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Sample records for chloride monolithic column

  1. Pressure drop in CIM disk monolithic columns.

    Science.gov (United States)

    Mihelic, Igor; Nemec, Damjan; Podgornik, Ales; Koloini, Tine

    2005-02-11

    Pressure drop analysis in commercial CIM disk monolithic columns is presented. Experimental measurements of pressure drop are compared to hydrodynamic models usually employed for prediction of pressure drop in packed beds, e.g. free surface model and capillary model applying hydraulic radius concept. However, the comparison between pressure drop in monolith and adequate packed bed give unexpected results. Pressure drop in a CIM disk monolithic column is approximately 50% lower than in an adequate packed bed of spheres having the same hydraulic radius as CIM disk monolith; meaning they both have the same porosity and the same specific surface area. This phenomenon seems to be a consequence of the monolithic porous structure which is quite different in terms of the pore size distribution and parallel pore nonuniformity compared to the one in conventional packed beds. The number of self-similar levels for the CIM monoliths was estimated to be between 1.03 and 2.75.

  2. 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.

  3. Monolithic columns in plant proteomics and metabolomics.

    Science.gov (United States)

    Rigobello-Masini, Marilda; Penteado, José Carlos Pires; Masini, Jorge Cesar

    2013-03-01

    Since "omics" techniques emerged, plant studies, from biochemistry to ecology, have become more comprehensive. Plant proteomics and metabolomics enable the construction of databases that, with the help of genomics and informatics, show the data obtained as a system. Thus, all the constituents of the system can be seen with their interactions in both space and time. For instance, perturbations in a plant ecosystem as a consequence of application of herbicides or exposure to pollutants can be predicted by using information gathered from these databases. Analytical chemistry has been involved in this scientific evolution. Proteomics and metabolomics are emerging fields that require separation, identification, and quantification of proteins, peptides, and small molecules of metabolites in complex biological samples. The success of this work relies on efficient chromatographic and electrophoretic techniques, and on mass spectrometric detection. This paper reviews recent developments in the use of monolithic columns, focusing on their applications in "top-down" and "bottom-up" approaches, including their use as supports for immobilization of proteolytic enzymes and their use in two-dimensional and multidimensional chromatography. Whereas polymeric columns have been predominantly used for separation of proteins and polypeptides, silica-based monoliths have been more extensively used for separation of small molecules of metabolites. Representative applications in proteomics and in analysis of plant metabolites are given and summarized in tables.

  4. 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.

  5. Numerical Simulation of Fluid Dynamics in a Monolithic Column

    Directory of Open Access Journals (Sweden)

    Kazuhiro Yamamoto

    2017-01-01

    Full Text Available As for the measurement of polycyclic aromatic hydrocarbons (PAHs, ultra-performance liquid chromatography (UPLC is used for PAH identification and densitometry. However, when a solvent containing a substance to be identified passes through a column of UPLC, a dedicated high-pressure-proof device is required. Recently, a liquid chromatography instrument using a monolithic column technology has been proposed to reduce the pressure of UPLC. The present study tested five types of monolithic columns produced in experiments. To simulate the flow field, the lattice Boltzmann method (LBM was used. The velocity profile was discussed to decrease the pressure drop in the ultra-performance liquid chromatography (UPLC system.

  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. 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.

  10. Polymethacrylate monolithic and hybrid particle-monolithic columns for reversed-phase and hydrophilic interaction capillary liquid chromatography.

    Science.gov (United States)

    Jandera, Pavel; Urban, Jirí; Skeríková, Veronika; Langmaier, Pavel; Kubícková, Romana; Planeta, Josef

    2010-01-01

    We prepared hybrid particle-monolithic polymethacrylate columns for micro-HPLC by in situ polymerization in fused silica capillaries pre-packed with 3-5microm C(18) and aminopropyl silica bonded particles, using polymerization mixtures based on laurylmethacrylate-ethylene dimethacrylate (co)polymers for the reversed-phase (RP) mode and [2-(methacryloyloxy)ethyl]-dimethyl-(3-sulfopropyl) zwitterionic (co)polymers for the hydrophilic interaction (HILIC) mode. The hybrid particle-monolithic columns showed reduced porosity and hold-up volumes, approximately 2-2.5 times lower in comparison to the pure monolithic columns prepared in the whole volume of empty capillaries. The elution volumes of sample compounds are also generally lower in comparison to packed or pure monolithic columns. The efficiency and permeability of the hybrid columns are intermediate in between the properties of the reference pure monolithic and particle-packed columns. The chemistries of the embedded solid particles and of the interparticle monolithic moiety in the hybrid capillary columns contribute to the retention to various degrees, affecting the selectivity of separation. Some hybrid columns provided improved separations of proteins in comparison to the reference particle-packed columns in the reversed-phase mode. Zwitterionic hybrid particle-monolithic columns show dual mode retention HILIC/RP behaviour depending on the composition of the mobile phase and allow separations of polar compounds such as phenolic acids in the HILIC mode at lower concentrations of acetonitrile and, often in shorter analysis time in comparison to particle-packed and full-volume monolithic columns.

  11. Methacrylate-bonded covalent-organic framework monolithic columns for high performance liquid chromatography.

    Science.gov (United States)

    Liu, Li-Hua; Yang, Cheng-Xiong; Yan, Xiu-Ping

    2017-01-06

    Covalent-organic frameworks (COFs) are a newfangled class of intriguing microporous materials. Considering their unique properties, COFs should be promising as packing materials for high performance liquid chromatography (HPLC). However, the irregular shape and sub-micrometer size of COFs synthesized via the traditional methods render the main obstacles for the application of COFs in HPLC. Herein, we report the preparation of methacrylate-bonded COF monolithic columns for HPLC to overcome the above obstacles. The prepared COF bonded monolithic columns not only show good homogeneity and permeability, but also give high column efficiency, good resolution and precision for HPLC separation of small molecules including polycyclic aromatic hydrocarbons, phenols, anilines, nonsteroidal anti-inflammatory drugs and benzothiophenes. Compared with the bare polymer monolithic column, the COF bonded monolithic columns show enhanced hydrophobic, π-π and hydrogen bond interactions in reverse phase HPLC. The results reveal the great potential of COF bonded monoliths for HPLC and COFs in separation sciences.

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

    Energy Technology Data Exchange (ETDEWEB)

    Hong, Tingting; Yang, Xi; Xu, Yujing [Department of Analytical Chemistry, China Pharmaceutical University, Nanjing, 210009 (China); Key Laboratory of Drug Quality Control and Pharmacovigilance, Ministry of Education, Nanjing, 210009 (China); Ji, Yibing, E-mail: jiyibing@msn.com [Department of Analytical Chemistry, China Pharmaceutical University, Nanjing, 210009 (China); Key Laboratory of Drug Quality Control and Pharmacovigilance, Ministry of Education, Nanjing, 210009 (China)

    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. - Highlights: • Preparation of novel monolithic capillary columns have shown powerful potential in analytical chemistry field. • Various materials including ionic liquids and nanoparticles involved into capillary monolithic micro-devices are concluded. • Click chemistry strategy applied for preparing monolithic capillary columns is reviewed. • Recent strategies utilized in constructing different capillary monoliths for enantiomeric separation are summarized. • Advancement of capillary monoliths for complex samples analysis is comprehensively described.

  13. 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.

  14. Monolithic columns with organic sorbent based on poly-1-vinylimidazole for high performance liquid chromatography

    Science.gov (United States)

    Patrushev, Y. V.; Sidelnikov, V. N.; Yudina, Y. S.

    2017-03-01

    Monolithic chromatographic columns for HPLC with sorbent based on 1-vinylimidazole are prepared. It is shown that changing the 1-vinylimidazole content in the initial solution allows us to change the polarity of columns. An example of aromatic hydrocarbons separation is presented.

  15. 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

  16. 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.

  17. 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.

  18. 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.

  19. 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.

  20. 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.

  1. Chiral separation by (S)-naproxen imprinted monolithic column with mixed functional monomers

    Institute of Scientific and Technical Information of China (English)

    Zhen Ying Li; Zhao Sheng Liu; Qing Wei Zhang; Hong Quan Duan

    2007-01-01

    Molecularly imprinted polymers (MIPs), using (S)-naproxen as template and the combination of butyl methacrylate (BMA) and column was evaluated in HPLC mode. The result showed that the monolithic MIPs with the combination of two monomers produced better chiral resolution of rac-naproxen (Rs = 1.55) and column efficiencies of imprinted molecules (N = 2860 plates/m)than that with pure MAA.

  2. 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.

  3. 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.

  4. 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.

  5. Application of Convective Interaction Media (CIM) disk monolithic columns for fast separation and monitoring of organic acids.

    Science.gov (United States)

    Vodopivec, M; Podgornik, A; Berovic, M; Strancar, A

    2000-11-01

    The separation of organic acids on the anion-exchange monolithic support, commercially available as Convective Interaction Media (CIM), is presented in this study. It is demonstrated that citric, isocitric, pyruvic, fumaric, malic, and alpha-ketoglutaric acid can be successfully separated using a CIM monolithic column of suitable user-adjustable length. The effect of the mobile phase composition on the separation is investigated. CIM monolithic columns of adjustable length from 3 to 18 mm are compared regarding the resolution and the back pressure. It is shown that the CIM monolithic column of 12 mm in length enables a good separation of all six organic acids within 3 min and exhibits a linear dependence of back pressure versus flow rate. The resolution and the dynamic binding capacity are found to be flow-unaffected. A filtrated sample of bioprocess supernatant is analyzed without previous pretreatment, which indicates the possibility of online monitoring of small molecules during the bioprocess using CIM monolithic columns.

  6. 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.

  7. An innovative monolithic column preparation for the isolation of 25 kilo base pairs DNA.

    Science.gov (United States)

    Ongkudon, Clarence M; Pan, Sharadwata; Danquah, Michael K

    2013-11-29

    The use of large DNAs in preparing multivalent vaccines that will eventually give protective immunity against multiple pathogenic microbes is becoming a major debate nowadays. One of the important issues in ensuring the successful implementation of the new vaccine technology is the development of a chromatographic technique that can handle larger DNAs. This paper reports the development of a novel conical monolithic column format with pore and surface characteristics engineered for the isolation of 25 kbp DNA in a single step fashion. An effective method of eliminating wall channelling, a defect of most conventional monolithic chromatography systems which has caused significant loss of product, was applied to maximise DNA recovery. This method was based on a systematic reduction of wall channel size based on a predetermined correlation between column’s back pressure and wall channel size of a particular monolith pore size.

  8. 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.

  9. Aptamer modified organic-inorganic hybrid silica monolithic capillary columns for highly selective recognition of thrombin.

    Science.gov (United States)

    Deng, Nan; Liang, Zhen; Liang, Yu; Sui, Zhigang; Zhang, Liyuan; Wu, Qi; Yang, Kaiguang; Zhang, Lihua; Zhang, Yukui

    2012-12-04

    A novel kind of aptamer modified organic-inorganic hybrid silica monolithic capillary column has been developed, via the covalent bonding of 5'-NH(2)-modified aptamer for human α-thrombin on hybrid silica monolith, prepared by sol-gel method, with tetraethoxysilane and 3-aminopropyltriethoxysilane as precursors. Due to the large specific surface area of the hybrid matrix, the average coverage density of aptamer reached 568 pmol/μL, and the thrombin binding capacity was 1.15 μg/μL, 14 times higher than that of aptamer modified open tubular capillaries. By such an affinity capillary column, the limit of detection of thrombin was decreased to 3.4 nM with a UV detector. Furthermore, even when thrombin was mixed with 1000 times more concentrated human serum, it could be selectively enriched and detected with the signal-to-noise ratio as ca.10. These results indicate that the developed preparation strategy for aptamer based hybrid silica monolithic capillary column might provide an effective method to achieve highly selective recognition of trace targets.

  10. [Reparation and application of perfluorodecyl modified silica monolithic capillary column in extraction and enrichment of perfluorooctane sulfonates].

    Science.gov (United States)

    Huang, Ke; Zhou, Naiyuan; Chen, Bo

    2011-10-01

    A perfluorodecyl modified silica monolithic capillary column has been prepared by using sol-gel method. The preparation steps included hydrolysis of alkoxy silane, fasculation of silanol, gelation, aging, meso-pore preparation, drying and surface modification. It could be used as a solid phase extraction (SPE) microcolumn for extraction and enrichment of perfluorooctane sulfonate (PFOS). The enrichment characteristics and efficiency of the perfluorodecyl modified monolithic silica capillary column has been investigated and compared with C18 silica monolithic capillary column. The results indicated that the perfluorodecyl modified silica monolithic capillary column ( 15 cm x 75 microm) had a higher adsorption capacity and a better enrichment selectivity for PFOS. The average adsorption capacity of the perfluorodecyl modified silica monolithic capillary column was 75 ng. And when the PFOS mass concentration in sample was 0. 25 mg/L, the enrichment factor was 29-fold in average. Owing to the good performance of the perfluorodecyl modified silica monolithic capillary column, it can be used for the extraction and enrichment of trace PFOS in water to meet the requirements of water quality monitoring and analysis.

  11. 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.

  12. Improvement in Liquid Chromatographic Performance of Organic Polymer Monolithic Capillary Columns with Controlled Free-Radical Polymerization.

    Science.gov (United States)

    Gama, Mariana R; Aggarwal, Pankaj; Liu, Kun; Lee, Milton L; Bottoli, Carla B G

    2016-12-19

    Capillary columns containing butyl or lauryl methacrylate monoliths were prepared using two different free-radical polymerization methods: conventional free-radical polymerization and controlled/living free-radical polymerization, both initiated thermally, and these methods were compared for the first time. Both monolith morphology and chromatographic efficiency were compared for the synthesized stationary phases using scanning electronic microscopy (SEM) and capillary liquid chromatography, respectively. Columns prepared using controlled method gave better chromatographic performance for both monomers tested. The lauryl-based monolith showed 7-fold improvement in chromatographic efficiency with a plate count of 42,000 plates/m (corrected for dead volume) for a non-retained compound. Columns fabricated using controlled polymerization appeared more homogenous radially with fused small globular morphologies, evaluated by SEM, and lower column permeability. The columns were compared with respect to resolving power of a series of alkylbenzenes under isocratic and gradient elution conditions.

  13. 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.

  14. Miniaturized monolithic columns for the electrochromatographic separation and SERS detection of molecules of exobiological interest

    Science.gov (United States)

    Carbonnier, Benjamin; Guerrouache, Mohamed

    Development of miniaturized separation and detection media represents one of the major challenges in the field of modern analytical chemistry dedicated to space exploration. To date, gas chromatography-mass spectrometry has been selected as the method of choice for exobiology flight experiments for seeking for organic molecules and especially potential chemical indicators of life. [1] Liquid phase separation methods have also been developed with for instance, the so-called Mars Organic Analyzer (MOA) capillary electrophoresis (CE) microchip.[2] Although CE offers the advantages of easy miniaturization and high separation efficiency it suffers from a lack of selectivity towards a broad range of analytes with varied chemical nature. In this respect, we propose the use of capillary columns filled with monolithic stationary phases for the electrochromatographic separation of organic molecules of exobiology interest. Polymer monoliths have attracted a great deal of interest in analytical science over the last years as (electro)chromatographic stationary phases [3], immunosensors [4]. Beyond the intrinsic properties of monolithic polymers, i.e. fast mass transport between the monolithic support and the surrounding fluid and high permeability, other major advantages are their easy in situ preparation and tuning of surface functionality. Indeed, monoliths can be simply prepared through free radical copolymerization of a homogeneous mixture made of monomers, cross-linkers, porogenic solvents and initiator. UV-initiation process has been exploited to the synthesis of a discrete section of monolith as a flow-through active element within the confines of micro channels [5,6] while two-step strategies have been reported for the design of varied adsorbent starting with a generic monolith [7,8]. Although a nearly limitless range of monolithic supports can be prepared by this traditional method, the resulting monoliths exhibit unique function. In this contribution, we describe an

  15. 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

    2005-05-06

    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.

  16. 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.

  17. Kinetic performance appraisal of poly(styrene-co-divinylbenzene) monolithic high-performance liquid chromatography columns for biomolecule analysis.

    Science.gov (United States)

    Causon, Tim J; Shellie, Robert A; Hilder, Emily F

    2010-06-11

    A broad appraisal of the kinetic performance of organic polymeric monolithic columns is reported using commercially available poly(styrene-co-divinylbenzene) monolithic columns (Dionex ProSwift RP-1S). Analysis of a protein digest sample at elevated temperatures (> or =80 degrees C) indicated no apparent analyte degradation using an inert polymeric stationary phase. Comparison between low molecular weight solute and peptide separations highlighted the markedly different mass transport processes observed on macroporous monolithic beds and an improved C term at elevated temperature in both instances. The current usefulness of this column format for biomolecule analysis was further studied via employment of a kinetic performance characterisation for the first time to provide direction for column development servicing this application.

  18. Efficient application of monolithic silica column to determination of illicit heroin street sample by HPLC.

    Science.gov (United States)

    Macchia, Marco; Bertini, Simone; Mori, Claudio; Orlando, Caterina; Papi, Chiara; Placanica, Giorgio

    2004-03-01

    In this paper, an HPLC method is proposed for a routine, rapid and simple analysis of heroin samples confiscated from the illicit market, based on a new type of packing for HPLC columns (monolithic silica). Acetonitrile and pH 3.5 phosphate buffer solution were used under both isocratic and gradient conditions. Under our analytical conditions, all the components of a typical mixture of an illicit heroin sample proved to be fully separated into well-resolved peaks in 7 min. Analytical linearity and accuracy of the method were also studied for all analytes using tetracaine hydrochloride as the internal standard.

  19. Advances in the development of organic polymer monolithic columns and their applications in food analysis--a review.

    Science.gov (United States)

    Jandera, Pavel

    2013-10-25

    Monolithic continuous separation media are gradually finding their way to sample pre-treatment, isolation, enrichment and final analytical separations of a plethora of compounds, occurring as food components, additives or contaminants, including pharmaceuticals, pesticides and toxins, which have traditionally been the domain of particulate chromatographic materials. In the present review, recent advances in the technology of monolithic columns and the applications in food analysis are addressed. Silica-based monoliths are excellent substitutes to conventional particle-packed columns, improving the speed of analysis for low-molecular weight compounds, due to their excellent efficiency and high permeability. These properties have been recently appreciated in two-dimensional HPLC, where the performance in the second dimension is of crucial importance. Organic-polymer monoliths in various formats provide excellent separations of biopolymers. Thin monolithic disks or rod columns are widely employed in isolation, purification and pre-treatment of sample containing proteins, peptides or nucleic acid fragments. Monolithic capillaries were originally intended for use in electrochromatography, but are becoming more frequently used for capillary and micro-HPLC. Monoliths are ideal highly porous support media for immobilization or imprinting template molecules, to provide sorbents for shape-selective isolation of target molecules from various matrices occurring in food analysis. The separation efficiency of organic polymer monoliths for small molecules can be significantly improved by optimization of polymerization approach, or by post-polymerization modification. This will enable full utilization of a large variety of available monomers to prepare monoliths with chemistry matching the needs of selectivity of separations of various food samples containing even very polar or ionized compounds.

  20. Rapid Preparation Methods of Biological Samples for Ionic Compounds Using Ion Exchange Type Monolithic Silica Spin Column

    OpenAIRE

    宮崎, 将太; 山田, 智子; 太田, 茂徳; 斉藤, 剛; 奈女良, 昭; 大平, 真義

    2010-01-01

    We developed a device comprising a spin column packed with ion exchange type (SCX and SAX) monolithic silica for extracting ionic compounds from biological samples. The methods involving the use of these spin column are not useful for the extraction of ionic analytes, but are highly reproducible for the analysis in serum and urine. This spin column enabled sample preparation in less than 10 min. Handling such as sample loading, washing, and elution of analytes, was exhibited by the centrifuga...

  1. [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.

  2. 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.

  3. 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

  4. 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.

  5. External polyacrylate-coating as alternative material for preparation of photopolymerized sol-gel monolithic column.

    Science.gov (United States)

    Vaz, Fernando Antonio Simas; de Castro, Patrícia Mendonça; Molina, Celso; Ribeiro, Sidney José Lima; Polachini, Ferminio César; Messaddeq, Younes; Nunes, Adriana Palombo; de Oliveira, Marcone Augusto Leal

    2008-06-30

    Photopolymerized sol-gel monolithic columns for use in capillary electrochromatography were prepared in 125 microm i.d. polyacrylate-coated fused-silica capillaries. The polyacrylate-coating, unlike the polyimide one, is transparent to the radiation used (approximately 370 nm), and thus, no coating removal is necessary. This is a very important particularity since intrinsic capillary column characteristics, such as flexibility and mechanical resistance, are unchanged. A mixture containing metacryloxypropyltrimethoxysilane (MPTMS) as the polymeric precursor, hydrochloric acid as the catalyst, toluene as the porogen and bis(2,4,6-trimethylbenzoyl)-phenylphosphine oxide (Irgacure 819) as the photoinitiator was irradiated at 370 nm for 20 min inside the capillaries to prepare the columns through sol-gel approach. The versatility and viability of the use of polyacrilate as a new capillary external coating were shown through preparation of two columns under different conditions, which were tested in electrochromatography for separation of standard mixture containing thiourea (marker compound), propylbenzene, phenanthrene and pyrene.

  6. 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

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

    Directory of Open Access Journals (Sweden)

    Mohammad K. Alkam

    2015-01-01

    Full Text Available 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 been discussed. Effects of the concrete cover thickness and the water cement ratio on the service life of the concrete column at hand have been presented. A new approach for arranging locations of reinforcement steel bars has been introduced. This approach is intended to prolong the service life of the concrete column under consideration against chloride induced corrosion.

  8. 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

  9. Chromatographic selectivity of poly(alkyl methacrylate-co-divinylbenzene) monolithic columns for polar aromatic compounds by pressure-driven capillary liquid chromatography.

    Science.gov (United States)

    Lin, Shu-Ling; Wang, Chih-Chieh; Fuh, Ming-Ren

    2016-10-05

    In this study, divinylbenzene (DVB) was used as the cross-linker to prepare alkyl methacrylate (AlMA) monoliths for incorporating π-π interactions between the aromatic analytes and AlMA-DVB monolithic stationary phases in capillary LC analysis. Various AlMA/DVB ratios were investigated to prepare a series of 30% AlMA-DVB monolithic stationary phases in fused-silica capillaries (250-μm i.d.). The physical properties (such as porosity, permeability, and column efficiency) of the synthesized AlMA-DVB monolithic columns were investigated for characterization. Isocratic elution of phenol derivatives was first employed to evaluate the suitability of the prepared AlMA-DVB columns for small molecule separation. The run-to-run (0.16-1.20%, RSD; n = 3) and column-to-column (0.26-2.95%, RSD; n = 3) repeatabilities on retention times were also examined using the selected AlMA-DVB monolithic columns. The π-π interactions between the aromatic ring and the DVB-based stationary phase offered better recognition on polar analytes with aromatic moieties, which resulted in better separation resolution of aromatic analytes on the AlMA-DVB monolithic columns. In order to demonstrate the capability of potential environmental and/or food safety applications, eight phenylurea herbicides with single benzene ring and seven sulfonamide antibiotics with polyaromatic moieties were analyzed using the selected AlMA-DVB monolithic columns.

  10. Preparation and characterization of fluorophenylboronic acid-functionalized affinity monolithic columns for the selective enrichment of cis-diol-containing biomolecules.

    Science.gov (United States)

    Li, Qianjin; Liu, Zhen

    2015-01-01

    Boronate affinity monolithic columns have been developed into an important means for the selective recognition and capture of cis-diol-containing biomolecules, such as glycoproteins, nucleosides and saccharides. The ligands of boronic acids are playing an important role in boronate affinity monolithic columns. Although several boronate affinity monoliths with high affinity toward cis-diol-containing biomolecules have been reported, only few publications are focused on their detailed procedures for preparation and characterization. This chapter describes in detail the preparation and characterization of a boronate affinity monolithic column applying 2,4-difluoro-3-formyl-phenylboronic acid (DFFPBA) as a ligand. The DFFPBA-functionalized monolithic column not only exhibited an ultrahigh boronate affinity toward cis-diol-containing biomolecules, but also showed great potential for the selective enrichment of cis-diol-containing biomolecules in real samples.

  11. Detection of processed genetically modified food using CIM monolithic columns for DNA isolation.

    Science.gov (United States)

    Jerman, Sergej; Podgornik, Ales; Cankar, Katarina; Cadet, Neza; Skrt, Mihaela; Zel, Jana; Raspor, Peter

    2005-02-11

    The availability of sufficient quantities of DNA of adequate quality is crucial in polymerase chain reaction (PCR)-based methods for genetically modified food detection. In this work, the suitability of anion-exchange CIM (Convective Interaction Media; BIA Separations, Ljubljana, Slovenia) monolithic columns for isolation of DNA from food was studied. Maize and its derivates corn meal and thermally pretreated corn meal were chosen as model food. Two commercially available CIM disk columns were tested: DEAE (diethylaminoethyl) and QA (quaternary amine). Preliminary separations were performed with standard solution of salmon DNA at different pH values and different NaCl concentrations in mobile phase. DEAE groups and pH 8 were chosen for further isolations of DNA from a complex matrix-food extract. The quality and quantity of isolated DNA were tested on agarose gel electrophoresis, with UV-scanning spectrophotometry, and by amplification with real-time PCR. DNA isolated in this way was of suitable quality for further PCR analyses. The described method is also applicable for DNA isolation from processed foods with decreased DNA content. Furthermore, it is more effective and less time-consuming in comparison with the existing proposed methods for isolation of DNA from plant-derived foods.

  12. 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.

  13. 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 mechanism as the retention increased with the isoelectric points.

  14. 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.

  15. 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).

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

    Energy Technology Data Exchange (ETDEWEB)

    Costin, Jason W. [School of Life and Environmental Sciences, Deakin University, Geelong, Victoria 3217 (Australia); Lewis, Simon W. [Department of Applied Chemistry, Curtin University of Technology, Perth, WA 6845 (Australia); Purcell, Stuart D. [GlaxoSmithKline, Port Fairy, Victoria 3284 (Australia); Waddell, Lucy R. [GlaxoSmithKline, Port Fairy, Victoria 3284 (Australia); Francis, Paul S. [School of Life and Environmental Sciences, Deakin University, Geelong, Victoria 3217 (Australia); Barnett, Neil W. [School of Life and Environmental Sciences, Deakin University, Geelong, Victoria 3217 (Australia)]. E-mail: barnie@deakin.edu.au

    2007-07-30

    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{sup -10} M, 5 x 10{sup -10} M, 5 x 10{sup -10} M and 1 x 10{sup -9} M, for morphine, codeine, oripavine and thebaine, respectively.

  17. Development of radiation tolerant monolithic active pixel sensors with fast column parallel read-out

    Science.gov (United States)

    Koziel, M.; Dorokhov, A.; Fontaine, J.-C.; De Masi, R.; Winter, M.

    2010-12-01

    Monolithic active pixel sensors (MAPS) [1] (Turchetta et al., 2001) are being developed at IPHC—Strasbourg to equip the EUDET telescope [2] (Haas, 2006) and vertex detectors for future high energy physics experiments, including the STAR upgrade at RHIC [3] (T.S. Collaboration, 2005) and the CBM experiment at FAIR/GSI [4] (Heuser, 2006). High granularity, low material budget and high read-out speed are systematically required for most applications, complemented, for some of them, with high radiation tolerance. A specific column-parallel architecture, implemented in the MIMOSA-22 sensor, was developed to achieve fast read-out MAPS. Previous studies of the front-end architecture integrated in this sensor, which includes in-pixel amplification, have shown that the fixed pattern noise increase consecutive to ionizing radiation can be controlled by means of a negative feedback [5] (Hu-Guo et al., 2008). However, an unexpected rise of the temporal noise was observed. A second version of this chip (MIMOSA-22bis) was produced in order to search for possible improvements of the radiation tolerance, regarding this type of noise. In this prototype, the feedback transistor was tuned in order to mitigate the sensitivity of the pixel to ionizing radiation. The performances of the pixels after irradiation were investigated for two types of feedback transistors: enclosed layout transistor (ELT) [6] (Snoeys et al., 2000) and "standard" transistor with either large or small transconductance. The noise performance of all test structures was studied in various conditions (expected in future experiments) regarding temperature, integration time and ionizing radiation dose. Test results are presented in this paper. Based on these observations, ideas for further improvement of the radiation tolerance of column parallel MAPS are derived.

  18. Development of a silica monolith modified with Fe3O4 nano-particles in centrifugal spin column format for the extraction of phosphorylated compounds.

    Science.gov (United States)

    Alwy, Ali; Clarke, Sarah P; Brougham, Dermot F; Twamley, Brendan; Paull, Brett; White, Blánaid; Connolly, Damian

    2015-01-01

    In this study, citrate-stabilised iron oxide nano-particles (∼16 nm) have been immobilised on commercial silica monolithic centrifugal spin columns (MonoSpin) for the extraction of phosphorylated compounds. Two alternative strategies were adopted involving either direct electrostatic attachment to an aminated MonoSpin (single-layer method) in the first instance, or the use of a layer-by-layer method with poly(diallyldimethylammonium) chloride. Field-emission scanning electron spectroscopy and energy-dispersive X-ray spectroscopy was used for confirming notably higher coverage of nano-particles using the layer-by-layer method (2.49 ± 0.53 wt%) compared with the single-layer method (0.43 ± 0.30 wt%). The modified monolith was used for the selective separation/extraction of adenosine monophosphate, adenosine diphosphate and adenosine triphosphate with elution using a phosphate buffer. A reversed-phase liquid chromatographic assay was used for confirming that adenosine, as a non-phosphorylated control was not retained on the modified MonoSpin devices, whereas recovery of 80% for adenosine monophosphate, 86% for adenosine diphosphate and 82% for adenosine triphosphate was achieved.

  19. Synthesis of a specific monolithic column with artificial recognition sites for L-glutamic acid via cryo-crosslinking of imprinted nanoparticles.

    Science.gov (United States)

    Göktürk, Ilgım; Üzek, Recep; Uzun, Lokman; Denizli, Adil

    2016-06-01

    In this study, a new molecular imprinting (MIP)-based monolithic cryogel column was prepared using chemically crosslinked molecularly imprinted nanoparticles, to achieve a simplified chromatographic separation (SPE) for a model compound, L-glutamic acid (L-Glu). Cryogelation through crosslinking of imprinted nanoparticles forms stable monolithic cryogel columns. This technique reduces the leakage of nanoparticles and increases the surface area, while protecting the structural features of the cryogel for stable and efficient recognition of the template molecule. A non-imprinted monolithic cryogel column (NIP) was also prepared, using non-imprinted nanoparticles produced without the addition of L-Glu during polymerization. The molecularly imprinted monolithic cryogel column (MIP) indicates apparent recognition selectivity and a good adsorption capacity compared to the NIP. Also, we have achieved a significant increase in the adsorption capacity, using the advantage of high surface area of the nanoparticles.

  20. On-line clean-up and screening of oxacillin and cloxacillin in human urine and plasma with a weak ion exchange monolithic column.

    Science.gov (United States)

    Yang, Gengliang; Feng, Sha; Liu, Haiyan; Yin, Junfa; Zhang, Li; Cai, Liping

    2007-07-01

    A weak ion exchange monolithic column prepared by modifying the GMA-MAA-EDMA (glycidyl methacrylate-methacrylic acid-ethylene glycol dimethacrylate) monoliths with ethylenediamine was applied to remove matrix compounds in biological fluid. Using this monolithic column, on-line clean-up and screening of oxacillin and cloxacillin in human urine and plasma samples had been investigated. Chromatography was performed by reversed-phase HPLC on a C(18) column with ultraviolet detection at 225 nm. Results showed that the ion exchange monolithic column could be used for deproteinization and retaining oxacillin and cloxacillin in human urine and plasma, which provided a simple and fast method for assaying drugs in human urine and plasma.

  1. Molecularly imprinted solid-phase extraction monolithic capillary column for selective extraction and sensitive determination of safranine T in wolfberry.

    Science.gov (United States)

    Su, Zihao; Zhai, Haiyun; Chen, Zuanguang; Zhou, Qing; Li, Jiangmei; Liu, Zhenping

    2014-02-01

    A method was developed to sensitively determine safranine T in wolfberry by molecularly imprinted solid-phase extraction (MISPE) coupled with high-performance liquid chromatography and laser-induced fluorescence detection (HPLC-LIF). The MISPE capillary monolithic column was prepared by water-bath in situ polymerization, using safranine T, methacrylic acid (MAA), and ethylene dimethacrylate (EDMA) as template, functional monomer, and cross-linker, respectively. The properties of the homemade MISPE capillary monolithic column, including capacity and specificity, were investigated under optimized conditions and the morphologies of inner polymers were characterized by scanning electron microscopy (SEM). The mean recoveries of safranine T in wolfberry ranged from 91.2 % to 92.9 % and the intraday and interday relative standard deviation (RSD) values all ranged from 3.4 % to 4.2 %. Good linearity was obtained over 0.001-1.0 μg mL(-1) (r = 0.9999) with a detection limit (S/N = 3) of 0.4 ng g(-1). Under the selected conditions, enrichment factors of over 90-fold were obtained and the extraction on the monolithic column effectively cleaned up the wolfberry matrix. The results demonstrated that the proposed MISPE-HPLC-LIF method could be applied to sensitively determine safranine T in wolfberry.

  2. 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.

  3. 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.

  4. 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.

  5. 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.

  6. 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.

  7. 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.

  8. Histidine-modified organic-silica hybrid monolithic column for mixed-mode per aqueous and ion-exchange capillary electrochromatography.

    Science.gov (United States)

    Tang, Sheng; Liu, Shujuan; Liang, Xiaojing; Tang, Xiaofen; Wu, Xingcai; Guo, Yong; Liu, Xia; Jiang, Shengxiang

    2015-06-01

    A novel organic-silica hybrid monolith was prepared through the binding of histidine onto the surface of monolithic matrix for mixed-mode per aqueous and ion-exchange capillary electrochromatography. The imidazolium and amino groups on the surface of the monolithic stationary phase were used to generate an anodic electro-osmotic flow as well as to provide electrostatic interaction sites for the charged compounds at low pH. Typical per aqueous chromatographic behavior was observed in water-rich mobile phases. Various polar and hydrophilic analytes were selected to evaluate the characteristics and chromatographic performance of the obtained monolith. Under per aqueous conditions, the mixed-mode mechanism of hydrophobic and ion-exchange interactions was observed and the resultant monolithic column proved to be very versatile for the efficient separations of these polar and hydrophilic compounds (including amides, nucleosides and nucleotide bases, benzoic acid derivatives, and amino acids) in highly aqueous mobile phases. The successful applications suggested that the histidine-modified organic-silica hybrid monolithic column could offer a wide range of retention behaviors and flexible selectivities toward polar and hydrophilic compounds.

  9. Preparation of hybrid monolithic columns via "one-pot" photoinitiated thiol-acrylate polymerization for retention-independent performance in capillary liquid chromatography.

    Science.gov (United States)

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

    2015-09-01

    A novel "one-pot" approach was developed for ultrarapid preparation of various hybrid monolithic columns in UV-transparent fused-silica capillaries via photoinitiated thiol-acrylate polymerization of an acrylopropyl polyhedral oligomertic silsesquioxane (acryl-POSS) and a monothiol monomer (1-octadecanethiol or sodium 3-mercapto-1-propanesulfonate) within 5 min, in which the acrylate not only homopolymerizes, but also couples with the thiol. This unique combination of two types of free-radical reaction mechanisms offers a simple way to fabricate various acrylate-based hybrid monoliths. The physical characterization, including scanning electron microscopy (SEM), Fourier transform infrared (FT-IR) spectroscopy, and thermal gravimetric analysis was performed. The results indicated that the monothiol monomers were successfully incorporated into acryl-POSS-based hybrid monoliths. The column efficiencies for alkylbenzenes on the C18-functionalized hybrid monolithic column reached to 60 000-73 500 plates/m at the velocity of 0.33 mm/s in capillary liquid chromatography, which was far higher than that of previously reported POSS-based columns prepared via thermal-initiated free-radical polymerization without adding any thiol monomers. By plotting the plate height (H) of the alkylbenzenes versus the linear velocity (u) of the mobile phase, the results revealed a retention-independent efficient performance of small molecules in the isocratic elution. These results indicated that more homogeneous hybrid monoliths formed via photoinitiated thiol-acrylate polymerization; particularly, the use of the multifunctional cross-linker possibly prevented the generation of gel-like micropores, reducing mass transfer resistance (C-term). Another sulfonate-containing hybrid monolithic column also exhibited hydrophobicity and ion-exchange mechanism, and the dynamic binding capacity was calculated as 71.1 ng/cm (75 μm i.d.).

  10. Determination of ricin by nano liquid chromatography/mass spectrometry after extraction using lactose-immobilized monolithic silica spin column.

    Science.gov (United States)

    Kanamori-Kataoka, Mieko; Kato, Haruhito; Uzawa, Hirotaka; Ohta, Shigenori; Takei, Yoshiyuki; Furuno, Masahiro; Seto, Yasuo

    2011-08-01

    Ricin is a glycosylated proteinous toxin that is registered as toxic substance by Chemical Weapons convention. Current detection methods can result in false negatives and/or positives, and their criteria are not based on the identification of the protein amino acid sequences. In this study, lactose-immobilized monolithic silica extraction followed by tryptic digestion and liquid chromatography/mass spectrometry (LC/MS) was developed as a method for rapid and accurate determination of ricin. Lactose, which was immobilized on monolithic silica, was used as a capture ligand for ricin extraction from the sample solution, and the silica was supported in a disk-packed spin column. Recovery of ricin was more than 40%. After extraction, the extract was digested with trypsin and analyzed by LC/MS. The accurate masses of molecular ions and MS/MS spectra of the separated peptide peaks were measured by Fourier transform-MS and linear iontrap-MS, respectively. Six peptides, which were derived from the ricin A-(m/z 537.8, 448.8 and 586.8) and B-chains (m/z 701.3, 647.8 and 616.8), were chosen as marker peptides for the identification of ricin. Among these marker peptides, two peptides were ricin-specific. This method was applied to the determination of ricin from crude samples. The monolithic silica extraction removed most contaminant peaks from the total ion chromatogram of the sample, and the six marker peptides were clearly detected by LC/MS. It takes about 5 h for detection and identification of more than 8 ng/ml of ricin through the whole handling, and this procedure will be able to deal with the terrorism using chemical weapon.

  11. 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.

  12. 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.

  13. Effect of monomer mixture composition on structure and chromatographic properties of poly(divinylbenzene-co-ethylvinylbenzene-co-2-hydroxyethyl methacrylate) monolithic rod columns for separation of small molecules.

    Science.gov (United States)

    Smirnov, Konstantin N; Dyatchkov, Ivan A; Telnov, Maxim V; Pirogov, Andrey V; Shpigun, Oleg A

    2011-07-29

    Porous poly(divinylbenzene-co-ethylvinylbenzene-co-2-hydroxyethyl methacrylate) monoliths were synthesized via thermally initiated free-radical polymerization in confines of surface-vinylized glass columns (150 mm × 3 mm i.d.) and applied to the reversed-phase separation of low-molecular-weight aromatic compounds. In order to compensate for the polymer shrinkage during the synthesis and prevent the monolith from detachment from the column wall, polymerization was conducted under nitrogen pressure. The reaction proceeded at 60°C for 22 h. 2,2'-Azo-bis-isobutironitrile was used as the initiator and 1-dodecanol was used as the porogen. A series of monoliths with different monomer ratios were obtained. All the monoliths had high specific surface areas ranging from 370 to 490 m(2)/g. In the studied range of monomer mixture compositions, the mechanical stability of the stationary phase in water/acetonitrile eluents was found to be high enough and practically insensitive to the fraction of 2-hydroxyethyl methacrylate (HEMA). Increasing the molar fraction of HEMA from 10.5% to 14.7% resulted in the decrease of column permeability by two orders of magnitude (from 1.1×10(-12) to 1.8×10(-14) m(2)) and led to weaker retention of alkylbenzenes. The higher HEMA content was shown to reduce the plate height of the columns in the separation of small molecules from 160-490 μm to 40-76 μm. This was attributed mainly to the decrease of the domain size of the monoliths leading to lower eddy dispersion and mass transfer resistance in the column.

  14. 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.

  15. 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.

  16. 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.

  17. Chelation ion chromatography of alkaline earth and transition metals a using monolithic silica column with bonded N-hydroxyethyliminodiacetic acid functional groups.

    Science.gov (United States)

    McGillicuddy, Nicola; Nesterenko, Ekaterina P; Nesterenko, Pavel N; Jones, Phil; Paull, Brett

    2013-02-08

    A commercially available porous silica monolithic column (Onyx Monolithic Si, 100 mm×4.6 mm I.D.) was 'in-column' covalently functionalised with 2-hydroxyethyliminodiacetic acid (HEIDA) groups, and applied to the simultaneous and rapid separation of alkaline earth and transition metal ions, using high-performance chelation ion chromatography (HPCIC). With a 0.3mM dipicolinic acid (DPA) containing eluent, the baseline separation of various common transition and heavy metal ions and the four alkaline earth metal ions could be achieved in under 14 min with a flow rate of just 0.8 mL/min. Detection was achieved using spectrophotometric detection at 540 nm after post-column reaction (PCR) with 4-(2-pyridylazo)-resorcinol (PAR). Significant effects from variation of eluent nature, concentration and temperature upon selectivity and retention were demonstrated with the new monolithic silica chelating phase. Under optimised conditions (0.165 M LiNO(3) eluent, pH 2.5), peak efficiencies of 54,000, 60,000 and 64,000 N/m, for Zn(2+), Mn(2+) and Cd(2+), respectively, were recorded, far exceeding that previously reported for IDA based chelation ion exchange columns.

  18. Preparation of poly(butyl methacrylate-co-ethyleneglyceldimethacrylate) monolithic column modified with β-cyclodextrin and nano-cuprous oxide and its application in polymer monolithic microextraction of polychlorinated biphenyls.

    Science.gov (United States)

    Zheng, Haijiao; Liu, Qingwen; Jia, Qiong

    2014-05-23

    A poly(butyl methacrylate-co-ethyleneglyceldimethacrylate) (poly(BMA-EDMA)) monolithic column was prepared with in situ polymerization method and modified with allylamine-β-cyclodextrin (ALA-β-CD) and nano-cuprous oxide (Cu2O). A polymer monolith microextraction method was developed with the modified monolithic column for the preconcentration of polychlorinated biphenyls combined with gas chromatography-electron capture detector. Various parameters affecting the extraction efficiency were investigated and optimized. Under the optimum experimental conditions, we obtained acceptable linearities, low limits of detection, and good intra-day/inter-day relative standard deviations. Because of the hydrophobic properties of β-CD and the porous nano structure of Cu2O, the enrichment capacity of the poly(BMA-EDMA) monolithic column was significantly improved. The extraction efficiency followed the order: poly(BMA-EDMA-ALA-β-CD-Cu2O)>poly(BMA-EDMA-ALA-β-CD)>poly(BMA-EDMA)>direct GC analysis. When applied to the determination of polychlorinated biphenyls in wine samples, low limits of detection (0.09ngmL(-1)) were obtained under the preoptimized conditions (sample volume 1.0mL, sample flow rate 0.1mLmin(-1), eluent volume 0.1mL, and eluent flow rate 0.05mLmin(-1)). In addition, the present method was employed to determine polychlorinated biphenyls in red wine samples and the accuracy was assessed through recovery experiments. The obtained recovery values were in the range of 78.8-104.1% with relative standard deviations less than 9.0%.

  19. Purification of ß-glucosidases from Pichia etchellsii using CIM monolith columns.

    Science.gov (United States)

    Gaonkar, Roopa K; Mishra, Saroj; Vijayalakshmi, M A

    2011-05-01

    β-Glucosidases (EC 3.2.1.21) are industrially important glycosyl hydrolases used for cellulose saccharification as well as for synthesis of glyco-conjugates. Crystal structure of only one β-glucosidase of family 3 of the glycosyl hydrolase families is available due to difficulty in purification of these closely related enzymes from a given source. Multiple steps used during purification result in low yield, making it difficult to study their properties. Conditions for purification of two closely related β-glucosidases (BGL I and BGL II) of family 3 from Pichia etchellsii were investigated in this study. Two weak anion exchange columns convective interaction media-diethyl amino ethyl (CIM-DEAE) and CIM-ethylenediamine (CIM-EDA) were used for this purpose. The results obtained at 0.34 ml disk (CIM-DEAE) level were scaled up to 8 ml CIM-DEAE tube column wherein BGL I and BGL II were separated from the major contaminants in the cell-free extract. The recovered enzymes were completely resolved in the second step using CIM-EDA. A final specific activity of 9,180 IU/mg and 2,345.3 IU/mg was achieved for BGL I and BGL II respectively with an overall yield of 33%. The system should be applicable to resolution of other closely related enzymes from this family.

  20. Enantioseparation of N-derivatized amino acids by micro-liquid chromatography/laser induced fluorescence detection using quinidine-based monolithic columns.

    Science.gov (United States)

    Wu, Huihui; Wang, Qiqin; Ruan, Meng; Peng, Kun; Zhu, Peijie; Crommen, Jacques; Han, Hai; Jiang, Zhengjin

    2016-03-20

    A novel carbamoylated quinidine based monolith, namely poly(O-9-[2-(methacryloyloxy)-ethylcarbamoyl]-10,11-dihydroquinidine-co-ethylene dimethacrylate (poly(MQD-co-EDMA)), was prepared for the micro-LC enantioseparation of N-derivatized amino acids. The influence of the mobile phase composition, including the organic modifier proportion, the apparent pH and the buffer concentration, on the enantioresolution of N-derivatized amino acids was systematically investigated. Satisfactory column performance in terms of permeability, efficiency and reproducibility was obtained in most cases. The majority of the enantiomers of the tested N-protected amino acids, including 3,5-DNB, 3,5-DClB, FMOC, 3,5-DMB, p-NB, m-ClB, p-ClB and B derivatives, could be baseline separated on the poly(MQD-co-EDMA) monolithic column within 25min. A self-assembled laser induced fluorescence (LIF) detector was employed to improve sensitivity when analyzing 7-nitro-2,1,3-benzoxadiazole (NBD) derivatives of amino acids. Ten NBD-derivatized amino acids, including arginine and histidine whose enantioseparation on quinidine carbamate based CSPs has not been reported so far, were enantioresolved on the poly(MQD-co-EDMA) monolith column. It is worth noting that the d-enantiomers of NBD-derivatized amino acids eluted first, except in the case of glutamic acid. The LOD values obtained with the LIF detector were comparable to those reported using conventional LC-FL methods. The prepared poly(MQD-co-EDMA) monolithic column coupled with the LIF detector opens up interesting perspectives to the determination of trace D-amino acids in biological samples.

  1. One-pot preparation of a mixed-mode organic-silica hybrid monolithic capillary column and its application in determination of endogenous gibberellins in plant tissues.

    Science.gov (United States)

    Zhang, Zheng; Hao, Yan-Hong; Ding, Jun; Xu, Sheng-Nan; Yuan, Bi-Feng; Feng, Yu-Qi

    2015-10-16

    A newly improved one-pot method, based on "thiol-ene" click chemistry and sol-gel approach in microemulsion system, was developed for the preparation of C8/PO(OH)2-silica hybrid monolithic capillary column. The prepared monolith possesses large specific surface area, narrow mesopore size distribution and high column efficiency. The monolithic column was demonstrated to have cation exchange/reversed-phase (CX/RP) mixed-mode retention for analytes on nano-liquid chromatography (nano-LC). On the basis of the developed nano-LC system with MS detector coupled to pipette tip solid phase extraction (PT-SPE) and derivatization process, we then realized simultaneous determination of 10 gibberellins (GAs) with low limits of detection (LODs, 0.003-0.025 ng/mL). Furthermore, 6 endogenous GAs in only 5mg rice leaves (fresh weight) were successfully detected and quantified. The developed PT-SPE-nano-LC-MS strategy may offer promising applications in the determination of low abundant bioactive molecules from complex matrix.

  2. 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.

  3. 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.

  4. The fabrication of monolithic capillary column based on poly (bisphenol A epoxy vinyl ester resin-co-ethylene glycol dimethacrylate) and its applications for the separation of small molecules in high performance liquid chromatography.

    Science.gov (United States)

    Niu, Wenjing; Wang, Lijuan; Bai, Ligai; Yang, Gengliang

    2013-07-05

    A new polymeric monolith was synthesized in fused-silica capillary by in situ polymerization technique. In the polymerization, bisphenol A epoxy vinyl ester resin (VER) was used as the functional monomer, ethylene glycol dimethacrylate (EDMA) as the crosslinking monomer, 1,4-butanediol, 1-propanol and water as the co-porogens, and azobisisobutyronitrile (AIBN) as the initiator. The conditions of polymerization have been optimized. Morphology of the prepared poly (VER-co-EDMA) monolith was investigated by the scanning electron microscopy (SEM); pore properties were assayed by mercury porosimetry and nitrogen adsorption. The optimized poly (VER-co-EDMA) monolith showed a uniform structure, good permeability and mechanical stability. Then, the column was used as the stationary phase of high performance liquid chromatography (HPLC) to separate the mixture of benzene derivatives. The best column efficiency achieved for phenol was 235790 theoretical plates per meter. Baseline separations of benzene derivatives and halogenated benzene compounds under optimized isocratic mode conditions were achieved with high column efficiency. The column showed good reproducibility: the relative standard deviation (RSD) values based on the retention times (n=3) for run-to-run, column-to-column and batch-to-batch were less than 0.98, 1.68, 5.48%, respectively. Compared with poly (BMA-co-EDMA) monolithic column, the proposed monolith exhibited more efficiency in the separation of small molecules.

  5. 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.

  6. Extraction of amphetamines and methylenedioxyamphetamines from urine using a monolithic silica disk-packed spin column and high-performance liquid chromatography-diode array detection.

    Science.gov (United States)

    Namera, Akira; Nakamoto, Akihiro; Nishida, Manami; Saito, Takeshi; Kishiyama, Izumi; Miyazaki, Shota; Yahata, Midori; Yashiki, Mikio; Nagao, Masataka

    2008-10-24

    To overcome the limitations of solid-phase extraction, we developed a device comprising a spin column packed with octadecyl silane-bonded monolithic silica for extracting amphetamines and methylenedioxyamphetamines from urine. Urine (0.5mL), buffer (0.4mL), and methoxyphenamine (internal standard) were directly put into the preactivated column. The column was centrifuged (3000rpm, 5min) for sample loading and washed. The adsorbed analytes were eluted and analyzed by high-performance liquid chromatography, without evaporation. The results were as follows: linear curves (drug concentrations of 0.2-20microg/mL); correlation coefficients >0.99; detection limit, 0.1microg/mL. The proposed method is not only useful for drugs from biological materials but also highly reproducible for the analysis of these drugs in urine.

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

    Science.gov (United States)

    Nakamoto, Akihiro; Nishida, Manami; Saito, Takeshi; Kishiyama, Izumi; Miyazaki, Shota; Murakami, Katsunori; Nagao, Masataka; Namura, Akira

    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(5) was used as an internal standard. The linear ranges were 0.01-5.0 microg mL(-1) for methamphetamine (MA) and 3,4-methylenedioxymethamphetamine (MDMA) and 0.02-5.0 microg mL(-1) for amphetamine (AP) and 3,4-methylenedioxyamphetamine (MDA) (coefficient of correlation > or = 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 microg mL(-1) of APs and MDAs ranged from 1.4% to 13.6%. The lowest detection limit (signal-to-noise ratio > or = 3) in urine was 5 ng mL(-1) for MA and MDMA and 10 ng mL(-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.

  8. High-performance liquid chromatography analysis of polyacetylenes and polyenes in Echinacea pallida by using a monolithic reversed-phase silica column.

    Science.gov (United States)

    Pellati, Federica; Calò, Samuele; Benvenuti, Stefania

    2007-05-11

    In this study, a RP-HPLC method for the analysis of polyacetylenes and polyenes in Echinacea pallida roots and phytopharmaceuticals was developed. The reference compounds used for quantification were isolated from the plant material and their structures were determined on the basis of the analysis of UV, IR, NMR and MS data. The complete structure elucidation of three compounds, namely 8-hydroxy-tetradec-(9E)-ene-11,13-diyn-2-one (1), tetradec-(8Z)-ene-11,13-diyn-2-one (6) and pentadec-(8Z)-en-2-one (9) is described. In the analysis of the n-hexane extracts of E. pallida roots, the comparison between conventional and monolithic columns showed that the elution order in both cases is identical and the selectivity is equivalent. However, the retention times achieved by the monolithic column are shorter, resulting in a faster separation (20 min). Therefore, the analyses were carried out on a Chromolith Performance RP-18e (100 mm x 4.6 mm i.d.), with a gradient mobile phase composed by H(2)O and ACN at the flow rate of 2 mL/min. The column was thermostatted at 20 degrees C. The photodiode array detector monitored the eluent at 210 nm. The validation procedure confirmed that this technique affords reliable analysis of these components and is appropriate for the quality control of complex matrices, such as E. pallida roots and phytopharmaceuticals.

  9. 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.

  10. 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

    2016-09-02

    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

  11. 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.

  12. Charge heterogeneity profiling of monoclonal antibodies using low ionic strength ion-exchange chromatography and well-controlled pH gradients on monolithic columns.

    Science.gov (United States)

    Talebi, Mohammad; Nordborg, Anna; Gaspar, Andras; Lacher, Nathan A; Wang, Qian; He, Xiaoping Z; Haddad, Paul R; Hilder, Emily F

    2013-11-22

    In this work, the suitability of employing shallow pH gradients generated using single component buffer systems as eluents through cation-exchange (CEX) monolithic columns is demonstrated for the high-resolution separation of monoclonal antibody (mAb) charge variants in three different biopharmaceuticals. A useful selection of small molecule buffer species is described that can be used within very narrow pH ranges (typically 1 pH unit) defined by their buffer capacity for producing controlled and smooth pH profiles when used together with porous polymer monoliths. Using very low ionic strength eluents also enabled direct coupling with electrospray ionisation mass spectrometry. The results obtained by the developed pH gradient approach for the separation of closely related antibody species appear to be consistent with those obtained by imaged capillary isoelectric focusing (iCE) in terms of both resolution and separation profile. Both determinants of resolution, i.e., peak compression and peak separation contribute to the gains in resolution, evidently through the Donnan potential effect, which is increased by decreasing the eluent concentration, and also through the way electrostatic charges are distributed on the protein surface. Retention mechanisms based on the trends observed in retention of proteins at pH values higher than the electrophoretic pI are also discussed using applicable theories. Employing monolithic ion-exchangers is shown to enable fast method development, short analysis time, and high sample throughput owing to the accelerated mass transport of the monolithic media. The possibility of short analysis time, typically less than 15 min, and high sample throughput is extremely useful in the assessment of charge-based changes to the mAb products, such as during manufacturing or storage.

  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. [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.

  15. 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…

  16. 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.

  17. 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.

  18. Determination of anions using monolithic capillary column ion chromatography with end-to-end differential contactless conductometric detectors under resonance approach.

    Science.gov (United States)

    Zhang, Zhenli; Li, Dongdong; Liu, Xueyong; Subhani, Qamar; Zhu, Yan; Kang, Qi; Shen, Dazhong

    2012-06-21

    An end-to-end differential measurement approach with capacitively coupled contactless conductivity detection (C(4)D) was applied to anion-exchange monolithic capillary column ion chromatography. The column was prepared by thermally initiated radical polymerization of poly(glycidyl methacrylate) in a fused-silica capillary of 320 μm i.d. and modified by quaternary ammonium latex surface coating. Two C(4)Ds were placed near both ends of the capillary column and the output difference between them was measured. With 15 mM potassium hydrogen phthalate used as the eluent, good separation of a mixture of inorganic anions (F(-), Cl(-), NO(2)(-), NO(3)(-)) was achieved. The detection limits of conventional C(4)D are 1.6, 0.28, 0.53, and 0.47 mg L(-1) for F(-), Cl(-), NO(2)(-), and NO(3)(-), respectively. To further enhance the sensitivity, the capacitive impedance from C(4)D was neutralized by an inductive impedance from a piezoelectric resonator. An increase in sensitivity by a factor of 7-8 was achieved in the resonating C(4)D in comparison with the conventional C(4)D. The detection limits of the resonating C(4)D are 0.23, 0.041, 0.065, and 0.059 mg L(-1) for F(-), Cl(-), NO(2)(-), and NO(3)(-), respectively. The response of the resonating C(4)D was analyzed based on an equivalent circuit model.

  19. Determination of lycopene in food by on-line SFE coupled to HPLC using a single monolithic column for trapping and separation.

    Science.gov (United States)

    Pól, Jaroslav; Hyötylänen, Tuulia; Ranta-Aho, Outi; Riekkola, Marja-Liisa

    2004-10-15

    A method that would eliminate the degradation of lycopene during analysis was developed. Supercritical fluid extraction (SFE) with carbon dioxide as the extraction medium was connected on-line to high performance liquid chromatography (HPLC) where a single monolithic column was used for trapping and the subsequent separation of analytes. The method was linear over the studied range (0.1-2.5 microg), and it was repeatable (R.S.D. 3.9%), sensitive (LOD = 0.5 ng) and fast (35 min). Lycopene was determined in tomatoes, fruit and several food products. Because of the on-line construction, lycopene was not in contact with air or light during the whole procedure and the amount analysed should therefore correspond to the real amount in the sample.

  20. A sensitive and robust lc-ms/ms method with monolithic column and electrospray ionization for the quantitation of efavirenz in human plasma: application to a bioequivalence study

    Directory of Open Access Journals (Sweden)

    Danilo Cesar Galindo Bedor

    2011-01-01

    Full Text Available An LC-MS/MS method has been developed for the determination of efavirenz (EFZ in human plasma using hydrochlorothiazide as internal standard (I.S.. An ESI negative mode with multiple reaction-monitoring was used monitoring the transitions m/z 313.88→69.24 (EFZ and 296.02→204.76 (I.S.. Samples were extracted using liquid-liquid extraction. The total run time was 2.0 min. The separation was achieved with HPLC-RP using a monolithic column. The assay was linear in the concentration range of 100 - 5000 ng mL-1. The mean recovery was 83%. Intra- and inter-day precision were < 9.5% and < 8.9%, respectively and accuracy was in the range ± 8.33%. The method was successfully applied to a bioequivalence study.

  1. 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%.

  2. Influence of the polymerization-mixture composition for monolithic methacrylate-based columns on the electrochromatographic performance of drug molecules.

    Science.gov (United States)

    Tanret, Indiana; Mangelings, Debby; Vander Heyden, Yvan

    2008-09-29

    Methacrylate-based monolithic stationary phases were evaluated for the analysis of drug molecules using capillary electrochromatography (CEC) as separation technique. The effect of the polymerization-mixture composition on the retention behavior of a small test set of mainly drug molecules was studied. Two factors were varied in a central-composite design-based approach: the ratio between the pore-forming solvents and the monomers on one hand, and the ratio within the pore-forming solvents on the other hand, resulting in nine different stationary phases. The central point of the design was chosen at 70% (m/m) pore-forming solvents (PFS) of which 30% (m/m) is 1,4-butanediol, i.e. 21% of the total polymerization mixture. Experiments were conducted using both a basic (pH 11.5) and an acidic (pH 3) mobile phase. Retention times, retention factors, peak asymmetry and number of theoretical plates are the responses used to evaluate the performance of the resulting monoliths. The best compromise between the different responses was found around 67% PFS and 18% 1,4-butanediol (relative to the total mass), i.e. rather close to the center point. At these conditions, retention times were generally below 15min and retention factors below 5. Asymmetry values between close to 1 were found, and theoretical plate numbers up to 10,900, which were improvements compared to the central point of the design.

  3. 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.

  4. Facile one-pot synthesis of a aptamer-based organic-silica hybrid monolithic capillary column by "thiol-ene" click chemistry for detection of enantiomers of chemotherapeutic anthracyclines.

    Science.gov (United States)

    Jiang, Han-Peng; Zhu, Jiu-Xia; Peng, Chunyan; Gao, Jiajia; Zheng, Fang; Xiao, Yu-Xiu; Feng, Yu-Qi; Yuan, Bi-Feng

    2014-10-07

    In the current study, we developed a facile strategy for the one-pot synthesis of an aptamer-based organic-silica hybrid monolithic capillary column. A 5'-SH-modified aptamer, specifically targeting doxorubicin, was covalently modified in the hybrid silica monolithic column by a sol-gel method combined with "thiol-ene" click reaction. The prepared monolithic column had good stability and permeability, large specific surface, and showed excellent selectivity towards chemotherapeutic anthracyclines of doxorubicin and epirubicin. In addition, the enantiomers of doxorubicin and epirubicin can be easily separated by aptamer-based affinity monolithic capillary liquid chromatography. Furthermore, doxorubicin and epirubicin spiked in serum and urine were also successfully determined, which suggested that the complex biological matrix had a negligible effect on the detection of doxorubicin and epirubicin. Finally, we quantified the concentration of epirubicin in the serum of breast cancer patients treated with epirubicin by intravenous injection. The developed analytical method is cost-effective and rapid, and biological samples can be directly analyzed without any tedious sample pretreatment, which is extremely useful for monitoring medicines in serum and urine for pharmacokinetic studies.

  5. 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

  6. Sodium desoxycholate-assisted capillary electrochromatography with methacrylate ester-based monolithic column on fast separation and determination of coumarin analogs in Angelica dahurica extract.

    Science.gov (United States)

    Chen, Zhao; Wang, Jiajing; Chen, Danxia; Fan, Guorong; Wu, Yutian

    2012-09-01

    A rapid and sensitive CEC method with methacrylate ester-based monolithic column has been developed for separation and determination of five coumarins (byakangelicin, oxypeucedanin hydrate, xanthotoxol, 5-hydroxy-8-methoxypsoralen and bergapten) in Angelica dahurica extract. Surfactant sodium desoxycholate (SDC) was introduced into the mobile phase as the pseudostationary to dynamically increase the selectivity of analytes instead of increasing the hydrophobicity of stationary phase. In addition, other factors, pH of phosphate buffer, ACN content and applied voltage, for instance, have also an obvious effect on the resolution but little on the retention time. Satisfactory separation of these five coumarins was achieved within 6 min under a 30:70 v/v ACN-buffer containing 20 mM sodium dihydrogen phosphate (NaH(2) PO(4) ) and 0.25 mM SDC at pH 2.51. The RSDs of intraday and interday for relative peak areas were less than 3.0% and 4.7%, respectively; and the recoveries were between 87.5% and 95.0%. The LODs were lower than 0.15 μg/mL and the LOQs were lower than 0.30 μg/mL, respectively, while calibration curves showed a good linearity (r(2) > 0.9979). Finally, five target coumarins from the crude extracts of A. dahurica were separated, purified, and concentrated by D-101 macroporous resin, and were successfully separated and quantitatively determined within 6 min.

  7. Sonic spray ionization technology: performance study and application to a LC/MS analysis on a monolithic silica column for heroin impurity profiling.

    Science.gov (United States)

    Dams, Riet; Benijts, Tom; Günther, Wolfgang; Lambert, Willy; De Leenheer, André

    2002-07-01

    Sonic spray (SS) ionization is a relatively novel atmospheric pressure ionization technique for LC/MS, based on the principle of "spray ionization", which only recently became commercially available. In this paper, we evaluate the performance of this ion source as an interface for LC/MS in comparison with the more traditional and better studied pneumatically assisted electrospray or ion spray (IS). The effect of organic modifiers, volatile acids, and buffer systems in the LC eluent on the ionization efficiency of both interfaces is described and some possible explanations for the observed phenomena are highlighted. We could conclude that the presence of organic solvents gradually increased the ionization efficiency for IS and SS, while volatile acids or buffers gave a significant signal suppression. Furthermore, we present the application of the sonic spray interface to a fast LC/MS analysis, for the simultaneous determination of the seven prime opium alkaloids in heroin impurity profiling. Chromatographic separation is performed in 5 min on a monolithic silica column (Chromolith Performance) with a gradient elution system and an optimized flow of 5 mL/min. By means of a postcolumn split of approximately 1/20, a coupling between the fast LC system and the mass spectrometer is made. The method is validated and successfully applied to the analysis of real-time seized heroin street samples.

  8. 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.

  9. Validated method for bioactive lignans in Schisandra chinensis in vitro cultures using a solid phase extraction and a monolithic column application.

    Science.gov (United States)

    Brezinová, Lenka; Vlasínová, Helena; Havel, Ladislav; Humpa, Otakar; Slanina, Jirí

    2010-09-01

    A simple and rapid method for determination of six lignans found in plant cell cultures of Schisandra chinensis was developed and validated. The lignans were extracted from plant samples with methanol and the extracts were effectively cleaned by solid-phase extraction using Strata C18-E (Phenomenex) cartridges. Chromatographic separation was carried out on a Chromolith Performance RP-18e monolithic column (100 x 4.6 mm, Merck) using an isocratic mobile phase of acetonitrile and water in a 50:50 (v/v) ratio. The eluent was monitored at 220 nm. The baseline separation of schizandrin, gomisin A, deoxyschizandrin, gamma-schizandrin, gomisin N and wuweizisu C was achieved in a relatively short time period (20 min), which was made possible by the relatively high flow rate of the mobile phase (2 mL/min). The lower limit of quantitation was 0.1 mg/L for schizandrin and gomisin A, 0.3 mg/L for deoxyschizandrin, gamma-schizandrin, and gomisin N and 1 mg/L for wuweizisu C. The analysis of spiked samples containing six lignans provided absolute recoveries between 93 and 101% in all cases. The validated method was successfully applied to the determination of lignans in embryogenic plant cell cultures of Schisandra chinensis.

  10. Ultra-fast gradient LC method for omeprazole analysis using a monolithic column: assay development, validation, and application to the quality control of omeprazole enteric-coated pellets.

    Science.gov (United States)

    Borges, Keyller Bastos; Sánchez, Antonio José Macías; Pupo, Mônica Tallarico; Bonato, Pierina Sueli; Collado, Isidro González

    2010-01-01

    A method was optimized for the analysis of omeprazole (OMZ) by ultra-high speed LC with diode array detection using a monolithic Chromolith Fast Gradient RP 18 endcapped column (50 x 2.0 mm id). The analyses were performed at 30 degrees C using a mobile phase consisting of 0.15% (v/v) trifluoroacetic acid (TFA) in water (solvent A) and 0.15% (v/v) TFA in acetonitrile (solvent B) under a linear gradient of 5 to 90% B in 1 min at a flow rate of 1.0 mL/min and detection at 220 nm. Under these conditions, OMZ retention time was approximately 0.74 min. Validation parameters, such as selectivity, linearity, precision, accuracy, and robustness, showed results within the acceptable criteria. The method developed was successfully applied to OMZ enteric-coated pellets, showing that this assay can be used in the pharmaceutical industry for routine QC analysis. Moreover, the analytical conditions established allow for the simultaneous analysis of OMZ metabolites, 5-hydroxyomeprazole and omeprazole sulfone, in the same run, showing that this method can be extended to other matrixes with adequate procedures for sample preparation.

  11. 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.

  12. Sequential extraction of inorganic arsenic compounds and methyl arsenate in human urine using mixed-mode monolithic silica spin column coupled with gas chromatography-mass spectrometry.

    Science.gov (United States)

    Namera, Akira; Takeuchi, Akito; Saito, Takeshi; Miyazaki, Shota; Oikawa, Hiroshi; Saruwatari, Tatsuro; Nagao, Masataka

    2012-09-01

    A sequential analytical method was developed for the detection of arsenite, arsenate, and methylarsenate in human urine by gas chromatography-mass spectrometry (GC-MS). The combination of a derivatization of trivalent arsenic compounds by 2,3-dithio-1-propanol (British antilewisite; BAL) and a reduction of pentavalent arsenic compounds (arsenate and methylarsenate) were accomplished to carry out the analysis of arsenic compounds in urine. The arsenic derivatives obtained using BAL were extracted in a stepwise manner using a monolithic spin column and analyzed by GC-MS. A linear curve was observed for concentrations of arsenic compounds of 2.0 to 200 ng/mL, where the correlation coefficients of calibration curves were greater than 0.996 (for a signal-to-noise (S/N) ratio >10). The detection limits were 1 ng/mL (S/N > 3). Recoveries of the targets in urine were in the range 91.9-106.5%, and RSDs of the intra- and interday assay for urine samples containing 5, 50, and 150 ng/mL of arsenic compounds varied between 2.95 and 13.4%. The results from real samples obtained from a patient suspected of having ingested As containing medications using this proposed method were in good agreement with those obtained using high-performance liquid chromatography with inductively coupled plasma mass spectrometry.

  13. Preparation and modification of polyhedral oligomeric silsesquioxane-containing hybrid monolithic capillary columns%含多面体低聚倍半硅氧烷杂化毛细管整体柱的制备及修饰

    Institute of Scientific and Technical Information of China (English)

    欧俊杰; 林辉; 刘哲益; 张振宾; 董靖; 邹汉法

    2013-01-01

    Two kinds of hybrid monolithic capillary columns were prepared via free radical polymerization. First, the hybrid monolithic column was in situ fabricated by using two polyhedral oligomeric silsesquioxanes (POSS) , POSS-methacryl substituted ( cage mixture, n = 8 , 10, 12) (POSS-MA) and POSS-( 1-propylmethacrylate )-heptaisobutyl substituted ( Bu-POSS ) , as crosslinker and monomer, respectively, in the presence of porogenic solvents ( propanol/ PEG400) and initiator (azodisobutyronitrile). Second, the hybrid monolithic column was similarly prepared by using POSS-MA, as sole monomer under the same conditions. The resulting two kinds of hybrid monolithic columns, poly( Bu-POSS-co-POSS-MA) and poly ( POSS-MA) , were characterized and applied for the separation of alkylbenzenes by capillary liquid chroma-tography (cLC) , showing good mechanical stability and reproducibility. Additionally, the poly (POSS-MA) monolith could be easily modified with other organic monomers, such as stearyl methacrylate (SMA) and benzyl metacrylate (BeMA) , with the presence of methacryl groups on the surface of the poly( POSS-MA) monolith. Compared with the raw poly( POSS-MA) monolith, the post-modified poly (POSS-MA) monolith exhibited higher column efficiency and better selectivity. This simple process of using POSS reagents via free radical polymerization is providing a novel way for the preparation of the organic-silica hybrid monolithic columns.%本文采用自由基聚合法原位制备了两种杂化毛细管整体柱.首先以含有一个甲基丙烯酸基团的多面体低聚倍半硅氧烷(POSS)试剂(Bu-POSS)为单体、以含有多个甲基丙烯酸基团的POSS试剂(POSS-MA)为交联剂在二元致孔剂(正丙醇/聚乙二醇400)和引发剂(偶氮二异丁腈)存在下发生热引发聚合,在毛细管中形成聚(Bu-POSS-co-POSS-MA)杂化整体柱;另外仅以POSS-MA为单体在相同条件下制备聚(POSS-MA)杂化整体柱,并将这两种杂化整体柱应用于小

  14. 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”.

  15. Application of Tin(II Chloride Catalyst for High FFA Jatropha Oil Esterification in Continuous Reactive Distillation Column

    Directory of Open Access Journals (Sweden)

    Ratna Dewi Kusumaningtyas

    2016-03-01

    Full Text Available The application of heterogeneous solid acid catalysts in biodiesel production has become popular and gained significant attention over the last few years. It is since these types of catalysts hold the benefits in terms of easy separation from the product, reusability of the catalyst, high selectivity of the reaction. They are also considered sustainable and powerful particularly in organic synthesis. This work studied the use of tin(II chloride as solid Lewis acid catalyst to promote the esterification reaction of high Free Fatty Acid (FFA jatropha oil in continuous reactive distillation column. To obtain the optimum condition, the influences of reaction time, molar ratio of the reactant, and catalyst were investigated. It was revealed that the optimum condition was achieved at the molar ratio of methanol to FFA at 1:60, catalyst concentration of 5%, and reaction temperature of 60°C with the reaction conversion of 90%. This result was significantly superior to the identical reaction performed using batch reactor. The esterification of high FFA jatropha oil using reactive distillation in the presence of tin(II chloride provided higher conversion than that of Amberlyst-15 heterogeneous catalyst and was comparable to that of homogenous sulfuric acid catalyst, which showed 30 and 94.71% conversion, respectively. The esterification reaction of high FFA jatropha oil was subsequently followed by transesterification reaction for the completion of the biodiesel production. Transesterification was carried out at 60 °C, molar ratio of methanol to oil of 1:6, NaOH catalyst of 1%, and reaction time of one hour. The jatropha biodiesel product resulted from this two steps process could satisfy the ASTM and Indonesian biodiesel standard in terms of ester content (97.79 %, density, and viscosity. Copyright © 2016 BCREC GROUP. All rights reserved Received: 10th November 2015; Revised: 4th February 2016; Accepted: 4th February 2016 How to Cite: Kusumaningtyas

  16. 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.

  17. In situ sol-gel preparation of porous alumina monoliths for chromatographic separations of adenosine phosphates.

    Science.gov (United States)

    Zajickova, Zuzana; Rubi, Emir; Svec, Frantisek

    2011-06-03

    A method enabling the in situ preparation of porous alumina monoliths within 100 μm i.d. fused silica capillaries has been developed. These monoliths were prepared using the sol-gel process from a mixture consisting of an inorganic aluminum salt, a porogen, an epoxide, and a solvent. We investigated the effects of varying the preparation conditions on the physical characteristics of the monoliths with respect to their potential application in chromatographic separations. The best columns were obtained from a mixture of aluminum chloride hexahydrate, N,N-dimethylformamide, water, ethanol and propylene oxide. Adenosine phosphates were then separated in the optimized column with retention increasing according to number of phosphate functionalities.

  18. Effect of pore water velocities and solute input methods on chloride transport in the undisturbed soil columns of Loess Plateau

    Science.gov (United States)

    Zhou, BeiBei; Wang, QuanJiu

    2016-04-01

    Studies on solute transport under different pore water velocity and solute input methods in undisturbed soil could play instructive roles for crop production. Based on the experiments in the laboratory, the effect of solute input methods with small pulse input and large pulse input, as well as four pore water velocities, on chloride transport in the undisturbed soil columns obtained from the Loess Plateau under controlled condition was studied. Chloride breakthrough curves (BTCs) were generated using the miscible displacement method under water-saturated, steady flow conditions. Using the 0.15 mol L-1 CaCl2 solution as a tracer, a small pulse (0.1 pore volumes) was first induced, and then, after all the solution was wash off, a large pulse (0.5 pore volumes) was conducted. The convection-dispersion equation (CDE) and the two-region model (T-R) were used to describe the BTCs, and their prediction accuracies and fitted parameters were compared as well. All the BTCs obtained for the different input methods and the four pore water velocities were all smooth. However, the shapes of the BTCs varied greatly; small pulse inputs resulted in more rapid attainment of peak values that appeared earlier with increases in pore water velocity, whereas large pulse inputs resulted in an opposite trend. Both models could fit the experimental data well, but the prediction accuracy of the T-R was better. The values of the dispersivity, λ, calculated from the dispersion coefficient obtained from the CDE were about one order of magnitude larger than those calculated from the dispersion coefficient given by the T-R, but the calculated Peclet number, Pe, was lower. The mobile-immobile partition coefficient, β, decreased, while the mass exchange coefficient increased with increases in pore water velocity.

  19. Separation and Analysis of Organic Acids in Food by Capillary Silica Monolithic Column%毛细管硅胶整体柱分离分析食品中有机酸

    Institute of Scientific and Technical Information of China (English)

    高文惠; 杨桂君; 贾英民

    2012-01-01

    A capillary electrochromatographic method for the separation and analysis of organic acids in food was proposed using a capillary silica monolithic column.Optimization of experimental parameters that influence separation efficiency was carried out.A capillary silica monolithic C18 column was prepared in our lab for the separation of organic acids using a mobile phase(pH 5.2) consisting of 150 mmol/L sodium dihydrogen phosphate-60 mmol/L borax buffer solution with a final concentration of 5:2 in the mixture and 0.5 mmol/L cetyl trimethyl ammonium bromide.Other experimental conditions were as follows: voltage-6 kV;injection time 10 s;column temperature 25 ℃;and detection wavelength 200 nm.Results showed that the linear range was 10–1000 μg/mL for oxalic acid and fumaric acid,20–500 μg/mL for succinic acid,15–1000 μg/mL for tartaric acid and citric acid.The average recovery rates for the organic acids were between 89.8% and 101.1%,with a relative standard deviation(RSD) less than or equal to 6.23%(n = 5).The detection limits of the proposed methods were between 3.0 and 7.5 μg/mL.In conclusion,capillary silica monolithic column is inexpensive,stable to heat and organic solvents,and repeatedly usable.Capillary electrochromatography with capillary silica monolithic column allows simple,rapid and effective separation and analysis of organic acids in food.%建立应用毛细管硅胶整体柱采用毛细管电色谱法分离分析食品中有机酸的方法。对影响毛细管电色谱分离效率的条件进行优化,色谱柱为本实验室制作的毛细管硅胶整体C18柱(100μm×40cm)、电压-6kV、进样时间10s、紫外检测波长200nm,流动相为150mmol/L磷酸二氢钠-60mmol/L硼砂缓冲溶液(浓度比为5:2)和0.5mmol/L十六烷基三甲基溴化铵,pH7.5、25℃。结果表明:草酸和富马酸的线性范围为10~1000μg/mL,丁二酸线性范围20~500μg/mL,酒石酸和柠檬酸的线性范围为15~1000μg

  20. 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.

  1. Monolithic spectrometer

    Science.gov (United States)

    Rajic, Slobodan; Egert, Charles M.; Kahl, William K.; Snyder, Jr., William B.; Evans, III, Boyd M.; Marlar, Troy A.; Cunningham, Joseph P.

    1998-01-01

    A monolithic spectrometer is disclosed for use in spectroscopy. The spectrometer is a single body of translucent material with positioned surfaces for the transmission, reflection and spectral analysis of light rays.

  2. 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.

  3. 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...

  4. 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.

  5. Penicillin analyses by capillary electrochromatography-mass spectrometry with different charged poly(stearyl methacrylate-divinylbenzene) monoliths as stationary phases.

    Science.gov (United States)

    Liu, Wan-Ling; Wu, Ching-Yi; Li, Yi-Ting; Huang, Hsi-Ya

    2012-11-15

    This study describes the ability of an on-line concentration capillary electrochromatography (CEC) coupled with mass spectrometry (MS) for the determination of eight common penicillin antibiotics. Poly(stearyl methacrylate-divinylbenzene) (poly(SMA-DVB)) based monolithic columns prepared under the same conditions but differing only in the charged monomer were used as separation columns. Vinylbenzyl trimethylammonium chloride (VBTA) and vinylbenzenesulfonate (VBSA) were employed as the positively charged monolith and negatively charged monolith, respectively. Results indicated that poly(SMA-DVB-VBTA) monolithic column provided reproducible performance for penicillin separation through ion-exchange interaction, while the negatively charged poly(SMA-DVB-VBSA) column produced unstable separation due to the electrostatic repulsion between the electrophilic analytes and the negatively charged stationary phase. On-line concentration steps of step-gradient elution combined with anion selective injection (ASEI) were used to enhance the detection sensitivity of the CEC-MS method and all penicillin detection sensitivities were further improved (reduction in the limits of detection from 1.9-31 μg/L (normal injection mode) to 0.05-0.2 μg/L (on-line concentration mode)). Finally, this optimal on-line concentration CEC-MS method was applied to trace penicillin analyses in milk samples.

  6. Column preconcentration of gold by adsorbing AuCl4- onto methyltrioctyl ammonium chloride-naphthalene and subsequent atomic absorption spectrometric determination.

    Science.gov (United States)

    Behpour, M; Attaran, A M; Ghoreishi, S M; Soltani, N

    2005-05-01

    A sensitive, selective and simple preconcentration method for ultra-trace gold determination has been developed that uses naphthalene-methyltrioctyl ammonium chloride (Aliquat 336s) as an adsorbent. Gold, in the form of AuCl4-, was retained by the adsorbent in the column at a flow rate of 1 ml min(-1). After filtration, the solid mass consisting of the gold complex and naphthalene was dissolved out of the column with 5 ml of N,N-dimethylformamide (DMF), and the metal was then determined by atomic absorption spectrometry. In the initial solution, the calibration graph of absorbance versus gold concentration was found to be linear in the range 0.5-150 ng ml(-1) Au(III) with r=0.997 (n=9), and the 3 s detection limit was 0.428 ng ml(-1). The relative standard deviation for eight replicate measurements of 20 microg of gold was 2.14%. Preconcentration factors of 390 and 650 were achieved using 5 ml and 3 ml of DMF, respectively. The proposed method was successfully applied to the determination of gold in wastewater, processed pool water, slurry pool water, and raw well-water from the Moteh gold mine, and synthetic samples.

  7. Preparation and characterization of poly(triallyl isocyanurate-co-trimethylolpropane triacrylate) monolith and its applications in the separation of small molecules by liquid chromatography.

    Science.gov (United States)

    Zhong, Jing; Hao, Mengbei; Li, Ruo; Bai, Ligai; Yang, Gengliang

    2014-03-14

    A new polymeric monolith was prepared in stainless-steel column and fused-silica capillary, respectively, by atom transfer radical polymerization technique. In the polymerization, triallyl isocyanurate (TAIC) was used as the functional monomer; trimethylolpropane triacrylate (TMPTA) as the crosslinking agent; polyethylene glycol 200 and 1,2-propanediol as the co-porogens; carbon tetrachloride as the initiator and ferrous chloride as the catalyst. The conditions of polymerization were optimized. Morphology of the prepared poly(TAIC-co-TMPTA) monolith was investigated by scanning electron microscopy; pore properties were assayed by mercury porosimetry and nitrogen adsorption. The characterization indicated that the prepared reversed-phase monolith possessed uniform structure, good permeability and mechanical stability. The column was used as the stationary phase of reversed phase high performance liquid chromatography (RP-HPLC) and capillary liquid chromatography (CLC) to separate the mixture of aromatic compounds. The new column performed around 125,000 theoretical plates per meter. The column showed good reproducibility: the relative standard deviation values of the retention factor values for aromatic compounds were less than 1.52% (n=7, column-to-column).

  8. Porous polymer monolithic col

    Directory of Open Access Journals (Sweden)

    Lydia Terborg

    2015-05-01

    Full Text Available A new approach has been developed for the preparation of mixed-mode stationary phases to separate proteins. The pore surface of monolithic poly(glycidyl methacrylate-co-ethylene dimethacrylate capillary columns was functionalized with thiols and coated with gold nanoparticles. The final mixed mode surface chemistry was formed by attaching, in a single step, alkanethiols, mercaptoalkanoic acids, and their mixtures on the free surface of attached gold nanoparticles. Use of these mixtures allowed fine tuning of the hydrophobic/hydrophilic balance. The amount of attached gold nanoparticles according to thermal gravimetric analysis was 44.8 wt.%. This value together with results of frontal elution enabled calculation of surface coverage with the alkanethiol and mercaptoalkanoic acid ligands. Interestingly, alkanethiols coverage in a range of 4.46–4.51 molecules/nm2 significantly exceeded that of mercaptoalkanoic acids with 2.39–2.45 molecules/nm2. The mixed mode character of these monolithic stationary phases was for the first time demonstrated in the separations of proteins that could be achieved in the same column using gradient elution conditions typical of reverse phase (using gradient of acetonitrile in water and ion exchange chromatographic modes (applying gradient of salt in water, respectively.

  9. Research advance of polymer-based monoliths column for electrochromatography on a microfluidic chip%微流控芯片上电色谱聚合物整体柱研究进展

    Institute of Scientific and Technical Information of China (English)

    郑晖; 李秋顺; 马耀宏; 高广恒; 史建国

    2013-01-01

    Microfluidic chip technology is a recently rapidly developing area, which receives attention for its miniaturization, integration and automation. Electrochromatography is an important branch in the area. It has such advantages as high efficiency of conventional capillary electrophoresis and high selectivity of high-performance liquid chromatography. This paper surveys the status quo of manufacturing technology of electrochromatography coloumn and the research advance of polymer-based monoliths column on a microfluidic chip.%微流控芯片是近年来发展迅速的一个研究领域,其微型化、集成化、自动化的特性为人们所关注.芯片电色谱是微流控芯片的一个重要研究方向,兼具高效液相色谱的高选择性和毛细管电泳的高效性.本文介绍了芯片电色谱柱制造工艺的研究现状,并综述了微流控芯片上聚合物整体柱的研究进展.

  10. Comparison of a new high-resolution monolithic column with core-shell and fully porous columns for the analysis of retinol and α-tocopherol in human serum and breast milk by ultra-high-performance liquid chromatography.

    Science.gov (United States)

    Kučerová, Barbora; Krčmová, Lenka; Solichová, Dagmar; Plíšek, Jiří; Solich, Petr

    2013-07-01

    The reduction of analysis time, cost, and improvement of separation efficiency are the main requirements in the development of high-throughput assay methods in bioanalysis. It can be achieved either by ultra-high-performance liquid chromatography (UHPLC) using stationary phases with small particles (separation efficiency, peak shape, resolution, time of analysis, consumption of mobile phase, and lifetime of columns were calculated and compared. The main purpose of the study was to find a new, not only economical option of separation of liposoluble vitamins for routine practice.

  11. Comparison of perfusion media and monoliths for protein and virus-like particle chromatography.

    Science.gov (United States)

    Wu, Yige; Abraham, Dicky; Carta, Giorgio

    2016-05-20

    Structural and performance characteristics of perfusion chromatography media (POROS HS 20 and 50) and those of a polymethacrylate monolith (CIM SO3-1 tube monolith column) are compared for protein and virus-like particle chromatography using 1mL columns. Axial flow columns are used for POROS while the monolith has a radial flow configuration, which provides comparable operating pressures. The POROS beads contain a bimodal distribution of pore sizes, some as large as 0.5μm, which allow a small fraction of the mobile phase to flow within the particles, while the monolith contains 1-2μm flow channels. For proteins (lysozyme and IgG), the dynamic binding capacity of the POROS columns is more than twice that of the monolith at longer residence times. While the DBC of the POROS HS 50 column decreases at shorter residence times, the DBC of the POROS HS 20 column for IgG remains nearly twice that of the monolith at residence times at least as low as 0.2min as a result of intraparticle convection. Protein recoveries are comparable for all three columns. For VLPs, however, the eluted peaks are broader and recovery is lower for the monolith than for the POROS columns and is dependent on the direction of flow in the monolith, which is attributed to denser layer observed by SEM at the inlet surface of the monolith that appears to trap VLPs when loading in the normal flow direction.

  12. 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.

  13. Preparation of a zeolite-modified polymer monolith for identification of synthetic colorants in lipsticks

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Huiqi; Li, Zheng [College of Chemistry, Jilin University, Changchun 130012 (China); Niu, Qian [Jilin Entry-Exit Inspection and Quarantine Bureau, Changchun 130062 (China); Ma, Jiutong [College of Chemistry, Jilin University, Changchun 130012 (China); Jia, Qiong, E-mail: jiaqiong@jlu.edu.cn [College of Chemistry, Jilin University, Changchun 130012 (China)

    2015-10-30

    Graphical abstract: Poly(methacrylic acid-ethylene dimethacrylate) monolithic column embedded with zeolites was prepared and employed for the polymer monolith microextraction of colorants combined with HPLC. - Highlights: • Zeolite, as a kind of mesoporous material, was firstly combined with PMME. • Zeolite@poly(MAA-EDMA) monolith columns were prepared for the enrichment of colorants. • Zeolite@poly(MAA-EDMA) monolith columns demonstrated relatively high extraction capacity. - Abstract: A novel zeolite-modified poly(methacrylic acid-ethylenedimethacrylate) (zeolite@poly(MAA-EDMA)) monolithic column was prepared with the in situ polymerization method and employed in polymer monolith microextraction for the separation and preconcentration of synthetic colorants combined with high performance liquid chromatography. The polymer was characterized by scanning electronmicroscopy, Fourier-transform infrared spectroscopy, X-ray photoelectron spectroscopy, and thermo-gravimetric analysis. Various parameters affecting the extraction efficiency were investigated and optimized. Under the optimum experimental conditions, we obtained acceptable linearities, low limits of detection, and good intra-day/inter-day relative standard deviations. The method was applied to the determination of synthetic colorants in lipsticks with recoveries ranged from 70.7% to 109.7%. Compared with conventional methacrylic acid-based monoliths, the developed monolith exhibited high enrichment capacity because of the introduction of zeolites into the preparation process. The extraction efficiency followed the order: zeolite@poly(MAA-EDMA) > poly(MAA-EDMA) > direct HPLC analysis.

  14. 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).

  15. 阳离子交换毛细管整体柱的制备及其在毛细管离子色谱中的应用%Preparation and Application of Cation-exchange Capillary Monolithic Column in Capillary Ion Chromatography

    Institute of Scientific and Technical Information of China (English)

    李晶; 朱岩

    2013-01-01

    Polymer-based cation exchange capillary monolithic column was prepared for capillary ion chromatography (CIC) by radical polymerization in a 320-μm-i. d. fused-silica capillary tube, taking glycidyl methacrylate ( GMA ) as the functional monomer, ethylene dimethacrylate ( EDMA) as the cross-linking agent and in the presence of 1 ,4-butanediol, 1-propanol and water as the porogen solvents and azobisisobutyronitrile (AIBN) as a suitable initiator. Introduction of cation exchange sites was achieved by reacting with Na2SO3. Coupled with the prepared cation exchange capillary monolithic column, a capillary ion chromatography system was constructed with a pump (in μL/min level) , a capillary detection cell and a UV detector, on which more chromatographic characteristics were further studied. With the CIC system, 9 common univalent and divalent cations (Li+ , Na+ , NH4+ , K+ , Cs+ , Mg2+, Ca2+ , Sr2+, Ba2+) were successfully separated and determined by flow rate gradient. Another interesting separation of cations and melamine was also tested on the prepared column.%以甲基丙烯酸缩水甘油酯(GMA)为功能单体,亚乙基二甲基丙烯酸酯(EDMA)为交联剂,偶氮二异丁腈(AIBN)为自由基引发剂,在三元致孔剂(正丙醇,1,4-丁二醇,水)的存在下,在320μm内径的弹性石英毛细管柱内制备得到带有环氧功能基团的聚合物整体柱基质;利用Na2SO3对其改性,制备得到磺酸基型阳离子交换毛细管整体柱.采用微流泵、毛细管检测池和紫外检测器构建了毛细管离子色谱系统,并对所制备的整体柱的流体力学参数、色谱性能参数进行评价;采用流速梯度洗脱的方式实现9种常见阳离子(Li+,Na+,NH4+,K+,Cs+,Mg2+,Ca2+,Sr2+,Ba2+)的分离分析;此色谱系统还可应用于牛奶中阳离子和三聚氰胺的分离检测.

  16. Construction and Evaluation of Continuous Two-dimensional Open-tubular Ion Exchange/Reversed Phase Monolithic Column Capillary Electrochromatography System%连续二维开管离子交换/反相整体柱毛细管电色谱的构建与评价

    Institute of Scientific and Technical Information of China (English)

    朱亚仙; 张凌怡; 雷雯; 张维冰

    2011-01-01

    在毛细管中原位合成反相整体色谱柱,并在同一根毛细管柱中的其余部分通过在内表面涂覆N-[3-(三甲氧基硅烷)-丙基)]-乙二胺(PEDA)使其具有离子交换功能,制备成连续二维开管离子交换/反相整体柱毛细管电色谱柱.通过对7种有机酸的分离探讨了开管柱中离子交换对分离的影响,进一步以天麻提取物为样品,对二维分离系统加以评价,出峰数量达到34个.在构建的新型电色谱柱系统中,可以通过电渗流、电泳流以及溶质与固定相的作用同时对分离选择性加以调节,适用于强疏水性和强亲水性同时存在的复杂样品的分析方法的建立.%A continuous two-dimensional open-tubular ion exchange/reversed phase monolithic column capillary electrochromatography system was developed. Reversed phase monolithic column was firstly synthesized in the end part of the capillary, then N-[3-(trimethoxysilyl)-propyl]-ethlenediamine was surface coated to the other part of the capillary. The separation of seven organic acids verified the effect on the separation of ion exchange in the open-tubular capillary. Rhizoma gastrodiae was separated to evaluate the system, and 34 peaks were recognized. This system is designed for complex samples with highly hydrophobicity components and highly hydrophilicity components simultaneous. This new column system combining advantages of multidimensional separation and adjusted stationary phase selectivity is suitable for the analysis method development of complicated samples.

  17. Preparation and Characterization of Temperature-responsive Porous Monoliths

    Institute of Scientific and Technical Information of China (English)

    ZHANG, Rongyue; QI, Li; XIN, Peiyong; YANG, Gengliang; CHEN, Yi

    2009-01-01

    A new temperature-responsive porous monolith has been prepared by surface-initiated activators generated by electron transfer atom transfer radical polymerization (AGET ATRP) grafting poly(N-isopropylacrylamide) (PNIPAAm) within the pores of the porous polymer monolith. The grafting copolymerization was carried out by a method based on a continuous flow-through technique without special deoxygenation procedure needed in the general ATRP. The addition of ascorbic acid could counteract the oxidation effect of oxygen diffusing into the reaction system. The resulting grafted monolith was characterized by a mercury intrusion method and the size of macropore was 3.65 μm, which was suitable for flow through the monolith for HPLC. The thermally responsive property of the grafted monolith was evaluated by HPLC using steroids with various hydrophobicities as probes. Through determination of retention factor of each steroid on the grafted monolith at different temperatures using water as mobile phase, it was found that the slope of the plot of retention factor of each steroid versus the temperature changed around the low critical solution temperature (LCST, 32 ℃) of PNIPAAm in water. It was relative to the grafted PNIPAAm temperature sensitivity that a hydrophobic and hydrophilic alternation would take place around its LCST.Based on this thermally responsive property, the grafted monolith was used as stationary phase for HPLC and to separate the steroids using water as mobile phase by changing the column temperature. As a mobile phase, water is much better than organic solvents concerning the environment.

  18. High-performance liquid chromatographic assay for catecholamines and metanephrines using fluorimetric detection with pre-column 9-fluorenylmethyloxycarbonyl chloride derivatization.

    Science.gov (United States)

    Chan, E C; Wee, P Y; Ho, P Y; Ho, P C

    2000-12-01

    A convenient HPLC-fluorescent assay of norepinephrine (NE), epinephrine (E), dopamine (DA) and their 3-O-methylated metabolites, normetanephrine (NM) and metanephrine (MN) was developed. These analytes were coupled to 9-fluorenylmethyloxycarbonyl chloride (FMOC-Cl) before assays. Results showed that using a linear gradient elution, peaks of FMOC-NE, FMOC-E, FMOC-DA, FMOC-NM, FMOC-MN and FMOC-DHBA (3,4-dihydroxybenzylamine, internal standard) were simultaneously resolved within 40 min. Optimization of the chromatographic and derivatization conditions, and validation of the assay were further discussed in the paper. The structures of these derivatives were confirmed by atmospheric pressure chemical ionization mass spectrometry (APCI-MS). The molecular ions [M+H]- of FMOC-NE, FMOC-E, FMOC-DA, FMOC-NM and FMOC-MN were m/z 836, 850, 820, 628 and 642, respectively. Based on these findings, the FMOC-derivatives of metanephrines and catecholamines were confirmed to be bi-substituted and tri-substituted respectively at the amino and catechol functional groups. Finally, the assay was successfully applied to the measurement of urinary E, DA, NM and MN after direct derivatization and simple cleaning.

  19. Molecularly imprinted macroporous monolithic materials for protein recognition

    Institute of Scientific and Technical Information of China (English)

    Qi Liang Deng; Yan Li Li; Li Hua Zhang; Yu Kui Zhang

    2011-01-01

    Synthetic materials that can specifically recognize proteins will find wide application in many fields. In this report, bovine serum albumin was chosen as the template protein. Acrylamide and N, N'-methylenebisacrylamide were employed as the functional and cross-linker monomers, respectively. Molecularly imprinted macroporous monolithic materials that can preferentially bind the template protein in an aqueous environment were prepared by combination of molecular imprinting technique and freezing/thawing preparation method. The resulted imprinted macroporous monolithic columns were evaluated by utilizing as stationary phase in high performance liquid chromatography and solid-phase extraction materials. The experimental results indicated that the imprinted macroporous monolithic column exhibited good recognition for template protein, as compared with the control protein (hemoglobin), whereas the non-imprinted polymer (prepared under the same conditions except without addition template protein) had no selective properties.

  20. 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.

  1. Convective Interaction Media (CIM)--short layer monolithic chromatographic stationary phases.

    Science.gov (United States)

    Podgornik, Ales; Strancar, Ales

    2005-01-01

    Modern downstream processing requires fast and highly effective methods to obtain large quantities of highly pure substances. Commonly applied method for this purpose is chromatography. However, its main drawback is its throughput since purification, especially of large molecules, requires long process time. To overcome this problem several new stationary phases were introduced, among which short layer monoliths show superior properties for many applications. The purpose of this review is to give an overview about short methacrylate monolithic columns commercialised under the trademark Convective Interaction Media (CIM). Their unique properties are described from different perspectives, explaining reasons for their application on various areas. Approaches to prepare large volume methacrylate monolithic column are discussed and optimal solutions are given. Different examples of CIM monolithic column implementation are summarised in the last part of the article to give the reader an idea about their advantages.

  2. Quantitative determination of the macrolide antibiotics erythromycin, roxithromycin, azithromycin and clarithromycin in human serum by high-performance liquid chromatography using pre-column derivatization with 9-fluorenylmethyloxycarbonyl chloride and fluorescence detection.

    Science.gov (United States)

    Sastre Toraño, J; Guchelaar, H J

    1998-12-11

    A validated, highly sensitive and precise high-performance liquid chromatographic (HPLC) method for the determination of the macrolides erythromycin, azithromycin, clarithromycin and roxithromycin in human serum is described. A diethyl ether extract, obtained from serum using a saturated sodium carbonate solution, was treated with 9-fluorenylmethyl-oxycarbonyl chloride (FMOC-Cl) for 40 min at 40 degrees C and chromatographed on a base-deactivated octadecyl column, maintained at 50 degrees C during elution, using an eluent composed of acetonitrile-hydrogenphosphate buffer, pH 7.5, with 0.125% triethylamine (3:2, v/v). Fluorescence detection was used at an excitation wavelength of 255 nm and an emission wavelength of 315 nm. Erythromycin, clarithromycin, roxithromycin and azithromycin were found to have retention times of 8.8, 15.7, 17.1 and 20.7 min, respectively. Recoveries ranging from 93 to 104% were found with reproducibility coefficients of variation of 1.1-5%. Mean correlation coefficients of 0.9997, 0.9998, 0.9996 and 0.9994 were found for the linear calibration curves (n = 2) of erythromycin (0.320-16.1 mg/l), roxithromycin (3.24-19.4 mg/l), clarithromycin (0.190-19.4 mg/l) and azithromycin (0.0988-4.94 mg/l), respectively.

  3. Preparation of Anion-exchange Polymer-based Monolithic Column and Its Application in Ion Chromatography%阴离子交换聚合物整体柱的制备及其在离子色谱中的应用

    Institute of Scientific and Technical Information of China (English)

    李晶; 周琰春; 张嘉捷; 朱岩

    2012-01-01

    An anion-exchange monolithic column was prepared by a polymerization inside a stainless steel tube( 150 mm x 4. 6 i. d. mm) , taking glycidyl methacrylate( GMA) as functional monomer, ethylene dimethacrylate ( EDMA) as cross-linking agent and in the presence of 1, 4-butanediol, 1 -propanol and water as the porogen solvents and azobisisobutyronitrile ( AIBN) as a suitable initiator. Introduction of anion-exchange sites were achieved by reacting with tirmethylamine. Under the optimized reaction conditions and the modified conditions, the chromatographic characteristics of the prepared anion-exchange columns were further studied, and the separation of 5 common anions ( such as, acetate, bromate, nitrite, bromide, nitrate) on the prepared anion-exchange column was investigated. The prepared column exhibits more advantages such as simple preparation and low cost, and could be coupled with a commercial ion chromatography system directly, which will be favorable for more applications and investigations.%以偶氮二异丁腈( AIBN)为自由基引发剂,将甲基丙烯酸缩水甘油酯(GMA)单体和亚乙基二甲基丙烯酸酯(EDMA)交联剂通过原位聚合的方法,在不锈钢管柱(150 mm ×4.6 i.d.mm)中合成为具有一定机械性能和一定孔径结构的聚合物整体色谱柱;利用三甲胺动态修饰反应将整体柱改性为具有阴离子交换功能的整体型离子色谱分离柱.实验优化了制备条件和改性修饰条件,考察了相关离子交换容量、流体动力学参数和色谱性能等.采用直接紫外检测的方法,在205 nm检测波长下,常规阴离子乙酸根、溴酸根、亚硝酸根、溴离子、硝酸根均能得到较好的分离检测.结果表明,该阴离子交换整体色谱柱制备方法简便,成本较低,可以方便地与常规色谱系统进行联用,具有一定分析实用价值和较大的开发前景.

  4. Embedded-monolith armor

    Science.gov (United States)

    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.

  5. 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.

  6. Facile preparation of organic-silica hybrid monolith for capillary hydrophilic liquid chromatography based on "thiol-ene" click chemistry.

    Science.gov (United States)

    Chen, Ming-Luan; Zhang, Jun; Zhang, Zheng; Yuan, Bi-Feng; Yu, Qiong-Wei; Feng, Yu-Qi

    2013-04-05

    In this work, a one-step approach to facile preparation of organic-inorganic hybrid monoliths was successfully developed. After vinyl-end organic monomers and azobisisobutyronitrile (AIBN) were mixed with hydrolyzed tetramethoxysilane (TMOS) and 3-mercaptopropyltrimethoxysilane (MPTMS), the homogeneous mixture was introduced into a fused-silica capillary for simultaneous polycondensation and "thiol-ene" click reaction to form the organic-silica hybrid monoliths. By employing this strategy, two types of organic-silica hybrid monoliths with positively charged quaternary ammonium and amide groups were prepared, respectively. The functional groups were successfully introduced onto the monoliths during the sol-gel process with "thiol-ene" click reaction, which was demonstrated by ζ-potential assessment, energy dispersive X-ray spectroscopy (EDX), and Fourier transform infrared (FT-IR) spectroscopy. The porous structure of the prepared monolithic columns was examined by scanning electron microscopy (SEM), nitrogen adsorption-desorption measurement, and mercury intrusion porosimetry. These results indicate the prepared organic-silica hybrid monoliths possess homogeneous column bed, large specific surface area, good mechanical stability, and excellent permeability. The prepared monolithic columns were then applied for anion-exchange/hydrophilic interaction liquid chromatography. Different types of analytes, including benzoic acids, inorganic ions, nucleosides, and nucleotides, were well separated with high column efficiency around 80,000-130,000 plates/m. Taken together, we present a facile and universal strategy to prepare organic-silica hybrid monoliths with a variety of organic monomers using one-step approach.

  7. Preparation of strong cation-exchange monolithic column and its application in polypeptide separation by capillary electrochromatography%强阳离子交换整体柱的研制及其在电色谱多肽分离中的应用

    Institute of Scientific and Technical Information of China (English)

    齐楠; 崔瑞红; 尤慧艳

    2011-01-01

    以丙烯酸、2-丙烯酰胺-2-甲基丙磺酸为功能单体,N,N'-亚甲基双丙烯酰胺为交联剂,正十二醇、1,4-丁二醇及二甲基亚砜为致孔剂,偶氮二异丁腈为引发剂,原位聚合制备了丙烯酰胺类强阳离子交换整体柱.考察了驱动电压、有机调节剂、盐浓度、pH值等对电渗流的影响.结果表明,电渗流与驱动电压的线性关系良好,相关系数为0.998 1;有机调节剂乙腈对电渗流的影响除与流动相的黏度有关外,还与同定相的溶胀有关,当浓度低时,电渗流随乙腈浓度的增加有反常的下降趋势;随着磷酸盐浓度逐渐增加,电渗流降低,与理论相符;在pH值为3~9范围内,电渗流基本上保持恒定,体现了整体柱使用酸碱范围宽的优越性.在优化的实验条件下,采用毛细管电色谱法在此整体柱上成功分离了5种多肽,体现了该类整体柱在多肽分离研究中的优势,为进一步将其应用于蛋白质分离研究打下了基础.%A strong cation-exchange monolithic column was prepared by polymerization inside the fused-silica capillary. The solution consisted of acrylic acid and 2-acrylamido-2-methyl-l-propanesulfonic acid as functional monomers, 7V,AT'-methyIenebisacrylamide as a cross-linking agent, dimethyl sulphoxide and dodecanol, 1,4-butanediol as organic porogenic solvents and azobisisobutyronitrile as a suitable initiator. The effects of the applied voltage, concentrations of organic modifier and salt solution, pH value on the electroosmotic flow were investigated. The experimental results showed that there existed a good linear relationship between the applied voltage and electroosmotic flow with a correlation coefficient of 0. 998 1 ; When the concentration of organic modifier (acetonitrile, CAN) was less than 70% , the swelling degree of stationary phase played a main role and the electroosmotic flow was decreased abnormally with the increase of CAN concentration; The electroosmotic flow

  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. 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.

  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. A novel ionic liquid-modified organic-polymer monolith as the sorbent for in-tube solid-phase microextraction of acidic food additives.

    Science.gov (United States)

    Wang, Ting-Ting; Chen, Yi-Hui; Ma, Jun-Feng; Hu, Min-Jie; Li, Ying; Fang, Jiang-Hua; Gao, Hao-Qi

    2014-08-01

    A novel ionic liquid-modified organic-polymer monolithic capillary column was prepared and used for in-tube solid-phase microextraction (SPME) of acidic food additives. The primary amino group of 1-aminopropyl-3-methylimidazolium chloride was reacted with the epoxide group of glycidyl methacrylate. The as-prepared new monomer was then copolymerized in situ with acrylamide and N,N'-methylenebisacrylamide in the presence of polyethylene glycol (PEG)-8000 and PEG-10,000 as porogens. The extraction performance of the developed monolithic sorbent was evaluated for benzoic acid, 3-hydroxybenzoic acid, cinnamic acid, 2,4-dichlorophenoxyacetic acid, and 3-(trifluoromethyl)-cinnamic acid. Such a sorbent, bearing hydrophobic and anion-exchange groups, had high extraction efficiency towards the test compounds. The adsorption capacities for the analytes dissolved in water ranged from 0.18 to 1.74 μg cm(-1). Good linear calibration curves (R(2) > 0.99) were obtained, and the limits of detection (S/N = 3) for the analytes were found to be in the range 1.2-13.5 ng mL(-1). The recoveries of five acidic food additives spiked in Coca-Cola beverage samples ranged from 85.4 % to 98.3 %, with RSD less than 6.9 %. The excellent applicability of the ionic liquid (IL)-modified monolithic column was further tested by the determination of benzoic acid content in Sprite samples, further illustrating its good potential for analyzing food additives in complex samples.

  12. Development of an epoxy-based monolith used for the affinity capturing of Escherichia coli bacteria.

    Science.gov (United States)

    Peskoller, Caroline; Niessner, Reinhard; Seidel, Michael

    2009-05-01

    An epoxy-based monolith has been developed for use as hydrophilic support in bioseparation. This monolith is produced by self-polymerization of polyglycerol-3-glycidyl ether in organic solvents as porogens at room temperature within 1 h. One receives a highly cross-linked structure that provides useful mechanical properties. The porosity and pore diameter can be controlled by varying the composition of the porogen. In this work, an epoxy-based monolith with a high porosity (79%) and large pore size (22 microm) is prepared and used in affinity capturing of bacterial cells. These features allow the passage of bacterial cells through the column. As affinity ligand polymyxin B is used, which allows the binding of gram-negative bacteria. The efficiency of the monolithic affinity column is studied with Escherichia coli spiked in water. Bacterial cells are concentrated on the column at pH 4 and eluted with a recovery of 97+/-3% in 200 microL by changing the pH value without impairing viability of bacteria. The dynamic capacity for the monolithic column is nearly independent of the flow rate (4x10(9)cells/column). Thereby, it is possible to separate and enrich gram-negative bacterial cells, such as E. coli, with high flow rates (10 mL/min) and low back pressure (<1 bar) in a volume as low as 200 microL compatible for real-time polymerase chain reaction, microarray formats, and biosensors.

  13. 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.

  14. 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

  15. Design of monoliths through their mechanical properties.

    Science.gov (United States)

    Podgornik, Aleš; Savnik, Aleš; Jančar, Janez; Krajnc, Nika Lendero

    2014-03-14

    Chromatographic monoliths have several interesting properties making them attractive supports for analytics but also for purification, especially of large biomolecules and bioassemblies. Although many of monolith features were thoroughly investigated, there is no data available to predict how monolith mechanical properties affect its chromatographic performance. In this work, we investigated the effect of porosity, pore size and chemical modification on methacrylate monolith compression modulus. While a linear correlation between pore size and compression modulus was found, the effect of porosity was highly exponential. Through these correlations it was concluded that chemical modification affects monolith porosity without changing the monolith skeleton integrity. Mathematical model to describe the change of monolith permeability as a function of monolith compression modulus was derived and successfully validated for monoliths of different geometries and pore sizes. It enables the prediction of pressure drop increase due to monolith compressibility for any monolith structural characteristics, such as geometry, porosity, pore size or mobile phase properties like viscosity or flow rate, based solely on the data of compression modulus and structural data of non-compressed monolith. Furthermore, it enables simple determination of monolith pore size at which monolith compressibility is the smallest and the most robust performance is expected. Data of monolith compression modulus in combination with developed mathematical model can therefore be used for the prediction of monolith permeability during its implementation but also to accelerate the design of novel chromatographic monoliths with desired hydrodynamic properties for particular application.

  16. High surface area, high permeability carbon monoliths

    Energy Technology Data Exchange (ETDEWEB)

    Lagasse, R.R.; Schroeder, J.L. [Sandia National Labs., Albuquerque, NM (United States). Organic Materials Processing Dept.

    1994-12-31

    The goal of this work is to prepare carbon monoliths having precisely tailored pore size distribution. Prior studies have demonstrated that poly(acrylonitrile) can be processed into a precursor having tailored macropore structure. Since the macropores were preserved during pyrolysis, this synthetic process provided a route to porous carbon having macropores with size =0.1 to 10{mu}m. No micropores of size <2 nm could be detected in the carbon, however, by nitrogen adsorption. In the present work, the authors have processed a different polymer, poly(vinylidene chloride) into a macroporous precursor, Pyrolysis produced carbon monoliths having macropores derived from the polymer precursor as well as extensive microporosity produced during the pyrolysis of the polymer. One of these carbons had BET surface area of 1,050 m{sup 2}/g and about 1.2 cc/g total pore volume, with about 1/3 of the total pore volume in micropores and the remainder in 1{mu}m macropores. No mesopores in the intermediate size range could be detected by nitrogen adsorption. Carbon materials having high surface area as well as micron size pores have potential applications as electrodes for double layer supercapacitors containing liquid electrolyte, or as efficient media for performing chemical separations.

  17. Separation of Immunoglobulin in Conjunction with High Performance Liquid Chromatography Using Poly(vinyl ester resin) Monolith

    Institute of Scientific and Technical Information of China (English)

    YANG,Guanqun; YANG,Gengliang; LIU,Haiyan; BAI,Ligai; FENG,Xiaojuan; YANG,Xinru

    2009-01-01

    Using vinyl ester resin both as the monomer and the crosslinker,2,2-azobis(2-methylpropionitrile) (AIBN) as initiator,poly(vinyl ester resin) monolithic column was prepared to separate the immunoglobulin G (lgG) and yolk of eggs (lgY) from human plasma and egg yolk by HPLC respectively.The influence of concentration and pH of mobile phase on the chromatographic performance was investigated.Scanning electron microcopy showed that the poly(vinyl ester resin) monolithic stationary phase had a through-pore structure.Dynamic capacity of IgG on the polymeric monolithic column was investigated.The monolithic column had good flow-through properties and high resolution.The maximum adsorptive amount of IgG was 144 μg·g-1.

  18. 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

  19. Reading Columns

    OpenAIRE

    Coutts, Marion

    2008-01-01

    Reading Columns are twin permanent public sculptures commissioned as part of a £245m scheme for the redevelopment of the Chatham Place area in Reading. Dimensions: 3.5m high x 1.3m diameter each Field of knowledge: The work consists of twin bespoke columns of stainless steel and glass over digital colour transparencies. The piece revisits and reworks the idea of the Morris Column, a 19th C feature characteristic of major European metropolitan centres. A wraparound image on each of ...

  20. Application of two types of CIM tube column for purification of microbial enzymes.

    Science.gov (United States)

    Isobe, Kimiyasu; Kawakami, Yoshimitsu

    2005-02-11

    Chromatography conditions for two types of convection interaction media (CIM) tube monolithic column, DEAE-8 and C4-8, were investigated using three enzymes from different microorganisms. The enzymes were adsorbed on a CIM DEAE-8 tube column under the same conditions as conventional DEAE columns. The CIM C4-8 tube column required a high concentration of ammonium sulfate compared to the conventional C4 column for adsorbing the enzymes. The separation of enzymes on the CIM tube column chromatography was not affected at flow rates between 0.15 and 1.25 volumes of the column per min. Both columns were successfully applied to the purification of enzymes from crude enzyme solution. Thus, both CIM tube monolithic columns proved useful in greatly reducing the purification time, and could be used at any stage of enzyme purification.

  1. Design and evaluation of synthetic silica-based monolithic materials in shrinkable tube for efficient protein extraction.

    Science.gov (United States)

    Alzahrani, Eman; Welham, Kevin

    2011-10-21

    Sample pretreatment is a required step in proteomics in order to remove interferences and preconcentrate the samples. Much research in recent years has focused on porous monolithic materials since they are highly permeable to liquid flow and show high mass transport compared with more common packed beds. These features are due to the micro-structure within the monolithic silica column which contains both macropores that reduce the back pressure, and mesopores that give good interaction with analytes. The aim of this work was to fabricate a continuous porous silica monolithic rod inside a heat shrinkable tube and to compare this with the same material whose surface has been modified with a C(18) phase, in order to use them for preconcentration/extraction of proteins. The performance of the silica-based monolithic rod was evaluated using eight proteins; insulin, cytochrome C, lysozyme, myoglobin, β-lactoglobulin, ovalbumin, hemoglobin, and bovine serum albumin at a concentration of 60 μM. The results show that recovery of the proteins was achieved by both columns with variable yields; however, the C(18) modified silica monolith gave higher recoveries (92.7 to 109.7%) than the non-modified silica monolith (25.5 to 97.9%). Both silica monoliths can be used with very low back pressure indicating a promising approach for future fabrication of the silica monolith inside a microfluidic device for the extraction of proteins from biological media.

  2. Monolithic microchannel heatsink

    Science.gov (United States)

    Benett, William J.; Beach, Raymond J.; Ciarlo, Dino R.

    1996-01-01

    A silicon wafer has slots sawn in it that allow diode laser bars to be mounted in contact with the silicon. Microchannels are etched into the back of the wafer to provide cooling of the diode bars. To facilitate getting the channels close to the diode bars, the channels are rotated from an angle perpendicular to the diode bars which allows increased penetration between the mounted diode bars. This invention enables the fabrication of monolithic silicon microchannel heatsinks for laser diodes. The heatsinks have low thermal resistance because of the close proximity of the microchannels to the laser diode being cooled. This allows high average power operation of two-dimensional laser diode arrays that have a high density of laser diode bars and therefore high optical power density.

  3. Monolithic silica-based capillary reversed-phase liquid chromatography/electrospray mass spectrometry for plant metabolomics

    NARCIS (Netherlands)

    Tolstikov, V.V.; Lommen, A.; Nakanishi, K.; Tanaka, N.; Fiehn, O.

    2003-01-01

    Application of C18 monolithic silica capillary columns in HPLC coupled to ion trap mass spectrometry detection was studied for probing the metabolome of the model plant Arabidopsis thaliana. It could be shown that the use of a long capillary column is an easy and effective approach to reduce ionizat

  4. Comparison of various silica-based monoliths for the analysis of large biomolecules.

    Science.gov (United States)

    Vuignier, Karine; Fekete, Szabolcs; Carrupt, Pierre-Alain; Veuthey, Jean-Luc; Guillarme, Davy

    2013-07-01

    In the present study, three types of silica-based monoliths, i.e. the first and second generations of commercial silica monolithic columns and a wide-pore prototype monolith were compared for the analysis of large biomolecules. These molecules possess molecular weights between 1 and 66 kDa. The gradient kinetic performance of the first-generation monolith was lower than that of the second generation, for large biomolecules (>14 kDa) but very close with smaller ones (1.3-5.8 kDa). In contrast, the wide-pore prototype column was particularly attractive with proteins larger than 19 kDa (higher peak capacity). Among these three columns, the selectivity and retention remained quite similar but a possible larger number of accessible and charged residual silanols was noticed on the wide-pore prototype material, which led to unpredicted small changes in selectivity and slightly broader peaks than expected. The peak shapes attained with the addition of 0.1% formic acid in the mobile phase remained acceptable for MS coupling, particularly for biomolecules of less than 6 kDa. It was found that one of the major issues with all of these silica-based monoliths is the possible poor recovery of large biomolecules (principally with monoclonal antibody fragments of more than 25 kDa).

  5. 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.

  6. 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)

  7. 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.

  8. 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

  9. Radial heterogeneity of some analytical columns used in high-performance liquid chromatography

    Energy Technology Data Exchange (ETDEWEB)

    Mriziq, Khaled S [ORNL; Guiochon, Georges A [ORNL

    2009-01-01

    An on-column electrochemical microdetector was used to determine accurately the radial distribution of the mobile phase velocity and of the column efficiency at the exit of three common analytical columns, namely a 100 mm x 4.6 mm C18 bonded silica-based monolithic column, a 150 mm x 4.6 mm column packed with 2.7 {micro}m porous shell particles of C18 bonded silica (HALO), and a 150 mm x 4.6 mm column packed with 3 {micro}m fully porous C18 bonded silica particles (LUNA). The results obtained demonstrate that all three columns are not radially homogeneous. In all three cases, the efficiency was found to be lower in the wall region of the column than in its core region (the central core with a radius of 1/3 the column inner radius). The decrease in local efficiency from the core to the wall regions was lower in the case of the monolith (ca. 25%) than in that of the two particle-packed columns (ca. 35-50%). The mobile phase velocity was found to be ca. 1.5% higher in the wall than in the core region of the monolithic column while, in contrast, it was ca. 2.5-4.0% lower in the wall region for the two particle-packed columns.

  10. A new anion-exchange/hydrophobic monolith as stationary phase for nano liquid chromatography of small organic molecules and inorganic anions.

    Science.gov (United States)

    Aydoğan, Cemil

    2015-05-01

    In this study, an anion-exchange/hydrophobic polymethacrylate-based stationary phase was prepared for nano-liquid chromatography of small organic molecules and inorganic anions. The stationary phase was synthesized by in situ polymerization of 3-chloro-2-hydroxypropylmethacrylate and ethylene dimethacrylate inside silanized 100 μm i.d. fused silica capillary. The porogen mixture consisted of toluene and dodecanol. The pore size distrubution profiles of the resulting monolith were determined by mercury intrusion porosimetry and the morphology of the prepared monolith was investigated by scanning electron microscope. Good permeability, stability and column efficiency were observed on the monolithic column with nano flow. The produced monolithic column, which contains reactive chloro groups, was then modified by reaction with N,N-dimethyl-N-dodecylamine to obtain an anion-exchange/hydrophobic monolithic stationary phase. The functionalized monolith contained ionizable amine groups and hydrophobic groups that are useful of anion-exchange/hydrophobic mixed-mode chromatography. The final monolithic column performance with respect to anion-exchange and hydrophobic interactions was assesed by the separation of alkylbenzene derivatives, phenolic compounds and inorganic anions, respectively. Theoretical plate numbers up to 23,000 plates/m were successfully achieved in the separation of inorganic anions.

  11. 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.

  12. 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.

  13. Controlled porosity monolithic material as permselective ion exchange membranes.

    Science.gov (United States)

    Huang, Xiaojia; Dasgupta, Purnendu K

    2011-03-18

    Ion exchange membranes (IEMs) are used in a variety of analytical devices, including suppressors, eluent generators and other components used in ion chromatography. Such membranes are flexible and undergo substantial dimensional changes on hydration. Presently the push to miniaturization continues; a resurgent interest in open tubular ion chromatography requires microscale adaptation of these components. Incorporating IEMs in microscale devices is difficult. Although both macroporous and microporous ion exchange materials have been made for use as chromatographic packing, ion exchange material used as membranes are porous only on a molecular scale. Because such pores have vicinal ion exchange sites, ions of the same charge sign as those of the fixed sites are excluded from the IEMs. Monolithic polymers, including ion exchangers derived therefrom, are presently extensively used. When used in a separation column, such a monolithic structure contains an extensively connected porous network. We show here that by controlling the amount of porogen added during the synthesis of monolithic polymers derived from ethylene dimethacrylate - glycidyl methacrylate, which are converted to an anion exchanger by treatment with trimethylamine, it is possible to obtain rigid ion exchange polymers that behave like IEMs and allow only one charge type of ions to pass through, i.e., are permselective. We demonstrate successful open tubular cation chromatography suppressor performance.

  14. 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.

  15. One-pot preparation of glutathione-silica hybrid monolith for mixed-mode capillary liquid chromatography based on "thiol-ene" click chemistry.

    Science.gov (United States)

    Lin, Zian; Tan, Xiaoqing; Yu, Ruifang; Lin, Jiashi; Yin, Xiaofei; Zhang, Lan; Yang, Huanghao

    2014-08-15

    A novel glutathione (GSH)-silica hybrid monolithic column synthesized via a combination of thiol-ene click reaction and one-pot process was described, where thiol-end GSH organic monomer and 2,2-azobisisobutyronitrile (AIBN) were mixed with hydrolyzed tetramethyloxysilane (TMOS) and γ-methacryloxypropyltrimethoxysilane (γ-MAPS) and then introduced into a fused-silica capillary for simultaneous polycondensation and "thiol-ene" click reaction to form the GSH-silica hybrid monolith. The effects of the molar ratio of TMOS/γ-MAPS, the amount of GSH, and the volume of porogen on the morphology, permeability and pore properties of the prepared GSH-silica hybrid monoliths were studied in detail. A uniform monolithic network with high porosity was obtained. A series of test compounds including alkylbenzenes, amides, and anilines were used to evaluate the retention behaviors of the GSH-silica hybrid monolithic column. The results demonstrated that the prepared GSH-silica hybrid monolith exhibited multiple interactions including hydrophobicity, hydrophilicity, as well as cation exchange interaction. The run-to-run, column-to-column and batch-to-batch reproducibilities of the GSH-silica hybrid monolith for phenols' retention were satisfactory with the relative standard deviations (RSDs) less than 1.3% (n=5), 2.6% (n=3) and 3.2% (n=3), respectively, indicating the effectiveness and practicability of the proposed method. In addition, the GSH-silica hybrid monolith was applied to the separation of nucleotides, peptides and protein tryptic digests, respectively. The successful applications suggested the potential of the GSH-silica hybrid monolith in complex sample analysis.

  16. Chloride transference during electrochemical chloride extraction process

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    Chemical titration method and lab-made chloride probes were jointly adopted to investigate the effects of water-to-cement (W/C) ratio and the impressed current density on chloride transport for cement-based materials during electrochemical chloride extraction (ECE) process.The dissolution of bound chlorides and the effect of current density on dissolution were analyzed.The variations of chloride concentration at different depths and the chloride transference process were monitored.Test results show that W/C ratios adopted have slight influence on chloride extraction,while chloride extraction efficiency is mainly determined by the impressed current density.During ECE process a portion of bound chloride ions dissolved and the amount of bound chlorides released is directly proportional to current density.

  17. One-pot synthesis of N-methylimidazolium-based porous polymer monolith for capillary electrochromatography via free radical copolymerization and quaterisation.

    Science.gov (United States)

    Li, Yi; Chen, Yingzhuang; Wang, Keyi; Nie, Lihua; Yao, Shouzhuo

    2012-07-01

    One-pot synthesis of porous polymer monolith decorated with N-methylimidazolium in a capillary was described. The polymer matrix was synthesized by in situ copolymerization and quaterization of 3-chloro-2-hydroxylpropyl methacrylate (CHPMA), ethylene dimethacrylate (EDMA), and N-methylimidazole (N-MIz). The influencing factors including amount of cross-linkers, composition of porogenic solvents, and polymerization temperature on the formation of the monolithic column were investigated. The monolithic column exhibited high column efficiency for thiourea, up to 135 000 plates per meter, and phenylmethanol, up to 102 000 plates per meter. Different types of compounds including alkylbenzenes, phenols, and inorganic anions were successfully baseline separated by capillary electrochromatography (CEC). The separation of theses analytes on the column indicated typical reversed-phase and anion-exchange chromatographic retention mechanism.

  18. Behavior of reinforced concrete columns strenghtened by partial jacketing

    Directory of Open Access Journals (Sweden)

    D. B. FERREIRA

    Full Text Available This article presents the study of reinforced concrete columns strengthened using a partial jacket consisting of a 35mm self-compacting concrete layer added to its most compressed face and tested in combined compression and uniaxial bending until rupture. Wedge bolt connectors were used to increase bond at the interface between the two concrete layers of different ages. Seven 2000 mm long columns were tested. Two columns were cast monolithically and named PO (original column e PR (reference column. The other five columns were strengthened using a new 35 mm thick self-compacting concrete layer attached to the column face subjected to highest compressive stresses. Column PO had a 120mm by 250 mm rectangular cross section and other columns had a 155 mm by 250mm cross section after the strengthening procedure. Results show that the ultimate resistance of the strengthened columns was more than three times the ultimate resistance of the original column PO, indicating the effectiveness of the strengthening procedure. Detachment of the new concrete layer with concrete crushing and steel yielding occurred in the strengthened columns.

  19. Aptamer-based organic-silica hybrid affinity monolith prepared via "thiol-ene" click reaction for extraction of thrombin.

    Science.gov (United States)

    Wang, Zheng; Zhao, Jin-cheng; Lian, Hong-zhen; Chen, Hong-yuan

    2015-06-01

    A novel strategy for preparing aptamer-based organic-silica hybrid monolithic column was developed via "thiol-ene" click chemistry. Due to the large specific surface area of the hybrid matrix and the simplicity, rapidness and high efficiency of "thiol-ene" click reaction, the average coverage density of aptamer on the organic-silica hybrid monolith reached 420 pmol μL(-1). Human α-thrombin can be captured on the prepared affinity monolithic column with high specificity and eluted by NaClO4 solution. N-p-tosyl-Gly-Pro-Arg p-nitroanilide acetate was used as the sensitive chromogenic substrate of thrombin. The thrombin enriched by this affinity column was detected with a detection of limit of 0.01 μM by spectrophotometry. Furthermore, the extraction recovery of thrombin at 0.15 μM in human serum was 91.8% with a relative standard deviation of 4.0%. These results indicated that "thiol-ene" click chemistry provided a promising technique to immobilize aptamer on organic-inorganic hybrid monolith and the easily-assembled affinity monolithic material could be used to realize highly selective recognition of trace proteins.

  20. Purification of Astaxanthin from Laminariajaponica by Ionic Liquid-based Monolithic Cartridge

    Institute of Scientific and Technical Information of China (English)

    YOON Chang-hwan; ZHU Tao; ROW Kyung-ho

    2012-01-01

    An effective and accurate method was developed for the extraction of astaxanthin from Laminariajaponica with subsequent separation by ionic liquid-based monolithic cartridge.The optimized extraction conditions including extraction solvent(ethanol),extraction time(90 min) and ultrasonic power(75 W) were obtained by systematical investigation.Chromatographic analysis was performed on a C18 column with ultraviolet(UV) detection at 476nm,and a solution consisting of methanol/acetonitrile/H20/dichloromethane(83:6:6:5,volume ratio) was used as the mobile phase at a flow rate of 0.7 mL/min.After ionic liquid-based monolithic solid phase extraction,17.82 μg/g astaxanthin was obtained from Laminariajaponica.This ionic liquid-based monolithic cartridge exhibits high affinity and selectivity for astaxanthin,and it can be potentially used as the stationary phase of high performance liquid chromatography( HPLC).

  1. Experimental characterization of the transport phenomena, adsorption, and elution in a protein A affinity monolithic medium.

    Science.gov (United States)

    Herigstad, M Omon; Dimartino, Simone; Boi, Cristiana; Sarti, Giulio C

    2015-08-14

    A commercially available convective interaction media (CIM) Protein A monolithic column was fully characterized in view of its application for the affinity capture of IgG in monoclonal antibody production processes. By means of moment analysis, the interstitial porosity and axial dispersion coefficient were determined. The frontal analysis method of characteristic points was employed, for the first time with monolithic media, to determine the dynamic binding capacity. The effects of the flow rate and pH on the total recovery of polyclonal IgG and elution profile were evaluated. A comparison with literature data for Protein A chromatography beads demonstrate the superior bed utilization of monolithic media, which gave better performance at lower residence times.

  2. Monolithic Fuel Fabrication Process Development

    Energy Technology Data Exchange (ETDEWEB)

    C. R. Clark; N. P. Hallinan; J. F. Jue; D. D. Keiser; J. M. Wight

    2006-05-01

    The pursuit of a high uranium density research reactor fuel plate has led to monolithic fuel, which possesses the greatest possible uranium density in the fuel region. Process developments in fabrication development include friction stir welding tool geometry and cooling improvements and a reduction in the length of time required to complete the transient liquid phase bonding process. Annealing effects on the microstructures of the U-10Mo foil and friction stir welded aluminum 6061 cladding are also examined.

  3. Strong cation-exchange chromatography of proteins on a sulfoalkylated monolithic cryogel.

    Science.gov (United States)

    Perçin, Işık; Khalaf, Rushd; Brand, Bastian; Morbidelli, Massimo; Gezici, Orhan

    2015-03-20

    A new strong cation exchanger (SCX) monolithic column was synthesized by at-line surface modification of a cryogel prepared by copolymerization of 2-hydroxyethylmethacrylate (HEMA) and glycidylmethacrylate (GMA). Sodium salt of 3-Mercaptopropane sulfonic acid (3-MPS) was used as the ligand to transform the surface of the monolith into a strong cation exchanger. The obtained material was characterized in terms of elemental analysis, infrared spectroscopy (FTIR), Scanning Electron Microscopy (SEM), Brunauer-Emmett-Teller (BET) N2 adsorption, and used as a stationary phase for strong-cation exchange chromatography of some proteins, such as α-chymotrypsinogen, cytochrome c and lysozyme. Water permeability of the column was calculated according to Darcy's law (2.66×10(-13)m(2)). The performance of the monolithic cryogel column was evaluated on the basis of Height Equivalent to a Theoretical Plate (HETP). Retention behavior of the studied proteins was modeled on the basis of Yamamoto model to understand the role of the ion-exchange mechanism in retention behaviors. The considered proteins were successfully separated, and the obtained chromatogram was compared with that obtained with a non-functionalized cryogel column.

  4. Graphene-supported metal oxide monolith

    Energy Technology Data Exchange (ETDEWEB)

    Worsley, Marcus A.; Baumann, Theodore F.; Biener, Juergen; Biener, Monika A.; Wang, Yinmin; Ye, Jianchao; Tylski, Elijah

    2017-01-10

    A composition comprising at least one graphene-supported metal oxide monolith, said monolith comprising a three-dimensional structure of graphene sheets crosslinked by covalent carbon bonds, wherein the graphene sheets are coated by at least one metal oxide such as iron oxide or titanium oxide. Also provided is an electrode comprising the aforementioned graphene-supported metal oxide monolith, wherein the electrode can be substantially free of any carbon-black and substantially free of any binder.

  5. Incorporation of ionic liquid into porous polymer monoliths to enhance the separation of small molecules in reversed-phase high-performance liquid chromatography.

    Science.gov (United States)

    Wang, Jiafei; Bai, Ligai; Wei, Zhen; Qin, Junxiao; Ma, Yamin; Liu, Haiyan

    2015-06-01

    An ionic liquid was incorporated into the porous polymer monoliths to afford stationary phases with enhanced chromatographic performance for small molecules in reversed-phase high-performance liquid chromatography. The effect of the ionic liquid in the polymerization mixture on the performance of the monoliths was studied in detail. While monoliths without ionic liquid exhibited poor resolution and low efficiency, the addition of ionic liquid to the polymerization mixture provides highly increased resolution and high efficiency. The chromatographic performances of the monoliths were demonstrated by the separations of various small molecules including aromatic hydrocarbons, isomers, and homologues using a binary polar mobile phase. The present column efficiency reached 27 000 plates/m, which showed that the ionic liquid monoliths are alternative stationary phases in the separation of small molecules by high-performance liquid chromatography.

  6. Poly(methacrylic acid-ethylene glycol dimethacrylate) monolith in-tube solid phase microextraction coupled to high performance liquid chromatography and analysis of amphetamines in urine samples.

    Science.gov (United States)

    Fan, Yi; Feng, Yu-Qi; Zhang, Jian-Tao; Da, Shi-Lu; Zhang, Min

    2005-05-13

    In-tube solid-phase microextraction (SPME) based on a poly(methacrylic acid-ethylene glycol dimethacrylate) monolithic capillary column was investigated for the extraction of amphetamine, methamphetamine and their methylenedioxy derivatives. The monolithic capillary column showed high extraction efficiency towards target analytes, which could be attributed to its larger loading amount of extraction phase than conventional open-tubular extraction capillaries and the convective mass transfer procedure provided by its monolithic structure. The extraction mechanism was studied, and the results indicated that the extraction process of the target analytes was involved with hydrophobic interaction and ion-exchange interaction. The polymer monolith in-tube SPME-HPLC system with UV detection was successfully applied to the determination of amphetamine, methamphetamine and their methylenedioxy derivatives in urine samples, yielding the detection limits of 1.4 - 4.0 ng/mL. Excellent method reproducibility (RSD urine samples.

  7. Preparation of poly(N-isopropylacrylamide)-grafted well-controlled 3D skeletal monolith based on E-51 epoxy resin for protein separation.

    Science.gov (United States)

    Xin, Peiyong; Shen, Ying; Qi, Li; Yang, Gengliang; Chen, Yi

    2011-08-15

    A novel type of poly(N-isopropylacrylamide) grafted E-51 epoxy-based monoliths in a 100 mm × 4.6mm I.D. stainless steel column with well-controlled three-dimensional skeletal structures has been prepared and proposed for the separation of proteins. The grafted PNIPAAm chain via surface-initiated atom transfer radical polymerization was successfully performed. The proposed method provided a new route to modify the E-51 epoxy-based monoliths for widening their applications. Meanwhile, the temperature and the salt concentration responses of the grafted monolithic columns were investigated. Under the salt gradient, six proteins were well separated in hydrophobic interaction mode. Moreover, for further confirming the application of the prepared monolith was meaningful for proteome analysis in actual system, the separation of human serum sample was performed.

  8. Tribenzylammonium chloride

    Directory of Open Access Journals (Sweden)

    Waly Diallo

    2014-05-01

    Full Text Available Single crystals of the title salt, C21H21NH+·Cl−, were isolated as a side product from the reaction involving [(C6H5CH23NH]2[HPO4] and Sn(CH33Cl in ethanol. Both the cation and the anion are situated on a threefold rotation axis. The central N atom in the cation has a slightly distorted tetrahedral environment, with angles ranging from 107.7 to 111.16 (10°. In the crystal, the tribenzylammonium cations and chloride anions are linked through N—H...Cl and C—H...Cl hydrogen bonds, leading to the formation of infinite chains along [001]. The crystal studied was a merohedral twin.

  9. 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.

  10. Development of a monolithic polymer pipette for solid-phase extraction of liquiritigenin in rat plasma

    Institute of Scientific and Technical Information of China (English)

    Hong Wu Zhang; Kang Li; Zhi Xian Liang; Feng Yang Wang; Qi Wen Lu

    2012-01-01

    A monolithic polymer column with mixed-mode interaction was prepared by in situ polymerization in a 1000 μ,L pipette.Two kinds of monomers,butyl methacrylate (BMA) and 2-(dimethylamino)ethyl methacrylate (DMAM) were applied to constructing the mixed-mode interaction of monolithic polymer column.Its solid-phase extraction properties for liquiritigenin (LQG) were evaluated by high performance liquid chromatography (HPLC) with a gradient elution procedure.After the extraction procedure was optimized,the maximum binding capacity and extraction recovery following the optimal extraction procedure were investigated.Calibration curve was expressed as A =65.9C + 4.53 (r2 =0.998) with a linear range of 0.151-1.80 μg/mL.The experimental results indicate that the monolithic polymer pipette presents good extraction efficiency for LQG.It can be envisaged that the developed monolithic polymer pipette possesses the potential for its application to the enrichment of other flavonoids compounds being siniilar to the structure of LQG.

  11. [Headspace GC/MS analysis of residual vinyl chloride and vinylidene chloride in polyvinyl chloride and polyvinylidene chloride products].

    Science.gov (United States)

    Ohno, Hiroyuki; Mutsuga, Motoh; Kawamura, Yoko; Suzuki, Masako; Aoyama, Taiki

    2005-02-01

    A headspace GC/MS analysis method for the simultaneous determination of residual vinyl chloride (VC) and vinylidene chloride (VDC) in polyvinyl chloride (PVC) and polyvinylidene chloride (PVDC) products was developed. A test sample was swelled overnight with N,N-dimethylacetamide in a sealed vial. The vial was incubated for 1 hour at 90 degrees C, then the headspace gas was analyzed by GC/MS using a PLOT capillary column. The recoveries from spiked PVC and PVDC samples were 90.0-112.3% for VC and 85.2-108.3% for VDC. The determination limits were 0.01 microg/g for VC and 0.06/microg/g for VDC, respectively. By this method, VC was detected in two PVC water supply pipes at the levels of 0.61 and 0.01 microg/g. On the other hand, VC and VDC were not detected in any of the food container-packages or toys tested.

  12. Unsteady State Simulation and Process Design of a Batch Reactive Distillation Column with Multiple Side Reactors for Benzyl Chloride Production%带多台侧反应器的间歇反应精馏生产氯化苄非稳态模拟与过程设计

    Institute of Scientific and Technical Information of China (English)

    孙玉玉; 汤吉海; 陈献; 崔咪芬; 费兆阳; 乔旭

    2015-01-01

    建立了带多台侧反应器的间歇反应精馏过程,采用Aspen Plus模拟软件构建该过程的非稳态模拟方法。以甲苯氯化生产氯化苄为对象,研究了侧反应器台数、侧线采出率和采出位置、氯气分配、反应精馏时间及再沸器蒸发量等设计参数对间歇反应精馏过程的影响规律。模拟结果表明反应能力和分离达到最佳匹配的最优设计参数为:精馏塔塔板数8块、侧反应器2台、氯气分配7:3、从第3块塔板侧线采出、采出率85%、再沸器蒸发量25 kmol⋅h−1。在此结构参数和操作条件下完成50 kmol甲苯氯化所需时间为9 h,甲苯的转化率和氯化苄的选择性均可达到98.0%以上。%A batch distillation column coupled with multiple side reactors was established to produce benzyl chloride through toluene chlorination, and its unsteady state process was simulated using Aspen Plus. The influences of reactor number, extraction ratio, extraction position, chlorine distribution, distillation time and boil-up ratio on the performance of batch reactive distillation were investigated. The simulation results indicate that the best match between reaction and separation can be achieved, and the optimal parameters are as follows: column tray 8, side reactor number 2, chlorine distribution 7:3, 85% of the liquid flow extracted from the 3 rd stage into the 2nd reactor and boil-up ratio 25 kmol⋅h−1. Under the optimum conditions, 50 kmol toluene can be converted to benzyl chloride in 9 h with both conversion and selectivity up to 98.0%.

  13. 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.

  14. Nanosecond monolithic CMOS readout cell

    Science.gov (United States)

    Souchkov, Vitali V.

    2004-08-24

    A pulse shaper is implemented in monolithic CMOS with a delay unit formed of a unity gain buffer. The shaper is formed of a difference amplifier having one input connected directly to an input signal and a second input connected to a delayed input signal through the buffer. An elementary cell is based on the pulse shaper and a timing circuit which gates the output of an integrator connected to the pulse shaper output. A detector readout system is formed of a plurality of elementary cells, each connected to a pixel of a pixel array, or to a microstrip of a plurality of microstrips, or to a detector segment.

  15. Compact monolithic capacitive discharge unit

    Science.gov (United States)

    Roesler, Alexander W.; Vernon, George E.; Hoke, Darren A.; De Marquis, Virginia K.; Harris, Steven M.

    2007-06-26

    A compact monolithic capacitive discharge unit (CDU) is disclosed in which a thyristor switch and a flyback charging circuit are both sandwiched about a ceramic energy storage capacitor. The result is a compact rugged assembly which provides a low-inductance current discharge path. The flyback charging circuit preferably includes a low-temperature co-fired ceramic transformer. The CDU can further include one or more ceramic substrates for enclosing the thyristor switch and for holding various passive components used in the flyback charging circuit. A load such as a detonator can also be attached directly to the CDU.

  16. Probabilistic evaluation of initiation time of chloride-induced corrosion

    Energy Technology Data Exchange (ETDEWEB)

    Val, Dimitri V. [Department of Structural Engineering and Construction Management, Faculty of Civil and Environmental Engineering, Technion, Israel Institute of Technology, Haifa 32000 (Israel)], E-mail: val@tx.technion.ac.il; Trapper, Pavel A. [Department of Structural Engineering and Construction Management, Faculty of Civil and Environmental Engineering, Technion, Israel Institute of Technology, Haifa 32000 (Israel)

    2008-03-15

    The paper presents a model for chloride ingress into concrete. The model accounts for two mechanisms which control the chloride ingress-diffusion and convection. Using one-dimensional (1-D) formulation of the model, the influence of chloride binding and ambient humidity on chloride ingress into concrete has been investigated. Based on results of this investigation parameters for probabilistic analysis have been selected. Probabilistic evaluation of the time to corrosion initiation has then been carried out for a reinforced concrete (RC) wall (1-D problem) and a RC column (2-D problem) in a marine environment. Results of the analysis show that for the same thickness of the concrete cover the probability of corrosion initiation in the corner reinforcing bars of the RC column is much higher than in reinforcing bars in the middle part of the RC wall. The results demonstrate the importance of 2-D modelling for correct prediction of corrosion initiation in such RC elements as columns and beams.

  17. Mechanism of Molecular Recognition on Tetrapetide-imprinted Monolith by Capillary Electrochromatography

    Institute of Scientific and Technical Information of China (English)

    ZHENG,Chao; LIU,Zhao-Sheng; GAO,Ru-Yu; ZHANG,Yu-Kui

    2008-01-01

    A tetrapeptide-imprinted capillary monolithic column was synthesized successfully in the presence of YPLG (Tyr-Pro-Leu-Gly) as template by in situ thermo-initiated polymerization. For exploring the recognition mechanism of molecularly imprinted polymer in a capillary electrochromatography (CEC) mode, YPLG and its structural analogue, YPGL (Tyr-Pro-Gly-Leu), differing in amino acid sequence, were used as model compounds. It is hard work to separate the two tetrapeptides by a simple CEC or a capillary electrophoresis mode due to their similar chemical structures and values of pi. However, the results showed that YPLG could be recognized specially by the imprinted monolith. The separation factor (a) and the resolution (Rs) between YPLG and YPGL were 1.73 and 3.72, respectively. The effects of organic modifier concentration, pH value of buffer, salt concentration of buffer and column temperature on the recognition of YPLG and YPGL were investigated. A non-linear Van't Hoff behavior of the template was observed on a YPLG-imprinted column, which suggested the presence of multiple types of retention mechanisms or multiple types of binding sites. The results showed that the molecular recognition on MIP monolith in the CEC mode mainly derived from hydrogen bonding between YPLG and MIP and three-dimensional structure of the imprinting cavities.

  18. 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.

  19. Hybrid organic-inorganic silica monolith with hydrophobic/strong cation-exchange functional groups as a sorbent for micro-solid phase extraction.

    Science.gov (United States)

    Zheng, Ming-Ming; Ruan, Ge-Deng; Feng, Yu-Qi

    2009-11-06

    A hybrid organic-inorganic silica monolith with hydrophobic and strong cation-exchange functional groups was prepared and used as a sorbent for micro-solid phase extraction (micro-SPE). The hybrid silica monolith functionalized with octyl and thiol groups was conveniently synthesized by hydrolysis and polycondensation of a mixture of tetraethoxysilane (TEOS), n-octyltriethoxysilane (C8-TEOS) and 3-mercaptopropyltrimethoxysilane (MPTMS) via a two-step catalytic sol-gel process. Due to the favorable chemical reactivity of mercapto pendant moieties, the obtained hybrid monolith was oxidized using hydrogen peroxide (30%, w/w) to yield sulfonic acid groups, which provided strong cation-exchange sites. The obtained hybrid monolith was characterized by diffused infrared spectroscopy, elemental analysis, scanning electron microscopy and mercury intrusion porosimetry. The results show that the resulting monolith contains much higher carbon (31.6%) and sulfur (4.8%) contents than traditionally bonded silica materials. The extraction performance of the hybrid monolith was evaluated using sulfonamides as testing analytes by micro-SPE on-line coupled to HPLC. The results show that the hybrid monolith with hydrophobic and strong cation-exchange functional groups exhibits high extraction efficiency towards the testing analytes. The column-to-column RSD values were 1.3-9.8% for the extraction of SAs investigated. The extraction performance of the hybrid silica monolith remained practically unchanged after treated with acid (pH 1.0) and basic solutions (pH 10.5). Finally, the application of the hybrid monolith was demonstrated by micro-SPE of sulfonamide residues from milk followed by HPLC-UV analysis. The limits of detection (S/N=3) for eight SAs were found to be 1.0-3.0ng/mL in milk. The recoveries of eight SAs spiked in milk sample ranged from 80.2% to 115.6%, with relative standard deviations less than 11.8%.

  20. Automated Composite Column Wrapping

    OpenAIRE

    ECT Team, Purdue

    2007-01-01

    The Automated Composite Column Wrapping is performed by a patented machine known as Robo-Wrapper. Currently there are three versions of the machine available for bridge retrofit work depending on the size of the columns being wrapped. Composite column retrofit jacket systems can be structurally just as effective as conventional steel jacketing in improving the seismic response characteristics of substandard reinforced concrete columns.

  1. Solvothermal removal of the organic template from L{sub 3} ('sponge') templated silica monoliths

    Energy Technology Data Exchange (ETDEWEB)

    Dabbs, Daniel M. [Princeton University, Department of Chemical Engineering (United States); Mulders, Norbert [University of Delaware, Department of Physics and Astronomy (United States); Aksay, Ilhan A. [Princeton University, Department of Chemical Engineering (United States)], E-mail: iaksay@princeton.EDU

    2006-10-15

    We compare the methods of continuous solvent (Soxhlet) and supercritical solvent extractions for the removal of the organic template from nanostructured silica monoliths. Our monoliths are formed by templating the L{sub 3} liquid crystal phase of cetylpyridinium chloride in aqueous solutions with tetramethoxy silane. The monoliths that result from both Soxhlet and supercritical extraction methods are mechanically robust, optically clear, and free of cracks. The Soxhlet method compares favorably with supercritical solvent extraction in that equivalent L{sub 3}-templated silica can be synthesized without the use of specialized reactor hardware or higher temperatures and high pressures, while avoiding noxious byproducts. The comparative effectiveness of various solvents in the Soxhlet process is related to the Hildebrand solubility parameter, determined by the effective surface area of the extracted silica.

  2. Synthesis of silver nanoparticles confined in hierarchically porous monolithic silica: a new function in aromatic hydrocarbon separations.

    Science.gov (United States)

    Zhu, Yang; Morisato, Kei; Li, Wenyan; Kanamori, Kazuyoshi; Nakanishi, Kazuki

    2013-03-01

    Silver nanoparticles (Ag NPs) have been homogeneously introduced into hierarchically porous monolithic silica columns with well-defined macropores and SBA-15-type hexagonally ordered mesopores by using ethanol as the mild reductant. Within the cylindrical silica mesopores treated with aminopropyl groups as the host, monocrystalline Ag NPs and nanorods are obtained after being treated in silver nitrate/ethanol solution at room temperature for different durations of reducing time. The loading of Ag NPs in the monolith can be increased to 33 wt % by the repetitive treatment, which also led to the formation of polycrystalline Ag nanorods in the mesopores. Although the bare silica column cannot separate aromatic hydrocarbons, good separation of those molecules by noncharged Ag NPs confined in the porous structure of the monolith has been for the first time demonstrated with the Ag NP-embedded silica column. The NP-embedded monolithic silica would be a powerful separation tool for hydrocarbons with different number, position, and configuration of unsaturated bonds.

  3. Profiling of drug binding proteins by monolithic affinity chromatography in combination with liquid chromatography-tandem mass spectrometry.

    Science.gov (United States)

    Zhang, Xuepei; Wang, Tongdan; Zhang, Hanzhi; Han, Bing; Wang, Lishun; Kang, Jingwu

    2014-09-12

    A new approach for proteome-wide profiling drug binding proteins by using monolithic capillary affinity chromatography in combination with HPLC-MS/MS is reported. Two immunosuppresive drugs, namely FK506 and cyclosporin A, were utilized as the experimental models for proof-of-concept. The monolithic capillary affinity columns were prepared through a single-step copolymerization of the drug derivatives with glycidyl methacrylate and ethylene dimethacrylate. The capillary chromatography with the affinity monolithic column facilitates the purification of the drug binding proteins from the cell lysate. By combining the capillary affinity column purification and the shot-gun proteomic analysis, totally 33 FK506- and 32 CsA-binding proteins including all the literature reported target proteins of these two drugs were identified. Among them, two proteins, namely voltage-dependent anion-selective channel protein 1 and serine/threonine-protein phosphatase PGAM5 were verified by using the recombinant proteins. The result supports that the monolithic capillary affinity chromatography is likely to become a valuable tool for profiling of binding proteins of small molecular drugs as well as bioactive compounds.

  4. A weak cation-exchange monolith as stationary phase for the separation of peptide diastereomers by CEC.

    Science.gov (United States)

    Ludewig, Ronny; Nietzsche, Sandor; Scriba, Gerhard K E

    2011-01-01

    A CEC weak cation-exchange monolith has been prepared by in situ polymerization of acrylamide, methylenebisacrylamide and 4-acrylamidobutyric acid in a decanol-dimethylsulfoxide mixture as porogen. The columns were evaluated by SEM and characterized with regard to the separation of diastereomers and α/β-isomers of aspartyl peptides. Column preparation was reproducible as evidenced by comparison of the analyte retention times of several columns prepared simultaneously. Analyte separation was achieved using mobile phases consisting of acidic phosphate buffer and ACN. Under these conditions the peptides migrated due to their electrophoretic mobility but the EOF also contributed as driving force as a function of the pH of the mobile phase due to increasing dissociation of the carboxyl groups of the polymer. Raising the pH of the mobile phase also resulted in deprotonation of the peptides reducing analyte mobility. Due to these mechanisms each pair of diastereomeric peptides displayed the highest resolution at a different pH of the buffer component of the mobile phase. Comparing the weak-cation exchange monolith to an RP monolith and a strong cation-exchange monolith different elution order of some peptide diastereomers was observed, clearly illustrating that interactions with the stationary phase contribute to the CEC separations.

  5. 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.

  6. Minicircle DNA purification using a CIM® DEAE-1 monolithic support.

    Science.gov (United States)

    Diamantino, Tatiana; Pereira, Patrícia; Queiroz, João A; Sousa, Ângela; Sousa, Fani

    2016-09-01

    Minicircle DNA is a new biotechnological product with beneficial therapeutic perspectives for gene therapy because it is constituted only by the eukaryotic transcription unit. These features improve minicircle DNA safety and increase its therapeutic effect. However, being a recently developed product, there is a need to establish efficient purification methodologies, enabling the recovery of the supercoiled minicircle DNA isoform. Thus, this work describes the minicircle DNA purification using an anion exchange monolithic support. The results show that with this column it is possible to achieve a good selectivity, which allows the isolation of the supercoiled minicircle DNA isoform from impurities. Overall, this study shows a promising approach to obtain the minicircle DNA sample with adequate quality for future therapeutic applications.

  7. Design model and recommendations of column-foundation connection through socket with rough interfaces

    Directory of Open Access Journals (Sweden)

    R. M. F. Canha

    Full Text Available The present work proposes design models and recommendations for column-foundation connection through socket with rough interfaces, including the shear key configuration, the socket and the precast column base. In the experimental investigations, the behavior of socket and column as a monolithic connection was verified. However, for this to occur, the shear key dimensions must be between the limits suggested by the study. Considering the total transfer of internal forces in the connections, the vertical reinforcement should be designed based on the bending theory. The proposed model for the design of the transverse horizontal reinforcement, considering monolithic behavior of the connection, was found to be in good agreement with the observed experimental results. With adjustments to this model for the socket, a new model for the design of precast column bases is proposed and compared with other model adapted for rough interfaces.

  8. Monolithic cells for solar fuels.

    Science.gov (United States)

    Rongé, Jan; Bosserez, Tom; Martel, David; Nervi, Carlo; Boarino, Luca; Taulelle, Francis; Decher, Gero; Bordiga, Silvia; Martens, Johan A

    2014-12-07

    Hybrid energy generation models based on a variety of alternative energy supply technologies are considered the best way to cope with the depletion of fossil energy resources and to limit global warming. One of the currently missing technologies is the mimic of natural photosynthesis to convert carbon dioxide and water into chemical fuel using sunlight. This idea has been around for decades, but artificial photosynthesis of organic molecules is still far away from providing real-world solutions. The scientific challenge is to perform in an efficient way the multi-electron transfer reactions of water oxidation and carbon dioxide reduction using holes and single electrons generated in an illuminated semiconductor. In this tutorial review the design of photoelectrochemical (PEC) cells that combine solar water oxidation and CO2 reduction is discussed. In such PEC cells simultaneous transport and efficient use of light, electrons, protons and molecules has to be managed. It is explained how efficiency can be gained by compartmentalisation of the water oxidation and CO2 reduction processes by proton exchange membranes, and monolithic concepts of artificial leaves and solar membranes are presented. Besides transferring protons from the anode to the cathode compartment the membrane serves as a molecular barrier material to prevent cross-over of oxygen and fuel molecules. Innovative nano-organized multimaterials will be needed to realise practical artificial photosynthesis devices. This review provides an overview of synthesis techniques which could be used to realise monolithic multifunctional membrane-electrode assemblies, such as Layer-by-Layer (LbL) deposition, Atomic Layer Deposition (ALD), and porous silicon (porSi) engineering. Advances in modelling approaches, electrochemical techniques and in situ spectroscopies to characterise overall PEC cell performance are discussed.

  9. 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

  10. 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...

  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. 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.

  13. Preparation and evaluation of micro and meso porous silica monoliths with embedded carbon nanoparticles for the extraction of non-polar compounds from waters.

    Science.gov (United States)

    Fresco-Cala, Beatriz; Cárdenas, Soledad; Valcárcel, Miguel

    2016-10-14

    A novel hybrid micro and meso porous silica monolith with embedded carbon nanoparticles (Si-CNPs monolith) was prepared inside a fused silica capillary (3cm in length) and used as a sorbent for solid-phase microextraction. The hybrid monolithic capillary was synthetized by hydrolysis and polycondensation of a mixture of tetraethoxysilane (TEOS), ethanol, and three different carbon nanoparticles such as carboxylated single-walled carbon nanotubes (c-SWCNTs), carboxylated multi-walled carbon nanotubes (c-MWCNTs), and oxidized single-walled carbon nanohorns (o-SWNHs) via a two-step catalytic sol-gel process. Compared with silica monolith without carbon nanoparticles, the developed monolithic capillary column exhibited a higher extraction efficiency towards the analytes which can be ascribed to the presence of the carbon nanoparticles. In this regard, the best performance was achieved for silica monolith with embedded c-MWCNTs. The resulted monolithic capillaries were also characterized by scanning electron microscopy (SEM), elemental analysis and nitrogen intrusion porosimetry. Variables affecting to the preparation of the sorbent phase including three different carbon nanoparticles and extraction parameters were studied in depth using polycyclic aromatic hydrocarbons (PAHs) as target analytes. Gas chromatography-mass spectrometry was selected as instrumental technique. Detection limits range from 0.1 to 0.3μgL(-1), and the inter-extraction units precision (expressed as relative standard deviation) is between 5.9 and 14.4%.

  14. 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

  15. Preparation of macroporous methacrylate-based monoliths for chromatographic applications by the Reactive Gelation Process.

    Science.gov (United States)

    Bechtle, M; Butté, A; Storti, G; Morbidelli, M

    2010-07-09

    Polymeric monoliths are a relatively new separation medium for chromatographic applications. The innovative approach to produce such monoliths, the Reactive Gelation Process, presented by Marti et al. [1] for polystyrene macroporous materials is applied to a methacrylate-based material. It is shown that it is possible to create a macroporous structure by Reactive Gelation also with this polymer even if the properties of the material are different. Besides the analysis of the material by SEM and BET, several chromatographic methods are used to analyze the material properties. The ISEC experiments showed a much smaller size exclusion effect than in conventional packed beds. The permeability of the material is comparable to a packed bed with 4.13 μm particles. The column efficiency is not changing for increasing flow rates. Because of the high efficiency of the material, shorter columns are needed and therefore the comparatively low permeability is compensated. The monolith also exhibits a significant adsorption capacity for hydrophobic interaction, which makes it suitable for chromatographic purification processes.

  16. Fabrication of aluminum terephthalate metal-organic framework incorporated polymer monolith for the microextraction of non-steroidal anti-inflammatory drugs in water and urine samples.

    Science.gov (United States)

    Lyu, Dan-Ya; Yang, Cheng-Xiong; Yan, Xiu-Ping

    2015-05-08

    Polymer monolith microextraction (PMME) based on capillary monolithic column is an effective and useful technique to preconcentrate trace analytes from environmental and biological samples. Here, we report the fabrication of a novel aluminum terephthalate metal-organic framework (MIL-53(Al)) incorporated capillary monolithic column via in situ polymerization for the PMME of non-steroidal anti-inflammatory drugs (NSAIDs) (ketoprofen, fenbufen and ibuprofen) in water and urine samples. The fabricated MIL-53(Al) incorporated monolith was characterized by X-ray powder diffractometry, scanning electron microscopy, Fourier transform infrared spectrometry, and nitrogen adsorption experiment. The MIL-53(Al) incorporated monolith gave larger surface area than the neat polymer monolith. A 2-cm long MIL-53(Al) incorporated capillary monolith was applied for PMME coupled with high-performance liquid chromatography for the determination of the NSAIDs. Potential factors affecting the PMME were studied in detail. Under the optimized conditions, the developed method gave the enhancement factors of 46-51, the linear range of 0.40-200μgL(-1), the detection limits (S/N=3) of 0.12-0.24μgL(-1), and the quantification limits (S/N=10) of 0.40-0.85μgL(-1). The recoveries for spiked NSAIDs (20μgL(-1)) in water and urine samples were in the range of 77.3-104%. Besides, the MIL-53(Al) incorporated monolith was stable enough for 120 extraction cycles without significant loss of extraction efficiency. The developed method was successfully applied to the determination of NSAIDs in water and urine samples.

  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. Monolithically integrated Ge CMOS laser

    Science.gov (United States)

    Camacho-Aguilera, Rodolfo

    2014-02-01

    Ge-on-Si devices are explored for photonic integration. Through the development of better growth techniques, monolithic integration, laser design and prototypes, it was possible to probe Ge light emitters with emphasis on lasers. Preliminary worked shows thermal photonic behavior capable of enhancing lamination at high temperatures. Increase luminescence is observed up to 120°C from L-band contribution. Higher temperatures show contribution from Δ -band. The increase carrier thermal contribution suggests high temperature applications for Ge light emitters. A Ge electrically pumped laser was probed under 0.2% biaxial strain and doping concentration ~4.5×1019cm-3 n-type. Ge pnn lasers exhibit a gain >1000cm-1 with 8mW power output, presenting a spectrum range of over 200nm, making Ge the ideal candidate for Si photonics. Large temperatures fluctuations and process limit the present device. Theoretically a gain of >4000cm- gain is possible with a threshold of as low as 1kA/cm2. Improvements in Ge work

  19. Evaluation of steric exclusion chromatography on cryogel column for the separation of serum proteins.

    Science.gov (United States)

    Wang, Chuan; Bai, Shu; Tao, Shi-Peng; Sun, Yan

    2014-03-14

    Steric exclusion chromatography (SXC) is a new mode of protein chromatography, in which large proteins are retained on hydrophilic stationary phase surface due to the steric exclusion of polyethylene glycol (PEG) in the mobile phase, and thereafter the retained proteins can be eluted by reducing PEG concentration. In this work, SXC was evaluated on a polyacrylamide cryogel monolith. Microscopic observation of γ-globulin precipitates on the gel surface in SXC was reported for the first time. Due to the compact packing of protein precipitates on the stationary phase surface, the dynamic retention capacity of the cryogel monolith for γ-globulin reached 20 mg/mL bed volume, much higher than those of cryogel beds in adsorption-based chromatography. The effect of molecular weight and concentration of PEG, solution pH and salt concentration on protein retention capacity was in agreement with the earlier work on SXC. Because the cryogel monoliths with interconnected macropores (10-100 μm) allow much easy flow-through of viscous PEG buffer, the SXC can be operated at low back pressure. Hence, the cryogel monoliths are more suitable for SXC than other monoliths of narrow pores reported previously. In the separation of bovine serum proteins, albumin was recovered in the breakthrough fraction with high purity, and globulin was over eight times concentrated in the elution pool. This work has, thus, demonstrated the rapid serum protein separation and concentration by SXC on the cryogel monolith columns.

  20. 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

    This is the accepted manuscript version. Published version is available at Acta Odontologica Scandinavica 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 zi...

  1. 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.

  2. 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.

  3. Development of a monolithic ferrite memory array

    Science.gov (United States)

    Heckler, C. H., Jr.; Bhiwandker, N. C.

    1972-01-01

    The results of the development and testing of ferrite monolithic memory arrays are presented. This development required the synthesis of ferrite materials having special magnetic and physical characteristics and the development of special processes; (1) for making flexible sheets (laminae) of the ferrite composition, (2) for embedding conductors in ferrite, and (3) bonding ferrite laminae together to form a monolithic structure. Major problems encountered in each of these areas and their solutions are discussed. Twenty-two full-size arrays were fabricated and fired during the development of these processes. The majority of these arrays were tested for their memory characteristics as well as for their physical characteristics and the results are presented. The arrays produced during this program meet the essential goals and demonstrate the feasibility of fabricating monolithic ferrite memory arrays by the processes developed.

  4. Eigenpolarization theory of monolithic nonplanar ring oscillators

    Science.gov (United States)

    Nilsson, Alan C.; Gustafson, Eric K.; Byer, Robert L.

    1989-01-01

    Diode-laser-pumped monolithic nonplanar ring oscillators (NPROs) in an applied magnetic field can operate as unidirectional traveling-wave lasers. The diode laser pumping, monolithic construction, and unidirectional oscillation lead to narrow linewidth radiation. Here, a comprehensive theory of the eigenpolarizations of a monolithic NPRO is presented. It is shown how the properties of the integral optical diode that forces unidirectional operation depend on the choice of the gain medium, the applied magnetic field, the output coupler, and the geometry of the nonplanar ring light path. Using optical equivalence theorems to gain insight into the polarization characteristics of the NPRO, a strategy for designing NPROs with low thresholds and large loss nonreciprocities is given. An analysis of the eigenpolarizations for one such NPRO is presented, alternative optimization approaches are considered, and the prospects for further reducing the linewidths of these lasers are briefly discussed.

  5. Physical and chemical sensing using monolithic semiconductor optical transducers

    Science.gov (United States)

    Zappe, Hans P.; Hofstetter, Daniel; Maisenhoelder, Bernd; Moser, Michael; Riel, Peter; Kunz, Rino E.

    1997-09-01

    We present two monolithically integrated optical sensor systems based on semiconductor photonic integrated circuits. These compact, robust and highly functional transducers perform all necessary optical and electro-optical functions on-chip; extension to multi-sensor arrays is easily envisaged. A monolithic Michelson interferometer for high-resolution displacement measurement and a monolithic Mach-Zehnder interferometer for refractometry are discussed.

  6. 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 the state-of-the art: an analytical model which describes chloride profiles in concrete as function of depth...... 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....

  7. Integration of monolithic porous polymer with droplet-based microfluidics on a chip for nano/picoliter volume sample analysis

    OpenAIRE

    Kim, Jin-Young; Chang, Soo-Ik; Andrew J deMello; O’Hare, Danny

    2014-01-01

    In this paper, a porous polymer nanostructure has been integrated with droplet-based microfluidics in a single planar format. Monolithic porous polymer (MPP) was formed selectively within a microfluidic channel. The resulting analyte bands were sequentially comartmentalised into droplets. This device reduces band broadening and the effects of post-column dead volume by the combination of the two techniques. Moreover it offers the precise control of nano/picoliter volume samples.

  8. 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.

  9. Characterization of CIM monoliths as enzyme reactors.

    Science.gov (United States)

    Vodopivec, Martina; Podgornik, Ales; Berovic, Marin; Strancar, Ales

    2003-09-25

    The immobilization of the enzymes citrate lyase, malate dehydrogenase, isocitrate dehydrogenase and lactate dehydrogenase to CIM monolithic supports was performed. The long-term stability, reproducibility, and linear response range of the immobilized enzyme reactors were investigated along with the determination of the kinetic behavior of the enzymes immobilized on the CIM monoliths. The Michaelis-Menten constant K(m) and the turnover number k(3) of the immobilized enzymes were found to be flow-unaffected. Furthermore, the K(m) values of the soluble and immobilized enzyme were found to be comparable. Both facts indicate the absence of a diffusional limitation in immobilized CIM enzyme reactors.

  10. Spiral multicapillary columns

    Science.gov (United States)

    Efimenko, A. P.; Naumenko, I. I.; Soboleva, V. K.

    2008-08-01

    It was shown in a theoretical study and confirmed by experiment that a spiral multicapillary column had maximum efficiency if the bunch of capillaries was additionally coiled around its longitudinal axis to produce an integral number of coils. This technique made it possible to manufacture gas-chromatographic columns with performance as high as 12 to 16 thousand theoretical plates. These columns can find various applications, especially if quick separation is required.

  11. 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 marine atmospheric and submersed South Scandinavian environment. The design parameters are based on sequential measurements of 86 chloride profiles taken over ten years from 13 different types of concrete. The design parameters provide the input for an analytical model for chloride profiles as function...

  12. Monolithic Integration of GaN-based LEDs

    Energy Technology Data Exchange (ETDEWEB)

    Ao, Jin-Ping, E-mail: jpao@ee.tokushima-u.ac.jp [Institute of Technology and Science, University of Tokushima 2-1 Minami-Josanjima, Tokushima 770-8506 (Japan)

    2011-02-01

    The technology of monolithically integrated GaN-based light-emitting diodes (LEDs) is reported. First, the technology details to realize monolithic integration are described, including the circuit design for high-voltage and alternating current (AC) operation and the technologies for device isolation. The performances of the fabricated monolithic LED arrays are then demonstrated. A monolithic series array with totally 40 LEDs exhibited expected operation function under AC bias. The operation voltage of the array is 72 V when 20 LEDs were connected in series. Some modified circuit designs for high-voltage operation and other monolithic LED arrays are finally reviewed.

  13. Cyclic performance and simplified pushover analyses of precast segmental concrete bridge columns with circular section

    Science.gov (United States)

    Bu, Zhanyu; Guo, Jian; Zheng, Rongyue; Song, Jianwei; Lee, George C.

    2016-06-01

    In recent years, precast segmental concrete bridge columns became prevalent because of the benefits of accelerated construction, low environmental impact, high quality and low life cycle costs. The lack of a detailed configuration and appropriate design procedure to ensure a comparable performance with monolithic construction has impeded this structural system from being widely used in areas of high seismicity. In this study, precast segmental bridge column cyclic loading tests were conducted to investigate the performance of unbonded post-tensioned segmental bridge columns. One monolithic and two precast segmental columns were tested. The precast segmental column exhibited minor damage and small residual displacement after the maximum 7% cyclic drift; energy dissipation (ED) can be enhanced byadding ED bars. The experimental results were modeled by a simplified pushover method (SPOM), as well as a fiber model (FIBM) finite element method. Forty-five cases of columns with different aspect ratios, axial load ratios and ED bar ratios were analyzed with the SPOM and FIBM, respectively. Using these parametric results, a simplified design method was suggested by regressive analysis. Satisfactory correlation was found between the experimental results and the simplified design method for precast segmental columns with different design parameters.

  14. JCE Feature Columns

    Science.gov (United States)

    Holmes, Jon L.

    1999-05-01

    The Features area of JCE Online is now readily accessible through a single click from our home page. In the Features area each column is linked to its own home page. These column home pages also have links to them from the online Journal Table of Contents pages or from any article published as part of that feature column. Using these links you can easily find abstracts of additional articles that are related by topic. Of course, JCE Online+ subscribers are then just one click away from the entire article. Finding related articles is easy because each feature column "site" contains links to the online abstracts of all the articles that have appeared in the column. In addition, you can find the mission statement for the column and the email link to the column editor that I mentioned above. At the discretion of its editor, a feature column site may contain additional resources. As an example, the Chemical Information Instructor column edited by Arleen Somerville will have a periodically updated bibliography of resources for teaching and using chemical information. Due to the increase in the number of these resources available on the WWW, it only makes sense to publish this information online so that you can get to these resources with a simple click of the mouse. We expect that there will soon be additional information and resources at several other feature column sites. Following in the footsteps of the Chemical Information Instructor, up-to-date bibliographies and links to related online resources can be made available. We hope to extend the online component of our feature columns with moderated online discussion forums. If you have a suggestion for an online resource you would like to see included, let the feature editor or JCE Online (jceonline@chem.wisc.edu) know about it. JCE Internet Features JCE Internet also has several feature columns: Chemical Education Resource Shelf, Conceptual Questions and Challenge Problems, Equipment Buyers Guide, Hal's Picks, Mathcad

  15. Photopolymerization of acrylamide as a new functionalization way of silica monoliths for hydrophilic interaction chromatography and coated silica capillaries for capillary electrophoresis.

    Science.gov (United States)

    El-Debs, R; Marechal, A; Dugas, V; Demesmay, C

    2014-01-24

    A simple, rapid and localizable photochemical process for the preparation of hydrophilic coated capillary and silica-based monolithic capillary columns is described. The process involves the free radical polymerization of acrylamide monomers onto acrylate pre-activated silica surface triggered by UV photoinitiation. The experimental conditions (monomer content, time of irradiation) were optimized on silica monolithic columns by monitoring the evolution of the chromatographic properties (retention, permeability, efficiency) in HILIC mode using a set of nucleosides as test solutes. Compared to thermal polymerization process, the photoinitiation allows the preparation of highly retentive and efficient HILIC monolithic columns in less than 10min of irradiation. This process was then successfully applied to the surface coating of fused silica capillary walls. In addition to its relative high stability and ability to reduce the electroosmotic flow, this polyacrylamide coating is localizable. Benefits of this localizable photochemical process are highlighted through the conception of an in-line integrated bimodal microseparation tool combining a SPE preconcentration step on a photografted silica monolith and an electrokinetic separation step in a polyacrylamide photopolymerized capillary section. Two neuropeptides are used as model solutes to illustrate the suitability of this approach.

  16. Magnetism-Enhanced Monolith-Based In-Tube Solid Phase Microextraction.

    Science.gov (United States)

    Mei, Meng; Huang, Xiaojia; Luo, Qing; Yuan, Dongxin

    2016-02-02

    Monolith-based in-tube solid phase microextraction (MB/IT-SPME) has received wide attention because of miniaturization, automation, expected loading capacity, and environmental friendliness. However, the unsatisfactory extraction efficiency becomes the main disadvantage of MB/IT-SPME. To overcome this circumstance, magnetism-enhanced MB/IT-SPME (ME-MB/IT-SPME) was developed in the present work, taking advantage of magnetic microfluidic principles. First, modified Fe3O4 nanoparticles were mixed with polymerization solution and in situ polymerized in the capillary to obtain a magnetic monolith extraction phase. After that, the monolithic capillary column was placed inside a magnetic coil that allowed the exertion of a variable magnetic field. The effects of intensity of magnetic field, adsorption and desorption flow rate, volume of sample, and desorption solvent on the performance of ME-MB/IT-SPME were investigated in detail. The analysis of six steroid hormones in water samples by the combination of ME-MB/IT-SPME with high-performance liquid chromatography with diode array detection was selected as a paradigm for the practical evaluation of ME-MB/IT-SPME. The application of a controlled magnetic field resulted in an obvious increase of extraction efficiencies of the target analytes between 70% and 100%. The present work demonstrated that application of different magnetic forces in adsorption and desorption steps can effectively enhance extraction efficiency of MB/IT-SPME systems.

  17. 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%.

  18. 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.

  19. 3D photon impact determination in monolithic crystals based on autocorrelation filters and RTP methods

    Energy Technology Data Exchange (ETDEWEB)

    Conde, Pablo; Gonzalez, Antonio [Institute for Instrumentation in Molecular Imaging, I3M-CSIC, Valencia (Spain); Bettiol, Marco; Fabbri, Andrea; Pani, Roberto [Department of Molecular Medicine, Sapienza University of Rome (Italy); Benlloch Baviera, José María; Talens Aguilar, Albert; Hernandez, Liczandro; Sanchez, Filomeno [Institute for Instrumentation in Molecular Imaging, I3M-CSIC, Valencia (Spain)

    2015-05-18

    In PET detectors based on monolithic scintillators, the photon impact position can be estimated from the light intensity distribution (LD) on the photodetector pixels. Typically, there is a poor estimation of the interaction positions towards the edges when linear algorithms such as Center of Gravity (CoG) are used. We present a novel method to determine the interaction coordinates in thick monolithic crystals filtering the digitized LDs from each gamma-event by means of an autocorrelation filter and the raise to power (RTP) positioning algorithm to reduce the border effects. The experimental setup was based on two detector blocks based on monolithic LYSO scintillator crystals (50x50x20 mm{sup 3}). Each crystal is coupled to a SiPMs array as 12x12 photosensors and an electronic readout that outputs information of each SiPM row and column. Between the detector blocks, a collimated array of 9x9 {sup 22}Na sources, separated 5 mm each other, was placed. The optimum power to use in the RTP positioning algorithm was determined using the third order intercept point (IP3) from plots of the measured coordinates versus known positions. After applying the autocorrelation and RTP fifth to the data, we found an improvement of the spatial resolution from 2.5 mm when CoG is used, to 1.2 mm in the crystal center region. In this work we show how to accurately resolve 3D photon impact coordinates in thick monolithic crystals using autocorrelation filters merged with RTP methods. After applying the new approach it is possible to accurately resolve impacts close to the entrance of 20 mm thick LYSO scintillators. The reached spatial resolution at any photon depth of interaction is comparable with state-of-the-art crystal array approaches with the advantage of the proposed work to also provide continuous depth of interaction information.

  20. Lithium Sulfuryl Chloride Battery.

    Science.gov (United States)

    Primary batteries , Electrochemistry, Ionic current, Electrolytes, Cathodes(Electrolytic cell), Anodes(Electrolytic cell), Thionyl chloride ...Phosphorus compounds, Electrical conductivity, Calibration, Solutions(Mixtures), Electrical resistance, Performance tests, Solvents, Lithium compounds

  1. 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).

  2. Development of L-histidine immobilized CIM(®) monolithic disks for purification of immunoglobulin G.

    Science.gov (United States)

    Prasanna, Rajasekar R; Kamalanathan, Agamudi S; Vijayalakshmi, Mookambeswaran A

    2015-03-01

    The pseudobiospecific affinity ligand l-histidine was immobilized on epoxy, carbonyldiimidazole (CDI), and ethylenediamine (EDA) convective interaction media (BIA Separations, Slovenia) monolithic disks to obtain the histidyl affinity column for purification of immunoglobulin G (IgG). The kinetics and the mass transfer properties of the affinity columns were studied to determine the optimum buffer condition, flow rate, and concentration of IgG for maximum IgG adsorption. The binding capacities of all the three affinity columns were higher with zwitterionic buffer morpholinopropanesulfonic acid than with charged buffers such as tris-HCl and phosphate buffers, and the optimum pH was 6.5. The interaction of IgG with histidine immobilized CDI and epoxy disks was found to be predominantly driven by ionic interaction, while the interaction with EDA-histidine disk could be partially governed by multiple non-covalent forces of interaction. The maximum binding capacity (Qm ) of l-histidine immobilized on EDA-, CDI-, and epoxy-activated convective interaction media disks were 19.83 ± 0.25, 15.85 ± 0.18 and 12.11 ± 0.17 mg/ml of support, respectively, and the dissociation constant (Kd ) were calculated to be in the micromolar range for all the three histidyl monolithic columns. Purification of IgG from untreated human serum was also attempted, and the results indicate the high potential of this method for purification of total IgG from complex biological sources and also for separation of IgG1 from other subclasses.

  3. 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.

  4. 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.

  5. A monolithic integrated photonic microwave filter

    Science.gov (United States)

    Fandiño, Javier S.; Muñoz, Pascual; Doménech, David; Capmany, José

    2016-12-01

    Meeting the increasing demand for capacity in wireless networks requires the harnessing of higher regions in the radiofrequency spectrum, reducing cell size, as well as more compact, agile and power-efficient base stations that are capable of smoothly interfacing the radio and fibre segments. Fully functional microwave photonic chips are promising candidates in attempts to meet these goals. In recent years, many integrated microwave photonic chips have been reported in different technologies. To the best of our knowledge, none has monolithically integrated all the main active and passive optoelectronic components. Here, we report the first demonstration of a tunable microwave photonics filter that is monolithically integrated into an indium phosphide chip. The reconfigurable radiofrequency photonic filter includes all the necessary elements (for example, lasers, modulators and photodetectors), and its response can be tuned by means of control electric currents. This is an important step in demonstrating the feasibility of integrated and programmable microwave photonic processors.

  6. Ground Organic Monolith Particles Having a Large Volume of Macropores as Chromatographic Separation Media

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Jin Wook; Ali, Faiz; Kim, Yune Sung; Cheong, Won Jo [Inha Univ., Incheon (Korea, Republic of)

    2014-07-15

    A reaction mixture was developed for formation of soft organic monolith that was easily smashed, rinsed, refluxed, filtered, and dried to give monolith particles having high pore volume of macropores. This phase was almost without mesopores. The reaction mixture was composed of methacrylic acid, ethylene glycol dimethacrylate, polyethylene glycol (porogen), and an initiator in a mixed solvent of toluene and isooctane. The selection of porogen and its amount was carefully carried out to obtain the optimized separation efficiency of the resultant phase. The median macropore size was 1.6 μm, and the total pore volume was 3.0-3.4 mL/g. The median particle size (volume based) was 15 μm, and the range of particle size distribution was very broad. Nevertheless the column (1 Χ 300 mm) packed with this phase showed good separation efficiency (N∼10,000-16,000) comparable to that of a commercial column packed with 5 μm C18 silica particles.

  7. Monolithically integrated interferometer for optical displacement measurement

    Science.gov (United States)

    Hofstetter, Daniel; Zappe, Hans P.

    1996-01-01

    We discuss the fabrication of a monolithically integrated optical displacement sensors using III-V semiconductor technology. The device is configured as a Michelson interferometer and consists of a distributed Bragg reflector laser, a photodetector and waveguides forming a directional coupler. Using this interferometer, displacements in the 100 nm range could be measured at distances of up to 45 cm. We present fabrication, device results and characterization of the completed interferometer, problems, limitations and future applications will also be discussed.

  8. 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.

  9. 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.

  10. An overview of monolithic zirconia in dentistry

    Directory of Open Access Journals (Sweden)

    Özlem Malkondu

    2016-07-01

    Full Text Available Zirconia restorations have been used successfully for years in dentistry owing to their biocompatibility and good mechanical properties. Because of their lack of translucency, zirconia cores are generally veneered with porcelain, which makes restorations weaker due to failure of the adhesion between the two materials. In recent years, all-ceramic zirconia restorations have been introduced in the dental sector with the intent to solve this problem. Besides the elimination of chipping, the reduced occlusal space requirement seems to be a clear advantage of monolithic zirconia restorations. However, scientific evidence is needed to recommend this relatively new application for clinical use. This mini-review discusses the current scientific literature on monolithic zirconia restorations. The results of in vitro studies suggested that monolithic zirconia may be the best choice for posterior fixed partial dentures in the presence of high occlusal loads and minimal occlusal restoration space. The results should be supported with much more in vitro and particularly in vivo studies to obtain a final conclusion.

  11. Enantioselective nano liquid chromatographic separation of racemic pharmaceuticals: a facile one-pot in situ preparation of lipase-based polymer monoliths in capillary format.

    Science.gov (United States)

    Ahmed, Marwa; Ghanem, Ashraf

    2014-11-01

    New affinity monolithic capillary columns of 150 µm internal diameter were prepared in situ fused glass capillary via either immobilization or encapsulation of Candida antarctica lipase B (CALB) on or within polymer monoliths, respectively. The immobilized lipase-based monoliths were prepared via copolymerization of 19.1% monomers (8.9% MMA and 10.2% GMA), 19.8% EDMA, and 61.1% porogens (54.2% formamide and 6.9% 1-propanol) w/w or 20% GMA, 20% EDMA, and 60% porogens (51.6% cyclohexanol and 8.4% 1-dodecanol) in the presence of AIBN (1%) as a radical initiator. This was followed by pumping a solution of lipase through the capillaries and rinsing with potassium phosphate buffer. On the other hand, the encapsulated lipase-based monoliths were prepared via copolymerization of 20% monomers (GMA), 20% EDMA, and 60% porogens (48% 1-propanol, 6% 1,4-butanediol) or 16.4% monomers (16% BuMA, 0.4% SPMA), 23.6% EDMA, and 60% porogens (36% 1-propanol, 18% 1,4-butanediol along with 6% lipase aqueous solution in potassium phosphate buffer. The prepared capillary columns were investigated for the enantioselective nano liquid chromatographic separation of a set of different classes of racemic pharmaceuticals, 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. Run-to-run repeatability was quite satisfactory. The encapsulated lipase-based capillary monolith showed better enantioselective separations of most of the investigated compounds. Baseline separation was achieved for alprenolol, atenolol, bromoglutithimide, carbuterol, chloropheneramine, cizolertine carbinol, 4-hydroxy-3-methoxymandelic acid, desmethylcizolertine, nomifensine, normetanephrine, and sulconazole under reversed phase chromatographic conditions. A speculation about the understanding of the chiral recognition mechanism of

  12. Monolithic Lumped Element Integrated Circuit (M2LEIC) Transistors.

    Science.gov (United States)

    INTEGRATED CIRCUITS, *MONOLITHIC STRUCTURES(ELECTRONICS), *TRANSISTORS, CHIPS(ELECTRONICS), FABRICATION, EPITAXIAL GROWTH, ULTRAHIGH FREQUENCY, POLYSILICONS, PHOTOLITHOGRAPHY, RADIOFREQUENCY POWER, IMPEDANCE MATCHING .

  13. Eruption column physics

    Energy Technology Data Exchange (ETDEWEB)

    Valentine, G.A.

    1997-03-01

    In this paper the author focuses on the fluid dynamics of large-scale eruption columns. The dynamics of these columns are rooted in multiphase flow phenomena, so a major part of the paper sets up a foundation on that topic that allows one to quickly assess the inherent assumptions made in various theoretical and experimental approaches. The first part is centered on a set of complex differential equations that describe eruption columns, but the focus is on a general understanding of important physical processes rather than on the mathematics. The author discusses briefly the relative merits and weaknesses of different approaches, emphasizing that the largest advances in understanding are made by combining them. He then focuses on dynamics of steady eruption columns and then on transient phenomena. Finally he briefly reviews the effects of varying behavior of the ambient medium through which an eruption column moves. These final sections will emphasize concepts and a qualitative understanding of eruption dynamics. This paper relies on principles of continuum mechanics and transport processes but does not go into detail on the development of those principles. 36 refs., 36 figs., 3 tabs.

  14. Poly(glycidyl methacrylate-co-N-methylolacrylamide-co-ethylene dimethacrylate) monolith coupled to high-performance liquid chromatography for the determination of adenosine phosphates in royal jelly.

    Science.gov (United States)

    Liu, Dan; Zhang, Tianbin; Cheng, Yechun; Jia, Qiong

    2014-07-01

    A polymer monolith microextraction method coupled with high-performance liquid chromatography was developed for the determination of adenosine triphosphate, adenosine diphosphate, and adenosine monophosphate. The monolithic column was synthesized inside fused-silica capillaries using thermal initiation free-radical polymerization with glycidyl methacrylate as the monomer, ethylene dimethacrylate as the cross-linker, cyclohexanol, and 1-dodecanol as the porogen. N-Methylolacrylamide, an important hydrophilic monomer, was incorporated into the polymerization mixture to enhance the hydrophilicity of the poly(glycidyl methacrylate-co-ethylene dimethacrylate) column. The obtained poly(glycidyl methacrylate-co-N-methylolacrylamide-co-ethylene dimethacrylate) monolith was characterized by scanning electron microscopy, Fourier-transform infrared spectra, and X-ray photoelectron spectroscopy. Optimum conditions for the preconcentration and separation of the target adenosines were also investigated. Under the optimum conditions, we obtained acceptable linearities, low limits of detection, and good relative standard deviations. The developed polymer monolith microextraction with high-performance liquid chromatography method exhibited a good performance with recovery values in the range of 76.9-104.7% when applied to the determination of the adenosines in five royal jelly samples.

  15. 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.

  16. 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...

  17. Columns in Clay

    Science.gov (United States)

    Leenhouts, Robin

    2010-01-01

    This article describes a clay project for students studying Greece and Rome. It provides a wonderful way to learn slab construction techniques by making small clay column capitols. With this lesson, students learn architectural vocabulary and history, understand the importance of classical architectural forms and their influence on today's…

  18. 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 separation...

  19. Rapid determination of simple polyphenols in grapes by HPLC using a monolithic column

    OpenAIRE

    Liazid, Ali; Fernández Barbero, Gerardo; Palma Lovillo, Miguel; Brigui, Jamal; García Barroso, Carmelo

    2010-01-01

    The development of a rapid, reliable and reproducible LC method for the determination and quantification of 13 polyphenols (gallic acid, protocatechuic aldehyde, gentisic acid, catechin, vanillinic acid, caffeic acid, vanillin, epicatechin, syringaldehyde, p-coumaric acid, ferulic acid, sinapic acid and resveratrol) in grapes and derived products is reported.

  20. 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.

  1. CIM(®) monolithic anion-exchange chromatography as a useful alternative to CsCl gradient purification of bacteriophage particles.

    Science.gov (United States)

    Adriaenssens, Evelien M; Lehman, Susan M; Vandersteegen, Katrien; Vandenheuvel, Dieter; Philippe, Didier L; Cornelissen, Anneleen; Clokie, Martha R J; García, Andrés J; De Proft, Maurice; Maes, Martine; Lavigne, Rob

    2012-12-20

    The use of anion-exchange chromatography was investigated as an alternative method to concentrate and purify bacterial viruses, and parameters for different bacteriophages were compared. Chromatography was performed with Convective Interactive Media(®) monoliths, with three different volumes and two matrix chemistries. Eleven morphologically distinct phages were tested, infecting five different bacterial species. For each of the phages tested, a protocol was optimized, including the choice of column chemistry, loading, buffer and elution conditions. The capacity and recovery of the phages on the columns varied considerably between phages. We conclude that anion-exchange chromatography with monoliths is a valid alternative to the more traditional CsCl purification, has upscaling advantages, but it requires more extensive optimization.

  2. 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

  3. A Monolithic Perovskite Structure for Use as a Magnetic Regenerator

    DEFF Research Database (Denmark)

    Pryds, Nini; Clemens, Frank; Menon, Mohan

    2011-01-01

    A La0.67Ca0.26Sr0.07Mn1.05O3 (LCSM) perovskite was prepared for the first time as a ceramic monolithic regenerator used in a regenerative magnetic refrigeration device. The parameters influencing the extrusion process and the performance of the regenerator, such as the nature of the monolith paste...

  4. Time-based position estimation in monolithic scintillator detectors

    NARCIS (Netherlands)

    Tabacchini, V.; Borghi, G.; Schaart, D.R.

    2015-01-01

    Gamma-ray detectors based on bright monolithic scintillation crystals coupled to pixelated photodetectors are currently being considered for several applications in the medical imaging field. In a typical monolithic detector, both the light intensity and the time of arrival of the earliest scintilla

  5. 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

  6. 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.

  7. A new large area monolithic silicon telescope

    CERN Document Server

    Tudisco, S; Cabibbo, M; Cardella, G; De Geronimo, G; Di Pietro, A; Fallica, G; Figuera, P; Musumarra, A; Papa, M; Pappalardo, G S; Rizzo, F; Valvo, G

    1999-01-01

    A new prototype of large area (20x20 mm sup 2) monolithic silicon telescope with an ultrathin DELTA E stage (1 mu m) has been built and tested. A particular mask for the ground electrode has been developed to improve the charge collection reducing the induction between the E and DELTA E stages. A special designed preamplifier has been used for the readout of the signal from the DELTA E stage to overcome the problem of the large input capacitance (40 nF). A rather low energy threshold charge discrimination has been obtained. Small side effects due to the electric field deformation near the ground electrode were observed and quantified.

  8. High-internal-phase-emulsion polymeric monolith coupled with liquid chromatography-electrospray tandem mass spectrometry for enrichment and sensitive detection of trace cytokinins in plant samples.

    Science.gov (United States)

    Du, Fuyou; Sun, Lin; Zhen, Xian; Nie, Honggang; Zheng, Yanjie; Ruan, Guihua; Li, Jianping

    2015-08-01

    High-internal-phase-emulsion polymers (polyHIPEs) show great promise as solid-phase-extraction (SPE) materials because of the tremendous porosity and highly interconnected framework afforded by the high-internal-phase-emulsion (HIPE) technique. In this work, polyHIPE monolithic columns as novel SPE materials were prepared and applied to trace enrichment of cytokinins (CKs) from complex plant samples. The polyHIPE monoliths were synthesized via the in-situ polymerization of the continuous phase of a HIPE containing styrene (STY) and divinylbenzene (DVB) in a stainless column, and revealed highly efficient and selective enrichment ability for aromatic compounds. Under the optimized experimental conditions, a method using a monolithic polyHIPE column combined with liquid chromatography-electrospray tandem mass spectrometry (LC-MS-MS) was developed for the simultaneous extraction and sensitive determination of trans-zeatin (tZ), meta-topolin (mT), kinetin (K), and kinetin riboside (KR). The proposed method had good linearity, with correlation coefficients (R (2)) from 0.9957 to 0.9984, and low detection limits (LODs, S/N = 3) in the range 2.4-47 pg mL(-1) for the four CKs. The method was successfully applied to the determination of CKs in real plant samples, and obtained good recoveries ranging from 68.8 % to 103.0 % and relative standard deviations (RSDs) lower than 16 %.

  9. 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.

  10. Impact of mobile phase composition on the performance of porous polymeric monoliths in the elution of small molecules.

    Science.gov (United States)

    Causon, Tim J; Hilder, Emily F; Nischang, Ivo

    2012-11-09

    The influence of mobile phase solvent composition and consequently retention factor on the chromatographic performance for a set of small molecules was studied using a commercially available poly(styrene-co-divinyl benzene) analytical scale porous polymeric monolithic column as an example. Chromatographic elution performance was studied across retention factors from close to 0 up to 100 realized for a set of structurally similar small molecules in a binary reversed-phase solvent environment of acetonitrile and water. By altering the mobile phase composition from volume fractions of acetonitrile of just 10% (v/v) to only acetonitrile it was systematically shown that gel porosity of the monolithic column plays a dominant role in modulating mass transport and the associated chromatographic efficiency in a consistent manner. Up to a sixfold difference in plate height was recorded for the most strongly retained hydrophobic solute (ethylbenzene) at a constant, low flow velocity simply by varying the amount of acetonitrile in the mobile phase. Plate height curves recorded for the set of solutes that comprise benzene, toluene, ethylbenzene as well as phenol and benzyl alcohol further demonstrate the importance of functional group content of the solute and the modulated porous gel structure on mass transport. These results highlight some important practical considerations for characterizing the chromatographic properties of any polymeric monolithic column. First, it is imperative that any chromatographic performance characterization using plate height data explicitly considers the influence of mobile phase composition, retention factor, molecular size and functional groups of the probe solute. Second, as the physicochemical conditions of the material are directly reflected in the gel porosity, a range of different mobile phase compositions, retention factors and probe-specific effects must be investigated to yield a fair appraisal of the chromatographic performance.

  11. Slurry bubble column hydrodynamics

    Science.gov (United States)

    Rados, Novica

    Slurry bubble column reactors are presently used for a wide range of reactions in both chemical and biochemical industry. The successful design and scale up of slurry bubble column reactors require a complete understanding of multiphase fluid dynamics, i.e. phase mixing, heat and mass transport characteristics. The primary objective of this thesis is to improve presently limited understanding of the gas-liquid-solid slurry bubble column hydrodynamics. The effect of superficial gas velocity (8 to 45 cm/s), pressure (0.1 to 1.0 MPa) and solids loading (20 and 35 wt.%) on the time-averaged solids velocity and turbulent parameter profiles has been studied using Computer Automated Radioactive Particle Tracking (CARPT). To accomplish this, CARPT technique has been significantly improved for the measurements in highly attenuating systems, such as high pressure, high solids loading stainless steel slurry bubble column. At a similar set of operational conditions time-averaged gas and solids holdup profiles have been evaluated using the developed Computed Tomography (CT)/Overall gas holdup procedure. This procedure is based on the combination of the CT scans and the overall gas holdup measurements. The procedure assumes constant solids loading in the radial direction and axially invariant cross-sectionally averaged gas holdup. The obtained experimental holdup, velocity and turbulent parameters data are correlated and compared with the existing low superficial gas velocities and atmospheric pressure CARPT/CT gas-liquid and gas-liquid-solid slurry data. The obtained solids axial velocity radial profiles are compared with the predictions of the one dimensional (1-D) liquid/slurry recirculation phenomenological model. The obtained solids loading axial profiles are compared with the predictions of the Sedimentation and Dispersion Model (SDM). The overall gas holdup values, gas holdup radial profiles, solids loading axial profiles, solids axial velocity radial profiles and solids

  12. 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.

  13. 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 collapses....

  14. 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

  15. 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.

  16. 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.

  17. Chromatographic Monoliths for High-Throughput Immunoaffinity Isolation of Transferrin from Human Plasma

    Directory of Open Access Journals (Sweden)

    Irena Trbojević-Akmačić

    2016-06-01

    Full Text Available Changes in protein glycosylation are related to different diseases and have a potential as diagnostic and prognostic disease biomarkers. Transferrin (Tf glycosylation changes are common marker for congenital disorders of glycosylation. However, biological interindividual variability of Tf N-glycosylation and genes involved in glycosylation regulation are not known. Therefore, high-throughput Tf isolation method and large scale glycosylation studies are needed in order to address these questions. Due to their unique chromatographic properties, the use of chromatographic monoliths enables very fast analysis cycle, thus significantly increasing sample preparation throughput. Here, we are describing characterization of novel immunoaffinity-based monolithic columns in a 96-well plate format for specific high-throughput purification of human Tf from blood plasma. We optimized the isolation and glycan preparation procedure for subsequent ultra performance liquid chromatography (UPLC analysis of Tf N-glycosylation and managed to increase the sensitivity for approximately three times compared to initial experimental conditions, with very good reproducibility. This work is licensed under a Creative Commons Attribution 4.0 International License.

  18. Benzalkonium Chloride and Glaucoma

    OpenAIRE

    Rasmussen, Carol A.; Kaufman, Paul L.; Kiland, Julie A.

    2014-01-01

    Glaucoma patients routinely take multiple medications, with multiple daily doses, for years or even decades. Benzalkonium chloride (BAK) is the most common preservative in glaucoma medications. BAK has been detected in the trabecular meshwork (TM), corneal endothelium, lens, and retina after topical drop installation and may accumulate in those tissues. There is evidence that BAK causes corneal and conjunctival toxicity, including cell loss, disruption of tight junctions, apoptosis and preapo...

  19. Hierarchically Structured Monolithic ZSM-5 through Macroporous Silica Gel Zeolitization

    Institute of Scientific and Technical Information of China (English)

    Lei Qian; Zhao Tianbo; Li Fengyan; Zong Baoning; Tong Yangchuan

    2006-01-01

    The hierarchically structured ZSM-5 monolith was prepared through transforming the skeletons of the macroporous silica gel into ZSM-5 by the steam-assisted conversion method. The morphology and monolithic shapes of macroporous silica gel were well preserved. The hierarchically structured ZSM-5 monolith exhibited the hierarchical porosity, with mesopores and macropores existing inside the macroporous silica gel, and micropores formed by the ZSM-5. The products have been characterized properly by using the XRD, SEM and N2 adsorption-desorption methods.

  20. 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.

  1. 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.

  2. Preliminary comparison of monolithic and aperture optics for XRMF

    Energy Technology Data Exchange (ETDEWEB)

    Havrilla, G.J.; Worley, C.G.

    1997-08-01

    Comparisons between standard aperture optics and a custom designed monolithic capillary x-ray optic for the Kevex Omicron are presented. The results demonstrate the feasibility of retrofitting an Omicron with a monolithic capillary. Increased flux is observed especially at lower energies which results in an increase in sensitivity and potentially an increase in spatial resolution. Alignment is a critical factor in achieving optimal performance of the monolithic capillary. Further improvements in flux output, spot size and overall sensitivity are expected with better alignment.

  3. 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.

  4. 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

  5. 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%

  6. A monolithic thin film electrochromic window

    Energy Technology Data Exchange (ETDEWEB)

    Goldner, R.B.; Arntz, F.O.; Berera, G.; Haas, T.E.; Wong, K.K. (Tufts Univ., Medford, MA (United States). Electro-Optics Technology Center); Wei, G. (Mobil Solar Energy Corp., Billerica, MA (United States)); Yu, P.C. (PPG Industries, Inc., Monroeville, PA (United States))

    1991-01-01

    Three closely related thin film solid state ionic devices that are potentially important for applications are: electrochromic smart windows, high energy density thin film rechargeable batteries, and thin film electrochemical sensors. Each usually has at least on mixed ion/electron conductor, an electron-blocking ion conductor, and an ion-blocking electron conductor, and many of the technical issues associated with thin film solid state ionics are common to all three devices. Since the electrochromic window has the added technical requirement of electrically-controlled optical modulation, (over the solar spectrum), and since research at the authors' institution has focused primarily on the window structure, this paper will address the electrochromic window, and particularly a monolithic variable reflectivity electrochromic window, as an illustrative example of some of the challenges and opportunities that are confronting the thin film solid state ionics community. 33 refs.

  7. A monolithic thin film electrochromic window

    Energy Technology Data Exchange (ETDEWEB)

    Goldner, R.B.; Arntz, F.O.; Berera, G.; Haas, T.E.; Wong, K.K. [Tufts Univ., Medford, MA (United States). Electro-Optics Technology Center; Wei, G. [Mobil Solar Energy Corp., Billerica, MA (United States); Yu, P.C. [PPG Industries, Inc., Monroeville, PA (United States)

    1991-12-31

    Three closely related thin film solid state ionic devices that are potentially important for applications are: electrochromic smart windows, high energy density thin film rechargeable batteries, and thin film electrochemical sensors. Each usually has at least on mixed ion/electron conductor, an electron-blocking ion conductor, and an ion-blocking electron conductor, and many of the technical issues associated with thin film solid state ionics are common to all three devices. Since the electrochromic window has the added technical requirement of electrically-controlled optical modulation, (over the solar spectrum), and since research at the authors` institution has focused primarily on the window structure, this paper will address the electrochromic window, and particularly a monolithic variable reflectivity electrochromic window, as an illustrative example of some of the challenges and opportunities that are confronting the thin film solid state ionics community. 33 refs.

  8. Monolithically Peltier-cooled laser diodes

    Energy Technology Data Exchange (ETDEWEB)

    Hava, S.; Hunsperger, R.G.; Sequeira, H.B.

    1984-04-01

    A new method of cooling a GaAs/GaAlAs laser in an optical integrated circuit or on a discrete chip, by adding an integral thermoelectric (Peltier) cooling and heat spreading device to the laser, is presented. This cooling both reduces and stabilizes the laser junction temperature to minimize such deleterious effects as wavelength drift due to heating. A unified description of the electrical and thermal properties of a monolithic semiconductor mesa structure is given. Here it is shown that an improvement in thermal characteristics is obtained by depositing a relatively thick metallic layer, and by using this layer as a part of an active Peltier structure. Experimental results reveal a 14-percent increase in emitted power (external quantum efficiency) due to passive heat spreading and a further 8-percent if its Peltier cooler is operated. Fabrication techniques used to obtain devices exhibiting the above performance characteristics are given. 21 references.

  9. LSST primary/tertiary monolithic mirror

    Science.gov (United States)

    Sebag, J.; Gressler, W.; Liang, M.; Neill, D.; Araujo-Hauck, C.; Andrew, J.; Angeli, G.; Cho, M.; Claver, C.; Daruich, F.; Gessner, C.; Hileman, E.; Krabbendam, V.; Muller, G.; Poczulp, G.; Repp, R.; Wiecha, O.; Xin, B.; Kenagy, K.; Martin, H. M.; Tuell, M. T.; West, S. C.

    2016-08-01

    At the core of the Large Synoptic Survey Telescope (LSST) three-mirror optical design is the primary/tertiary (M1M3) mirror that combines these two large mirrors onto one monolithic substrate. The M1M3 mirror was spin cast and polished at the Steward Observatory Mirror Lab at The University of Arizona (formerly SOML, now the Richard F. Caris Mirror Lab at the University of Arizona (RFCML)). Final acceptance of the mirror occurred during the year 2015 and the mirror is now in storage while the mirror cell assembly is being fabricated. The M1M3 mirror will be tested at RFCML after integration with its mirror cell before being shipped to Chile.

  10. Solid oxide fuel cell having monolithic core

    Science.gov (United States)

    Ackerman, J. P.; Young, J. E.

    1983-10-01

    A solid oxide fuel cell is described for electrochemically combining fuel and oxidant for generating galvanic output, wherein the cell core has an array of electrolyte and interconnect walls that are substantially devoid of any composite inert materials for support. The core is monolithic, where each electrolyte wall consists of thin layers of cathode and anode materials sandwiching a thin layer of electrolyte material. The electrolyte walls are arranged and backfolded between adjacent interconnect walls operable to define a plurality of core passageways alternately arranged where the inside faces have only the anode material or only the cathode material exposed. Each layer of the electrolyte and interconnect materials 0.002 to 0.01 cm thick; and each layer of the cathode and anode materials is 0.002 to 0.05 cm thick.

  11. Purification of papain using reactive green 5 attached supermacroporous monolithic cryogel.

    Science.gov (United States)

    Uygun, Deniz Aktaş; Akduman, Begüm; Uygun, Murat; Akgöl, Sinan; Denizli, Adil

    2012-06-01

    Supermacroporous poly(2-hydroxyethyl methacrylate) [poly(HEMA)] monolithic cryogel was prepared by radical cryocopolymerization of HEMA with N,N'-methylene bisacrylamide as crosslinker. Reactive Green 5 dye was immobilized to the cryogel with nucleophilic substitution reaction, and this dye attached cryogel column was used for affinity purification of papain from Carica papaya latex. Reactive Green 5-immobilized poly(HEMA) cryogel was characterized by swelling studies, Fourier transform infrared spectroscopy, scanning electron microscopy, and energy dispersive X-ray analysis. Maximum papain adsorption capacity was found to be 68.5 mg/g polymer while nonspecific papain adsorption onto plain cryogel was negligible (3.07 mg/g polymer). Papain from C. papaya was purified 42-fold in single step with dye attached cryogel, and purity of papain was shown by silver-stained sodium dodecyl sulfate-polyacrylamide gel electrophoresis.

  12. Determination of imidazole derivatives by micellar electrokinetic chromatography combined with solid-phase microextraction using activated carbon-polymer monolith as adsorbent.

    Science.gov (United States)

    Shih, Yung-Han; Lirio, Stephen; Li, Chih-Keng; Liu, Wan-Ling; Huang, Hsi-Ya

    2016-01-08

    In this study, an effective method for the separation of imidazole derivatives 2-methylimidazole (2-MEI), 4- methylimidazole (4-MEI) and 2-acetyl-4-tetrahydroxybutylimidazole (THI) in caramel colors using cation-selective exhaustive injection and sweeping micellar electrokinetic chromatography (CSEI-sweeping-MEKC) was developed. The limits of detection (LOD) and quantitation (LOQ) for the CSEI-sweeping-MEKC method were in the range of 4.3-80μgL(-1) and 14-270μgL(-1), respectively. Meanwhile, a rapid fabrication activated carbon-polymer (AC-polymer) monolithic column as adsorbent for solid-phase microextraction (SPME) of imidazole colors was developed. Under the optimized SPME condition, the extraction recoveries for intra-day, inter-day and column-to-column were in the range of 84.5-95.1% (<6.3% RSDs), 85.6-96.1% (<4.9% RSDs), and 81.3-96.1% (<7.1% RSDs), respectively. The LODs and LOQs of AC-polymer monolithic column combined with CSEI-sweeping-MEKC method were in the range of 33.4-60.4μgL(-1) and 111.7-201.2μgL(-1), respectively. The use of AC-polymer as SPME adsorbent demonstrated the reduction of matrix effect in food samples such as soft drink and alcoholic beverage thereby benefiting successful determination of trace-level caramel colors residues using CSEI-sweeping-MEKC method. The developed AC-polymer monolithic column can be reused for more than 30 times without any significant loss in the extraction recovery for imidazole derivatives.

  13. 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.

  14. 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 ions....

  15. 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.

  16. 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.

  17. Reliability Analysis and Optimal Design of Monolithic Vertical Wall Breakwaters

    DEFF Research Database (Denmark)

    Sørensen, John Dalsgaard; Burcharth, Hans F.; Christiani, E.

    1994-01-01

    Reliability analysis and reliability-based design of monolithic vertical wall breakwaters are considered. Probabilistic models of the most important failure modes, sliding failure, failure of the foundation and overturning failure are described . Relevant design variables are identified and relia......Reliability analysis and reliability-based design of monolithic vertical wall breakwaters are considered. Probabilistic models of the most important failure modes, sliding failure, failure of the foundation and overturning failure are described . Relevant design variables are identified...

  18. Sol-Gel Synthesis of Non-Silica Monolithic Materials

    Directory of Open Access Journals (Sweden)

    Bartłomiej Gaweł

    2010-04-01

    Full Text Available Monolithic materials have become very popular because of various applications, especially within chromatography and catalysis. Large surface areas and multimodal porosities are great advantages for these applications. New sol-gel preparation methods utilizing phase separation or nanocasting have opened the possibility for preparing materials of other oxides than silica. In this review, we present different synthesis methods for inorganic, non-silica monolithic materials. Some examples of application of the materials are also included.

  19. 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.

  20. 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.

  1. Mechanically stable, hierarchically porous Cu3(btc)2 (HKUST-1) monoliths via direct conversion of copper(II) hydroxide-based monoliths.

    Science.gov (United States)

    Moitra, Nirmalya; Fukumoto, Shotaro; Reboul, Julien; Sumida, Kenji; Zhu, Yang; Nakanishi, Kazuki; Furukawa, Shuhei; Kitagawa, Susumu; Kanamori, Kazuyoshi

    2015-02-28

    The synthesis of highly crystalline macro-meso-microporous monolithic Cu3(btc)2 (HKUST-1; btc(3-) = benzene-1,3,5-tricarboxylate) is demonstrated by direct conversion of Cu(OH)2-based monoliths while preserving the characteristic macroporous structure. The high mechanical strength of the monoliths is promising for possible applications to continuous flow reactors.

  2. Oxomemazine hydro-chloride.

    Science.gov (United States)

    Siddegowda, M S; Butcher, Ray J; Akkurt, Mehmet; Yathirajan, H S; Ramesh, A R

    2011-08-01

    IN THE TITLE COMPOUND [SYSTEMATIC NAME: 3-(5,5-dioxo-phen-othia-zin-10-yl)-N,N,2-trimethyl-propanaminium chloride], C(18)H(23)N(2)O(2)S(+)·Cl(-), the dihedral angle between the two outer aromatic rings of the phenothia-zine unit is 30.5 (2)°. In the crystal, the components are linked by N-H⋯Cl and C-H⋯Cl hydrogen bonds and C-H⋯π inter-actions.

  3. 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...

  4. 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

  5. Why Hexagonal Basalt Columns?

    Science.gov (United States)

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

    2015-10-09

    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.

  6. 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.

  7. Monoliths: A Review of the Basics, Preparation Methods and Their Relevance to Oxidation

    Directory of Open Access Journals (Sweden)

    Sandeeran Govender

    2017-02-01

    Full Text Available Considerable research has been conducted on monolithic catalysts for various applications. Strategies toward coating monoliths are of equal interest and importance. In this paper, the preparation of monoliths and monolithic catalysts have been summarized. More specifically, a brief explanation for the manufacturing of ceramic and metallic monoliths has been provided. Also, different methods for coating γ-alumina, as a secondary support, are included. Techniques used to deposit metal-based species, zeolites and carbon onto monoliths are discussed. Furthermore, monoliths extruded with metal oxides, zeolites and carbon are described. The main foci are on the reasoning and understanding behind the preparation of monolithic catalysts. Ideas and concerns are also contributed to encourage better approaches when designing these catalysts. More importantly, the relevance of monolithic structures to reactions, such as the selective oxidation of alkanes, catalytic combustion for power generation and the preferential oxidation of carbon monoxide, has been described.

  8. 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.

  9. 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

    2016-01-08

    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% (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 river water and 81.1% to 100

  10. 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

  11. 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.

  12. 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.

  13. 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.

  14. Dedicated monolithic infrared spectrometer for process monitoring

    Science.gov (United States)

    Chadha, Suneet; Kyle, William; Bolduc, Roy A.; Curtiss, Lawrence E.

    1999-12-01

    Foster-Miller has leveraged its innovations in IR fiber- optic probes and the recent development of a miniature spectrometer to build a novel IR sensor system for process applications. The developed sensor systems is a low-cost alternative to process FTIR and filter based systems. A monolithic wedge-grating optic provides the spectral dispersion with low cost thermopile point or array detectors picking off the diffracted wavelengths from the optic. The integrated optic provides spectral discrimination between 3- 12 micrometers with resolution at 8 cm-1 or better and high overall optical throughput. The device has a fixed cylindrical grating uniquely bonded to the edge of a ZnSe conditioning 'wedge'. The conditioning optic overcomes limitations of concave gratings as it accepts high angle light at the narrow end of the wedge and progressively conditions it to be near normal to the grating. On return, the diffracted wavelengths are concentrated on the discrete or array detector elements by the wedge, providing throughput comparable to that of an FTIR. The miniature spectrometer coupled to flow through liquid cells or multipass gas cells provides significant cost advantage over conventional sampling methodologies. Currently, we are investigating process applications for the petroleum and dairy markets. The sensor system eliminates the cost, complexity, reliability and bandwidth/resolution problems associated with either Fabry Perot or Michelson Interferometer based approaches for low-cost process applications.

  15. The Advanced Virgo monolithic fused silica suspension

    Energy Technology Data Exchange (ETDEWEB)

    Aisa, D.; Aisa, S.; Campeggi, C.; Colombini, M. [University of Perugia and INFN Perugia (Italy); Conte, A. [University of Roma Sapienza and INFN Roma (Italy); Farnesini, L. [University of Perugia and INFN Perugia (Italy); Majorana, E.; Mezzani, F. [University of Roma Sapienza and INFN Roma (Italy); Montani, M. [University of Urbino and INFN Firenze (Italy); Naticchioni, L.; Perciballi, M. [University of Roma Sapienza and INFN Roma (Italy); Piergiovanni, F. [University of Urbino and INFN Firenze (Italy); Piluso, A. [University of Perugia and INFN Perugia (Italy); Puppo, P., E-mail: paola.puppo@roma1.infn.it [University of Roma Sapienza and INFN Roma (Italy); Rapagnani, P. [University of Roma Sapienza and INFN Roma (Italy); Travasso, F. [University of Perugia and INFN Perugia (Italy); Vicerè, A. [University of Urbino and INFN Firenze (Italy); Vocca, H. [University of Perugia and INFN Perugia (Italy)

    2016-07-11

    The detection of gravitational waves is one of the most challenging prospects faced by experimental physicists. Suspension thermal noise is an important noise source at operating frequencies between approximately 10 and 30 Hz, and represents a limit to the sensitivity of the ground based interferometric gravitational wave detectors. Its effects can be reduced by minimizing the losses and by optimizing the geometry of the suspension fiber as well as its attachment system. In this proceeding we will describe the mirrors double stage monolithic suspension system to be used in the Advanced Virgo (AdV) detector. We also present the results of the thermal noise study, performed with the help of a finite elements model, taking into account the precise geometry of the fibers attachment systems on the suspension elements. We shall demonstrate the suitability of this suspension for installation in AdV. - Highlights: • Suspension system design for the test masses of the gravitational wave detectors. • Finite element model studies. • Suspension thermal noise studies.

  16. 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.

  17. Benzalkonium chloride and glaucoma.

    Science.gov (United States)

    Rasmussen, Carol A; Kaufman, Paul L; Kiland, Julie A

    2014-01-01

    Glaucoma patients routinely take multiple medications, with multiple daily doses, for years or even decades. Benzalkonium chloride (BAK) is the most common preservative in glaucoma medications. BAK has been detected in the trabecular meshwork (TM), corneal endothelium, lens, and retina after topical drop installation and may accumulate in those tissues. There is evidence that BAK causes corneal and conjunctival toxicity, including cell loss, disruption of tight junctions, apoptosis and preapoptosis, cytoskeleton changes, and immunoinflammatory reactions. These same effects have been reported in cultured human TM cells exposed to concentrations of BAK found in common glaucoma drugs and in the TM of primary open-angle glaucoma donor eyes. It is possible that a relationship exists between chronic exposure to BAK and glaucoma. The hypothesis that BAK causes/worsens glaucoma is being tested experimentally in an animal model that closely reflects human physiology.

  18. Chloride on the Move

    KAUST Repository

    Li, Bo

    2017-01-09

    Chloride (Cl−) is an essential plant nutrient but under saline conditions it can accumulate to toxic levels in leaves; limiting this accumulation improves the salt tolerance of some crops. The rate-limiting step for this process – the transfer of Cl− from root symplast to xylem apoplast, which can antagonize delivery of the macronutrient nitrate (NO3−) to shoots – is regulated by abscisic acid (ABA) and is multigenic. Until recently the molecular mechanisms underpinning this salt-tolerance trait were poorly defined. We discuss here how recent advances highlight the role of newly identified transport proteins, some that directly transfer Cl− into the xylem, and others that act on endomembranes in ‘gatekeeper’ cell types in the root stele to control root-to-shoot delivery of Cl−.

  19. Practical design of stepped columns

    NARCIS (Netherlands)

    Girao Coelho, A.M.; Simao, P.D.; Bijlaard, F.S.K.

    2012-01-01

    This paper deals with buckling aspects of the design of stepped columns in heavy mill buildings. In these structures, columns have to carry significant axial loads that usually act eccentrically and strength reducing bending moments due to lateral loads. A simple physical model for buckling behaviou

  20. 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)

  1. 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

  2. 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

  3. 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.

  4. Recent advances in polymer monoliths for ion-exchange chromatography.

    Science.gov (United States)

    Nordborg, Anna; Hilder, Emily F

    2009-05-01

    The use of polymeric materials in ion-exchange chromatography applications is advantageous because of their typically high mechanical stability and tolerance of a wide range of pH conditions. The possibility of using polymeric monoliths in ion-exchange chromatography is therefore obvious and many of the same strategies developed for polymeric particles have been adapted for use with polymeric monoliths. In this review different strategies for the synthesis of polymeric monoliths with ion-exchange functionality are discussed. The incorporation of ion-exchange functionality by co-polymerization is included, as also are different post-polymerization alterations to the monolith surface such as grafting. The formulations and strategies presented include materials intended for use in analytical separations in ion-exchange chromatography, sample pre-treatment or enrichment applications, and materials for capillary electrochromatography. Finally, examples of the use of polymeric monoliths in ion-exchange chromatography applications are included with examples published in the years 2003 to 2008.

  5. 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.

  6. 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

  7. 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

  8. Monolithic Solid Oxide Fuel Cell development

    Science.gov (United States)

    Myles, K. M.; McPheeters, C. C.

    1989-12-01

    The Monolithic Solid Oxide Fuel Cell (MSOFC) is an oxide-ceramic structure in which appropriate electronic and ionic conductors are fabricated in a honeycomb shape similar to a block of corrugated paperboard. These electronic and ionic conductors are arranged to provide short conduction paths to minimize resistive losses. The power density achievable with the MSOFC is expected to be about 8 kW/kg or 4 kW/L, at fuel efficienceis over 50 percent, because of small cell size and low resistive losses in the materials. The MSOFC operates in the range of 700 to 1000 C, at which temperatures rapid reform of hydrocarbon fuels is expected within the nickel-YSZ fuel channels. Tape casting and hot roll calendering are used to fabricate the MSOFC structure. The performance of the MSOFC has improved significantly during the course of development. The limitation of this system, based on materials resistance alone without interfacial resistances, is 0.093 ohm-sq cm area-specific resistance (ASR). The current typical performance of MSOFC single cells is characterized by ASRs of about 0.4 to 0.5 ohm-sq cm. With further development the ASR is expected to be reduced below 0.2 ohm-sq cm, which will result in power levels greater than 1.4 W/sq cm. The feasibility of the MSOFC concept was proven, and the performance was dramatically improved. The differences in thermal expansion coefficients and firing shrinkages among the fuel cell materials were minimized. As a result of good matching of these properties, the MSOFC structure was successfully fabricated with few defects, and the system shows excellent promise for development into a practical power source.

  9. Exergetic and economic analysis of an industrial distillation column

    Directory of Open Access Journals (Sweden)

    A. C. B. Araújo

    2007-09-01

    Full Text Available In this work, applications of exergy and economic concepts to compression, heat exchange, and separation processes were used for calculation of the irreversibility rate, thermodynamic efficiency, and internal rate of return (IRR of the profitability. A case study based on a real process, the purification of 1,2-dichloroethane (DCE in a high-purity distillation column, is presented. This column has the highest steam flow rate in any vinyl chloride monomer (VCM plant. A configuration using a vapor compression heat pump is proposed for improvement of the energy efficiency without having to make important process modifications. Existing and proposed configurations were implemented using the Aspen Plus™ commercial simulator; the results of the existing configuration were validated with data extracted from the plant. The objective of this work was to compare the existing configuration with the proposed one, using a thermodynamic and an economic approach.

  10. 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.

  11. 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.

  12. MONOLITHIC FUEL FABRICATION PROCESS DEVELOPMENT AT THE IDAHO NATIONAL LABORATORY_

    Energy Technology Data Exchange (ETDEWEB)

    G. A. Moore; F. J. Rice; N. E. Woolstenhulme; J-F. Jue; B. H. Park; S. E. Steffler; N. P. Hallinan; M. D. Chapple; M. C. Marshall; B. L. Mackowiak; C. R. Clark; B. H. Rabin

    2009-11-01

    Full-size/prototypic U10Mo monolithic fuel-foils and aluminum clad fuel plates are being developed at the Idaho National Laboratory’s (INL) Materials and Fuels Complex (MFC). These efforts are focused on realizing Low Enriched Uranium (LEU) high density monolithic fuel plates for use in High Performance Research and Test Reactors. The U10Mo fuel foils under development afford a fuel meat density of ~16 gU/cc and thus have the potential to facilitate LEU conversions without any significant reactor-performance penalty. An overview is provided of the ongoing monolithic UMo fuel development effort, including application of a zirconium barrier layer on fuel foils, fabrication scale-up efforts, and development of complex/graded fuel foils. Fuel plate clad bonding processes to be discussed include: Hot Isostatic Pressing (HIP) and Friction Bonding (FB).

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

    Science.gov (United States)

    Brown, Daniel; Alder, Andy; Bemand, Elizabeth

    2015-05-01

    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 otherwise dispersed small communities.

  14. 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.

  15. 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.

  16. Preparation of poly(γ-glutamic acid)/hydroxyapatite monolith via biomineralization for bone tissue engineering.

    Science.gov (United States)

    Park, Sung-Bin; Hasegawa, Urara; van der Vlies, André J; Sung, Moon-Hee; Uyama, Hiroshi

    2014-01-01

    A hybrid monolith of poly(γ-glutamic acid) and hydroxyapatite (PGA/HAp monolith) was prepared via biomineralization and used as a macroporous cell scaffold in bone tissue engineering. The PGA monolith having a bimodal pore size distribution was used as a substrate to induce biomineralization. The PGA/HAp monolith was obtained by immersing the PGA monolith in simulated body fluid. Pretreatment with CaCl2 enhanced the apatite-forming ability of the PGA monolith. Murine osteoblastic MC3T3-E1 cells efficiently attached and proliferated on the PGA/HAp monolith. MTT assay showed that both the PGA and PGA/HAp monolith did not have apparent cytotoxicity. Moreover, the PGA and PGA/HAp monoliths adsorbed bone morphogenetic protein-2 (BMP-2) by electrostatic interaction which was slowly released in the medium during cell culture. The PGA/HAp monolith enhanced BMP-2 induced alkaline phosphatase activity compared to the PGA monolith and a polystyrene culture plate. Thus, these PGA/HAp monoliths may have potential in bone tissue engineering.

  17. Synthesis of ZSM-5 Monoliths with Hierarchical Porosity

    Institute of Scientific and Technical Information of China (English)

    Tong Yangchuan; Zhao Tianbo; Li Fengyan; Zong Baoning; Wang Yue

    2006-01-01

    A new route to synthesize ZSM-5 monoliths with hierarchical pore structure has been referred to in this stud y. The successful incorporation of the macropores and mesopores within the ZSM-5 structure was achieved through transforming the skeleton of the macroporous silica gel into zeolite ZSM-5 using carbon materials as the transitional template. The ZSM-5 crystal covered part of the macroporous material, and provided micropores to the macroporous silica gel. The structure of carbon monolith was studied after dissolving the silica contained in the carbon/silica composite.

  18. Monolithic Michelson Interferometer as ultra stable wavelength reference

    Science.gov (United States)

    Wan, Xiaoke; Ge, Jian

    2010-07-01

    Ultra-stable Monolithic Michelson interferometer can be an ideal reference for highprecision applications such as RV measurement in planet searching and orbit study. The advantages include wide wavelength range, simple sinusoidal spectral format, and high optical efficiency. In this paper, we report that a monolithic Michelson interferometers has been in-house developed with minimized thermal sensitivity with compensation tuning. With a scanning white light interferometer, the thermal sensitivity is measured ~ 6x10-7/°C at 550 nm and it decreases to zero near 1000 nm. We expect the wideband wavelength reference source to be stabilized better than 0.3 m/s for RV experiments

  19. A Monolithic Oxide-Based Transversal Thermoelectric Energy Harvester

    Science.gov (United States)

    Teichert, S.; Bochmann, A.; Reimann, T.; Schulz, T.; Dreßler, C.; Udich, S.; Töpfer, J.

    2016-03-01

    We report the fabrication and properties of a monolithic transversal thermoelectric energy harvester based on the combination of a thermoelectric oxide and a metal. The fabrication of the device is done with a ceramic multilayer technology using printing and co-firing processes. Five transversal devices were combined to a meander-like thermoelectric generator. Electrical measurements and finite element calculations were performed to characterize the resulting thermoelectric generator. A maximum experimental electrical power output of 30.2 mW at a temperature difference of {Δ }T = 208 K was found. The prepared monolithic thermoelectric generator provides at {Δ }T = 35 K sufficient energy to drive a simple electronic sensor application.

  20. 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.

  1. Lectin-carbohydrate interactions on nanoporous gold monoliths.

    Science.gov (United States)

    Tan, Yih Horng; Fujikawa, Kohki; Pornsuriyasak, Papapida; Alla, Allan J; Ganesh, N Vijaya; Demchenko, Alexei V; Stine, Keith J

    2013-07-01

    Monoliths of nanoporous gold (np-Au) were modified with self-assembled monolayers of octadecanethiol (C18-SH), 8-mercaptooctyl α-D-mannopyranoside (αMan-C8-SH), and 8-mercapto-3,6-dioxaoctanol (HO-PEG2-SH), and the loading was assessed using thermogravimetric analysis (TGA). Modification with mixed SAMs containing αMan-C8-SH (at a 0.20 mole fraction in the SAM forming solution) with either octanethiol or HO-PEG2-SH was also investigated. The np-Au monoliths modified with αMan-C8-SH bind the lectin Concanavalin A (Con A), and the additional mass due to bound protein was assessed using TGA analysis. A comparison of TGA traces measured before and after exposure of HO-PEG2-SH modified np-Au to Con A showed that the non-specific binding of Con A was minimal. In contrast, np-Au modified with octanethiol showed a significant mass loss due to non-specifically adsorbed Con A. A significant mass loss was also attributed to binding of Con A to bare np-Au monoliths. TGA revealed a mass loss due to the binding of Con A to np-Au monoliths modified with pure αMan-C8-SH. The use of mass losses determined by TGA to compare the binding of Con A to np-Au monoliths modified by mixed SAMs of αMan-C8-SH and either octanethiol or HO-PEG2-SH revealed that binding to mixed SAM modified surfaces is specific for the mixed SAMs with HO-PEG2-SH but shows a significant contribution from non-specific adsorption for the mixed SAMs with octanethiol. Minimal adsorption of immunoglobulin G (IgG) and peanut agglutinin (PNA) towards the mannoside modified np-Au monoliths was demonstrated. A greater mass loss was found for Con A bound onto the monolith than for either IgG or PNA, signifying that the mannose presenting SAMs in np-Au retain selectivity for Con A. TGA data also provide evidence that Con A bound to the αMan-C8-SH modified np-Au can be eluted by flowing a solution of methyl α-D-mannopyranoside through the structure. The presence of Con A proteins on the modified np-Au surface was

  2. 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...

  3. Studies Update Vinyl Chloride Hazards.

    Science.gov (United States)

    Rawls, Rebecca

    1980-01-01

    Extensive study affirms that vinyl chloride is a potent animal carcinogen. Epidemiological studies show elevated rates of human cancers in association with extended contact with the compound. (Author/RE)

  4. Constitutive Theory Developed for Monolithic Ceramic Materials

    Science.gov (United States)

    Janosik, Lesley A.

    1998-01-01

    with these service conditions by developing a multiaxial viscoplastic constitutive model that accounts for time-dependent hereditary material deformation (such as creep and stress relaxation) in monolithic structural ceramics. Using continuum principles of engineering mechanics, we derived the complete viscoplastic theory from a scalar dissipative potential function.

  5. 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

  6. Parameters Affecting Hydrogen Chloride Measurements

    Science.gov (United States)

    1993-06-01

    contain sea salt, which is hygroscopic because of the magnesium chloride present, or ammonium bisulfate , which mostly comes from sulfur pollution and is...boosters release hydrogen chloride as a combustion product, and hydrazines or nitric acid can be spilled from liquid fuel motors. Monitoring the...solubility constant, and the second is the acid ionization constant. From experimental work, the product of the two constants is well established (Reference

  7. Poly(N-vinylcarbazole-co-divinylbenzene) monolith microextraction coupled to liquid chromatography-high resolution Orbitrap mass spectrometry to analyse benzodiazepines in beer and urine.

    Science.gov (United States)

    Yao, Weixuan; Fan, Zhefeng; Zhang, Suling

    2016-09-23

    A poly(N-vinylcarbazole-co-divinylbenzene) (NVC/DVB) monolithic column was successfully prepared in a silanized capillary for microextraction of six benzodiazepines (BZPs) in complex samples. The polymerization was optimized primarily by changing the ratio of porogen content. The optimized polymer monolith had a homogeneous and continuous column bed, good permeability and mechanical stability. Poly(NVC/DVB) had good affinity to BZPs because of its through-pore structure and strong π-π stacking interactions derived from the rich benzene functional groups in the polymer. Potential factors that affect the extraction efficiency were studied in detail. In the optimized method, 3mL of sample (pH 2) was extracted with the polymer monolithic column and eluted with 80μL of methanol, and the eluent was analysed with ultra-high-performance liquid chromatography and quadrupole high resolution Orbitrap mass spectrometry (UHPLC/Q-Orbitrap MS). Under these conditions, the developed method gave the linear range of 0.005-0.5ng/mL for most of the six BZPs, whereas 0.05-0.5ng/mL for nitrazepam, 0.01-0.5ng/mL for lorazepam, respectively, with coefficients of determination (R(2))≥0.9991. The detection limits (LODs) were 1.08-6.04ng/L, and the quantification limits (LOQs) were 3.60-20.1ng/L. The method repeatability was investigated in terms of intra- and inter-day precision, which were indicated by relative standard deviations (RSDs) of ≤8.3% and ≤9.9%, respectively. Finally, the proposed method was successfully applied to detect BZPs in beer and human urine samples. The percentages of extraction recovery were 80.4-94.2% for beer and 79.6-95.2% for urine.

  8. Chromatographic comparison of bupivacaine imprinted polymers prepared in crushed monolith, microsphere, silica-based composite and capillary monolith formats.

    Science.gov (United States)

    Oxelbark, Joakim; Legido-Quigley, Cristina; Aureliano, Carla S A; Titirici, Maria-Magdalena; Schillinger, Eric; Sellergren, Börje; Courtois, Julien; Irgum, Knut; Dambies, Laurent; Cormack, Peter A G; Sherrington, David C; De Lorenzi, Ersilia

    2007-08-10

    A comprehensive comparison of five chromatographic stationary phases based on molecularly imprinted polymers is presented. Efficiency, imprinting factors, water compatibility and batch-to-batch reproducibility are discussed for crushed monolith, microspheres, two silica-based composites and capillary monoliths, all imprinted with the local anaesthetic bupivacaine. Synthesis protocol and chromatographic test conditions have been kept fixed within certain limits, in order to provide further insight into the strengths and weaknesses of the different formats. Excluding microparticles, all formats give satisfactory performance, especially in aqueous mobile phases. An assessment of batch-to-batch reproducibility in different mobile phases adds further value to this comparison study.

  9. 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.

  10. 21 CFR 184.1138 - Ammonium chloride.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Ammonium chloride. 184.1138 Section 184.1138 Food... Specific Substances Affirmed as GRAS § 184.1138 Ammonium chloride. (a) Ammonium chloride (NH4Cl, CAS Reg. No. 12125-02-9) is produced by the reaction of sodium chloride and an ammonium salt in solution....

  11. 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...

  12. 46 CFR 151.50-34 - Vinyl chloride (vinyl chloride monomer).

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 5 2010-10-01 2010-10-01 false Vinyl chloride (vinyl chloride monomer). 151.50-34... chloride (vinyl chloride monomer). (a) Copper, aluminum, magnesium, mercury, silver, and their alloys shall... equipment that may come in contact with vinyl chloride liquid or vapor. (b) Valves, flanges, and...

  13. 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... AIR POLLUTANTS National Emission Standard for Vinyl Chloride § 61.65 Emission standard for ethylene dichloride, vinyl chloride and polyvinyl chloride plants. An owner or operator of an ethylene...

  14. Extraction and Determination of Quercetin and Myricetin from Chamaecyparis obtusa by Ionic Liquids-based Monolithic Cartridge%Extraction and Determination of Quercetin and Myricetin from Chamaecyparis obtusa by Ionic Liquids-based Monolithic Cartridge

    Institute of Scientific and Technical Information of China (English)

    朱涛; 毕文韬; 卢敬昊

    2011-01-01

    A short ionic liquids (ILs)-based monolithic cartridge was prepared and used as the selective extraction sorbent. After the material was evaluated by field emission-scanning electron microscopy (FE-SEM), a new approach for the extraction and determination of quercetin and myricetin from Chamaecyparis obtusa (C. obtusa) by using ILs-based, monolithic cartridge system was developed. Chromatographic analysis was conducted on a C18 column with UV detection at 372 nm, an eluting solution consisting of acetonitrile-water (25/75, V/V) as the mobile phase, and a flow rate of 0.7 mLomin 1. A good linear relationship was demonstrated when the concentrations of quercetin and myricetin were in the range of 0.5--100.0 ggomL-1. The recoveries ranged from 101.6% to 104.6% and the inter- and intra-day relative standard deviations (RSD) were less than 5.0%. This method effectively removed the impurities and avoided tedious pretreatment. It provided a fast, economic and effective method for assaying trace drugs from natural plants.

  15. 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.

  16. Monolithic silica aerogel - material design on the nano-scale

    DEFF Research Database (Denmark)

    Jensen, Karsten Ingerslev; Schultz, Jørgen Munthe; Kristiansen, Finn Harken

    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...

  17. 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...

  18. Carbon monolith: preparation, characterization and application as microextraction fiber.

    Science.gov (United States)

    Shi, Zhi-Guo; Chen, Fei; Xing, Jun; Feng, Yu-Qi

    2009-07-10

    A carbon monolith was synthesized via a polymerization-carbonization method, styrene and divinylbenzene being adopted as precursors and dodecanol as a porogen during polymerization. The resultant monolith had bimodal porous substructure, narrowly distributed nano skeleton pores and uniform textural pores or throughpores. The carbon monolith was directly used as an extracting fiber, taking place of the coated silica fibers in commercially available solid-phase microextraction device, for the extraction of phenols followed by gas chromatography-mass spectrometry. Under the studied conditions, the calibration curves were linear from 0.5 to 50 ng mL(-1) for phenol, o-nitrophenol, 2,4-dichlorophenol and p-chlorophenol. The limits of detection were between 0.04 and 0.43 ng mL(-1). The recoveries of the phenols spiked in real water samples at 10 ng mL(-1) were between 85% and 98% with the relative standard deviations below 10%. Compared with the commercial coated ones (e.g. PDMS, CW/DVB and DVB/CAR/PDMS), the carbon monolith-based fiber had advantages of faster extraction equilibrium and higher extraction capacity due to the superior pore connectivity and pore openness resulting from its bimodal porous substructure.

  19. 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.

  20. 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. PMID:27555895

  1. 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.

  2. Behavior of wet precast beam column connections under progressive collapse scenario: an experimental study

    Science.gov (United States)

    Nimse, Rohit B.; Joshi, Digesh D.; Patel, Paresh V.

    2014-12-01

    Progressive collapse denotes a failure of a major portion of a structure that has been initiated by failure of a relatively small part of the structure such as failure of any vertical load carrying element (typically columns). Failure of large part of any structure will results into substantial loss of human lives and natural resources. Therefore, it is important to prevent progressive collapse which is also known as disproportionate collapse. Nowadays, there is an increasing trend toward construction of buildings using precast concrete. In precast concrete construction, all the components of structures are produced in controlled environment and they are being transported to the site. At site such individual components are connected appropriately. Connections are the most critical elements of any precast structure, because in past major collapse of precast structure took place because of connection failure. In this study, behavior of three different 1/3rd scaled wet precast beam column connections under progressive collapse scenario are studied and its performance is compared with monolithic connection. Precast connections are constructed by adopting different connection detailing at the junction by considering reinforced concrete corbel for two specimens and steel billet for one specimen. Performance of specimen is evaluated on the basis of ultimate load carrying capacity, maximum deflection and deflection measured along the span of the beam. From the results, it is observed that load carrying capacity and ductility of precast connections considered in this study are more than that of monolithic connections.

  3. Separation optimization of long porous-layer open-tubular columns for nano-LC-MS of limited proteomic samples.

    Science.gov (United States)

    Rogeberg, Magnus; Vehus, Tore; Grutle, Lene; Greibrokk, Tyge; Wilson, Steven Ray; Lundanes, Elsa

    2013-09-01

    The single-run resolving power of current 10 μm id porous-layer open-tubular (PLOT) columns has been optimized. The columns studied had a poly(styrene-co-divinylbenzene) porous layer (~0.75 μm thickness). In contrast to many previous studies that have employed complex plumbing or compromising set-ups, SPE-PLOT-LC-MS was assembled without the use of additional hardware/noncommercial parts, additional valves or sample splitting. A comprehensive study of various flow rates, gradient times, and column length combinations was undertaken. Maximum resolution for LC conditions or long silica monolith nanocolumns. Nearly 500 proteins (1958 peptides) could be identified in just one single injection of an extract corresponding to 1000 BxPC3 beta catenin (-/-) cells, and ~1200 and 2500 proteins in extracts of 10,000 and 100,000 cells, respectively, allowing detection of central members and regulators of the Wnt signaling pathway.

  4. Preparation and characterization of silica monolith modified with bovine serum albumin-gold nanoparticles conjugates and its use as chiral stationary phases for capillary electrochromatography.

    Science.gov (United States)

    Lu, Junyu; Ye, Fanggui; Zhang, Aizhu; Wei, Zong; Peng, Yan; Zhao, Shulin

    2011-08-01

    This paper describes the development of silica monolith modified with bovine serum albumin-gold nanoparticles (BSA-GNPs) conjugates as chiral stationary phases for capillary electrochromatography (CEC). The bare monolithic silica column was prepared by a sol-gel process and has been modified chemically with 3-mercaptopropyltrimethoxysilane to provide thiol groups, followed by immobilization of gold nanoparticles via the formation of an Au-S bond and modification with BSA as the chiral selector via the nitrogen lone pair of electrons. It has been demonstrated that the monolithic chiral stationary phases can be used for the enantioseparation of a number of phenylthiocarbamyl amino acids (PTC-D/L-AAs) by CEC. Ten pairs of tested amino acids enantiomers were successfully resolved within 18 min under optimized conditions, and the resolution values were in the range of 1.486-2.083. With PTC-D/L-tryptophan used as the probe solute, the influences of applied voltage, organic modifier and buffer pH in mobile phase on apparent retention factor, enantioselectivity and resolution factor were also investigated.

  5. 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...

  6. Lubiprostone: a chloride channel activator.

    Science.gov (United States)

    Lacy, Brian E; Levy, L Campbell

    2007-04-01

    In January 2006 the Food and Drug Administration approved lubiprostone for the treatment of chronic constipation in men and women aged 18 and over. Lubiprostone is categorized as a prostone, a bicyclic fatty acid metabolite of prostaglandin E1. Lubiprostone activates a specific chloride channel (ClC-2) in the gastrointestinal (GI) tract to enhance intestinal fluid secretion, which increases GI transit and improves symptoms of constipation. This article reviews the role of chloride channels in the GI tract, describes the structure, function, and pharmacokinetics of lubiprostone, and discusses clinically important data on this new medication.

  7. 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.

  8. Open tubular lab-on-column/mass spectrometry for targeted proteomics of nanogram sample amounts.

    Directory of Open Access Journals (Sweden)

    Hanne Kolsrud Hustoft

    Full Text Available A novel open tubular nanoproteomic platform featuring accelerated on-line protein digestion and high-resolution nano liquid chromatography mass spectrometry (LC-MS has been developed. The platform features very narrow open tubular columns, and is hence particularly suited for limited sample amounts. For enzymatic digestion of proteins, samples are passed through a 20 µm inner diameter (ID trypsin + endoproteinase Lys-C immobilized open tubular enzyme reactor (OTER. Resulting peptides are subsequently trapped on a monolithic pre-column and transferred on-line to a 10 µm ID porous layer open tubular (PLOT liquid chromatography LC separation column. Wnt/ß-catenein signaling pathway (Wnt-pathway proteins of potentially diagnostic value were digested+detected in targeted-MS/MS mode in small cell samples and tumor tissues within 120 minutes. For example, a potential biomarker Axin1 was identifiable in just 10 ng of sample (protein extract of ∼1,000 HCT15 colon cancer cells. In comprehensive mode, the current OTER-PLOT set-up could be used to identify approximately 1500 proteins in HCT15 cells using a relatively short digestion+detection cycle (240 minutes, outperforming previously reported on-line digestion/separation systems. The platform is fully automated utilizing common commercial instrumentation and parts, while the reactor and columns are simple to produce and have low carry-over. These initial results point to automated solutions for fast and very sensitive MS based proteomics, especially for samples of limited size.

  9. 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

  10. 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

  11. Development of stable monolithic wide-field Michelson interferometers.

    Science.gov (United States)

    Wan, Xiaoke; Ge, Jian; Chen, Zhiping

    2011-07-20

    Bulk wide-field Michelson interferometers are very useful for high precision applications in remote sensing and astronomy. A stable monolithic Michelson interferometer is a key element in high precision radial velocity (RV) measurements for extrasolar planets searching and studies. Thermal stress analysis shows that matching coefficients of thermal expansion (CTEs) is a critical requirement for ensuring interferometer stability. This requirement leads to a novel design using BK7 and LAK7 materials, such that the monolithic interferometer is free from thermal distortion. The processes of design, fabrication, and testing of interferometers are described in detail. In performance evaluations, the field angle is typically 23.8° and thermal sensitivity is typically -2.6×10(-6)/°C near 550 nm, which corresponds to ∼800 m/s/°C in the RV scale. Low-cost interferometer products have been commissioned in multiple RV instruments, and they are producing high stability performance over long term operations.

  12. 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.

  13. Development of stable monolithic wide-field Michelson interferometers

    Science.gov (United States)

    Wan, Xiaoke; Ge, Jian; Chen, Zhiping

    2011-07-01

    Bulk wide-field Michelson interferometers are very useful for high precision applications in remote sensing and astronomy. A stable monolithic Michelson interferometer is a key element in high precision radial velocity (RV) measurements for extrasolar planets searching and studies. Thermal stress analysis shows that matching coefficients of thermal expansion (CTEs) is a critical requirement for ensuring interferometer stability. This requirement leads to a novel design using BK7 and LAK7 materials, such that the monolithic interferometer is free from thermal distortion. The processes of design, fabrication, and testing of interferometers are described in detail. In performance evaluations, the field angle is typically 23.8° and thermal sensitivity is typically -2.6×10-6/° C near 550nm, which corresponds to ˜800m/s/°C in the RV scale. Low-cost interferometer products have been commissioned in multiple RV instruments, and they are producing high stability performance over long term operations.

  14. 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

  15. Material Engineering for Monolithic Semiconductor Mode-Locked Lasers

    DEFF Research Database (Denmark)

    Kulkova, Irina

    application in MLLs. Improved QW laser performance was demonstrated using the asymmetric barrier layer approach. The analysis of the gain characteristics showed that the high population inversion beneficial for noise reduction cannot be achieved for 10 GHz QW MLLs and would have required lowering the modal......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...... 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...

  16. Fabrication and characterization of monolithic solid oxide fuel cells

    Science.gov (United States)

    Minh, N. Q.; Horne, C. R.; Liu, F. S.; Moffatt, D. M.; Staszak, P. R.

    The monolithic solid oxide fuel cell (MSOFC) is an all-ceramic structure in which cell components are configured in a compact corrugated array. The MSOFC shows promise for use in a wide range of sizes (kilowatt to megawatt) and a broad spectrum of applications (electric utility, cogeneration, on-site, and aerospace power). A process based on the tape calendering technique is being developed for the fabrication of the MSOFC. MSOFC single cells have been fabricated by this process without cracking or delamination. Stacks of various sizes have been formed and processed to demonstrate fabricability of the monolithic structure. Extensive physical, chemical, electrical, and electrochemical characterization of fabricated samples has been carried out to confirm the required properties of each cell component. The characterization results reported have been used to support material and fabrication improvements.

  17. 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.

  18. 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.

  19. 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

  20. 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%.

  1. Preparation and evaluation of open tubular C18-silica monolithic microcartridges for preconcentration of peptides by on-line solid phase extraction capillary electrophoresis.

    Science.gov (United States)

    Ortiz-Villanueva, Elena; Benavente, Fernando; Giménez, Estela; Yilmaz, Fatma; Sanz-Nebot, Victoria

    2014-10-10

    In this study, C18-silica monoliths were synthesized as a porous layer in open tubular capillary columns, to be cut later into microcartridges for the analysis of neuropeptides by on-line solid-phase extraction capillary electrophoresis with UV and MS detection (SPE-CE-UV and SPE-CE-MS). First, several types of C18-silica monolithic (MtC18) microcartridges were used to analyse standard solutions of five neuropeptides (i.e. dynorphin A (1-7), substance P (7-11), endomorphin 1, methionine enkephalin and [Ala]-methionine enkephalin). The MtC18 sorbents were especially selective against endomorphin 1 and substance P (7-11)). The best results in terms of sensitivity and inter-microcartridge reproducibility were achieved with the microcartridges obtained from a 10-cm open tubular capillary column with a thin monolithic coating with large through-pores (1-5μm). Run-to-run repeatability, microcartridge durability, linearity ranges and LODs were studied by MtC18-SPE-CE-MS. As expected due to their greater selectivity, the best LOD enhancement was obtained for End1 and SP (7-11) (50 times with regard to CE-MS). Finally, the suitability of the methodology for analysing biological fluids was tested with plasma samples spiked with End1 and SP (7-11). Results obtained were promising because both neuropeptides could be detected at 0.05μgmL(-1), which was almost the same concentration level as for the standard solutions (0.01μgmL(-1)).

  2. 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.

  3. 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...

  4. A Distributed Model of Four-Port Monolithic Transformer

    OpenAIRE

    Lee, Dong Ho; Ko, Sangsoo; Jeon, Sang-Hoon; Park, Jae-Woo; Hong, Songcheol

    2004-01-01

    This paper deals with modeling of a monolithic spiral transformer. The transformer is designed and fabricated as a symmetrical octagonal spiral structure using two-metal layer process on GaAs substrate for input balun applications of 2 GHz and 5 GHz push-pull power amplifiers. A distributed model of the transformer is developed to fit in wide frequency range with four ports. The model includes the skin effect which describes increase in series resistance with frequency. Six different se...

  5. Advanced on-chip divider for monolithic microwave VCO's

    Science.gov (United States)

    Peterson, Weddell C.

    1989-01-01

    High frequency division on a monolithic circuit is a critical technology required to significantly enhance the performance of microwave and millimeter-wave phase-locked sources. The approach used to meet this need is to apply circuit design practices which are essentially 'microwave' in nature to the basically 'digital' problem of high speed division. Following investigation of several promising circuit approaches, program phase 1 culminated in the design and layout of an 8.5 GHz (Deep Space Channel 14) divide by four circuit based on a dynamic mixing divider circuit approach. Therefore, during program phase 2, an 8.5 GHz VCO with an integral divider which provides a phase coherent 2.125 GHz reference signal for phase locking applications was fabricated and optimized. Complete phase locked operation of the monolithic GaAs devices (VCO, power splitter, and dynamic divider) was demonstrated both individually and as an integrated unit. The fully functional integrated unit in a suitable test fixture was delivered to NASA for engineering data correlation. Based on the experience gained from this 8.5 GHz super component, a monolithic GaAs millimeter-wave dynamic divider for operation with an external VCO was also designed, fabricated, and characterized. This circuit, which was also delivered to NASA, demonstrated coherent division by four at an input frequency of 24.3 GHz. The high performance monolithic microwave VCO with a coherent low frequency reference output described in this report and others based on this technology will greatly benefit advanced communications systems in both the DoD and commercial sectors. Signal processing and instrumentation systems based on phase-locking loops will also attain enhanced performance at potentially reduced cost.

  6. Advanced on-chip divider for monolithic microwave VCO's

    Science.gov (United States)

    Peterson, Weddell C.

    1989-05-01

    High frequency division on a monolithic circuit is a critical technology required to significantly enhance the performance of microwave and millimeter-wave phase-locked sources. The approach used to meet this need is to apply circuit design practices which are essentially 'microwave' in nature to the basically 'digital' problem of high speed division. Following investigation of several promising circuit approaches, program phase 1 culminated in the design and layout of an 8.5 GHz (Deep Space Channel 14) divide by four circuit based on a dynamic mixing divider circuit approach. Therefore, during program phase 2, an 8.5 GHz VCO with an integral divider which provides a phase coherent 2.125 GHz reference signal for phase locking applications was fabricated and optimized. Complete phase locked operation of the monolithic GaAs devices (VCO, power splitter, and dynamic divider) was demonstrated both individually and as an integrated unit. The fully functional integrated unit in a suitable test fixture was delivered to NASA for engineering data correlation. Based on the experience gained from this 8.5 GHz super component, a monolithic GaAs millimeter-wave dynamic divider for operation with an external VCO was also designed, fabricated, and characterized. This circuit, which was also delivered to NASA, demonstrated coherent division by four at an input frequency of 24.3 GHz. The high performance monolithic microwave VCO with a coherent low frequency reference output described in this report and others based on this technology will greatly benefit advanced communications systems in both the DoD and commercial sectors. Signal processing and instrumentation systems based on phase-locking loops will also attain enhanced performance at potentially reduced cost.

  7. Dynamic response of monolithic and laminate/particulate reactive mixtures

    OpenAIRE

    Wei, Chung-Ting

    2011-01-01

    Two dynamic compression methods were applied to a monolithic metal and reactive mixtures to investigate their responses: (a) Dynamic experiments using a split Hopkinson pressure bar were applied to reactive mixtures densified by explosive consolidation in order to establish their mechanical response and failure mechanisms. (b) Laser compression and release, which can impart high stresses, up to hundreds GPa, in times of nanoseconds and fractions thereof, was applied to establish the spalling ...

  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. Columns

    Institute of Scientific and Technical Information of China (English)

    于晓悠; 丁燕燕; 韩多妮; Ray; Carrie; 未冉

    2010-01-01

    <正>New York Whitney艺术双年展今年第75届纽约Whitney双年展不设题目,但以"2010"指示策展方向,继续以发掘年轻艺术家、展示创作实验为目标。参展的55位艺术家,最年轻的是23岁摄影师Tam Tran,最老资历的是75岁的概念艺术家Lorraine O’Grady。这届的另一先创性,是每位艺术家只限一件或一个系列的作品,避免了去届双年展的"小型个人回顾展"现象,而五层楼的展场各有特色,如录像及短片将独立于三楼展出,而美术馆馆藏则移师五楼。这届双年展由著名的意大利策展人Francesco Bonami联同助手Gary Carrion-Murayarn共同制作,两位策展人说明,双年展的重要性是预示未来,创新及前瞻性依然是取决原则。

  10. 21 CFR 173.375 - Cetylpyridinium chloride.

    Science.gov (United States)

    2010-04-01

    ... CONSUMPTION Specific Usage Additives § 173.375 Cetylpyridinium chloride. Cetylpyridinium chloride (CAS Reg. No... Nutrition's Library, Food and Drug Administration, 5100 Paint Branch Pkwy., College Park, MD 20740, or...

  11. 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...

  12. Strong cation exchange monoliths for HPLC by Reactive Gelation.

    Science.gov (United States)

    Brand, Bastian; Krättli, Martin; Storti, Giuseppe; Morbidelli, Massimo

    2011-08-01

    Polymeric monolithic stationary phases for HPLC can be produced by Reactive Gelation. Unlike the conventional method of using porogens, such novel process consists of a number of separate steps, thus enabling a better control of the quality of the final material. A suspension of polymer nanoparticles in water is produced and subsequently swollen with hydrophobic monomers. The particles are then destabilised (usually by salt addition) to make them aggregate into a large percolating structure, the so-called monolith. Finally, the added monomer can then be polymerised to harden the structure. In this work, a polystyrene latex is used as the base material and functionalised by introduction of epoxide groups on the surface and subsequent reaction to sulphonic acid groups, yielding a SO3(-) density of 0.7 mmol/g dry material. Morphological investigations show 54% porosity made of 300 nm large pores. Van Deemter measurements of a large protein show no practical influence of diffusion limitations on the plate number. Finally, a preliminary separation of a test protein mixture is shown, demonstrating the potential of using ion-exchange chromatography on Reactive Gelation monoliths.

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

    Science.gov (United States)

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

    2013-12-01

    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 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.

  14. UPDATE ON MECHANICAL ANALYSIS OF MONOLITHIC FUEL PLATES

    Energy Technology Data Exchange (ETDEWEB)

    D. E. Burkes; F. J. Rice; J.-F. Jue; N. P. Hallinan

    2008-03-01

    Results on the relative bond strength of the fuel-clad interface in monolithic fuel plates have been presented at previous RRFM conferences. An understanding of mechanical properties of the fuel, cladding, and fuel / cladding interface has been identified as an important area of investigation and quantification for qualification of monolithic fuel forms. Significant progress has been made in the area of mechanical analysis of the monolithic fuel plates, including mechanical property determination of fuel foils, cladding processed by both hot isostatic pressing and friction bonding, and the fuel-clad composite. In addition, mechanical analysis of fabrication induced residual stress has been initiated, along with a study to address how such stress can be relieved prior to irradiation. Results of destructive examinations and mechanical tests are presented along with analysis and supporting conclusions. A brief discussion of alternative non-destructive evaluation techniques to quantify not only bond quality, but also bond integrity and strength, will also be provided. These are all necessary steps to link out-of-pile observations as a function of fabrication with in-pile behaviours.

  15. A Ferrite LTCC-Based Monolithic SIW Phased Antenna Array

    KAUST Repository

    Nafe, Ahmed

    2016-11-17

    In this work, we present a novel configuration for realizing monolithic SIW-based phased antenna arrays using Ferrite LTCC technology. Unlike the current common schemes for realizing SIW phased arrays that rely on surface-mount component (p-i-n diodes, etc) for controlling the phase of the individual antenna elements, here the phase is tuned by biasing of the ferrite filling of the SIW. This approach eliminates the need for mounting of any additional RF components and enables seamless monolithic integration of phase shifters and antennas in SIW technology. As a proof of concept, a two-element slotted SIW-based phased array is designed, fabricated and measured. The prototype exhibits a gain of 4.9 dBi at 13.2 GHz and a maximum E-plane beam-scanning of 28 degrees using external windings for biasing the phase shifters. Moreover, the array can achieve a maximum beam-scanning of 19 degrees when biased with small windings that are embedded in the package. This demonstration marks the first time a fully monolithic SIW-based phased array is realized in Ferrite LTCC technology and paves the way for future larger-size implementations.

  16. Preparing silica aerogel monoliths via a rapid supercritical extraction method.

    Science.gov (United States)

    Carroll, Mary K; Anderson, Ann M; Gorka, Caroline A

    2014-02-28

    A procedure for the fabrication of monolithic silica aerogels in eight hours or less via a rapid supercritical extraction process is described. The procedure requires 15-20 min of preparation time, during which a liquid precursor mixture is prepared and poured into wells of a metal mold that is placed between the platens of a hydraulic hot press, followed by several hours of processing within the hot press. The precursor solution consists of a 1.0:12.0:3.6:3.5 x 10(-3) molar ratio of tetramethylorthosilicate (TMOS):methanol:water:ammonia. In each well of the mold, a porous silica sol-gel matrix forms. As the temperature of the mold and its contents is increased, the pressure within the mold rises. After the temperature/pressure conditions surpass the supercritical point for the solvent within the pores of the matrix (in this case, a methanol/water mixture), the supercritical fluid is released, and monolithic aerogel remains within the wells of the mold. With the mold used in this procedure, cylindrical monoliths of 2.2 cm diameter and 1.9 cm height are produced. Aerogels formed by this rapid method have comparable properties (low bulk and skeletal density, high surface area, mesoporous morphology) to those prepared by other methods that involve either additional reaction steps or solvent extractions (lengthier processes that generate more chemical waste).The rapid supercritical extraction method can also be applied to the fabrication of aerogels based on other precursor recipes.

  17. 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 ...

  18. 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.

  19. 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.

  20. 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.

  1. 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.

  2. 21 CFR 184.1426 - Magnesium chloride.

    Science.gov (United States)

    2010-04-01

    ... mineral bischofite. It is prepared by dissolving magnesium oxide, hydroxide, or carbonate in aqueous... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Magnesium chloride. 184.1426 Section 184.1426 Food... Specific Substances Affirmed as GRAS § 184.1426 Magnesium chloride. (a) Magnesium chloride (MgC12·6H2O,...

  3. Cystic Fibrosis (CF): Chloride Sweat Test

    Science.gov (United States)

    ... Old Feeding Your 1- to 2-Year-Old Cystic Fibrosis (CF) Chloride Sweat Test KidsHealth > For Parents > Cystic Fibrosis (CF) Chloride Sweat Test Print A A A ... It Is A chloride sweat test helps diagnose cystic fibrosis (CF) , an inherited disorder that makes kids sick ...

  4. 75 FR 33824 - Barium Chloride From China

    Science.gov (United States)

    2010-06-15

    ... COMMISSION Barium Chloride From China Determination On the basis of the record\\1\\ developed in the subject... order on barium chloride from China would be likely to lead to continuation or recurrence of material... Barium Chloride from China: Investigation No. 731-TA-149 (Third Review). By order of the...

  5. 75 FR 19657 - Barium Chloride From China

    Science.gov (United States)

    2010-04-15

    ... 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 review... revocation of the antidumping duty order on barium chloride from China would be likely to lead...

  6. 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...

  7. 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.

  8. Comparison of drug substance impurity profiles generated with extended length columns during packed-column SFC.

    Science.gov (United States)

    Roston, D A; Ahmed, S; Williams, D; Catalano, T

    2001-10-01

    The current study assesses the effect of extending column length during gradient packed column sub/supercritical fluid chromatography (PCSFC) experiments on the detection of known and unknown impurities in a drug substance sample. Quantitative drug substance impurity profiles were generated and compared using multiple column PCSFC and HPLC conditions. Also, chromatographic figures of merit were estimated and compared for components of a standard mixture during PCSFC experiments, which used one column, four columns, and six columns in series.

  9. 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

  10. Beam Studies with Electron Columns

    Energy Technology Data Exchange (ETDEWEB)

    Shiltsev, V.; Valishev, A.; Kuznetsov, G.; /Fermilab; Kamerdzhiev, V.; /Julich, Forschungszentrum; Romanov, A.; /Novosibirsk, IYF

    2009-04-01

    We report preliminary results of experimental studies of 'electron columns' in the Tevatron and in a specialized test setup. In the Tevatron, a beam of 150 GeV protons ionizes residual gas and ionization electrons are stored in an electrostatic trap immersed into strong longitudinal magnetic field. Shifts of proton betatron frequencies are observed. In the test setup, we observe effects pointing to accumulation and escape of ionization electrons.

  11. Water Column Methylation in Estuaries

    Science.gov (United States)

    Schartup, A. T.; Calder, R.; Soerensen, A. L.; Mason, R. P.; Balcom, P. H.; Sunderland, E. M.

    2014-12-01

    Methylmercury (MeHg) is a neurotoxin that bioaccumulates in aquatic food webs and affects humans and wildlife through fish consumption. Many studies have measured active methylation/demethylation in ocean margin sediments but few have reported similar rates for the marine water column. This presentation will review available evidence for water column methylation in estuaries, including new experimental measurements of methylation/demethylation rates from a deep subarctic fjord in Labrador Canada collected in Spring and Fall of 2012-2013. We used these and other data to construct a mass budget for MeHg in the estuary and show that water column methylation (with rates ranging from 1.5 to 2.8 % day-1), is the largest contributor, followed by inputs from rivers (4.9 mol year-1), to the in situ pool of MeHg available for uptake by biota. By contrast, the sediment in this system is a net sink for MeHg (-1.5 mol year-1). We discuss the relationship between observed MeHg and other ancillary environmental factors (organic carbon, sulfur and nutrients) as well as implications for the response time of fish to future changes in mercury inputs.

  12. 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

  13. Oxomemazine hydro­chloride

    OpenAIRE

    Siddegowda, M. S.; Butcher, Ray J.; Mehmet Akkurt; Yathirajan, H.S.; Ramesh, A. R.

    2011-01-01

    In the title compound [systematic name: 3-(5,5-dioxophenothiazin-10-yl)-N,N,2-trimethylpropanaminium chloride], C18H23N2O2S+·Cl−, the dihedral angle between the two outer aromatic rings of the phenothiazine unit is 30.5 (2)°. In the crystal, the components are linked by N—H...Cl and C—H...Cl hydrogen bonds and C—H...π interactions.

  14. 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.

  15. Developing chloride resisting concrete using PFA

    Energy Technology Data Exchange (ETDEWEB)

    Dhir, R.K.; El-Mohr, M.A.K.; Dyer, T.D. [Univ. of Dundee (United Kingdom). Dept. of Civil Engineering

    1997-11-01

    PFA concrete mixes were designed to optimize resistance to chloride ingress. Chloride binding capacity, intrinsic permeability and their concomitant influence on the coefficient of chloride diffusion have been investigated. PFA replacements up to 67% and exposure concentrations of 0.1, 0.5, 1.0 and 5.0 mole/liter were used. Chloride binding capacity was found to increase with increasing PFA replacement up to 50% and to then decline. It increased with chloride exposure concentration as well as water/binder ratio. The coefficient of chloride diffusion of concrete samples was found to be dependent on both the intrinsic permeability of the concrete and the ability of its cement matrix to bind chlorides.

  16. Salt, chloride, bleach, and innate host defense.

    Science.gov (United States)

    Wang, Guoshun; Nauseef, William M

    2015-08-01

    Salt provides 2 life-essential elements: sodium and chlorine. Chloride, the ionic form of chlorine, derived exclusively from dietary absorption and constituting the most abundant anion in the human body, plays critical roles in many vital physiologic functions, from fluid retention and secretion to osmotic maintenance and pH balance. However, an often overlooked role of chloride is its function in innate host defense against infection. Chloride serves as a substrate for the generation of the potent microbicide chlorine bleach by stimulated neutrophils and also contributes to regulation of ionic homeostasis for optimal antimicrobial activity within phagosomes. An inadequate supply of chloride to phagocytes and their phagosomes, such as in CF disease and other chloride channel disorders, severely compromises host defense against infection. We provide an overview of the roles that chloride plays in normal innate immunity, highlighting specific links between defective chloride channel function and failures in host defense.

  17. 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.

  18. 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

  19. 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

  20. 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

  1. Reprocessing of LEU U-Mo Dispersion and Monolithic Fuels

    Energy Technology Data Exchange (ETDEWEB)

    Vandegrift, G.F.; Jerden, J.; Stepinski, D.C.; Figueroa, J.; Williamson, M.A.; Kleeck, M.A. Van; Blaskovitz, R.J.; Ziegler, A.J.; Maggos, L.E.; Swanson, J.; Fortner, J.; Bakel, A.J. [Chemical Sciences and Engineering Division, Argonne National Laboratory, 9700 S. Cass Ave., Argonne, IL 60439 (United States)

    2011-07-01

    For conversion of high-performance research reactors from high-enriched uranium (HEU) to low-enriched uranium (LEU) fuel, a fuel material with a higher density than uranium aluminide is required. Development studies are underway to develop U-Mo dispersion and monolithic fuels for conversion of several high- performance reactors. For dispersion fuels, development is narrowing down to a composition of U-7Mo dispersed in an aluminium matrix containing {approx}5% silicon. For monolithic fuels to be used in high performance research reactors in the United States, a zirconium-bonded U-10Mo foil appears to be the fuel of choice. For conversion to be realized a back-end disposition path is required for both fuels; one disposition pathway is reprocessing. Argonne National Laboratory is developing a pyroprocess for reprocessing spent monolithic fuel. Pyroprocessing was chosen over conventional aqueous solvent extraction due to the necessity of adding fluoride to the fuel-dissolution solution in order to dissolve the zirconium bonding layer on the U-Mo fuel. The proposed flowsheet and development activities will be described. A literature survey points to the ability to reprocess U-Mo dispersion fuels by an aqueous process, but due to several special characteristics of the fuel, the solvent-extraction flowsheets will be a departure from that normally used for the reprocessing of power reactor fuel. Special concerns that must be addressed in reprocessing these fuels are, for example, the low solubilities of uranyl molybdate, molybdic acid, and silicic acid in nitric acid solutions. This paper will address these concerns and development activities required to overcome them. (author)

  2. 10Gbps monolithic silicon FTTH transceiver for PON

    Science.gov (United States)

    Zhang, J.; Liow, T. Y.; Lo, G. Q.; Kwong, D. L.

    2010-05-01

    We propose a new passive optical network (PON) configuration and a novel silicon photonic transceiver architecture for optical network unit (ONU), eliminating the need for an internal laser source in ONU. We adopt dual fiber network configuration. The internal light source in each of the ONUs is eliminated. Instead, an extra seed laser source in the optical line termination (OLT) operates in continuous wave mode to serve the ONUs in the PON as a shared and centralized laser source. λ1 from OLT Tx and λ2 from the seed laser are combined by using a WDM combiner and connected to serve the multiple ONUs through the downstream fibers. The ONUs receive the data in λ1. Meanwhile, the ONUs encode and transmit data in λ2, which are sent back to OLT. The monolithic ONU transceiver contains a wavelength-division-multiplexing (WDM) filter component, a silicon modulator and a Ge photo-detector. The WDM in ONU selectively guides λ1 to the Ge-PD where the data in λ1 are detected and converted to electrical signals, and λ2 to the transmitter where the light is modulated by upstream data. The modulated optical signals in λ2 from ONUs are connected back to OLT through upstream fibers. The monolithic ONU transceiver chip size is only 2mm by 4mm. The crosstalk between the Tx and Rx is measured to be less than -20dB. The transceiver chip is integrated on a SFP+ transceiver board. Both Tx and Rx demonstrated data rate capabilities of up to 10Gbps. By implementing this scheme, the ONU transceiver size can be significantly reduced and the assembly processes will be greatly simplified. The results demonstrate the feasibility of mass manufacturing monolithic silicon ONU transceivers via low cost

  3. Hydrolysis of cupric chloride in aqueous ammoniacal ammonium chloride solutions

    Directory of Open Access Journals (Sweden)

    Limpo, J. L.

    1995-06-01

    Full Text Available Cupric solubility in the CuCl2-NH4Cl-NH3-H2O system for chloride concentrations lower than 4 molal in the temperature range 25-60 °C was studied. The experimental results show that for chloride concentration between 3.0 and 1.0 molal the cupric solubility is determined by the solubility of the cupric hydroxychloride Cu(OH1.5Cl0.5. For a chloride concentration value of 4.0 molal, there are two cupric compounds, the hydroxychloride Cu(OH1.5Cl0.5 or the diammine chloride Cu(NH32Cl2, on which the solubility of Cu(II depends, according to the temperature and the value of the ratio [NH3]Total/[Cu]Total.

    Se estudia la solubilidad del Cu(II en el sistema CuCl2-NH4Cl-NH3-H2O para concentraciones de cloruro inferiores a 4 molal en el intervalo de temperaturas 25-60 °C. Los resultados experimentales muestran que, para concentraciones de cloruros comprendidas entre 3,0 y 1,0 molal, la solubilidad cúprica viene determinada por la solubilidad del hidroxicloruro cúprico, Cu(OH1.5Cl0.5. Para concentraciones de cloruro 4,0 molal, existen dos compuestos cúpricos, el hidroxicloruro, Cu(OH1.5Cl0.5 o el cloruro de diamina, Cu(NH32Cl2, de los que, de acuerdo con la temperatura y con el valor de la relación [NH3]Total/[Cu]Total depende la solubilidad del Cu(II.

  4. W-band monolithic oscillator using InAlAs/InGaAs HEMT

    Science.gov (United States)

    Kwon, Y.; Pavlidis, D.; Tutt, M.; Ng, G. I.; Lai, R.

    1990-01-01

    A W-band monolithic integrated oscillator circuit was designed and fabricated using submicron HEMT technology. The oscillation frequency was around 81 GHz and the power was -7 dBm at the chip level. This is the first report of an InAlAs/InGaAs monolithic oscillator operating at the W-band.

  5. Hybrid and monolithic integration of planar lightwave circuits (PLCs)

    Science.gov (United States)

    Chen, Ray T.

    2008-02-01

    In this paper, we review the status of monolithic and hybrid integration of planar lightwave circuits (PLCs). Building blocks needed for system integration based on polymeric materials, III-V semiconductor materials, LiNbO 3 and SOI on Silicon are summarized with pros and cons. Due to the maturity of silicon CMOS technology, silicon becomes the platform of choice for optical application specific integrated circuits (OASICs). However, the indirect bandgap of silicon makes the formation of electrically pumped silicon laser a remote plausibility which requires hybrid integration of laser sources made out of III-V compound semicouductor.

  6. A Monolithic Filter Cavity for Experiments in Quantum Optics

    CERN Document Server

    Palittapongarnpim, Pantita; Lvovsky, A I

    2012-01-01

    By applying a high-reflectivity dielectric coating on both sides of a commercial plano-convex lens, we produce a stable monolithic Fabry-Perot cavity suitable for use as a narrow band filter in quantum optics experiments. The resonant frequency is selected by means of thermal expansion. Owing to the long term mechanical stability, no optical locking techniques are required. We characterize the cavity performance as an optical filter, obtaining a 45 dB suppression of unwanted modes while maintaining a transmission of 60%.

  7. 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....

  8. 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

  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. A monolithically integrated torsional CMOS-MEMS relay

    Science.gov (United States)

    Riverola, M.; Sobreviela, G.; Torres, F.; Uranga, A.; Barniol, N.

    2016-11-01

    We report experimental demonstrations of a torsional microelectromechanical (MEM) relay fabricated using the CMOS-MEMS approach (or intra-CMOS) which exploits the full foundry inherent characteristics enabling drastic reduction of the fabrication costs and batch production. In particular, the relay is monolithically integrated in the back end of line of a commercial standard CMOS technology (AMS 0.35 μm) and released by means of a simple one-step mask-less wet etching. The fabricated torsional relay exhibits an extremely steep switching behaviour symmetrical about both contact sides with an on-state contact resistance in the k Ω -range throughout the on-off cycling test.

  11. Elastic stability of non-uniform columns

    Science.gov (United States)

    Lee, S. Y.; Kuo, Y. H.

    1991-07-01

    A simple and efficient method is proposed to investigate the elastic stability of three different tapered columns subjected to uniformly distributed follower forces. The influences of the boundary conditions and taper ratio on critical buckling loads are investigated. The critical buckling loads of columns of rectangular cross section with constant depth and linearly varied width ( T1), constant width and linearly varied depth ( T2) and double taper ( T3) are investigated. Among the three different non-uniform columns considered, taper ratio has the greatest influence on the critical buckling load of column T3 and the lowest influence on that of column T1. The types of instability mechanisms for hinged-hinged and cantilever non-uniform columns are divergence and flutter respectively. However, for clamped-hinged and clamped-clamped non-uniform columns, the type of instability mechanism for column T1 is divergence, while that for columns T2 and T3 is divergence only when the taper ratio of the columns is greater than certain critical values and flutter for the rest value of taper ratio. When the type of instability mechanism changes from divergence to flutter, there is a finite jump for the critical buckling load. The influence of taper ratio on the elastic stability of cantilever column T3 is very sensitive for small values of the taper ratio and there also exist some discontinieties in the critical buckling loads of flutter instability. For a hinged-hinged non-uniform column ( T2 or T3) with a rotational spring at the left end of the column, when the taper ratio is less than the critical value the instability mechanism changes from divergence to flutter as the rotational spring constant is increased. For a clamped-elastically supported non-uniform column, when the taper ratio is greater than the critical value the instability mechanism changes from flutter to divergence as the translational spring constant is increased.

  12. 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 ...... with other surface or bulk sensitive techniques, e.g. Raman and UV-vis spectroscopy.......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....... The observations reported here serve as a demonstration of the great potential for the application of operando spectroscopy on monolithic systems. This cross disciplinary approach aims to identify reaction pathways, active sites, intermediate- and spectator-species for catalytic reactions under truly industrial...

  13. 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.

  14. 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.

  15. Damping and impact properties of laminated scaffolds and glass columns evaluated through the use of computational methods

    Science.gov (United States)

    Nieves, Ian

    Dynamic finite element analysis (FEA) was used to verify the ability of a novel percussion instrument to characterize the composition and structure of laminated materials and glass columns and to elucidate key facets of this process. Initial simulations modeling the percussion process with varying probe geometries were performed to access which configuration most accurately represented in situ diagnostic activity. Percussion testing of monoliths and laminated duplex scaffolds consisting of PTFE and 6061 Al was simulated to assess the ability of the numeric methodology to model intrinsic damping in laminated scaffolds and determine the potential contributions of size effects, gripping configurations, and probe friction to the loading response of the material being tested. Percussion testing of laminated scaffolds and monoliths composed of either PMMA or PLGA was modeled to investigate the effects of defects on the impact response and to evaluate promising strategies for enhancing damping that promotes tissue regeneration in biomedical materials. Percussion testing of virgin and cracked glass columns was modeled and the resulting probe acceleration predictions compared to corresponding experimental findings to evaluate the overall accuracy of the methodology and to discern its capacity for elucidating facets of defect detection in rigid materials. Overall, the modeling the results validated the effectiveness of the numeric methodology for modeling and elucidating the mechanics of percussion testing and suggested strategies whereby this procedure can facilitate the development of innovative biomedical materials designed to promote tissue regeneration.

  16. Oxomemazine hydro­chloride

    Science.gov (United States)

    Siddegowda, M. S.; Butcher, Ray J.; Akkurt, Mehmet; Yathirajan, H. S.; Ramesh, A. R.

    2011-01-01

    In the title compound [systematic name: 3-(5,5-dioxo­phen­othia­zin-10-yl)-N,N,2-trimethyl­propanaminium chloride], C18H23N2O2S+·Cl−, the dihedral angle between the two outer aromatic rings of the phenothia­zine unit is 30.5 (2)°. In the crystal, the components are linked by N—H⋯Cl and C—H⋯Cl hydrogen bonds and C—H⋯π inter­actions. PMID:22090928

  17. Mechanical Performance and Chloride Diffusivity of Cracked RC Specimens Exposed to Freeze-Thaw Cycles and Intermittent Immersion in Seawater

    Directory of Open Access Journals (Sweden)

    Bei Shen

    2016-01-01

    Full Text Available The effects of crack width on chloride ingress and mechanical behavior of reinforced concrete (RC specimens were experimentally studied after exposure to 300 cycles of freeze-thaw and seawater immersion (75 times. Cracks were induced prior to exposure by an eccentric compression load which was sustained until the end of the exposure period. The maximum cracks widths induced in the four column specimens were 0, 0.06, 0.11, and 0.15 mm, respectively. Results show that when the crack width was less than 0.06 mm, the effect of cracks on chloride ingress could be neglected. However, when the crack width was more than 0.11 mm, chloride ingress was accelerated. Results of static loading tests show that both yield load and ultimate load of RC columns decreased as crack width increased. When the crack width was 0.15 mm, yield load and ultimate load of RC column specimen decreased by 17.0% and 18.9%, respectively, compared to a specimen without cracks. It was concluded that crack width significantly promoted local chloride ingress and mechanical performance degradation of RC structures in cold coastal regions or exposed to deicing salts.

  18. 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....

  19. Chloride Ion Critical Content in Reinforced Concrete

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    Chloride ion critical content was studied under soaking and cycle of dry and wet conditions,with three electrochemical nondestructive measuring techniques, i e, half-cell potential, A C impedance, and time potential. The experimental results show that chloride ion critical content is primarily determined by the water cement ratio, while for the same concrete mixture the chloride ion critical content in soaking conditions is larger than that in a cycle of dry and wet conditions.

  20. Produced fluids separation using a coalascer column

    Energy Technology Data Exchange (ETDEWEB)

    Renouf, G.; Soveran, D.; Soveran, L. [Saskatchewan Research Council, Saskatoon, SK (Canada)

    2005-07-01

    This paper reports the results of a laboratory study in which a coalescer column was used to successfully remove water from produced heavy oil emulsions. The coalescer column is a simple, inexpensive, and environmentally friendly technology that can improve basic sediment and water values after 4 hours of settling time by about 38 per cent. The laboratory study tested the use of the column, and the effects of column length, column packing size, temperature, flow rate, demulsifier concentration, and water addition. More than 100 tests were conducted and 24 pairs of tests compared the treating effects with and without the column. The use of the coalescer column in the treatment facility resulted in a a reduction of demulsifier concentration from 250 ppm to 70 ppm, translating to an annual cost savings of $320,000 to $1,100,000 per battery. Incorporating the coalescer column also allowed operators to reduce both temperatures and demulsifier concentrations. The column also promoted faster treating. Water droplets grew by as much as 34 per cent, suggesting that treating time could be faster by 21 to 80 per cent. It was concluded that the coalescer column was very successful at improving water removal from heavy oil battery emulsions. 22 refs., 9 tabs., 7 figs.

  1. 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.

  2. Monolithically integrated Helmholtz coils by 3-dimensional printing

    Energy Technology Data Exchange (ETDEWEB)

    Li, Longguang [Department of Electrical Engineering, University of Michigan–Shanghai Jiao Tong University Joint Institute, Shanghai Jiao Tong University, Shanghai 200240 (China); Abedini-Nassab, Roozbeh; Yellen, Benjamin B., E-mail: yellen@duke.edu [Department of Electrical Engineering, University of Michigan–Shanghai Jiao Tong University Joint Institute, Shanghai Jiao Tong University, Shanghai 200240 (China); Department of Mechanical Engineering and Materials Science, Duke University, P.O. Box 90300, Hudson Hall, Durham, North Carolina 27708 (United States)

    2014-06-23

    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.

  3. 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.

  4. 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.

  5. 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.

  6. 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.

  7. New 3-D microarray platform based on macroporous polymer monoliths.

    Science.gov (United States)

    Rober, M; Walter, J; Vlakh, E; Stahl, F; Kasper, C; Tennikova, T

    2009-06-30

    Polymer macroporous monoliths are widely used as efficient sorbents in different, mostly dynamic, interphase processes. In this paper, monolithic materials strongly bound to the inert glass surface are suggested as operative matrices at the development of three-dimensional (3-D) microarrays. For this purpose, several rigid macroporous copolymers differed by reactivity and hydrophobic-hydrophilic properties were synthesized and tested: (1) glycidyl methacrylate-co-ethylene dimethacrylate (poly(GMA-co-EDMA)), (2) glycidyl methacrylate-co-glycerol dimethacrylate (poly(GMA-co-GDMA)), (3) N-hydroxyphthalimide ester of acrylic acid-co-glycidyl methacrylate-co-ethylene dimethacrylate (poly(HPIEAA-co-GMA-co-EDMA)), (4) 2-cyanoethyl methacrylate-co-ethylene dimethacrylate (poly(CEMA-co-EDMA)), and (5) 2-cyanoethyl methacrylate-co-2-hydroxyethyl methacrylate-co-ethylene dimethacrylate (poly(CEMA-co-HEMA-co-EDMA)). The constructed devices were used as platforms for protein microarrays construction and model mouse IgG-goat anti-mouse IgG affinity pair was used to demonstrate the potential of developed test-systems, as well as to optimize microanalytical conditions. The offered microarray platforms were applied to detect the bone tissue marker osteopontin directly in cell culture medium.

  8. Methacrylate-based monolithic layers for planar chromatography of polymers.

    Science.gov (United States)

    Maksimova, E F; Vlakh, E G; Tennikova, T B

    2011-04-29

    A series of macroporous monolithic methacrylate-based materials was synthesized by in situ free radical UV-initiated copolymerization of functional monomers, such as glycidyl methacrylate (GMA), butyl methacrylate (BuMA), 2-aminoethyl methacrylate (AEMA), 2-hydroxyethyl methacrylate (HEMA) and 2-cyanoethyl methacrylate (CEMA), with crosslinking agent, namely, ethylene glycol dimethacrylate (EDMA). The materials obtained were applied as the stationary phases in simple and robust technique - planar chromatography (PLC). The method of separation layer fabrication representing macroporous polymer monolith bound to the specially prepared glass surface was developed and optimized. The GMA-EDMA and BuMA-EDMA matrixes were successfully applied for the separation of low molecular weight compounds (the mixture of several dies), as well as poly(vinylpyrrolidone) and polystyrene homopolymers of different molecular weights using reversed-phase mechanism. The materials based on copolymers AEMA-HEMA-EDMA and CEMA-HEMA-EDMA were used for normal-phase PLC separation of 2,4-dinitrophenyl amino acids and polystyrene standards.

  9. Fabrication of Monolithic RERTR Fuels by Hot Isostatic Pressing

    Energy Technology Data Exchange (ETDEWEB)

    Jan-Fong Jue; Blair H. Park; Curtis R. Clark; Glenn A. Moore; Dennis D. Keiser, Jr.

    2010-11-01

    The RERTR (Reduced Enrichment for Research and Test Reactors) Program is developing advanced nuclear fuels for high-power test reactors. Monolithic fuel design provides higher uranium loading than that of the traditional dispersion fuel design. Hot isostatic pressing is a promising process for low-cost batch fabrication of monolithic RERTR fuel plates for these high-power reactors. Bonding U Mo fuel foil and 6061 Al cladding by hot isostatic press bonding was successfully developed at Idaho National Laboratory. Due to the relatively high processing temperature, the interaction between fuel meat and aluminum cladding is a concern. Two different methods were employed to mitigate this effect: (1) a diffusion barrier and (2) a doping addition to the interface. Both types of fuel plates have been fabricated by hot isostatic press bonding. Preliminary results show that the direct fuel/cladding interaction during the bonding process was eliminated by introducing a thin zirconium diffusion barrier layer between the fuel and the cladding. Fuel plates were also produced and characterized with a silicon-rich interlayer between fuel and cladding. This paper reports the recent progress of this developmental effort and identifies the areas that need further attention.

  10. Monolithic crystals for PET devices: Optical coupling optimization

    Energy Technology Data Exchange (ETDEWEB)

    González, A.J., E-mail: agonzalez@i3m.upv.es; Peiró, A.; Conde, P.; Hernández, L.; Moliner, L.; Orero, A.; Rodríguez-Álvarez, M.J.; Sánchez, F.; Soriano, A.; Vidal, L.F.; Benlloch, J.M.

    2013-12-11

    In this work we present a method to efficiently collect scintillation light when using monolithic scintillator crystals. The acceptance angle of the scintillation light has been reduced by means of optical devices reducing the border effect which typically affects continuous crystals. We have applied this procedure on gamma detectors for PET systems using both position sensitive PMTs and arrays of SiPMs. In the case of using SiPMs, this approach also helps to reduce the photosensor active area. We evaluated the method using PMTs with a variety of different crystals with thicknesses ranging from 10 to 24 mm. We found that our design allows the use of crystal blocks with a thickness of up to 18 mm without degrading the spatial resolution caused by edge effects and without a significant detriment to the energy resolution. These results were compared with simulated data. The first results of monolithic LYSO crystals coupled to an array of 256 SiPMs by means of individual optical light guides are also presented. -- Highlights: •Acceptance angle reduction decreases border effect in continuous crystals. •Experimental measurements with PMTs correlate well with simulated data. •Optical devices called faceplates serve to control the scintillation light angle. •Simulation on the light propagation for SiPMs requires exhaustive modeling.

  11. Column flotation testing at Suncor Energy Inc.

    Energy Technology Data Exchange (ETDEWEB)

    Cleyle, P.; Lee, L. [Suncor Energy Inc. Oil Sands, Fort McMurray, AB (Canada)

    2006-07-01

    The operations at Suncor's primary extraction plant were reviewed with reference to the column flotation process and the history of column flotation testing at Suncor. Tertiary bitumen recovery processes were also reviewed. In March and August 2005, an in-plant pilot scale column flotation test was conducted at Suncor's Millennium Primary Extraction plant near Fort McMurray, Alberta. The purpose was to evaluate the feasibility of using column flotation for tertiary bitumen recovery from cyclone overflow. The test was performed in a 4 ft diameter by 25 ft high column to determine the effects of column feed flow rate, froth wash water supply, and froth depth. The feed ranged from 0.14 to 3.79 wt per cent bitumen. Feed flow rate ranged from 59 to 237 USGPM. The test results indicated that wash water reduced froth mineral content. Increasing the wash water did not make any difference in mineral rejection. Although bitumen upgrading improved when the test column was operated at a deeper froth depth, the mineral content was not reduced. Both mechanical cell and flotation column tailings samples were collected in the flotation column tests. The average tailings composition for the last cell in the tertiary mechanical bank was 0.22 per cent bitumen, 12.10 per cent mineral, and 87.66 per cent water. At an average test column feed rate of 158 USGPM, the average tailings composition was 0.23 per cent bitumen, 12.13 per cent mineral, and 87.62 per cent water. It was concluded that flotation columns are capable of producing a tailings product similar to that of the tertiary mechanical bank. Therefore, it is feasible to use flotation columns as an alternative to mechanical cells. In fact, since there are no rotating parts requiring off-line maintenance work, flotation columns may be a better alternative from a maintenance and operations perspective. tabs., figs.

  12. 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...... have a serine. The LeuT-E290S mutant displays chloride-dependent activity. We show that, in LeuT-E290S cocrystallized with bromide or chloride, the anion is coordinated by side chain hydroxyls from Tyr47, Ser290, and Thr254 and the side chain amide of Gln250. The bound anion and the nearby sodium ion...

  13. Chloride ingress in cement paste and mortar

    Energy Technology Data Exchange (ETDEWEB)

    Jensen, O.M.; Hansen, P.F.; Coats, A.M.; Glasser, F.P.

    1999-09-01

    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 are 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 diffusion rates.

  14. 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.

  15. 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.

  16. 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.

  17. Miniaturized DNA aptamer-based monolithic sorbent for selective extraction of a target analyte coupled on-line to nanoLC.

    Science.gov (United States)

    Brothier, Fabien; Pichon, Valérie

    2014-12-01

    A complete characterization of a novel target-specific DNA aptamer-based miniaturized solid phase extraction (SPE)-sorbent coupled on-line to nanoLC is presented. A miniaturized oligosorbent (mOS) was prepared via the in situ sol-gel synthesis of a hybrid organic-inorganic monolith in 100 μm i.d. capillary columns using tetraethoxysilane and 3-aminopropyltriethoxysilane as precursors, followed by covalent binding of a 5'-amino-modified DNA aptamer with a C12 spacer arm specific for a molecule of small molecular weight. Ochratoxin A (OTA), one of the most abundant naturally occurring mycotoxins, was chosen as model analyte to demonstrate the principle of such an approach. The mOS was coupled on-line to RP-nanoLC-LIF. Selective extraction of OTA on several mOSs was demonstrated with an average extraction recovery above 80 % when percolating spiked binding buffer and a low recovery on control monoliths grafted with a non-specific aptamer. Reproducibility of mOSs preparation was highlighted by comparing extraction yields. Otherwise, the mOSs demonstrated no cross-reactivity towards an OTA structural analogue, i.e., ochratoxin B. Due to the high specific surface area of the hybrid silica-based monolith, the coverage density of DNA aptamers covalently immobilized in the capillaries was very high and reached 6.27 nmol μL(-1), thus leading to a capacity above 5 ng of OTA. This miniaturized device was then applied to the selective extraction of OTA from beer samples. It revealed to be effective in isolating OTA from this complex matrix, thus improving the reliability of its analysis at the trace level.

  18. The jet flotation column control system

    Energy Technology Data Exchange (ETDEWEB)

    Xu Zhiqiang; Ming Shangzhi; Liu Lijian; Huangfu Jinghua; Huo Sen; Zhang Rongzeng [China Univ. of Mining and Technology, Beijing (China). Mineral Processing Dept.; Yang Hongjun [Hebi Coal Mine Administrative (China)

    1998-12-31

    Compared with the conventional mechanical flotation column, the jet flotation column has the advantages of high selectivity of separation, low investment and production cost, low floor space requirement, low dosage of reagent, easy control; it is more suitable to process fine particles. Recently, many new types of flotation columns have been developed with new methods. Mineral Processing Dept., China University of Mining and Technology (Beijing) designed an aerated, double-jet flotation column in the lab and the industrial trial will be put into operation. One of the significant characteristics of the new type of flotation column is high selectivity of separation, fast bubble mineralization speed. As it is sensitive to various factors, a control system for flotation column has been developed to stabilize the working condition, and this set of control system has been operated in the lab experiment.

  19. Comparing polyaluminum chloride and ferric chloride for antimony removal.

    Science.gov (United States)

    Kang, Meea; Kamei, Tasuku; Magara, Yasumoto

    2003-10-01

    Antimony has been one of the contaminants required to be regulated, however, only limited information has been collected to date regarding antimony removal by polyaluminium chloride (PACl) and ferric chloride (FC). Accordingly, the possible use of coagulation by PACl or FC for antimony removal was investigated. Jar tests were used to determine the effects of solution pH, coagulant dosage, and pre-chlorination on the removal of various antimony species. Although high-efficiency antimony removal by aluminum coagulation has been expected because antimony is similar to arsenic in that both antimony and arsenic are a kind of metalloid in group V of the periodic chart, this study indicated: (1) removal density (arsenic or antimony removed per mg coagulant) for antimony by PACl was about one forty-fifth as low as observed for As(V); (2) although the removal of both Sb(III) and Sb(V) by coagulation with FC was much higher than that of PACl, a high coagulant dose of 10.5mg of FeL(-1) at optimal pH of 5.0 was still not sufficient to meet the standard antimony level of 2 microg as SbL(-1) for drinking water when around 6 microg as SbL(-1) were initially present. Consequently, investigation of a more appropriate treatment process is necessary to develop economical Sb reduction; (3) although previous studies concluded that As(V) is more effectively removed than As(III), this study showed that the removal of Sb(III) by coagulation with FC was much more pronounced than that of Sb(V); (4) oxidation of Sb(III) with chlorine decreased the ability of FC to remove antimony. Accordingly, natural water containing Sb(III) under anoxic condition should be coagulated without pre-oxidation.

  20. SNAP-TITE Composite Column Reinforcement

    OpenAIRE

    ECT Team, Purdue

    2007-01-01

    Recent earthquakes throughout the world have demonstrated the vulnerabilities of older reinforced concrete columns to seismic deformation demands. The Snap Tite Composite Column Reinforcement strengthens a concrete column by confining it in an external composite jacket, which prevents the concrete from expanding during seismic activity or prolonged freeze-thaw cycles. The pre-manufactured fiberglass jacket is comprised of glass fibers and corrosion resistant isopolyester resins.

  1. Parametric resonance in concrete beam-columns

    OpenAIRE

    Sharma,Mamta R.; Singh,Arbind K; Benipal,Gurmail S

    2014-01-01

    A dynamic instability, called parametric resonance, is exhibited by undampedelastic beam-columns when under the action of pulsating axial force. The scope of the existing theory of parametric resonance is restricted to physically linear beam-columns undergoing finite lateral displacements. In this Paper, the dynamic behaviour of physically nonlinear elastic cracked concrete beam-columns under pulsating axial force and constant lateral force is investigated. The constitutive equations derived ...

  2. Electrochemical Behavior of Copper in Thionyl Chloride Solutions.

    Science.gov (United States)

    1980-12-01

    lithium - thionyl chloride batteries . Thionyl chloride is known *3 to react...electrolyte for lithium - thionyl chloride batteries . 8R. K. McAlpine and B. A. Soule, Prescott and Johnson’s Qualitative Chemical Analysis, D. Van...black carbon electrodes, cupric chloride appears to be a useful cathode additive for lithium - thionyl chloride batteries . Preliminary results2l

  3. 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

  4. Synthesis and characterization of hierarchically porous metal, metal oxide, and carbon monoliths with highly ordered nanostructure

    Science.gov (United States)

    Grano, Amy Janine

    Hierarchically porous materials are of great interest in such applications as catalysis, separations, fuel cells, and advanced batteries. One such way of producing these materials is through the process of nanocasting, in which a sacrificial template is replicated and then removed to form a monolithic replica. This replica consists of mesopores, which can be ordered or disordered, and bicontinuous macropores, which allow flow throughout the length of the monolith. Hierarchically porous metal oxide and carbon monoliths with an ordered mesopores system are synthesized for the first time via nanocasting. These replicas were used as supports for the deposition of silver particles and the catalytic efficiency was evaluated. The ordered silica template used in producing these monoliths was also used for an in-situ TEM study involving metal nanocasting, and an observation of the destruction of the silica template during nanocasting made. Two new methods of removing the silica template were developed and applied to the synthesis of copper, nickel oxide, and zinc oxide monoliths. Finally, hollow fiber membrane monoliths were examined via x-ray tomography in an attempt to establish the presence of this structure throughout the monolith.

  5. 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

  6. Sensitive determination of parabens in human urine and serum using methacrylate monoliths and reversed-phase capillary liquid chromatography-mass spectrometry.

    Science.gov (United States)

    Carrasco-Correa, Enrique Javier; Vela-Soria, Fernando; Ballesteros, Oscar; Ramis-Ramos, Guillermo; Herrero-Martínez, José Manuel

    2015-01-30

    A method for the determination of parabens in human urine and serum by capillary liquid chromatography (cLC) with UV-Vis and mass spectrometry (MS) detection using methacrylate ester-based monolithic columns has been developed. The influence of composition of polymerization mixture was studied. The optimum monolith was obtained with butyl methacrylate monomer at 60/40% (wt/wt) butyl methacrylate/ethylene dimethacrylate ratio and 50wt% porogens (composed of 36wt% of 1,4-butanediol, 54wt% 1-propanol and 10wt% water). Baseline resolution of analytes was achieved through a mobile phase of acetonitrile/water in gradient elution mode. Additionally, dispersive liquid-liquid microextraction (DLLME) was combined with both cLC-UV-Vis and cLC-MS to achieve the determination of parabens in human urine and serum samples with very low limits of detection. Satisfactory intra- and inter-day repeatabilities were obtained in UV-Vis and MS detection, although the latter provided lower detection limits (up to 300-fold) than the UV-Vis detection. Recoveries for the target analytes from spiked biological samples ranged from 95.2% to 106.7%. The proposed methodology for the ultra-low determination of parabens in human urine and serum samples is simple and fast, the consumption of reagents is very low, and very small samples can be analyzed.

  7. 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.

  8. 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

  9. 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

  10. 29 CFR 1915.1017 - Vinyl chloride.

    Science.gov (United States)

    2010-07-01

    ... 29 Labor 7 2010-07-01 2010-07-01 false Vinyl chloride. 1915.1017 Section 1915.1017 Labor Regulations Relating to Labor (Continued) OCCUPATIONAL SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR... § 1915.1017 Vinyl chloride. Note: The requirements applicable to shipyard employment under this...

  11. 29 CFR 1926.1117 - Vinyl chloride.

    Science.gov (United States)

    2010-07-01

    ... 29 Labor 8 2010-07-01 2010-07-01 false Vinyl chloride. 1926.1117 Section 1926.1117 Labor... (CONTINUED) SAFETY AND HEALTH REGULATIONS FOR CONSTRUCTION Toxic and Hazardous Substances § 1926.1117 Vinyl chloride. Note: The requirements applicable to construction work under this section are identical to...

  12. 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

  13. 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...

  14. 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.

  15. 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.

  16. 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.

  17. 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...

  18. 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

  19. GaN Monolithic Power Amplifiers for Microwave Backhaul Applications

    Directory of Open Access Journals (Sweden)

    Roberto Quaglia

    2016-06-01

    Full Text Available Gallium nitride integrated technology is very promising not only for wireless applications at mobile frequencies (below 6 GHz but also for network backhaul radiolink deployment, now under deep revision for the incoming 5G generation of mobile communications. This contribution presents three linear power amplifiers realized on 0.25 μ m Gallium Nitride on Silicon Carbide monolithic integrated circuits for microwave backhaul applications: two combined power amplifiers working in the backhaul band around 7 GHz, and a more challenging third one working in the higher 15 GHz band. Architectures and main design steps are described, highlighting the pros and cons of Gallium Nitride with respect to the reference technology which, for these applications, is represented by gallium arsenide.

  20. Monolithic single mode interband cascade lasers with wide wavelength tunability

    Science.gov (United States)

    von Edlinger, M.; Weih, R.; Scheuermann, J.; Nähle, L.; Fischer, M.; Koeth, J.; Kamp, M.; Höfling, S.

    2016-11-01

    Monolithic two-section interband cascade lasers offering a wide wavelength tunability in the wavelength range around 3.7 μm are presented. Stable single mode emission in several wavelength channels was realized using the concept of binary superimposed gratings and two-segment Vernier-tuning. The wavelength selective elements in the two segments were based on specially designed lateral metal grating structures defined by electron beam lithography. A dual-step dry etch process provided electrical separation between the segments. Individual current control of the segments allowed wavelength channel selection as well as continuous wavelength tuning within channels. A discontinuous tuning range extending over 158 nm in up to six discrete wavelength channels was achieved. Mode hop free wavelength tuning up to 14 nm was observed within one channel. The devices can be operated in continuous wave mode up to 30 °C with the output powers of 3.5 mW around room temperature.

  1. Monolithic growth of partly cured polydimethylsiloxane thin film layers

    DEFF Research Database (Denmark)

    Yu, Liyun; Skov, Anne Ladegaard

    2014-01-01

    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...... at different curing times. The monolithic films are investigated by rheology, scanning electron microscope, mechanical testing, dielectric relaxation spectroscopy, thermal gravimetric analysis (TGA) and differential scanning calorimetry (DSC). The morphology, mechanical and dielectric properties, as well...... 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...

  2. Optical displacement measurement using a monolithic Michelson interferometer

    Science.gov (United States)

    Hofstetter, Daniel; Zappe, Hans P.

    1997-04-01

    Contactless optical displacement measurement has the potential for a variety of industrial and scientific applications. For highly accurate displacement measurements at distances below 1 m, interferometric methods are preferred over most other methods. This is mainly because of the good resolution and the possibility of doing the measurements in real-time. Furthermore, the use of direct bandgap semiconductor materials also enables the fabrication of a compact interferometer-based device which unites all necessary components, including the light emitter, on a single chip. In this paper, a monolithically integrated optical displacement sensor fabricated in the GaAs/AlGaAs material system is reported. This single chip microsystem is configured as a double Michelson interferometer and comprises a distributed Bragg reflector laser, photodetectors, phase shifters and waveguide couplers. In the course of this paper, we will also briefly discuss possible scientific and industrial applications of such devices.

  3. Monolithic interferometer for high precision radial velocity measurements

    Science.gov (United States)

    Wan, Xiaoke; Ge, Jian; Wang, Ji; Lee, Brian

    2009-08-01

    In high precision radial velocity (RV) measurements for extrasolar planets searching and studies, a stable wide field Michelson interferometer is very critical in Exoplanet Tracker (ET) instruments. Adopting a new design, monolithic interferometers are homogenous and continuous in thermal expansion, and field compensation and thermal compensation are both satisfied. Interferometer design and fabrication are decrypted in details. In performance evaluations, field angle is typically 22° and thermal sensitivity is typically -1.7 x 10-6/°C, which corresponds to ~500 m/s /°C in RV scale. In interferometer stability monitoring using a wavelength stabilized laser source, phase shift data was continuously recorded for nearly seven days. Appling a frequent calibration every 30 minutes as in typical star observations, the interferometer instability contributes less than 1.4 m/s in RV error, in a conservative estimation.

  4. Heterogeneous Monolithic Integration of Single-Crystal Organic Materials.

    Science.gov (United States)

    Park, Kyung Sun; Baek, Jangmi; Park, Yoonkyung; Lee, Lynn; Hyon, Jinho; Koo Lee, Yong-Eun; Shrestha, Nabeen K; Kang, Youngjong; Sung, Myung Mo

    2017-02-01

    Manufacturing high-performance organic electronic circuits requires the effective heterogeneous integration of different nanoscale organic materials with uniform morphology and high crystallinity in a desired arrangement. In particular, the development of high-performance organic electronic and optoelectronic devices relies on high-quality single crystals that show optimal intrinsic charge-transport properties and electrical performance. Moreover, the heterogeneous integration of organic materials on a single substrate in a monolithic way is highly demanded for the production of fundamental organic electronic components as well as complex integrated circuits. Many of the various methods that have been designed to pattern multiple heterogeneous organic materials on a substrate and the heterogeneous integration of organic single crystals with their crystal growth are described here. Critical issues that have been encountered in the development of high-performance organic integrated electronics are also addressed.

  5. 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.

  6. Highly tailorable thiol-ene based emulsion-templated monoliths

    DEFF Research Database (Denmark)

    Lafleur, J. P.; Kutter, J. P.

    2014-01-01

    The attractive surface properties of thiol-ene polymers combined with their ease of processing make them ideal substrates in many bioanalytical applications. We report the synthesis of highly tailorable emulsion-templated porous polymers and beads in microfluidic devices based on off-stoichiometr......The attractive surface properties of thiol-ene polymers combined with their ease of processing make them ideal substrates in many bioanalytical applications. We report the synthesis of highly tailorable emulsion-templated porous polymers and beads in microfluidic devices based on off......-stoichiometry thiolene chemistry. The method allows monolith synthesis and anchoring inside thiol-ene microchannels in a single step. Variations in the monomer stoichiometric ratios and/or amount of porogen used allow for the creation of extremely varied polymer morphologies, from foam-like materials to dense networks...

  7. 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.

  8. A monolithic time stretcher for precision time recording

    Energy Technology Data Exchange (ETDEWEB)

    Varner, Gary S.

    2007-04-20

    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.

  9. 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.

  10. 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.

  11. 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.

  12. 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.

  13. 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

  14. Monolithic microwave integrated circuit devices for active array antennas

    Science.gov (United States)

    Mittra, R.

    1984-01-01

    Two different aspects of active antenna array design were investigated. The transition between monolithic microwave integrated circuits and rectangular waveguides was studied along with crosstalk in multiconductor transmission lines. The boundary value problem associated with a discontinuity in a microstrip line is formulated. This entailed, as a first step, the derivation of the propagating as well as evanescent modes of a microstrip line. The solution is derived to a simple discontinuity problem: change in width of the center strip. As for the multiconductor transmission line problem. A computer algorithm was developed for computing the crosstalk noise from the signal to the sense lines. The computation is based on the assumption that these lines are terminated in passive loads.

  15. 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.

  16. Radiation hardness studies on CMOS monolithic pixel sensors

    Energy Technology Data Exchange (ETDEWEB)

    Battaglia, Marco [Department of Physics, University of California at Berkeley, CA 94720 (United States); Lawrence Berkeley National Laboratory, 1 Cyclotron Road, Berkeley, CA 94720 (United States); Bisello, Dario [Dipartimento di Fisica, Universita di Padova and INFN, Sezione di Padova, I-35131 Padova (Italy); Contarato, Devis, E-mail: DContarato@lbl.go [Lawrence Berkeley National Laboratory, 1 Cyclotron Road, Berkeley, CA 94720 (United States); Denes, Peter; Doering, Dionisio [Lawrence Berkeley National Laboratory, 1 Cyclotron Road, Berkeley, CA 94720 (United States); Giubilato, Piero [Lawrence Berkeley National Laboratory, 1 Cyclotron Road, Berkeley, CA 94720 (United States); Dipartimento di Fisica, Universita di Padova and INFN, Sezione di Padova, I-35131 Padova (Italy); Sung Kim, Tae [Lawrence Berkeley National Laboratory, 1 Cyclotron Road, Berkeley, CA 94720 (United States); Mattiazzo, Serena [Dipartimento di Fisica, Universita di Padova and INFN, Sezione di Padova, I-35131 Padova (Italy); Radmilovic, Velimir [Lawrence Berkeley National Laboratory, 1 Cyclotron Road, Berkeley, CA 94720 (United States); Zalusky, Sarah [Department of Physics, University of California at Berkeley, CA 94720 (United States); Lawrence Berkeley National Laboratory, 1 Cyclotron Road, Berkeley, CA 94720 (United States)

    2010-12-11

    This paper presents irradiation studies performed on a CMOS monolithic pixel sensor prototype implementing different optimizations of the pixel cell aimed at a superior radiation tolerance. Irradiations with 200 keV electrons up to a total dose of 1.1 Mrad have been performed in view of the utilization of such a design in Transmission Electron Microscopy (TEM) applications. Comparative irradiations were performed with 29 MeV protons up to a 2 Mrad total dose and with 1-14 MeV neutrons up to fluences in excess of 10{sup 13} n{sub eq} cm{sup -2}. Experimental results show an improved performance of pixels designed with Enclosed Layout Transistor (ELT) rules and an optimized layout of the charge collecting diodes.

  17. 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.

  18. 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.

  19. 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.

  20. Nondestructive characterization methods for monolithic solid oxide fuel cells

    Energy Technology Data Exchange (ETDEWEB)

    Ellingson, W.A.

    1993-01-01

    Monolithic solid oxide fuel cells (MSOFCS) represent a potential breakthrough in fuel cell technology, provided that reliable fabrication methods can be developed. Fabrication difficulties arise in several steps of the processing: First is the fabrication of uniform thin (305 {mu}m) single-layer and trilayer green tapes (the trilayer tapes of anode/electrolyte/cathode and anode/interconnect/cathode must have similar coefficients of thermal expansion to sinter uniformly and to have the necessary electrochemical properties); Second is the development of fuel and oxidant channels in which residual stresses are likely to develop in the tapes; Third is the fabrication of a ``complete`` cell for which the bond quality between layers and the quality of the trilayers must be established; and Last, attachment of fuel and oxidant manifolds and verification of seal integrity. Purpose of this report is to assess nondestructive characterization methods that could be developed for application to laboratory, prototype, and full-scale MSOFCs.