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Sample records for integrated sequential injection

  1. Determination of Pb(II) by sequential injection/stripping analysis at all-plastic electrochemical fluidic cells with integrated composite electrodes.

    PubMed

    Kokkinos, Christos; Economou, Anastasios; Goddard, Nicholas G; Fielden, Peter R; Baldock, Sara J

    2016-06-01

    This work reports the development of a sequential injection/stripping analysis method for the determination of trace Pb(II) at injection-moulded electrochemical fluidic cells. Conducting carbon fibre-loaded polystyrene electrodes were integrated within the plastic cells. The flow-through cells were incorporated into a home-made sequential injection analysis (SIA) manifold. Different experimental parameters for the detection of Pb(II) were investigated including the type and concentration of the supporting electrolyte, the conditions of the stripping step, the volume of the sample, the flow rate and the accumulation potential. The LOD for Pb(II) was 0.5μgL(-1), the within-cell % relative standard deviation (n=8) was 3.1% and the between-cell % relative standard deviation (n=5) was 8.9% for 25μgL(-1) Pb(II). The cells were applied to the determination of Pb(II) in tapwater and a phosphate fertilizer sample. PMID:27130105

  2. Sequential injection immunoassay for environmental measurements.

    PubMed

    Soh, Nobuaki; Tanaka, Mayumi; Hirakawa, Koji; Zhang, RuiQi; Nakajima, Hizuru; Nakano, Koji; Imato, Toshihiko

    2011-01-01

    Sequential injection immunoassay systems for environmental measurements based on the selective immunoreaction between antigen and antibody were described. A sequential injection analysis (SIA) technique is suitable to be applied for the procedure of enzyme-linked immunosorbent assay (ELISA), because the washing and the addition of reagent solutions can be automated by using a computer-controlled syringe pump and switching valve. We selected vitellogenin (Vg), which is a biomarker for evaluating environmental risk caused by endocrine-disrupting chemicals in the hydrosphere, and linear alkylbenzene sulfonates (LAS) and alkylphenol polyethoxylates (APEO), which are versatile surfactants, as target analytes in the flow immunoassay systems. For Vg monitoring, SIA systems based on spectrophotometric, chemiluminescence, and electrochemical determinations were constructed. On the other hand, chemiluminescence determination was applied to the detection of LAS and APEO. For APEO, an SIA system combined with surface plasmon resonance (SPR) sensor was also developed. These new sequential injection immunoassay systems are expected to be useful systems for environmental analysis. PMID:22076332

  3. Sequential injection gas guns for accelerating projectiles

    DOEpatents

    Lacy, Jeffrey M.; Chu, Henry S.; Novascone, Stephen R.

    2011-11-15

    Gas guns and methods for accelerating projectiles through such gas guns are described. More particularly, gas guns having a first injection port located proximate a breech end of a barrel and a second injection port located longitudinally between the first injection port and a muzzle end of the barrel are described. Additionally, modular gas guns that include a plurality of modules are described, wherein each module may include a barrel segment having one or more longitudinally spaced injection ports. Also, methods of accelerating a projectile through a gas gun, such as injecting a first pressurized gas into a barrel through a first injection port to accelerate the projectile and propel the projectile down the barrel past a second injection port and injecting a second pressurized gas into the barrel through the second injection port after passage of the projectile and to further accelerate the projectile are described.

  4. Sequential capillary electrophoresis analysis using optically gated sample injection and UV/vis detection.

    PubMed

    Liu, Xiaoxia; Tian, Miaomiao; Camara, Mohamed Amara; Guo, Liping; Yang, Li

    2015-10-01

    We present sequential CE analysis of amino acids and L-asparaginase-catalyzed enzyme reaction, by combing the on-line derivatization, optically gated (OG) injection and commercial-available UV-Vis detection. Various experimental conditions for sequential OG-UV/vis CE analysis were investigated and optimized by analyzing a standard mixture of amino acids. High reproducibility of the sequential CE analysis was demonstrated with RSD values (n = 20) of 2.23, 2.57, and 0.70% for peak heights, peak areas, and migration times, respectively, and the LOD of 5.0 μM (for asparagine) and 2.0 μM (for aspartic acid) were obtained. With the application of the OG-UV/vis CE analysis, sequential online CE enzyme assay of L-asparaginase-catalyzed enzyme reaction was carried out by automatically and continuously monitoring the substrate consumption and the product formation every 12 s from the beginning to the end of the reaction. The Michaelis constants for the reaction were obtained and were found to be in good agreement with the results of traditional off-line enzyme assays. The study demonstrated the feasibility and reliability of integrating the OG injection with UV/vis detection for sequential online CE analysis, which could be of potential value for online monitoring various chemical reaction and bioprocesses. PMID:26040711

  5. Sequential injection spectrophotometric determination of oxybenzone in lipsticks.

    PubMed

    Salvador, A; Chisvert, A; Camarasa, A; Pascual-Martí, M C; March, J G

    2001-08-01

    A sequential injection (SI) procedure for the spectrophotometric determination of oxybenzone in lipsticks is reported. The colorimetric reaction between nickel and oxybenzone was used. SI parameters such as sample solution volume, reagent solution volume, propulsion flow rate and reaction coil length were studied. The limit of detection was 3 microg ml(-1). The sensitivity was 0.0108+/-0.0002 ml microg(-1). The relative standard deviations of the results were between 6 and 12%. The real concentrations of samples and the values obtained by HPLC were comparable. Microwave sample pre-treatment allowed the extraction of oxybenzone with ethanol, thus avoiding the use of toxic organic solvents. Ethanol was also used as carrier in the SI system. Seventy-two injections per hour can be performed, which means a sample frequency of 24 h(-1) if three replicates are measured for each sample. PMID:11534627

  6. Development of Decision Making: Sequential versus Integrative Rules

    ERIC Educational Resources Information Center

    Jansen, Brenda R. J.; van Duijvenvoorde, Anna C. K.; Huizenga, Hilde M.

    2012-01-01

    Decisions can be made by applying a variety of decision-making rules--sequential rules in which decisions are based on a sequential evaluation of choice dimensions and the integrative normative rule in which decisions are based on an integration of choice dimensions. In this study, we investigated the developmental trajectory of such…

  7. An automatic system for acidity determination based on sequential injection titration and the monosegmented flow approach.

    PubMed

    Kozak, Joanna; Wójtowicz, Marzena; Gawenda, Nadzieja; Kościelniak, Paweł

    2011-06-15

    An automatic sequential injection system, combining monosegmented flow analysis, sequential injection analysis and sequential injection titration is proposed for acidity determination. The system enables controllable sample dilution and generation of standards of required concentration in a monosegmented sequential injection manner, sequential injection titration of the prepared solutions, data collecting, and handling. It has been tested on spectrophotometric determination of acetic, citric and phosphoric acids with sodium hydroxide used as a titrant and phenolphthalein or thymolphthalein (in the case of phosphoric acid determination) as indicators. Accuracy better than |4.4|% (RE) and repeatability better than 2.9% (RSD) have been obtained. It has been applied to the determination of total acidity in vinegars and various soft drinks. The system provides low sample (less than 0.3 mL) consumption. On average, analysis of a sample takes several minutes. PMID:21641455

  8. Screening of conditions controlling spectrophotometric sequential injection analysis

    PubMed Central

    2011-01-01

    Background Despite its potential benefits over univariate, chemometrics is rarely utilized for optimizing sequential injection analysis (SIA) methods. Specifically, in previous vis-spectrophotometric SIA methods, chemometrically optimized conditions were confined within flow rate and reagent concentrations while other conditions were ignored. Results The current manuscript reports, for the first time, a comprehensive screening of conditions controlling vis-spectrophotometric SIA. A new diclofenac assay method was adopted. The method was based on oxidizing diclofenac by permanganate (a major reagent) with sulfuric acid (a minor reagent). The reaction produced a spectrophotometrically detectable diclofenac form. The 26 full-factorial design was utilized to study the effect of volumes of reagents and sample, in addition to flow rate and concentrations of reagents. The main effects and all interaction order effects on method performance, i.e. namely sensitivity, rapidity and reagent consumption, were determined. The method was validated and applied to pharmaceutical formulations (tablets, injection and gel). Conclusions Despite 64 experiments those conducted in the current study were cumbersome, the results obtained would reduce effort and time when developing similar SIA methods in the future. It is recommended to critically optimize effective and interacting conditions using other such optimization tools as fractional-factorial design, response surface and simplex, rather than full-factorial design that used at an initial optimization stage. In vis-spectrophotometric SIA methods those involve developing reactions with two reagents (major and minor), conditions affecting method performance are in the following order: sample volume > flow rate ≈ major reagent concentration >> major reagent volume ≈ minor reagent concentration >> minor reagent volume. PMID:21333024

  9. Integral optical system design of injection molded optics

    NASA Astrophysics Data System (ADS)

    Baumer, Stefan M.; Shulepova, Lena; Willemse, Jan; Renkema, Kor

    2003-11-01

    Injection molded optics are frequently applied in many high volume applications. Bar code scanners, CD / DVD systems, CMOS cameras are a few examples. In all of these applications cost effective and fast design cycles are essential. At Philips High Tech Plastics we developed a design system that touches on all different aspects of the system design. Starting with traditional lens design (sequential ray tracing) and tolernacing we transport the initial design into mechanical solid modeling. During mechanical modeling, tolerances, injection molding design rules and integration of mechanical features, reference marks, etc. are incorporated as well. Here the full advantage of injection molding can be utilized. After the opto - mechanical modeling the system is ported back to non - sequential ray tracing for ghost - and stray light analysis. Finally extended tolerancing is performed in order to come to a robust high volume product. If necessary all or several steps in this design process are repeated in order to arrive at the final design. As an additional requirement the metrology possibilities for the design are checked in at an early stage. This integral system approach to optical design, including optical modeling (sequential and non-sequential) combined with mechanical solid modeling is presented using some recent examples.

  10. Multiplex microfluidic system integrating sequential operations of microalgal lipid production.

    PubMed

    Kwak, Ho Seok; Kim, Jaoon Young Hwan; Na, Sang Cheol; Jeon, Noo Li; Sim, Sang Jun

    2016-02-21

    The unit cost for the production of algal biofuel needs to be reduced in order to be a substitute for fossil fuel. To achieve this goal, the development of a novel system is needed for a rapid screening of numerous microalgal species to isolate superior strains with the highest lipid productivity. Here, we developed a PDMS-based multiplex microfluidic system with eight chambers and micropillar arrays to expedite multiple steps for lipid sample preparation from different microalgal strains. We could rapidly and efficiently perform sequential operations from cell culture to lipid extraction of eight different microalgal strains simultaneously on a single device without harvesting and purification steps, which are labor- and energy-intensive, by the simple injection of medium and solvent into the central inlet due to the integrated micropillar arrays connecting the chambers and central inlet. The lipid extraction efficiency using this system was comparable (94.5-102.6%) to the conventional Bligh-Dyer method. We investigated the cell growth and lipid productivity of different strains using the microfluidic device. We observed that each strain has a different lipid accumulation pattern according to stress conditions. These results demonstrate that our multiplex microfluidic approach can provide an efficient analytical tool for the rapid analysis of strain performances (e.g. cell growth and lipid productivities) and the determination of the optimal lipid induction condition for each strain. PMID:26783562

  11. Theoretical and experimental studies on sequential two-diffusional sample injection for capillary electrophoresis.

    PubMed

    Liu, Lina; Tian, Miaomiao; Liu, Xiaoxia; Guo, Liping; Yang, Li

    2015-02-13

    We report here theoretical and experimental studies on the sequential diffusion injection (SDI) for CE analysis. Based on the Fick's second law, a theoretical model for two-dimensional (2-D) diffusion has been developed for our SDI system. The 2-D diffusion model has been demonstrated via systematic experimental studies using standard nicotinamide adenine dinucleotide (NADH) as the model analyte. The results show that the dependence of the NADH peak area (corresponding to the injection amount) on the initial sample concentration, the injection time or the capillary-gap distance is consistent with the deduction of the 2-D diffusion model. It is indicated that the 2-D diffusion, both in longitudinal and transverse directions of the capillary, enhances the injection efficiency in comparison to classical concentration diffusion on the plane interface, and improves the accuracy of the sequential injection without any physical disturbance of the capillary inlet. With the insight understanding of the injection mechanism, we have successfully applied the SDI method for sequential CE analysis of amino acids mixture and online assay of the glucose-6-phosphate dehydrogenase-catalyzed reaction. The present study showed that the SDI is a versatile tool for efficient and accurate sequential CE analysis, not only for online monitoring various bioprocesses but also for continuous analyzing complex samples based on capillary electrophoresis. PMID:25596761

  12. Sequential-Injection Analysis: Principles, Instrument Construction, and Demonstration by a Simple Experiment

    ERIC Educational Resources Information Center

    Economou, A.; Tzanavaras, P. D.; Themelis, D. G.

    2005-01-01

    The sequential-injection analysis (SIA) is an approach to sample handling that enables the automation of manual wet-chemistry procedures in a rapid, precise and efficient manner. The experiments using SIA fits well in the course of Instrumental Chemical Analysis and especially in the section of Automatic Methods of analysis provided by chemistry…

  13. Development of Integration and Adjustment Method for Sequential Range Images

    NASA Astrophysics Data System (ADS)

    Nagara, K.; Fuse, T.

    2015-05-01

    With increasing widespread use of three-dimensional data, the demand for simplified data acquisition is also increasing. The range camera, which is a simplified sensor, can acquire a dense-range image in a single shot; however, its measuring coverage is narrow and its measuring accuracy is limited. The former drawback had be overcome by registering sequential range images. This method, however, assumes that the point cloud is error-free. In this paper, we develop an integration method for sequential range images with error adjustment of the point cloud. The proposed method consists of ICP (Iterative Closest Point) algorithm and self-calibration bundle adjustment. The ICP algorithm is considered an initial specification for the bundle adjustment. By applying the bundle adjustment, coordinates of the point cloud are modified and the camera poses are updated. Through experimentation on real data, the efficiency of the proposed method has been confirmed.

  14. Enzymatic Microreactors for the Determination of Ethanol by an Automatic Sequential Injection Analysis System

    NASA Astrophysics Data System (ADS)

    Alhadeff, Eliana M.; Salgado, Andrea M.; Cos, Oriol; Pereira, Nei; Valdman, Belkis; Valero, Francisco

    A sequential injection analysis system with two enzymatic microreactors for the determination of ethanol has been designed. Alcohol oxidase and horseradish peroxidase were separately immobilized on glass aminopropyl beads, and packed in 0.91-mL volume microreactors, working in line with the sequential injection analysis system. A stop flow of 120 s was selected for a linear ethanol range of 0.005-0.04 g/L±0.6% relative standard deviation with a throughput of seven analyses per hour. The system was applied to measure ethanol concentrations in samples of distilled and nondistilled alcoholic beverages, and of alcoholic fermentation with good performance and no significant difference compared with other analytical procedures (gas chromatography and high-performance liquid chromatography).

  15. Integrated injection-locked semiconductor diode laser

    DOEpatents

    Hadley, G.R.; Hohimer, J.P.; Owyoung, A.

    1991-02-19

    A continuous wave integrated injection-locked high-power diode laser array is provided with an on-chip independently-controlled master laser. The integrated injection locked high-power diode laser array is capable of continuous wave lasing in a single near-diffraction limited output beam at single-facet power levels up to 125 mW (250 mW total). Electronic steering of the array emission over an angle of 0.5 degrees is obtained by varying current to the master laser. The master laser injects a laser beam into the slave array by reflection of a rear facet. 18 figures.

  16. Integrated injection-locked semiconductor diode laser

    DOEpatents

    Hadley, G. Ronald; Hohimer, John P.; Owyoung, Adelbert

    1991-01-01

    A continuous wave integrated injection-locked high-power diode laser array is provided with an on-chip independently-controlled master laser. The integrated injection locked high-power diode laser array is capable of continuous wave lasing in a single near-diffraction limited output beam at single-facet power levels up to 125 mW (250 mW total). Electronic steering of the array emission over an angle of 0.5 degrees is obtained by varying current to the master laser. The master laser injects a laser beam into the slave array by reflection of a rear facet.

  17. Automated sample preparation and analysis using a sequential-injection-capillary electrophoresis (SI-CE) interface.

    PubMed

    Kulka, Stephan; Quintás, Guillermo; Lendl, Bernhard

    2006-06-01

    A fully automated sequential-injection-capillary electrophoresis (SI-CE) system was developed using commercially available components as the syringe pump, the selection and injection valves and the high voltage power supply. The interface connecting the SI with the CE unit consisted of two T-pieces, where the capillary was inserted in one T-piece and a Pt electrode in the other (grounded) T-piece. By pressurising the whole system using a syringe pump, hydrodynamic injection was feasible. For characterisation, the system was applied to a mixture of adenosine and adenosine monophosphate at different concentrations. The calibration curve obtained gave a detection limit of 0.5 microg g(-1) (correlation coefficient of 0.997). The reproducibility of the injection was also assessed, resulting in a RSD value (5 injections) of 5.4%. The total time of analysis, from injection, conditioning and separation to cleaning the capillary again was 15 minutes. In another application, employing the full power of the automated SIA-CE system, myoglobin was mixed directly using the flow system with different concentrations of sodium dodecyl sulfate (SDS), a known denaturing agent. The different conformations obtained in this way were analysed with the CE system and a distinct shift in migration time and decreasing of the native peak of myoglobin (Mb) could be observed. The protein samples prepared were also analysed with off-line infrared spectroscopy (IR), confirming these results. PMID:16732362

  18. Titration of strong and weak acids by sequential injection analysis technique.

    PubMed

    Maskula, S; Nyman, J; Ivaska, A

    2000-05-31

    A sequential injection analysis (SIA) titration method has been developed for acid-base titrations. Strong and weak acids in different concentration ranges have been titrated with a strong base. The method is based on sequential aspiration of an acidic sample zone and only one zone of the base into a carrier stream of distilled water. On their way to the detector, the sample and the reagent zones are partially mixed due to the dispersion and thereby the base is partially neutralised by the acid. The base zone contains the indicator. An LED-spectrophotometer is used as detector. It senses the colour of the unneutralised base and the signal is recorded as a typical SIA peak. The peak area of the unreacted base was found to be proportional to the logarithm of the acid concentration. Calibration curves with good linearity were obtained for a strong acid in the concentration ranges of 10(-4)-10(-2) and 0.1-3 M. Automatic sample dilution was implemented when sulphuric acid at concentration of 6-13 M was titrated. For a weak acid, i.e. acetic acid, a linear calibration curve was obtained in the range of 3x10(-4)-8x10(-2) M. By changing the volumes of the injected sample and the reagent, different acids as well as different concentration ranges of the acids can be titrated without any other adjustments in the SIA manifold or the titration protocol. PMID:18967966

  19. Sequential injection chromatographic determination of ambroxol hydrochloride and doxycycline in pharmaceutical preparations.

    PubMed

    Satínský, Dalibor; Santos, Lucia M L Dos; Sklenárová, Hana; Solich, Petr; Montenegro, M Conceição B S M; Araújo, Alberto N

    2005-12-15

    A new separation method based on a novel reversed-phase sequential injection chromatography (SIC) technique was used for simultaneous determination of ambroxol hydrochloride and doxycycline in pharmaceutical preparations in this contribution. The coupling of short monolith with SIA system results in an implementation of separation step to until no-separation low-pressure method. A Chromolith((R)) Flash RP-18e, 25-4.6mm column (Merck, Germany) and a FIAlab((R)) 3000 system (USA) with a six-port selection valve and 5ml syringe were used for sequential injection chromatographic separations in our study. The mobile phase used was acetonitrile-water (20:90, v/v), pH 2.5 adjusted with 98% phosphoric acid, flow rate 0.48mlmin(-1), UV detection was at 213nm. The validation parameters have shown good results: linearity of determination for both compounds including internal standard (ethylparaben) >0.999; repeatability of determination (R.S.D.) in the range 0.5-5.4% at three different concentration levels, detection limits in the range 0.5-2.0mugml(-1), and recovery from the pharmaceutical preparation in the range 99.3-99.9%. The chromatographic resolution between peak compounds was >5.0 and analysis time was <9min under the optimal conditions. The method was found to be applicable for routine analysis of the active compounds ambroxol hydrochloride and doxycycline in various pharmaceutical preparations. PMID:18970307

  20. Sequential Injection/Electrochemical Immunoassay for Quantifying the Pesticide Metabolite 3, 5, 6-Trichloro-2-Pyridinol

    SciTech Connect

    Liu, Guodong; Riechers, Shawn L.; Timchalk, Chuck; Lin, Yuehe

    2005-12-04

    An automated and sensitive sequential injection electrochemical immunoassay was developed to monitor a potential insecticide biomarker, 3, 5, 6-trichloro-2-pyridinol. The current method involved a sequential injection analysis (SIA) system equipped with a thin-layer electrochemical flow cell and permanent magnet, which was used to fix 3,5,6-trichloro-2-pyridinol (TCP) antibody coated magnetic beads (TCP-Ab-MBs) in the reaction zone. After competitive immunoreactions among TCP-Ab-MBs, TCP analyte, and horseradish peroxidase (HRP) labeled TCP, a 3, 3?, 5, 5?-tetramethylbenzidine dihydrochloride and hydrogen peroxide (TMB-H2O2) substrate solution was injected to produce an electroactive enzymatic product. The activity of HRP tracers was monitored by a square wave voltammetric scanning electroactive enzymatic product in the thin-layer flow cell. The voltammetric characteristics of the substrate and the enzymatic product were investigated under batch conditions, and the parameters of the immunoassay were optimized in the SIA system. Under the optimal conditions, the system was used to measure as low as 6 ng L-1 (ppt) TCP, which is around 50-fold lower than the value indicated by the manufacturer of the TCP RaPID Assay? kit (0.25 ug/L, colorimetric detection). The performance of the developed immunoassay system was successfully evaluated on tap water and river water samples spiked with TCP. This technique could be readily used for detecting other environmental contaminants by developing specific antibodies against contaminants and is expected to open new opportunities for environmental and biological monitoring.

  1. Implementation of terbium-sensitized luminescence in sequential-injection analysis for automatic analysis of orbifloxacin.

    PubMed

    Llorent-Martínez, E J; Ortega-Barrales, P; Molina-Díaz, A; Ruiz-Medina, A

    2008-12-01

    Orbifloxacin (ORBI) is a third-generation fluoroquinolone developed exclusively for use in veterinary medicine, mainly in companion animals. This antimicrobial agent has bactericidal activity against numerous gram-negative and gram-positive bacteria. A few chromatographic methods for its analysis have been described in the scientific literature. Here, coupling of sequential-injection analysis and solid-phase spectroscopy is described in order to develop, for the first time, a terbium-sensitized luminescent optosensor for analysis of ORBI. The cationic resin Sephadex-CM C-25 was used as solid support and measurements were made at 275/545 nm. The system had a linear dynamic range of 10-150 ng mL(-1), with a detection limit of 3.3 ng mL(-1) and an R.S.D. below 3% (n = 10). The analyte was satisfactorily determined in veterinary drugs and dog and horse urine. PMID:18958455

  2. Automated IR determination of petroleum products in water based on sequential injection analysis.

    PubMed

    Falkova, Marina; Vakh, Christina; Shishov, Andrey; Zubakina, Ekaterina; Moskvin, Aleksey; Moskvin, Leonid; Bulatov, Andrey

    2016-02-01

    The simple and easy performed automated method for the IR determination of petroleum products (PP) in water using extraction-chromatographic cartridges has been developed. The method assumes two stages: on-site extraction of PP during a sampling by using extraction-chromatographic cartridges and subsequent determination of the extracted PP using sequential injection analysis (SIA) with IR detection. The appropriate experimental conditions for extraction of the dissolved in water PP and for automated SIA procedure were investigated. The calibration plot constructed using the developed procedure was linear in the range of 3-200 μg L(-1). The limit of detection (LOD), calculated from a blank test based on 3σ was 1 µg L(-1). The sample volume was 1L. The system throughput was found to be 12 h(-1). PMID:26653498

  3. Practical applications of digital integrated circuits. Part 3: Practical sequential theory and synchronous circuits

    NASA Technical Reports Server (NTRS)

    1973-01-01

    Here, the 7400 line of transistor to transistor logic (TTL) devices is emphasized almost exclusively where hardware is concerned. However, it should be noted that the logic theory contained herein applies to all hardware. Discussed here are synchronous binary UP counters, synchronous DOWN and UP/DOWN counters, integrated circuit counters, shift registers, sequential techniques, and designing sequential counting machines.

  4. Exploring Liquid Sequential Injection Chromatography to Teach Fundamentals of Separation Methods: A Very Fast Analytical Chemistry Experiment

    ERIC Educational Resources Information Center

    Penteado, Jose C.; Masini, Jorge Cesar

    2011-01-01

    Influence of the solvent strength determined by the addition of a mobile-phase organic modifier and pH on chromatographic separation of sorbic acid and vanillin has been investigated by the relatively new technique, liquid sequential injection chromatography (SIC). This technique uses reversed-phase monolithic stationary phase to execute fast…

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

    PubMed

    Masini, Jorge Cesar

    2016-02-01

    Since sequential injection chromatography (SIC) emerged in 2003, it has been used for separation of small molecules in diverse samples, but separations of high molar mass compounds such as proteins have not yet been described. In the present work a poly(glycidyl methacrylate-co-ethylene dimethacrylate) (GMA-co-EDMA) monolithic column was prepared by free radical polymerization inside a 2.1-mm-i.d. activated fused silica-lined stainless steel tubing and modified with iminodiacetic acid (IDA). The column was prepared from a mixture of 24% GMA, 16% EDMA, 20% cyclohexanol, and 40% 1-dodecanol (all% as w/w) containing 1% of azobisisobutyronitrile (AIBN) (in relation to monomers). Polymerization was done at 60 °C for 24 h. The polymer was modified with 1.0 M IDA (in 2 M Na2CO3, pH 10.5) at 80 °C for 16 h. Separation of myoglobin, ribonuclease A, cytochrome C, and lysozyme was achieved at pH 7.0 (20 mM KH2PO4/K2HPO4) using a salt gradient (NaCl). Myoglobin was not retained, and the other proteins were separated by a gradient of NaCl created inside the holding coil (4 m of 0.8-mm-i.d. PTFE tubing) by sequential aspiration of 750 and 700 μL of 0.2 and 0.1 M NaCl, respectively. As the flow was reversed toward the column (5 μL s(-1)) the interdispersion of these solutions created a reproducible gradient which separated the proteins in 10 min, with the following order of retention: ribonuclease A < cytochrome C < lysozyme. The elution order was consistent with a cation-exchange mechanism as the retention increased with the isoelectric points. PMID:26677024

  6. Sequential injection chemiluminescence immunoassay for anionic surfactants using magnetic microbeads immobilized with an antibody.

    PubMed

    Zhang, Ruiqi; Hirakawa, Koji; Seto, Daisuke; Soh, Nobuaki; Nakano, Koji; Masadome, Takashi; Nagata, Kazumi; Sakamoto, Kazuhira; Imato, Toshihiko

    2005-12-15

    A rapid and sensitive immunoassay for the determination of linear alkylbenzene sulfonates (LAS) is described. The method involves a sequential injection analysis (SIA) system equipped with a chemiluminescence detector and a neodymium magnet. Magnetic beads, to which an anti-LAS monoclonal antibody was immobilized, were used as a solid support in an immunoassay. The introduction, trapping and release of the magnetic beads in the flow cell were controlled by means of a neodymium magnet and adjusting the flow of the carrier solution. The immunoassay was based on an indirect competitive immunoreaction of an anti-LAS monoclonal antibody on the magnetic beads and the LAS sample and horseradish peroxidase (HRP)-labeled LAS, and was based on the subsequent chemiluminscence reaction of HRP with hydrogen peroxide and p-iodophenol, in a luminol solution. The anti-LAS antibody was immobilized on the beads by coupling the antibody with the magnetic beads after activation of a carboxylate moiety on the surface of magnetic beads that had been coated with a polylactic acid film. The antibody immobilized magnetic beads were introduced, and trapped in the flow cell equipped with the neodymium magnet, an LAS solution containing HRP-labeled LAS at constant concentration and the luminol solution were sequentially introduced into the flow cell based on an SIA programmed sequence. Chemiluminescence emission was monitored by means of a photon counting unit located at the upper side of the flow cell by collecting the emitted light with a lens. A typical sigmoid calibration curve was obtained, when the logarithm of the concentration of LAS was plotted against the chemiluminescence intensity using various concentrations of standard LAS samples (0-500ppb) under optimum conditions. The time required for analysis is less than 15min. PMID:18970310

  7. A multisyringe sequential injection method for monitoring water in the energy cogeneration system of a municipal waste incinerator.

    PubMed

    de Mirabó, F M Bauzá; Forteza, R; Cerdà, V

    2009-09-15

    Leading-edge urban solid waste ashing plants use burning heat energy to obtain electrical power. Water fed to their boilers for conversion into steam should be highly pure in order to minimize corrosion, scaling and similar phenomena, which can lead to malfunctioning and a reduced useful life but can be avoided by proper management and control of the water supply. In this work, we developed a multiparameter monitor based on multisyringe sequential injection for the sequential determination of up to eight important parameters, namely: pH, specific and acid conductivity, hydrazine, ammonium, phosphate, silicate and total iron. Acid conductivity was determined by passing the sample through a cation-exchange resin in order to retain ammonium ion and release protons. This parameter was deemed the most accurate indicator of dissolved solids in boiler water. Chemical parameters were determined spectrophotometrically: hydrazine by reaction with p-dimethylaminobenzaldehyde, ammonium by the modified Berthelot reaction, iron with o-phenanthroline, and phosphate and silica by formation of a molybdoheteropoly blue dye in the presence of ascorbic acid as reductant. Use of the optimum chemical and physical operating conditions provided 3s(blank) detection limits of 0.01 mg l(-1) N(2)H(4), 0.13 mg l(-1) NH(4)(+), 0.04 mg l(-1) Fe, 0.03 mg l(-1) SiO2 and 0.05 mg l(-1) PO(4)(3-), and relative standard deviations not greater than 2.5%. The methods integrated in the proposed monitor were successfully applied to real samples from the water-steam cycle at the Son Reus ashing plant in Palma de Mallorca (Spain). PMID:19615501

  8. Deferiprone, a non-toxic reagent for determination of iron in samples via sequential injection analysis

    NASA Astrophysics Data System (ADS)

    Pragourpun, Kraivinee; Sakee, Uthai; Fernandez, Carlos; Kruanetr, Senee

    2015-05-01

    We present for the first time the use of deferiprone as a non-toxic complexing agent for the determination of iron by sequential injection analysis in pharmaceuticals and food samples. The method was based on the reaction of Fe(III) and deferiprone in phosphate buffer at pH 7.5 to give a Fe(III)-deferiprone complex, which showed a maximum absorption at 460 nm. Under the optimum conditions, the linearity range for iron determination was found over the range of 0.05-3.0 μg mL-1 with a correlation coefficient (r2) of 0.9993. The limit of detection and limit of quantitation were 0.032 μg mL-1 and 0.055 μg mL-1, respectively. The relative standard deviation (%RSD) of the method was less than 5.0% (n = 11), and the percentage recovery was found in the range of 96.0-104.0%. The proposed method was satisfactorily applied for the determination of Fe(III) in pharmaceuticals, water and food samples with a sampling rate of 60 h-1.

  9. Miniaturized sequential injection analyzer for the monitoring and quantitation of chemical weapons degradation compounds

    NASA Astrophysics Data System (ADS)

    Lancaster, Herbert L., III; Postlethwaite, Timothy A.; Zhang, Peng; Sorrells, Richard

    2002-06-01

    The ability to monitor and detect chemical warfare agents and their degradation compounds continues to be of utmost importance. Remote on-site field analysis of these compounds is also extremely important as it relates to treaty verification for the Chemical Weapons Convention, as well as the minimization and elimination of human exposure. A portable instrument has been developed and miniaturized that allows for the detection of these compounds in the field with better quantitative results and higher reproducibility than traditional field test kits. All sample and reagent manipulations are conducted in a completely automated fashion. Quantitative results may be determined colorimetrically using the molybdenum blue reaction for the final degradation product of phosphonic acid based chemical warfare agents with a detection limit of 0.05 ppm. The instrument is based on the flow analysis technique of sequential injection analysis (SIA). The benefits of this approach are that the method provides rapid response, high reproducibility of results, high sensitivity and minimal waste production.

  10. Spectrophotometric cocaine determination in a biphasic medium employing flow-batch sequential injection analysis.

    PubMed

    da Silva, Maria José; dos Anjos, Edijane V; Honorato, Ricardo S; Pimentel, Maria Fernanda; Paim, Ana Paula S

    2008-11-23

    Quantifying cocaine in apprehended samples is important to the Brazilian Federal Police because the concentration can indicate the origin of the drug and consequently the traffic route. In addition to the other risks of using this drug is the variability in cocaine concentration, which makes large doses lethal. Gas Chromatography with a Flame Ionization Detector (GC-FID) and a Mass Selective Detector (GC-MS) are the techniques usually employed, but these systems are not available in all police laboratories, due to the relatively high cost. In the present work, a flow-system procedure for the spectrophotometric determination of cocaine using cobalt thiocyanate as a complexing reagent was developed. In this reaction, two phases are formed: the superior (pink) contains an excess of cobalt thiocyanate solution and the lower layer (blue) contains the complex cocaine-cobalt thiocyanate. Samples and reagent are inserted through a sequential-injection valve between two air bubbles inside a reaction chamber. An optic fiber sensor connected to the chamber recorded the absorbance at 630 nm signal. The detection and quantification limits were 29.4 mg L(-1) and 98 mg L(-1), respectively. Relative standard deviation was 4.9% for solutions containing 400 mg L(-1) (n=10), with stable baselines. The analytical throughput was 12 determinations per hour. PMID:18940326

  11. Sequential injection fluorimetric determination of Sn in juices of canned fruits.

    PubMed

    Morte, Elane S Boa; Korn, Maria Graças A; Saraiva, M Lúcia M F S; Lima, José L F C; Pinto, Paula C A G

    2009-09-15

    The present work describes the development of a fast and robust sequential injection fluorimetric procedure for the determination of Sn in juices of canned fruits. The developed automatic methodology is based on the complexation of Sn with 8-hydroxyquinoline-5-sulfonic acid (HQSA) to form a fluorimetric product (lambda(exc)=354 nm; lambda(em)=510 nm). The influence of dimethylsulfoxide (DMSO) and cetylpyridinium bromide (CPB) on the sensitivity of the fluorimetric determination was evaluated. Linear calibration plots were obtained for Sn concentrations between 1 and 10 mg L(-1), with a detection limit of 0.38 mg L(-1). In each analytical cycle 0.006 mg of HQSA and 0.47 mg of CPB were consumed and 1.5 mL of effluent was generated. The developed methodology was applied to the determination of Sn in juices of canned fruits and the results complied with those furnished by an electrothermal atomic absorption spectrometry comparison procedure, with relative deviations lower than 5.2%. The automatic procedure exhibited good precision (R.S.D.<1.4%) and the sampling rate was about 70 determinations per hour. PMID:19615516

  12. Amperometric Determination of Sulfite by Gas Diffusion-Sequential Injection with Boron-Doped Diamond Electrode

    PubMed Central

    Chinvongamorn, Chakorn; Pinwattana, Kulwadee; Praphairaksit, Narong; Imato, Toshihiko; Chailapakul, Orawon

    2008-01-01

    A gas diffusion sequential injection system with amperometric detection using a boron-doped diamond electrode was developed for the determination of sulfite. A gas diffusion unit (GDU) was used to prevent interference from sample matrices for the electrochemical measurement. The sample was mixed with an acid solution to generate gaseous sulfur dioxide prior to its passage through the donor channel of the GDU. The sulfur dioxide diffused through the PTFE hydrophobic membrane into a carrier solution of 0.1M phosphate buffer (pH 8)/0.1% sodium dodecyl sulfate in the acceptor channel of the GDU and turned to sulfite. Then the sulfite was carried to the electrochemical flow cell and detected directly by amperometry using the boron-doped diamond electrode at 0.95 V (versus Ag/AgCl). Sodium dodecyl sulfate was added to the carrier solution to prevent electrode fouling. This method was applicable in the concentration range of 0.2-20 mg SO32−/L and a detection limit (S/N = 3) of 0.05 mg SO32−/L was achieved. This method was successfully applied to the determination of sulfite in wines and the analytical results agreed well with those obtained by iodimetric titration. The relative standard deviations for the analysis of sulfite in wines were in the range of 1.0-4.1 %. The sampling frequency was 65 h−1.

  13. Sequential circuit design for radiation hardened multiple voltage integrated circuits

    DOEpatents

    Clark, Lawrence T.; McIver, III, John K.

    2009-11-24

    The present invention includes a radiation hardened sequential circuit, such as a bistable circuit, flip-flop or other suitable design that presents substantial immunity to ionizing radiation while simultaneously maintaining a low operating voltage. In one embodiment, the circuit includes a plurality of logic elements that operate on relatively low voltage, and a master and slave latches each having storage elements that operate on a relatively high voltage.

  14. Simple automated generation of gradient elution conditions in sequential injection chromatography using monolithic column.

    PubMed

    Koblová, Petra; Sklenářová, Hana; Chocholouš, Petr; Polášek, Miroslav; Solich, Petr

    2011-06-15

    The paper deals with the concept of simple automated creation of gradient profile of the mobile phase for gradient-elution sequential injection chromatography (GE-SIC). The feasibility and merits of this concept are demonstrated on the separation and simultaneous assay of indomethacin as active principle and of its two degradation products (5-methoxy-2-methylindoleacetic acid and 4-chloro-benzoic acid) in a topical pharmaceutical formulation. The GE-SIC separation was performed with a FIAlab(®) 3000 SIC set-up (USA) equipped with an Onyx™ Monolithic C18 (25 mm × 4.6mm, Phenomenex(®)) column, a six-port selection valve, a 5-mL syringe pump and a fiber-optics UV CCD detector. Ketoprofen was used as an internal standard (IS). The gradient elution was achieved by automated reproducible mixing of acetonitrile and aqueous 0.2% phosphoric acid in the holding coil of the SIC system. Different profiles of the gradient elution were tested. The optimal gradient using two mobile phases 30:70 and 50:50 of acetonitrile/0.2% phosphoric acid (v/v) was achieved under the optimum flow rate 1.2 mL min(-1). The chromatographic resolution R between the peaks of all solutes (including the IS) was >2.00. The repeatability of retention times was characterized by the RSD values 0.18-0.30% (n=6). Net separation time was 3.5 min and the mobile phase consumption was 4.5 mL for a single GE-SIC assay. The figures of merit of the novel GE-SIC method compared well with those of conventional HPLC. PMID:21641437

  15. Mechanical System Reliability and Cost Integration Using a Sequential Linear Approximation Method

    NASA Technical Reports Server (NTRS)

    Kowal, Michael T.

    1997-01-01

    The development of new products is dependent on product designs that incorporate high levels of reliability along with a design that meets predetermined levels of system cost. Additional constraints on the product include explicit and implicit performance requirements. Existing reliability and cost prediction methods result in no direct linkage between variables affecting these two dominant product attributes. A methodology to integrate reliability and cost estimates using a sequential linear approximation method is proposed. The sequential linear approximation method utilizes probability of failure sensitivities determined from probabilistic reliability methods as well a manufacturing cost sensitivities. The application of the sequential linear approximation method to a mechanical system is demonstrated.

  16. Use of solid phase extraction for the sequential injection determination of alkaline phosphatase activity in dynamic water systems.

    PubMed

    Santos, Inês C; Mesquita, Raquel B R; Bordalo, Adriano A; Rangel, António O S S

    2012-08-30

    In this work, a solid phase extraction sequential injection methodology for the determination of alkaline phosphatase activity in dynamic water systems was developed. The determination of the enzymatic activity was based on the spectrophotometric detection of a coloured product, p-nitrophenol, at 405 nm. The p-nitrophenol is the product of the catalytic decomposition of p-nitrophenyl phosphate, a non-coloured substrate. Considering the low levels expected in natural waters and exploiting the fact of alkaline phosphatase being a metalloprotein, the enzyme was pre-concentrated in-line using a NTA Superflow resin charged with Zn(2+) ions. The developed sequential injection method enabled a quantification range of 0.044-0.441 unit mL(-1) of enzyme activity with a detection limit of 0.0082 unit mL(-1) enzyme activity (1.9 μmol L(-1) of pNP) and a determination rate of 17 h(-1). Recovery tests confirmed the accuracy of the developed sequential injection method and it was effectively applied to different natural waters and to plant root extracts. PMID:22939148

  17. A Green Sequential Injection Spectrophotometric Approach Using Natural Reagent Extracts from Heartwood of Ceasalpinia sappan Linn. for Determination of Aluminium.

    PubMed

    Siriangkhawut, Watsaka; Khanhuathon, Yaowalak; Chantiratikul, Piyanete; Ponhong, Kraingkrai; Grudpan, Kate

    2016-01-01

    A cost-effective and environmentally friendly approach using a simple sequential injection spectrophotometric system with a non-synthetic reagent from plant extracts was proposed for a green analytical-chemistry methodology. The crude aqueous extracts from heartwood of Ceasalpinia sappan Linn. in acetate buffer pH 5.5 were utilized as an alternative natural reagent for the quantification of aluminium. The extracts contained homoisoflavonoid compounds, brazilin, and brazilein, which reacted with Al(3+) to form reddish complexes with the maximum absorption wavelength at 530 nm. The optimum conditions for the sequential injection parameters, such as sequential profile, sample and reagent volumes, and the pH effect, were investigated. Under the optimum conditions, a linear calibration graph in the range of 0.075 - 1.0 mg L(-1) Al(3+) was obtained with limits of detection and quantification of 0.021 and 0.072 mg L(-1) Al(3+), respectively. Relative standard deviations of 3.2 and 2.4% for 0.1 and 0.25 mg L(-1) Al(3+) (n = 11), respectively, and sampling rate of 128 injections h(-1) were achieved. The developed system was successfully applied to pharmaceutical preparations, water, and beverage samples. The results agreed well with those obtained from the ICP-AES method. Good recoveries between 87 and 104% were obtained. PMID:26960614

  18. Determination of ambroxol hydrochloride, methylparaben and benzoic acid in pharmaceutical preparations based on sequential injection technique coupled with monolithic column.

    PubMed

    Satínský, Dalibor; Huclová, Jitka; Ferreira, Raquel L C; Montenegro, Maria Conceição B S M; Solich, Petr

    2006-02-13

    The porous monolithic columns show high performance at relatively low pressure. The coupling of short monoliths with sequential injection technique (SIA) results in a new approach to implementation of separation step to non-separation low-pressure method. In this contribution, a new separation method for simultaneous determination of ambroxol, methylparaben and benzoic acid was developed based on a novel reversed-phase sequential injection chromatography (SIC) technique with UV detection. A Chromolith SpeedROD RP-18e, 50-4.6 mm column with 10 mm precolumn and a FIAlab 3000 system with a six-port selection valve and 5 ml syringe were used for sequential injection chromatographic separations in our study. The mobile phase used was acetonitrile-tetrahydrofuran-0.05M acetic acid (10:10:90, v/v/v), pH 3.75 adjusted with triethylamine, flow rate 0.48 mlmin(-1), UV-detection was at 245 nm. The analysis time was <11 min. A new SIC method was validated and compared with HPLC. The method was found to be useful for the routine analysis of the active compounds ambroxol and preservatives (methylparaben or benzoic acid) in various pharmaceutical syrups and drops. PMID:16165338

  19. On-line dynamic fractionation and automatic determination of inorganic phosphorus in environmental solid substrates exploiting sequential injection microcolumn extraction and flow injection analysis.

    PubMed

    Buanuam, Janya; Miró, Manuel; Hansen, Elo Harald; Shiowatana, Juwadee

    2006-06-16

    Sequential injection microcolumn extraction (SI-MCE) based on the implementation of a soil-containing microcartridge as external reactor in a sequential injection network is, for the first time, proposed for dynamic fractionation of macronutrients in environmental solids, as exemplified by the partitioning of inorganic phosphorus in agricultural soils. The on-line fractionation method capitalises on the accurate metering and sequential exposure of the various extractants to the solid sample by application of programmable flow as precisely coordinated by a syringe pump. Three different soil phase associations for phosphorus, that is, exchangeable, Al- and Fe-bound, and Ca-bound fractions, were elucidated by accommodation in the flow manifold of the three steps of the Hieltjes-Lijklema (HL) scheme involving the use of 1.0M NH4Cl, 0.1M NaOH and 0.5M HCl, respectively, as sequential leaching reagents. The precise timing and versatility of SI for tailoring various operational extraction modes were utilized for investigating the extractability and the extent of phosphorus re-distribution for variable partitioning times. Automatic spectrophotometric determination of soluble reactive phosphorus in soil extracts was performed by a flow injection (FI) analyser based on the Molybdenum Blue (MB) chemistry. The 3sigma detection limit was 0.02 mg P L(-1) while the linear dynamic range extended up to 20 mg P L(-1) regardless of the extracting media. Despite the variable chemical composition of the HL extracts, a single FI set-up was assembled with no need for either manifold re-configuration or modification of chemical composition of reagents. The mobilization of trace elements, such as Cd, often present in grazed pastures as a result of the application of phosphate fertilizers, was also explored in the HL fractions by electrothermal atomic absorption spectrometry. PMID:17723403

  20. TEMPERATURE, RADIOACTIVE TRACER, AND NOISE LOGGING FOR INJECTION WELL INTEGRITY

    EPA Science Inventory

    Regulations of the Environmental Protection Agency require that an injection well exhibit both internal and external mechanical integrity. The external mechanical integrity consideration is that there is no significant fluid movement into an underground source of drinking water ...

  1. Advantages of core-shell particle columns in Sequential Injection Chromatography for determination of phenolic acids.

    PubMed

    Chocholouš, Petr; Vacková, Jana; Srámková, Ivana; Satínský, Dalibor; Solich, Petr

    2013-01-15

    Currently, for Sequential Injection Chromatography (SIC), only reversed phase C18 columns have been used for chromatographic separations. This article presents the first use of three different stationary phases: three core-shell particle-packed reversed phase columns in flow systems. The aim of this work was to extend the chromatographic capabilities of the SIC system. Despite the particle-packed columns reaching system pressures of ≤ 610 PSI, their conditions matched those of a commercially produced and optimised SIC system (SIChrom™ (FIAlab(®), USA)) with a 8-port high-pressure selection valve and medium-pressure Sapphire™ syringe pump with a 4 mL reservoir and maximum system pressure of ≤ 1000 PSI. The selectivity of each of the tested columns, Ascentis(®) Express RP-Amide, Ascentis(®) Express Phenyl-Hexyl and Ascentis(®) Express C18 (30 mm × 4.6mm, core-shell particle size 2.7 μm), was compared by their ability to separate seven phenolic acids that are secondary metabolite substances widely distributed in plants. The separations of all of the components were performed by isocratic elution using binary mobile phases composed of acetonitrile and 0.065% phosphoric acid at pH 2.4 (a specific ratio was used for each column) at a flow-rate of 0.60 mL/min. The volume of the mobile phase was 3.8 mL for each separation. The injection volume of the sample was 10 μL for each separation. The UV detection wavelengths were set to 250, 280 and 325 nm. The RP-Amide column provided the highest chromatographic resolution and allowed for complete baseline separation of protocatechuic, syringic, vanillic, ferulic, sinapinic, p-coumaric and o-coumaric acids. The Phenyl-Hexyl and C18 columns were unable to completely separate the tested mixture, syringic and vanillic acid and ferulic and sinapinic acids could not be separated from one another. The analytical parameters were a LOD of 0.3 mg L(-1), a LOQ of 1.0 mg L(-1), a calibration range of 1.0-50.0 (100.0) mg L(-1

  2. A study of the effect of sequential injection of 5-androstenediol on irradiation-induced myelosuppression in mice.

    PubMed

    Kim, Joong Sun; Jang, Won Suk; Lee, Sunjoo; Son, Yeonghoon; Park, Sunhoo; Lee, Seung Sook

    2015-06-01

    Herein, we aimed at examining the therapeutic effects of 5-androstenediol (5-AED), a natural hormone produced in the adrenal cortex, on radiation-induced myelosuppression in C3H/HeN mice. The mice were subjected to whole-body irradiation with a sublethal dose of 5 Gy gamma-irradiation to induce severe myelosuppression, and 5-AED (50 mg/kg) was administered subcutaneously. 5-AED was administrated 1 day before irradiation (pre-treatment) or twice weekly for 3 weeks starting from 1 h after irradiation (post-treatment). Treatment with 5-AED significantly ameliorated the decrease in the peripheral blood neutrophil and platelet populations in irradiated myelosuppressive mice, but had no effect on the lymphocyte population. It also ameliorated hypocellularity and disruption of bone marrow induced by irradiation and led to rapid recovery of myeloid cells. Further, it attenuated the decrease in spleen weight and megakaryocyte and myeloid cell populations in the spleen and promoted multilineage hematopoietic recovery. We found that a single injection of 5-AED produced only a temporary therapeutic effect, while sequential injection of 5-AED after irradiation had a more pronounced and prolonged therapeutic effect and reduced myelosuppression by irradiation. Thus, sequential injection of 5-AED after irradiation has therapeutic potential for radiation-induced myelosuppression when administered continuously and can be a significant therapeutic candidate for the management of acute radiation syndrome, particularly in a mass casualty scenario where rapid and economic intervention is important. PMID:25234002

  3. Solutions of TEAM Problem No. 13 using integral equations in a sequential and parallel computing environment

    SciTech Connect

    Kettunen, L.; Forsman, K.; Levine, D.; Gropp, W.

    1993-12-31

    In this paper a brief discussion of h-type volume integral formulations implemented in GFUNET/CORAL code is given and solutions of TEAM benchmark No. 13 are shown. GFUNET/CORAL is a general purpose code for 2D and 3D magnetostatics. Solutions of TEAM problem No. 13 are computed using both a sequential and parallel version of GFUNET/CORAL.

  4. Monitoring Lipase/Esterase Activity by Stopped Flow in a Sequential Injection Analysis System Using p-Nitrophenyl Butyrate

    PubMed Central

    Pliego, Jorge; Mateos, Juan Carlos; Rodriguez, Jorge; Valero, Francisco; Baeza, Mireia; Femat, Ricardo; Camacho, Rosa; Sandoval, Georgina; Herrera-López, Enrique J.

    2015-01-01

    Lipases and esterases are biocatalysts used at the laboratory and industrial level. To obtain the maximum yield in a bioprocess, it is important to measure key variables, such as enzymatic activity. The conventional method for monitoring hydrolytic activity is to take out a sample from the bioreactor to be analyzed off-line at the laboratory. The disadvantage of this approach is the long time required to recover the information from the process, hindering the possibility to develop control systems. New strategies to monitor lipase/esterase activity are necessary. In this context and in the first approach, we proposed a lab-made sequential injection analysis system to analyze off-line samples from shake flasks. Lipase/esterase activity was determined using p-nitrophenyl butyrate as the substrate. The sequential injection analysis allowed us to measure the hydrolytic activity from a sample without dilution in a linear range from 0.05–1.60 U/mL, with the capability to reach sample dilutions up to 1000 times, a sampling frequency of five samples/h, with a kinetic reaction of 5 min and a relative standard deviation of 8.75%. The results are promising to monitor lipase/esterase activity in real time, in which optimization and control strategies can be designed. PMID:25633600

  5. Integrated semiconductor twin-microdisk laser under mutually optical injection

    SciTech Connect

    Zou, Ling-Xiu; Liu, Bo-Wen; Lv, Xiao-Meng; Yang, Yue-De; Xiao, Jin-Long; Huang, Yong-Zhen

    2015-05-11

    We experimentally study the characteristics of an integrated semiconductor twin-microdisk laser under mutually optical injection through a connected optical waveguide. Based on the lasing spectra, four-wave mixing, injection locking, and period-two oscillation states are observed due to the mutually optical injection by adjusting the injected currents applied to the two microdisks. The enhanced 3 dB bandwidth is realized for the microdisk laser at the injection locking state, and photonic microwave is obtained from the electrode of the microdisk laser under the period-two oscillation state. The plentifully dynamical states similar as semiconductor lasers subject to external optical injection are realized due to strong optical interaction between the two microdisks.

  6. Rapid Self-Integrating, Injectable Hydrogel for Tissue Complex Regeneration.

    PubMed

    Hou, Sen; Wang, Xuefei; Park, Sean; Jin, Xiaobing; Ma, Peter X

    2015-07-15

    A novel rapid self-integrating, injectable, and bioerodible hydrogel is developed for bone-cartilage tissue complex regeneration. The hydrogels are able to self-integrate to form various structures, as can be seen after dying some hydrogel disks pink with rodamine. This hydrogel is demonstrated to engineer cartilage-bone complex. PMID:25946414

  7. Electrogenerated chemiluminescence induced by sequential hot electron and hole injection into aqueous electrolyte solution.

    PubMed

    Salminen, Kalle; Kuosmanen, Päivi; Pusa, Matti; Kulmala, Oskari; Håkansson, Markus; Kulmala, Sakari

    2016-03-17

    Hole injection into aqueous electrolyte solution is proposed to occur when oxide-coated aluminum electrode is anodically pulse-polarized by a voltage pulse train containing sufficiently high-voltage anodic pulses. The effects of anodic pulses are studied by using an aromatic Tb(III) chelate as a probe known to produce intensive hot electron-induced electrochemiluminescence (HECL) with plain cathodic pulses and preoxidized electrodes. The presently studied system allows injection of hot electrons and holes successively into aqueous electrolyte solutions and can be utilized in detecting electrochemiluminescent labels in fully aqueous solutions, and actually, the system is suggested to be quite close to a pulse radiolysis system providing hydrated electrons and hydroxyl radicals as the primary radicals in aqueous solution without the problems and hazards of ionizing radiation. The analytical power of the present excitation waveforms are that they allow detection of electrochemiluminescent labels at very low detection limits in bioaffinity assays such as in immunoassays or DNA probe assays. The two important properties of the present waveforms are: (i) they provide in situ oxidation of the electrode surface resulting in the desired oxide film thickness and (ii) they can provide one-electron oxidants for the system by hole injection either via F- and F(+)-center band of the oxide or by direct hole injection to valence band of water at highly anodic pulse amplitudes. PMID:26920769

  8. Sequential injection titration method using second-order signals: determination of acidity in plant oils and biodiesel samples.

    PubMed

    del Río, Vanessa; Larrechi, M Soledad; Callao, M Pilar

    2010-06-15

    A new concept of flow titration is proposed and demonstrated for the determination of total acidity in plant oils and biodiesel. We use sequential injection analysis (SIA) with a diode array spectrophotometric detector linked to chemometric tools such as multivariate curve resolution-alternating least squares (MCR-ALS). This system is based on the evolution of the basic specie of an acid-base indicator, alizarine, when it comes into contact with a sample that contains free fatty acids. The gradual pH change in the reactor coil due to diffusion and reaction phenomenona allows the sequential appearance of both species of the indicator in the detector coil, recording a data matrix for each sample. The SIA-MCR-ALS method helps to reduce the amounts of sample, the reagents and the time consumed. Each determination consumes 0.413ml of sample, 0.250ml of indicator and 3ml of carrier (ethanol) and generates 3.333ml of waste. The frequency of the analysis is high (12 samples h(-1) including all steps, i.e., cleaning, preparing and analysing). The utilized reagents are of common use in the laboratory and it is not necessary to use the reagents of perfect known concentration. The method was applied to determine acidity in plant oil and biodiesel samples. Results obtained by the proposed method compare well with those obtained by the official European Community method that is time consuming and uses large amounts of organic solvents. PMID:20441941

  9. Determination of sulphate in water and biodiesel samples by a sequential injection analysis--multivariate curve resolution method.

    PubMed

    del Río, Vanessa; Larrechi, M Soledad; Callao, M Pilar

    2010-08-31

    A spectrophotometric sequential injection analysis (SIA-DAD) method linked to multivariate curve resolution-alternating least squares (MCR-ALS) has been developed for sulphate determination. This method involves the reaction, inside the tubes of the SIA system, of sulphate with barium-dimethylsulphonazo (III) complex, Ba-DMSA (III), displacing Ba(2+) from the complex and forming DMSA (III). When the reaction products reach the detector a data matrix is obtained, which allows a second-order calibration to be developed. The experimental conditions (concentration and sample and reagent volumes) to obtain the highest sensitivity have been chosen applying a 2(4-1) fractional factorial design. The proposed sequential flow procedure permits up to 15 mg SO(4)(2-) L(-1) to be determined with a limit of detection of 1.42 mg L(-1) and it is able to monitor sulphate in samples at a frequency of 15 samples per hour. The method was applied to determine sulphate in natural and residual waters and in biodiesel. The reliability of the method was established for water samples by parallel determination using a standard turbidimetric method for sulphate in natural and residual water samples with results within statistical variation. For biodiesel samples, the method was validated comparing the concentration of some spiked samples with the expected concentration using a test-t. PMID:20800738

  10. Design of LabVIEW®-based software for the control of sequential injection analysis instrumentation for the determination of morphine

    PubMed Central

    Lenehan, Claire E.; Lewis, Simon W.

    2002-01-01

    LabVIEW®-based software for the automation of a sequential injection analysis instrument for the determination of morphine is presented. Detection was based on its chemiluminescence reaction with acidic potassium permanganate in the presence of sodium polyphosphate. The calibration function approximated linearity (range 5 × 10-10 to 5 × 10-6 M) with a line of best fit of y=1.05x+8.9164 (R2 =0.9959), where y is the log10 signal (mV) and x is the log10 morphine concentration (M). Precision, as measured by relative standard deviation, was 0.7% for five replicate analyses of morphine standard (5 × 10-8 M). The limit of detection (3σ) was determined as 5 × 10-11 M morphine. PMID:18924729

  11. Sequential injection of domain walls into ferroelectrics at different bias voltages: Paving the way for “domain wall memristors”

    SciTech Connect

    Whyte, J. R.; McQuaid, R. G. P.; Einsle, J. F.; Gregg, J. M.; Ashcroft, C. M.; Canalias, C.; Gruverman, A.

    2014-08-14

    Simple meso-scale capacitor structures have been made by incorporating thin (∼300 nm) single crystal lamellae of KTiOPO{sub 4} (KTP) between two coplanar Pt electrodes. The influence that either patterned protrusions in the electrodes or focused ion beam milled holes in the KTP have on the nucleation of reverse domains during switching was mapped using piezoresponse force microscopy imaging. The objective was to assess whether or not variations in the magnitude of field enhancement at localised “hot-spots,” caused by such patterning, could be used to both control the exact locations and bias voltages at which nucleation events occurred. It was found that both the patterning of electrodes and the milling of various hole geometries into the KTP could allow controlled sequential injection of domain wall pairs at different bias voltages; this capability could have implications for the design and operation of domain wall electronic devices, such as memristors, in the future.

  12. Sequential injection analysis for automation of the Winkler methodology, with real-time SIMPLEX optimization and shipboard application.

    PubMed

    Horstkotte, Burkhard; Tovar Sánchez, Antonio; Duarte, Carlos M; Cerdà, Víctor

    2010-01-25

    A multipurpose analyzer system based on sequential injection analysis (SIA) for the determination of dissolved oxygen (DO) in seawater is presented. Three operation modes were established and successfully applied onboard during a research cruise in the Southern ocean: 1st, in-line execution of the entire Winkler method including precipitation of manganese (II) hydroxide, fixation of DO, precipitate dissolution by confluent acidification, and spectrophotometric quantification of the generated iodine/tri-iodide (I(2)/I(3)(-)), 2nd, spectrophotometric quantification of I(2)/I(3)(-) in samples prepared according the classical Winkler protocol, and 3rd, accurate batch-wise titration of I(2)/I(3)(-) with thiosulfate using one syringe pump of the analyzer as automatic burette. In the first mode, the zone stacking principle was applied to achieve high dispersion of the reagent solutions in the sample zone. Spectrophotometric detection was done at the isobestic wavelength 466 nm of I(2)/I(3)(-). Highly reduced consumption of reagents and sample compared to the classical Winkler protocol, linear response up to 16 mg L(-1) DO, and an injection frequency of 30 per hour were achieved. It is noteworthy that for the offline protocol, sample metering and quantification with a potentiometric titrator lasts in general over 5 min without counting sample fixation, incubation, and glassware cleaning. The modified SIMPLEX methodology was used for the simultaneous optimization of four volumetric and two chemical variables. Vertex calculation and consequent application including in-line preparation of one reagent was carried out in real-time using the software AutoAnalysis. The analytical system featured high signal stability, robustness, and a repeatability of 3% RSD (1st mode) and 0.8% (2nd mode) during shipboard application. PMID:20103088

  13. Hyphenation of sequential- and flow injection analysis with FTIR-spectroscopy for chemical analysis in aqueous solutions

    NASA Astrophysics Data System (ADS)

    Lendl, B.; Schindler, R.; Kellner, R.

    1998-06-01

    A survey of the principles of sequential (SIA)-and flow injection analysis (FIA) systems with FTIR spectroscopic detection is presented to introduce these hyphenations as powerful techniques for performing chemical analysis in aqueous solution. The strength of FIA/SIA-FTIR systems lies in the possibility to perform highly reproducible and automated sample manipulations such as sample clean-up and/or chemical reactions prior to spectrum acquisition. It is shown that the hyphenation of FIA/SIA systems with an FTIR spectrometer enhances the problem solving capabilities of the FTIR spectrometer as also parameters which can not be measured directly (e.g. enzyme activities) can be determined. On the other hand application of FTIR spectroscopic detection in FIA or SIA is also of advantage as it allows to shorten conventional analysis procedures (e.g. sucrose or phosphate analysis) or to establish and apply a multivariate calibration model for simultaneous determinations (e.g. glucose, fructose and sucrose analysis). In addition to these examples two recent instrumental developments in miniaturized FIA/SIA-FTIR systems, a μ-Flow through cell based on IR fiber optics and a micromachined SI-enzyme reactor are presented in this paper.

  14. Sequential injection method for rapid and simultaneous determination of 236U, 237Np, and Pu isotopes in seawater.

    PubMed

    Qiao, Jixin; Hou, Xiaolin; Steier, Peter; Golser, Robin

    2013-11-19

    An automated analytical method implemented in a novel dual-column tandem sequential injection (SI) system was developed for simultaneous determination of (236)U, (237)Np, (239)Pu, and (240)Pu in seawater samples. A combination of TEVA and UTEVA extraction chromatography was exploited to separate and purify target analytes, whereupon plutonium and neptunium were simultaneously isolated and purified on TEVA, while uranium was collected on UTEVA. The separation behavior of U, Np, and Pu on TEVA-UTEVA columns was investigated in detail in order to achieve high chemical yields and complete purification for the radionuclides of interest. (242)Pu was used as a chemical yield tracer for both plutonium and neptunium. (238)U was quantified in the sample before the separation for deducing the (236)U concentration from the measured (236)U/(238)U atomic ratio in the separated uranium target using accelerator mass spectrometry. Plutonium isotopes and (237)Np were measured using inductively coupled plasma mass spectrometry after separation. The analytical results indicate that the developed method is robust and efficient, providing satisfactory chemical yields (70-100%) of target analytes and relatively short analytical time (8 h/sample). PMID:24134480

  15. Use of Sequential Injection Analysis to construct a Potentiometric Electronic Tongue: Application to the Multidetermination of Heavy Metals

    SciTech Connect

    Mimendia, Aitor; Merkoci, Arben; Valle, Manel del; Legin, Andrey

    2009-05-23

    An automated potentiometric electronic tongue (ET) was developed for the quantitative determination of heavy metal mixtures. The Sequential Injection Analysis (SIA) technique was used in order to automate the obtaining of input data, and the combined response was modeled by means of Artificial Neural Networks (ANN). The sensor array was formed by four sensors: two based on chalcogenide glasses Cd sensor and Cu sensor, and the rest on poly(vinyl chloride) membranes Pb sensor and Zn sensor. The Ion Selective Electrode (ISE) sensors were first characterized with respect to one and two analytes, by means of high-dimensionality calibrations, thanks to the use of the automated flow system; this characterization enabled an interference study of great practical utility. To take profit of the dynamic nature of the sensor's response, the kinetic profile of each sensor was compacted by Fast Fourier Transform (FFT) and the extracted coefficients were used as inputs for the ANN in the multidetermination applications. In order to identify the ANN which provided the best model of the electrode responses, some of the network parameters were optimized. Finally analyses were performed employing synthetic samples and water samples of the river Ebro; obtained results were compared with reference methods.

  16. Sequential injection analysis of lead using time-based colorimetric detection and preconcentration on an anionic-exchange resin.

    PubMed

    Aracama, Nestor Zárate; Araújo, Alberto N; Perez-Olmos, Ricardo

    2004-04-01

    The development of a sequential injection analysis manifold for the colorimetric determination of lead in water samples is described The concentration of lead was assessed from its catalytic effect on the reaction of resazurine reduction caused by sulfide in an alkali medium. To that effect, the reaction zone was stopped at the detector, and the time interval required for the attainment of an absorbance decrease of 0.800 at the wavelength of 610 nm was estimated. Interference of other transition metals of the samples was minimized by adding potassium iodide to the sample and retaining the iodocomplexes formed in an on-line anionic resin (AGI X8). Elution was made with a 2 mol/L sodium hydroxide solution. The relationship [SIA] microg/L = 0.99 (+/- 0.11) x [ETAAS] microg/L + 0 (+/- 4) was obtained upon comparing the results given by the proposed system and by electrothermal atomization atomic absorption spectrometry (ETAAS) after the analysis of ten water samples. PMID:15116968

  17. Sequential injection chromatography with a miniaturized multi-channel fiber optic detector for separation and quantification of propranolol and hydrochlorothiazide

    PubMed Central

    2011-01-01

    Background Sequential injection chromatography (SIC) is a new alternative separation technology. It has some advantages over high performance liquid chromatography (HPLC) regarding simplicity, inexpensiveness, portability, ease of use, maintenance requirement and operation time. In contrast, SIC has had suffered from some limitations. Results The current work involves four achievements. (a) One of the limitations of SIC has been overcome. A higher pressure resistant selection valve with additional ports was installed in an SIC system. This development allows propelling solution without showing solution leakage. (b) A new inexpensive rapid and green method for the separation and quantification of propranolol (PRP) and hydrochlorothiazide (HTZ) in their formulations was optimized and validated. (c) A miniaturized multi-channel fiber optic detector was coupled with the newly developed SIC system to detect PRP and HTZ at 270 and 290 nm, respectively. This issue enhanced the sensitivity rather than using a single-channel detector. (d) A comparative study on the efficiency of the SIC method with that of previous HPLC methods was conducted. Conclusions Besides the benefits of the instrumentation of SIC, the proposed method is rapider and more reagent-saving than previous HPLC methods. The total volume of consumed reagents and sample was 4.04 mL. The sample frequency was 22 samples/h. Other such analytical characters of the SIC method as resolution, peak symmetry, numbers of theoretical plates, linearity range, accuracy, precision and limits of detection and quantification recorded comparable results. PMID:21658210

  18. On-line preconcentration and determination of lead and cadmium by sequential injection/anodic stripping voltammetry.

    PubMed

    Ninwong, Benjawan; Chuanuwatanakul, Suchada; Chailapakul, Orawon; Dungchai, Wijitar; Motomizu, Shoji

    2012-07-15

    The highly sensitive determination of lead (Pb(II)) and cadmium (Cd(II)) ions, with a limit of detection of 0.01μgL(-1) for Pb(II) and Cd(II), by on-line preconcentration and anodic stripping voltammetry (ASV) controlled by a sequential injection analysis (SIA) system is reported here. The SIA system consisted of a syringe pump, an 8-port selection valve and a 6-port switching valve and was incorporated with a bismuth coated screen-printed carbon nanotube electrode (Bi-SPCNTE). The preconcentration of metal ions was performed by solid phase extraction using an Analig TE-05 chelating resin mini-column on a switching valve. The metal ions collected were then eluted from the resin with 1M hydrochloric acid (HCl), deposited on the electrode surface at -1.3V vs. Ag/AgCl and then measured with ASV. The pH of the sample, eluent volume, flow rate, concentration of the bismuth plating solution and the square-wave voltammetric parameters were optimized. Under the optimum conditions, an enrichment factor of 11.9-fold and 6.6-fold for Pb(II) and Cd(II) ions, respectively, was attained. Detection of Pb(II) and Cd(II) had two different linear ranges (0.5-15μgL(-1) and 15-70μgL(-1)). PMID:22817931

  19. Use of Sequential Injection Analysis to construct a Potentiometric Electronic Tongue: Application to the Multidetermination of Heavy Metals

    NASA Astrophysics Data System (ADS)

    Mimendia, Aitor; Legin, Andrey; Merkoçi, Arben; del Valle, Manel

    2009-05-01

    An automated potentiometric electronic tongue (ET) was developed for the quantitative determination of heavy metal mixtures. The Sequential Injection Analysis (SIA) technique was used in order to automate the obtaining of input data, and the combined response was modeled by means of Artificial Neural Networks (ANN). The sensor array was formed by four sensors: two based on chalcogenide glasses Cd sensor and Cu sensor, and the rest on poly(vinyl chloride) membranes Pb sensor and Zn sensor. The Ion Selective Electrode (ISE) sensors were first characterized with respect to one and two analytes, by means of high-dimensionality calibrations, thanks to the use of the automated flow system; this characterization enabled an interference study of great practical utility. To take profit of the dynamic nature of the sensor's response, the kinetic profile of each sensor was compacted by Fast Fourier Transform (FFT) and the extracted coefficients were used as inputs for the ANN in the multidetermination applications. In order to identify the ANN which provided the best model of the electrode responses, some of the network parameters were optimized. Finally analyses were performed employing synthetic samples and water samples of the river Ebro; obtained results were compared with reference methods.

  20. On-line speciation analysis of inorganic arsenic in complex environmental aqueous samples by pervaporation sequential injection analysis.

    PubMed

    Boonjob, Warunya; Miró, Manuel; Kolev, Spas D

    2013-12-15

    A proof of concept of a novel pervaporation sequential injection (PSI) analysis method for automatic non-chromatographic speciation analysis of inorganic arsenic in complex aqueous samples is presented. The method is based on hydride generation of arsine followed by its on-line pervaporation-based membrane separation and CCD spectrophotometric detection. The concentrations of arsenite (As(III)) and arsenate (As(V)) are determined sequentially in a single sample zone. The leading section of the sample zone merges with a citric acid/citrate buffer solution (pH 4.5) for the selective reduction of As(III) to arsine while the trailing section of the sample zone merges with hydrochloric acid solution to allow the reduction of both As(III) and As(V) to arsine at pH lower than 1. Virtually identical analytical sensitivity is obtained for both As(III) and As(V) at this high acidity. The flow analyzer also accommodates in-line pH detector for monitoring of the acidity throughout the sample zone prior to hydride generation. Under optimal conditions the proposed PSI method is characterized by a limit of detection, linear calibration range and repeatability for As(III) of 22 μg L(-1) (3sblank level criterion), 50-1000 μg L(-1) and 3.0% at the 500 μg L(-1) level and for As(V) of 51 μg L(-1), 100-2000 μg L(-1) and 2.6% at the 500 μg L(-1) level, respectively. The method was validated with mixed As(III)/As(V) standard aqueous solutions and successfully applied to the determination of As(III) and As(V) in river water samples with elevated content of dissolved organic carbon and suspended particulate matter with no prior sample pretreatment. Excellent relative recoveries ranging from 98% to 104% were obtained for both As(III) and As(V). PMID:24209302

  1. Middleware for Processing Message Queues with Elasticity Support and Sequential Integrity of Asynchronous Message Processing

    NASA Astrophysics Data System (ADS)

    Henrique Teixeira, Eduardo; Patrícia Favacho de Araújo, Aletéia

    2015-10-01

    Elasticity in computing refers to dynamically adjusting the amount of allocated resources to process a distributed application. In order to achieve this, mechanisms are needed to avoid the phenomenon of the elasticity threshold detection moving constantly up or down. The existing work fails to deliver sequential integrity of asynchronous messages processing and the asymmetries of data distribution to achieve parallel consumption. This paper fills this gaps and proposes a middleware solution to dynamically analyze the flow of message queue, and a mechanism to increase the parallelized consumption based on the output behavior. An architecture for IOD (Increase On Demand) middleware is presented, with support for the increase and decrease of thread's to cope with the growth of message queues, using the technique of limit-based heuristics over a given period of time and grouping messages into sub-queues based on classification criteria.

  2. Design, fabrication and test of a pneumatically controlled, renewable, microfluidic bead trapping device for sequential injection analysis applications.

    PubMed

    Shao, Guocheng; Lu, Donglai; Fu, Zhifeng; Du, Dan; Ozanich, Richard M; Wang, Wanjun; Lin, Yuehe

    2016-01-01

    This paper describes the design, fabrication, and testing of a pneumatically controlled, renewable, microfluidic device for conducting bead-based assays in an automated sequential injection analysis system. The device used a "brick wall"-like pillar array (pillar size: 20 μm length × 50 μm width × 45 μm height) with 5 μm gaps between the pillars serving as the micro filter. The flow channel where bead trapping occurred is 500 μm wide × 75 μm deep. An elastomeric membrane and an air chamber were located underneath the flow channel. By applying pressure to the air chamber, the membrane is deformed and pushed upward against the filter structure. This effectively traps beads larger than 5 μm and creates a "bed" or micro column of beads that can be perfused and washed with liquid samples and reagents. Upon completion of the assay process, the pressure is released and the beads are flushed out from underneath the filter structure to renew the device. Mouse IgG was used as a model analyte to test the feasibility of using the proposed device for immunoassay applications. Resulting microbeads from an on-chip fluorescent immunoassay were individually examined using flow cytometry. The results show that the fluorescence signal intensity distribution is fairly narrow indicating high chemical reaction uniformity among the beads population. Electrochemical on-chip assay was also conducted. A detection limit of 1 ppb was achieved and good device reliability and repeatability were demonstrated. The novel microfluidic-based beads-trapping device thus opens up a new pathway to design micro-bead based immunoassays for various applications. PMID:26566573

  3. Sequential injection approach for simultaneous determination of ultratrace plutonium and neptunium in urine with accelerator mass spectrometry.

    PubMed

    Qiao, Jixin; Hou, Xiaolin; Roos, Per; Lachner, Johannes; Christl, Marcus; Xu, Yihong

    2013-09-17

    An analytical method was developed for simultaneous determination of ultratrace level plutonium (Pu) and neptunium (Np) using iron hydroxide coprecipitation in combination with automated sequential injection extraction chromatography separation and accelerator mass spectrometry (AMS) measurement. Several experimental parameters affecting the analytical performance were investigated and compared including sample preboiling operation, aging time, amount of coprecipitating reagent, reagent for pH adjustment, sedimentation time, and organic matter decomposition approach. The overall analytical results show that preboiling and aging are important for obtaining high chemical yields for both Pu and Np, which is possibly related to the aggregation and adsorption behavior of organic substances contained in urine. Although the optimal condition for Np and Pu simultaneous determination requires 5-day aging time, an immediate coprecipitation without preboiling and aging could also provide fairly satisfactory chemical yields for both Np and Pu (50-60%) with high sample throughput (4 h/sample). Within the developed method, (242)Pu was exploited as chemical yield tracer for both Pu and Np isotopes. (242)Pu was also used as a spike in the AMS measurement for quantification of (239)Pu and (237)Np concentrations. The results show that, under the optimal experimental condition, the chemical yields of (237)Np and (242)Pu are nearly identical, indicating the high feasibility of (242)Pu as a nonisotopic tracer for (237)Np determination in real urine samples. The analytical method was validated by analysis of a number of urine samples spiked with different levels of (237)Np and (239)Pu. The measured values of (237)Np and (239)Pu by AMS exhibit good agreement (R(2) ≥ 0.955) with the spiked ones confirming the reliability of the proposed method. PMID:23952680

  4. Single peak parameters technique for simultaneous measurements: Spectrophotometric sequential injection determination of Fe(II) and Fe(III).

    PubMed

    Kozak, J; Paluch, J; Węgrzecka, A; Kozak, M; Wieczorek, M; Kochana, J; Kościelniak, P

    2016-02-01

    Spectrophotometric sequential injection system (SI) is proposed to automate the method of simultaneous determination of Fe(II) and Fe(III) on the basis of parameters of a single peak. In the developed SI system, sample and mixture of reagents (1,10-phenanthroline and sulfosalicylic acid) are introduced into a vessel, where in an acid environment (pH≅3) appropriate compounds of Fe(II) and Fe(III) with 1,10-phenanthroline and sulfosalicylic acid are formed, respectively. Then, in turn, air, sample, EDTA and sample again, are introduced into a holding coil. After the flow reversal, a segment of air is removed from the system by an additional valve and as EDTA replaces sulfosalicylic acid forming a more stable colorless compound with Fe(III), a complex signal is registered. Measurements are performed at wavelength 530 nm. The absorbance measured at minimum of the negative peak and the area or the absorbance measured at maximum of the signal can be used as measures corresponding to Fe(II) and Fe(III) concentrations, respectively. The time of the peak registration is about 2 min. Two-component calibration has been applied to analysis. Fe(II) and Fe(III) can be determined within the concentration ranges of 0.04-4.00 and 0.1-5.00 mg L(-1), with precision less than 2.8% and 1.7% (RSD), respectively and accuracy better than 7% (RE). The detection limit is 0.04 and 0.09 mg L(-1) for Fe(II) and Fe(III), respectively. The method was applied to analysis of artesian water samples. PMID:26653493

  5. Design, fabrication and test of a pneumatically controlled, renewable, microfluidic bead trapping device for sequential injection analysis applications

    SciTech Connect

    Shao, Guocheng; Lu, Donglai; Fu, Zhifeng; Du, Dan; Ozanich, Richard M.; Wang, Wanjun; Lin, Yuehe

    2016-01-01

    This paper describes the design, fabrication, and testing of a pneumatically controlled,renewable, microfluidic device for conducting bead-based assays in an automated sequential injection analysis system. The device used a “brick wall”-like pillar array (pillar size: 20 μm length X 50 μm width X 45 μm height) with 5 μm gaps between the pillars serving as the micro filter. The flow channel where bead trapping occurred is 500 μm wide X 75 μm deep. An elastomeric membrane and an air chamber were located underneath the flow channel. By applying pressure to the air chamber, the membrane is deformed and pushed upward against the filter structure. This effectively traps beads larger than 5 μm and creates a “bed” or micro column of beads that can be perfused and washed with liquid samples and reagents. Upon completion of the assay process, the pressure is released and the beads are flushed out from underneath the filter structure to renew the device. Mouse IgG was used as a model analyte to test the feasibility of using the proposed device for immunoassay applications. Resulting microbeads from an on-chip fluorescent immunoassay were individually examined using flow cytometry. The results show that the fluorescence signal intensity distribution is fairly narrow indicating high chemical reaction uniformity among the beads population. Electrochemical onchip assay was also conducted. A detection limit of 0.1 ng/mL1 ppb was achieved and good device reliability and repeatability were demonstrated. The novel microfluidic-based beadstrapping device thus opens up a new pathway to design micro-bead based biosensor immunoassays for clinical and othervarious applications.

  6. Sequential injection-bead injection-lab-on-valve coupled to high-performance liquid chromatography for online renewable micro-solid-phase extraction of carbamate residues in food and environmental samples.

    PubMed

    Vichapong, Jitlada; Burakham, Rodjana; Srijaranai, Supalax; Grudpan, Kate

    2011-07-01

    A sequential injection-bead injection-lab-on-valve system was hyphenated to HPLC for online renewable micro-solid-phase extraction of carbamate insecticides. The carbamates studied were isoprocarb, methomyl, carbaryl, carbofuran, methiocarb, promecarb, and propoxur. LiChroprep(®) RP-18 beads (25-40 μm) were employed as renewable sorbent packing in a microcolumn situated inside the LOV platform mounted above the multiposition valve of the sequential injection system. The analytes sorbed by the microcolumn were eluted using 80% acetonitrile in 0.1% acetic acid before online introduction to the HPLC system. Separation was performed on an Atlantis C-18 column (4.6 × 150 mm, 5 μm) utilizing gradient elution with a flow rate of 1.0 mL/min and a detection wavelength at 270 nm. The sequential injection system offers the means of performing automated handling of sample preconcentration and matrix removal. The enrichment factors ranged between 20 and 125, leading to limits of detection (LODs) in the range of 1-20 μg/L. Good reproducibility was obtained with relative standard deviations of <0.7 and 5.4% for retention time and peak area, respectively. The developed method has been successfully applied to the determination of carbamate residues in fruit, vegetable, and water samples. PMID:21557471

  7. Highly sensitive determination of mercury using copper enhancer by diamond electrode coupled with sequential injection-anodic stripping voltammetry.

    PubMed

    Chaiyo, Sudkate; Chailapakul, Orawon; Siangproh, Weena

    2014-12-10

    A highly sensitive determination of mercury in the presence of Cu(II) using a boron-doped diamond (BDD) thin film electrode coupled with sequential injection-anodic stripping voltammetry (SI-ASV) was proposed. The Cu(II) was simultaneously deposited with Hg(II) in a 0.5 M HCl supporting electrolyte by electrodeposition. In presence of an excess of Cu(II), the sensitivity for the determination of Hg(II) was remarkably enhanced. Cu(II) and Hg(II) were on-line deposited onto the BDD electrode surface at -1.0 V (vs. Ag/AgCl, 3 M KCl) for 150 s with a flow rate of 14 μL s(-1). An anodic stripping voltammogram was recorded from -0.4 V to 0.25 V using a frequency of 60 Hz, an amplitude of 50 mV, and a step potential of 10 mV at a stopped flow. Under the optimal conditions, well-defined peaks of Cu(II) and Hg(II) were found at -0.25 V and +0.05 V (vs. Ag/AgCl, 3 M KCl), respectively. The detection of Hg(II) showed two linear dynamic ranges (0.1-30.0 ng mL(-1) and 5.0-60.0 ng mL(-1)). The limit of detection (S/N=3) obtained from the experiment was found to be 0.04 ng mL(-1). The precision values for 10 replicate determinations were 1.1, 2.1 and 2.9% RSD for 0.5, 10 and 20 ng mL(-1), respectively. The proposed method has been successfully applied for the determination of Hg(II) in seawater, salmon, squid, cockle and seaweed samples. A comparison between the proposed method and an inductively coupled plasma optical emission spectrometry (ICP-OES) standard method was performed on the samples, and the concentrations obtained via both methods were in agreement with the certified values of Hg(II), according to the paired t-test at a 95% confidence level. PMID:25441879

  8. Development of a sequential injection-square wave voltammetry method for determination of paraquat in water samples employing the hanging mercury drop electrode.

    PubMed

    dos Santos, Luciana B O; Infante, Carlos M C; Masini, Jorge C

    2010-03-01

    This work describes the development and optimization of a sequential injection method to automate the determination of paraquat by square-wave voltammetry employing a hanging mercury drop electrode. Automation by sequential injection enhanced the sampling throughput, improving the sensitivity and precision of the measurements as a consequence of the highly reproducible and efficient conditions of mass transport of the analyte toward the electrode surface. For instance, 212 analyses can be made per hour if the sample/standard solution is prepared off-line and the sequential injection system is used just to inject the solution towards the flow cell. In-line sample conditioning reduces the sampling frequency to 44 h(-1). Experiments were performed in 0.10 M NaCl, which was the carrier solution, using a frequency of 200 Hz, a pulse height of 25 mV, a potential step of 2 mV, and a flow rate of 100 µL s(-1). For a concentration range between 0.010 and 0.25 mg L(-1), the current (i(p), µA) read at the potential corresponding to the peak maximum fitted the following linear equation with the paraquat concentration (mg L(-1)): i(p) = (-20.5 ± 0.3)C (paraquat) - (0.02 ± 0.03). The limits of detection and quantification were 2.0 and 7.0 µg L(-1), respectively. The accuracy of the method was evaluated by recovery studies using spiked water samples that were also analyzed by molecular absorption spectrophotometry after reduction of paraquat with sodium dithionite in an alkaline medium. No evidence of statistically significant differences between the two methods was observed at the 95% confidence level. PMID:20084371

  9. Accurate Prediction of Transposon-Derived piRNAs by Integrating Various Sequential and Physicochemical Features

    PubMed Central

    Luo, Longqiang; Li, Dingfang; Zhang, Wen; Tu, Shikui; Zhu, Xiaopeng; Tian, Gang

    2016-01-01

    Background Piwi-interacting RNA (piRNA) is the largest class of small non-coding RNA molecules. The transposon-derived piRNA prediction can enrich the research contents of small ncRNAs as well as help to further understand generation mechanism of gamete. Methods In this paper, we attempt to differentiate transposon-derived piRNAs from non-piRNAs based on their sequential and physicochemical features by using machine learning methods. We explore six sequence-derived features, i.e. spectrum profile, mismatch profile, subsequence profile, position-specific scoring matrix, pseudo dinucleotide composition and local structure-sequence triplet elements, and systematically evaluate their performances for transposon-derived piRNA prediction. Finally, we consider two approaches: direct combination and ensemble learning to integrate useful features and achieve high-accuracy prediction models. Results We construct three datasets, covering three species: Human, Mouse and Drosophila, and evaluate the performances of prediction models by 10-fold cross validation. In the computational experiments, direct combination models achieve AUC of 0.917, 0.922 and 0.992 on Human, Mouse and Drosophila, respectively; ensemble learning models achieve AUC of 0.922, 0.926 and 0.994 on the three datasets. Conclusions Compared with other state-of-the-art methods, our methods can lead to better performances. In conclusion, the proposed methods are promising for the transposon-derived piRNA prediction. The source codes and datasets are available in S1 File. PMID:27074043

  10. Dynamic fractionation of trace metals in soil and sediment samples using rotating coiled column extraction and sequential injection microcolumn extraction: a comparative study.

    PubMed

    Rosende, Maria; Savonina, Elena Yu; Fedotov, Petr S; Miró, Manuel; Cerdà, Víctor; Wennrich, Rainer

    2009-09-15

    Dynamic fractionation has been recognized as an appealing alternative to conventional equilibrium-based sequential extraction procedures (SEPs) for partitioning of trace elements (TE) in environmental solid samples. This paper reports the first attempt for harmonization of flow-through dynamic fractionation using two novel methods, the so-called sequential injection microcolumn (SIMC) extraction and rotating coiled column (RCC) extraction. In SIMC extraction, a column packed with the solid sample is clustered in a sequential injection system, while in RCC, the particulate matter is retained under the action of centrifugal forces. In both methods, the leachants are continuously pumped through the solid substrates by the use of either peristaltic or syringe pumps. A five-step SEP was selected for partitioning of Cu, Pb and Zn in water soluble/exchangeable, acid-soluble, easily reducible, easily oxidizable and moderately reducible fractions from 0.2 to 0.5 g samples at an extractant flow rate of 1.0 mL min(-1) prior to leachate analysis by inductively coupled plasma-atomic emission spectrometry. Similarities and discrepancies between both dynamic approaches were ascertained by fractionation of TE in certified reference materials, namely, SRM 2711 Montana Soil and GBW 07311 sediment, and two real soil samples as well. Notwithstanding the different extraction conditions set by both methods, similar trends of metal distribution were in generally found. The most critical parameters for reliable assessment of mobilizable pools of TE in worse-case scenarios are the size-distribution of sample particles, the density of particles, the content of organic matter and the concentration of major elements. For reference materials and a soil rich in organic matter, the extraction in RCC results in slightly higher recoveries of environmentally relevant fractions of TE, whereas SIMC leaching is more effective for calcareous soils. PMID:19615513

  11. METHODS FOR DETERMINING THE MECHANICAL INTEGRITY OF CLASS II INJECTION WELLS

    EPA Science Inventory

    The mechanical integrity of injection wells must be determined to insure that there is no significant leak in the casing, tubing or packer, and that there is no significant fluid movement through vertical channels adjacent to the injection well. Methods for mechanical integrity t...

  12. Microbially Enhanced Oil Recovery by Sequential Injection of Light Hydrocarbon and Nitrate in Low- And High-Pressure Bioreactors.

    PubMed

    Gassara, Fatma; Suri, Navreet; Stanislav, Paul; Voordouw, Gerrit

    2015-10-20

    Microbially enhanced oil recovery (MEOR) often involves injection of aqueous molasses and nitrate to stimulate resident or introduced bacteria. Use of light oil components like toluene, as electron donor for nitrate-reducing bacteria (NRB), offers advantages but at 1-2 mM toluene is limiting in many heavy oils. Because addition of toluene to the oil increased reduction of nitrate by NRB, we propose an MEOR technology, in which water amended with light hydrocarbon below the solubility limit (5.6 mM for toluene) is injected to improve the nitrate reduction capacity of the oil along the water flow path, followed by injection of nitrate, other nutrients (e.g., phosphate) and a consortium of NRB, if necessary. Hydrocarbon- and nitrate-mediated MEOR was tested in low- and high-pressure, water-wet sandpack bioreactors with 0.5 pore volumes of residual oil in place (ROIP). Compared to control bioreactors, those with 11-12 mM of toluene in the oil (gained by direct addition or by aqueous injection) and 80 mM of nitrate in the aqueous phase produced 16.5 ± 4.4% of additional ROIP (N = 10). Because toluene is a cheap commodity chemical, HN-MEOR has the potential to be a cost-effective method for additional oil production even in the current low oil price environment. PMID:26406569

  13. On-line sequential injection-capillary electrophoresis for near-real-time monitoring of extracellular lactate in cell culture flasks.

    PubMed

    Alhusban, Ala A; Gaudry, Adam J; Breadmore, Michael C; Gueven, Nuri; Guijt, Rosanne M

    2014-01-01

    Cell culture has replaced many in vivo studies because of ethical and regulatory measures as well as the possibility of increased throughput. Analytical assays to determine (bio)chemical changes are often based on end-point measurements rather than on a series of sequential determinations. The purpose of this work is to develop an analytical system for monitoring cell culture based on sequential injection-capillary electrophoresis (SI-CE) with capacitively coupled contactless conductivity detection (C(4)D). The system was applied for monitoring lactate production, an important metabolic indicator, during mammalian cell culture. Using a background electrolyte consisting of 25mM tris(hydroxymethyl)aminomethane, 35mM cyclohexyl-2-aminoethanesulfonic acid with 0.02% poly(ethyleneimine) (PEI) at pH 8.65 and a multilayer polymer coated capillary, lactate could be resolved from other compounds present in media with relative standard deviations 0.07% for intraday electrophoretic mobility and an analysis time of less than 10min. Using the human embryonic kidney cell line HEK293, lactate concentrations in the cell culture medium were measured every 20min over 3 days, requiring only 8.73μL of sample per run. Combining simplicity, portability, automation, high sample throughput, low limits of detection, low sample consumption and the ability to up- and outscale, this new methodology represents a promising technique for near real-time monitoring of chemical changes in diverse cell culture applications. PMID:24309712

  14. Using Sequential Injection Analysis to Improve System and Data Reliability of Online Methods: Determination of Ammonium and Phosphate in Coastal Waters

    PubMed Central

    Frank, Carsten; Schroeder, Friedhelm

    2007-01-01

    This article summarises the advantages of the sequential injection analysis (SIA) for the online determination of nutrients in coastal waters. It concentrates on techniques to improve the reliability of the gained data by continuously monitoring one or more standards and on the advantages of online standard additions and offline determination of manually collected samples with the online SIA system. These measures are advantageous during method development and validation and can be used to verify the system performance on a regular base to reduce the amount of erroneous results. No changes in the flow system are necessary and the sample throughput is only slightly reduced. These techniques have been applied to a SIA system which is able to simultaneously determine ammonium and phosphate at a rate of more than 100 samples per hour each and detection limits (3σ) of 0.06 μM and 0.05 μM. Results from a campaign in summer 2005 are shown. PMID:17671610

  15. Miniaturizing and automation of free acidity measurements for uranium (VI)-HNO3 solutions: Development of a new sequential injection analysis for a sustainable radio-analytical chemistry.

    PubMed

    Néri-Quiroz, José; Canto, Fabrice; Guillerme, Laurent; Couston, Laurent; Magnaldo, Alastair; Dugas, Vincent

    2016-10-01

    A miniaturized and automated approach for the determination of free acidity in solutions containing uranium (VI) is presented. The measurement technique is based on the concept of sequential injection analysis with on-line spectroscopic detection. The proposed methodology relies on the complexation and alkalimetric titration of nitric acid using a pH 5.6 sodium oxalate solution. The titration process is followed by UV/VIS detection at 650nm thanks to addition of Congo red as universal pH indicator. Mixing sequence as well as method validity was investigated by numerical simulation. This new analytical design allows fast (2.3min), reliable and accurate free acidity determination of low volume samples (10µL) containing uranium/[H(+)] moles ratio of 1:3 with relative standard deviation of <7.0% (n=11). The linearity range of the free nitric acid measurement is excellent up to 2.77molL(-1) with a correlation coefficient (R(2)) of 0.995. The method is specific, presence of actinide ions up to 0.54molL(-1) does not interfere on the determination of free nitric acid. In addition to automation, the developed sequential injection analysis method greatly improves the standard off-line oxalate complexation and alkalimetric titration method by reducing thousand fold the required sample volume, forty times the nuclear waste per analysis as well as the analysis time by eight fold. These analytical parameters are important especially in nuclear-related applications to improve laboratory safety, personnel exposure to radioactive samples and to drastically reduce environmental impacts or analytical radioactive waste. PMID:27474315

  16. Methodology for thermal budget reduction of SPER down to 450 °C for 3D sequential integration

    NASA Astrophysics Data System (ADS)

    Luce, F. P.; Pasini, L.; Sklénard, B.; Mathieu, B.; Licitra, C.; Batude, P.; Mazen, F.

    2016-03-01

    3D sequential integration enables the full use of the third dimension thanks to its unique contact density far above the possibilities of 3D packaging solutions. However, as the transistors are sequentially stacked over each other, the thermal budget allowed for the fabrication of the top transistor is limited by the maximal temperature accepted by the already made bottom one. It was previously described that a thermal budget of T > 500 °C is enough to degrade the bottom transistors performance. So the technological challenge is to develop low temperature routines for the fabrication of the top devices. For that, different processes have to be adapted, mainly the dopant activation step, where the T > 1000 °C spike annealing must be replaced. In this contribution, we present the feasibility to dope by solid phase epitaxial regrowth (SPER) at 450 °C thin Si films (22 nm) containing high dopant concentration of 5 × 1020 at/cm3. For n- and p-type dopants, the 450 °C SPER rendered low sheet resistance values, as low as the ones obtained with the high temperature activation method.

  17. Speciation of arsenic (III) and arsenic (V) based on quenching of CdS quantum dots fluorescence using hybrid sequential injection-stopped flow injection gas-diffusion system

    NASA Astrophysics Data System (ADS)

    Butwong, Nutthaya; Srijaranai, Supalax; Ngeontae, Wittaya; Burakham, Rodjana

    2012-11-01

    A hybrid sequential injection-stopped flow injection system was developed for the speciation of arsenic based on the quenching of mercaptoacetic acid capped cadmium sulfide quantum dots (CdS-MAA QDs) fluorescence intensity. The analytical procedure involves the generation of arsine from As(III) by sodium borohydride in acetate buffer medium pH 6.0. The generated arsine (donor stream) diffuses across the PTFE membrane of the gas-diffusion unit into an acceptor stream and then interacts with CdS-MAA QDs. Total arsenic was determined after pre-reduction of As(V) to As(III) with 1% (m/v) mercaptoacetic acid. Concentration of As(V) in the sample solutions can be deduced from the difference of total arsenic and As(III). Optimization of the experimental conditions and instrumental parameters were investigated. Under optimal conditions, limits of detection were 20 μg L-1 for As(III) and 40 μg L-1 for As(V). Recoveries in the range 84-103% were obtained from sediment sample.

  18. Developmental 3,4-methylenedioxymethamphetamine (MDMA) impairs sequential and spatial but not cued learning independent of growth, litter effects or injection stress.

    PubMed

    Williams, Michael T; Morford, LaRonda L; Wood, Sandra L; Rock, Stephanie L; McCrea, Anne E; Fukumura, Masao; Wallace, Tanya L; Broening, Harry W; Moran, Mary S; Vorhees, Charles V

    2003-04-01

    Previously, we have shown that rats administered MDMA from postnatal (P) days 11-20 had reductions in body weight during the period of treatment and as adults they had deficits in sequential and spatial learning and memory. In the present study, to control for weight reductions, we used litters with double the number of offspring to induce growth restriction comparable to that of standard size litters treated with MDMA. Litters were treated twice daily from P11 to 20 with vehicle or MDMA (20 mg/kg) or only weighed. Males, but not females, exposed to MDMA had longer latencies and more errors in the Cincinnati water maze compared to males of the other treatments. In the Morris water maze (210 cm pool, 10x10 cm platform), the MDMA animals were impaired relative to all other treatments during acquisition. Only the MDMA females showed deficits when the platform was shifted to a new location, however, both MDMA males and females were impaired when the location of the platform was again shifted and a reduced platform (5x5 cm) used. No differences were observed in the ability to swim a straight channel, locate a platform with a cue, or the endocrine response to forced swim among the treatment groups. No differences were seen between animals injected with saline and those only weighed. The data suggest that factors, such as growth retardation, multiple injections, or the composition of the litter, do not affect the development of learning and memory impairments resulting from P11 to 20 MDMA exposure. The large litter approach offers a novel method to control for undernutrition during the preweaning period in rodents. PMID:12644267

  19. Rapid isolation of plutonium in environmental solid samples using sequential injection anion exchange chromatography followed by detection with inductively coupled plasma mass spectrometry.

    PubMed

    Qiao, Jixin; Hou, Xiaolin; Roos, Per; Miró, Manuel

    2011-01-31

    This paper reports an automated analytical method for rapid determination of plutonium isotopes ((239)Pu and (240)Pu) in environmental solid extracts. Anion exchange chromatographic columns were incorporated in a sequential injection (SI) system to undertake the automated separation of plutonium from matrix and interfering elements. The analytical results most distinctly demonstrated that the crosslinkage of the anion exchanger is a key parameter controlling the separation efficiency. AG 1-×4 type resin was selected as the most suitable sorbent material for analyte separation. Investigation of column size effect upon the separation efficiency revealed that small-sized (2 mL) columns sufficed to handle up to 50 g of environmental soil samples. Under the optimum conditions, chemical yields of plutonium exceeded 90% and the decontamination factors for uranium, thorium and lead ranged from 10(3) to 10(4). The determination of plutonium isotopes in three standard/certified reference materials (IAEA-375 soil, IAEA-135 sediment and NIST-4359 seaweed) and two reference samples (Irish Sea sediment and Danish soil) revealed a good agreement with reference/certified values. The SI column-separation method is straightforward and less labor intensive as compared with batch-wise anion exchange chromatographic procedures. Besides, the automated method features low consumption of ion-exchanger and reagents for column washing and elution, with the consequent decrease in the generation of acidic waste, thus bearing green chemical credentials. PMID:21168558

  20. Rapid determination of technetium-99 in large volume seawater samples using sequential injection extraction chromatographic separation and ICP-MS measurement.

    PubMed

    Shi, Keliang; Qiao, Jixin; Wu, Wangsuo; Roos, Per; Hou, Xiaolin

    2012-08-01

    An automated method was developed for rapid determination of (99)Tc in large volume seawater samples. The analytical procedure involves preconcentration of technetium with coprecipitation, online separation using extraction chromatography (two TEVA columns) implemented in a sequential injection setup, and measurement of (99)Tc by inductively coupled plasma mass spectrometry (ICP-MS). Chromatographic behaviors of technetium, molybdenum, and ruthenium were investigated, and the mechanism of adsorption and elution of TcO(4)(-) on a TEVA column using HNO(3) was explored. The results show that not only NO(3)(-) but also acidity (or concentration of H(+)) of the loading or eluting solution affect the adsorption and desorption of TcO(4)(-) on TEVA resin. Decontamination factors of more than 1 × 10(6) for ruthenium and 5 × 10(5) for molybdenum are achieved. Chemical yields of technetium in the overall procedure range from 60% to 75% depending on the sample volumes, and a detection limit of 7.5 mBq/m(3) (or 11.5 pg/m(3)) for 200 L of seawater was obtained. Compared with the conventional analytical procedure, the developed method significantly reduces analytical time. A batch of samples (n > 4) can be analyzed within 24 h. The method has been successfully applied for rapid and automated determination of low level (99)Tc in large volume seawater samples. The analytical results of seawater samples collected in Denmark show a good agreement with the values obtained using the conventional method. PMID:22783983

  1. Sequential injection kinetic spectrophotometric determination of quaternary mixtures of carbamate pesticides in water and fruit samples using artificial neural networks for multivariate calibration

    NASA Astrophysics Data System (ADS)

    Chu, Ning; Fan, Shihua

    2009-12-01

    A new analytical method was developed for the simultaneous kinetic spectrophotometric determination of a quaternary carbamate pesticide mixture consisting of carbofuran, propoxur, metolcarb and fenobucarb using sequential injection analysis (SIA). The procedure was based upon the different kinetic properties between the analytes reacted with reagent in flow system in the non-stopped-flow mode, in which their hydrolysis products coupled with diazotized p-nitroaniline in an alkaline medium to form the corresponding colored complexes. The absorbance data from SIA peak time profile were recorded at 510 nm and resolved by the use of back-propagation-artificial neural network (BP-ANN) algorithms for multivariate quantitative analysis. The experimental variables and main network parameters were optimized and each of the pesticides could be determined in the concentration range of 0.5-10.0 μg mL -1, at a sampling frequency of 18 h -1. The proposed method was compared to other spectrophotometric methods for simultaneous determination of mixtures of carbamate pesticides, and it was proved to be adequately reliable and was successfully applied to the simultaneous determination of the four pesticide residues in water and fruit samples, obtaining the satisfactory results based on recovery studies (84.7-116.0%).

  2. A green analytical method for rapid determination of pectin degree of esterification using micro sequential injection lab-on-valve system.

    PubMed

    Naghshineh, Mahsa; Larsen, Jan; Georgiou, Constantinos; Olsen, Karsten

    2016-08-01

    A novel method for automated determination pectin degree of esterification (DE) using micro sequential injection lab-on-valve (μSI-LOV) system is developed. A face-centered central composite response surface methodology (RSM) was used to optimise system parameters. A calibration graph for determination of non-esterified galacturonic acid (GalA) content in pectin solutions with linear range of 0.08-0.34% (w/v) and the limit of detection (LOD) of 0.057% (w/v) under optimal condition was achieved. The difference between concentrations (w/v, %) of total GalA and non-esterified GalA was applied to estimate DE (%) of pectin samples. Results indicated a good agreement (tstat

  3. Sequential injection system with higher dimensional electrochemical sensor signals Part 2. Potentiometric e-tongue for the determination of alkaline ions.

    PubMed

    Cortina, M; Gutés, A; Alegret, S; Del Valle, Manuel

    2005-06-15

    An intelligent, automatic system based on an array of non-specific-response chemical sensors was developed. As a great amount of information is required for its correct modelling, we propose a system generating it itself. The sequential injection analysis (SIA) technique was chosen as it enables the processes of training, calibration, validation and operation to be automated simply. Detection was carried out using an array of potentiometric sensors based on PVC membranes of different selectivity. The diluted standard solutions needed for system learning and response modelling are automatically prepared from more concentrated standards. The electrodes used were characterised with respect to one and two analytes, by means of high-dimensionality calibrations, and the response surface of each was represented; this characterisation enabled an interference study of great practical utility. The combined response was modelled by means of artificial neural networks (ANNs), and thus it was possible to obtain an automated electronic tongue based on SIA. In order to identify the ANN which provided the best model of the electrode responses, some of the network's parameters were optimised and its usefulness in determining NH(4)(+), K(+) and Na(+) ions in synthetic samples was then tested. Finally, it was used to determine these ions in commercial fertilisers, the obtained results being compared with reference methods. PMID:18970109

  4. Sequential injection system with higher dimensional electrochemical sensor signals Part 1. Voltammetric e-tongue for the determination of oxidizable compounds.

    PubMed

    Gutés, A; Céspedes, F; Alegret, S; Del Valle, M

    2005-06-15

    A sequential injection analysis (SIA) system was developed with the aim of obtaining an automatic and versatile way to prepare standards needed in the study of systems with higher dimensional sensor signals. To illustrate this, different analytical techniques were used in determinations of several analytes. Automated potentiometric calibrations of different potentiometric sensors, with and without interference, were carried out. Useful determinations of selectivity coefficients with two degrees of freedom were obtained. Simultaneous voltammetric determinations have also been done. Firstly, simultaneous determinations of lead and cadmium, using epoxy-graphite composite as the working electrode, have enabled a separate calibration for each metal to be obtained. Next, a voltammetric electronic tongue was designed and applied to the determination of oxidizable species. The use of artificial neural networks has solved the overlapped signal of ascorbic acid, 4-aminophenol and 4-acetamidophenol (paracetamol). A set of 63 data points was prepared automatically and has facilitated the training of an electronic tongue for these three analytes. Accurate predictions of test solutions, in the range of 12-410muM for ascorbic acid, 17-530muM for 4-aminophenol and 10-420muM for paracetamol, have been achieved with RMSEs lower than 0.10muM. PMID:18970108

  5. Determination of polybrominated diphenyl ethers and polychlorinated biphenyls in fishery and aquaculture products using sequential solid phase extraction and large volume injection gas chromatography/tandem mass spectrometry.

    PubMed

    Lu, Dasheng; Lin, Yuanjie; Feng, Chao; Wang, Dongli; Qiu, Xinlei; Jin, Yu'e; Xiong, Libei; Jin, Ying; Wang, Guoquan

    2014-01-15

    A new method was developed to determine polybrominated diphenyl ethers (PBDEs) and polychlorinated biphenyls (PCBs) in fishery and aquaculture products. Samples were extracted by an accelerated solvent extraction system and cleaned up by sequential solid phase extraction (SPE) including dispersive SPE (D-SPE) and tandem SPE. PBDEs and PCBs were analyzed by a large-volume injection gas chromatography triple quadrupole mass spectrometry (LVI-GC-QqQ-MS/MS). Good linearity (R(2)≥0.9958) was achieved. Method detection limits (MDLs) were 0.16-3.3pgg(-1) (wet weight, ww) for PBDEs and 0.13-0.97pgg(-1)ww for PCBs. Mean recoveries were 60-140% with relative standard deviations (RSDs) of less than 20% in weever fish, scallop and shrimp samples spiked at a lower level of 13-31pgg(-1)ww and a higher level of 50-125pgg(-1)ww. Certified reference materials were analyzed with acceptable results. The method reduced solvent consumption, analytical time and labor, and is suitable for the routine analysis of PBDEs and PCBs in fishery and aquaculture products. PMID:24321764

  6. Iodine speciation in coastal and inland bathing waters and seaweeds extracts using a sequential injection standard addition flow-batch method.

    PubMed

    Santos, Inês C; Mesquita, Raquel B R; Bordalo, Adriano A; Rangel, António O S S

    2015-02-01

    The present work describes the development of a sequential injection standard addition method for iodine speciation in bathing waters and seaweeds extracts without prior sample treatment. Iodine speciation was obtained by assessing the iodide and iodate content, the two inorganic forms of iodine in waters. For the determination of iodide, an iodide ion selective electrode (ISE) was used. The indirect determination of iodate was based on the spectrophotometric determination of nitrite (Griess reaction). For the iodate measurement, a mixing chamber was employed (flow batch approach) to explore the inherent efficient mixing, essential for the indirect determination of iodate. The application of the standard addition method enabled detection limits of 0.14 µM for iodide and 0.02 µM for iodate, together with the direct introduction of the target water samples, coastal and inland bathing waters. The results obtained were in agreement with those obtained by ICP-MS and a colorimetric reference procedure. Recovery tests also confirmed the accuracy of the developed method which was effectively applied to bathing waters and seaweed extracts. PMID:25435219

  7. Sequential lateral solidification of silicon thin films on low-k dielectrics for low temperature integration

    NASA Astrophysics Data System (ADS)

    Carta, Fabio; Gates, Stephen M.; Limanov, Alexander B.; Hlaing, Htay; Im, James S.; Edelstein, Daniel C.; Kymissis, Ioannis

    2014-12-01

    We present the excimer laser crystallization of amorphous silicon on a low dielectric constant (low-k) insulator for very large scale integration monolithic 3D integration and demonstrate that low dielectric constant materials are suitable substrates for 3D integration through laser crystallization of silicon thin films. We crystallized 100 nm amorphous silicon on top of SiO2 and SiCOH (low-k) dielectrics, at different material thicknesses (1 μm, 0.75 μm, and 0.5 μm). The amorphous silicon crystallization on low-k dielectric requires 35% less laser energy than on an SiO2 dielectric. This difference is related to the thermal conductivity of the two materials, in agreement with one dimensional simulations of the crystallization process. We analyzed the morphology of the material through defect-enhanced microscopy, Raman spectroscopy, and X-ray diffraction analysis. SEM micrographs show that polycrystalline silicon is characterized by micron-long grains with an average width of 543 nm for the SiO2 sample and 570 nm for the low-k samples. Comparison of the Raman spectra does not show any major difference in film quality for the two different dielectrics, and polycrystalline silicon peaks are closely placed around 517 cm-1. From X-ray diffraction analysis, the material crystallized on SiO2 shows a preferential (111) crystal orientation. In the SiCOH case, the 111 peak strength decreases dramatically and samples do not show preferential crystal orientation. A 1D finite element method simulation of the crystallization process on a back end of line structure shows that copper (Cu) damascene interconnects reach a temperature of 70 °C or lower with a 0.5 μm dielectric layer between the Cu and the molten Si layer, a favorable condition for monolithic 3D integration.

  8. The integration of sequential aiming movements: Switching hand and direction at the first target.

    PubMed

    Lawrence, G P; Khan, Michael A; Mottram, Thomas M; Adam, Jos J; Buckolz, Eric

    2016-02-01

    Movement times to a single target are typically shorter compared to when movement to a second target is required. This one target movement time advantage has been shown to emerge when participants use a single hand throughout the target sequence and when there is a switch between hands at the first target. Our goal was to investigate the lacuna in the movement integration literature surrounding the interactive effects between switching hands and changing movement direction at the first target. Participants performed rapid hand movements in five conditions; movements to a single target; two target movements with a single hand in which the second target required an extension or reversal in direction; and movements to two targets where the hands were switched at the first target and the second target required an extension or reversal in direction. The significance of including these latter two (multiple hand-multiple direction) movements meant that for the first time research could differentiate between peripheral and central processes within movement integration strategies. Reaction times were significantly shorter in the single task compared to the two target tasks. More importantly, movement times to the first target were significantly shorter in the single target task compared to all two target tasks (reflecting the so-called one target advantage), except when the second movement was a reversal movement with the same hand. These findings demonstrate for the first time the contrasting effects of movement integration at central and peripheral levels. PMID:26829022

  9. Sequential lateral solidification of silicon thin films on low-k dielectrics for low temperature integration

    SciTech Connect

    Carta, Fabio Hlaing, Htay; Kymissis, Ioannis; Gates, Stephen M.; Edelstein, Daniel C.; Limanov, Alexander B.; Im, James S.

    2014-12-15

    We present the excimer laser crystallization of amorphous silicon on a low dielectric constant (low-k) insulator for very large scale integration monolithic 3D integration and demonstrate that low dielectric constant materials are suitable substrates for 3D integration through laser crystallization of silicon thin films. We crystallized 100 nm amorphous silicon on top of SiO{sub 2} and SiCOH (low-k) dielectrics, at different material thicknesses (1 μm, 0.75 μm, and 0.5 μm). The amorphous silicon crystallization on low-k dielectric requires 35% less laser energy than on an SiO{sub 2} dielectric. This difference is related to the thermal conductivity of the two materials, in agreement with one dimensional simulations of the crystallization process. We analyzed the morphology of the material through defect-enhanced microscopy, Raman spectroscopy, and X-ray diffraction analysis. SEM micrographs show that polycrystalline silicon is characterized by micron-long grains with an average width of 543 nm for the SiO{sub 2} sample and 570 nm for the low-k samples. Comparison of the Raman spectra does not show any major difference in film quality for the two different dielectrics, and polycrystalline silicon peaks are closely placed around 517 cm{sup −1}. From X-ray diffraction analysis, the material crystallized on SiO{sub 2} shows a preferential (111) crystal orientation. In the SiCOH case, the 111 peak strength decreases dramatically and samples do not show preferential crystal orientation. A 1D finite element method simulation of the crystallization process on a back end of line structure shows that copper (Cu) damascene interconnects reach a temperature of 70 °C or lower with a 0.5 μm dielectric layer between the Cu and the molten Si layer, a favorable condition for monolithic 3D integration.

  10. Rapid determination of plutonium isotopes in environmental samples using sequential injection extraction chromatography and detection by inductively coupled plasma mass spectrometry.

    PubMed

    Qiao, Jixin; Hou, Xiaolin; Roos, Per; Miró, Manuel

    2009-10-01

    This article presents an automated method for the rapid determination of 239Pu and 240Pu in various environmental samples. The analytical method involves the in-line separation of Pu isotopes using extraction chromatography (TEVA) implemented in a sequential injection (SI) network followed by detection of isolated analytes with inductively coupled plasma mass spectrometry (ICP-MS). The method has been devised for the determination of Pu isotopes at environmentally relevant concentrations, whereby it has been successfully applied to the analyses of large volumes/amounts of samples, for example, 100-200 g of soil and sediment, 20 g of seaweed, and 200 L of seawater following analyte preconcentration. The investigation of the separation capability of the assembled SI system revealed that up to 200 g of soil or sediment can be treated using a column containing about 0.70 g of TEVA resin. The analytical results of Pu isotopes in the reference materials showed good agreement with the certified or reference values at the 0.05 significance level. Chemical yields of Pu ranged from 80 to 105%, and the decontamination factors for uranium, thorium, mercury and lead were all above 10(4). The duration of the in-line extraction chromatographic run was <1.5 h, and the proposed setup was able to handle up to 20 samples (14 mL each) in a fully automated mode using a single chromatographic column. The SI manifold is thus suitable for rapid and automated determination of Pu isotopes in environmental risk assessment and emergency preparedness scenarios. PMID:19722516

  11. On-line sequential injection dispersive liquid-liquid microextraction system for flame atomic absorption spectrometric determination of copper and lead in water samples.

    PubMed

    Anthemidis, Aristidis N; Ioannou, Kallirroy-Ioanna G

    2009-06-30

    A simple, sensitive and powerful on-line sequential injection (SI) dispersive liquid-liquid microextraction (DLLME) system was developed as an alternative approach for on-line metal preconcentration and separation, using extraction solvent at microlitre volume. The potentials of this novel schema, coupled to flame atomic absorption spectrometry (FAAS), were demonstrated for trace copper and lead determination in water samples. The stream of methanol (disperser solvent) containing 2.0% (v/v) xylene (extraction solvent) and 0.3% (m/v) ammonium diethyldithiophosphate (chelating agent) was merged on-line with the stream of sample (aqueous phase), resulting a cloudy mixture, which was consisted of fine droplets of the extraction solvent dispersed entirely into the aqueous phase. By this continuous process, metal chelating complexes were formed and extracted into the fine droplets of the extraction solvent. The hydrophobic droplets of organic phase were retained into a microcolumn packed with PTFE-turnings. A portion of 300 microL isobutylmethylketone was used for quantitative elution of the analytes, which transported directly to the nebulizer of FAAS. All the critical parameters of the system such as type of extraction solvent, flow-rate of disperser and sample, extraction time as well as the chemical parameters were studied. Under the optimum conditions the enhancement factor for copper and lead was 560 and 265, respectively. For copper, the detection limit and the precision (R.S.D.) were 0.04 microg L(-1) and 2.1% at 2.0 microg L(-1) Cu(II), respectively, while for lead were 0.54 microg L(-1) and 1.9% at 30.0 microg L(-1) Pb(II), respectively. The developed method was evaluated by analyzing certified reference material and applied successfully to the analysis of environmental water samples. PMID:19376348

  12. Preconcentration and speciation of chromium in a sequential injection system incorporating dual mini-columns coupled with electrothermal atomic absorption spectrometry

    NASA Astrophysics Data System (ADS)

    Zou, Ai-Mei; Tang, Xiao-Yan; Chen, Ming-Li; Wang, Jian-Hua

    2008-05-01

    A procedure for chromium preconcentration and speciation with a dual mini-column sequential injection system coupled with electrothermal atomic absorption spectrometry (ETAAS) was developed. At pH 6, the sample solution was firstly aspirated to flow through a Chlorella vulgaris cell mini-column on which the Cr(III) was retained. The effluent was afterwards directed to flow through a 717 anion exchange resin mini-column accompanied by the retention of Cr(VI). Thereafter, Cr(III) and Cr(VI) were eluted by 0.04 mol L - 1 and 1.0 mol L - 1 nitric acid, respectively, and the eluates were quantified with ETAAS. Chemical and flow variables governing the performance of the system were investigated. By using a sampling volume of 600 µL, sorption efficiencies of 99.7% for Cr(III) and 99% for Cr(VI) were achieved along with enrichment factors of 10.5 for Cr(III) and 11.6 for Cr(VI), within linear ranges of 0.1-2.5 µg L - 1 for Cr(III) and 0.12-2.0 µg L - 1 for Cr(VI). Detection limits of 0.02 µg L - 1 for Cr(III) and 0.03 µg L - 1 for Cr(VI) along with RSD values of 1.9% for Cr(III) and 2.5% for Cr(VI) (1.0 µg L - 1 , n = 11) were obtained. The procedure was validated by analyzing a certified reference material of GBW08608 and further demonstrated by chromium speciation in river and tap water samples.

  13. Sequential injection spectrophotometric determination of tetracycline antibiotics in pharmaceutical preparations and their residues in honey and milk samples using yttrium (III) and cationic surfactant.

    PubMed

    Thanasarakhan, Wish; Kruanetr, Senee; Deming, Richard L; Liawruangrath, Boonsom; Wangkarn, Sunantha; Liawruangrath, Saisunee

    2011-06-15

    A sequential injection analysis (SIA) spectrophotometric method for determining tetracycline (TC), chlortetracycline (CTC) and oxytetracycline (OTC) in different sample matrices were described. The method was based on the reaction between tetracyclines and yttrium (III) in weak basic micellar medium, yielding the light yellow complexes, which were monitored at 390, 392 and 395 nm, respectively. A cationic surfactant, cetyltrimethylammonium bromide (CTAB) was used to obtain the micellar system. The linear ranges of calibration graphs were between 1.0 × 10(-5) and 4 × 10(-4) mol L(-1), respectively. The molar absorptivities were 5.24 × 10(5), 4.98 × 10(4) and 4.78 × 10(4) L mol(-1)cm(-1). The detection limits (3σ) were between 4.9 × 10(-6) and 7.8 × 10(-6) mol L(-1) whereas the limit of quantitations (10σ) were between 1.63 × 10(-5) and 2.60 × 10(-5) mol L(-1) the interday and intraday precisions within a weak revealed as the relative standard deviations (R.S.D., n=11) were less than 4%. The method was rapid with a sampling rate of over 60 samples h(-1) for the three drugs. The proposed method has been satisfactorily applied for the determination of tetracycline and its derivatives in pharmaceutical preparations together with their residues in milk and honey samples collected in Chiang Mai Province. The accuracy was found to be high as the Student's t-values were found to be less than the theoretical ones. The results were compared favorably with those obtained by the conventional spectrophotometric method. PMID:21641459

  14. Y-branch integrated dual wavelength laser diode for microwave generation by sideband injection locking.

    PubMed

    Huang, Jin; Sun, Changzheng; Xiong, Bing; Luo, Yi

    2009-11-01

    A Y-branch integrated dual wavelength laser diode is fabricated for optical microwave generation based on the principle of sideband injection locking. The device integrates a master laser and a slave laser with associated Y-branch coupler. By directly modulating the master laser near its relaxation resonance frequency, multiple sidebands are generated due to enhanced modulation nonlinearity. Beat signal with high spectral purity is obtained by injection locking the slave laser to one of the modulation sidebands. A millimeter-wave carrier of 42-GHz with a phase noise of -94.6 dBc/Hz at 10 kHz offset is demonstrated. PMID:19997304

  15. Comparison of Hydrologic Parameter Estimates Using Sequential and Integrated Data Fusion During a GPR Monitored Infiltration Event

    NASA Astrophysics Data System (ADS)

    Sicilia, G. T.; Moysey, S. M.

    2007-12-01

    Constraining parameters that govern variably saturated flow is important for applications ranging from quantifying water availability for ecosystems to constraining recharge rates and contaminant fluxes to groundwater. In this study we explore the effectiveness of sequential versus integrated data fusion for estimating unsaturated flow parameters using ground penetrating radar (GPR) data. In Sequential Data Fusion (SDF), geophysical imaging is used to create a map of the geophysical properties of the subsurface. Subsequently these properties are transformed to hydrologic properties that can be used to constrain an independent hydrologic inverse problem. In contrast, Integrated Data Fusion (IDF) uses the geophysical data to directly constrain hydrologic properties of interest without performing the intermediate geophysical imaging step. Our comparison of SDF and IDF is performed for a synthetic study of 2D infiltration into a homogeneous soil from a constant flux point source located at the ground surface. Here we focus on results for the estimation of intrinsic permeability (k) from cross- borehole GPR travel times collected throughout the duration of the infiltration event. The target permeability (k=7.4x10-12m2) is uniform over the 20 meter by 20 meter area modeled in this study; though the soil is homogeneous, we emphasize that water content is both spatially variable and transient. We use TOUGH2 to simulate infiltration, MATLAB to simulate GPR travel times, and PEST to perform the parameter estimation. To quantitatively compare SDF and IDF, we calculate the normalized error in estimated permeability for each method. In our study, we investigated the performance of the data fusion methods under varying survey geometries by changing the antenna spacing. In all cases we have found that IDF significantly outperforms SDF. For large antenna separations (1.7-6.7m) SDF produces an average error in estimated permeability of 78.6% while IDF errors are only 35.4%. As ray

  16. Regional-scale integration of multiresolution hydrological and geophysical data using a two-step Bayesian sequential simulation approach

    NASA Astrophysics Data System (ADS)

    Ruggeri, Paolo; Irving, James; Gloaguen, Erwan; Holliger, Klaus

    2013-07-01

    Significant progress has been made with regard to the quantitative integration of geophysical and hydrological data at the local scale for the purpose of improving predictions of groundwater flow and solute transport. However, extending corresponding approaches to the regional scale still represents one of the major challenges in the domain of hydrogeophysics. To address this problem, we have developed a regional-scale data integration methodology based on a two-step Bayesian sequential simulation approach. Our objective is to generate high-resolution stochastic realizations of the regional-scale hydraulic conductivity field in the common case where there exist spatially exhaustive but poorly resolved measurements of a related geophysical parameter, as well as highly resolved but spatially sparse collocated measurements of this geophysical parameter and the hydraulic conductivity. To integrate this multi-scale, multi-parameter database, we first link the low- and high-resolution geophysical data via a stochastic downscaling procedure. This is followed by relating the downscaled geophysical data to the high-resolution hydraulic conductivity distribution. After outlining the general methodology of the approach, we demonstrate its application to a realistic synthetic example where we consider as data high-resolution measurements of the hydraulic and electrical conductivities at a small number of borehole locations, as well as spatially exhaustive, low-resolution estimates of the electrical conductivity obtained from surface-based electrical resistivity tomography. The different stochastic realizations of the hydraulic conductivity field obtained using our procedure are validated by comparing their solute transport behaviour with that of the underlying "true" hydraulic conductivity field. We find that, even in the presence of strong subsurface heterogeneity, our proposed procedure allows for the generation of faithful representations of the regional-scale hydraulic

  17. Integrated Fuel Injection and Mixing System with Impingement Cooling Face

    NASA Technical Reports Server (NTRS)

    Mansour, Adel B. (Inventor); Harvey, Rex J. (Inventor); Tacina, Robert R. (Inventor); Laing, Peter (Inventor)

    2003-01-01

    An atomizing injector includes a metering set having a swirl chamber, a spray orifice and one or more feed slots etched in a thin plate. The swirl chamber is etched in a first side of the plate and the spray orifice is etched through a second side to the center of the swirl chamber. Fuel feed slots extend non-radially to the swirl chamber. The injector also includes integral swirler structure. The swirler structure includes a cylindrical air swirler passage, also shaped by etching, through at least one other thin plate. The cylindrical air swirler passage is located in co-axial relation to the spray orifice of the plate of the fuel metering set such that fuel directed through the spray orifice passes through the air swirler passage and swirling air is imparted to the fuel such that the fuel has a swirling component of motion. At least one air feed slot is provided in fluid communication with the air swirler passage and extends in non-radial relation thereto. Air supply passages extend through the plates of the metering set and the swirler structure to feed the air feed slot in each plate of the swirler structure.

  18. The Sequential Aerosol Technique: A Major Component in an Integrated Strategy of Intervention against Riverine Tsetse in Ghana

    PubMed Central

    Adam, Yahaya; Cecchi, Giuliano; Kgori, Patrick M.; Marcotty, Tanguy; Mahama, Charles I.; Abavana, Martin; Anderson, Benita; Paone, Massimo; Mattioli, Raffaele; Bouyer, Jérémy

    2013-01-01

    Background An integrated strategy of intervention against tsetse flies was implemented in the Upper West Region of Ghana (9.62°–11.00° N, 1.40°–2.76° W), covering an area of ≈18,000 km2 within the framework of the Pan-African Tsetse and Trypanosomosis Eradication Campaign. Two species were targeted: Glossina tachinoides and Glossina palpalis gambiensis. Methodology/Principal Findings The objectives were to test the potentiality of the sequential aerosol technique (SAT) to eliminate riverine tsetse species in a challenging subsection (dense tree canopy and high tsetse densities) of the total sprayed area (6,745 km2) and the subsequent efficacy of an integrated strategy including ground spraying (≈100 km2), insecticide treated targets (20,000) and insecticide treated cattle (45,000) in sustaining the results of tsetse suppression in the whole intervention area. The aerial application of low-dosage deltamethrin aerosols (0.33–0.35 g a.i/ha) was conducted along the three main rivers using five custom designed fixed-wings Turbo thrush aircraft. The impact of SAT on tsetse densities was monitored using 30 biconical traps deployed from two weeks before until two weeks after the operations. Results of the SAT monitoring indicated an overall reduction rate of 98% (from a pre-intervention mean apparent density per trap per day (ADT) of 16.7 to 0.3 at the end of the fourth and last cycle). One year after the SAT operations, a second survey using 200 biconical traps set in 20 sites during 3 weeks was conducted throughout the intervention area to measure the impact of the integrated control strategy. Both target species were still detected, albeit at very low densities (ADT of 0.27 inside sprayed blocks and 0.10 outside sprayed blocks). Conclusions/Significance The SAT operations failed to achieve elimination in the monitored section, but the subsequent integrated strategy maintained high levels of suppression throughout the intervention area, which will

  19. Sequential elution process

    DOEpatents

    Kingsley, Ilse S.

    1987-01-01

    A process and apparatus for the separation of complex mixtures of carbonaceous material by sequential elution with successively stronger solvents. In the process, a column containing glass beads is maintained in a fluidized state by a rapidly flowing stream of a weak solvent, and the sample is injected into this flowing stream such that a portion of the sample is dissolved therein and the remainder of the sample is precipitated therein and collected as a uniform deposit on the glass beads. Successively stronger solvents are then passed through the column to sequentially elute less soluble materials.

  20. Sequential elution process

    DOEpatents

    Kingsley, I.S.

    1987-01-06

    A process and apparatus are disclosed for the separation of complex mixtures of carbonaceous material by sequential elution with successively stronger solvents. In the process, a column containing glass beads is maintained in a fluidized state by a rapidly flowing stream of a weak solvent, and the sample is injected into this flowing stream such that a portion of the sample is dissolved therein and the remainder of the sample is precipitated therein and collected as a uniform deposit on the glass beads. Successively stronger solvents are then passed through the column to sequentially elute less soluble materials. 1 fig.

  1. Preliminary analysis of the sequential simultaneous integrated boost technique for intensity-modulated radiotherapy for head and neck cancers

    PubMed Central

    Miyazaki, Masayoshi; Nishiyama, Kinji; Ueda, Yoshihiro; Ohira, Shingo; Tsujii, Katsutomo; Isono, Masaru; Masaoka, Akira; Teshima, Teruki

    2016-01-01

    The aim of this study was to compare three strategies for intensity-modulated radiotherapy (IMRT) for 20 head-and-neck cancer patients. For simultaneous integrated boost (SIB), doses were 66 and 54 Gy in 30 fractions for PTVboost and PTVelective, respectively. Two-phase IMRT delivered 50 Gy in 25 fractions to PTVelective in the First Plan, and 20 Gy in 10 fractions to PTVboost in the Second Plan. Sequential SIB (SEQ-SIB) delivered 55 Gy and 50 Gy in 25 fractions, respectively, to PTVboost and PTVelective using SIB in the First Plan and 11 Gy in 5 fractions to PTVboost in the Second Plan. Conformity indexes (CIs) (mean ± SD) for PTVboost and PTVelective were 1.09 ± 0.05 and 1.34 ± 0.12 for SIB, 1.39 ± 0.14 and 1.80 ± 0.28 for two-phase IMRT, and 1.14 ± 0.07 and 1.60 ± 0.18 for SEQ-SIB, respectively. CI was significantly highest for two-phase IMRT. Maximum doses (Dmax) to the spinal cord were 42.1 ± 1.5 Gy for SIB, 43.9 ± 1.0 Gy for two-phase IMRT and 40.3 ± 1.8 Gy for SEQ-SIB. Brainstem Dmax were 50.1 ± 2.2 Gy for SIB, 50.5 ± 4.6 Gy for two-phase IMRT and 47.4 ± 3.6 Gy for SEQ-SIB. Spinal cord Dmax for the three techniques was significantly different, and brainstem Dmax was significantly lower for SEQ-SIB. The compromised conformity of two-phase IMRT can result in higher doses to organs at risk (OARs). Lower OAR doses in SEQ-SIB made SEQ-SIB an alternative to SIB, which applies unconventional doses per fraction. PMID:26983983

  2. Analysis of an nn+ low-high junction and the application to integrated injection logic devices

    NASA Astrophysics Data System (ADS)

    Gannon, T. L.

    1980-12-01

    The literature on pnn+ devices is reviewed with an itemization of the assumptions typically made as well as a derivation of the most widely accepted theory. These assumptions are analyzed separately with the aid of sample calculations made using numerical analysis. The effects associated with heavy doping and Auger recombination are introduced with the associated theories described. A computational approach for the analysis of nn+ is developed that provides excellent agreement with the more complex and rigorous numerical analysis. The basic operation of integrated injection logic is described along with a development of a d.c. model. The a.c. or transient analysis of an integrated injection logic device using a charge control model is discussed. An extended Ebers-Moll model is described with a technique for calculating the model parameters for diffusion capacitance determination. The numerical techniques utilized in the derivations as well as determining how heavy doping and Auger effects can be incorporated into the algorithm are considered.

  3. Study of Southern Tyrrhenian and Sicilian regions by a sequential procedure to integrate WAM seismic tomographies and Bouguer anomaly data

    NASA Astrophysics Data System (ADS)

    Panepinto, S.; Calo, M. M.; Luzio, D.; Dorbath, C.

    2009-12-01

    A procedure to obtain 3D velocity-density models and earthquake relocation by integrated inversion of P and S wave traveltimes and Bouguer anomaly distribution was applied to a large dataset concerning the Southern Tyrrhenian and Sicilian areas. The seismic dataset was subdivided into two subsets for separate inversions, whose results were later on joined by the WAM (Weighted Average Model) technique. This is a post-processing technique proposed by Calò et al. (2009) by which preliminary tomographic models are unified in a common 3D grid. The first dataset concerns 28873 P and 9990 S arrival times of 1800 earthquakes located in the area 14°30‧ E - 17°E, 37°N - 41°N while the second dataset contains 31250 P and 13588 S arrival-times related to 1951 events located in the area 11° E - 15°48‧ E, 36°30‧N - 39°N. The selected events were recorded at least by 10 stations in the period 1981-2005 and marked by RMS < 0.50 s. The second dataset was integrated with P-wave traveltimes picked in several sesmic profiles carried out in the study region. The Bouguer anomaly measurements were interpolated in the nodes of a 8x8 km regular grid covering the area 12° E - 16°01‧ E, 36°13‧ N - 38°31‧ N. The proposed procedure allows to invert seismic and gravimetric data with a sequential technique to avoid the problematic optimization of the relative weights to assign to the different type of data. A first WAM provides a preliminary Vp, Vs and Vp/Vs models and a first ipocentral relocation. Since the obtained Vs model seems poorly constrained by the S wave arrival times, the Vp model is converted in a new Vs model, through a Vs-Vp correlation law proposed by T.M. Brocher (2005), and used, jointly to the Vp model, as input for a second WAM. The results of this second step are used to derive, by the empirical Brocher’s equations, 2 density distributions associated to the Vp and Vs models. These density models are statistically compared and the distribution of

  4. Wide bandwidth chaotic signal generation in a monolithically integrated semiconductor laser via optical injection

    NASA Astrophysics Data System (ADS)

    Yin, Xue-Mei; Zhong, Zhu-Qiang; Zhao, Ling-Juan; Lu, Dan; Qiu, Hai-Ying; Xia, Guang-Qiong; Wu, Zheng-Mao

    2015-11-01

    Wide bandwidth chaotic signal generation in a three-section monolithically integrated semiconductor laser (MISL) under external optical injection is investigated experimentally. Through evaluating the effective bandwidth of chaotic signals, the influences of the optical injection on the bandwidth of chaotic signal from the MISL are analyzed. The experimental results indicate that, for the currents of the DFB section (IDFB) and the phase section (IP) are fixed at 70.00 mA and 34.00 mA, respectively, the effective bandwidth of chaos signal generated by the solitary MISL reaches its maximum value of 14.36 GHz when the current of the amplification section (IA) takes 23.22 mA. After an external optical injection is introduced into the MISL, the effective bandwidth of the generated chaotic signal can be beyond 2.5 times of the maximum value. Furthermore, the effects of the injection strength and the frequency detuning on the effective bandwidth of the generated chaotic signal are also discussed.

  5. Investigation of caprock integrity during high-volume injection into the Utsira formation

    NASA Astrophysics Data System (ADS)

    Gasda, S. E.; Wangen, M.; Bjørnarå, T. I.

    2015-12-01

    The Utsira formation is a large offshore saline aquifer in the North Sea that is considered a likely candidate for storage of CO2 emissions. Currently, the Utsira is host to the longest operating CO2 storage project, the Sleipner project, which has injected 1 Mt CO2/y since 1996. The entire Utsira formation has an estimated storage capacity of 15 Gt, which is equal to 300 Sleipner-sized projects in simultaneous operation for the next 50 years. Injectivity into the Utsira is exceptionally good, and no pressurization has been observed at Sleipner. The formation is over 100-m thick and comprised of unconsolidated sand with high porosity and permeability (30-40% and 1-3 Darcy). The Nordland shale has been characterized as a high-quality seal that is regionally thick, extensive and absent of significant faults. Significant scale-up of CO2 injection into the Utsira is required to increase storage of regional CO2 emissions well beyond what is currently stored today. Full utilization of the Utsira storage capacity would result in injection rates >100 Mt/y, significantly larger than Sleipner. Despite the lack of pressure effects at Sleipner, higher injection rates will likely lead to pressure build-up in the Utsira. Relatively little is known about the magnitude of pressure build-up and resulting impact on caprock integrity with high-volume injection. The problem is complex, involving multiphase flow and mechanical deformation of the storage reservoir and the surrounding formations, and covers large spatial scales, ranging several hundred kilometers in lateral extent. There are significant challenges in applying fully coupled hydromechanical simulators to problems of this scale. The computational effort required to solve a resolved is significant, and efforts to reduce the complexity of the model are needed. In this study, simplified modeling approaches are investigated. A reduced order multiphase flow model coupled with a geomechanical model results in greater efficiency

  6. In-line sequential injection-based hollow-fiber sorptive microextraction as a front-end to gas chromatography-mass spectrometry: a novel fully automatic sample processing technique for residue analysis.

    PubMed

    Boonjob, Warunya; Quintana, José Benito; Rodil, Rosario; Cela, Rafael; Miró, Manuel

    2013-10-01

    A novel and affordable analytical setup is herein reported for automatic flow-through sorptive microextraction of organic contaminants, exploiting polydimethylsiloxane (PDMS) as a front-end to gas chromatography-ion trap-tandem mass spectrometry. The analytical procedure involves a short single-strand PDMS hollow fiber integrated in a sequential injection (SI) network for automatic fluidic handling by programmable flow. The target species are in-line extracted from 10 mL of sample containing 20% (v/v) methanol followed by elution with a metered volume of organic solvent, which is whereupon quantitatively transferred into the programmed temperature vaporization (PTV) injector of the GC. Diffusional resistance to mass transfer was overcome by effecting the overall concentration and stripping steps at a single PDMS tubing interface. The proof of concept of the novel hyphenated system was demonstrated for extraction and determination of organochlorine pesticides (OCPs), namely, heptachlor, dieldrin, endrin, endosulfan, p,p'-dichlorodiphenyldichloroethane, p,p'-dichlorodiphenyltrichloroethane, dichlorodiphenyldichloroethylene, and endrin ketone, taken as model analytes, in environmental and industrial waters. Four organic solvents with a broad spectrum of polarity were investigated as eluents in the SI-based assembly, namely, ethyl acetate, methyl tert-butyl ether, hexane, and chloroform. Chloroform was proven the most suitable solvent for expedient elution and fast evaporation in the PTV injector. Under the selected experimental variables, limits of detection (signal-to-noise ratio (S/N) = 3) within the range of 0.3-1.1 ng L(-1), limits of quantification (S/N = 10) of 1.0-3.6 ng L(-1), and method repeatabilities spanning from 1.7 to 4.7% were obtained for the suite of OCPs. The hyphenated flow analyzer was harnessed to the analysis of samples of varying matrix complexity with good relative recoveries (86-112%) in drinking water, surface water, and influent and effluent

  7. Sequential cloning of chromosomes

    DOEpatents

    Lacks, Sanford A.

    1995-07-18

    A method for sequential cloning of chromosomal DNA of a target organism is disclosed. A first DNA segment homologous to the chromosomal DNA to be sequentially cloned is isolated. The first segment has a first restriction enzyme site on either side. A first vector product is formed by ligating the homologous segment into a suitably designed vector. The first vector product is circularly integrated into the target organism's chromosomal DNA. The resulting integrated chromosomal DNA segment includes the homologous DNA segment at either end of the integrated vector segment. The integrated chromosomal DNA is cleaved with a second restriction enzyme and ligated to form a vector-containing plasmid, which is replicated in a host organism. The replicated plasmid is then cleaved with the first restriction enzyme. Next, a DNA segment containing the vector and a segment of DNA homologous to a distal portion of the previously isolated DNA segment is isolated. This segment is then ligated to form a plasmid which is replicated within a suitable host. This plasmid is then circularly integrated into the target chromosomal DNA. The chromosomal DNA containing the circularly integrated vector is treated with a third, retrorestriction (class IIS) enzyme. The cleaved DNA is ligated to give a plasmid that is used to transform a host permissive for replication of its vector. The sequential cloning process continues by repeated cycles of circular integration and excision. The excision is carried out alternately with the second and third enzymes.

  8. Sequential cloning of chromosomes

    DOEpatents

    Lacks, S.A.

    1995-07-18

    A method for sequential cloning of chromosomal DNA of a target organism is disclosed. A first DNA segment homologous to the chromosomal DNA to be sequentially cloned is isolated. The first segment has a first restriction enzyme site on either side. A first vector product is formed by ligating the homologous segment into a suitably designed vector. The first vector product is circularly integrated into the target organism`s chromosomal DNA. The resulting integrated chromosomal DNA segment includes the homologous DNA segment at either end of the integrated vector segment. The integrated chromosomal DNA is cleaved with a second restriction enzyme and ligated to form a vector-containing plasmid, which is replicated in a host organism. The replicated plasmid is then cleaved with the first restriction enzyme. Next, a DNA segment containing the vector and a segment of DNA homologous to a distal portion of the previously isolated DNA segment is isolated. This segment is then ligated to form a plasmid which is replicated within a suitable host. This plasmid is then circularly integrated into the target chromosomal DNA. The chromosomal DNA containing the circularly integrated vector is treated with a third, retrorestriction (class IIS) enzyme. The cleaved DNA is ligated to give a plasmid that is used to transform a host permissive for replication of its vector. The sequential cloning process continues by repeated cycles of circular integration and excision. The excision is carried out alternately with the second and third enzymes. 9 figs.

  9. Reducing Risk in CO2 Sequestration: A Framework for Integrated Monitoring of Basin Scale Injection

    NASA Astrophysics Data System (ADS)

    Seto, C. J.; Haidari, A. S.; McRae, G. J.

    2009-12-01

    Geological sequestration of CO2 is an option for stabilization of atmospheric CO2 concentrations. Technical ability to safely store CO2 in the subsurface has been demonstrated through pilot projects and a long history of enhanced oil recovery and acid gas disposal operations. To address climate change, current injection operations must be scaled up by a factor of 100, raising issues of safety and security. Monitoring and verification is an essential component in ensuring safe operations and managing risk. Monitoring provides assurance that CO2 is securely stored in the subsurface, and the mechanisms governing transport and storage are well understood. It also provides an early warning mechanism for identification of anomalies in performance, and a means for intervention and remediation through the ability to locate the CO2. Through theoretical studies, bench scale experiments and pilot tests, a number of technologies have demonstrated their ability to monitor CO2 in the surface and subsurface. Because the focus of these studies has been to demonstrate feasibility, individual techniques have not been integrated to provide a more robust method for monitoring. Considering the large volumes required for injection, size of the potential footprint, length of time a project must be monitored and uncertainty, operational considerations of cost and risk must balance safety and security. Integration of multiple monitoring techniques will reduce uncertainty in monitoring injected CO2, thereby reducing risk. We present a framework for risk management of large scale injection through model based monitoring network design. This framework is applied to monitoring CO2 in a synthetic reservoir where there is uncertainty in the underlying permeability field controlling fluid migration. Deformation and seismic data are used to track plume migration. A modified Ensemble Kalman filter approach is used to estimate flow properties by jointly assimilating flow and geomechanical

  10. Optimal characterization of pollutant sources in contaminated aquifers by integrating sequential-monitoring-network design and source identification: methodology and an application in Australia

    NASA Astrophysics Data System (ADS)

    Prakash, Om; Datta, Bithin

    2015-09-01

    Often, when pollution is first detected in groundwater, very few spatiotemporal pollutant concentration measurements are available. The contaminant concentration measurement data initially available are generally sparse and insufficient for accurate source characterization. This requires development of a contaminant monitoring plan and its field implementation to collect more data. The location of scientifically chosen monitoring points and the number of measurements are important considerations in improving the source-characterization process, especially in a complex contamination scenario. In order to improve the efficiency of source characterization, a feedback-based methodology is implemented, integrating sequential-monitoring-network design and a source identification method. The simulated annealing (SA) optimization algorithm is used to solve the models for optimal source identification and the monitoring-network-design optimization. This sequence is repeated a few times to improve the accuracy of source characterization. The methodology is based on the premise that concentration measurements from a sequence of implemented monitoring networks provide feedback information on the actual concentration in the site. This additional information, obtained as feedback from monitoring networks designed and implemented based on intermediate source characterization, can result in sequential improvement in the resulting source characterization. The performance of this methodology is evaluated by application to a contaminated aquifer site in New South Wales, Australia, where source location, source-activity initiation time and source-flux (mass per unit time) release history are considered as unknown variables. The performance evaluation results demonstrate potential applicability of the proposed sequential methodology.

  11. Sequential cloning of chromosomes

    SciTech Connect

    Lacks, S.A.

    1991-12-31

    A method for sequential cloning of chromosomal DNA and chromosomal DNA cloned by this method are disclosed. The method includes the selection of a target organism having a segment of chromosomal DNA to be sequentially cloned. A first DNA segment, having a first restriction enzyme site on either side. homologous to the chromosomal DNA to be sequentially cloned is isolated. A first vector product is formed by ligating the homologous segment into a suitably designed vector. The first vector product is circularly integrated into the target organism`s chromosomal DNA. The resulting integrated chromosomal DNA segment includes the homologous DNA segment at either end of the integrated vector segment. The integrated chromosomal DNA is cleaved with a second restriction enzyme and ligated to form a vector-containing plasmid, which is replicated in a host organism. The replicated plasmid is then cleaved with the first restriction enzyme. Next, a DNA segment containing the vector and a segment of DNA homologous to a distal portion of the previously isolated DNA segment is isolated. This segment is then ligated to form a plasmid which is replicated within a suitable host. This plasmid is then circularly integrated into the target chromosomal DNA. The chromosomal DNA containing the circularly integrated vector is treated with a third, retrorestriction enzyme. The cleaved DNA is ligated to give a plasmid that is used to transform a host permissive for replication of its vector. The sequential cloning process continues by repeated cycles of circular integration and excision. The excision is carried out alternately with the second and third enzymes.

  12. Free flow isotachophoresis in an injection moulded miniaturised separation chamber with integrated electrodes.

    PubMed

    Stone, Victoria N; Baldock, Sara J; Croasdell, Laura A; Dillon, Leonard A; Fielden, Peter R; Goddard, Nick J; Thomas, C L Paul; Treves Brown, Bernard J

    2007-07-01

    An injection moulded free flow isotachophoresis (FFITP) microdevice with integrated carbon fibre loaded electrodes with a separation chamber of 36.4mm wide, 28.7 mm long and 100 microm deep is presented. The microdevice was completely fabricated by injection moulding in carbon fibre loaded polystyrene for the electrodes and crystal polystyrene for the remainder of the chip and was bonded together using ultrasonic welding. Two injection moulded electrode designs were compared, one with the electrode surface level with the separation chamber and one with a recessed electrode. Separations of two anionic dyes, 0.2mM each of amaranth and acid green and separations of 0.2mM each of amaranth, bromophenol blue and glutamate were performed on the microdevice. Flow rates of 1.25 ml min(-1) for the leading and terminating electrolytes were used and a flow rate of 0.63 ml min(-1) for the sample. Electric fields of up to 370 V cm(-1) were applied across the separation chamber. Joule heating was not found to be significant although out-gassing was observed at drive currents greater than 3 mA. PMID:17229431

  13. Caprock Integrity during Hydrocarbon Production and CO2 Injection in the Goldeneye Reservoir

    NASA Astrophysics Data System (ADS)

    Salimzadeh, Saeed; Paluszny, Adriana; Zimmerman, Robert

    2016-04-01

    Carbon Capture and Storage (CCS) is a key technology for addressing climate change and maintaining security of energy supplies, while potentially offering important economic benefits. UK offshore, depleted hydrocarbon reservoirs have the potential capacity to store significant quantities of carbon dioxide, produced during power generation from fossil fuels. The Goldeneye depleted gas condensate field, located offshore in the UK North Sea at a depth of ~ 2600 m, is a candidate for the storage of at least 10 million tons of CO2. In this research, a fully coupled, full-scale model (50×20×8 km), based on the Goldeneye reservoir, is built and used for hydro-carbon production and CO2 injection simulations. The model accounts for fluid flow, heat transfer, and deformation of the fractured reservoir. Flow through fractures is defined as two-dimensional laminar flow within the three-dimensional poroelastic medium. The local thermal non-equilibrium between injected CO2 and host reservoir has been considered with convective (conduction and advection) heat transfer. The numerical model has been developed using standard finite element method with Galerkin spatial discretisation, and finite difference temporal discretisation. The geomechanical model has been implemented into the object-oriented Imperial College Geomechanics Toolkit, in close interaction with the Complex Systems Modelling Platform (CSMP), and validated with several benchmark examples. Fifteen major faults are mapped from the Goldeneye field into the model. Modal stress intensity factors, for the three modes of fracture opening during hydrocarbon production and CO2 injection phases, are computed at the tips of the faults by computing the I-Integral over a virtual disk. Contact stresses -normal and shear- on the fault surfaces are iteratively computed using a gap-based augmented Lagrangian-Uzawa method. Results show fault activation during the production phase that may affect the fault's hydraulic conductivity

  14. Gigascale Silicon Photonic Transmitters Integrating HBT-based Carrier-injection Electroabsorption Modulator Structures

    NASA Astrophysics Data System (ADS)

    Fu, Enjin

    Demand for more bandwidth is rapidly increasing, which is driven by data intensive applications such as high-definition (HD) video streaming, cloud storage, and terascale computing applications. Next-generation high-performance computing systems require power efficient chip-to-chip and intra-chip interconnect yielding densities on the order of 1Tbps/cm2. The performance requirements of such system are the driving force behind the development of silicon integrated optical interconnect, providing a cost-effective solution for fully integrated optical interconnect systems on a single substrate. Compared to conventional electrical interconnect, optical interconnects have several advantages, including frequency independent insertion loss resulting in ultra wide bandwidth and link latency reduction. For high-speed optical transmitter modules, the optical modulator is a key component of the optical I/O channel. This thesis presents a silicon integrated optical transmitter module design based on a novel silicon HBT-based carrier injection electroabsorption modulator (EAM), which has the merits of wide optical bandwidth, high speed, low power, low drive voltage, small footprint, and high modulation efficiency. The structure, mechanism, and fabrication of the modulator structure will be discussed which is followed by the electrical modeling of the post-processed modulator device. The design and realization of a 10Gbps monolithic optical transmitter module integrating the driver circuit architecture and the HBT-based EAM device in a 130nm BiCMOS process is discussed. For high power efficiency, a 6Gbps ultra-low power driver IC implemented in a 130nm BiCMOS process is presented. The driver IC incorporates an integrated 27-1 pseudo-random bit sequence (PRBS) generator for reliable high-speed testing, and a driver circuit featuring digitally-tuned pre-emphasis signal strength. With outstanding drive capability, the driver module can be applied to a wide range of carrier

  15. Investigations on injection molded, glass-fiber reinforced polyamide 6 integral foams using breathing mold technology

    NASA Astrophysics Data System (ADS)

    Roch, A.; Kehret, L.; Huber, T.; Henning, F.; Elsner, P.

    2015-05-01

    Investigations on PA6-GF50 integral foams have been carried out using different material systems: longfiber- and shortfiber-reinforced PA6 as well as unreinforced PA6 as a reference material. Both chemical and physical blowing agents were applied. Breathing mold technology (decompression of the mold) was selected for the foaming process. The integral foam design, which can be conceived as a sandwich structure, helps to save material in the neutral axis area and maintains a distance between load-bearing, unfoamed skin layers. For all test series an initial mold gap of 2.5 mm was chosen and the same amount of material was injected. In order to realize different density reductions, the mold opening stroke was varied. The experiments showed that, at a constant mass per unit area, integral polyamide 6 foams have a significantly higher bending stiffness than compact components, due to their higher area moment of inertia after foaming. At a constant surface weight the bending stiffness in these experiments could be increased by up to 600 %. Both shortfiber- and longfiber-reinforced polyamide 6 showed an increase in energy absorption during foaming.

  16. Reusable EGaIn-Injected Substrate-Integrated-Waveguide Resonator for Wireless Sensor Applications.

    PubMed

    Memon, Muhammad Usman; Lim, Sungjoon

    2015-01-01

    The proposed structure in this research is constructed on substrate integrated waveguide (SIW) technology and has a mechanism that produces 16 different and distinct resonant frequencies between 2.45 and 3.05 GHz by perturbing a fundamental TE10 mode. It is a unique method for producing multiple resonances in a radio frequency planar structure without any extra circuitry or passive elements is developed. The proposed SIW structure has four vertical fluidic holes (channels); injecting eutectic gallium indium (EGaIn), also known commonly as liquid metal (LM), into these vertical channels produces different resonant frequencies. Either a channel is empty, or it is filled with LM. In total, the combination of different frequencies produced from four vertical channels is 16. PMID:26569257

  17. Reusable EGaIn-Injected Substrate-Integrated-Waveguide Resonator for Wireless Sensor Applications

    PubMed Central

    Memon, Muhammad Usman; Lim, Sungjoon

    2015-01-01

    The proposed structure in this research is constructed on substrate integrated waveguide (SIW) technology and has a mechanism that produces 16 different and distinct resonant frequencies between 2.45 and 3.05 GHz by perturbing a fundamental TE10 mode. It is a unique method for producing multiple resonances in a radio frequency planar structure without any extra circuitry or passive elements is developed. The proposed SIW structure has four vertical fluidic holes (channels); injecting eutectic gallium indium (EGaIn), also known commonly as liquid metal (LM), into these vertical channels produces different resonant frequencies. Either a channel is empty, or it is filled with LM. In total, the combination of different frequencies produced from four vertical channels is 16. PMID:26569257

  18. Time Resolved Contrast Enhanced Intracranial MRA Using a Single Dose Delivered as Sequential Injections and Highly Constrained Projection Reconstruction (HYPR CE)

    PubMed Central

    Wu, Yijing; Johnson, Kevin; Kecskemeti, Steven R.; Wang, Kang; Wieben, Oliver; Aagaard-Kienitz, Beverly L.; Rowley, Howard; Korosec, Frank R.; Mistretta, Charles; Turski, Patrick

    2011-01-01

    Time-resolved contrast-enhanced magnetic resonance angiography of the brain is challenging due to the need for rapid imaging and high spatial resolution. Moreover, the significant dispersion of the intravenous contrast bolus as it passes through the heart and lungs increases the overlap between arterial and venous structures, regardless of the acquisition speed and reconstruction window. An innovative technique is presented that divides a single dose contrast into two injections. Initially a small volume of contrast material (2–3 mL) is used to acquiring time-resolved weighting images with a high frame rate (2 frames/s) during the first pass of the contrast agent. The remaining contrast material is used to obtain a high resolution whole brain contrast-enhanced (CE) magnetic resonance angiography (0.57 × 0.57 × 1 mm3) that is used as the spatial constraint for Local Highly Constrained Projection Reconstruction (HYPR LR) reconstruction. After HYPR reconstruction, the final dynamic images (HYPR CE) have both high temporal and spatial resolution. Furthermore, studies of contrast kinetics demonstrate that the shorter bolus length from the reduced contrast volume used for the first injection significantly improves the arterial and venous separation. PMID:21413059

  19. Activated Protein C Enhances Human Keratinocyte Barrier Integrity via Sequential Activation of Epidermal Growth Factor Receptor and Tie2*

    PubMed Central

    Xue, Meilang; Chow, Shu-Oi; Dervish, Suat; Chan, Yee-Ka Agnes; Julovi, Sohel M.; Jackson, Christopher J.

    2011-01-01

    Keratinocytes play a critical role in maintaining epidermal barrier function. Activated protein C (APC), a natural anticoagulant with anti-inflammatory and endothelial barrier protective properties, significantly increased the barrier impedance of keratinocyte monolayers, measured by electric cell substrate impedance sensing and FITC-dextran flux. In response to APC, Tie2, a tyrosine kinase receptor, was rapidly activated within 30 min, and relocated to cell-cell contacts. APC also increased junction proteins zona occludens, claudin-1 and VE-cadherin. Inhibition of Tie2 by its peptide inhibitor or small interfering RNA abolished the barrier protective effect of APC. Interestingly, APC did not activate Tie2 through its major ligand, angiopoietin-1, but instead acted by binding to endothelial protein C receptor, cleaving protease-activated receptor-1 and transactivating EGF receptor. Furthermore, when activation of Akt, but not ERK, was inhibited, the barrier protective effect of APC on keratinocytes was abolished. Thus, APC activates Tie2, via a mechanism requiring, in sequential order, the receptors, endothelial protein C receptor, protease-activated receptor-1, and EGF receptor, which selectively enhances the PI3K/Akt signaling to enhance junctional complexes and reduce keratinocyte permeability. PMID:21173154

  20. Integrated experimental and simulation study of the response to sequential treatment with erlotinib and gemcitabine in pancreatic cancer

    PubMed Central

    Ubezio, Paolo; Falcetta, Francesca; Carrassa, Laura; Lupi, Monica

    2016-01-01

    The combination of erlotinib with gemcitabine is one of the most promising therapies for advanced pancreatic cancer. Aiming at optimizing this combination, we analyzed in detail the response to sequential treatments with erlotinib → gemcitabine and gemcitabine → erlotinib with an 18 h interval, adopting a previously established experimental/computational approach to quantify the cytostatic and cytotoxic effects at G1, S and G2M checkpoints. This assessment was achieved by contemporary fits of flow cytometric and time-lapse experiments in two human pancreatic cancer cell lines (BxPC-3 and Capan-1) with a mathematical model reproducing the fluxes of cells through the cycle during and after treatment. The S-phase checkpoint contributes in the response to erlotinib, suggesting that the G1 arrest may hamper S-phase cytotoxicity. The response to gemcitabine was driven by the dynamics of the progressive resumption from the S-phase arrest after drug washout. The effects induced by single drugs were used to simulate combined treatments, introducing changes when required. Gemcitabine → erlotinib was more than additive in both cell lines, strengthening the cytostatic effects on cells recovering from the arrest induced by gemcitabine. The interval in the erlotinib → gemcitabine sequence enabled to overcome the antagonist effect of G1 block on gemcitabine efficacy and improved the outcome in Capan-1 cells. PMID:26909860

  1. Cognitive Behavioral Theories Used to Explain Injection Risk Behavior Among Injection Drug Users: A Review and Suggestions for the Integration of Cognitive and Environmental Models

    PubMed Central

    Wagner, Karla D.; Unger, Jennifer B.; Bluthenthal, Ricky N.; Andreeva, Valentina A.; Pentz, Mary Ann

    2011-01-01

    Injection drug users (IDUs) are at risk for HIV and viral hepatitis, and risky injection behavior persists despite decades of intervention. Cognitive behavioral theories (CBT) are commonly used to help understand risky injection behavior. We review findings from CBT-based studies of injection risk behavior among IDUs. An extensive literature search was conducted in Spring 2007. In total 33 studies were reviewed—26 epidemiological and 7 intervention studies. Findings suggest that some theoretical constructs have received fairly consistent support (e.g., self-efficacy, social norms), while others have yielded inconsistent or null results (e.g., perceived susceptibility, knowledge, behavioral intentions, perceived barriers, perceived benefits, response efficacy, perceived severity). We offer some possible explanations for these inconsistent findings, including differences in theoretical constructs and measures across studies and a need to examine the environmental structures that influence risky behaviors. Greater integration of CBT with a risk environment perspective may yield more conclusive findings and more effective interventions in the future. PMID:20705809

  2. A microfluidic device with integrated fluorimetric detection for flow injection analysis.

    PubMed

    Fonseca, Alexandre; Raimundo, Ivo M; Rohwedder, Jarbas J R; Lima, Renato S; Araújo, Mário C Ugulino

    2010-01-01

    This work describes the development of flow analysis microsystems with integrated fluorimetric detection cells. Channels (width of 300-540 microm and depth of 200-590 microm) were manufactured by deep-UV lithography in urethane-acrylate (UA) resin. Plastic optical fibers (diameter of 250 microm) were coupled to a 2.0-mm-long detection channel in order to guide the excitation radiation from an LED (470 nm) and collect the emitted radiation at a right angle towards a photomultiplier. A single-line miniaturized system, with a total internal volume of 10.4 microL, was evaluated by means of standard fluorescein solutions (0.53-2.66 micromol L(-1), pH 8.5). The analytical signals presented a linear relationship in the concentration range studied, with a relative standard deviation of 1.9% (n = 5), providing a detection limit of 0.37 micromol L(-1) and an analytical frequency of 60 samples/h, using a flow rate of 60 microL min(-1). Optical microscopy images and videos acquired in real time for the hydrodynamic injection of 130 and 320 nL of sample solutions indicated the good performance of the proposed sampling strategy. Another microsystem with a total internal volume of 38 microL was developed, incorporating a confluence point for two solutions. This device was applied to the determination of the total concentration of Ca(2+) and Mg(2+) in commercial mineral waters using the calcein method. Microscopy images and videos demonstrated the mixing efficiency of the solutions in the microchannels. A linear relationship was observed for the analytical signal in the Ca(2+) concentration range from 25 to 125 micromol L(-1), with relative standard deviations of 3.5%. The analysis of mineral waters with the proposed system provided results that did not differ significantly from those obtained by the EDTA titration method at a confidence level of 95%. These results demonstrate the viability of developing micro flow injection systems with an integrated fluorimetric detection cell

  3. Integrated interferometric injection laser; Novel fast and broad-band tunable monolithic light source

    SciTech Connect

    Schilling, M.; Idler, W.; Kuehn, E.; Laube, G.; Schweizer, H.; Wuenstel, K.; Hildebrand, O. )

    1991-06-01

    This paper reports on a new wide-range electronically wavelength-tunable InGaAsP-InP laser that has been developed. This monolithic single-mode light source is based on interferometric principles. We report on successful fabrication and first experimental device characteristic obtained with these novel Y-coupled-cavity integrated interferometric injection (YCC-I{sup 3}) lasers. For both the 1300 and 1500 nm wavelength regions, very large tuning ranges of 22 and 23 nm, respectively, were achieved by proper current adjustment. The minimum achieved linewidth of the present nonoptimized devices is 35 MHz. Within the complete tuning range, the selection of 12 individual single-mode channels spaced by 2 nm is demonstrated with high-modulation bandwidths up to 5 GHz. A preliminary test of the wavelength switching behavior between two individual single modes additionally indicates promising high-speed switching capabilities in the gigahertz range. Thus, the new monolithic YCC-I{sup 3} laser light source shows excellent potential for a wide range of applications in lightwave communications.

  4. A hybrid lightwave transmission system based on light injection/optoelectronic feedback techniques and fiber-VLLC integration

    NASA Astrophysics Data System (ADS)

    Tsai, Wen-Shing; Lu, Hai-Han; Li, Chung-Yi; Chen, Bo-Rui; Lin, Hung-Hsien; Lin, Dai-Hua

    2016-04-01

    A hybrid lightwave transmission system based on light injection/optoelectronic feedback techniques and fiber-visible laser light communication (VLLC) integration is proposed and experimentally demonstrated. To be the first one of its kind in employing light injection and optoelectronic feedback techniques in a fiber-VLLC integration lightwave transmission system, the light is successfully directly modulated with Community Access Television (CATV), 16-QAM, and 16-QAM-OFDM signals. Over a 40 km SMF and a 10 m free-space VLLC transport, good performances of carrier-to-noise ratio (CNR)/composite second-order (CSO)/composite triple-beat (CTB)/bit error rate (BER) are achieved for CATV/16-QAM/16-QAM-OFDM signals transmission. Such a hybrid lightwave transmission system would be very useful since it can provide broadband integrated services including CATV, Internet, and telecommunication services over both distribute fiber and in-building networks.

  5. Sequential injection immunoassay for human bone morphogenic protein-7 using an immunoreactor immobilized with anti-human bone morphogenic protein-7 antibody--CdSe/ZnS quantum dot conjugates.

    PubMed

    Kim, Chun-Kwang; Duong, Hong Dinh; Rhee, Jong Il

    2013-07-01

    The detection of human bone morphogenic protein-7 (BMP-7) was achieved using a sequential injection immunoassay (SIIA) system. The SIIA system is based on the binding between BMP-7 and anti-human BMP-7 (AbBMP7)-CdSe/ZnS quantum dot (QD) conjugates immobilized onto a glass disk or an optical fiber, using fluorescence detection at excitation and emission wavelengths of 470 nm and 580 nm, respectively. The AbBMP7-QD conjugates were prepared by conjugating anti-human BMP-7 antibody (AbBMP7) to hydrophilic CdSe/ZnS core/shell quantum dots (QDs). The SIIA system was fully automated using software written in the LabVIEW™ development environment. The analytical performance of the SIIA system was characterized with a number of variables such as carrier flow rate and elution buffer. Under partially optimized operating conditions, the SIIA system had a linear calibration graph at up to 10.0 ng mL(-1) BMP-7 (R(2)≥0.975) and a sample frequency of two samples per hour. The SIIA system with an optical fiber immunosensor was used to detect and quantify BMP-7 in spiked real samples obtained from a biological process with recoveries in the range of 95-102%. PMID:23790295

  6. Towards the Integration of Dark- and Photo-Fermentative Waste Treatment. 4. Repeated Batch Sequential Dark- and Photofermentation using Starch as Substrate

    SciTech Connect

    Laurinavichene, T. V.; Belokopytov, B. F.; Laurinavichius, K. S.; Khusnutdinova, A. N.; Seibert, M.; Tsygankov, A. A.

    2012-05-01

    In this study we demonstrated the technical feasibility of a prolonged, sequential two-stage integrated process under a repeated batch mode of starch fermentation. In this durable scheme, the photobioreactor with purple bacteria in the second stage was fed directly with dark culture from the first stage without centrifugation, filtration, or sterilization (not demonstrated previously). After preliminary optimization, both the dark- and the photo-stages were performed under repeated batch modes with different process parameters. Continuous H{sub 2} production in this system was observed at a H{sub 2} yield of up to 1.4 and 3.9 mole mole{sup -1} hexose during the dark- and photo-stage, respectively (for a total of 5.3 mole mole{sup -1} hexose), and rates of 0.9 and 0.5 L L{sup -1} d{sup -1}, respectively. Prolonged repeated batch H{sub 2} production was maintained for up to 90 days in each stage and was rather stable under non-aseptic conditions. Potential for improvements in these results are discussed.

  7. Sequentially Integrated Optimization of the Conditions to Obtain a High-Protein and Low-Antinutritional Factors Protein Isolate from Edible Jatropha curcas Seed Cake.

    PubMed

    León-López, Liliana; Dávila-Ortiz, Gloria; Jiménez-Martínez, Cristian; Hernández-Sánchez, Humberto

    2013-01-01

    Jatropha curcas seed cake is a protein-rich byproduct of oil extraction which could be used to produce protein isolates. The purpose of this study was the optimization of the protein isolation process from the seed cake of an edible provenance of J. curcas by an alkaline extraction followed by isoelectric precipitation method via a sequentially integrated optimization approach. The influence of four different factors (solubilization pH, extraction temperature, NaCl addition, and precipitation pH) on the protein and antinutritional compounds content of the isolate was evaluated. The estimated optimal conditions were an extraction temperature of 20°C, a precipitation pH of 4, and an amount of NaCl in the extraction solution of 0.6 M for a predicted protein content of 93.3%. Under these conditions, it was possible to obtain experimentally a protein isolate with 93.21% of proteins, 316.5 mg 100 g(-1) of total phenolics, 2891.84 mg 100 g(-1) of phytates and 168 mg 100 g(-1) of saponins. The protein content of the this isolate was higher than the content reported by other authors. PMID:25937971

  8. A new numerical approach to solve Thomas-Fermi model of an atom using bio-inspired heuristics integrated with sequential quadratic programming.

    PubMed

    Raja, Muhammad Asif Zahoor; Zameer, Aneela; Khan, Aziz Ullah; Wazwaz, Abdul Majid

    2016-01-01

    In this study, a novel bio-inspired computing approach is developed to analyze the dynamics of nonlinear singular Thomas-Fermi equation (TFE) arising in potential and charge density models of an atom by exploiting the strength of finite difference scheme (FDS) for discretization and optimization through genetic algorithms (GAs) hybrid with sequential quadratic programming. The FDS procedures are used to transform the TFE differential equations into a system of nonlinear equations. A fitness function is constructed based on the residual error of constituent equations in the mean square sense and is formulated as the minimization problem. Optimization of parameters for the system is carried out with GAs, used as a tool for viable global search integrated with SQP algorithm for rapid refinement of the results. The design scheme is applied to solve TFE for five different scenarios by taking various step sizes and different input intervals. Comparison of the proposed results with the state of the art numerical and analytical solutions reveals that the worth of our scheme in terms of accuracy and convergence. The reliability and effectiveness of the proposed scheme are validated through consistently getting optimal values of statistical performance indices calculated for a sufficiently large number of independent runs to establish its significance. PMID:27610319

  9. Sequentially Integrated Optimization of the Conditions to Obtain a High-Protein and Low-Antinutritional Factors Protein Isolate from Edible Jatropha curcas Seed Cake

    PubMed Central

    León-López, Liliana; Dávila-Ortiz, Gloria; Jiménez-Martínez, Cristian; Hernández-Sánchez, Humberto

    2013-01-01

    Jatropha curcas seed cake is a protein-rich byproduct of oil extraction which could be used to produce protein isolates. The purpose of this study was the optimization of the protein isolation process from the seed cake of an edible provenance of J. curcas by an alkaline extraction followed by isoelectric precipitation method via a sequentially integrated optimization approach. The influence of four different factors (solubilization pH, extraction temperature, NaCl addition, and precipitation pH) on the protein and antinutritional compounds content of the isolate was evaluated. The estimated optimal conditions were an extraction temperature of 20°C, a precipitation pH of 4, and an amount of NaCl in the extraction solution of 0.6 M for a predicted protein content of 93.3%. Under these conditions, it was possible to obtain experimentally a protein isolate with 93.21% of proteins, 316.5 mg 100 g−1 of total phenolics, 2891.84 mg 100 g−1 of phytates and 168 mg 100 g−1 of saponins. The protein content of the this isolate was higher than the content reported by other authors. PMID:25937971

  10. Cognitive Behavioral Theories Used to Explain Injection Risk Behavior among Injection Drug Users: A Review and Suggestions for the Integration of Cognitive and Environmental Models

    ERIC Educational Resources Information Center

    Wagner, Karla Dawn; Unger, Jennifer B.; Bluthenthal, Ricky N.; Andreeva, Valentina A.; Pentz, Mary Ann

    2010-01-01

    Injection drug users (IDUs) are at risk for HIV and viral hepatitis, and risky injection behavior persists despite decades of intervention. Cognitive behavioral theories (CBTs) are commonly used to help understand risky injection behavior. The authors review findings from CBT-based studies of injection risk behavior among IDUs. An extensive…

  11. High-throughput sequential injection method for simultaneous determination of plutonium and neptunium in environmental solids using macroporous anion-exchange chromatography, followed by inductively coupled plasma mass spectrometric detection.

    PubMed

    Qiao, Jixin; Hou, Xiaolin; Roos, Per; Miró, Manuel

    2011-01-01

    This paper reports an automated analytical method for rapid and simultaneous determination of plutonium and neptunium in soil, sediment, and seaweed, with detection via inductively coupled plasma mass spectrometry (ICP-MS). A chromatographic column packed with a macroporous anion exchanger (AG MP-1 M) was incorporated in a sequential injection (SI) system for the efficient retrieval of plutonium, along with neptunium, from matrix elements and potential interfering nuclides. The sorption and elution behavior of plutonium and neptunium onto AG MP-1 M resin was compared with a commonly utilized AG 1-gel-type anion exchanger. Experimental results reveal that the pore structure of the anion exchanger plays a pivotal role in ensuring similar separation behavior of plutonium and neptunium along the separation protocol. It is proven that plutonium-242 ((242)Pu) performs well as a tracer for monitoring the chemical yield of neptunium when using AG MP-1 M resin, whereby the difficulties in obtaining a reliable and practicable isotopic neptunium tracer are overcome. An important asset of the SI setup is the feasibility of processing up to 100 g of solid substrates using a small-sized (ca. 2 mL) column with chemical yields of neptunium and plutonium being ≥79%. Analytical results of three certified/standard reference materials and two solid samples from intercomparison exercises are in good agreement with the reference values at the 0.05 significance level. The overall on-column separation can be completed within 3.5 h for 10 g of soil samples. Most importantly, the anion-exchange mini-column suffices to be reused up to 10-fold with satisfactory chemical yields (>70%), as demanded in environmental monitoring and emergency scenarios, making the proposed automated assembly well-suited for unattended and high-throughput analysis. PMID:21121695

  12. Towards chemiluminescence detection in micro-sequential injection lab-on-valve format: a proof of concept based on the reaction between Fe(II) and luminol in seawater.

    PubMed

    Oliveira, Hugo M; Grand, Maxime M; Ruzicka, Jaromir; Measures, Christopher I

    2015-02-01

    Micro-sequential injection lab-on-valve (µSI-LOV) is a well-established analytical platform for absorbance and fluorescence based assays but its applicability to chemiluminescence detection remains largely unexplored. In this work, we describe a novel fluidic protocol and two distinct strategies for photon collection that enable chemiluminescence detection using µSI-LOV for the first time. To illustrate this proof of concept, we selected the reaction between Fe(II) and luminol and developed a preliminary protocol for Fe(II) determinations in acidified seawater. The optimized fluidic strategy consists of holding 100 µL of the luminol reagent in a confined zone of the LOV and then displacing it with 50 µL of sample while monitoring the chemiluminescent product. Detection is achieved using two strategies: one based on a bifurcated optical fiber and the other based on a customized detection window created by mounting a photomultiplier tube atop of the LOV device. We show that detection is possible using both strategies but that the window strategy yields significantly enhanced sensitivity (355×) due to the larger detection area. In our final experimental conditions and using window detection, it was possible to achieve a limit of detection (LOD) of 1 nmol L(-1) and to quantify Fe(II) in acidified seawater samples up to 20.00 nmol L(-1) with high precision (RSD<6%). These analytical features combined with the long-term stability of luminol solution and the full automation and low reagent consumption make this approach a promising analytical tool for shipboard analysis of Fe(II). The intrinsic capacity of the LOV to operate at a low microliter level and to handle solid phases also opens up a new avenue for chemiluminescence applications. Moreover, this contribution shows that LOV can be a universal platform for optical detection, capable of absorbance, fluorescence and luminescence measurements in a single instrument setup. PMID:25435235

  13. CIRF.B Reaction-Transport-Mechanical Simulator: Applications to CO2 Injection and Reservoir Integrity Prediction

    NASA Astrophysics Data System (ADS)

    Park, A. J.; Tuncay, K.; Ortoleva, P. J.

    2003-12-01

    An important component of CO2 sequestration in geologic formations is the reactions between the injected fluid and the resident geologic material. In particular, carbonate mineral reaction rates are several orders of magnitude faster than those of siliciclastic minerals. The reactions between resident and injected components can create complex flow regime modifications, and potentially undermine the reservoir integrity by changing their mineralogic and textural compositions on engineering time scale. This process can be further enhanced due to differences in pH and temperature of the injectant from the resident sediments and fluids. CIRF.B is a multi-process simulator originally developed for basin simulations. Implemented processes include kinetic and thermodynamic reactions between minerals and fluid, fluid flow, mass-transfer, composite-media approach to sediment textural description and dynamics, elasto-visco-plastic rheology, and fracturing dynamics. To test the feasibility of applying CIRF.B to CO2 sequestration, a number of engineering scale simulations are carried out to delineate the effects of changing injectant chemistry and injection rates on both carbonate and siliciclastic sediments. Initial findings indicate that even moderate amounts of CO2 introduced into sediments can create low pH environments, which affects feldspar-clay interactions. While the amount of feldspars reacting in engineering time scale may be small, its consequence to clay alteration and permeability modfication can be significant. Results also demonstrate that diffusion-imported H+ can affect sealing properties of both siliciclastic and carbonate formations. In carbonate systems significant mass transfer can occur due to dissolution and reprecipitation. The resulting shifts in in-situ stresses can be sufficient to initiate fracturing. These simulations allow characterization of injectant fluids, thus assisting in the implementation of effective sequestration procedures.

  14. Optical injection locking of monolithically integrated photonic source for generation of high purity signals above 100 GHz.

    PubMed

    Balakier, Katarzyna; Fice, Martyn J; van Dijk, Frederic; Kervella, Gael; Carpintero, Guillermo; Seeds, Alwyn J; Renaud, Cyril C

    2014-12-01

    A monolithically integrated photonic source for tuneable mm-wave signal generation has been fabricated. The source consists of 14 active components, i.e. semiconductor lasers, amplifiers and photodetectors, all integrated on a 3 mm(2) InP chip. Heterodyne signals in the range between 85 GHz and 120 GHz with up to -10 dBm output power have been successfully generated. By optically injection locking the integrated lasers to an external optical comb source, high-spectral-purity signals at frequencies >100 GHz have been generated, with phase noise spectral density below -90 dBc/Hz being achieved at offsets from the carrier greater than 10 kHz. PMID:25606875

  15. CO-INJECTION RESIN TRANSFER MOLDING FOR OPTIMIZATION OF INTEGRAL ARMOR

    EPA Science Inventory

    To address the cost and performance barriers which hinder the introduction of composite materials for combat ground vehicle applications, Co-Injection Resin Transfer Molding (CIRTM) and Diffusion Enhanced Adhesion (DEA) have been recently invented and developed at the Army Resear...

  16. On-chip integrated multi-thermo-actuated microvalves of poly(N-isopropylacrylamide) for microflow injection analysis.

    PubMed

    Li, Zhiming; He, Qiaohong; Ma, Dan; Chen, Hengwu

    2010-04-30

    An array of thermo-actuated poly(N-isopropylacrylamide) (PNIPAAm) multivalves was designed and fabricated to perform volume-based sample injection for microflow injection analysis on a glass microfluidic chip. The PNIPAAm monolithic plug valves were prepared inside the vinylized glass channels by photopolymerization in water-ethanol (1:1) medium using 2-hydroxy-2-methyl propiophenone (Darocure-1173) as the initiator and a photo-mask for micropattern transferring. Experimental conditions for the photopolymerization were studied, and the thermo-responsive behavior of the synthesized monolithic plug valves was investigated. To perform active heating and cooling of the on-chip integrated thermo-actuated valves, micro-Peltier devices were used and operation times of 3-s for opening and 7-s for closing were obtained. In the close status, a 2-mm long monolithic plug valve could endure a pressure of no higher than 0.45 MPa. The volume-based sample and reagent injector was composed of two groups of valves (total valve number of 5) and two loops. When the two groups of valves were alternatively opened and closed via thermo-actuation, the sampling loops were able to be switched between loading and injection position without any mechanical moving parts. Cooperating with syringe pumps, the microfluidic chip with the integrated sample injector has been demonstrated for microflow injection chemiluminescence detection of hydrogen peroxide. For a sampling volume of 6 nL, linear response was observed over the H(2)O(2) concentration range of 0-2 mmol L(-1), and a precision of 0.6% (RSD, n=11) was achieved for a standard H(2)O(2) solution 2 mmol L(-1). PMID:20417320

  17. Patterns of integration of DNA microinjected into cultured mammalian cells: evidence for homologous recombination between injected plasmid DNA molecules.

    PubMed Central

    Folger, K R; Wong, E A; Wahl, G; Capecchi, M R

    1982-01-01

    We examined the fate of DNA microinjected into nuclei of cultured mammalian cells. The sequence composition and the physical form of the vector carrying the selectable gene affected the efficiency of DNA-mediated transformation. Introduction of sequences near the simian virus 40 origin of DNA replication or in the long terminal repeat of avian sarcoma provirus into a recombinant plasmid containing the herpes simplex virus thymidine kinase gene. (pBR322/HSV-tk) enhanced the frequency of transformation of LMtk- and RAT-2tk- cells to the TK+ phenotype 20- to 40-fold. In cells receiving injections of only a few plasmid DNA molecules, the transformation frequency was 40-fold higher after injection of linear molecules than after injection of supercoiled molecules. By controlling the number of gene copies injected into a recipient cell, we could obtain transformants containing a single copy or as many as 50 to 100 copies of the selectable gene. Multiple copies of the transforming gene were not scattered throughout the host genome but were integrated as a concatemer at one or a very few sites in the host chromosome. Independent transformants contained the donated genes in different chromosomes. The orientation of the gene copies within the concatemer was not random; rather, the copies were organized as tandem head-to-tail arrays. By analyzing transformants obtained by coinjecting two vectors which were identical except that in one a portion of the vector was inverted, we were able to conclude that the head-to-tail concatemers were generated predominantly by homologous recombination. Surprisingly, these head-to-tail concatemers were found in transformants obtained by injecting either supercoiled or linear plasmid DNA. Even though we demonstrated that cultured mammalian cells contain the enzymes for ligating two DNA molecules very efficiently irrespective of the sequences or topology at their ends, we found that even linear plasmid DNA was recruited into the concatemer by

  18. Integrative analysis of proteomics and metabolomics of anaphylactoid reaction induced by Xuesaitong injection.

    PubMed

    Xu, Yubin; Dou, Deqiang; Ran, Xiaoku; Liu, Chunyan; Chen, Jing

    2015-10-16

    Injection with natural compounds is an important method in the application of natural medicine, but its adverse drug reactions (ADRs) occur frequently, particularly the anaphylactoid reaction, which accounts for more than 77% of all reactions and has become a serious threat to public health. Here, the Xuesaitong injection (XSTI) was employed as an example to elucidate its anaphylactoid mechanism and look for potential biomarkers to assay the anaphylactoid reaction of herbal medicine injection by proteomics and metabolomics. These results disclosed that 13 differential proteins and 28 metabolites, which were further approved using the ELISA method and reference standards, respectively, were suggested as potential biomarkers to examine the anaphylactoid mechanism. The up-regulated expression of Gpx1, Sc5b9, C4d and down-regulated expression of F12, Kng1, C2 and C6 revealed that the XSTI-induced anaphylactoid reaction occurs via direct stimulation, complement and the kallikrein-kinin pathway. In addition, substances that induce an anaphylactoid effect include histamine, LTB4, uric acid and other drugs, which have been confirmed to be involved in arginine and proline metabolism, histidine metabolism, arachidonic acid metabolism purine metabolism and the TCA cycle. Furthermore, separation experiments have indicated that 10-kDa molecules of XSTI are the main allergenic factor inducing an anaphylactoid reaction. PMID:26372445

  19. Whole breast and excision cavity radiotherapy plan comparison: Conformal radiotherapy with sequential boost versus intensity-modulated radiation therapy with a simultaneously integrated boost

    SciTech Connect

    Small, Katherine; Kelly, Chris; Beldham-Collins, Rachael; Gebski, Val

    2013-03-15

    A comparative study was conducted comparing the difference between (1) conformal radiotherapy (CRT) to the whole breast with sequential boost excision cavity plans and (2) intensity-modulated radiation therapy (IMRT) to the whole breast with simultaneously integrated boost to the excision cavity. The computed tomography (CT) data sets of 25 breast cancer patients were used and the results analysed to determine if either planning method produced superior plans. CT data sets from 25 past breast cancer patients were planned using (1) CRT prescribed to 50 Gy in 25 fractions (Fx) to the whole-breast planning target volume (PTV) and 10 Gy in 5Fx to the excision cavity and (2) IMRT prescribed to 60 Gy in 25Fx, with 60 Gy delivered to the excision cavity PTV and 50 Gy delivered to the whole-breast PTV, treated simultaneously. In total, 50 plans were created, with each plan evaluated by PTV coverage using conformity indices, plan maximum dose, lung dose, and heart maximum dose for patients with left-side lesions. CRT plans delivered the lowest plan maximum doses in 56% of cases (average CRT = 6314.34 cGy, IMRT = 6371.52 cGy). They also delivered the lowest mean lung dose in 68% of cases (average CRT = 1206.64 cGy, IMRT = 1288.37 cGy) and V20 in 88% of cases (average CRT = 20.03%, IMRT = 21.73%) and V30 doses in 92% of cases (average CRT = 16.82%, IMRT = 17.97%). IMRT created more conformal plans, using both conformity index and conformation number, in every instance, and lower heart maximum doses in 78.6% of cases (average CRT = 5295.26 cGy, IMRT = 5209.87 cGy). IMRT plans produced superior dose conformity and shorter treatment duration, but a slightly higher planning maximum and increased lung doses. IMRT plans are also faster to treat on a daily basis, with shorter fractionation.

  20. Intravitreal injection

    MedlinePlus

    Retinal vein occlusion-intravitreal injection; Triamcinolone-intravitreal injection; Dexamethasone-intravitreal injection; Lucentis-intravitreal injection; Avastin-intravitreal injection; Bevacizumab-intravitreal injection; Ranibizumab- ...

  1. Organic integrated circuits for information storage based on ambipolar polymers and charge injection engineering

    NASA Astrophysics Data System (ADS)

    Dell'Erba, Giorgio; Luzio, Alessandro; Natali, Dario; Kim, Juhwan; Khim, Dongyoon; Kim, Dong-Yu; Noh, Yong-Young; Caironi, Mario

    2014-04-01

    Ambipolar semiconducting polymers, characterized by both high electron (μe) and hole (μh) mobility, offer the advantage of realizing complex complementary electronic circuits with a single semiconducting layer, deposited by simple coating techniques. However, to achieve complementarity, one of the two conduction paths in transistors has to be suppressed, resulting in unipolar devices. Here, we adopt charge injection engineering through a specific interlayer in order to tune injection into frontier energy orbitals of a high mobility donor-acceptor co-polymer. Starting from field-effect transistors with Au contacts, showing a p-type unbalanced behaviour with μh = 0.29 cm2/V s and μe = 0.001 cm2/V s, through the insertion of a caesium salt interlayer with optimized thickness, we obtain an n-type unbalanced transistor with μe = 0.12 cm2/V s and μh = 8 × 10-4 cm2/V s. We applied this result to the development of the basic pass-transistor logic building blocks such as inverters, with high gain and good noise margin, and transmission-gates. In addition, we developed and characterized information storage circuits like D-Latches and D-Flip-Flops consisting of 16 transistors, demonstrating both their static and dynamic performances and thus the suitability of this technology for more complex circuits such as display addressing logic.

  2. Organic integrated circuits for information storage based on ambipolar polymers and charge injection engineering

    SciTech Connect

    Dell'Erba, Giorgio; Natali, Dario; Luzio, Alessandro; Caironi, Mario E-mail: yynoh@dongguk.edu; Noh, Yong-Young E-mail: yynoh@dongguk.edu

    2014-04-14

    Ambipolar semiconducting polymers, characterized by both high electron (μ{sub e}) and hole (μ{sub h}) mobility, offer the advantage of realizing complex complementary electronic circuits with a single semiconducting layer, deposited by simple coating techniques. However, to achieve complementarity, one of the two conduction paths in transistors has to be suppressed, resulting in unipolar devices. Here, we adopt charge injection engineering through a specific interlayer in order to tune injection into frontier energy orbitals of a high mobility donor-acceptor co-polymer. Starting from field-effect transistors with Au contacts, showing a p-type unbalanced behaviour with μ{sub h} = 0.29 cm{sup 2}/V s and μ{sub e} = 0.001 cm{sup 2}/V s, through the insertion of a caesium salt interlayer with optimized thickness, we obtain an n-type unbalanced transistor with μ{sub e} = 0.12 cm{sup 2}/V s and μ{sub h} = 8 × 10{sup −4} cm{sup 2}/V s. We applied this result to the development of the basic pass-transistor logic building blocks such as inverters, with high gain and good noise margin, and transmission-gates. In addition, we developed and characterized information storage circuits like D-Latches and D-Flip-Flops consisting of 16 transistors, demonstrating both their static and dynamic performances and thus the suitability of this technology for more complex circuits such as display addressing logic.

  3. Integrated gasification combined cycle and steam injection gas turbine powered by biomass joint-venture evaluation

    SciTech Connect

    Sterzinger, G J

    1994-05-01

    This report analyzes the economic and environmental potential of biomass integrated gasifier/gas turbine technology including its market applications. The mature technology promises to produce electricity at $55--60/MWh and to be competitive for market applications conservatively estimated at 2000 MW. The report reviews the competitiveness of the technology of a stand-alone, mature basis and finds it to be substantial and recognized by DOE, EPRI, and the World Bank Global Environmental Facility.

  4. Paper-based enzyme immobilization for flow injection electrochemical biosensor integrated with reagent-loaded cartridge toward portable modular device.

    PubMed

    Tan, Swee Ngin; Ge, Liya; Tan, Hsih Yin; Loke, Weng Keong; Gao, Jinrong; Wang, Wei

    2012-11-20

    Paper-based enzyme immobilization for a flow injection electrochemical biosensor integrated with a reagent-loaded cartridge toward a portable device was developed. A paper disk was immobilized with enzyme, then it was integrated in a flow cell as an electrochemical biosensor. A silicon tube reagent-loaded cartridge was integrated into the system, a complicated procedure was simplified as a one-click operation toward development for point-of-care applications. In this research, glucose oxidase (GOx) was employed as a model enzyme, silver ion as an inhibition reagent for GOx, and EDTA as a regeneration reagent. When GOx was inhibited by silver ions, glucose was introduced for electrochemical measurements before and after inhibited enzyme regeneration and the difference was caused by silver inhibition. The modular device has great potential for other applications, e.g., detection of enzyme activity and substrate. The platform based on double-test mode provided accurate results due to elimination of an average or control value in comparison with classical routine approaches. PMID:23116304

  5. A simple microfluidic integrated with an optical sensor for micro flow injection colorimetric determination of glutathione.

    PubMed

    Supharoek, Sam-ang; Youngvises, Napaporn; Jakmunee, Jaroon

    2012-01-01

    A simple and inexpensive method for fabricating a microfluidic platform was developed. A printed circuit board (PCB) was used to make a master mold for replicating a polydimethylsiloxane (PDMS) microchannel. The master mold was fabricated by a simple photolithographic method, employing a photoresist dry film. The process did not use hazardous chemicals, a clean room or any expensive instrument. The PDMS microchannel was clamped with polymethylmethacrylate (PMMA) plates, where a light emitting diode (LED) as a light source and a light dependent resistor (LDR) as a light sensor were attached to form a simple optical sensor. The system was successfully employed as a micro flow injection analysis for the determination of glutathione in dietary supplement samples. A linear calibration graph in the range of 5.0 - 60.0 mg L(-1) glutathione was obtained with a detection limit of 0.01 mg L(-1). The system provided a sample throughput of 48 h(-1), with microliter consumption of the reagent. PMID:22790365

  6. Integration of FTTH and GI-POF in-house networks based on injection locking and direct-detection techniques.

    PubMed

    Peng, Hsiao-Chun; Lu, Hai-Han; Li, Chung-Yi; Su, Heng-Sheng; Hsu, Chin-Tai

    2011-03-28

    An integration of fiber-to-the-home (FTTH) and graded-index plastic optical fiber (GI-POF) in-house networks based on injection-locked vertical cavity surface emitting lasers (VCSELs) and direct-detection technique is proposed and experimentally demonstrated. Sufficient low bit error rate (BER) values were obtained over a combination of 20-km single-mode fiber (SMF) and 50-m GI-POF links. Signal qualities satisfy the worldwide interoperability for microwave access (WiMAX) requirement with data signals of 20 Mbps/5.8 GHz and 70 Mbps/10 GHz, respectively. Since our proposed network does not use sophisticated and expensive RF devices in premises, it reveals a prominent one with simpler and more economic advantages. Our proposed architecture is suitable for the SMF-based primary and GI-POF-based in-house networks. PMID:21451701

  7. Sector Tests of a Low-NO(sub x), Lean, Direct- Injection, Multipoint Integrated Module Combustor Concept Conducted

    NASA Technical Reports Server (NTRS)

    Tacina, Robert R.; Wey, Chang-Lie; Laing, Peter; Mansour, Adel

    2002-01-01

    The low-emissions combustor development described is directed toward advanced high pressure aircraft gas-turbine applications. The emphasis of this research is to reduce nitrogen oxides (NOx) at high-power conditions and to maintain carbon monoxide and unburned hydrocarbons at their current low levels at low power conditions. Low-NOx combustors can be classified into rich-burn and lean-burn concepts. Lean-burn combustors can be further classified into lean-premixed-prevaporized (LPP) and lean direct injection (LDI) concepts. In both concepts, all the combustor air, except for liner cooling flow, enters through the combustor dome so that the combustion occurs at the lowest possible flame temperature. The LPP concept has been shown to have the lowest NOx emissions, but for advanced high-pressure-ratio engines, the possibility of autoignition or flashback precludes its use. LDI differs from LPP in that the fuel is injected directly into the flame zone, and thus, it does not have the potential for autoignition or flashback and should have greater stability. However, since it is not premixed and prevaporized, good atomization is necessary and the fuel must be mixed quickly and uniformly so that flame temperatures are low and NOx formation levels are comparable to those of LPP. The LDI concept described is a multipoint fuel injection/multiburning zone concept. Each of the multiple fuel injectors has an air swirler associated with it to provide quick mixing and a small recirculation zone for burning. The multipoint fuel injection provides quick, uniform mixing and the small multiburning zones provide for reduced burning residence time, resulting in low NOx formation. An integrated-module approach was used for the construction where chemically etched laminates, diffusion bonded together, combine the fuel injectors, air swirlers, and fuel manifold into a single element. The multipoint concept combustor was demonstrated in a 15 sector test. The configuration tested had 36

  8. An Integrated Approach Linking Process to Structural Modeling With Microstructural Characterization for Injections-Molded Long-Fiber Thermoplastics

    SciTech Connect

    Nguyen, Ba Nghiep; Bapanapalli, Satish K.; Smith, Mark T.; Kunc, Vlastimil; Frame, Barbara; Norris, Robert E.; Phelps, Jay; Tucker III, Charles L.; Jin, Xiaoshi; Wang, Jin

    2008-09-01

    The objective of our work is to enable the optimum design of lightweight automotive structural components using injection-molded long fiber thermoplastics (LFTs). To this end, an integrated approach that links process modeling to structural analysis with experimental microstructural characterization and validation is developed. First, process models for LFTs are developed and implemented into processing codes (e.g. ORIENT, Moldflow) to predict the microstructure of the as-formed composite (i.e. fiber length and orientation distributions). In parallel, characterization and testing methods are developed to obtain necessary microstructural data to validate process modeling predictions. Second, the predicted LFT composite microstructure is imported into a structural finite element analysis by ABAQUS to determine the response of the as-formed composite to given boundary conditions. At this stage, constitutive models accounting for the composite microstructure are developed to predict various types of behaviors (i.e. thermoelastic, viscoelastic, elastic-plastic, damage, fatigue, and impact) of LFTs. Experimental methods are also developed to determine material parameters and to validate constitutive models. Such a process-linked-structural modeling approach allows an LFT composite structure to be designed with confidence through numerical simulations. Some recent results of our collaborative research will be illustrated to show the usefulness and applications of this integrated approach.

  9. Integration approach for developing a high-performance biointerface: Sequential formation of hydroxyapatite and calcium carbonate by an improved alternate soaking process

    NASA Astrophysics Data System (ADS)

    Watanabe, Junji; Akashi, Mitsuru

    2008-11-01

    Biointerfaces are crucial for regulating biofunctions. An effective method of producing new biomaterials is surface modification, in particular, the hybrid organic-inorganic approach. In this paper, we propose a method for the sequential formation of hydroxyapatite and calcium carbonate on porous polyester membranes by using an improved alternate soaking process. The resulting hybrid membranes were characterized in terms of their calcium and phosphorus ion contents; further, their structure was analyzed by scanning electron microscopy (SEM), X-ray diffraction (XRD), and infrared spectroscopy (IR). As a typical biofunction, protein adsorption by these hybrid membranes was investigated. Sequential hydroxyapatite and calcium carbonate formation on the membranes was successfully achieved, and the total amounts of hydroxyapatite and calcium carbonate formed were precisely regulated by the preparative conditions. The SEM and XRD characterizations were verified by comparing with the IR results. The amount of adsorbed protein correlated well with not only the amount of hydroxyapatite formed but also the combined amounts of hydroxyapatite and calcium carbonate formed. The results indicate that the hybrid membranes can function as high-performance biointerfaces that are capable of loading biomolecules such as proteins.

  10. Evaluation of Brine Migration Risks Due to CO2 Injection - an Integrated Natural and Social Science Modeling Approach

    NASA Astrophysics Data System (ADS)

    Noack, V.; Kissinger, A.; Class, H.; Knopf, S.; Konrad, W.; Scheer, D.

    2014-12-01

    Evaluation of possible risks for shallow groundwater systems caused by brine displacement due to CO2 injection requires an investigation of possible vertical pathways in regional-scale structural settings. The project CO2BRIM investigates this crucial issue in collaboration with external stakeholders to integrate expert feedback on migration scenarios. To evaluate possible brine displacement scenarios we construct a regional-scale 3D structural model based on data which represent a typical geological setting of the North German Basin. The model has a horizontal size of 39 km times 58 km and includes 11 geological layers from the Permian Zechstein salt up to the Quaternary. It comprises an anticlinal structure on top of a salt pillow and an elongated salt wall that dissect the overburden. For the risk scenarios we include discontinuities in the regionally important Rupelian aquitard (Tertiary) and a transition zone along the salt flank as such discontinuities are supposed to provide permeable pathways for brines which could reach shallow drinking water horizons. Based on this model we develop scenarios in which we vary for example hydro-geological parameters of the geological discontinuities, the injection rate and the initial state of the system in terms of the salinity distribution. Furthermore we compare different levels of model complexity with regard to the physical processes considered and their effects on our results. During the process of scenario development, external experts were invited to participate and share knowledge and concerns on both brine migration risks and possible migration paths and mechanisms. The results may help in site selection as they provide improved knowledge of pressure build-up in the reservoir and the overburden for such complex geological systems. Additionally, we want to identify the level of model complexity which is sufficient for this kind of setting with regard to the limited data availability at hand for the far field.

  11. Sequential Bayesian Detection: A Model-Based Approach

    SciTech Connect

    Sullivan, E J; Candy, J V

    2007-08-13

    Sequential detection theory has been known for a long time evolving in the late 1940's by Wald and followed by Middleton's classic exposition in the 1960's coupled with the concurrent enabling technology of digital computer systems and the development of sequential processors. Its development, when coupled to modern sequential model-based processors, offers a reasonable way to attack physics-based problems. In this chapter, the fundamentals of the sequential detection are reviewed from the Neyman-Pearson theoretical perspective and formulated for both linear and nonlinear (approximate) Gauss-Markov, state-space representations. We review the development of modern sequential detectors and incorporate the sequential model-based processors as an integral part of their solution. Motivated by a wealth of physics-based detection problems, we show how both linear and nonlinear processors can seamlessly be embedded into the sequential detection framework to provide a powerful approach to solving non-stationary detection problems.

  12. Sequential Bayesian Detection: A Model-Based Approach

    SciTech Connect

    Candy, J V

    2008-12-08

    Sequential detection theory has been known for a long time evolving in the late 1940's by Wald and followed by Middleton's classic exposition in the 1960's coupled with the concurrent enabling technology of digital computer systems and the development of sequential processors. Its development, when coupled to modern sequential model-based processors, offers a reasonable way to attack physics-based problems. In this chapter, the fundamentals of the sequential detection are reviewed from the Neyman-Pearson theoretical perspective and formulated for both linear and nonlinear (approximate) Gauss-Markov, state-space representations. We review the development of modern sequential detectors and incorporate the sequential model-based processors as an integral part of their solution. Motivated by a wealth of physics-based detection problems, we show how both linear and nonlinear processors can seamlessly be embedded into the sequential detection framework to provide a powerful approach to solving non-stationary detection problems.

  13. Sequential Anion and Cation Exchange Reactions for Complete Material Transformations of Nanoparticles with Morphological Retention.

    PubMed

    Hodges, James M; Kletetschka, Karel; Fenton, Julie L; Read, Carlos G; Schaak, Raymond E

    2015-07-20

    Ion exchange reactions of colloidal nanocrystals provide access to complex products that are synthetically challenging using traditional hot-injection methods. However, such reactions typically achieve only partial material transformations by employing either cation or anion exchange processes. It is now shown that anion and cation exchange reactions can be coupled together and applied sequentially in one integrated pathway that leads to complete material transformations of nanocrystal templates. Although the product nanocrystals do not contain any of the original constituent elements, the original morphology is retained, thereby fully decoupling morphology and composition control. The sequential anion/cation exchange process was applied to pseudo-spherical CdO nanocrystals and ZnO tetrapods, producing fully transformed and shape-controlled nanocrystals of copper and silver sulfides and selenides. Furthermore, hollow core-shell tetrapod ZnS@CdS heterostructures were readily accessible. PMID:26110653

  14. A Low NO(x) Lean-Direct Injection, Multipoint Integrated Module Combuster Concept for Advanced Aircraft Gas Turbines

    NASA Technical Reports Server (NTRS)

    Tacina, Robert; Wey, Changlie; Laing, Peter; Mansour, Adel

    2002-01-01

    A low NO(x) emissions combustor has been demonstrated in flame-tube tests. A multipoint, lean-direct injection concept was used. Configurations were tested that had 25- and 36- fuel injectors in the size of a conventional single fuel injector. An integrated-module approach was used for the construction where chemically etched laminates, diffusion bonded together, combine the fuel injectors, air swirlers and fuel manifold into a single element. Test conditions were inlet temperatures up to 810 K, inlet pressures up to 2760 kPa, and flame temperatures up to 2100 K. A correlation was developed relating the NO(x) emissions with the inlet temperature, inlet pressure, fuel-air ratio and pressure drop. Assuming that 10 percent of the combustion air would be used for liner cooling and using a hypothetical engine cycle, the NO(x) emissions using the correlation from flame-tube tests were estimated to be less than 20 percent of the 1996 ICAO standard.

  15. Procedural Network Representations of Sequential Data.

    ERIC Educational Resources Information Center

    Cooke, Nancy J.; And Others

    1996-01-01

    Describes PRONET (PROcedural NETworks), an integrated exploratory sequential data analysis technique that uses Pathfinder network scaling to highlight frequently occurring transitions among user, system, and environmental events. Illustrates the success and limitations of the method through two case studies. Thirteen figures highlight protocols of…

  16. Sequential inductive learning

    SciTech Connect

    Gratch, J.

    1996-12-31

    This article advocates a new model for inductive learning. Called sequential induction, it helps bridge classical fixed-sample learning techniques (which are efficient but difficult to formally characterize), and worst-case approaches (which provide strong statistical guarantees but are too inefficient for practical use). Learning proceeds as a sequence of decisions which are informed by training data. By analyzing induction at the level of these decisions, and by utilizing the only enough data to make each decision, sequential induction provides statistical guarantees but with substantially less data than worst-case methods require. The sequential inductive model is also useful as a method for determining a sufficient sample size for inductive learning and as such, is relevant to learning problems where the preponderance of data or the cost of gathering data precludes the use of traditional methods.

  17. Integration of hydrological and geophysical data beyond the local scale: Application of Bayesian sequential simulation to field data from the Saint-Lambert-de-Lauzon site, Québec, Canada

    NASA Astrophysics Data System (ADS)

    Ruggeri, Paolo; Gloaguen, Erwan; Lefebvre, René; Irving, James; Holliger, Klaus

    2014-06-01

    Adequate characterization of aquifer heterogeneity is critically important for the sustainable use, protection, and remediation of groundwater resources. The combined use of hydrological and geophysical measurements is arguably the most effective means of achieving this objective. In this regard, significant progress has been made on the quantitative integration of geophysical and hydrological data at the local scale. However, the extension of such approaches to larger, more regional scales remains a major research challenge. In this paper, we demonstrate the application of a recently developed regional-scale hydrogeophysical data integration approach, which is based on Bayesian sequential simulation, to a field database from Quebec, Canada consisting of low-resolution, surface-based geoelectrical measurements as well as high-resolution direct-push and borehole-based measurements of the electrical and hydraulic conductivities. The results of our study, which involved the integration of data along an approximately 250-m-long survey line, confirm that this novel methodology, with suitable adaptation, is fully applicable to field data and has the potential of providing realistic estimates of the spatial distribution of hydraulic target parameters at the regional-scale. Equally importantly, through the generation of multiple stochastic realizations, the methodology allows for quantitative assessment of the uncertainty associated with the inferred subsurface models, which in turn is essential for interpreting subsequent predictions of the flow and transport characteristics of the studied region.

  18. Integrating mercury injection and nitrogen adsorption data to characterize marine sediment pore systems: An example from the Nankai Trough

    NASA Astrophysics Data System (ADS)

    Daigle, H.; Thomas, B.

    2013-12-01

    Fine-grained, clay-rich marine sediments typically exhibit complex pore geometries due to the presence of high-aspect-ratio clay particles, nannofossils, and diagenetically altered grain fragments. The pore systems in these sediments have a wide range of shapes and may contain significant pore volume in mesopores (1-25 nm radius) and micropores (< 1 nm radius). This renders pore size measurements difficult, even in samples with high porosity. Porosity values from mercury injection capillary pressure (MICP) measurements performed on samples from Integrated Ocean Drilling Program (IODP) Sites C0011, C0012, and C0018 in the Nankai Trough offshore Japan were compared to porosity determined by proton nuclear magnetic resonance (NMR) in the laboratory. The MICP porosities were systematically lower than the NMR porosities by up to 26% of the NMR porosity value. This porosity mismatch is due to the presence of pores with radii smaller than the effective lower limit of MICP measurements, which is 10-40 nm for this data set. Nitrogen gas adsorption offers a means to characterize pores between ~0.87 nm and ~100 nm radius, thus measuring the portion of the pore size distribution not investigated by MICP measurements. Combining MICP and nitrogen gas adsorption data yields a more complete characterization of the pore system of marine sediments. Merged MICP and nitrogen gas adsorption data obtained for the Nankai Trough samples yield porosity values that more accurately match the NMR porosity values, indicating that the entire pore space of the samples can be measured by a combination of the two techniques. These samples possess significant quantities of porosity below the resolution of MICP (>10% of pore volume), even in samples with porosity exceeding 65%. This work illustrates the complexity of marine sediment pore systems even at shallow depths of burial, and provides a new method for assessing pore sizes in scientific ocean drilling studies.

  19. Sequential Dependencies in Driving

    ERIC Educational Resources Information Center

    Doshi, Anup; Tran, Cuong; Wilder, Matthew H.; Mozer, Michael C.; Trivedi, Mohan M.

    2012-01-01

    The effect of recent experience on current behavior has been studied extensively in simple laboratory tasks. We explore the nature of sequential effects in the more naturalistic setting of automobile driving. Driving is a safety-critical task in which delayed response times may have severe consequences. Using a realistic driving simulator, we find…

  20. Sequential memory: Binding dynamics

    NASA Astrophysics Data System (ADS)

    Afraimovich, Valentin; Gong, Xue; Rabinovich, Mikhail

    2015-10-01

    Temporal order memories are critical for everyday animal and human functioning. Experiments and our own experience show that the binding or association of various features of an event together and the maintaining of multimodality events in sequential order are the key components of any sequential memories—episodic, semantic, working, etc. We study a robustness of binding sequential dynamics based on our previously introduced model in the form of generalized Lotka-Volterra equations. In the phase space of the model, there exists a multi-dimensional binding heteroclinic network consisting of saddle equilibrium points and heteroclinic trajectories joining them. We prove here the robustness of the binding sequential dynamics, i.e., the feasibility phenomenon for coupled heteroclinic networks: for each collection of successive heteroclinic trajectories inside the unified networks, there is an open set of initial points such that the trajectory going through each of them follows the prescribed collection staying in a small neighborhood of it. We show also that the symbolic complexity function of the system restricted to this neighborhood is a polynomial of degree L - 1, where L is the number of modalities.

  1. Sequential memory: Binding dynamics.

    PubMed

    Afraimovich, Valentin; Gong, Xue; Rabinovich, Mikhail

    2015-10-01

    Temporal order memories are critical for everyday animal and human functioning. Experiments and our own experience show that the binding or association of various features of an event together and the maintaining of multimodality events in sequential order are the key components of any sequential memories-episodic, semantic, working, etc. We study a robustness of binding sequential dynamics based on our previously introduced model in the form of generalized Lotka-Volterra equations. In the phase space of the model, there exists a multi-dimensional binding heteroclinic network consisting of saddle equilibrium points and heteroclinic trajectories joining them. We prove here the robustness of the binding sequential dynamics, i.e., the feasibility phenomenon for coupled heteroclinic networks: for each collection of successive heteroclinic trajectories inside the unified networks, there is an open set of initial points such that the trajectory going through each of them follows the prescribed collection staying in a small neighborhood of it. We show also that the symbolic complexity function of the system restricted to this neighborhood is a polynomial of degree L - 1, where L is the number of modalities. PMID:26520084

  2. Some Practical Examples of Computer-Adaptive Sequential Testing.

    ERIC Educational Resources Information Center

    Luecht, Richard M.; Nungester, Ronald J.

    1998-01-01

    Describes an integrated approach to test development and administration called computer-adaptive sequential testing (CAST). CAST incorporates adaptive testing methods with automated test assembly. Describes the CAST framework and demonstrates several applications using a medical-licensure example. (SLD)

  3. Proof of concept testing of an integrated dry injection system for SO{sub 2}/NO{sub x} control. Final report

    SciTech Connect

    Helfritch, D.J.; Bortz, S.J.; Beittel, R.

    1994-03-01

    The integrated Dry Injection Process (IDIP) consists of combustion modification using low NO{sub x} burners to reduce NO{sub x} emissions, dry injection of hydrated line at economizer temperatures for primary capture of SO{sub 2}, dry injection of a commercial grade sodium bicarbonate at the air heater exit for additional SO{sub 2} and NO{sub x} removal, and humidification for precipitator conditioning. IDIP offers the potential for simultaneously achieving 90% SO{sub 2} removal, and 65% NO{sub x} removal from a high sulfur flue gas. The process is well suited for new or retrofit applications since it can be incorporated within existing economizer and downstream ductwork. Subscale tests were performed in order to identify the best calcium and sodium sorbents. These tests involved the injection of calcium hydroxide and sodium sorbents at various points of the flue gas system downstream of a 0.25 MM BTU/hr. coal fired combustor, and the gas residence times, cooling rates and temperatures were comparable to those found for full-scale utility boilers. These tests verified that a high surface area hydrated lime provides maximum sorbent utilization and identified an alcohol-water hydrated lime as yielding the highest surface area and the best SO{sub 2} removal capability. The tests also identified sodium bicarbonate to be somewhat more effective than sodium sesquicarbonate for SO{sub 2} removal. The proof of concept demonstration was conducted on the large combustor at the Riley Stoker Research Facility in Worcester, MA. When economically compared to conventional limestone slurry scrubbing on a 300 MW plant, the dry injection process shows lower capital cost but higher operating cost. Hydrated lime injection can be less costly than limestone scrubbing when two or more of the following conditions exist: plant is small (less than 100MW); yearly operating hours are small (less than 3000); and the remaining plant lifetime is small (less than 10 years).

  4. Golimumab Injection

    MedlinePlus

    ... it.Golimumab injection comes in prefilled syringes and auto-injection devices for subcutaneous injection. Use each syringe ... method.Do not remove the cap from the auto-injection device or the cover from the prefilled ...

  5. Patterns of integration of DNA microinjected into cultured mammalian cells: Evidence for homologous recombination between injected plasmid DNA molecules

    SciTech Connect

    Folger, K.R.; Wong, E.A.; Wahl, G.; Capecchi, M.R.

    1982-11-01

    The authors examined the fate of DNA microinjected into nuclei of cultured mammalian cells. The sequence composition and the physical form of the vector carrying the selectable gene affected the efficiency of DNA-mediated transformation. Introduction of sequences near the simian virus 40 origin of DNA replication or in the long terminal repeat of avian sarcoma provirus into a recombinant plasmid containing the herpes simplex virus thymidine kinase gene (pBR322/HSV-tk) enhanced the frequency of transformation of LMtk/sup -/ and RAT-2tk/sup -/ cells to the TK/sup +/ phenotype 20- to 40-fold. In cells receiving injections of only a few plasmid DNA molecules, the transformation frequency was 40-fold higher after injection of linear molecules than after injection of supercoiled molecules. By controlling the number of gene copies injected into a recipient cell, we could obtain transformants containing a single copy or as many as 50 to 100 copies of the selectable gene. By analyzing transformants obtained by coinjecting two vectors which were identical except that in one a portion of the vector was inverted, the authors were able to conclude that the head-to-tail concatemers were generated predominantly by homologous recombination. Surprisingly, these head-to-tail concatemers were found in transformants obtained by injecting either supercoiled or linear plasmid DNA.

  6. Hyaluronan injection in murine osteoarthritis prevents TGFbeta 1-induced synovial neovascularization and fibrosis and maintains articular cartilage integrity by a CD44-dependent mechanism

    PubMed Central

    2012-01-01

    Introduction The mechanism by which intra-articular injection of hyaluronan (HA) ameliorates joint pathology is unknown. Animal studies have shown that HA can reduce synovial activation, periarticular fibrosis and cartilage erosion; however, its specific effects on the different cell types involved remain unclear. We have used the TTR (TGFbeta1 injection and Treadmill Running) model of murine osteoarthritis (OA), which exhibits many OA-like changes, including synovial activation, to examine in vivo tissue-specific effects of intra-articular HA. Methods The kinetics of clearance of fluorotagged HA from joints was examined with whole-body imaging. Naïve and treated knee joints were examined macroscopically for cartilage erosion, meniscal damage and fibrosis. Quantitative histopathology was done with Safranin O for cartilage and with Hematoxylin & Eosin for synovium. Gene expression in joint tissues for Acan, Col1a1, Col2a1, Col3a1, Col5a1, Col10a1, Adamts5 and Mmp13 was done by quantitative PCR. The abundance and distribution of aggrecan, collagen types I, II, III, V and X, ADAMTS5 and MMP13 were examined by immunohistochemistry. Results Injected HA showed a half-life of less than 2 h in the murine knee joint. At the tissue level, HA protected against neovascularization and fibrosis of the meniscus/synovium and maintained articular cartilage integrity in wild-type but not in Cd44 knockout mice. HA injection enhanced the expression of chondrogenic genes and proteins and blocked that of fibrogenic/degradative genes and proteins in cartilage/subchondral bone, whereas it blocked activation of both groups in meniscus/synovium. In all locations it reduced the expression/protein for Mmp13 and blocked Adamts5 expression but not its protein abundance in the synovial lining. Conclusions The injection of HA, 24 h after TGFbeta1 injection, inhibited the cascade of OA-like joint changes seen after treadmill use in the TTR model of OA. In terms of mechanism, tissue protection by

  7. Sequential/parallel production of potential Malaria vaccines--A direct way from single batch to quasi-continuous integrated production.

    PubMed

    Luttmann, Reiner; Borchert, Sven-Oliver; Mueller, Christian; Loegering, Kai; Aupert, Florian; Weyand, Stephan; Kober, Christian; Faber, Bart; Cornelissen, Gesine

    2015-11-10

    An intensification of pharmaceutical protein production processes can be achieved by the integration of unit operations and application of recurring sequences of all biochemical process steps. Within optimization procedures each individual step as well as the overall process has to be in the focus of scientific interest. This paper includes a description of the development of a fully automated production plant, starting with a two step upstream followed by a four step downstream line, including cell clarification, broth cleaning with microfiltration, product concentration with ultrafiltration and purification with column chromatography. Recursive production strategies are developed where a cell breeding, the protein production and the whole downstream is operated in series but also in parallel, each main operation shifted by one day. The quality and reproducibility of the recursive protein expression is monitored on-line by Golden Batch and this is controlled by Model Predictive Multivariate Control (MPMC). As a demonstration process the production of potential Malaria vaccines with Pichia pastoris is under investigation. PMID:25736485

  8. Sequential products on effect algebras

    NASA Astrophysics Data System (ADS)

    Gudder, Stan; Greechie, Richard

    2002-02-01

    A sequential effect algebra (SEA) is an effect algebra on which a sequential product with natural properties is defined. The properties of sequential products on Hilbert space effect algebras are discussed. For a general SEA, relationships between sequential independence, coexistence and compatibility are given. It is shown that the sharp elements of a SEA form an orthomodular poset. The sequential center of a SEA is discussed and a characterization of when the sequential center is isomorphic to a fuzzy set system is presented. It is shown that the existence, of a sequential product is a strong restriction that eliminates many effect algebras from being SEA's. For example, there are no finite nonboolean SEA's, A measure of sharpness called the sharpness index is studied. The existence of horizontal sums of SEA's is characterized and examples of horizontal sums and tensor products are presented.

  9. The Activity-Integrated Method for Quality Assessment of Reduning Injection by On-Line DPPH-CE-DAD

    PubMed Central

    Bai, Yang; Li, Jin; Liu, Er-wei; He, Jun; Jiao, Xiu-cheng; Wang, Zhen-zhong; Gao, Xiu-Mei; Zhang, Bo-li; Xiao, Wei

    2014-01-01

    A sensitive on-line DPPH-CE-DAD method was developed and validated for both screening and determining the concentration of seven antioxidants of Reduning injection. The pH and concentrations of buffer solution, SDS, β-CD and organic modifier were studied for the detection of DPPH and seven antioxidants. By on-line mixing DPPH and sample solution, a DPPH-CE method for testing the antioxidant activity of the complex matrix was successfully established and used to screen the antioxidant components of Reduning injection. Then, antioxidant components including caffeic acid, isochlorogenic acid A, isochlorogenic acid B, isochlorogenic acid C, chlorogenic acid, neochlorogenic acid and cryptochlorogenic acid were quantified by the newly established CE–DAD method. Finally, the total antioxidant activity and the multiple active components were selected as markers to evaluate the quality of Reduning injection. The results demonstrated that the on-line DPPH-CE-DAD method was reagent-saving, rapid and feasible for on-line simultaneous determination of total pharmacological activity and contents of multi-components samples. It was also a powerful method for evaluating the quality control and mechanism of action of TCM injection. PMID:25181475

  10. Reliable VLSI sequential controllers

    NASA Technical Reports Server (NTRS)

    Whitaker, S.; Maki, G.; Shamanna, M.

    1990-01-01

    A VLSI architecture for synchronous sequential controllers is presented that has attractive qualities for producing reliable circuits. In these circuits, one hardware implementation can realize any flow table with a maximum of 2(exp n) internal states and m inputs. Also all design equations are identical. A real time fault detection means is presented along with a strategy for verifying the correctness of the checking hardware. This self check feature can be employed with no increase in hardware. The architecture can be modified to achieve fail safe designs. With no increase in hardware, an adaptable circuit can be realized that allows replacement of faulty transitions with fault free transitions.

  11. Golimumab Injection

    MedlinePlus

    ... at golimumab injection before injecting it. Check the expiration date printed on the auto-injection device or carton and do not use the medication if the expiration date has passed. Do not use a prefilled syringe ...

  12. The structure of sequential effects.

    PubMed

    Gökaydin, Dinis; Navarro, Daniel J; Ma-Wyatt, Anna; Perfors, Amy

    2016-01-01

    There is a long history of research into sequential effects, extending more than one hundred years. The pattern of sequential effects varies widely with both experimental conditions as well as for different individuals performing the same experiment. Yet this great diversity of results is poorly understood, particularly with respect to individual variation, which save for some passing mentions has largely gone unreported in the literature. Here we seek to understand the way in which sequential effects vary by identifying the causes underlying the differences observed in sequential effects. In order to achieve this goal we perform principal component analysis on a dataset of 158 individual results from participants performing different experiments with the aim of identifying hidden variables responsible for sequential effects. We find a latent structure consisting of 3 components related to sequential effects-2 main and 1 minor. A relationship between the 2 main components and the separate processing of stimuli and of responses is proposed on the basis of previous empirical evidence. It is further speculated that the minor component of sequential effects arises as the consequence of processing delays. Independently of the explanation for the latent variables encountered, this work provides a unified descriptive model for a wide range of different types of sequential effects previously identified in the literature. In addition to explaining individual differences themselves, it is demonstrated how the latent structure uncovered here is useful in understanding the classical problem of the dependence of sequential effects on the interval between successive stimuli. PMID:26523425

  13. Multi-Attribute Sequential Search

    ERIC Educational Resources Information Center

    Bearden, J. Neil; Connolly, Terry

    2007-01-01

    This article describes empirical and theoretical results from two multi-attribute sequential search tasks. In both tasks, the DM sequentially encounters options described by two attributes and must pay to learn the values of the attributes. In the "continuous" version of the task the DM learns the precise numerical value of an attribute when she…

  14. Student Storytelling through Sequential Art

    ERIC Educational Resources Information Center

    Fay, David

    2007-01-01

    If you are interested in using sequential art forms such as comic books in your EFL classroom, this article is full of helpful advice. Reading sequential art is beneficial because students can work with authentic texts with real language and graphic support. Students can also apply research and cultural knowledge to the creation of their own…

  15. Continuity of the sequential product of sequential quantum effect algebras

    NASA Astrophysics Data System (ADS)

    Lei, Qiang; Su, Xiaochao; Wu, Junde

    2016-04-01

    In order to study quantum measurement theory, sequential product defined by A∘B = A1/2BA1/2 for any two quantum effects A, B has been introduced. Physically motivated conditions ask the sequential product to be continuous with respect to the strong operator topology. In this paper, we study the continuity problems of the sequential product A∘B = A1/2BA1/2 with respect to other important topologies, such as norm topology, weak operator topology, order topology, and interval topology.

  16. Adaptive sequential controller

    DOEpatents

    El-Sharkawi, Mohamed A.; Xing, Jian; Butler, Nicholas G.; Rodriguez, Alonso

    1994-01-01

    An adaptive sequential controller (50/50') for controlling a circuit breaker (52) or other switching device to substantially eliminate transients on a distribution line caused by closing and opening the circuit breaker. The device adaptively compensates for changes in the response time of the circuit breaker due to aging and environmental effects. A potential transformer (70) provides a reference signal corresponding to the zero crossing of the voltage waveform, and a phase shift comparator circuit (96) compares the reference signal to the time at which any transient was produced when the circuit breaker closed, producing a signal indicative of the adaptive adjustment that should be made. Similarly, in controlling the opening of the circuit breaker, a current transformer (88) provides a reference signal that is compared against the time at which any transient is detected when the circuit breaker last opened. An adaptive adjustment circuit (102) produces a compensation time that is appropriately modified to account for changes in the circuit breaker response, including the effect of ambient conditions and aging. When next opened or closed, the circuit breaker is activated at an appropriately compensated time, so that it closes when the voltage crosses zero and opens when the current crosses zero, minimizing any transients on the distribution line. Phase angle can be used to control the opening of the circuit breaker relative to the reference signal provided by the potential transformer.

  17. Impact of 4-year CO2 injection on reservoir-rock integrity at the CO2 pilot site Ketzin (Germany)

    NASA Astrophysics Data System (ADS)

    Bock, S.; Förster, H.; Meier, A.; Pudlo, D.; Förster, A.; Gaupp, R.

    2013-12-01

    The CO2 Ketzin pilot site offers the possibility to study the short-term effects of injected CO2 on the mineralogy, geochemistry and porosity/permeability of siliciclastic reservoir rocks in a saline aquifer. Ketzin is located 30 kilometers west of Berlin in the Northeast German Basin, a sedimentary basin containing Paleozoic to Cenozoic sediments. The site is characterized by an anticlinal structure formed through halokinetic uprise of Permian salt. The reservoir in the Upper Triassic Stuttgart Formation, in which about 64,000 tons of CO2 are stored at depth of 630-700 m, is heterogeneous, comprising sandstones and siltstones. The Stuttgart Formation is overlain by a 200-m-thick caprock system of massive mudstones pertaining to the Upper Triassic Weser Formation and Arnstadt Formation. Argillaceous Tertiary sediments form an additional caprock in the shallow subsurface. Core material was recovered in 2007 for a baseline study and again in August 2012, almost four years after start of CO2 injection, to evaluate the fluid-rock reactions that took place. Preliminary results of an ongoing study, which focuses on petrographic-mineralogical and geochemical features, reveal negligible changes in bulk-rock composition almost in the range of the pristine natural heterogeneity of the reservoir. No significant dissolution or precipitation of minerals occurred implying that CO2 was trapped mainly structurally and residually as well as became dissolved in the formation brine. Additional studies concentrated on the fixation of CO2 by mineral trapping. Analytical work was focused on small-scale variations and reactions within and on the surface of minerals. X-ray Photoelectron Spectroscopy (XPS) supplied information about the alteration of Fe-rich grain coatings. This surface-sensitive method provides, beyond the quantitative analysis of certain elements, information on the valence state and quantity of iron. A weak tendency of transformation from hematite to goethite coatings

  18. Method for sequential injection of liquid samples for radioisotope separations

    DOEpatents

    Egorov, Oleg B.; Grate, Jay W.; Bray, Lane A.

    2000-01-01

    The present invention is a method of separating a short-lived daughter isotope from a longer lived parent isotope, with recovery of the parent isotope for further use. Using a system with a bi-directional pump and one or more valves, a solution of the parent isotope is processed to generate two separate solutions, one of which contains the daughter isotope, from which the parent has been removed with a high decontamination factor, and the other solution contains the recovered parent isotope. The process can be repeated on this solution of the parent isotope. The system with the fluid drive and one or more valves is controlled by a program on a microprocessor executing a series of steps to accomplish the operation. In one approach, the cow solution is passed through a separation medium that selectively retains the desired daughter isotope, while the parent isotope and the matrix pass through the medium. After washing this medium, the daughter is released from the separation medium using another solution. With the automated generator of the present invention, all solution handling steps necessary to perform a daughter/parent radionuclide separation, e.g. Bi-213 from Ac-225 "cow" solution, are performed in a consistent, enclosed, and remotely operated format. Operator exposure and spread of contamination are greatly minimized compared to the manual generator procedure described in U.S. patent application Ser. No. 08/789,973, now U.S. Pat. No. 5,749,042, herein incorporated by reference. Using 16 mCi of Ac-225 there was no detectable external contamination of the instrument components.

  19. Preservation of Geometrical Integrity of Supersolidus-Liquid-Phase-Sintered SKD11 Tool Steels Prepared with Powder Injection Molding

    NASA Astrophysics Data System (ADS)

    Chuang, K. H.; Hwang, K. S.

    2011-07-01

    The powder injection molded SKD11 tool steels often manifest shape retention problems during supersolidus liquid phase sintering due to the difficulties in controlling the amount of liquid phase. The typical temperature range for the sintering of SKD11 is only 10 K, between 1503 and 1513 K (1230 and 1240 °C), and this narrow sintering range demands a special furnace with very uniform temperature distribution. Through the addition of carbides, in particular TiC, this problem is resolved by enlarging the liquid + γ + carbide region in the phase diagram and by impeding the grain growth with the carbides. The resulting sintering window is broadened to 40 K, between 1513 and 1553 K (1240 and 1280 °C). The relevant mechanisms on the improvement of shape retention are discussed with a focus on the effect of carbide addition on the changes in the phase diagram and the microstructure. A guideline for the selection of effective carbides is also proposed based on the experimental results and the phase diagram analyses.

  20. Application of direct-injection detector integrated with the multi-pumping flow system to chemiluminescence determination of the total polyphenol index.

    PubMed

    Nalewajko-Sieliwoniuk, Edyta; Iwanowicz, Magdalena; Kalinowski, Sławomir; Kojło, Anatol

    2016-03-10

    In this work, we present a novel chemiluminescence (CL) method based on direct-injection detector (DID) integrated with the multi-pumping flow system (MPFS) to chemiluminescence determination of the total polyphenol index. In this flow system, the sample and the reagents are injected directly into the cone-shaped detection cell placed in front of the photomultiplier window. Such construction of the detection chamber allows for fast measurement of the CL signal in stopped-flow conditions immediately after mixing the reagents. The proposed DID-CL-MPFS method is based on the chemiluminescence of nanocolloidal manganese(IV)-hexametaphosphate-ethanol system. The application of ethanol as a sensitizer, eliminated the use of carcinogenic formaldehyde. Under the optimized experimental conditions, the chemiluminescence intensities are proportional to the concentration of gallic acid in the range from 5 to 350 ng mL(-1). The DID-CL-MPFS method offers a number of advantages, including low limit of detection (0.80 ng mL(-1)), high precision (RSD = 3.3%) and high sample throughput (144 samples h(-1)) as well as low consumption of reagents, energy and low waste generation. The proposed method has been successfully applied to determine the total polyphenol index (expressed as gallic acid equivalent) in a variety of plant-derived food samples (wine, tea, coffee, fruit and vegetable juices, herbs, spices). PMID:26893089

  1. Application of direct-injection detector integrated with the multi-pumping flow system to photometric stop-flow determination of total iron.

    PubMed

    Koronkiewicz, Stanislawa; Kalinowski, Slawomir

    2012-07-15

    A novel direct-injection detector (DID) integrated with multi-pumping flow system (MPFS) for the photometric determination of iron is proposed. Paired emitter-detector diodes have been used as a photometric detection system. The sample and reagent were injected using appropriate solenoid pulse micro-pumps directly into the detection chamber where effective mixing occured. The use of proposed stop-flow detector considerably simplified the analytical procedure. The potassium thiocyanate has been chosen as a chromogenic reagent for photometric Fe(III) detection. The total volume of reagent and sample/standard solutions involved in the detection process was adjusted to the volume of the reaction-detection chamber. Calibration graph was found to be linear in the range up to 10mgL(-1). The detection limit (3s(b)/S) was 0.15mgL(-1). The repeatability (R.S.D.), calculated from 10 analyses of sample containing 5mgL(-1) Fe(III), was 1.5% and the sample throughput 180 determinations per hour. The consumption of sample and reagent was 20μL each with the waste generation at the level of 0.24mL. The applicability of the proposed method to the determination of total iron in groundwater samples has been proved. The analytical parameters are compared to those obtained exploiting the MPFS system with typical configuration containing a confluence point and reaction coil. PMID:22817930

  2. Integrating care for hepatitis C virus (HCV) and primary care for HIV for injection drug users coinfected with HIV and HCV.

    PubMed

    Kresina, Thomas F; Bruce, R Douglas; Cargill, Victoria A; Cheever, Laura W

    2005-07-01

    Injection drug use accounts for most of the incident infections with hepatitis C virus (HCV) and for at least one-third of new human immunodeficiency virus (HIV) infections. Coinfection with HCV and HIV presents complex and challenging medical conditions. Ensuring access to and maintaining care for HIV and HCV for drug users presents special challenges to the health care team that require a nonjudgmental attitude, experience, and patience. Care for HCV infection, however, can be used as an instrument to engage drug-using persons in ongoing primary care relationships. Common elements to both care for HCV infection and primary care for HIV infection are testing for and counseling about HCV and HIV, substance abuse and mental health services, social support, and subspecialty referral. These elements, in particular treatment for substance abuse, can be focal points for model care systems that provide integrative care for both HCV and HIV infections. PMID:16265621

  3. Medroxyprogesterone Injection

    MedlinePlus

    ... Medroxyprogesterone subcutaneous injection is also used to treat endometriosis (a condition in which the type of tissue ... parts of the body in women who have endometriosis. Medroxyprogesterone injection is a very effective method of ...

  4. Chloramphenicol Injection

    MedlinePlus

    Chloramphenicol injection is used to treat certain types of serious infections caused by bacteria when other antibiotics cannot be used. Chloramphenicol injection is in a class of medications called ...

  5. Levoleucovorin Injection

    MedlinePlus

    ... injection is used to prevent harmful effects of methotrexate (Rheumatrex, Trexall) when methotrexate is used to to treat certain types of ... people who have accidentally received an overdose of methotrexate or similar medications. Levoleucovorin injection is in a ...

  6. Estrogen Injection

    MedlinePlus

    ... forms of estrogen injection are used to treat hot flushes (hot flashes; sudden strong feelings of heat and sweating) ... If you are using estrogen injection to treat hot flushes, your symptoms should improve within 1 to ...

  7. Palonosetron Injection

    MedlinePlus

    Palonosetron injection is used to prevent nausea and vomiting that may occur within 24 hours after receiving ... occur several days after receiving certain chemotherapy medications. Palonosetron injection is in a class of medications called ...

  8. Leuprolide Injection

    MedlinePlus

    ... normal number of red blood cells) caused by uterine fibroids (noncancerous growths in the uterus). Leuprolide injection is ... Your doctor will tell you how long your treatment with leuprolide injection will last. When used in ...

  9. Naltrexone Injection

    MedlinePlus

    Naltrexone injection is used along with counseling and social support to help people who have stopped drinking large ... injection is also used along with counseling and social support to help people who have stopped abusing opiate ...

  10. Posaconazole Injection

    MedlinePlus

    Posaconazole injection is used to prevent fungal infections in people with a weakened ability to fight infection. Posaconazole injection is in a class of medications called azole antifungals. It works ...

  11. Paclitaxel Injection

    MedlinePlus

    ... with other medications. Paclitaxel injection manufactured with polyoxyethylated castor oil is used to treat ovarian cancer (cancer that ... cancer, and lung cancer. Paclitaxel injection with polyoxyethylated castor oil is also used to treat Kaposi's sarcoma (a ...

  12. Mipomersen Injection

    MedlinePlus

    ... become pregnant during your treatment, stop using mipomersen injection and call your doctor immediately. ... Mipomersen injection may cause side effects. Tell your doctor if any of these ... and tiredness that are most likely to occur during the first 2 days ...

  13. Levofloxacin Injection

    MedlinePlus

    ... infections. Levofloxacin injection is also used to prevent anthrax (a serious infection that may be spread on ... in people who may have been exposed to anthrax germs in the air. Levofloxacin injection is in ...

  14. Ciprofloxacin Injection

    MedlinePlus

    ... injection is also used to prevent or treat anthrax (a serious infection that may be spread on ... in people who may have been exposed to anthrax germs in the air. Ciprofloxacin injection is in ...

  15. Romidepsin Injection

    MedlinePlus

    ... with at least one other medication given by mouth or by injection. Romidepsin injection is in a ... antifungals such as itraconazole (Sporanox), ketoconazole (Nizoral), and voriconazole (Vfend); cisapride (Propulsid) (not available in the U.S.); ...

  16. Degarelix Injection

    MedlinePlus

    Degarelix injection is used to treat advanced prostate cancer (cancer that begins in the prostate [a male reproductive gland]). Degarelix injection is in a class of medications called gonadotropin-releasing hormone (GnRH) ...

  17. Paclitaxel Injection

    MedlinePlus

    ... other medications. Paclitaxel injection manufactured with polyoxyethylated castor oil is used to treat ovarian cancer (cancer that ... and lung cancer. Paclitaxel injection with polyoxyethylated castor oil is also used to treat Kaposi's sarcoma (a ...

  18. Glatiramer Injection

    MedlinePlus

    ... course of disease where symptoms flare up from time to time) of multiple sclerosis (MS; a disease in which ... to inject glatiramer, inject it around the same time every day. Follow the directions on your prescription ...

  19. Daratumumab Injection

    MedlinePlus

    ... any laboratory test, tell your doctor and the laboratory personnel that you are receiving or received daratumumab injection. ... a blood transfusion, tell your doctor and the laboratory personnel that you are receiving or received daratumumab injection. ...

  20. Pralatrexate Injection

    MedlinePlus

    ... will need to take folic acid and vitamin B12 during your treatment with pralatrexate injection to help ... that you will need to receive a vitamin B12 injection no more than 10 weeks before your ...

  1. Cefoxitin Injection

    MedlinePlus

    ... injection is used to treat infections caused by bacteria including pneumonia and other lower respiratory tract (lung) ... medications called cephamycin antibiotics. It works by killing bacteria.Antibiotics such as cefoxitin injection will not work ...

  2. Chloramphenicol Injection

    MedlinePlus

    ... treat certain types of serious infections caused by bacteria when other antibiotics cannot be used. Chloramphenicol injection ... antibiotics. It works by stopping the growth of bacteria..Antibiotics such as chloramphenicol injection will not work ...

  3. Oxacillin Injection

    MedlinePlus

    ... is used to treat infections caused by certain bacteria. Oxacillin injection is in a class of medications called penicillins. It works by killing bacteria.Antibiotics such as oxacillin injection will not work ...

  4. Nafcillin Injection

    MedlinePlus

    ... to treat infections caused by certain types of bacteria. Nafcillin injection is in a class of medications called penicillins. It works by killing bacteria.Antibiotics such as nafcillin injection will not work ...

  5. Doripenem Injection

    MedlinePlus

    ... tract, kidney, and abdomen that are caused by bacteria. Doripenem injection is not approved by the Food ... medications called carbapenem antibiotics. It works by killing bacteria.Antibiotics such as doripenem injection will not work ...

  6. Medroxyprogesterone Injection

    MedlinePlus

    ... Medroxyprogesterone injection is a very effective method of birth control but does not prevent the spread of human ... you have been using a different method of birth control and are switching to medroxyprogesterone injection, your doctor ...

  7. Doxycycline Injection

    MedlinePlus

    Doxycycline injection is used to treat or prevent bacterial infections, including pneumonia and other respiratory tract infections. ... certain skin, genital, intestine, and urinary system infections. Doxycycline injection may be used to treat or prevent ...

  8. Ferumoxytol Injection

    MedlinePlus

    Ferumoxytol injection is used to treat iron-deficiency anemia (a lower than normal number of red blood ... and may cause the kidneys to stop working). Ferumoxytol injection is in a class of medications called ...

  9. Fondaparinux Injection

    MedlinePlus

    ... using fondaparinux injection while you are in the hospital at least 6 to 8 hours after your ... you will continue to use fondaparinux after your hospital stay, you can inject fondaparinux yourself or have ...

  10. Epinephrine Injection

    MedlinePlus

    Adrenalin® Chloride Solution ... a pre-filled automatic injection device containing a solution (liquid) to inject under the skin or into ... device when this date passes. Look at the solution in the device from time to time. If ...

  11. Trastuzumab Injection

    MedlinePlus

    Trastuzumab injection is used along with other medications or after other medications have been used to treat ... has spread to other parts of the body. Trastuzumab injection is also used during and after treatment ...

  12. Aripiprazole Injection

    MedlinePlus

    ... aripiprazole injection and aripiprazole extended-release injection developed gambling problems or other intense urges or behaviors that ... even if you do not realize that your gambling or any other intense urges or unusual behaviors ...

  13. Integrating services for injection drug users infected with hepatitis C virus with methadone maintenance treatment: challenges and opportunities.

    PubMed

    Litwin, Alain H; Soloway, Irene; Gourevitch, Marc N

    2005-04-15

    Despite the high prevalence of hepatitis C virus (HCV) infection among drug users enrolled in methadone maintenance treatment programs, few drug users are being treated with combination therapy. The most significant barrier to treatment is lack of access to comprehensive HCV-related care. We describe a pilot program to integrate care for HCV infection with substance abuse treatment in a setting of maintenance treatment with methadone. This on-site, multidisciplinary model of care includes comprehensive screening and treatment for HCV infection, assessment of eligibility, counseling with regard to substance abuse, psychiatric services, HCV support groups, directly observed therapy, and enhanced linkages to a tertiary care system for diagnostic procedures. Our approach has led to high levels of adherence, with liver biopsy and substantial rates of initiation of antiviral therapy. Two cases illustrate the successful application of this model to patients with HCV infection complicated by active substance abuse and psychiatric comorbidity. PMID:15768345

  14. Self-aligned BCB planarization method for high-frequency signal injection in a VCSEL with an integrated modulator

    NASA Astrophysics Data System (ADS)

    Marigo-Lombart, Ludovic; Doucet, Jean-Baptiste; Lecestre, Aurélie; Reig, Benjamin; Rousset, Bernard; Thienpont, Hugo; Panajotov, Krassimir; Almuneau, Guilhem

    2016-04-01

    The huge increase of datacom capacities requires lasers sources with more and more bandwidth performances. Vertical-Cavity Surface-Emitting Lasers (VCSEL) in direct modulation is a good candidate, already widely used for short communication links such as in datacenters. Recently several different approaches have been proposed to further extend the direct modulation bandwidth of these devices, by improving the VCSEL structure, or by combining the VCSEL with another high speed element such as lateral slow light modulator or transistor/laser based structure (TVCSEL). We propose to increase the modulation bandwidth by vertically integrating a continuous-wave VCSEL with a high-speed electro-modulator. This vertical structure implies multiple electrodes with sufficiently good electrical separation between the different input electrical signals. This high frequency modulation requires both good electrical insulation between metal electrodes and an optimized design of the coplanar lines. BenzoCyclobutene (BCB) thanks to its low dielectric constant, low losses, low moisture absorption and good thermal stability, is often used as insulating layer. Also, BCB planarization offers the advantages of simpler and more reliable technological process flow in such integrated VCSEL/modulator structures with important reliefs. As described by Burdeaux et al. a degree of planarization (DOP) of about 95% can be achieved by simple spin coating whatever the device thickness. In most of the cases, the BCB planarization process requires an additional photolithography step in order to open an access to the mesa surface, thus involving a tight mask alignment and resulting in a degraded planarization. In this paper, we propose a self-aligned process with improved BCB planarization by combining a hot isostatic pressing derived from nanoimprint techniques with a dry plasma etching step.

  15. Sequentially pulsed traveling wave accelerator

    DOEpatents

    Caporaso, George J.; Nelson, Scott D.; Poole, Brian R.

    2009-08-18

    A sequentially pulsed traveling wave compact accelerator having two or more pulse forming lines each with a switch for producing a short acceleration pulse along a short length of a beam tube, and a trigger mechanism for sequentially triggering the switches so that a traveling axial electric field is produced along the beam tube in synchronism with an axially traversing pulsed beam of charged particles to serially impart energy to the particle beam.

  16. A Bayesian Theory of Sequential Causal Learning and Abstract Transfer.

    PubMed

    Lu, Hongjing; Rojas, Randall R; Beckers, Tom; Yuille, Alan L

    2016-03-01

    Two key research issues in the field of causal learning are how people acquire causal knowledge when observing data that are presented sequentially, and the level of abstraction at which learning takes place. Does sequential causal learning solely involve the acquisition of specific cause-effect links, or do learners also acquire knowledge about abstract causal constraints? Recent empirical studies have revealed that experience with one set of causal cues can dramatically alter subsequent learning and performance with entirely different cues, suggesting that learning involves abstract transfer, and such transfer effects involve sequential presentation of distinct sets of causal cues. It has been demonstrated that pre-training (or even post-training) can modulate classic causal learning phenomena such as forward and backward blocking. To account for these effects, we propose a Bayesian theory of sequential causal learning. The theory assumes that humans are able to consider and use several alternative causal generative models, each instantiating a different causal integration rule. Model selection is used to decide which integration rule to use in a given learning environment in order to infer causal knowledge from sequential data. Detailed computer simulations demonstrate that humans rely on the abstract characteristics of outcome variables (e.g., binary vs. continuous) to select a causal integration rule, which in turn alters causal learning in a variety of blocking and overshadowing paradigms. When the nature of the outcome variable is ambiguous, humans select the model that yields the best fit with the recent environment, and then apply it to subsequent learning tasks. Based on sequential patterns of cue-outcome co-occurrence, the theory can account for a range of phenomena in sequential causal learning, including various blocking effects, primacy effects in some experimental conditions, and apparently abstract transfer of causal knowledge. PMID:25902728

  17. Giant intracranial aneurysms: rapid sequential computed tomography

    SciTech Connect

    Pinto, R.S.; Cohen, W.A.; Kricheff, I.I.; Redington, R.W.; Berninger, W.H.

    1982-11-01

    Giant intracranial aneurysms often present as mass lesions rather than with subarachnoid hemorrhage. Routine computed tomographic (CT) scans with contrast material will generally detect them, but erroneous diagnosis of basal meningioma is possible. Rapid sequential scanning (dynamic CT) after bolus injection of 40 ml of Renografin-76 can conclusively demonstrate an intracranial aneurysm, differentiating it from other lesions by transit-time analysis of the passage of contrast medium. In five patients, the dynamics of contrast bolus transit in aneurysms were consistently different from the dynamics in pituitary tumors, craniopharyngiomas, and meningiomas, thereby allowing a specific diagnosis. Dynamic CT was also useful after treatment of the aneurysms by carotid artery ligation and may be used as an alternative to angiographic evaluation in determining luminal patency or thrombosis.

  18. Solution-Processed Gold Nanorods Integrated with Graphene for Near-Infrared Photodetection via Hot Carrier Injection.

    PubMed

    Xia, Zhouhui; Li, Pengfei; Wang, Yusheng; Song, Tao; Zhang, Qiao; Sun, Baoquan

    2015-11-01

    Graphene-based photodetectors have attracted wide interest due to their high-speed, wide-band photodetection and potential as highly energy-efficient integrated devices. However, the inherently low-absorption cross-section and nonselective spectra response hinder its utilization as a high-performance photodetector. Here, we report a solution-processed and high-spectral-selectivity photodetector based on a gold nanorods (Au NRs)-graphene heterojunction with near-infrared (NIR) detection. Au NRs are used as a subwavelength scattering source, and nanoantennas with wide light absorption range from ultraviolet to near-infrared via tuning their geometry. Photons couple into Au NRs, exciting resonant plasmas and generating hot carriers that pump into graphene, resulting in selective NIR photodetection. A flexible NIR photodetector is also demonstrated based on this simple structure. Au NRs can achieve variable resonance frequencies by the design of different aspect ratios as nanoantennae for graphene, which promises the selective amplifying of the photoresponsivity and enables highly specific detection. PMID:26468669

  19. Sequential Syndrome Decoding of Convolutional Codes

    NASA Technical Reports Server (NTRS)

    Reed, I. S.; Truong, T. K.

    1984-01-01

    The algebraic structure of convolutional codes are reviewed and sequential syndrome decoding is applied to those codes. These concepts are then used to realize by example actual sequential decoding, using the stack algorithm. The Fano metric for use in sequential decoding is modified so that it can be utilized to sequentially find the minimum weight error sequence.

  20. Time-lapse integrated geophysical imaging of magmatic injections and fluid-induced fracturing causing Campi Flegrei 1983-84 Unrest

    NASA Astrophysics Data System (ADS)

    De Siena, Luca; Crescentini, Luca; Amoruso, Antonella; Del Pezzo, Edoardo; Castellano, Mario

    2016-04-01

    Geophysical precursors measured during Unrest episodes are a primary source of geophysical information to forecast eruptions at the largest and most potentially destructive volcanic calderas. Despite their importance and uniqueness, these precursors are also considered difficult to interpret and unrepresentative of larger eruptive events. Here, we show how novel geophysical imaging and monitoring techniques are instead able to represent the dynamic evolution of magmatic- and fluid-induced fracturing during the largest period of Unrest at Campi Flegrei caldera, Italy (1983-1984). The time-dependent patterns drawn by microseismic locations and deformation, once integrated by 3D attenuation tomography and absorption/scattering mapping, model injections of magma- and fluid-related materials in the form of spatially punctual microseismic bursts at a depth of 3.5 km, west and offshore the city of Pozzuoli. The shallowest four kilometres of the crust work as a deformation-based dipolar system before and after each microseismic shock. Seismicity and deformation contemporaneously focus on the point of injection; patterns then progressively crack the medium directed towards the second focus, a region at depths 1-1.5 km south of Solfatara. A single high-absorption and high-scattering aseismic anomaly marks zones of fluid storage overlying the first dipolar centre. These results provide the first direct geophysical signature of the processes of aseismic fluid release at the top of the basaltic basement, producing pozzolanic activity and recently observed via rock-physics and well-rock experiments. The microseismicity caused by fluids and gasses rises to surface via high-absorption north-east rising paths connecting the two dipolar centres, finally beingq being generally expelled from the maar diatreme Solfatara structure. Geophysical precursors during Unrest depict how volcanic stress was released at the Campi Flegrei caldera during its period of highest recorded seismicity

  1. Large-scale qualitative and quantitative characterization of components in Shenfu injection by integrating hydrophilic interaction chromatography, reversed phase liquid chromatography, and tandem mass spectrometry.

    PubMed

    Song, Yuelin; Zhang, Na; Shi, Shepo; Li, Jun; Zhang, Qian; Zhao, Yunfang; Jiang, Yong; Tu, Pengfei

    2015-08-14

    It is of great importance to clarify in depth the chemical composition, including qualitative and quantitative aspects, of traditional Chinese medicine (TCM) injection that contains a great number of hydrophilic and hydrophobic ingredients to guarantee its safe medication in clinic. Column-switching hydrophilic interaction liquid chromatography-reversed phase liquid chromatography coupled with tandem mass spectrometry (HILIC-RPLC-MS/MS) has been revealed to be advantageous at simultaneous measurement of compounds covering a broad polarity range. Previous studies have profiled the hydrophobic components, mainly aconite alkaloids and ginsenosides, in Shenfu Injection (SFI); however, the hydrophilic substances haven't been taken into account. In the present study, we aim to holistically characterize the hydrophilic constituents and to simultaneously quantitate both hydrophilic and hydrophobic components in SFI. A strategy integrating predefined multiple reaction monitoring, step-wise multiple ion monitoring, and enhanced product ion scans was proposed to universally screen the hydrophilic substances using a hybrid triple quadrupole-linear ion trap mass spectrometer. Structural identification was carried out by comparing with authentic compounds, analyzing MS(2) spectra, and referring to accessible databases (e.g., MassBank, METLIN and HMDB). A total of 157 hydrophilic compounds were detected from SFI, and 154 ones were identified as amino acids, nucleosides, organic acid, carbohydrates, etc. A column-switching HILIC-RPLC-MS/MS system was developed and validated for simultaneously quantitative analysis of 40 primary hydrophilic and hydrophobic ingredients in SFI, including eleven amino acids, nine nucleosides, nine aconite alkaloids, and eleven ginsenosides. Taken together, the findings obtained could provide meaningful information for comprehensively understanding the chemical composition and offer a reliable approach for the quality control of SFI. PMID:26143607

  2. Human sympathetic and vagal baroreflex responses to sequential nitroprusside and phenylephrine

    NASA Technical Reports Server (NTRS)

    Rudas, L.; Crossman, A. A.; Morillo, C. A.; Halliwill, J. R.; Tahvanainen, K. U.; Kuusela, T. A.; Eckberg, D. L.

    1999-01-01

    We evaluated a method of baroreflex testing involving sequential intravenous bolus injections of nitroprusside followed by phenylephrine and phenylephrine followed by nitroprusside in 18 healthy men and women, and we drew inferences regarding human sympathetic and vagal baroreflex mechanisms. We recorded the electrocardiogram, photoplethysmographic finger arterial pressure, and peroneal nerve muscle sympathetic activity. We then contrasted least squares linear regression slopes derived from the depressor (nitroprusside) and pressor (phenylephrine) phases with 1) slopes derived from spontaneous fluctuations of systolic arterial pressures and R-R intervals, and 2) baroreflex gain derived from cross-spectral analyses of systolic pressures and R-R intervals. We calculated sympathetic baroreflex gain from integrated muscle sympathetic nerve activity and diastolic pressures. We found that vagal baroreflex slopes are less when arterial pressures are falling than when they are rising and that this hysteresis exists over pressure ranges both below and above baseline levels. Although pharmacological and spontaneous vagal baroreflex responses correlate closely, pharmacological baroreflex slopes tend to be lower than those derived from spontaneous fluctuations. Sympathetic baroreflex slopes are similar when arterial pressure is falling and rising; however, small pressure elevations above baseline silence sympathetic motoneurons. Vagal, but not sympathetic baroreflex gains vary inversely with subjects' ages and their baseline arterial pressures. There is no correlation between sympathetic and vagal baroreflex gains. We recommend repeated sequential nitroprusside followed by phenylephrine doses as a simple, efficientmeans to provoke and characterize human vagal and sympathetic baroreflex responses.

  3. Integrated respondent-driven sampling and peer support for persons who inject drugs in Haiphong, Vietnam: a case study with implications for interventions.

    PubMed

    Des Jarlais, Don; Duong, Huong Thi; Pham Minh, Khue; Khuat, Oanh Hai Thi; Nham, Thanh Tuyet Thi; Arasteh, Kamyar; Feelemyer, Jonathan; Heckathorn, Douglas D; Peries, Marianne; Moles, Jean Pierre; Laureillard, Didier; Nagot, Nicolas

    2016-10-01

    Combined prevention for HIV among persons who inject drugs (PWID) has led to greatly reduced HIV transmission among PWID in many high-income settings, but these successes have not yet been replicated in resource-limited settings. Haiphong, Vietnam experienced a large HIV epidemic among PWID, with 68% prevalence in 2006. Haiphong has implemented needle/syringe programs, methadone maintenance treatment (MMT), and anti-retroviral treatment (ART), but there is an urgent need to identify high-risk PWID and link them to services. We examined integration of respondent-driven sampling (RDS) and strong peer support groups as a mechanism for identifying high-risk PWID and linking them to services. The peer support staff performed the key tasks that required building and maintaining trust with the participants, including recruiting the RDS seeds, greeting and registering participants at the research site, taking electronic copies of participant fingerprints (to prevent multiple participation in the study), and conducting urinalyses. A 6-month cohort study with 250 participants followed the RDS cross-sectional study. The peer support staff maintained contact with these participants, tracking them if they missed appointments, and providing assistance in accessing methadone and ART. The RDS recruitment was quite rapid, with 603 participants recruited in three weeks. HIV prevalence was 25%, Hepatitis C (HCV) prevalence 67%, and participants reported an average of 2.7 heroin injections per day. Retention in the cohort study was high, with 86% of participants re-interviewed at 6-month follow-up. Assistance in accessing services led to half of the participants in need of methadone enrolled in methadone clinics, and half of HIV-positive participants in need of ART enrolled in HIV clinics by the 6-month follow-up. This study suggests that integrating large-scale RDS and strong peer support may provide a method for rapidly linking high-risk PWID to combined prevention and care, and

  4. A bit serial sequential circuit

    NASA Technical Reports Server (NTRS)

    Hu, S.; Whitaker, S.

    1990-01-01

    Normally a sequential circuit with n state variables consists of n unique hardware realizations, one for each state variable. All variables are processed in parallel. This paper introduces a new sequential circuit architecture that allows the state variables to be realized in a serial manner using only one next state logic circuit. The action of processing the state variables in a serial manner has never been addressed before. This paper presents a general design procedure for circuit construction and initialization. Utilizing pass transistors to form the combinational next state forming logic in synchronous sequential machines, a bit serial state machine can be realized with a single NMOS pass transistor network connected to shift registers. The bit serial state machine occupies less area than other realizations which perform parallel operations. Moreover, the logical circuit of the bit serial state machine can be modified by simply changing the circuit input matrix to develop an adaptive state machine.

  5. Universality of sequential quantum measurements

    NASA Astrophysics Data System (ADS)

    Heinosaari, Teiko; Miyadera, Takayuki

    2015-02-01

    We show that any jointly measurable pair of quantum observables can be obtained in a sequential measurement scheme, even if the second observable will be decided after the first measurement. This means that it is possible to perform a measurement of any quantum observable in a way that does not disturb the subsequent measurements more than is dictated by joint measurability. Only measurements with a specific structure have this universality feature. As a supplementing result, we provide a characterization of all possible joint measurements obtained from a sequential measurement lacking universality.

  6. Astragalus polysaccharide injection integrated with vinorelbine and cisplatin for patients with advanced non-small cell lung cancer: effects on quality of life and survival.

    PubMed

    Guo, Li; Bai, Shu-Ping; Zhao, Ling; Wang, Xiao-Hong

    2012-09-01

    A platinum-based two-drug regimen is currently the standard of care for patients with advanced non-small-cell lung cancer (NSCLC). However, chemotherapy-induced side effects still remain a significant clinical problem. Astragalus polysaccharide (APS) is a polysaccharide isolated from the radix of astragalus membranaceus, a commonly used herbal compound in traditional Chinese medicine. APS was reported to increase tumor response, stabilize and improve performance status, and reduce chemotherapy toxicity. We designed this trial to determine whether APS injection integrated with vinorelbine and cisplatin (VC) offered an improved QOL over VC for patients with advanced NSCLC. Secondary objectives were tumor response, toxicity, and survival results. One hundred thirty-six patients with histologically or cytologically confirmed NSCLC were enrolled in this study from May 2008 to March 2010. Patients were randomized to receive either VC (VC arm) or VC combined with APS (VC-APS arm). The objective response rate of was 42.64% in the VC-APS arm and 36.76% in the VC arm. The difference was not statistically significant (P = 0.483). Median survival time was 10.7 and 10.2 months (P = 0.76) in VC-APS arm and VC arm, with 1-year survival rates of 35.3 and 32.4% (P = 0.717), respectively. After 3 cycles of treatment, there were significant differences in the overall patient QOL (P = 0.003), physical function (P = 0.01), fatigue (P < 0.001), nausea and vomiting (P < 0.001), pain (P = 0.007), and loss of appetite (P = 0.023) between the two study groups. In summary, we have proved that the treatment of APS integrated with VC had significantly improved QOL in patients with advanced NSCLC compared with VC alone. PMID:21928106

  7. Integrating candidate metabolites and biochemical factors to elucidate the action mechanism of Xue-sai-tong injection based on (1)H NMR metabolomics.

    PubMed

    Jiang, Miaomiao; Zhao, Xiaoping; Wang, Linli; Xu, Lei; Zhang, Yan; Li, Zheng

    2016-07-15

    A strategy of integrating candidate metabolites with crucial biochemical factors was proposed in this study to discover relevant biological functions for interpreting the action mechanism of Traditional Chinese Medicines (TCM). This approach was applied to Xue-Sai-Tong injection (XST) to reveal the action mechanism based on the metabolic response in an ischemia/reperfusion (I/R) rat model by analyzing NMR profile. Partial least squares discriminate analysis (PLS-DA) was used to compare metabolic profiles of serum samples and revealed nine metabolites altered by I/R injury could be restored to normal status (sham-operated group) under the therapy of XST. The pathway enrichment analysis suggested the metabolic changes were mainly involved in pyruvate metabolism, glycolysis, and citrate cycle. The functional roles of the candidate metabolites were further identified by Pearson correlation analysis with the key biochemical factors in serum. The results indicated pyruvate, succinate, acetate and lysine showed significant associations with the oxidative stress factors. Elevated level of pyruvate was found as an essential metabolic response for the major effect of XST against I/R injury by enhancing glycolysis and overcoming the induced reactive oxygen species (ROS). This metabolomics approach provides a better understanding of the mechanisms of TCM and helps to develop a holistic view of TCM efficacy. PMID:26862062

  8. Evaluating the integrity of the reinforced concrete structure repaired by epoxy injection using simulated transfer function of impact-echo response

    SciTech Connect

    Cheng, Chia-Chi; Yu, Chih-peng; Wu, Jiunn-Hong; Hsu, Keng-Tsan; Ke, Ying-Tsu

    2014-02-18

    Cracks and honeycombs are often found inside reinforced concrete (RC) structure caused by excessive external force, or improper casting of concrete. The repairing method usually involves epoxy injection. The impact-echo method, which is a sensitive for detecting of the interior voids, may not be applicable to assess the integrity of the repaired member as both air and epoxy are less in acoustic impedances. In this study, the repaired RC structure was evaluated by the simulated transfer function of the IE displacement waveform where the R-wave displacement waveform is used as a base of a simulated force-time function. The effect of different thickness of the epoxy layer to the amplitude corresponding to the interface is studied by testing on specimen containing repaired naturally delaminated cracks with crack widths about 1 mm, 3 mm and 5 mm. The impact-echo responses were compared with the drilling cores at the test positions. The results showed the cracks were not fully filled with epoxy when the peak amplitude corresponding to the interface dropped less than 20%. The peak corresponding to the thicker epoxy layer tends to be larger in amplitude. A field study was also performed on a column damaged by earthquake before and after repairing.

  9. Lacosamide Injection

    MedlinePlus

    ... may be prescribed for other uses; ask your doctor or pharmacist for more information. ... Before using lacosamide injection,tell your doctor and pharmacist if you are allergic to lacosamide, any other medications, or any of the ingredients in lacosamide injection. Ask your pharmacist for a ...

  10. Dexamethasone Injection

    MedlinePlus

    ... lines under the skin skin depressions at the injection site increased body fat or movement to different areas of your body inappropriate happiness difficulty falling asleep or staying asleep extreme ... increased appetite injection site pain or redness Some side effects can ...

  11. Etanercept Injection

    MedlinePlus

    ... and colorless. The liquid may contain small white particles, but should not contain large or colored particles. Do not use a syringe or dosing pen ... liquid is cloudy or contains large or colored particles.The best place to inject etanercept injection is ...

  12. Pralatrexate Injection

    MedlinePlus

    ... you that you will need to receive a vitamin B12 injection no more than 10 weeks before your first ... tests to check your body's response to pralatrexate injection.Ask your ... such as vitamins, minerals, or other dietary supplements. You should bring ...

  13. Leucovorin Injection

    MedlinePlus

    ... lack of vitamin B12 or inability to absorb vitamin B12. Your doctor will not prescribe leucovorin injection to treat this type of anemia.tell your ... tests to check your body's response to leucovorin injection.It is ... such as vitamins, minerals, or other dietary supplements. You should bring ...

  14. Musculoskeletal Injection

    PubMed Central

    Wittich, Christopher M.; Ficalora, Robert D.; Mason, Thomas G.; Beckman, Thomas J.

    2009-01-01

    Patients commonly present to primary care physicians with musculoskeletal symptoms. Clinicians certified in internal medicine must be knowledgeable about the diagnosis and management of musculoskeletal diseases, yet they often receive inadequate postgraduate training on this topic. The musculoskeletal problems most frequently encountered in our busy injection practice involve, in decreasing order, the knees, trochanteric bursae, and glenohumeral joints. This article reviews the clinical presentations of these problems. It also discusses musculoskeletal injections for these problems in terms of medications, indications, injection technique, and supporting evidence from the literature. Experience with joint injection and the pharmacological principles described in this article should allow primary care physicians to become comfortable and proficient with musculoskeletal injections. PMID:19720781

  15. Sequential Effects in Essay Ratings

    ERIC Educational Resources Information Center

    Attali, Yigal

    2011-01-01

    Contrary to previous research on sequential ratings of student performance, this study found that professional essay raters of a large-scale standardized testing program produced ratings that were drawn toward previous ratings, creating an assimilation effect. Longer intervals between the two adjacent ratings and higher degree of agreement with…

  16. Sequential Processes In Image Generation.

    ERIC Educational Resources Information Center

    Kosslyn, Stephen M.; And Others

    1988-01-01

    Results of three experiments are reported, which indicate that images of simple two-dimensional patterns are formed sequentially. The subjects included 48 undergraduates and 16 members of the Harvard University (Cambridge, Mass.) community. A new objective methodology indicates that images of complex letters require more time to generate. (TJH)

  17. Fuel injection

    SciTech Connect

    Iiyoshi, A.; Vogoshi, S.

    1983-12-01

    The Plasma Physics Laboratory and the Dept. of Electrical Engineering report on three types of pellet injectors which have different applications: injection of a pellet into a magnetic bottle for magnetic confinement; injection of a pellet into a vacuum chamber for an inertial confinement experiment; and injection of a pellet into a magnetic bottle where the pellet is ionized by high-power laser irradiation for target plasma production. The requirements of pellet injectors are summarized in a table. Theoretical studies on pellet ablation in hot plasma and ablated particle diffusion are underway.

  18. Ganciclovir Injection

    MedlinePlus

    ... injection is for intravenous (into a vein) use only. Giving ganciclovir through intramuscular (into a muscle) or ... the storage of ganciclovir solution. Store your medication only as directed. Make sure you understand what you ...

  19. Methylnaltrexone Injection

    MedlinePlus

    ... injection is used to treat constipation caused by opioid (narcotic) pain medications in patients with advanced illnesses ... a class of medications called peripherally acting mu-opioid receptor antagonists. It works by protecting the bowel ...

  20. Dexamethasone Injection

    MedlinePlus

    ... severe allergic reactions. It is used in the management of certain types of edema (fluid retention and ... needed for normal body functioning) and in the management of certain types of shock. Dexamethasone injection is ...

  1. Pembrolizumab Injection

    MedlinePlus

    ... treat a certain type of non-small-cell lung cancer that has spread to nearby tissues or to ... successfully with other medications for non-small-cell lung cancer. Pembrolizumab injection is in a class of medications ...

  2. Ibandronate Injection

    MedlinePlus

    ... Ibandronate is in a class of medications called bisphosphonates. It works by preventing bone breakdown and increasing ... while receiving this medication.Being treated with a bisphosphonate medication such as ibandronate injection for osteoporosis may ...

  3. Omalizumab Injection

    MedlinePlus

    ... asthma attacks (sudden episodes of wheezing, shortness of breath, and trouble breathing) in people with allergic asthma ( ... receiving a dose of omalizumab injection shortness of breath coughing up blood skin sores severe pain, numbness ...

  4. Necitumumab Injection

    MedlinePlus

    ... chest pain; shortness of breath; dizziness; loss of consciousness; or fast, irregular, or pounding heartbeat.Keep all appointments with your doctor and the laboratory.Talk to your doctor about the risks of receiving necitumumab injection.

  5. Dolasetron Injection

    MedlinePlus

    ... receiving cancer chemotherapy medications. Dolasetron is in a class of medications called serotonin 5-HT3 receptor antagonists. ... stiff or twitching muscles seizures coma (loss of consciousness) Dolasetron injection may cause other side effects. Call ...

  6. Topotecan Injection

    MedlinePlus

    ... also used together with other medications to treat cervical cancer (cancer that begins in the opening of the ... days. When topotecan injection is used to treat cervical cancer, it is usually given once a day for ...

  7. Ertapenem Injection

    MedlinePlus

    Ertapenem injection is used to treat certain serious infections, including pneumonia and urinary tract, skin, diabetic foot, ... for the prevention of infections following colorectal surgery. Ertapenem is in a class of medications called carbapenem ...

  8. Octreotide Injection

    MedlinePlus

    ... immediate-release injection is also used to control diarrhea and flushing caused by carcinoid tumors (slow-growing ... symptoms are severe or do not go away: diarrhea constipation pale, bulky, foul-smelling stools constantly feeling ...

  9. Infliximab Injection

    MedlinePlus

    ... injection may cause serious allergic reactions during an infusion and for 2 hours afterward. A doctor or ... the following symptoms during or shortly after your infusion: hives; rash; itching; swelling of the face, eyes, ...

  10. Vedolizumab Injection

    MedlinePlus

    ... injection may cause serious allergic reactions during an infusion and for several hours afterward. A doctor or ... of the following symptoms during or after your infusion: rash; itching; swelling of the face, eyes, mouth, ...