5 h (monomer conversions, 33% for styrene and 59% for divinylbenzene) allowed preparation of a column with both high separation efficiency (around 60,000 plates m(-1) for alkylbenzenes) and a quite low back pressure of 0.14 MPa at a linear flow rate of 1 mm s(-1) (2.8 × 10(-13) m(2) in permeability). The base column prepared under the above conditions was coated with a nonionic surfactant, polyoxyethylene nonylphenyl ether (PONPE, average oxyethylene unit numbers (n) = 3, 7.5, 15, and 20), and used for evaluation of the interactions between PONPEs and metal ions in 6 M HCl. The interactions between PONPEs and Au(III), Ga(III), Fe(III), Zn(II), and Cu(II) were successfully evaluated using both breakthrough and chromatographic methods. Furthermore, a study of the effect of the polyoxyethylene (POE) chain length revealed that the use of PONPE with the longer POE moiety enhanced the magnitude of the interaction together with the increase in the amount of oxyethylene (OE) units coated on the monolith. Moreover, the interactions of metal ions with a single OE unit were almost constant in the range of n = 7.5-20, whereas the suppression of the interaction between Au(III) with the shortest PONPE chain (n = 3) was also observed. PMID:23884474

  11. Preparation of hydrophilic monolithic capillary column by in situ photo-polymerization of N-vinyl-2-pyrrolidinone and acrylamide for highly selective and sensitive enrichment of N-linked glycopeptides.

    Science.gov (United States)

    Jiang, Hao; Yuan, Huiming; Qu, Yanyan; Liang, Yu; Jiang, Bo; Wu, Qi; Deng, Nan; Liang, Zhen; Zhang, Lihua; Zhang, Yukui

    2016-01-01

    In this study, a novel kind of amide functionalized hydrophilic monolith was synthesized by the in situ photo-polymerization of N-vinyl-2-pyrrolidinone (NVP), acrylamide (AM), and N, N'-methylenebisacrylamide (MBA) in a UV transparent capillary, and successfully applied for hydrophilic interaction chromatography (HILIC) based enrichment of N-linked glycopeptides. With 2 μg of the tryptic digests of IgG as the sample, after enrichment, 18 glycopeptides could be identified by MALDI-TOF/TOF MS analysis. Furthermore, with the mixture of BSA and IgG digests (10,000:1, m/m) as the sample, 6 N-linked glycopeptides were unambiguously identified after enrichment, indicating the high selectivity and good specificity of such material. Moreover, such a monolithic capillary column was also applied for the N-glycosylation sites profiling of 6 μg protein digests from HeLa cells and 1 μL human serum. In total, 530 and 262 unique N-glycosylated peptides were identified, respectively, corresponding to 282 and 124N-glycoproteins, demonstrating its great potential for the large scale glycoproteomics analysis.

  12. Modified monolithic silica capillary for preconcentration of catecholamines

    Institute of Scientific and Technical Information of China (English)

    Wei Chang; Tusyo-shi Komazu

    2009-01-01

    Preconcentration of catecholamines by the modified monolithic silica in the capillary was investigated in this study. In order to achieve a microchip-based method for determining catecholamines in the saliva, the monolithic silica was fabricated in the capillary and the monolithic silica was chemically modified by on-column reaction with phenylboronate. Different modified methods were compared. The concentration conditions were optimized. This study indicates the applicability of the modified monolithic silica capillary when it was used to concentrate catecholamines.

  13. Modified monolithic silica capillary for preconcentration of catecholamines

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    Preconcentration of catecholamines by the modified monolithic silica in the capillary was investigated in this study. In order to achieve a microchip-based method for determining catecholamines in the saliva,the monolithic silica was fabricated in the capillary and the monolithic silica was chemically modified by on-column reaction with phenylboronate. Different modified methods were compared. The concentration conditions were optimized. This study indicates the applicability of the modified monolithic sili...

  14. Automated pre-column derivatization of thiolic fruit-antibrowning agents by sequential injection coupled to high-performance liquid chromatography using a monolithic stationary phase and an in-loop stopped-flow approach.

    Science.gov (United States)

    Karakosta, Theano D; Tzanavaras, Paraskevas D; Themelis, Demetrius G

    2011-08-01

    The present study reports the very first application of ethyl propiolate (EP) as an advantageous pre-column derivatization reagent for the determination of thiols by liquid chromatography (LC). Cysteine (CYS), glutathione (GSH) and N-acetylcysteine (NAC) were derivatized online under stopped-flow conditions in a sequential injection (SI) system coupled to HPLC. The formed derivatives were separated isocratically with a monolithic stationary phase (100×4.6 mm id) and UV detected at 285 nm. Critical parameters that affected the online pre-column derivatization reaction (e.g. the reaction time and the amount concentration of EP) and the separation (e.g. pH and the composition of the mobile phase) were investigated. The developed analytical scheme offers a total analysis time of less than 10 min, limits of detection in the range of 0.24-0.35 μmol/L and satisfactory linearity up to 200 μmol/L for all analytes. The proposed method was applied to the analysis of the selected thiols--that are often employed as antibrowning agents--in fresh fruit samples.

  15. Determination of rimantadine in human urine by HPLC using a monolithic stationary phase and on-line post-column derivatization.

    Science.gov (United States)

    Zacharis, Constantinos K; Tzanavaras, Paraskevas D; Vlessidis, Athanasios G

    2013-06-01

    In the present study, we propose the first HPLC method coupled to postcolumn derivatization for the determination of rimantadine in human urine samples. The analyte and amantadine (internal standard) were isocratically separated using an RP monolithic stationary phase (100 × 4.6 mm id) with a mobile phase consisting of CH3OH/phosphate buffer (25 mmol/L, pH 3.0) at a volume ratio of 50:50. Postcolumn derivatization involved on-line reaction with o-phthalaldehyde (20 mmol/L) and N-acetyl-cysteine (5 mmol/L) at alkaline medium (100 mmol/L borate pH 11.0). Spectrofluorimetric detection at λ(ex)/λ(em) = 340/455 nm enabled the selective and sensitive determination of rimantadine in urine samples at a range of 50-500 ng/mL with an LOD of 5 ng/mL. Human urine samples were analyzed successfully after SPE using hydrophilic-lipophilic balanced RP cartridges (30 mg/mL, Oasis HLB). Recoveries ranged between 89.7 and 102.7%. PMID:23650193

  16. Assessing the performance of curtain flow first generation silica monoliths.

    Science.gov (United States)

    Soliven, Arianne; Foley, Dominic; Pereira, Luisa; Dennis, Gary R; Shalliker, R Andrew; Cabrera, Karin; Ritchie, Harald; Edge, Tony

    2014-07-18

    Analytical scale active flow technology first generation silica monolithic columns kitted out in curtain flow mode of operation were studied for the first time. A series of tests were undertaken assessing the column efficiency, peak asymmetry and detection sensitivity. Two curtain flow columns were tested, one with a fixed outlet ratio of 10% through the central exit port, the other with 30%. Tests were carried out using a wide range in inlet flow segmentation ratios. The performance of the curtain flow columns were compared to a conventional monolithic column. The gain in theoretical plates achieved in the curtain flow mode of operation was as much as 130%, with almost Gaussian bands being obtained. Detection sensitivity increased by as much as 250% under optimal detection conditions. The permeability advantage of the monolithic structure together with the active flow technology makes it a priceless tool for high throughput, sensitive, low detection volume analyses. PMID:24906299

  17. Surface modified aerogel monoliths

    Science.gov (United States)

    Leventis, Nicholas (Inventor); Johnston, James C. (Inventor); Kuczmarski, Maria A. (Inventor); Meador, Mary Ann B. (Inventor)

    2013-01-01

    This invention comprises reinforced aerogel monoliths such as silica aerogels having a polymer coating on its outer geometric surface boundary, and to the method of preparing said aerogel monoliths. The polymer coatings on the aerogel monoliths are derived from polymer precursors selected from the group consisting of isocyanates as a precursor, precursors of epoxies, and precursors of polyimides. The coated aerogel monoliths can be modified further by encapsulating the aerogel with the polymer precursor reinforced with fibers such as carbon or glass fibers to obtain mechanically reinforced composite encapsulated aerogel monoliths.

  18. Porous Monoliths: Stationary Phases of Choice for High Performance Liquid Chromatography in Various Formats%用于高效液相色谱的不同形式的多孔整体固定相

    Institute of Scientific and Technical Information of China (English)

    SVEC Frantisek

    2005-01-01

    Modern porous monoliths have been conceived as a new class of stationary phases for high performance liquid chromatography (HPLC) in classical columns in the early 1990s and later extended to the capillary format. These monolithic materials are prepared using simple processes carried out in an external mold (inorganic monoliths) or within the confines of the column (organic monoliths and all capillary columns). These methods afford macroporous materials with large through-pores that enable applications in a rapid flow-through mode. Since all the mobile phase must flow through the monolith, the convection considerably accelerates mass transport within the monolithic separation medium and improves the separations. As a result, the monolithic columns perform well even at very high flow rates. The applications of monolithic capillary columns are demonstrated on numerous separations in the HPLC mode.

  19. Feasibility of the preparation of silica monoliths for gas chromatography: fast separation of light hydrocarbons.

    Science.gov (United States)

    Azzouz, Imadeddine; Essoussi, Anouar; Fleury, Joachim; Haudebourg, Raphael; Thiebaut, Didier; Vial, Jerome

    2015-02-27

    The preparation conditions of silica monoliths for gas chromatography were investigated. Silica-based monolithic capillary columns based on sol-gel process were tested in the course of high-speed gas chromatographic separations of light hydrocarbons mixture (C1-C4). The impact of modifying the amount of porogen and/or catalyst on the monolith properties were studied. At the best precursor/catalyst/porogen ratio evaluated, a column efficiency of about 6500 theoretical plates per meter was reached with a very good resolution (4.3) for very light compounds (C1-C2). The test mixture was baseline separated on a 70cm column. To our knowledge for the first time a silica-based monolithic capillary column was able to separate light hydrocarbons from methane to n-butane at room temperature with a back pressure in the range of gas chromatography facilities (under 4.1bar). PMID:25622518

  20. Porous layer open tubular columns with immobilized trypsin for protein digestion

    OpenAIRE

    Knob, R.

    2013-01-01

    We have developed a monolithic porous layer open tubular (PLOT) column with immobilized trypsin for protein digestion. The PLOT column was prepared in a 10 (mikro)m ID fused silica capillary. Trypsin was immobilized on the monolithic surface and the developed enzyme reactor was used for protein digestion followed by on-line ESI/MS analysis.

  1. Simulation and optimization of divided wall column for separating thionyl chloride%隔板精馏塔分离氯化亚砜的模拟及工艺优化

    Institute of Scientific and Technical Information of China (English)

    黄国强; 靳权; 王红星

    2014-01-01

    The indirect sequence as a conventional process was simulated by using Aspen Plus software for the separation of thionyl chloride.And divided wall column (DWC)was proposed as an innovative process to separate thionyl chloride.Furthermore,the effect of feed stage,side draw stage,the ratio of reflux rate to feed and distribution ratio on the product purity and reboiler duty was discussed.The optimum operating conditions determined are as follows:the feed stage is the 6th tray of pre-fractionator,the side draw stage is the 55th tray of main column,the ratio of reflux rate to feed is 4.45,the liquid distribution ratio is 1.60,and the vapor distribution ratio is 1.98.The results show that DWC operated in optimal conditions can save condenser duty and reboiler duty by 34.62% and 34.64% respectively,compared with the conventional indirect sequence.Meanwhile,DWC can save capital cost by 17.27% from the calculating result of CAPCOST software.So DWC for the separation of thionyl chloride is an energy saving and efficient separation technology.%利用 AspenPlus 软件对常规的两塔间接序列精馏工艺分离氯化亚砜进行了模拟计算,并提出了一种新型分离工艺-隔板精馏塔工艺。通过对隔板精馏塔的模拟计算,研究了预分离段进料位置、侧线采出位置、回流进料比和分配比对产品纯度和再沸器能耗的影响,结果说明最佳的工艺条件为:预分离段第6块板进料,主塔第55块板采出,回流进料比为4.45,液相分配比为1.60,汽相分配比为1.98。将隔板塔在最佳操作条件下的能耗与常规两塔工艺操作能耗和设备投资进行比较,隔板精馏塔节约冷凝器负荷和再沸器负荷分别为34.62%和34.64%;然后运用专业的设备投资计算软件 CAPCOST 计算2种工艺设备投资,结果表明,隔板精馏塔新工艺可以降低17.27%的设备投资。综上可知隔板精馏分离氯化亚砜是一种节能、高效的新型分离工艺。

  2. Monolithic microwave integrated circuits

    Science.gov (United States)

    Pucel, R. A.

    Monolithic microwave integrated circuits (MMICs), a new microwave technology which is expected to exert a profound influence on microwave circuit designs for future military systems as well as for the commercial and consumer markets, is discussed. The book contains an historical discussion followed by a comprehensive review presenting the current status in the field. The general topics of the volume are: design considerations, materials and processing considerations, monolithic circuit applications, and CAD, measurement, and packaging techniques. All phases of MMIC technology are covered, from design to testing.

  3. Capillary electrochromatography enantiomeric separation of guaifenesin by allyl-β-cyclodextrin monolithic column%烯丙基-β-环糊精毛细管电色谱整体柱分离愈创甘油醚对映体

    Institute of Scientific and Technical Information of China (English)

    李英杰; 李芳; 张春雨; 高晴; 吕仁江

    2011-01-01

    Objective : To develop a method for enantiomeric separation of guaifenesin in capillary electrochromatography. Methods : Under capillary electrochromatography mode, guaifenesin enantiomers were separated by the prepared allyl -β - cyclodextrin chiral capillary monolithic column. The influences of mobile phase ratio , background buffer pH , temperature and applied voltage were investigated. Result : In the optimal conditions, guaifenesin enantiomers were separated by based - line. Conclusion : The capillary electrochromatography is simple, quick and suitable for the first separation of guaifenesin.%目的:建立一种用毛细管电色谱拆分愈创甘油醚对映体的方法.方法:采用制备的烯丙基-β-环糊精手性毛细管整体柱,在电色谱模式下,对愈创甘油醚对映体进行手性分离,考察了流动相配比、背景电解质溶液pH、柱温及分离电压等因素对分离的影响.结果:在优化的实验条件下,愈创甘油醚对映体达到基线分离.结论:毛细管电色谱首次分离愈创甘油醚对映体,该方法操作简单,分离效果好.

  4. Spatial and temporal distribution of the leaching of surface applied tracers from an irrigated monolith of a loamy vineyard soil.

    Science.gov (United States)

    Bloem, E; Hermon, K M; de Rooij, G H; Stagnitti, F

    2014-01-01

    Fresh water scarcity is an increasing problem worldwide. Strategies to alleviate water scarcity include the use of low-quality water for irrigation. The risk of groundwater contamination by pollutants in this water is affected by soil heterogeneity and preferential flow. These risk factors can be assessed by measuring the spatio-temporal redistribution of uniformly applied water and solutes. We placed a soil monolith (height 29 cm) from an Australian vineyard on a 100-cell multi-compartment sampler (MCS). At this vineyard, treated wastewater is used in response to the severe shortage of water in the summer. We studied the leaching risk associated with heterogeneous or preferential flow by irrigating the soil column with 24 applications to simulate one year. We applied simulated rainfall as well as wastewater (which contained chloride) during summer while relying on rainfall only in winter. We compared the chloride leaching with the leaching of bromide, which was applied during one of the applications as a pulse. During the entire simulated year, leaching of solutes from the monolith was measured. The results indicate that the assumption of uniform flow would underestimate the risk for the fresh groundwater reserves: 25% of the solutes are transported though 6% of the soil's cross-section. The spatial distribution of drainage and solute leaching varied little during the experiment. Consequently, the mass flux density pattern of the bromide pulse was comparable to that of the repeatedly applied chloride. However, the MCS data suggested lateral 'escape' from chloride to non-mobile areas, which means in the long run, considerable quantities of these solutes can build up in areas that do not receive irrigation water. PMID:24638830

  5. Embedded-monolith armor

    Energy Technology Data Exchange (ETDEWEB)

    McElfresh, Michael W.; Groves, Scott E; Moffet, Mitchell L.; Martin, Louis P.

    2016-07-19

    A lightweight armor system utilizing a face section having a multiplicity of monoliths embedded in a matrix supported on low density foam. The face section is supported with a strong stiff backing plate. The backing plate is mounted on a spall plate.

  6. Microfluidic Precolumn Derivatization of Environmental Phenols with Coumarin-6-Sulfonyl Chloride and HPLC Separation.

    Science.gov (United States)

    Suliman, FakhrEldin O; Al-Busaidi, Jihad N; Al-Lawati, Hiader A J; Al-Kindy, Salma M Z

    2015-09-01

    A simple, fast, sensitive and versatile method for the analysis of phenols in water is proposed using microfluidic precolumn derivatization with the fluorogenic label coumarin-6-sulfonyl chloride (C6SCl) and HPLC separation on monolithic columns. Phenols react with C6SCl within 3.0 min in the microreactor at ambient temperature to produce phenol-coumarin sulphonamides derivatives which were separated in reversed phase high-performance liquid chromatography followed by postcolumn ring-opening and fluorescence detection at λexc = 360 nm and λem = 460 nm. The optimum conditions for the derivatization, separation and ring-opening reaction have been established. The calibration curves were linear for the studied phenols in the range of 0.75-12.5 mg L(-1). The application of the method to environmental samples was demonstrated by analyzing tap and fountain water samples spiked with the phenolic compounds. PMID:25809998

  7. Column flotation

    Energy Technology Data Exchange (ETDEWEB)

    Kohmuench, J.N.; Norrgran, D.A.; Luttrell, E.; Luttrell, G.H. [Virginia Tech. (United States)

    2008-04-15

    Over the last decade, column flotation has been recognised in the industry to be most efficient and economical means of recovering fine coal while maximizing product grade. When designed properly, flotation columns provide a high combustible recovery while maintaining a low product ash. The paper looks at the benefits of using column flotation for fine coal recovery. 2 refs., 5 figs.

  8. Silica-based polypeptide-monolithic stationary phase for hydrophilic chromatography and chiral separation.

    Science.gov (United States)

    Zhao, Licong; Yang, Limin; Wang, Qiuquan

    2016-05-13

    Glutathione (GSH)-, somatostatin acetate (ST)- and ovomucoid (OV)-functionalized silica-monolithic stationary phases were designed and synthesized for HILIC and chiral separation using capillary electrochromatography (CEC). GSH, ST and OV were covalently incorporated into the silica skeleton via the epoxy ring-opening reaction between their amino groups and the glycidyl moiety in γ-glycidoxypropyltrimethoxysilane (GPTMS) together with polycondensation and copolymerization of tetramethyloxysilane and GPTMS. Not only could the direction and electroosmotic flow magnitude on the prepared GSH-, ST- and OV-silica hybrid monolithic stationary phases be controlled by the pH of the mobile phase, but also a typical HILIC behavior was observed so that the nucleotides and HPLC peptide standard mixture could be baseline separated using an aqueous mobile phase without any acetonitrile during CEC. Moreover, the prepared monolithic columns had a chiral separation ability to separate dl-amino acids. The OV-silica hybrid monolithic column was most effective in chiral separation and could separate dl-glutamic acid (Glu) (the resolution R=1.07), dl-tyrosine (Tyr) (1.57) and dl-histidine (His) (1.06). Importantly, the chiral separation ability of the GSH-silica hybrid monolithic column could be remarkably enhanced when using gold nanoparticles (AuNPs) to fabricate an AuNP-mediated GSH-AuNP-GSH-silica hybrid monolithic column. The R of dl-Glu, dl-Tyr and dl-His reached 1.19, 1.60 and 2.03. This monolithic column was thus applied to separate drug enantiomers, and quantitative separation of all four R/S drug enantiomers were achieved with R ranging from 4.36 to 5.64. These peptide- and protein-silica monolithic stationary phases with typical HILIC separation behavior and chiral separation ability implied their promise for the analysis of not only the future metabolic studies, but also drug enantiomers recognition.

  9. Silica-based polypeptide-monolithic stationary phase for hydrophilic chromatography and chiral separation.

    Science.gov (United States)

    Zhao, Licong; Yang, Limin; Wang, Qiuquan

    2016-05-13

    Glutathione (GSH)-, somatostatin acetate (ST)- and ovomucoid (OV)-functionalized silica-monolithic stationary phases were designed and synthesized for HILIC and chiral separation using capillary electrochromatography (CEC). GSH, ST and OV were covalently incorporated into the silica skeleton via the epoxy ring-opening reaction between their amino groups and the glycidyl moiety in γ-glycidoxypropyltrimethoxysilane (GPTMS) together with polycondensation and copolymerization of tetramethyloxysilane and GPTMS. Not only could the direction and electroosmotic flow magnitude on the prepared GSH-, ST- and OV-silica hybrid monolithic stationary phases be controlled by the pH of the mobile phase, but also a typical HILIC behavior was observed so that the nucleotides and HPLC peptide standard mixture could be baseline separated using an aqueous mobile phase without any acetonitrile during CEC. Moreover, the prepared monolithic columns had a chiral separation ability to separate dl-amino acids. The OV-silica hybrid monolithic column was most effective in chiral separation and could separate dl-glutamic acid (Glu) (the resolution R=1.07), dl-tyrosine (Tyr) (1.57) and dl-histidine (His) (1.06). Importantly, the chiral separation ability of the GSH-silica hybrid monolithic column could be remarkably enhanced when using gold nanoparticles (AuNPs) to fabricate an AuNP-mediated GSH-AuNP-GSH-silica hybrid monolithic column. The R of dl-Glu, dl-Tyr and dl-His reached 1.19, 1.60 and 2.03. This monolithic column was thus applied to separate drug enantiomers, and quantitative separation of all four R/S drug enantiomers were achieved with R ranging from 4.36 to 5.64. These peptide- and protein-silica monolithic stationary phases with typical HILIC separation behavior and chiral separation ability implied their promise for the analysis of not only the future metabolic studies, but also drug enantiomers recognition. PMID:27083263

  10. Monolithic MACS micro resonators

    Science.gov (United States)

    Lehmann-Horn, J. A.; Jacquinot, J.-F.; Ginefri, J. C.; Bonhomme, C.; Sakellariou, D.

    2016-10-01

    Magic Angle Coil Spinning (MACS) aids improving the intrinsically low NMR sensitivity of heterogeneous microscopic samples. We report on the design and testing of a new type of monolithic 2D MACS resonators to overcome known limitations of conventional micro coils. The resonators' conductors were printed on dielectric substrate and tuned without utilizing lumped element capacitors. Self-resonance conditions have been computed by a hybrid FEM-MoM technique. Preliminary results reported here indicate robust mechanical stability, reduced eddy currents heating and negligible susceptibility effects. The gain in B1 /√{ P } is in agreement with the NMR sensitivity enhancement according to the principle of reciprocity. A sensitivity enhancement larger than 3 has been achieved in a monolithic micro resonator inside a standard 4 mm rotor at 500 MHz. These 2D resonators could offer higher performance micro-detection and ease of use of heterogeneous microscopic substances such as biomedical samples, microscopic specimens and thin film materials.

  11. Affinity Monolith-Integrated Microchips for Protein Purification and Concentration.

    Science.gov (United States)

    Gao, Changlu; Sun, Xiuhua; Wang, Huaixin; Qiao, Wei; Hu, Bo

    2016-01-01

    Affinity chromatography is a valuable method to purify and concentrate minute amount of proteins. Monoliths with epoxy groups for affinity immobilization were prepared by direct in-situ photopolymerization of glycidyl methacrylate and ethylene glycol dimethacrylate in porogenic solvents consisting of 1-dodecanol and cyclohexanol. By integrating affinity monoliths onto a microfluidic system, targeted biomolecules can be captured and retained on affinity column, while other biomolecules having no specific interactions toward the immobilized ligands flow through the microchannel. Therefore, proteins which remain on the affinity column are purified and concentrated, and then eluted by appropriate solutions and finally, separated by microchip capillary electrophoresis. This integrated microfluidic device has been applied to the purification and separation of specific proteins (FITC-labeled human serum albumin and IgG) in a mixture.

  12. Bioaffinity chromatography on monolithic supports

    NARCIS (Netherlands)

    Tetala, K.K.R.; Beek, van T.A.

    2010-01-01

    Affinity chromatography on monolithic supports is a powerful analytical chemical platform because it allows for fast analyses, small sample volumes, strong enrichment of trace biomarkers and applications in microchips. In this review, the recent research using monolithic materials in the field of bi

  13. Review of recent advances in the preparation of organic polymer monoliths for liquid chromatography of large molecules.

    Science.gov (United States)

    Arrua, R Dario; Talebi, Mohammad; Causon, Tim J; Hilder, Emily F

    2012-08-13

    In recent years the use of monolithic polymers in separation science has greatly increased due to the advantages these materials present over particle-based stationary phases, such as their relative ease of preparation and good permeability. For these reasons, these materials present high potential as stationary phases for the separation and purification of large molecules such as proteins, peptides, nucleic acids and cells. An example of this is the wide range of commercial available polymer-based monolithic columns now present in the market. This review summarizes recent developments in the synthesis of monolithic polymers for separation science, such as the incorporation of nanostructures in the polymeric scaffold as well as the preparation of hybrid structures. The different methods used in the surface functionalization of monolithic columns are also reviewed. Finally, we critically discuss the recent applications of this column technology in the separation of large molecules under different chromatographic mode. PMID:22790694

  14. 整体柱离子对色谱-紫外检测法快速测定对甲苯磺酸根%Rapid determination of p-toluenesulfonate using monolithic column ion-pair chromatography coupled with ultraviolet detection

    Institute of Scientific and Technical Information of China (English)

    李红杏; 于泓; 张于

    2014-01-01

    In this article,ion-pair chromatography with ultraviolet detection was used in the analysis of p-toluenesulfonate. The ana-lyte was separated using a mobile phase of tetrabutylammonium hydroxide( TBA)-citric acid-acetonitrile on a reversed-phase silica-based monolithic column. The ultraviolet detection wavelength,the composition of mobile phase,column temperature and flow rate on the ion retention and separation were investigated,retention rule was discussed. The chromatographic conditions were optimized:at 230 nm wavelength,when 0. 4 mmol·L-1 TBA-0. 13 mmol·L-1 citric acid-15%(v/v)acetonitrile(pH 5. 5)was used as mobile phase with column temperature of 40℃ and flow rate of 3. 0 mL·min-1 ,retention time of C7 H7 SO3-was less than 1. 25 min. Common inor-ganic anions( Cl-,NO3-) did not interfere with the determination. In the range of 0. 7-100 mg·L-1 ,the correlation coefficient of line-ar regression equation was 0. 9997. Relative standard deviation(RSD)of chromatographic peak area was 1. 0%(n=5). Detection limit(S/N=3)was 0. 2 mg·L-1. The method has been applied to the determination of p-toluenesulfonate ionic liquid samples syn-thesized by chemistry laboratory. Standard addition recovery rate was 101%. The method was simple and rapid.%研究了整体柱离子对色谱结合紫外检测的方法分析对甲苯磺酸根( C7 H7 SO3-)。采用反相硅胶整体柱,以氢氧化四丁基铵-柠檬酸-乙腈为流动相,考察了紫外检测波长、流动相组成、色谱柱温度和流速对离子保留的影响。色谱条件经过优化,在紫外检测波长230 nm,流动相为0.4 mmol·L-1氢氧化四丁基胺( TBA)-0.13 mmol·L-1柠檬酸-15%(v/v)乙腈(pH 5.5),流速3.0 mL·min-1,柱温40℃的条件下,C7H7SO3-的保留时间为1.25 min内。常见无机阴离子( Cl-,NO3-)不干扰测定。在0.7~100 mg·L-1范围内,线性回归方程的相关系数为0.9997,峰面积的相对标准偏差(RSD,n=5)为1.0%,检出限(S/N=3)为0.2 mg·L-1

  15. SOI monolithic pixel detector

    Science.gov (United States)

    Miyoshi, T.; Ahmed, M. I.; Arai, Y.; Fujita, Y.; Ikemoto, Y.; Takeda, A.; Tauchi, K.

    2014-05-01

    We are developing monolithic pixel detector using fully-depleted (FD) silicon-on-insulator (SOI) pixel process technology. The SOI substrate is high resistivity silicon with p-n junctions and another layer is a low resistivity silicon for SOI-CMOS circuitry. Tungsten vias are used for the connection between two silicons. Since flip-chip bump bonding process is not used, high sensor gain in a small pixel area can be obtained. In 2010 and 2011, high-resolution integration-type SOI pixel sensors, DIPIX and INTPIX5, have been developed. The characterizations by evaluating pixel-to-pixel crosstalk, quantum efficiency (QE), dark noise, and energy resolution were done. A phase-contrast imaging was demonstrated using the INTPIX5 pixel sensor for an X-ray application. The current issues and future prospect are also discussed.

  16. Organic monolith frits encased in polyether ether ketone tubing with improved durability for liquid chromatography.

    Science.gov (United States)

    Park, Sin Young; Cheong, Won Jo

    2015-09-01

    This study introduces a preparation method for polymer-encased monolith frits with improved durability for liquid chromatography columns. The inner surface of the polyether ether ketone tubing is pretreated with sulfuric acid in the presence of catalysts (vanadium oxide and sodium sulfate). The tubing was rinsed with water and acetone, flushed with nitrogen, and treated with glycidyl methacrylate. After washing, the monolith reaction mixture composed of lauryl methacrylate, ethylene glycol dimethacrylate, initiator, and porogenic solvent was filled in the tubing and subjected to in situ polymerization. The tubing was cut into thin slices and used as frits for microcolumns. To check their durability, the frit slices were placed in a vial and a heavy impact was applied on the vial by a vortex mixer for various periods. The frits made in the presence of catalysts were found to be more durable than those made without catalysts. Furthermore, when the monolith-incorporated tubing was used as a chromatography column, the column prepared in the presence of catalysts resulted in a better separation efficiency. The separation performance of the columns installed with the polyether ether ketone encased monolith frits was comparable to that of the columns installed with the commercial stainless-steel screen frits. PMID:26097071

  17. Optoelectronic devices toward monolithic integration

    Science.gov (United States)

    Ghergia, V.

    1992-12-01

    Starting from the present state of tl art of discrete devices up to the on going realization of monolithic semicorxtuctor integrated prototypes an overview ofoptoelectronic devices for telecom applications is given inchiding a short classification of the different kind of integrated devices. On the future perspective of IBCN distribution network some economica of hybrid and monolithic forms of integration are attempted. lnaflyashoitpresentationoftheactivitiesperformedintbefieldofmonolithic integration by EEC ESPR1T and RACE projects is reported. 1.

  18. Ground, sieved, and C18 modified monolithic silica particles for packing material of microcolumn high-performance liquid chromatography.

    Science.gov (United States)

    Ko, Joung Ho; Baik, Yoon Suk; Park, Seong Tae; Cheong, Won Jo

    2007-03-16

    We here report a new type of stationary phase for microcolumns. C18 modified silica monolith particles were prepared by grinding and sieving the silica monolith followed by C18 modification and end-capping, and were used as packing material. Ground silica monolith particles were not spherical but irregular with some residual monolithic network structure. The separation efficiency of the stationary phase made of sieved monolith particles (5-10 microm) was better than that of the stationary phase made of unsieved particles. The microcolumn packed with the sieved C18 ground monolith particles (5-10 microm) showed quite good separation efficiency (height equivalent to theoretical plate, HETP, as low as 15 microm) and it was even superior to the microcolumn packed with a commercial spherical 5 microm C18 stationary phase. The column pressure drop of C18 monolith particles was about two-third of that of the commercial spherical C18 phase. The preparation method of C18 stationary phase with ground and sieved silica monolith particles presumably suggests advantages of simplicity and convenience in modification and washing procedures compared to bulk silica monolith. It also showed both improved separation efficiency and low back pressure. PMID:17289065

  19. A monolithically-integrated μGC chemical sensor system.

    Science.gov (United States)

    Manginell, Ronald P; Bauer, Joseph M; Moorman, Matthew W; Sanchez, Lawrence J; Anderson, John M; Whiting, Joshua J; Porter, Daniel A; Copic, Davor; Achyuthan, Komandoor E

    2011-01-01

    Gas chromatography (GC) is used for organic and inorganic gas detection with a range of applications including screening for chemical warfare agents (CWA), breath analysis for diagnostics or law enforcement purposes, and air pollutants/indoor air quality monitoring of homes and commercial buildings. A field-portable, light weight, low power, rapid response, micro-gas chromatography (μGC) system is essential for such applications. We describe the design, fabrication and packaging of μGC on monolithically-integrated Si dies, comprised of a preconcentrator (PC), μGC column, detector and coatings for each of these components. An important feature of our system is that the same mechanical micro resonator design is used for the PC and detector. We demonstrate system performance by detecting four different CWA simulants within 2 min. We present theoretical analyses for cost/power comparisons of monolithic versus hybrid μGC systems. We discuss thermal isolation in monolithic systems to improve overall performance. Our monolithically-integrated μGC, relative to its hybrid cousin, will afford equal or slightly lower cost, a footprint that is 1/2 to 1/3 the size and an improved resolution of 4 to 25%. PMID:22163970

  20. A Monolithically-Integrated μGC Chemical Sensor System

    Directory of Open Access Journals (Sweden)

    Davor Copic

    2011-06-01

    Full Text Available Gas chromatography (GC is used for organic and inorganic gas detection with a range of applications including screening for chemical warfare agents (CWA, breath analysis for diagnostics or law enforcement purposes, and air pollutants/indoor air quality monitoring of homes and commercial buildings. A field-portable, light weight, low power, rapid response, micro-gas chromatography (μGC system is essential for such applications. We describe the design, fabrication and packaging of mGC on monolithically-integrated Si dies, comprised of a preconcentrator (PC, μGC column, detector and coatings for each of these components. An important feature of our system is that the same mechanical micro resonator design is used for the PC and detector. We demonstrate system performance by detecting four different CWA simulants within 2 min. We present theoretical analyses for cost/power comparisons of monolithic versus hybrid μGC systems. We discuss thermal isolation in monolithic systems to improve overall performance. Our monolithically-integrated μGC, relative to its hybrid cousin, will afford equal or slightly lower cost, a footprint that is 1/2 to 1/3 the size and an improved resolution of 4 to 25%.

  1. One-pot preparation of a novel monolith for high performance liquid chromatography applications.

    Science.gov (United States)

    Jiao, Xiaoyan; Shen, Shigang; Shi, Tiesheng

    2015-12-15

    Various novel porous organic-based monoliths with the mode of hydrophobicity were synthesized by in situ free-radical crosslinking copolymerization and optimized for the separations of small molecules and high-performance reversed-phase chromatography (RP-chromatography). These monoliths contained co-polymers based on glycidyl methacrylate (GMA)/ethylene glycol dimethacrylate (EDMA)/tripropylene glycol diacrylate (TPGDA) or EDMA/TPGDA. A mixture of cetanol, methanol and poly (ethylene glycol) (PEG) was used as the porogen, with the ratio of these solvents being varied along with the polymerization temperature to generate a library of monoliths. The conditions were optimized and the resulting poly (GMA-co-TPGDA-co-EDMA) monolith was investigated by infrared spectrometer (IR), field emission scanning electron microscope (FESEM), and mercury intrusion porosimetry (MIP), respectively. The column performance was assessed by the separation of a series of neutral solutes of benzene derivatives. The result demonstrated that the prepared monolith exhibited an RP-chromatographic behavior and relatively homogeneous structure, good permeability and separation performance. Moreover, the relative standard deviations (RSDs) of the retention factor values for benzene derivatives were less than 1.5% (n=7, column-to-column). The approach used in this study was extended to the separation of anilines.

  2. PULSE COLUMN

    Science.gov (United States)

    Grimmett, E.S.

    1964-01-01

    This patent covers a continuous countercurrent liquidsolids contactor column having a number of contactor states each comprising a perforated plate, a layer of balls, and a downcomer tube; a liquid-pulsing piston; and a solids discharger formed of a conical section at the bottom of the column, and a tubular extension on the lowest downcomer terminating in the conical section. Between the conical section and the downcomer extension is formed a small annular opening, through which solids fall coming through the perforated plate of the lowest contactor stage. This annular opening is small enough that the pressure drop thereacross is greater than the pressure drop upward through the lowest contactor stage. (AEC)

  3. Column: lef

    NARCIS (Netherlands)

    Reep, Frans van der

    2012-01-01

    1e alinea column: Ook in je beleggingsbeslissingen is het voor echte performance wellicht tijd om eens voorbij best practices (dan word je namelijk hoogstens tweede) te kijken naar next practices. Als je op zeker speelt, verdien je weinig geld. Want anderen gingen je al voor. Maar kun je nog meer op

  4. Monolithic afocal telescope

    Science.gov (United States)

    Roberts, William T. (Inventor)

    2010-01-01

    An afocal monolithic optical element formed of a shallow cylinder of optical material (glass, polymer, etc.) with fast aspheric surfaces, nominally confocal paraboloids, configured on the front and back surfaces. The front surface is substantially planar, and this lends itself to deposition of multi-layer stacks of thin dielectric and metal films to create a filter for rejecting out-of-band light. However, an aspheric section (for example, a paraboloid) can either be ground into a small area of this surface (for a Cassegrain-type telescope) or attached to the planar surface (for a Gregorian-type telescope). This aspheric section of the surface is then silvered to create the telescope's secondary mirror. The rear surface of the cylinder is figured into a steep, convex asphere (again, a paraboloid in the examples), and also made reflective to form the telescope's primary mirror. A small section of the rear surface (approximately the size of the secondary obscuration, depending on the required field of the telescope) is ground flat to provide an unpowered surface through which the collimated light beam can exit the optical element. This portion of the rear surface is made to transmit the light concentrated by the reflective surfaces, and can support the deposition of a spectral filter.

  5. Monolithic metal oxide transistors.

    Science.gov (United States)

    Choi, Yongsuk; Park, Won-Yeong; Kang, Moon Sung; Yi, Gi-Ra; Lee, Jun-Young; Kim, Yong-Hoon; Cho, Jeong Ho

    2015-04-28

    We devised a simple transparent metal oxide thin film transistor architecture composed of only two component materials, an amorphous metal oxide and ion gel gate dielectric, which could be entirely assembled using room-temperature processes on a plastic substrate. The geometry cleverly takes advantage of the unique characteristics of the two components. An oxide layer is metallized upon exposure to plasma, leading to the formation of a monolithic source-channel-drain oxide layer, and the ion gel gate dielectric is used to gate the transistor channel effectively at low voltages through a coplanar gate. We confirmed that the method is generally applicable to a variety of sol-gel-processed amorphous metal oxides, including indium oxide, indium zinc oxide, and indium gallium zinc oxide. An inverter NOT logic device was assembled using the resulting devices as a proof of concept demonstration of the applicability of the devices to logic circuits. The favorable characteristics of these devices, including (i) the simplicity of the device structure with only two components, (ii) the benign fabrication processes at room temperature, (iii) the low-voltage operation under 2 V, and (iv) the excellent and stable electrical performances, together support the application of these devices to low-cost portable gadgets, i.e., cheap electronics. PMID:25777338

  6. Assessment of the Grouted IXC Monolith in Support of K East Basin Hazard Categorization

    Energy Technology Data Exchange (ETDEWEB)

    Short, Steven M.; Dodson, Michael G.; Alzheimer, James M.; Meyer, Perry A.

    2007-10-12

    Addendum to original report updating the structural analysis of the I-beam accident to reflect a smaller I-beam than originally assumed (addendum is 2 pages). The K East Basin currently contains six ion exchange columns (IXCs) that were removed from service over 10 years ago. Fluor Hanford plans to immobilize the six ion exchange columns (IXCs) in place in a concrete monolith. PNNL performed a structural assessment of the concrete monolith to determine its capability to absorb the forces imposed by postulated accidents and protect the IXCs from damage and thus prevent a release of radioactive material. From this assessment, design specifications for the concrete monolith were identified that would prevent a release of radioactive material for any of the postulated hazardous conditions.

  7. Covalent attachment of polymeric monolith to polyether ether ketone (PEEK) tubing.

    Science.gov (United States)

    Lv, Chunguang; Heiter, Jaana; Haljasorg, Tõiv; Leito, Ivo

    2016-08-17

    A new method of reproducible preparation of vinylic polymeric monolithic columns with a key step of covalently anchoring the monolith to PEEK surface is described. In order to chemically attach the polymer monolith to the tube wall, methacrylate functional groups were introduced onto PEEK surface by a three-step procedure, including surface etching, surface reduction and surface methacryloylation. The chemical state of the modified tubing surface was characterized by attenuated total reflectance infrared (ATR-IR) spectroscopy. It was found that the etching step is the key to successfully modifying the PEEK tubing surface. Poly(styrene-co-divinylbenzene) monoliths were in situ synthesized by thermally initiated free radical copolymerization within the confines of surface-vinylized PEEK tubings of dimensions close to ones conventionally used in HPLC and UHPLC (1.6 mm internal diameter, 10.0-12.5 cm length). Adhesion test was done by measuring the operating pressure drop, which the prepared stationary phases can withstand. Good pressure resistance, up to 140 bar/10 cm (flow rate 0.5 mL min(-1), acetonitrile as a mobile phase), indicates strong bonding of monolith to the tubing wall. The monolithic material was proven to have a permeability of 1.7 × 10 (-14) m(2), applying acetonitrile-water 70:30 (v/v) as a mobile phase. The column performance was reproducible from column to column and was evaluated via the isocratic separation of a series of alkylbenzenes in the reversed-phase mode (acetonitrile-water 70:30, v/v). The numbers of plates per meter at optimal flow rate were found to be between 26 000 and 32 000 for the different analytes. PMID:27286776

  8. Enhancing the separation performance of the first-generation silica monolith using active flow technology: parallel segmented flow mode of operation.

    Science.gov (United States)

    Soliven, Arianne; Foley, Dominic; Pereira, Luisa; Dennis, Gary R; Shalliker, R Andrew; Cabrera, Karin; Ritchie, Harald; Edge, Tony

    2014-03-21

    Active flow technology (AFT) columns are designed to minimise inefficient flow processes associated with the column wall and radial heterogeneity of the stationary phase bed. This study is the first to investigate AFT on an analytical scale 4.6mm internal diameter first-generation silica monolith. The performance was compared to a conventional first-generation silica monolith and it was observed that the AFT monolith had an increase in efficiency values that ranged from 15 to 111%; the trend demonstrating efficiency gains increasing as the volumetric flow to the detector was decreased, but with no loss in sensitivity. PMID:24565232

  9. Influence of the linking spacer length and type on the enantioseparation ability of β-cyclodextrin functionalized monoliths.

    Science.gov (United States)

    Guo, Jialiang; Xiao, Yuan; Lin, Yuanjing; Zhang, Qiaoxuan; Chang, Yiqun; Crommen, Jacques; Jiang, Zhengjin

    2016-05-15

    In order to investigate the effect of the linking spacer on the enantioseparation ability of β-cyclodextrin (β-CD) functionalized polymeric monoliths, three β-CD-functionalized organic polymeric monoliths with different spacer lengths were prepared by using three amino-β-CDs, i.e. mono-6-amino-6-deoxy-β-CD, mono-6-ethylenediamine-6-deoxy-β-CD, mono-6-hexamethylenediamine-6-deoxy-β-CD, as starting materials. These amino-β-CDs reacted with glycidyl methacrylate to produce functional monomers which were then copolymerized with ethylene dimethacrylate. The enantioseparation ability of the three monoliths was evaluated using 14 chiral acidic compounds, including mandelic acid derivatives, nonsteroidal anti-inflammatory drugs, N-derivatized amino acids, and chiral herbicides under optimum chromatographic conditions. Notably, the poly(GMA-NH2-β-CD-co-EDMA) column provides higher enantioresolution and enantioselectivity than the poly(GMA-EDA-β-CD-co-EDMA) and poly(GMA-HDA-β-CD-co-EDMA) columns for most tested chiral analytes. Furthermore, the enantioseparation performance of triazole-linker containing monoliths was compared to that of ethylenediamine-linker containing monoliths. The results indicate that the enantioselectivity of β-CD monolithic columns is strongly related to the length and type of spacer tethering β-CD to the polymeric support. PMID:26992519

  10. Monolithic precolumns as efficient tools for guiding the design of nanoparticulate drug-delivery formulations.

    Science.gov (United States)

    Gatschelhofer, Christina; Prasch, Agnes; Buchmeiser, Michael R; Zimmer, Andreas; Wernig, Karin; Griesbacher, Martin; Pieber, Thomas R; Sinner, Frank M

    2012-09-01

    The development of nanomedicines for improved diagnosis and treatment of diseases is pushing current analytical methods to their limits. More efficient, quantitative high-throughput screening methods are needed to guide the optimization of promising nanoparticulate drug delivery formulations. In response to this need, we present herein a novel approach using monolithic separation media. The unique porosity of our capillary monolithic precolumns allows the direct injection and online removal of protamine-oligonucleotide nanoparticles ("proticles") without column clogging, thus avoiding the need for time-consuming off-line sample workup. Furthermore, ring-opening metathesis polymerization (ROMP)-derived monoliths show equivalent preconcentration efficiency for the target drug vasoactive intestinal peptide (VIP) as conventional particle-packed precolumns. The performance of the ROMP-derived monolithic precolumns was constant over at least 100 injections of crude proticle-containing and 300 injections of highly acidic samples. Applying a validated LC-MS/MS capillary monolithic column switching method, we demonstrate the rapid determination of both drug load and in vitro drug release kinetics of proticles within the critical first 2 h and investigate the stability of VIP-loaded proticles in aqueous storage medium intended for inhalation therapy.

  11. Preparation of porous polymer monoliths featuring enhanced surface coverage with gold nanoparticles

    KAUST Repository

    Lv, Yongqin

    2012-10-01

    A new approach to the preparation of porous polymer monoliths with enhanced coverage of pore surface with gold nanoparticles has been developed. First, a generic poly(glycidyl methacrylate-co-ethylene dimethacrylate) monolith was reacted with cystamine followed by the cleavage of its disulfide bonds with tris(2-carboxylethyl)phosphine, which liberated the desired thiol groups. Dispersions of gold nanoparticles with sizes varying from 5 to 40. nm were then pumped through the functionalized monoliths. The materials were then analyzed using both energy dispersive X-ray spectroscopy and thermogravimetric analysis. We found that the quantity of attached gold was dependent on the size of nanoparticles, with the maximum attachment of more than 60. wt% being achieved with 40. nm nanoparticles. Scanning electron micrographs of the cross sections of all the monoliths revealed the formation of a non-aggregated, homogenous monolayer of nanoparticles. The surface of the bound gold was functionalized with 1-octanethiol and 1-octadecanethiol, and these monolithic columns were used successfully for the separations of proteins in reversed phase mode. The best separations were obtained using monoliths modified with 15, 20, and 30. nm nanoparticles since these sizes produced the most dense coverage of pore surface with gold. © 2012 Elsevier B.V.

  12. Monolithic fiber optic sensor assembly

    Energy Technology Data Exchange (ETDEWEB)

    Sanders, Scott

    2015-02-10

    A remote sensor element for spectrographic measurements employs a monolithic assembly of one or two fiber optics to two optical elements separated by a supporting structure to allow the flow of gases or particulates therebetween. In a preferred embodiment, the sensor element components are fused ceramic to resist high temperatures and failure from large temperature changes.

  13. In situ Fabrication of Monolithic Copper Azide

    Science.gov (United States)

    Li, Bing; Li, Mingyu; Zeng, Qingxuan; Wu, Xingyu

    2016-04-01

    Fabrication and characterization of monolithic copper azide were performed. The monolithic nanoporous copper (NPC) with interconnected pores and nanoparticles was prepared by decomposition and sintering of the ultrafine copper oxalate. The preferable monolithic NPC can be obtained through decomposition and sintering at 400°C for 30 min. Then, the available monolithic NPC was in situ reacted with the gaseous HN3 for 24 h and the monolithic NPC was transformed into monolithic copper azide. Additionally, the copper particles prepared by electrodeposition were also reacted with the gaseous HN3 under uniform conditions as a comparison. The fabricated monolithic copper azide was characterized by Fourier transform infrared (FTIR), inductively coupled plasma-optical emission spectrometry (ICP-OES), and differential scanning calorimetry (DSC).

  14. Protective Skins for Aerogel Monoliths

    Science.gov (United States)

    Leventis, Nicholas; Johnston, James C.; Kuczmarski, Maria A.; Meador, Ann B.

    2007-01-01

    A method of imparting relatively hard protective outer skins to aerogel monoliths has been developed. Even more than aerogel beads, aerogel monoliths are attractive as thermal-insulation materials, but the commercial utilization of aerogel monoliths in thermal-insulation panels has been inhibited by their fragility and the consequent difficulty of handling them. Therefore, there is a need to afford sufficient protection to aerogel monoliths to facilitate handling, without compromising the attractive bulk properties (low density, high porosity, low thermal conductivity, high surface area, and low permittivity) of aerogel materials. The present method was devised to satisfy this need. The essence of the present method is to coat an aerogel monolith with an outer polymeric skin, by painting or spraying. Apparently, the reason spraying and painting were not attempted until now is that it is well known in the aerogel industry that aerogels collapse in contact with liquids. In the present method, one prevents such collapse through the proper choice of coating liquid and process conditions: In particular, one uses a viscous polymer precursor liquid and (a) carefully controls the amount of liquid applied and/or (b) causes the liquid to become cured to the desired hard polymeric layer rapidly enough that there is not sufficient time for the liquid to percolate into the aerogel bulk. The method has been demonstrated by use of isocyanates, which, upon exposure to atmospheric moisture, become cured to polyurethane/polyurea-type coats. The method has also been demonstrated by use of commercial epoxy resins. The method could also be implemented by use of a variety of other resins, including polyimide precursors (for forming high-temperature-resistant protective skins) or perfluorinated monomers (for forming coats that impart hydrophobicity and some increase in strength).

  15. Porous polymer monoliths functionalized through copolymerization of a C60 fullerene-containing methacrylate monomer for highly efficient separations of small molecules

    KAUST Repository

    Chambers, Stuart D.

    2011-12-15

    Monolithic poly(glycidyl methacrylate-co-ethylene dimethacrylate) and poly(butyl methacrylate-co-ethylene dimethacrylate) capillary columns, which incorporate the new monomer [6,6]-phenyl-C 61-butyric acid 2-hydroxyethyl methacrylate ester, have been prepared and their chromatographic performance have been tested for the separation of small molecules in the reversed phase. While addition of the C60-fullerene monomer to the glycidyl methacrylate-based monolith enhanced column efficiency 18-fold, to 85 000 plates/m at a linear velocity of 0.46 mm/s and a retention factor of 2.6, when compared to the parent monolith, the use of butyl methacrylate together with the carbon nanostructured monomer afforded monolithic columns with an efficiency for benzene exceeding 110 000 plates/m at a linear velocity of 0.32 mm/s and a retention factor of 4.2. This high efficiency is unprecedented for separations using porous polymer monoliths operating in an isocratic mode. Optimization of the chromatographic parameters affords near baseline separation of 6 alkylbenzenes in 3 min with an efficiency of 64 000 plates/m. The presence of 1 wt % or more of water in the polymerization mixture has a large effect on both the formation and reproducibility of the monoliths. Other factors such as nitrogen exposure, polymerization conditions, capillary filling method, and sonication parameters were all found to be important in producing highly efficient and reproducible monoliths. © 2011 American Chemical Society.

  16. 3D printed metal columns for capillary liquid chromatography.

    Science.gov (United States)

    Sandron, S; Heery, B; Gupta, V; Collins, D A; Nesterenko, E P; Nesterenko, P N; Talebi, M; Beirne, S; Thompson, F; Wallace, G G; Brabazon, D; Regan, F; Paull, B

    2014-12-21

    Coiled planar capillary chromatography columns (0.9 mm I.D. × 60 cm L) were 3D printed in stainless steel (316L), and titanium (Ti-6Al-4V) alloys (external dimensions of ~5 × 30 × 58 mm), and either slurry packed with various sized reversed-phase octadecylsilica particles, or filled with an in situ prepared methacrylate based monolith. Coiled printed columns were coupled directly with 30 × 30 mm Peltier thermoelectric direct contact heater/cooler modules. Preliminary results show the potential of using such 3D printed columns in future portable chromatographic devices. PMID:25285334

  17. Preparation of Silica Monoliths with Macropores and Mesopores and of High Specific Surface Area with Low Shrinkage using a Template Induced Method

    Energy Technology Data Exchange (ETDEWEB)

    Guo, Jianyu [Shanghai Normal Univ., Shanghai (China); Lu, Yan [Shanghai Institute of Technology, Shanghai (China); Whiting, Roger [AUT Univ., Auckland (New Zealand)

    2013-02-15

    In this study we report a new method for the synthesis of a silica monolithic column bed with bimodal pores (throughpores and mesopores). The template induced synthesis method was used to direct bimodal pores simultaneously instead of the usual post base-treating method. Block polymer Pluronic F127 was chosen as a dual-function template to form hierarchically porous silica monolith with both macropores and mesopores. This is a simplification of the method of monolithic column preparation. Poly(ethylene glycol) was used as a partial substitute for F127 can effectively prevent shrinkage during the monolith aging process without losing much surface area (944 m{sup 2}/g to 807 m{sup 2}/g). More importantly, the resultant material showed a much narrower mesopore size (centered at 6 nm) distribution than that made using only F127 as the template reagent, which helps the mass transfer process. The solvent washing method was used to remove the remaining organic template, and it was proved to be effective enough. The new synthesis method makes the fabrication of the silica monolithic column (especially capillary column) much easier. All the structure parameters indicate that monolith PFA05 prepared by the above method is a good material for separation, with the merits of much higher surface area than usual commercial HPLC silica particles, suitable mesopore volume, narrow mesopore size distribution, low shrinkage and it is easily prepared.

  18. Monolithic cell for frequency conversion

    International Nuclear Information System (INIS)

    We report the successful design, assembly, and operation of a single cell for frequency conversion of Nd:glass laser radiation from lambda = 1054 nm to lambda = 351 nm. Our approach combines the highly energy-efficient polarization mismatch scheme previously conceived and developed with the simplicity of the tandem crystal approach recently demonstrated. The resultant monolithic conversion cell consists of two KDP Type II crystals, assembled with tuning axes orthogonal and contained between a single pair of windows. An index-matching liquid is used to eliminate reflections from all internal surfaces. In this paper we describe a simple birefringence-sensitive method for marking and orienting circular doubler and mixer crystals with tuning axes orthogonal to better than 60 seconds of arc. The monolithic cell design is described, with emphasis on the chemical compatibility of component materials (crystals, spacers, seals, and metal surfaces) with index-matching liquids. A comparison between Halocarbon and Koolase index-matching fluids, after several months of operation (greater than 400 shots), shows the latter to exhibit better long-term, photochemical stability. The performance of the monolithic cell is superior to that of separate doubler and mixer cells. It exhibits better long-term pointing stability and produces a cleaner 3 #betta# beam

  19. Synthesis of high porosity, monolithic alumina aerogels

    Energy Technology Data Exchange (ETDEWEB)

    Poco, J F; Satcher, J H; Hrubesh, L W

    2000-09-20

    Many non-silica aerogels are notably weak and fragile in monolithic form. Particularly, few monolithic aerogels with densities less than 50kg/m3 have any significant strength. It is especially difficult to prepare uncracked monoliths of pure alumina aerogels that are robust and moisture stable. In this paper, we discuss the synthesis of strong, stable, monolithic, high porosity (>98% porous) alumina aerogels, using a two-step sol-gel process. The alumina aerogels have a polycrystalline morphology that results in enhanced physical properties. Most of the measured physical properties of the alumina aerogels are superior to those for silica aerogels for equivalent densities.

  20. Interactions of bupivacaine with a molecularly imprinted polymer in a monolithic format studied by NMR.

    Science.gov (United States)

    Courtois, Julien; Fischer, Gerd; Schauff, Siri; Albert, Klaus; Irgum, Knut

    2006-01-15

    A trimethylolpropane trimethacrylate-based monolith of dimensions carefully chosen to fit exactly in a standard 4-mm solid-state CP/MAS NMR rotor was photopolymerized and subsequently molecularly imprinted with bupivacaine using a grafting protocol with methacrylic acid and ethylene dimethacrylate as monomers. As no crushing or grinding of the monolith was necessary, additional unspecific surface area was not created. This procedure ascertains that differences observed between imprinted and nonimprinted polymers are due only to graft imprinted surfaces and give therefore better results in NMR spectroscopy due to less unspecific interactions between analyte and monolith. This improves the comparability to chromatographic evaluations where uncrushed monolithic columns are also used. To track interactions between analyte and stationary phase, the saturation transfer difference (STD) technique was applied on the polymer in the suspended state using the same solvent as in the chromatographic evaluation. This relatively new NMR method has to our knowledge not been used on chromatographic materials before. By using STD NMR on pristine monoliths, it was possible to measure large differences between the imprinted or nonimprinted polymers and the analyte indicating significant differences in the interaction mechanisms. These could be directly correlated with retention differences observed in chromatographic evaluations. PMID:16408943

  1. Characterization of polymer monoliths containing embedded nanoparticles by scanning transmission X-ray microscopy (STXM).

    Science.gov (United States)

    Arrua, R Dario; Hitchcock, Adam P; Hon, Wei Boon; West, Marcia; Hilder, Emily F

    2014-03-18

    The structural and chemical homogeneity of monolithic columns is a key parameter for high efficiency stationary phases in liquid chromatography. Improved characterization techniques are needed to better understand the polymer morphology and its optimization. Here the analysis of polymer monoliths by scanning transmission X-ray microscopy (STXM) is presented for the first time. Poly(butyl methacrylate-co-ethyleneglycoldimethacrylate) [poly(BuMA-co-EDMA)] monoliths containing encapsulated divinylbenzene (DVB) nanoparticles were characterized by STXM, which gives a comprehensive, quantitative chemical analysis of the monolith at a spatial resolution of 30 nm. The results are compared with other methods commonly used for the characterization of polymer monoliths [scanning electron microscopy (SEM), transmission electron microscopy (TEM), mercury porosimetry, and nitrogen adsorption]. The technique permitted chemical identification and mapping of the nanoparticles within the polymeric scaffold. Residual surfactant, which was used during the manufacture of the nanoparticles, was also detected. We show that STXM can give more in-depth chemical information for these types of materials and therefore lead to a better understanding of the link between polymer morphology and chromatographic performance.

  2. Determination of azithromycin residue in pork using a molecularly imprinted monolithic microcolumn coupled to liquid chromatography with tandem mass spectrometry.

    Science.gov (United States)

    Zhou, Tong; Yang, Haicui; Jin, Zhen; Liu, Qingying; Song, Xuqin; He, Limin; Fang, Binghu; Meng, Chenying

    2016-04-01

    Using spiramycin as a dummy template, a molecularly imprinted polymer monolithic micro-column with high selection to azithromycin was prepared in a micropipette tip. The imprinting factor of the monolithic micro-column prepared was approximately 2.67 and the morphological structure of the polymers was characterized by scanning electron microscopy. A simple, sensitive, and reproducible method based on the imprinted monolithic micro-column coupled to liquid chromatography with tandem mass spectrometry was developed for determining the residues of azithromycin in pork. Pork samples were extracted with acetonitrile, cleaned up under the optimal monolithic micro-column conditions, and analyzed using liquid chromatography with tandem mass spectrometry in the multiple reaction monitoring mode. The assay exhibited a linear dynamic range of 0.50-50 μg/L with the correlation coefficient (r(2) ) above 0.99. In the three spiking levels of 0.50, 1.0, and 10 μg/kg, the average recoveries of azithromycin from pork samples were between 85.8 and 96.5% with a relative standard deviation below 10%. The limit of detection and limit of quantitation were 0.03 and 0.1 μg/kg, respectively. PMID:26854282

  3. Monolithically integrated absolute frequency comb laser system

    Energy Technology Data Exchange (ETDEWEB)

    Wanke, Michael C.

    2016-07-12

    Rather than down-convert optical frequencies, a QCL laser system directly generates a THz frequency comb in a compact monolithically integrated chip that can be locked to an absolute frequency without the need of a frequency-comb synthesizer. The monolithic, absolute frequency comb can provide a THz frequency reference and tool for high-resolution broad band spectroscopy.

  4. Adsorption over polyacrylonitrile based carbon monoliths

    Science.gov (United States)

    Nandi, Mahasweta; Dutta, Arghya; Patra, Astam Kumar; Bhaumik, Asim; Uyama, Hiroshi

    2013-02-01

    Highly porous activated carbon monoliths have been prepared from mesoporous polyacrylonitrile (PAN) monolith as the carbon precursor. The mesoporous PAN monoliths are fabricated by a unique and facile template-free method which on carbonization gives N-doped activated carbon monoliths. The carbonization is achieved via two step thermal process which includes pretreatment in air leading to cyclization and subsequent aromatization of the PAN moieties followed by carbonization in a mixture of argon and carbon dioxide to give a layered carbon framework. Nitrogen sorption experiments carried over these carbon monoliths revealed high surface area (ca. 2500 m2g-1) for these materials with precise micropore size distribution. The activated carbons show extraordinarily high CO2 capture capacity and the uptake up to 3 bar has been found to be as high as 22.5 and 10.6 mmol/g at 273 K and 298 K, respectively.

  5. Assessment of dynamic surface leaching of monolithic surface road materials.

    Science.gov (United States)

    Paulus, Hélène; Schick, Joachim; Poirier, Jean-Eric

    2016-07-01

    Construction materials have to satisfy, among others, health and environment requirements. To check the environmental compatibility of road construction materials, release of hazardous substances into water must be assessed. Literature mostly describes the leaching behaviour of recycled aggregates for potential use in base or sub-base layers of roads. But little is known about the release of soluble substances by materials mixed with binders and compacted for intended use on road surface. In the present study, we thus performed a diffusion test with sequential renewal of water during a 64 day period according to CEN/TS 16637-2 specifications, on asphalt concretes and hydraulically bound monoliths, two common surface road materials. It is shown that release of dangerous substances is limited in these hydrodynamic conditions. It was particularly true for asphalt concrete leachates where no metallic trace element, sulphate, chloride or fluoride ion could be quantified. This is because of the low hydraulic conductivity and the low polarity of the petroleum hydrocarbon binder of these specimens. For hydraulically bound materials around 20,000 mg/m(2) of sulphate diffused from the monoliths. It is one order of magnitude higher than chloride diffusion and two orders of magnitude higher than fluoride release. No metallic trace element, except small quantities of copper in the last eluate could be quantified. No adverse effect is to be expected for human and environmental health from the leachates of these compacted surface road construction materials, because all the measured parameters were below EU (Council Directive 98/83/EC) or WHO guidelines for drinking water standards. PMID:27039367

  6. Microfluidic devices and methods including porous polymer monoliths

    Science.gov (United States)

    Hatch, Anson V; Sommer, Gregory J; Singh, Anup K; Wang, Ying-Chih; Abhyankar, Vinay V

    2014-04-22

    Microfluidic devices and methods including porous polymer monoliths are described. Polymerization techniques may be used to generate porous polymer monoliths having pores defined by a liquid component of a fluid mixture. The fluid mixture may contain iniferters and the resulting porous polymer monolith may include surfaces terminated with iniferter species. Capture molecules may then be grafted to the monolith pores.

  7. Monolithic Continuous-Flow Bioreactors

    Science.gov (United States)

    Stephanopoulos, Gregory; Kornfield, Julia A.; Voecks, Gerald A.

    1993-01-01

    Monolithic ceramic matrices containing many small flow passages useful as continuous-flow bioreactors. Ceramic matrix containing passages made by extruding and firing suitable ceramic. Pores in matrix provide attachment medium for film of cells and allow free movement of solution. Material one not toxic to micro-organisms grown in reactor. In reactor, liquid nutrients flow over, and liquid reaction products flow from, cell culture immobilized in one set of channels while oxygen flows to, and gaseous reaction products flow from, culture in adjacent set of passages. Cells live on inner surfaces containing flowing nutrient and in pores of walls of passages. Ready access to nutrients and oxygen in channels. They generate continuous high yield characteristic of immobilized cells, without large expenditure of energy otherwise incurred if necessary to pump nutrient solution through dense biomass as in bioreactors of other types.

  8. Anisotropically structured magnetic aerogel monoliths

    Science.gov (United States)

    Heiligtag, Florian J.; Airaghi Leccardi, Marta J. I.; Erdem, Derya; Süess, Martin J.; Niederberger, Markus

    2014-10-01

    Texturing of magnetic ceramics and composites by aligning and fixing of colloidal particles in a magnetic field is a powerful strategy to induce anisotropic chemical, physical and especially mechanical properties into bulk materials. If porosity could be introduced, anisotropically structured magnetic materials would be the perfect supports for magnetic separations in biotechnology or for magnetic field-assisted chemical reactions. Aerogels, combining high porosity with nanoscale structural features, offer an exceptionally large surface area, but they are difficult to magnetically texture. Here we present the preparation of anatase-magnetite aerogel monoliths via the assembly of preformed nanocrystallites. Different approaches are proposed to produce macroscopic bodies with gradient-like magnetic segmentation or with strongly anisotropic magnetic texture.Texturing of magnetic ceramics and composites by aligning and fixing of colloidal particles in a magnetic field is a powerful strategy to induce anisotropic chemical, physical and especially mechanical properties into bulk materials. If porosity could be introduced, anisotropically structured magnetic materials would be the perfect supports for magnetic separations in biotechnology or for magnetic field-assisted chemical reactions. Aerogels, combining high porosity with nanoscale structural features, offer an exceptionally large surface area, but they are difficult to magnetically texture. Here we present the preparation of anatase-magnetite aerogel monoliths via the assembly of preformed nanocrystallites. Different approaches are proposed to produce macroscopic bodies with gradient-like magnetic segmentation or with strongly anisotropic magnetic texture. Electronic supplementary information (ESI) available: Digital photographs of dispersions and gels with different water-to-ethanol ratios; magnetic measurements of an anatase aerogel containing 0.25 mol% Fe3O4 nanoparticles; XRD patterns of the iron oxide and

  9. Monolithic Time Delay Integrated APD Arrays Project

    Data.gov (United States)

    National Aeronautics and Space Administration — The overall goal of the proposed program by Epitaxial Technologies is to develop monolithic time delay integrated avalanche photodiode (APD) arrays with sensitivity...

  10. Activated carbon monoliths for methane storage

    Science.gov (United States)

    Chada, Nagaraju; Romanos, Jimmy; Hilton, Ramsey; Suppes, Galen; Burress, Jacob; Pfeifer, Peter

    2012-02-01

    The use of adsorbent storage media for natural gas (methane) vehicles allows for the use of non-cylindrical tanks due to the decreased pressure at which the natural gas is stored. The use of carbon powder as a storage material allows for a high mass of methane stored for mass of sample, but at the cost of the tank volume. Densified carbon monoliths, however, allow for the mass of methane for volume of tank to be optimized. In this work, different activated carbon monoliths have been produced using a polymeric binder, with various synthesis parameters. The methane storage was studied using a home-built, dosing-type instrument. A monolith with optimal parameters has been fabricated. The gravimetric excess adsorption for the optimized monolith was found to be 161 g methane for kg carbon.

  11. Monolithic multinozzle emitters for nanoelectrospray mass spectrometry

    Science.gov (United States)

    Wang, Daojing; Yang, Peidong; Kim, Woong; Fan, Rong

    2011-09-20

    Novel and significantly simplified procedures for fabrication of fully integrated nanoelectrospray emitters have been described. For nanofabricated monolithic multinozzle emitters (NM.sup.2 emitters), a bottom up approach using silicon nanowires on a silicon sliver is used. For microfabricated monolithic multinozzle emitters (M.sup.3 emitters), a top down approach using MEMS techniques on silicon wafers is used. The emitters have performance comparable to that of commercially-available silica capillary emitters for nanoelectrospray mass spectrometry.

  12. Monolithically integrated waveguide-coupled silica microtoroids

    CERN Document Server

    Richter, Jens; Witzens, Jeremy

    2015-01-01

    We report on the design and fabrication of a new type of microtoroid high-Q silica resonators monolithically coupled to on-chip silicon nanowire waveguides. In order to enable monolithic waveguide coupling, the microtoroid geometry is inverted such that the resonator is formed by thermal reflow at the circumference of a hole etched in a suspended SiO2 membrane. This configuration is shown to be conducive to integration with a fully functional Silicon Photonics technology platform.

  13. Monolithic JFET preamplifier for ionization chamber calorimeter

    International Nuclear Information System (INIS)

    A monolithic charge sensitive preamplifier using exclusively n-channel diffused JFETs has been designed and is now being fabricated by INTERFET Corp. by means of a dielectrically isolated process which allows preserving as much as possible the technology upon which discrete JFETs are based. A first prototype built by means of junction isolated process has been delivered. The characteristics of monolithically integrated JFETs compare favorably with discrete devices. First results of tests of a preamplifier which uses these devices are reported

  14. Preparation of a thermoresponsive polymer grafted polystyrene monolithic capillary for the separation of bioactive compounds.

    Science.gov (United States)

    Koriyama, Takuya; Asoh, Taka-Aki; Kikuchi, Akihiko

    2016-11-01

    To develop aqueous microseparation columns for bioactive compounds, a thermoresponsive polymer grafted polymer monolith was prepared inside silica capillaries having an I.D. of 100μm by polymerization of styrene (St) with m/p-divinylbenzene (DVB) in the presence of polydimethylsiloxane as porogen, followed by surface-initiated atom transfer radical polymerization (SI-ATRP) of N-isopropylacrylamide (NIPAAm). SEM analysis indicated that the resulting poly(N-isopropylacrylamide) (PNIPAAm) grafted polystyrene monolith had a consecutive three-dimensionally interconnected structure and through-pores, similar to the base polystyrene (PSt) monolith. The elution behavior of steroids with different hydrophobicity was evaluated using micro-high-performance liquid chromatography in sole aqueous mobile phase. Temperature dependent interaction changes were observed between steroids and the PNIPAAm modified surfaces. Furthermore, the interaction between bioactive compounds and the PNIPAAm grafted PSt surfaces was controlled and eventually separate these molecules with different hydrophobicities by simple temperature modulation in aqueous environment. The PNIPAAm grafted PSt monolithic capillary showed improved separation properties of bioactive compounds, compared with a PNIPAAm grafted hollow capillary in aqueous environment.

  15. Methacrylate Polymer Monoliths for Separation Applications

    Directory of Open Access Journals (Sweden)

    Robert J. Groarke

    2016-06-01

    Full Text Available This review summarizes the development of methacrylate-based polymer monoliths for separation science applications. An introduction to monoliths is presented, followed by the preparation methods and characteristics specific to methacrylate monoliths. Both traditional chemical based syntheses and emerging additive manufacturing methods are presented along with an analysis of the different types of functional groups, which have been utilized with methacrylate monoliths. The role of methacrylate based porous materials in separation science in industrially important chemical and biological separations are discussed, with particular attention given to the most recent developments and challenges associated with these materials. While these monoliths have been shown to be useful for a wide variety of applications, there is still scope for exerting better control over the porous architectures and chemistries obtained from the different fabrication routes. Conclusions regarding this previous work are drawn and an outlook towards future challenges and potential developments in this vibrant research area are presented. Discussed in particular are the potential of additive manufacturing for the preparation of monolithic structures with pre-defined multi-scale porous morphologies and for the optimization of surface reactive chemistries.

  16. Ionic liquids as porogens in the microwave-assisted synthesis of methacrylate monoliths for chromatographic application

    Energy Technology Data Exchange (ETDEWEB)

    Singco, Brenda; Lin, Chen-Lan; Cheng, Yi-Jie; Shih, Yung-Han [Department of Chemistry and Center for Nanotechnology, CYCU (Chung Yuan Christian University), 200 Chung Pei Road, Chung-Li 320, Taiwan (China); Huang, Hsi-Ya, E-mail: hyhuang@cycu.edu.tw [Department of Chemistry and Center for Nanotechnology, CYCU (Chung Yuan Christian University), 200 Chung Pei Road, Chung-Li 320, Taiwan (China)

    2012-10-09

    Highlights: Black-Right-Pointing-Pointer An efficient and cleaner monoliths preparation utilizing ionic liquids in conjunction with microwave Black-Right-Pointing-Pointer These ionic liquids with varied cation alkyl chain and anion type successfully tuned the morphology of different alkyl methacrylates Black-Right-Pointing-Pointer Small molecules and peptide digests separated well in these monoliths. - Abstract: Several imidazolium-based ionic liquids (ILs) with varying cation alkyl chain length (C{sub 4}-C{sub 10}) and anion type (tetrafluoroborate ([BF{sub 4}]{sup -}), hexafluorophosphate ([PF{sub 6}]{sup -}) and bis(trifluoromethylsulfonyl)imide ([Tf{sub 2}N]{sup -})) were used as reaction media in the microwave polymerization of methacrylate-based stationary phases. Scanning electron micrographs and backpressures of poly(butyl methacrylate-ethylene dimethacrylate) (poly(BMA-EDMA)) monoliths synthesized in the presence of these ionic liquids demonstrated that porosity and permeability decreased when cation alkyl chain length and anion hydrophobicity were increased. Performance of these monoliths was assessed for their ability to separate parabens by capillary electrochromatography (CEC). Intra-batch precision (n = 3 columns) for retention time and peak area ranged was 0.80-1.13% and 3.71-4.58%, respectively. In addition, a good repeatability of RSD{sub Retentiontime} = <0.30% and {approx}1.0%, RSD{sub Peakarea} = <1.30% and <4.3%, and RSD{sub Efficiency} = <0.6% and <11.5% for intra-day and inter-day, respectively exemplify monolith performance reliability for poly(BMA-EDMA) fabricated using 1-hexyl-3-methylimidazolium tetrafluoroborate ([C{sub 6}mim][BF{sub 4}]) porogen. This monolith was also tested for its potential in nanoLC to separate protein digests in gradient mode. ILs as porogens also fabricated different alkyl methacrylate (AMA) (C4-C18) monoliths. Furthermore, employing binary IL porogen mixture such as 1-butyl-3-methylimidazolium tetrafluoroborate

  17. Column Liquid Chromatography.

    Science.gov (United States)

    Majors, Ronald E.; And Others

    1984-01-01

    Reviews literature covering developments of column liquid chromatography during 1982-83. Areas considered include: books and reviews; general theory; columns; instrumentation; detectors; automation and data handling; multidimensional chromatographic and column switching techniques; liquid-solid chromatography; normal bonded-phase, reversed-phase,…

  18. Chloride ingress prediction

    DEFF Research Database (Denmark)

    Frederiksen, Jens Mejer; Geiker, Mette Rica

    2008-01-01

    Prediction of chloride ingress into concrete is an important part of durability design of reinforced concrete structures exposed to chloride containing environment. This paper presents experimentally based design parameters for Portland cement concretes with and without silica fume and fly ash in...

  19. Multiplexing strategies for monolithic crystal PET detector modules

    International Nuclear Information System (INIS)

    To reduce the number of output channels and associated cost in PET detectors, strategies to multiplex the signal channels have been investigated by several researchers. This work aims to find an optimal multiplexing strategy for detector modules consisting of a monolithic LYSO scintillator coupled to a 64-channel PMT. We apply simulated multiplexing strategies to measured data from two continuous miniature crystal element (cMiCE) detector modules. The strategies tested include standard methods such as row column summation and its variants, as well as new data-driven methods involving the principal components of measured data and variants of those components. The detector positioning resolution and bias are measured for each multiplexing strategy and the results are compared. The mean FWHM over the entire detector was 1.23 mm for no multiplexing (64 channels). Using 16 principal component channels yielded a mean FWHM resolution of 1.21 mm, while traditional row/column summation (16 channels) yielded 1.28 mm. Using 8 principal component output channels resulted in a resolution of 1.30 mm. Using the principal components of the calibration data to guide the multiplexing scheme appears to be a viable method for reducing the number of output data channels. Further study is needed to determine if the depth-of-interaction resolution can be preserved with this multiplexing scheme. (paper)

  20. Chloride ingress prediction

    DEFF Research Database (Denmark)

    Frederiksen, Jens Mejer; Geiker, Mette Rica

    2008-01-01

    makes physical sense for the design engineer, i.e. the achieved chloride diffusion coefficients at 1 year and 100 years, D1 and D100 respectively, and the corresponding achieved chloride concentrations at the exposed concrete surface, C1 and C100. Data from field exposure supports the assumption of time...... dependent surface chloride concentrations and the diffusion coefficients. Model parameters for Portland cement concretes with and without silica fume and fly ash in marine atmospheric and submerged South Scandinavian environment are suggested in a companion paper based on 10 years field exposure data....

  1. N,N-Dimethyldehydroabietylammonium chloride ethanol monosolvate

    Directory of Open Access Journals (Sweden)

    Xiu-Zhi Huang

    2013-06-01

    Full Text Available The title compound {systematic name: 1-[(1R,4aS,10aR-7-isopropyl-1,4a-dimethyl-1,2,3,4,4a,9,10,10a-octahydrophenanthren-1-yl]-N,N-dimethylmethanaminium chloride ethanol monosolvate}, C22H36N+·Cl−·C2H6O, was synthesized from dehydroabietylamine by N-methylation with formaldehyde/formic acid and transformation into the hydrochloride. The dehydroabietyl moiety exhibits the usual conformation with the two cyclohexane rings in chair and half-chair conformations and a trans-ring junction. The crystal structure is built up from columns of the dehydroabietyl moieties stacked along the a axis. These columns are held together by the chloride ions via N—H...Cl and C—H...Cl interactions, which establish a two-dimensional network parallel to (010. The ethanol solvent molecules are located between the columns and anchored via O—H...Cl hydrogen bonds.

  2. Open cycle lithium chloride cooling system

    Science.gov (United States)

    Lenz, T. G.; Loef, G. O. G.; Iyer, R.; Wenger, J.

    1983-05-01

    A lithium chloride open cycle absorption chiller has been designed, built and tested. Solution reconcentration takes place in a small counter current packed column supplied with solar heated air. Removal of noncondensable gases that enter the chiller dissolved in the strong solution and the make-up refrigerant streams is accomplished by a liquid-jet ejector and a small vacuum pump. Cooling capacities approaching 1.4 tons and COP levels of 0.58 have been achieved at non-optimum operating conditions. Test results from preliminary system operation suggest that mass transfer processes in both the packed column reconcentrator and the absorber are controlled by concentration gradients in the lithium chloride solution. Liquid phase controlled mass transfer dictates an operating strategy different from the previously assumed gas phase controlled process to obtain maximum rates of evaporation in the packed column. Determination of optimal operating conditions leading to decreased electrical power consumption and improved cooling capacity and coefficient of performance will require further analysis and testing.

  3. Fracture resistance of monolithic zirconia molar crowns with reduced thickness

    OpenAIRE

    Nakamura, Keisuke; Harada, A.; Inagaki, R.; Kanno, Taro; Niwano, Y; Milleding, Percy; Ørtengren, Ulf Thore

    2015-01-01

    Objectives. The purpose of the present study was to analyze the relationship between fracture load of monolithic zirconia crowns and axial/occlusal thickness, and to evaluate the fracture resistance of monolithic zirconia crowns with reduced thickness in comparison with that of monolithic lithium disilicate crowns with regular thickness. Materials and methods. Monolithic zirconia crowns (Lava Plus Zirconia, 3M/ESPE) with specified axial/occlusal thicknesses and lithium disilica...

  4. Carbon Fiber Composite Monoliths as Catalyst Supports

    Energy Technology Data Exchange (ETDEWEB)

    Contescu, Cristian I [ORNL; Gallego, Nidia C [ORNL; Pickel, Joseph M [ORNL; Blom, Douglas Allen [ORNL; Burchell, Timothy D [ORNL

    2006-01-01

    Carbon fiber composite monoliths are rigid bodies that can be activated to a large surface area, have tunable porosity, and proven performance in gas separation and storage. They are ideal as catalyst supports in applications where a rigid support, with open structure and easy fluid access is desired. We developed a procedure for depositing a dispersed nanoparticulate phase of molybdenum carbide (Mo2C) on carbon composite monoliths in the concentration range of 3 to 15 wt% Mo. The composition and morphology of this phase was characterized using X-ray diffraction and electron microscopy, and a mechanism was suggested for its formation. Molybdenum carbide is known for its catalytic properties that resemble those of platinum group metals, but at a lower cost. The materials obtained are expected to demonstrate catalytic activity in a series of hydrocarbon reactions involving hydrogen transfer. This project demonstrates the potential of carbon fiber composite monoliths as catalyst supports.

  5. Carbon Fiber Composite Monoliths for Catalyst Supports

    Energy Technology Data Exchange (ETDEWEB)

    Contescu, Cristian I [ORNL; Gallego, Nidia C [ORNL; Pickel, Joseph M [ORNL; Blom, Douglas Allen [ORNL; Burchell, Timothy D [ORNL

    2006-01-01

    Carbon fiber composite monoliths are rigid bodies that can be activated to a large surface area, have tunable porosity, and proven performance in gas separation and storage. They are ideal as catalyst supports in applications where a rigid support, with open structure and easy fluid access is desired. We developed a procedure for depositing a dispersed nanoparticulate phase of molybdenum carbide (Mo2C) on carbon composite monoliths in the concentration range of 3 to 15 wt% Mo. The composition and morphology of this phase was characterized using X-ray diffraction and electron microscopy, and a mechanism was suggested for its formation. Molybdenum carbide is known for its catalytic properties that resemble those of platinum group metals, but at a lower cost. The materials obtained are expected to demonstrate catalytic activity in a series of hydrocarbon reactions involving hydrogen transfer. This project demonstrates the potential of carbon fiber composite monoliths as catalyst supports.

  6. Increased thermal conductivity monolithic zeolite structures

    Science.gov (United States)

    Klett, James; Klett, Lynn; Kaufman, Jonathan

    2008-11-25

    A monolith comprises a zeolite, a thermally conductive carbon, and a binder. The zeolite is included in the form of beads, pellets, powders and mixtures thereof. The thermally conductive carbon can be carbon nano-fibers, diamond or graphite which provide thermal conductivities in excess of about 100 W/mK to more than 1,000 W/mK. A method of preparing a zeolite monolith includes the steps of mixing a zeolite dispersion in an aqueous colloidal silica binder with a dispersion of carbon nano-fibers in water followed by dehydration and curing of the binder is given.

  7. UPDATE ON MONOLITHIC FUEL FABRICATION METHODS

    Energy Technology Data Exchange (ETDEWEB)

    C. R. Clark; J. F. Jue; G. A. Moore; N. P. Hallinan; B. H. Park; D. E. Burkes

    2006-10-01

    Efforts to develop a viable monolithic research reactor fuel plate have continued at Idaho National Laboratory. These efforts have concentrated on both fabrication process refinement and scale-up to produce full sized fuel plates. Progress at INL has led to fabrication of hot isostatic pressed uranium-molybdenum bearing monolithic fuel plates. These miniplates are part of the RERTR-8 miniplate irradiation test. Further progress has also been made on friction stir weld processing which has been used to fabricate full size fuel plates which will be irradiated in the ATR and OSIRIS reactors.

  8. Monolithic JFET preamplifier for ionization chamber calorimeter

    International Nuclear Information System (INIS)

    A monolithic charge sensitive preamplifier using exclusively n-channel diffused JFETs has been designed and is now being fabricated by INTERFET Corp. by means of a dielectrically isolated process which allows preserving as much as possible the technology upon which discrete JFETs are based. A first prototype built by means of junction isolated process has been delivered. The characteristics of monolithically integrated JFETs compare favorably with discrete devices. First results of tests of a preamplifier which uses these devices are reported. 4 refs

  9. Gold nanoparticles immobilized hydrophilic monoliths with variable functional modification for highly selective enrichment and on-line deglycosylation of glycopeptides.

    Science.gov (United States)

    Liang, Yu; Wu, Ci; Zhao, Qun; Wu, Qi; Jiang, Bo; Weng, Yejing; Liang, Zhen; Zhang, Lihua; Zhang, Yukui

    2015-11-01

    The poly (glycidyl methacrylate-co-poly (ethylene glycol) diacrylate) monoliths modified with gold nanoparticles, with advantages of enhanced reactive sites, good hydrophilicity and facile modification, were prepared as the matrix, followed by variable functionalization with cysteine and PNGase F for glycopeptide enrichment and on-line deglycosylation respectively. By the cysteine functionalized monolithic column, glycopeptides could be efficiently and selectively enriched with good reproducibility based on hydrophilic interaction chromatography (HILIC). Furthermore, the enrichment was specially achieved in weak alkaline environment, with 10 mM NH4HCO3 as the elution buffer, compatible with deglycosylation conditions. Therefore, the glycopeptides could be on-line deglycosylated with high efficiency and throughput by directly coupling the PNGase F functionalized monolithic column with the enrichment column during elution without the requirement of buffer exchange and pH adjustment. By such a method, within only 70-min pretreatment, 196 N-linked glycopeptides, corresponding to 122 glycoproteins, could be identified from 5 μg of human plasma with 14 high-abundant proteins removed, and the N-linked glycopeptides occupied 81% of all identified peptides, achieving to the best of our knowledge, the highest selectivity of HILIC-based methods. All the results demonstrated the high efficiency, selectivity and throughput of our proposed strategy for the large scale glycoproteome analysis. PMID:26572842

  10. Immobilized enzyme reactor chromatography: Optimization of protein retention and enzyme activity in monolithic silica stationary phases

    Energy Technology Data Exchange (ETDEWEB)

    Besanger, Travis R. [Department of Chemistry, McMaster University, 1280 Main St. West, Hamilton, Ont. L8S 4M1 (Canada); Hodgson, Richard J. [Department of Chemistry, McMaster University, 1280 Main St. West, Hamilton, Ont. L8S 4M1 (Canada); Green, James R.A. [Department of Chemistry, McMaster University, 1280 Main St. West, Hamilton, Ont. L8S 4M1 (Canada); Brennan, John D. [Department of Chemistry, McMaster University, 1280 Main St. West, Hamilton, Ont. L8S 4M1 (Canada)]. E-mail: brennanj@mcmaster.ca

    2006-03-30

    Our group recently reported on the application of protein-doped monolithic silica columns for immobilized enzyme reactor chromatography, which allowed screening of enzyme inhibitors present in mixtures using mass spectrometry for detection. The enzyme was immobilized by entrapment within a bimodal meso/macroporous silica material prepared by a biocompatible sol-gel processing route. While such columns proved to be useful for applications such as screening of protein-ligand interactions, significant amounts of entrapped proteins leached from the columns owing to the high proportion of macropores within the materials. Herein, we describe a detailed study of factors affecting the morphology of protein-doped bioaffinity columns and demonstrate that specific pH values and concentrations of poly(ethylene glycol) can be used to prepare essentially mesoporous columns that retain over 80% of initially loaded enzyme in an active and accessible form and yet still retain sufficient porosity to allow pressure-driven flow in the low {mu}L/min range. Using the enzyme {gamma}-glutamyl transpeptidase ({gamma}-GT), we further evaluated the catalytic constants of the enzyme entrapped in capillary columns with different silica morphologies as a function of flowrate and backpressure using the enzyme reactor assay mode. It was found that the apparent activity of the enzyme was highest in mesoporous columns that retained high levels of enzyme. In such columns, enzyme activity increased by {approx}2-fold with increases in both flowrate (from 250 to 1000 nL/min) and backpressure generated (from 500 to 2100 psi) during the chromatographic activity assay owing to increases in k {sub cat} and decreases in K {sub M}, switching from diffusion controlled to reaction controlled conditions at ca. 2000 psi. These results suggest that columns with minimal macropore volumes (<5%) are advantageous for the entrapment of soluble proteins for bioaffinity and bioreactor chromatography.

  11. Development of a novel monolith frit-based solid-phase microextraction method for determination of hexanal and heptanal in human serum samples.

    Science.gov (United States)

    Xu, Hui; Yan, Zhihua; Song, Dandan

    2012-03-01

    In this paper, a polypropylene frit with porous network structure and high area-to-thickness ratio (4.8 mm diameter, 1.6 mm thickness, 20 mm pore size) was utilized as a mould of monolith. Poly(methacrylic acid-ethlyene glycol dimethacrylate) (MAA-EGDMA) monolith was in situ synthesized in the micro-channel of frit by photopolymerization. A monolith frit-based solid-phase microextraction method (SPME) was developed for the determination of hexanal and heptanal in serum samples by combining with high-performance liquid chromatography. 2,4-Dinitrophenylhydrazine (DNPH) as the derivatizing reagent was absorbed on a monolith frit, then its derivatization reaction with aldehydes and the absorption of formed hydrazones on the monolith disk occurred simultaneously. The condition parameters for polymerization, derivatization and extraction were optimized systematically. Under the optimum conditions, rigid structure, low back-pressure and high column capacity were achieved for the monolith frit. The limits of detection for hexanal and heptanal were 1.86 and 1.38 nmol/L, respectively. The inter- and intra-day relative standard deviations were less than 7.7% (n = 6). This method was applied successfully to aldehydes analysis in human serum samples. The method possesses advantages such as simplicity, efficiency, low cost and good biocompatibility. It provides an alternative approach for quantification of aldehydes in complex biological samples. PMID:22271665

  12. Purification and reconstitution of chloride channels from kidney and trachea

    International Nuclear Information System (INIS)

    Chloride channels mediate absorption and secretion of fluid in epithelia, and the regulation of these channels is now known to be defective in cystic fibrosis. Indanyl-oxyacetic acid 94 (IAA-94) is a high-affinity ligand for the chloride channel, and an affinity resin based on that structure was developed. Solubilized proteins from kidney and trachea membranes were applied to the affinity matrix, and four proteins with apparent molecular masses of 97, 64, 40, and 27 kilodaltons were eluted from the column by excess IAA-94. A potential-dependent 36Cl- uptake was observed after reconstituting these proteins into liposomes. Three types of chloride channels with single-channel conductances of 26, 100, and 400 picosiemens were observed after fusion of these liposomes with planar lipid bilayers. Similar types of chloride channels have been observed in epithelia

  13. Slender CRC Columns

    DEFF Research Database (Denmark)

    Aarup, Bendt; Jensen, Lars Rom; Ellegaard, Peter

    2005-01-01

    CRC is a high-performance steel fibre reinforced concrete with a typical compressive strength of 150 MPa. Design methods for a number of structural elements have been developed since CRC was invented in 1986, but the current project set out to further investigate the range of columns for which...... current design guides can be used. The columns tested had a slenderness varying from 1.11 to 12.76 and a reinforcement ratio (area of rebar to area of concrete) ranging from 0 to 8.8 %. A total of 77 tests were carried out - 61 columns were tested in ambient conditions and 16 columns were tested in...... standard fire conditions. The tests showed good correlation between test results and results calculated according to established deisgn guides. The fire tests demonstrate that the load capacity of slender columns can be reduced very quickly due to thermal stresses and a reduction of stiffness - also in...

  14. Distillation Column Flooding Predictor

    Energy Technology Data Exchange (ETDEWEB)

    George E. Dzyacky

    2010-11-23

    The Flooding Predictor™ is a patented advanced control technology proven in research at the Separations Research Program, University of Texas at Austin, to increase distillation column throughput by over 6%, while also increasing energy efficiency by 10%. The research was conducted under a U. S. Department of Energy Cooperative Agreement awarded to George Dzyacky of 2ndpoint, LLC. The Flooding Predictor™ works by detecting the incipient flood point and controlling the column closer to its actual hydraulic limit than historical practices have allowed. Further, the technology uses existing column instrumentation, meaning no additional refining infrastructure is required. Refiners often push distillation columns to maximize throughput, improve separation, or simply to achieve day-to-day optimization. Attempting to achieve such operating objectives is a tricky undertaking that can result in flooding. Operators and advanced control strategies alike rely on the conventional use of delta-pressure instrumentation to approximate the column’s approach to flood. But column delta-pressure is more an inference of the column’s approach to flood than it is an actual measurement of it. As a consequence, delta pressure limits are established conservatively in order to operate in a regime where the column is never expected to flood. As a result, there is much “left on the table” when operating in such a regime, i.e. the capacity difference between controlling the column to an upper delta-pressure limit and controlling it to the actual hydraulic limit. The Flooding Predictor™, an innovative pattern recognition technology, controls columns at their actual hydraulic limit, which research shows leads to a throughput increase of over 6%. Controlling closer to the hydraulic limit also permits operation in a sweet spot of increased energy-efficiency. In this region of increased column loading, the Flooding Predictor is able to exploit the benefits of higher liquid

  15. Connection Between Liquid Distribution and Gas-Liquid Mass Transfer in Monolithic Bed

    Institute of Scientific and Technical Information of China (English)

    许闽; 刘辉; 李成岳; 周媛; 季生福

    2011-01-01

    With a particular focus on the connection between liquid flow distribution and gas-liquid mass transfer in monolithic beds in the Taylor flow regime, hydrodynamic and gas-liquid mass transfer experiments were carriedout in a column with a monolithic bed of cell density of 50 cpsi with trio different distributors (nozzle and packed bed distributors). Liquid saturation in individual channels was measured by using self-made micro-conductivity probes. A mal-distribution factor was used to evaluate uniform degree of phase distribution in monoliths. Overall bed pressure drop and mass transfer coefficients were measured. For liquid flow distribution and gas-liquid masstransfer, it is found that the superficial liquid velocity is a crucial factor and the packed bed distributor is better than the nozzle distributor. A semi-theoretical analysis using single channel models shows that the packed bed distributor always yields shorter and uniformly distributed liquid slugs compared to the nozzle distributor, which in turn ensures a better mass transfer performance. A bed scale mass transfer model is proposed by employing the single channel models in individual channels and incorporating effects of non-uniform liquid distribution along the bedcross-section. The model predicts the overall gas-liquid mass transfer coefficient wig a relative error within +30%.

  16. Chloride removal from vitrification offgas

    International Nuclear Information System (INIS)

    This study identified and investigated techniques of selectively purging chlorides from the low-level waste (LLW) vitrification process with the purge stream acceptable for burial on the Hanford Site. Chlorides will be present in high concentration in several individual feeds to the LLW Vitrification Plant. The chlorides are highly volatile in combustion type melters and are readily absorbed by wet scrubbing of the melter offgas. The Tank Waste Remediation System (TWRS) process flow sheets show that the resulting chloride rich scrub solution is recycled back to the melter. The chlorides must be purged from the recycle loop to prevent the buildup of excessively high chloride concentrations

  17. Preparation of low flow-resistant methacrylate-based monolithic stationary phases of different hydrophobicity and the application to rapid reversed-phase liquid chromatographic separation of alkylbenzenes at high flow rate and elevated temperature.

    Science.gov (United States)

    Ueki, Yuji; Umemura, Tomonari; Iwashita, Yoshikazu; Odake, Tamao; Haraguchi, Hiroki; Tsunoda, Kin-ichi

    2006-02-17

    Low flow-resistant alkyl methacrylate-based monolithic stationary phases of different hydrophobicity were constructed for reversed-phase capillary liquid chromatography by thermally initiated radical polymerization of respective methacrylate ester monomer with different alkyl chain (C2, C4, C6, C12, C18) and ethylene glycol dimethacrylate (EDMA) in a 250 microm i.d. fused silica capillary. The hydrophobicity was basically controlled by changing the length and/or the density of the alkyl-chain, while the composition and the ratio of porogenic solvent were adjusted to obtain highly permeable rigid monoliths with adequate column efficiency. Among the prepared monolithic stationary phases, C18-methacrylate monoliths polymerized from a binary porogenic solvent of isoamyl alcohol and 1,4-buthandiol exhibited the most promising performance in terms of hydraulic resistance and column efficiency. The pressure drops of 20-cm long monolithic columns were below approximately 0.4 MPa at a normal linear velocity of 1mm/s (a flow rate of 3 microL/min), and the numbers of theoretical plates for alkylbenzenes mostly exceeded 3000 plates/20 cm. The produced monolithic columns had good mechanical strength for high pressure and temperature, and could be properly operated even at a temperature of 80 degrees C and at a pressure of at least 33 MPa. At 80 degrees C, the theoretical plate numbers reached 6000 plates/20 cm because of the enhanced mass transfer. Due to the novel hydraulic resistance and mechanical strength, the separation time could be reduced 120-fold simply by raising the flow rate and column temperature.

  18. Polyether ether ketone encased monolith frits made of polyether ether ketone tubing with a 0.25 mm opening resulting in an improved separation performance in liquid chromatography.

    Science.gov (United States)

    Park, Sin Young; Cheong, Won Jo

    2016-05-01

    Tiny polyether ether ketone encased monolith frits have been prepared by modified catalytic sulfonation of the inner surface of polyether ether tubing (1.6 mm od, 0.25 mm id) followed by modified formation of organic monolith and cutting of the tubing into slices. The frit was placed below the central hole of the column outlet union and supported by a combination of a silica capillary (0.365 mm od, 0.05 mm id) and a polyether ether ketone sleeve (1.6 mm od, 0.38 mm id) tightened with a nut and a ferrule when the column was packed to prevent sinking of the frit element into the union hole (0.25 mm opening) otherwise. The column packed this way with the frits investigated in this study has shown better separation performance owing to the reduced frit volume in comparison to the column packed with a commercial stainless-steel screen frit. This study establishes the strategy of disposable microcolumns in which cheap disposable frits are used whenever the column is re-packed to yield columns of even better chromatographic performance than the columns with commercial frits. PMID:26910135

  19. Mass transfer kinetics, band broadening and column efficiency.

    Science.gov (United States)

    Gritti, Fabrice; Guiochon, Georges

    2012-01-20

    Important progress was recently made in our understanding of the physico-chemical aspects of mass transfer kinetics in chromatographic columns, in methods used for accurate determination of the different contributions to the height equivalent to a theoretical plate (HETP), and in the application of these advances to the elucidation of mass transfer mechanisms in columns packed with recent chromatographic supports (sub-2 μm fully porous particles, sub-3 μm core-shell particles, and monoliths). The independent contributions to the HETP are longitudinal diffusion, eddy dispersion, liquid-solid mass transfer (including trans-particle or trans-skeleton mass transfer and external film mass transfer), and the contributions caused by the thermal heterogeneity of the column. The origin and importance of these contributions are investigated in depth. This work underlines the areas in which improvements are needed, an understanding of the contribution of the external film mass transfer term, a better design of HPLC instruments providing a decrease of the extra-column band broadening contributions to the apparent HETP, the development of better packing procedures giving more radially homogeneous column beds, and new packing materials having a higher thermal conductivity to eliminate the nefarious impact of heat effects in very high pressure liquid chromatography (vHPLC) and supercritical fluid chromatography (SFC).

  20. Application-specific architectures of CMOS monolithic active pixel sensors

    Science.gov (United States)

    Szelezniak, Michal; Besson, Auguste; Claus, Gilles; Colledani, Claude; Degerli, Yavuz; Deptuch, Grzegorz; Deveaux, Michael; Dorokhov, Andrei; Dulinski, Wojciech; Fourches, Nicolas; Goffe, Mathieu; Grandjean, Damien; Guilloux, Fabrice; Heini, Sebastien; Himmi, Abdelkader; Hu, Christine; Jaaskelainen, Kimmo; Li, Yan; Lutz, Pierre; Orsini, Fabienne; Pellicioli, Michel; Shabetai, Alexandre; Valin, Isabelle; Winter, Marc

    2006-11-01

    Several development directions intended to adapt and optimize monolithic active pixel sensors for specific applications are presented in this work. The first example, compatible with the STAR microvertex upgrade, is based on a simple two-transistor pixel circuitry. It is suited for a long integration time, room-temperature operation and minimum power dissipation. In another approach for this application, a specific readout method is proposed, allowing optimization of the integration time independently of the full frame-readout time. The circuit consists of an in-pixel front-end voltage amplifier, with a gain on the order of five, followed by two analog memory cells. The extended version of this scheme, based on the implementation of more memory cells per pixel, is the solution considered for the outer layers of a microvertex detector at the international linear collider. For the two innermost layers, a circuit allowing fast frame scans together with on-line, on-chip data sparsification is proposed. The first results of this prototype demonstrate that the fixed pattern dispersion is reduced below a noise level of 15 e -, allowing the use of a single comparator or a low-resolution ADC per pixel column. A common element for most of the mentioned readout schemes is a low-noise, low power consumption, layout efficient in-pixel amplifier. A review of possible solutions for this element together with some experimental results is presented.

  1. Monolithic pixel detectors for high energy physics

    CERN Document Server

    Snoeys, W

    2013-01-01

    Monolithic pixel detectors integrating sensor matrix and readout in one piece of silicon have revolutionized imaging for consumer applications, but despite years of research they have not yet been widely adopted for high energy physics. Two major requirements for this application, radiation tolerance and low power consumption, require charge collection by drift for the most extreme radiation levels and an optimization of the collected signal charge over input capacitance ratio ( Q / C ). It is shown that monolithic detectors can achieve Q / C for low analog power consumption and even carryout the promise to practically eliminate analog power consumption, but combining suf fi cient Q / C , collection by drift, and integration of readout circuitry within the pixel remains a challenge. An overview is given of different approaches to address this challenge, with possible advantages and disadvantages.

  2. Macroporous Monolithic Polymers: Preparation and Applications

    Directory of Open Access Journals (Sweden)

    Cecilia Inés Alvarez Igarzabal

    2009-12-01

    Full Text Available In the last years, macroporous monolithic materials have been introduced as a new and useful generation of polymers used in different fields. These polymers may be prepared in a simple way from a homogenous mixture into a mold and contain large interconnected pores or channels allowing for high flow rates at moderate pressures. Due to their porous characteristics, they could be used in different processes, such as stationary phases for different types of chromatography, high-throughput bioreactors and in microfluidic chip applications. This review reports the contributions of several groups working in the preparation of different macroporous monoliths and their modification by immobilization of specific ligands on the products for specific purposes.

  3. Monolithic Optical-To-Electronic Receiver

    Science.gov (United States)

    Kunath, Richard; Mactaggert, Ross

    1994-01-01

    Monolithic optoelectronic integrated circuit converts multiplexed digital optical signals into electrical signals, separates, and distributes them to intended destinations. Developed to deliver phase and amplitude commands to monolithic microwave integrated circuits (MMIC's) at elements of millimeter-wave phased-array antenna from single optical fiber driven by external array controller. Also used in distribution of high-data-rate optical communications in local-area networks (LAN's). Notable features include options for optical or electrical clock inputs; outputs for raw data, addresses, and instructions for diagnosis; and optical-signal-detection circuit used to reduce power consumption by 80 percent between data-transmission times. Chip fabricated by processes available at many major semiconductor foundries. Distribution of digital signals in aircraft, automobiles, and ships potential application.

  4. Comparison of soil-monolith extraction techniques

    Science.gov (United States)

    Meissner, R.; Rupp, H.; Weller, U.; Vogel, H.-J.

    2009-04-01

    In the international literature the term „lysimeter" is used for different objectives, e.g. suction cups, fluxmeters, etc. According to our understanding it belongs to the direct methods to measure water and solute fluxes in soil. Depending on the scientific task the shape and dimensions of the lysimeter as well as the type of filling (disturbed or undisturbed) and the specific instrumentation can be different. In any case where water dynamics or solute transport in natural soil is considered, lysimeters should be filled with 'undisturbed' monoliths which are large enough to contain the small scale heterogeneity of a site since flow and transport is highly sensitive to soil structure. Furthermore, lysimeters with vegetation should represent the natural crop inventory and the maximum root penetration depth should be taken into account. The aim of this contribution is to give an overview about different methods for obtaining undisturbed soil monoliths, in particular about i) techniques for the vertical and ii) for the horizontal extraction and iii) to evaluate the most frequently used procedures based on X-ray tomography images. Minimal disturbance of the soil monolith during extraction and subsequence filling of the lysimeter vessel is of critical importance for establishing flow and transport conditions corresponding approximately to natural field conditions. In the past, several methods were used to extract and fill lysimeter vessels vertically - including hand digging, employing sets of trihedral scaffold with lifting blocks and ballast, or using heavy duty excavators, which could shear and cut large blocks of soil. More recently, technologies have been developed to extract cylindrical soil monoliths by using ramming equipment or screw presses. One of the great disadvantages of the mentioned methods is the compaction or settling of soil that occurs during the "hammering" or "pressing". For this reason a new technology was developed, which cuts the outline of

  5. Solgel-derived photosensitive germanosilicate glass monoliths.

    Science.gov (United States)

    Heaney, A D; Erdogan, T

    2000-12-15

    We demonstrate volume gratings written in solgel-derived, Ge-doped silica monoliths. Glass was fabricated both with and without germanium oxygen deficient center (GODC) defects. The UV absorption and UV-induced index changes of these glasses, with and without hydrogen loading, are reported. The presence of GODC defects greatly enhances the photosensitivity of Ge-doped silica with and without the presence of hydrogen. PMID:18066337

  6. FLUIDIZED BED STEAM REFORMER MONOLITH FORMATION

    Energy Technology Data Exchange (ETDEWEB)

    Jantzen, C

    2006-12-22

    Fluidized Bed Steam Reforming (FBSR) is being considered as an alternative technology for the immobilization of a wide variety of aqueous high sodium containing radioactive wastes at various DOE facilities in the United States. The addition of clay, charcoal, and a catalyst as co-reactants converts aqueous Low Activity Wastes (LAW) to a granular or ''mineralized'' waste form while converting organic components to CO{sub 2} and steam, and nitrate/nitrite components, if any, to N{sub 2}. The waste form produced is a multiphase mineral assemblage of Na-Al-Si (NAS) feldspathoid minerals with cage-like structures that atomically bond radionuclides like Tc-99 and anions such as SO{sub 4}, I, F, and Cl. The granular product has been shown to be as durable as LAW glass. Shallow land burial requires that the mineralized waste form be able to sustain the weight of soil overburden and potential intrusion by future generations. The strength requirement necessitates binding the granular product into a monolith. FBSR mineral products were formulated into a variety of monoliths including various cements, Ceramicrete, and hydroceramics. All but one of the nine monoliths tested met the <2g/m{sup 2} durability specification for Na and Re (simulant for Tc-99) when tested using the Product Consistency Test (PCT; ASTM C1285). Of the nine monoliths tested the cements produced with 80-87 wt% FBSR product, the Ceramicrete, and the hydroceramic produced with 83.3 wt% FBSR product, met the compressive strength and durability requirements for an LAW waste form.

  7. Update On Monolithic Fuel Fabrication Development

    Energy Technology Data Exchange (ETDEWEB)

    C. R Clark; J. M. Wight; G. C. Knighton; G. A. Moore; J. F. Jue

    2005-11-01

    Efforts to develop a viable monolithic research reactor fuel plate have continued at Idaho National Laboratory. These efforts have concentrated on both fabrication process refinement and scale-up to produce full sized fuel plates. Advancements have been made in the production of U-Mo foil including full sized foils. Progress has also been made in the friction stir welding and transient liquid phase bonding fabrication processes resulting in better bonding, more stable processes and the ability to fabricate larger fuel plates.

  8. [Degradation of succinylcholine chloride].

    Science.gov (United States)

    Németh, G; Török, I; Paál, T

    1993-05-01

    Quantitative thin-layer chormatographic method has been developed for the investigation of the degradation of injection formulations containing succinylcholinium chloride. The method is based on the denistometric determination of the main degradation product, choline at 430 nm after visualization with iodine vapour. The stability of the injection was investigated under various storage conditions and it has been stated that considerable decomposition takes place during as short a period as one week. PMID:8362654

  9. Slender CRC Columns

    OpenAIRE

    Aarup, Bendt; Jensen, Lars Rom; Ellegaard, Peter

    2005-01-01

    CRC is a high-performance steel fibre reinforced concrete with a typical compressive strength of 150 MPa. Design methods for a number of structural elements have been developed since CRC was invented in 1986, but the current project set out to further investigate the range of columns for which current design guides can be used. The columns tested had a slenderness varying from 1.11 to 12.76 and a reinforcement ratio (area of rebar to area of concrete) ranging from 0 to 8.8 %. A total of 77 te...

  10. Solute transport through large uniform and layered soil columns

    Science.gov (United States)

    Porro, I.; Wierenga, P. J.; Hills, R. G.

    1993-04-01

    Solute transport experiments are often conducted with homogeneous soils, whereas transport in real situations takes place in heterogeneous soils. An experiment was conducted to compare unsaturated solute transport through uniform and layered soils. Pulse inputs of tritiated water, bromide and chloride were applied under steady flow conditions to the tops of two large (0.95 m diameter by 6 m deep) soil columns. One column was uniformly filled with loamy fine sand and the other filled with alternating 20-cm-thick layers of loamy fine sand and silty clay loam. Soil solution samples were collected during the experiment with suction candles installed at various depths in the columns. Solute transport parameters were estimated by fitting the convection-dispersion equation to the observed breakthrough curves for each solute at various depths in each column. The match between the resulting calibrated curves and the experiment was better for the layered soil column than for the uniform soil column. The results displayed no clear relationship between the dispersion coefficients and depth for any of the tracers for either column. However, dispersivities were greater in the uniform column (3.5 cm) than in the layered column (1.2 cm), while retardation factors for bromide and chloride were similar (0.8 and 0.83, respectively, for the uniform and layered columns). A retardation factor less than one is attributed to anion exclusion. There was evidence of preferential flow in the uniform soil column. The peak concentrations at 5 m depth were greater than those observed at 4 m. Such behavior is inconsistent with one-dimensional flow. Similar results were observed in an experiment performed 3.5 years earlier using the same soil column and approximately the same flow rates, but using a different tracer and associated chemical analysis, different soil saturation prior to the execution of the experiment, and different experimental personnel. This supports the thesis that the anomalous

  11. Development and validation of polymerized high internal phase emulsion monoliths coupled with HPLC and fluorescence detection for the determination of trace tetracycline antibiotics in environmental water samples.

    Science.gov (United States)

    Du, Fuyou; Zheng, Xian; Sun, Lin; Qin, Qun; Guo, Lin; Ruan, Guihua

    2015-11-01

    A polymerized high internal phase emulsion monolith was used as a novel sorbent for solid-phase extraction coupled with high-performance liquid chromatography and fluorescence detection for the determination of oxytetracycline, tetracycline, doxycycline, and chlorotetracycline in environmental water samples. The polymerized high internal phase emulsion monolithic column was prepared by the in situ polymerization of the continuous phase of a high internal phase emulsion containing glycidyl methacrylate, styrene, and divinylbenzene in pipette tips, and then functionalized with iminodiacetic acid. The resulting monolith exhibited highly interconnected porosity and large surface areas, making it an excellent candidate as an solid-phase extraction sorbent for the enrichment of trace tetracycline antibiotics. Several factors affecting the extraction performance of polymerized high internal phase emulsion monoliths, including the pH of sample solution, the eluting solvents, the sample loading flow rate and volume, were investigated, respectively. Under the optimized conditions, the mean recoveries of oxytetracycline, tetracycline, doxycycline, and chlorotetracycline spiked in pond and farm wastewater samples ranged from 78.1 to 119.3% with relative standard deviation less than 15%. The detection limits (S/N = 3) of the proposed method were in the range of 51-137 pg/mL. This study demonstrated that the monolithic polymerized high internal phase emulsion would be promising solid-phase extraction sorbents in the extraction and proconcentration of trace analytes from complex samples. PMID:26331390

  12. Column: Job crafting

    NARCIS (Netherlands)

    Reep, Frans van der

    2012-01-01

    1e alinea column: Organisaties dienen tegenwoordig randvoorwaarden te creëren waarbij ook behoeftes van de medewerkers aan autonomie, identificatie en zingeving worden vervuld. In organisaties die dit snappen geven de medewerkers zelf vorm aan eigen functie zodat die voldoet aan de behoeftes van de

  13. Selective oxidation of cyclohexene through gold functionalized silica monolith microreactors

    Science.gov (United States)

    Alotaibi, Mohammed T.; Taylor, Martin J.; Liu, Dan; Beaumont, Simon K.; Kyriakou, Georgios

    2016-04-01

    Two simple, reproducible methods of preparing evenly distributed Au nanoparticle containing mesoporous silica monoliths are investigated. These Au nanoparticle containing monoliths are subsequently investigated as flow reactors for the selective oxidation of cyclohexene. In the first strategy, the silica monolith was directly impregnated with Au nanoparticles during the formation of the monolith. The second approach was to pre-functionalize the monolith with thiol groups tethered within the silica mesostructure. These can act as evenly distributed anchors for the Au nanoparticles to be incorporated by flowing a Au nanoparticle solution through the thiol functionalized monolith. Both methods led to successfully achieving even distribution of Au nanoparticles along the length of the monolith as demonstrated by ICP-OES. However, the impregnation method led to strong agglomeration of the Au nanoparticles during subsequent heating steps while the thiol anchoring procedure maintained the nanoparticles in the range of 6.8 ± 1.4 nm. Both Au nanoparticle containing monoliths as well as samples with no Au incorporated were tested for the selective oxidation of cyclohexene under constant flow at 30 °C. The Au free materials were found to be catalytically inactive with Au being the minimum necessary requirement for the reaction to proceed. The impregnated Au-containing monolith was found to be less active than the thiol functionalized Au-containing material, attributable to the low metal surface area of the Au nanoparticles. The reaction on the thiol functionalized Au-containing monolith was found to depend strongly on the type of oxidant used: tert-butyl hydroperoxide (TBHP) was more active than H2O2, likely due to the thiol induced hydrophobicity in the monolith.

  14. Microchip-based monolithic column for high performance liquid chromatography Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Fabricate the microchannels using DDL facilities. Develop a process for in situ polymerization inside the microchannels and optimize the chemistry Perform...

  15. Preparation and Evaluation of Molecularly Imprinted Monolithic Column for Felodipine in Micro-liquid Chromatography

    Institute of Scientific and Technical Information of China (English)

    Qi Liang DENG; Zhi Hong LUN; Chao YAN; Ru Yu GAO

    2005-01-01

    This study concentrated on the production of molecularly imprinted polymers (MIPs) as highly selective sorbents for felodipine (FLD), a representive dihydropyridine calcium antagonists.Demonstrated chromatographically through a selection factor, these MIPs showed high selectivity for the template molecule among a group of structurally similar compounds. The recognition was found to correlate with structural similarity to the template compound.

  16. Monolithic LTCC seal frame and lid

    Energy Technology Data Exchange (ETDEWEB)

    Krueger, Daniel S.; Peterson, Kenneth A.; Stockdale, Dave; Duncan, James Brent; Riggs, Bristen

    2016-06-21

    A method for forming a monolithic seal frame and lid for use with a substrate and electronic circuitry comprises the steps of forming a mandrel from a ceramic and glass based material, forming a seal frame and lid block from a ceramic and glass based material, creating a seal frame and lid by forming a compartment and a plurality of sidewalls in the seal frame and lid block, placing the seal frame and lid on the mandrel such that the mandrel fits within the compartment, and cofiring the seal frame and lid block.

  17. Monolithic aerogels with nanoporous crystalline phases

    Science.gov (United States)

    Daniel, Christophe; Guerra, Gaetano

    2015-05-01

    High porosity monolithic aerogels with nanoporous crystalline phases can be obtained from syndiotactic polystyrene and poly(2,6-dimethyl-1,4-phenylene)oxide thermoreversible gels by removing the solvent with supercritical CO2. The presence of crystalline nanopores in the aerogels based on these polymers allows a high uptake associated with a high selectivity of volatile organic compounds from vapor phase or aqueous solutions even at very low activities. The sorption and the fast kinetics make these materials particularly suitable as sorption medium to remove traces of pollutants from water and moist air.

  18. Fibrous monoliths: Economic ceramic matrix composites from powders [Final report

    Energy Technology Data Exchange (ETDEWEB)

    Rigali, Mark; Sutaria, Manish; Mulligan, Anthony; Creegan, Peter; Cipriani, Ron

    1999-05-26

    The project was to develop and perform pilot-scale production of fibrous monolith composites. The principal focus of the program was to develop damage-tolerant, wear-resistant tooling for petroleum drilling applications and generate a basic mechanical properties database on fibrous monolith composites.

  19. Hydrogel coated monoliths for enzymatic hydrolysis of penicillin G

    NARCIS (Netherlands)

    De Lathouder, K.M.; Smeltink, M.W.; Straathof, A.J.J.; Paasman, M.A.; Van de Sandt, E.J.A.X.; Kapteijn, F.; Moulijn, J.A.

    2008-01-01

    The objective of this work was to develop a hydrogel-coated monolith for the entrapment of penicillin G acylase (E. coli, PGA). After screening of different hydrogels, chitosan was chosen as the carrier material for the preparation of monolithic biocatalysts. This protocol leads to active immobilize

  20. Media Presentation Synchronisation for Non-monolithic Rendering Architectures

    NARCIS (Netherlands)

    Vaishnavi, I.; Bulterman, D.C.A.; Cesar Garcia, P.S.; Gao, B.

    2007-01-01

    Non-monolithic renderers are physically distributed media playback engines. Non-monolithic renderers may use a number of different underlying network connection types to transmit media items belonging to a presentation. There is therefore a need for a media based and inter-network- type synchronizat

  1. Energy Absorption of Monolithic and Fibre Reinforced Aluminium Cylinders

    NARCIS (Netherlands)

    De Kanter, J.L.C.G.

    2006-01-01

    Summary accompanying the thesis: Energy Absorption of Monolithic and Fibre Reinforced Aluminium Cylinders by Jens de Kanter This thesis presents the investigation of the crush behaviour of both monolithic aluminium cylinders and externally fibre reinforced aluminium cylinders. The research is based

  2. Design considerations for monolithic unidirectional planar ring oscillators

    Science.gov (United States)

    Li, Zhenhua; Bao, Guojun; Ge, Yi; Wang, Zhongming; He, Anzhi; Tao, Hailin

    1996-09-01

    In this paper, the characteristics of monolithic unidirectional planar ring oscillator (PROs) are analyzed, and design criteria for PROs with low thresholds and large nonreciprocities are expounded on the basis of the eigenpolarization theory of monolithic nonplanar ring oscillators. A Nd:BGO PRO is designed to take advantage of its large Verdet coefficient.

  3. Batch and Column Experiments on Fluoride Removal from Waters Using Modified Zeolite

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    High fluoride groundwater occurs widely in China, presenting a quite serious environmental problem. Zeolite from Xinyang, China was tested as the fluoride-removing adsorbent. Batch and column experiments on fluoride removal using modified zeolites treated with hydrochloric acid,sodium hydroxide, sodium chloride and ferric chloride, respectively show that 0. 1 mol/L HCImodified zeolite can be used as an adsorbent for fluoride, with an adsorption capacity of 173. 16mg/kg.

  4. Decoding the Pantheon Columns

    OpenAIRE

    Gerd Grasshoff; Christian Berndt

    2014-01-01

    The goal of this study has been to reconstruct the design principles underlying the construction of the Pantheon’s portico columns as well as to demonstrate how digital investigation methods and models can be used to improve our understanding of ancient architectural knowledge. Thanks to the data of the Bern Digital Pantheon Model, a synthesis of all the scanned surface points obtained during a digitization campaign of the Karman Center for Advanced Studies in the Humanities of the University...

  5. Catastrophic failure of a monolithic zirconia prosthesis.

    Science.gov (United States)

    Chang, Jae-Seung; Ji, Woon; Choi, Chang-Hoon; Kim, Sunjai

    2015-02-01

    Recently, monolithic zirconia restorations have received attention as an alternative to zirconia veneered with feldspathic porcelain to eliminate chipping failures of veneer ceramics. In this clinical report, a patient with mandibular edentulism received 4 dental implants in the interforaminal area, and a screw-retained monolithic zirconia prosthesis was fabricated. The patient also received a maxillary complete removable dental prosthesis over 4 anterior roots. At the 18-month follow-up, all of the zirconia cylinders were seen to be fractured, and the contacting abutment surfaces had lost structural integrity. The damaged abutments were replaced with new abutments, and a new prosthesis was delivered with a computer-assisted design and computer-assisted manufacturing fabricated titanium framework with denture teeth and denture base resins. At the 6-month recall, the patient did not have any problems. Dental zirconia has excellent physical properties; however, care should be taken to prevent excessive stresses on the zirconia cylinders when a screw-retained zirconia restoration is planned as a definitive prosthesis.

  6. Determination of Two Columns Performance

    Institute of Scientific and Technical Information of China (English)

    2011-01-01

    When protein is analyzed by high performance liquid chromatography (HPLC), the selection of column is one of the most important factors. There are four quality control parameters for the column, which are theoretical plates n, capacity facto

  7. NMFS Water Column Sonar Database

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Water column sonar data are an important component of fishery independent surveys, habitat studies and other research. NMFS water column sonar data are archived here.

  8. Behavior of Columns During Earthquakes

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The behavior of columns during earthquakes is very important since column failures may lead to additional structural failures and result in total building...

  9. Valyl benzyl ester chloride

    Directory of Open Access Journals (Sweden)

    Grzegorz Dutkiewicz

    2010-02-01

    Full Text Available In the title compound (systematic name: 1-benzyloxy-3-methyl-1-oxobutan-2-aminium chloride, C12H18NO2+·Cl−, the ester group is approximately planar, with a maximum deviation of 0.040 (2 Å from the least-squares plane, and makes a dihedral angle of 28.92 (16° with the phenyl ring. The crystal structure is organized by N—H...Cl hydrogen bonds which join the two components into a chain along the b axis. Pairs of chains arranged antiparallel are interconnected by further N—H...Cl hydrogen bonds, forming eight-membered rings. Similar packing modes have been observed in a number of amino acid ester halides with a short unit-cell parameter of ca 5.5 Å along the direction in which the chains run.

  10. Effect of PET Wrapping on Shear Performance of Corroded Reinforced Concrete Columns

    OpenAIRE

    Zhang, Dawei; Zhao, Yuxi; Jin, Weiliang; Ueda, Tamon

    2016-01-01

    In this paper, an experimental study is presented on the influence of PET warping on shear performance, such as diagonal shear cracking load, peak load, and energy dissipation of RC columns with stirrup corrosion before strengthening. The experimental program involved an electrochemical process to accelerate the migration of chlorides from an external electrolyte into the tested columns, a wetting–drying cycle process with a controlled current to speed up the corrosion of the stirrup in the t...

  11. Reactive transport experiments of linear alkylbenzene sulfonate in laboratory soil columns

    OpenAIRE

    Boluda Botella, Nuria; Cases López, Vicente; León León, Victor Manuel; Gomis Yagües, Vicente; Prats Rico, Daniel

    2007-01-01

    Laboratory column experiments aids in the understanding of hydrogeochemistry dynamics of different linear alkylbenzene sulfonate homologues when they interact with different sand/soil proportions. Previously it was necessary to characterize the soil columns with a tracer. In this paper, the method to obtain breakthrough curves for the conductivity and chloride concentration of a tracer is verified, and also permits the calculation of transport parameters with an easy-to-use interface, ACUAINT...

  12. Influence of different carbon monolith preparation parameters on pesticide adsorption

    Directory of Open Access Journals (Sweden)

    Vukčević Marija

    2013-01-01

    Full Text Available The capacity of carbon monolith for pesticide removal from water, and the mechanism of pesticide interaction with carbon surface were examined. Different carbon monolith samples were obtained by varying the carbonization and activation parameters. In order to examine the role of surface oxygen groups in pesticide adsorption, carbon monolith surface was functionalized by chemical treatment in HNO3, H2O2 and KOH. The surface properties of the obtained samples were investigated by BET surface area, pore size distribution and temperature-programmed desorption. Adsorption of pesticides from aqueous solution onto activated carbon monolith samples was studied by using five pesticides belonging to different chemical groups (acetamiprid, dimethoate, nicosulfuron, carbofuran and atrazine. Presented results show that higher temperature of carbonization and the amount of activating agent allow obtaining microporous carbon monolith with higher amount of surface functional groups. Adsorption properties of the activated carbon monolith were more readily affected by the amount of the surface functional groups than by specific surface area. Results obtained by carbon monolith functionalisation showed that π-π interactions were the main force for adsorption of pesticides with aromatic structure, while acidic groups play an important role in adsorption of pesticides with no aromatic ring in the chemical structure.

  13. Column and Batch Experiments

    Directory of Open Access Journals (Sweden)

    Jorge L. Gardea-Torresdey

    2005-01-01

    Full Text Available Batch and column experiments were performed to determine the Cu(II binding capacity of silica-immobilized humin biomass. For column studies, 500 bed volumes of a 0.1 mM Cu(II solution were passed through humin packed columns at the flow rates of 1, 1.5, 2, and 3 mL/min. The biopolymer showed an average Cu binding capacity of 12 ± 1.5 mg/g and a Cu recovery of about 96.5 % ± 1.5. The breakthrough points for Cu(II alone were approximately 420, 390, 385, and 300 bed volumes for the flow rates of 1, 1.5, 2 and 3 mL/min, respectively. The interference studies demonstrated that at low concentrations, the hard cations Ca(II and Mg(II did not seem to represent a major interference on Cu(II binding to the humin biopolymer. The selectivity showed by this biopolymer was Cu(II>Ca(II>Mg(II. On the other hand, batch experiments showed that Ca(II + Mg(II at 100mM each reduced the Cu(II binding to 73 %. However, 1000 mM concentrations of Ca(II and Mg(II, separately and in mixture, reduced the Cu(II binding to 47 %, 44 % and 31 %, respectively. The results of this study showed that immobilized humin in a silica matrix could represent an inexpensive bio-source for Cu removal from contaminated water, even in the presence of low concentrations of the hard cations Ca(II and Mg(II.

  14. Column: Every Last Byte

    Directory of Open Access Journals (Sweden)

    Simson Garfinkel

    2011-06-01

    Full Text Available Inheritance powder is the name that was given to poisons, especially arsenic, that were commonly used in the 17th and early 18th centuries to hasten the death of the elderly. For most of the 17th century, arsenic was deadly but undetectable, making it nearly impossible to prove that someone had been poisoned. The first arsenic test produced a gas—hardly something that a scientist could show to a judge. Faced with a growing epidemic of poisonings, doctors and chemists spent decades searching for something better.(see PDF for full column

  15. Research and Development of Monolithic Active Pixel Sensors for the Detection of the Elementary Particles

    International Nuclear Information System (INIS)

    In order to develop high spatial resolution and readout speed vertex detectors for the future International Linear Collider (ILC), fast CMOS Monolithic Active Pixel Sensors (MAPS) are studied on this work. Two prototypes of MAPS, MIMOSA 8 and MIMOSA 16, based on the same micro-electronic architecture were developed in CMOS processes with different thickness of epitaxial layer. The size of pixel matrix is 32 x 128: 8 columns of the pixel array are readout directly with analog outputs and the other 24 columns are connected to the column level auto-zero discriminators. The Correlated Double Sampling (CDS) structures are successfully implemented inside pixel and discriminator. The photo diode type pixels with different diode sizes are used in these prototypes. With a 55Fe X-ray radioactive source, the important parameters, such as Temporal Noise, Fixed Pattern Noise (FPN), Signal-to-Noise Ratio (SNR), Charge-to-Voltage conversion Factor (CVF) and Charge Collection Efficiency (CCE), are studied as function of readout speed and diode size. For MIMOSA 8, the effect of fast neutrons irradiation is also. Two beam tests campaigns were made: at DESY with a 5 GeV electrons beam and at CERN with a 180 GeV pions beam. Detection Efficiency and Spatial Resolution are studied in function of the discriminator threshold. For these two parameters, the influences of diode size and SNR of the central pixel of a cluster are also discussed. In order to improve the spatial resolution of the digital outputs, a very compact (25 μm x 1 mm) and low consumption (300 μW) column level ADC is designed in AMS 0.35 μm OPTO process. Based on successive approximation architecture, the auto-offset cancellation structure is integrated. A new column level auto-zero discriminator using static latch is also designed. (author)

  16. Preparation of carbon monoliths from orange peel for NOx retention

    Directory of Open Access Journals (Sweden)

    Liliana Giraldo

    2014-12-01

    Full Text Available A series of monoliths are prepared from orange peels and chemically activated with H3PO4, KOH, ZnCl2, and water vapor without a binder. The monoliths were characterized by N2 adsorption-desorption isotherms at 77 K, Boehm titrations and XPS. Thereafter, monoliths were tested for their ability to establish NOx retention. The results show that the retention capacities of NOx were a function of the textural properties and chemistries. The carbons synthesized with ZnCl2 and KOH retained similar amounts of NOx.

  17. On monolithic stability and reinforcement analysis of high arch dams

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    Monolithic stability safety and reinforcement based on monolithic stability are very important for arch dam design.In this paper,the issue is addressed based on deformation reinforcement theory.In this approach,plastic complementary energy norm can be taken as safety Index for monolithic stability.According to deformation reinforcement theory,the areas where unbalanced force exists require reinforcement,and the required reinforcement forces are just the unbalanced forces with opposite direction.Results show that areas with unbalanced force mainly concentrate in dam-toes,dam-heels and faults.

  18. A decoupled monolithic projection method for natural convection problems

    Science.gov (United States)

    Pan, Xiaomin; Kim, Kyoungyoun; Lee, Changhoon; Choi, Jung-Il

    2016-06-01

    We propose an efficient monolithic numerical procedure based on a projection method for solving natural convection problems. In the present monolithic method, the buoyancy, linear diffusion, and nonlinear convection terms are implicitly advanced by applying the Crank-Nicolson scheme in time. To avoid an otherwise inevitable iterative procedure in solving the monolithic discretized system, we use a linearization of the nonlinear convection terms and approximate block lower-upper (LU) decompositions along with approximate factorization. Numerical simulations demonstrate that the proposed method is more stable and computationally efficient than other semi-implicit methods, preserving temporal second-order accuracy.

  19. Determination of 5-hydroxymethylfurfural using derivatization combined with polymer monolith microextraction by high-performance liquid chromatography.

    Science.gov (United States)

    Wu, Jian-Yuan; Shi, Zhi-Guo; Feng, Yu-Qi

    2009-05-27

    A simple and sensitive method for the determination of 5-hydroxymethylfurfural (HMF) in coffee, honey, beer, Coke, and urine by high-performance liquid chromatography (HPLC) is presented. This method is based on the formation of the 2,4-dinitrophenylhydrazone of HMF and subsequent polymer monolith microextraction (PMME) of this derivative. A poly(methacrylic acid-co-ethylene glycol dimethacrylate) (MAA-co-EGDMA) monolithic capillary column was selected as the extraction medium. Several parameters affecting the derivatization of HMF with 2,4-dinitrophenylhydrazine (DNPH) followed by extraction of the derivative were optimized. The procedure is simple and offers high sensitivity and specificity since the derivative of HMF is well preconcentrated by PMME with poly(MAA-co-EGDMA) monolith and well separated from the other components of the samples under examination. The recoveries in coffee, honey, beer, Coke, and urine samples were in the range of 83.9-110.8% spiked at different levels with HMF. The inter- and intraday precisions were less than 10%. The LOD (S/N = 3) and LOQ (S/N = 10) for HMF were 1.0 ng/mL and 3.4 ng/mL, respectively. PMID:19397264

  20. 40 CFR 61.65 - Emission standard for ethylene dichloride, vinyl chloride and polyvinyl chloride plants.

    Science.gov (United States)

    2010-07-01

    ... dichloride, vinyl chloride and polyvinyl chloride plants. 61.65 Section 61.65 Protection of Environment... dichloride, vinyl chloride and polyvinyl chloride plants. An owner or operator of an ethylene dichloride, vinyl chloride, and/or polyvinyl chloride plant shall comply with the requirements of this section....

  1. Monolithic fuel injector and related manufacturing method

    Science.gov (United States)

    Ziminsky, Willy Steve; Johnson, Thomas Edward; Lacy, Benjamin; York, William David; Stevenson, Christian Xavier

    2012-05-22

    A monolithic fuel injection head for a fuel nozzle includes a substantially hollow vesicle body formed with an upstream end face, a downstream end face and a peripheral wall extending therebetween, an internal baffle plate extending radially outwardly from a downstream end of the bore, terminating short of the peripheral wall, thereby defining upstream and downstream fuel plenums in the vesicle body, in fluid communication by way of a radial gap between the baffle plate and the peripheral wall. A plurality of integral pre-mix tubes extend axially through the upstream and downstream fuel plenums in the vesicle body and through the baffle plate, with at least one fuel injection hole extending between each of the pre-mix tubes and the upstream fuel plenum, thereby enabling fuel in the upstream plenum to be injected into the plurality of pre-mix tubes. The fuel injection head is formed by direct metal laser sintering.

  2. A monolithic bolometer array suitable for FIRST

    Science.gov (United States)

    Bock, J. J.; LeDuc, H. G.; Lange, A. E.; Zmuidzinas, J.

    1997-01-01

    The development of arrays of infrared bolometers that are suitable for use in the Far Infrared and Submillimeter Telescope (FIRST) mission is reported. The array architecture is based on the silicon nitride micromesh bolometer currently baselined for use in the case of the Planck mission. This architecture allows each pixel to be efficiently coupled to one or both polarizations and to one or more spatial models of radiation. Micromesh structures are currently being developed, coupled with transistor-edge sensors and read out by a SQUID amplifier. If these devices are successful, then the relatively large cooling power available at 300 mK may enable a SQUID-based multiplexer to be integrated on the same wafer as the array, creating a monolithic, fully multiplexed, 2D array with relatively few connections to the sub-Kelvin stage.

  3. Machining distortion prediction of aerospace monolithic components

    Institute of Scientific and Technical Information of China (English)

    Yun-bo BI; Qun-lin CHENG; Hui-yue DONG; Ying-lin KE

    2009-01-01

    To predict the distortion of aerospace monolithic components.a model is established to simulate the numerical control (NC)milling process using 3D finite element method(FEM).In this model,the cutting layer is simplified firstly.Then,the models of cutting force and cutting temperature are established to gain the cutting loads,which are applied to the mesh model of the part.Finally,a prototype of machining simulation environment is developed to simulate the milling process of a spar.Key factors influencing the distortion,such as initial residual stress,cutting loads,fixture layout,cutting sequence,and tool path are considered all together.The total distortion of the spar is predicted and an experiment is conducted to validate the numerical results.It is found that the maximum discrepancy between the simulation results and experiment values is 19.0%

  4. HgCdTe monolithic infrared detector

    Energy Technology Data Exchange (ETDEWEB)

    Yakushev, Maxim V.; Dvoretsky, Sergei A.; Kozlov, Alexander I.; Sabinina, Irina V.; Sidorov, Yu.G.; Sorochkin, Alexander V.; Fomin, Boris I.; Aseev, Alexander L. [A.V. Rzhanov Institute of Semiconductor Physics, Siberian Branch RAS, Novosibirsk (Russian Federation)

    2010-06-15

    We report the processes of fabricating monolithic 32 x 32 infrared detector based on (310) HgCdTe/CdTe/ZnTe/ Si photosensitive heterostructure which was grown by a molecular-beam epitaxy technique in the free surface of ROIC cells. Optimum parameters of the technological processes were determined. The minimum temperature of preepitaxial thermal annealing in vacuum of ROIC was determined as 450 C. The dark and photo current-voltage characteristics were measured and analyzed. A good sensitivity of diodes was observed. The product R{sub 0} x A {proportional_to} 10{sup 5} Ohm x cm{sup 2}. (copyright 2010 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  5. Monolithic CMOS pixel detector for international linear collider vertex detection

    Indian Academy of Sciences (India)

    J E Brau; O Igonkina; N Sinew; D Strom; C Baltay; W Emmet; H Neal; D Rabinowitz

    2007-12-01

    A monolithic CMS pixel detector is under development for an ILC experiment. This chronopixel array provides a time stamp resolution of one bunch crossing, a critical feature for background suppression. The status of this effort is summarized.

  6. Plant oil-based shape memory polymer using acrylic monolith

    Directory of Open Access Journals (Sweden)

    T. Tsujimoto

    2015-09-01

    Full Text Available This article deals with the synthesis of a plant oil-based material using acrylic monolith. An acrylic monolith bearing oxirane groups was prepared via simple technique that involved the dissolution of poly(glycidyl methacrylate-comethyl methacrylate (PGMA in ethanolic – aqueous solution by heating and subsequent cooling. The PGMA monolith had topologically porous structure, which was attributed to the phase separation of the polymer solution. The PGMA monolith was impregnated by epoxidized soybean oil (ESO containing thermally-latent catalyst, and the subsequent curing produced a crosslinked material with relatively good transparency. The Young’s modulus and the tensile strength of polyESO/PGMA increased compared with the ESO homopolymer. The strain at break of polyESO/PGMA was larger than that of the ESO homopolymer and crosslinked PGMA. Furthermore, polyESO/PGMA exhibited good shape memory-recovery behavior.

  7. Monolithic Rare Earth Doped PTR Glass Laser Project

    Data.gov (United States)

    National Aeronautics and Space Administration — The main goal of the project is to demonstrate the feasibility of a monolithic solid state laser on the basis of PTR glass co-doped with luminescent rare earth...

  8. Enantiomer separation of acidic chiral compounds on a quinine-silica/zirconia hybrid monolith by capillary electrochromatography.

    Science.gov (United States)

    Tran, Le Ngoc; Park, Jung Hag

    2015-05-29

    A weak anion-exchanger chiral selector, quinine-incorporated silica/zirconia hybrid monolithic (QUI-S/ZHM) capillary column was prepared by sol-gel technology. The performance of the QUI-S/ZHM column was investigated for enantioresolution of a set of acidic chiral drugs and dinitrobenzoyl (DNB)-amino acids by capillary electrochromatography in aqueous organic mobile phases composed of acetonitrile (ACN) and triethylammonium acetate (TEAA) buffer. Effects of several parameters including the ACN content, concentration and pH of the mobile phase on the chiral separation were examined. Baseline resolutions of all the compounds were obtained in the mobile phase consisting of 70:30 ACN/TEAA (10mM, pH 6) under applied voltage of -10kV at 25°C within 20min.

  9. Sodium chloride, potassium chloride, and virulence in Listeria monocytogenes.

    OpenAIRE

    MYERS, E. R.; Dallmier, A W; Martin, S E

    1993-01-01

    Virulence, as determined in a mouse model, and the virulence factor activities of catalase, superoxide dismutase, and listeriolysin O were examined in a parental strain (10403S) and in a nonhemolytic mutant strain (DP-L224) of Listeria monocytogenes. The cells were propagated in media containing various concentrations of sodium chloride or potassium chloride. Strains 10403S and DP-L224 exhibited significant increases in catalase activity and listeriolysin O activity when grown in medium conta...

  10. SPIRAL CONTACTOR FOR SOLVENT EXTRACTION COLUMN

    Science.gov (United States)

    Cooley, C.R.

    1961-06-13

    The patented extraction apparatus includes a column, perforated plates extending across the column, liquid pulse means connected to the column, and an imperforate spiral ribbon along the length of the column.

  11. Why Hexagonal Basalt Columns?

    Science.gov (United States)

    Hofmann, Martin; Anderssohn, Robert; Bahr, Hans-Achim; Weiß, Hans-Jürgen; Nellesen, Jens

    2015-10-01

    Basalt columns with their preferably hexagonal cross sections are a fascinating example of pattern formation by crack propagation. Junctions of three propagating crack faces rearrange such that the initial right angles between them tend to approach 120°, which enables the cracks to form a pattern of regular hexagons. To promote understanding of the path on which the ideal configuration can be reached, two periodically repeatable models are presented here involving linear elastic fracture mechanics and applying the principle of maximum energy release rate. They describe the evolution of the crack pattern as a transition from rectangular start configuration to the hexagonal pattern. This is done analytically and by means of three-dimensional finite element simulation. The latter technique reproduces the curved crack path involved in this transition.

  12. European Analytical Column

    DEFF Research Database (Denmark)

    Karlberg, B.; Grasserbauer, M.; Andersen, Jens Enevold Thaulov

    2009-01-01

    The European Analytical Column has once more invited a guest columnist to give his views on various matters related to analytical chemistry in Europe. This year, we have invited Professor Manfred Grasserbauer of the Vienna University of Technology to present some of the current challenges...... for European analytical chemistry. During the period 2002–07, Professor Grasserbauer was Director of the Institute for Environment and Sustainability, Joint Research Centre of the European Commission (EC), Ispra, Italy. There is no doubt that many challenges exist at the present time for all of us representing...... a major branch of chemistry, namely analytical chemistry. The global financial crisis is affecting all branches of chemistry, but analytical chemistry, in particular, since our discipline by tradition has many close links to industry. We have already noticed decreased industrial commitment with respect...

  13. Column: File Cabinet Forensics

    Directory of Open Access Journals (Sweden)

    Simson Garfinkel

    2011-12-01

    Full Text Available Researchers can spend their time reverse engineering, performing reverse analysis, or making substantive contributions to digital forensics science. Although work in all of these areas is important, it is the scientific breakthroughs that are the most critical for addressing the challenges that we face.Reverse Engineering is the traditional bread-and-butter of digital forensics research. Companies like Microsoft and Apple deliver computational artifacts (operating systems, applications and phones to the commercial market. These artifacts are bought and used by billions. Some have evil intent, and (if society is lucky, the computers end up in the hands of law enforcement. Unfortunately the original vendors rarely provide digital forensics tools that make their systems amenable to analysis by law enforcement. Hence the need for reverse engineering.(see PDF for full column

  14. Extended Leach Testing of Simulated LAW Cast Stone Monoliths

    Energy Technology Data Exchange (ETDEWEB)

    Serne, R. Jeffrey [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Westsik, Joseph H. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Williams, Benjamin D. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Jung, H. B. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Wang, Guohui [Pacific Northwest National Lab. (PNNL), Richland, WA (United States)

    2015-07-09

    This report describes the results from long-term laboratory leach tests performed at Pacific Northwest National Laboratory (PNNL) for Washington River Protection Solutions (WRPS) to evaluate the release of key constituents from monoliths of Cast Stone prepared with four simulated low-activity waste (LAW) liquid waste streams. Specific objectives of the Cast Stone long-term leach tests described in this report focused on four activities: 1. Extending the leaching times for selected ongoing EPA-1315 tests on monoliths made with LAW simulants beyond the conventional 63-day time period up to 609 days reported herein (with some tests continuing that will be documented later) in an effort to evaluate long-term leaching properties of Cast Stone to support future performance assessment activities. 2. Starting new EPA-1315 leach tests on archived Cast Stone monoliths made with four LAW simulants using two leachants (deionized water [DIW] and simulated Hanford Integrated Disposal Facility (IDF) Site vadose zone pore water [VZP]). 3. Evaluating the impacts of varying the iodide loading (starting iodide concentrations) in one LAW simulant (7.8 M Na Hanford Tank Waste Operations Simulator (HTWOS) Average) by manufacturing new Cast Stone monoliths and repeating the EPA-1315 leach tests using DIW and the VZP leachants. 4. Evaluating the impacts of using a non-pertechnetate form of Tc that is present in some Hanford tanks. In this activity one LAW simulant (7.8 M Na HTWOS Average) was spiked with a Tc(I)-tricarbonyl gluconate species and then solidified into Cast Stone monoliths. Cured monoliths were leached using the EPA-1315 leach protocol with DIW and VZP. The leach results for the Tc-Gluconate Cast Stone monoliths were compared to Cast Stone monoliths pertechnetate.

  15. Monolithic arrays of surface emitting laser NOR logic devices

    OpenAIRE

    Song, J.-I-; Lee, Y. H.; Yoo, J. Y.; Shin, J H; Scherer, A.; Leibenguth, R. E.

    1993-01-01

    Monolithic, cascadable, laser-logic-device arrays have been realized and characterized. The monolithic surface-emitting laser logic (SELL) device consists of an AlGaAs superlattice lasing around 780 nm connected to a heterojunction phototransistor (HPT) in parallel and a resistor in series. Arrays up to 8×8 have been fabricated, and 2×2 arrays show uniform characteristics. The optical logic output is switched off with 40 μW incident optical input.

  16. Preparation of a pipette tip-based molecularly imprinted solid-phase microextraction monolith by epitope approach and its application for determination of enkephalins in human cerebrospinal fluid.

    Science.gov (United States)

    Li, Hua; Li, Dan

    2015-11-10

    In this study, a novel molecularly imprinted polymer (MIP) monolith for highly selective extraction of enkephalins was synthesized and prepared in a micropipette tip using epitope imprinting technique. The synthesized MIPs were characterized by scanning electron microscope (SEM) and infrared spectroscopy. A molecularly imprinted solid-phase microextraction (MISPME) method was developed for extraction of enkephalins in aqueous solutions. The parameters affecting MISPME were optimized. The results indicated that this MIP monolith exhibited specific recognition capability, high enrichment efficiency and excellent reusability for enkephalins. MALDI-TOF MS analysis demonstrated that this MIP monolith can act as a useful tool for highly selective purification and enrichment of enkephalin, a kind of low abundance protein, from high-abundance proteins in human cerebrospinal fluids (CSF). Employed this MIP monolith as solid-phase microextraction column, quantitative assay of enkephalins in human CSF was developed by HPLC-ultraviolet (UV) detection in this work. The detection limits were 0.05-0.08nM. This MISPME/HPLC-UV method was used to quantify Met-enkephalin and Leu-enkephalin levels in the CSF of patients with cancer pain. PMID:26263061

  17. Preparation of a pipette tip-based molecularly imprinted solid-phase microextraction monolith by epitope approach and its application for determination of enkephalins in human cerebrospinal fluid.

    Science.gov (United States)

    Li, Hua; Li, Dan

    2015-11-10

    In this study, a novel molecularly imprinted polymer (MIP) monolith for highly selective extraction of enkephalins was synthesized and prepared in a micropipette tip using epitope imprinting technique. The synthesized MIPs were characterized by scanning electron microscope (SEM) and infrared spectroscopy. A molecularly imprinted solid-phase microextraction (MISPME) method was developed for extraction of enkephalins in aqueous solutions. The parameters affecting MISPME were optimized. The results indicated that this MIP monolith exhibited specific recognition capability, high enrichment efficiency and excellent reusability for enkephalins. MALDI-TOF MS analysis demonstrated that this MIP monolith can act as a useful tool for highly selective purification and enrichment of enkephalin, a kind of low abundance protein, from high-abundance proteins in human cerebrospinal fluids (CSF). Employed this MIP monolith as solid-phase microextraction column, quantitative assay of enkephalins in human CSF was developed by HPLC-ultraviolet (UV) detection in this work. The detection limits were 0.05-0.08nM. This MISPME/HPLC-UV method was used to quantify Met-enkephalin and Leu-enkephalin levels in the CSF of patients with cancer pain.

  18. Characterization of methacrylate chromatographic monoliths bearing affinity ligands.

    Science.gov (United States)

    Černigoj, Urh; Vidic, Urška; Nemec, Blaž; Gašperšič, Jernej; Vidič, Jana; Lendero Krajnc, Nika; Štrancar, Aleš; Podgornik, Aleš

    2016-09-16

    We investigated effect of immobilization procedure and monolith structure on chromatographic performance of methacrylate monoliths bearing affinity ligands. Monoliths of different pore size and various affinity ligands were prepared and characterized using physical and chromatographic methods. When testing protein A monoliths with different protein A ligand densities, a significant nonlinear effect of ligand density on dynamic binding capacity (DBC) for IgG was obtained and accurately described by Langmuir isotherm curve enabling estimation of protein A utilization as a function of ligand density. Maximal IgG binding capacity was found to be at least 12mg/mL exceeding theoretical monolayer adsorption value of 7.8mg/mL assuming hexagonal packing and IgG hydrodynamic diameter of 11nm. Observed discrepancy was explained by shrinkage of IgG during adsorption on protein A experimentally determined through calculated adsorbed IgG layer thickness of 5.4nm from pressure drop data. For monoliths with different pore size maximal immobilized densities of protein A as well as IgG dynamic capacity linearly correlates with monolith surface area indicating constant ligand utilization. Finally, IgGs toward different plasma proteins were immobilized via the hydrazide coupling chemistry to provide oriented immobilization. DBC was found to be flow independent and was increasing with the size of bound protein. Despite DBC was lower than IgG capacity to immobilized protein A, ligand utilization was higher. PMID:27554023

  19. Single-walled carbon nanotube-based polymer monoliths for the enantioselective nano-liquid chromatographic separation of racemic pharmaceuticals.

    Science.gov (United States)

    Ahmed, Marwa; Yajadda, Mir Massoud Aghili; Han, Zhao Jun; Su, Dawei; Wang, Guoxiu; Ostrikov, Kostya Ken; Ghanem, Ashraf

    2014-09-19

    Single-walled carbon nanotubes were encapsulated into different polymer-based monolithic backbones. The polymer monoliths were prepared via the copolymerization of 20% monomers, glycidyl methacrylate, 20% ethylene glycol dimethacrylate and 60% porogens (36% 1-propanol, 18% 1,4-butanediol) or 16.4% monomers (16% butyl methacrylate, 0.4% sulfopropyl methacrylate), 23.6% ethylene glycol dimethacrylate and 60% porogens (36% 1-propanol, 18% 1,4-butanediol) along with 6% single-walled carbon nanotubes aqueous suspension. The effect of single-walled carbon nanotubes on the chiral separation of twelve classes of pharmaceutical racemates namely; α- and β-blockers, antiinflammatory drugs, antifungal drugs, dopamine antagonists, norepinephrine-dopamine reuptake inhibitors, catecholamines, sedative hypnotics, diuretics, antihistaminics, anticancer drugs and antiarrhythmic drugs was investigated. The enantioselective separation was carried out under multimodal elution to explore the chiral recognition capabilities of single-walled carbon nanotubes using reversed phase, polar organic and normal phase chromatographic conditions using nano-liquid chromatography. Baseline separation was achieved for celiprolol, chlorpheniramine, etozoline, nomifensine and sulconazole under multimodal elution conditions. Satisfactory repeatability was achieved through run-to-run, column-to-column and batch-to-batch investigations. Our findings demonstrate that single-walled carbon nanotubes represent a promising stationary phase for the chiral separation and may open the field for a new class of chiral selectors.

  20. Chloride channels in stroke

    Institute of Scientific and Technical Information of China (English)

    Ya-ping ZHANG; Hao ZHANG; Dayue Darrel DUAN

    2013-01-01

    Vascular remodeling of cerebral arterioles,including proliferation,migration,and apoptosis of vascular smooth muscle cells (VSMCs),is the major cause of changes in the cross-sectional area and diameter of the arteries and sudden interruption of blood flow or hemorrhage in the brain,ie,stroke.Accumulating evidence strongly supports an important role for chloride (Clˉ) channels in vascular remodeling and stroke.At least three Clˉ channel genes are expressed in VSMCs:1) the TMEM16A (or Ano1),which may encode the calcium-activated Clˉ channels (CACCs); 2) the CLC-3 Clˉ channel and Clˉ/H+ antiporter,which is closely related to the volume-regulated Clˉ channels (VRCCs); and 3) the cystic fibrosis transmembrane conductance regulator (CFTR),which encodes the PKA-and PKC-activated Clˉ channels.Activation of the CACCs by agonist-induced increase in intracellular Ca2+ causes membrane depolarization,vasoconstriction,and inhibition of VSMC proliferation.Activation of VRCCs by cell volume increase or membrane stretch promotes the production of reactive oxygen species,induces proliferation and inhibits apoptosis of VSMCs.Activation of CFTR inhibits oxidative stress and may prevent the development of hypertension.In addition,Clˉ current mediated by gammaaminobutyric acid (GABA) receptor has also been implicated a role in ischemic neuron death.This review focuses on the functional roles of Clˉ channels in the development of stroke and provides a perspective on the future directions for research and the potential to develop Clˉ channels as new targets for the prevention and treatment of stroke.

  1. Compact electron beam focusing column

    Energy Technology Data Exchange (ETDEWEB)

    Persaud, Arun; Leung, Ka-Ngo; Reijonen, Jani

    2001-07-13

    A novel design for an electron beam focusing column has been developed at LBNL. The design is based on a low-energy spread multicusp plasma source which is used as a cathode for electron beam production. The focusing column is 10 mm in length. The electron beam is focused by means of electrostatic fields. The column is designed for a maximum voltage of 50 kV. Simulations of the electron trajectories have been performed by using the 2-D simulation code IGUN and EGUN. The electron temperature has also been incorporated into the simulations. The electron beam simulations, column design and fabrication will be discussed in this presentation.

  2. Aluminum based metal-organic framework-polymer monolith in solid-phase microextraction of penicillins in river water and milk samples.

    Science.gov (United States)

    Lirio, Stephen; Liu, Wan-Ling; Lin, Chen-Lan; Lin, Chia-Her; Huang, Hsi-Ya

    2016-01-01

    In this study, aluminum based metal-organic framework (Al-MOF)-organic polymer monoliths were prepared via microwave-assisted polymerization of ethylene dimethacrylate (EDMA), butyl methacrylate (BMA) with different weight percentages of Al-MOF (MIL-53; 37.5-62.5%) and subsequently utilized as sorbent in solid-phase microextraction (SPME) of penicillins (penicillin G, penicillin V, oxacillin, cloxacillin, dicloxacillin, nafcillin). The Al-MOF-polymer was characterized using Fourier transform infrared (FTIR) spectroscopy, powder X-ray diffraction (XRD), scanning electron microscopy (SEM) and SEM-energy-dispersive X-ray spectroscopy (SEM-EDS) to clarify the retained crystalline structure well as the homogeneous dispersion of Al-MOF (MIL-53) in polymer monolith. The developed Al-MOF-polymer (MIL-53) monolithic column was evaluated according to its extraction recovery of penicillins. Several parameters affecting the extraction recoveries of penicillins using fabricated Al-MOF-polymer (MIL-53) monolithic column including different MIL-53 weight percentages, column length, pH, desorption solvent, and mobile phase flow rate were investigated. For comparison, different Al-based MOFs (MIL-68, CYCU-4 and DUT-5) were fabricated using the optimized condition for MIL-53-polymer (sample matrix at pH 3, 200μL desorption volume using methanol, 37.5% of MOF, 4-cm column length at 0.100mLmin(-1) flow rate). Among all the Al-MOF-polymers, MIL-53(Al)-polymer still afforded the best extraction recovery for penicillins ranging from 90.5 to 95.7% for intra-day with less than 3.5% relative standard deviations (RSDs) and inter-day precision were in the range of 90.7-97.6% with less than 4.2% RSDs. Meanwhile, the recoveries for column-to-column were in the range of 89.5-93.5% (<3.4% RSDs) while 88.5-90.5% (<5.8% RSDs) for batch-to-batch (n=3). Under the optimal conditions, the limit of detections were in the range of 0.06-0.26μgL(-1) and limit of quantifications between 0.20 and 0.87

  3. Aluminum based metal-organic framework-polymer monolith in solid-phase microextraction of penicillins in river water and milk samples.

    Science.gov (United States)

    Lirio, Stephen; Liu, Wan-Ling; Lin, Chen-Lan; Lin, Chia-Her; Huang, Hsi-Ya

    2016-01-01

    In this study, aluminum based metal-organic framework (Al-MOF)-organic polymer monoliths were prepared via microwave-assisted polymerization of ethylene dimethacrylate (EDMA), butyl methacrylate (BMA) with different weight percentages of Al-MOF (MIL-53; 37.5-62.5%) and subsequently utilized as sorbent in solid-phase microextraction (SPME) of penicillins (penicillin G, penicillin V, oxacillin, cloxacillin, dicloxacillin, nafcillin). The Al-MOF-polymer was characterized using Fourier transform infrared (FTIR) spectroscopy, powder X-ray diffraction (XRD), scanning electron microscopy (SEM) and SEM-energy-dispersive X-ray spectroscopy (SEM-EDS) to clarify the retained crystalline structure well as the homogeneous dispersion of Al-MOF (MIL-53) in polymer monolith. The developed Al-MOF-polymer (MIL-53) monolithic column was evaluated according to its extraction recovery of penicillins. Several parameters affecting the extraction recoveries of penicillins using fabricated Al-MOF-polymer (MIL-53) monolithic column including different MIL-53 weight percentages, column length, pH, desorption solvent, and mobile phase flow rate were investigated. For comparison, different Al-based MOFs (MIL-68, CYCU-4 and DUT-5) were fabricated using the optimized condition for MIL-53-polymer (sample matrix at pH 3, 200μL desorption volume using methanol, 37.5% of MOF, 4-cm column length at 0.100mLmin(-1) flow rate). Among all the Al-MOF-polymers, MIL-53(Al)-polymer still afforded the best extraction recovery for penicillins ranging from 90.5 to 95.7% for intra-day with less than 3.5% relative standard deviations (RSDs) and inter-day precision were in the range of 90.7-97.6% with less than 4.2% RSDs. Meanwhile, the recoveries for column-to-column were in the range of 89.5-93.5% (polymer was applied for the extraction of penicillin in river water and milk by spiking trace-level penicillin for as low as 50μgL(-1) and 100μgL(-1) with recoveries ranging from 80.8% to 90.9% (<6.7% RSDs) in

  4. Use of small diameter column particles to enhance HPLC determination of histamine and other biogenic amines in seafood

    DEFF Research Database (Denmark)

    Simat, Vida; Dalgaard, Paw

    2011-01-01

    Pre-column and post-column HPLC derivatization methods were modified and evaluated for the identification and quantification of nine biogenic amines in seafood Two HPLC methods with column particles of 1 8 mu m or 3 mu m in diameter were modified and compared to classical methods using 5 mu m...... column particles Both pre-column derivatization with dansyl chloride and post-column derivatization with O-phthalaldehyde were studied The HPLC methods were compared with respect to the time of elution eluent consumption backpressure as well as separation sensitivity recovery and repeatability...... for determination of biogenic amines in lean canned tuna and fatty frozen herring The modified methods using smaller column particles of 1 8 mu m or 3 mu m allowed biogenic amines to be separated and quantified faster (23-59%) and with less eluent consumption (59-62%) than classical HPLC methods Backpressures were...

  5. Use of emulsified vegetable oil to support bioremediation of TCE DNAPL in soil columns

    Science.gov (United States)

    Harkness, Mark; Fisher, Angela

    2013-08-01

    The interaction between emulsified vegetable oil (EVO) and trichloroethylene (TCE) dense non-aqueous phase liquid (DNAPL) was observed using two soil columns and subsequent reductive dechlorination of TCE was monitored over a three year period. Dyed TCE DNAPL (~ 75 g) was emplaced in one column (DNAPL column), while the second was DNAPL-free (plume column). EVO was added to both columns and partitioning of the EVO into the TCE DNAPL was measured and quantified. TCE (1.9 mM) was added to the influent of the plume column to simulate conditions down gradient of a DNAPL source area and the columns were operated independently for more than one year, after which they were connected in series. Initially limited dechlorination of TCE to cDCE was observed in the DNAPL column, while the plume column supported complete reductive dechlorination of TCE to ethene. Upon connection and reamendment of the plume column with EVO, near saturation levels of TCE from the effluent of the DNAPL column were rapidly dechlorinated to c-DCE and VC in the plume column; however, this high rate dechlorination produced hydrochloric acid which overwhelmed the buffering capacity of the system and caused the pH to drop below 6.0. Dechlorination efficiency in the columns subsequently deteriorated, as measured by the chloride production and Dehalococcoides counts, but was restored by adding sodium bicarbonate buffer to the influent groundwater. Robust dechlorination was eventually observed in the DNAPL column, such that the TCE DNAPL was largely removed by the end of the study. Partitioning of the EVO into the DNAPL provided significant operational benefits to the remediation system both in terms of electron donor placement and longevity.

  6. Monolithic CMOS imaging x-ray spectrometers

    Science.gov (United States)

    Kenter, Almus; Kraft, Ralph; Gauron, Thomas; Murray, Stephen S.

    2014-07-01

    The Smithsonian Astrophysical Observatory (SAO) in collaboration with SRI/Sarnoff is developing monolithic CMOS detectors optimized for x-ray astronomy. The goal of this multi-year program is to produce CMOS x-ray imaging spectrometers that are Fano noise limited over the 0.1-10keV energy band while incorporating the many benefits of CMOS technology. These benefits include: low power consumption, radiation "hardness", high levels of integration, and very high read rates. Small format test devices from a previous wafer fabrication run (2011-2012) have recently been back-thinned and tested for response below 1keV. These devices perform as expected in regards to dark current, read noise, spectral response and Quantum Efficiency (QE). We demonstrate that running these devices at rates ~> 1Mpix/second eliminates the need for cooling as shot noise from any dark current is greatly mitigated. The test devices were fabricated on 15μm, high resistivity custom (~30kΩ-cm) epitaxial silicon and have a 16 by 192 pixel format. They incorporate 16μm pitch, 6 Transistor Pinned Photo Diode (6TPPD) pixels which have ~40μV/electron sensitivity and a highly parallel analog CDS signal chain. Newer, improved, lower noise detectors have just been fabricated (October 2013). These new detectors are fabricated on 9μm epitaxial silicon and have a 1k by 1k format. They incorporate similar 16μm pitch, 6TPPD pixels but have ~ 50% higher sensitivity and much (3×) lower read noise. These new detectors have undergone preliminary testing for functionality in Front Illuminated (FI) form and are presently being prepared for back thinning and packaging. Monolithic CMOS devices such as these, would be ideal candidate detectors for the focal planes of Solar, planetary and other space-borne x-ray astronomy missions. The high through-put, low noise and excellent low energy response, provide high dynamic range and good time resolution; bright, time varying x-ray features could be temporally and

  7. Biasable, Balanced, Fundamental Submillimeter Monolithic Membrane Mixer

    Science.gov (United States)

    Siegel, Peter; Schlecht, Erich; Mehdi, Imran; Gill, John; Velebir, James; Tsang, Raymond; Dengler, Robert; Lin, Robert

    2010-01-01

    This device is a biasable, submillimeter-wave, balanced mixer fabricated using JPL s monolithic membrane process a simplified version of planar membrane technology. The primary target application is instrumentation used for analysis of atmospheric constituents, pressure, temperature, winds, and other physical and chemical properties of the atmospheres of planets and comets. Other applications include high-sensitivity gas detection and analysis. This innovation uses a balanced configuration of two diodes allowing the radio frequency (RF) signal and local oscillator (LO) inputs to be separated. This removes the need for external diplexers that are inherently narrowband, bulky, and require mechanical tuning to change frequency. Additionally, this mixer uses DC bias-ability to improve its performance and versatility. In order to solve problems relating to circuit size, the GaAs membrane process was created. As much of the circuitry as possible is fabricated on-chip, making the circuit monolithic. The remainder of the circuitry is precision-machined into a waveguide block that holds the GaAs circuit. The most critical alignments are performed using micron-scale semiconductor technology, enabling wide bandwidth and high operating frequencies. The balanced mixer gets superior performance with less than 2 mW of LO power. This can be provided by a simple two-stage multiplier chain following an amplifier at around 90 GHz. Further, the diodes are arranged so that they can be biased. Biasing pushes the diodes closer to their switching voltage, so that less LO power is required to switch the diodes on and off. In the photo, the diodes are at the right end of the circuit. The LO comes from the waveguide at the right into a reduced-height section containing the diodes. Because the diodes are in series to the LO signal, they are both turned on and off simultaneously once per LO cycle. Conversely, the RF signal is picked up from the RF waveguide by the probe at the left, and flows

  8. Monolithic JFET preamplifier for ionization chamber calorimeters

    International Nuclear Information System (INIS)

    A prototype preamplifier circuit is presented for use in SSC ionization chamber calorimeters. It consists of a new type of silicon integrated circuit comprised of very low noise junction FET (JFET) components. Presently, monolithic preamplifier circuits for use in highly segmented detectors are made of implanted channel JFETs or MOS devices. While such circuits solve the density problems, they do not perform to the same level of low noise characteristics as found in discrete JFET components. The JFETs which comprise this new integrated circuit preserve the excellent low noise performance normally found only in discrete JFETs. JFETs also are much more radiation resistant and less prone to damage by electromagnetic discharges than MOS transistors. Two innovative fabrication processes are discussed. They solve the difficult gate-to-gate isolation problem needed to manufacture JFET integrated circuits. Both allow the use of an epitaxially formed channel and a diffused gate, as in standard discrete JFET processing. This, presumably, results in JFETs which exhibit lower noise than those made with implanted channels. 11 refs., 9 figs

  9. Monolithic supports with unique geometries and enhanced mass transfer.

    Energy Technology Data Exchange (ETDEWEB)

    Stuecker, John Nicholas; Ferrizz, Robert Matthew; Cesarano, Joseph, III; Miller, James Edward

    2004-01-01

    The catalytic combustion of natural gas has been the topic of much research over the past decade. Interest in this technology results from a desire to decrease or eliminate the emissions of harmful nitrogen oxides (NOX) from gas turbine power plants. A low-pressure drop catalyst support, such as a ceramic monolith, is ideal for this high-temperature, high-flow application. A drawback to the traditional honeycomb monoliths under these operating conditions is poor mass transfer to the catalyst surface in the straight-through channels. 'Robocasting' is a unique process developed at Sandia National Laboratories that can be used to manufacture ceramic monoliths with alternative 3-dimensional geometries, providing tortuous pathways to increase mass transfer while maintaining low pressure drops. This report details the mass transfer effects for novel 3-dimensional robocast monoliths, traditional honeycomb-type monoliths, and ceramic foams. The mass transfer limit is experimentally determined using the probe reaction of CO oxidation over a Pt / {gamma}-Al{sub 2}O{sub 3} catalyst, and the pressure drop is measured for each monolith sample. Conversion versus temperature data is analyzed quantitatively using well-known dimensionless mass transfer parameters. The results show that, relative to the honeycomb monolith support, considerable improvement in mass transfer efficiency is observed for robocast samples synthesized using an FCC-like geometry of alternating rods. Also, there is clearly a trade-off between enhanced mass transfer and increased pressure drop, which can be optimized depending on the particular demands of a given application.

  10. An Undergraduate Column Chromatography Experiment.

    Science.gov (United States)

    Danot, M.; And Others

    1984-01-01

    Background information, list of materials needed, and procedures used are provided for an experiment designed to introduce undergraduate students to the theoretical and technical aspects of column chromatography. The experiment can also be shortened to serve as a demonstration of the column chromatography technique. (JN)

  11. Considerations on influence of charge distribution on determination of biomolecules and microorganisms and tailoring the monolithic (continuous bed) materials for bioseparations.

    Science.gov (United States)

    Szumski, Michał; Kłodzińska, Ewa; Jarmalaviciene, Reda; Maruska, Audrius; Buszewski, Bogusław

    2007-02-23

    The importance of continuous beds (monoliths) as separation materials is connected with their better chromatographic properties and easier preparation in comparison to particulate-packed columns. Moreover the tuning of porosity as well as surface chemistry can lead to obtaining of highly selective materials, especially useful in separation of biologically important compounds or even microorganisms. To obtain high selectivity for such analytes as e.g. proteins, it is often important to have a knowledge about their shape, size, charge and finally charge distribution. This article presents our considerations on the charge distribution on the monolithic stationary phase and surface of such species as proteins or microorganisms as well as its eventual influence on the separation or sample preparation processes and tuning of their selectivity. PMID:17137631

  12. Mush Column Magma Chambers

    Science.gov (United States)

    Marsh, B. D.

    2002-12-01

    Magma chambers are a necessary concept in understanding the chemical and physical evolution of magma. The concept may well be similar to a transfer function in circuit or time series analysis. It does what needs to be done to transform source magma into eruptible magma. In gravity and geodetic interpretations the causative body is (usually of necessity) geometrically simple and of limited vertical extent; it is clearly difficult to `see' through the uppermost manifestation of the concentrated magma. The presence of plutons in the upper crust has reinforced the view that magma chambers are large pots of magma, but as in the physical representation of a transfer function, actual magma chambers are clearly distinct from virtual magma chambers. Two key features to understanding magmatic systems are that they are vertically integrated over large distances (e.g., 30-100 km), and that all local magmatic processes are controlled by solidification fronts. Heat transfer considerations show that any viable volcanic system must be supported by a vertically extensive plumbing system. Field and geophysical studies point to a common theme of an interconnected stack of sill-like structures extending to great depth. This is a magmatic Mush Column. The large-scale (10s of km) structure resembles the vertical structure inferred at large volcanic centers like Hawaii (e.g., Ryan et al.), and the fine scale (10s to 100s of m) structure is exemplified by ophiolites and deeply eroded sill complexes like the Ferrar dolerites of the McMurdo Dry Valleys, Antarctica. The local length scales of the sill reservoirs and interconnecting conduits produce a rich spectrum of crystallization environments with distinct solidification time scales. Extensive horizontal and vertical mushy walls provide conditions conducive to specific processes of differentiation from solidification front instability to sidewall porous flow and wall rock slumping. The size, strength, and time series of eruptive behavior

  13. ADVANCED GASIFICATION MERCURY/TRACE METAL CONTROL WITH MONOLITH TRAPS

    Energy Technology Data Exchange (ETDEWEB)

    Mark A. Musich; Michael L. Swanson; Grant E. Dunham; Joshua J. Stanislowski

    2010-07-31

    Two Corning monoliths and a non-carbon-based material have been identified as potential additives for mercury capture in syngas at temperatures above 400°F and pressure of 600 psig. A new Corning monolith formulation, GR-F1-2189, described as an active sample appeared to be the best monolith tested to date. The Corning SR Liquid monolith concept continues to be a strong candidate for mercury capture. Both monolith types allowed mercury reduction to below 5-μg/m3 (~5 ppb), a current U.S. Department of Energy (DOE) goal for trace metal control. Preparation methods for formulating the SR Liquid monolith impacted the ability of the monolith to capture mercury. The Energy & Environmental Research Center (EERC)-prepared Noncarbon Sorbents 1 and 2 appeared to offer potential for sustained and significant reduction of mercury concentration in the simulated fuel gas. The Noncarbon Sorbent 1 allowed sustained mercury reduction to below 5-μg/m3 (~5 ppb). The non-carbon-based sorbent appeared to offer the potential for regeneration, that is, desorption of mercury by temperature swing (using nitrogen and steam at temperatures above where adsorption takes place). A Corning cordierite monolith treated with a Group IB metal offered limited potential as a mercury sorbent. However, a Corning carbon-based monolith containing prereduced metallic species similar to those found on the noncarbon sorbents did not exhibit significant or sustained mercury reduction. EERC sorbents prepared with Group IB and IIB selenide appeared to have some promise for mercury capture. Unfortunately, these sorbents also released Se, as was evidenced by the measurement of H2Se in the effluent gas. All sorbents tested with arsine or hydrogen selenide, including Corning monoliths and the Group IB and IIB metal-based materials, showed an ability to capture arsine or hydrogen selenide at 400°F and 600 psig. Based on current testing, the noncarbon metal-based sorbents appear to be the most effective arsine

  14. Prepared polymethacrylate-based monoliths for the separation of cations by non-suppressed capillary ion chromatography.

    Science.gov (United States)

    Li, Jing; Zhu, Yan

    2014-01-01

    This paper describes a novel analytical system for non-suppressed capillary ion chromatography. Methacrylate monolithic columns were prepared from silanized fused-silica capillaries of 320 µm i.d. by in situ polymerization of glycidyl methacrylate and ethylene dimethacrylate in the presence of 1,4-butanediol, 1-propanol and water as the porogen solvents. The introduction of cation-exchange sites was achieved by sulfonating the matrix with sodium sulfite to produce total cation-exchange capacities in the range of 45-105 μequiv/mL for a 25 cm column. The conditions (concentrations of sodium sulfite solution, reacting time and modified flow rate) of sulfonation were optimized. The hydrodynamic and chromatographic performances were estimated. Coupled with a conductivity detector, a capillary ion chromatography system was set up with the prepared column. Finally, the resultant column was used for the separations of five common univalent cations (Li(+), Na(+), NH4(+), K(+) and Cs(+)) using methanesulfonic acid as the eluent and four divalent cations (Mg(2+), Ca(2+), Sr(2+) and Ba(2+)) by non-suppressed capillary ion chromatography; the chromatographic parameters were further researched.

  15. New Graphene Form of Nanoporous Monolith for Excellent Energy Storage.

    Science.gov (United States)

    Bi, Hui; Lin, Tianquan; Xu, Feng; Tang, Yufeng; Liu, Zhanqiang; Huang, Fuqiang

    2016-01-13

    Extraordinary tubular graphene cellular material of a tetrahedrally connected covalent structure was very recently discovered as a new supermaterial with ultralight, ultrastiff, superelastic, and excellent conductive characteristics, but no high specific surface area will keep it from any next-generation energy storage applications. Herein, we prepare another new graphene monolith of mesoporous graphene-filled tubes instead of hollow tubes in the reported cellular structure. This graphene nanoporous monolith is also composed of covalently bonded carbon network possessing high specific surface area of ∼1590 m(2) g(-1) and electrical conductivity of ∼32 S cm(-1), superior to graphene aerogels and porous graphene forms self-assembled by graphene oxide. This 3D graphene monolith can support over 10 000 times its own weight, significantly superior to CNT and graphene cellular materials with a similar density. Furthermore, pseudocapacitance-active functional groups are introduced into the new nanoporous graphene monolith as an electrode material in electrochemical capacitors. Surprisingly, the electrode of 3D mesoporous graphene has a specific capacitance of 303 F g(-1) and maintains over 98% retention after 10 000 cycles, belonging to the list for the best carbon-based active materials. The macroscopic mesoporous graphene monolith suggests the great potential as an electrode for supercapacitors in energy storage areas.

  16. 整体材料的研制及其在蛋白质组色谱分离中的应用%Preparation of monolithic materials and applications in proteomic chromatographic separation

    Institute of Scientific and Technical Information of China (English)

    吴慈; 梁玉; 梁振; 张丽华; 张玉奎

    2016-01-01

    With the advantages of facile preparation,fast mass transfer,low backpressure and easy modifica-tion,monolithic materials have been widely used in chromatographic separation.In order to familiarize profes-sionals of home and abroad with the present situation of monolithic materials,this review mainly summarizes the preparation methods of different kinds of monolithic materials (including organic polymer monoliths,silica-based monoliths,organic-inorganic hybrid silica monoliths)and their applications in the separation of proteins or peptides in proteomics.It was pointed out that compared with packed column,monolithic packed column efficiency was to be further improved from the performance of monolithic materials,such as specific surface area,pore size distribution,stablity and hydrophilicity.Taking advantage of the low backpressure of monolithic materials,the capillary monolithic column with superlong and superfine inner diameter was prepared in order to make high efficient separation analysis of macro proteomics samples.With the further study of monolithic materials preparation technology,monolithic materials will play more important role in the fields of food safety, life science and environment.%整体材料由于具有制备简单、传质速度快、低背压、表面易于修饰等优势,在色谱分离领域中应用非常广泛。为使业界了解国内外对整体材料研制的现状,对有机聚合物整体材料、硅胶整体材料、有机-无机杂化整体材料三种整体材料的制备方法及其在蛋白质组学中蛋白质和肽段色谱分离中的应用进行了综述,指出:与填充柱相比,整体柱的分离柱效仍有待进一步提高,可以从整体材料的性能,如比表面积、孔径分布、稳定性、亲水性等方面进行改进。利用整体材料低背压的优势,可制备超长、超细内径毛细管整体柱,有利于微量蛋白质组学样品的高效分离分析。随着对整体材料制备

  17. Monolithic View of Galaxy Formation and Evolution

    Directory of Open Access Journals (Sweden)

    Cesare Chiosi

    2014-07-01

    Full Text Available We review and critically discuss the current understanding of galaxy formation and evolution limited to Early Type Galaxies (ETGs as inferred from the observational data and briefly contrast the hierarchical and quasi-monolithic paradigms of formation and evolution. Since in Cold Dark Matter (CDM cosmogony small scale structures typically collapse early and form low-mass haloes that subsequently can merge to assembly larger haloes, galaxies formed in the gravitational potential well of a halo are also expected to merge thus assembling their mass hierarchically. Mergers should occur all over the Hubble time and large mass galaxies should be in place only recently. However, recent observations of high redshift galaxies tell a different story: massive ETGs are already in place at high redshift. To this aim, we propose here a revision of the quasi-monolithic scenario as an alternative to the hierarchical one, in which mass assembling should occur in early stages of a galaxy lifetime and present recent models of ETGs made of Dark and Baryonic Matter in a Λ-CDM Universe that obey the latter scheme. The galaxies are followed from the detachment from the linear regime and Hubble flow at z ≥ 20 down to the stage of nearly complete assembly of the stellar content (z ∼ 2 − 1 and beyond.  It is found that the total mass (Mh = MDM + MBM and/or initial over-density of the proto-galaxy drive the subsequent star formation histories (SFH. Massive galaxies (Mh ~ _1012M⊙ experience a single, intense burst of star formation (with rates ≥ 103M⊙/yr at early epochs, consistently with observations, with a weak dependence on the initial over-density; intermediate mass haloes (Mh~_ 1010 − 1011M⊙ have star formation histories that strongly depend on their initial over-density; finally, low mass haloes (Mh ~_ 109M⊙ always have erratic, burst-like star forming histories. The present-day properties (morphology, structure, chemistry and photometry of the

  18. Stability of column-supported steel cylinders with engaged columns

    OpenAIRE

    DOERICH, Cornelia; Vanlaere, Wesley; Lagae, Guy; Rotter, J. Michael

    2009-01-01

    p. 2535-2546 Steel silos are often supported on a small number of columns to facilitate emptying operations. The connection between these columns and an elevated cylindrical metal silo shell is a long-standing difficult problem in shell analysis. The presence of local supports beneath a cylinder leads to stress concentrations in the cylindrical wall just above the supports, which can cause buckling or plastic collapse and consequently failure of the entire structure. Engaged co...

  19. Stability of succinylcholine chloride injection.

    Science.gov (United States)

    Schmutz, C W; Mühlebach, S F

    1991-03-01

    The stability of succinylcholine chloride injection prepared by a hospital pharmacy was studied under a wide variety of conditions. Batches of succinylcholine chloride injection 10 mg/mL containing sodium chloride, methyl-4-hydroxybenzoate, hydrochloric acid, and water were prepared. Samples were tested for the effect of initial pH (3.0 and 4.2) and sterilization (steam treatment at 100 degrees C for 30 minutes and 121 degrees C for 20 minutes) on stability after three weeks; long-term stability under refrigeration (12, 17, and 23 months of storage at 4 degrees C); and the effect of storage temperature (4-6 degrees C, 20-26 degrees C, 35 degrees C, and 70 degrees C) and light exposure at various intervals up to 12 months. Samples were analyzed by thin-layer chromatography (TLC) and high-performance liquid chromatography (HPLC). Unlike heating at 121 degrees C, heating at 100 degrees C produced no significant loss of succinylcholine chloride, independent of the initial pH. Succinylcholine chloride was hydrolyzed only minimally over 23 months if the solution was stored at 4-6 degrees C. A 10% loss of drug content occurred if solutions were kept at 20-26 degrees C for five months, at 35 degrees C for one month, or at 70 degrees C for one day. Initial degradation was slowed if the solution was protected from light. The assessments by TLC proved to be more sensitive than the HPLC measurements. Succinylcholine chloride injection sterilized at 100 degrees C for 30 minutes can be stored for up to five months at room temperature if protected from light. The preparation is stable for at least two years under refrigeration. PMID:2028996

  20. Chloride in vesicular trafficking and function.

    Science.gov (United States)

    Stauber, Tobias; Jentsch, Thomas J

    2013-01-01

    Luminal acidification is of pivotal importance for the physiology of the secretory and endocytic pathways and its diverse trafficking events. Acidification by the proton-pumping V-ATPase requires charge compensation by counterion currents that are commonly attributed to chloride. The molecular identification of intracellular chloride transporters and the improvement of methodologies for measuring intraorganellar pH and chloride have facilitated the investigation of the physiology of vesicular chloride transport. New data question the requirement of chloride for pH regulation of various organelles and furthermore ascribe functions to chloride that are beyond merely electrically shunting the proton pump. This review surveys the currently established and proposed intracellular chloride transporters and gives an overview of membrane-trafficking steps that are affected by the perturbation of chloride transport. Finally, potential mechanisms of membrane-trafficking modulation by chloride are discussed and put into the context of organellar ion homeostasis in general. PMID:23092411

  1. Electrochemical Chloride extraction using external electrodes?

    DEFF Research Database (Denmark)

    Ottosen, Lisbeth M.; Pedersen, Anne Juul

    2006-01-01

    Electrochemical methods for the removal of chloride from concrete have been developed and the methods are primarily designed for situations where corrosion has started due to an increased chloride concentration in the vicinity of the reinforcement. In these methods the reinforcement is used...... as the cathode. However, some unwanted side effects can occur, including alkali-silica reaction and in some cases hydrogen embrittlement. It is also suggested also to use electrochemical chloride extraction in a preventive way in constructions where chloride induced corrosion is likely to be a problem after...... a period of time, i.e. remove the chlorides before the chloride front reaches the reinforcement. If the chlorides are removed from outer few centimetres from the surface, the chloride will not reach the reinforcement and cause damage. By using the electrochemical chloride removal in this preventive way...

  2. Chloride binding of cement-based materials subjected to external chloride environment - A review

    OpenAIRE

    Yuan, Q.; Shi, C; Schutter, G. de; Audenaert, K.; Deng, D.

    2009-01-01

    This paper reviews the chloride binding of cement-based materials subjected to external chloride environments. Chloride ion exist either in the pore solution, chemically bound to the hydration products, or physically held to the surface of the hydration products. Chloride binding of cement-based material is very complicated and influenced by many factors, such as chloride concentration, cement composition, hydroxyl concentration, cation of chloride salt, temperature, supplementary cementing m...

  3. Monolithic fuel cell based power source for burst power generation

    Science.gov (United States)

    Fee, D. C.; Blackburn, P. E.; Busch, D. E.; Dees, D. W.; Dusek, J.; Easler, T. E.; Ellingson, W. A.; Flandermeyer, B. K.; Fousek, R. J.; Heiberger, J. J.

    A unique fuel cell coupled with a low power nuclear reactor presents an attractive approach for SDI burst power requirements. The monolithic fuel cell looks attractive for space applications and represents a quantum jump in fuel cell technology. Such a breakthrough in design is the enabling technology for lightweight, low volume power sources for space based pulse power systems. The monolith is unique among fuel cells in being an all solid state device. The capability for miniaturization, inherent in solid state devices, gives the low volume required for space missions. In addition, the solid oxide fuel cell technology employed in the monolith has high temperature reject heat and can be operated in either closed or open cycles. Both these features are attractive for integration into a burst power system.

  4. Preliminary shielding analysis for the CSNS target station monolith

    Institute of Scientific and Technical Information of China (English)

    张斌; 陈义学; 杨寿海; 吴军; 殷雯; 梁天骄; 贾学军

    2010-01-01

    The construction of the China Spallation Neutron Source (CSNS) has been initiated at Dongguan,Guangdong,China.In spallation neutron sources the target station monolith is contaminated by a large number of fast neutrons whose energies can be as large as those of the protons of the proton beam directed towards the tungsten target.A detailed radiation transport analysis of the target station monolith is important for the construction of the CSNS.The analysis is performed using the coupled Monte Carlo and multi-dimensional discrete ordinates method.Successful elimination of the primary ray effects via the two-dimensional uncollided flux and first collision source methodology is also illustrated.The dose at the edge of the monolith is calculated.The results demonstrate that the doses received by the hall staff members are below the required standard limit.

  5. A Possible Astronomically Aligned Monolith at Gardom's Edge

    CERN Document Server

    Brown, D; Bemand, E

    2012-01-01

    A unique triangular shaped monolith located within the Peak District National Park at Gardom's Edge could be intentionally astronomically aligned. It is set within a landscape rich in late Neolithic and Bronze Age remains. We show that the stone is most likely in its original orientation owing to its clear signs of erosion and associated to the time period of the late Neolithic. It is tilted towards South and its North side slopes at an angle equal to the maximum altitude of the Sun at mid-summer. This alignment emphasizes the changing declinations of the Sun during the seasons as well as giving an indication of mid-summers day. This functionality is achieved by an impressive display of light and shadow on the North-facing side of the Monolith. Together with other monuments in the close vicinity the monolith would have represented an ideal marker or social arena for seasonal gatherings for the else dispersed small communities.

  6. Tooth-colored CAD/CAM monolithic restorations.

    Science.gov (United States)

    Reich, S

    2015-01-01

    A monolithic restoration (also known as a full contour restoration) is one that is manufactured from a single material for the fully anatomic replacement of lost tooth structure. Additional staining (followed by glaze firing if ceramic materials are used) may be performed to enhance the appearance of the restoration. For decades, monolithic restoration has been the standard for inlay and partial crown restorations manufactured by both pressing and computer-aided design and manufacturing (CAD/CAM) techniques. A limited selection of monolithic materials is now available for dental crown and bridge restorations. The IDS (2015) provided an opportunity to learn about and evaluate current trends in this field. In addition to new developments, established materials are also mentioned in this article to complete the picture. In line with the strategic focus of the IJCD, the focus here is naturally on CAD/CAM materials. PMID:26110926

  7. Cerec anterior crowns: restorative options with monolithic ceramic materials.

    Science.gov (United States)

    Reich, Sven; Fiedlar, Kurt

    2013-01-01

    The aim of this article is to discuss the different types of monolithic ceramic crowns that can be placed on anterior teeth with existing shoulder preparations. Anterior crowns were indicated for the teeth 12 to 22 in the present case. The patient, a 65-year-old male, had received all-ceramic crowns 20 years earlier, which had started to develop cracks and palatal fractures over the last few years. The patient's teeth were prepared and four sets of crowns were fabricated using different monolithic ceramic materials: IPS e.max CAD, Cerec Blocs C In, VITABLOCS Real Life, and ENAMIC. Both shade characterization and crystallization firing were performed on the monolithic lithium disilicate glass ceramic crowns. The silicate ceramic crowns received glaze firing alone. The crowns made of hybrid ceramic (ENAMIC) were treated with a polymer sealant. PMID:24555406

  8. 102 W monolithic single frequency Tm-doped fiber MOPA.

    Science.gov (United States)

    Wang, Xiong; Zhou, Pu; Wang, Xiaolin; Xiao, Hu; Si, Lei

    2013-12-30

    We demonstrate a high power all-fiber single frequency Tm-doped fiber amplifier. The maximum output power reached 102 W and the central wavelength was 1.97 μm. The single frequency laser signal from a seed laser was amplified based on a monolithic master oscillator power amplifier (MOPA) configuration. The slope efficiency was about 50% against the absorbed pump power. Neither parasitic lasing nor nonlinear effect was observed in the monolithic fiber amplifier. The SBS threshold of the single frequency Tm-doped fiber amplifier was analyzed and estimated. The output power is not limited by the SBS threshold and could be further improved by increasing the pump power. To the best of our knowledge, this is the first demonstration of average power exceeding 100 W from monolithic all-fiber laser near 2 μm wavelength. PMID:24514831

  9. Shear bond strength of indirect composite material to monolithic zirconia

    Science.gov (United States)

    2016-01-01

    PURPOSE This study aimed to evaluate the effect of surface treatments on bond strength of indirect composite material (Tescera Indirect Composite System) to monolithic zirconia (inCoris TZI). MATERIALS AND METHODS Partially stabilized monolithic zirconia blocks were cut into with 2.0 mm thickness. Sintered zirconia specimens were divided into different surface treatment groups: no treatment (control), sandblasting, glaze layer & hydrofluoric acid application, and sandblasting + glaze layer & hydrofluoric acid application. The indirect composite material was applied to the surface of the monolithic zirconia specimens. Shear bond strength value of each specimen was evaluated after thermocycling. The fractured surface of each specimen was examined with a stereomicroscope and a scanning electron microscope to assess the failure types. The data were analyzed using one-way analysis of variance (ANOVA) and Tukey LSD tests (α=.05). RESULTS Bond strength was significantly lower in untreated specimens than in sandblasted specimens (Pzirconia. PMID:27555895

  10. Design of Monolithic Integrator for Strain-to-Frequency Converter

    Directory of Open Access Journals (Sweden)

    Tuan Mohd. Khairi Tuan Mat

    2012-01-01

    Full Text Available Strain-to-Frequency converter (SFC is a one of the analog conditioner tools that converts any strain signal to the frequency signal. The basic concept of SFC is by detecting any changing of strains, then converting the strain to the voltage signal and converting the voltage signal to the frequency signal. This tool consists of 3 main  components which are strain gauge, differential integrator and comparator. This paper presents the designing and analysis of monolithic integrator that to be used in the Strain-toFrequency converter. The primary goal is to design and simulate the performance of monolithic integrator for SFC using GATEWAY Silvaco Electronic Design Automation (S EDA tools and EXPERT software. The performances of SFC using the designed monolithic integrator are also investigated.

  11. Water Column Sonar Data Collection

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The collection and analysis of water column sonar data is a relatively new avenue of research into the marine environment. Primary uses include assessing biological...

  12. Characterization of a Depleted Monolithic Active Pixel Sensor (DMAPS) prototype

    Science.gov (United States)

    Obermann, T.; Havranek, M.; Hemperek, T.; Hügging, F.; Kishishita, T.; Krüger, H.; Marinas, C.; Wermes, N.

    2015-03-01

    New monolithic pixel detectors integrating CMOS electronics and sensor on the same silicon substrate are currently explored for particle tracking in future HEP experiments, most notably at the LHC . The innovative concept of Depleted Monolithic Active Pixel Sensors (DMAPS) is based on high resistive silicon bulk material enabling full substrate depletion and the application of an electrical drift field for fast charge collection, while retaining full CMOS capability for the electronics. The technology (150 nm) used offers quadruple wells and allows to implement the pixel electronics with independently isolated N- and PMOS transistors. Results of initial studies on the charge collection and sensor performance are presented.

  13. Characterization of a Depleted Monolithic Active Pixel Sensor (DMAPS) prototype

    International Nuclear Information System (INIS)

    New monolithic pixel detectors integrating CMOS electronics and sensor on the same silicon substrate are currently explored for particle tracking in future HEP experiments, most notably at the LHC . The innovative concept of Depleted Monolithic Active Pixel Sensors (DMAPS) is based on high resistive silicon bulk material enabling full substrate depletion and the application of an electrical drift field for fast charge collection, while retaining full CMOS capability for the electronics. The technology (150 nm) used offers quadruple wells and allows to implement the pixel electronics with independently isolated N- and PMOS transistors. Results of initial studies on the charge collection and sensor performance are presented

  14. Paladin Enterprises: Monolithic particle physics models global climate.

    CERN Multimedia

    2002-01-01

    Paladin Enterprises presents a monolithic particle model of the universe which will be used by them to build an economical fusion energy system. The model is an extension of the work done by James Clerk Maxwell. Essentially, gravity is unified with electro-magnetic forces and shown to be a product of a closed loop current system, i.e. a particle - monolithic or sub atomic. This discovery explains rapid global climate changes which are evident in the geological record and also provides an explanation for recent changes in the global climate.

  15. Dense carbon monoliths for supercapacitors with outstanding volumetric capacitances

    OpenAIRE

    Kunowsky, Mirko; García Gómez, Alejandra; Barranco, V.; Rojo, José M.; Ibáñez Ulargui, Joaquín; Carruthers, James Donald; Linares Solano, Ángel

    2014-01-01

    A commercially available dense carbon monolith (CM) and four carbon monoliths obtained from it have been studied as electrochemical capacitor electrodes in a two-electrode cell. CM has: (i) very high density (1.17 g cm−3), (ii) high electrical conductivity (9.3 S cm−1), (iii) well-compacted and interconnected carbon spheres, (iv) homogeneous microporous structure and (v) apparent BET surface area of 957 m2g−1. It presents interesting electrochemical behaviors (e.g., excellent gravimetric capa...

  16. Facile "one-pot" synthesis of poly(methacrylic acid)-based hybrid monolith via thiol-ene click reaction for hydrophilic interaction chromatography.

    Science.gov (United States)

    Lv, Xumei; Tan, Wangming; Chen, Ye; Chen, Yingzhuang; Ma, Ming; Chen, Bo; Yao, Shouzhuo

    2016-07-01

    A novel sol-gel "one-pot" approach in tandem with a radical-mediated thiol-ene reaction for the synthesis of a methacrylic acid-based hybrid monolith was developed. The polymerization monomers, tetramethoxysilane (TMOS) and 3-mercaptopropyl trimethoxysilane (MPTS), were hydrolyzed in high-concentration methacrylic acid solution that also served as a hydrophilic functional monomer. The resulting solution was then mixed with initiator (2, 2'-azobis (2-methylpropionamide) dihydrochloride) and porogen (urea, polyethylene glycol 20,000) in a capillary column and polymerized in water bath. The column had a uniform porous structure and a good permeability. The evaluation of the monolith was performed by separation of small molecules including nucleosides, phenols, amides, bases and Triton X-100. The calibration curves for uridine, inosine, adenosine and cytidine were determined. All the calibration curves exhibited good linear regressions (R(2)≥0.995) within the test ranges of 0.5-40μg/mL for four nucleosides. Additionaliy, atypical hydrophilic mechanism was proved by elution order from low to high according to polarity retention time increased with increases in the content of the organic solvent in the mobile phase. Further studies indicated that hydrogen bond and electrostatic interactions existed between the polar analytes and the stationary phase. This was the mechanism of retention. The excellent separation of the BSA digest showed good hydrophility of the column and indicated the potential in separation of complex biological samples. PMID:27264742

  17. 1,5-Diaminotetrazolium chloride

    Directory of Open Access Journals (Sweden)

    Ling-Qiao Meng

    2010-04-01

    Full Text Available The title compound, CH5N6+·Cl−, crystallized with two indepedent 1,5-diaminotetrazolium cations and two independent chloride anions in the asymmetric unit. In the crystal, there are a number of N—H...Cl hydrogen-bonding interactions, which generate a three-dimensional network.

  18. Chloride : The queen of electrolytes?

    NARCIS (Netherlands)

    Berend, Kenrick; van Hulsteijn, Leonard Hendrik; Gans, Rijk O. B.

    2012-01-01

    Background: Channelopathies, defined as diseases that are caused by mutations in genes encoding ion channels, are associated with a wide variety of symptoms and have been documented extensively over the past decade. In contrast, despite the important role of chloride in serum, textbooks in general d

  19. Polyurea-Based Aerogel Monoliths and Composites

    Science.gov (United States)

    Lee, Je Kyun

    2012-01-01

    aerogel insulation material was developed that will provide superior thermal insulation and inherent radiation protection for government and commercial applications. The rubbery polyureabased aerogel exhibits little dustiness, good flexibility and toughness, and durability typical of the parent polyurea polymer, yet with the low density and superior insulation properties associated with aerogels. The thermal conductivity values of polyurea-based aerogels at lower temperature under vacuum pressures are very low and better than that of silica aerogels. Flexible, rubbery polyurea-based aerogels are able to overcome the weak and brittle nature of conventional inorganic and organic aerogels, including polyisocyanurate aerogels, which are generally prepared with the one similar component to polyurethane rubber aerogels. Additionally, with higher content of hydrogen in their structures, the polyurea rubber-based aerogels will also provide inherently better radiation protection than those of inorganic and carbon aerogels. The aerogel materials also demonstrate good hydrophobicity due to their hydrocarbon molecular structure. There are several strategies to overcoming the drawbacks associated with the weakness and brittleness of silica aerogels. Development of the flexible fiber-reinforced silica aerogel composite blanket has proven to be one promising approach, providing a conveniently fielded form factor that is relatively robust in industrial environments compared to silica aerogel monoliths. However, the flexible, silica aerogel composites still have a brittle, dusty character that may be undesirable, or even intolerable, in certain application environments. Although the cross - linked organic aerogels, such as resorcinol- formaldehyde (RF), polyisocyanurate, and cellulose aerogels, show very high impact strength, they are also very brittle with little elongation (i.e., less rubbery). Also, silica and carbon aerogels are less efficient radiation shielding materials due

  20. Monolithic Flexure Pre-Stressed Ultrasonic Horns

    Science.gov (United States)

    Sherrit, Stewart; Bao, Xiaoqi; Badescu, Mircea; Bar-Cohen, Yoseph; Allen, Phillip Grant

    2011-01-01

    High-power ultrasonic actuators are generally assembled with a horn, backing, stress bolt, piezoelectric rings, and electrodes. The manufacturing process is complex, expensive, difficult, and time-consuming. The internal stress bolt needs to be insulated and presents a potential internal discharge point, which can decrease actuator life. Also, the introduction of a center hole for the bolt causes many failures, reducing the throughput of the manufactured actuators. A new design has been developed for producing ultrasonic horn actuators. This design consists of using flexures rather than stress bolts, allowing one to apply pre-load to the piezoelectric material. It also allows one to manufacture them from a single material/plate, rapid prototype them, or make an array in a plate or 3D structure. The actuator is easily assembled, and application of pre-stress greater than 25 MPa was demonstrated. The horn consists of external flexures that eliminate the need for the conventional stress bolt internal to the piezoelectric, and reduces the related complexity. The stress bolts are required in existing horns to provide prestress on piezoelectric stacks when driven at high power levels. In addition, the manufacturing process benefits from the amenability to produce horn structures with internal cavities. The removal of the pre-stress bolt removes a potential internal electric discharge point in the actuator. In addition, it significantly reduces the chances of mechanical failure in the piezoelectric stacks that result from the hole surface in conventional piezoelectric actuators. The novel features of this disclosure are: 1. A design that can be manufactured from a single piece of metal using EDM, precision machining, or rapid prototyping. 2. Increased electromechanical coupling of the horn actuator. 3. Higher energy density. 4. A monolithic structure of a horn that consists of an external flexure or flexures that can be used to pre-stress a solid piezoelectric structure

  1. Optimizing the experimental design of soil columns in saturated and unsaturated transport experiments.

    Science.gov (United States)

    Lewis, Jeffrey; Sjöstrom, Jan

    2010-06-25

    Soil column experiments in both the saturated and unsaturated regimes are widely used for applied and theoretical studies in such diverse fields as transport model evaluation, fate and transport of pesticides, explosives, microbes, heavy metals and non aqueous phase liquids, and for evapotranspiration studies. The apparent simplicity of constructing soil columns conceals a number of technical issues which can seriously affect the outcome of an experiment, such as the presence or absence of macropores, artificial preferential flow paths, non-ideal infiltrate injection and unrealistic moisture regimes. This review examines the literature to provide an analysis of the state of the art for constructing both saturated and unsaturated soil columns. Common design challenges are discussed and best practices for potential solutions are presented. This article discusses both basic principles and the practical advantages and disadvantages of various experimental approaches. Both repacked and monolith-type columns are discussed. The information in this review will assist soil scientists, hydrogeologists and environmental professionals in optimizing the construction and operation of soil column experiments in order to achieve their objectives, while avoiding serious design flaws which can compromise the integrity of their results. PMID:20452088

  2. Determination of urinary 8-hydroxy-2′-deoxyguanosine by capillary electrophoresis with molecularly imprinted monolith in-tube solid phase microextraction

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    Urinary 8-hydroxy-2'-deoxyguanosine(8-OHdG) is an excellent marker of oxidative DNA damage.In this study,employing guanosine as dummy template a novel molecularly imprinted(MIP) monolithic capillary column had been synthesized,and that was used as medium of in-tube solid phase microextraction(SPME).Coupled with capillary electrophoresis-electrochemical detection(CE-ECD),the system of extraction and detection of 8-OHdG in urinary sample had been developed.Because of its greater phase ratio combined with c...

  3. Microbial reductive dehalogenation of vinyl chloride

    Energy Technology Data Exchange (ETDEWEB)

    Spormann, Alfred M [Stanford, CA; Muller, Jochen A [Baltimore, MD; Rosner, Bettina M [Berlin, DE; Von Abendroth, Gregory [Mannheim, DE; Meshulam-Simon, Galit [Los Angeles, CA; McCarty, Perry L [Stanford, CA

    2014-02-11

    Compositions and methods are provided that relate to the bioremediation of chlorinated ethenes, particularly the bioremediation of vinyl chloride by Dehalococcoides-like organisms. An isolated strain of bacteria, Dehalococcoides sp. strain VS, that metabolizes vinyl chloride is provided; the genetic sequence of the enzyme responsible for vinyl chloride dehalogenation; methods of assessing the capability of endogenous organisms at an environmental site to metabolize vinyl chloride; and a method of using the strains of the invention for bioremediation.

  4. Progress of Carbonation in Chloride Contaminated Concretes

    OpenAIRE

    Wang, Yaocheng; Basheer, P.A.M.; Nanukuttan, S; Bai, Y.

    2016-01-01

    Concretes used in marine environment are generally under the cyclic effect of CO2 and chloride ions (Cl-). To date, the influence of carbonation on ingress of chloride ions in concretes has been widely studied; in comparison, study on the influence of Cl- on the progress of carbonation is limited. During the study, concretes were exposed to independent and combined mechanisms of carbonation and chloride ingress regimes. Profiles of apparent pH and chloride concentration were used to indicate ...

  5. From 1D to 3D - macroscopic nanowire aerogel monoliths.

    Science.gov (United States)

    Cheng, Wei; Rechberger, Felix; Niederberger, Markus

    2016-08-01

    Here we present a strategy to assemble one-dimensional nanostructures into a three-dimensional architecture with macroscopic size. With the assistance of centrifugation, we successfully gel ultrathin W18O49 nanowires with diameters of 1 to 2 nm and aspect ratios larger than 100 into 3D networks, which are transformed into monolithic aerogels by supercritical drying.

  6. Translucency of monolithic and core zirconia after hydrothermal aging

    Science.gov (United States)

    Fathy, Salma M.; El-Fallal, Abeer A.; El-Negoly, Salwa A.; El Bedawy, Abu Baker

    2015-01-01

    Abstract Objective: To evaluate the hydrothermal aging effect on the translucency of partially stabilized tetragonal zirconia with yttria (Y-TZP) used as monolithic or fully milled zirconia and of core type. Methods: Twenty disc-shaped specimens (1 and 10 mm) for each type of monolithic and core Y-TZP materials were milled and sintered according to the manufacturer’s instruction. The final specimens were divided into two groups according to the type of Y-TZP used. Translucency parameter (TP) was measured over white and black backgrounds with the diffuse reflectance method; X-ray diffraction (XRD) and scanning electron microscope (SEM) were used to analyze the microstructure of both Y-TZP types before and after aging. Data for TP values was statistically analyzed using Student’s t-test. Results: Monolithic Y-TZP showed the highest TP mean value (16.4 ± 0.316) before aging while core Y-TZP showed the lowest TP mean value (7.05 ± 0.261) after aging. There was a significant difference between the two Y-TZP types before and after hydrothermal aging. XRD analysis showed increases in monoclinic content in both Y-TZP surfaces after aging. Conclusion: Monolithic Y-TZP has a higher chance to low-temperature degradation than core type, which may significantly affect the esthetic appearance and translucency hence durability of translucent Y-TZP. PMID:27335897

  7. Wavelength conversion by optimized monolithic integrated Mach-Zehnder interferometer

    DEFF Research Database (Denmark)

    Jørgensen, Carsten; Danielsen, Søren Lykke; Durhuus, Terji;

    1996-01-01

    Semiconductor optical amplifiers have been monolithic integrated in a passive symmetric Mach-Zehnder interferometer to form a compact polarization insensitive all-optical wavelength converter operating at up to 10 Gb/s. A simple method for reducing the impact of input power variations is proposed...

  8. A semiconductor laser with monolithically integrated dynamic polarization control.

    Science.gov (United States)

    Holmes, B M; Naeem, M A; Hutchings, D C; Marsh, J H; Kelly, A E

    2012-08-27

    We report the first demonstration of a semiconductor laser monolithically integrated with an active polarization controller, which consists of a polarization mode converter followed by an active, differential phase shifter. High speed modulation of the device output polarization is demonstrated via current injection to the phase shifter section. PMID:23037101

  9. Wavelength conversion by optimized monolithic integrated Mach-Zehnder interferometer

    OpenAIRE

    Jørgensen, Carsten; Danielsen, Søren Lykke; Durhuus, Terji; Mikkelsen, Benny; Stubkjær, Kristian; Vodjdani, N.; Ratovelomanana, F.; Enard, A.; Glastre, G.; Rondi, D.; Blondeau, R.

    1996-01-01

    Semiconductor optical amplifiers have been monolithic integrated in a passive symmetric Mach-Zehnder interferometer to form a compact polarization insensitive all-optical wavelength converter operating at up to 10 Gb/s. A simple method for reducing the impact of input power variations is proposed that increases the input power dynamic range from 4-8 dB.

  10. Monolithic HTGR - reformer design and cost summary: thermochemical pipeline application

    International Nuclear Information System (INIS)

    This summary report updates conceptual designs and cost estimates for monolithic High Temperature Gas-Cooled Reactor (HTGR) plants used as a source of process heat. The GFY 82 studies summarized in this report address design improvements and cost reductions for High Temperature Process Heat Systems selected in GFY 81. The GFY 81 studies consisted primarily of evaluating various configurations for a single (monolithic) HTGR rated at 1170 MWt used as part of a Thermochemical Pipeline (TCP) System. In the TCP concept, a helium-heated reformer produces syngas which can be transported up to 100 miles via pipeline to a methanation plant, where it is converted to methane. This exothermic process generates high-temperature steam for nearby process steam users. The methane is then returned to the nuclear plant site for conversion to syngas in the reformers. The work performed in GFY 82 on the monolithic HTGR-R plants is described. The results of the cost improvement studies are reviewed. A cost evaluation of the HTGR-R plants incorporating the GFY 82 changes is included. Recommendations for follow-on work on the HTGR-R monolithic plants are provided

  11. From 1D to 3D - macroscopic nanowire aerogel monoliths.

    Science.gov (United States)

    Cheng, Wei; Rechberger, Felix; Niederberger, Markus

    2016-08-01

    Here we present a strategy to assemble one-dimensional nanostructures into a three-dimensional architecture with macroscopic size. With the assistance of centrifugation, we successfully gel ultrathin W18O49 nanowires with diameters of 1 to 2 nm and aspect ratios larger than 100 into 3D networks, which are transformed into monolithic aerogels by supercritical drying. PMID:27389477

  12. A radiation hard bipolar monolithic front-end readout

    CERN Document Server

    Baschirotto, A; Cappelluti, I; Castello, R; Cermesoni, M; Gola, A; Pessina, G; Pistolesi, E; Rancoita, P G; Seidman, A

    1999-01-01

    A fast bipolar monolithic charge sensitive preamplifier (CSP), implemented in the monolithic 2 mu m BiCMOS technology (called HF2CMOS) was designed and built in a quad monolithic chip. Studies of radiation effects in the CSP $9 performance, from non-irradiated and up to neutron irradiation of 5.3*10/sup 14/ n/cm/sup 2/, have confirmed that the use of bipolar npn transistors is suitable for the radiation level of the future LHC collider environment. The CSP $9 presents a new circuit solution for obtaining adequate slew rate performances which results in an integral linearity better than 0.8554330n 5 V at 20 ns of shaping time, regardless of the bias current selected for the CSP. This way $9 the bias current of the CSP can be set for optimizing the power dissipation with respect to series and parallel noise, especially useful when the CSP is put in a radiation environment. A prototype test with a novel monolithic 20 ns $9 time constant RC-CR shaper, capable to sum up four inputs has been also realized, featurin...

  13. Monolithic natural gas storage delivery system based on sorbents

    Energy Technology Data Exchange (ETDEWEB)

    Hornbostel, Marc; Krishnan, Gopala N.; Sanjurjo, Angel

    2016-09-27

    The invention provides methods for producing a strong, light, sorbent-based storage/dispenser system for gases and fuels. The system comprises a porous monolithic material with an adherent strong impervious skin that is capable of storing a gas under pressure in a safe and usable manner.

  14. CMOS Monolithic Active Pixel Sensors (MAPS): developments and future outlook

    NARCIS (Netherlands)

    R. Turchetta; A. Fant; P. Gasiorek; C. Esbrand; J.A. Griffiths; M.G. Metaxas; G.J. Royle; R. Speller; C. Venanzi; P.F. van der Stelt; H.G.C. Verheij; G. Li; S. Theodoridis; H. Georgiou; D. Cavouras; G. Hall; M. Noy; J. Jones; J. Leaver; D. Machin; S. Greenwood; M. Khaleeq; H. Schulerud; J.M. Østby; F. Triantis; A. Asimidis; D. Bolanakis; N. Manthos; R. Longo; A. Bergamaschi

    2007-01-01

    Re-invented in the early 1990s, on both sides of the Atlantic, Monolithic Active Pixel Sensors (MAPS) in a CMOS technology are today the most sold solid-state imaging devices, overtaking the traditional technology of Charge-Coupled Devices (CCD). The slow uptake of CMOS MAPS started with low-end app

  15. CMOS Monolithic Active Pixel Sensors (MAPS): developments and future outlook

    NARCIS (Netherlands)

    R. Turchetta; A. Fant; P. Gasiorek; C. Esbrand; J.A. Griffiths; M.G. Metaxas; G.J. Royle; R. Speller; C. Venanzi; P.F. van der Stelt; H.G.C. Verheij; G. Li; S. Theodoridis; H. Georgiou; D. Cavouras; G. Hall; M. Noy; J. Jones; J. Leaver; D. Machin; S. Greenwood; M. Khaleeq; H. Schulerud; J.M. Østby; F. Triantis; A. Asimidis; D. Bolanakis; N. Manthos; R. Longo; A. Bergamaschi

    2006-01-01

    Re-invented in the early 1990s, on both sides of the Atlantic, Monolithic Active Pixel Sensors (MAPS) in a CMOS technology are today the most sold solid-state imaging devices, overtaking the traditional technology of Charge-Coupled Devices (CCD). The slow uptake of CMOS MAPS started with low-end app

  16. Shear bond strength of indirect composite material to monolithic zirconia

    Science.gov (United States)

    2016-01-01

    PURPOSE This study aimed to evaluate the effect of surface treatments on bond strength of indirect composite material (Tescera Indirect Composite System) to monolithic zirconia (inCoris TZI). MATERIALS AND METHODS Partially stabilized monolithic zirconia blocks were cut into with 2.0 mm thickness. Sintered zirconia specimens were divided into different surface treatment groups: no treatment (control), sandblasting, glaze layer & hydrofluoric acid application, and sandblasting + glaze layer & hydrofluoric acid application. The indirect composite material was applied to the surface of the monolithic zirconia specimens. Shear bond strength value of each specimen was evaluated after thermocycling. The fractured surface of each specimen was examined with a stereomicroscope and a scanning electron microscope to assess the failure types. The data were analyzed using one-way analysis of variance (ANOVA) and Tukey LSD tests (α=.05). RESULTS Bond strength was significantly lower in untreated specimens than in sandblasted specimens (P<.05). No difference between the glaze layer and hydrofluoric acid application treated groups were observed. However, bond strength for these groups were significantly higher as compared with the other two groups (P<.05). CONCLUSION Combined use of glaze layer & hydrofluoric acid application and silanization are reliable for strong and durable bonding between indirect composite material and monolithic zirconia.

  17. Monolithic femtosecond Yb-fiber laser with photonic crystal fibers

    DEFF Research Database (Denmark)

    Liu, Xiaomin; Lægsgaard, Jesper; Turchinovich, Dmitry

    We demonstrate a monolithic stable SESAM-modelocked self-starting Yb-fiber laser. A novel PM all-solid photonic bandgap fiber is used for intra-cavity of dispersion management. The ex-cavity final pulse compression is performed in a spliced-on PM hollow-core photonic crystal fiber. The laser...

  18. Chloride sublimation of gold-arsenic concentrates

    International Nuclear Information System (INIS)

    Present article is devoted to chloride sublimation of gold-arsenic concentrates. The results of studies of chloride sublimation of gold-arsenic comprising concentrates of Chore deposit of Tajikistan are considered. It is found that by application sodium chloride for gold-arsenic comprising concentrates it is possible to extract gold and silver from flotation concentrates.

  19. 21 CFR 172.180 - Stannous chloride.

    Science.gov (United States)

    2010-04-01

    ... Preservatives § 172.180 Stannous chloride. The food additive stannous chloride may be safely used for color... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Stannous chloride. 172.180 Section 172.180 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD FOR...

  20. A hydrometallurgical process for recovering total metal values from waste monolithic ceramic capacitors.

    Science.gov (United States)

    Prabaharan, G; Barik, S P; Kumar, B

    2016-06-01

    A hydrometallurgical process for recovering the total metal values from waste monolithic ceramic capacitors was investigated. The process parameters such as time, temperature, acid concentration, hydrogen peroxide concentration and other reagents (amount of zinc dust and sodium formate) were optimized. Base metals such as Ba, Ti, Sn, Cu and Ni are leached out in two stages using HCl in stage 1 and HCl with H2O2 in stage 2. More than 99% of leaching efficiency for base metals (Cu, Ni, Ba, Ti and Sn) was achieved. Precious metals such as Au and Pd are leached out using aquaregia and nitric acid was used for the leaching of Ag. Base metals (Ba, Ti, Sn, Cu and Ni) are recovered by selective precipitation using H2SO4 and NaOH solution. In case of precious metals, Au and Pd from the leach solution were precipitated out using sodium metabisulphite and sodium formate, respectively. Sodium chloride was used for the precipitation of Ag from leach solution. Overall recovery for base metals and precious metals are 95% and 92%, respectively. Based on the results of the present study, a process flow diagram was proposed for commercial application. PMID:27084106

  1. Residual Strength Analyses of Monolithic Structures

    Science.gov (United States)

    Forth, Scott (Technical Monitor); Ambur, Damodar R. (Technical Monitor); Seshadri, B. R.; Tiwari, S. N.

    2003-01-01

    Finite-element fracture simulation methodology predicts the residual strength of damaged aircraft structures. The methodology uses the critical crack-tip-opening-angle (CTOA) fracture criterion to characterize the fracture behavior of the material. The CTOA fracture criterion assumes that stable crack growth occurs when the crack-tip angle reaches a constant critical value. The use of the CTOA criterion requires an elastic- plastic, finite-element analysis. The critical CTOA value is determined by simulating fracture behavior in laboratory specimens, such as a compact specimen, to obtain the angle that best fits the observed test behavior. The critical CTOA value appears to be independent of loading, crack length, and in-plane dimensions. However, it is a function of material thickness and local crack-front constraint. Modeling the local constraint requires either a three-dimensional analysis or a two-dimensional analysis with an approximation to account for the constraint effects. In recent times as the aircraft industry is leaning towards monolithic structures with the intention of reducing part count and manufacturing cost, there has been a consistent effort at NASA Langley to extend critical CTOA based numerical methodology in the analysis of integrally-stiffened panels.In this regard, a series of fracture tests were conducted on both flat and curved aluminum alloy integrally-stiffened panels. These flat panels were subjected to uniaxial tension and during the test, applied load-crack extension, out-of-plane displacements and local deformations around the crack tip region were measured. Compact and middle-crack tension specimens were tested to determine the critical angle (wc) using three-dimensional code (ZIP3D) and the plane-strain core height (hJ using two-dimensional code (STAGS). These values were then used in the STAGS analysis to predict the fracture behavior of the integrally-stiffened panels. The analyses modeled stable tearing, buckling, and crack

  2. Shock compression of polyvinyl chloride

    Science.gov (United States)

    Neogi, Anupam; Mitra, Nilanjan

    2016-04-01

    This study presents shock compression simulation of atactic polyvinyl chloride (PVC) using ab-initio and classical molecular dynamics. The manuscript also identifies the limits of applicability of classical molecular dynamics based shock compression simulation for PVC. The mechanism of bond dissociation under shock loading and its progression is demonstrated in this manuscript using the density functional theory based molecular dynamics simulations. The rate of dissociation of different bonds at different shock velocities is also presented in this manuscript.

  3. Column Holdup Formula of Soil Solute Transport

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    The shortcomings of the present two formulae for describing column holdup are analyzed and deductions are made to find a new formula. The column holdup, Hw, described by the new formula is dimensional,and related to soil solute transport kinesis and column physical properties. Compared with the other two column holdups, Hw is feasible to describe dimensional column holdup during solute transport process. The relationships between Hw and retardation factor, R, in different solute transport boundary conditions are established.

  4. A 512x512 CMOS Monolithic Active Pixel Sensor with integrated ADCs for space science

    International Nuclear Information System (INIS)

    In the last few years, CMOS sensors have become widely used for consumer applications, but little has been done for scientific instruments. In this paper we present the design and experimental characterisation of a Monolithic Active Pixel Sensor (MAPS) intended for a space science application. The sensor incorporates a 525x525 array of pixels on a 25 μm pitch. Each pixel contains a detector together with three transistors that are used for pixel reset, pixel selection and charge-to-voltage conversion. The detector consists of four n-well/p-substrate diodes combining optimum charge collection and low noise performance. The array readout is column-parallel with adjustable gain column amplifiers and a 10-bit single slope ADC. Data conversion takes place simultaneously for all the 525 pixels in one row. The ADC slope can be adjusted in order to give the best dynamic range for a given brightness of a scene. The digitised data are output on a 10-bit bus at 3 MHz. An on-chip state machine generates all of the control signals needed for the readout. All of the bias currents and voltages are generated on chip by a DAC that is programmable through an I2C compatible interface. The sensor was designed and fabricated on a standard 0.5 μm CMOS technology. The overall die size is 16.7 mmx19.9 mm including the associated readout electronics and bond pads. Preliminary test results show that the full-scale design works well, meeting the Star Tracker requirements with less than 1-bit noise, good linearity and good optical performance

  5. A 512×512 CMOS Monolithic Active Pixel Sensor with integrated ADCs for space science

    Science.gov (United States)

    Prydderch, M. L.; Waltham, N. J.; Turchetta, R.; French, M. J.; Holt, R.; Marshall, A.; Burt, D.; Bell, R.; Pool, P.; Eyles, C.; Mapson-Menard, H.

    2003-10-01

    In the last few years, CMOS sensors have become widely used for consumer applications, but little has been done for scientific instruments. In this paper we present the design and experimental characterisation of a Monolithic Active Pixel Sensor (MAPS) intended for a space science application. The sensor incorporates a 525×525 array of pixels on a 25 μm pitch. Each pixel contains a detector together with three transistors that are used for pixel reset, pixel selection and charge-to-voltage conversion. The detector consists of four n-well/p-substrate diodes combining optimum charge collection and low noise performance. The array readout is column-parallel with adjustable gain column amplifiers and a 10-bit single slope ADC. Data conversion takes place simultaneously for all the 525 pixels in one row. The ADC slope can be adjusted in order to give the best dynamic range for a given brightness of a scene. The digitised data are output on a 10-bit bus at 3 MHz. An on-chip state machine generates all of the control signals needed for the readout. All of the bias currents and voltages are generated on chip by a DAC that is programmable through an I 2C compatible interface. The sensor was designed and fabricated on a standard 0.5 μm CMOS technology. The overall die size is 16.7 mm×19.9 mm including the associated readout electronics and bond pads. Preliminary test results show that the full-scale design works well, meeting the Star Tracker requirements with less than 1-bit noise, good linearity and good optical performance.

  6. Conversion of Hydrogen Sulfide in Coal Gases to Liquid Elemental Sulfur with Monolithic Catalysts

    Energy Technology Data Exchange (ETDEWEB)

    K. C. Kwon

    2006-09-30

    Removal of hydrogen sulfide (H{sub 2}S) from coal gasifier gas and sulfur recovery are key steps in the development of Department of Energy's (DOE's) advanced power plants that produce electric power and clean transportation fuels with coal and natural gas. These plants will require highly clean coal gas with H{sub 2}S below 1 ppmv and negligible amounts of trace contaminants such as hydrogen chloride, ammonia, alkali, heavy metals, and particulate. The conventional method of sulfur removal and recovery employing amine, Claus, and tail-gas treatment is very expensive. A second generation approach developed under DOE's sponsorship employs hot-gas desulfurization (HGD) using regenerable metal oxide sorbents followed by Direct Sulfur Recovery Process (DSRP). However, this process sequence does not remove trace contaminants and is targeted primarily towards the development of advanced integrated gasification combined cycle (IGCC) plants that produce electricity (not both electricity and transportation fuels). There is an immediate as well as long-term need for the development of cleanup processes that produce highly clean coal gas for next generation power plants. To this end, a novel process is now under development at several research organizations in which the H{sub 2} in coal gas is directly oxidized to elemental sulfur over a selective catalyst. Such a process is ideally suited for coal gas from commercial gasifiers with a quench system to remove essentially all the trace contaminants except H{sub 2}S In the Single-Step Sulfur Recovery Process (SSRP), the direct oxidation of H{sub 2}S to elemental sulfur in the presence of SO{sub 2} is ideally suited for coal gas from commercial gasifiers with a quench system to remove essentially all the trace contaminants except H{sub 2}S. This direct oxidation process has the potential to produce a super clean coal gas more economically than both conventional amine-based processes and HGD/DSRP. The H{sub 2} and

  7. Conversion of Hydrogen Sulfide in Coal Gases to Liquid Elemental Sulfur with Monolithic Catalysts

    Energy Technology Data Exchange (ETDEWEB)

    K. C. Kwon

    2006-09-30

    Removal of hydrogen sulfide (H{sub 2}S) from coal gasifier gas and sulfur recovery are key steps in the development of Department of Energy's (DOE's) advanced power plants that produce electric power and clean transportation fuels with coal and natural gas. These plants will require highly clean coal gas with H{sub 2}S below 1 ppmv and negligible amounts of trace contaminants such as hydrogen chloride, ammonia, alkali, heavy metals, and particulate. The conventional method of sulfur removal and recovery employing amine, Claus, and tail-gas treatment is very expensive. A second generation approach developed under DOE's sponsorship employs hot-gas desulfurization (HGD) using regenerable metal oxide sorbents followed by Direct Sulfur Recovery Process (DSRP). However, this process sequence does not remove trace contaminants and is targeted primarily towards the development of advanced integrated gasification combined cycle (IGCC) plants that produce electricity (not both electricity and transportation fuels). There is an immediate as well as long-term need for the development of cleanup processes that produce highly clean coal gas for next generation power plants. To this end, a novel process is now under development at several research organizations in which the H{sub 2} in coal gas is directly oxidized to elemental sulfur over a selective catalyst. Such a process is ideally suited for coal gas from commercial gasifiers with a quench system to remove essentially all the trace contaminants except H{sub 2}S In the Single-Step Sulfur Recovery Process (SSRP), the direct oxidation of H{sub 2}S to elemental sulfur in the presence of SO{sub 2} is ideally suited for coal gas from commercial gasifiers with a quench system to remove essentially all the trace contaminants except H{sub 2}S. This direct oxidation process has the potential to produce a super clean coal gas more economically than both conventional amine-based processes and HGD/DSRP. The H{sub 2} and

  8. Columns

    Institute of Scientific and Technical Information of China (English)

    Carrie Tsang; 丁燕燕; 韩多妮; RAY

    2009-01-01

    <正>Paris承诺的展现33岁的墨西哥艺术家Mario Garcia Torres是近年国际艺坛炙手可热的新星,他以录象、摄影、幻灯及装置为创作形式,透过个人视点及独特演绎手法来重新思考历史。他是一个思考型艺术家,同时又是一个淘气的大孩子,作品往往反映了他的双重性格——嬉戏中带有深沉的历史感。这次是GarciaTorres首次在法国的国家博物馆举行展览,整合出版了他过往两年间在

  9. Design and Testing of Prototypic Elements Containing Monolithic Fuel

    Energy Technology Data Exchange (ETDEWEB)

    N.E. Woolstenhulme; M.K. Meyer; D.M. Wachs

    2011-10-01

    The US fuel development team has performed numerous irradiation tests on small to medium sized specimens containing low enriched uranium fuel designs. The team is now focused on qualification and demonstration of the uranium-molybdenum Base Monolithic Design and has entered the next generation of testing with the design and irradiation of prototypic elements which contain this fuel. The designs of fuel elements containing monolithic fuel, such as AFIP-7 (which is currently under irradiation) and RERTR-FE (which is currently under fabrication), are appropriate progressions relative to the technology life cycle. The culmination of this testing program will occur with the design, fabrication, and irradiation of demonstration products to include the base fuel demonstration and design demonstration experiments. Future plans show that design, fabrication, and testing activities will apply the rigor needed for a demonstration campaign.

  10. Highly efficient monolithic dye-sensitized solar cells.

    Science.gov (United States)

    Kwon, Jeong; Park, Nam-Gyu; Lee, Jun Young; Ko, Min Jae; Park, Jong Hyeok

    2013-03-01

    Monolithic dye-sensitized solar cells (M-DSSCs) provide an effective way to reduce the fabrication cost of general DSSCs since they do not require transparent conducting oxide substrates for the counter electrode. However, conventional monolithic devices have low efficiency because of the impediments resulting from counter electrode materials and spacer layers. Here, we demonstrate highly efficient M-DSSCs featuring a highly conductive polymer combined with macroporous polymer spacer layers. With M-DSSCs based on a PEDOT/polymer spacer layer, a power conversion efficiency of 7.73% was achieved, which is, to the best of our knowledge, the highest efficiency for M-DSSCs to date. Further, PEDOT/polymer spacer layers were applied to flexible DSSCs and their cell performance was investigated. PMID:23432389

  11. Low-bandgap, monolithic, multi-bandgap, optoelectronic devices

    Science.gov (United States)

    Wanlass, Mark W.; Carapella, Jeffrey J.

    2014-07-08

    Low bandgap, monolithic, multi-bandgap, optoelectronic devices (10), including PV converters, photodetectors, and LED's, have lattice-matched (LM), double-heterostructure (DH), low-bandgap GaInAs(P) subcells (22, 24) including those that are lattice-mismatched (LMM) to InP, grown on an InP substrate (26) by use of at least one graded lattice constant transition layer (20) of InAsP positioned somewhere between the InP substrate (26) and the LMM subcell(s) (22, 24). These devices are monofacial (10) or bifacial (80) and include monolithic, integrated, modules (MIMs) (190) with a plurality of voltage-matched subcell circuits (262, 264, 266, 270, 272) as well as other variations and embodiments.

  12. From 1D to 3D - macroscopic nanowire aerogel monoliths

    Science.gov (United States)

    Cheng, Wei; Rechberger, Felix; Niederberger, Markus

    2016-07-01

    Here we present a strategy to assemble one-dimensional nanostructures into a three-dimensional architecture with macroscopic size. With the assistance of centrifugation, we successfully gel ultrathin W18O49 nanowires with diameters of 1 to 2 nm and aspect ratios larger than 100 into 3D networks, which are transformed into monolithic aerogels by supercritical drying.Here we present a strategy to assemble one-dimensional nanostructures into a three-dimensional architecture with macroscopic size. With the assistance of centrifugation, we successfully gel ultrathin W18O49 nanowires with diameters of 1 to 2 nm and aspect ratios larger than 100 into 3D networks, which are transformed into monolithic aerogels by supercritical drying. Electronic supplementary information (ESI) available: Experimental details, SEM and TEM images, and digital photographs. See DOI: 10.1039/c6nr04429h

  13. Material Engineering for Monolithic Semiconductor Mode-Locked Lasers

    DEFF Research Database (Denmark)

    Kulkova, Irina

    This thesis is devoted to the materials engineering for semiconductor monolithic passively mode-locked lasers (MLLs) as a compact energy-efficient source of ultrashort optical pulses. Up to the present day, the achievement of low-noise sub-picosecond pulse generation has remained a challenge....... This work has considered the role of the combined ultrafast gain and absorption dynamics in MLLs as a main factor limiting laser performance. An independent optimization of MLL amplifier and saturable absorber active materials was performed. Two promising approaches were considered: quantum dot (QD...... quality and low internal reflection compatible with the severe requirements of monolithic MLLs. Experimental characterization of static material parameters of the fabricated devices revealed QW-like gain behavior of a self-assembled InAs/InP QD material and low internal efficiency which limited its...

  14. Effective extraction of triazines from environmental water samples using magnetism-enhanced monolith-based in-tube solid phase microextraction.

    Science.gov (United States)

    Mei, Meng; Huang, Xiaojia; Yang, Xiaodong; Luo, Qing

    2016-09-21

    This article reports on the effective extraction of triazines from environmental water samples using magnetism-enhanced monolith-based in-tube solid phase microextraction (ME-MB/IT-SPME). Firstly, monolithic poly (octyl methacrylate-co-ethyleneglycol dimethacrylate) capillary column doped with magnetic nanoparticles was synthesized inside a fused silica. After that, the monolithic capillary column was placed inside a magnetic coil that allowed the exertion of a variable magnetic field during adsorption and desorption steps. The effects of intensity of magnetic field, adsorption and desorption flow rate, volume of sample and desorption solvent, pH value and ionic strength in sample matrix on the performance of ME-MB/IT-SPME for triazines were investigated in details. Under the optimized conditions, the developed ME-MB/IT-SPME showed satisfactory quantitative extraction efficiencies of the target analytes between 64.8% and 99.7%. At the same time, the ME-MB/IT-SPME was combined with high-performance liquid chromatography with diode array detection to detect six triazines in water samples. The limits of detection (S/N = 3) and limits of quantification (S/N = 10) were in the ranges of 0.074-0.23 μg/L and 0.24-0.68 μg/L, respectively. The precision of the proposed method was evaluated in terms of intra- and inter-assay variability calculated as relative standard deviation, and it was found that the values were all below 10%. Finally, the developed method was successfully applied for environmental water samples such as farmland, lake and river water with spiked recoveries in the range of 70.7-119%. PMID:27590547

  15. Effective extraction of triazines from environmental water samples using magnetism-enhanced monolith-based in-tube solid phase microextraction.

    Science.gov (United States)

    Mei, Meng; Huang, Xiaojia; Yang, Xiaodong; Luo, Qing

    2016-09-21

    This article reports on the effective extraction of triazines from environmental water samples using magnetism-enhanced monolith-based in-tube solid phase microextraction (ME-MB/IT-SPME). Firstly, monolithic poly (octyl methacrylate-co-ethyleneglycol dimethacrylate) capillary column doped with magnetic nanoparticles was synthesized inside a fused silica. After that, the monolithic capillary column was placed inside a magnetic coil that allowed the exertion of a variable magnetic field during adsorption and desorption steps. The effects of intensity of magnetic field, adsorption and desorption flow rate, volume of sample and desorption solvent, pH value and ionic strength in sample matrix on the performance of ME-MB/IT-SPME for triazines were investigated in details. Under the optimized conditions, the developed ME-MB/IT-SPME showed satisfactory quantitative extraction efficiencies of the target analytes between 64.8% and 99.7%. At the same time, the ME-MB/IT-SPME was combined with high-performance liquid chromatography with diode array detection to detect six triazines in water samples. The limits of detection (S/N = 3) and limits of quantification (S/N = 10) were in the ranges of 0.074-0.23 μg/L and 0.24-0.68 μg/L, respectively. The precision of the proposed method was evaluated in terms of intra- and inter-assay variability calculated as relative standard deviation, and it was found that the values were all below 10%. Finally, the developed method was successfully applied for environmental water samples such as farmland, lake and river water with spiked recoveries in the range of 70.7-119%.

  16. Clinical assessment of enamel wear caused by monolithic zirconia crowns.

    Science.gov (United States)

    Stober, T; Bermejo, J L; Schwindling, F S; Schmitter, M

    2016-08-01

    The purpose of this study was to measure enamel wear caused by antagonistic monolithic zirconia crowns and to compare this with enamel wear caused by contralateral natural antagonists. Twenty monolithic zirconia full molar crowns were placed in 20 patients. Patients with high activity of the masseter muscle at night (bruxism) were excluded. For analysis of wear, vinylpolysiloxane impressions were prepared after crown incorporation and at 6-, 12-, and 24-month follow-up. Wear of the occlusal contact areas of the crowns, of their natural antagonists, and of two contralateral natural antagonists (control teeth) was measured by use of plaster replicas and a 3D laser-scanning device. Differences of wear between the zirconia crown antagonists and the control teeth were investigated by means of two-sided paired Student's t-tests and linear regression analysis. After 2 years, mean vertical loss was 46 μm for enamel opposed to zirconia, 19-26 μm for contralateral control teeth and 14 μm for zirconia crowns. Maximum vertical loss was 151 μm for enamel opposed to zirconia, 75-115 μm for control teeth and 60 μm for zirconia crowns. Statistical analysis revealed significant differences between wear of enamel by zirconia-opposed teeth and by control teeth. Gender, which significantly affected wear, was identified as a possible confounder. Monolithic zirconia crowns generated more wear of opposed enamel than did natural teeth. Because of the greater wear caused by other dental ceramics, the use of monolithic zirconia crowns may be justified.

  17. Monolithic mm-wave ICs for smart weapons

    Science.gov (United States)

    Duffield, T. L.

    1988-04-01

    An approach to developing a low-cost mm-wave transceiver with application to a broad range of smart weapons systems is described. The proposed transceiver technology consists of monolithic mm-wave integrated circuits on GaAs substrates. The relevant transceiver configurations, FET material, and electron beam lithography are discussed. The types of devices to which the approach is applicable are addressed, emphasizing the use of three-terminal devices for all active elements.

  18. Design of Monolithic Integrator for Strain-to-Frequency Converter

    OpenAIRE

    Tuan Mohd. Khairi Tuan Mat; Chew Sue Ping; Akram Abdul Azid

    2012-01-01

    Strain-to-Frequency converter (SFC) is a one of the analog conditioner tools that converts any strain signal to the frequency signal. The basic concept of SFC is by detecting any changing of strains, then converting the strain to the voltage signal and converting the voltage signal to the frequency signal. This tool consists of 3 main  components which are strain gauge, differential integrator and comparator. This paper presents the designing and analysis of monolithic integrator that to be u...

  19. Design of ultra-lightweight concrete: towards monolithic concrete structures

    OpenAIRE

    Yu Qing Liang; Spiesz Przemek; Brouwers Jos

    2013-01-01

    This study addresses the development of ultra-lightweight concrete. A moderate strength and an excellent thermal conductivity of the lightweight concrete are set as the design targets. The designed lightweight aggregates concrete is targeted to be used in monolithic concrete façade structure, performing as both load bearing element and thermal insulator. The developed lightweight concrete shows excellent thermal properties, with a low thermal conductivity of about 0.12 W/(m·K); and moderate m...

  20. Monolithic AlGaAs second-harmonic nanoantennas

    CERN Document Server

    Gili, V F; Locatelli, A; Rocco, D; Finazzi, M; Ghirardini, L; Favero, I; Gomez, C; Lemaître, A; Celebrano, M; De Angelis, C; Leo, G

    2016-01-01

    We demonstrate monolithic aluminum gallium arsenide (AlGaAs) optical anoantennas. Using a selective oxidation technique, we fabricate such epitaxial semiconductor nanoparticles on an aluminum oxide substrate. Second harmonic generation from an AlGaAs nanocylinder of height h=400 nm and varying radius pumped with femtosecond pulses delivered at 1554-nm wavelength has been measured, revealing a peak conversion efficiency exceeding 10-5 for nanocylinders with an otpimized geometry.

  1. Clinical assessment of enamel wear caused by monolithic zirconia crowns.

    Science.gov (United States)

    Stober, T; Bermejo, J L; Schwindling, F S; Schmitter, M

    2016-08-01

    The purpose of this study was to measure enamel wear caused by antagonistic monolithic zirconia crowns and to compare this with enamel wear caused by contralateral natural antagonists. Twenty monolithic zirconia full molar crowns were placed in 20 patients. Patients with high activity of the masseter muscle at night (bruxism) were excluded. For analysis of wear, vinylpolysiloxane impressions were prepared after crown incorporation and at 6-, 12-, and 24-month follow-up. Wear of the occlusal contact areas of the crowns, of their natural antagonists, and of two contralateral natural antagonists (control teeth) was measured by use of plaster replicas and a 3D laser-scanning device. Differences of wear between the zirconia crown antagonists and the control teeth were investigated by means of two-sided paired Student's t-tests and linear regression analysis. After 2 years, mean vertical loss was 46 μm for enamel opposed to zirconia, 19-26 μm for contralateral control teeth and 14 μm for zirconia crowns. Maximum vertical loss was 151 μm for enamel opposed to zirconia, 75-115 μm for control teeth and 60 μm for zirconia crowns. Statistical analysis revealed significant differences between wear of enamel by zirconia-opposed teeth and by control teeth. Gender, which significantly affected wear, was identified as a possible confounder. Monolithic zirconia crowns generated more wear of opposed enamel than did natural teeth. Because of the greater wear caused by other dental ceramics, the use of monolithic zirconia crowns may be justified. PMID:27198539

  2. Applications of monolithic fiber interferometers and actively controlled fibers

    OpenAIRE

    Rugeland, Patrik

    2013-01-01

    The objective of this thesis was to develop applications of monolithic fiber devices and actively controlled fibers. A special twin-core fiber known as a ‘Gemini’ fiber was used to construct equal arm-length fiber interferometers, impervious to temperature and mechanical perturbations. A broadband add/drop multiplexer was constructed by inscribing fiber Bragg gratings in the arms of a Gemini Mach-Zehnder interferometer. A broadband interferometric nanosecond switch was constructed from a micr...

  3. A monolithic radiaiton-tolerant charge-sensitive preamplifier

    International Nuclear Information System (INIS)

    A monolithic charge-sensitive preamplifier based on N-channel junction field-effect transistors (NJFETs) and P-channel MOS (PMOS) has been realized for applications with multielectrode detectors in elementary particle physics. Radiation resistance tests carried out with the preamplifier exposed to γ-rays emitted by a 60Co source have shown no degradation in equivalent noise charge up to 150 krad absorbed dose. (orig.)

  4. A monolithic radiaiton-tolerant charge-sensitive preamplifier

    Energy Technology Data Exchange (ETDEWEB)

    Buttler, W. (Fraunhofer-Institut fuer Mikroelektronische Schaltungen und Systeme, Duisburg (Germany, F.R.)); Citterio, M.; Manfredi, P.F.; Re, V.; Speziali, V. (Pavia Univ. (Italy). Dipt. di Elettronica Istituto Nazionale di Fisica Nucleare, Milan (Italy)); Lutz, G. (Max-Planck-Institut fuer Physik und Astrophysik, Muenchen (Germany, F.R.))

    1990-07-01

    A monolithic charge-sensitive preamplifier based on N-channel junction field-effect transistors (NJFETs) and P-channel MOS (PMOS) has been realized for applications with multielectrode detectors in elementary particle physics. Radiation resistance tests carried out with the preamplifier exposed to {gamma}-rays emitted by a {sup 60}Co source have shown no degradation in equivalent noise charge up to 150 krad absorbed dose. (orig.).

  5. Smart Bolometer: Toward Monolithic Bolometer with Smart Functions

    OpenAIRE

    Matthieu, Denoual; Olivier, de Sagazan; Patrick, Attia; Gilles, Allègre

    2012-01-01

    The content of this chapter refers to uncooled resistive bolometers amd the challenge that consists in their integration into monolithic devices exhibiting smart functions. Uncooled resistive bolometers are the essential constitutive element of the majority of existing uncooled infrared imaging systems; they are referred to as microbolometer pixels in that type of application where matrixes of such elementary devices are used. uncooled bolometers represent more than 95% of the market of infra...

  6. Simple chloride sensors for continuous groundwater monitoring

    DEFF Research Database (Denmark)

    Thorn, Paul; Mortensen, John

    2012-01-01

    The development of chloride sensors which can be used for continuous, on-line monitoring of groundwater could be very valuable in the management of our coastal water resources. However, sensor stability, drift, and durability all need to be addressed in order for the sensors to be used...... in continuous application. This study looks at the development of a simple, inexpensive chloride electrode, and evaluates its performance under continuous use, both in the laboratory and in a field test in a monitoring well. The results from the study showed a consistent response to changing chloride...... sensor remained responsive even at low chloride concentrations, where the conductivity electrode was no longer responding to changing chloride levels. With the results, it is believed that the simple chloride sensor could be used for continuous monitoring of groundwater quality....

  7. Tannin-based monoliths from emulsion-templating

    International Nuclear Information System (INIS)

    Highlights: • Efficient preparation procedures are presented for new and “green” tannin-based organic polyHIPEs. • Highest homogeneity and strength are obtained at an oil fraction near the close-packing value. • Structural and mechanical properties abruptly change above such critical value. - Abstract: Highly porous monoliths prepared by emulsion-templating, frequently called polymerised High Internal Phase Emulsions (polyHIPEs) in the literature, were prepared from “green” precursors such as Mimosa bark extract, sunflower oil and ethoxylated castor oil. Various oil fractions, ranging from 43 to 80 vol.%, were used and shown to have a dramatic impact on the resultant porous structure. A critical oil fraction around 70 vol.% was found to exist, close to the theoretical values of 64% and 74% for random and compact sphere packing, respectively, at which the properties of both emulsions and derived porous monoliths changed. Such change of behaviour was observed by many different techniques such as viscosity, electron microscopy, mercury intrusion, and mechanical studies. We show and explain why this critical oil fraction is the one leading to the strongest and most homogeneous porous monoliths

  8. Monolithic pixels on moderate resistivity substrate and sparsifying readout architecture

    International Nuclear Information System (INIS)

    The LePix projects aim realizing a new generation monolithic pixel detectors with improved performances at lesser cost with respect to both current state of the art monolithic and hybrid pixel sensors. The detector is built in a 90 nm CMOS process on a substrate of moderate resistivity. This allows charge collection by drift while maintaining the other advantages usually offered by MAPS, like having a single piece detector and using a standard CMOS production line. The collection by drift mechanism, coupled to the low capacitance design of the collecting node made possible by the monolithic approach, provides an excellent signal to noise ratio straight at the pixel cell together with a radiation tolerance far superior to conventional un-depleted MAPS. The excellent signal-to-noise performance is demonstrated by the device ability to separate the 6 keV 55Fe double peak at room temperature. To achieve high granularity (10–20 µm pitch pixels) over large detector areas maintaining high readout speed, a completely new compressing architecture has been devised. This architecture departs from the mainstream hybrid pixel sparsification approach, which uses in-pixel logic to reduce data, by using topological compression to minimize pixel area and power consumption

  9. Monolithic pixels on moderate resistivity substrate and sparsifying readout architecture

    CERN Document Server

    Giubilato, P; Snoeys, W; Bisello, D; Marchioro, A; Battaglia, M; Demaria, L; Mansuy, S C; Pantano, D; Rousset, J; Mattiazzo, S; Kloukinas, K; Potenza, A; Ikemoto, Y; Rivetti, A; Chalmet, P; Mugnier, H; Silvestrin, L

    2013-01-01

    The LePix projects aim realizing a new generation monolithic pixel detectors with improved performances at lesser cost with respect to both current state of the art monolithic and hybrid pixel sensors. The detector is built in a 90 nm CMOS process on a substrate of moderate resistivity. This allows charge collection by drift while maintaining the other advantages usually offered by MAPS, like having a single piece detector and using a standard CMOS production line. The collection by drift mechanism, coupled to the low capacitance design of the collecting node made possible by the monolithic approach, provides an excellent signal to noise ratio straight at the pixel cell together with a radiation tolerance far superior to conventional un-depleted MAPS. The excellent signal-to-noise performance is demonstrated by the device ability to separate the 6 keV Fe-55 double peak at room temperature. To achieve high granularity (10-20 mu m pitch pixels) over large detector areas maintaining high readout speed, a complet...

  10. Modeling of column apparatus processes

    CERN Document Server

    Boyadjiev, Christo; Boyadjiev, Boyan; Popova-Krumova, Petya

    2016-01-01

    This book presents a new approach for the modeling of chemical and interphase mass transfer processes in industrial column apparatuses, using convection-diffusion and average-concentration models. The convection-diffusion type models are used for a qualitative analysis of the processes and to assess the main, small and slight physical effects, and then reject the slight effects. As a result, the process mechanism can be identified. It also introduces average concentration models for quantitative analysis, which use the average values of the velocity and concentration over the cross-sectional area of the column. The new models are used to analyze different processes (simple and complex chemical reactions, absorption, adsorption and catalytic reactions), and make it possible to model the processes of gas purification with sulfur dioxide, which form the basis of several patents.

  11. Biotransformation of Tributyltin chloride by Pseudomonas stutzeri strain DN2

    Directory of Open Access Journals (Sweden)

    Dnyanada S. Khanolkar

    2014-12-01

    Full Text Available A bacterial isolate capable of utilizing tributyltin chloride (TBTCl as sole carbon source was isolated from estuarine sediments of west coast of India and identified as Pseudomonas stutzeri based on biochemical tests and Fatty acid methyl ester (FAME analysis. This isolate was designated as strain DN2. Although this bacterial isolate could resist up to 3 mM TBTCl level, it showed maximum growth at 2 mM TBTCl in mineral salt medium (MSM. Pseudomonas stutzeri DN2 exposed to 2 mM TBTCl revealed significant alteration in cell morphology as elongation and shrinkage in cell size along with roughness of cell surface. FTIR and NMR analysis of TBTCl degradation product extracted using chloroform and purified using column chromatography clearly revealed biotransformation of TBTCl into Dibutyltin dichloride (DBTCl2 through debutylation process. Therefore, Pseudomonas stutzeri strain DN2 may be used as a potential bacterial strain for bioremediation of TBTCl contaminated aquatic environmental sites.

  12. ENVIRONMENTAL EXPOSURE TO VINYL CHLORIDE

    Directory of Open Access Journals (Sweden)

    Henryka Langauer-Lewowicka

    2010-09-01

    Full Text Available Vinyl chloride (VC monomer is a wellknown carcinogenic and mutagenic substance causes liver damages, angiosarcoma of the liver, acro – osteolysis, sclerodermalike changes in workers chronically exposed to this gas. There are following VC emitors to the environment: VC production plants, polymerization facilities and planes where polyvinyl products are fabricated. Because of that, the general population is coming into VC contact through polluted air, food and water. VC concentration in all mentioned sites is very low, often not detectable. There was found any health risk for the general population. The VC air concentration in the vicinity to antropogenic emitors is always higher. Such a situation may causes undesirable health effect for residents living in the neighbourhood. Epidemiological studies are performed to detect the adverse VC effect in selected cohorts. Non of the study did not confirmed cases of angiosarcoma among residents living near a vinyl chloride sites. VC production is growing permanently, so VC emission will be higher. Because of that health monitoring of general population and especially of selected groups seems to be necessary in the future.

  13. Preparation and characterization of polystyrene-based monolith with ordered macroporous structure

    Institute of Scientific and Technical Information of China (English)

    Quan Zhou Wu; Jian Feng He; Ji Ming Ou

    2012-01-01

    In this paper,polystyrene-based monoliths with highly ordered macroporous structure were synthesized by using SiO2 colloidal crystal as template.SEM observation shows that the macropores are highly ordered and are interconnected by small windows.The BET surface area of PS monolith is about 36.17 m2/g.The polymer monoliths can resist 5 MPa pressure,showing high mechanical and compressive strength.

  14. Photoinitiated grafting of porous polymer monoliths and thermoplastic polymers for microfluidic devices

    Science.gov (United States)

    Frechet, Jean M. J.; Svec, Frantisek; Rohr, Thomas

    2008-10-07

    A microfluidic device preferably made of a thermoplastic polymer that includes a channel or a multiplicity of channels whose surfaces are modified by photografting. The device further includes a porous polymer monolith prepared via UV initiated polymerization within the channel, and functionalization of the pore surface of the monolith using photografting. Processes for making such surface modifications of thermoplastic polymers and porous polymer monoliths are set forth.

  15. Application of Monolithic Zirconia Ceramics in Dental Practice: A Case History Report.

    Science.gov (United States)

    Kim, Hee-Kyung; Kim, Sung-Hun; Lee, Jai-Bong; Han, Jung-Suk; Yeo, In-Sung

    2016-01-01

    Monolithic zirconia restorations increasingly have been used in dental practice in recent years and demonstrate superior mechanical performance compared with porcelain-veneered zirconia restorations. Recent advances in manufacturing technology have made possible the fabrication of translucent monolithic zirconia ceramics. This case report describes three clinical examples of monolithic zirconia fixed dental prostheses being used in the anterior and posterior regions and exhibiting acceptable esthetic results.

  16. Application of Monolithic Zirconia Ceramics in Dental Practice: A Case History Report.

    Science.gov (United States)

    Kim, Hee-Kyung; Kim, Sung-Hun; Lee, Jai-Bong; Han, Jung-Suk; Yeo, In-Sung

    2016-01-01

    Monolithic zirconia restorations increasingly have been used in dental practice in recent years and demonstrate superior mechanical performance compared with porcelain-veneered zirconia restorations. Recent advances in manufacturing technology have made possible the fabrication of translucent monolithic zirconia ceramics. This case report describes three clinical examples of monolithic zirconia fixed dental prostheses being used in the anterior and posterior regions and exhibiting acceptable esthetic results. PMID:27611758

  17. Green process to recover magnesium chloride from residue solution of potassium chloride production plant

    Institute of Scientific and Technical Information of China (English)

    Lin WANG; Yunliang HE; Yanfei WANG; Ying BAO; Jingkang WANG

    2008-01-01

    The green process to recover magnesium chlor-ide from the residue solution of a potassium chloride pro-duction plant, which comes from the leach solution of a potash mine in Laos, is designed and optimized. The res-idue solution contains magnesium chloride above 25 wt-%, potassium chloride and sodium chloride together below 5 wt-% and a few other ions such as Br-, SO2-4and Ca2+. The recovery process contains two steps: the previous impurity removal operation and the two-stage evapora-tion-cooling crystallization procedure to produce magnes-ium chloride. The crystallized impurity carnallite obtained from the first step is recycled to the potassium chloride plant to recover the potassium salt. The developed process is a zero discharge one and thus fulfills the requirements for green chemical industrial production. The produced magnesium chloride is up to industrial criteria.

  18. Feasibility evaluation of the monolithic braided ablative nozzle

    Science.gov (United States)

    Director, Mark N.; McPherson, Douglass J., Sr.

    1992-02-01

    The feasibility of the monolithic braided ablative nozzle was evaluated as part of an independent research and development (IR&D) program complementary to the National Aeronautics and Space Administration/Marshall Space Flight Center (NASA/MSFC) Low-Cost, High-Reliability Case, Insulation and Nozzle for Large Solid Rocket Motors (LOCCIN) Program. The monolithic braided ablative nozzle is a new concept that utilizes a continuous, ablative, monolithic flame surface that extends from the nozzle entrance, through the throat, to the exit plane. The flame surface is fabricated using a Through-the-Thickness braided carbon-fiber preform, which is impregnated with a phenolic or phenolic-like resin. During operation, the braided-carbon fiber/resin material ablates, leaving the structural backside at temperatures which are sufficiently low to preclude the need for any additional insulative materials. The monolithic braided nozzle derives its potential for low life cycle cost through the use of automated processing, one-component fabrication, low material scrap, low process scrap, inexpensive raw materials, and simplified case attachment. It also has the potential for high reliability because its construction prevents delamination, has no nozzle bondlines or leak paths along the flame surface, is amenable to simplified analysis, and is readily inspectable. In addition, the braided construction has inherent toughness and is damage-tolerant. Two static-firing tests were conducted using subscale, 1.8 - 2.0-inch throat diameter, hardware. Tests were approximately 15 seconds in duration, using a conventional 18 percent aluminum/ammonium perchlorate propellant. The first of these tests evaluated the braided ablative as an integral backside insulator and exit cone; the second test evaluated the monolithic braided ablative as an integral entrance/throat/exit cone nozzle. Both tests met their objectives. Radial ablation rates at the throat were as predicted, approximately 0.017 in

  19. Leaching of Salmonella Senftenberg and Cryptosporidium Parvum in Intact Clay Columns

    Science.gov (United States)

    Bech, T. B.; Forslund, A.; Dalsgaard, A.; Jacobsen, O.; Jacobsen, C. S.

    2008-12-01

    Manure application on land has been associated with both environmental and public health problems, even when management is within the current guidelines. Outbreaks of infection have been associated with water or food, including processed fruits and vegetables, contaminated with animal manure. A wide range of pathogenic microorganisms can be found in animal waste, including bacteria, protozoan, and viruses. When animal waste is disposed on agricultural land different factors will influence the risk for contaminating the groundwater. 1) Animal waste application method, rate, volume and frequency will have an effect on contamination. 2) Survival of the pathogens in the soil will e.g. depend on soil water content, temperature and pH. Salmonella species can survive up to 332 days and Cryptosporidium species can remain viable for several years in the soil environment. In the present study we compared the transport between the pathogenic bacteria S. senftenberg and the pathogenic protozoan C. parvum in intact clay columns. Furthermore, we compared the effect from surface and sub-surface manure application on the transport potential. 15 intact clay columns were placed in an outdoor multi-column lysimeter for 36 days. Manure inoculated with S. senftenberg, C. parvum and chloride was added to the soil surface or injected 8 cm into the columns. Drainage water was collected from the soil columns and DNA was extracted to quantify S. senftenberg and C. parvum by quantitative PCR. In addition S. senftenberg was enumerated by plate counting. Acid yellow was applied to selected columns to visualize the pathway down through the soil column. The highest concentration of S. senftenberg was in the first drainage sample ranging from 100-10000 CFU/ml. Breakthrough curves for chloride and S. senftenberg indicates the importance of preferential flow as well as a faster transport for the bacteria compared to chloride. C. parvum is retained to a higher degree in the soil but is still found

  20. Influence of Chloride-Ion Adsorption Agent on Chloride Ions in Concrete and Mortar

    OpenAIRE

    Gai-Fei Peng; Nai-Qian Feng; Qi-Ming Song

    2014-01-01

    The influence of a chloride-ion adsorption agent (Cl agent in short), composed of zeolite, calcium aluminate hydrate and calcium nitrite, on the ingress of chloride ions into concrete and mortar has been experimentally studied. The permeability of concrete was measured, and the chloride ion content in mortar was tested. The experimental results reveal that the Cl agent could adsorb chloride ions effectively, which had penetrated into concrete and mortar. When the Cl agent was used at a dosage...

  1. Factors influencing chloride deposition in a coastal hilly area and application to chloride deposition mapping

    OpenAIRE

    H. Guan; Love, A. J.; C. T. Simmons; Makhnin, O.; A. S. Kayaalp

    2010-01-01

    Chloride is commonly used as an environmental tracer for studying water flow and solute transport in the environment. It is especially useful for estimating groundwater recharge based on the commonly used chloride mass balance (CMB) method. Strong spatial variability in chloride deposition in coastal areas is one difficulty encountered in appropriately applying the method. A high-resolution bulk chloride deposition map in the coastal region is thus needed. The aim of this study is to construc...

  2. Factors influencing chloride deposition in a coastal hilly area and application to chloride deposition mapping

    OpenAIRE

    H. Guan; Love, A. J.; C. T. Simmons; Makhnin, O.; A. S. Kayaalp

    2010-01-01

    Chloride is commonly used as an environmental tracer for studying water flow and solute transport in the environment. It is especially useful for estimating groundwater recharge based on the commonly used chloride mass balance (CMB) method. Strong spatial variability in chloride deposition in coastal areas is one difficulty encountered in appropriately applying the method. A high-resolution bulk chloride deposition map in the coastal region is thus needed. The aim of this st...

  3. Application of column tests and electrical resistivity methods for leachate transport monitoring

    Directory of Open Access Journals (Sweden)

    Wychowaniak Dorota

    2015-09-01

    Full Text Available Development of the human civilization leads to the pollution of environment. One of the contamination which are a real threat to soil and groundwater are leachates from landfills. In this paper the solute transport through soil was considered. For this purpose, the laboratory column tests of chlorides tracer and leachates transport on two soil samples have been carried out. Furthermore, the electrical resistivity method was applied as auxiliary tool to follow the movements of solute through the soil column what allowed to compare between the results obtained with column test method and electrical resistivity measurements. Breakthrough curves obtained by conductivity and resistivity methods represents similar trends which leads to the conclusion about the suitability of electrical resistivity methods for contamination transport monitoring in soil-water systems.

  4. An Exact Algorithm for IP Column Generation

    OpenAIRE

    Vanderbeck, François; Wolsey, Laurence

    1994-01-01

    An exact column generation algorithm for integer programs with a large (implicit) number of columns is presented. The family of problems that can be treated includes not only standard partitioning problems such as bin packing and certain vehicle routing problems in which the columns generated have 0 - 1 components and a right hand side vector of 1 's, but also the cutting stock problem in which the columns and right hand side are nonnegative integer vectors. We develop a combined branching an...

  5. FRP rupture strains in FRP wrapped columns

    OpenAIRE

    Li, Shiqing

    2012-01-01

    Applying lateral confinement to concrete columns using fibre-reinforced polymer (FRP) composites is a very promising technique. FRP rupture is the typical failure mode of FRP wrapped columns under axial compression. numerous experiments have shown that the FRP rupture strain in an FRP wrapped circular column is significantly lower than the FRP ultimate rupture strain determined from flat coupon test of FRP. Despite a large number of studies on the application of FRP confined columns, the mech...

  6. Carboxyl modified magnetic nanoparticles coated open tubular column for capillary electrochromatographic separation of biomolecules.

    Science.gov (United States)

    Wang, Wentao; Xiao, Xing; Chen, Jia; Jia, Li

    2015-09-11

    Carboxyl modified magnetic nanoparticles (Fe3O4-COOH MNPs) coated open tubular (OT) columns were prepared for capillary electrochromatography. The Fe3O4-COOH MNPs coatings were constructed on the surface of positively charged poly(diallydimethylammonium chloride) (PDDA) modified capillaries through electrostatic self-assembly approach. The as-prepared PDDA@Fe3O4-COOH MNPs coated OT columns were characterized by scanning electron microscopy and electroosmotic flow measurement. The electrochromatographic characterization of the OT columns was evaluated by separation of amino acids, dipeptides and proteins. The influences of background solution pH, concentration, and organic modifier content on separation were investigated. The separation of these analytes was primarily based on the electrophoretic mechanism in combination with chromatographic mechanism. The Fe3O4-COOH MNPs coatings improved the separation resolution of these analytes due to their large surface area. Three variants of bovine serum albumin, two variants of β-lactoglobulin and nine glycoisoforms of ovalbumin were successfully separated. The relative standard deviations of migration times of analytes representing run-to-run, day-to-day and column-to-column were less than 4.3%. Furthermore, the feasibility of the PDDA@Fe3O4-COOH MNPs coated OT column was verified by successful separation of acidic proteins in egg white. PMID:26265004

  7. A new anionic exchange stir bar sorptive extraction coating based on monolithic material for the extraction of inorganic anion.

    Science.gov (United States)

    Huang, Xiaojia; Lin, Jianbing; Yuan, Dongxing

    2010-07-23

    A novel anionic exchange stir bar sorptive extraction (SBSE) coating based on poly(2-(methacryloyloxy)ethyltrimethylammonium chloride-co-divinylbenzene) monolithic material for the extraction of inorganic anion was prepared. The effect of preparation conditions such as ratio of functional monomer to cross-linker, content of porogenic solvent on the extraction efficiencies were investigated in detailed. The monolithic material was characterized by elemental analysis, scanning electron microscopy and infrared spectroscopy. In order to investigate the extraction capacity of the new coating for inorganic anion, the new SBSE was combined with ionic chromatography with conductivity detection, Br-, NO3-, PO4(3-) and SO4(2-) were selected as detected solutes. Several extractive parameters, including pH value and ionic strength in sample matrix, desorption solvent, extraction and desorption time were optimized. The results showed that strongly ionic strength did not favor the extraction of anlaytes. Under the optimum experimental conditions, low detection limits (S/N=3) and quantification limits (S/N=10) of the proposed method for the target anions were achieved within the range of 0.92-2.62 and 3.03-9.25 microg/L, respectively. The method also showed good linearity, simplicity, practicality and low cost for the extraction inorganic anions. Finally, the proposed method was successfully used to detect the two different trademarks of commercial purified water with satisfactory recovery in the range of 70.0-92.6%. To the best of our knowledge, this is the first to use SBSE to enrich inorganic anions. PMID:20576270

  8. Chloride ingress in cement paste and mortar

    DEFF Research Database (Denmark)

    Jensen, Ole Mejlhede; Hansen, Per Freiesleben; Coats, Alison M.;

    1999-01-01

    modelled on Fick's law modified by a term for chloride binding. Inclusion of chloride binding significantly improves the profile shape of the modelled ingress profiles. The presence of fine aggregate and formation of interfacial transition zones at paste-aggregate boundaries does not significantly affect...

  9. Chloride ingress in cement paste and mortar

    DEFF Research Database (Denmark)

    Jensen, Ole Mejlhede; Hansen, Per Freiesleben; Coats, Alison M.;

    1999-01-01

    In this paper chloride ingress in cement paste and mortar is followed by electron probe microanalysis. The influence of several paste and exposure parameters on chloride ingress are examined (e.g., water-cement ratio, silica fume addition, exposure time, and temperature), The measurements...

  10. 75 FR 19657 - Barium Chloride From China

    Science.gov (United States)

    2010-04-15

    ... Commission found that the domestic interested party group response to its notice of institution (74 FR 31757... COMMISSION Barium Chloride From China AGENCY: United States International Trade Commission. ACTION: Notice of... chloride from China. SUMMARY: The Commission hereby gives notice that it will proceed with a full...

  11. Chloride binding site of neurotransmitter sodium symporters

    DEFF Research Database (Denmark)

    Kantcheva, Adriana Krassimirova; Quick, Matthias; Shi, Lei;

    2013-01-01

    Neurotransmitter:sodium symporters (NSSs) play a critical role in signaling by reuptake of neurotransmitters. Eukaryotic NSSs are chloride-dependent, whereas prokaryotic NSS homologs like LeuT are chloride-independent but contain an acidic residue (Glu290 in LeuT) at a site where eukaryotic NSSs...

  12. Chronopotentiometric chloride sensing using transition time measurement

    NARCIS (Netherlands)

    Abbas, Y.; Graaf, de D.B.; Olthuis, W.; Berg, van den A.

    2013-01-01

    Detection of chloride ions is crucial to accurately access the concrete structure durability[1]. The existing electrochemical method of chloride ions detection in concrete, potentiometry[1], is not suitable for in-situ measurement due to the long term stability issue of conventional reference electr

  13. Chemische contaminanten in diervoeder additief Choline Chloride

    NARCIS (Netherlands)

    Traag, W.A.; Hoogenboom, L.A.P.; Jong, de J.; Egmond, van H.J.; Dam, ten G.

    2010-01-01

    Dit briefrapport beschrijft de resultaten van een onderzoek naar chemische contaminanten in Choline Chloride. De doelstellingen waren: 1) Inzicht te verkrijgen in het voorkomen van (gebromeerde) vlamvertragers en broomdioxines in het diervoederadditief Choline Chloride en het, op basis van de result

  14. Data quality objectives summary report for the 105-N monolith off-gas issue

    International Nuclear Information System (INIS)

    The 105-N Basin hardware waste with radiation exposure rates high enough to make above-water handling and packaging impractical has been designated high exposure rate hardware (HERH) waste. This material, consisting primarily of irradiated reactor components, is packaged underwater for subsequent disposal as a grout-encapsulated solid monolith. The third HERH waste package that was created (Monolith No. 3) was not immediately removed from the basin because of administrative delays. During a routine facility walkdown, Monolith No. 3 was observed to be emitting bubbles. Mass spectroscopic analysis of a gas sample from Monolith No. 3 indicated that the gas was 85.2% hydrogen along with a trace of fission gases (stable isotopes of xenon). Gamma energy analysis of a gas sample from Monolith No. 3 also identified trace quantities of 85Kr. The monolith off-gas Data Quality Objective (DQO) process concluded the following: Monolith No. 3 and similar monoliths can be safely transported following installation of spacers between the lids of the L3-181 transport cask to vent the hydrogen gas; The 85Kr does not challenge personnel or environmental safety; Fumaroles in the surface of gassing monoliths renders them incompatible with Hanford Site Solid Waste Acceptance Criteria requirements unless placed in a qualified high integrity container overpack; and Gassing monoliths do meet Environmental Restoration Disposal Facility Waste Acceptance Criteria requirements. This DQO Summary Report is both an account of the Monolith Off-Gas DQO Process and a means of documenting the concurrence of each of the stakeholder organizations

  15. Conversion of Hydrogen Sulfide in Coal Gases to Liquid Elemental Sulfur with Monolithic Catalysts

    Energy Technology Data Exchange (ETDEWEB)

    K. C. Kwon

    2007-09-30

    Removal of hydrogen sulfide (H{sub 2}S) from coal gasifier gas and sulfur recovery are key steps in the development of Department of Energy's (DOE's) advanced power plants that produce electric power and clean transportation fuels with coal and natural gas. These plants will require highly clean coal gas with H{sub 2}S below 1 ppmv and negligible amounts of trace contaminants such as hydrogen chloride, ammonia, alkali, heavy metals, and particulate. The conventional method of sulfur removal and recovery employing amine, Claus, and tail-gas treatment is very expensive. A second generation approach developed under DOE's sponsorship employs hot-gas desulfurization (HGD) using regenerable metal oxide sorbents followed by Direct Sulfur Recovery Process (DSRP). However, this process sequence does not remove trace contaminants and is targeted primarily towards the development of advanced integrated gasification combined cycle (IGCC) plants that produce electricity (not both electricity and transportation fuels). There is an immediate as well as long-term need for the development of cleanup processes that produce highly clean coal gas for next generation power plants. To this end, a novel process is now under development at several research organizations in which the H{sub 2}S in coal gas is directly oxidized to elemental sulfur over a selective catalyst. Such a process is ideally suited for coal gas from commercial gasifiers with a quench system to remove essentially all the trace contaminants except H{sub 2}S In the Single-Step Sulfur Recovery Process (SSRP), the direct oxidation of H{sub 2}S to elemental sulfur in the presence of SO{sub 2} is ideally suited for coal gas from commercial gasifiers with a quench system to remove essentially all the trace contaminants except H{sub 2}S. This direct oxidation process has the potential to produce a super clean coal gas more economically than both conventional amine-based processes and HGD/DSRP. The H{sub 2} and

  16. Conversion of Hydrogen Sulfide in Coal Gases to Liquid Elemental Sulfur with Monolithic Catalysts

    Energy Technology Data Exchange (ETDEWEB)

    K.C. Kwon

    2009-09-30

    Removal of hydrogen sulfide (H{sub 2}S) from coal gasifier gas and sulfur recovery are key steps in the development of Department of Energy's (DOE's) advanced power plants that produce electric power and clean transportation fuels with coal and natural gas. These plants will require highly clean coal gas with H{sub 2}S below 1 ppmv and negligible amounts of trace contaminants such as hydrogen chloride, ammonia, alkali, heavy metals, and particulate. The conventional method of sulfur removal and recovery employing amine, Claus, and tail-gas treatment is very expensive. A second generation approach developed under DOE's sponsorship employs hot-gas desulfurization (HGD) using regenerable metal oxide sorbents followed by Direct Sulfur Recovery Process (DSRP). However, this process sequence does not remove trace contaminants and is targeted primarily towards the development of advanced integrated gasification combined cycle (IGCC) plants that produce electricity (not both electricity and transportation fuels). There is an immediate as well as long-term need for the development of cleanup processes that produce highly clean coal gas for next generation power plants. To this end, a novel process is now under development at several research organizations in which the H{sub 2}S in coal gas is directly oxidized to elemental sulfur over a selective catalyst. Such a process is ideally suited for coal gas from commercial gasifiers with a quench system to remove essentially all the trace contaminants except H{sub 2}S In the Single-Step Sulfur Recovery Process (SSRP), the direct oxidation of H{sub 2}S to elemental sulfur in the presence of SO{sub 2} is ideally suited for coal gas from commercial gasifiers with a quench system to remove essentially all the trace contaminants except H{sub 2}S. This direct oxidation process has the potential to produce a super clean coal gas more economically than both conventional amine-based processes and HGD/DSRP. The H{sub 2} and

  17. Conversion of Hydrogen Sulfide in Coal Gases to Liquid Elemental Sulfur with Monolithic Catalysts

    Energy Technology Data Exchange (ETDEWEB)

    K. C. Kwon

    2007-09-30

    Removal of hydrogen sulfide (H{sub 2}S) from coal gasifier gas and sulfur recovery are key steps in the development of Department of Energy's (DOE's) advanced power plants that produce electric power and clean transportation fuels with coal and natural gas. These plants will require highly clean coal gas with H{sub 2}S below 1 ppmv and negligible amounts of trace contaminants such as hydrogen chloride, ammonia, alkali, heavy metals, and particulate. The conventional method of sulfur removal and recovery employing amine, Claus, and tail-gas treatment is very expensive. A second generation approach developed under DOE's sponsorship employs hot-gas desulfurization (HGD) using regenerable metal oxide sorbents followed by Direct Sulfur Recovery Process (DSRP). However, this process sequence does not remove trace contaminants and is targeted primarily towards the development of advanced integrated gasification combined cycle (IGCC) plants that produce electricity (not both electricity and transportation fuels). There is an immediate as well as long-term need for the development of cleanup processes that produce highly clean coal gas for next generation power plants. To this end, a novel process is now under development at several research organizations in which the H{sub 2}S in coal gas is directly oxidized to elemental sulfur over a selective catalyst. Such a process is ideally suited for coal gas from commercial gasifiers with a quench system to remove essentially all the trace contaminants except H{sub 2}S In the Single-Step Sulfur Recovery Process (SSRP), the direct oxidation of H{sub 2}S to elemental sulfur in the presence of SO{sub 2} is ideally suited for coal gas from commercial gasifiers with a quench system to remove essentially all the trace contaminants except H{sub 2}S. This direct oxidation process has the potential to produce a super clean coal gas more economically than both conventional amine-based processes and HGD/DSRP. The H{sub 2} and

  18. Diffusion behavior of chloride ions in concrete

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, T.; Gjoerv, O.E. [Norwegian Univ. of Science and Technology, Trondheim (Norway). Div. of Building Materials

    1996-06-01

    In the present paper, an analysis of the diffusion behavior of chloride ions in concrete is presented. In concentrated electrolytic aqueous solutions such as seawater or that typically used in laboratory experiments, the effect of ionic interaction may significantly reduce the chemical potential and thus the driving force of the diffusing species. Because of different drift velocities of the cations and chloride ions in the solution, the lagging motion of the cations will also retard the drift velocity of the chlorides. In addition, both the electrical double layer forming on the solid surface and the chemical binding may significantly interfere with the transport of the chloride ions. As a result, the diffusion behavior of the chloride ions in concrete is a more complex and complicated transport process than what can be described by Fick`s law of diffusion.

  19. Mode beating and heterodyning of monolithically integrated semiconductor ring lasers

    Science.gov (United States)

    Liu, Chiyu

    Monolithically integrated semiconductor ring lasers (SRLs) are attractive optical sources for optoelectronic integrated circuits (OEICs) because they do not require any feedback elements, do not have parts exposed to external ambient, and can operate in a traveling-wave mode. They are promising candidates for wavelength filtering, unidirectional traveling-wave operation, and multiplexing/demultiplexing applications. Ring lasers can also be used as ultrashort pulse generators using various mode-locking schemes and as active gyro components. However, the SRL is a very complicated dynamic system, which requires more investigations to understand the performance regarding details of the design and fabrication. As a part of NASA-supported project "Monolithically Integrated Semiconductor Ring Laser Gyro for Space Applications", this dissertation research was focused on design and characterization of a novel monolithically integrated rotation sensor based on two large-size independent SRLs. Numerical modeling based on the beam propagation method (BPM) was used to design the fabrication parameters for the single-mode ridge-waveguide ring cavity and directional coupler waveguides. The mode internal coupling in single lateral-mode laser diodes with InGaAs/GaAs material system was investigated by optical experiments and numerical modeling. To gain the understanding of the SRL performance, optical and electrical characterization was performed on fabricated SRLs. Particular emphasis was placed on the study of optical and radio frequency (RF) beating spectra of longitudinal modes of ring lasers. RF measurements provide high accuracy in the diagnosis of laser oscillation parameters by purely electronic means, particularly in the measurement of the group index and its dependence on current and temperature. Theoretical analysis based on the effective index method provides good agreement between the experimental data and numerical calculations. Finally, optical heterodyning spectra

  20. Monolithic passively Q-switched Cr:Nd:GSGG microlaser

    Science.gov (United States)

    Schmitt, Randal L.

    2005-09-01

    Optical firing sets need miniature, robust, reliable pulsed laser sources for a variety of triggering functions. In many cases, these lasers must withstand high transient radiation environments. In this paper we describe a monolithic passively Q-switched microlaser constructed using Cr:Nd:GSGG as the gain material and Cr4+:YAG as the saturable absorber, both of which are radiation hard crystals. This laser consists of a 1-mm-long piece of undoped YAG, a 7-mm-long piece of Cr:Nd:GSGG, and a 1.5-mm-long piece of Cr4+:YAG diffusion bonded together. The ends of the assembly are polished flat and parallel and dielectric mirrors are coated directly on the ends to form a compact, rugged, monolithic laser. When end pumped with a diode laser emitting at ~807.6 nm, this passively Q-switched laser produces ~1.5-ns-wide pulses. While the unpumped flat-flat cavity is geometrically unstable, thermal lensing and gain guiding produce a stable cavity with a TEM00 gaussian output beam over a wide range of operating parameters. The output energy of the laser is scalable and dependent on the cross sectional area of the pump beam. This laser has produced Q-switched output energies from several μJ per pulse to several 100 μJ per pulse with excellent beam quality. Its short pulse length and good beam quality result in high peak power density required for many applications such as optically triggering sprytrons. In this paper we discuss the design, construction, and characterization of this monolithic laser as well as energy scaling of the laser up to several 100 μJ per pulse.

  1. Monolithic passively Q-switched Cr:Nd:GSGG microlaser.

    Energy Technology Data Exchange (ETDEWEB)

    Schmitt, Randal L.

    2005-07-01

    Optical firing sets need miniature, robust, reliable pulsed laser sources for a variety of triggering functions. In many cases, these lasers must withstand high transient radiation environments. In this paper we describe a monolithic passively Q-switched microlaser constructed using Cr:Nd:GSGG as the gain material and Cr{sup 4+}:YAG as the saturable absorber, both of which are radiation hard crystals. This laser consists of a 1-mm-long piece of undoped YAG, a 7-mm-long piece of Cr:Nd:GSGG, and a 1.5-mm-long piece of Cr{sup 4+}:YAG diffusion bonded together. The ends of the assembly are polished flat and parallel and dielectric mirrors are coated directly on the ends to form a compact, rugged, monolithic laser. When end pumped with a diode laser emitting at -807.6 nm, this passively Q-switched laser produces -1.5-ns-wide pulses. While the unpumped flat-flat cavity is geometrically unstable, thermal lensing and gain guiding produce a stable cavity with a TEM{sub 00} gaussian output beam over a wide range of operating parameters. The output energy of the laser is scalable and dependent on the cross sectional area of the pump beam. This laser has produced Q-switched output energies from several {micro}J per pulse to several 100 {micro}J per pulse with excellent beam quality. Its short pulse length and good beam quality result in high peak power density required for many applications such as optically triggering sprytrons. In this paper we discuss the design, construction, and characterization of this monolithic laser as well as energy scaling of the laser up to several 100 {micro}J per pulse.

  2. Effect of cements on fracture resistance of monolithic zirconia crowns

    OpenAIRE

    Nakamura, Keisuke; Mouhat, Mathieu; Nergård, John Magnus; Lægreid, Solveig Jenssen; Kanno, Taro; Milleding, Percy; Örtengren, Ulf

    2016-01-01

    Abstract Objectives The present study investigated the effect of cements on fracture resistance of monolithic zirconia crowns in relation to their compressive strength. Materials and methods Four different cements were tested: zinc phosphate cement (ZPC), glass-ionomer cement (GIC), self-adhesive resin-based cement (SRC) and resin-based cement (RC). RC was used in both dual cure mode (RC-D) and chemical cure mode (RC-C). First, the compressive strength of each cement was tested according to a...

  3. Remote Sensing with Commutable Monolithic Laser and Detector

    Science.gov (United States)

    2016-01-01

    The ubiquitous trend toward miniaturized sensing systems demands novel concepts for compact and versatile spectroscopic tools. Conventional optical sensing setups include a light source, an analyte interaction region, and a separate external detector. We present a compact sensor providing room-temperature operation of monolithic surface-active lasers and detectors integrated on the same chip. The differentiation between emitter and detector is eliminated, which enables mutual commutation. Proof-of-principle gas measurements with a limit of detection below 400 ppm are demonstrated. This concept enables a crucial miniaturization of sensing devices. PMID:27785455

  4. 0.18μm CMOS, MONOLITHIC MSTP ASIC

    Institute of Scientific and Technical Information of China (English)

    Wang Peng; Jin Depeng; Zeng Lieguang

    2006-01-01

    A highly integrated monolithic Multi-Service Transport Platform (MSTP) Application Specified Integrated Circuit (ASIC) MSEOSX8-6 has been fabricated with 0.18μm CMOS technology incorporating 26×106 transistors. The chip is designed to provide standard framing and mapping of 10/100/1000Mbit/s Ethernet, Resilient Packet Ring (RPR) and E1 traffics into protected Synchronous Digital Hierarchy (SDH) STM-1 transport payloads using hitless rate adaptation for optimum bandwidth utilization. It consumes 4W of power on average and utilizes 756 pin enhanced BGA package.

  5. Microveneering technique for esthetic enhancement of monolithic zirconia restorations.

    Science.gov (United States)

    Kurbad, Andreas

    2016-01-01

    The importance of monolithic ceramic restorations is growing, given the safe and cost-effective options for fabrication of such dental crowns and fixed dental prostheses. The optical characteristics of traditional zirconia do not suffice for this purpose. Improved restorative materials that can achieve satisfactory results in posterior restorations have been proposed to solve the problem. In the anterior region, however, even "esthetic" zirconia ceramic is unable to attain results comparable to those of glass-ceramic. Microveneering is a simple, reliable, and timesaving solution. Minimal reduction and veneering can significantly improve the results. A characteristic case is presented here. PMID:27274564

  6. Monolithic active-passive 16 × 16 optoelectronic switch.

    Science.gov (United States)

    Stabile, R; Albores-Mejia, A; Williams, K A

    2012-11-15

    We present what is to our knowledge the first active-passive monolithically integrated 16×16 switch. The active InP/InGaAsP elements provide semiconductor optical amplifier gates in a multistage rearrangeably nonblocking switch design. Thirty-two representative connections, including the shortest, longest, and comprehensive range of intermediate paths have been assessed across the switch circuit. The 10 Gb/s signal routing is demonstrated with an optical signal-to-noise ratio up to 28.3 dB/0.1 nm and a signal extinction ratio exceeding 50 dB. PMID:23164873

  7. Calibration Designs for Non-Monolithic Wind Tunnel Force Balances

    Science.gov (United States)

    Johnson, Thomas H.; Parker, Peter A.; Landman, Drew

    2010-01-01

    This research paper investigates current experimental designs and regression models for calibrating internal wind tunnel force balances of non-monolithic design. Such calibration methods are necessary for this class of balance because it has an electrical response that is dependent upon the sign of the applied forces and moments. This dependency gives rise to discontinuities in the response surfaces that are not easily modeled using traditional response surface methodologies. An analysis of current recommended calibration models is shown to lead to correlated response model terms. Alternative modeling methods are explored which feature orthogonal or near-orthogonal terms.

  8. CMOS Monolithic Active Pixel Sensors (MAPS) for future vertex detectors

    International Nuclear Information System (INIS)

    This paper reviews the development of CMOS Monolithic Active Pixel Sensors (MAPS) for future vertex detectors. MAPS are developed in a standard CMOS technology. In the imaging field, where the technology found its first applications, they are also known as CMOS Image Sensors. The use of MAPS as a detector for particle physics was first proposed at the end of 1999. Since then, their good performance in terms of spatial resolution, efficiency, radiation hardness have been demonstrated and work is now well under way to deliver the first MAPS-based vertex detectors

  9. A novel carbon fiber based porous carbon monolith

    Energy Technology Data Exchange (ETDEWEB)

    Burchell, T.D.; Klett, J.W.; Weaver, C.E.

    1995-06-01

    A novel porous carbon material based on carbon fibers has been developed. The material, when activated, develops a significant micro- or mesopore volume dependent upon the carbon fiber type utilized (isotropic pitch or polyacrylonitrile). The materials will find applications in the field of fluid separations or as a catalyst support. Here, the manufacture and characterization of our porous carbon monoliths are described. A novel adsorbent carbon composite material has been developed comprising carbon fibers and a binder. The material, called carbon fiber composite molecular sieve (CFCMS), was developed through a joint research program between Oak Ridge National Laboratory (ORNL) and the University of Kentucky, Center for Applied Energy Research (UKCAER).

  10. Inherent polarization entanglement generated from a monolithic semiconductor chip

    DEFF Research Database (Denmark)

    Horn, Rolf T.; Kolenderski, Piotr; Kang, Dongpeng;

    2013-01-01

    Creating miniature chip scale implementations of optical quantum information protocols is a dream for many in the quantum optics community. This is largely because of the promise of stability and scalability. Here we present a monolithically integratable chip architecture upon which is built...... a photonic device primitive called a Bragg reflection waveguide (BRW). Implemented in gallium arsenide, we show that, via the process of spontaneous parametric down conversion, the BRW is capable of directly producing polarization entangled photons without additional path difference compensation, spectral...... as a serious contender on which to build large scale implementations of optical quantum processing devices....

  11. Development of highly sensitive monolithic interferometer for infrared planet search

    OpenAIRE

    Jiang P.; Lee B; Wan X.; Ge J; Wang J.

    2011-01-01

    We present the design, fabrication and testing of a highly sensitive monolithic interferometer for InfraRed Exoplanet Tracker (IR-ET). This interferometer is field-compensated, thermal-stable for working in the wavelength range between 0.8 and 1.35 μm. Two arms of the interferometer creates a fixed delay of 18.0 mm, which is optimized to have the best sensitivity for radial velocity measurements of slow-rotating M dwarfs for planet detection. IR-ET is aiming to reach 3–20 m/s Doppler precisio...

  12. CMOS Monolithic Active Pixel Sensors (MAPS) for future vertex detectors

    CERN Document Server

    Turchetta, R

    2006-01-01

    This paper reviews the development of CMOS Monolithic Active Pixel Sensors (MAPS) for future vertex detectors. MAPS are developed in a standard CMOS technology. In the imaging field, where the technology found its first applications, they are also known as CMOS Image Sensors. The use of MAPS as a detector for particle physics was first proposed at the end of 1999. Since then, their good performance in terms of spatial resolution, efficiency, radiation hardness have been demonstrated and work is now well under way to deliver the first MAPS-based vertex detectors.

  13. A monolithic (Si) massively broadband non-reverberant monopole

    International Nuclear Information System (INIS)

    A novel monolithic implementation of a Wu–King profiled antenna intended for use in critical time-domain/UWB/imaging applications is presented. The simulated device was fabricated on a high-resistivity Si substrate on top of which a layer of GaAs is grown, segmented and patterned to serve as the radiating element. The device's measured return loss indicates a −10 dB BW > 50 GHz and time-domain measurements using a 500 pS input pulse prove that the device is practically non-reverberant in air

  14. Monitoring catalysts at work in their final form: spectroscopic investigations on a monolithic catalyst

    DEFF Research Database (Denmark)

    Rasmussen, Søren B.; Bañares, Miguel A.; Bazin, Philippe;

    2012-01-01

    A monolithic vanadia–titania based catalyst has been subjected to studies with in situ FTIR spectroscopy coupled with mass spectrometry, during the SCR (Selective Catalytic Reduction) reaction. A device based on a transmission reactor cell for monolithic samples was constructed, dedicated to the...

  15. Monolithic junction field-effect transistor charge preamplifier for calorimetry at high luminosity hadron colliders

    International Nuclear Information System (INIS)

    The outstanding noise and radiation hardness characteristics of epitaxial-channel junction field-effect transistors (JFET) suggest that a monolithic preamplifier based upon them may be able to meet the strict specifications for calorimetry at high luminosity colliders. Results obtained so far with a buried layer planar technology, among them an entire monolithic charge-sensitive preamplifier, are described

  16. Fibrous monoliths: Economic ceramic matrix composites from powders[Final report]; FINAL

    International Nuclear Information System (INIS)

    The project was to develop and perform pilot-scale production of fibrous monolith composites. The principal focus of the program was to develop damage-tolerant, wear-resistant tooling for petroleum drilling applications and generate a basic mechanical properties database on fibrous monolith composites

  17. Synthesis and methane storage of binder-free porous graphene monoliths

    Institute of Scientific and Technical Information of China (English)

    Guoqing Ning; Hao Wang; Xiaoxin Zhang; Chenggen Xu; Guangjin Chen; Jinsen Gao

    2013-01-01

    Nanomesh graphene (NMG) obtained by template chemical vapor deposition was used to synthesize the binder-free graphene monoliths by simple tablet pressing.The stacking manner of the NMG sheets was crucial to the cohesion interaction between the graphene sheets,only the NMG materials with a loosely stacking manner could be pressed into binder-free monoliths.At the tableting pressure of 2-8 MPa,both the bulk densities and the specific surface areas of the monoliths keep nearly constant as the tableting pressure increases,indicating that the NMG monoliths have obvious elasticity and a porous structure due to the large corrugations and the mesh structures of the graphene sheets.As a result,an extraordinary methane storage capacity of 236 (v/v) at 9MPa was obtained in the graphene monolith prepared by tableting at 4 MPa.

  18. Chloride Transport in Undersea Concrete Tunnel

    Directory of Open Access Journals (Sweden)

    Yuanzhu Zhang

    2016-01-01

    Full Text Available Based on water penetration in unsaturated concrete of underwater tunnel, a diffusion-advection theoretical model of chloride in undersea concrete tunnel was proposed. The basic parameters including porosity, saturated hydraulic conductivity, chloride diffusion coefficient, initial water saturation, and moisture retention function of concrete specimens with two water-binder ratios were determined through lab-scale experiments. The variation of chloride concentration with pressuring time, location, solution concentration, initial saturation, hydraulic pressure, and water-binder ratio was investigated through chloride transport tests under external water pressure. In addition, the change and distribution of chloride concentration of isothermal horizontal flow were numerically analyzed using TOUGH2 software. The results show that chloride transport in unsaturated concrete under external water pressure is a combined effect of diffusion and advection instead of diffusion. Chloride concentration increased with increasing solution concentration for diffusion and increased with an increase in water pressure and a decrease in initial saturation for advection. The dominant driving force converted with time and saturation. When predicting the service life of undersea concrete tunnel, it is suggested that advection is taken into consideration; otherwise the durability tends to be unsafe.

  19. Shelf life of unrefrigerated succinylcholine chloride injection.

    Science.gov (United States)

    Boehm, J J; Dutton, D M; Poust, R I

    1984-02-01

    The shelf life of succinylcholine chloride injection at several pH values when stored at room temperature was evaluated. Solutions containing 20 mg/ml of succinylcholine chloride were stored at 25 and 40 degrees C. The reaction was studied at pH values ranging from 3.0 to 4.5. At two-week intervals, the solutions were assayed by high-pressure liquid chromatography. The initial amount of succinylcholine chloride in all samples was 100.1 +/- 2.37% of label claim. Hydrolysis of succinylcholine chloride in unbuffered solutions followed apparent zero-order kinetics. The pH range of maximum stability was found to be from 3.75 to 4.50. Succinylcholine chloride decomposed at a considerably higher rate at 40 degrees C. Allowing for the effects of pH adjustment during manufacture and degradation during shipping, losses of 7.0% and 9.0% potency can be expected after storage at 25 degrees C for four and six weeks, respectively. Succinylcholine Chloride Injection, USP, should be stored in the refrigerator; if unbuffered succinylcholine chloride injection complying with USP pH limits must be stored at room temperature, it should not be kept for longer than four weeks. PMID:6702837

  20. Axisymmetric collapses of granular columns

    Science.gov (United States)

    Lube, Gert; Huppert, Herbert E.; Sparks, R. Stephen J.; Hallworth, Mark A.

    2004-06-01

    Experimental observations of the collapse of initially vertical columns of small grains are presented. The experiments were performed mainly with dry grains of salt or sand, with some additional experiments using couscous, sugar or rice. Some of the experimental flows were analysed using high-speed video. There are three different flow regimes, dependent on the value of the aspect ratio a {=} h_i/r_i, where h_i and r_i are the initial height and radius of the granular column respectively. The differing forms of flow behaviour are described for each regime. In all cases a central, conically sided region of angle approximately 59(°) , corresponding to an aspect ratio of 1.7, remains undisturbed throughout the motion. The main experimental results for the final extent of the deposit and the time for emplacement are systematically collapsed in a quantitative way independent of any friction coefficients. Along with the kinematic data for the rate of spread of the front of the collapsing column, this is interpreted as indicating that frictional effects between individual grains in the bulk of the moving flow only play a role in the last instant of the flow, as it comes to an abrupt halt. For a {<} 1.7, the measured final runout radius, r_infty, is related to the initial radius by r_infty {=} r_i(1 {+} 1.24a); while for 1.7 {<} a the corresponding relationship is r_infty {=} r_i(1 {+} 1.6a(1/2) ). The time, t_infty, taken for the grains to reach r_infty is given by t_infty {=} 3(h_i/g)(1/2} {=} 3(r_i/g)({1/2}a^{1/2)) , where g is the gravitational acceleration. The insights and conclusions gained from these experiments can be applied to a wide range of industrial and natural flows of concentrated particles. For example, the observation of the rapid deposition of the grains can help explain details of the emplacement of pyroclastic flows resulting from the explosive eruption of volcanoes.

  1. Factors influencing chloride deposition in a coastal hilly area and application to chloride deposition mapping

    Directory of Open Access Journals (Sweden)

    H. Guan

    2010-05-01

    Full Text Available Chloride is commonly used as an environmental tracer for studying water flow and solute transport in the environment. It is especially useful for estimating groundwater recharge based on the commonly used chloride mass balance (CMB method. Strong spatial variability in chloride deposition in coastal areas is one difficulty encountered in appropriately applying the method. A high-resolution bulk chloride deposition map in the coastal region is thus needed. The aim of this study is to construct a chloride deposition map in the Mount Lofty Ranges (MLR, a coastal hilly area of approximately 9000 km2 spatial extent in South Australia. We examined geographic (related to coastal distance, orographic, and atmospheric factors that may influence chloride deposition, using partial correlation and regression analyses. The results indicate that coastal distance, elevation, as well as terrain aspect and slope, appear to be significant factors controlling chloride deposition in the study area. Coastal distance accounts for 70% of spatial variability in bulk chloride deposition, with elevation, terrain aspect and slope an additional 15%. The results are incorporated into a de-trended residual kriging model (ASOADeK to produce a 1 km×1 km resolution bulk chloride deposition and concentration maps. The average uncertainty of the deposition map is about 20–30% in the western MLR, and 40–50% in the eastern MLR. The maps will form a useful basis for examining catchment chloride balance for the CMB application in the study area.

  2. Reliability-Based Planning of Chloride Measurements

    DEFF Research Database (Denmark)

    Sørensen, John Dalsgaard; Engelund, S.

    1996-01-01

    on measurements of the chloride content obtained from the given structure. In the present paper optimal planning of measurements of the chloride content in reinforced concrete structures is considered. It is shown how optimal experimental plans can be obtained using FORM-analysis. Bayesian statistics are used......In reinforced concrete structures corrosion is initiated when the chloride concentration around the reinforcement exceeds a threshold value. If corrosion starts then expensive repairs can be necessary. The estimation of the probability that corrosion has been initiated in a given structure is based...

  3. Binary Nucleation of Water and Sodium Chloride

    Energy Technology Data Exchange (ETDEWEB)

    Nemec, Thomas [Institute of Thermomechanics ASCR, Prague, Czech Republic; Marsik, Frantisek [Institute of Thermomechanics ASCR, Prague, Czech Republic; Palmer, Donald [ORNL

    2005-01-01

    Nucleation processes in the binary water-sodium chloride system are investigated in the sense of the classical nucleation theory (CNT). The CNT is modified to be able to handle the electrolytic nature of the system and is employed to investigate the acceleration of the nucleation process due to the presence of sodium chloride in the steam. This phenomenon, frequently observed in the Wilson zone of steam turbines, is called early condensation. Therefore, the nucleation rates of the water-sodium chloride mixture are of key importance in the power cycle industry.

  4. Oscillating water column structural model

    Energy Technology Data Exchange (ETDEWEB)

    Copeland, Guild [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Bull, Diana L [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Jepsen, Richard Alan [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Gordon, Margaret Ellen [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

    2014-09-01

    An oscillating water column (OWC) wave energy converter is a structure with an opening to the ocean below the free surface, i.e. a structure with a moonpool. Two structural models for a non-axisymmetric terminator design OWC, the Backward Bent Duct Buoy (BBDB) are discussed in this report. The results of this structural model design study are intended to inform experiments and modeling underway in support of the U.S. Department of Energy (DOE) initiated Reference Model Project (RMP). A detailed design developed by Re Vision Consulting used stiffeners and girders to stabilize the structure against the hydrostatic loads experienced by a BBDB device. Additional support plates were added to this structure to account for loads arising from the mooring line attachment points. A simplified structure was designed in a modular fashion. This simplified design allows easy alterations to the buoyancy chambers and uncomplicated analysis of resulting changes in buoyancy.

  5. Monolithic Cylindrical Fused Silica Resonators with High Q Factors.

    Science.gov (United States)

    Pan, Yao; Wang, Dongya; Wang, Yanyan; Liu, Jianping; Wu, Suyong; Qu, Tianliang; Yang, Kaiyong; Luo, Hui

    2016-01-01

    The cylindrical resonator gyroscope (CRG) is a typical Coriolis vibratory gyroscope whose performance is determined by the Q factor and frequency mismatch of the cylindrical resonator. Enhancing the Q factor is crucial for improving the rate sensitivity and noise performance of the CRG. In this paper, for the first time, a monolithic cylindrical fused silica resonator with a Q factor approaching 8 × 10⁵ (ring-down time over 1 min) is reported. The resonator is made of fused silica with low internal friction and high isotropy, with a diameter of 25 mm and a center frequency of 3974.35 Hz. The structure of the resonator is first briefly introduced, and then the experimental non-contact characterization method is presented. In addition, the post-fabrication experimental procedure of Q factor improvement, including chemical and thermal treatment, is demonstrated. The Q factor improvement by both treatments is compared and the primary loss mechanism is analyzed. To the best of our knowledge, the work presented in this paper represents the highest reported Q factor for a cylindrical resonator. The proposed monolithic cylindrical fused silica resonator may enable high performance inertial sensing with standard manufacturing process and simple post-fabrication treatment. PMID:27483263

  6. Supercapacitor Electrodes from Activated Carbon Monoliths and Carbon Nanotubes

    Science.gov (United States)

    Dolah, B. N. M.; Othman, M. A. R.; Deraman, M.; Basri, N. H.; Farma, R.; Talib, I. A.; Ishak, M. M.

    2013-04-01

    Binderless monoliths of supercapacitor electrodes were prepared by the carbonization (N2) and activation (CO2) of green monoliths (GMs). GMs were made from mixtures of self-adhesive carbon grains (SACG) of fibers from oil palm empty fruit bunches and a combination of 5 & 6% KOH and 0, 5 & 6% carbon nanotubes (CNTs) by weight. The electrodes from GMs containing CNTs were found to have lower specific BET surface area (SBET). The electrochemical behavior of the supercapacitor fabricated using the prepared electrodes were investigated by electrochemical impedance spectroscopy (EIS) and galvanostatic charge-discharge (GCD). In general an addition of CNTs into the GMs reduces the equivalent series resistance (ESR) value of the cells. A cell fabricated using electrodes from GM with 5% CNT and 5% KOH was found to have the largest reduction of ESR value than that from the others GMs containing CNT. The cell has steeper Warburg's slope than that from its respective non-CNT GM, which reflect the smaller resistance for electrolyte ions to move into pores of electrodes despite these electrodes having largest reduction in specific BET surface area. The cell also has the smallest reduction of specific capacitance (Csp) and maintains the specific power range despite a reduction in the specific energy range due to the CNT addition.

  7. Monolithic Cylindrical Fused Silica Resonators with High Q Factors

    Science.gov (United States)

    Pan, Yao; Wang, Dongya; Wang, Yanyan; Liu, Jianping; Wu, Suyong; Qu, Tianliang; Yang, Kaiyong; Luo, Hui

    2016-01-01

    The cylindrical resonator gyroscope (CRG) is a typical Coriolis vibratory gyroscope whose performance is determined by the Q factor and frequency mismatch of the cylindrical resonator. Enhancing the Q factor is crucial for improving the rate sensitivity and noise performance of the CRG. In this paper, for the first time, a monolithic cylindrical fused silica resonator with a Q factor approaching 8 × 105 (ring-down time over 1 min) is reported. The resonator is made of fused silica with low internal friction and high isotropy, with a diameter of 25 mm and a center frequency of 3974.35 Hz. The structure of the resonator is first briefly introduced, and then the experimental non-contact characterization method is presented. In addition, the post-fabrication experimental procedure of Q factor improvement, including chemical and thermal treatment, is demonstrated. The Q factor improvement by both treatments is compared and the primary loss mechanism is analyzed. To the best of our knowledge, the work presented in this paper represents the highest reported Q factor for a cylindrical resonator. The proposed monolithic cylindrical fused silica resonator may enable high performance inertial sensing with standard manufacturing process and simple post-fabrication treatment. PMID:27483263

  8. Monolithic integrated optic fiber Bragg grating sensor interrogator

    Science.gov (United States)

    Mendoza, Edgar A.; Esterkin, Yan; Kempen, Cornelia; Sun, Songjian

    2010-04-01

    Fiber Bragg gratings (FBGs) are a mature sensing technology that has gained rapid acceptance in civil, aerospace, chemical and petrochemical, medicine, aviation and automotive industries. Fiber Bragg grating sensors can be use for a variety of measurements including strain, stress, vibration, acoustics, acceleration, pressure, temperature, moisture, and corrosion distributed at multiple locations within the structure using a single fiber element. The most prominent advantages of FBGs are: small size and light weight, multiple FBG transducers on a single fiber, and immunity to radio frequency interference. A major disadvantage of FBG technology is that conventional state-of-the-art fiber Bragg grating interrogation systems are typically bulky, heavy, and costly bench top instruments that are assembled from off-the-shelf fiber optic and optical components integrated with a signal electronics board into an instrument console. Based on the need for a compact FBG interrogation system, this paper describes recent progress towards the development of a miniature fiber Bragg grating sensor interrogator (FBG-TransceiverTM) system based on multi-channel monolithic integrated optic sensor microchip technology. The integrated optic microchip technology enables the monolithic integration of all of the functionalities, both passive and active, of conventional bench top FBG sensor interrogators systems, packaged in a miniaturized, low power operation, 2-cm x 5-cm small form factor (SFF) package suitable for the long-term structural health monitoring in applications where size, weight, and power are critical for operation.

  9. SU8 diaphragm micropump with monolithically integrated cantilever check valves.

    Science.gov (United States)

    Ezkerra, Aitor; Fernández, Luis José; Mayora, Kepa; Ruano-López, Jesús Miguel

    2011-10-01

    This paper presents a SU8 unidirectional diaphragm micropump with embedded out-of-plane cantilever check valves. The device represents a reliable and low-cost solution for integration of microfluidic control in lab-on-a-chip devices. Its planar architecture allows monolithic definition of its components in a single step and potential integration with previously reported PCR, electrophoresis and flow-sensing SU8 microdevices. Pneumatic actuation is applied on a PDMS diaphragm, which is bonded to the SU8 body at wafer level, further enhancing its integration and mass production capabilities. The cantilever check valves move synchronously with the diaphragm, feature fast response (10ms), low dead volume (86nl) and a 94% flow blockage up to 300kPa. The micropump achieves a maximum flow rate of 177 μl min(-1) at 6 Hz and 200 kPa with an effective area of 10 mm(2). The device is reliable, self-priming and tolerant to particles and big bubbles. To the knowledge of the authors, this is the first micropump in SU8 with monolithically integrated cantilever check valves. PMID:21853192

  10. Novel monolithic electrochemically promoted catalytic reactor for environmentally important reactions

    Energy Technology Data Exchange (ETDEWEB)

    Balomenou, S.; Tsiplakides, D.; Katsaounis, A.; Vayenas, C.G. [Department of Chemical Engineering, University of Patras, Caratheodory 1 St., GR-26504 Patras (Greece); Thiemann-Handler, S.; Cramer, B. [Robert Bosch GmbH Stuttgart, FV/FLC, PF 10 60 50, 70 049 Stuttgart (Germany); Foti, G.; Comninellis, Ch. [Institute of Chemical Sciences and Engineering, Swiss Federal Institute of Technology, CH-1015 Lausanne (Switzerland)

    2004-09-28

    A novel dismantlable monolithic-type electrochemically promoted catalytic reactor and 'smart' sensor-catalytic reactor unit has been constructed and tested for hydrocarbon oxidation and NO reduction by C{sub 2}H{sub 4} in presence of O{sub 2}. In this novel reactor, thin (=20-40nm) porous catalyst films made of two different materials are sputter-deposited on opposing surfaces of thin (0.25mm) parallel solid electrolyte plates supported in the grooves of a ceramic monolithic holder and serve as sensor or electropromoted catalyst elements. Using Rh/YSZ/Pt-type catalyst elements, the 22-plate reactor operated with apparent Faradaic efficiency exceeding 25 achieving near complete fuel and NO conversion at 300C in presence of up to 1.1% O{sub 2} in the feed at gas flow rates exceeding 1.3l/min. The metal catalyst dispersion was of the order of at least 15%. The novel reactor design requires only two external electrical connections and permits easy practical utilization of the electrochemical promotion of catalysis.

  11. Monolithically Integrated High-β Nanowire Lasers on Silicon.

    Science.gov (United States)

    Mayer, B; Janker, L; Loitsch, B; Treu, J; Kostenbader, T; Lichtmannecker, S; Reichert, T; Morkötter, S; Kaniber, M; Abstreiter, G; Gies, C; Koblmüller, G; Finley, J J

    2016-01-13

    Reliable technologies for the monolithic integration of lasers onto silicon represent the holy grail for chip-level optical interconnects. In this context, nanowires (NWs) fabricated using III-V semiconductors are of strong interest since they can be grown site-selectively on silicon using conventional epitaxial approaches. Their unique one-dimensional structure and high refractive index naturally facilitate low loss optical waveguiding and optical recirculation in the active NW-core region. However, lasing from NWs on silicon has not been achieved to date, due to the poor modal reflectivity at the NW-silicon interface. We demonstrate how, by inserting a tailored dielectric interlayer at the NW-Si interface, low-threshold single mode lasing can be achieved in vertical-cavity GaAs-AlGaAs core-shell NW lasers on silicon as measured at low temperature. By exploring the output characteristics along a detection direction parallel to the NW-axis, we measure very high spontaneous emission factors comparable to nanocavity lasers (β = 0.2) and achieve ultralow threshold pump energies ≤11 pJ/pulse. Analysis of the input-output characteristics of the NW lasers and the power dependence of the lasing emission line width demonstrate the potential for high pulsation rates ≥250 GHz. Such highly efficient nanolasers grown monolithically on silicon are highly promising for the realization of chip-level optical interconnects. PMID:26618638

  12. Monolithically Integrated Ge-on-Si Active Photonics

    Directory of Open Access Journals (Sweden)

    Jifeng Liu

    2014-07-01

    Full Text Available Monolithically integrated, active photonic devices on Si are key components in Si-based large-scale electronic-photonic integration for future generations of high-performance, low-power computation and communication systems. Ge has become an interesting candidate for active photonic devices in Si photonics due to its pseudo-direct gap behavior and compatibility with Si complementary metal oxide semiconductor (CMOS processing. In this paper, we present a review of the recent progress in Ge-on-Si active photonics materials and devices for photon detection, modulation, and generation. We first discuss the band engineering of Ge using tensile strain, n-type doping, Sn alloying, and separate confinement of Γ vs. L electrons in quantum well (QW structures to transform the material towards a direct band gap semiconductor for enhancing optoelectronic properties. We then give a brief overview of epitaxial Ge-on-Si materials growth, followed by a summary of recent investigations towards low-temperature, direct growth of high crystallinity Ge and GeSn alloys on dielectric layers for 3D photonic integration. Finally, we review the most recent studies on waveguide-integrated Ge-on-Si photodetectors (PDs, electroabsorption modulators (EAMs, and laser diodes (LDs, and suggest possible future research directions for large-scale monolithic electronic-photonic integrated circuits on a Si platform.

  13. Monolithic Active Pixel Matrix with Binary Counters (MAMBO) ASIC

    Energy Technology Data Exchange (ETDEWEB)

    Khalid, Farah F.; Deptuch, Grzegorz; Shenai, Alpana; Yarema, Raymond J.; /Fermilab

    2010-11-01

    Monolithic Active Matrix with Binary Counters (MAMBO) is a counting ASIC designed for detecting and measuring low energy X-rays from 6-12 keV. Each pixel contains analogue functionality implemented with a charge preamplifier, CR-RC{sup 2} shaper and a baseline restorer. It also contains a window comparator which can be trimmed by 4 bit DACs to remove systematic offsets. The hits are registered by a 12 bit ripple counter which is reconfigured as a shift register to serially output the data from the entire ASIC. Each pixel can be tested individually. Two diverse approaches have been used to prevent coupling between the detector and electronics in MAMBO III and MAMBO IV. MAMBO III is a 3D ASIC, the bottom ASIC consists of diodes which are connected to the top ASIC using {mu}-bump bonds. The detector is decoupled from the electronics by physically separating them on two tiers and using several metal layers as a shield. MAMBO IV is a monolithic structure which uses a nested well approach to isolate the detector from the electronics. The ASICs are being fabricated using the SOI 0.2 {micro}m OKI process, MAMBO III is 3D bonded at T-Micro and MAMBO IV nested well structure was developed in collaboration between OKI and Fermilab.

  14. Squeezed light from a diamond-turned monolithic cavity

    CERN Document Server

    Brieussel, A; Campbell, G; Guccione, G; Janousek, J; Hage, B; Buchler, B C; Treps, N; Fabre, C; Fang, F Z; Li, X Y; Symul, T; Lam, P K

    2016-01-01

    For some crystalline materials, a regime can be found where continuous ductile cutting is feasible. Using precision diamond turning, such materials can be cut into complex optical components with high surface quality and form accuracy. In this work we use diamond-turning to machine a monolithic, square-shaped, doubly-resonant $LiNbO_3$ cavity with two flat and two convex facets. When additional mild polishing is implemented, the Q-factor of the resonator is found to be limited only by the material absorption loss. We show how our monolithic square resonator may be operated as an optical parametric oscillator that is evanescently coupled to free-space beams via birefringent prisms. The prism arrangement allows for independent and large tuning of the fundamental and second harmonic coupling rates. We measure $2.6\\pm0.5$ dB of vacuum squeezing at 1064 nm using our system. Potential improvements to obtain higher degrees of squeezing are discussed.

  15. Macroporous monoliths for trace metal extraction from seawater

    Energy Technology Data Exchange (ETDEWEB)

    Yue, Yanfeng; Mayes, Richard; Gill, Gary A.; Kuo, Li-Jung; Wood, Jordana R.; Binder, Andrew; Brown, Suree; Dai, Sheng

    2015-05-29

    The viability of seawater-based uranium recovery depends on the uranium adsorption rate and capacity, since the concentration of uranium in the oceans is relatively low (3.3 μgL⁻¹). An important consideration for a fast adsorption is to maximize the adsorption properties of adsorbents such as surface areas and pore structures, which can greatly improve the kinetics of uranium extraction and the adsorption capacity simultaneously. Following this consideration, macroporous monolith adsorbents were prepared from the copolymerization of acrylonitrile (AN) and N,N’-methylenebis(acrylamide) (MBAAm) based on a cryogel method using both hydrophobic and hydrophilic monomers. The monolithic sorbents were tested with simulated seawater containing a high uranyl concentration (–6 ppm) and the uranium adsorption results showed that the adsorption capacities are strongly influenced by the ratio of monomer to the crosslinker, i.e., the density of the amidoxime groups. The preliminary seawater testing indicates the high salinity content of seawater does not hinder the adsorption of uranium.

  16. Monolithically integrated Helmholtz coils by 3-dimensional printing

    International Nuclear Information System (INIS)

    3D printing technology is of great interest for the monolithic fabrication of integrated systems; however, it is a challenge to introduce metallic components into 3D printed molds to enable broader device functionality. Here, we develop a technique for constructing a multi-axial Helmholtz coil by injecting a eutectic liquid metal Gallium Indium alloy (EGaIn) into helically shaped orthogonal cavities constructed in a 3D printed block. The tri-axial solenoids each carry up to 3.6 A of electrical current and produce magnetic field up to 70 G. Within the central section of the coil, the field variation is less than 1% and is in agreement with theory. The flow rates and critical pressures required to fill the 3D cavities with liquid metal also agree with theoretical predictions and provide scaling trends for filling the 3D printed parts. These monolithically integrated solenoids may find future applications in electronic cell culture platforms, atomic traps, and miniaturized chemical analysis systems based on nuclear magnetic resonance.

  17. Off-line hyphenation of boronate affinity monolith-based extraction with matrix-assisted laser desorption/ionization time-of-flight mass spectrometry for efficient analysis of glycoproteins/glycopeptides.

    Science.gov (United States)

    Bie, Zijun; Chen, Yang; Li, Hengye; Wu, Ronghu; Liu, Zhen

    2014-06-27

    Boronate affinity materials have attracted increasing attentions as sample enrichment platforms for glycoproteomic analysis in recent years. However, most of the boronate affinity materials that have already employed for proteomic analysis are suffering from apparent disadvantages, such as alkaline pH for binding, weak affinity, and relatively poor selectivity. Benzoboroxoles are a unique class of boronic acids which have showed excellent binding properties for the recognition of cis-diol-containing compounds. Recently, a 3-carboxy-benzoboroxole-functionalized monolithic column had been reported and it had exhibited the best selectivity and affinity as well as the lowest binding pH among all reported boronate affinity monolithic columns. In this study, an off-line hyphenation of this boronate affinity monolithic column-based extraction with matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) was developed and the powerfulness of this hyphenated approach in the analysis of glycoproteins and glycopeptides in complex samples was investigated. The approach was first applied to the analysis of glycopeptides in the tryptic digest of horseradish peroxidase (HRP). Totally 22 glycopeptides were identified. To the best of our knowledge, this is the best performance among all the boronic acid-functionalized materials. We further employed this approach to the analysis of intact proteins in human saliva. Totally 6 intact glycoproteins were successfully identified. As comparison, when the samples were analyzed without extraction, only a few glycopeptides were identified from the tryptic digest of HRP while no glycoproteins were found from the saliva samples. PMID:24928239

  18. Interstitial gas effect on vibrated granular columns

    OpenAIRE

    Pastenes, Javier,; Géminard, Jean-Christophe; Melo, Francisco

    2014-01-01

    Vibrated granular materials have been intensively used to investigate particle segregation, convection and heaping. We report on the behavior of a column of heavy grains bouncing on an oscillating solid surface. Measurements indicate that, for weak effects of the interstitial gas, the temporal variations of the pressure at the base of the column are satisfactorily described by considering that the column, in spite of the observed dilation, behaves like a porous solid. In addition, direct obse...

  19. Dynamic Effects of Diabatization in Distillation Columns

    OpenAIRE

    Bisgaard, Thomas; Huusom, Jakob Kjøbsted; Abildskov, Jens

    2012-01-01

    The dynamic eects of diabatization in distillation columns are investigated in simulation with primary focus on the heat-integrated distillation column (HIDiC). A generic, dynamic, rst-principle model has been formulated, which is exible to describe various diabatic distillation congurations. Dynamic Relative Gain Array and Singular Value Analysis have been applied in a comparative study of a conventional distillation column and a HIDiC. The study showed increased input-output coupling due to...

  20. Surface adsorption in strontium chloride ammines

    DEFF Research Database (Denmark)

    Ammitzbøll, Andreas L.; Lysgaard, Steen; Klukowska, Agata;

    2013-01-01

    An adsorbed state and its implications on the ab- and desorption kinetics of ammonia in strontium chloride ammine is identified using a combination of ammonia absorption measurements, thermogravimetric analysis, and density functional theory calculations. During thermogravimetric analysis, ammoni...

  1. Catastrophic event modeling. [lithium thionyl chloride batteries

    Science.gov (United States)

    Frank, H. A.

    1981-01-01

    A mathematical model for the catastrophic failures (venting or explosion of the cell) in lithium thionyl chloride batteries is presented. The phenomenology of the various processes leading to cell failure is reviewed.

  2. Reinforced concrete columns of variable cross section

    OpenAIRE

    Brant, N.F.A.

    1984-01-01

    The results of a series of 19 full scale tests carried out on pin-ended reinforced concrete columns are reported. The columns tested had either tapered rectangular sections along the length or octagonal cross sections. All columns, except the last 6, were subjected to uniaxial eccentricities at one of the ends (the stronger end), and a nominally concentric load at the other end. For the case of the last six columns the loading applied at the stronger end was biaxially eccentric. For each of t...

  3. Picobubble enhanced column flotation of fine coal

    Energy Technology Data Exchange (ETDEWEB)

    Tao, D.; Yu, S.; Parekh, B.K. [University of Kentucky, Lexington, KY (United States). Mining Engineering

    2006-07-01

    The purpose is to study the effectiveness of picobubbles in the column flotation of -28 mesh fine coal particles. A flotation column with a picobubble generator was developed and tested for enhancing the recovery of ultrafine coal particles. The picobubble generator was designed using the hydrodynamic cavitation principle. A metallurgical and a steam coal were tested in the apparatus. The results show that the use of picobubbles in a 2in. flotation column increased the recovery of fine coal by 10 to 30%. The recovery rate varied with feed rate, collector dosage, and other column conditions. 40 refs., 8 figs., 2 tabs.

  4. Choline chloride-based deep eutectic solvents as additives for optimizing chromatographic behavior of caffeic acid

    Energy Technology Data Exchange (ETDEWEB)

    Li, Guizhen; Zhu, Tao; Lei, Yingjie [Tianjin University of Technology, Tianjin (China)

    2015-10-15

    A series of deep eutectic solvents (DESs) were prepared using glycerol and choline chloride (ChCl), and Fourier transform infrared spectrometer (FT-IR) was used to analyze the spectra of glycerol, choline chloride and DESs based on glycerol and choline chloride. Then DESs were used as the additives of mobile phase to optimize chromatographic behavior of caffeic acid in high performance liquid chromatography (HPLC). A 17-run Box-Behnken design (BBD) was employed to evaluate effect of DESs as additives by analyzing the maximum theoretical plate number. Three factors, reaction temperature (60 .deg. C, 80 .deg. C, 100 .deg. C), molar ratio of glycerol and choline chloride (2 : 1, 3 : 1, 4 : 1, n/n), and volume percent of additives (0.05%, 0.10%, 0.15%, v/v), were investigated in BBD. The optimum experiment condition was that of reaction temperature (80 .deg. C), molar ratio of glycerol and ChCl (3 : 1, n/n), and volume percent of additive (0.10%, v/v). The mean chromatographic theoretical plate number of the caffeic acid this condition was 1567.5, and DESs as additives shorten the retention time and modify the chromatogram shape, proving DESs as additives for effective theoretical plate number and column efficiency in HPLC.

  5. Soil column leaching of pesticides.

    Science.gov (United States)

    Katagi, Toshiyuki

    2013-01-01

    In this review, I address the practical and theoretical aspects of pesticide soil mobility.I also address the methods used to measure mobility, and the factors that influence it, and I summarize the data that have been published on the column leaching of pesticides.Pesticides that enter the unsaturated soil profile are transported downwards by the water flux, and are adsorbed, desorbed, and/or degraded as they pass through the soil. The rate of passage of a pesticide through the soil depends on the properties of the pesticide, the properties of the soil and the prevailing environmental conditions.Because large amounts of many different pesticides are used around the world, they and their degradates may sometimes contaminate groundwater at unacceptable levels.It is for this reason that assessing the transport behavior and soil mobility of pesticides before they are sold into commerce is important and is one indispensable element that regulators use to assess probable pesticide safety. Both elementary soil column leaching and sophisticated outdoor lysimeter studies are performed to measure the leaching potential for pesticides; the latter approach more reliably reflects probable field behavior, but the former is useful to initially profile a pesticide for soil mobility potential.Soil is physically heterogeneous. The structure of soil varies both vertically and laterally, and this variability affects the complex flow of water through the soil profile, making it difficult to predict with accuracy. In addition, macropores exist in soils and further add to the complexity of how water flow occurs. The degree to which soil is tilled, the density of vegetation on the surface, and the type and amounts of organic soil amendments that are added to soil further affect the movement rate of water through soil, the character of soil adsorption sites and the microbial populations that exist in the soil. Parameters that most influence the rate of pesticide mobility in soil are

  6. Telomerization of Vinyl Chloride with Chloroform Initiated by Ferrous Chloride-Dimethylacetamide under Ultrasonic Conditions

    Directory of Open Access Journals (Sweden)

    Hua Qian

    2015-01-01

    Full Text Available Telomerization of vinyl chloride with chloroform was investigated using ferrous chloride-dimethylacetamide system, and 42.1% yield, more than four times the one reported before, was achieved. The addition of ultrasound further improved the reaction and yield was raised to 51.9% with trace byproducts at highly reduced reaction time and temperature. Ferrous chloride-dimethylacetamide under ultrasonic irradiation acts as a very efficient catalyst system for the 1 : 1 telomerization.

  7. Factors influencing chloride deposition in a coastal hilly area and application to chloride deposition mapping

    OpenAIRE

    H. Guan; Love, A. J.; C. T. Simmons; A. S. Kayaalp

    2009-01-01

    Chloride is commonly used as an environmental tracer for studying water flow and solute transport in the environment. It is especially useful for estimating groundwater recharge based on the commonly used chloride mass balance (CMB) method. Strong spatial variability in chloride deposition in coastal areas is one difficulty encountered in appropriately applying the CMB approach. Furthermore, intensive vegetation clearance for agriculture, for example during the European settlement in many...

  8. Estimating the chloride transport in cement paste

    OpenAIRE

    Princigallo, A.

    2012-01-01

    A method was developed to measure the diffusion coefficient of chloride ions in cement paste based on an analytical solution to Fick’s 2nd law in a cylindrical coordinate system. This natural method yielded diffusivity results within as little as a month. Testing time was reduced by exploiting the three-dimensional inward flux in the specimen. In an attempt to determine the saturation concentration, dense portland cement pastes were exposed to a concentrated chloride solution. The method prov...

  9. Punching Shear Behavior of RC Slab-Column Connections with Nonrectangular Columns

    Institute of Scientific and Technical Information of China (English)

    Liu Wenting; Huang Chengkui; Zhang Ruihe

    2005-01-01

    This paper present an experimental study on the RC slab-column connections with nonrectangular columns, namely cross-shaped column, T-shaped column and L-shaped column. The punching shear deformation and strength characteristics of slab-column connections with nonrectangular columns under punching shear load are investigated. Nine specimens with the three kinds of nonrectangular columns and two reference specimens with square columns are tested. The tested ultimate loads, deformations, and failure modes of specimens are presented and discussed. Test results reveal that the punching shear strength and ductility of the connections with nonrectangular columns are higher than those of the corresponding connections with square columns, and also prove that the application of nonrectangular columns to flat-plate structure was feasible. Based on the test results, one method of calculating punching shear strength of connections with nonrectangular columns is proposed, which conforms with the current design practice of China. The test results on the punching shear strength are compared with the predictions of the formulas proposed by codes of several different countrie; and the predictions given by ACI code and China code are found to be conservative as the reinforcement ratio is increased.

  10. Studies on Acetone Powder and Purified Rhus Laccase Immobilized on Zirconium Chloride for Oxidation of Phenols

    Directory of Open Access Journals (Sweden)

    Rong Lu

    2012-01-01

    Full Text Available Rhus laccase was isolated and purified from acetone powder obtained from the exudates of Chinese lacquer trees (Rhus vernicifera from the Jianshi region, Hubei province of China. There are two blue bands appearing on CM-sephadex C-50 chromatography column, and each band corresponding to Rhus laccase 1 and 2, the former being the major constituent, and each had an average molecular weight of approximately 110 kDa. The purified and crude Rhus laccases were immobilized on zirconium chloride in ammonium chloride solution, and the kinetic properties of free and immobilized Rhus laccase, such as activity, molecular weight, optimum pH, and thermostability, were examined. In addition, the behaviors on catalytic oxidation of phenols also were conducted.

  11. Conversion of Hydrogen Sulfide in Coal Gases to Liquid Elemental Sulfur with Monolithic Catalysts

    Energy Technology Data Exchange (ETDEWEB)

    K.C. Kwon

    2009-09-30

    Removal of hydrogen sulfide (H{sub 2}S) from coal gasifier gas and sulfur recovery are key steps in the development of Department of Energy's (DOE's) advanced power plants that produce electric power and clean transportation fuels with coal and natural gas. These plants will require highly clean coal gas with H{sub 2}S below 1 ppmv and negligible amounts of trace contaminants such as hydrogen chloride, ammonia, alkali, heavy metals, and particulate. The conventional method of sulfur removal and recovery employing amine, Claus, and tail-gas treatment is very expensive. A second generation approach developed under DOE's sponsorship employs hot-gas desulfurization (HGD) using regenerable metal oxide sorbents followed by Direct Sulfur Recovery Process (DSRP). However, this process sequence does not remove trace contaminants and is targeted primarily towards the development of advanced integrated gasification combined cycle (IGCC) plants that produce electricity (not both electricity and transportation fuels). There is an immediate as well as long-term need for the development of cleanup processes that produce highly clean coal gas for next generation power plants. To this end, a novel process is now under development at several research organizations in which the H{sub 2}S in coal gas is directly oxidized to elemental sulfur over a selective catalyst. Such a process is ideally suited for coal gas from commercial gasifiers with a quench system to remove essentially all the trace contaminants except H{sub 2}S In the Single-Step Sulfur Recovery Process (SSRP), the direct oxidation of H{sub 2}S to elemental sulfur in the presence of SO{sub 2} is ideally suited for coal gas from commercial gasifiers with a quench system to remove essentially all the trace contaminants except H{sub 2}S. This direct oxidation process has the potential to produce a super clean coal gas more economically than both conventional amine-based processes and HGD/DSRP. The H{sub 2} and

  12. Influence of Chloride-Ion Adsorption Agent on Chloride Ions in Concrete and Mortar

    Directory of Open Access Journals (Sweden)

    Gai-Fei Peng

    2014-04-01

    Full Text Available The influence of a chloride-ion adsorption agent (Cl agent in short, composed of zeolite, calcium aluminate hydrate and calcium nitrite, on the ingress of chloride ions into concrete and mortar has been experimentally studied. The permeability of concrete was measured, and the chloride ion content in mortar was tested. The experimental results reveal that the Cl agent could adsorb chloride ions effectively, which had penetrated into concrete and mortar. When the Cl agent was used at a dosage of 6% by mass of cementitious materials in mortar, the resistance to the penetration of chloride ions could be improved greatly, which was more pronounced when a combination of the Cl agent and fly ash or slag was employed. Such an effect is not the result of the low permeability of the mortar, but might be a result of the interaction between the Cl agent and the chloride ions penetrated into the mortar. There are two possible mechanisms for the interaction between the Cl agent and chloride ion ingress. One is the reaction between calcium aluminate hydrate in the Cl agent and chloride ions to form Friedel’s salt, and the other one is that calcium aluminate hydrate reacts with calcium nitrite to form AFm during the early-age hydration of mortar and later the NO2− in AFm is replaced by chloride ions, which then penetrate into the mortar, also forming Friedel’s salt. More research is needed to confirm the mechanisms.

  13. Effect of Chloride Type on Penetration of Chloride Ions in Concrete

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    The influence of chloride type on the diffusivity of chloride ions in concrete was studied by experiment. The result shows that the glectric resistance of concrete and the chloride diffusion coefficient are influenced by chloride type. For the same water/cement ratio (W/C), the diffusion coefficient D in KCl solution is larger than that in NaCl solution; however, the concrete resistance in KCl solution is smaller than that in NaCl solution. The experimental result is analyzed with theory of diffusion.

  14. Agglomerated polymer monoliths with bimetallic nano-particles as flow-through micro-reactors

    International Nuclear Information System (INIS)

    Polymer monoliths in capillary format have been prepared as solid supports for the immobilisation of platinum/palladium bimetallic nano-flowers. Optimum surface coverage of nano-flowers was realised by photografting the monoliths with vinyl azlactone followed by amination with ethylenediamine prior to nano-particle immobilisation. Field emission SEM imaging was used as a characterisation tool for evaluating nano-particle coverage, together with BET surface area analysis to probe the effect of nano-particle immobilisation upon monolith morphology. Ion exchange chromatography was also used to confirm the nature of the covalent attachment of nano-flowers on the monolithic surface. In addition, EDX and ICP analyses were used to quantify platinum and palladium on modified polymer monoliths. Finally the catalytic properties of immobilised bimetallic Pd/Pt nano-flowers were evaluated in flow-through mode, exploiting the porous interconnected flow-paths present in the prepared monoliths (pore diameter ∼ 1-2 μm). Specifically, the reduction of Fe (III) to Fe (II) and the oxidation of NADH to NAD+ were selected as model redox reactions. The use of a porous polymer monolith as an immobilisation substrate (rather than aminated micro-spheres) eliminated the need for a centrifugation step after the reaction. (author)

  15. Observed and simulated time evolution of HCl, ClONO2, and HF total column abundances

    OpenAIRE

    R. Kohlhepp; Ruhnke, R.; M. P. Chipperfield; De Mazière, M.; Notholt, J.; S. Barthlott; Batchelor, R.L.; R. D. Blatherwick; Blumenstock, Th.; Coffey, M. T.; Demoulin, P.; Fast, H.; Feng, W.; Goldman, A.; Griffith, D. W. T.

    2012-01-01

    Time series of total column abundances of hydrogen chloride (HCl), chlorine nitrate (ClONO2), and hydrogen fluoride (HF) were determined from ground-based Fourier transform infrared (FTIR) spectra recorded at 17 sites belonging to the Network for the Detection of Atmospheric Composition Change (NDACC) and located between 80.05° N and 77.82° S. By providing such a near-global overview on ground-based measurements of the two major stratospheric chlorine reservoir species, HCl ...

  16. Column flotation in an oilsand application

    Energy Technology Data Exchange (ETDEWEB)

    Wiwchar, K.; Dang, L.; Marks, A.; Mbaja, E. [Suncor Energy Inc. Oil Sands, Fort McMurray, AB (Canada); Furey, J. [Canadian Process Technologies Inc., Vancouver, BC (Canada)

    2004-07-01

    In March 2003, Suncor Energy Inc. began pilot operation of a flotation column designed by Canadian Process Technologies Inc. (CPT). Oilsands from the Suncor mine are mixed with hot process water and the bitumen is slurried in a pipeline. Large separation cells float off the bitumen product, which is then steam or static deaerated and sent to a secondary extraction plant for further cleaning. The tailings flotation froth product is processed at the final tails pumphouse where it is recycled to the oilsand feed. This pilot operation tested the performance of the CPT column against the performance of scavenger banks that use middlings streams. It was determined that if the flotation column recovery results surpassed the scavenger banks, columns would replace the Denver scavenger banks used in existing extraction plants. Pilot scale tests used a CPT 4 foot diameter flotation column. Previous bench scale tests at the University of Alberta were based on 2.4 inch and 20 inch diameter columns. The columns received middlings stream feed from deep cone separation cells. The column operates in parallel with a set of WEMCO flotation cells. The evaluation compared the recovery, tails losses, and concentrate quality of the two systems. All types of mine ore grades were tested. In order to optimize recovery and final product quality, adjustments were made to wash water flow and temperature, sparger nozzle size and location, sparger air/water flow rates, and column residence time. Column flotation is typically used in the final stages of sulphide cleaning and flotation of phosphate or iron ore. Preliminary results indicate that the use of the CPT flotation column in an oilsand application was successful and may prove to be an inexpensive method to recover bitumen from a middlings stream and to produce a product suitable for froth treatment. 2 refs., 1 tab., 5 figs.

  17. Wideband monolithically integrated front-end subsystems and components

    Science.gov (United States)

    Mruk, Joseph Rene

    This thesis presents the analysis, design, and measurements of passive, monolithically integrated, wideband recta-coax and printed circuit board front-end components. Monolithic fabrication of antennas, impedance transformers, filters, and transitions lowers manufacturing costs by reducing assembly time and enhances performance by removing connectors and cabling between the devices. Computational design, fabrication, and measurements are used to demonstrate the capabilities of these front-end assemblies. Two-arm wideband planar log-periodic antennas fed using a horizontal feed that allows for filters and impedance transformers to be readily fabricated within the radiating region of the antenna are demonstrated. At microwave frequencies, low-cost printed circuit board processes are typically used to produce planar devices. A 1.8 to 11 GHz two-arm planar log-periodic antenna is designed with a monolithically integrated impedance transformer. Band rejection methods based on modifying the antenna aperture, use of an integrated filter, and the application of both methods are investigated with realized gain suppressions of over 25 dB achieved. The ability of standard circuit board technology to fabricate millimeter-wave devices up to 110 GHz is severely limited. Thin dielectrics are required to prevent the excitation of higher order modes in the microstrip substrate. Fabricating the thin line widths required for the antenna aperture also becomes prohibitively challenging. Surface micro-machining typically used in the fabrication of MEMS devices is capable of producing the extremely small features that can be used to fabricate antennas extending through W-band. A directly RF fed 18 to 110 GHz planar log-periodic antenna is developed. The antenna is fabricated with an integrated impedance transformer and additional transitions for measurement characterization. Singly terminated low-loss wideband millimeter-wave filters operating over V- and W- band are developed. High

  18. Recovery of active anti TNF-α ScFv through matrix-assisted refolding of bacterial inclusion bodies using CIM monolithic support.

    Science.gov (United States)

    Sushma, Krishnan; Bilgimol, Chuvappumkal Joseph; Vijayalakshmi, Mookambeswaran A; Satheeshkumar, Padikara Kutty

    2012-04-01

    Anti TNF-α molecules are important as therapeutic agents for many of the autoimmune diseases in chronic stage. Here we report the expression and purification of a recombinant single chain variable fragment (ScFv) specific to TNF-α from inclusion bodies. In contrast to the conventional on column refolding using the soft gel supports, an efficient methodology using monolithic matrix has been employed. Nickel (II) coupled to convective interaction media (CIM) support was utilized for this purpose with 6M guanidine hydrochloride (GuHCl) as the chaotropic agent. The protein purified after solubilization and refolding proved to be biologically active with an IC₅₀ value of 15 μg. To the best of our knowledge, this is the first report showing the application of methacrylate based chromatographic supports for matrix-assisted refolding and purification of Escherichia coli inclusion bodies. The results are promising to elaborate the methodology further to exploit the potential positive features of monoliths in protein refolding science. PMID:22386363

  19. 21 CFR 178.3290 - Chromic chloride complexes.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Chromic chloride complexes. 178.3290 Section 178... SANITIZERS Certain Adjuvants and Production Aids § 178.3290 Chromic chloride complexes. Myristo chromic chloride complex and stearato chromic chloride complex may be safely used as release agents in the...

  20. 49 CFR 179.102-17 - Hydrogen chloride, refrigerated liquid.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 2 2010-10-01 2010-10-01 false Hydrogen chloride, refrigerated liquid. 179.102-17...) § 179.102-17 Hydrogen chloride, refrigerated liquid. Each tank car used to transport hydrogen chloride... on or after March 16, 2009 used for the transportation of hydrogen chloride, refrigerated...

  1. Development of molecular imprinted column-on line-two dimensional liquid chromatography for selective determination of clenbuterol residues in biological samples.

    Science.gov (United States)

    Guo, Pengqi; Luo, Zhimin; Xu, Xinya; Zhou, Yulan; Zhang, Bilin; Chang, Ruimiao; Du, Wei; Chang, Chun; Fu, Qiang

    2017-02-15

    A novel method coupling molecular imprinted monolithic column with two-dimensional liquid chromatography was developed and validated for the analysis of clenbuterol in pork liver and swine urine samples. The polymers were characterized by using Fourier transform infrared spectroscopy, nitrogen adsorption desorption analyses, frontal analysis and the adsorption of selectivity. The results indicated that the imprinted columns were well prepared and possessed high selectivity adsorption capacity. Subsequently, the MIMC-2D-LC (molecular imprinted monolithic column-two dimensional liquid chromatography) method was developed for the selective analysis of clenbuterol in practical samples. The accuracy ranged from 94.3% to 99.7% and from 93.7% to 99.6% for liver and urine, respectively. The relative standard deviation (RSD) of repeatability was lower than 8.6% for both analyses. The limit of detections was 16ng·mL(-1) for liver and 25ng·mL(-1) for urine, respectively. Compared with the reported methods, the disturbance of endogenous impurity could be avoided by the 2D-LC method.

  2. Development of molecular imprinted column-on line-two dimensional liquid chromatography for selective determination of clenbuterol residues in biological samples.

    Science.gov (United States)

    Guo, Pengqi; Luo, Zhimin; Xu, Xinya; Zhou, Yulan; Zhang, Bilin; Chang, Ruimiao; Du, Wei; Chang, Chun; Fu, Qiang

    2017-02-15

    A novel method coupling molecular imprinted monolithic column with two-dimensional liquid chromatography was developed and validated for the analysis of clenbuterol in pork liver and swine urine samples. The polymers were characterized by using Fourier transform infrared spectroscopy, nitrogen adsorption desorption analyses, frontal analysis and the adsorption of selectivity. The results indicated that the imprinted columns were well prepared and possessed high selectivity adsorption capacity. Subsequently, the MIMC-2D-LC (molecular imprinted monolithic column-two dimensional liquid chromatography) method was developed for the selective analysis of clenbuterol in practical samples. The accuracy ranged from 94.3% to 99.7% and from 93.7% to 99.6% for liver and urine, respectively. The relative standard deviation (RSD) of repeatability was lower than 8.6% for both analyses. The limit of detections was 16ng·mL(-1) for liver and 25ng·mL(-1) for urine, respectively. Compared with the reported methods, the disturbance of endogenous impurity could be avoided by the 2D-LC method. PMID:27664680

  3. Column: Factors Affecting Data Decay

    Directory of Open Access Journals (Sweden)

    Kevin Fairbanks

    2012-06-01

    Full Text Available In nuclear physics, the phrase decay rate is used to denote the rate that atoms and other particles spontaneously decompose. Uranium-235 famously decays into a variety of daughter isotopes including Thorium and Neptunium, which themselves decay to others. Decay rates are widely observed and wildly different depending on many factors, both internal and external. U-235 has a half-life of 703,800,000 years, for example, while free neutrons have a half-life of 611 seconds and neutrons in an atomic nucleus are stable.We posit that data in computer systems also experiences some kind of statistical decay process and thus also has a discernible decay rate. Like atomic decay, data decay fluctuates wildly. But unlike atomic decay, data decay rates are the result of so many different interplaying processes that we currently do not understand them well enough to come up with quantifiable numbers. Nevertheless, we believe that it is useful to discuss some of the factors that impact the data decay rate, for these factors frequently determine whether useful data about a subject can be recovered by forensic investigation.(see PDF for full column

  4. CFD simulation of bubble column

    Energy Technology Data Exchange (ETDEWEB)

    Ekambara, K., E-mail: ekambara@ualberta.c [Department of Chemical and Materials Engineering, University of Alberta, 536 CME Building, Edmonton, AB, T6G 2G6 (Canada); Dhotre, M.T. [Thermal-Hydraulics Laboratory, Nuclear Energy and Safety Department, Paul Scherrer Institute, CH-5232 Villigen PSI (Switzerland)

    2010-05-15

    Three-dimensional simulations of gas-liquid flow in the bubble column using the Euler-Euler approach is presented. The attempt is made to assess the performance and applicability of different turbulence models namely, k-epsilon, k-epsilon RNG, k-omega, Reynolds stress model (RSM) and large eddy simulation (LES) using a commercial code (ANSYS-CFX). For this purpose, the predictions are compared against the experimental data of . Performance of the turbulence models is assessed on basis of comparison of axial liquid velocity, fractional gas hold-up, turbulent kinetic energy and turbulent eddy dissipation rate. All the non-drag (turbulent dispersion, virtual mass and lift force) and drag force were incorporated in the model. The low-Reynolds number treatment of the k-omega yields a better qualitative prediction than the k-epsilon model. The RSM predictions are comparable with LES results and seemed to give better prediction near the sparger, where the flow is more anisotropic and gives a clue why RANS approaches fails to predict the flow in this region. However, the large eddy simulations showed good agreement with the experimental data, but requires higher computational time than RSM.

  5. Monolitni katalizatori i reaktori: osnovne značajke, priprava i primjena (Monolith catalysts and reactors: preparation and applications

    Directory of Open Access Journals (Sweden)

    Tomašić, V.

    2004-12-01

    Full Text Available Monolithic (honeycomb catalysts are continuous unitary structures containing many narrow, parallel and usually straight channels (or passages. Catalytically active components are dispersed uniformly over the whole porous ceramic monolith structure (so-called incorporated monolithic catalysts or are in a layer of porous material that is deposited on the walls of channels in the monolith's structure (washcoated monolithic catalysts. The material of the main monolithic construction is not limited to ceramics but includes metals, as well. Monolithic catalysts are commonly used in gas phase catalytic processes, such as treatment of automotive exhaust gases, selective catalytic reduction of nitrogen oxides, catalytic removal of volatile organic compounds from industrial processes, etc. Monoliths continue to be the preferred support for environmental applications due to their high geometric surface area, different design options, low pressure drop, high temperature durability, mechanical strength, ease of orientation in a reactor and effectiveness as a support for a catalytic washcoat. As known, monolithic catalysts belong to the class of the structured catalysts and/or reactors (in some cases the distinction between "catalyst" and "reactor" has vanished. Structured catalysts can greatly intensify chemical processes, resulting in smaller, safer, cleaner and more energy efficient technologies. Monolith reactors can be considered as multifunctional reactors, in which chemical conversion is advantageously integrated with another unit operation, such as separation, heat exchange, a secondary reaction, etc. Finally, structured catalysts and/or reactors appear to be one of the most significant and promising developments in the field of heterogeneous catalysis and chemical engineering of the recent years. This paper gives a description of the background and perspectives for application and development of monolithic materials. Different methods and techniques

  6. Recent Accomplishments in the Irradiation Testing of Engineering-Scale Monolithic Fuel Specimens

    Energy Technology Data Exchange (ETDEWEB)

    N.E. Woolstenhulme; D.M. Wachs; M.K. Meyer; H.W. Glunz; R.B. Nielson

    2012-10-01

    The US fuel development team is focused on qualification and demonstration of the uranium-molybdenum monolithic fuel including irradiation testing of engineering-scale specimens. The team has recently accomplished the successful irradiation of the first monolithic multi-plate fuel element assembly within the AFIP-7 campaign. The AFIP-6 MKII campaign, while somewhat truncated by hardware challenges, exhibited successful irradiation of a large-scale monolithic specimen under extreme irradiation conditions. The channel gap and ultrasonic data are presented for AFIP-7 and AFIP-6 MKII, respectively. Finally, design concepts are summarized for future irradiations such as the base fuel demonstration and design demonstration experiment campaigns.

  7. Data in support of preparation and functionalization of a clickable polycarbonate monolith

    Directory of Open Access Journals (Sweden)

    Yuanrong Xin

    2016-06-01

    Full Text Available This data article provides supplementary figures to the research article entitled, “Phase separation approach to a reactive polycarbonate monolith for “click” modifications” (Xin et al., Polymer, 2015, doi:10.1016/j.polymer.2015.04.008. Here, the nitrogen adsorption/desorption isotherms of the prepared porous polycarbonate monolith are shown to classify its inner structure and calculate the specific surface area. The monoliths were modified by using the thiol-ene click chemistry and the olefin metathesis, which was examined by contact angle measurements, FT-IR, solid state 13C NMR spectroscopy as well as thermogravimetric analysis.

  8. Synergism between polyurethane and polydopamine in the synthesis of Ni-Fe alloy monoliths.

    Science.gov (United States)

    Naresh Kumar, Thangavel; Sivabalan, Santhana; Chandrasekaran, Naveen; Phani, Kanala Lakshminarasimha

    2015-02-01

    Herein, we report the first synthesis of a light-weight macroporous 3-D alloy monolith of Ni-Fe/C using synergism between polydopamine (pDA) and polyurethane (pU); in situ formed polyurethane (pU) enables efficient mixing of pDA (carbon source) and Ni-FeOx resulting in Ni-Fe alloy monoliths at a temperature as low as ∼600 °C. The monolithic Ni-Fe/C exhibits enhanced oxygen evolution activity. PMID:25531680

  9. Stanley Kubrick and B.F. Skinner : Is a Teaching Machine a Monolith ?

    OpenAIRE

    浜野, 保樹; ハマノ, ヤスキ; Yasuki, Hamano

    1990-01-01

    The teaching machine invented by B.F. Skinner was recog-nized as one of few clear achievements of scientific pedagogy and even appeared in SF. Arthur C. Clarke who wrote the script of the SF movie "2001: A Space Odyssey" with Stanley Kubrick wanted to scientifically define a monolith to be a God who had given intelligence to our ancestors. In other words, he wanted to describe a monolith as a teaching machine as well as a God. However Kubrick did not want to make clear about what a monolith i...

  10. Factors influencing chloride deposition in a coastal hilly area and application to chloride deposition mapping

    Directory of Open Access Journals (Sweden)

    H. Guan

    2009-09-01

    Full Text Available Chloride is commonly used as an environmental tracer for studying water flow and solute transport in the environment. It is especially useful for estimating groundwater recharge based on the commonly used chloride mass balance (CMB method. Strong spatial variability in chloride deposition in coastal areas is one difficulty encountered in appropriately applying the CMB approach. Furthermore, intensive vegetation clearance for agriculture, for example during the European settlement in many coastal areas of Australia, may have perturbed catchment chloride balance conditions for appropriate use in CMB applications. In order to deal with these issues, a high resolution chloride deposition map in the coastal region is needed. In this study, we examined geographic, orographic, and atmospheric factors influencing chloride deposition in the Mount Lofty Ranges (MLR, a coastal hilly area of approximately 9000 km2 spatial extent in South Australia, using partial correlation and regression analyses. The results indicate that coastal distance, and terrain aspect and slope are two most significant factors controlling chloride deposition. Coastal distance accounts for 65% spatial variability in chloride deposition, with terrain aspect and slope for 8%. The deposition gradient is about 0.08 gm-2 year-1 km-1 as one progresses inland. The results are incorporated into a published de-trended residual kriging approach (ASOADeK to produce a 1 km×1 km resolution annual chloride deposition map and a bulk precipitation chloride concentration map. The average uncertainty of the deposition map is about 30% in the western MLR, and over 50% in the eastern MLR. The maps will form a very useful basis for examining catchment chloride balances for use in the CMB application in the study area.

  11. Rasch models with exchangeable rows and columns

    DEFF Research Database (Denmark)

    Lauritzen, Steffen Lilholt

    The article studies distributions of doubly infinite binary matrices with exchangeable rows and columns which satify the further property that the probability of any $m \\times n$ submatrix is a function of the row- and column sums of that matrix. We show that any such distribution is a (unique...

  12. A Monolithic Time Stretcher for Precision Time Recording

    CERN Document Server

    Varner, G S; Ruckman, Larry L.; Varner, Gary S.

    2007-01-01

    Identifying light mesons which contain only up/down quarks (pions) from those containing a strange quark (kaons) over the typical meter length scales of a particle physics detector requires instrumentation capable of measuring flight times with a resolution on the order of 20ps. In the last few years a large number of inexpensive, multi-channel Time-to-Digital Converter (TDC) chips have become available. These devices typically have timing resolution performance in the hundreds of ps regime. A technique is presented that is a monolithic version of ``time stretcher'' solution adopted for the Belle Time-Of-Flight system to address this gap between resolution need and intrinsic multi-hit TDC performance.

  13. Development of highly sensitive monolithic interferometer for infrared planet search

    Directory of Open Access Journals (Sweden)

    Jiang P.

    2011-07-01

    Full Text Available We present the design, fabrication and testing of a highly sensitive monolithic interferometer for InfraRed Exoplanet Tracker (IR-ET. This interferometer is field-compensated, thermal-stable for working in the wavelength range between 0.8 and 1.35 μm. Two arms of the interferometer creates a fixed delay of 18.0 mm, which is optimized to have the best sensitivity for radial velocity measurements of slow-rotating M dwarfs for planet detection. IR-ET is aiming to reach 3–20 m/s Doppler precision for J<10 M dwarfs in less than 15 min exposures. We plan to conduct a planet survey around hundreds of nearby M dwarfs through collaborations with Astrophysical Research Consortium scientists in 2011–2014.

  14. Monolithic growth of partly cured polydimethylsiloxane thin film layers

    DEFF Research Database (Denmark)

    Yu, Liyun; Skov, Anne Ladegaard

    2014-01-01

    The demand for monolithic structures in many applications has increased to enable more reliable and optimized performances such as for dielectric electroactive polymers (DEAPs). For the layers of the elements to grow efficiently together, it is first of all required that the layers adhere together...... to enable interlayer crosslinking reactions either by application of an adhesion promoter or by ensuring that there are reactive, complementary sites available on the two surfaces. Polydimethylsiloxane (PDMS) is a widely used polymer for DEAPs. In this work, two-layered PDMS films are adhered together...... as thermal stabilities of the bilayer elastomer films are observed to change with the curing time of the monolayers before lamination. The objective of this work is to create adhesion of two layers without destroying the original viscoelastic properties of the PDMS films, and hence enable, for example...

  15. FLUIDIZED BED STEAM REFORMER (FBSR) PRODUCT: MONOLITH FORMATION AND CHARACTERIZATION

    Energy Technology Data Exchange (ETDEWEB)

    Jantzen, C

    2006-09-13

    The most important requirement for Hanford's low activity waste (LAW) form for shallow land disposal is the chemical durability of the product. A secondary, but still essential specification, is the compressive strength of the material with regards to the strength of the material under shallow land disposal conditions, e.g. the weight of soil overburden and potential intrusion by future generations, because the term ''near-surface disposal'' indicates disposal in the uppermost portion, or approximately the top 30 meters, of the earth's surface. The THOR{reg_sign} Treatment Technologies (TTT) mineral waste form for LAW is granular in nature because it is formed by Fluidized Bed Steam Reforming (FBSR). As a granular product it has been shown to be as durable as Hanford's LAW glass during testing with ASTM C-1285-02 known as the Product Consistency Test (PCT) and with the Single Pass Flow Through Test (SPFT). Hanford Envelope A and Envelope C simulants both performed well during PCT and SPFT testing and during subsequent performance assessment modeling. This is partially due to the high aluminosilicate content of the mineral product which provides a natural aluminosilicate buffering mechanism that inhibits leaching and is known to occur in naturally occurring aluminosilicate mineral analogs. In order for the TTT Na-Al-Si (NAS) granular mineral product to meet the compressive strength requirements (ASTM C39) for a Hanford waste form, the granular product needs to be made into a monolith or disposed of in High Integrity Containers (HIC's). Additionally, the Hanford intruder scenario for disposal in the Immobilized Low Activity Waste (ILAW) trench is mitigated as there is reduced intruder exposure when a waste form is in a monolithic form. During the preliminary testing of a monolith binder for TTT's FBSR mineral product, four parameters were monitored: (1) waste loading (not optimized for each waste form tested); (2) density

  16. Monolithic carbide-derived carbon films for micro-supercapacitors.

    Science.gov (United States)

    Chmiola, John; Largeot, Celine; Taberna, Pierre-Louis; Simon, Patrice; Gogotsi, Yury

    2010-04-23

    Microbatteries with dimensions of tens to hundreds of micrometers that are produced by common microfabrication techniques are poised to provide integration of power sources onto electronic devices, but they still suffer from poor cycle lifetime, as well as power and temperature range of operation issues that are alleviated with the use of supercapacitors. There have been a few reports on thin-film and other micro-supercapacitors, but they are either too thin to provide sufficient energy or the technology is not scalable. By etching supercapacitor electrodes into conductive titanium carbide substrates, we demonstrate that monolithic carbon films lead to a volumetric capacity exceeding that of micro- and macroscale supercapacitors reported thus far, by a factor of 2. This study also provides the framework for integration of high-performance micro-supercapacitors onto a variety of devices.

  17. Design of a Broadband Millimeter-Wave Monolithic IQ Mixer

    Science.gov (United States)

    Xu, Leijun; Wang, Zhigong; Li, Qin

    2010-05-01

    A 26˜40 GHz millimeter-wave monolithic passive IQ mixer was designed by using Win’s 0.15-µm GaAs pHEMT process. It utilizes a ring diode structure, and the performance can be improved effectively by a modified Marchand balun and U-type coupled lines. Through on-wafer measurement, the mixer shows a conversion loss of 6.6˜9 dB over a bandwidth of 26˜40 GHz, an IF bandwidth from DC to 6 GHz, an image rejection ratio of 21˜30 dB, an LO-RF isolation of above 24 dB, an LO-IF isolation of above 35 dB, and an RF-IF isolation of above 25 dB.

  18. Technological Advancement in Preparation and Application of Monolithic Refractories

    Institute of Scientific and Technical Information of China (English)

    LIZaigeng; ZHOUNingsheng

    2001-01-01

    This paper highlighted the advancement in preparation and application technologies of monolithic refactories in recent two decaes,in terms of raw materials,processing technology,particle size distrbution,binders,additives,workabiity,installation and applications,Facts and dicussions indicated that monolitihic refractoriesare advancing rapidly,from material point of view,towards higher grade and higher performance mateials and oxide-non-oxide composites;from installation point of view,towards higher efficiency,less man-power and time consuming terchinques;from drying-out point of view,towards quicker or even drying-out free,and from application point of view,towards the working linings of high temperature smelters and vessles under tougher serivce conditions ,and on the other hand,with more functions.

  19. Monolithic active pixel radiation detector with shielding techniques

    Energy Technology Data Exchange (ETDEWEB)

    Deptuch, Grzegorz W.

    2016-09-06

    A monolithic active pixel radiation detector including a method of fabricating thereof. The disclosed radiation detector can include a substrate comprising a silicon layer upon which electronics are configured. A plurality of channels can be formed on the silicon layer, wherein the plurality of channels are connected to sources of signals located in a bulk part of the substrate, and wherein the signals flow through electrically conducting vias established in an isolation oxide on the substrate. One or more nested wells can be configured from the substrate, wherein the nested wells assist in collecting charge carriers released in interaction with radiation and wherein the nested wells further separate the electronics from the sensing portion of the detector substrate. The detector can also be configured according to a thick SOA method of fabrication.

  20. Design of ultra-lightweight concrete: towards monolithic concrete structures

    Directory of Open Access Journals (Sweden)

    Yu Qing Liang

    2014-04-01

    Full Text Available This study addresses the development of ultra-lightweight concrete. A moderate strength and an excellent thermal conductivity of the lightweight concrete are set as the design targets. The designed lightweight aggregates concrete is targeted to be used in monolithic concrete façade structure, performing as both load bearing element and thermal insulator. The developed lightweight concrete shows excellent thermal properties, with a low thermal conductivity of about 0.12 W/(m·K; and moderate mechanical properties, with 28-day compressive strengths of about 10-12 N/mm . This combination of values exceeds, to the researchers’ knowledge, the performance of all other lightweight building materials. Furthermore, the developed lightweight concrete possesses excellent durability properties.

  1. Ion-implanted GaAs slow wave monolithic structure

    International Nuclear Information System (INIS)

    The use of MeV ion-implantation for realization of a GaAs monolithically compatible device is demonstrated. Ion implants up to 6 MeV in energy are used employing Si and S atoms. The fabricated device is an electromagnetic slow wave microstrip-like structure designed for performance into the millimeter wave regime. Phase shift theta and insertion loss L measurements are performed for frequencies 2-18 GHz at room temperature. Comparison of the experimental ion-implanted device results to epitaxial device results indicates comparable electrical performance, with no more than a 30% reduction in theta but with an improvement in loss behavior, namely a L reduction up to 40%. These theta and L differences between the ion-implanted and epitaxial devices are attributed to differences in doping profiles. Theoretical modelling of theta characteristics produces agreement with experimental data to within a few percent. (author)

  2. Two-dimensional optical scanner with monolithically integrated glass microlens

    Science.gov (United States)

    Yoo, Sunghyun; Jin, Joo-Young; Ha, Joon-Geun; Ji, Chang-Hyeon; Kim, Yong-Kweon

    2014-05-01

    A miniaturized two-dimensional forward optical scanner with a monolithically integrated glass microlens was developed for microendoscopic imaging applications. The fabricated device measures 2.26 × 1.97 × 0.62 mm3 in size and a through-silicon microlens with a diameter of 400 µm and numerical aperture of 0.37 has been successfully integrated within the silicon layer. An XY stage structure with lens shuttle and comb actuators was designed, and proprietary glass isolation blocks were utilized in mechanical and electric isolation of X- and Y-axis actuators. Resonant frequencies of the stage in X and Y directions were 3.238 and 2.198 kHz and quality factors were 168 and 69.1, respectively, at atmospheric pressure. Optical scanning test has been performed and scan angles of ±4.7° and ±4.9° were achieved for X and Y directions, respectively.

  3. Monolithic silica aerogel - material design on the nano-scale

    DEFF Research Database (Denmark)

    Jensen, Karsten Ingerslev; Schultz, Jørgen Munthe; Kristiansen, Finn Harken

    of piezoelectric transducers. - Other applications could be; waste encapsulation, spacers for vacuum insulation panels, membranes, etc. Department of Civil Engineering is co-ordinator of a current EU FP5 research project1, which deals with the application of aerogel as transparent insulation materials in windows......By means of a production process in two major steps - a sol/gel process and a supercritical drying – open-cell, monolithic silica aerogel can be made. This material can have a density in the range of 30- to 300 kg/m3, corresponding to porosities between 86 and 98 %. The solid structure has...... characteristic dimensions of 2 – 5 nm and the typical pore diameter is about 20 nm. A number of different applications of aerogel have been proposed: - Because of the large internal surface of aerogel (up to 1000 m²/g), the material is proposed to serve as substrate for catalytic materials. - The special pore...

  4. A nanofabricated, monolithic, path-separated electron interferometer

    CERN Document Server

    Agarwal, Akshay; Hobbs, Richard; van Dyck, Dirk; Berggren, Karl K

    2016-01-01

    We report a self-aligned, monolithic electron interferometer, consisting of two 45 nm thick silicon layers separated by 20 $\\mu$m. This interferometer was fabricated from a single crystal silicon cantilever on a transmission electron microscope grid by gallium focused ion-beam milling. Using this interferometer, we demonstrate beam path-separation, and obtain interference fringes in a Mach-Zehnder geometry, in an unmodified 200 kV transmission electron microscope. The fringes have a period of 0.32 nm, which corresponds to the $\\left[\\bar{1}\\bar{1}1\\right]$ lattice planes of silicon, and a maximum contrast of 15 %. This design can potentially be scaled to millimeter-scale, and used in electron holography. It can also be applied to perform fundamental physics experiments, such as interaction-free measurement with electrons.

  5. Method of producing monolithic ceramic cross-flow filter

    Energy Technology Data Exchange (ETDEWEB)

    Larsen, D.A.; Bacchi, D.P.; Connors, T.F.; Collins, E.L. III

    1998-02-10

    Ceramic filter of various configuration have been used to filter particulates from hot gases exhausted from coal-fired systems. Prior ceramic cross-flow filters have been favored over other types, but those previously have been assemblies of parts somehow fastened together and consequently subject often to distortion or delamination on exposure hot gas in normal use. The present new monolithic, seamless, cross-flow ceramic filters, being of one-piece construction, are not prone to such failure. Further, these new products are made by a novel casting process which involves the key steps of demolding the ceramic filter green body so that none of the fragile inner walls of the filter is cracked or broken. 2 figs.

  6. Method of producing monolithic ceramic cross-flow filter

    Energy Technology Data Exchange (ETDEWEB)

    Larsen, David A. (Clifton Park, NY); Bacchi, David P. (Schenectady, NY); Connors, Timothy F. (Watervliet, NY); Collins, III, Edwin L. (Albany, NY)

    1998-01-01

    Ceramic filter of various configuration have been used to filter particulates from hot gases exhausted from coal-fired systems. Prior ceramic cross-flow filters have been favored over other types, but those previously horn have been assemblies of parts somehow fastened together and consequently subject often to distortion or delamination on exposure hot gas in normal use. The present new monolithic, seamless, cross-flow ceramic filters, being of one-piece construction, are not prone to such failure. Further, these new products are made by novel casting process which involves the key steps of demolding the ceramic filter green body so that none of the fragile inner walls of the filter is cracked or broken.

  7. CMOS Monolithic Active Pixel Sensors (MAPS): Developments and future outlook

    Energy Technology Data Exchange (ETDEWEB)

    Turchetta, R. [Rutherford Appleton Laboratory, Chilton, Didcot, Oxon OX11 0QX (United Kingdom)], E-mail: r.turchetta@rl.ac.uk; Fant, A.; Gasiorek, P. [Rutherford Appleton Laboratory, Chilton, Didcot, Oxon OX11 0QX (United Kingdom); Esbrand, C.; Griffiths, J.A.; Metaxas, M.G.; Royle, G.J.; Speller, R.; Venanzi, C. [Department of Medical Physics and Bioengineering, University College London (United Kingdom); Stelt, P.F. van der; Verheij, H.; Li, G. [Academic Centre for Dentistry, Vrije Universiteit and University of Amsterdam (Netherlands); Theodoridis, S.; Georgiou, H. [Department of Informatics and Telecommunications, University of Athens (Greece); Cavouras, D. [Medical Image and Signal Processing Laboratory, Department of Medical Instrument Technology, Technological Education Institution of Athens (Greece); Hall, G.; Noy, M.; Jones, J.; Leaver, J.; Machin, D. [High Energy Physics Group, Department of Physics, Imperial College, London (United Kingdom)] (and others)

    2007-12-01

    Re-invented in the early 1990s, on both sides of the Atlantic, Monolithic Active Pixel Sensors (MAPS) in a CMOS technology are today the most sold solid-state imaging devices, overtaking the traditional technology of Charge-Coupled Devices (CCD). The slow uptake of CMOS MAPS started with low-end applications, for example web-cams, and is slowly pervading the high-end applications, for example in prosumer digital cameras. Higher specifications are required for scientific applications: very low noise, high speed, high dynamic range, large format and radiation hardness are some of these requirements. This paper will present a brief overview of the CMOS Image Sensor technology and of the requirements for scientific applications. As an example, a sensor for X-ray imaging will be presented. This sensor was developed within a European FP6 Consortium, intelligent imaging sensors (I-ImaS)

  8. An Energy Preserving Monolithic Eulerian Fluid-Structure Numerical Scheme

    CERN Document Server

    Pironneau, Olivier

    2016-01-01

    The conservation laws of continuum mechanic written in an Eulerian frame make no difference between fluids and solids except in the expression of the stress tensors, usually with Newton's hypothesis for the fluids and Helmholtz potentials of energy for hyperelastic solids. By taking the velocities as unknown , monolithic methods for fluid structure interactions (FSI) are built. In this article such a formulation is analyzed when the fluid is compressible and the fluid is incompressible. The idea is not new but the progress of mesh generators and numerical schemes like the Characteristics-Galerkin method render this approach feasible and reasonably robust. In this article the method and its discretization are presented, stability is discussed by through an energy estimate. A numerical section discusses implementation issues and presents a few simple tests.

  9. Monolithic optofluidic ring resonator lasers created by femtosecond laser nanofabrication.

    Science.gov (United States)

    Chandrahalim, Hengky; Chen, Qiushu; Said, Ali A; Dugan, Mark; Fan, Xudong

    2015-05-21

    We designed, fabricated, and characterized a monolithically integrated optofluidic ring resonator laser that is mechanically, thermally, and chemically robust. The entire device, including the ring resonator channel and sample delivery microfluidics, was created in a block of fused-silica glass using a 3-dimensional femtosecond laser writing process. The gain medium, composed of Rhodamine 6G (R6G) dissolved in quinoline, was flowed through the ring resonator. Lasing was achieved at a pump threshold of approximately 15 μJ mm(-2). Detailed analysis shows that the Q-factor of the optofluidic ring resonator is 3.3 × 10(4), which is limited by both solvent absorption and scattering loss. In particular, a Q-factor resulting from the scattering loss can be as high as 4.2 × 10(4), suggesting the feasibility of using a femtosecond laser to create high quality optical cavities.

  10. Towards monolithic integration of germanium light sources on silicon chips

    Science.gov (United States)

    Saito, Shinichi; Zaher Al-Attili, Abdelrahman; Oda, Katsuya; Ishikawa, Yasuhiko

    2016-04-01

    Germanium (Ge) is a group-IV indirect band gap semiconductor, and therefore bulk Ge cannot emit light efficiently. However, the direct band gap energy is close to the indirect one, and significant engineering efforts are being made to convert Ge into an efficient gain material monolithically integrated on a Si chip. In this article, we will review the engineering challenges of developing Ge light sources fabricated using nano-fabrication technologies compatible with complementary metal-oxide-semiconductor processes. In particular, we review recent progress in applying high-tensile strain to Ge to reduce the direct band gap. Another important technique is doping Ge with donor impurities to fill the indirect band gap valleys in the conduction band. Realization of carrier confinement structures and suitable optical cavities will be discussed. Finally, we will discuss possible applications of Ge light sources in potential photonics-electronics convergent systems.

  11. Government systems and GaAs monolithic components

    Science.gov (United States)

    Sieger, K. J.

    1983-12-01

    The current state of monolithic GaAs technology and its current and future applications to government systems are reviewed, with attention given to the government investment strategy, commercial market impact, new technology, and challenges from silicon technology. Data obtained from a survey to determine the status of GaAs IC technology are presented. These contain the system type and acronym, a technical description of the system, the critical research and development needed to develop the particular IC, specific applications and functions of the IC in the system, the year of implementation, and the potential chip buyer. High volume applications, with chip counts of one million and more, are identified as phased arrays (radar and communication), expendable decoys, missile seekers, and satellite signal processors. Problem areas, future trends, and areas of uncertainty are discussed.

  12. Cost and Potential of Monolithic CIGS Photovoltaic Modules

    Energy Technology Data Exchange (ETDEWEB)

    Horowitz, Kelsey; Woodhouse, Michael

    2015-06-17

    A bottom-up cost analysis of monolithic, glass-glass Cu(In,Ga)(Se,S)2 (CIGS) modules is presented, illuminating current cost drivers for this technology and possible pathways to reduced cost. At 14% module efficiency, for the case of U.S. manufacturing, a manufacturing cost of $0.56/WDC and a minimum sustainable price of $0.72/WDC were calculated. Potential for reduction in manufacturing costs to below $0.40/WDC in the long-term may be possible if module efficiency can be increased without significant increase in $/m2 costs. The levelized cost of energy (LCOE) in Phoenix, AZ under different conditions is assessed and compared to standard c-Si.

  13. Monolith filter apparatus and membrane apparatus, and method using same

    Energy Technology Data Exchange (ETDEWEB)

    Goldsmith, Robert L. (Wayland, MA)

    2012-04-03

    A filtration apparatus that separates a liquid feedstock mixed with a gas into filtrate and retentate, the apparatus including at least one filtration device comprised of at least one monolith segment of porous material that defines a plurality of passageways extending longitudinally from a feed face of the structure to a retentate end face. The filtration device contains at least one filtrate conduit within it for carrying filtrate toward a filtrate collection zone, the filtrate conduit providing a path of lower flow resistance than that of alternative flow paths through the porous material of the device. The filtration device can also be utilized as a membrane support for a device for microfiltration, ultrafiltration, nanofiltration, reverse osmosis, or pervaporation. Also disclosed is a method for using such a filtration apparatus.

  14. Pressure Drop Measurements on Distillation Columns

    Institute of Scientific and Technical Information of China (English)

    T.J. Cai; M.R. Resetarits

    2011-01-01

    Pressure drops are of major importance for distillation/absorption columns. This paper mainly discusses how to correctly measure, interpret and use pressure drop data. The possible causes of incorrect pressure drop measurements are studied including the effects of pressure tap dimensions, locations, and vapor condensation etc. The effect of the static head of vapor on the pressure drop data and column pressures is evaluated. Variations of sectional pressure drops along the column are investigated based on the experimental data obtained from commercial size distillation columns at Fractionation Research, Inc. (FRI). For a packed column, it is found that the spacing between the liquid distributor and the top of the bed affects the overall pressure drop measurements, which is confirmed by a fundamental fluid dynamics analysis.

  15. How to Calculate Molecular Column Density

    CERN Document Server

    Mangum, Jeffrey G

    2015-01-01

    The calculation of the molecular column density from molecular spectral (rotational or ro-vibrational) transition measurements is one of the most basic quantities derived from molecular spectroscopy. Starting from first principles where we describe the basic physics behind the radiative and collisional excitation of molecules and the radiative transfer of their emission, we derive a general expression for the molecular column density. As the calculation of the molecular column density involves a knowledge of the molecular energy level degeneracies, rotational partition functions, dipole moment matrix elements, and line strengths, we include generalized derivations of these molecule-specific quantities. Given that approximations to the column density equation are often useful, we explore the optically thin, optically thick, and low-frequency limits to our derived general molecular column density relation. We also evaluate the limitations of the common assumption that the molecular excitation temperature is con...

  16. 3D statistical failure analysis of monolithic dental ceramic crowns.

    Science.gov (United States)

    Nasrin, Sadia; Katsube, Noriko; Seghi, Robert R; Rokhlin, Stanislav I

    2016-07-01

    For adhesively retained ceramic crown of various types, it has been clinically observed that the most catastrophic failures initiate from the cement interface as a result of radial crack formation as opposed to Hertzian contact stresses originating on the occlusal surface. In this work, a 3D failure prognosis model is developed for interface initiated failures of monolithic ceramic crowns. The surface flaw distribution parameters determined by biaxial flexural tests on ceramic plates and point-to-point variations of multi-axial stress state at the intaglio surface are obtained by finite element stress analysis. They are combined on the basis of fracture mechanics based statistical failure probability model to predict failure probability of a monolithic crown subjected to single-cycle indentation load. The proposed method is verified by prior 2D axisymmetric model and experimental data. Under conditions where the crowns are completely bonded to the tooth substrate, both high flexural stress and high interfacial shear stress are shown to occur in the wall region where the crown thickness is relatively thin while high interfacial normal tensile stress distribution is observed at the margin region. Significant impact of reduced cement modulus on these stress states is shown. While the analyses are limited to single-cycle load-to-failure tests, high interfacial normal tensile stress or high interfacial shear stress may contribute to degradation of the cement bond between ceramic and dentin. In addition, the crown failure probability is shown to be controlled by high flexural stress concentrations over a small area, and the proposed method might be of some value to detect initial crown design errors. PMID:27215334

  17. FIBROUS MONOLITH WEAR RESISTANT COMPONENTS FOR THE MINING INDUSTRY

    Energy Technology Data Exchange (ETDEWEB)

    Mark J. Rigali; Mike L. Fulcher

    2003-03-25

    During the reporting period, work continued on development of formulations using the materials down-selected from the initially identified contenders for the fibrous monolith wear resistant components. In the previous reporting period, a two-stage binder removal process was developed that resulted in prototype parts free of voids and other internal defects. During the current reporting period, work was performed to characterize the two-stage binder removal process for WC-Co based FM material systems. Use of this process has resulted in the fabrication of defect free sintered WC-Co FM bodies, with minimal free carbon porosity and densities approaching 100% theoretical. With the elimination of free carbon porosity and other binder removal process related defects, development work focused on optimizing the densification and eliminating defects observed in WC-Co based FM consolidated by pressureless sintering. Shrinkage of the monolithic core and shell materials used in the WC-Co based FM system was measured, and differences in material shrinkage were identified as a potential cause of cell boundary cracking observed in sintered parts. Re-formulation of material blends for this system was begun, with the goal of eliminating mechanical stresses during sintering by matching the volumetric shrinkage of the core and shell materials. Thirty-three 7/8 inch drill bit inserts (WC-Co(6%)/WC-Co(16%) FM) were hot pressed during the reporting period. Six of these inserts were delivered for field-testing by Superior Rock Bit during the upcoming reporting period. In addition, Al{sub 2}O{sub 3}/Al{sub 2}O{sub 3}-TiCN FM cutting tool inserts were fabricated, and cutting tests performed.

  18. A High Resolution Monolithic Crystal, DOI, MR Compatible, PET Detector

    Energy Technology Data Exchange (ETDEWEB)

    Robert S Miyaoka

    2012-03-06

    The principle objective of this proposal is to develop a positron emission tomography (PET) detector with depth-of-interaction (DOI) positioning capability that will achieve state of the art spatial resolution and sensitivity performance for small animal PET imaging. When arranged in a ring or box detector geometry, the proposed detector module will support <1 mm3 image resolution and >15% absolute detection efficiency. The detector will also be compatible with operation in a MR scanner to support simultaneous multi-modality imaging. The detector design will utilize a thick, monolithic crystal scintillator readout by a two-dimensional array of silicon photomultiplier (SiPM) devices using a novel sensor on the entrance surface (SES) design. Our hypothesis is that our single-ended readout SES design will provide an effective DOI positioning performance equivalent to more expensive dual-ended readout techniques and at a significantly lower cost. Our monolithic crystal design will also lead to a significantly lower cost system. It is our goal to design a detector with state of the art performance but at a price point that is affordable so the technology can be disseminated to many laboratories. A second hypothesis is that using SiPM arrays, the detector will be able to operate in a MR scanner without any degradation in performance to support simultaneous PET/MR imaging. Having a co-registered MR image will assist in radiotracer localization and may also be used for partial volume corrections to improve radiotracer uptake quantitation. The far reaching goal of this research is to develop technology for medical research that will lead to improvements in human health care.

  19. Simple, specific analysis of organophosphorus and carbamate pesticides in sediments using column extraction and gas chromatography

    Science.gov (United States)

    Belisle, A.A.; Swineford, D.M.

    1988-01-01

    A simple, specific procedure was developed for the analysis of organophosphorus and carbamate pesticides in sediment. The wet soil was mixed with anhydrous sodium sulfate to bind water and the residues were column extracted in acetone:methylene chloride (1:l,v/v). Coextracted water was removed by additional sodium sulfate packed below the sample mixture. The eluate was concentrated and analyzed directly by capillary gas chromatography using phosphorus and nitrogen specific detectors. Recoveries averaged 93 % for sediments extracted shortly after spiking, but decreased significantly as the samples aged.

  20. Inhibition of nitrite-induced toxicity in channel catfish by calcium chloride and sodium chloride

    Science.gov (United States)

    Tommasso J.R., Wright; Simco, B.A.; Davis, K.B.

    1980-01-01

    Environmental chloride has been shown to inhibit methemoglobin formation in fish, thereby offering a protective effect against nitrite toxicity. Channel catfish (Ictalurus punctatus) were simultaneously exposed to various environmental nitrite and chloride levels (as either CaCl2 or NaCl) in dechlorinated tap water (40 mg/L total hardness, 47 mg/L alkalinity, 4 mg/L chloride, pH = 6.9-7.1, and temperature 21-24°C). Methemoglobin levels in fish simultaneously exposed to 2.5 mg/L nitrite and up to 30 mg/L chloride as either CaCl2 or NaCl were similar but significantly lower than in unprotected fish. Exposure to 10 mg/L nitrite and 60 mg/L chloride resulted in methemoglobin levels similar to those of the controls; most unprotected fish died. Fish exposed to 10 mg/L nitrite had significantly lower methemoglobin levels when protected with 15.0 mg/L chloride as CaCl2 than with NaCl. Fish exposed to nitrite in the presence of 60 mg/L chloride (as either CaCl2 or NaCl) had similar 24-h LC50 values that were significantly elevated above those obtained in the absence of chloride. Calcium had little effect on tolerance to nitrite toxicity in channel catfish in contrast to its large effect reported in steelhead trout (Salmo gairdneri).

  1. Congenital Chloride Diarrhea: Diagnosis by Easy-Accessible Chloride Measurement in Feces

    Directory of Open Access Journals (Sweden)

    C. Gils

    2016-01-01

    Full Text Available Background. Congenital chloride diarrhea (CCD is an autosomal recessive disorder caused by mutations in the genes encoding the intestinal Cl−/HCO3- exchanger and is clinically characterized by watery, profound diarrhea, electrolyte disturbances, and metabolic alkalosis. The CCD diagnosis is based on the clinical symptoms and measurement of high chloride concentration in feces (>90 mmol/L and is confirmed by DNA testing. Untreated CCD is lethal, while long-term clinical outcome improves when treated correctly. Case Presentation. A 27-year-old woman had an emergency caesarian due to pain and discomfort in gestational week 36 + 4. The newborn boy had abdominal distension and yellow fluid per rectum. Therapy with intravenous glucose and sodium chloride decreased his stool frequency and improved his clinical condition. A suspicion of congenital chloride diarrhea was strongly supported using blood gas analyzer to measure an increased chloride concentration in the feces; the diagnosis was confirmed by DNA testing. Discussion. Measurement of chloride in feces using an ordinary blood gas analyzer can serve as a preliminary analysis when congenital chloride diarrhea is suspected. This measurement can be easily performed with a watery feces composition. An easy-accessible chloride measurement available will facilitate the diagnostics and support the initial treatment if CCD is suspected.

  2. Amine and Titanium (IV Chloride, Boron (III Chloride or Zirconium (IV Chloride-Promoted Baylis-Hillman Reactions

    Directory of Open Access Journals (Sweden)

    Shi-Cong Cui

    2001-10-01

    Full Text Available The Baylis-Hillman reactions of various aryl aldehydes with methyl vinyl ketone at temperatures below -20oC using Lewis acids such as titanium (IV chloride, boron (III chloride or zirconium (IV chloride in the presence of a catalytic amount of selected amines used as a Lewis bases afford the chlorinated compounds 1 as the major product in very high yields. Acrylonitrile can also undergo the same reaction to give the corresponding chlorinated product in moderate yield. A plausible reaction mechanism is proposed. However, if the reaction was carried out at room temperature (ca. 20oC, then the Z-configuration of the elimination product 3, derived from 1, was formed as the major product.

  3. Chloride equilibrium potential in salamander cones

    Directory of Open Access Journals (Sweden)

    Bryson Eric J

    2004-12-01

    Full Text Available Abstract Background GABAergic inhibition and effects of intracellular chloride ions on calcium channel activity have been proposed to regulate neurotransmission from photoreceptors. To assess the impact of these and other chloride-dependent mechanisms on release from cones, the chloride equilibrium potential (ECl was determined in red-sensitive, large single cones from the tiger salamander retinal slice. Results Whole cell recordings were done using gramicidin perforated patch techniques to maintain endogenous Cl- levels. Membrane potentials were corrected for liquid junction potentials. Cone resting potentials were found to average -46 mV. To measure ECl, we applied long depolarizing steps to activate the calcium-activated chloride current (ICl(Ca and then determined the reversal potential for the current component that was inhibited by the Cl- channel blocker, niflumic acid. With this method, ECl was found to average -46 mV. In a complementary approach, we used a Cl-sensitive dye, MEQ, to measure the Cl- flux produced by depolarization with elevated concentrations of K+. The membrane potentials produced by the various high K+ solutions were measured in separate current clamp experiments. Consistent with electrophysiological experiments, MEQ fluorescence measurements indicated that ECl was below -36 mV. Conclusions The results of this study indicate that ECl is close to the dark resting potential. This will minimize the impact of chloride-dependent presynaptic mechanisms in cone terminals involving GABAa receptors, glutamate transporters and ICl(Ca.

  4. Dynamic Electrochemical Measurement of Chloride Ions.

    Science.gov (United States)

    Abbas, Yawar; de Graaf, Derk B; Olthuis, Wouter; van den Berg, Albert

    2016-02-05

    This protocol describes the dynamic measurement of chloride ions using the transition time of a silver silver chloride (Ag/AgCl) electrode. Silver silver chloride electrode is used extensively for potentiometric measurement of chloride ions concentration in electrolyte. In this measurement, long-term and continuous monitoring is limited due to the inherent drift and the requirement of a stable reference electrode. We utilized the chronopotentiometric approach to minimize drift and avoid the use of a conventional reference electrode. A galvanostatic pulse is applied to an Ag/AgCl electrode which initiates a faradic reaction depleting the Cl- ions near the electrode surface. The transition time, which is the time to completely deplete the ions near the electrode surface, is a function of the ion concentration, given by the Nernst equation. The square root of the transition time is in linear relation to the chloride ion concentration. Drift of the response over two weeks is negligible (59 µM/day) when measuring 1 mM [Cl-]using a current pulse of 10 Am(-2). This is a dynamic measurement where the moment of transition time determines the response and thus is independent of the absolute potential. Any metal wire can be used as a pseudo-reference electrode, making this approach feasible for long-term measurement inside concrete structures.

  5. Wall modified photonic crystal fibre capillaries as porous layer open tubular columns for in-capillary micro-extraction and capillary chromatography.

    Science.gov (United States)

    Kazarian, Artaches A; Sanz Rodriguez, Estrella; Deverell, Jeremy A; McCord, James; Muddiman, David C; Paull, Brett

    2016-01-28

    Wall modified photonic crystal fibre capillary columns for in-capillary micro-extraction and liquid chromatographic separations is presented. Columns contained 126 internal parallel 4 μm channels, each containing a wall bonded porous monolithic type polystyrene-divinylbenzene layer in open tubular column format (PLOT). Modification longitudinal homogeneity was monitored using scanning contactless conductivity detection and scanning electron microscopy. The multichannel open tubular capillary column showed channel diameter and polymer layer consistency of 4.2 ± 0.1 μm and 0.26 ± 0.02 μm respectively, and modification of 100% of the parallel channels with the monolithic polymer. The modified multi-channel capillaries were applied to the in-capillary micro-extraction of water samples. 500 μL of water samples containing single μg L(-1) levels of polyaromatic hydrocarbons were extracted at a flow rate of 10 μL min(-1), and eluted in 50 μL of acetonitrile for analysis using HPLC with fluorescence detection. HPLC LODs were 0.08, 0.02 and 0.05 μg L(-1) for acenaphthene, anthracene and pyrene, respectively, with extraction recoveries of between 77 and 103%. The modified capillaries were also investigated briefly for direct application to liquid chromatographic separations, with the retention and elution of a standard protein (cytochrome c) under isocratic conditions demonstrated, proving chromatographic potential of the new column format, with run-to-run retention time reproducibility of below 1%.

  6. Highly efficient capillary columns packed with superficially porous particles via sequential column packing.

    Science.gov (United States)

    Treadway, James W; Wyndham, Kevin D; Jorgenson, James W

    2015-11-27

    Highly efficient capillary columns packed with superficially porous particles were created for use in ultrahigh pressure liquid chromatography. Superficially porous particles around 1.5μm in diameter were packed into fused silica capillary columns with 30, 50, and 75μm internal diameters. To create the columns, several capillary columns were serially packed from the same slurry, with packing progress plots being generated to follow the packing of each column. Characterization of these columns using hydroquinone yielded calculated minimum reduced plate heights as low as 1.24 for the most efficient 30μm internal diameter column, corresponding to over 500,000plates/m. At least one highly efficient column (minimum reduced plate height less than 2) was created for all three of the investigated column inner diameters, with the smallest diameter columns having the highest efficiency. This study proves that highly efficient capillary columns can be created using superficially porous particles and shows the efficiency potential of these particles.

  7. A glass-encapsulated calcium phosphate wasteform for the immobilization of actinide-, fluoride-, and chloride-containing radioactive wastes from the pyrochemical reprocessing of plutonium metal

    Science.gov (United States)

    Donald, I. W.; Metcalfe, B. L.; Fong, S. K.; Gerrard, L. A.; Strachan, D. M.; Scheele, R. D.

    2007-03-01

    Chloride-containing radioactive wastes are generated during the pyrochemical reprocessing of Pu metal. Immobilization of these wastes in borosilicate glass or Synroc-type ceramics is not feasible due to the very low solubility of chlorides in these hosts. Alternative candidates have therefore been sought including phosphate-based glasses, crystalline ceramics and hybrid glass/ceramic systems. These studies have shown that high losses of chloride or evolution of chlorine gas from the melt make vitrification an unacceptable solution unless suitable off-gas treatment facilities capable of dealing with these corrosive by-products are available. On the other hand, both sodium aluminosilicate and calcium phosphate ceramics are capable of retaining chloride in stable mineral phases, which include sodalite, Na 8(AlSiO 4) 6Cl 2, chlorapatite, Ca 5(PO 4) 3Cl, and spodiosite, Ca 2(PO 4)Cl. The immobilization process developed in this study involves a solid state process in which waste and precursor powders are mixed and reacted in air at temperatures in the range 700-800 °C. The ceramic products are non-hygroscopic free-flowing powders that only require encapsulation in a relatively low melting temperature phosphate-based glass to produce a monolithic wasteform suitable for storage and ultimate disposal.

  8. Monolithic three-dimensional electrochemical energy storage system on aerogel or nanotube scaffold

    Science.gov (United States)

    Farmer, Joseph Collin; Stadermann, Michael

    2014-07-15

    A monolithic three-dimensional electrochemical energy storage system is provided on an aerogel or nanotube scaffold. An anode, separator, cathode, and cathodic current collector are deposited on the aerogel or nanotube scaffold.

  9. Monolithically integrated AlN/GaN electronics for harsh environments Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Recently, resonant-tunneling-diode (RTD) based circuits employing monolithically-integrated RTD on high electron mobility (HEMT) structures have been developed in a...

  10. A monolithic strategy based on an hybrid domain decomposition method for multiphysic problems

    OpenAIRE

    Gosselet, Pierre; Chiaruttini, Vincent; Rey, Christian; Feyel, Frédéric

    2004-01-01

    International audience A monolithic strategy based on an hybrid domain decomposition method for the numerical simulation of multiphysic problems is presented. It relies on a "physical" choice of primal interface unknowns. First numerical assessments are described for poroelasticity problems.

  11. Development of new type passive autocatalytic recombiner. Part 1. Characterization of monolithic catalyst

    International Nuclear Information System (INIS)

    For hydrogen mitigation, a new type passive autocatalytic recombiner has been developed, as one of safety accident managements at a nuclear power plant. This new recombiner has an automotive monolithic substrate catalyst in order to reduce weight and to improve hydrogen treating capacity, environmental resistance, and product quality. The activation energy has been experimentally estimated at 5.75 kJ/mol with stoichiometric composition gas flow. The fed hydrogen and oxygen to the monolithic catalyst were immediately recombined in both the dry and the humid atmospheres. Moreover, it has been found that gamma-ray irradiation up to 1.0 MGy could promote catalytic activity, because the specific area of the catalyst and the surface area of the precious metals increased. In addition, no significant difference was observed in the compositional distribution in the monolithic catalyst by EPMA. As the result, an automotive monolithic catalyst is applicable to practical installation of PAR into NPPs. (author)

  12. Monolithic three-dimensional electrochemical energy storage system on aerogel or nanotube scaffold

    Science.gov (United States)

    Farmer, Joseph C; Stadermann, Michael

    2013-11-12

    A monolithic three-dimensional electrochemical energy storage system is provided on an aerogel or nanotube scaffold. An anode, separator, cathode, and cathodic current collector are deposited on the aerogel or nanotube scaffold.

  13. Synthesis of novel hierarchical ZSM-5 monoliths and their application in trichloroethylene removal

    Institute of Scientific and Technical Information of China (English)

    João Pires; Ana C.Fernandes; Divakar Duraiswami

    2014-01-01

    A self-supporting ZSM-5 monolith with a hierarchical porosity was prepared using polyurethane foam (PUF) as a structural template and a hydrothermal synthesis procedure. The synthesized monolith was characterized and investigated towards the adsorption and catalytic oxidation of trichloroethylene (TCE). Adsorption of TCE was studied gravimetrically and oxidation of TCE was studied using a vapor-phase down-flow reactor. Monolithic ZSM-5 displayed good sorption proper-ties and completely oxidized TCE. Conversion levels of 50%and 90%were achieved at reduced temperatures (by~50 °C) when compared with the conversion temperatures obtained from the powder counterparts. Besides the activity of the monolith towards TCE adsorption and oxidation, it was stable and enhanced diffusion, thereby reducing pressure drops to a great extent owing to its hierarchical porous nature.

  14. A Monolithic, Non-Field-Widened Spatial Heterodyne Spectrometer for Solar System Exploration Project

    Data.gov (United States)

    National Aeronautics and Space Administration — The goal of this project is to produce a monolithic Spatial Heterodyne Spectrometer (a Fourier Transform Interferometer) for use in Solar System exploration. In...

  15. Temperature excursions during the transient behaviour of high temperature catalytic combustion monoliths

    Energy Technology Data Exchange (ETDEWEB)

    Di Benedetto, Almerinda; Cimino, Stefano; Pirone, Raffaele; Russo, Gennaro [Istituto Ricerche sulla Combustione-CNR, P. le Tecchio 80, 80125 Naples (Italy)

    2003-08-15

    Spatio-temporal temperature profiles experimentally observed during the operation of a structured perovskite-based catalytic monolith for the combustion of methane were simulated by means of a transient heterogeneous one-dimensional model which accounts for heat losses to the surroundings and thermal conductivity inside the monolith substrate. In fact it is shown that such thermal phenomena are essential to correctly reproduce the slow warm-up transients and the wrong-way behaviour observed in a low conductivity ceramic monolith. Model simulations reveal that at higher values of solid conductivity the catalyst does not exhibit hot spot both in time and space, but needs higher inlet gas temperatures to reach complete methane conversion. Bifurcation analysis of the catalytic monolith reactor model were carried out to study steady-state multiplicity. We show that the origin of multiplicity is purely thermal as it is mainly ruled by the heat transfer through the external surface.

  16. 2R-regeneration in a monolithically integrated four-section SOA-EA chip

    DEFF Research Database (Denmark)

    Vivero, Tania; Calabretta, Nicola; Tafur Monroy, Idelfonso;

    2009-01-01

    Optical regeneration using a monolithically integrated chip formed by a cascade of semiconductor optical amplifiers and saturable absorbers is investigated. Static transfer functions, signal reshaping, extinction ratio enhancement, noise dynamics and device dependence on operation conditions...

  17. Broadband EM Performance Characteristics of Single Square Loop FSS Embedded Monolithic Radome

    Directory of Open Access Journals (Sweden)

    Raveendranath U. Nair

    2013-01-01

    Full Text Available A monolithic half-wave radome panel, centrally loaded with aperture-type single square loop frequency selective surface (SSL-FSS, is proposed here for broadband airborne radome applications. Equivalent transmission line method in conjunction with equivalent circuit model (ECM is used for modeling the SSL-FSS embedded monolithic half-wave radome panel and evaluating radome performance parameters. The design parameters of the SSL-FSS are optimized at different angles of incidence such that the new radome wall configuration offers superior EM performance from L-band to X-band as compared to the conventional monolithic half-wave slab of identical material and thickness. The superior EM performance of SSL-FSS embedded monolithic radome wall makes it suitable for the design of normal incidence and streamlined airborne radomes.

  18. Monoliths of activated carbon from coconut shell and impregnation with nickel and copper

    International Nuclear Information System (INIS)

    A series of different monoliths of activated carbon were prepared from coconut shell By means of chemical activation with phosphoric acid at different concentrations Without using binders or plastics. The monolith that developed the biggest surface area was impregnated by humidic route with solutions of Ni and Cu at different molar relations. The structures were characterized by N2 adsorption at 77 K, and the morphology was explored by means of scanning electron microscopy. The carbonaceous materials obtained, Nickel-Copper-Monolith, were analyzed by Thermal Programmed Reduction (TPR). The experimental results indicated that the activation with the acid generated a micro porosity, with micropores volume between 0.40 and 0.81 cm3g-1 and surface areas between 703 and 1450 m2g-1, and a good mechanical properties. It shows that, both the copper and the nickel, are fixed to the monolith and TPR's results are interpreted when these molar relation are modified.

  19. Recycle Adsorption of Cu2+ on Amine-functionalized Mesoporous Silica Monolithic

    Institute of Scientific and Technical Information of China (English)

    ZHAO Da-zhou; JING Shu-bo; XU Jia-ning; YANG Hong; ZHENG Wei; SONG Tian-you; ZHANG Ping

    2013-01-01

    3-Aminopropyltriethoxysilane functionalized worm-like mesoporous silica monolithic(WMSM-NH2) was prepared and used as a new regenerable adsorbent for the removal of Cu2+ ions.The analysis results show that the WMSM-NH2 monolithic had a high efficiency value of 99.3% for Cu2+ remediation when the Cu2+ solution was at an initial concentration of 10.32 mg/L.The regeneration study of the WMSM-NH2 monolithic presented that the adsorption efficiency of 89.0% was remained and a mass of 92.0% was left after seven adsorption-desorption cycles were executed.The monolithic material with high resistance to the acid and good mechanical stability can facilitate the operations of adsorption and regeneration of the adsorbent.

  20. Electromechano-optically tuned ring resonator in silicon on insulator, monolithically integrated with a microcantilever

    NARCIS (Netherlands)

    Kauppinen, Lasse J.; Abdulla, Shahina M.C.; Krijnen, Gijs J.M.; Pollnau, Markus; Ridder, de René M.

    2011-01-01

    Monolithic integration of a micromechanical cantilever with an optical ring resonator in silicon on insulator is demonstrated. The ring can be tuned over a 50 pm wavelength range by applying 8.5 V, without affecting its Q-factor.