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Sample records for voltammetry cv scanning

  1. Ultramicroelectrode voltammetry and scanning electrochemical microscopy in room-temperature ionic liquid electrolytes.

    Science.gov (United States)

    Walsh, Darren A; Lovelock, Kevin R J; Licence, Peter

    2010-11-01

    The high viscosity and unusual properties of room temperature ionic liquids (RTILs) present a number of challenges when performing steady-state voltammetry and scanning electrochemical microscopy in RTILs. These include difficulties in recording steady-state currents at ultramicroelectrode surfaces due to low diffusion coefficients of redox species and problems associated with unequal diffusion coefficients of oxidised and reduced species in RTILs. In this tutorial review, we highlight the recent progress in the use of RTILs as electrolytes for ultramicroelectrode voltammetry and SECM. We describe the basic principles of ultramicroelectrode voltammetry and SECM and, using examples from the recent literature, we discuss the conditions that must be met to perform steady-state voltammetry and SECM measurements in RTILs. Finally, we briefly discuss the electrochemical insights that can be obtained from such measurements.

  2. Voltammetry and in situ scanning tunnelling spectroscopy of osmium, iron, and ruthenium complexes of 2,2′:6′,2′′-terpyridine covalently linked to Au(111)-electrodes

    DEFF Research Database (Denmark)

    Salvatore, Princia; Hansen, Allan Glargaard; Moth-Poulsen, Kasper

    2011-01-01

    prepared in situ by first linking the terpy ligand to the surface via the S-atom, followed by addition of suitable metal compounds. The metal-terpy SAMs were studied by cyclic voltammetry (CV), and in situ scanning tunnelling microscopy with full electrochemical potential control of substrate and tip (in...

  3. Simultaneous measurement and quantitation of 4-hydroxyphenylacetic acid and dopamine with fast-scan cyclic voltammetry.

    Science.gov (United States)

    Shin, Mimi; Kaplan, Sam V; Raider, Kayla D; Johnson, Michael A

    2015-05-07

    Caged compounds have been used extensively to investigate neuronal function in a variety of preparations, including cell culture, ex vivo tissue samples, and in vivo. As a first step toward electrochemically measuring the extent of caged compound photoactivation while also measuring the release of the catecholamine neurotransmitter, dopamine, fast-scan cyclic voltammetry at carbon-fiber microelectrodes (FSCV) was used to electrochemically characterize 4-hydroxyphenylacetic acid (4HPAA) in the absence and presence of dopamine. 4HPAA is a by-product formed during the process of photoactivation of p-hydroxyphenacyl-based caged compounds, such as p-hydroxyphenylglutamate (pHP-Glu). Our data suggest that the oxidation of 4HPAA occurs through the formation of a conjugated species. Moreover, we found that a triangular waveform of -0.4 V to +1.3 V to -0.4 V at 600 V s(-1), repeated every 100 ms, provided an oxidation current of 4HPAA that was enhanced with a limit of detection of 100 nM, while also allowing the detection and quantitation of dopamine within the same scan. Along with quantifying 4HPAA in biological preparations, the results from this work will allow the electrochemical measurement of photoactivation reactions that generate 4HPAA as a by-product as well as provide a framework for measuring the photorelease of electroactive by-products from caged compounds that incorporate other chromophores.

  4. Elimination Voltammetry with Linear Scan as a New Detection Method for DNA Sensors

    Directory of Open Access Journals (Sweden)

    Rene Kizek

    2005-11-01

    Full Text Available The paper describes successful coupling of adsorptive transfer stripping (AdTS andelimination voltammetry with linear scan (EVLS for the resolution of reduction signals of cytosine (Cand adenine (A residues in hetero-oligodeoxynucleotides (ODNs. Short ODNs (9-mers and 20-merswere adsorbed from a small volume on a hanging mercury drop electrode (HMDE. After washing ofthe ODN-modified electrode by water and its transferring to an electrochemical cell, voltammetric curves were measured. The AdTS EVLS was able to determine of C/A ratio of ODNs through theelimination function conserving the diffusion current component and eliminating kinetic and chargingcurrent components. This function, which provides the elimination signal in a peak-counterpeak form,increased the current sensitivity for A and C resolution, and for the recognition of bases sequences inODN chains. Optimal conditions of elimination experiments such as pH, time of adsorption, and scanrate were found. The combination of EVLS with AdTS procedure can be considered as a newdetection method in a DNA sensor.

  5. Characterisation of biosynthesised silver nanoparticles by scanning electrochemical microscopy (SECM) and voltammetry.

    Science.gov (United States)

    Battistel, Dario; Baldi, Franco; Gallo, Michele; Faleri, Claudia; Daniele, Salvatore

    2015-01-01

    Silver nanoparticles (AgNPs) were biosynthesised by a Klebsiella oxytoca strain BAS-10, which, during its growth, is known to produce a branched exopolysaccharide (EPS). Klebsiella oxytoca cultures, treated with AgNO3 and grown under either aerobic or anaerobic conditions, produced silver nanoparticles embedded in EPS (AgNPs-EPS) containing different amounts of Ag(0) and Ag(I) forms. The average size of the AgNPs-EPS was determined by transmission electron microscopy, while the relative abundance of Ag(0)- or Ag(I)-containing AgNPs-EPS was established by scanning electrochemical microscopy (SECM). Moreover, the release of silver(I) species from the various types of AgNPs-EPS was investigated by combining SECM with anodic stripping voltammetry. These measurements allowed obtaining information on the kinetic of silver ions release from AgNPs-EPS and their concentration profiles at the substrate/water interface. Copyright © 2014 Elsevier B.V. All rights reserved.

  6. Voltammetry and In Situ Scanning Tunneling Microscopy of Cytochrome c Nitrite Reductase on Au(111)-Electrodes

    DEFF Research Database (Denmark)

    Gwyer, James; Zhang, Jingdong; Butt, Julea

    2006-01-01

    of the density and orientational distribution of NrfA molecules are disclosed. The submonolayer coverage resolved by in situ STM is readily reconciled with the failure to detect nonturnover signals in cyclic voltammetry of the NrfA films. The molecular structures show a range of lateral dimensions...... a direct approach to correlate electrocatalytic and molecular properties of the protein layer, a long-standing issue in protein film voltammetry....

  7. Fast-scan cyclic voltammetry (FSCV) detection of endogenous octopamine in Drosophila melanogaster ventral nerve cord

    Science.gov (United States)

    Pyakurel, Poojan; Privman, Eve; Venton, B. Jill

    2016-01-01

    Octopamine is an endogenous biogenic amine neurotransmitter, neurohormone, and neuromodulator in invertebrates, and has functional analogy with norepinephrine in vertebrates. Fast-scan cyclic voltammetry (FSCV) can detect rapid changes in neurotransmitters, but FSCV has not been optimized for octopamine detection in situ. The goal of this study was to characterize octopamine release in the ventral nerve cord of Drosophila larvae for the first time. An FSCV waveform was optimized so that the potential for octopamine oxidation would not be near the switching potential where interferences can occur. Endogenous octopamine release was stimulated by genetically inserting either the ATP sensitive channel, P2X2, or the red-light sensitive channelrhodopsin, CsChrimson, into cells expressing tyrosine decarboxylase (TDC), an octopamine synthesis enzyme. To ensure that release is due to octopamine and not the precursor tyramine, the octopamine synthesis inhibitor disulfiram was applied, and the signal decreased by 80%. Stimulated release was vesicular and a 2 s continuous light stimulation of CsChrimson evoked 0.22 ± 0.03 μM of octopamine release in the larval VNC. Repeated stimulations were stable with 2 or 5 minutes interstimulation times. With pulsed stimulations, the release was dependent on the frequency of applied light pulse. An octopamine transporter has not been identified, and blockers of the dopamine transporter and serotonin transporter had no significant effect on the clearance time of octopamine, suggesting they do not take up octopamine. This study shows that octopamine can be monitored in Drosophila, facilitating future studies of how octopamine release functions in the insect brain. PMID:27326831

  8. Development and Characterization of Carbon-Fiber Microbiosensors for Fast-Scan Cyclic Voltammetry

    Science.gov (United States)

    Lugo-Morales, Leyda Zoraida

    Electrochemistry has been shown to be a robust tool in neuroscience. The use of carbon-fiber microelectrodes coupled with background-subtracted fast-scan cyclic voltammetry (FSCV) offers high sensitivity, selectivity, as well as the spatial and temporal resolution necessary for monitoring rapid fluctuations of electroactive molecules in live brain tissue. Dopamine (DA) is a neurotransmitter playing a key role in the regulation of reward and motivated behavior. FSCV has been used to understand DA dynamics and how these underlie discrete aspects of brain function. The methodological aspects of real-time DA detection at carbon-fiber microelectrodes using FSCV in anesthetized and awake animals are presented. Furthermore, the combination of FSCV with other neuroanalytical techniques is also explained. The advantages of FSCV and carbon-fiber microelectrodes can be expanded to the detection of non-electroactive analytes. This broadens the scope of FSCV such that it can be used to investigate how changes in non-electroactive chemicals underlie disease, cognition, and behavior. Carbon-fiber microelectrodes can be modified with an enzyme to monitor non-electroactive molecules, generating an electroactive product (usually hydrogen peroxide, H2O2). The first voltammetric detection of H2O 2 at bare carbon-fiber microelectrodes using FSCV has recently been reported. Thus, an avenue exists to utilize FSCV at enzyme-modified microelectrodes to voltammetrically identify and quantify non-electroactive analytes in real-time. Such an approach will overcome many limitations associated with the traditional amperometric detection scheme, which lacks electrochemical selectivity. Electrodeposition of the biopolymer chitosan with glucose oxidase (GOx) at the carbon surface yields a stable, sensitive, and selective glucose microbiosensor that has been utilized to detect glucose fluctuations in vivo with unprecedented speed. This new method has revealed the first rapid glucose fluctuations in

  9. Quasi-steady-state voltammetry of rapid electron transfer reactions at the macroscopic substrate of the scanning electrochemical microscope.

    Science.gov (United States)

    Nioradze, Nikoloz; Kim, Jiyeon; Amemiya, Shigeru

    2011-02-01

    We report on a novel theory and experiment for scanning electrochemical microscopy (SECM) to enable quasi-steady-state voltammetry of rapid electron transfer (ET) reactions at macroscopic substrates. With this powerful approach, the substrate potential is cycled widely across the formal potential of a redox couple while the reactant or product of a substrate reaction is amperometrically detected at the tip in the feedback or substrate generation/tip collection mode, respectively. The plot of tip current versus substrate potential features the retraceable sigmoidal shape of a quasi-steady-state voltammogram although a transient voltammogram is obtained at the macroscopic substrate. Finite element simulations reveal that a short tip-substrate distance and a reversible substrate reaction (except under the tip) are required for quasi-steady-state voltammetry. Advantageously, a pair of quasi-steady-state voltammograms is obtained by employing both operation modes to reliably determine all transport, thermodynamic, and kinetic parameters as confirmed experimentally for rapid ET reactions of ferrocenemethanol and 7,7,8,8-tetracyanoquinodimethane at a Pt substrate with ∼0.5 μm-radius Pt tips positioned at 90 nm-1 μm distances. Standard ET rate constants of ∼7 cm/s were obtained for the latter mediator as the largest determined for a substrate reaction by SECM. Various potential applications of quasi-steady-state voltammetry are also proposed.

  10. Thorium effect on the oxidation of uranium: Photoelectron spectroscopy (XPS/UPS) and cyclic voltammetry (CV) investigation on (U1 − xThx)O2 (x = 0 to 1) thin films

    NARCIS (Netherlands)

    Cakir, P.; Eloirdi, R; Huber, F.; Konings, R.J.M.; Gouder, T

    2017-01-01

    Thin films of U1− xThxO2 (x = 0 to 1) have been deposited via reactive DC sputter technique and characterized by X-ray/Ultra-violet Photoelectron Spectroscopy (XPS/UPS), X-ray Powder Diffractometer (XRD) and Cyclic Voltammetry (CV) in order to understand the

  11. A combined SEM, CV and EIS study of multi-layered porous ceramic reactors for flue gas purification

    DEFF Research Database (Denmark)

    He, Zeming; Andersen, Kjeld Bøhm; Nygaard, Frederik Berg

    2013-01-01

    The effect of sintering temperature of 12-layered porous ceramic reactors (comprising 5 cells) was studied using scanning electron microscopy (SEM), cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS). The difference in microstructures of the reactors was evaluated by SEM...

  12. Cyclic voltammetry and scanning electrochemical microscopy studies of methylene blue immobilized on the self-assembled monolayer of n-dodecanethiol

    International Nuclear Information System (INIS)

    Salamifar, Seyed Ehsan; Mehrgardi, Masoud Ayatollahi; Kazemi, Sayed Habib; Mousavi, Mir Fazllollah

    2010-01-01

    Electron transfer (ET) kinetics through n-dodecanethiol (C 12 SH) self-assembled monolayer on gold electrode was studied using cyclic voltammetry (CV), scanning electrochemical microscopy (SECM) and electrochemical impedance spectroscopy (EIS). An SECM model for compensating pinhole contribution, was used to measure the ET kinetics of solution-phase probes of ferrocyanide/ferricyanide (Fe(CN) 6 4-/3- ) and ferrocenemethanol/ferrociniummethanol (FMC 0/+ ) through the C 12 SH monolayer yielding standard tunneling rate constant (k ET 0 ) of (4 ± 1) x 10 -11 and (3 ± 1) x 10 -10 cm s -1 for Fe(CN) 6 4-/3- and FMC 0/+ respectively. Decay tunneling constants (β) of 0.97 and 0.96 A -1 for saturated alkane thiol chains were obtained using Fe(CN) 6 4- and FMC respectively. Also, it was found that methylene blue (MB) molecules are effectively immobilized on the C 12 SH monolayer and can mediate the ET between the solution-phase probes and underlying gold substrate. SECM-mediated model was used to simultaneously measure the bimolecular ET between the solution-phase probes and the monolayer-immobilized MB molecules, as well as tunneling ET between the monolayer-immobilized MB molecules and the underlying gold electrode, allowing the measurement of k BI = (5 ± 1) x 10 6 and (4 ± 2) x 10 7 cm 3 mol -1 s -1 for the bimolecular ET and k ET/MB 0 =(1±0.3)x10 -3 and (7 ± 3) x 10 -2 s -1 for the standard tunneling rate constant of ET using Fe(CN) 6 4-/3- and FMC 0/+ probes respectively.

  13. Cyclic voltammetry and scanning electrochemical microscopy studies of methylene blue immobilized on the self-assembled monolayer of n-dodecanethiol

    Energy Technology Data Exchange (ETDEWEB)

    Salamifar, Seyed Ehsan [Department of Chemistry, Tarbiat Modares University, P.O. Box 14115-175, Tehran (Iran, Islamic Republic of); Mehrgardi, Masoud Ayatollahi [Department of Chemistry, University of Isfahan, Isfahan (Iran, Islamic Republic of); Kazemi, Sayed Habib [Department of Chemistry, Institute for Advanced Studies in Basic Sciences (IASBS), Zanjan (Iran, Islamic Republic of); Mousavi, Mir Fazllollah, E-mail: mousavim@modares.ac.i [Department of Chemistry, Tarbiat Modares University, P.O. Box 14115-175, Tehran (Iran, Islamic Republic of)

    2010-12-30

    Electron transfer (ET) kinetics through n-dodecanethiol (C{sub 12}SH) self-assembled monolayer on gold electrode was studied using cyclic voltammetry (CV), scanning electrochemical microscopy (SECM) and electrochemical impedance spectroscopy (EIS). An SECM model for compensating pinhole contribution, was used to measure the ET kinetics of solution-phase probes of ferrocyanide/ferricyanide (Fe(CN){sub 6}{sup 4-/3-}) and ferrocenemethanol/ferrociniummethanol (FMC{sup 0/+}) through the C{sub 12}SH monolayer yielding standard tunneling rate constant (k{sub ET}{sup 0}) of (4 {+-} 1) x 10{sup -11} and (3 {+-} 1) x 10{sup -10} cm s{sup -1} for Fe(CN){sub 6}{sup 4-/3-} and FMC{sup 0/+} respectively. Decay tunneling constants ({beta}) of 0.97 and 0.96 A{sup -1} for saturated alkane thiol chains were obtained using Fe(CN){sub 6}{sup 4-} and FMC respectively. Also, it was found that methylene blue (MB) molecules are effectively immobilized on the C{sub 12}SH monolayer and can mediate the ET between the solution-phase probes and underlying gold substrate. SECM-mediated model was used to simultaneously measure the bimolecular ET between the solution-phase probes and the monolayer-immobilized MB molecules, as well as tunneling ET between the monolayer-immobilized MB molecules and the underlying gold electrode, allowing the measurement of k{sub BI} = (5 {+-} 1) x 10{sup 6} and (4 {+-} 2) x 10{sup 7} cm{sup 3} mol{sup -1} s{sup -1} for the bimolecular ET and k{sub ET/MB}{sup 0}=(1{+-}0.3)x10{sup -3} and (7 {+-} 3) x 10{sup -2} s{sup -1} for the standard tunneling rate constant of ET using Fe(CN){sub 6}{sup 4-/3-} and FMC{sup 0/+} probes respectively.

  14. Trace metal characterization and speciation in geothermal effluent by multiple scanning anodic stripping voltammetry and atomic absorption analysis

    Energy Technology Data Exchange (ETDEWEB)

    Kowalski, B.R.

    1979-05-25

    Recent studies have shown geothermal power plants to have a significant environmental impact on the ground water of the area. The heavy metals arsenic and mercury are special problems, as both are concentrated by flora and fauna exposed to the effluent waters. Because the toxicity of these and other metallic pollutants present in geothermal effluent depends on the chemical form, or speciation, of the particular metal, any serious study of the environmental impact of a geothermal development should include studies of trace metal speciation, in addition to trace metal concentration. This proposal details a method for determining metal speciation in dilute waters. The method is based on ion-exchange and backed by atomic absorption spectrometry and multiple scanning anodic stripping voltammetry. Special laboratory studies will be performed on mercury, arsenic and selenium speciation in synthetic geothermal water. The method will be applied to three known geothermal areas in Washington and Oregon, with emphasis on the speciation of mercury, arsenic and selenium in these waters. The computer controlled electrochemical instrumentation was built and tested. Using this instrumentation, a new experimental procedure was developed to determine the chemical form (speciation) of metal ions in very dilute solutions (ng/ml). This method was tested on model systems including Pb, Cd, and As with C1/sup -/, CO/sub 3//sup 2 -/ and glycine ligands. Finally, the speciation of lead in a geothermal water was examined and the PbC1/sup +/ complex was observed and quantified.

  15. Impulse radio ultra wideband wireless transmission of dopamine concentration levels recorded by fast-scan cyclic voltammetry.

    Science.gov (United States)

    Ebrazeh, Ali; Bozorgzadeh, Bardia; Mohseni, Pedram

    2015-01-01

    This paper demonstrates the feasibility of utilizing impulse radio ultra wideband (IR-UWB) signaling technique for reliable, wireless transmission of dopamine concentration levels recorded by fast-scan cyclic voltammetry (FSCV) at a carbon-fiber microelectrode (CFM) to address the problem of elevated data rates in high-channel-count neurochemical monitoring. Utilizing an FSCV-sensing chip fabricated in AMS 0.35μm 2P/4M CMOS, a 3-5-GHz, IR-UWB transceiver (TRX) chip fabricated in TSMC 90nm 1P/9M RF CMOS, and two off-chip, miniature, UWB antennae, wireless transfer of pseudo-random binary sequence (PRBS) data at 50Mbps over a distance of wireless transmission of dopamine concentration levels prerecorded with FSCV at a CFM during flow injection analysis (FIA) is also demonstrated with transmitter (TX) power dissipation of only ~4.4μW from 1.2V, representing two orders of magnitude reduction in TX power consumption compared to that of a conventional frequency-shift-keyed (FSK) link operating at ~433MHz.

  16. Dopamine Dynamics during Continuous Intracranial Self-Stimulation: Effect of Waveform on Fast-Scan Cyclic Voltammetry Data

    Science.gov (United States)

    2016-01-01

    The neurotransmitter dopamine is heavily implicated in intracranial self-stimulation (ICSS). Many drugs of abuse that affect ICSS behavior target the dopaminergic system, and optogenetic activation of dopamine neurons is sufficient to support self-stimulation. However, the patterns of phasic dopamine release during ICSS remain unclear. Early ICSS studies using fast-scan cyclic voltammetry (FSCV) rarely observed phasic dopamine release, which led to the surprising conclusion that it is dissociated from ICSS. However, several advances in the sensitivity (i.e., the use of waveforms with extended anodic limits) and analysis (i.e., principal component regression) of FSCV measurements have made it possible to detect smaller, yet physiologically relevant, dopamine release events. Therefore, this study revisits phasic dopamine release during ICSS using these tools. It was found that the anodic limit of the voltammetric waveform has a substantial effect on the patterns of dopamine release observed during continuous ICSS. While data collected with low anodic limits (i.e., +1.0 V) support the disappearance of phasic dopamine release observed in previous investigation, the use of high anodic limits (+1.3 V, +1.4 V) allows for continual detection of dopamine release throughout ICSS. However, the +1.4 V waveform lacks the ability to resolve narrowly spaced events, with the best balance of temporal resolution and sensitivity provided by the +1.3 V waveform. Ultimately, it is revealed that the amplitude of phasic dopamine release decays but does not fully disappear during continuous ICSS. PMID:27548680

  17. Measurement of the ground-state distributions in bistable mechanically interlocked molecules using slow scan rate cyclic voltammetry.

    Science.gov (United States)

    Fahrenbach, Albert C; Barnes, Jonathan C; Li, Hao; Benítez, Diego; Basuray, Ashish N; Fang, Lei; Sue, Chi-Hau; Barin, Gokhan; Dey, Sanjeev K; Goddard, William A; Stoddart, J Fraser

    2011-12-20

    In donor-acceptor mechanically interlocked molecules that exhibit bistability, the relative populations of the translational isomers--present, for example, in a bistable [2]rotaxane, as well as in a couple of bistable [2]catenanes of the donor-acceptor vintage--can be elucidated by slow scan rate cyclic voltammetry. The practice of transitioning from a fast scan rate regime to a slow one permits the measurement of an intermediate redox couple that is a function of the equilibrium that exists between the two translational isomers in the case of all three mechanically interlocked molecules investigated. These intermediate redox potentials can be used to calculate the ground-state distribution constants, K. Whereas, (i) in the case of the bistable [2]rotaxane, composed of a dumbbell component containing π-electron-rich tetrathiafulvalene and dioxynaphthalene recognition sites for the ring component (namely, a tetracationic cyclophane, containing two π-electron-deficient bipyridinium units), a value for K of 10 ± 2 is calculated, (ii) in the case of the two bistable [2]catenanes--one containing a crown ether with tetrathiafulvalene and dioxynaphthalene recognition sites for the tetracationic cyclophane, and the other, tetrathiafulvalene and butadiyne recognition sites--the values for K are orders (one and three, respectively) of magnitude greater. This observation, which has also been probed by theoretical calculations, supports the hypothesis that the extra stability of one translational isomer over the other is because of the influence of the enforced side-on donor-acceptor interactions brought about by both π-electron-rich recognition sites being part of a macrocyclic polyether.

  18. Development of the Wireless Instantaneous Neurotransmitter Concentration System for intraoperative neurochemical monitoring using fast-scan cyclic voltammetry.

    Science.gov (United States)

    Bledsoe, Jonathan M; Kimble, Christopher J; Covey, Daniel P; Blaha, Charles D; Agnesi, Filippo; Mohseni, Pedram; Whitlock, Sidney; Johnson, David M; Horne, April; Bennet, Kevin E; Lee, Kendall H; Garris, Paul A

    2009-10-01

    Emerging evidence supports the hypothesis that modulation of specific central neuronal systems contributes to the clinical efficacy of deep brain stimulation (DBS) and motor cortex stimulation (MCS). Real-time monitoring of the neurochemical output of targeted regions may therefore advance functional neurosurgery by, among other goals, providing a strategy for investigation of mechanisms, identification of new candidate neurotransmitters, and chemically guided placement of the stimulating electrode. The authors report the development of a device called the Wireless Instantaneous Neurotransmitter Concentration System (WINCS) for intraoperative neurochemical monitoring during functional neurosurgery. This device supports fast-scan cyclic voltammetry (FSCV) at a carbon-fiber microelectrode (CFM) for real-time, spatially and chemically resolved neurotransmitter measurements in the brain. The FSCV study consisted of a triangle wave scanned between -0.4 and 1 V at a rate of 300 V/second and applied at 10 Hz. All voltages were compared with an Ag/AgCl reference electrode. The CFM was constructed by aspirating a single carbon fiber (r = 2.5 mum) into a glass capillary and pulling the capillary to a microscopic tip by using a pipette puller. The exposed carbon fiber (that is, the sensing region) extended beyond the glass insulation by approximately 100 microm. The neurotransmitter dopamine was selected as the analyte for most trials. Proof-of-principle tests included in vitro flow injection and noise analysis, and in vivo measurements in urethane-anesthetized rats by monitoring dopamine release in the striatum following high-frequency electrical stimulation of the medial forebrain bundle. Direct comparisons were made to a conventional hardwired system. The WINCS, designed in compliance with FDA-recognized consensus standards for medical electrical device safety, consisted of 4 modules: 1) front-end analog circuit for FSCV (that is, current-to-voltage transducer); 2

  19. CERES BiDirectional Scans (BDS) data in HDF (CER_BDS_Terra-FM1_Edition1-CV)

    Science.gov (United States)

    Wielicki, Bruce A. (Principal Investigator)

    Each BiDirectional Scans (BDS) data product contains twenty-four hours of Level-1b data for each CERES scanner instrument mounted on each spacecraft. The BDS includes samples taken in normal and short Earth scan elevation profiles in both fixed and rotating azimuth scan modes (including space, internal calibration, and solar calibration views). The BDS contains Level-0 raw (unconverted) science and instrument data as well as the geolocated converted science and instrument data. The BDS contains additional data not found in the Level-0 input file, including converted satellite position and velocity data, celestial data, converted digital status data, and parameters used in the radiance count conversion equations. The following CERES BDS data sets are currently available: CER_BDS_TRMM-PFM_Edition1 CER_BDS_Terra-FM1_Edition1 CER_BDS_Terra-FM2_Edition1 CER_BDS_Terra-FM1_Edition2 CER_BDS_Terra-FM2_Edition2 CER_BDS_Aqua-FM3_Edition1 CER_BDS_Aqua-FM4_Edition1 CER_BDS_Aqua-FM3_Edition2 CER_BDS_Aqua-FM4_Edition2 CER_BDS_Aqua-FM3_Edition1-CV CER_BDS_Aqua-FM4_Edition1-CV CER_BDS_Terra-FM1_Edition1-CV CER_BDS_Terra-FM2_Edition1-CV. [Location=GLOBAL] [Temporal_Coverage: Start_Date=1997-12-27; Stop_Date=2006-11-02] [Spatial_Coverage: Southernmost_Latitude=-90; Northernmost_Latitude=90; Westernmost_Longitude=-180; Easternmost_Longitude=180] [Data_Resolution: Temporal_Resolution=1 day; Temporal_Resolution_Range=Daily - < Weekly].

  20. Thorium effect on the oxidation of uranium: Photoelectron spectroscopy (XPS/UPS) and cyclic voltammetry (CV) investigation on (U{sub 1−x}Th{sub x})O{sub 2} (x = 0 to 1) thin films

    Energy Technology Data Exchange (ETDEWEB)

    Cakir, P., E-mail: pelincakir@outlook.com [European Commission, Joint Research Centre, P.O. Box 2340, D-76125, Karlsruhe (Germany); Department of Radiation Science and Technology, Delft University of Technology, Mekelweg 15, 2629, JB Delft (Netherlands); Eloirdi, R.; Huber, F. [European Commission, Joint Research Centre, P.O. Box 2340, D-76125, Karlsruhe (Germany); Konings, R.J.M. [European Commission, Joint Research Centre, P.O. Box 2340, D-76125, Karlsruhe (Germany); Department of Radiation Science and Technology, Delft University of Technology, Mekelweg 15, 2629, JB Delft (Netherlands); Gouder, T. [European Commission, Joint Research Centre, P.O. Box 2340, D-76125, Karlsruhe (Germany)

    2017-01-30

    Highlights: • XRD and XPS data of U{sub x}Th{sub 1-x}O{sub 2} films are in agreement with data obtained on bulk. • Oxygen affinity of thorium is much stronger than uranium. • Oxidation of uranium decreases as a function of thorium in the matrix. • XPS made pre and post CV shows thorium enrichment indicating a protective layer. • Higher initial uranium content is directly proportional to higher oxidation states. - Abstract: Thin films of U{sub 1−x}Th{sub x}O{sub 2} (x = 0 to 1) have been deposited via reactive DC sputter technique and characterized by X-ray/Ultra-violet Photoelectron Spectroscopy (XPS/UPS), X-ray Powder Diffractometer (XRD) and Cyclic Voltammetry (CV) in order to understand the effect of Thorium on the oxidation mechanism. During the deposition, the competition between uranium and thorium for oxidation showed that thorium has a much higher affinity for oxygen. Deposition conditions, time and temperature were also the subject of this study, to look at the homogeneity and the stability of the films. While core level and valence band spectra were not altered by the time of deposition, temperature was affecting the oxidation state of uranium and the valence band due to the mobility increase of oxygen through the film. X-ray diffraction patterns, core level spectra obtained for U{sub 1−x}Th{sub x}O{sub 2} versus the composition showed that lattice parameters follow the Vegard's law and together with the binding energies of U-4f and Th-4f are in good agreement with literature data obtained on bulk compounds. To study the effect of thorium on the oxidation of U{sub 1−x}Th{sub x}O{sub 2} films, we used CV experiments at neutral pH of a NaCl solution in contact with air. The results indicated that thorium has an effect on the uranium oxidation as demonstrated by the decrease of the current of the oxidation peak of uranium. XPS measurements made before and after the CV, showed a relative enrichment of thorium at the extent of uranium at

  1. Integrated wireless fast-scan cyclic voltammetry recording and electrical stimulation for reward-predictive learning in awake, freely moving rats

    Science.gov (United States)

    Li, Yu-Ting; Wickens, Jeffery R.; Huang, Yi-Ling; Pan, Wynn H. T.; Chen, Fu-Yu Beverly; Chen, Jia-Jin Jason

    2013-08-01

    Objective. Fast-scan cyclic voltammetry (FSCV) is commonly used to monitor phasic dopamine release, which is usually performed using tethered recording and for limited types of animal behavior. It is necessary to design a wireless dopamine sensing system for animal behavior experiments. Approach. This study integrates a wireless FSCV system for monitoring the dopamine signal in the ventral striatum with an electrical stimulator that induces biphasic current to excite dopaminergic neurons in awake freely moving rats. The measured dopamine signals are unidirectionally transmitted from the wireless FSCV module to the host unit. To reduce electrical artifacts, an optocoupler and a separate power are applied to isolate the FSCV system and electrical stimulator, which can be activated by an infrared controller. Main results. In the validation test, the wireless backpack system has similar performance in comparison with a conventional wired system and it does not significantly affect the locomotor activity of the rat. In the cocaine administration test, the maximum electrically elicited dopamine signals increased to around 230% of the initial value 20 min after the injection of 10 mg kg-1 cocaine. In a classical conditioning test, the dopamine signal in response to a cue increased to around 60 nM over 50 successive trials while the electrically evoked dopamine concentration decreased from about 90 to 50 nM in the maintenance phase. In contrast, the cue-evoked dopamine concentration progressively decreased and the electrically evoked dopamine was eliminated during the extinction phase. In the histological evaluation, there was little damage to brain tissue after five months chronic implantation of the stimulating electrode. Significance. We have developed an integrated wireless voltammetry system for measuring dopamine concentration and providing electrical stimulation. The developed wireless FSCV system is proven to be a useful experimental tool for the continuous

  2. Two-Dimensional Cysteine and Cystine Cluster Networks on Au(111) Disclosed by Voltammetry and in Situ Scanning Tunneling Microscopy

    DEFF Research Database (Denmark)

    Zhang, Jingdong; Chi, Qijin; Nielsen, Jens Ulrik

    2000-01-01

    Microscopic structures for molecular monolayers of L-cysteine and L-cystine assembled on Au(111) have been disclosed by employing electrochemistry and in situ scanning tunneling microscopy (STM). HighresolutionSTMimages show that the adlayers of both cyteine and cystine exhibit highly......-ordered networklike clusters with (3x3 6)R30° structure. By combining the surface coverage estimated from voltammetric data, each cluster is demonstrated to include six individual cysteine molecules or three cystine molecules. As a comparison, no cluster structure is observed for the 1-butanethiol adlayer prepared...... and examined under the same conditions as those for cysteine and cystine. This suggests that intermolecular and intramolecular hydrogen bonds among adsorbed cysteine or cystine molecules could be responsible for the origin of the cluster-network structures for the adlayers. Several models are proposed and used...

  3. Voltammetry and In Situ Scanning Tunnelling Microscopy of De Novo Designed Heme Protein Monolayers on Au(111)-Electrode Surfaces

    DEFF Research Database (Denmark)

    Albrecht, Tim; Li, Wu; Haehnel, Wolfgang

    2006-01-01

    to the tunnelling current, apparently due to slow electron transfer kinetics. As a consequence, STM images of heme-containing and heme-free MOP-C did not reveal any notable differences in apparent height or physical extension. The apparent height of heme-containing MOP-C did not show any dependence on the substrate...... potential being varied around the redox potential of the protein. The mere presence of an accessible molecular energy level is not sufficient to result in detectable tunnelling current modulation. (c) 2006 Elsevier B.V. All rights reserved.......In the present work, we report the electrochemical characterization and in situ scanning tunnelling microscopy (STM) studies of monolayers of an artificial de novo designed heme protein MOP-C, covalently immobilized on modified Au(111) surfaces. The protein forms closely packed monolayers, which...

  4. Catalytic monolayer voltammetry and in situ scanning tunneling microscopy of copper nitrite reductase on cysteamine-modified Au(111) electrodes

    DEFF Research Database (Denmark)

    Zhang, Jingdong; Welinder, A.C.; Hansen, Allan Glargaard

    2003-01-01

    electrochemical scanning tunneling microscopy (in situ STM) directly in aqueous acetate buffer, pH 6.0 has been used. High-resolution in situ STM shows that cysteamine packs into ordered domains with strip features of a periodic distance of 11.7 +/- 0.3 Angstrom. No voltammetric signals of the nitrite substrate...... on this surface could be detected. A strong cathodic catalytic wave appears in the presence of nitrite. The catalytic current follows a Michaelis-Menten pattern with a Michaelis constant of K-m approximate to 44 muM, which is close to the value for AxCuNiR in homogeneous solution. The apparent catalytic rate...

  5. Stripping Voltammetry

    Science.gov (United States)

    Lovrić, Milivoj

    Electrochemical stripping means the oxidative or reductive removal of atoms, ions, or compounds from an electrode surface (or from the electrode body, as in the case of liquid mercury electrodes with dissolved metals) [1-5]. In general, these atoms, ions, or compounds have been preliminarily immobilized on the surface of an inert electrode (or within it) as the result of a preconcentration step, while the products of the electrochemical stripping will dissolve in the electrolytic solution. Often the product of the electrochemical stripping is identical to the analyte before the preconcentration. However, there are exemptions to these rules. Electroanalytical stripping methods comprise two steps: first, the accumulation of a dissolved analyte onto, or in, the working electrode, and, second, the subsequent stripping of the accumulated substance by a voltammetric [3, 5], potentiometric [6, 7], or coulometric [8] technique. In stripping voltammetry, the condition is that there are two independent linear relationships: the first one between the activity of accumulated substance and the concentration of analyte in the sample, and the second between the maximum stripping current and the accumulated substance activity. Hence, a cumulative linear relationship between the maximum response and the analyte concentration exists. However, the electrode capacity for the analyte accumulation is limited and the condition of linearity is satisfied only well below the electrode saturation. For this reason, stripping voltammetry is used mainly in trace analysis. The limit of detection depends on the factor of proportionality between the activity of the accumulated substance and the bulk concentration of the analyte. This factor is a constant in the case of a chemical accumulation, but for electrochemical accumulation it depends on the electrode potential. The factor of proportionality between the maximum stripping current and the analyte concentration is rarely known exactly. In fact

  6. Orthogonal identification of gunshot residue with complementary detection principles of voltammetry, scanning electron microscopy, and energy-dispersive X-ray spectroscopy: sample, screen, and confirm.

    Science.gov (United States)

    O'Mahony, Aoife M; Samek, Izabela A; Sattayasamitsathit, Sirilak; Wang, Joseph

    2014-08-19

    Field-deployable voltammetric screening coupled with complementary laboratory-based analysis to confirm the presence of gunshot residue (GSR) from the hands of a subject who has handled, loaded, or discharged a firearm is described. This protocol implements the orthogonal identification of the presence of GSR utilizing square-wave stripping voltammetry (SWSV) as a rapid screening tool along with scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDX) to confirm the presence of the characteristic morphology and metal composition of GSR particles. This is achieved through the judicious modification of the working electrode of a carbon screen-printed electrode (CSPE) with carbon tape (used in SEM analysis) to fix and retain a sample. A comparison between a subject who has handled and loaded a firearm and a subject who has had no contact with GSR shows the significant variations in voltammetric signals and the presence or absence of GSR-consistent particles and constituent metals. This initial electrochemical screening has no effect on the integrity of the metallic particles, and SEM/EDX analysis conducted prior to and postvoltammetry show no differences in analytical output. The carbon tape is instrumental in retaining the GSR sample after electrochemical analysis, supported by comparison with orthogonal detection at a bare CSPE. This protocol shows great promise as a two-tier detection system for the presence of GSR from the hands of a subject, whereby initial screening can be conducted rapidly onsite by minimally trained operators; confirmation can follow at the same substrate to substantiate the voltammetric results.

  7. Quantitative roughness characterization and 3D reconstruction of electrode surface using cyclic voltammetry and SEM image

    Energy Technology Data Exchange (ETDEWEB)

    Dhillon, Shweta; Kant, Rama, E-mail: rkant@chemistry.du.ac.in

    2013-10-01

    Area measurements from cyclic voltammetry (CV) and image from scanning electron microscopy (SEM) are used to characterize electrode statistical morphology, 3D surface reconstruction and its electroactivity. SEM images of single phased materials correspond to two-dimensional (2D) projections of 3D structures, leading to an incomplete characterization. Lack of third dimension information in SEM image is circumvented using equivalence between denoised SEM image and CV area measurements. This CV-SEM method can be used to estimate power spectral density (PSD), width, gradient, finite fractal nature of roughness and local morphology of the electrode. We show that the surface morphological statistical property like distribution function of gradient can be related to local electro-activity. Electrode surface gradient micrographs generated here can provide map of electro-activity sites. Finally, the densely and uniformly packed small gradient over the Pt-surface is the determining criterion for high intrinsic electrode activity.

  8. Quantitative roughness characterization and 3D reconstruction of electrode surface using cyclic voltammetry and SEM image

    International Nuclear Information System (INIS)

    Dhillon, Shweta; Kant, Rama

    2013-01-01

    Area measurements from cyclic voltammetry (CV) and image from scanning electron microscopy (SEM) are used to characterize electrode statistical morphology, 3D surface reconstruction and its electroactivity. SEM images of single phased materials correspond to two-dimensional (2D) projections of 3D structures, leading to an incomplete characterization. Lack of third dimension information in SEM image is circumvented using equivalence between denoised SEM image and CV area measurements. This CV-SEM method can be used to estimate power spectral density (PSD), width, gradient, finite fractal nature of roughness and local morphology of the electrode. We show that the surface morphological statistical property like distribution function of gradient can be related to local electro-activity. Electrode surface gradient micrographs generated here can provide map of electro-activity sites. Finally, the densely and uniformly packed small gradient over the Pt-surface is the determining criterion for high intrinsic electrode activity.

  9. Clay matrix voltammetry

    International Nuclear Information System (INIS)

    Perdicakis, Michel

    2012-01-01

    Document available in extended abstract form only. In many countries, it is planned that the long life highly radioactive nuclear spent fuel will be stored in deep argillaceous rocks. The sites selected for this purpose are anoxic and satisfy several recommendations as mechanical stability, low permeability and low redox potential. Pyrite (FeS 2 ), iron(II) carbonate, iron(II) bearing clays and organic matter that are present in very small amounts (about 1% w:w) in soils play a major role in their reactivity and are considered today as responsible for the low redox potential values of these sites. In this communication, we describe an electrochemical technique derived from 'Salt matrix voltammetry' and allowing the almost in-situ voltammetric characterization of air-sensitive samples of soils after the only addition of the minimum humidity required for electrolytic conduction. Figure 1 shows the principle of the developed technique. It consists in the entrapment of the clay sample between a graphite working electrode and a silver counter/quasi-reference electrode. The sample was previously humidified by passing a water saturated inert gas through the electrochemical cell. The technique leads to well-defined voltammetric responses of the electro-active components of the clays. Figure 2 shows a typical voltammogram relative to a Callovo-Oxfordian argillite sample from Bure, the French place planned for the underground nuclear waste disposal. During the direct scan, one can clearly distinguish the anodic voltammetric signals for the oxidation of the iron (II) species associated with the clay and the oxidation of pyrite. The reverse scan displays a small cathodic signal for the reduction of iron (III) associated with the clay that demonstrates that the majority of the previously oxidized iron (II) species were transformed into iron (III) oxides reducible at lower potentials. When a second voltammetric cycle is performed, one can notice that the signal for iron (II

  10. Voltammetry Method Evaluation

    Energy Technology Data Exchange (ETDEWEB)

    Hoyt, N. [Argonne National Lab. (ANL), Argonne, IL (United States); Pereira, C. [Argonne National Lab. (ANL), Argonne, IL (United States); Willit, J. [Argonne National Lab. (ANL), Argonne, IL (United States); Williamson, M. [Argonne National Lab. (ANL), Argonne, IL (United States)

    2016-07-29

    The purpose of the ANL MPACT Voltammetry project is to evaluate the suitability of previously developed cyclic voltammetry techniques to provide electroanalytical measurements of actinide concentrations in realistic used fuel processing scenarios. The molten salts in these scenarios are very challenging as they include high concentrations of multiple electrochemically active species, thereby creating a variety of complications. Some of the problems that arise therein include issues related to uncompensated resistance, cylindrical diffusion, and alloying of the electrodeposited metals. Improvements to the existing voltammetry technique to account for these issues have been implemented, resulting in good measurements of actinide concentrations across a wide range of adverse conditions.

  11. Surface area and pore size characteristics of nanoporous gold subjected to thermal, mechanical, or surface modification studied using gas adsorption isotherms, cyclic voltammetry, thermogravimetric analysis, and scanning electron microscopy

    Science.gov (United States)

    Tan, Yih Horng; Davis, Jason A.; Fujikawa, Kohki; Ganesh, N. Vijaya; Demchenko, Alexei V.

    2012-01-01

    Nitrogen adsorption/desorption isotherms are used to investigate the Brunauer, Emmett, and Teller (BET) surface area and Barrett-Joyner-Halenda (BJH) pore size distribution of physically modified, thermally annealed, and octadecanethiol functionalized np-Au monoliths. We present the full adsorption-desorption isotherms for N2 gas on np-Au, and observe type IV isotherms and type H1 hysteresis loops. The evolution of the np-Au under various thermal annealing treatments was examined using scanning electron microscopy (SEM). The images of both the exterior and interior of the thermally annealed np-Au show that the porosity of all free standing np-Au structures decreases as the heat treatment temperature increases. The modification of the np-Au surface with a self-assembled monolayer (SAM) of C18-SH (coverage of 2.94 × 1014 molecules cm−2 based from the decomposition of the C18-SH using thermogravimetric analysis (TGA)), was found to reduce the strength of the interaction of nitrogen gas with the np-Au surface, as reflected by a decrease in the ‘C’ parameter of the BET equation. From cyclic voltammetry studies, we found that the surface area of the np-Au monoliths annealed at elevated temperatures followed the same trend with annealing temperature as found in the BET surface area study and SEM morphology characterization. The study highlights the ability to control free-standing nanoporous gold monoliths with high surface area, and well-defined, tunable pore morphology. PMID:22822294

  12. Cyclic voltammetry response of an undoped CVD diamond electrodes

    Energy Technology Data Exchange (ETDEWEB)

    Fabisiak, K., E-mail: kfab@ukw.edu.pl [Institute of Physics, Kazimierz Wielki University, Powstancow Wielkopolskich 2, 85-090 Bydgoszcz (Poland); Torz-Piotrowska, R. [Faculty of Chemical Technology and Engineering, UTLS Seminaryjna 3, 85-326 Bydgoszcz (Poland); Staryga, E. [Institute of Physics, Technical University of Lodz, Wolczanska 219, 90-924 Lodz (Poland); Szybowicz, M. [Faculty of Technical Physics, Poznan University of Technology, Nieszawska 13A, 60-965 Poznan (Poland); Paprocki, K.; Popielarski, P.; Bylicki, F. [Institute of Physics, Kazimierz Wielki University, Powstancow Wielkopolskich 2, 85-090 Bydgoszcz (Poland); Wrzyszczynski, A. [Institute of Physics, Technical University of Lodz, Wolczanska 219, 90-924 Lodz (Poland)

    2012-09-01

    Highlights: Black-Right-Pointing-Pointer Correlation was found between diamond quality and its electrochemical performance. Black-Right-Pointing-Pointer The electrode sensitivity depends on the content of sp{sup 2} carbon phase in diamond layer. Black-Right-Pointing-Pointer The sp{sup 2} carbon phase content has little influence on the CV peak separation ({Delta}E{sub p}). - Abstract: The polycrystalline undoped diamond layers were deposited on tungsten wire substrates by using hot filament chemical vapor deposition (HFCVD) technique. As a working gas the mixture of methanol in excess of hydrogen was used. The morphologies and quality of as-deposited films were monitored by means of scanning electron microscopy (SEM), X-ray diffraction (XRD) and Raman spectroscopy respectively. The electrochemical activity of the obtained diamond layers was monitored by using cyclic voltammetry measurements. Analysis of the ferrocyanide-ferricyanide couple at undoped diamond electrode suggests that electrochemical reaction at diamond electrode has a quasireversibile character. The ratio of the anodic and cathodic peak currents was always close to unity. In this work we showed that the amorphous carbon admixture in the CVD diamond layer has a crucial influence on its electrochemical performance.

  13. Direct electrodeposition of gold nanotube arrays of rough and porous wall by cyclic voltammetry and its applications of simultaneous determination of ascorbic acid and uric acid

    International Nuclear Information System (INIS)

    Yang Guangming; Li Ling; Jiang Jinhe; Yang Yunhui

    2012-01-01

    Gold nanotube arrays of rough and porous wall has been synthesized by direct electrodeposition with cyclic voltammetry utilizing anodic aluminum oxide template (AAO) and polycarbonate membrane (PC) during short time (only 3 min and 2 min, respectively). The mechanism of the direct electrodeposition of gold nanotube arrays by cyclic voltammetry (CV) has been discussed. The morphological characterizations of the gold nanotube arrays have been investigated by scanning electron microscopy (SEM). A simultaneous determination of ascorbic acid (AA) and uric acid (UA) by differential pulse voltammetry (DPV) was constructed by attaching gold nanotube arrays (using AAO) onto the surface of a glassy carbon electrode (GCE). The electrochemical behavior of AA and UA at this modified electrode has been studied by CV and differential pulse voltammetry (DPV). The sensor offers an excellent response for AA and UA and the linear response range for AA and UA were 1.02 × 10 −7 –5.23 × 10 −4 mol L −1 and 1.43 × 10 −7 –4.64 × 10 −4 mol L −1 , the detection limits were 1.12 × 10 −8 mol L −1 and 2.24 × 10 −8 mol L −1 , respectively. This sensor shows good regeneration, stability and selectivity and has been used for the determination of AA and UA in real human urine and serum samples with satisfied results. - Graphical abstract: The schematic diagram of formation of Au nanotube arrays (a) and the stepwise procedure of the sensor (b). Highlights: ► Gold nanotubes array has been synthesized by cyclic voltammetry. ► The mechanism of deposition of gold nanotube has been discussed. ► A determination of ascorbic acid and uric acid was constructed by gold array. ► A satisfied determination of samples can be obtained by this sensor.

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

    International Nuclear Information System (INIS)

    Magallanes, J.F.

    1984-01-01

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

  15. Differential Pulse Anodic Stripping Voltammetry for Mercury Determination

    OpenAIRE

    Vereștiuc Paul C.; Tucaliuc Oana-Maria; Breabăn Iuliana G.; Crețescu Igor; Nemțoi Gheorghe

    2015-01-01

    In the present work voltammetric investigations have been performed on HgCl2 aqueous solutions prepared from a Cz 9024 reagent. Carbon paste electrode (CPE), eriochrome black T modified carbon paste electrode (MCPE/EBT) and KCl 1M as background electrolyte, were involved within the experimental procedures. Cyclic voltammetry (CV) has been performed in order to compare the behaviour of the two electrodes in both K3[Fe(CN)6] and mercury calibration aqueous solution. Differential pulse anodic st...

  16. Monolayer Assemblies of a De Novo Designed 4-alpha-Helix Bundle Carboprotein and Its Sulfur Anchor Fragment on Au(111) Surfaces Addressed by Voltammetry and In Situ Scanning Tunneling Microscopy

    DEFF Research Database (Denmark)

    Brask, Jesper; Wackerbarth, Hainer; Jensen, Knud J.

    2003-01-01

    carboprotein without thiol anchor have been prepared and investigated for comparison. Cyclic and differential pulse voltammetry (DPV) of the proteins show desorption peaks around -750 mV (SCE), whereas the thiol anchor desorption peak is at -685 mV. The peaks are by far the highest for thiol monomeric 4-R...

  17. Smartphone-based cyclic voltammetry system with graphene modified screen printed electrodes for glucose detection.

    Science.gov (United States)

    Ji, Daizong; Liu, Lei; Li, Shuang; Chen, Chen; Lu, Yanli; Wu, Jiajia; Liu, Qingjun

    2017-12-15

    Smartphone-based electrochemical devices have such advantages as the low price, miniaturization, and obtaining the real-time data. As a popular electrochemical method, cyclic voltammetry (CV) has shown its great practicability for quantitative detection and electrodes modification. In this study, a smartphone-based CV system with a simple method of electrode modification was constructed to perform electrochemical detections. The system was composed of these main portions: modified electrodes, portable electrochemical detector and smartphone. Among them, the detector was comprised of an energy transformation module applying the stimuli signals, and a low-cost potentiostat module for CV measurements with a Bluetooth module for transmitting data and commands. With an Application (App), the smartphone was used as the controller and displayer of the system. Through controlling of different scan rates, the smartphone-based system could perform CV detections for redox couples with test errors less than 3.8% compared to that of commercial electrochemical workstation. Also, the reduced graphene oxide (rGO) and sensitive substance could be modified by the system on the screen printed electrodes for detections. As a demonstration, 3-amino phenylboronic acid (APBA) was used as the sensitive substance to fabricate a glucose sensor. Finally, the experimental data of the system were shown the linear, sensitive, and specific responses to glucose at different doses, even in blood serum as low as about 0.026mM with 3δ/slope calculation. Thus, the system could show great potentials of detection and modification of electrodes in various fields, such as public health, water monitoring, and food quality. Copyright © 2017 Elsevier B.V. All rights reserved.

  18. Cyclic voltammetry deposition of copper nanostructure on MWCNTs modified pencil graphite electrode: An ultra-sensitive hydrazine sensor

    Energy Technology Data Exchange (ETDEWEB)

    Heydari, Hamid [Faculty of Sciences, Razi University, Kermanshah (Iran, Islamic Republic of); Gholivand, Mohammad B., E-mail: mbgholivand@razi.ac.ir [Faculty of Sciences, Razi University, Kermanshah (Iran, Islamic Republic of); Abdolmaleki, Abbas [Department of Chemistry, Malek Ashtar University of Technology, Tehran (Iran, Islamic Republic of)

    2016-09-01

    In this study, Copper (Cu) nanostructures (CuNS) were electrochemically deposited on a film of multiwall carbon nanotubes (MWCNTs) modified pencil graphite electrode (MWCNTs/PGE) by cyclic voltammetry method to fabricate a CuNS–MWCNTs composite sensor (CuNS–MWCNT/PGE) for hydrazine detection. Scanning electron microscopy (SEM) and Energy-dispersive X-ray spectroscopy (EDX) were used for the characterization of CuNS on the MWCNTs matrix. The composite of CuNS-MWCNTs was characterized with cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS). The preliminary studies showed that the proposed sensor have a synergistic electrocatalytic activity for the oxidation of hydrazine in phosphate buffer. The catalytic currents of square wave voltammetry had a linear correlation with the hydrazine concentration in the range of 0.1 to 800 μM with a low detection limit of 70 nM. Moreover, the amperometric oxidation current exhibited a linear correlation with hydrazine concentration in the concentration range of 50–800 μM with the detection limit of 4.3 μM. The proposed electrode was used for the determination of hydrazine in real samples and the results were promising. Empirical results also indicated that the sensor had good reproducibility, long-term stability, and the response of the sensor to hydrazine was free from interferences. Moreover, the proposed sensor benefits from simple preparation, low cost, outstanding sensitivity, selectivity, and reproducibility for hydrazine determination. - Highlights: • The Copper nanostructures (CuNS) were prepared by cyclic voltammetry deposition. • The CuNS-MWCNT/PGE sensor shows high activity toward hydrazine (N{sub 2}H{sub 4}). • The proposed sensor exhibits a wide linear range (0.1 to 800 μM), low detection limit (70 nM), high sensitivity and stability for hydrazine.

  19. Cyclic Voltammetry Simulations with DigiSim Software: An Upper-Level Undergraduate Experiment

    Science.gov (United States)

    Messersmith, Stephania J.

    2014-01-01

    An upper-division undergraduate chemistry experiment is described which utilizes DigiSim software to simulate cyclic voltammetry (CV). Four mechanisms were studied: a reversible electron transfer with no subsequent or proceeding chemical reactions, a reversible electron transfer followed by a reversible chemical reaction, a reversible chemical…

  20. Comparison of analytical possibilities of inversion voltammetry of tellurium with cathodic and anodic potential scanning taking layer-by-layer analysis of GaAs-Te films as example

    International Nuclear Information System (INIS)

    Kaplin, A.A.; Portnyagina, Eh.O.; Gridaev, V.F.

    1979-01-01

    Possibility of application in analytical purposes of the process of tellurium precipitation electrosolution from the surfaces of graphite and mercury-graphite electrodes at the cathode scanning of the potential is shown. As a result of comparison of direct and inversion scanning with cathodic and anodic scanning of the potential, variants of voltammetric method of tellurium determination in artificial solutions and, taking the developed method of layer-by-layer analysis of the GaAsTe films as an example, advantage of mercury-graphite electrode with cathodic scanning as compared to graphite electrode with cathode scanning of the potential is shown. Reproducibility of the GaAs film analysis results according to anodic and cathodic tellurium peaks is satisfactory. Maximum deviation from the results of analysis of oxidation peaks and tellurium peduction does not exceed 15 rel. %. Thus, for tellurium concentrations, exceeding 5x10 -6 g-ion/l, both anodic and cathodic scanning of the potential can be used, though error in tellurium determination according to cathodic peaks is 1.5-2.0 times higher. At tellurium amounts lower 5x10 -6 g-ion/l the determination should be carried out according to the peaks of tellurium anodic oxidation from the surface of graphite electrode or according to the peaks of tellurium cathodic reduction from the surface of mercury-graphite electrode

  1. Direct electrodeposition of gold nanotube arrays of rough and porous wall by cyclic voltammetry and its applications of simultaneous determination of ascorbic acid and uric acid

    Energy Technology Data Exchange (ETDEWEB)

    Yang Guangming, E-mail: yangguangmingbs@126.com [Department of Resources and Environment, Baoshan University, Baoshan 678000 (China); Ling, Li [Department of Resources and Environment, Baoshan University, Baoshan 678000 (China); Jinhe, Jiang; Yunhui, Yang [College of Chemistry and Chemical Engineering, Yunnan Normal University, Kunming 650092 (China)

    2012-08-01

    Gold nanotube arrays of rough and porous wall has been synthesized by direct electrodeposition with cyclic voltammetry utilizing anodic aluminum oxide template (AAO) and polycarbonate membrane (PC) during short time (only 3 min and 2 min, respectively). The mechanism of the direct electrodeposition of gold nanotube arrays by cyclic voltammetry (CV) has been discussed. The morphological characterizations of the gold nanotube arrays have been investigated by scanning electron microscopy (SEM). A simultaneous determination of ascorbic acid (AA) and uric acid (UA) by differential pulse voltammetry (DPV) was constructed by attaching gold nanotube arrays (using AAO) onto the surface of a glassy carbon electrode (GCE). The electrochemical behavior of AA and UA at this modified electrode has been studied by CV and differential pulse voltammetry (DPV). The sensor offers an excellent response for AA and UA and the linear response range for AA and UA were 1.02 Multiplication-Sign 10{sup -7}-5.23 Multiplication-Sign 10{sup -4} mol L{sup -1} and 1.43 Multiplication-Sign 10{sup -7}-4.64 Multiplication-Sign 10{sup -4} mol L{sup -1}, the detection limits were 1.12 Multiplication-Sign 10{sup -8} mol L{sup -1} and 2.24 Multiplication-Sign 10{sup -8} mol L{sup -1}, respectively. This sensor shows good regeneration, stability and selectivity and has been used for the determination of AA and UA in real human urine and serum samples with satisfied results. - Graphical abstract: The schematic diagram of formation of Au nanotube arrays (a) and the stepwise procedure of the sensor (b). Highlights: Black-Right-Pointing-Pointer Gold nanotubes array has been synthesized by cyclic voltammetry. Black-Right-Pointing-Pointer The mechanism of deposition of gold nanotube has been discussed. Black-Right-Pointing-Pointer A determination of ascorbic acid and uric acid was constructed by gold array. Black-Right-Pointing-Pointer A satisfied determination of samples can be obtained by this sensor.

  2. Supercapacitive evaluation of carbon black/exfoliated graphite/MnO{sub 2} ternary nanocomposite electrode by continuous cyclic voltammetry

    Energy Technology Data Exchange (ETDEWEB)

    Naderi, Hamid Reza, E-mail: hrnaderi@ut.ac.ir [Center of Excellence in Electrochemistry, Faculty of Chemistry, University of Tehran, Tehran (Iran, Islamic Republic of); Norouzi, Parviz, E-mail: norouzi@khayam.ut.ac.ir [Center of Excellence in Electrochemistry, Faculty of Chemistry, University of Tehran, Tehran (Iran, Islamic Republic of); Biosensor Research Center, Endocrinology & Metabolism Molecular-Cellular Sciences Institute, Tehran University of Medical Sciences, Tehran (Iran, Islamic Republic of); Ganjali, Mohammad Reza, E-mail: ganjali@khayam.ut.ac.ir [Center of Excellence in Electrochemistry, Faculty of Chemistry, University of Tehran, Tehran (Iran, Islamic Republic of); Biosensor Research Center, Endocrinology & Metabolism Molecular-Cellular Sciences Institute, Tehran University of Medical Sciences, Tehran (Iran, Islamic Republic of)

    2015-08-01

    A new ternary nanocomposite was prepared by using MnO{sub 2}, carbon black (CB), and exfoliated graphite (EG) through a sonochemical method. In this process, the MnO{sub 2} nanoparticles was anchored on the mixture of CB and EG to maximize the specific capacitances of these materials. Structure and morphology of the CB/EG/MnO{sub 2} nanocomposites were examined by X-ray diffraction (XRD) and scanning electron microscopy (SEM). The electrochemical properties of the CB/EG/MnO{sub 2} nanocomposites with different content of MnO{sub 2} were studied by cyclic voltammetry (CV), fast Fourier transformation continuous cyclic voltammetry (FFTCCV) technique, galvanostatic charge–discharge, and electrochemical impedance spectroscopy (EIS). The best nanocomposite electrode displayed specific capacitance of 364 F g{sup −1} at the scan rate of 2 mV s{sup −1} in 0.5 M Na{sub 2}SO{sub 4} aqueous solution, which is higher than pure MnO{sub 2} (289 F g{sup −1}). The capacitance stability of the nanocomposite electrode was studied by FFTCCV at the scan rate of 500 mV s{sup −1}. The result shows that after recording 4000 CVs, the specific capacitance of the nanocomposite decline only 5%. Furthermore, the nanocomposite electrode showed higher energy density than MnO{sub 2} electrode. - Highlights: • MnO{sub 2}/exfoliated graphite/Carbon black nanocomposites were synthesized by ultrasonic vibration. • The best nanocomposite electrode exhibits specific capacitance of 364 F g{sup −1} in 2 mV s{sup −1}. • The stability of the nanocomposite electrode was study FFTCCV technique. • The capacitance decreases only 5.2% of initial capacitance after 4000 cycles.

  3. Adsorptive stripping voltammetry in lipophilic vitamins determination

    Directory of Open Access Journals (Sweden)

    Milan Sýs

    2016-06-01

    Full Text Available The aim of this contribution was to check if adsorptive stripping differential pulse voltammetry (AdSDPV is suitable tool for sensitive simultenous electrochemical detection of lipophilic vitamins. Retinol (vitamin A1, cholecalciferol (vitamin D3, α-tocopherol (vitamin E and phylloquinone (vitamin K1 were selected as representatives. All electrochemical measurements were performed in two separate steps due to the lipophilic character of the analytes. In the first step, an accumulation of lipophilic vitamin on the surface of glassy carbon electrode (GCE was done by immersing working electrode into the aqueous‑acetonitrile solutions (50%, v/v of each vitamin (50.0 µmol.L-1 at 400 rpm for 5 min. In the second one, differential pulse voltammetry of accumulated vitamins was performed in 0.01 mol.L-1 acetate (pH 4.5 buffer at potential step (Estep 5 mV, potential of amplitude (Eampl 25 mV, interval time (t 0.1 s and scan rate (ν 50 mV.s-1. It was observed that electrochemical behaviour of lipophilic vitamins adsorbed on surface of solid GCE in the aqueous electrolyte was very similar to those performed in organic/aqueous electrolyte in literature. Due to reversible electrochemical behaviour of vitamin K1 (phylloquinone/phyllohydroquinone redox couple, it was possible to detect all lipophilic vitamins only in one analysis. Observed values of peak potentials (Ep were sufficiently different for their recognition which was confirmed by the analysis of real sample. The results obtained in this study showed that simultaneous determination of some lipophilic vitamins is possible requiring further optimization study. For this reason, it is necessary to understand this work as an initial step in simultaneous determination of lipophilic vitamins without application of any chromatographic technique.

  4. A novel framework for intelligent signal detection via artificial neural networks for cyclic voltammetry in pyroprocessing technology

    International Nuclear Information System (INIS)

    Rakhshan Pouri, Samaneh; Manic, Milos; Phongikaroon, Supathorn

    2018-01-01

    Highlights: •First time ANN implementation toward pyroprocessing safeguards. •Real time monitoring in terms of intelligent materials detection and accountability. •CV simulation via ANN showing a high accuracy of prediction for the unseen situation. •Elimination of trial and error approach to avoid overfitting in learning. -- Abstract: Electrorefiner (ER) is the heart of pyroprocessing technology which contains different fission, rare-earth, and transuranic chloride compositions during the operation. This is still a developing technology that needs to be advanced for the commercial reprocessing design of used nuclear fuel (UNF) in terms of intelligent materials detection and accountability towards safeguards. A novel signal detection, artificial neural network (ANN), has been proposed in this study to apply on massive ER systemic parameters to simulate cyclic voltammetry (CV) graphs for the unseen situation. ANN could be trained to mimic the system by driving the data sets interrelation between variables to provide current and potential simulated data sets with a high accuracy of prediction. For this purpose, over 230,000 experimental data points reported in literature have been explored—0.5–5 wt% of zirconium chloride (ZrCl 4 ) in LiCl-KCl molten salt with different scan rates at 773 K. This study has illustrated a new framework of ANN implementation to eliminate trial and error approach by comparing the average error of one to three hidden layers with different number of neurons. In addition, this framework results in finding a preferable balance between underfitting and overfitting in deep learning. Furthermore, simulated CV graphs were compared with the experimental data and illustrated a reasonable prediction. The results reveal two structures with three hidden layers providing a good prediction with a low average error. The outcomes indicate that ANN has a strong potential in applying toward safeguards for pyroprocessing technology.

  5. SPR imaging combined with cyclic voltammetry for the detection of neural activity

    Directory of Open Access Journals (Sweden)

    Hui Li

    2014-03-01

    Full Text Available Surface plasmon resonance (SPR detects changes in refractive index at a metal-dielectric interface. In this study, SPR imaging (SPRi combined with cyclic voltammetry (CV was applied to detect neural activity in isolated bullfrog sciatic nerves. The neural activities induced by chemical and electrical stimulation led to an SPR response, and the activities were recorded in real time. The activities of different parts of the sciatic nerve were recorded and compared. The results demonstrated that SPR imaging combined with CV is a powerful tool for the investigation of neural activity.

  6. Hairy carbon electrodes studied by cyclic voltammetry and battery discharge testing

    Science.gov (United States)

    Chung, Deborah D. L.; Shui, Xiaoping; Frysz, Christine A.

    1993-01-01

    Hairy carbon is a new material developed by growing submicron carbon filaments on conventional carbon substrates. Typical substrate materials include carbon black, graphite powder, carbon fibers, and glassy carbon. A catalyst is used to initiate hair growth with carbonaceous gases serving as the carbon source. To study the electrochemical behavior of hairy carbons, cyclic voltammetry (CV) and discharge testing were conducted. In both cases, hairy carbon results surpassed those of the substrate material alone.

  7. Double elimination voltammetry of short oligonucleotides

    Czech Academy of Sciences Publication Activity Database

    Mikelová, R.; Trnková, L.; Jelen, František

    2007-01-01

    Roč. 19, č. 17 (2007), s. 1807-1814 ISSN 1040-0397 R&D Projects: GA AV ČR(CZ) IAA100040602 Institutional research plan: CEZ:AV0Z50040507; CEZ:AV0Z50040702 Keywords : adsorptive stripping voltammetry * elimination voltammetry * oligodeoxynucleotide Subject RIV: BO - Biophysics Impact factor: 2.949, year: 2007

  8. CV equipment responsibilities

    CERN Document Server

    Pirollet, B

    2008-01-01

    This document describes the limits of the responsibilities of the TS/CV for fire fighting equipment at the LHC. The various interfaces, providers and users of the water supply systems and clean water raising systems are described.

  9. Emgu CV essentials

    CERN Document Server

    Shi, Shin

    2013-01-01

    This book provides a practical guide to Emgu CV libraries, with sample code and examples used throughout to explain the concepts clearly. Each chapter deals with a different aspect of the Computer Vision field and the implementation of that topic in Emgu CV.If you are a C# programmer working on computer vision projects, this book is for you. You should have prior experience with C#.

  10. CYCLIC VOLTAMMETRY AND REDUCTION MECHANISTIC ...

    African Journals Online (AJOL)

    Preferred Customer

    potential at different scan rates and upon substrate concentrations confirm, ... All the experiments were performed in acetonitrile purchased from Sigma. ... on the pyrylium cation is followed by chemical reaction of the generated radical, as well.

  11. Differential Pulse Anodic Stripping Voltammetry for Mercury Determination

    Directory of Open Access Journals (Sweden)

    Vereștiuc Paul C.

    2015-07-01

    Full Text Available In the present work voltammetric investigations have been performed on HgCl2 aqueous solutions prepared from a Cz 9024 reagent. Carbon paste electrode (CPE, eriochrome black T modified carbon paste electrode (MCPE/EBT and KCl 1M as background electrolyte, were involved within the experimental procedures. Cyclic voltammetry (CV has been performed in order to compare the behaviour of the two electrodes in both K3[Fe(CN6] and mercury calibration aqueous solution. Differential pulse anodic stripping voltammetry (DPASV was used to determine the most suitable parameters for mercury determination. All experiments were performed at 25 ± 1 ℃, using an electrochemical cell with three-electrodes connected to an Autolab PG STAT 302N (Metrohm-Autolab potentiostat that is equipped with Nova 1.11 software. The measured potential values were generated by using the silver chloride electrode (AgClE as reference and a platinum wire electrode as auxiliary. A series of time depending equations for the pre-concentration and concentration steps were established, with the observation that a higher sensitivity can be obtained while increasing the pre-concentration time. DPASV were drawn using the CPE in 11.16 % coriander, as mercury complex, the voltamograms signals indicating mercury oxidation, with signal intensity increasing in time.

  12. Boron doped diamond sensor for sensitive determination of metronidazole: Mechanistic and analytical study by cyclic voltammetry and square wave voltammetry

    Energy Technology Data Exchange (ETDEWEB)

    Ammar, Hafedh Belhadj, E-mail: hbelhadjammar@yahoo.fr; Brahim, Mabrouk Ben; Abdelhédi, Ridha; Samet, Youssef

    2016-02-01

    The performance of boron-doped diamond (BDD) electrode for the detection of metronidazole (MTZ) as the most important drug of the group of 5-nitroimidazole was proven using cyclic voltammetry (CV) and square wave voltammetry (SWV) techniques. A comparison study between BDD, glassy carbon and silver electrodes on the electrochemical response was carried out. The process is pH-dependent. In neutral and alkaline media, one irreversible reduction peak related to the hydroxylamine derivative formation was registered, involving a total of four electrons. In acidic medium, a prepeak appears probably related to the adsorption affinity of hydroxylamine at the electrode surface. The BDD electrode showed higher sensitivity and reproducibility analytical response, compared with the other electrodes. The higher reduction peak current was registered at pH 11. Under optimal conditions, a linear analytical curve was obtained for the MTZ concentration in the range of 0.2–4.2 μmol L{sup −1}, with a detection limit of 0.065 μmol L{sup −1}. - Highlights: • SWV for the determination of MTZ • Boron-doped diamond as a new electrochemical sensor • Simple and rapid detection of MTZ • Efficiency of BDD for sensitive determination of MTZ.

  13. Boron doped diamond sensor for sensitive determination of metronidazole: Mechanistic and analytical study by cyclic voltammetry and square wave voltammetry

    International Nuclear Information System (INIS)

    Ammar, Hafedh Belhadj; Brahim, Mabrouk Ben; Abdelhédi, Ridha; Samet, Youssef

    2016-01-01

    The performance of boron-doped diamond (BDD) electrode for the detection of metronidazole (MTZ) as the most important drug of the group of 5-nitroimidazole was proven using cyclic voltammetry (CV) and square wave voltammetry (SWV) techniques. A comparison study between BDD, glassy carbon and silver electrodes on the electrochemical response was carried out. The process is pH-dependent. In neutral and alkaline media, one irreversible reduction peak related to the hydroxylamine derivative formation was registered, involving a total of four electrons. In acidic medium, a prepeak appears probably related to the adsorption affinity of hydroxylamine at the electrode surface. The BDD electrode showed higher sensitivity and reproducibility analytical response, compared with the other electrodes. The higher reduction peak current was registered at pH 11. Under optimal conditions, a linear analytical curve was obtained for the MTZ concentration in the range of 0.2–4.2 μmol L"−"1, with a detection limit of 0.065 μmol L"−"1. - Highlights: • SWV for the determination of MTZ • Boron-doped diamond as a new electrochemical sensor • Simple and rapid detection of MTZ • Efficiency of BDD for sensitive determination of MTZ

  14. Cyclic voltammetry and reduction mechanistic studies of ...

    African Journals Online (AJOL)

    styrylpyrylium perchlorates have been evaluated using cyclic voltammetry, in comparison to their non-methylated derivatives values. The reduction peak of all studied compounds remained chemically irreversible. The presence of the ...

  15. Thin-film voltammetry and its analytical applications: A review

    International Nuclear Information System (INIS)

    Tian, Huihui; Li, Yunchao; Shao, Huibo; Yu, Hua-Zhong

    2015-01-01

    Highlights: • Electrochemistry at immiscible liquid–liquid interfaces is fundamentally important. • Methods for studying redox processes at liquid–liquid interfaces are reviewed. • Thin-film voltammetry is simple in experimental operation and kinetic data analysis. • Thin-film voltammetry’s analytical applications are prevailing and comprehensive. - Abstract: Electrochemical reactions at the interfaces of immiscible electrolyte solutions (ITIES) are of fundamental importance in the fields of chemical, biological and pharmaceutical sciences. Four-electrode cell setup, scanning electrochemical microscopy (SECM) and thin-film voltammetry are the three most frequently used methods for studying the electrochemical processes at these interfaces. The principle, experimental design, advantages and challenges of the three methods are described and compared. The thin-film voltammetry is highlighted for its simplicity in experimental operation and kinetic data analysis. Its versatile analytical applications are discussed in detail, including the study of redox properties of hydrophobic compounds, evaluation of interfacial electron transfer kinetics, synthesis of nanoparticles/nanostructures, and illustration of cross-membrane ion transport phenomena

  16. Voltammetry and Electrocatalysis of Achrornobacter Xylosoxidans Copper Nitrite Reductase on Functionalized Au(111)-Electrode Surfaces

    DEFF Research Database (Denmark)

    Welinder, Anna C.; Zhang, Jingdong; Hansen, Allan G.

    2007-01-01

    A long-standing issue in protein film voltammetry (PFV), particularly electrocatalytic voltammetry of redox enzyme monolayers, is the variability of protein adsorption modes, reflected in distributions of catalytic activity of the adsorbed protein/enzyme molecules. Use of well-defined, atomically...... planar electrode surfaces is a step towards the resolution of this central issue. We report here the voltammetry of copper nitrite reductase (CNiR, Achromobacter xylosoxidons) on Au(111)-electrode surfaces modified by monolayers of a broad variety of thiol-based linker molecules. These represent......NiR thus shows highly efficient, close to ideal reversible electrocatalytic voltammetry on cysteamine-covered Au(111)-electrode surfaces, most likely due to two cysteamine orientations previously disclosed by in situ scanning tunnelling microscopy. Such a dual orientation exposes both a hydrophobic...

  17. CV : [luuletused] / Mari Vallisoo

    Index Scriptorium Estoniae

    Vallisoo, Mari, 1950-2013

    2007-01-01

    Sisu: CV ; Sõnaraamat ; Tegijad ; "Kus leemekulp?..." ; "Veel üks viimnepäev mis asja teha sellega..." ; "Ülemise riiuli ääre pääl...", "Alkeemik Alberti elamus...", "Valge pulber veel enam valgega...", "Meie isa, kes sa...", "Ükskord, kui Maa...", "Kevadvesi ja -pori...", "Mõisnik Meeskurat müüs mu vaarisale..."

  18. Stripping voltammetry in environmental and food analysis.

    Science.gov (United States)

    Brainina, K Z; Malakhova, N A; Stojko, N Y

    2000-10-01

    The review covers over 230 papers published mostly in the last 5 years. The goal of the review is to attract the attention of researchers and users to stripping voltammetry in particular, its application in environmental monitoring and analysis of foodstuffs. The sensors employed are impregnated graphite, carbon paste, thick film carbon/graphite and thin film metallic electrodes modified in-situ or beforehand. Hanging mercury drop electrodes and mercury coated glassy carbon electrodes are also mentioned. Strip and long-lived sensors for portable instruments and flow through systems are discussed as devices for future development and application of stripping voltammetry.

  19. Applications of voltammetry in environmental science

    Energy Technology Data Exchange (ETDEWEB)

    Richardson, D.H.S.

    1985-01-01

    The wide-ranging applications of voltammetry to the analysis of trace metals and other ions of interest to environmental scientists are reviewed. It is concluded that the availability of modern microprocessor controlled instrumentation, capable of performing both anodic stripping and square wave voltammetry, provides a flexible and powerful technique to aid in solving analytical problems and carrying out routine analyses. The recent identification of many sensitizing agents which reduce detection limits to part per thousand million level, or below, is a further exciting development in this field.

  20. Application of Elimination Voltammetry to the Study of Electrochemical Reduction and Determination of the Herbicide Metribuzin

    Czech Academy of Sciences Publication Activity Database

    Skopalová, J.; Navrátil, Tomáš

    2007-01-01

    Roč. 52, č. 6 (2007), s. 961-977 ISSN 0009-2223 R&D Projects: GA ČR GA203/07/1195 Institutional research plan: CEZ:AV0Z40400503 Keywords : Elimination voltammetry with linear scan (EVLS) * metribuzin * electrochemical reduction * mercury electrodes Subject RIV: CG - Electrochemistry Impact factor: 0.529, year: 2007

  1. Characterization of an electrochemical mercury sensor using alternating current, cyclic, square wave and differential pulse voltammetry

    International Nuclear Information System (INIS)

    Guerreiro, Gabriela V.; Zaitouna, Anita J.; Lai, Rebecca Y.

    2014-01-01

    Graphical abstract: -- Highlights: •An electrochemical Hg(II) sensor based on T–Hg(II)–T sensing motif was fabricated. •A methylene blue-modified DNA probe was used to fabricate the sensor. •Sensor performance was evaluated using ACV, CV, SWV, and DPV. •The sensor behaves as a “signal-off” sensor in ACV and CV. •The sensor behaves as either a “signal-on” or “signal-off” sensor in SWV and DPV. -- Abstract: Here we report the characterization of an electrochemical mercury (Hg 2+ ) sensor constructed with a methylene blue (MB)-modified and thymine-containing linear DNA probe. Similar to the linear probe electrochemical DNA sensor, the resultant sensor behaved as a “signal-off” sensor in alternating current voltammetry and cyclic voltammetry. However, depending on the applied frequency or pulse width, the sensor can behave as either a “signal-off” or “signal-on” sensor in square wave voltammetry (SWV) and differential pulse voltammetry (DPV). In SWV, the sensor showed “signal-on” behavior at low frequencies and “signal-off” behavior at high frequencies. In DPV, the sensor showed “signal-off” behavior at short pulse widths and “signal-on” behavior at long pulse widths. Independent of the sensor interrogation technique, the limit of detection was found to be 10 nM, with a linear dynamic range between 10 nM and 500 nM. In addition, the sensor responded to Hg 2+ rather rapidly; majority of the signal change occurred in 2+ , which has not been previously reported. More importantly, the observed “switching” behavior in SWV and DPV is potentially generalizable and should be applicable to most sensors in this class of dynamics-based electrochemical biosensors

  2. Linear sweep anodic stripping voltammetry: Determination of ...

    Indian Academy of Sciences (India)

    The aim of this work is to determine Cr(VI) in water resources by anodic stripping voltammetry using SPE-. AuNPs modified electrode .... surface area about 4 fold). 3.2 Optimization of Parameters ..... in water samples. The above system offers a.

  3. Steady state oxygen reduction and cyclic voltammetry

    DEFF Research Database (Denmark)

    Rossmeisl, Jan; Karlberg, Gustav; Jaramillo, Thomas

    2008-01-01

    The catalytic activity of Pt and Pt3Ni for the oxygen reduction reaction is investigated by applying a Sabatier model based on density functional calculations. We investigate the role of adsorbed OH on the activity, by comparing cyclic voltammetry obtained from theory with previously published ex...

  4. Electrochemistry and in situ scanning tunnelling microscopy of pure and redox-marked DNA- and UNA-based oligonucleotides on Au(111)-electrode surfaces

    DEFF Research Database (Denmark)

    Hansen, Allan Glargaard; Salvatore, Princia; Karlsen, K.

    2013-01-01

    the strongest and in accord with multiple site Ru-attachment. In situ STM disclosed molecular scale features in varying coverage on addition of the metal ions. The Ru-derivatives showed a bias voltage dependent broad maximum in the tunnelling current–overpotential correlation which could be correlated......We have studied adsorption and electrochemical electron transfer of several 13- and 15-base DNA and UNA (unlocked nucleic acids) oligonucleotides (ONs) linked to Au(111)-electrode surfaces via a 50-C6-SH group using cyclic voltammetry (CV) and scanning tunnelling microscopy in aqueous buffer under...

  5. Microanalysis of DNA by stripping transfer voltammetry

    Czech Academy of Sciences Publication Activity Database

    Jelen, František; Kouřilová, Alena; Pečinka, Petr; Paleček, Emil

    2004-01-01

    Roč. 63, 1-2 (2004), s. 249-252 ISSN 1567-5394 R&D Projects: GA ČR GA203/02/0422; GA AV ČR IAA1163201; GA AV ČR IBS5004107 Institutional research plan: CEZ:AV0Z5004920 Keywords : DNA determination * determination of purine base s * linear sweep voltammetry Subject RIV: BO - Biophysics Impact factor: 2.261, year: 2004

  6. Cyclic voltammetry and reduction mechanistic studies of styrylpyrylium perchlorates

    Directory of Open Access Journals (Sweden)

    Y. L. Bonzi-Coulibaly

    2013-04-01

    Full Text Available The reduction and oxidation potentials of methylated 4-styrylpyrylium and 6-styrylpyrylium perchlorates have been evaluated using cyclic voltammetry, in comparison to their non-methylated derivatives values. The reduction peak of all studied compounds remained chemically irreversible. The presence of the electron-donating methyl group on pyrylium ring leads to a shift of the styrylpyrylium perchlorates reduction potential towards cathodic values. Kinetic studies on platinum electrodes based on the variation of the peak potential at different scan rates and upon substrate concentrations confirm, in another way, the mechanism of electron transfer.DOI: http://dx.doi.org/10.4314/bcse.v27i1.12

  7. Electrodeposition of Iridium Oxide by Cyclic Voltammetry: Application of Response Surface Methodology

    Directory of Open Access Journals (Sweden)

    Kakooei Saeid

    2014-07-01

    Full Text Available The effects of scan rate, temperature, and number of cycles on the coating thickness of IrOX electrodeposited on a stainless steel substrate by cyclic voltammetry were investigated in a statistical system. The central composite design, combined with response surface methodology, was used to study condition of electrodeposition. All fabricated electrodes were characterized using electrochemical methods. Field emission scanning electron microscopy and energy-dispersive X-ray spectroscopy were performed for IrOX film characterization. Results showed that scan rate significantly affects the thickness of the electrodeposited layer. Also, the number of cycles has a greater effect than temperature on the IrOX thickness.

  8. Voltammetry at micro-mesh electrodes

    Directory of Open Access Journals (Sweden)

    Wadhawan Jay D.

    2003-01-01

    Full Text Available The voltammetry at three micro-mesh electrodes is explored. It is found that at sufficiently short experimental durations, the micro-mesh working electrode first behaves as an ensemble of microband electrodes, then follows the behaviour anticipated for an array of diffusion-independent micro-ring electrodes of the same perimeter as individual grid-squares within the mesh. During prolonged electrolysis, the micro-mesh electrode follows that behaviour anticipated theoretically for a cubically-packed partially-blocked electrode. Application of the micro-mesh electrode for the electrochemical determination of carbon dioxide in DMSO electrolyte solutions is further illustrated.

  9. Voltammetry study of quinoxaline in aqueous electrolytes

    International Nuclear Information System (INIS)

    Milshtein, Jarrod D.; Su, Liang; Liou, Catherine; Badel, Andres F.; Brushett, Fikile R.

    2015-01-01

    Organic compounds have recently received considerable attention as active materials in redox flow batteries (RFBs) due to their good electrochemical reversibility, high theoretical energy densities, and promise for low cost production. Until now, organic active material candidates for aqueous RFBs have been limited to the quinone family, a set of aromatic-derived organic molecules, distinguished by an even number of ketone (R−C(=O)−R′) groups. This work aims to elucidate and optimize the electrochemical behavior of quinoxaline, an organic molecule consisting of fused benzene and pyrazine rings, in aqueous electrolytes. More than 30 electrolytes are screened by cyclic voltammetry, and the five most promising electrolytes are investigated further using rotating disk voltammetry. Electrochemical behavior of quinoxaline shows pH dependent thermodynamics and reaction mechanisms, while chloride-containing supporting electrolytes greatly enhance solubility. This study sheds light on the promising characteristics of quinoxaline as a low potential compound for aqueous RFBs; quinoxaline has a redox potential of E° ≈ −0.02 V vs. RHE, is soluble up to ∼4.5 M in water, exhibits a two-electron transfer capability, and possesses a low molecular weight (130.15 g mol"−"1), resulting in a theoretical capacity of 410 mAh g"−"1.

  10. Anodic Stripping Voltammetry at Nanoelectrodes: Trapping of Mn2+ by Crown Ethers

    International Nuclear Information System (INIS)

    Danis, Laurence; Gateman, Samantha Michelle; Snowden, Michael Edward; Halalay, Ion C.; Howe, Jane Y.; Mauzeroll, Janine

    2015-01-01

    The work presented here describes the development and characterization of platinum-mercury hemispherical nanoelectrodes for the spatially resolved quantitative detection of manganese cations. The electrochemical probes were made by electrodeposition of metallic mercury from a mercuric ion solution onto Pt/quartz laser-pulled concentric disk nanoelectrodes (with disk radii ranging from 3 to 500 nm). The nanoelectrodes were characterized by steady-state voltammetry, scanning electrochemical microscopy, environmental scanning electron microscopy, energy-dispersive X-ray spectroscopy and calibrated with respect to the concentration of Mn 2+ ions using anodic stripping voltammetry. The fully characterized probes were employed for the quantitative detection of Mn 2+ . The technique has been used to evaluate the impact of a novel approach for mitigating the undesirable consequences of manganese dissolution in Li-ion batteries

  11. Use of cyclic voltammetry and electrochemical impedance spectroscopy for determination of active surface area of modified carbon-based electrodes

    International Nuclear Information System (INIS)

    Souza, Leticia Lopes de

    2011-01-01

    Carbon-based electrodes as well the ion exchange electrodes among others have been applied mainly in the treatment of industrial effluents and radioactive wastes. Carbon is also used in fuel cells as substrate for the electrocatalysts, having high surface area which surpasses its geometric area. The knowledge of the total active area is important for the determination of operating conditions of an electrochemical cell with respect to the currents to be applied (current density). In this study it was used two techniques to determine the electrochemical active surface area of glassy carbon, electrodes and ion exchange electrodes: cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS). The experiments were carried out with KNO 3 0.1 mol.L -1 solutions in a three-electrode electrochemical cell: carbon-based working electrode, platinum auxiliary electrode and Ag/AgCl reference electrode. The glassy carbon and porous carbon electrodes with geometric areas of 3.14 x 10 -2 and 2.83 X 10 -1 cm 2 , respectively, were used. The ion exchange electrode was prepared by mixing graphite, carbon, ion exchange resin and a binder, and this mixture was applied in three layers on carbon felt, using a geometric area of 1.0 cm 2 during the experiments. The capacitance (Cd) of the materials was determined by EIS using Bode diagrams. The value of 172 μF.cm -2 found for the glassy carbon is consistent with the literature data (∼ 200 μF.cm'- 2 ). By VC, varying the scan rate from 0.2 to 2.0 mV.s-1, the capacitance CdS (S = active surface area) in the region of the electric double layer (EDL) of each material was determined. By EIS, the values of C d , 3.0 x 10 -5 μF.cm'- 2 and 11 x 10 3 μF.cm-2, were found for the porous carbon and ion exchange electrodes, respectively, which allowed the determination of active surface areas as 3.73 x 106 cm 2 and 4.72 cm 2 . To sum up, the combined use of EIS and CV techniques is a valuable tool for the calculation of active surface

  12. Optimising carbon electrode materials for adsorptive stripping voltammetry

    OpenAIRE

    Chaisiwamongkhol, K; Batchelor-McAuley, C; Sokolov, S; Holter, J; Young, N; Compton, R

    2017-01-01

    Different types of carbon electrode materials for adsorptive stripping voltammetry are studied through the use of cyclic voltammetry. Capsaicin is utilised as a model compound for adsorptive stripping voltammetry using unmodified and modified basal plane pyrolytic graphite (BPPG) electrodes modified with multi-walled carbon nanotubes, carbon black or graphene nanoplatelets, screen printed carbon electrodes (SPE), carbon nanotube modified screen printed electrodes, and carbon paste electrodes....

  13. Voltammetry under a Controlled Temperature Gradient

    Directory of Open Access Journals (Sweden)

    Jan Krejci, Jr.

    2010-07-01

    Full Text Available Electrochemical measurements are generally done under isothermal conditions. Here we report on the application of a controlled temperature gradient between the working electrode surface and the solution. Using electrochemical sensors prepared on ceramic materials with extremely high specific heat conductivity, the temperature gradient between the electrode and solution was applied here as a second driving force. This application of the Soret phenomenon increases the mass transfer in the Nernst layer and enables more accurate control of the electrode response enhancement by a combination of diffusion and thermal diffusion. We have thus studied the effect of Soret phenomenon by cyclic voltammetry measurements in ferro/ferricyanide. The time dependence of sensor response disappears when applying the Soret phenomenon, and the complicated shape of the cyclic voltammogram is replaced by a simple exponential curve. We have derived the Cotrell-Soret equation describing the steady-state response with an applied temperature difference.

  14. Characterization of an electrochemical mercury sensor using alternating current, cyclic, square wave and differential pulse voltammetry

    Energy Technology Data Exchange (ETDEWEB)

    Guerreiro, Gabriela V.; Zaitouna, Anita J.; Lai, Rebecca Y., E-mail: rlai2@unl.edu

    2014-01-31

    Graphical abstract: -- Highlights: •An electrochemical Hg(II) sensor based on T–Hg(II)–T sensing motif was fabricated. •A methylene blue-modified DNA probe was used to fabricate the sensor. •Sensor performance was evaluated using ACV, CV, SWV, and DPV. •The sensor behaves as a “signal-off” sensor in ACV and CV. •The sensor behaves as either a “signal-on” or “signal-off” sensor in SWV and DPV. -- Abstract: Here we report the characterization of an electrochemical mercury (Hg{sup 2+}) sensor constructed with a methylene blue (MB)-modified and thymine-containing linear DNA probe. Similar to the linear probe electrochemical DNA sensor, the resultant sensor behaved as a “signal-off” sensor in alternating current voltammetry and cyclic voltammetry. However, depending on the applied frequency or pulse width, the sensor can behave as either a “signal-off” or “signal-on” sensor in square wave voltammetry (SWV) and differential pulse voltammetry (DPV). In SWV, the sensor showed “signal-on” behavior at low frequencies and “signal-off” behavior at high frequencies. In DPV, the sensor showed “signal-off” behavior at short pulse widths and “signal-on” behavior at long pulse widths. Independent of the sensor interrogation technique, the limit of detection was found to be 10 nM, with a linear dynamic range between 10 nM and 500 nM. In addition, the sensor responded to Hg{sup 2+} rather rapidly; majority of the signal change occurred in <20 min. Overall, the sensor retains all the characteristics of this class of sensors; it is reagentless, reusable, sensitive, specific and selective. This study also highlights the feasibility of using a MB-modified probe for real-time sensing of Hg{sup 2+}, which has not been previously reported. More importantly, the observed “switching” behavior in SWV and DPV is potentially generalizable and should be applicable to most sensors in this class of dynamics-based electrochemical biosensors.

  15. Electrochemical behaviour of carbon paste electrodes enriched with tin oxide nanoparticles using voltammetry and electrochemical impedance spectroscopy.

    Science.gov (United States)

    Muti, Mihrican; Erdem, Arzum; Caliskan, Ayfer; Sınag, Ali; Yumak, Tugrul

    2011-08-01

    The effect of the SnO(2) nanoparticles (SNPs) on the behaviour of voltammetric carbon paste electrodes were studied for possible use of this material in biosensor development. The electrochemical behaviour of SNP modified carbon paste electrodes (CPE) was first investigated by using cyclic voltammetry (CV), differential pulse voltammetry (DPV) and electrochemical impedance spectroscopy (EIS) techniques. The performance of the SNP modified electrodes were compared to those of unmodified ones and the parameters affecting the response of the modified electrode were optimized. The SNP modified electrodes were then tested for the electrochemical sensing of DNA purine base adenine to explore their further development in biosensor applications. Copyright © 2011 Elsevier B.V. All rights reserved.

  16. Instant OpenCV starter

    CERN Document Server

    Dalal, Jayneil

    2013-01-01

    Get to grips with a new technology, understand what it is and what it can do for you, and then get to work with the most important features and tasks.A practical, quick, and hands-on guide for Python developers and hobbyists who want to get started with computer vision with OpenCV.This book is great for developers, hobbyists, and students new to computer vision who are looking to get a good grounding in how to use the OpenCV library. It's assumed that you will have some basic experience in C/C++ programming.

  17. A Practical Beginner's Guide to Cyclic Voltammetry

    Science.gov (United States)

    Elgrishi, Noémie; Rountree, Kelley J.; McCarthy, Brian D.; Rountree, Eric S.; Eisenhart, Thomas T.; Dempsey, Jillian L.

    2018-01-01

    Despite the growing popularity of cyclic voltammetry, many students do not receive formalized training in this technique as part of their coursework. Confronted with self-instruction, students can be left wondering where to start. Here, a short introduction to cyclic voltammetry is provided to help the reader with data acquisition and…

  18. Voltammetry of Organic Pollutants on FeOOH Nanorods

    International Nuclear Information System (INIS)

    Zhang, Yuanyuan; Wan, Qijin; Yang, Nianjun

    2017-01-01

    FeOOH nanorods synthesized using a solvothermal approach have been employed to investigate the electrochemistry of organic pollutions, including ponceau 4R (PR), sunset yellow (SY), and tetrabromobisphenol A (TBBPA). The as-prepared FeOOH nanorods have been characterized using scanning electron microscopes (SEM), transmission electron microscope (TEM), X-ray photoelectron spectrometry, Brunauer-Emmett-Teller measurements, and electrochemical techniques. The modified electrode based on FeOOH nanorods exhibits a porous and net-like structure, resulting in a high surface area and many reactive/adsorption sites for soluble compounds. On this modified electrode, fast electron transfer processes of redox probes have been achieved. Electrochemistry of PR, SY, and TBBPA has been studied in detail using voltammetry, impedance, and chronocoulometry. The sensitive monitoring of both individual and total concentrations of three organic pollutions has been realized. The detection limits are 0.2, 1.0, and 0.55 nM for PR, SY, and TBBPA, respectively. Such an electrode is then promising for the electrochemical investigation and analysis of organic pollutions in different environments.

  19. Experimentation and numerical modeling of cyclic voltammetry for electrochemical micro-sized sensors under the influence of electrolyte flow

    DEFF Research Database (Denmark)

    Adesokan, Bolaji James; Quan, Xueling; Evgrafov, A.

    2016-01-01

    of the recorded CV. However, at high scan rates (250 mV/s) and slow flow rates (50 - 200 μ/L), peak currents are recorded which means that mass transport is dominated by the diffusion mechanism and a quasi-steady state of CV is recorded. In the case of insufficient supporting electrolyte, the excess charges....... The numerical results and the experimental data show both qualitative good agreement and quantitative good agreement....

  20. Cyclic voltammetry on n-alkylphosphonic acid self-assembled monolayer modified large area indium tin oxide electrodes

    Energy Technology Data Exchange (ETDEWEB)

    Habich, Dana Berlinde [Siemens AG, CT T DE HW 3 Organic Electronics, Guenther-Scharowsky-Strasse 1, 91058 Erlangen (Germany); Halik, Marcus [Lehrstuhl fuer Polymerwerkstoffe, Department Werkstoffwissenschaften, Friedrich-Alexander-Universitaet Erlangen-Nuernberg, Martensstrasse 7, 91058 Erlangen (Germany); Schmid, Guenter, E-mail: guenter.schmid@siemens.com [Siemens AG, CT T DE HW 3 Organic Electronics, Guenther-Scharowsky-Strasse 1, 91058 Erlangen (Germany)

    2011-09-01

    We show stable bonding of n-alkylphosphonic acid self-assembled monolayers (SAMs) to indium tin oxide electrodes and their direct electrical characterization by cyclic voltammetry (CV). The functional coatings were investigated with regards to the addressability and stability of the electrodes, which are related to small changes in molecular layer thickness. The response of a redox active compound in solution to the faradic current is indirectly proportional to the molecular chain length of the SAMs. We observed a decrease of the electrode sensitivity with enhanced surface protection and slow long term degradation of the SAM under electrochemical stress by CV, and therefore conclude a trade-off optimum for molecules with the C10 chain.

  1. Characteristics of curcumin using cyclic voltammetry, UV–vis, fluorescence and thermogravimetric analysis

    International Nuclear Information System (INIS)

    Masek, Anna; Chrzescijanska, Ewa; Zaborski, Marian

    2013-01-01

    Highlights: • Electrooxidation of curcumin was investigated with cyclic voltammetry. • The curcumin is irreversibly oxidized at the platinum electrode in anhydrous media. • Absorbance, fluorescence and thermogravimetric analysis of curcumin was studied. • The HOMO and Mapped Electron Densities were calculated using HyperChem. • Oxidation mechanism for curcumin proposed. -- Abstract: Curcumin, the yellow, primary bioactive component of turmeric, has recently received attention from chemists due its wide range of potential biological applications as an antioxidant, anti-inflammatory, and anti-carcinogenic agent. The electrochemical behaviour of curcumin at a platinum electrode has been studied by cyclic voltammetry (CV) and differential pulse voltammetry (DPV). The oxidation of curcumin is an irreversible process that proceeds in two steps in 0.1 M (C 4 H 9 ) 4 NClO 4 in acetonitrile. The process of oxidation and its kinetics have been investigated. The rate constant, electron transfer coefficient and diffusion coefficients for the electrochemical oxidation of curcumin were determined. A mechanism for the oxidation of curcumin is proposed. The data obtained are consistent with the current literature and suggest that voltammetric studies on mechanically transferred solids may be a convenient method for elucidating the electrochemical oxidation mechanisms of compounds in anhydrous media. Theoretical calculations regarding the optimization of curcumin, electronic properties like highest occupied molecular orbital (HOMO) and lowest unoccupied molecular orbital (LUMO) were calculated using with HyperChem software by AM1 semi-empirical method. The properties of curcumin in a homogeneous environment were investigated using spectroscopic techniques and thermogravimetric analysis

  2. A combined SEM and CV Study of Solid Oxide Fuel Cell Interconnect Steels

    DEFF Research Database (Denmark)

    Kammer Hansen, Kent; Ofoegbu, Stanley; Mikkelsen, Lars

    2012-01-01

    Scanning electron microscopy and cyclic voltammetry were used to investigate the high temperature oxidation behavior of two solid oxide fuel cell interconnect steels. One alloy had a low content of manganese; the other alloy had a high content of manganese. Four reduction and four oxidation peaks...

  3. Electrochemical impedance spectroscopy versus cyclic voltammetry for the electroanalytical sensing of capsaicin utilising screen printed carbon nanotube electrodes.

    Science.gov (United States)

    Randviir, Edward P; Metters, Jonathan P; Stainton, John; Banks, Craig E

    2013-05-21

    Screen printed carbon nanotube electrodes (SPEs) are explored as electroanalytical sensing platforms for the detection of capsaicin in both synthetic capsaicin solutions and capsaicin extracted from chillies and chilli sauces utilising both cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS). It is found that the technique which is most applicable to the electroanalytical detection of capsaicin depends upon the analyte concentration: for the case of low capsaicin concentrations, CV is a more appropriate method as capsaicin exhibits characteristic voltammetric waves of peak heights relevant to the capsaicin concentration; but for the case of high capsaicin concentrations where the voltammetric waves merge and migrate out of the potential window, EIS is shown to be a more appropriate technique, owing to the observed linear increases in R(ct) with increasing concentration. Furthermore, we explore different types of screen printed carbon nanotube electrodes, namely single- and multi- walled carbon nanotubes, finding that they are technique-specific: for the case of low capsaicin concentrations, single-walled carbon nanotube SPEs are preferable (SW-SPE); yet for the case of EIS at high capsaicin concentrations, multi-walled carbon nanotube SPEs (MW-SPE) are preferred, based upon analytical responses. The analytical performance of CV and EIS is applied to the sensing of capsaicin in grown chillies and chilli sauces and is critically compared to 'gold standard' HPLC analysis.

  4. Parameters affecting the determination of paraquat at silver rotating electrodes using differential pulse voltammetry

    Directory of Open Access Journals (Sweden)

    A. Farahi

    2014-08-01

    Full Text Available The electrochemical determination of aqueous paraquat PQ(II by differential pulse voltammetry at a solid rotating silver electrode (RSE is described. The aim of this work is to optimize all factors that can influence this determination. Potential wave forms, potential scan parameters and deposition time were examined for their effect on the paraquat peak shape and intensity. The best responses were obtained with differential pulse voltammetry in 0.1 mol L−1 Na2SO4 as supporting electrolyte using amplitude 50 mV, scan increment 5 mV, deposition time 120 s, frequency 50 s−1 and step amplitude 0.05 V. Electrochemical and mechanical surface cleaning, aimed at removing the amount of paraquat deposited onto the silver surface, were necessary for obtaining a good performance of the electrode. Response linearity, repeatability, accuracy and detection limit were also evaluated. The obtained detection limits were 7.1 × 10−9 mol L−1 and 2.8 × 10−9 mol L−1 for peak 1 and peak 2 respectively. The relative standard deviation (RSD was found to be 1.19% in 1.0 × 10−4 mol L−1 paraquat. The applicability of the RSE for PQ(II determination in milk samples, without any sample pretreatment, was successfully demonstrated.

  5. Anodic Stripping Voltammetry for Arsenic Determination on Composite Gold Electrode

    Czech Academy of Sciences Publication Activity Database

    Navrátil, Tomáš; Kopanica, M.; Krista, J.

    2003-01-01

    Roč. 48, č. 2 (2003), s. 265-272 ISSN 0009-2223 Grant - others:GIT(AR) 101/02/U111/CZ Institutional research plan: CEZ:AV0Z4040901 Keywords : arsenic determination * stripping voltammetry * composite gold electrode Subject RIV: CG - Electrochemistry Impact factor: 0.415, year: 2003

  6. Cyclic Voltammetry of Biopolymer Heparin at PVC Plasticized Liquid Membrane

    Czech Academy of Sciences Publication Activity Database

    Samec, Zdeněk; Trojánek, Antonín; Langmaier, Jan; Samcová, E.

    2003-01-01

    Roč. 5, - (2003), s. 867-870 ISSN 1388-2481 R&D Projects: GA ČR GA203/04/0424 Institutional research plan: CEZ:AV0Z4040901 Keywords : cyclic voltammetry * PVC plasticized liquit membrane * heparin Subject RIV: CG - Electrochemistry Impact factor: 2.300, year: 2003

  7. Een bepalingsmethode voor thallium in regenwater met behulp van voltammetrie

    NARCIS (Netherlands)

    Struijs; J.; Wolfs; P.M.; Esseveld; F.G.van

    1985-01-01

    In dit rapport wordt een bepalingmethode beschreven voor thallium in het nanogram/liter-gebied, waarbij gebruik wordt gemaakt van differentiele pulse-anodic stripping voltammetry (DPASV) aan de dunne kwikfilm. Met deze techniek blijkt het mogelijk om de concentratie van dit element rechtstreeks

  8. Voltammetry of hypoxic cells radiosensitizer etanidazole radical anion in water

    Czech Academy of Sciences Publication Activity Database

    Gál, Miroslav; Hromadová, Magdaléna; Pospíšil, Lubomír; Híveš, J.; Sokolová, Romana; Kolivoška, Viliam; Kocábová, Jana

    2010-01-01

    Roč. 78, č. 2 (2010), s. 118-123 ISSN 1567-5394 R&D Projects: GA ČR GP203/09/P502 Institutional research plan: CEZ:AV0Z40400503 Keywords : etanidazole * radiosensitizer * electron transfer * voltammetry Subject RIV: CG - Electrochemistry Impact factor: 3.520, year: 2010

  9. Electrochemical dissolution of chalcopyrite studied by voltammetry of immobilized microparticles

    Czech Academy of Sciences Publication Activity Database

    Pikna, L.; Lux, L.; Grygar, Tomáš

    2006-01-01

    Roč. 60, č. 4 (2006), s. 293-296 ISSN 0366-6352 Grant - others:VEGA(SK) No1/1108/04; APVT(SK) No20-009404 Institutional research plan: CEZ:AV0Z40320502 Keywords : chalcopyrite * cyclic voltammetry Subject RIV: CA - Inorganic Chemistry Impact factor: 0.360, year: 2006

  10. INTERSTOCK EFFECT ON THE GROWTH OF MANDARIN CV BATU 55, TANGERINE CV PONTIANAK AND LIME CV NIMAS PROPAGATED BY GRAFTING

    Directory of Open Access Journals (Sweden)

    Sugiyatno A.

    2017-10-01

    Full Text Available Japansche citroen (JC rootstock is still the main choice for producing citrus seeds for its high availability and compatibility. Other rootstocks have been used in the production, yet they produce unsatisfying results. Based on the theory, there is an alternative to use rootstock as interstock in order to stimulate the growth of scion. The objective of this reseach is to understand the effect of interstock on the growth of Mandarin cv. Batu 55, Tangerine cv. Pontianak and Lime cv. Nimas. This research was conducted in the screen house of Tlekung Experimental Field of Indonesian Citrus and Subtropical Fruits Research Institute (ICSFRI in Batu-East Java, located on 950 m asl, from January to April 2016. This research was arranged in a CRD design with 4 replications and 24 interstock-scion combination treatments. The interstocks used in this study were Carizzo citrange, Citrumello, Poncirus trifoliata, Volkameriana, Rough lemon, Troyer citrange, Kanci and control (JC combined with 3 scions namely Mandarin cv. Batu 55, Tangerine cv. Pontianak and Lime cv. Nimas propagated by grafting. The result showed the percentage of successful grafting ranged between 37.5% to 100%, while the percentage of the shoot formed on grafted plants was 75%-100%. The use of Poncirus trifoliata as interstock has stimulated fastest bud break on Tangerine cv. Pontianak in just 24.75 days while the Troyer citrange has stimulated better shoot growth in Lime cv. Nimas, resulted to the highest shoot around 52.20 cm which was significantly different from other treatments. Meanwhile, Carizzo citrange has been found to have some influences to the plant diameter and the number of leave of Lime cv. Nimas but showed insignificant effect on the growth of its own diameter. The use of interstock showed that it can be used to promote the growth of scion which usually has slow growth when it is directly grafted on the rootstock.

  11. Cyclic voltammetry on sputter-deposited films of electrochromic Ni oxide: Power-law decay of the charge density exchange

    Energy Technology Data Exchange (ETDEWEB)

    Wen, Rui-Tao, E-mail: Ruitao.Wen@angstrom.uu.se; Granqvist, Claes G.; Niklasson, Gunnar A. [Department of Engineering Sciences, The A°ngström Laboratory, Uppsala University, P. O. Box 534, SE-75121 Uppsala (Sweden)

    2014-10-20

    Ni-oxide-based thin films were produced by reactive direct-current magnetron sputtering and were characterized by X-ray diffraction and Rutherford backscattering spectroscopy. Intercalation of Li{sup +} ions was accomplished by cyclic voltammetry (CV) in an electrolyte of LiClO{sub 4} in propylene carbonate, and electrochromism was documented by spectrophotometry. The charge density exchange, and hence the optical modulation span, decayed gradually upon repeated cycling. This phenomenon was accurately described by an empirical power law, which was valid for at least 10{sup 4} cycles when the applied voltage was limited to 4.1 V vs Li/Li{sup +}. Our results allow lifetime assessments for one of the essential components in an electrochromic device such as a “smart window” for energy-efficient buildings.

  12. Thin-layer voltammetry of soluble species on screen-printed electrodes: proof of concept.

    Science.gov (United States)

    Botasini, S; Martí, A C; Méndez, E

    2016-10-17

    Thin-layer diffusion conditions were accomplished on screen-printed electrodes by placing a controlled-weight onto the cast solution and allowing for its natural spreading. The restricted diffusive conditions were assessed by cyclic voltammetry at low voltage scan rates and electrochemical impedance spectroscopy. The relationship between the weight exerted over the drop and the thin-layer thickness achieved was determined, in such a way that the simple experimental set-up designed for this work could be developed into a commercial device with variable control of the thin-layer conditions. The experimental results obtained resemble those reported for the voltammetric features of electroactive soluble species employing electrodes modified with carbon nanotubes or graphene layers, suggesting that the attainment of the benefits reported for these nanomaterials could be done simply by forcing the solution to spread over the screen-printed electrodic system to form a thin layer solution. The advantages of thin-layer voltammetry in the kinetic characterization of quasi-reversible and irreversible processes are highlighted.

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

    Directory of Open Access Journals (Sweden)

    Tarik Attar

    2014-02-01

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

  14. Anodic stripping voltammetry – ASV for determination of heavy metals

    International Nuclear Information System (INIS)

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

    2013-01-01

    Although voltammetric methods presented a number of difficulties in its early stages, nowadays ''ASV'' anodic stripping voltammetry is considered one of the most sensitive electro-analytical and suitable for trace-level determination of many metals and compounds in environmental samples, clinical and industrial. Its sensitivity is attributed to the combination of a step of pre-concentration effective together with an electrochemical advanced measurement of accumulated analyte. This paper presents an overview of the voltammetry, which includes a group of electro-analytical methods, in them the information about analyte is obtained from measurements of the current flowing in an electrochemical cell when applied a potential difference to an suitable electrode system

  15. VOLTAMMETRY OF AQUEOUS CHLOROAURIC ACID WITH HANGING MERCURY DROP ELECTRODE

    Czech Academy of Sciences Publication Activity Database

    Korshunov, A.; Josypčuk, Bohdan; Heyrovský, Michael

    2011-01-01

    Roč. 76, č. 7 (2011), s. 929-936 ISSN 0010-0765 R&D Projects: GA ČR GAP206/11/1638; GA AV ČR IAA400400806; GA MŠk(CZ) LC06063 Institutional research plan: CEZ:AV0Z40400503 Keywords : aqueous chloauric acid * voltammetry * hanging mercury drop electrode Subject RIV: CG - Electrochemistry Impact factor: 1.283, year: 2011

  16. Anodic stripping voltammetry using graphite composite solid electrode

    Czech Academy of Sciences Publication Activity Database

    Navrátil, Tomáš; Barek, J.; Kopanica, Miloslav

    2009-01-01

    Roč. 74, 11-12 (2009), s. 1807-1826 ISSN 0010-0765 R&D Projects: GA AV ČR IAA400400806; GA ČR GA203/07/1195; GA MŠk(CZ) LC06035 Institutional research plan: CEZ:AV0Z40400503 Keywords : Graphite composite solid electrode * voltammetry * metals Subject RIV: CG - Electrochemistry Impact factor: 0.856, year: 2009

  17. Wyoming CV Pilot Traveler Information Message Sample

    Data.gov (United States)

    Department of Transportation — This dataset contains a sample of the sanitized Traveler Information Messages (TIM) being generated by the Wyoming Connected Vehicle (CV) Pilot. The full set of TIMs...

  18. cv. “Sukali Ndiizi”- AAB

    African Journals Online (AJOL)

    Clara

    2013-03-27

    Mar 27, 2013 ... improve transformation and regeneration efficiency of banana (cv. “Sukali .... Vuylsteke (1989) proliferation medium in the tissue culture .... DNA repair machinery is more active during cell division ... Biology-Plant 40:31-45.

  19. Mechanistic modeling of cyclic voltammetry: A helpful tool for understanding biosensor principles and supporting design optimization

    DEFF Research Database (Denmark)

    Semenova, Daria; Zubov, Alexandr; Silina, Yuliya E.

    2018-01-01

    Abstract Design, optimization and integration of biosensors hold a great potential for the development of cost-effective screening and point-of-care technologies. However, significant progress in this field can still be obtained on condition that sufficiently accurate mathematical models......, oxidized/reduced forms of the mediator - Prussian Blue/Prussian White). Furthermore, the developed model was applied under various operating conditions as a crucial tool for biosensor design optimization. The obtained qualitative and quantitative dependencies towards amperometric biosensors design...... optimization were independently supported by results of cyclic voltammetry and multi-analytical studies, such as scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDX) and liquid chromatography-electrospray ionization-tandem mass spectrometry (LC-ESI-MS/MS). Remarkably, a linear...

  20. Anodic stripping voltammetry of antimony using gold nanoparticle-modified carbon screen-printed electrodes

    International Nuclear Information System (INIS)

    Dominguez Renedo, Olga; Arcos Martinez, M. Julia

    2007-01-01

    Carbon screen-printed electrodes (CSPE) modified with gold nanoparticles present an interesting alternative in the determination of antimony using differential pulse anodic stripping voltammetry. Metallic gold nanoparticles deposits have been obtained by direct electrochemical deposition. Scanning electron microscopy measurements show that the electrochemically synthesized gold nanoparticles are deposited in aggregated form. Any undue effects caused by the presence of foreign ions in the solution were also analyzed to ensure that common interferents in the determination of antimony by ASV. The detection limit for Sb(III) obtained was 9.44 x 10 -10 M. In terms of reproducibility, the precision of the above mentioned method in %R.S.D. values was calculated at 2.69% (n = 10). The method was applied to determine levels of antimony in seawater samples and pharmaceutical preparations

  1. Direct determination of molybdenum in seawater by adsorption cathodic stripping square-wave voltammetry.

    Science.gov (United States)

    Sun, Y C; Mierzwa, J; Lan, C R

    2000-06-30

    A reliable and very sensitive procedure for the determination of trace levels of molybdenum in seawater is proposed. The complex of molybdenum with 8-hydroxyquinoline (Oxine) is analyzed by cathodic stripping square-wave voltammetry based on the adsorption collection onto a hanging mercury drop electrode (HMDE). This procedure of molybdenum determination was found to be more favorable than differential pulse cathodic stripping voltammetry because of inherently faster scan rate and much better linearity obtained through the one-peak (instead of one-of-two peaks) calibration. The variation of polarographic peak and peak current with a pH, adsorption time, adsorption potential, and some instrumental parameters such as scan rate and pulse height were optimized. The alteration of polarographic wave and its likely mechanism are also discussed. The relationship between peak current and molybdenum concentration is linear up to 150 mug l(-1). Under the optimal analytical conditions, the determination limit of 0.5 mug l(-1) Mo was reached after 60 s of the stirred collection. The estimated detection limit is better than 0.1 mug l(-1) of Mo. The applicability of this method to analysis of seawater was assessed by the determination of molybdenum in two certified reference seawater samples (CASS-2 and NASS-2) and the comparison of the analytical results for real seawater samples (study on a vertical distribution of Mo in the seawater column) with the results obtained by Zeeman-corrected electrothermal atomization atomic absorption spectrometry (Zeeman ETAAS). A good agreement between two used methods of molybdenum determination was obtained.

  2. Probing the electrochemical properties of TiO{sub 2}/graphene composite by cyclic voltammetry and impedance spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Yadav, Pankaj [Department of Physics, Marwadi Education Foundation, Rajkot 360003 (India); Pandey, Kavita; Bhatt, Parth [School of Solar Energy, Pandit Deendayal Petroleum University, Gandhinagar 382007 (India); Tripathi, Brijesh, E-mail: brijesh.tripathi@sse.pdpu.ac.in [School of Technology, Pandit Deendayal Petroleum University, Gandhinagar 382007 (India); Pandey, Manoj Kumar; Kumar, Manoj [School of Technology, Pandit Deendayal Petroleum University, Gandhinagar 382007 (India)

    2016-04-15

    Highlights: • Role of TiO{sub 2}/graphene composite in charge transport within supercapacitors. • DC and AC characterization to investigate voltage dependence of charge transport. • Physical insight into the electrochemistry of electrode–electrolyte interface. - Abstract: This work describes the role of graphene in charge transport and diffusion mechanism at TiO{sub 2}/graphene electrode–electrolyte interface. To explore the mechanism, cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS) were used. The CV results depict that TiO{sub 2} and TiO{sub 2}/graphene electrodes behave differently in terms of charge transport and ion adsorption under the steady state conditions. The performance of TiO{sub 2} electrode–electrolyte interface is mainly limited by the charge transport and pseudo-capacitive effects while the response of TiO{sub 2}/graphene electrode–electrolyte interface is mainly dominated by the double layer capacitive effects. The EIS measurement leads to the direct determination of broad range of parameters, i.e. series resistance, charge transport, rate capability and ion diffusion. The experimental results and their analysis will have a significant impact on understanding the role of graphene in the electrochemical response of an electrode–electrolyte interface.

  3. Investigation of using wavelet analysis for classifying pattern of cyclic voltammetry signals

    Science.gov (United States)

    Jityen, Arthit; Juagwon, Teerasak; Jaisuthi, Rawat; Osotchan, Tanakorn

    2017-09-01

    Wavelet analysis is an excellent technique for data processing analysis based on linear vector algebra since it has an ability to perform local analysis and is able to analyze an unspecific localized area of a large signal. In this work, the wavelet analysis of cyclic waveform was investigated in order to find the distinguishable feature from the cyclic data. The analyzed wavelet coefficients were proposed to be used as selected cyclic feature parameters. The cyclic voltammogram (CV) of different electrodes consisting of carbon nanotube (CNT) and several types of metal phthalocyanine (MPc) including CoPc, FePc, ZnPc and MnPc powders was used as several sets of cyclic data for various types of coffee. The mixture powder was embedded in a hollow Teflon rod and used as working electrodes. Electrochemical response of the fabricated electrodes in Robusta, blend coffee I, blend coffee II, chocolate malt and cocoa at the same concentrations was measured with scanning rate of 0.05V/s from -1.5 to 1.5V respectively to Ag/AgCl electrode for five scanning loops. The CV of blended CNT electrode with some MPc electrodes indicated the ionic interaction which can be the effect of catalytic oxidation of saccharides and/or polyphenol on the sensor surface. The major information of CV response can be extracted by using several mother wavelet families viz. daubechies (dB1 to dB3), coiflets (coiflet1), biorthogonal (Bior1.1) and symlets (sym2) and then the discrimination of these wavelet coefficients of each data group can be separated by principal component analysis (PCA). The PCA results indicated the clearly separate groups with total contribution more than 62.37% representing from PC1 and PC2.

  4. Fast-scan cyclic voltammetry with thiol-modified mercury electrodes distinguishes native from denatured BSA

    Czech Academy of Sciences Publication Activity Database

    Černocká, Hana; Ostatná, Veronika; Paleček, Emil

    2015-01-01

    Roč. 61, DEC2015 (2015), s. 114-116 ISSN 1388-2481 R&D Projects: GA ČR(CZ) GA15-15479S Institutional support: RVO:68081707 Keywords : catalyzed hydrogen evolution * proteins * electrocatalysis Subject RIV: BO - Biophysics Impact factor: 4.569, year: 2015

  5. Scan-Mode Atmospheric-Pressure Plasma Jet Processed Reduced Graphene Oxides for Quasi-Solid-State Gel-Electrolyte Supercapacitors

    Directory of Open Access Journals (Sweden)

    Aliyah R. Hsu

    2018-01-01

    Full Text Available A scanning atmospheric-pressure plasma jet (APPJ is essential for high-throughput large-area and roll-to-roll processes. In this study, we evaluate scan-mode APPJ for processing reduced graphene oxides (rGOs that are used as the electrodes of quasi-solid-state gel-electrolyte supercapacitors. rGO nanoflakes are mixed with ethyl cellulose (EC and terpineol to form pastes for screen-printing. After screen-printing the pastes on carbon cloth, a DC-pulse nitrogen APPJ is used to process the pastes in the scan mode. The maximal temperature attained is ~550 °C with a thermal influence duration of ~10 s per scan. The pastes are scanned by APPJ for 0, 1, 3 and 5 times. X-ray photoelectron spectroscopy (XPS indicates the reduction of C-O binding content as the number of scan increases, suggesting the oxidation/decomposition of EC. The areal capacitance increases and then decreases as the number of scan increases; the best achieved areal capacitance is 15.93 mF/cm2 with one APPJ scan, in comparison to 4.38 mF/cm2 without APPJ processing. The capacitance retention rate of the supercapacitor with the best performance is ~93% after a 1000-cycle cyclic voltammetry (CV test. The optimal number of APPJ scans should enable the proper removal of inactive EC and improved wettability while minimizing the damage caused to rGOs by nitrogen APPJ processing.

  6. Characterization of a novel gene encoding ankyrin repeat domain from Cotesia vestalis polydnavirus (CvBV)

    International Nuclear Information System (INIS)

    Shi Min; Chen Yafeng; Huang Fang; Liu Pengcheng; Zhou Xueping; Chen Xuexin

    2008-01-01

    Cotesia vestalis (Haliday) is an endoparasitoid of Plutella xylostella (L.) larvae and injects a polydnavirus (CvBV) into its host during oviposition. In this report we describe the characterization of a gene (CvBV805) and its products. CvBV805 is located on the segment S8 of CvBV genome; it has a size of 909 bp and encodes a predicted protein of 125 amino acids. This protein contains an ankyrin repeat domain with a high degree of similarity with IκB-like genes. Gene transcripts were detected in extracts of the host as early as 2 h post-parasitization (p.p.) and continued to be detected through 24 h. Tissue-specific expression patterns showed that CvBV805 might be involved in early host immunosuppression. CvBV805 was detected in parasitized hosts at 12 h p.p. and in rBac-eGFP-CvBV805-infected Tn-5B1-4 cells at 72 h.p.i. by using western blots analysis. The size of the protein expressed in the host hemocytes and infected Tn-5B1-4 cells was 17 kDa and 56 kDa (including eGFP), respectively, which nearly corresponded with the predicted molecular weight (14.31 kDa) of CvBV805, suggesting that the protein did not undergo extensive post-translational modification. The protein was confirmed to be present within the nuclear region in hemocytes of the parasitized P. xylostella larvae at 48 h p.p. using confocal laser scanning microscopy

  7. Nuclear Scans

    Science.gov (United States)

    Nuclear scans use radioactive substances to see structures and functions inside your body. They use a special ... images. Most scans take 20 to 45 minutes. Nuclear scans can help doctors diagnose many conditions, including ...

  8. Comparison of adsorptive with extractive stripping voltammetry in electrochemical determination of retinol

    Directory of Open Access Journals (Sweden)

    Milan Sýs

    2017-01-01

    Full Text Available Adsorptive stripping voltammetry (AdSV of retinol at solid glassy carbon electrode (GCE, carbon paste electrode (CPE covered by thin layer of multi-wall carbon nanotubes (CPE/MWCNTs and carbon paste electrode covered by thin layer of single layer graphene (CPE/Graphene was compared with an extractive stripping voltammetry (ExSV into silicone oil (SO as lipophilic binder of glassy carbon paste electrode (GCPE. All types of selected working electrodes were characterized by a scanning electron microscopy to determine overall morphology of electrode surfaces together with spatial arrangement of used carbon particles. The retinol, also known as vitamin A1, was chosen as a model analyte because it is the most biologically active representative of retinoids which are classified as a significant group of lipophilic vitamins. Based on this comparison, it was observed that electrochemical method with high sensitivity (ExSV at GPCE is generally characterized by shorter linear range of the calibration curve than in case of AdSV at CPE/MWCNTs or CPE/Graphene. Unlike AdSV at solid GCE, all other tested electrochemical methods could represent suitable analytical tools for monitoring of retinoids in different types of foodstuffs. Especially, content of retinol up to tenths milligrams can be easily determined using ExSV. Additionally, negative interference of chemical species present in real samples is minimal in comparison with direct voltammetric methods performed in supporting electrolytes based on organic solvents due to application of accumulation step in "ex-situ" mode.

  9. Determination of Selenium in infant formula by differential pulse cathodic stripping voltammetry

    Directory of Open Access Journals (Sweden)

    "Oveisi MR

    2002-07-01

    Full Text Available Selenium as a nonmetallic chemical element has received high attention of biologists because of its dual role as an essential trace nutrient and a toxic element. This interest has created a need for reliable analytical methods for determination of selenium. In this investigation determination of selenium by differential pulse cathodic stripping voltammetry and the influence of various parameters such as deposition potentials, deposition time. Cu concentration pH, etc. on selenium peak in voltammogram are described. Determination of selenium was accomplished in mixture of acetic acid, hydrochloric acid and sodium chloride buffer (pH=1 with a scan rate of 60 mv/s and a pulse height of 100 my by hanging mercury drop electrode (HMDE as working electrode. The solution was stirred during pre-electrolysis at - 350 mv (vs SCE for 30 s and the potential was scanned between - 350 mv and - 800 mv. The determination limit of the method was 0.005 mg/kg for the sample. The calibration curves were linear in the range of 0-30 μg/L (R2=0.996, p<0.001. Repeatability of the method at concentrations of 30 and 0.5 μg/L were 2.5 and 10.5% respectively.

  10. OpenCV for secret agents

    CERN Document Server

    Howse, Joseph

    2015-01-01

    This book is for programmers who want to expand their skills by building fun, smart, and useful systems with OpenCV. The projects are ideal in helping you to think creatively about the uses of computer vision, natural user interfaces, and ubiquitous computers (in your home, car, and hand).

  11. AstroCV: Astronomy computer vision library

    Science.gov (United States)

    González, Roberto E.; Muñoz, Roberto P.; Hernández, Cristian A.

    2018-04-01

    AstroCV processes and analyzes big astronomical datasets, and is intended to provide a community repository of high performance Python and C++ algorithms used for image processing and computer vision. The library offers methods for object recognition, segmentation and classification, with emphasis in the automatic detection and classification of galaxies.

  12. Electron transfer kinetics of cytochrome c immobilized on a phenolic terminated thiol self assembled monolayer determined by scanning electrochemical microscopy

    International Nuclear Information System (INIS)

    Alizadeh, Vali; Mousavi, Mir Fazlollah; Mehrgardi, Masoud Ayatollahi; Kazemi, Sayed Habib; Sharghi, Hashem

    2011-01-01

    Highlights: → Preparing a thiolated phenolic self-assembled monolayer surface (SAM). → Application of this SAM to immobilize cytochrome C. → Scanning electrochemical microscopy used for these studies. → Determination of both tunneling electron transfer and bimolecular rate constants between the immobilized protein-substrate and probe. - Abstract: In the present manuscript, the electrochemical behavior of cytochrome c (cyt-c) immobilized onto a phenolic terminated self assembled monolayer (SAM) on a gold electrode is investigated using cyclic voltammetry (CV) and scanning electrochemical microscopy (SECM). The tunneling electron transfer (ET) rate constant between the immobilized protein and the underlying electrode surface, and also the bimolecular ET rate constant between the immobilized protein and a probe has been obtained using approach curves that were obtained by SECM. The approach curves were recorded at different substrate overpotentials in the presence of various concentrations of ferrocyanide as a probe and various surface concentrations of cyt-c; then the standard tunneling ET and bimolecular rate constants are obtained as 3.4 ± 0.3 s -1 and (2.0 ± 0.5) x 10 7 cm 3 mol -1 s -1 , respectively.

  13. Electron transfer kinetics of cytochrome c immobilized on a phenolic terminated thiol self assembled monolayer determined by scanning electrochemical microscopy

    Energy Technology Data Exchange (ETDEWEB)

    Alizadeh, Vali [Department of Chemistry, Tarbiat Modares University, P.O. Box 14115-175, Tehran (Iran, Islamic Republic of); Mousavi, Mir Fazlollah, E-mail: mousavim@modares.ac.ir [Department of Chemistry, Tarbiat Modares University, P.O. Box 14115-175, Tehran (Iran, Islamic Republic of); Mehrgardi, Masoud Ayatollahi [Department of Chemistry, University of Isfahan, Isfahan (Iran, Islamic Republic of); Kazemi, Sayed Habib [Department of Chemistry, Institute for Advanced Studies in Basic Sciences (IASBS), Zanjan (Iran, Islamic Republic of); Sharghi, Hashem [Department of Chemistry, Shiraz University, Shiraz (Iran, Islamic Republic of)

    2011-07-01

    Highlights: > Preparing a thiolated phenolic self-assembled monolayer surface (SAM). > Application of this SAM to immobilize cytochrome C. > Scanning electrochemical microscopy used for these studies. > Determination of both tunneling electron transfer and bimolecular rate constants between the immobilized protein-substrate and probe. - Abstract: In the present manuscript, the electrochemical behavior of cytochrome c (cyt-c) immobilized onto a phenolic terminated self assembled monolayer (SAM) on a gold electrode is investigated using cyclic voltammetry (CV) and scanning electrochemical microscopy (SECM). The tunneling electron transfer (ET) rate constant between the immobilized protein and the underlying electrode surface, and also the bimolecular ET rate constant between the immobilized protein and a probe has been obtained using approach curves that were obtained by SECM. The approach curves were recorded at different substrate overpotentials in the presence of various concentrations of ferrocyanide as a probe and various surface concentrations of cyt-c; then the standard tunneling ET and bimolecular rate constants are obtained as 3.4 {+-} 0.3 s{sup -1} and (2.0 {+-} 0.5) x 10{sup 7} cm{sup 3} mol{sup -1} s{sup -1}, respectively.

  14. The Limbic-Prefrontal Network Modulated by Electroacupuncture at CV4 and CV12

    Directory of Open Access Journals (Sweden)

    Jiliang Fang

    2012-01-01

    Full Text Available fMRI studies showed that acupuncture could induce hemodynamic changes in brain networks. Many of these studies focused on whether specific acupoints could activate specific brain regions and were often limited to manual acupuncture at acupoints on the limbs. In this fMRI study, we investigated acupuncture's modulation effects on brain functional networks by electroacupuncture (EA at acupoints on the midline of abdomen. Acupoints Guanyuan (CV4 and Zhongwan (CV12 were stimulated in 21 healthy volunteers. The needling sensations, brain activation, and functional connectivity were studied. We found that the limbic-prefrontal functional network was deactivated by EA at CV4 and CV12. More importantly, the local functional connectivity was significantly changed during EA stimulation, and the change persisted during the period after the stimulation. Although minor differences existed, both acupoints similarly modulated the limbic-prefrontal functional network, which is overlapped with the functional circuits associated with emotional and cognitive regulation.

  15. Effect of Sodium Cyanide on Wheat (Triticum durum cv. Altar and T. aestivum cv. Cumhuriyet)

    DEFF Research Database (Denmark)

    Gemici, Meliha; Karshenass, A.M.; Tan, Kit

    2008-01-01

    The effect of sodium cyanide on the morphology of stem, leaves and grain yields of Triticum durum cv. Altar and Triticum aestivum cv. Cumhuriyet grown under glass was studied. Seeds were planted in six different sets of pots containing ordinary garden soil. After formation of the first leaves......, the first set was used as the control and watered using ordinary bottled water sold commercially. The other five sets with T. durum cv. Altar and T. aestivum cv. Cumhuriyet seedlings were additionally watered with various concentrations of sodium cyanide, the test-quantity used being 10-50 mg/L. Growth...... of individual plants was monitored until grain production. It was found that the sodium cyanide concentrations in the feed solutions affected plant stature, with the plants becoming progressively dwarfed with increasing dosage. Anomalies in the morphological and anatomical structure of the plant were also noted...

  16. Cloud Point Extraction for Electroanalysis: Anodic Stripping Voltammetry of Cadmium.

    Science.gov (United States)

    Rusinek, Cory A; Bange, Adam; Papautsky, Ian; Heineman, William R

    2015-06-16

    Cloud point extraction (CPE) is a well-established technique for the preconcentration of hydrophobic species from water without the use of organic solvents. Subsequent analysis is then typically performed via atomic absorption spectroscopy (AAS), UV-vis spectroscopy, or high performance liquid chromatography (HPLC). However, the suitability of CPE for electroanalytical methods such as stripping voltammetry has not been reported. We demonstrate the use of CPE for electroanalysis using the determination of cadmium (Cd(2+)) by anodic stripping voltammetry (ASV). Rather than using the chelating agents which are commonly used in CPE to form a hydrophobic, extractable metal complex, we used iodide and sulfuric acid to neutralize the charge on Cd(2+) to form an extractable ion pair. This offers good selectivity for Cd(2+) as no interferences were observed from other heavy metal ions. Triton X-114 was chosen as the surfactant for the extraction because its cloud point temperature is near room temperature (22-25 °C). Bare glassy carbon (GC), bismuth-coated glassy carbon (Bi-GC), and mercury-coated glassy carbon (Hg-GC) electrodes were compared for the CPE-ASV. A detection limit for Cd(2+) of 1.7 nM (0.2 ppb) was obtained with the Hg-GC electrode. ASV with CPE gave a 20x decrease (4.0 ppb) in the detection limit compared to ASV without CPE. The suitability of this procedure for the analysis of tap and river water samples was demonstrated. This simple, versatile, environmentally friendly, and cost-effective extraction method is potentially applicable to a wide variety of transition metals and organic compounds that are amenable to detection by electroanalytical methods.

  17. Functionalized Nanoporous Track Etched {beta}-PVDF Membrane Electrodes for Lead (II) Determination by Square Wave Anodic Stripping Voltammetry

    Energy Technology Data Exchange (ETDEWEB)

    Bessbousse, H [Laboratoire des Solides Irradies, CEA-CNRS-Ecole Polytechnique, 91128 Palaiseau (France); Nadhakumar, I [School of Chemistry, University of Southampton, University Road, Southampton S017 1BJ (United Kingdom); Decker, M; Clochard, M -C; Wade, T L [Laboratoire des Solides Irradies, CEA-CNRS-Ecole Polytechnique, 91128 Palaiseau (France); Barsbay, M [Hacettepe University, Department of Chemistry, Polymer Chemistry Division, 06800 Beytepe Ankara (Turkey)

    2012-09-15

    Track etched functionalized nanoporous {beta}-PVDF membrane electrodes, or functionalized membrane electrodes (FME), are thin-layer cells made from poly(acrylic acid) (PAA) functionalized nanoporous {beta}-poly(vinylidene fluoride) ({beta}-PVDF) membranes with thin Au films sputtered on each side as electrodes. The Au film is thin enough that the pores of the membranes are not completely covered. The PAA functionalization is specifically localised in the walls of the nanoporous {beta}-PVDF membrane by grafting. The PAA is a cation exchange polymer that adsorbs metal ions, such as Pb{sup 2+}, from aqueous solutions concentrating the ions into the membrane. After a time the FME is transferred to an electrochemical cell for analysis. A negative potential is applied to the Au film of the FME for a set time to reduce the adsorbed ions onto the Au film working electrode. The other metalized side of the FME functions as a counter electrode. Finally, square-wave anodic stripping voltammetry (SW-ASV) is performed on the FME to determine the metal ion concentrations in the original solution. The calibration curve of charge versus log concentration has a Temkin isotherm form. The FME membranes are 9 {mu}m thick and have 40 nm diameter pores with a density of 10{sup 10} pores/cm{sup 2}. This high pore density provides a large capacity for ion adsorption. Au ingress in the pores during sputtering forms a random array of nanoelectrodes. Like surface modified electrodes for adsorptive stripping voltammetry, the pre-concentration step for the FME is performed at open circuit. The zero current intercept of the calibration for Pb{sup 2+} is 0.13 ppb ({mu}g/L) and a detection limit of 0.050 ppb based on 3S/N from blank measurements. Voltammetry (CV) and chronoapmerometry (CA) were used to characterize the system. The apparent diffusion coefficient (D) for Pb{sup 2+} in the PAA functionalized pores was determined to be 2.44 x 10{sup -7} cm{sup 2}/s and the partition coefficient (p

  18. Cyclic voltammetry, square wave voltammetry, electrochemical impedance spectroscopy and colorimetric method for hydrogen peroxide detection based on chitosan/silver nanocomposite

    Directory of Open Access Journals (Sweden)

    Hoang V. Tran

    2018-05-01

    Full Text Available In this paper, we demonstrate a promising method to fabricate a non-enzymatic stable, highly sensitive and selective hydrogen peroxide sensor based on a chitosan/silver nanoparticles (CS/AgNPs hybrid. Using this composite, we elaborated both electrochemical and colorimetric sensors for hydrogen peroxide detection. The colorimetric sensor is based on a homogenous reaction which fades the color of CS/AgNPs solutions from red-orange to colorless depending on hydrogen peroxide concentration. For the electrochemical sensor, CS/AgNPs were immobilized on glassy carbon electrodes and hydrogen peroxide was measured using cyclic voltammetry, square wave voltammetry and electrochemical impedance spectroscopy. The response time is less than 10 s and the detection limit is 5 μM. Keywords: Spectrophotometric detection, Electrochemical impedance spectroscopy, Square wave voltammetry, Cyclic voltammetry, Chitosan/silver nanoparticles (CS/AgNPs hybrid, Hydrogen peroxide

  19. Renal scan

    Science.gov (United States)

    ... this page: //medlineplus.gov/ency/article/003790.htm Renal scan To use the sharing features on this ... anaphylaxis . Alternative Names Renogram; Kidney scan Images Kidney anatomy Kidney - blood and urine flow References Chernecky CC, ...

  20. CT Scan

    Science.gov (United States)

    ... disease, lung nodules and liver masses Monitor the effectiveness of certain treatments, such as cancer treatment Detect ... scan done in a hospital or an outpatient facility. CT scans are painless and, with newer machines, ...

  1. CV controls from design to operation

    CERN Document Server

    Blanc, D

    2002-01-01

    The cooling and Ventilation (CV) group has emphasised the need to redefine its organisational structure at the end of 98. The main objective of this operation was to ensure the CV group to be more competitive and efficient through the growing tasks of the LHC projects. The main evolution given to this reorganisation is that the new structure is more project oriented and then operates on three distinct axes: Design, Work and Operation. Process control project management requires a complete and early interaction and participation of all the actors involved. This procedure to be efficient and constructive must be considered and performed not only during the design stage but along the project planning phases and must go beyond the completion work including the process control operation activity. The paper explains the present project management for process control. It describes the present constraints and gives suggestions to a different approach to these projects to improve performances and efficiency of a contr...

  2. Immobilization, hybridization, and oxidation of synthetic DNA on gold surface: Electron transfer investigated by electrochemistry and scanning tunneling microscopy

    Energy Technology Data Exchange (ETDEWEB)

    McEwen, Gerald D.; Chen Fan [Biological Engineering Program, Department of Biological and Irrigation Engineering, Utah State University, 4105 Old Main Hill, Logan, UT 84322-4105 (United States); Zhou Anhong, E-mail: Anhong.Zhou@usu.edu [Biological Engineering Program, Department of Biological and Irrigation Engineering, Utah State University, 4105 Old Main Hill, Logan, UT 84322-4105 (United States)

    2009-06-08

    Fundamental understanding of interfacial electron transfer (ET) among electrolyte/DNA/solid-surface will facilitate the design for electrical detection of DNA molecules. In this report, the electron transfer characteristics of synthetic DNA (sequence from pathogenic Cryptosporidium parvum) self-assembled on a gold surface was electrochemically studied. The effects of immobilization order on the interface ET related parameters such as diffusion coefficient (D{sub 0}), surface coverage ({theta}{sub R}), and monolayer thickness (d{sub i}) were determined by cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS). DNA surface density ({Gamma}{sub DNA}) was determined by the integration of the charge of the electro-oxidation current peaks during the initial cyclic voltammetry scans. It was found that the DNA surface densities at different modifications followed the order: {Gamma}{sub DNA} (dsS-DNA/Au) > {Gamma}{sub DNA} (MCH/dsS-DNA/Au) > {Gamma}{sub DNA} (dsS-DNA/MCH/Au). It was also revealed that the electro-oxidation of the DNA modified gold surface would involve the oxidation of nucleotides (guanine and adenine) with a 5.51 electron transfer mechanism and the oxidative desorption of DNA and MCH molecules by a 3 electron transfer mechanism. STM topography and current image analysis indicated that the surface conductivity after each surface modification followed the order: dsS-DNA/Au < MCH/dsS-DNA/Au < oxidized MCH/dsS-DNA/Au < Hoechst/oxidized MCH/dsS-DNA/Au. The results from this study suggested a combination of variations in immobilization order may provide an alternative approach for the optimization of DNA hybridization and the further development for electrical detection of DNA.

  3. EARTH, MOON, SUN, AND CV ACCRETION DISKS

    International Nuclear Information System (INIS)

    Montgomery, M. M.

    2009-01-01

    Net tidal torque by the secondary on a misaligned accretion disk, like the net tidal torque by the Moon and the Sun on the equatorial bulge of the spinning and tilted Earth, is suggested by others to be a source to retrograde precession in non-magnetic, accreting cataclysmic variable (CV) dwarf novae (DN) systems that show negative superhumps in their light curves. We investigate this idea in this work. We generate a generic theoretical expression for retrograde precession in spinning disks that are misaligned with the orbital plane. Our generic theoretical expression matches that which describes the retrograde precession of Earths' equinoxes. By making appropriate assumptions, we reduce our generic theoretical expression to those generated by others, or to those used by others, to describe retrograde precession in protostellar, protoplanetary, X-ray binary, non-magnetic CV DN, quasar, and black hole systems. We find that spinning, tilted CV DN systems cannot be described by a precessing ring or by a precessing rigid disk. We find that differential rotation and effects on the disk by the accretion stream must be addressed. Our analysis indicates that the best description of a retrogradely precessing spinning, tilted, CV DN accretion disk is a differentially rotating, tilted disk with an attached rotating, tilted ring located near the innermost disk annuli. In agreement with the observations and numerical simulations by others, we find that our numerically simulated CV DN accretion disks retrogradely precess as a unit. Our final, reduced expression for retrograde precession agrees well with our numerical simulation results and with selective observational systems that seem to have main-sequence secondaries. Our results suggest that a major source to retrograde precession is tidal torques like that by the Moon and the Sun on the Earth. In addition, these tidal torques should be common to a variety of systems where one member is spinning and tilted, regardless if

  4. Penentuan Unsur Tanah Jarang Kelompok Sedang secara Voltammetri Pindai Linier Menggunakan Elektrode Grafit Pensil

    Directory of Open Access Journals (Sweden)

    Yeni Wahyuni Hartati

    2016-01-01

    Full Text Available Rare earth elements play an important role in a variety of applications, mostly for high-tech industries. But their presence in mineral jointly separation makes it difficult to determine the content of rare earths because each element has physical and chemical properties are almost identical. The purpose of this study is the use of a linear scan voltammetry method to study the electrochemical characteristics of the medium rare earth element group (Sm, Gd, Eu, Tb, as an alternative method of separation and analysis of rare earth elements. The electrode used is a graphite pencil electrodes without modification, with a variety of supporting electrolyte. The results obtained show some supporting electrolyte provides good reduction peak for gadolinium, compared to the peaks of the reduction potential of the single rare earth ions other. The potential range of the most well using pencil graphite electrode obtained at 0.50 V to -1.00 V. Analysis of single gadolinium provide linear regression equation in a concentration range of 4.0 to 10.0 mg/L by the equation Y = 0.9862 X + 0.828 with R2 = 0.9954. The limit of detection is determined from the linear regression obtained 0.72 mg / L.

  5. An environmental friendly electrode and extended cathodic potential window for anodic stripping voltammetry of zinc detection

    International Nuclear Information System (INIS)

    Dueraning, Anisah; Kanatharana, Proespichaya; Thavarungkul, Panote; Limbut, Warakorn

    2016-01-01

    This work reports on a novel polyeriochrome black T (poly(EBT) modified electrode for use as an environmentally-friendly electrode material that extends the cathodic potential window and improves the sensitivity and repeatability to detect zinc in industrial wastewater. The poly(EBT) film on the GCE surface was fabricated by electropolymerization. The surface morphology and electrochemical behavior of the modified electrode were characterized by scanning electron microscopy, fourier transform infrared spectroscopy and anodic stripping voltammetry. Under optimal conditions, the poly(EBT)/GCE exhibited a high hydrogen overvoltage (extended cathodic potential window). It provided a high sensitivity, a wide linear range (1.0 to 400.0 μg L −1 ), a low detection limit (0.9 μg L −1 ), had excellent repeatability and good recoveries (95% to 105%). This proposed modified electrode was applied to the determination of zinc in wastewater samples, and the results were consistent with those of an inductively coupled plasma atomic emission spectroscopy analysis.

  6. Voltammetry for the charge transfer at two immiscible electrolyte solutions interface

    International Nuclear Information System (INIS)

    Kihara, S.; Suzuki, M.; Maeda, K.; Ogura, K.; Matsui, M.; Yoshida, Z.

    1989-01-01

    The voltammetry for the charge transfer (VCT) at the interface of immicible solutions is a very powerful method for understanding the dynamic features of the charge transfer because of its unmatched advantage that the transfer energy and the number of charges transferred can be measured simultaneously and in situ. In the present paper, several novel systems for electron transfer are outlined, and the following topics are discussed based on results obtained by the current scan polarography at the solution dropping electrode developed as a technique for VCT: the relation between the half-wave potential in VCT for ion transfer and the characteristics of the ion transferred; the relation between the half-wave potential in VCT for electron transfer and the electrochemical nature of a redox couple added in water and that added in organic solution; and the ion transfer through a liquid membrane promoted by electron transfer. Observations are presented and discussion is made on the characteristics of ion transfer polarograms, those of electron transfer polarograms, and ion transfer promoted by electron transfer at a liquid/membrane interface. (N.K.)

  7. Nanostructured platform for the detection of Neisseria gonorrhoeae using electrochemical impedance spectroscopy and differential pulse voltammetry

    International Nuclear Information System (INIS)

    Singh, R.; Matharu, Z.; Srivastava, A.K.; Sood, S.; Gupta, R.K.; Malhotra, B.D.

    2012-01-01

    We report on a nanocomposite based genosensor for the detection of Neisseria gonorrhoeae, a bacterium causing the sexually transmitted disease gonorrhoea. Amino-labeled probe DNA was covalently immobilized on electrochemically prepared polyaniline and iron oxide (PANI-Fe 3 O 4 ) nanocomposite film on an indium tin oxide (ITO) electrode. Scanning electron microscopy, transmission electron microscopy, electrochemical impedance spectroscopy (EIS) and differential pulse voltammetry (DPV) techniques have been employed to characterize surface of the modified electrode. The genosensor has detection limits of 1 x 10 -15 M and 1 x 10 -17 M, respectively, using the EIS and DPV techniques. This biosensor can discriminate a complementary sequence from a single-base mismatch and from non-complementary DNA, and has been utilized for detection of DNA extracted from N. gonorrhoeae culture, and from patient samples with N. gonorrhoeae. It is found to exhibit good specificity for N. gonorrhoeae species and shows no response towards non-gonorrhoeae type of Neisseria species (NgNs) and other gram-negative bacterias (GNBs). The affinity constant for hybridization calculated using the Langmuir adsorption isotherm model is found to be 3. 39 x 10 8 M -1 . (author)

  8. Surface characterization by X-ray photoelectron spectroscopy and cyclic voltammetry of products formed during the potentiostatic reduction of chalcopyrite

    International Nuclear Information System (INIS)

    Nava, Dora; Gonzalez, Ignacio; Leinen, Dietmar; Ramos-Barrado, Jose R.

    2008-01-01

    Surface characterization of the transient products that precede chalcocite formation during chalcopyrite reduction was carried out. The experimental strategy employed in the present work consisted of the application of different potential pulses (fixed energetic conditions) on the surface of chalcopyrite electrodes in 1.7 M H 2 SO 4 . The chemical products formed at different potential pulses were characterized by cyclic voltammetry (CV) and XPS. Each electrogenerated species presented a specific voltammetric behavior and an XPS spectrum, in which the values of principal photoelectronic peak bond energies for Cu 2p 3/2 , Fe 2p 3/2 and S 2p 3/2 and the atomic concentrations were considered. Several potential intervals could be identified: in 0.115 ≥ E cat ≥ -0.085 V vs. SHE, an intermediate copper sulfide is formed whose composition is between those of chalcopyrite and bornite, such as talnakhite. The reduction of this product occurs slowly, giving bornite at potentials less than -0.085 V. In the applied potential region -0.085 ≥ E cat > -0.185 V, the bornite gradually decomposes causing the incomplete conversion to chalcocite. In the potential interval -0.185 > E cat ≥ -0.285 V, energetic conditions are large enough to allow the immediate decomposition of bornite, forming chalcocite in a more quantitative manner

  9. Kinetics of degradation of ascorbic acid by cyclic voltammetry method

    Directory of Open Access Journals (Sweden)

    Grudić Veselinka V.

    2015-01-01

    Full Text Available Cyclic voltammetry was used to examine the kinetics of degradation of ascorbic acid (AA at different temperatures. It has been shown that the reduction of the concentration of AA in all temperatures follow the kinetics of the first order reaction. The rate constant of the oxidation reaction increases with temperature as follows: 5x10-5; 2x10-4; 1x10-3 and 3x10-3 min-1 at temperatures of 25°C, 35°C, 65°C and 90°C, respectively. The temperature dependence of the rate constant follows Arrhenius equation, and the value of activation energy of the reaction degradation is 48.2 kJ mol-1 . The effect of storage time at a temperature of 90 °C on AA content in fresh juice of green peppers was investigated. It was shown that AA oxidation reaction in the juice is also the first order reaction, while the lower rate constant in relation to the pure AA (5x10-3 min-1 indicates the influence of other substances present in peppers.

  10. Fast Selective Detection of Pyocyanin Using Cyclic Voltammetry

    Science.gov (United States)

    Alatraktchi, Fatima AlZahra’a; Breum Andersen, Sandra; Krogh Johansen, Helle; Molin, Søren; Svendsen, Winnie E.

    2016-01-01

    Pyocyanin is a virulence factor uniquely produced by the pathogen Pseudomonas aeruginosa. The fast and selective detection of pyocyanin in clinical samples can reveal important information about the presence of this microorganism in patients. Electrochemical sensing of the redox-active pyocyanin is a route to directly quantify pyocyanin in real time and in situ in hospitals and clinics. The selective quantification of pyocyanin is, however, limited by other redox-active compounds existing in human fluids and by other metabolites produced by pathogenic bacteria. Here we present a direct selective method to detect pyocyanin in a complex electroactive environment using commercially available electrodes. It is shown that cyclic voltammetry measurements between −1.0 V to 1.0 V reveal a potential detection window of pyocyanin of 0.58–0.82 V that is unaffected by other redox-active interferents. The linear quantification of pyocyanin has an R2 value of 0.991 across the clinically relevant concentration range of 2–100 µM. The proposed method was tested on human saliva showing a standard deviation of 2.5% ± 1% (n = 5) from the known added pyocyanin concentration to the samples. This inexpensive procedure is suggested for clinical use in monitoring the presence and state of P. aeruginosa infection in patients. PMID:27007376

  11. Cyclic voltammetry and RBS study of paint components

    International Nuclear Information System (INIS)

    Bowman, Lynn; Spencer, Dirk; Muntele, Claudiu; Muntele, Iulia; Ila, D.

    2007-01-01

    Heavy metals and metalloid ions are found in environmental matrices. The most toxic are lead, cadmium and mercury. These three heavy metals have no biological function and are toxic at all concentrations. Lead is one of the most insidious heavy metals and is introduced into the environment by many different means. It persists in both urban and rural settings, being found in paint chips, pottery, crystal and pharmaceutical and nutritional products. The analysis of heavy elements such as lead in soil is of particular importance [W.T. Sturges, R.M. Harrison, Sci. Total Environ. 44 (3) (1985) 225; M.L. Lepow, L. Bruckman, M. Gillette, S. Markowitz, R. Robino, J. Kapish, Environ. Res. 10 (3) (1975) 415; A.E. Daniels, J.R. Kominsky, P.J. Clark, J. Hazard. Mater. B 87 (2001) 117; G. Hutter, D. Moshman, J. Hazard. Mater. 40 (1995) 1]. In preparing the methods for lead detection in paint, we have used Rutherford backscattering spectrometry (RBS) in order to study the type and amount of heavy metal content in paint samples collected at various sites in the historic campus at A and M University (AAMU). We will show the results of our study with emphasis on comparison of what we learned about presence of lead in paints using our ion beam methods compared with the analysis of lead in paints using cyclic voltammetry

  12. Anodic stripping voltammetry of synthesized CdS nanoparticles at boron-doped diamond electrodes

    Energy Technology Data Exchange (ETDEWEB)

    Hayat, Mohammad; Ivandini, Tribidasari A., E-mail: ivandini.tri@sci.ui.ac.id; Saepudin, Endang [Department of Chemistry, FMIPA, Universitas Indonesia, Kampus UI Depok (Indonesia); Einaga, Yasuaki [Department of Chemistry, Keio University (Japan)

    2016-04-19

    Cadmium sulphide (CdS) nanoparticles were chemically synthesized using reverse micelles microreactor methods. By using different washing treatments, UV-Vis spectroscopy showed that the absorption peaks appeared at 465 nm, 462 nm, 460 nm, and 459 nm respectively for CdS nanoparticles without and with 1, 2, and 3 times washing treatments using pure water. In comparison with the absorbance peak of bulk CdS at 512 nm, the shifted absorption peaks, indicates that the different sizes of CdS can be prepared. Anodic stripping voltammetry of the CdS nanoparticles was then studied at a boron-doped diamond electrode using 0.1 M KClO{sub 4} and 0.1 M HClO{sub 4} as the electrolytes. A scan rate of 100 mV/s with a deposition potential of -1000 mV (vs. Ag/AgCl) for 60 s at a potential scan from -1600 mV to +800 mV (vs. Ag/AgCl) was applied as the optimum condition of the measurements. Highly-accurate linear calibration curves (R{sup 2} = 0.99) in 0.1 M HClO{sub 4} with the sensitivity of 0.075 mA/mM and the limit of detection of 81 µM in 0.1 M HClO{sub 4} can be achieved, which is promising for an application of CdS nanoparticles as a label for biosensors.

  13. Simultaneous determination of copper, lead and cadmium by cathodic adsorptive stripping voltammetry using artificial neural network

    International Nuclear Information System (INIS)

    Ensafi, Ali A.; Khayamian, T.; Benvidi, A.; Mirmomtaz, E.

    2006-01-01

    In this work, simultaneous determination of two groups of elements consisting of Pb(II)-Cd(II) and Cu(II)-Pb(II)-Cd(II) using adsorptive cathodic stripping voltammetry are described. The method is based on accumulation of these metal ions on mercury electrode using xylenol orange as a suitable complexing agent. The potential was scanned to the negative direction and the differential pulse stripping voltammograms were recorded. The instrumental and chemical factors were optimized using artificial neural network. The optimized conditions were obtained in pH of 5.5, xylenol orange concentration of 4.0 μM, accumulation potential of -0.50 V, accumulation time of 30 s, scan rate of 10 mV/s and pulse height of 70 mV. The relationship between the peak current versus concentration was linear over the range of 5.0-150.0 ng ml -1 for cadmium and 5.0-150.0 ng ml -1 for lead. The limits of detection were 0.98 and 1.18 ng ml -1 for lead and cadmium ions, respectively. In simultaneous determination of Cu(II), Pb(II) and Cd(II) there are inter-metallic interactions, which result a non-linear relationship between the peak current and the ionic concentration for each of the element. Therefore, an artificial neural network was used as the multivariate calibration method. The ANN was constructed with three neurons as the output layer for the simultaneous determination of the three elements. The constructed model was able to predict the concentration of the elements in the ranges of 1.0-50.0, 5.0-200.0 and 10.0-200.0 ng ml -1 , for Cu(II), Pb(II) and Cd(II), respectively

  14. Non-conductive nanomaterial enhanced electrochemical response in stripping voltammetry: The use of nanostructured magnesium silicate hollow spheres for heavy metal ions detection.

    Science.gov (United States)

    Xu, Ren-Xia; Yu, Xin-Yao; Gao, Chao; Jiang, Yu-Jing; Han, Dong-Dong; Liu, Jin-Huai; Huang, Xing-Jiu

    2013-08-06

    Nanostructured magnesium silicate hollow spheres, one kind of non-conductive nanomaterials, were used in heavy metal ions (HMIs) detection with enhanced performance for the first time. The detailed study of the enhancing electrochemical response in stripping voltammetry for simultaneous detection of ultratrace Cd(2+), Pb(2+), Cu(2+) and Hg(2+) was described. Electrochemical properties of modified electrodes were characterized by cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS). The operational parameters which have influence on the deposition and stripping of metal ions, such as supporting electrolytes, pH value, and deposition time were carefully studied. The anodic stripping voltammetric performance toward HMIs was evaluated using square wave anodic stripping voltammetry (SWASV) analysis. The detection limits achieved (0.186nM, 0.247nM, 0.169nM and 0.375nM for Cd(2+), Pb(2+), Cu(2+) and Hg(2+)) are much lower than the guideline values in drinking water given by the World Health Organization (WHO). In addition, the interference and stability of the modified electrode were also investigated under the optimized conditions. An interesting phenomenon of mutual interference between different metal ions was observed. Most importantly, the sensitivity of Pb(2+) increased in the presence of certain concentrations of other metal ions, such as Cd(2+), Cu(2+) and Hg(2+) both individually and simultaneously. The proposed electrochemical sensing method is thus expected to open new opportunities to broaden the use of SWASV in analysis for detecting HMIs in the environment. Copyright © 2013 Elsevier B.V. All rights reserved.

  15. Characterization of carbon nanotubes decorated with NiFe2O4 magnetic nanoparticles as a novel electrochemical sensor: Application for highly selective determination of sotalol using voltammetry

    International Nuclear Information System (INIS)

    Ensafi, Ali A.; Allafchian, Ali R.; Rezaei, B.; Mohammadzadeh, R.

    2013-01-01

    A magnetic nano‐composite of multiwall carbon nanotube, decorated with NiFe 2 O 4 nanoparticles, was synthesized with citrate sol–gel method. The multiwall carbon nanotubes decorated with NiFe 2 O 4 nanoparticles (NiFe 2 O 4 –MWCNTs) were characterized with different methods such as Fourier transform infrared spectroscopy (FT‐IR), transmission electron microscopy (TEM), atomic force microscopy (AFM), vibrating sample magnetometer (VSM), cyclic voltammetry (CV), and electrochemical impedance spectroscopy (EIS). The new nano-composite acts as a suitable electrocatalyst for the oxidation of sotalol at a potential of 500 mV at the surface of the modified electrode. Linear sweep voltammetry exhibited two wide linear dynamic ranges of 0.5–1000 μmol L −1 sotalol with a detection limit of 0.09 μmol L −1 . The modified electrode was used as a novel electrochemical sensor for the determination of sotalol in real samples such as pharmaceutical, patient and safe human urine. - Graphical abstract: Multiwall carbon nanotube, decorated with NiFe 2 O 4 nanoparticles, was prepared using citrate sol–gel method. We characterized the new nanoparticles with different spectroscopic and voltammetric methods. The nano sensor was used as a voltammetric sensor for the determination of trace amounts of sotalol at pH 7.0. Highlights: ► We synthesized and prepared new sensor, multiwall carbon nanotubes decorated with NiFe 2 O 4 . ► Several spectroscopic and voltammetric methods were used to study its characteristics. ► The nanoparticles act as suitable electrocatalyst for the oxidation of sotalol. ► Sotalol could be measured as low as 0.09 μmol L −1 using linear sweep voltammetry.

  16. Learning openCV computer vision with the openCV library

    CERN Document Server

    Bradski, Gary

    2008-01-01

    Learning OpenCV puts you right in the middle of the rapidly expanding field of computer vision. Written by the creators of OpenCV, the widely used free open-source library, this book introduces you to computer vision and demonstrates how you can quickly build applications that enable computers to see" and make decisions based on the data. With this book, any developer or hobbyist can get up and running with the framework quickly, whether it's to build simple or sophisticated vision applications

  17. Cooperative scans

    NARCIS (Netherlands)

    M. Zukowski (Marcin); P.A. Boncz (Peter); M.L. Kersten (Martin)

    2004-01-01

    textabstractData mining, information retrieval and other application areas exhibit a query load with multiple concurrent queries touching a large fraction of a relation. This leads to individual query plans based on a table scan or large index scan. The implementation of this access path in most

  18. Organisation des travaux ST-CV

    CERN Document Server

    Martel, C; CERN. Geneva. ST Division

    2003-01-01

    Débutée il y a deux ans, la phase de construction des installations de refroidissement du LHC a atteint en 2003 son apogée. De nombreux autres projets sont également gérés par le groupe dans divers secteurs du laboratoire. La spécificité du groupe est de réaliser des installations complexes impliquant des spécificités diverses telles qu’aéraulique, hydraulique, électrique, etc. Pour faire face à ces demandes la section travaux du groupe ST CV a adopté une structure capable de réaliser ces divers projets avec un minimum de personnel. La première partie de ce document décrit l’organisation de la section travaux ST CV. Dans une deuxième partie, les auteurs dressent un état des lieux des chantiers par projet en décrivant plus particulièrement les activités dans les domaines du traitement d’air et de refroidissement par eau.

  19. Retendering of ST-CV maintenance contract

    CERN Document Server

    Battistin, M

    2003-01-01

    During the next three years, the ST/CV group will be deeply involved in the installation works for the LHC project. During this period the need for maintenance activity will decrease. The minimum level will be reached during the “long shutdown” of the PS and SPS machines in 2005. The budget for the maintenance will decrease accordingly, thus the CV group had to review its maintenance strategy. The new contract, which started on January 1st 2003, has been defined to cope with these workload variations during the next years and to guarantee the minimum maintenance activity on the existing equipment. A lump-sum contract based on a win-win strategy has been discarded. The contractor no longer has to guarantee the performance of the CERN cooling and ventilation systems. A new price list strategy based on performance indicators and penalties has been chosen. The contractor now has to guarantee the performance of every maintenance operation demanded by CERN. This modification obliged the Operation section of the...

  20. Electrochemical Study of Delta-9-Tetrahydrocannabinol by Cyclic Voltammetry Using Screen Printed Electrode, Improvements in Forensic Analysis

    Directory of Open Access Journals (Sweden)

    Marco Antonio BALBINO

    2016-12-01

    Full Text Available Rapid screening of seized drugs is a continuing problem for governmental laboratories and customs agents. Recently new and cheaper methods based on electrochemical sensing have been developed for the detection of illicit drugs. Screen printed electrodes are particularly useful in this regard and can provide excellent sensitivity. In this study, a carbon screen printed electrode for the voltammetric analysis of D9-THC was developed. The analysis was performed using cyclic voltammetry with 0.15 mol×L-1 potassium nitrate as a supporting electrolyte. In the analysis, a D9-THC standard solution was added to the surface electrode by a drop coating method. A study of scan rate, time of pre-concentration, and concentration influence parameters showed versatility during the investigation. The high sensitivity, quantitative capability and low limit of detection (1.0 µmol×L-1 demonstrate that this electrochemical method should be an attractive alternative in forensic investigations of seized samples.

  1. Electrocatalytic Oxidation of Hydroxylamine at a Quinizarine Modified Glassy Carbon Electrode: Application to Differential Pulse Voltammetry Detection of Hydroxylamine

    OpenAIRE

    MAZLOUMARDAKANI, Mohammad; KARAMI, Payam EBRAHIMI

    2014-01-01

    The electrocatalytic behavior of hydroxylamine was studied on a glassy carbon electrode modified by electrodeposition of quinizarine, using cyclic voltammetry, chronoamperometry, and rotating disk voltammetry as diagnostic techniques. Cyclic voltammetry showed that the catalytic current of the system depends on the concentration of hydroxylamine. The magnitude of the peak current for quinizarine increased sharply in the presence of hydroxylamine and proportional to hydroxylamine conc...

  2. Study of temperature, air dew point temperature and reactant flow effects on proton exchange membrane fuel cell performances using electrochemical spectroscopy and voltammetry techniques

    Energy Technology Data Exchange (ETDEWEB)

    Wasterlain, S.; Hissel, D. [FC LAB, Techn' Hom, rue Thierry Mieg, 90010 Belfort Cedex (France); FEMTO-ST (UMR CNRS 6174), ENISYS Department, University of Franche-Comte, Techn' Hom, rue Thierry Mieg, 90010 Belfort Cedex (France); Candusso, D.; Harel, F. [FC LAB, Techn' Hom, rue Thierry Mieg, 90010 Belfort Cedex (France); INRETS, The French National Institute for Transport and Safety Research, Techn' Hom, rue Thierry Mieg, 90010 Belfort Cedex (France); Bergman, P.; Menard, P.; Anwar, M. [University of Connecticut, Connecticut Global Fuel Cell Center Department of Electrical and Computer Engineering, 44 Weaver Road, Unit 5233, Storrs, CT 06269-5233 (United States)

    2010-02-15

    A single PEMFC has been operated by varying the assembly temperature, the air dew point temperature and the anode/cathode stoichiometry rates with the aim to identify the parameters and combinations of factors affecting the cell performance. Some of the experiments were conducted with low humidified reactants (relative humidity of 12%). The FC characterizations tests have been conducted using in situ electrochemical methods based on load current and cell voltage signal analysis, namely: polarization curves, EIS measurements, cyclic and linear sweep voltammetries (CV and LSV). The impacts of the parameters on the global FC performances were observed using the polarization curves whereas EIS, CV and LSV test results were used to discriminate the different voltage loss sources. The test results suggest that some parameter sets allow maximal output voltages but can also induce material degradation. For instance, higher FC temperature and air flow values can induce significant electrical efficiency benefits, notably by increasing the reversible potential and the reaction kinetics. However, raising the cell temperature can also gradually dry the FC and increase the risk of membrane failure. LSV has also shown that elevated FC temperature and relative humidity can also accelerate the electrolyte degradation (i.e. slightly higher fuel crossover rate) and reduce the lifetime consequently. (author)

  3. Study of temperature, air dew point temperature and reactant flow effects on proton exchange membrane fuel cell performances using electrochemical spectroscopy and voltammetry techniques

    Science.gov (United States)

    Wasterlain, S.; Candusso, D.; Hissel, D.; Harel, F.; Bergman, P.; Menard, P.; Anwar, M.

    A single PEMFC has been operated by varying the assembly temperature, the air dew point temperature and the anode/cathode stoichiometry rates with the aim to identify the parameters and combinations of factors affecting the cell performance. Some of the experiments were conducted with low humidified reactants (relative humidity of 12%). The FC characterizations tests have been conducted using in situ electrochemical methods based on load current and cell voltage signal analysis, namely: polarization curves, EIS measurements, cyclic and linear sweep voltammetries (CV and LSV). The impacts of the parameters on the global FC performances were observed using the polarization curves whereas EIS, CV and LSV test results were used to discriminate the different voltage loss sources. The test results suggest that some parameter sets allow maximal output voltages but can also induce material degradation. For instance, higher FC temperature and air flow values can induce significant electrical efficiency benefits, notably by increasing the reversible potential and the reaction kinetics. However, raising the cell temperature can also gradually dry the FC and increase the risk of membrane failure. LSV has also shown that elevated FC temperature and relative humidity can also accelerate the electrolyte degradation (i.e. slightly higher fuel crossover rate) and reduce the lifetime consequently.

  4. Radionuclide scanning

    International Nuclear Information System (INIS)

    Shapiro, B.

    1986-01-01

    Radionuclide scanning is the production of images of normal and diseased tissues and organs by means of the gamma-ray emissions from radiopharmaceutical agents having specific distributions in the body. The gamma rays are detected at the body surface by a variety of instruments that convert the invisible rays into visible patterns representing the distribution of the radionuclide in the body. The patterns, or images, obtained can be interpreted to provide or to aid diagnoses, to follow the course of disease, and to monitor the management of various illnesses. Scanning is a sensitive technique, but its specificity may be low when interpreted alone. To be used most successfully, radionuclide scanning must be interpreted in conjunction with other techniques, such as bone radiographs with bone scans, chest radiographs with lung scans, and ultrasonic studies with thyroid scans. Interpretation is also enhanced by providing pertinent clinical information because the distribution of radiopharmaceutical agents can be altered by drugs and by various procedures besides physiologic and pathologic conditions. Discussion of the patient with the radionuclide scanning specialist prior to the study and review of the results with that specialist after the study are beneficial

  5. Modern applications of polarography and voltammetry to inorganic analysis

    International Nuclear Information System (INIS)

    Lee, A.F.

    1983-01-01

    This report summarized developments in polarography and voltametry up to 1982. Modern electronic equipment and scanning waveforms are explained briefly. Extensive tables of recent inorganic applications, mainly in the geochemical and metallurgical fields, are included, and show results based on the new approaches

  6. IJ-OpenCV: Combining ImageJ and OpenCV for processing images in biomedicine.

    Science.gov (United States)

    Domínguez, César; Heras, Jónathan; Pascual, Vico

    2017-05-01

    The effective processing of biomedical images usually requires the interoperability of diverse software tools that have different aims but are complementary. The goal of this work is to develop a bridge to connect two of those tools: ImageJ, a program for image analysis in life sciences, and OpenCV, a computer vision and machine learning library. Based on a thorough analysis of ImageJ and OpenCV, we detected the features of these systems that could be enhanced, and developed a library to combine both tools, taking advantage of the strengths of each system. The library was implemented on top of the SciJava converter framework. We also provide a methodology to use this library. We have developed the publicly available library IJ-OpenCV that can be employed to create applications combining features from both ImageJ and OpenCV. From the perspective of ImageJ developers, they can use IJ-OpenCV to easily create plugins that use any functionality provided by the OpenCV library and explore different alternatives. From the perspective of OpenCV developers, this library provides a link to the ImageJ graphical user interface and all its features to handle regions of interest. The IJ-OpenCV library bridges the gap between ImageJ and OpenCV, allowing the connection and the cooperation of these two systems. Copyright © 2017 Elsevier Ltd. All rights reserved.

  7. Study of colored anodized aluminum with calcon in sulfuric acidic solution using cyclic voltammetry and impedance measurement methods

    Energy Technology Data Exchange (ETDEWEB)

    Norouzi, P.; Ganjali, M.R.; Golmohamaddi, M.; Mousavi, S. [Department of Chemistry, Faculty of Science, University of Tehran, Tehran (Iran); Vatankhah, G. [Iranian Organization for Science and Technology (IROST), Isfahan Center, A5 Ghezelbash Avenue, Tohid Street, Isfahan 8173954541 (Iran)

    2003-04-01

    The effect of coloring condition of Al with Calcon (sodium 2,2'-dihydroxy-azonaphthalene-4-sulfonate), on the corrosion resistance of Al in 0.1 M sulfuric acid solution was studied, using cyclic voltammetry and measurement of impedance noise methods. The changes in the corrosion resistance of colored aluminum electrodes were evaluated by measuring the magnitude of impedance and cyclic voltammetric responses of anodized and colored electrodes. An irreversible corrosion response was observed at the cyclic voltammogram of the colored aluminum electrode. The current and threshold potential of corrosion responses strongly depends on the applied conditions during anodizing, coloring and sealing stages. In addition, significant changes in impedance at the ac voltammogram and noise level at some ac frequencies were observed, when the electrodes were colored under various conditions. In this regard, the surface of the electrode was studied by Scanning Electron Microscopy (SEM). Comparison of SEM images of the colored and uncolored aluminum specimens showed that the colored surface contained a significant numbers of pits. The results indicated that coloring aluminum with Calcon could reduce corrosion resistance of aluminum and increase roughness of the oxide film. (Abstract Copyright [2003], Wiley Periodicals, Inc.) [German] Mit Hilfe zyklischer Voltammetrie und Messungen mit Impedanzrauschmethoden wurde der Einfluss der Faerbungsbedingungen von Aluminium mit Calcon (Natrium 2,2'-Dihydroxyazonaphthalen-4-Sulfonat) auf den Korrosionswiderstand von Aluminium in 0,1 M Schwefelsaeure untersucht. Die Veraenderungen des Korrosionswiderstandes von gefaerbten Aluminiumelektroden wurden durch Messungen der Hoehe der Impedanzreaktion bzw. der Reaktion bei der zyklischen Voltammetrie von anodisierten und gefaerbten Elektroden beurteilt. Eine irreversible Korrosionsreaktion wurde beim zyklischen Voltammogramm der gefaerbten Aluminiumelektrode beobachtet. Der Strom und das

  8. Scanning table

    CERN Multimedia

    1960-01-01

    Before the invention of wire chambers, particles tracks were analysed on scanning tables like this one. Today, the process is electronic and much faster. Bubble chamber film - currently available - (links can be found below) was used for this analysis of the particle tracks.

  9. Scan Statistics

    CERN Document Server

    Glaz, Joseph

    2009-01-01

    Suitable for graduate students and researchers in applied probability and statistics, as well as for scientists in biology, computer science, pharmaceutical science and medicine, this title brings together a collection of chapters illustrating the depth and diversity of theory, methods and applications in the area of scan statistics.

  10. Temperature-programmed reduction and cyclic voltammetry of Pt/carbon-fibre paper catalysts for methanol electrooxidation

    International Nuclear Information System (INIS)

    Attwood, P.A.; McNicol, B.D.; Short, R.T.

    1981-01-01

    Temperature-programmed reduction (TPR) and cyclic voltammetry (CV) studies of platinum catalysts supported on pyrographite-coated carbon-fibre paper, and prepared by either ion exchange or impregnation, clearly demonstrate the nature of the interactions between the platinum species and the support. After drying the above catalysts at 120 0 C, the ion-exchanged preparation exhibits the stronger interaction with the carbon support, as might be expected since a chemical interaction with carbon surface groups is known to occur in such catalysts. The presence of a fraction of bulk Pt(NH 3 ) 4 (OH) 2 impregnating salt in the impregnated catalyst has been detected using TPR. After air activation at 300 0 C, subambient reduction peaks were observed and the strength of binding of Pt in the ion-exchanged catalyst was reflected by its increased difficulty of reduction in comparison with that of the impregnated catalyst. The stoichiometry of reduction in ion-exchanged catalysts corresponds to Pt 2+ → Pt 0 in both dried and activated catalysts, with a small amount of Pt 4+ present in the latter. Upon activation the impregnated catalyst showed the presence of some Pt metal, which was thought to arise from the decomposition of the fraction of bulk Pt(NH 3 ) 4 (OH) 2 in the dried catalyst. Activation of ion-exchanged catalysts at temperatures higher than 300 0 C led to a progressive weakening of the Pt-support interaction and consequent smaller Pt surface areas. Activation at 500 0 C in air produced Pt metal exclusively and very low Pt surface areas. The strong interaction between Pt and the carbon support upon activation of the ion-exchanged catalyst at 300 0 C is thought to be the origin of the large metal surface area and the high catalytic activity for methanol electrooxidation found upon reduction

  11. Developing electrodes chemically modified with cucurbit[6]uril to detect 3,4-methylenedioxymethamphetamine (MDMA) by voltammetry

    International Nuclear Information System (INIS)

    Tadini, Maraine Catarina; Balbino, Marco Antonio; Eleoterio, Izabel Cristina; Siqueirade Oliveira, Laura; Dias, Luis Gustavo; Jean-François Demets, Grégoire; Firmino de Oliveira, Marcelo

    2014-01-01

    Graphical abstract: - Highlights: • A new stand in forensic chemistry. • Voltammetric method for the determination of MDMA in seized samples. • A new voltammetric sensor for MDMA. - Abstract: This study aimed to develop an electrode chemically modified with cucurbit[6]uril to detect 3,4-methylenedioxymethamphetamine (MDMA), the main active principle of ecstasy samples, by voltammetry. We modified the electrode surface with a film containing cucurbit[6]uril, Nafion, and methanol, using the dip coating or the spin coating technique. During analysis, we employed an electrochemical cell with a conventional three-electrode system and KCl solution (0.1 mol L −1 ) as the supporting electrolyte. We conducted cyclic voltammetry at concentrations ranging from 4.2 × 10 −6 to 4.8 × 10 −5 mol L −1 . We also accomplished scanning electron microscopy, to investigate the structural behavior of the film that originated on the electrode surface. We obtained the following results when we used dip coating to prepare the modified electrode: standard deviation (SD) = 0.024 μA, limit of detection (LOD) = 3.5 μmol L −1 , limit of quantification (LOQ) = 11.7 μmol L −1 , and amperometric sensitivity (m) = 20.9 × 10 3 μA L mol −1 . As for spin coating, we obtained SD = 0.024 μA, LOD = 2.7 μmol L −1 , LOQ = 9.1 μmol L −1 and m = 25.9 × 10 3 μA mol L −1 . These are very promising data: the modified electrode is more sensitive than the conventional glassy carbon electrode under the studied experimental conditions

  12. Simultaneous determination of paracetamol and penicillin V by square-wave voltammetry at a bare boron-doped diamond electrode

    International Nuclear Information System (INIS)

    Švorc, Ľubomír; Sochr, Jozef; Tomčík, Peter; Rievaj, Miroslav; Bustin, Dušan

    2012-01-01

    Highlights: ► Unmodified BDD electrode = sensitive electrochemical sensor for drugs determination. ► No special pretreatment of samples except simple dilution. ► Selective method, common compounds present in urine do not interfere in high excess. ► Simultaneous determination of PAR and PEN has yet not been published in literature. - Abstract: A simple, sensitive and selective square-wave voltammetry method for simultaneous determination of paracetamol and penicillin V on a bare (unmodified) boron-doped diamond electrode has been developed. The good potential separation of about 0.35 V between the oxidation peak potentials of both drugs present in mixture was found. It was found by cyclic voltammetry that paracetamol gave quasireversible wave and penicillin V provided irreversible oxidation peak. The effect of supporting electrolyte, pH and scan rate on voltammetric response of both drugs was studied to select the optimum experimental conditions. The optimal conditions for quantitative simultaneous determination were obtained in acetate buffer solution at pH 5.0. The oxidation peak of paracetamol and penicillin V showed a systematic increase in peak currents with increase of their concentration. The calibration curves for the simultaneous determination of paracetamol and penicillin V exhibited the good linear responses within the concentration range from 0.4 to 100 μM for both drugs. The detection limit was established to 0.21 and 0.32 μM for paracetamol and penicillin V, respectively. The method proved the good sensitivity, repeatability (RSD of 1.5 and 2.1% for mixture solution of 10 μM PCM and PEN) and selectivity when influence of interferents commonly existing in human urine was negligible. The practical analytical utility of proposed method was demonstrated by simultaneous determination of paracetamol and penicillin V in human urine samples, with results similar to those obtained using a high-performance liquid chromatography method as an

  13. Improving Postharvest Storage of Apple Cv.

    Directory of Open Access Journals (Sweden)

    H. Etemadi Nasab

    2013-06-01

    Full Text Available Apple is one of the important fruit in Iran. according to respiration and ethylene production behaviors, apple classified as a climacteric fruit. Therefore, any treatments, which can inhibit or prevent the action of ethylene, they can increase the postharvest life of horticultural production. 1-methylcyclopropane (1-MCP is one of the chemical which is environmental save and use as a very small concentrations. In this experiment, the effects of 1-MCP at concentrations of 0 (as a control, 0.25, 0.5, 0.75 and 1 µl.l-1 were used in apple cv. "Golab Kohanz", a land race fruits which is cultivated from long times ago in Iran. After the 1-MCP treatment, they were moved to cold room at 2 ºC and RH of ca 90% for 60 days. Samples were removed from the cold room and analysis for physicochemical characteristics. "Golab Kohanz" apples treated with 1-MCP showed improved fruit firmness, titratable acidity (TA, and total soluble solid after 147 days at 2ºC , compared to the control non-treated fruits. Also, treatment with 1-MCP significantly reduced the incidence of superficial scald in "Golab Kohanze". In general, 1-MCP-treated apples delay ripening during storing in cold room and increased shelf life. Overall, the results indicate that 1-MCP has tremendous potential for maintaining apple quality during storage and post storage.

  14. Preparation and Evaluation of Acetabularia-Modified Carbon Paste Electrode in Anodic Stripping Voltammetry of Copper and Lead Ions

    Directory of Open Access Journals (Sweden)

    Muhammad Raziq Rahimi Kooh

    2013-01-01

    Full Text Available Seaweed is well known about for potential in chelating heavy metals. In this study, carbon paste electrodes were fabricated with siphonous seaweed Acetabularia acetabulum as the modifiers to sense lead (II and copper (II by square-wave anodic stripping voltammetry. Various scan rates and deposition potentials were measured to obtain the optimal peak current for Pb(II and Cu(II. Optimum conditions of Acetabularia-CPE for sensing Pb(II were at the scan rate of 75 mV/s and deposition potential of −800 mV, while for Cu(II sensing were at 100 mV/s and −300 mV, respectively. The electrodes were characterized by the duration of accumulation time, preconcentration over a range of standards, supporting electrolyte, and standard solutions of various pH values. Interference studies were carried out. Both Zn(II and Cu(II were found to interfere with Pb(II sensing, whereas only Zn(II causes interference with Cu(II sensing. The electrode was found to have good regeneration ability via electrochemical cleaning. Preliminary testing of complex samples such as NPK fertilisers, black soil, and sea salt samples was included.

  15. Evaluation of kinetic parameters of 1, 1'-dibenzoylferrocene in non aqueous methanol solution by cyclic voltammetry (abstract)

    International Nuclear Information System (INIS)

    Parveen, R.; Kirmani, M.Z.; Naqvi, I.I.

    2011-01-01

    The electrochemical Kinetic study of 1, 1/sup '/- Dibenzoylferrocene (DBF) at a platinum working electrode in 0.1 mol dm/sup -3/ NaClO/sub 4/ non aqueous medium has been studied by Cyclic voltammetry. The heterogeneous electron transfer rate constants (ks) and the diffusion coefficients (Do) of DBF were estimated at various temperatures (283 - 323 K) and at different scan rates (0.05 - 0.5 V s/sup -1/). A calibration curve, linear over the range of 1 X 10/sup -3/ - 9 X 10/sup -3/ mol dm/sup -3/ ,was plotted at the scan rate of 0.25 Vs/sup -1/. This plot can be used to analyze an unknown sample of the compound. The kinetic data was also used to evaluate the Activation energy (Ea). The thermodynamic parameters such as enthalpy change of activation (delta H/sup */), Entropy change (delta S/sup */) and Gibbs free energy change (delta GH/sup */) were also investigated during the study. (author)

  16. Scanning holograms

    International Nuclear Information System (INIS)

    Natali, S.

    1984-01-01

    This chapter reports on the scanning of 1000 holograms taken in HOBC at CERN. Each hologram is triggered by an interaction in the chamber, the primary particles being pions at 340 GeV/c. The aim of the experiment is the study of charm production. The holograms, recorded on 50 mm film with the ''in line'' technique, can be analyzed by shining a parallel expanded laser beam through the film, obtaining immediately above it the real image of the chamber which can then be scanned and measured with a technique half way between emulsions and bubble chambers. The results indicate that holograms can be analyzed as quickly and reliably as in other visual techniques and that to them is open the same order of magnitude of large scale experiments

  17. Bone scans

    International Nuclear Information System (INIS)

    Hetherington, V.J.

    1989-01-01

    Oftentimes, in managing podiatric complaints, clinical and conventional radiographic techniques are insufficient in determining a patient's problem. This is especially true in the early stages of bone infection. Bone scanning or imaging can provide additional information in the diagnosis of the disorder. However, bone scans are not specific and must be correlated with clinical, radiographic, and laboratory evaluation. In other words, bone scanning does not provide the diagnosis but is an important bit of information aiding in the process of diagnosis. The more useful radionuclides in skeletal imaging are technetium phosphate complexes and gallium citrate. These compounds are administered intravenously and are detected at specific time intervals postinjection by a rectilinear scanner with minification is used and the entire skeleton can be imaged from head to toe. Minification allows visualization of the entire skeleton in a single image. A gamma camera can concentrate on an isolated area. However, it requires multiple views to complete the whole skeletal image. Recent advances have allowed computer augmentation of the data received from radionucleotide imaging. The purpose of this chapter is to present the current radionuclides clinically useful in podiatric patients

  18. Probing the electrochemical double layer of an ionic liquid using voltammetry and impedance spectroscopy: a comparative study of carbon nanotube and glassy carbon electrodes in [EMIM](+)[EtSO(4)](-).

    Science.gov (United States)

    Zheng, J P; Goonetilleke, P C; Pettit, C M; Roy, D

    2010-05-15

    Cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS) are compared as techniques for analyzing double layer capacitances of ionic liquids (ILs) at the surfaces of two carbon-based electrodes. These systems are relevant for energy storage supercapacitors and often are associated with unconventional electrochemical properties. Certain theoretical and experimental aspects of CV and EIS necessary for quantitative evaluation of the capacitance characteristics of such systems are explored. The experiments use 1-ethyl-3-methyl imidazolium ethylsulfate as a model IL electrolyte in combination with a porous electrode of carbon nanotubes (CNTs). The results are compared with those obtained with a nonporous glassy carbon (GC) electrode. The time is constant, and hence the power delivery characteristics of the experimental cell are affected by the electrolyte resistance and residual faradaic reactions of the IL, as well as by the spatially inhomogeneous electrode surfaces. It is shown that adequate characterization of these IL-electrode systems can be achieved by combining CV with EIS. A phenomenological framework for utilizing this combination is discussed.

  19. Molecular assembly and electro polymerization of 3,4-ethylenedioxy thiophene on Au(100) single crystal electrode using in-situ electrochemical scanning tunneling microscopy

    International Nuclear Information System (INIS)

    Garcia, Jonyl L.; Tongol, Bernard John V.; ShuehLin Yau

    2012-01-01

    Electrochemical scanning tunneling microscopy (Ec-STM) is a powerful technique that can provide molecular-level information regarding electrode surface processes in-situ in electrolyte solvent under ambient conditions. In this study, the adsorption and electro polymerization of an industrially important conducting polymer precursor, 3,4-ethylenedioxy thiophene (EDOT), on Au (100) single crystal was probed using Ec-STM. The Au (100) single crystal electrode substrate used for this study was fabricated using the well-known Clavilier's flame melting procedure. Cyclic voltammetry (CV) was used along with Ec-STM to characterize the bare, EDOT-modified, and poly(EDOT)-modified Au (100) single crystal electrode. Time-dependent Ec-STM imaging at 0.550 V showed the formation of an EDOT self-assembled monolayer through 2-D surface dillusion. The resulting EDOT molecular assembly on Au (100) single crystal electrode was found to fit in a 4√2χ3√2 unit cell. Difference in apparent corrugation between molecular rows was attributed to different angular orientation with respect to the substrate. The electro polymerization of EDOT on Au (100) single crystal electrode was done by potentiostatic and potentiodynamic methods. Both methods suggested a solution-process mechanism for EDOT electro polymerization. (author)

  20. A practical introduction to computer vision with OpenCV

    CERN Document Server

    Dawson-Howe, Kenneth

    2014-01-01

    Explains the theory behind basic computer vision and provides a bridge from the theory to practical implementation using the industry standard OpenCV libraries Computer Vision is a rapidly expanding area and it is becoming progressively easier for developers to make use of this field due to the ready availability of high quality libraries (such as OpenCV 2).  This text is intended to facilitate the practical use of computer vision with the goal being to bridge the gap between the theory and the practical implementation of computer vision. The book will explain how to use the relevant OpenCV

  1. Determination of Zalcitabine in Medicaments by Differential Pulse Voltammetry

    Directory of Open Access Journals (Sweden)

    Katia Christina Leandro

    2013-01-01

    Full Text Available The zalcitabine (ddC has been extensively used in the treatment of HIV patients due to its antiretroviral activity. The quality control of this active principle in medications is of outstanding importance to public health. The principal objective of the current study was the development of an alternative analytical methodology for the zalcitabine determination using a voltammetric process. The zalcitabine gives a reduction peak (at -1.22 V versus Ag/AgCl at the hanging mercury drop electrode (HMDE. The differential pulse voltammetric response is evaluated with respect to the scan rate (20 mV/s, pulse amplitude (50 mV, support electrolyte (Clark-Lubs buffer, pH (2.0, and other variables. The response is linear over the 10.0 to 28.0 mg/L (47 to 133 μM concentration range, and the detection limit is 2.08 mg/L. The validation of this method was realized using a governmental Brazilian document (Inmetro, 2007 and the results are reported for medication drugs.

  2. Ruthenium determination by the method of inversion voltammetry on graphite electrode

    Energy Technology Data Exchange (ETDEWEB)

    Dominova, I G; Kolpakova, N A; Stromberg, A G [Tomskij Politekhnicheskij Inst. (USSR)

    1978-12-01

    Optimal conditions for determining ruthenium by inversion voltammetry on a graphite electrode are 0.1 M KCl or KNO/sub 3/, pH 2-3, electrolysis potential - 1.0 V. A linear dependence of ruthenium electrodissolution current on its concentration in the solution makes it possible to use inversion voltammetry for determining 5x10/sup -7/ - 1x10/sup -4/ g-ion Ru/l. Ruthenium can be determined in the presence of a large excess of nickel and copper but commensurable amounts of mercury adn platinum metals interfere.

  3. Guidelines on CV networking information flow optimization for Texas.

    Science.gov (United States)

    2017-03-01

    Recognizing the fundamental role of information flow in future transportation applications, the research team investigated the quality and security of information flow in the connected vehicle (CV) environment. The research team identified key challe...

  4. Calibration of ADRET voltage generator type CV102. Program CODAV

    International Nuclear Information System (INIS)

    Lagarde, Gerard.

    1978-07-01

    The CODAV programm studied by the Metrology SES/SME laboratory is used for the calibration of ADRET voltage generator type CV.102. A JCAM.10 microcomputer run the measurement cycle and the printout of the results [fr

  5. Nutritive evaluation of Medicago truncutula (cv. jernalong) pasture ...

    African Journals Online (AJOL)

    Nutritive evaluation of Medicago truncutula (cv. jernalong) pasture for sheep. 1. Seasonal .... obtained by laboratory work, using in vitro techniques. (Engels et al. .... model that was used to explain 92,3% of the variance in. IVDOM content.

  6. Insight into the template effect of vesicles on the laccase-catalyzed oligomerization of N-phenyl-1,4-phenylenediamine from Raman spectroscopy and cyclic voltammetry measurements

    Science.gov (United States)

    Ležaić, Aleksandra Janoševic; Luginbühl, Sandra; Bajuk-Bogdanović, Danica; Pašti, Igor; Kissner, Reinhard; Rakvin, Boris; Walde, Peter; Ćirić-Marjanović, Gordana

    2016-08-01

    We report about the first Raman spectroscopy study of a vesicle-assisted enzyme-catalyzed oligomerization reaction. The aniline dimer N-phenyl-1,4-phenylenediamine (= p-aminodiphenylamine, PADPA) was oxidized and oligomerized with Trametes versicolor laccase and dissolved O2 in the presence of sodium bis(2-ethylhexyl)sulfosuccinate (AOT) vesicles (80-100 nm diameter) as templates. The conversion of PADPA into oligomeric products, poly(PADPA), was monitored during the reaction by in situ Raman spectroscopy. The results obtained are compared with UV/vis/NIR and EPR measurements. All three complementary methods indicate that at least some of the poly(PADPA) products, formed in the presence of AOT vesicles, resemble the conductive emeraldine salt form of polyaniline (PANI-ES). The Raman measurements also show that structural units different from those of “ordinary” PANI-ES are present too. Without vesicles PANI-ES-like products are not obtained. For the first time, the as-prepared stable poly(PADPA)-AOT vesicle suspension was used directly to coat electrodes (without product isolation) for investigating redox activities of poly(PADPA) by cyclic voltammetry (CV). CV showed that poly(PADPA) produced with vesicles is redox active not only at pH 1.1-as expected for PANI-ES-but also at pH 6.0, unlike PANI-ES and poly(PADPA) synthesized without vesicles. This extended pH range of the redox activity of poly(PADPA) is important for applications.

  7. Facilitated ion transfer of protonated primary organic amines studied by square wave voltammetry and chronoamperometry

    Energy Technology Data Exchange (ETDEWEB)

    Torralba, E. [Departamento de Química Física, Facultad de Química, Universidad de Murcia, Murcia 30100 (Spain); Ortuño, J.A. [Departamento de Química Analítica, Facultad de Química, Universidad de Murcia, Murcia 30100 (Spain); Molina, A., E-mail: amolina@um.es [Departamento de Química Física, Facultad de Química, Universidad de Murcia, Murcia 30100 (Spain); Serna, C. [Departamento de Química Física, Facultad de Química, Universidad de Murcia, Murcia 30100 (Spain); Karimian, F. [Department of Chemistry, Faculty of Sciences, Ferdowsi University of Mashhad, Mashhad (Iran, Islamic Republic of)

    2014-05-01

    Highlights: • Facilitated ion transfer of organic protonated amines is studied. • Cyclic square wave voltammetry is used as main technique. • Complexation constants and standard ion transfer potentials are determined. • Diffusion coefficients in the organic and aqueous phases are determined. • The goodness of square wave voltammetry as analytical tool is shown. - Abstract: The transfer of the protonated forms of heptylamine, octylamine, decylamine, procaine and procainamide facilitated by dibenzo-18-crown-6 from water to a solvent polymeric membrane has been investigated by using cyclic square wave voltammetry. The experimental voltammograms obtained are in good agreement with theoretical predictions. The values of the standard ion transfer potential, complexation constant and diffusion coefficient in water have been obtained from these experiments, and have been used to draw some conclusions about the lipophilicity of these species and the relative stability of the organic ammonium complexes with dibenzo-18-crown-6. The results have been compared with those provided by linear sweep voltammetry. Calibration graphs were obtained with both techniques. An interesting chronoamperometric method for the determination of the diffusion coefficient of the target ion in the membrane has been developed and applied to all these protonated amines.

  8. Ion transfer voltammetry of metformin and phenformin at a polarized ionic liquid-membrane

    Czech Academy of Sciences Publication Activity Database

    Langmaier, Jan; Samec, Zdeněk; Samcová, E.

    2015-01-01

    Roč. 61, č. 3 (2015), s. 214-214 ISSN 0034-6691. [Annual Meeting of the Polarographic Society of Japan /61./. 24.11.2015-25.11.2015, Himeji] R&D Projects: GA ČR(CZ) GA15-03139S Institutional support: RVO:61388955 Keywords : electrochemistry * voltammetry Subject RIV: CG - Electrochemistry

  9. Cyclic Voltammetry of Highly Hydrophilic Ions at a Supported Liquid Membrane

    Czech Academy of Sciences Publication Activity Database

    Ulmeanu, S. M.; Jensen, H.; Samec, Zdeněk; Bouchard, G.; Carrupt, P. A.; Giraut, H. H.

    2002-01-01

    Roč. 530, 1/2 (2002), s. 10-15 ISSN 0022-0728 R&D Projects: GA AV ČR IAA4040902 Institutional research plan: CEZ:AV0Z4040901 Keywords : liquid-liquid interface * membrane * cyclic voltammetry Subject RIV: CG - Electrochemistry Impact factor: 2.027, year: 2002

  10. Simulation of square wave voltammetry of three electrode reactions coupled by two reversible chemical reactions

    OpenAIRE

    Lovrić, Milivoj

    2017-01-01

    Three fast and reversible electrode reactions that are connected by two reversible chemical reactions that are permanently in the equilibrium are analysed theoretically for square wave voltammetry. The dependence of peak potentials on the dimensionless equilibrium constants of chemical reactions is calculated. The influence of the basic thermodynamic parameters on the square wave voltammetric responses is analysed.

  11. Polymyxin-coated Au and carbon nanotube electrodes for stable [NiFe]-hydrogenase film voltammetry.

    NARCIS (Netherlands)

    Hoeben, F.J.M.; Heller, I.; Albracht, S.P.J.; Dekker, C.; Lemay, S.G.; Heering, H.A.

    2008-01-01

    We report on the use of polymyxin (PM), a cyclic cationic lipodecapeptide, as an electrode modifier for studying protein film voltammetry (PFV) on Au and single-walled carbon nanotube (SWNT) electrodes. Pretreating the electrodes with PM allows for the subsequent immobilization of an active

  12. Practical measurement of silicon in low alloy steels by differential pulse stripping voltammetry

    International Nuclear Information System (INIS)

    Rahier, A.; Lunardi, S.; Triki, C.

    2005-01-01

    A sensitive differential pulse anodic stripping voltammetry has been adapted to allow the determination of Si in low-alloy steels using a hanging mercury drop electrode. The method has been qualified using certified ASTM standards and is now running in routine. The present report describes the experimental details, thereby allowing the reader to carry out the measurements precisely. (author)

  13. Stripping voltammetry of thallium, indium and gallium on mercury-graphite electrodes

    International Nuclear Information System (INIS)

    Kamenev, A.I.; Kharitonova, O.I.; Chernova, N.A.; Agasyan, P.K.

    1986-01-01

    Electrochemical Tl(1), In(3) and Ga(3) behaviour in mercury-graphite electrodes by the method of direct-current and alternating-current voltammetry is studied. Comparison of mathematical models and their experimental check are carried out. Possibility to forecast the investigation results is shown, and the procedure for mercury-graphite electrode surface formation necessary in measurements is chosen

  14. The detection of Cd and Pb in soil solution by differential pulse anodic stripping voltammetry

    Czech Academy of Sciences Publication Activity Database

    Jakl, M.; Jaklová Dytrtová, J.; Šestáková, Ivana; Szaková, J.; Tlustoš, P.

    2008-01-01

    Roč. 102, - (2008), s. 99-100 E-ISSN 1213-7103. [International Conference on Electroanalysis /12./. 16.06.2008-19.06.2008, Prague] R&D Projects: GA ČR GA521/06/0496 Institutional research plan: CEZ:AV0Z40400503 Keywords : heavy metals * voltammetry Subject RIV: CG - Electrochemistry

  15. Evidence of metallic plating on archaeological artefacts by voltammetry of microparticles

    Czech Academy of Sciences Publication Activity Database

    Ottenwelter, Estelle; Costa, V.

    2015-01-01

    Roč. 57, č. 3 (2015), s. 497-504 ISSN 0003-813X Institutional support: RVO:67985912 Keywords : metallic plating * voltammetry of microparticles * non-invasive analysis * medieval period * archaeological artefacts Subject RIV: AC - Archeology, Anthropology, Ethnology Impact factor: 1.364, year: 2015

  16. Cathodic Stripping Voltammetry of Cysteine Using Silver and Copper Solid Amalgam Electrodes

    Czech Academy of Sciences Publication Activity Database

    Josypčuk, Bohdan; Novotný, Ladislav

    2002-01-01

    Roč. 56, č. 5 (2002), s. 971-976 ISSN 0039-9140 R&D Projects: GA ČR GV204/97/K084 Institutional research plan: CEZ:AV0Z4040901 Keywords : silver or copper solid amalgam electrode * cysteine * voltammetry Subject RIV: CG - Electrochemistry Impact factor: 2.054, year: 2002

  17. Extreme Basicity of Biguanide Drugs in Aqueous Solutions: Ion Transfer Voltammetry and DFT Calculations

    Czech Academy of Sciences Publication Activity Database

    Langmaier, Jan; Pižl, Martin; Samec, Zdeněk; Záliš, Stanislav

    2016-01-01

    Roč. 120, č. 37 (2016), s. 7344-7350 ISSN 1089-5639 R&D Projects: GA ČR(CZ) GA15-03139S Institutional support: RVO:61388955 Keywords : voltammetry * Alkalinity * Complexation Subject RIV: CG - Electrochemistry Impact factor: 2.847, year: 2016

  18. Submolecular Electronic Mapping of Single Cysteine Molecules by in Situ Scanning Tunneling Imaging

    DEFF Research Database (Denmark)

    Zhang, Jingdong; Chi, Qijin; Nazmutdinov, R. R.

    2009-01-01

    We have used L-Cysteine (Cys) as a model system to study the surface electronic structures of single molecules at the submolecular level in aqueous buffer solution by a combination of electrochemical scanning tunneling microscopy (in situ STM), electrochemistry including voltammetry and chronocou...

  19. Surface modification of pyrolyzed carbon fibres by cyclic voltammetry and their characterization with XPS and dye adsorption

    International Nuclear Information System (INIS)

    Georgiou, P.; Walton, J.; Simitzis, J.

    2010-01-01

    Commercial carbon fibres were pyrolyzed up to 1000 deg. C and were then electrochemically treated by cyclic voltammetry in aqueous electrolyte solutions of H 2 SO 4 , in two potential sweep ranges: a narrow region, N, and a wide region, W, avoiding and including water decomposition, respectively. The anodic and cathodic peaks were correlated with oxide formation and their partial reduction, respectively. The nature of oxygen containing groups on the fibre surfaces was determined by XPS. Wide scan spectra and high energy resolution spectra were recorded through the C 1s, O 1s, N 1s and S 2p photoelectron regions. The ability of the fibres to adsorb methylene blue and alizarin yellow dyes from their aqueous solutions indicates the presence of electron acceptor or donor groups on the fibres, respectively. The carbon fibres were classified into two categories. The first includes electrochemically untreated and treated in the N region, and the second those treated in the W region. The high oxygen concentration and effective dye adsorption on the carbon fibres in the second category indicates that their surfaces were effectively modified. The adsorption of dyes on carbon fibres constitutes a complementary method to XPS for an indirect estimation of oxygen and other groups present on the carbon fibre surfaces.

  20. Head CT scan

    Science.gov (United States)

    ... scan - orbits; CT scan - sinuses; Computed tomography - cranial; CAT scan - brain ... head size in children Changes in thinking or behavior Fainting Headache, when you have certain other signs ...

  1. Anonymous voting for multi-dimensional CV quantum system

    International Nuclear Information System (INIS)

    Shi Rong-Hua; Xiao Yi; Shi Jin-Jing; Guo Ying; Lee, Moon-Ho

    2016-01-01

    We investigate the design of anonymous voting protocols, CV-based binary-valued ballot and CV-based multi-valued ballot with continuous variables (CV) in a multi-dimensional quantum cryptosystem to ensure the security of voting procedure and data privacy. The quantum entangled states are employed in the continuous variable quantum system to carry the voting information and assist information transmission, which takes the advantage of the GHZ-like states in terms of improving the utilization of quantum states by decreasing the number of required quantum states. It provides a potential approach to achieve the efficient quantum anonymous voting with high transmission security, especially in large-scale votes. (paper)

  2. Finite-element simulations of the influence of pore wall adsorption on cyclic voltammetry of ion transfer across a liquid-liquid interface formed at a micropore.

    Science.gov (United States)

    Ellis, Jonathan S; Strutwolf, Jörg; Arrigan, Damien W M

    2012-02-21

    Adsorption onto the walls of micropores was explored by computational simulations involving cyclic voltammetry of ion transfer across an interface between aqueous and organic phases located at the micropore. Micro-interfaces between two immiscible electrolyte solutions (micro-ITIES) have been of particular research interest in recent years and show promise for biosensor and biomedical applications. The simulation model combines diffusion to and within the micropore, Butler-Volmer kinetics for ion transfer at the liquid-liquid interface, and Langmuir-style adsorption on the pore wall. Effects due to pore radius, adsorption and desorption rates, surface adsorption site density, and scan rates were examined. It was found that the magnitude of the reverse peak current decreased due to adsorption of the transferring ion on the pore wall; this decrease was more marked as the scan rate was increased. There was also a shift in the half-wave potential to lower values following adsorption, consistent with a wall adsorption process which provides a further driving force to transfer ions across the ITIES. Of particular interest was the disappearance of the reverse peak from the cyclic voltammogram at higher scan rates, compared to the increase in the reverse peak size in the absence of wall adsorption. This occurred for scan rates of 50 mV s(-1) and above and may be useful in biosensor applications using micropore-based ITIES.

  3. Instant OpenCV for iOS

    CERN Document Server

    Kornyakov, Kirill

    2013-01-01

    Filled with practical, step-by-step instructions and clear explanations for the most important and useful tasks. This book uses a very practical approach, with each recipe and their associated sample projects or examples focusing on a particular aspect of the technology.This book is intended for OpenCV developers who are interested in porting their applications to the iOS platform. Basic experience with OpenCV, computer vision, Objective C, and other iOS tools is encouraged.

  4. Voltammetry of Aluminum Nanoparticles in Aqueous Media with Hanging Mercury Drop Electrode

    Czech Academy of Sciences Publication Activity Database

    Korshunov, A.; Heyrovský, Michael

    2010-01-01

    Roč. 22, 17-18 (2010), s. 1989-1993 ISSN 1040-0397. [International Conference on Modern Electroanalytical Methods. Prague, 09.12.2009-14.12.2009] R&D Projects: GA AV ČR IAA400400806 Institutional research plan: CEZ:AV0Z40400503 Keywords : linear cyclic voltammetry * Hanging mercury drop electrode * Aluminum nanoparticles dispersion Subject RIV: CG - Electrochemistry Impact factor: 2.721, year: 2010

  5. Determination of azidothymidine - an antiproliferative and virostatic drug by square-wave voltammetry

    Czech Academy of Sciences Publication Activity Database

    Vacek, Jan; Andrysík, Zdeněk; Trnková, L.; Kizek, René

    2004-01-01

    Roč. 16, č. 3 (2004), s. 224-230 ISSN 1040-0397 R&D Projects: GA ČR GA203/02/0422; GA AV ČR IAA1163201; GA AV ČR IBS5004009 Institutional research plan: CEZ:AV0Z5004920 Keywords : azidothymidine (AZT) * square-wave voltammetry * hanging mercury drop electrode (HMDE) Subject RIV: BO - Biophysics Impact factor: 2.038, year: 2004

  6. Correlation of the first reduction potential of selected radiosensitizers determined by cyclic voltammetry with theoretical calculations

    Czech Academy of Sciences Publication Activity Database

    Gál, Miroslav; Kolivoška, Viliam; Ambrová, M.; Híveš, J.; Sokolová, Romana

    2011-01-01

    Roč. 76, č. 8 (2011), s. 937-946 ISSN 0010-0765 R&D Projects: GA ČR GP203/09/P502; GA ČR GA203/09/0705; GA MŠk LC510 Institutional research plan: CEZ:AV0Z40400503 Keywords : cyclic voltammetry * radical ions * radiochemistry Subject RIV: CG - Electrochemistry Impact factor: 1.283, year: 2011

  7. Copper-based electrochemical sensor with palladium electrode for cathodic stripping voltammetry of manganese.

    Science.gov (United States)

    Kang, Wenjing; Pei, Xing; Bange, Adam; Haynes, Erin N; Heineman, William R; Papautsky, Ian

    2014-12-16

    In this work, we report on the development of a palladium-based, microfabricated point-of-care electrochemical sensor for the determination of manganese using square wave cathodic stripping voltammetry. Heavy metals require careful monitoring, yet current methods are too complex for a point-of-care system. Voltammetry offers an attractive approach to metal detection on the microscale, but traditional carbon, gold, or platinum electrodes are difficult or expensive to microfabricate, preventing widespread use. Our sensor uses palladium working and auxiliary electrodes and integrates them with a copper-based reference electrode for simple fabrication and compatibility with microfabrication and printed circuit board processing, while maintaining competitive performance in electrochemical detection. Copper electrodes were prepared on glass substrate using a combination of microfabrication procedures followed by electrodeposition of palladium. The disposable sensor system was formed by bonding a poly(dimethylsiloxane) (PDMS) well to the glass substrate. Cathodic stripping voltammetry of manganese using our new disposable palladium-based sensors exhibited 334 nM (18.3 ppb) limit of detection in borate buffer. The sensor was used to demonstrate manganese determination in natural water samples from a pond in Burnet Woods, located in Cincinnati, OH, and the Ohio River.

  8. Corrosion Cyclic Voltammetry of Two Types of Heat-Affected Zones (HAZs) of API-X100 Steel in Bicarbonate Solutions

    Science.gov (United States)

    Eliyan, Faysal Fayez; Alfantazi, Akram

    2014-12-01

    This paper examined the electrochemical corrosion behavior and corrosion products of two types of heat-affected HAZs made from API-X100 steel. Cyclic voltammetry, with different scan rates and potential ranges at 10 cycles, was applied to analyze the interdependent corrosion reactions of cathodic reduction, anodic dissolution, passivation, and transpassivation. The HAZ cooled at 60 K/s, from a peak temperature of 1470 K (1197 °C) that was held for 15 seconds, exhibited better passivation and lower cathodic activity than the HAZ cooled at 10 K/s. Increasing bicarbonate concentration, from 0.05 and 0.2 to 0.6 M, increases the anodic activity and cathodic reduction, but accordingly protects the active surfaces and enhances passivation.

  9. Ensacamento de frutos de pereira cv. Housui Bagging of nashi pear cv. Housui

    Directory of Open Access Journals (Sweden)

    Ivan Dagoberto Faoro

    2004-04-01

    Full Text Available Foi avaliada a qualidade de frutos de pêra japonesa cv. Housui (Pyrus pyrifolia var. culta ensacados com diferentes tipos de sacos de papel e em duas épocas: 34 e 83 dias após a florada. O ensacamento não influenciou na firmeza, no teor de sólidos solúveis totais e no peso médio dos frutos. Sacos vermelhos não induziram aumento do pH da polpa, mas o uso de sacos duplos, sacos marrons, sacos de papel kraft marrons e sacos de pipoca brancos aumentaram significativamente o pH. Ao buscar-se maior precocidade de colheita, os melhores resultados foram obtidos com o uso de sacos pequenos de papel manteiga aos 34 dias após a floração e o uso de sacos grandes duplos ou sacos grandes marrons, 83 dias após a plena floração. O ensacamento 34 dias após a plena floração, com sacos grandes de papel duplo de cor marrom ou sacos de papel kraft marrons, ou ainda o uso de sacos pequenos parafinados transparentes de papel manteiga, aos 34 dias, seguidos pela colocação, aos 83 dias, dos dois tipos de sacos grandes citados anteriormente, resultaram em frutos de melhor qualidade externa (película de coloração homogênea e mais clara, lisa e com lenticelas pouco salientes. O uso de sacos vermelhos de papel manteiga e de sacos de pipoca brancos, com ou sem ensacamento prévio com sacos pequenos de papel manteiga parafinado, não resultaram em melhoria substancial da qualidade externa do fruto.The fruit quality of Nashi pears cv. Housui (Pyrus pyrifolia var. culta have been evaluated after bagging with different paper bags at two bagging dates: 34 and 83 days after full bloom. The bagging did not affect the fruit firmness, the total soluble solids and the average fruit weight. Red bags did not affect the pH of the fruit flesh. However the fruit bagged with double bags of brown color, brown kraft paper and white popcorn paper increased the pH. In order to harvest precociously, the use of small transparent paraffin paper bags 34 days after full bloom

  10. Plant regeneration of Brassica oleracea subsp. italica (Broccoli) CV ...

    African Journals Online (AJOL)

    STORAGESEVER

    2009-06-03

    Jun 3, 2009 ... Department of Agriculture Technology, Faculty of Agriculture, Universiti Putra Malaysia, 43400 Serdang, Selangor Darul. Ehsan, Malaysia. Accepted 20 March, 2009. Hypocotyls and shoot tips were used as explants in in vitro plant regeneration of broccoli (Brassica oleracea subsp.italica) cv. Green Marvel.

  11. Microelectrode voltammetry of multi-electron transfers complicated by coupled chemical equilibria: a general theory for the extended square scheme.

    Science.gov (United States)

    Laborda, Eduardo; Gómez-Gil, José María; Molina, Angela

    2017-06-28

    A very general and simple theoretical solution is presented for the current-potential-time response of reversible multi-electron transfer processes complicated by homogeneous chemical equilibria (the so-called extended square scheme). The expressions presented here are applicable regardless of the number of electrons transferred and coupled chemical processes, and they are particularized for a wide variety of microelectrode geometries. The voltammetric response of very different systems presenting multi-electron transfers is considered for the most widely-used techniques (namely, cyclic voltammetry, square wave voltammetry, differential pulse voltammetry and steady state voltammetry), studying the influence of the microelectrode geometry and the number and thermodynamics of the (electro)chemical steps. Most appropriate techniques and procedures for the determination of the 'interaction' between successive transfers are discussed. Special attention is paid to those situations where homogeneous chemical processes, such as protonation, complexation or ion association, affect the electrochemical behaviour of the system by different stabilization of the oxidation states.

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

    OpenAIRE

    Gulaboski, Rubin

    2001-01-01

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

  13. Direct in situ measurement of dissolved zinc in the presence of zinc oxide nanoparticles using anodic stripping voltammetry.

    Science.gov (United States)

    Jiang, Chuanjia; Hsu-Kim, Heileen

    2014-11-01

    The wide use of metal-based nanomaterials such as zinc oxide (ZnO) nanoparticles (NPs) has generated concerns regarding their environmental and health risks. For ZnO NPs, their toxicity in aquatic systems often depends on the release of dissolved zinc species, and the rate of dissolution is influenced by water chemistry, including the presence of zinc-chelating ligands. A challenge, however, remains in quantifying the dissolution of ZnO NPs, particularly for time scales that are short enough to determine rates. This paper reports the application of anodic stripping voltammetry (ASV) with a hanging mercury drop electrode to directly measure the concentration of dissolved zinc in ZnO NP suspensions, without separation of the ZnO NPs from the aqueous phase. The effects of the deposition time and the electrochemical potential scan rate on the ASV measurement were consistent with expectations for dissolved phase measurements. The dissolved zinc concentration measured by ASV ([Zn]ASV) was compared with that measured by inductively coupled plasma mass spectrometry (ICP-MS) after ultracentrifugation ([Zn]ICP-MS), for four types of ZnO NPs with different coatings and primary particle diameters. For small ZnO NPs (4-5 nm), [Zn]ASV was 20% higher than [Zn]ICP-MS, suggesting that these small NPs contributed to the voltammetric measurement. For larger ZnO NPs (approximately 20 nm), [Zn]ASV was (79 ± 19)% of [Zn]ICP-MS, despite the high concentrations of ZnO NPs in suspension. Using ASV, the dissolution of ZnO NPs was studied, with or without Suwannee River Fulvic Acid (SRFA). Although SRFA diminished the ASV stripping current, dissolution of 20 nm ZnO NPs was significantly promoted at high fulvic acid to ZnO NP ratios. The ASV method described in this paper provides a useful tool for studying the dissolution kinetics of ZnO NPs in complex environmental matrices.

  14. Determination of picloram in natural waters employing sequential injection square wave voltammetry using the hanging mercury drop electrode.

    Science.gov (United States)

    Dos Santos, Luciana B O; Masini, Jorge C

    2007-05-15

    This paper describes the development of a sequential injection analysis method to automate the determination of picloram by square wave voltammetry exploiting the concept of monosegmented flow analysis to perform in-line sample conditioning and standard addition. To perform these tasks, an 800muL monosegment is formed, composed by 400muL of sample and 400muL of conditioning/standard solution, in medium of 0.10molL(-1) H(2)SO(4). Homogenization of the monosegment is achieved by three flow reversals. After homogenization the mixture zone is injected toward the flow cell, which is adapted to the capillary of a hanging drop mercury electrode, at a flow rate of 50muLs(-1). After a suitable delay time, the potential is scanned from -0.5 to -1.0V versus Ag/AgCl at frequency of 300Hz and pulse height of 25mV. The linear dynamic range is observed for picloram concentrations between 0.10 and 2.50mgL(-1) fitting to the linear equation I(p)=(-2.19+/-0.03)C(picloram)+(0.096+/-0.039), with R(2)=0.9996, for which the slope is given in muALmg(-1). The detection and quantification limits are 0.036 and 0.12mgL(-1), respectively. The sampling frequency is 37h(-1) when the standard addition protocol is followed, but can be increased to 41h(-1) if the protocol to obtain in-line external calibration curve is used for quantification. The method was applied for determination of picloram in spiked water samples and the accuracy was evaluated by comparison with high performance liquid chromatography using molecular absorption at 220nm for detection. No evidences of statistically significant differences between the two methods were observed.

  15. Brain PET scan

    Science.gov (United States)

    ... results on a PET scan. Blood sugar or insulin levels may affect the test results in people with diabetes . PET scans may be done along with a CT scan. This combination scan is called a PET/CT. Alternative Names Brain positron emission tomography; PET scan - brain References Chernecky ...

  16. Oxidation management of white wines using cyclic voltammetry and multivariate process monitoring.

    Science.gov (United States)

    Martins, Rui C; Oliveira, Raquel; Bento, Fatima; Geraldo, Dulce; Lopes, Vitor V; Guedes de Pinho, Paula; Oliveira, Carla M; Silva Ferreira, Antonio C

    2008-12-24

    The development of a fingerprinting strategy capable to evaluate the "oxidation status" of white wines based on cyclic voltammetry is proposed here. It is known that the levels of specific antioxidants and redox mechanisms may be evaluated by cyclic voltammetry. This electrochemical technique was applied on two sets of samples. One group was composed of normal aged white wines and a second group obtained from a white wine forced aging protocol with different oxygen, SO(2), pH, and temperature regimens. A study of antioxidant additions, namely ascorbic acid, was also made in order to establish a statistical link between voltammogram fingerprints and chemical antioxidant substances. It was observed that the oxidation curve presented typical features, which enables sample discrimination according to age, oxygen consumption, and antioxidant additions. In fact, it was possible to place the results into four significant orthogonal directions, compressing 99.8% of nonrandom features. Attempts were made to make voltammogram fingerprinting a tool for monitoring oxidation management. For this purpose, a supervised multivariate control chart was developed using a control sample as reference. When white wines are plotted onto the chart, it is possible to monitor the oxidation status and to diagnose the effects of oxygen regimes and antioxidant activity. Finally, quantification of substances implicated in the oxidation process as reagents (antioxidants) and products (off-flavors) was tried using a supervised algorithmic the partial least square regression analysis. Good correlations (r > 0.93) were observed for ascorbic acid, Folin-Ciocalteu index, total SO(2), methional, and phenylacetaldehyde. These results show that cyclic voltammetry fingerprinting can be used to monitor and diagnose the effects of wine oxidation.

  17. Computer Vision Tool and Technician as First Reader of Lung Cancer Screening CT Scans.

    Science.gov (United States)

    Ritchie, Alexander J; Sanghera, Calvin; Jacobs, Colin; Zhang, Wei; Mayo, John; Schmidt, Heidi; Gingras, Michel; Pasian, Sergio; Stewart, Lori; Tsai, Scott; Manos, Daria; Seely, Jean M; Burrowes, Paul; Bhatia, Rick; Atkar-Khattra, Sukhinder; van Ginneken, Bram; Tammemagi, Martin; Tsao, Ming Sound; Lam, Stephen

    2016-05-01

    To implement a cost-effective low-dose computed tomography (LDCT) lung cancer screening program at the population level, accurate and efficient interpretation of a large volume of LDCT scans is needed. The objective of this study was to evaluate a workflow strategy to identify abnormal LDCT scans in which a technician assisted by computer vision (CV) software acts as a first reader with the aim to improve speed, consistency, and quality of scan interpretation. Without knowledge of the diagnosis, a technician reviewed 828 randomly batched scans (136 with lung cancers, 556 with benign nodules, and 136 without nodules) from the baseline Pan-Canadian Early Detection of Lung Cancer Study that had been annotated by the CV software CIRRUS Lung Screening (Diagnostic Image Analysis Group, Nijmegen, The Netherlands). The scans were classified as either normal (no nodules ≥1 mm or benign nodules) or abnormal (nodules or other abnormality). The results were compared with the diagnostic interpretation by Pan-Canadian Early Detection of Lung Cancer Study radiologists. The overall sensitivity and specificity of the technician in identifying an abnormal scan were 97.8% (95% confidence interval: 96.4-98.8) and 98.0% (95% confidence interval: 89.5-99.7), respectively. Of the 112 prevalent nodules that were found to be malignant in follow-up, 92.9% were correctly identified by the technician plus CV compared with 84.8% by the study radiologists. The average time taken by the technician to review a scan after CV processing was 208 ± 120 seconds. Prescreening CV software and a technician as first reader is a promising strategy for improving the consistency and quality of screening interpretation of LDCT scans. Copyright © 2016 International Association for the Study of Lung Cancer. Published by Elsevier Inc. All rights reserved.

  18. On the Usage of Cyclic Voltammetry and Impedance Spectroscopy for Measuring the Concentration of Aqueous Solutions

    Directory of Open Access Journals (Sweden)

    Manuel Fiedler

    2015-02-01

    Full Text Available This article describes sensors for concentration measurement based on the electro- chemical properties of the liquid being measured. Herein two electrical methods, namely cyclic voltammetry and impedance spectroscopy, are being presented. The measurement can be performed quasi simultaneously using the same measurement medium. Further optimization of the combined methods is possible by adapting the geometric design of the electrode structure, the electrode material, the optional passivation and the electric coupling (galvanically or capacitively. In summary, by combining multiple sensory principles on a device it becomes possible to analyze mixtures of substances contained in a solution with respect to their composition.

  19. Small-angle neutron scattering and cyclic voltammetry study on electrochemically oxidized and reduced pyrolytic carbon

    International Nuclear Information System (INIS)

    Braun, A.; Kohlbrecher, J.; Baertsch, M.; Schnyder, B.; Koetz, R.; Haas, O.; Wokaun, A.

    2004-01-01

    The electrochemical double layer capacitance and internal surface area of a pyrolytic carbon material after electrochemical oxidation and subsequent reduction was studied with cyclic voltammetry and small-angle neutron scattering. Oxidation yields an enhanced internal surface area (activation), and subsequent reduction causes a decrease of this internal surface area. The change of the Porod constant, as obtained from small-angle neutron scattering, reveals that the decrease in internal surface area is not caused merely by a closing or narrowing of the pores, but by a partial collapse of the pore network

  20. A one-dimensional stochastic approach to the study of cyclic voltammetry with adsorption effects

    Energy Technology Data Exchange (ETDEWEB)

    Samin, Adib J. [The Department of Mechanical and Aerospace Engineering, The Ohio State University, 201 W 19" t" h Avenue, Columbus, Ohio 43210 (United States)

    2016-05-15

    In this study, a one-dimensional stochastic model based on the random walk approach is used to simulate cyclic voltammetry. The model takes into account mass transport, kinetics of the redox reactions, adsorption effects and changes in the morphology of the electrode. The model is shown to display the expected behavior. Furthermore, the model shows consistent qualitative agreement with a finite difference solution. This approach allows for an understanding of phenomena on a microscopic level and may be useful for analyzing qualitative features observed in experimentally recorded signals.

  1. A one-dimensional stochastic approach to the study of cyclic voltammetry with adsorption effects

    International Nuclear Information System (INIS)

    Samin, Adib J.

    2016-01-01

    In this study, a one-dimensional stochastic model based on the random walk approach is used to simulate cyclic voltammetry. The model takes into account mass transport, kinetics of the redox reactions, adsorption effects and changes in the morphology of the electrode. The model is shown to display the expected behavior. Furthermore, the model shows consistent qualitative agreement with a finite difference solution. This approach allows for an understanding of phenomena on a microscopic level and may be useful for analyzing qualitative features observed in experimentally recorded signals.

  2. Screening of pharmacologic adulterant classes in herbal formulations using voltammetry of microparticles.

    Science.gov (United States)

    Doménech-Carbó, Antonio; Martini, Mariele; de Carvalho, Leandro Machado; Viana, Carine; Doménech-Carbó, María Teresa; Silva, Miguel

    2013-02-23

    A solid state electrochemical method for screening different families of adulterant chemicals illegally added to commercial phytotherapuetic formulations is described. The proposed method, based on the voltammetry of microparticles approach, permits a fast and sensitive way to distinguish between anorexics (amfepramone, fenproporex, sibutramine), benzozodiazepinic anxiolytics (clonazepam, flurazepam, alprazolam, midazolam, medazepam, chlordiazepoxide, diazepam), antidepressants (bupropione, fluoxetine, sertraline, paroxetine), diuretics (hydrochlorothiazide, furosemide, chlortalidone, amiloride, spironolactone), and hypoglycemics (glimepiride, chlorpropamide, glibenclamide) based on characteristic voltammetric signals recorded on solid micro- or nanosamples attached to graphite electrodes immersed into aqueous electrolytes. Copyright © 2012 Elsevier B.V. All rights reserved.

  3. Dependence of adenine isolation efficiency on the chain length evidenced using paramagnetic particles and voltammetry measurements

    Energy Technology Data Exchange (ETDEWEB)

    Huska, Dalibor [Department of Chemistry and Biochemistry, Faculty of Agronomy, Mendel University of Agriculture and Forestry, Zemedelska 1, CZ-613 00 Brno (Czech Republic); Adam, Vojtech [Department of Chemistry and Biochemistry, Faculty of Agronomy, Mendel University of Agriculture and Forestry, Zemedelska 1, CZ-613 00 Brno (Czech Republic); Department of Animal Nutrition and Forage Production, Faculty of Agronomy, Mendel University of Agriculture and Forestry, Zemedelska 1, CZ-613 00 Brno (Czech Republic); Trnkova, Libuse [Department of Chemistry, Faculty of Science, Masaryk University, Kamenice 5, CZ-625 00 Brno (Czech Republic); Kizek, Rene [Department of Chemistry and Biochemistry, Faculty of Agronomy, Mendel University of Agriculture and Forestry, Zemedelska 1, CZ-613 00 Brno (Czech Republic)], E-mail: kizek@sci.muni.cz

    2009-05-15

    The main aim of this work was to study the dependence of oligoadenine isolation efficiency on the chain length by using paramagnetic particles covered by homo-deoxythymidines ((dT)25) with subsequent detection by adsorptive transfer technique coupled with square wave voltammetry. For this purpose, the oligonucleotides of the length A5, A10, A15, A20, A25, A30, A35, A40 and poly(A) in various concentrations were chosen. We determined that the isolation efficiency defined as 'isolated oligonucleotide concentration'/'given oligonucleotide concentration' was about 55% on average. Sequence A25 demonstrated the best binding onto microparticles surface.

  4. Dependence of adenine isolation efficiency on the chain length evidenced using paramagnetic particles and voltammetry measurements

    International Nuclear Information System (INIS)

    Huska, Dalibor; Adam, Vojtech; Trnkova, Libuse; Kizek, Rene

    2009-01-01

    The main aim of this work was to study the dependence of oligoadenine isolation efficiency on the chain length by using paramagnetic particles covered by homo-deoxythymidines ((dT)25) with subsequent detection by adsorptive transfer technique coupled with square wave voltammetry. For this purpose, the oligonucleotides of the length A5, A10, A15, A20, A25, A30, A35, A40 and poly(A) in various concentrations were chosen. We determined that the isolation efficiency defined as 'isolated oligonucleotide concentration'/'given oligonucleotide concentration' was about 55% on average. Sequence A25 demonstrated the best binding onto microparticles surface.

  5. Heart PET scan

    Science.gov (United States)

    ... nuclear medicine scan; Heart positron emission tomography; Myocardial PET scan ... A PET scan requires a small amount of radioactive material (tracer). This tracer is given through a vein (IV), ...

  6. Voltammetry of uranyl chloride in the LiCl - KCl eutectic; Voltammetrie du chlorure d'uranyle dans l'eutectique LiCl - KC1

    Energy Technology Data Exchange (ETDEWEB)

    Fondanaiche, J C [Commissariat a l' Energie Atomique, Fontenay-aux-Roses (France). Centre d' Etudes Nucleaires

    1965-07-01

    Spent UO{sub 2} - PuO{sub 2} fuels can be reprocessed in a molten salt media. Uranium dioxide can easily be dissolved as UO{sub 2}Cl{sub 2} in a molten salt bath using chlorine gas. A study of quantitative analysis of an uranyl chloride solution in the LiCl-KCl eutectic at 400 C has been performed here using voltammetry (a large area-graphite indicator electrode has been employed). The precision which is obtained is around 6 per cent for concentrations below 10{sup -2} M. Precision decreases slightly for more concentrated solutions. The study of polarization curves allowed to give a reduction mechanism for the UO{sub 2}{sup ++} ion. For dilute solutions, this reduction proceeds through the UO{sub 2}{sup +} ion. But interpretation of current-potential curves is made difficult by the dismutation reaction of the UO{sub 2} ion and by the fact that the surface of the indicator electrode is not renewed. (author) [French] Le traitement des combustibles a base d'oxydes (UO{sub 2} - PUO{sub 2}) peut etre effectue au moyen des sels fondus. Le bioxyde d'uranium passe aisement en solution sous forme de UO{sub 2}Cl{sub 2} dans un bain de sels fondus par action du chlore. Nous avons etudie ici l'analyse quantitative d'une solution de chlorure d'uranyle dans l'eutectique LiCl - KCl a 400 C par voltammetrie (electrode indicatrice de graphite d'assez grande surface). La precision est d'environ 6 pour cent pour les concentrations inferieures a 10{sup -2} M; elle est legerement moins bonne pour les solutions plus concentrees. L'examen des courbes de polarisation a permis de donner un mecanisme de reduction de l'ion UO{sub 2}: pour les solutions diluees, cette reduction se fait par l'intermediaire de l'ion UO{sub 2}{sup +}. Mais l'interpretation des courbes intensite-potentiel est rendue delicate par la reaction de dismutation de l'ion UO{sub 2}{sup +} et par le fait que la surface de l'electrode indicatrice n'est pas renouvelee. (auteur)

  7. Analisis Kinerja CV. Fabamus Famili Utama Semarang Dengan Balanced Scorecard

    OpenAIRE

    Permata, Nilla Mega; Nugraha, Hari Susanta; Nurseto, Sendhang

    2014-01-01

    A method of measuring the performance of the company to assist in knowing the health condition of the company itself. The study was conducted on the CV. Fabamus First Family with Balanced Scorecard approach to measuring through four perspectives: financial perspective, customer perspective, internal business process perspective and learning and growth perspectives. In the financial aspects of performance measurement with a weight of 70%, 10% customer perspective, internal business process per...

  8. STRATEGI PEMASARAN PRODUK DIGITAL PRINTING PADA CV. FNB DIGITAL JAMBI

    OpenAIRE

    Yuniarti, Yenni; Mauliana, Sarah

    2012-01-01

    CV. Digital FNB is one of the companies that involved in Digital Printing business. Based on survey in the middle of 2011-2012, there are 31 digital printing businesses in the city of Jambi. In order to examine the marketing stratey implemented, descriptive study has been conducted, uses interview, observation, and documentation as instruments. The strategy that observed in this study consist of marketing strategy including market segmentation, targeting, product strategy, pricing strategy, ...

  9. Applications in Foreign Currency Prima CV Ellindo Money Changer

    OpenAIRE

    Wisnu Sutrisno; Ire Puspa Wardhani, Skom, MMSI

    2004-01-01

    This explains the scientific writing about the design of application programs forforeign currency transactions by using Visual Basic 6.0 programming language.In scientific writing database is also used by Visual Data Manager (VisData)integrated in Visual Basic 6.0 program itself. Consists of three tables namelyCurrency,Customer and Transaction.In the end application program for foreign currency transactions will be applied to theCV. Prima Ellindo Money Changer for ease in performing activitie...

  10. The draft genome of Corchorus olitorius cv. JRO-524 (Navin

    Directory of Open Access Journals (Sweden)

    Debabrata Sarkar

    2017-06-01

    Full Text Available Here, we present the draft genome (377.3 Mbp of Corchorus olitorious cv. JRO-524 (Navin, which is a leading dark jute variety developed from a cross between African (cv. Sudan Green and indigenous (cv. JRO-632 types. We predicted from the draft genome a total of 57,087 protein-coding genes with annotated functions. We identified a large number of 1765 disease resistance-like and defense response genes in the jute genome. The annotated genes showed the highest sequence similarities with that of Theobroma cacao followed by Gossypium raimondii. Seven chromosome-scale genetically anchored pseudomolecules were constructed with a total size of 8.53 Mbp and used for synteny analyses with the cocoa and cotton genomes. Like other plant species, gypsy and copia retrotransposons were the most abundant classes of repeat elements in jute. The raw data of our study are available in SRA database of NCBI with accession number SRX1506532. The genome sequence has been deposited at DDBJ/EMBL/GenBank under the accession LLWS00000000, and the version described in this paper will be the first version (LLWS01000000.

  11. DIFFERENTIAL PULSE ANODIC STRIPPING VOLTAMMETRY FOR DETERMINATION OF SOME HEAVY METALS IN URANIUM

    Directory of Open Access Journals (Sweden)

    Saryati Saryati

    2010-06-01

    Full Text Available The direct determination of some metals impurity in uranium by using differential pulse anodic stripping voltammetry (DPASV method at a hanging mercury drop electrode and in a carbonate buffer media was developed. It was found that the carbonate buffer show the strongest affinity for uranium and gives the best separation between the DPASV peaks of heavy metals impurities. The carbonate concentration markedly affects the oxidation and reduction the major and the minor constituents of the uranium samples. In 0.1 M carbonate buffer solution pH 10, copper, bismuth, thalium, lead, cadmium, zinc, could be determined without the removal of the uranium matrix. Recovery and relative standard deviation (RSD of this method was in the range of 174% - 85.2% for recovery and 36.8% - 1.2% for RSD. The larger error of analytical result was obtained for Zn at low concentration. In general, the analytic results error and RSD decreased with increasing metals concentration.   Keywords: heavy metal determination, differential pulse anodic stripping voltammetry, uranium

  12. Investigation of antioxidant capacity of the extracts of bilberry (VACCINUM MYRTILLIS L.) by voltammetry

    Science.gov (United States)

    Vtorushina, A. N.; Nikonova, E. D.

    2016-02-01

    This paper deals with the urgent issue of the search of new drugs based on plant raw materials that have an influence on various stages of oxidation processes occurring in the human body. The aim of this paper is to determine the antioxidant activity of the bilberry extracts that are used in the medicine practice by a cathodic voltammetry method. We consider the influence of water and alcohol bilberry extracts on the process of oxygen electroreduction. From these extracts the most activity relation to the process of cathodic oxygen reduction showed alcohol (40%) bilberry extract. It was also stated that the alcohol extract of bilberry has a greater antioxidant activity than other known antioxidants such as ascorbic acid, glucose, dihydroquercetin. Thus, after consideration of a number of plant objects, we showed the possibility of applying the method of cathodic voltammetry for the determination of total antioxidant activity of plant material and identifying and highlighting the most perspective sources of biologically active substances (BAS), as well as the ability of identifying extractants that fully extract BAS from plant raw materials. The activity data of extracts of plant raw materials gives an opportunity of establishing an effective yield phytopreparation based on bilberry that has an antioxidant effect.

  13. Glyphosate detection with ammonium nitrate and humic acids as potential interfering substances by pulsed voltammetry technique.

    Science.gov (United States)

    Martínez Gil, Pablo; Laguarda-Miro, Nicolas; Camino, Juan Soto; Peris, Rafael Masot

    2013-10-15

    Pulsed voltammetry has been used to detect and quantify glyphosate on buffered water in presence of ammonium nitrate and humic substances. Glyphosate is the most widely used herbicide active ingredient in the world. It is a non-selective broad spectrum herbicide but some of its health and environmental effects are still being discussed. Nowadays, glyphosate pollution in water is being monitored but quantification techniques are slow and expensive. Glyphosate wastes are often detected in countryside water bodies where organic substances and fertilizers (commonly based on ammonium nitrate) may also be present. Glyphosate also forms complexes with humic acids so these compounds have also been taken into consideration. The objective of this research is to study the interference of these common pollutants in glyphosate measurements by pulsed voltammetry. The statistical treatment of the voltammetric data obtained lets us discriminate glyphosate from the other studied compounds and a mathematical model has been built to quantify glyphosate concentrations in a buffer despite the presence of humic substances and ammonium nitrate. In this model, the coefficient of determination (R(2)) is 0.977 and the RMSEP value is 2.96 × 10(-5) so the model is considered statistically valid. Copyright © 2013 Elsevier B.V. All rights reserved.

  14. Variation sweep rate cyclic voltammetry on the capacitance electrode activated carbon/PVDF with polymer electrolyte

    Science.gov (United States)

    Rohmawati, L.; Setyarsih, W.; Nurjannah, T.

    2018-03-01

    Sweep rate of the process voltammetry cyclic characterization is very influential towards the electrode capacitance value, especially on activated carbon electrodes/PVDF. A simple method of this research by use a mixing for electrode activated carbon/10 wt. % PVDF and the separator is made of a polymer electrolyte (PVA/H3PO4) by a sol gel method. The prototype supercapacitor is made in the form of a sandwich with a separator placed between two electrodes. Electrodes and separators are arranged in layers at a pressure of 1500 psi, then heated at 50°C for 10 minutes. Next done cyclic voltammetry in a potential range of -1 V to 1 V with a sweep rate of 5 mV/s, 10 mV/s, 20 mV/s, 25 mV/s and 50 mV/s. This results of curves voltammogram is reversible, the most wide curve on the sweep rate of 5 mV/s and most narrow curve on a sweep rate of 50 mV/s. Supercapacitor capacitance values obtained by 86 F/g, 43 F/g, 21 F/g, 16 F/g, and 8 F/g.

  15. Investigation of antioxidant capacity of the extracts of bilberry (VACCINUM MYRTILLIS L.) by voltammetry

    International Nuclear Information System (INIS)

    Vtorushina, A N; Nikonova, E D

    2016-01-01

    This paper deals with the urgent issue of the search of new drugs based on plant raw materials that have an influence on various stages of oxidation processes occurring in the human body. The aim of this paper is to determine the antioxidant activity of the bilberry extracts that are used in the medicine practice by a cathodic voltammetry method.We consider the influence of water and alcohol bilberry extracts on the process of oxygen electroreduction. From these extracts the most activity relation to the process of cathodic oxygen reduction showed alcohol (40%) bilberry extract. It was also stated that the alcohol extract of bilberry has a greater antioxidant activity than other known antioxidants such as ascorbic acid, glucose, dihydroquercetin.Thus, after consideration of a number of plant objects, we showed the possibility of applying the method of cathodic voltammetry for the determination of total antioxidant activity of plant material and identifying and highlighting the most perspective sources of biologically active substances (BAS), as well as the ability of identifying extractants that fully extract BAS from plant raw materials. The activity data of extracts of plant raw materials gives an opportunity of establishing an effective yield phytopreparation based on bilberry that has an antioxidant effect. (paper)

  16. Analisis Daya Saing untuk Meningkatkan Kualitas Layanan terhadap Pelanggan dengan Pendekatan CRM di CV. BLITZSPOT

    Directory of Open Access Journals (Sweden)

    Suryadi Muhammad

    2017-04-01

    Full Text Available CV. Blitzspot adalah perusahaan yang bergerak di bidang jasa penyediaan layanan internet (internet service provider, yang berkantor pusat di Komplek Padasuka Indah Ruko Blok A-1, Cimahi, Jawa Barat. Berdasarkan hasil wawancara dan hasil observasi pada data transaksi CV. Blitzspot, konsumen CV. Blitzspot yang melakukan transaksi tiap tahunnya selalu berkurang, hal ini dikarenakan konsumen sering membandingkan layanan-layanan yang ditawarkan oleh para pesaing CV. Blitzspot. Bila permasalahan tersebut belum teratasi, konsumen CV. Blitzspot akan menurun tiap tahunnya dan akan selalu berpindah ke pesaing CV. Blitzspot. Direktur Utama CV. Blitzspot ingin menganalisis daya saing untuk menentukan layanan-layanan yang akan diberikan kepada pelanggan CV. Blitzspot dan penentuan strategi untuk mempertahankan konsumen CV. Blitzspot.  Metode Analisis daya saing yang digunakan adalah Model Analisis Berlian Porter dan Metode Pengelompokkan Pelanggan yang digunakan adalah Metode LRFM. Berdasarkan hasil pengujian dan pembahasan yang telah dibuat, maka dapat ditarik kesimpulan bahwa Direktur Utama dapat menganalisis daya saing CV. Blitzspot dengan menggunakan Berlian Porter untuk meningkatkan kualitas layanan terhadap pelanggan CV. Blitzspot.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2005-01-10

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

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

    International Nuclear Information System (INIS)

    Nedeltcheva, T.; Atanassova, M.; Dimitrov, J.; Stanislavova, L.

    2005-01-01

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

  19. Induction of single flower mutant in Hibiscus cv. 'Alipur Beauty'

    International Nuclear Information System (INIS)

    Banerji, B.K.; Datta, S.K.

    1986-01-01

    Stem cuttings of Hibicus cv. 'Alipur Beauty' were irradiated with 0, 1.0, 2.0 Krad of gamma rays in 60 Co source and planted just after irradiation. Data were recorded on days to sprout, number of sprouts, sprouting percentage, survival, plant height, leaf number and size, abnormal leaves and plants, floral abnormalities and induction of somatic mutations in flower colour/form. Some of the characters like plant height, leaf number, abnormal leaves and plants and leaf size were recorded after 60 and 120 days. 7 refs. (author)

  20. DETECTION OF MOTORCYCLISTS WITHOUT HELMET AND FINEPAYMENT USING OPEN CV

    OpenAIRE

    Stemy Simon, Divya Kumaran A.K.

    2018-01-01

    The helmet is the main safety equipment of motorcyclists, but many drivers do not use it. The main aim of this project is to construct an automatic detection of the motorcyclist without helmet from video using OpenCV library tools. If they are not wearing the helmet, the license plate of the motorcycle is focused automatically. By using Computer Vision technique we can detect and recognize the license plate number. We make the training set of different characters of different sizes. Based on ...

  1. Comparison of tracking algorithms implemented in OpenCV

    Directory of Open Access Journals (Sweden)

    Janku Peter

    2016-01-01

    Full Text Available Computer vision is very progressive and modern part of computer science. From scientific point of view, theoretical aspects of computer vision algorithms prevail in many papers and publications. The underlying theory is really important, but on the other hand, the final implementation of an algorithm significantly affects its performance and robustness. For this reason, this paper tries to compare real implementation of tracking algorithms (one part of computer vision problem, which can be found in the very popular library OpenCV. Moreover, the possibilities of optimizations are discussed.

  2. OpenCV 3.0 computer vision with Java

    CERN Document Server

    Baggio, Daniel Lélis

    2015-01-01

    If you are a Java developer, student, researcher, or hobbyist wanting to create computer vision applications in Java then this book is for you. If you are an experienced C/C++ developer who is used to working with OpenCV, you will also find this book very useful for migrating your applications to Java. All you need is basic knowledge of Java, with no prior understanding of computer vision required, as this book will give you clear explanations and examples of the basics.

  3. Simultaneous determination of three herbicides by differential pulse voltammetry and chemometrics.

    Science.gov (United States)

    Ni, Yongnian; Wang, Lin; Kokot, Serge

    2011-01-01

    A novel differential pulse voltammetry method (DPV) was researched and developed for the simultaneous determination of Pendimethalin, Dinoseb and sodium 5-nitroguaiacolate (5NG) with the aid of chemometrics. The voltammograms of these three compounds overlapped significantly, and to facilitate the simultaneous determination of the three analytes, chemometrics methods were applied. These included classical least squares (CLS), principal component regression (PCR), partial least squares (PLS) and radial basis function-artificial neural networks (RBF-ANN). A separately prepared verification data set was used to confirm the calibrations, which were built from the original and first derivative data matrices of the voltammograms. On the basis relative prediction errors and recoveries of the analytes, the RBF-ANN and the DPLS (D - first derivative spectra) models performed best and are particularly recommended for application. The DPLS calibration model was applied satisfactorily for the prediction of the three analytes from market vegetables and lake water samples.

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

    Science.gov (United States)

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

    2014-12-01

    Lysergic acid diethylamide (LSD) is hardly detectable and quantifiable in biological samples because of its low active dose. Although several analytical tests are available, routine analysis of this drug is rarely performed. In this article, we report a simple and accurate method for the determination of LSD, based on adsorptive stripping voltammetry in DMF/tetrabutylammonium perchlorate, with a linear range of 1-90 ng L(-1) for deposition times of 50s. LOD of 1.4 ng L(-1) and LOQ of 4.3 ng L(-1) were found. The method can be also applied to biological samples after a simple extraction with 1-chlorobutane. Copyright © 2014 Elsevier B.V. All rights reserved.

  5. Voltammetry of uranyl chloride in the LiCl - KCl eutectic

    International Nuclear Information System (INIS)

    Fondanaiche, J.C.

    1965-01-01

    Spent UO 2 - PuO 2 fuels can be reprocessed in a molten salt media. Uranium dioxide can easily be dissolved as UO 2 Cl 2 in a molten salt bath using chlorine gas. A study of quantitative analysis of an uranyl chloride solution in the LiCl-KCl eutectic at 400 C has been performed here using voltammetry (a large area-graphite indicator electrode has been employed). The precision which is obtained is around 6 per cent for concentrations below 10 -2 M. Precision decreases slightly for more concentrated solutions. The study of polarization curves allowed to give a reduction mechanism for the UO 2 ++ ion. For dilute solutions, this reduction proceeds through the UO 2 + ion. But interpretation of current-potential curves is made difficult by the dismutation reaction of the UO 2 ion and by the fact that the surface of the indicator electrode is not renewed. (author) [fr

  6. Lead migration from toys by anodic stripping voltammetry using a bismuth film electrode.

    Science.gov (United States)

    Leal, M Fernanda C; Catarino, Rita I L; Pimenta, Adriana M; Souto, M Renata S; Afonso, Christelle S; Fernandes, Ana F Q

    2016-09-02

    Metals may be released from toys via saliva during mouthing, via sweat during dermal contact, or via gastric and intestinal fluids after partial or whole ingestion. In this study, we determined the lead migration from toys bought on the Portuguese market for children below 3 years of age. The lead migration was performed according to the European Committee for Standardization EN 71-3, which proposes a 2-hour migration test that simulates human gastric conditions. The voltammetric determination of migrated lead was performed by anodic stripping voltammetry (ASV) at a bismuth film electrode (BiFE). For all the analyzed toys, the values of migrated lead did not exceed the limits imposed by the European Committee for Standardization EN 71-3 (90 mg kg -1 ) and by the EU Directive 2009/48/EC (13.5 mg kg -1 ) on the safety of toys.

  7. Determination of antioxidant activity of spices and their active principles by differential pulse voltammetry.

    Science.gov (United States)

    Palma, Alberto; Ruiz Montoya, Mercedes; Arteaga, Jesús F; Rodríguez Mellado, Jose M

    2014-01-22

    The anodic oxidation of mercury in the presence of hydrogen peroxide in differential pulse voltammetry (DPV) was used to determine the antioxidant (AO) character of radical scavengers. Hydroperoxide radical is formed at the potentials of the oxidation peak on mercury electrodes, such radical reacting with the antioxidants in different extension. The parameter C10 (antioxidant concentration at which the peak area decreases by 10%) is used to measure the scavenging activity of the individual antioxidants. To establish the scavenging activity of antioxidant mixtures as a whole, the parameter, μ10 as the reverse of V10, V10 being the volume necessary to decrease the peak area in DPV by 10%, was selected. Higher μ10 values correspond to higher scavenging activity. The studies have been extended to aqueous extracts of some species. The results may be useful in explaining the effect of spices in vitro and in vivo studies.

  8. Square Wave Voltammetry: An Alternative Technique to Determinate Piroxicam Release Profiles from Nanostructured Lipid Carriers.

    Science.gov (United States)

    Otarola, Jessica; Garrido, Mariano; Correa, N Mariano; Molina, Patricia G

    2016-08-04

    A new, simple, and fast electrochemical (EC) method has been developed to determine the release profile of piroxicam, a nonsteroidal anti-inflammatory drug, loaded in a drug delivery system based on nanostructured lipid carriers (NLCs). For the first time, the samples were analyzed by using square wave voltammetry, a sensitive EC technique. The piroxicam EC responses allow us to propose a model that explains the experimental results and to subsequently determine the amount of drug loaded into the NLCs formulation as a function of time. In vitro drug release studies showed prolonged drug release (up to 5 days), releasing 60 % of the incorporated drug. The proposed method is a promising and stable alternative for the study of different drug delivery systems. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  9. Embedded 32-bit Differential Pulse Voltammetry (DPV) Technique for 3-electrode Cell Sensing

    Science.gov (United States)

    N, Aqmar N. Z.; Abdullah, W. F. H.; Zain, Z. M.; Rani, S.

    2018-03-01

    This paper addresses the development of differential pulse voltammetry (DPV) embedded algorithm using an ARM cortex processor with new developed potentiostat circuit design for in-situ 3-electrode cell sensing. This project is mainly to design a low cost potentiostat for the researchers in laboratories. It is required to develop an embedded algorithm for analytical technique to be used with the designed potentiostat. DPV is one of the most familiar pulse technique method used with 3-electrode cell sensing in chemical studies. Experiment was conducted on 10mM solution of Ferricyanide using the designed potentiostat and the developed DPV algorithm. As a result, the device can generate an excitation signal of DPV from 0.4V to 1.2V and produced a peaked voltammogram with relatively small error compared to the commercial potentiostat; which is only 6.25% difference in peak potential reading. The design of potentiostat device and its DPV algorithm is verified.

  10. Arsenic speciation study using x ray fluorescence and cathodic stripping voltammetry

    International Nuclear Information System (INIS)

    Valcarcel, Lino; Montero, Alfredo; Estevez, Juan; Pupo, Ivan

    2006-01-01

    Two methods for the determination of total As concentration and its inorganic species by Energy Dispersive X Ray Fluorescence (EDXRF) and Cathodic Stripping Voltammetry (CSV) were developed. The effect of pH on As (III) recovery after precipitation with APDC and EDXRF measurement was studied. Quantification of As was done using the thin layer approach. A reduction of As(V) to As(III) with sodium thiosulphate was necessary in order to determine the total As concentration. The effect of the amount of reducing agent on the recovery was also studied. As(V) concentration was calculated by difference between total As and As(III) concentration. On the other hand, a polarographic method, using the cathodic stripping mode was implemented. As(III) deposition on the electrode was enhanced by addition of Se(IV). Factors affecting As determination (selenium concentration, deposition potential, deposition time) were studied

  11. Life assessment of PVD based hard coatings by linear sweep voltammetry for high performance industrial application

    International Nuclear Information System (INIS)

    Malik, M.; Alam, S.; Irfan, M.; Hassan, Z.

    2006-01-01

    PVD based hard coatings have remarkable achievements in order to improve Tribological and surface properties of coating tools and dies. As PVD based hard coatings have a wide range of industrial applications especially in aerospace and automobile parts where they met different chemical attacks and in order to improve industrial performance these coatings must provide an excellent resistance against corrosion, high temperature oxidation and chemical reaction. This paper focuses on study of behaviour of PVD based hard coatings under different corrosive environments like as H/sub 2/SO/sub 4/, HCl, NaCl, KCl, NaOH etc. Corrosion rate was calculate under linear sweep voltammetry method where the Tafel extrapolation curves used for continuously monitoring the corrosion rate. The results show that these coatings have an excellent resistance against chemical attack. (author)

  12. Chemometric study of Maya Blue from the voltammetry of microparticles approach.

    Science.gov (United States)

    Doménech, Antonio; Doménech-Carbó, María Teresa; de Agredos Pascual, María Luisa Vazquez

    2007-04-01

    The use of the voltammetry of microparticles at paraffin-impregnated graphite electrodes allows for the characterization of different types of Maya Blue (MB) used in wall paintings from different archaeological sites of Campeche and YucatAn (Mexico). Using voltammetric signals for electron-transfer processes involving palygorskite-associated indigo and quinone functionalities generated by scratching the graphite surface, voltammograms provide information on the composition and texture of MB samples. Application of hierarchical cluster analysis and other chemometric methods allows us to characterize samples from different archaeological sites and to distinguish between samples proceeding from different chronological periods. Comparison between microscopic, spectroscopic, and electrochemical examination of genuine MB samples and synthetic specimens indicated that the preparation procedure of the pigment evolved in time via successive steps anticipating modern synthetic procedures, namely, hybrid organic-inorganic synthesis, temperature control of chemical reactivity, and template-like synthesis.

  13. Duplex scanning in the diagnosis of acute deep vein thrombosis of the lower extremity

    NARCIS (Netherlands)

    van Ramshorst, B.; Legemate, D. A.; Verzijlbergen, J. F.; Hoeneveld, H.; Eikelboom, B. C.; de Valois, J. C.; Meuwissen, O. J.

    1991-01-01

    In a prospective study the value of duplex scanning in the diagnosis of acute femoro-popliteal thrombosis was compared to conventional contrast venography (CV) as a gold standard. A total of 126 legs in 117 patients suspected of having deep vein thrombosis (DVT) or pulmonary embolism (PE) were

  14. Composite films of poly-(ester-sulphonated) and poly-(3-methylthiophene) for ion-exchange voltammetry in acetonitrile solutions

    International Nuclear Information System (INIS)

    Scopece, Paolo; Moretto, Ligia M.; Polizzi, Stefano; Ugo, Paolo

    2006-01-01

    This paper describes the preparation and characterisation of a polymeric electrode coating based on a composite of the poly-(ester-sulphonated) Eastman AQ55[reg] (AQ55) and poly-(3-methylthiophene) (PMeT), which is used for the controlled uptake and partial release of electroactive cations in acetonitrile solutions. The film is prepared by electrochemical oxidation in acetonitrile of 3-methylthiophene on glassy carbon disks or Pt-quartz crystal electrodes pre-coated with a thin film of AQ55. The electropolymerisation process is controlled so that the overall number of positive charges of oxidised PMeT is equal to the number of negative charges of the sulphonate groups of AQ55. Cyclic voltammetry and quartz crystal microbalance measurements indicate that the AQ55/PMeT mixed film is stable in acetonitrile and that its cation-exchange properties depend on the applied potential. When the PMeT moieties are reduced, the film incorporate cations; following electrochemical oxidation of the coating causes a release of the incorporated cations which, however, is only partial. Scanning electron microscopy (SEM) examination of cross sections of the composite polymer layer indicate that it is really a bi-layer, made by an inner compact layer of AQ55 on which a thicker and porous PMeT layer is grown. The outer PMeT layer acts as a barrier whose ionic charges can be changed electrochemically from positive (oxidation) to neutral (reduction). These ionic charges hinder or allow, respectively, the permeation of redox cations which tend to interact with the negatively charged sulphonic sites of the AQ55 layer. Direct self-neutralization of part of the positive charges of oxidized PMeT by the AQ55 sulphonic groups allows the release of part of the redox cations incorporated previously in the mixed film when PMeT is in the reduced state. By operating in acetonitrile solutions without added electrolyte it is possible to increase the fraction of redox cations which are released in

  15. Alcohol and CV Health: Jekyll and Hyde J-Curves.

    Science.gov (United States)

    O'Keefe, Evan L; DiNicolantonio, James J; O'Keefe, James H; Lavie, Carl J

    2018-02-16

    A routine of light or moderate alcohol consumption (≤1 drink/day for women and 1 to 2 drinks/day for men) is associated with a lower risk for all-cause mortality, coronary artery disease (CAD), type 2 diabetes mellitus (T2D), heart failure (HF), and stroke. Conversely, heavy drinking, (>4 drinks/day) is associated with an increased risk for death and cardiovascular (CV) disease (CVD). Excessive alcohol intake trails behind only smoking and obesity among the 3 leading causes of premature deaths in the United States (US). Heavy alcohol use is a common cause of reversible hypertension (HTN), nonischemic dilated cardiomyopathy, atrial fibrillation (AF), and stroke (both ischemic and hemorrhagic). Among males aged 15 to 59 years, alcohol abuse is perhaps the leading cause of premature death. As such, the risk-to-benefit ratio of drinking is less favorable in younger individuals. A daily habit of light to moderate drinking is ideal for those who choose to consume alcohol regularly. Red wine in particular before or during the evening meal is linked with the best long-term CV outcomes. Most of the studies on alcohol and health are observational, and correlation does not prove causation. Health care professionals should not advise nondrinkers to begin drinking because of the paucity of randomized outcome data coupled with the potential for alcohol abuse even among seemingly low risk individuals. Copyright © 2017. Published by Elsevier Inc.

  16. Resistance selection on banana CV. Ambon Kuning Against Fusarium Wilt

    International Nuclear Information System (INIS)

    Sutarto, Ismiyarti; Meldia, Yeni; Jumjunidang

    1998-01-01

    This research was conducted in order to study the occurrence of mutation on irradiated plantlets and their resistance of plants of banana cv. Ambon Kuning against Fusarium wilt. Plantlets of banana cv. Ambon Kuning sized 5 cm were exposed to gamma rays at the doses 5 - 35 Gy intervals, then were subcultured for obtained M 1 V 5 plantlets. More over, the planlets were acclimatized and were planted in the field was already infected by Fasarium (f).culbense (FOC). The result indicated that irradiated plantlets of the doses 20 - 35 Gy were not able to survive up to 6 months after exposing to gamma rays. Abnormalities of M 1 V 5 plantlets originated from irradiated plantlets at the doses 10 and 15 Gy were shown on rossette plantlets with rigid and dark green leaves, and the formation of smooth mass morphologically shaped like calculus. The appearance of plant height and number of suckers of suckers of M 1 V 5 plants in the field was quite various. The number of survival plants after 8 moths planting was 8, 7, 15, and 28, respectively originated from untreated plants and irradiated plantlets at the doses 5, 10, and 15 Gy. After one year planting , only 2 plants were able to survive from irradiated plantlet at the dose 15 Gy. The plants could produce 27 plantlets obtained from culturing their shoot tips. Further study of these plantlets was needed in order create the stability of their resistance to FOC. (author)

  17. EN-CV during LS1: upgrade, consolidation, maintenance, operation

    International Nuclear Information System (INIS)

    Nonis, M.

    2012-01-01

    The Cooling and Ventilation (CV) Group in the Engineering Department (EN) will be heavily involved in several projects and activities during the long shutdown in 2013 and 2014 (LS1) within a time-frame limited to around twelve months. According to the requests received so far, most projects are related to the upgrade of users' equipment, consolidation work, and the construction of new plants. However, through the experience gained from the first years of the LHC run, some projects are also needed to adapt the existing installations to the new operating parameters. Some of these projects are presented hereafter, outlining the impact that they will have on operational working conditions or risks of breakdown. Among these projects we find: the PM32 raising pumps, the cooling of the CERN Control Center, R2E, the backup cooling towers for ATLAS and cryogenics, a thermosyphon for ATLAS, or new pumps in UWs. Finally, EN-CV activities during LS1 for maintenance, operation, and commissioning will be mentioned since they represent a major workload for the Group

  18. Perancangan Kemasan Transportasi Buah Jambu Air (Syzygium aqueum cv Camplong

    Directory of Open Access Journals (Sweden)

    Iswahyudi

    2015-04-01

    Full Text Available Jamboo cv Camplong was an exotic fruit from Sampang Indonesia which had high economic values. The quality of fresh Jamboo was greatly influenced by the types of packaging and ways of its transportation that affected its shelf life. The purpose of this research were designing a primary packaging and analyzing the quality of Jamboo cv Camplong after short transportation (from Sampang to Surabaya. Farmers used conventional packaging with capacity of 8.4 kg/box (dimension 478 mm x 146 mm x 354 mm. Based on theoretical packaging design showed that the flute BC cardboard (capacity 4.5 kg/box, dimension 357 mm x 217 mm x 216 mm with partition flute A cardboard. In fact, there was needed modification of the dimension (342 mm x 210 mm x 200 mm because of the fruits diameter (60-65 mm. This result did not change the efficiency usage of transportation space (91-95% and compression strength of box can support (7 boxes/ stack. The result showed that the mechanical damage after transportation were 20.87% for conventional packaging (as control and 7.70% for modification packaging design (packaging with partition.

  19. Radiopharmaceutical scanning agents

    International Nuclear Information System (INIS)

    1976-01-01

    This invention is directed to dispersions useful in preparing radiopharmaceutical scanning agents, to technetium labelled dispersions, to methods for preparing such dispersions and to their use as scanning agents

  20. Thyroid Scan and Uptake

    Medline Plus

    Full Text Available ... Scan and Uptake Thyroid scan and uptake uses small amounts of radioactive materials called radiotracers, a special ... is a branch of medical imaging that uses small amounts of radioactive material to diagnose and determine ...

  1. Nuclear Heart Scan

    Science.gov (United States)

    ... Home / Nuclear Heart Scan Nuclear Heart Scan Also known as Nuclear Stress Test , ... Learn More Connect With Us Contact Us Directly Policies Privacy Policy Freedom of Information Act (FOIA) Accessibility ...

  2. Thyroid Scan and Uptake

    Medline Plus

    Full Text Available ... of page What will I experience during and after the procedure? Most thyroid scan and thyroid uptake ... you otherwise, you may resume your normal activities after your nuclear medicine scan. If any special instructions ...

  3. RBC nuclear scan

    Science.gov (United States)

    ... page: //medlineplus.gov/ency/article/003835.htm RBC nuclear scan To use the sharing features on this page, please enable JavaScript. An RBC nuclear scan uses small amounts of radioactive material to ...

  4. Scanning gamma camera

    International Nuclear Information System (INIS)

    Engdahl, L.W.; Batter, J.F. Jr.; Stout, K.J.

    1977-01-01

    A scanning system for a gamma camera providing for the overlapping of adjacent scan paths is described. A collimator mask having tapered edges provides for a graduated reduction in intensity of radiation received by a detector thereof, the reduction in intensity being graduated in a direction normal to the scanning path to provide a blending of images of adjacent scan paths. 31 claims, 15 figures

  5. Speciation of Co(II) and Ni(II) in anaerobic bioreactors measured by competitive ligand exchange - adsorptive stripping voltammetry

    NARCIS (Netherlands)

    Jansen, S.; Steffen, F.; Threels, W.F.; Leeuwen, van H.P.

    2005-01-01

    Competitive ligand exchange-adsorptive stripping voltammetry is applied to speciation analysis of dissolved Ni(II) and Co(II) in an anaerobic bioreactor and similar batch media. Co and Ni speciation in these media can be measured down to concentration levels of ca. 1 nM. Sulfide interference is

  6. The learning machine in quantitative chemical analysis : Part I. Anodic Stripping Voltammetry of Cadmium, Lead and Thallium

    NARCIS (Netherlands)

    Bos, M.; Jasink, G.

    1978-01-01

    The linear learning machine method was applied to the determination of cadmium, lead and thallium down to 10-8 M by anodic stripping voltammetry at a hanging mercury drop electrode. With a total of three trained multicategory classifiers, concentrations of Cd, Pb and Tl could be predicted with an

  7. Cyclic voltammetry of ion transfer across a room temperature ionic liquid membrane supported by a microporous filter

    Czech Academy of Sciences Publication Activity Database

    Langmaier, Jan; Samec, Zdeněk

    2007-01-01

    Roč. 9, č. 9 (2007), s. 2633-2638 ISSN 1388-2481 R&D Projects: GA AV ČR IAA400400704 Institutional research plan: CEZ:AV0Z40400503 Keywords : room-temperature ionic membrane * cyclic voltammetry * standard Gibbs energy of ion transfer * linear Gibbs energy relationship Subject RIV: CG - Electrochemistry Impact factor: 4.186, year: 2007

  8. Analysis of low concentration of free ferric oxides in clays by vis diffuse reflectance spectroscopy and voltammetry

    Czech Academy of Sciences Publication Activity Database

    Grygar, Tomáš; Dědeček, Jiří; Hradil, David

    2002-01-01

    Roč. 53, č. 2 (2002), s. 71-77 ISSN 0016-7738 R&D Projects: GA ČR GA205/00/1349 Institutional research plan: CEZ:AV0Z4032918 Keywords : voltammetry * Vis spectroscopy * analysis Subject RIV: CA - Inorganic Chemistry

  9. Voltammetry of Lead Cations on a New Type of Silver Composite Electrode in the Presence of Other Cations

    Czech Academy of Sciences Publication Activity Database

    Navrátil, Tomáš; Šebková, Světlana; Kopanica, M.

    2004-01-01

    Roč. 379, - (2004), s. 294-301 ISSN 1618-2642 Grant - others:GIT(AR) 101/02/U111/CZ Institutional research plan: CEZ:AV0Z4040901 Keywords : voltammetry * silver composite electrode * lead cations Subject RIV: CG - Electrochemistry Impact factor: 2.098, year: 2004

  10. Characterization of the Redox reaction of V(V) in Ammonia Buffers with Square-Wave Voltammetry

    OpenAIRE

    Mirceski, Valentin; Gulaboski, Rubin; Petrovska-Jovanovic, Simka; Stojanova, Kornelija

    2001-01-01

    The redox reaction of V(V) in ammonia buffers solution with pH = 8.60 was studied by means of square-wave and cyclic voltammetry. The redox reaction studied exhibits properties of a surface redox process in which both the reactant and the product of the redox reaction are immobilized on the electrode surface.

  11. Combination of Scanning Probe Microscopy and Coordination Chemistry: Structural and Electronic Study of Bis(methylbenzimidazolyl)ketone and Its Iron Complex

    NARCIS (Netherlands)

    Folkertsma, Emma; Van Der Lit, Joost; Di Cicco, Francesca; Lutz, Martin; Klein Gebbink, Robertus J. M.; Swart, Ingmar; Moret, Marc-etienne

    2017-01-01

    Here, we report the bulk synthesis of [FeII(BMBIK)Cl2] bearing the redox noninnocent bis(methylbenzimidazolyl)ketone (BMBIK) ligand and the synthesis of the similar complex [FeI(BMBIK)]+ on a Au(111) surface using lateral manipulation at the atomic level. Cyclic voltammetry and scanning tunneling

  12. Wilting and biological additive effect on in situ degradability and chemical composition of Arachis pintoi cv Belomonte silage

    OpenAIRE

    Rosana Aparecida Possenti; Evaldo Ferrari Júnior; Valdinei Tadeu Paulino; Ivani Pozar Otsuk; Patrícia Brás

    2010-01-01

    The purpose of this work was to evaluate the effect of wilting and biological additive amendment on chemical composition, fermentation and ruminal degradability of Arachis pintoi cv Belmonte silage. The following treatments were analysed: T1- Arachis pintoi cv Belmonte fresh forage; T2 - Arachis pintoi cv Belmonte fresh forage plus bacterial additive added to the forage prior to the ensilage; T3- Arachis pintoi cv Belmonte wilted by the sun for 4 hours; T4- Arachis pintoi cv Belmonte wilted b...

  13. Analisis Tingkat Kepuasan Kerja Karyawan pada CV Sumber Pangan di Denpasar

    OpenAIRE

    SUPRATMAN, I WAYAN NOVA; USTRIYANA, I NYOMAN GEDE; DEWI, IDA AYU LISTIA

    2016-01-01

    Analysis of Job Satisfaction at CV Food Sources in DenpasarHuman resources is a factor of production which is very important for a company,compared with other factors of production include natural resources, capital, andskills. The purpose of this study was to determine the level of employee satisfactionCV Food Source in Denpasar. The location determination is done deliberately. Thetotal number of the population sampled that stout 40 employees CV Source of Foodin Denpasar. The factors used in...

  14. Pengaruh Budaya Organisasi, Kepemimpinan, dan Motivasi Kerja terhadap Kepuasan Kerja Karyawan CV Surya Raya

    Directory of Open Access Journals (Sweden)

    Laksmi Sito Dwi Irvianti

    2012-05-01

    Full Text Available This research was conducted on CV Surya Raya which is engaged in car shipping. The aim of this study is to determine the influence of organization culture, leadership, and working motivation partially to employees’ satisfaction in CV Surya Raya. The data was collected by conducting interviews with the company and distributing questionnaires to 67 employees as respondents and then analyzed using linear regression analysis method. From the research results, leadership variable does not have a significant impact on employees' job satisfaction in CV Surya Raya. Whereas, the motivation variable has greater influence on job satisfaction of CV Surya Raya employees compared to the organization's culture.

  15. CIVAC CV-01 type pressure gage for middle vacuum pumps

    International Nuclear Information System (INIS)

    Olaru, Grigore; Aculai, Agustin

    1997-01-01

    The digital display pressure gage CIVAC CV-01 measures absolute pressures in vacuum range of 10 2 - 10 -3 mbar in any installation or equipment generating or using low pressures. It uses a transducer type PIRANI, model TR-02. It is a portable device, easy to exploit and handle. It is applied in research, chemistry, metallurgical industry, mechanical engineering. The system of coupling the transducer to the enclosure where the pressure is to be measured is of type ISO-PNEUROP with flange, collar and adjusting ring with a DN 25 ring gasket. The technical and functional features are: - Measuring error: ± 35% of real conventional value ; - Response time: 20 ms; - Number of measuring points: 1; - Output signal: 0 - 10 V d.c.; - Repeatability error: 5%; - Max weight: 1,600 Kg; Size: 91 x 117 x 187 mm. (authors)

  16. Cytotoxic diterpenoids from Jatropha curcas cv. nigroviensrugosus CY Yang Roots.

    Science.gov (United States)

    Liu, JieQing; Yang, YuanFeng; Xia, JianJun; Li, XuYang; Li, ZhongRong; Zhou, Lin; Qiu, MingHua

    2015-09-01

    An investigation of phytochemicals from the roots of Jatropha curcas cv. nigroviensrugosus resulted in the isolation of twenty diterpenoids, including lathyranlactone, an unusual diterpenoid lactone possessing a 5/13/3 tricyclic skeleton, jatrocurcasenones A-E and jatrophodiones B-E, as well as 10 known analogues. All isolates were evaluated for cytotoxicity against the HL-60, SMMC-772, A-549, MCF-7 and SW480 human tumor cell lines using the MTS viability assay. Four of the known analogues showed cytotoxic activity in these cell lines, with IC50 values ranging from 2.0 to 23.0 μM. Moreover, the assessment of their cytotoxic structure-activity relationships showed the epoxy ring between C-5 and C-6 and the hydroxyl group at C-2 were the key functionalities for cytotoxicity. Copyright © 2015 Elsevier Ltd. All rights reserved.

  17. Sign Language Translator Application Using OpenCV

    Science.gov (United States)

    Triyono, L.; Pratisto, E. H.; Bawono, S. A. T.; Purnomo, F. A.; Yudhanto, Y.; Raharjo, B.

    2018-03-01

    This research focuses on the development of sign language translator application using OpenCV Android based, this application is based on the difference in color. The author also utilizes Support Machine Learning to predict the label. Results of the research showed that the coordinates of the fingertip search methods can be used to recognize a hand gesture to the conditions contained open arms while to figure gesture with the hand clenched using search methods Hu Moments value. Fingertip methods more resilient in gesture recognition with a higher success rate is 95% on the distance variation is 35 cm and 55 cm and variations of light intensity of approximately 90 lux and 100 lux and light green background plain condition compared with the Hu Moments method with the same parameters and the percentage of success of 40%. While the background of outdoor environment applications still can not be used with a success rate of only 6 managed and the rest failed.

  18. Gamma irradiation studies on Gladiolus cv. White Friendship

    International Nuclear Information System (INIS)

    Banerji, B.K.; Datta, S.K.; Sharma, S.C.

    1994-01-01

    Dormant corms of Gladiolus cv. White Friendship were irradiated with 250, 500, 750, 1000 and 1250 Gy of gamma rays. Reduction in survival, plant height, number of leaves and floret, spike length, leaf and corm size and delayed flowering were recorded after irradiation. Morphological abnormalities in foliage and florets and chromosomal aberration during root tip mitosis increased with increase in exposure. Flowering was ceased cent per cent in highest dose of 1250 Gy. LD 50 on survival basis was found in 750 Gy exposure. MV 2 and MV 3 also followed the similar pattern of results as exhibited by MV 1 plants. Pink flower colour mutation was detected in few plants as sectorial chimeric form in MV 2 in treated population. In MV 3 one plant produced spike with lighter pink florets in 750 Gy treatment. This mutant has been isolated in pure form. (author). 10 refs., 2 figs., 2 tabs

  19. Induced somatic mutation in mango, mangifera indica L. cv. Langra

    International Nuclear Information System (INIS)

    Siddiqui, S.H.

    1985-01-01

    Dormant buds of mango (Mangifera indica L. cv. Langra) exposed to acute gamma-irradiation dosages of 1.0, 2.0, 3.0, 4.0, 5.0 and 6.0 kiloroentgens (kR), were grafted on to one-year-old seedling stock. Dosages of 2.0 and 3.0 kR were found satisfactory for the purpose, as measured by bud lethality and scion growth. A bud graft from 3.0 kR bore fruits of excellent quality. Compared with the control, the fruits were heavier, larger and had more creamish-yellow pulp. None of the other morphological changes expressed by the mutant fruits, observed over three fruiting seasons, were disadvantageous. The tree habit is being further investigated before the mutant can be considered for release as an improved cultivar. (author)

  20. Analisis Pengukuran Produktivitas Perusahaan Alsintan CV. Cherry Sarana Agro

    Directory of Open Access Journals (Sweden)

    Prima Fithri

    2016-04-01

    Full Text Available CV Cherry Sarana Agro is a manufacturing company, which produces agricultural machinery. In reality, company evaluatesits work and performance based on level of profits. In order to maintain the company's performance, it is necessary to measures the productivity of company to see how effective the performance of this company. So it can be determined what is needed in order to improve the performance of the company and also can increase profits. Measuring the productivity can be seen from the financial data that obtained from the company. Then based on data processing, show this company's productivity levels decreased during the period of measurement and it means company requires efforts to increase the efficient use of inputs. It is necessary for company to increase its productivity for the future. This improvement was made by taking into account the partial productivity as inputs that affect the profitability of the company on an ongoing basis.

  1. CV activities on the LHC complex during the long shutdown

    CERN Document Server

    Deleval, S; Body, Y; Obrecht, M; Moccia, S; Peon, G

    2011-01-01

    The presentation gives an overview of the major projects and work foreseen to be performed during next long shutdown on cooling and ventilation plants. Several projects are needed following the experience of the last years when LHC was running, in particular the modifications in the water cooling circuits presently in overflow. Some other projects are linked to the CV consolidation plan. Finally, most of the work shall be done to respond to additional requests: SR buildings air conditioning, the need to be able to clean and maintain the LHC cooling towers without a complete stop of cooling circuits, the upgrade of the air conditioning of the CCC rack room cooling etc. For all these activities, the author will detail constraints and the impact on the schedule and on the operation of the plants that will however need to run for most of the shutdown duration. The consequence of postponing the long shutdown from 2012 to 2013 will be also covered.

  2. Electrocatalysis and kinetics of the direct alcohol fuel cells. DEMS and ac voltammetry studies

    Energy Technology Data Exchange (ETDEWEB)

    Othman Mostafa, Ehab Mostafa

    2013-01-11

    For the direct methanol fuel cell (DMFC) operating at low temperature, the main problem that arises at the anode is its poisoning (deactivation) due to the accumulation of the fuel adsorption product (CO{sub ad}) which can only be oxidized at high potentials (> 0.7 V). For low temperature direct ethanol fuel cells (DEFCs), the main problem that arises at the anode, beside its poisoning by ethanol adsorption products (CO{sub ad} and CH{sub x,ad}), is the incomplete ethanol oxidation due to the difficulty of (C-C) bond breaking. In the previous types of fuel cells, a sluggish oxygen reduction reaction (ORR) kinetics was observed at the cathode which results in a large voltage drop. Such behavior is due to strong inhibition of the cathodic ORR, resulting in high overpotentials and therefore, significant deterioration in the energy conversion efficiency of the cell. The slow kinetic behavior stems from the difficulty of (O=O) bond breaking. In order to model the conditions of continuous oxidation/reduction in a fuel cell, the continuous mass transfer to the electrode surface is necessary. Therefore, mass spectrometry and AC voltammetry measurements presented here were done using the thin layer flow through cell. This thesis aims at a determination of the rate constant of single reaction steps during the oxidation of CO, methanol and ethanol at different platinum surfaces. Towards that aim, I investigated the electrocatalytic oxidation and adsorption rate of methanol (chapter 3) and the electrocatalytic oxidation of ethanol (chapter 4) at different Pt surfaces, using DEMS. In chapter 5, the potential dependence of the bulk and adsorbed methanol oxidation reaction rate (presented by the apparent transfer coefficient, {alpha}') and the corresponding Tafel slope of the reaction have been determined under convection conditions using a potential modulation ac voltammetry technique. Finally, as an application of the method presented in chapter 5, my work in chapter 6

  3. Propolis extract in postharvest conservation Solo papaya cv. 'Golden'

    Directory of Open Access Journals (Sweden)

    Flávia Regina Passos

    2016-12-01

    Full Text Available The high perishability of papaya (Carica papaya L. reduces its lifespan as well as limits marketing. Coating the fruits is an alternative to aid food preservation. We aimed to evaluate the effects of coating propolis extract on the physicochemical characteristics of papaya stored at room temperature. Solo papayas cv. 'Golden' were randomly divided into five postharvest treatment groups, three forms of dip-coating (70% alcohol, hydroalcoholic extract of propolis to 2.5%, and hydroalcoholic extract of propolis to 5% and two controls (one uncoated and one with refrigerated uncoated fruits. The weight loss, firmness, soluble solids (SS, titratable acidity (TA, SS/TA, and hydrogen potential (pH were evaluated at the intervals of 4 days every 12th storage day. Sensory analysis was performed on the 4th day of storage of papayas and evaluated by untrained through the acceptance testing. Treatments “refrigerated”, “propolis 2.5%”, and “5% propolis” presented with the lowest weight loss. The firmness level for treatment propolis 5% was superior to that of control, alcohol, and 2.5% propolis treatments. The SS was greater for propolis 5% treatment, which only differed from the alcohol treatment. The TA and SS/TA did not vary with the treatments, but with the storage time. The pH of refrigerated papaya showed significant differences in relation to other treatments. The fruits subjected to refrigerated treatment presented with chilling injury. Papayas coated with propolis extract showed sensory acceptability similar to that in other treatments on the 4th day of storage. The coating of propolis extract is a promising alternative for the control of weight loss and for the maintenance of firmness in Solo papaya cv. 'Golden'.

  4. Core Problem: Does the CV Parent Body Magnetization require differentiation?

    Science.gov (United States)

    O'Brien, T.; Tarduno, J. A.; Smirnov, A. V.

    2016-12-01

    Evidence for the presence of past dynamos from magnetic studies of meteorites can provide key information on the nature and evolution of parent bodies. However, the suggestion of a past core dynamo for the CV parent body based on the study of the Allende meteorite has led to a paradox: a core dynamo requires differentiation, evidence for which is missing in the meteorite record. The key parameter used to distinguish core dynamo versus external field mechanisms is absolute field paleointensity, with high values (>>1 μT) favoring the former. Here we explore the fundamental requirements for absolute field intensity measurement in the Allende meteorite: single domain grains that are non-interacting. Magnetic hysteresis and directional data define strong magnetic interactions, negating a standard interpretation of paleointensity measurements in terms of absolute paleofield values. The Allende low field magnetic susceptibility is dominated by magnetite and FeNi grains, whereas the magnetic remanence is carried by an iron sulfide whose remanence-carrying capacity increases with laboratory cycling at constant field values, indicating reordering. The iron sulfide and FeNi grains are in close proximity, providing mineralogical context for interactions. We interpret the magnetization of Allende to record the intense early solar wind with metal-sulfide interactions amplifying the field, giving the false impression of a higher field value in some prior studies. An undifferentiated CV parent body is thus compatible with Allende's magnetization. Early solar wind magnetization should be the null hypothesis for evaluating the source of magnetization for chondrites and other meteorites.

  5. Trace vanadium analysis by catalytic adsorptive stripping voltammetry using mercury-coated micro-wire and polystyrene-coated bismuth film electrodes

    Energy Technology Data Exchange (ETDEWEB)

    Dansby-Sparks, Royce; Chambers, James Q. [Department of Chemistry, University of Tennessee, Knoxville, TN 37996-1600 (United States); Xue Ziling, E-mail: xue@ion.chem.utk.edu [Department of Chemistry, University of Tennessee, Knoxville, TN 37996-1600 (United States)

    2009-06-08

    An electrochemical technique has been developed for ultra-trace (ng L{sup -1}) vanadium (V) measurement. Catalytic adsorptive stripping voltammetry for V analysis was developed at mercury-coated gold micro-wire electrodes (MWEs, 100 {mu}m) in the presence of gallic acid (GA) and bromate ion. A potential of -0.275 V (vs Ag/AgCl) was used to accumulate the complex in acetate buffer (pH 5.0) at the electrode surface followed by a differential pulse voltammetric scan. Parameters affecting the electrochemical response, including pH, concentration of GA and bromate, deposition potential and time have been optimized. Linear response was obtained in the 0-1000 ng L{sup -1} range (2 min deposition), with a detection limit of 0.88 ng L{sup -1}. The method was validated by comparison of results for an unknown solution of V by atomic absorption measurement. The protocol was evaluated in a real sample by measuring the amount of V in river water samples. Thick bismuth film electrodes with protective polystyrene films have also been made and evaluated as a mercury free alternative. However, ng L{sup -1} level detection was only attainable with extended (10 min) deposition times. The proposed use of MWEs for the detection of V is sensitive enough for future use to test V concentration in biological fluids treated by the advanced oxidation process (AOP).

  6. A potentiostat featuring an integrator transimpedance amplifier for the measurement of very low currents—Proof-of-principle application in microfluidic separations and voltammetry

    Science.gov (United States)

    Koutilellis, G. D.; Economou, A.; Efstathiou, C. E.

    2016-03-01

    This work reports the design and construction of a novel potentiostat which features an integrator transimpedance amplifier as a current-monitoring unit. The integration approach addresses the limitations of the feedback resistor approach used for current monitoring in conventional potentiostat designs. In the present design, measurement of the current is performed by a precision switched integrator transimpedance amplifier operated in the dual sampling mode which enables sub-pA resolution. The potentiostat is suitable for measuring very low currents (typical dynamic range: 5 pA-4.7 μA) with a 16 bit resolution, and it can support 2-, 3- and 4-electrode cell configurations. Its operation was assessed by using it as a detection module in a home-made capillary electrophoresis system for the separation and amperometric detection of paracetamol and p-aminophenol at a 3-electrode microfluidic chip. The potential and limitations of the proposed potentiostat to implement fast potential-scan voltammetric techniques were demonstrated for the case of cyclic voltammetry.

  7. Simultaneous extraction and determination of trace amounts of diclofenac from whole blood using supported liquid membrane microextraction and fast Fourier transform voltammetry.

    Science.gov (United States)

    Mofidi, Zahra; Norouzi, Parviz; Sajadian, Masumeh; Ganjali, Mohammad Reza

    2018-04-01

    A novel, simple, and inexpensive analytical technique based on flat sheet supported liquid membrane microextraction coupled with fast Fourier transform stripping cyclic voltammetry on a reduced graphene oxide carbon paste electrode was used for the extraction and online determination of diclofenac in whole blood. First, diclofenac was extracted from blood samples using a polytetrafluoroethylene membrane impregnated with 1-octanol and then into an acceptor solution, subsequently it was oxidized on a carbon paste electrode modified with reduced graphene oxide nanosheets. The optimal values of the key parameters influencing the method were as follows: scan rate, 6 V/s; stripping potential, 200 mV; stripping time, 5 s; pH of the sample solution, 5; pH of the acceptor solution,7; and extraction time, 240 min. The calibration curves were plotted for the whole blood samples and the method was found to have a good linearity within the range of 1-25 μg/mL with a determination coefficient of 0.99. The limits of detection and quantification were 0.1 and 1.0 μg/mL, respectively. Using this coupled method, the extraction and determination were merged into one step. Accordingly, the speed of detection for sensitive determination of diclofenac in complex samples, such as blood, increased considerably. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  8. Micro-extraction and trace determination of cadmium by square wave voltammetry at the carbon paste electrode impregnated with Ca10(PO4)6(OH)2

    International Nuclear Information System (INIS)

    El Mhammedi, M.A.; Achak, M.; Najih, R.; Bakasse, M.; Chtaini, A.

    2009-01-01

    The electrochemical behavior of cadmium ions at hydroxyapatite modified carbon paste electrode (HAP-CPE) is reported. The electrode paste was prepared as a mixture of finely powdered hydroxyapatite (HAP) together with graphite powder. The influence of variables such as the accumulation time, pH solution and apatite loading was tested by square wave voltammetry (SWV). The best results were obtained under the following optimized conditions: 5 min accumulation time, 5 mV pulse amplitude, 1 mV s -1 scan rate in 1.0 mol L -1 HClO 4 . The electrochemical responses obtained by SWV at HAP-CPE were found to be analytically suitable to develop a method for the determination of cadmium at low concentration levels. Under optimized operational conditions, a linear response range from 2 x 10 -8 mol L -1 to 2.5 x 10 -5 mol L -1 was obtained. The detection limit for cadmium determination was 4.0 x 10 -9 mol L -1 . The proposed sensor presented good repeatability, evaluated in terms of relative standard deviation (R.S.D. = 3.8%) for n = 5 and was applied for cadmium determination in water samples. The average recovery for these samples was 104%.

  9. A potentiostat featuring an integrator transimpedance amplifier for the measurement of very low currents--Proof-of-principle application in microfluidic separations and voltammetry.

    Science.gov (United States)

    Koutilellis, G D; Economou, A; Efstathiou, C E

    2016-03-01

    This work reports the design and construction of a novel potentiostat which features an integrator transimpedance amplifier as a current-monitoring unit. The integration approach addresses the limitations of the feedback resistor approach used for current monitoring in conventional potentiostat designs. In the present design, measurement of the current is performed by a precision switched integrator transimpedance amplifier operated in the dual sampling mode which enables sub-pA resolution. The potentiostat is suitable for measuring very low currents (typical dynamic range: 5 pA-4.7 μA) with a 16 bit resolution, and it can support 2-, 3- and 4-electrode cell configurations. Its operation was assessed by using it as a detection module in a home-made capillary electrophoresis system for the separation and amperometric detection of paracetamol and p-aminophenol at a 3-electrode microfluidic chip. The potential and limitations of the proposed potentiostat to implement fast potential-scan voltammetric techniques were demonstrated for the case of cyclic voltammetry.

  10. Simultaneous determination of caffeine and paracetamol by square wave voltammetry at poly(4-amino-3-hydroxynaphthalene sulfonic acid)-modified glassy carbon electrode.

    Science.gov (United States)

    Tefera, Molla; Geto, Alemnew; Tessema, Merid; Admassie, Shimelis

    2016-11-01

    Poly(4-amino-3-hydroxynaphthalene sulfonic acid)-modified glassy carbon electrode (poly(AHNSA)/GCE) was prepared for simultaneous determination of caffeine and paracetamol using square-wave voltammetry. The method was used to study the effects of pH and scan rate on the voltammetric response of caffeine and paracetamol. Linear calibration curves in the range of 10-125μM were obtained for both caffeine and paracetamol in acetate buffer solution of pH 4.5 with a correlation coefficient of 0.9989 and 0.9986, respectively. The calculated detection limits (S/N=3) were 0.79μM for caffeine and 0.45μM for paracetamol. The effects of some interfering substances in the determination of caffeine and paracetamol were also studied and their interferences were found to be negligible which proved the selectivity of the modified electrode. The method was successfully applied for the quantitative determination of caffeine and paracetamol in Coca-Cola, Pepsi-Cola and tea samples. Copyright © 2016 Elsevier Ltd. All rights reserved.

  11. SQUARE WAVE CATHODIC STRIPPING VOLTAMMETRY ADSORPTIVE FOR NICKEL AND COBALT ANALYSIS

    Directory of Open Access Journals (Sweden)

    Saryati Saryati

    2010-06-01

    Full Text Available The adsorptive stripping voltammetric determination of Ni and Co based on adsorption of the Ni/Co and dimethylglioxime (DMG complex on a hanging mercury drop electrode is studied. The reduction current of the adsorbed DMG complex is measured by square wave cathodic stripping voltammetry method. The effect of various parameters such as ligand concentration, pH of supporting electrolytic, adsorption potential and adsorption time on the current peak of Ni and Co voltammogram were studied. Optimum condition of this method are supporting electrolyte pH 9, DMG concentration 5×10 -4 M, adsorption potential -0.7 V vs Ag/AgCl and adsorption time 180 second. A linier relationship between the current peak and Ni or Co concentration was obtained in the range 5 - 30 ng/mL and the detection limit 0.6 ng/ml for both Ni and Co. The recovery of Ni and Co were 98.11-104.17% using standard biological materials with RSD 2.59 - 10.37%. Based on ";t"; test can be conclude that the result are nearly equal to the standard reference material.   Keywords: adsorptive stripping voltammetric, dimethylglioxime complex, nickel, cobalt

  12. Tracking degradation in lithium iron phosphate batteries using differential thermal voltammetry

    Science.gov (United States)

    Shibagaki, Toshio; Merla, Yu; Offer, Gregory J.

    2018-01-01

    Diagnosing the state-of-health of lithium ion batteries in-operando is becoming increasingly important for multiple applications. We report the application of differential thermal voltammetry (DTV) to lithium iron phosphate (LFP) cells for the first time, and demonstrate that the technique is capable of diagnosing degradation in a similar way to incremental capacity analysis (ICA). DTV has the advantage of not requiring current and works for multiple cells in parallel, and is less sensitive to temperature introducing errors. Cells were aged by holding at 100% SOC or cycling at 1C charge, 6D discharge, both at an elevated temperature of 45 °C under forced air convection. Cells were periodically characterised, measuring capacity fade, resistance increase (power fade), and DTV fingerprints. The DTV results for both cells correlated well with both capacity and power, suggesting they could be used to diagnose SOH in-operando for both charge and discharge. The DTV peak-to-peak capacity correlated well with total capacity fade for the cycled cell, suggesting that it should be possible to estimate SOC and SOH from DTV for incomplete cycles within the voltage hysteresis region of an LFP cell.

  13. Estimation of uranium in different types of water and sand samples by adsorptive stripping voltammetry

    International Nuclear Information System (INIS)

    Bhalke, Sunil; Raghunath, Radha; Mishra, Suchismita; Suseela, B.; Tripathi, R.M.; Pandit, G.G.; Shukla, V.K.; Puranik, V.D.

    2005-01-01

    A method is standardized for the estimation of uranium by adsorptive stripping voltammetry using chloranilic acid (CAA) as complexing agent. The optimum parameters to get best sensitivity and good reproducibility for uranium were 60s adsorption time, pH 1.8, chloranilic acid (2x10 -4 M) and 0.002M EDTA. The peak potential under this condition was found to be -0.03 V. With these optimum parameters a sensitivity of 1.19 nA/nM uranium was observed. Detection limit for this optimum parameter was found to be 0.55 nM. This can be further improved by increasing adsorption time. Using this method, uranium was estimated in different type of water samples such as seawater, synthetic seawater, stream water, tap water, well water, bore well water and process water. This method has also been used for estimation of uranium in sand, organic solvent used for extraction of uranium from phosphoric acid and its raffinate. Sample digestion procedures used for estimation of uranium in various matrices are discussed. It has been observed from the analysis that the uranium peak potentials changes with matrix of the sample, hence, standard addition method is the best method to get reliable and accurate results. Quality assurance of the standardized method is verified by analyzing certified reference water sample from USDOE, participating intercomparison exercises and also by estimating uranium content in water samples both by differential pulse adsorptive stripping voltammetric and laser fluorimetric techniques. (author)

  14. Carbon paste electrode modified molecularly imprinted polymer as a sensor for creatinine analysis by stripping voltammetry

    Science.gov (United States)

    Khasanah, M.; Darmokoesoemo, H.; Rizki, D. A.

    2017-09-01

    Modification of carbon paste electrode with molecularly imprinted polymer (CP-MIP) as a voltammetric sensor for creatinine has been developed. MIP was synthesized by reacting melamine, chloranil and creatinine with a mole ratio of 1:1:0.1. Creatinine was extracted from polymer chain by using hot water to form a specific imprinted for creatinine molecule. Carbon paste-MIP electrode was prepared by mixing activated carbon, solid paraffin, and MIP in a 45:40:15(w/w %) ratio. The optimum conditions of creatinine analysis by differential pulse stripping voltammetry (DPSV) using the developed electrode were the accumulation potential -1000 mV during 90 s at pH 5. The precision of the method for 0.1-0.5 μlg/L creatinine was 88.7-96.3%, while the detection limit of this method was 0.0315 μlg/L. The accuracy compared by spectrophotometric method was 95.3-103.6%

  15. Cyclic voltammetry of Monel 400 in lithium hydroxide solution at elevated temperatures

    International Nuclear Information System (INIS)

    MacDonald, D.D.

    1976-01-01

    The electrochemistry of Monel 400 in 1 mole/kg -1 LiOH solution at 25, 125 and 250 0 C has been investigated using the technique of cyclic voltammetry. The general electrochemical behaviour is found to most closely approximate to that of the major component, nickel, although expansion of the current scale reveals anodic and cathodic peaks which probably arise from redox processes involving copper. The general similarity to nickel can be rationalized in terms of either the d electron theory for cupronickel alloys or phase separation, the latter being favoured in the present study. At 25 0 C the majority of charge consumed on sweeping the potential in the positive direction is involved in the formation of an oxide film at potentials close to oxygen evolution. This process is no longer observed at 2500C, due to a sharp reduction in the oxygen evolution overpotential with temperature. The majority of charge consumed on cyclic sweeping at this temperature is attributed to active dissolution of the nickel component of the alloy to form HNiO 2 - (or Ni(OH) 3 - ) at potentials slightly positive to the hydrogen evolution region. (author)

  16. Cyclic voltammetry study of PEO processing of porous Ti and resulting coatings

    Science.gov (United States)

    Shbeh, Mohammed; Yerokhin, Aleksey; Goodall, Russell

    2018-05-01

    Ti is one of the most commonly used materials for biomedical applications. However, there are two issues associated with the use of it, namely its bio-inertness and high elastic modulus compared to the elastic modulus of the natural bone. Both of these hurdles could potentially be overcome by introducing a number of pores in the structure of the Ti implant to match the properties of the bone as well as improve the mechanical integration between the bone and implant, and subsequently coating it with a biologically active ceramic coating to promote chemical integration. Hence, in this study we investigated the usage of cyclic voltammetry in PEO treatment of porous Ti parts with different amount of porosity produced by both Metal Injection Moulding (MIM) and MIM in combination with a space holder. It was found that porous samples with higher porosity and open pores develop much thicker surface layers that penetrate through the inner structure of the samples forming a network of surface and subsurface coatings. The results are of potential benefit in producing surface engineered porous samples for biomedical applications which do not only address the stress shielding problem, but also improve the chemical integration.

  17. Solid electrolyte gas sensors based on cyclic voltammetry with one active electrode

    Energy Technology Data Exchange (ETDEWEB)

    Jasinski, G; Jasinski, P, E-mail: gregor@biomed.eti.pg.gda.pl [Gdansk University of Technology, Faculty of Electronics, Telecommunication and Informatics, Narutowicza 11/12, 80-233 Gdansk (Poland)

    2011-10-29

    Solid state gas sensors are cost effective, small, rugged and reliable. Typically electrochemical solid state sensors operate in either potentiometric or amperometric mode. However, a lack of selectivity is sometimes a shortcoming of such sensors. It seems that improvements of selectivity can be obtained in case of the electrocatalytic sensors, which operate in cyclic voltammetry mode. Their working principle is based on acquisition of an electric current, while voltage ramp is applied to the sensor. The current-voltage response depends in a unique way on the type and concentration of ambient gas. Most electrocatalytic sensors have symmetrical structure. They are in a form of pellets with two electrodes placed on their opposite sides. Electrochemical reactions occur simultaneously on both electrodes. In this paper results for sensors with only one active electrode exposed to ambient gas are presented. The other electrode was isolated from ambient gas with dielectric sealing. This sensor construction allows application of advanced measuring procedures, which permit sensor regeneration acceleration. Experiments were conducted on Nasicon sensors. Properties of two sensors, one with one active electrode and second with symmetrical structure, used for the detection of mixtures of NO{sub 2} and synthetic air are compared.

  18. Anodic stripping voltammetry of mercury, zinc, cadmium, and lead in a rice farm ecosystem

    International Nuclear Information System (INIS)

    Del Mundo, F.R.; Vicente-Beckett, V.A.

    1990-01-01

    Analytical procedures based on differential pulse anodic stripping voltammetry were developed and applied to the analysis of some trace metals in a rice farm ecosystem. A gold wire served as working electrode for the analysis of mercury in 0.1M HNO 3 ; a hanging mercury drop electrode was used for the simultaneous analyses of zinc, cadmium, and lead in 0.1M sodium acetate buffer (pH 4.5). Mercury was pre-concentrated for five minutes at + 0.20 V vs SCE. The area of the anodic stripping peaks varied linearly over the concentration range 3x10 -10 -2x10 -8 M Hg(II); the limit of detection was 0.06 ppb or 3x10 -10 M Hg(II). The simultaneous analytical method involved pre-electrolysis at -1.2 V vs SCE for ten minutes. The heights of the individual anodic stripping peaks varied linearly with concentration in a mixture of the ions over the concentration range 0.020-0.10 ppm for each ion; the limits of detection were 0.004 ppm, 0.01 ppm, and 0.01 ppm for Cd, Pb, Zn, respectively. The developed procedures were used to determine the baseline levels of these metals in soil, water, and rice plant samples from a one-hectare traditional rice farm in San Pedro, Laguna. (auth.). 26 refs.; 4 tabs.; 6 figs

  19. Determination of Au, Pt, Pd in gold ore mineral raw materials by stripping voltammetry

    Directory of Open Access Journals (Sweden)

    Kolpakova N.A.

    2016-01-01

    Full Text Available The paper considers the possibilities of use of the method of stripping voltammetry for finding platinum metals in mineral gold and ore raw material. A review of new options of electro-concentration of platinum metals on the surface of graphite electrode with the following sediment electro-oxidation and receipt of an analytical signal is presented: platinum finding was carried out by picks of selective electro-oxidation of iridium from intermetallic compound with platinum; gold finding was carried out by picks of gold electro-oxidation on the surface of graphite electrode modified by bismuth; palladium finding was performed by picks of palladium electro-oxidation on the surface of graphite electrode. 1M HCL solution was selected as a supporting electrolyte. Gold and hydrogen elimination on the process of palladium electro-oxidation was performed by means of UV irradiation of solution in the process of electro-concentration of palladium sediment. Gold, platinum and palladium determination was carried out in mineral gold and ore raw material of Verkhneamylskiy gold and ore district.

  20. Death of pastures syndrome: tissue changes in Urochloa hybrida cv. Mulato II and Urochloa brizantha cv. Marandu

    Directory of Open Access Journals (Sweden)

    N. G. Ribeiro-Júnior

    Full Text Available Abstract The quality of forage production is a prerequisite to raising livestock. Therefore, income losses in this activity, primarily cattle raising, can result in the impossibility of economic activity. Through the qualitative and quantitative anatomical study of Urochloa hybrida cv. Mulato II and U. brizantha cv. Marandu, we searched for descriptions and compared changes in the individual vegetative body from populations with death syndrome pastures (DPS. Specimens were collected at different physiological stages from farms in northern Mato Grosso. After collection, the individuals were fixed in FAA50 and stored in 70% alcohol. Histological slides were prepared from the middle third of the sections of roots, rhizomes, and leaves, and the proportions and characteristics of tissues were evaluated in healthy, intermediate, and advanced stages of DPS. Changes were compared between cultivars. With the advancement of the syndrome, the following changes were observed: a more marked decrease in the length of roots in U. hybrida; disorganization of the cortical region of the roots and rhizome cultivars; fungal hyphae in roots and aerenchyma formation in U. hybrida; a decrease in sclerenchyma fiber proportions in roots and leaves; sclerification of the epidermis of U. brizantha rhizomes; and an increase in pericyclic fibers in U. hybrida. Furthermore, there was a decrease in the volume of epidermal cells of the abaxial face of the leaves of both cultivars, with a greater reduction in U. hybrida; a gradual decrease in thickness in the midrib of leaves similar to leaf mesophyll; conduction system obstructions; partial or total cell lysis in roots and rhizomes affected by the syndrome. Obstructions in sieve tube element and companion cells, and sometimes obstruction in xylem vessel elements. The evolution of DPS in cultivars was similar, but there were variations, arising probably from the physiological response to stress, such as aerenchyma formation in

  1. Lung PET scan

    Science.gov (United States)

    ... Chest PET scan; Lung positron emission tomography; PET - chest; PET - lung; PET - tumor imaging; ... Grainger & Allison's Diagnostic Radiology: A Textbook of Medical Imaging . 6th ed. Philadelphia, ...

  2. Scanning of bone metastases

    International Nuclear Information System (INIS)

    Robillard, J.

    1977-01-01

    The Centers against cancer of Caen, Angers, Montpellier, Strasbourg and 'the Curie Foundation' have confronted their experience in detection of bone metastases by total body scanning. From the investigation by this procedure, of 1,467 patients with cancer, it results: the confrontation between radio and scanning shows a rate of false positive and false negative identical to the literature ones; the countage scanning allows to reduce the number of false positive; scanning allows to direct bone biopsy and to improve efficiency of histological examination [fr

  3. Membrane Separated Flow Cell for Parallelized Electrochemical Impedance Spectroscopy and Confocal Laser Scanning Microscopy to Characterize Electro-Active Microorganisms

    International Nuclear Information System (INIS)

    Stöckl, Markus; Schlegel, Christin; Sydow, Anne; Holtmann, Dirk; Ulber, Roland; Mangold, Klaus-Michael

    2016-01-01

    Highlights: • Development of a membrane separated electrochemical flow cell. • Simultaneous combination of EIS and CLSM. • Monitoring of bacterial cell attachment to anode of MFC. • Cell attachment of Shewanella oneidensis is shown. - Abstract: Understanding the attachment of electro-active bacteria to electrode surfaces and their subsequent biofilm formation is one of the major challenges for the establishment of bacterial bioelectrochemial systems (BES). For a constant observation of biofilm growth, providing information on different stages of biofilm formation, continuous monitoring methods are required. In this paper a combination of two powerful analytical methods, Electrochemical Impedance Spectroscopy (EIS) and Confocal Laser Scanning Microscopy (CLSM), for biofilm monitoring is presented. A custom-built flow cell with a transparent indium tin oxide working electrode (WE) was constructed allowing monitoring of cell attachment to a working electrode simultaneously by EIS and CLSM. Cyclic Voltammetry (CV) and EIS of an iron (II)/iron (III) redox couple indicate that the flow cell is suitable for electrochemical experiments. An engineered Shewanella oneidensis MR-1 (ATCC700550) producing eGFP was used as electro-active model organism to demonstrate the practical application of the flow cell as BES to monitor cell attachment simultaneously with EIS and CLSM. Applying the flow cell as MFC (transparent working electrode poised as anode) produced a typical current curve for such a system. From the equivalent circuit used to interpret EIS data the charge transfer resistance R CT is sensitive to attachment of microorganisms. Fitted R CT was increased initially after cell inoculation and then lowered constantly with progressing experimental time. In parallel taken CLSM images show that bacteria already adhered to the WE 5 min after inoculation. A mono- respectively bilayer of electro-active cells was observed after 17 h on the WE surface. With the presented

  4. How Adequate is your CV? Analyzing French CVs with ReaderBench

    NARCIS (Netherlands)

    Gutu, Gabriel; Dascalu, Mihai; Trausan-Matu, Stefan; Lepoivre, Olivier

    2017-01-01

    This study is aimed at presenting a new ReaderBench-based tool built to support candidates in increasing the quality of their CV for a job opening. Both the visual quality and the textual content are considered while also providing an overview and corresponding feedback for the entire CV.

  5. CV-Online tahab Londoni börsile / Annika Matson

    Index Scriptorium Estoniae

    Matson, Annika, 1976-

    2004-01-01

    Personaliotsinguga tegelev firma tahab tulevikus minna Londoni ja OMXi börsile. Diagramm: CV-Online Group loodab tänavu esmakordselt positiivse kulumieelse ärikasumi. Vt. samas: Üks CV-Online'i aktsionäridest on ka Google'i aktsionär; Väsinud ootamast esimest IPOt

  6. PERUMUSAN STRATEGI BERSAING JAHE INSTAN PRODUK CV. INTRAFOOD SURAKARTA MENGGUNAKAN PERCEPTUAL MAPPING

    Directory of Open Access Journals (Sweden)

    Mohd. Harisudin

    2013-11-01

    Full Text Available Penelitian ini bertujuan untuk mengetahui posisi bersaing jahe instan produk CV. Intrafood dan strategi bersaing yang dapat direkomendasikan untuk meraih keberasilannya. Metode dasar yang digunakan adalah analisis deskriptif. Penentuan lokasi penelitian ditentukan dengan metode purposive, yaitu CV. Intrafood Surakarta. Jenis data yang digunakan dalam penelitian ini adalah data primer dan data sekunder. Metode analisis data menggunakan analisis Perceptual Mapping. Dari hasil penelitian diperoleh informasi bahwa jahe instan produk CV Intrafood berada pada peringkat ke-2 dari produk empat jahe instan yang diperbandingkan. Atribut yang dapat dijadikan kekuatan utama dalam meningkatkan pemasaran jahe instan produk CV. Intrafood adalah manfaat produk. Sisi yang paling lemah adalah atribut desain kemasan dan kinerja produk dalam kemasan. Abstract This study aims to determine the competitive position of the product instant ginger CV. Intrafood and competitive strategy can be recommended to achieve success. The basic method used is descriptive analysis. Determining the location of the study are determined by purposive method, namely CV. Intrafood Surakarta. Data used in this study is primary data and secondary data. Method analyzed using Perceptual Mapping. From the results of the study concluded that instant ginger of CV Intrafood product ranks second of four instant ginger products are compared. Attributes that can be used as a major force in improving product marketing instant ginger CV. Intrafood is the benefits of the product. The weakest side is the packaging design and performance attributes of the product in the packaging.

  7. Model PET Scan Activity

    Science.gov (United States)

    Strunk, Amber; Gazdovich, Jennifer; Redouté, Oriane; Reverte, Juan Manuel; Shelley, Samantha; Todorova, Vesela

    2018-05-01

    This paper provides a brief introduction to antimatter and how it, along with other modern physics topics, is utilized in positron emission tomography (PET) scans. It further describes a hands-on activity for students to help them gain an understanding of how PET scans assist in detecting cancer. Modern physics topics provide an exciting way to introduce students to current applications of physics.

  8. Scanning laser Doppler vibrometry

    DEFF Research Database (Denmark)

    Brøns, Marie; Thomsen, Jon Juel

    With a Scanning Laser Doppler Vibrometer (SLDV) a vibrating surface is automatically scanned over predefined grid points, and data processed for displaying vibration properties like mode shapes, natural frequencies, damping ratios, and operational deflection shapes. Our SLDV – a PSV-500H from...

  9. Thyroid Scan and Uptake

    Medline Plus

    Full Text Available Toggle navigation Test/Treatment Patient Type Screening/Wellness Disease/Condition Safety En Español More Info Images/Videos About Us News Physician Resources Professions Site Index A-Z Thyroid Scan and Uptake Thyroid scan and uptake uses ...

  10. ANALISIS KELAYAKAN INVESTASI PENAMBAHAN MESIN FRAIS BARU PADA CV. XYZ

    Directory of Open Access Journals (Sweden)

    Febri Muhammad Rachadian

    2013-04-01

    Full Text Available Perkembangan teknologi sangat pesat sehingga dunia perindustrian harus mengikuti perkembangannya. Penerapan teknologi diharapkan dapat meningkatkan proses produksi sehingga dapat menghasilkan produk yang berkualitas. Pada industri pembuatan mesin cetak di CV XYZ, mesin-mesin yang digunakan telah hampir lebih dari 20 tahun. Ada indikasi bahwa mesin-mesin tersebut sudah lewat umur pakainya. Alternatif yang digunakan selama ini ialah penggantian komponen yang rusak. Peneliti ingin membandingkan alternative tersebut dengan  penambahan mesin frais baru. Untuk itu diperlukan analisis kelayakan investasi penambahan mesin baru. Dalam perkiraan kurun waktu 10 tahun dan suku bunganya 15 % dengan menggunakan NPV, penambahan mesin frais menarik sebesar Rp 461.201.000 dibandingkan penggantian komponen yang rusak sebesar Rp 211.227.000. Sebaliknya pada PBP, penggantian komponen yang rusak masih mengungguli dengan 1 tahun 4 bulan dibandingkan penambahan mesin frais baru selama 2 tahun 1 bulan. Begitupun juga PI penggantian komponen yang rusak masih menarik sebesar 4,2 dibandingkan PI penambahan mesin frais baru sebesar 2,56. Dapat disimpulkan bahwa dalam jangka waktu 10 tahun, alternatif penggantian komponen yang rusak masih lebih baik dibandingkan penambahan mesin frais baru. Namun, untuk investasi jangka panjang, mungkin saja alternatif penambahan mesin frais baru lebih menarik. Kata Kunci: penggantian komponen rusak, mesin frais baru, mesin cetak Abstract The rapid development of technology makes the world of industry must follow its development. Application of technology is expected to improve the production process so it can be produce a quality product. On the industrial manufacture of printing machines in CV XYZ, the machines have been used almost more than 20 years. There are indications that those machines passed the age lifetime. The alternatives that have been used during this time are the replacement of defective parts. Researchers wanted to

  11. Transverse section scanning mechanism

    International Nuclear Information System (INIS)

    Doherty, E.J.

    1978-01-01

    Apparatus is described for scanning a transverse, radionuclide scan-field using an array of focussed collimators. The collimators are movable tangentially on rails, driven by a single motor via a coupled screw. The collimators are also movable in a radial direction on rails driven by a step motor via coupled screws and bevel gears. Adjacent bevel gears rotate in opposite directions so adjacent collimators move in radially opposite directions. In use, the focal point of each collimator scans at least half of the scan-field, e.g. a human head located in the central aperture, and the electrical outputs of detectors associated with each collimator are used to determine the distribution of radioactive emission intensity at a number of points in the scan-field. (author)

  12. Detection of trace levels of Pb2+ in tap water at boron-doped diamond electrodes with anodic stripping voltammetry

    International Nuclear Information System (INIS)

    Dragoe, Diana; Spataru, Nicolae; Kawasaki, Ryuji; Manivannan, Ayyakkannu; Spataru, Tanta; Tryk, Donald A.; Fujishima, Akira

    2006-01-01

    Boron-doped diamond (BDD) electrodes were used to investigate the possibility of detecting trace levels of lead by linear-sweep anodic stripping voltammetry. The low limit of detection (2 nM) is an advantage compared to other electrode materials, and it was found that at low pH values, copper concentrations that are usually present in drinking water do not affect to a large extent the detection of lead. These findings recommend anodic stripping voltammetry at the BDD electrodes as a suitable mercury-free method for the determination of trace levels of lead in drinking water. The results obtained for the lead detection in tap water real samples are in excellent agreement with those found by inductively coupled plasma-mass spectrometry (ICP-MS), demonstrating the practical analytical utility of the method

  13. Determination of band structure parameters and the quasi-particle gap of CdSe quantum dots by cyclic voltammetry.

    Science.gov (United States)

    Inamdar, Shaukatali N; Ingole, Pravin P; Haram, Santosh K

    2008-12-01

    Band structure parameters such as the conduction band edge, the valence band edge and the quasi-particle gap of diffusing CdSe quantum dots (Q-dots) of various sizes were determined using cyclic voltammetry. These parameters are strongly dependent on the size of the Q-dots. The results obtained from voltammetric measurements are compared to spectroscopic and theoretical data. The fit obtained to the reported calculations based on the semi-empirical pseudopotential method (SEPM)-especially in the strong size-confinement region, is the best reported so far, according to our knowledge. For the smallest CdSe Q-dots, the difference between the quasi-particle gap and the optical band gap gives the electron-hole Coulombic interaction energy (J(e1,h1)). Interband states seen in the photoluminescence spectra were verified with cyclic voltammetry measurements.

  14. LIDAR COMBINED SCANNING UNIT

    Directory of Open Access Journals (Sweden)

    V. V. Elizarov

    2016-11-01

    Full Text Available Subject of Research. The results of lidar combined scanning unit development for locating leaks of hydrocarbons are presented The unit enables to perform high-speed scanning of the investigated space in wide and narrow angle fields. Method. Scanning in a wide angular field is produced by one-line scanning path by means of the movable aluminum mirror with a frequency of 20Hz and amplitude of 20 degrees of swing. Narrowband scanning is performed along a spiral path by the deflector. The deflection of the beam is done by rotation of the optical wedges forming part of the deflector at an angle of ±50. The control function of the scanning node is performed by a specialized software product written in C# programming language. Main Results. This scanning unit allows scanning the investigated area at a distance of 50-100 m with spatial resolution at the level of 3 cm. The positioning accuracy of the laser beam in space is 15'. The developed scanning unit gives the possibility to browse the entire investigated area for the time not more than 1 ms at a rotation frequency of each wedge from 50 to 200 Hz. The problem of unambiguous definition of the beam geographical coordinates in space is solved at the software level according to the rotation angles of the mirrors and optical wedges. Lidar system coordinates are determined by means of GPS. Practical Relevance. Development results open the possibility for increasing the spatial resolution of scanning systems of a wide range of lidars and can provide high positioning accuracy of the laser beam in space.

  15. Lipophilicity of acetylcholine and related ions examined by ion transfer voltammetry at a polarized room-temperature ionic liquid membrane

    Czech Academy of Sciences Publication Activity Database

    Langmaier, Jan; Záliš, Stanislav; Samec, Zdeněk

    2018-01-01

    Roč. 815, APR 2018 (2018), s. 183-188 ISSN 1572-6657 R&D Projects: GA ČR(CZ) GA15-03139S; GA ČR(CZ) GA17-05387S Institutional support: RVO:61388955 Keywords : acetylcholine * choline * ion transfer voltammetry Subject RIV: CG - Electrochemistry OBOR OECD: Electrochemistry (dry cells, batteries, fuel cells, corrosion metals, electrolysis) Impact factor: 3.012, year: 2016

  16. Investigation of the Antioxidant Properties of Metallothionein in Transgenic Tobacco Plants using Voltammetry at a Carbon Paste Electrode

    Czech Academy of Sciences Publication Activity Database

    Shetivska, V.; Adam, V.; Prášek, J.; Macek, Tomáš; Macková, M.; Havel, L.; Dioplan, V.; Zehnálek, J.; Hubálek, J.; Kižek, R.

    2011-01-01

    Roč. 6, č. 7 (2011), s. 2869-2883 ISSN 1452-3981 Grant - others:GA ČR(CZ) GA522/07/0692; GA ČR(CZ) GA102/08/1546 Institutional research plan: CEZ:AV0Z40550506 Keywords : square wave voltammetry * carbon paste electrode * DNA * metallothionein Subject RIV: CG - Electrochemistry Impact factor: 3.729, year: 2011

  17. The Graphene/l-Cysteine/Gold-Modified Electrode for the Differential Pulse Stripping Voltammetry Detection of Trace Levels of Cadmium

    OpenAIRE

    Yu Song; Chao Bian; Jianhua Tong; Yang Li; Shanghong Xia

    2016-01-01

    Cadmium(II) is a common water pollutant with high toxicity. It is of significant importance for detecting aqueous contaminants accurately, as these contaminants are harmful to human health and environment. This paper describes the fabrication, characterization, and application of an environment-friendly graphene (Gr)/l-cysteine/gold electrode to detect trace levels of cadmium (Cd) by differential pulse stripping voltammetry (DPSV). The influence of hydrogen overflow was decreased and the curr...

  18. Development of pore interconnectivity/morphology in porous silica films investigated by cyclic voltammetry and slow positron annihilation spectroscopy

    International Nuclear Information System (INIS)

    Tang, Xiuqin; Xiong, Bangyun; Li, Qichao; Mao, Wenfeng; Xiao, Wei; Fang, Pengfei; He, Chunqing

    2015-01-01

    Highlights: •Porous silica films were studied by cyclic voltammetry and positron annihilation. •Highly interconnected pores were formed in the film fabricated with more CTAB. •Aligned nanochannels were observed in the porous flim prepared with 25 wt.% CTAB. •I − and Ps diffusion in the films was governed by pore interconnectivity/morphology. •Cyclic voltammetry is feasible to explore pore interconnectivity/morphology. -- Abstract: Cyclic voltammetry and positronium (Ps) 3γ-annihilation spectroscopy were applied to investigate pore interconnectivity/morphology of porous silica films fabricated with various loading of cetyltrimethyl ammonium bromide (CTAB). With increasing the ratio of CTAB up to 15 wt.%, the total charge Q, resulted from I − diffusion across the silica films, increased remarkably, indicative of formation of highly interconnected pores in the films prepared with more porogen. However, it decreased dramatically with further loading CTAB of 25 wt.%. Interestingly, 3γ-annihilation fraction I 3γ due to a triplet-state Ps (ortho-positronium, o-Ps) emission from the silica films showed a similar behavior as a function of CTAB loading. The abnormal decrement in Q and I 3γ in the film fabricated with 25 wt.% CTAB was well explained by formation of long nanochannels aligning parallel to the film surface. The results indicated that the total charge Q and Ps 3γ-annihilation fraction were closely associated with I − and Ps diffusion governed by the pore interconnectivity/morphology of the silica films, which made cyclic voltammetry possible to be a feasible tool to characterize pore interconnectivity/morphology of porous thin films

  19. Determination of carnosic acid in Rosmarinus officinalis L. using square wave voltammetry and electrochemical behavior

    Directory of Open Access Journals (Sweden)

    Ümmihan Taşkoparan Yilmaz

    2018-01-01

    Full Text Available A new, fast, sensitive and simple voltammetric method is established for the direct determination of carnosic acid (CA. And the electroreduction of carnosic acid (CA was studied using electrochemical methods. The number of electrons transferred in electrode mechanisms were calculated for reversible and adsorption-controlled electrochemical reduction of CA at 17 mV versus Ag/AgCl at pH 7.0 in Britton–Robinson buffer (BR on a hanging mercury drop electrode. Square-wave voltammetry was developed and validated for direct determination of CA. Square-wave parameters were optimized as accumulation potential = 0.0 mV, accumulation time = 5 s, frequency = 50 Hz, pulse amplitude = 50 mV, and staircase step potential = 5 mV. The developed method displays three linear responses from 2 to 9 μM, 10 to 30 and 40 to 90 μM for carnosic acid with a correlation coefficient of 0.996, 0.999 and 0.999. The detection limits were found to be 1.5 μM, 4.0 μM and 40.1 μM, respectively. The interference effect of most common organic and inorganic species was investigated. Proposed method was successfully applied for determination of CA in natural extract of rosemary and the average content was determined as 11.9 ± 1.0 (μg CA/1 g rosemary. The results were in agreement with that obtained by HPLC-UV comparison method. The developed method can be widely used in routine quality control of herbal materials as well as other in foods, medicinal, pharmaceutical and environmental analysis.

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

    Science.gov (United States)

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

    2016-07-01

    Tryptamine, a biogenic amine, is an indole derivative with an electrophilic substituent at the C3 position of the pyrrole ring of the indole moiety. The electrochemical oxidation of tryptamine was investigated using glassy carbon electrode (GCE), and focusing on trace level determination in food products by square wave adsorptive stripping voltammetry (SWAdSV). The electrochemical responses of tryptamine were evaluated using differing voltammetric techniques over a wide pH range, a quasi-reversible electron-transfer to redox system represented by coupled peaks P1-P3, and an irreversible reaction for peak P2 were demonstrated. The proton and electron counts associated with the oxidation reactions were estimated. The nature of the mass transfer process was predominantly diffusion-limited for the oxidation process of P1, the most selective and sensitive analytical response (acetate buffer solution pH 5.3), being used for the development of SWAdSV method, under optimum conditions. The excellent response allowed the development of an electroanalytical method with a linear response range of from 4.7-54.5)×10(-)(8)molL(-1), low detection limit (0.8×10(-)(9)molL(-)(1)), and quantification limit (2.7×10(-9)molL(-1)), and acceptable levels of repeatability (3.6%), and reproducibility (3.8%). Tryptamine content was determined in bananas, tomatoes, cheese (mozzarella and gorgonzola), and cold meats (chicken sausage and pepperoni sausage), yielding recoveries above 90%, with excellent analytical performance using simple and low cost instrumentation. Copyright © 2016 Elsevier B.V. All rights reserved.

  1. Nitrogen fertilization on the establishment of Arachis pintoi cv. Belmonte

    Directory of Open Access Journals (Sweden)

    Rita Manuele Porto Sales

    2012-11-01

    Full Text Available The objective was to evaluate the effect of nitrogen fertilization on the establishment of forage peanut (Arachis pintoi cv. Belmonte propagated vegetatively. The experiment was conducted in a greenhouse in a completely randomized design with treatments arranged in a 2 × 4 factorial design - two ages (70 and 85 days after planting and four nitrogen doses (0, 40, 80 and 120 kg/ha - with four replications. Morphogenetic and structural characteristics and production were evaluated. The nitrogen accelerated the establishment of the forage peanut with an increase in dry weight of green leaves and stolons. The greatest length of stolons (48.0 cm was obtained with a dose equivalent to 86 kg N/ha and higher density of stolons (20 stolons/vase between 78 and 82 kg N/ha. Nitrogen fertilization also reduced the phyllochron from 6.7 to 4.6 days/leaf. These data were more intense at 85 days, suggesting greater photosynthetic contribution during this period related to the large number of leaves after 70 days. Therefore, nitrogen can be an important tool to accelerate the establishment of pure stands of forage peanut.

  2. EVALUASI SISTEM INFORMASI PERSEDIAAN PADA CV. SARANA TELEMAXINDO

    Directory of Open Access Journals (Sweden)

    Nelly Nelly

    2010-10-01

    Full Text Available Evaluation objectives of inventory information systems at CV. Facilities Telemaxindo was to evaluate the weaknesses of the implementation of internal control, as well as estimating and assessing possible risks that might arise. The research method used is literature study of reference books in the library, and field study consisted of observation, interviews with relevant parties, creating check lists, check the inventory information systems documentation, and testing of inventory application systems. The results are findings of control weaknesses in the implementation of security management, operational management control, boundary control, input control, and output control on the present inventory information system. These weaknesses could pose a risk and if not dealt soon it could hurt the company. The resulting conclusion of the security management control, boundary control, control input, and output control is not running well so that it needs to be improved in accordance with the recommendations, while operational management control has been running fairly well.Keywords: evaluation, information system, inventory

  3. Infrared small target detection technology based on OpenCV

    Science.gov (United States)

    Liu, Lei; Huang, Zhijian

    2013-09-01

    Accurate and fast detection of infrared (IR) dim target has very important meaning for infrared precise guidance, early warning, video surveillance, etc. In this paper, some basic principles and the implementing flow charts of a series of algorithms for target detection are described. These algorithms are traditional two-frame difference method, improved three-frame difference method, background estimate and frame difference fusion method, and building background with neighborhood mean method. On the foundation of above works, an infrared target detection software platform which is developed by OpenCV and MFC is introduced. Three kinds of tracking algorithms are integrated in this software. In order to explain the software clearly, the framework and the function are described in this paper. At last, the experiments are performed for some real-life IR images. The whole algorithm implementing processes and results are analyzed, and those algorithms for detection targets are evaluated from the two aspects of subjective and objective. The results prove that the proposed method has satisfying detection effectiveness and robustness. Meanwhile, it has high detection efficiency and can be used for real-time detection.

  4. Seven health physics calculator programs for the HP-41CV

    International Nuclear Information System (INIS)

    Rittmann, P.D.

    1984-08-01

    Several user-oriented programs for the Hewlett-Packard HP-41CV are explained. The first program builds, stores, alters, and ages a list of radionuclides. This program only handles single- and double-decay chains. The second program performs convenient conversions for the six nuclides of concern in plutonium handling. The conversions are between mass, activity, and weight percents of the isotopes. The source can be aged and/or neutron generation rates can be computed. The third program is a timekeeping program that improves the process of manually estimating and tracking personnel exposure during high dose rate tasks by replacing the pencil, paper, and stopwatch method. This program requires a time module. The remaining four programs deal with computations of time-integrated air concentrations at various distances from an airborne release. Building wake effects, source depletion by ground deposition, and sector averaging can all be included in the final printout of the X/Q - Hanford and X/Q - Pasquill programs. The shorter versions of these, H/Q and P/Q, compute centerline or sector-averaged values and include a subroutine to facilitate dose estimation by entering dose factors and quantities released. The horizontal and vertical dispersion parameters in the Pasquill-Gifford programs were modeled with simple, two-parameter functions that agreed very well with the usual textbook graphs. 8 references, 7 appendices

  5. A virtual computing infrastructure for TS-CV SCADA systems

    CERN Document Server

    Poulsen, S

    2008-01-01

    In modern data centres, it is an emerging trend to operate and manage computers as software components or logical resources and not as physical machines. This technique is known as â€ワvirtualisation” and the new computers are referred to as â€ワvirtual machines” (VMs). Multiple VMs can be consolidated on a single hardware platform and managed in ways that are not possible with physical machines. However, this is not yet widely practiced for control system deployment. In TS-CV, a collection of VMs or a â€ワvirtual infrastructure” is installed since 2005 for SCADA systems, PLC program development, and alarm transmission. This makes it possible to consolidate distributed, heterogeneous operating systems and applications on a limited number of standardised high-performance servers in the Central Control Room (CCR). More generally, virtualisation assists in offering continuous computing services for controls and maintaining performance and assuring quality. Implementing our systems in a vi...

  6. MICROPROPAGAÇÃO DO KIWI CV. HAYWARD

    Directory of Open Access Journals (Sweden)

    SCALIZE FÁBIO EDUARDO

    2001-01-01

    Full Text Available O presente trabalho teve como objetivo desenvolver um protocolo para a obtenção de mudas de kiwi (Actinidia chinensis Planch, cv. Hayward, por meio do cultivo in vitro de cotilédones. Utilizou-se o meio de MURASHIGE & SKOOG (1962 -- MS, suplementado com dois tipos de auxina (AIA e AIB e uma citocinina (BAP. Foram verificados os efeitos de três doses de auxinas (0,125; 0,250 e 0,375 mg.L-1, combinadas com três doses de citocinina (0,5; 1,0 e 1,5 mg.L-1 na capacidade morfogênica dos explantes. Procedeu-se o estudo histológico dos órgãos das plântulas obtidas in vitro, e verificou-se, também, a capacidade de aclimatação das mudas ex vitro. A menor dose de AIB (0,125 mg.L-1, independentemente das doses de BAP, foi a mais eficaz na morfogênese dos explantes. Não foram verificadas alterações histológicas e anatômicas das plântulas obtidas in vitro. Aos três meses após o cultivo ex vitro dos explantes, verificou-se a sobrevivência de 88% das plantas transplantadas em condições de campo.

  7. Antidiabetic and anticancer activities of Mangifera indica cv. Okrong leaves

    Science.gov (United States)

    Ganogpichayagrai, Aunyachulee; Palanuvej, Chanida; Ruangrungsi, Nijsiri

    2017-01-01

    Diabetes and cancer are a major global public health problem. Plant-derived agents with undesirable side-effects were required. This study aimed to evaluate antidiabetic and anticancer activities of the ethanolic leaf extract of Mangifera indica cv. Okrong and its active phytochemical compound, mangiferin. Antidiabetic activities against yeast α-glucosidase and rat intestinal α-glucosidase were determined using 1 mM of p-nitro phenyl-α-D-glucopyranoside as substrate. Inhibitory activity against porcine pancreatic α-amylase was performed using 1 mM of 2-chloro-4 nitrophenol-α-D-maltotroside-3 as substrate. Nitrophenol product was spectrophotometrically measured at 405 nm. Anticancer activity was evaluated against five human cancer cell lines compared to two human normal cell lines using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay. Mango leaf extract and mangiferin exhibited dose-dependent inhibition against yeast α-glucosidase with the IC50 of 0.0503 and 0.5813 mg/ml, respectively, against rat α-glucosidase with the IC50 of 1.4528 and 0.4333 mg/ml, respectively, compared to acarbose with the IC50 of 11.9285 and 0.4493 mg/ml, respectively. For anticancer activity, mango leaf extract, at ≥200 μg/ml showed cytotoxic potential against all tested cancer cell lines. In conclusion, mango leaf possessed antidiabetic and anticancer potential in vitro. PMID:28217550

  8. Cathodic adsorptive stripping voltammetry of an anti-emetic agent Granisetron in pharmaceutical formulation and biological matrix

    Directory of Open Access Journals (Sweden)

    Rajeev Jain

    2012-12-01

    Full Text Available Granisetron showed one well-defined reduction peak at Hanging Mercury Drop Electrode (HMDE in the potential range from −1.3 to −1.5 V due to reduction of C=N bond. Solid-phase extraction technique was employed for extraction of Granisetron from spiked human plasma. Granisetron showed peak current enhancement of 4.45% at square-wave voltammetry and 5.33% at cyclic voltammetry as compared with the non stripping techniques. The proposed voltammetric method allowed quantification of Granisetron in pharmaceutical formulation over the target concentration range of 50–200 ng/mL with detection limit 13.63 ng/mL, whereas in human plasma 50–225 ng/mL with detection limit 11.75 ng/mL. Keywords: Granisetron, Human plasma, Solid-phase extraction, Pharmaceutical formulation, Voltammetry, Hanging mercury drop electrode

  9. Laser Scanning in Forests

    Directory of Open Access Journals (Sweden)

    Håkan Olsson

    2012-09-01

    Full Text Available The introduction of Airborne Laser Scanning (ALS to forests has been revolutionary during the last decade. This development was facilitated by combining earlier ranging lidar discoveries [1–5], with experience obtained from full-waveform ranging radar [6,7] to new airborne laser scanning systems which had components such as a GNSS receiver (Global Navigation Satellite System, IMU (Inertial Measurement Unit and a scanning mechanism. Since the first commercial ALS in 1994, new ALS-based forest inventory approaches have been reported feasible for operational activities [8–12]. ALS is currently operationally applied for stand level forest inventories, for example, in Nordic countries. In Finland alone, the adoption of ALS for forest data collection has led to an annual savings of around 20 M€/year, and the work is mainly done by companies instead of governmental organizations. In spite of the long implementation times and there being a limited tradition of making changes in the forest sector, laser scanning was commercially and operationally applied after about only one decade of research. When analyzing high-ranked journal papers from ISI Web of Science, the topic of laser scanning of forests has been the driving force for the whole laser scanning research society over the last decade. Thus, the topic “laser scanning in forests” has provided a significant industrial, societal and scientific impact. [...

  10. Bone scan in pediatrics

    International Nuclear Information System (INIS)

    Gordon, I.; Peters, A.M.

    1987-01-01

    In 1984, a survey carried out in 21 countries in Europe showed that bone scintigraphy comprised 16% of all paediatric radioisotope scans. Although the value of bone scans in paediatrics is potentially great, their quality varies greatly, and poor-quality images are giving this valuable technique a bad reputation. The handling of children requires a sensitive staff and the provision of a few simple inexpensive items of distraction. Attempting simply to scan a child between two adult patients in a busy general department is a recipe for an unhappy, uncooperative child with the probable result of poor images. The intravenous injection of isotope should be given adjacent to the gamma camera room, unless dynamic scans are required, so that the child does not associate the camera with the injection. This injection is best carried out by someone competent in paediatric venipunture; the entire procedure should be explained to the child and parent, who should remain with child throughout. It is naive to think that silence makes for a cooperative child. The sensitivity of bone-seeking radioisotope tracers and the marked improvement in gamma camera resolution has allowed the bone scanning to become an integrated technique in the assessment of children suspected of suffering from pathological bone conditions. The tracer most commonly used for routine bone scanning is 99m Tc diphosphonate (MDP); other isotopes used include 99m Tc colloid for bone marrow scans and 67 Ga citrate and 111 In white blood cells ( 111 In WBC) for investigation of inflammatory/infective lesions

  11. Voltammetry and single-molecule in situ scanning tunneling microscopy of laccases and bilirubin oxidase in electrocatalytic dioxygen reduction on Au(111) single-crystal electrodes

    DEFF Research Database (Denmark)

    Climent, Victor; Zhang, Jingdong; Friis, Esben Peter

    2012-01-01

    Laccases (E.C. 1.10.3.2) are multicopper oxidases catalytically active in the oxidation of diphenolics and related compounds by molecular dioxygen. The laccases contain a single-copper type I center and a trinuclear cluster of a single-copper type II and a dinuclear type III center. The oxidation...

  12. Assembly of the Lactuca sativa, L. cv. Tizian draft genome sequence reveals differences within major resistance complex 1 as compared to the cv. Salinas reference genome.

    Science.gov (United States)

    Verwaaijen, Bart; Wibberg, Daniel; Nelkner, Johanna; Gordin, Miriam; Rupp, Oliver; Winkler, Anika; Bremges, Andreas; Blom, Jochen; Grosch, Rita; Pühler, Alfred; Schlüter, Andreas

    2018-02-10

    Lettuce (Lactuca sativa, L.) is an important annual plant of the family Asteraceae (Compositae). The commercial lettuce cultivar Tizian has been used in various scientific studies investigating the interaction of the plant with phytopathogens or biological control agents. Here, we present the de novo draft genome sequencing and gene prediction for this specific cultivar derived from transcriptome sequence data. The assembled scaffolds amount to a size of 2.22 Gb. Based on RNAseq data, 31,112 transcript isoforms were identified. Functional predictions for these transcripts were determined within the GenDBE annotation platform. Comparison with the cv. Salinas reference genome revealed a high degree of sequence similarity on genome and transcriptome levels, with an average amino acid identity of 99%. Furthermore, it was observed that two large regions are either missing or are highly divergent within the cv. Tizian genome compared to cv. Salinas. One of these regions covers the major resistance complex 1 region of cv. Salinas. The cv. Tizian draft genome sequence provides a valuable resource for future functional and transcriptome analyses focused on this lettuce cultivar. Copyright © 2017 Elsevier B.V. All rights reserved.

  13. Thyroid Scan and Uptake

    Medline Plus

    Full Text Available ... for a thyroid scan is 30 minutes or less. Thyroid Uptake You will be given radioactive iodine ( ... for each thyroid uptake is five minutes or less. top of page What will I experience during ...

  14. Thyroid Scan and Uptake

    Medline Plus

    Full Text Available ... evaluate changes in the gland following medication use, surgery, radiotherapy or chemotherapy top of page How should ... such as an x-ray or CT scan, surgeries or treatments using iodinated contrast material within the ...

  15. Thyroid Scan and Uptake

    Medline Plus

    Full Text Available ... abnormal was found, and should not be a cause of concern for you. If you had an ... abnormal was found, and should not be a cause of concern for you. Actual scanning time for ...

  16. Tomographic scanning apparatus

    International Nuclear Information System (INIS)

    1981-01-01

    Details are given of a tomographic scanning apparatus, with particular reference to a multiplexer slip ring means for receiving output from the detectors and enabling interfeed to the image reconstruction station. (U.K.)

  17. Tomographic scanning apparatus

    International Nuclear Information System (INIS)

    1981-01-01

    Details are presented of a tomographic scanning apparatus, its rotational assembly, and the control and circuit elements, with particular reference to the amplifier and multiplexing circuits enabling detector signal calibration. (U.K.)

  18. Tomographic scanning apparatus

    International Nuclear Information System (INIS)

    1981-01-01

    This patent specification relates to a tomographic scanning apparatus using a fan beam and digital output signal, and particularly to the design of the gas-pressurized ionization detection system. (U.K.)

  19. Pediatric CT Scans

    Science.gov (United States)

    The Radiation Epidemiology Branch and collaborators have initiated a retrospective cohort study to evaluate the relationship between radiation exposure from CT scans conducted during childhood and adolescence and the subsequent development of cancer.

  20. Thyroid Scan and Uptake

    Medline Plus

    Full Text Available ... which are encased in metal and plastic and most often shaped like a box, attached to a ... will I experience during and after the procedure? Most thyroid scan and thyroid uptake procedures are painless. ...

  1. Heart CT scan

    Science.gov (United States)

    ... make to decrease the risk of heart disease. Risks Risks of CT scans include: Being exposed to ... urac.org). URAC's accreditation program is an independent audit to verify that A.D.A.M. follows ...

  2. Thyroid Scan and Uptake

    Medline Plus

    Full Text Available ... eat for several hours before your exam because eating can affect the accuracy of the uptake measurement. ... often unattainable using other imaging procedures. For many diseases, nuclear medicine scans yield the most useful information ...

  3. Thyroid Scan and Uptake

    Medline Plus

    Full Text Available ... A thyroid scan is a type of nuclear medicine imaging. The radioactive iodine uptake test (RAIU) is ... thyroid function, but does not involve imaging. Nuclear medicine is a branch of medical imaging that uses ...

  4. Thyroid Scan and Uptake

    Medline Plus

    Full Text Available ... that help physicians diagnose and evaluate medical conditions. These imaging scans use radioactive materials called radiopharmaceuticals or ... or had thyroid cancer. A physician may perform these imaging tests to: determine if the gland is ...

  5. Thyroid Scan and Uptake

    Medline Plus

    Full Text Available ... Because nuclear medicine procedures are able to pinpoint molecular activity within the body, they offer the potential ... or imaging device that produces pictures and provides molecular information. The thyroid scan and thyroid uptake provide ...

  6. Thyroid Scan and Uptake

    Medline Plus

    Full Text Available ... Actual scanning time for each thyroid uptake is five minutes or less. top of page What will ... diagnostic procedures have been used for more than five decades, and there are no known long-term ...

  7. Thyroid Scan and Uptake

    Medline Plus

    Full Text Available ... top of page Additional Information and Resources RTAnswers.org Radiation Therapy for Head and Neck Cancer top ... Scan and Uptake Sponsored by Please note RadiologyInfo.org is not a medical facility. Please contact your ...

  8. Thyroid Scan and Uptake

    Medline Plus

    Full Text Available ... often unattainable using other imaging procedures. For many diseases, nuclear medicine scans yield the most useful information needed to make a diagnosis or to determine appropriate treatment, if any. Nuclear medicine is less expensive and ...

  9. Thyroid Scan and Uptake

    Medline Plus

    Full Text Available ... the gamma camera and single-photon emission-computed tomography (SPECT). The gamma camera, also called a scintillation ... high as with other imaging techniques, such as CT or MRI. However, nuclear medicine scans are more ...

  10. Scanning Auger Electron Microscope

    Data.gov (United States)

    Federal Laboratory Consortium — A JEOL model 7830F field emission source, scanning Auger microscope.Specifications / Capabilities:Ultra-high vacuum (UHV), electron gun range from 0.1 kV to 25 kV,...

  11. Thyroid Scan and Uptake

    Medline Plus

    Full Text Available ... as an overactive thyroid gland, a condition called hyperthyroidism , cancer or other growths assess the nature of ... an x-ray or CT scan, surgeries or treatments using iodinated contrast material within the last two ...

  12. Thyroid Scan and Uptake

    Medline Plus

    Full Text Available ... painless. However, during the thyroid scan, you may feel uncomfortable when lying completely still with your head ... When the radiotracer is given intravenously, you will feel a slight pin prick when the needle is ...

  13. Thyroid Scan and Uptake

    Medline Plus

    Full Text Available ... energy. top of page What are some common uses of the procedure? The thyroid scan is used ... community, you can search the ACR-accredited facilities database . This website does not provide cost information. The ...

  14. Thyroid Scan and Uptake

    Medline Plus

    Full Text Available ... scan and thyroid uptake provide information about the structure and function of the thyroid. The thyroid is ... computer, create pictures offering details on both the structure and function of organs and tissues in your ...

  15. Thyroid Scan and Uptake

    Medline Plus

    Full Text Available ... found, and should not be a cause of concern for you. If you had an intravenous line ... found, and should not be a cause of concern for you. Actual scanning time for each thyroid ...

  16. Body CT (CAT Scan)

    Science.gov (United States)

    ... a CT scan can be reformatted in multiple planes, and can even generate three-dimensional images. These ... other medical conditions and whether you have a history of heart disease, asthma, diabetes, kidney disease or ...

  17. Thyroid Scan and Uptake

    Medline Plus

    Full Text Available ... the gland following medication use, surgery, radiotherapy or chemotherapy top of page How should I prepare? You ... You will receive specific instructions based on the type of scan you are undergoing. top of page ...

  18. Thyroid Scan and Uptake

    Medline Plus

    Full Text Available ... Uptake? A thyroid scan is a type of nuclear medicine imaging. The radioactive iodine uptake test (RAIU) ... of thyroid function, but does not involve imaging. Nuclear medicine is a branch of medical imaging that ...

  19. Tomographic scanning apparatus

    International Nuclear Information System (INIS)

    1981-01-01

    This patent specification describes a tomographic scanning apparatus, with particular reference to the adjustable fan beam and its collimator system, together with the facility for taking a conventional x-radiograph without moving the patient. (U.K.)

  20. Thyroid Scan and Uptake

    Medline Plus

    Full Text Available ... exam of any medications you are taking, including vitamins and herbal supplements. You should also inform them ... of scan you are undergoing. top of page What does the equipment look like? The special camera ...

  1. The Scanning Optical Microscope.

    Science.gov (United States)

    Sheppard, C. J. R.

    1978-01-01

    Describes the principle of the scanning optical microscope and explains its advantages over the conventional microscope in the improvement of resolution and contrast, as well as the possibility of producing a picture from optical harmonies generated within the specimen.

  2. Thyroid Scan and Uptake

    Medline Plus

    Full Text Available ... the gland following medication use, surgery, radiotherapy or chemotherapy top of page How should I prepare? You ... but is often performed on hospitalized patients as well. Thyroid Scan You will be positioned on an ...

  3. ANALISIS PENGUKURAN PRODUKTIVITAS PADA CV. CITRA JEPARA FURNITURE

    Directory of Open Access Journals (Sweden)

    Darminto Pujotomo

    2012-02-01

    Full Text Available CV. Citra Jepara adalah perusahaan furnitur ekspor. Pada masa itu, perusahaan hanya melihat level keuntungan untuk mengkaji perusahaan telah berjalan lebih baik atau kebalikannya. Hasil persepsi membuat perusahaan hanya sedikit memperhatikan efisiensi pemakaian sumber daya yang dimiliki (input sehingga perusahaan membutuhkan biaya besar untuk melakukan aktivitas perusahaan.Penelitian ini mempelajari evaluasi produktivitas perusahaan dan pengukuran serta hubungan antara level produktivitas dengan level profitabilitas (kemampuan perusahaan untuk menciptakan laba yang dapat dicapai oleh perusahaan.Hasil penelitian ini tentang pengukuran produktivitas parsial memperlihatkan level produktivitas berubah-ubah dan masih memerlukan usaha peningkatan produktivitas parsial terutama dalam pemakaian masing-masing input dengan efisien. Level Total Factor Productivity selama perioda pengukuran memperlihatkan level pertumbuhan positif. Ini melukiskan perusahaan sukses dalam mengelola input tenaga kerja dan modal kolektif yang dimiliki. Level Total Productivity selama perioda pengukuran menunjukkan level pertumbuhan yang berubah-ubah. Ini melukiskan perusahaan itu belum dapat mengelola input yang dimiliki keseluruhan dengan sukses. Untuk melukiskan hubungan antara produktivitas total dengan profitabilitas dari hasil penelitian bisa diketahui faktor produktivitas (0,998 mempunyai pengaruh lebih besar dibandingkan pemulihan harga (0,457 untuk peningkatan profitabilitas perusahaan selama kurun waktu satu tahun perioda pengukuran. Diperlukan usaha untuk meningkatkan profitabilitas perusahaan untuk periode mendatang disertai usaha untuk meningkatkan produktivitas yang memusatkan pada peningkatan produktivitas material dan produktivitas modal sebagai input yang sangat mempengaruhi profitabilitas perusahaan dengan cara berkelanjutkan dan berkesinambungan. Kata kunci: pengukuran evaluasi dan produktivitas, profitabilitas    CV. Citra Jepara is an export furniture

  4. Novel circulatory connection from the acupoint Zhong Wan(CV12 to pancreas

    Directory of Open Access Journals (Sweden)

    Minsoo Kim

    2008-03-01

    Full Text Available Objectives : Demonstrating a novel circulatory path from the acupoint(CV12 to the pancreas. Method : Alcian blue(1% solution, 20μl, pH 7.4 was injected into the acupoint(CV12. Two hours later the surfaces of internal organs were observed by using a stereomicroscope. Results : Alcian blue arrived and colored the omental fat band(OFB on the pancreas. The OFB connected the head and tail of the pancreas, the pancreas and the spleen, and the pancreas and the stomach. Conclusion : The existence of a novel circulatory path from the acupoint CV12 to the pancreas and its OFB was demonstrated.

  5. Analisis Strategi Mitigasi Resiko Pada Supply Chain CV Surya Cip Dengan House of Risk Model

    OpenAIRE

    Pertiwi, Yoana Ellen; Susanty, Aries

    2017-01-01

    Analysis of Risk Mitigation Strategies on CV Surya CIP's Supply Chain Using House of Risk Model. In the supply chain activities always has the potential of risk, therefore risk management is necessary for handling the risks. At the company that produces plastic molding machine such as CV Surya CIP, in its supply chain activities have a chance to arise risks. The purpose of this study is to identify the various risks that occur in the CV Surya CIP and its causes, severity and determine the ...

  6. Analisis Pengawasan Logistik Produk Aqua Ukuran 330ml Pada CV. Dlu'x Resto Samarinda

    OpenAIRE

    Mardiana, Ali Masuhud, H. Mulyadi Syp

    2016-01-01

    The problem in this research is "Are Determination Against Aqua Products Logistics Control 330ml sizes on CV. DLux Resto has been optimized? "This study aims to determine the amount of inventory on the CV aqua 330ml sizes. Dlu'x Resto in Samarinda.Formulation of the problem in this study is whether the determination of the logistical monitoring product inventory aqua 330ml sizes that have been carried out on the CV. Dlu'x Resto Samarinda already performed optimally.The hypothesis in this stud...

  7. Detection and classification of gaseous sulfur compounds by solid electrolyte cyclic voltammetry of cermet sensor array.

    Science.gov (United States)

    Kramer, Kirsten E; Rose-Pehrsson, Susan L; Hammond, Mark H; Tillett, Duane; Streckert, Holger H

    2007-02-12

    Electrochemical sensors composed of a ceramic-metallic (cermet) solid electrolyte are used for the detection of gaseous sulfur compounds SO(2), H(2)S, and CS(2) in a study involving 11 toxic industrial chemical (TIC) compounds. The study examines a sensor array containing four cermet sensors varying in electrode-electrolyte composition, designed to offer selectivity for multiple compounds. The sensors are driven by cyclic voltammetry to produce a current-voltage profile for each analyte. Raw voltammograms are processed by background subtraction of clean air, and the four sensor signals are concatenated to form one vector of points. The high-resolution signal is compressed by wavelet transformation and a probabilistic neural network is used for classification. In this study, training data from one sensor array was used to formulate models which were validated with data from a second sensor array. Of the 11 gases studied, 3 that contained sulfur produced the strongest responses and were successfully analyzed when the remaining compounds were treated as interferents. Analytes were measured from 10 to 200% of their threshold-limited value (TLV) according to the 8-h time weighted average (TWA) exposure limits defined by the National Institute of Occupational Safety and Health (NIOSH). True positive classification rates of 93.3, 96.7, and 76.7% for SO(2), H(2)S, and CS(2), respectively, were achieved for prediction of one sensor unit when a second sensor was used for modeling. True positive rates of 83.3, 90.0, and 90.0% for SO(2), H(2)S, and CS(2), respectively, were achieved for the second sensor unit when the first sensor unit was used for modeling. Most of the misclassifications were for low concentration levels (such 10-25% TLV) in which case the compound was classified as clean air. Between the two sensors, the false positive rates were 2.2% or lower for the three sulfur compounds, 0.9% or lower for the interferents (eight remaining analytes), and 5.8% or lower for

  8. Detection and classification of gaseous sulfur compounds by solid electrolyte cyclic voltammetry of cermet sensor array

    International Nuclear Information System (INIS)

    Kramer, Kirsten E.; Rose-Pehrsson, Susan L.; Hammond, Mark H.; Tillett, Duane; Streckert, Holger H.

    2007-01-01

    Electrochemical sensors composed of a ceramic-metallic (cermet) solid electrolyte are used for the detection of gaseous sulfur compounds SO 2 , H 2 S, and CS 2 in a study involving 11 toxic industrial chemical (TIC) compounds. The study examines a sensor array containing four cermet sensors varying in electrode-electrolyte composition, designed to offer selectivity for multiple compounds. The sensors are driven by cyclic voltammetry to produce a current-voltage profile for each analyte. Raw voltammograms are processed by background subtraction of clean air, and the four sensor signals are concatenated to form one vector of points. The high-resolution signal is compressed by wavelet transformation and a probabilistic neural network is used for classification. In this study, training data from one sensor array was used to formulate models which were validated with data from a second sensor array. Of the 11 gases studied, 3 that contained sulfur produced the strongest responses and were successfully analyzed when the remaining compounds were treated as interferents. Analytes were measured from 10 to 200% of their threshold-limited value (TLV) according to the 8-h time weighted average (TWA) exposure limits defined by the National Institute of Occupational Safety and Health (NIOSH). True positive classification rates of 93.3, 96.7, and 76.7% for SO 2 , H 2 S, and CS 2 , respectively, were achieved for prediction of one sensor unit when a second sensor was used for modeling. True positive rates of 83.3, 90.0, and 90.0% for SO 2 , H 2 S, and CS 2 , respectively, were achieved for the second sensor unit when the first sensor unit was used for modeling. Most of the misclassifications were for low concentration levels (such 10-25% TLV) in which case the compound was classified as clean air. Between the two sensors, the false positive rates were 2.2% or lower for the three sulfur compounds, 0.9% or lower for the interferents (eight remaining analytes), and 5.8% or lower for

  9. Electrochemical Genotoxicity Assay Based on a SOS/umu Test Using Hydrodynamic Voltammetry in a Droplet

    Science.gov (United States)

    Kuramitz, Hideki; Sazawa, Kazuto; Nanayama, Yasuaki; Hata, Noriko; Taguchi, Shigeru; Sugawara, Kazuharu; Fukushima, Masami

    2012-01-01

    The SOS/umu genotoxicity assay evaluates the primary DNA damage caused by chemicals from the β-galactosidase activity of S. typhimurium. One of the weaknesses of the common umu test system based on spectrophotometric detection is that it is unable to measure samples containing a high concentration of colored dissolved organic matters, sediment, and suspended solids. However, umu tests with electrochemical detection techniques prove to be a better strategy because it causes less interference, enables the analysis of turbid samples and allows detection even in small volumes without loss of sensitivity. Based on this understanding, we aim to develop a new umu test system with hydrodynamic chronoamperometry using a rotating disk electrode (RDE) in a microliter droplet. PAPG when used as a substrate is not electroactive at the potential at which PAP is oxidized to p-quinone imine (PQI), so the current response of chronoamperometry resulting from the oxidation of PAP to PQI is directly proportional to the enzymatic activity of S. typhimurium. This was achieved by performing genotoxicity tests for 2-(2-furyl)-3-(5-nitro-2-furyl)-acrylamide (AF-2) and 2-aminoanthracene (2-AA) as model genotoxic compounds. The results obtained in this study indicated that the signal detection in the genotoxicity assay based on hydrodynamic voltammetry was less influenced by the presence of colored components and sediment particles in the samples when compared to the usual colorimetric signal detection. The influence caused by the presence of humic acids (HAs) and artificial sediment on the genotoxic property of selected model compounds such as 4-nitroquinoline-N-oxide (4-NQO), 3-chloro-4-(dichloromethyl)-5-hydroxy-2(5H)-furanone (MX), 1,8-dinitropyrene (1,8-DNP) and 1-nitropyrene (1-NP) were also investigated. The results showed that the genotoxicity of 1-NP and MX changed in the presence of 10 mg·L−1 HAs. The genotoxicity of tested chemicals with a high hydrophobicity such as 1,8-DNP

  10. Fox grape cv. Bordô (Vitis labrusca L.) and grapevine cv. Chardonnay (Vitis vinifera L.) cultivated in vitro under different carbohydrates, amino acids and 6-Benzylaminopurine levels

    OpenAIRE

    Carvalho, Dayse Cristina de; Silva, André Luís Lopes da; Schuck, Mariane Ruzza; Purcino, Marivel; Tanno, Guilherme Nakao; Biasi, Luiz Antonio

    2013-01-01

    The aim of this work was to study the influence of sucrose and glucose, amino acids and BAP (6-Benzylaminopurine) levels on in vitro shoot regeneration of fox grape cv. Bordô and grapevine cv. Chardonnay. The nodal segments from micropropagated material were used as explants and half-strength MS medium as the basal medium. Sucrose and glucose at 15, 30 and 45 g.L-1 were tested as a carbon source and the supplementation of adenine, asparagine, alanine, glycine, cysteine, glutamine, arginine wa...

  11. Determination of trace amounts of indium in some sediments by means of coprecipitation with zirconium hydroxide and differential pulse anodic stripping voltammetry

    International Nuclear Information System (INIS)

    Yoshimura, Wataru; Uzawa, Atushi; Hong Luxin.

    1994-01-01

    Indium in some sediments was determined by means of coprecipitation and differential pulse anodic stripping voltammetry. The analytical procedure was as follows. Fifty milliliters of distilled water is added to 10 ml of sample solution containing 0.04 g of sediment. Then, constant amounts of indium standard solution and 1 ml of zirconium oxychloride solution are added and the pH adjusted to 8.8 with ammonia water (1:2). The precipitate is separated by filtration and then dissolved in 25 ml of 4 M hydrochloric acid. After 1 ml of 5% KCNS solution is added, this solution is diluted to 50 ml with distilled water. A portion of this solution is employed for the determination of indium. After bubbling nitrogen gas through the sample solution for 100 s it was pre-electrolyzed for 100 s. The potential was scanned from -0.9 V to -0.3 Vυs. SCE for dissolution of indium ion. Indium ion was determined from the peak current of the voltammogram. The results are as follows: (1) Zirconium hydroxide was the most effective collector of indium when the pH was adjusted to 8.8 with ammonia water (1:2). (2) Iron (III) and cadmium ions were found to interfere with the determination of indium. (3) The analytical procedure took about 90 min and 0.01 ppm of indium in sample solution could be determined. (4) This method is applicable to the determination of indium in river bottom and sea floor sediment. (author)

  12. Novel acyclonucleoside analog bearing a 1,2,4-triazole–Schiff base: Synthesis, characterization and analytical studies using square wave-adsorptive stripping voltammetry and HPLC

    Directory of Open Access Journals (Sweden)

    Ali F. Alghamdi

    2017-09-01

    Full Text Available New acyclonucleoside analogs tethered by a 1,2,4-triazole scaffold were synthesized through the condensation of 4-amino-5-(2-phenyleth-1-yl-2,4-dihydro-3H-1,2,4-triazole-3-thione (2 with benzaldehyde followed by the alkylation of the resulting Schiff base (3with 2-bromoethanol, 3-chloropropanol and/or 3-chloropropan-1,2-diol. Voltammetric studies were carried out for the analysis of 1 × 10−6 mol L−1 of the newly synthesized acyclonucleoside analogs (4–6 using square wave-adsorptive stripping voltammetry (SW-AdSV. The sharp voltammetric peak and high reduction current were recorded using a Britton–Robinson B–R pH 10 buffer at Ep = −1250 mV on the hanging mercury drop surface (HMDE and Ag/AgCl reference electrode. Several experimental conditions were studied, such as the supporting electrolytes, the pH, and the accumulation time, as well as the potential, the scan rate, the frequency and the step potential for 4-benzylideneamino-5-(2-phenyleth-1-yl-3-[(2,3-dihydroxyprop-1-ylthio]-1,2,4-triazole (6. The analytical performance of the voltammetric technique was investigated through the analysis of the calibration curve, the detection limit, the recovery and the stability. The voltammetric analytical applications were evaluated by the recovery of compound (6 in the urine and plasma samples. The HPLC technique was also applied for the separation of compound (6 from interference using a C-18 (5 μm column with UV detection at 254 nm.

  13. Simultaneous detection of metronidazole and chloramphenicol by differential pulse stripping voltammetry using a silver nanoparticles/sulfonate functionalized graphene modified glassy carbon electrode

    International Nuclear Information System (INIS)

    Zhai, Haiyun; Liang, Zhixian; Chen, Zuanguang; Wang, Haihang; Liu, Zhenping; Su, Zihao; Zhou, Qing

    2015-01-01

    Graphical abstract: Display Omitted -- Highlights: • A novel and reliable AgNPs/SF-GR modified glassy carbon electrode was constructed and characterized. • The AgNPs/SF-GR/GCE was successfully applied in the shrimp for simultaneous determination of MTZ and CAP. • Under optimized conditions, common substances such as UA, AA, DA and ion did not interfered in the electrode performance. • The modified electrode exhibited considerable sensitivity, stability and reproducibility. • This fabricated electrode achieved a satisfactory level compared with other electrodes toward MTZ and CAP. -- Abstract: A novel silver nanoparticles/sulfonated functionalized graphene modified glassy carbon electrode (AgNPs/SF-GR/GCE) was fabricated to determine chloramphenicol and metronidazole simultaneously. Taking advantage of sulfonic group, AgNPs were successfully electrodeposited on functionalized GR immobilized on the surface of a GCE. Scanning electron microscopy and energy spectrum analysis results confirmed that AgNPs were deposited on the functionalized GR film. Compared to the bare GCE or the pristine SF-GR modified electrode, AgNPs/SF-GR/GCE exhibited excellent electroreduction towards chloramphenicol and metronidazole. In addition, the two antibacterial drugs were separated completely in 0.10 M citric acid-sodium citrate buffer (pH 4.0) by differential pulse stripping voltammetry under optimum conditions. The cathodic current was linearly related with 0.02∼20.0 μM chloramphenicol and 0.10∼20.0 μM metronidazole, with the detection limits of 0.01 μM and 0.05 μM respectively. Furthermore, AgNPs/SF-GR/GCE was applied to the simultaneous determination of chloramphenicol and metronidazole in an aquatic product

  14. Limited geographic distribution of the novel cyclovirus CyCV-VN.

    Science.gov (United States)

    Le, Van Tan; de Jong, Menno D; Nguyen, Van Kinh; Nguyen, Vu Trung; Taylor, Walter; Wertheim, Heiman F L; van der Ende, Arie; van der Hoek, Lia; Canuti, Marta; Crusat, Martin; Sona, Soeng; Nguyen, Hanh Uyen; Giri, Abhishek; Nguyen, Thi Thuy Chinh Bkrong; Ho, Dang Trung Nghia; Farrar, Jeremy; Bryant, Juliet E; Tran, Tinh Hien; Nguyen, Van Vinh Chau; van Doorn, H Rogier

    2014-02-05

    A novel cyclovirus, CyCV-VN, was recently identified in cerebrospinal fluid (CSF) from patients with central nervous system (CNS) infections in central and southern Vietnam. To explore the geographic distribution of this novel virus, more than 600 CSF specimens from patients with suspected CNS infections in northern Vietnam, Cambodia, Nepal and The Netherlands were screened for the presence of CyCV-VN but all were negative. Sequence comparison and phylogenetic analysis between CyCV-VN and another novel cyclovirus recently identified in CSF from Malawian patients indicated that these represent distinct cycloviral species, albeit phylogenetically closely related. The data suggest that CyCV-VN has a limited geographic distribution within southern and central Vietnam. Further research is needed to determine the global distribution and diversity of cycloviruses and importantly their possible association with human disease.

  15. Analisis Pengaruh Lingkungan Kerja dan Pemberian Kompensasi terhadap Kinerja Karyawan CV Mum Indonesia

    Directory of Open Access Journals (Sweden)

    Jerry M. Logahan

    2012-05-01

    Full Text Available Mum CV is a company engaged in the sale of bread. To increase sales of bread (performance it needs to investigate the influence of work environment and compensation of employees. The method of analysis used in this study is descriptive, Pearson Regression, and Multiple Regression. The data were obtained from the employees performance by completing the questionnaires provided using Likert scale which was useful to determine the level of disagreement questions on the questionnaires. Results achieved in this study are the work environment has no significant influence on employees performance in CV Mum Indonesia, amounting to 0,068. Compensation has significant, no influence on employees performance in CV Mum Indonesia that is equal to 0,580 and there is a significant effect of 33.6%. Work environment and compensation have a significant impact on employees performance in CV Mum Indonesia. It is equal to 0,580 and there is a significant effect of 33.6%.

  16. Preoperative bone scans

    International Nuclear Information System (INIS)

    Charkes, N.D.; Malmud, L.S.; Caswell, T.; Goldman, L.; Hall, J.; Lauby, V.; Lightfoot, W.; Maier, W.; Rosemond, G.

    1975-01-01

    Strontium nitrate Sr-87m bone scans were made preoperatively in a group of women with suspected breast cancer, 35 of whom subsequently underwent radical mastectomy. In 3 of the 35 (9 percent), the scans were abnormal despite the absence of clinical or roentgenographic evidence of metastatic disease. All three patients had extensive axillary lymph node involvement by tumor, and went on to have additional bone metastases, from which one died. Roentgenograms failed to detect the metastases in all three. Occult bone metastases account in part for the failure of radical mastectomy to cure some patients with breast cancer. It is recommended that all candidates for radical mastectomy have a preoperative bone scan. (U.S.)

  17. Frequency scanning microstrip antennas

    DEFF Research Database (Denmark)

    Danielsen, Magnus; Jørgensen, Rolf

    1979-01-01

    The principles of using radiating microstrip resonators as elements in a frequency scanning antenna array are described. The resonators are cascade-coupled. This gives a scan of the main lobe due to the phase-shift in the resonator in addition to that created by the transmission line phase......-shift. Experimental results inX-band, in good agreement with the theory, show that it is possible to scan the main lobe an angle ofpm30degby a variation of the frequencypm300MHz, and where the 3 dB beamwidth is less than10deg. The directivity was 14.7 dB, while the gain was 8.1 dB. The efficiency might be improved...

  18. Hemispheric specialization in partial epilepsy role of dichotic listening cv task and central audiological evaluation in the neuropsychological assessment

    Directory of Open Access Journals (Sweden)

    Mauro Muszkat

    1991-12-01

    Full Text Available We studied 49 patients with partial epilepsy divided into lesional cases (i.e. with lesions on CT scan and non-lesional cases (i.e. without CT scan lesions, in relation to the Wechsler Intelligence Scale subtests (Coding, Digit span, dichotic listening CV task and Central Auditory Test (SSI, PSI. The aim of this paper was to study the hemispheric prevalence in dichotic listening task with regard to cognitive perforamance, as well as the presence or absence of central auditory dysfunction. Lesional cases presented a hemisphere prevalence in dichotic listening task with regard to cognitive performance, as well as the non-lesional cases tend to report the stimuli in the same side of EEC focus. Significant differences were found among the lesional and non lesional cases in relation to the digit span score and Coding subtest in right lesional cases versus right non-lesional cases. Both lesional and non-lesional group showed signs of central auditory dysfunction. We suggest that the dichotic listening and SSI and PSI test can be useful for a best comprehension of asymmetric neuropsychological performance in partial epilepsy.

  19. Biofuels from the Fresh Water Microalgae Chlorella vulgaris (FWM-CV for Diesel Engines

    Directory of Open Access Journals (Sweden)

    Saddam H. Al-lwayzy

    2014-03-01

    Full Text Available This work aims to investigate biofuels for diesel engines produced on a lab-scale from the fresh water microalgae Chlorella vulgaris (FWM-CV. The impact of growing conditions on the properties of biodiesel produced from FWM-CV was evaluated. The properties of FWM-CV biodiesel were found to be within the ASTM standards for biodiesel. Due to the limited amount of biodiesel produced on the lab-scale, the biomass of dry cells of FWM-CV was used to yield emulsified water fuel. The preparation of emulsion fuel with and without FWM-CV cells was conducted using ultrasound to overcome the problems of large size microalgae colonies and to form homogenized emulsions. The emulsified water fuels, prepared using ultrasound, were found to be stable and the size of FWM-CV colonies were effectively reduced to pass through the engine nozzle safely. Engine tests at 3670 rpm were conducted using three fuels: cottonseed biodiesel CS-B100, emulsified cottonseed biodiesel water fuel, water and emulsifier (CS-E20 and emulsified water containing FWM-CV cells CS-ME20. The results showed that the brake specific fuel consumption (BSFC was increased by about 41% when the engine was fueled with emulsified water fuels compared to CS-B100. The engine power, exhaust gas temperature, NOx and CO2 were significantly lower than that produced by CS-B100. The CS-ME20 produced higher power than CS-E20 due to the heating value improvement as a result of adding FWM-CV cells to the fuel.

  20. Analisis Pengaruh Kemampuan, Usaha dan Dukungan Perusahaan terhadap Kinerja Karyawan pada CV Sandang Gloria Konveksindo

    OpenAIRE

    Logahan, Jerry; Sari, Synthia Atas; Marisa, Dian

    2012-01-01

    Clothing Konveksindo CV Gloria is a trading company engaged in the sale of products and clothing items. Therefore, the performance of employees is very important in achieving that goal. The purpose of this study was to analyze the influence of ability, effort, and support the company towards the employee's performance CV Gloria Konveksindo Clothing. The method of analysis used in this study is descriptive, Pearson Regression, and Multiple Regression. Data obtained from the appraisal of employ...

  1. Cyclovirus CyCV-VN species distribution is not limited to Vietnam and extends to Africa.

    Science.gov (United States)

    Garigliany, Mutien-Marie; Hagen, Ralf Matthias; Frickmann, Hagen; May, Jürgen; Schwarz, Norbert Georg; Perse, Amanda; Jöst, Hanna; Börstler, Jessica; Shahhosseini, Nariman; Desmecht, Daniel; Mbunkah, Herbert Afegenwi; Daniel, Achukwi Mbunkah; Kingsley, Manchang Tanyi; Campos, Renata de Mendonca; de Paula, Vanessa Salete; Randriamampionona, Njary; Poppert, Sven; Tannich, Egbert; Rakotozandrindrainy, Raphael; Cadar, Daniel; Schmidt-Chanasit, Jonas

    2014-12-18

    Cycloviruses, small ssDNA viruses of the Circoviridae family, have been identified in the cerebrospinal fluid from symptomatic human patients. One of these species, cyclovirus-Vietnam (CyCV-VN), was shown to be restricted to central and southern Vietnam. Here we report the detection of CyCV-VN species in stool samples from pigs and humans from Africa, far beyond their supposed limited geographic distribution.

  2. Evaluation of faba beans ( Vicia faba cv. Fiord) and sweet lupins ...

    African Journals Online (AJOL)

    Evaluation of faba beans ( Vicia faba cv. Fiord) and sweet lupins ( Lupizus albus cv. Kiev) as protein sources for ... P igsi n the metabolisrna ndN balance trial consurned5 % less( P < 0.01)o 1'thel upind ietc omparedto the fabab eand iet (l 370 vs. | 440 gld).N o significandt ift'erenceisn the digestiblee nergy( DE) contenta nd ...

  3. Pengaruh Kualitas Pelayanan terhadap Loyalitas Pelanggan di Rental Mobil CV. Ilham Motor Gandu Mlarak Ponorogo

    OpenAIRE

    Dhika Amalia

    2015-01-01

    The purpose of this study was to determine the amount of quality customer service and loyalty to know a very dominant factor affecting customer loyalty in the CV . Ilham Motor. This research method is the primary data from the questionnaires , sampling technique is a technique associated with customer 100 CV Ilham Motor . Data analysis is a quantitative method to test the validity , reliability testing , multiple linear regression analysis , the correlation coefficient analytic , analytic det...

  4. Tomographic scanning apparatus

    International Nuclear Information System (INIS)

    Abele, M.

    1983-01-01

    A computerized tomographic scanning apparatus suitable for diagnosis and for improving target identification in stereotactic neurosurgery is described. It consists of a base, a source of penetrating energy, a detector which produces scanning signals and detector positioning means. A frame with top and bottom arms secures the detector and source to the top and bottom arms respectively. A drive mechanism rotates the frame about an axis along which the frame may also be moved. Finally, the detector may be moved relative to the bottom arm in a direction contrary to the rotation of the frame. (U.K.)

  5. Scanning the phenomenological MSSM

    CERN Document Server

    Wuerzinger, Jonas

    2017-01-01

    A framework to perform scans in the 19-dimensional phenomenological MSSM is developed and used to re-evaluate the ATLAS experiments' sensitivity to R-parity-conserving supersymmetry with LHC Run 2 data ($\\sqrt{s}=13$ TeV), using results from 14 separate ATLAS searches. We perform a $\\tilde{t}_1$ dedicated scan, only considering models with $m_{\\tilde{t}_1}<1$ TeV, while allowing both a neutralino ($\\tilde{\\chi}_1^0$) and a sneutrino ($\\tilde{\

  6. Calibration of scanning Lidar

    DEFF Research Database (Denmark)

    Gómez Arranz, Paula; Courtney, Michael

    This report describes the tests carried out on a scanning lidar at the DTU Test Station for large wind turbines, Høvsøre. The tests were divided in two parts. In the first part, the purpose was to obtain wind speed calibrations at two heights against two cup anemometers mounted on a mast. Additio......This report describes the tests carried out on a scanning lidar at the DTU Test Station for large wind turbines, Høvsøre. The tests were divided in two parts. In the first part, the purpose was to obtain wind speed calibrations at two heights against two cup anemometers mounted on a mast...

  7. Adaptive Optical Scanning Holography

    Science.gov (United States)

    Tsang, P. W. M.; Poon, Ting-Chung; Liu, J.-P.

    2016-01-01

    Optical Scanning Holography (OSH) is a powerful technique that employs a single-pixel sensor and a row-by-row scanning mechanism to capture the hologram of a wide-view, three-dimensional object. However, the time required to acquire a hologram with OSH is rather lengthy. In this paper, we propose an enhanced framework, which is referred to as Adaptive OSH (AOSH), to shorten the holographic recording process. We have demonstrated that the AOSH method is capable of decreasing the acquisition time by up to an order of magnitude, while preserving the content of the hologram favorably. PMID:26916866

  8. [Habitat factor analysis for Torreya grandis cv. Merrillii based on spatial information technology].

    Science.gov (United States)

    Wang, Xiao-ming; Wang, Ke; Ao, Wei-jiu; Deng, Jin-song; Han, Ning; Zhu, Xiao-yun

    2008-11-01

    Torreya grandis cv. Merrillii, a tertiary survival plant, is a rare tree species of significant economic value and expands rapidly in China. Its special habitat factor analysis has the potential value to provide guide information for its planting, management, and sustainable development, because the suitable growth conditions for this tree species are special and strict. In this paper, the special habitat factors for T. grandis cv. Merrillii in its core region, i.e., in seven villages of Zhuji City, Zhejiang Province were analyzed with Principal Component Analysis (PCA) and a series of data, such as IKONOS image, Digital Elevation Model (DEM), and field survey data supported by the spatial information technology. The results showed that T. grandis cv. Merrillii exhibited high selectivity of environmental factors such as elevation, slope, and aspect. 96.22% of T. grandis cv. Merrillii trees were located at the elevation from 300 to 600 m, 97.52% of them were found to present on the areas whose slope was less than 300, and 74.43% of them distributed on sunny and half-sunny slopes. The results of PCA analysis indicated that the main environmental factors affecting the habitat of T. grandis cv. Merrillii were moisture, heat, and soil nutrients, and moisture might be one of the most important ecological factors for T. grandis cv. Merrillii due to the unique biological and ecological characteristics of the tree species.

  9. Electrochemical sample preparation for the determination of Cd, Pb, and Cu in the presence of surfactants by stripping voltammetry

    International Nuclear Information System (INIS)

    Svintsova, L.D.; Chernysheva, N.N.

    1997-01-01

    The electrochemical pretreatment of aqueous solutions of synthetic surfactants in a diaphragm elelctrolyzer was used in order to diminish surfactant interference. The determination of cadmium, lead, and copper by stripping voltammetry with a mercury-film electrode in model solutions of cetylpyriridinium chloride, sodium lauryl sulfate, and OP-10 was taken as an example. It was found that the reproducibility of anodic peaks of the elements was improved, and the linearity of calibration characteristics was recovered; however, the sensitivity was not always as high as the value in the blank experiment

  10. Improvement of efficient in vitro regeneration potential of mature callus induced from Malaysian upland rice seed (Oryza sativa cv. Panderas).

    Science.gov (United States)

    Mohd Din, Abd Rahman Jabir; Iliyas Ahmad, Fauziah; Wagiran, Alina; Abd Samad, Azman; Rahmat, Zaidah; Sarmidi, Mohamad Roji

    2016-01-01

    A new and rapid protocol for optimum callus production and complete plant regeneration has been assessed in Malaysian upland rice (Oryza sativa) cv. Panderas. The effect of plant growth regulator (PGR) on the regeneration frequency of Malaysian upland rice (cv. Panderas) was investigated. Mature seeds were used as a starting material for callus induction experiment using various concentrations of 2,4-D and NAA. Optimal callus induction frequency at 90% was obtained on MS media containing 2,4-D (3 mg L(-1)) and NAA (2 mg L(-1)) after 6 weeks while no significant difference was seen on tryptophan and glutamine parameters. Embryogenic callus was recorded as compact, globular and light yellowish in color. The embryogenic callus morphology was further confirmed with scanning electron microscopy (SEM) analysis. For regeneration, induced calli were treated with various concentrations of Kin (0.5-1.5 mg L(-1)), BAP, NAA and 0.5 mg L(-1) of TDZ. The result showed that the maximum regeneration frequency (100%) was achieved on MS medium containing BAP (0.5 mg L(-1)), Kin (1.5 mg L(-1)), NAA (0.5 mg L(-1)) and TDZ (0.5 mg L(-1)) within four weeks. Developed shoots were successfully rooted on half strength MS free hormone medium and later transferred into a pot containing soil for acclimatization. This cutting-edge finding is unique over the other existing publishable data due to the good regeneration response by producing a large number of shoots.

  11. Scanning fluorescent microscopy is an alternative for quantitative fluorescent cell analysis.

    Science.gov (United States)

    Varga, Viktor Sebestyén; Bocsi, József; Sipos, Ferenc; Csendes, Gábor; Tulassay, Zsolt; Molnár, Béla

    2004-07-01

    Fluorescent measurements on cells are performed today with FCM and laser scanning cytometry. The scientific community dealing with quantitative cell analysis would benefit from the development of a new digital multichannel and virtual microscopy based scanning fluorescent microscopy technology and from its evaluation on routine standardized fluorescent beads and clinical specimens. We applied a commercial motorized fluorescent microscope system. The scanning was done at 20 x (0.5 NA) magnification, on three channels (Rhodamine, FITC, Hoechst). The SFM (scanning fluorescent microscopy) software included the following features: scanning area, exposure time, and channel definition, autofocused scanning, densitometric and morphometric cellular feature determination, gating on scatterplots and frequency histograms, and preparation of galleries of the gated cells. For the calibration and standardization Immuno-Brite beads were used. With application of shading compensation, the CV of fluorescence of the beads decreased from 24.3% to 3.9%. Standard JPEG image compression until 1:150 resulted in no significant change. The change of focus influenced the CV significantly only after +/-5 microm error. SFM is a valuable method for the evaluation of fluorescently labeled cells. Copyright 2004 Wiley-Liss, Inc.

  12. A Cuprous Oxide Thin Film Non-Enzymatic Glucose Sensor Using Differential Pulse Voltammetry and Other Voltammetry Methods and a Comparison to Different Thin Film Electrodes on the Detection of Glucose in an Alkaline Solution

    Directory of Open Access Journals (Sweden)

    Yifan Dai

    2018-01-01

    Full Text Available A cuprous oxide (Cu2O thin layer served as the base for a non-enzymatic glucose sensor in an alkaline medium, 0.1 NaOH solution, with a linear range of 50–200 mg/dL using differential pulse voltammetry (DPV measurement. An X-ray photoelectron spectroscopy (XPS study confirmed the formation of the cuprous oxide layer on the thin gold film sensor prototype. Quantitative detection of glucose in both phosphate-buffered saline (PBS and undiluted human serum was carried out. Neither ascorbic acid nor uric acid, even at a relatively high concentration level (100 mg/dL in serum, interfered with the glucose detection, demonstrating the excellent selectivity of this non-enzymatic cuprous oxide thin layer-based glucose sensor. Chronoamperometry and single potential amperometric voltammetry were used to verify the measurements obtained by DPV, and the positive results validated that the detection of glucose in a 0.1 M NaOH alkaline medium by DPV measurement was effective. Nickel, platinum, and copper are commonly used metals for non-enzymatic glucose detection. The performance of these metal-based sensors for glucose detection using DPV were also evaluated. The cuprous oxide (Cu2O thin layer-based sensor showed the best sensitivity for glucose detection among the sensors evaluated.

  13. Thyroid Scan and Uptake

    Medline Plus

    Full Text Available ... process that regulates the rate at which the body converts food to energy. top of page What are some common uses of the procedure? The thyroid scan is used to determine the size, shape and position of the thyroid gland. The ...

  14. Thyroid Scan and Uptake

    Medline Plus

    Full Text Available Toggle navigation Test/Treatment Patient Type Screening/Wellness Disease/Condition Safety En Español More Info Images/Videos About Us News Physician Resources Professions Site Index A-Z Thyroid Scan and Uptake ...

  15. Dialogue scanning measuring systems

    International Nuclear Information System (INIS)

    Borodyuk, V.P.; Shkundenkov, V.N.

    1985-01-01

    The main developments of scanning measuring systems intended for mass precision processsing of films in nuclear physics problems and in related fields are reviewed. A special attention is paid to the problem of creation of dialogue systems which permit to simlify the development of control computer software

  16. Scanning electron microscopy

    Energy Technology Data Exchange (ETDEWEB)

    Cox, B. [Atomic Energy of Canada Limited, Chalk River, Ontario (Canada)

    1970-05-15

    The JSM-11 scanning electron microscope at CRNL has been used extensively for topographical studies of oxidized metals, fracture surfaces, entomological and biological specimens. A non-dispersive X-ray attachment permits the microanalysis of the surface features. Techniques for the production of electron channeling patterns have been developed. (author)

  17. Scanning tunneling microscopy

    International Nuclear Information System (INIS)

    Binnig, G.; Rohrer, H.

    1983-01-01

    Based on vacuum tunneling, a novel type of microscope, the scanning tunneling microscope (STM) was developed. It has an unprecedented resolution in real space on an atomic scale. The authors review the important technical features, illustrate the power of the STM for surface topographies and discuss its potential in other areas of science and technology. (Auth.)

  18. Bone scan in rheumatology

    International Nuclear Information System (INIS)

    Morales G, R.; Cano P, R.; Mendoza P, R.

    1993-01-01

    In this chapter a revision is made concerning different uses of bone scan in rheumatic diseases. These include reflex sympathetic dystrophy, osteomyelitis, spondyloarthropaties, metabolic bone diseases, avascular bone necrosis and bone injuries due to sports. There is as well some comments concerning pediatric pathology and orthopedics. (authors). 19 refs., 9 figs

  19. Thyroid Scan and Uptake

    Medline Plus

    Full Text Available ... information. The thyroid scan and thyroid uptake provide information about the structure and function of the thyroid. The thyroid is a gland in the neck that controls metabolism , a chemical process that regulates the rate at which the body ...

  20. Tomographic scanning apparatus

    International Nuclear Information System (INIS)

    1981-01-01

    Details are given of a tomographic scanning apparatus, with particular reference to the means of adjusting the apparent gain of the signal processing means for receiving output signals from the detectors, to compensate for drift in the gain characteristics, including means for passing a reference signal. (U.K.)

  1. Stabilized radiographic scanning agent

    International Nuclear Information System (INIS)

    Fawzi, M.B.

    1979-01-01

    A stable composition useful in preparation of technetium-99m-based radiographic scanning agents has been developed. The composition contains a stabilizing amount of gentisate stabilizer selected from gentisic acid and its soluble pharmaceutically-acceptable salts and esthers. (E.G.)

  2. Scanning electron microscope

    International Nuclear Information System (INIS)

    Anon.

    1980-01-01

    The principle underlying the design of the scanning electron microscope (SEM), the design and functioning of SEM are described. Its applications in the areas of microcircuitry and materials science are outlined. The development of SEM in India is reviewed. (M.G.B.)

  3. Radiographic scanning agent

    International Nuclear Information System (INIS)

    Tofe, A.J.

    1976-01-01

    A stable radiographic scanning agent on a sup(99m)Tc basis has been developed. The substance contains a pertechnetate reduction agent, tin(II)-chloride, chromium(II)-chloride, or iron(II)-sulphate, as well as an organospecific carrier and ascorbic acid or a pharmacologically admissible salt or ester of ascorbic acid. (VJ) [de

  4. Thyroid Scan and Uptake

    Medline Plus

    Full Text Available ... you: have had any tests, such as an x-ray or CT scan, surgeries or treatments using iodinated ... page How does the procedure work? With ordinary x-ray examinations, an image is made by passing x- ...

  5. Thyroid Scan and Uptake

    Medline Plus

    Full Text Available ... for a thyroid scan is 30 minutes or less. Thyroid Uptake You will be given radioactive iodine (I-123 or I-131) in liquid or capsule form to swallow. The thyroid uptake will begin several hours to 24 hours later. Often, two separate uptake ...

  6. Thyroid Scan and Uptake

    Medline Plus

    Full Text Available ... an x-ray or CT scan, surgeries or treatments using iodinated contrast material within the last two months. are taking medications or ingesting other substances that contain iodine , including kelp, seaweed, cough syrups, multivitamins or heart medications. have any ...

  7. Characterization of inclusion complexes of organic ions with hydrophilic hosts by ion transfer voltammetry with solvent polymeric membranes.

    Science.gov (United States)

    Olmos, José Manuel; Laborda, Eduardo; Ortuño, Joaquín Ángel; Molina, Ángela

    2017-03-01

    The quantitative characterization of inclusion complexes formed in aqueous phase between organic ions and hydrophilic hosts by ion-transfer voltammetry with solvent polymeric membrane ion sensors is studied, both in a theoretical and experimental way. Simple analytical solutions are presented for the determination of the binding constant of the complex from the variation with the host concentration of the electrochemical signal. These solutions are valid for any voltammetric technique and for solvent polymeric membrane ion sensors comprising one polarisable interface (1PI) and also, for the first time, two polarisable interfaces (2PIs). Suitable experimental conditions and data analysis procedures are discussed and applied to the study of the interactions of a common ionic liquid cation (1-octyl-3-metyl-imidazolium) and an ionisable drug (clomipramine) with two hydrophilic cyclodextrins: α-cyclodextrin and 2-hydroxypropyl-β-cyclodextrin. The experimental study is performed via square wave voltammetry with 2PIs and 1PI solvent polymeric membranes and in both cases the electrochemical experiments enable the detection of inclusion complexes and the determination of the corresponding binding constant. Copyright © 2016 Elsevier B.V. All rights reserved.

  8. Voltammetry of ion transfer across a polarized room-temperature ionic liquid membrane facilitated by valinomycin: theoretical aspects and application.

    Science.gov (United States)

    Langmaier, Jan; Samec, Zdenek

    2009-08-01

    Cyclic voltammetry is used to investigate the transfer of alkali-metal cations, protons, and ammonium ions facilitated by the complex formation with valinomycin at the interface between an aqueous electrolyte solution and a room-temperature ionic liquid (RTIL) membrane. The membrane is made of a thin (approximately 112 microm) microporous filter impregnated with an RTIL that is composed of tridodecylmethylammonium cations and tetrakis[3,5-bis(trifluoromethyl)phenyl]borate anions. An extension of the existing theory of voltammetry of ion transfer across polarized liquid membranes makes it possible to evaluate the standard ion-transfer potentials for the hydrophilic cations studied, as well as the stability constants (K(i)) of their 1:1 complexes with valinomycin, as log K(i) = 9.0 (H(+)), 11.1 (Li(+)), 12.8 (Na(+)), 17.2 (K(+)), 15.7 (Rb(+)), 15.1 (Cs(+)), and 14.7 (NH(4)(+)). These data point to the remarkably enhanced stability of the valinomycin complexes within RTIL, and to the enhanced selectivity of valinomycin for K(+) over all other univalent ions studied, compared to the conventional K(+) ion-selective liquid-membrane electrodes. Selective complex formation allows one to resolve voltammetric responses of K(+) and Na(+) in the presence of an excess of Mg(2+) or Ca(2+), which is demonstrated by determination of K(+) and Na(+) in the table and tap water samples.

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

    International Nuclear Information System (INIS)

    Woldemichael, G.; Tulu, T.; Flechsig, G.-U.

    2012-01-01

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

  10. Theoretical treatment of high-frequency, large-amplitude ac voltammetry applied to ideal surface-confined redox systems

    International Nuclear Information System (INIS)

    Bell, Christopher G.; Anastassiou, Costas A.; O’Hare, Danny; Parker, Kim H.; Siggers, Jennifer H.

    2012-01-01

    Highlights: ► Theory of ac voltammetry on ideal surface-confined redox systems. ► Analytical description of the harmonics and transient of the current response. ► Solution valid for high frequency, large-amplitude sinusoidal input voltage. ► Protocol for determining system parameters from experimental current responses. - Abstract: Large-amplitude ac voltammetry, where the applied voltage is a large-amplitude sinusoidal waveform superimposed onto a dc ramp, is a powerful method for investigating the reaction kinetics of surface-confined redox species. Here we consider the large-amplitude ac voltammetric current response of a quasi-reversible, ideal, surface-confined redox system, for which the redox reaction is described by Butler–Volmer theory. We derive an approximate analytical solution, which is valid whenever the angular frequency of the sine-wave is much larger than the rate of the dc ramp and the standard kinetic rate constant of the redox reaction. We demonstrate how the third harmonic and the initial transient of the current response can be used to estimate parameters of the electrochemical system, namely the kinetic rate constant, the electron transfer coefficient, the adsorption formal potential, the initial proportion of oxidised molecules and the linear double-layer capacitance.

  11. Theoretical aspects of several successive two-step redox mechanisms in protein-film cyclic staircase voltammetry

    International Nuclear Information System (INIS)

    Gulaboski, Rubin; Kokoškarova, Pavlinka; Mitrev, Saša

    2012-01-01

    Highlights: ► Theoretical models for 2e− successive mechanisms are considered. ► The models are compatible for various metal-containing redox proteins. ► Diagnostic criteria are provided to recognize the particular redox mechanism. - Abstract: Protein-film voltammetry (PFV) is a versatile tool designed to provide insight into the enzymes physiological functions by studying the redox properties of various oxido-reductases with suitable voltammetric technique. The determination of the thermodynamic and kinetic parameters relevant to protein's physiological properties is achieved via methodologies established from theoretical considerations of various mechanisms in PFV. So far, the majority of the mathematical models in PFV have been developed for redox proteins undergoing a single-step electron transfer reactions. However, there are many oxido-reductases containing quinone moieties or polyvalent ions of transition metals like Mo, Mn, W, Fe or Co as redox centers, whose redox chemistry can be described only via mathematical models considering successive two-step electron transformation. In this work we consider theoretically the protein-film redox mechanisms of the EE (Electrochemical–Electrochemical), ECE (Electrochemical–Chemical–Electrochemical), and EECat (Electrochemical–Electrochemical–Catalytic) systems under conditions of cyclic staircase voltammetry. We also propose methodologies to determine the kinetics of electron transfer steps by all considered mechanisms. The experimentalists working with PFV can get large benefits from the simulated voltammograms given in this work.

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

    International Nuclear Information System (INIS)

    Vaze, Vishwanath D.; Srivastava, Ashwini K.

    2007-01-01

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

  13. Determination of trace mercury in water based on N-octylpyridinium ionic liquids preconcentration and stripping voltammetry.

    Science.gov (United States)

    Li, Zhenhan; Xia, Shanhong; Wang, Jinfen; Bian, Chao; Tong, Jianhua

    2016-01-15

    A novel method for determination of trace mercury in water is developed. The method is performed by extracting mercury firstly with ionic liquids (ILs) and then detecting the concentration of mercury in organic media with anodic stripping voltammetry. Liquid-liquid extraction of mercury(II) ions by four ionic liquids with N-octylpyridinium cations ([OPy](+)) was studied. N-octylpyridinium tetrafluoroborate and N-octylpyridinium trifluoromethylsulfonate were found to be efficient and selective extractant for mercury. Temperature controlled dispersive liquid phase microextraction (TC-DLPME) technique was utilized to improve the performance of preconcentration. After extraction, precipitated IL was diluted by acetonitrile buffer and mercury was detected by differential pulse stripping voltammetry (DPSV) with gold disc electrode. Mercury was enriched by 17 times while interfering ions were reduced by two orders of magnitude in the organic media under optimum condition. Sensitivity and selectivity for electrochemical determination of mercury were improved by using the proposed method. Tap, pond and waste water samples were analyzed with recoveries ranging from 81% to 107% and detection limit of 0.05 μg/L. Copyright © 2015 Elsevier B.V. All rights reserved.

  14. Determination of propylthiouracil in pharmaceuticals by differential pulse voltammetry using a cathodically pretreated boron-doped diamond electrode

    Energy Technology Data Exchange (ETDEWEB)

    Sartori, Elen Romao [Universidade Estadual de Londrina, PR (Brazil). Dept. de Quimica; Trench, Aline Barrios; Rocha-Filho, Romeu C.; Fatibello-Filho, Orlando, E-mail: bello@ufscar.br [Universidade Federal de Sao Carlos (UFSCAR), SP (Brazil). Dept. de Quimica

    2013-09-15

    A simple procedure is described for the determination of propylthiouracil (PTU) by differential pulse voltammetry (DPV) using a cathodically pretreated boron-doped diamond (BDD) electrode. Cyclic voltammetry studies indicate that the oxidation of PTU is irreversible at a peak potential of 1.42 V (vs. Ag/AgCl (3.0 mol L{sup -1} KCl)) in a Britton-Robinson (BR) buffer solution (pH 2.0). Under optimized conditions, the obtained analytical curve was linear (r = 0.9985) for the PTU concentration range of 1.0 to 29.1 {mu}mol L{sup -1} in a BR buffer solution (pH 2.0), with a detection limit of 0.90 {mu}mol L{sup -1}. The proposed method was successfully applied in the determination of PTU in pharmaceutical samples, with results in agreement at a 95% confidence level with those obtained using an official titration method. (author)

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2007-12-31

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

  16. Adsorption of human insulin on single-crystal gold surfaces investigated by in situ scanning tunnelling microscopy and electrochemistry

    DEFF Research Database (Denmark)

    Welinder, Anna Christina; Zhang, Jingdong; Steensgaard, D.B.

    2010-01-01

    sweep, LSV, cyclic, CV, and square wave (SQWV) voltammetry. Multifarious electrochemical patterns were observed. Most attention was given to reductive desorption caused by insulin binding to the Au-surfaces via up to three disulfide groups per insulin monomer, presumably converted to single Au-S links....... SQWV suggested the Au-S bond strength order Au(111) > Au(110) > Au(100) based on the reductive desorption potentials. The voltammetric diversity was paralleled by different in situ STM insulin adsorption modes on the three surfaces. Single-molecule resolution was achieved in all cases. The coverage...... followed the order Au(110) > Au(100) > Au(111) and differs from the reductive desorption order that records the Au-S bonding element. Evenly distributed single molecules were scattered over large Au(111)-terraces, with intriguing molecular arrays disclosed near the terrace edges. In comparison, high...

  17. Scanning probe microscopy

    International Nuclear Information System (INIS)

    Mainsbridge, B.

    1994-01-01

    In late 1959, Richard Feynman observed that manoeuvring atoms was something that could be done in principle but has not been done, 'because we are too big'. In 1982, the scanning tunnelling microscope (STM) was invented and is now a central tool for the construction of nanoscale devices in what was known as molecular engineering, and now, nanotechnology. The principles of the microscope are outlined and references are made to other scanning devices which have evolved from the original invention. The method of employment of the STM as a machine tool is described and references are made to current speculations on applications of the instrument in nanotechnology. A short bibliography on this topic is included. 27 refs., 7 figs

  18. Scanning probe microscopy

    Energy Technology Data Exchange (ETDEWEB)

    Mainsbridge, B [Murdoch Univ., WA (Australia). School of Mathematical and Physical Sciences

    1994-12-31

    In late 1959, Richard Feynman observed that manoeuvring atoms was something that could be done in principle but has not been done, `because we are too big`. In 1982, the scanning tunnelling microscope (STM) was invented and is now a central tool for the construction of nanoscale devices in what was known as molecular engineering, and now, nanotechnology. The principles of the microscope are outlined and references are made to other scanning devices which have evolved from the original invention. The method of employment of the STM as a machine tool is described and references are made to current speculations on applications of the instrument in nanotechnology. A short bibliography on this topic is included. 27 refs., 7 figs.

  19. 67Ga lung scan

    International Nuclear Information System (INIS)

    Niden, A.H.; Mishkin, F.S.; Khurana, M.M.L.; Pick, R.

    1977-01-01

    Twenty-three patients with clinical signs of pulmonary embolic disease and lung infiltrates were studied to determine the value of gallium citrate 67 Ga lung scan in differentiating embolic from inflammatory lung disease. In 11 patients without angiographically proved embolism, only seven had corresponding ventilation-perfusion defects compatible with inflammatory disease. In seven of these 11 patients, the 67 Ga concentration indicated inflammatory disease. In the 12 patients with angiographically proved embolic disease, six had corresponding ventilation-perfusion defects compatible with inflammatory disease. None had an accumulation of 67 Ga in the area of pulmonary infiltrate. Thus, ventilation-perfusion lung scans are of limited value when lung infiltrates are present. In contrast, the accumulation of 67 Ga in the lung indicates an inflammatory process. Gallium imaging can help select those patients with lung infiltrates who need angiography

  20. Horizon Scanning for Pharmaceuticals

    DEFF Research Database (Denmark)

    Lepage-Nefkens, Isabelle; Douw, Karla; Mantjes, GertJan

    for a joint horizon scanning system (HSS).  We propose to create a central “horizon scanning unit” to perform the joint HS activities (a newly established unit, an existing HS unit, or a third party commissioned and financed by the collaborating countries). The unit will be responsible for the identification...... and filtration of new and emerging pharmaceutical products. It will maintain and update the HS database, organise company pipeline meetings, and disseminate the HSS’s outputs.  The HS unit works closely together with the designated national HS experts in each collaborating country. The national HS experts...... will collect country-specific information, liaise between the central HS unit and country-specific clinical and other experts, coordinate the national prioritization process (to select products for early assessment), and communicate the output of the HSS to national decision makers.  The outputs of the joint...

  1. [Regularity of Clinical Application of Lianquan (CV 23) in Chinese Ancient Times According to Literature of Traditional Chinese Medicine].

    Science.gov (United States)

    Deng, Mei-Jun; Liu, Chun-Yan; Xie, Yu; Zhu, Jie-Bin; Xu, Zhen-Hua

    2018-03-25

    To summarize the regularity of application of Lianquan (CV 23) in clinical practice in Chinese ancient times through analysis of ancient traditional Chinese medical (TCM) literature. A total of 60 books involving CV 23 from the 1 156 ancient TCM books listed in the fifth edition of Encyclopedia of Traditional Chinese Medicine were collected by using CV 23 as the main keyword and "Sheben" "Benchi", and "Jieben" (the other names of CV 23 in TCM)as the supplementary keywords and analyzed systematically. A database was then constructed from the collected data, including the related types of disorders or symptoms, acupoint recipes, and methods of needling and moxibustion, contraindications, etc. A total of 196 articles related to the application of CV 23 from 60 ancient classical books were collected in accordance with the inclusive criteria. Among them, 155 articles are referred to the indications of CV 23, 35 to types of disorders such as asthma, cough, tongue swelling with difficulty in speaking, protracted tongue, acute contraction of tongue root, vomiting, spasm syndrome, stroke, aphtha, problems of mouth and teeth, throat problems, etc. of the internal medicine, surgery, pediatrics, and five-sense organs; 64 items are referred to the application of single CV 23, 91 to CV 23-included recipes containing 111 adjunct acupoints, and 78 to stimulation of CV 23 with acupuncture needle, moxibustion, pricking blood, and fire needle. Moreover, of the 111 adjunct acupoints, the most commonly used are Shaoshang (LU 11), Tiantu (CV 22), Hegu (LI 4), Yuye (EX-HN 13), Zhongchong (PC 9), etc. Lianquan (CV 23) is mainly used for glossopharyngeal problems chiefly by syndrome-meridian differentiation. The supplement of complementary acupoints or five-shu points in combination with CV 23 has a synergistic effect. Moxibustion (3 moxa- cones in general) is often employed, and the needling depth is usually about 7.5 mm. The common contraindication of CV 23 is severe tongue swelling.

  2. Multichannel scanning spectrophotometer

    International Nuclear Information System (INIS)

    Lagutin, A.F.

    1979-01-01

    A spectrophotometer designed in the Crimea astrophysical observatory is described. The spectrophotometer is intended for the installation at the telescope to measure energy distribution in the star spectra in the 3100-8550 A range. The device is made according to the scheme with a fixed diffraction lattice. The choice of the optical kinematic scheme is explained. The main design elements are shown. Some singularities of the scanning drive kinematics are considered. The device performance is given

  3. Scanning drop sensor

    Energy Technology Data Exchange (ETDEWEB)

    Jin, Jian; Xiang, Chengxiang; Gregoire, John

    2017-05-09

    Electrochemical experiments are performed on a collection of samples by suspending a drop of electrolyte solution between an electrochemical experiment probe and one of the samples that serves as a test sample. During the electrochemical experiment, the electrolyte solution is added to the drop and an output solution is removed from the drop. The probe and collection of samples can be moved relative to one another so the probe can be scanned across the samples.

  4. Scanning drop sensor

    Energy Technology Data Exchange (ETDEWEB)

    Jin, Jian; Xiang, Chengxiang; Gregoire, John M.; Shinde, Aniketa A.; Guevarra, Dan W.; Jones, Ryan J.; Marcin, Martin R.; Mitrovic, Slobodan

    2017-05-09

    Electrochemical or electrochemical and photochemical experiments are performed on a collection of samples by suspending a drop of electrolyte solution between an electrochemical experiment probe and one of the samples that serves as a test sample. During the electrochemical experiment, the electrolyte solution is added to the drop and an output solution is removed from the drop. The probe and collection of samples can be moved relative to one another so the probe can be scanned across the samples.

  5. IMEF gamma scanning system

    Energy Technology Data Exchange (ETDEWEB)

    Baek, Sang Yeol; Park, Dae Kyu; Ahn, Sang Bok; Ju, Yong Sun; Jeon, Yong Bum

    1997-06-01

    The gamma scanning system which is installed in IMEF is the equipment obtaining the gamma ray spectrum from irradiated fuels. This equipment could afford the useful data relating spent fuels like as burn-up measurements. We describe the specifications of the equipment and its accessories, and also described its operation procedure so that an operator can use this report as the operation procedure. (author). 1 tab., 11 figs., 11 refs.

  6. IMEF gamma scanning system

    International Nuclear Information System (INIS)

    Baek, Sang Yeol; Park, Dae Kyu; Ahn, Sang Bok; Ju, Yong Sun; Jeon, Yong Bum.

    1997-06-01

    The gamma scanning system which is installed in IMEF is the equipment obtaining the gamma ray spectrum from irradiated fuels. This equipment could afford the useful data relating spent fuels like as burn-up measurements. We describe the specifications of the equipment and its accessories, and also described its operation procedure so that an operator can use this report as the operation procedure. (author). 1 tab., 11 figs., 11 refs

  7. Scanning unit for collectrons

    International Nuclear Information System (INIS)

    Plaige, Yves.

    1976-01-01

    This invention concerns a measurement scanning assembly for collectron type detectors. It is used in measuring the neutron flux in nuclear reactors. As the number of these detectors in a reactor can be very great, they are not usually all connected permanently to the measuring facility but rather in turn by means of a scanning device which carries out, as it were, multiplexing between all the collectrons and the input of a single measuring system. The object of the invention is a scanning assembly which is of relative simplicity through an original organisation. Specifically, according to this organisation, the collectrons outputs are grouped together in bunches, each of these bunches being processed by a multiplexing sub-assembly belonging to a first stage, the different outputs of these multiplexing subassemblies of this first stage being grouped together yet again in bunches processed by multiplexors forming a new stage and so forth. Further, this structure is specially adapted for use with collectrons by utilising a current amplifier at each multiplexing level so that from one end to the other of the multiplexing system, the commutations are carried out on currents and not on voltages [fr

  8. Forensic Scanning Electron Microscope

    Science.gov (United States)

    Keeley, R. H.

    1983-03-01

    The scanning electron microscope equipped with an x-ray spectrometer is a versatile instrument which has many uses in the investigation of crime and preparation of scientific evidence for the courts. Major applications include microscopy and analysis of very small fragments of paint, glass and other materials which may link an individual with a scene of crime, identification of firearms residues and examination of questioned documents. Although simultaneous observation and chemical analysis of the sample is the most important feature of the instrument, other modes of operation such as cathodoluminescence spectrometry, backscattered electron imaging and direct x-ray excitation are also exploited. Marks on two bullets or cartridge cases can be compared directly by sequential scanning with a single beam or electronic linkage of two instruments. Particles of primer residue deposited on the skin and clothing when a gun is fired can be collected on adhesive tape and identified by their morphology and elemental composition. It is also possible to differentiate between the primer residues of different types of ammunition. Bullets may be identified from the small fragments left behind as they pass through the body tissues. In the examination of questioned documents the scanning electron microscope is used to establish the order in which two intersecting ink lines were written and to detect traces of chemical markers added to the security inks on official documents.

  9. Conservação de tangerina cv. Clemenules utilizando diferentes recobrimentos = Conservation of Mandarins cv. Clemenules with different cuticles

    Directory of Open Access Journals (Sweden)

    Rosa de Oliveira Treptow

    2007-01-01

    Full Text Available O objetivo deste trabalho foi verificar os efeitos de diferentes recobrimentos e períodos de armazenamento na conservação de tangerinas Clemenules. Após a colheita, as frutas foram submetidas ao pré-resfriamento por 12 horas a 5ºC e em seguida, aos seguintes tratamentos: T1 testemunha; T2 filme de polietileno microperfurado; T3 filme de polietileno não perfurado; T4 cera de carnaúba a 50%, diluída em água; T5 cera de carnaúba a 100% (não diluída. As tangerinas foram armazenadas por 20, 40 e 60 dias em temperatura de 5ºC e UR de 90-95%, depois foram mantidas em temperatura de 15±1ºC e UR de 75-80%, durante quatro dias simulando a comercialização. Na colheita e após cada período de armazenamento, seguido de simulação decomercialização, foram avaliadas as variáveis: perda de massa; cor; sólidos solúveis (SS; acidez titulável (AT; relação SS/AT; podridões, distúrbios fisiológicos e características sensoriais. Amodificação da atmosfera reduziu a perda de massa, a incidência de distúrbios e podridões de tangerinas Clemenules durante o armazenamento. As frutas acondicionadas em filme de polietilenosem perfuração ou aquelas revestidas com cera sem diluição apresentaram sabor estranho e menor qualidade geral. Tangerinas ‘Clemenules’ acondicionadas em filme de polietileno microperfurado ecera diluída em 50% de água podem ser armazenadas durante 60 dias a 5ºC e comercializadas durante quatro dias a 15±1ºC sem comprometer a qualidade sensorial.The aim of this work was to evaluate the effects of different cuticles and storage periods on the conservation of mandarins cv. Clemenules. After harvest the fruits were kept at 5ºC during 12 hours. Then, they were submitted to the following treatments: T1 control; T2 micro perforated polyethylene bag; T3 non-perforated polyethylene bag; T4 carnauba wax at 50% in water; T5 carnauba wax at 100% (without dilution. The mandarins were stored for 20, 40 and 60 days at 5

  10. Estimation of key physical properties for LaCl{sub 3} in molten eutectic LiCl–KCl by fitting cyclic voltammetry data to a BET-based electrode reaction kinetics model

    Energy Technology Data Exchange (ETDEWEB)

    Samin, Adib [Nuclear Engineering Program, Department of Mechanical and Aerospace Engineering, The Ohio State University, 201 W 19th Avenue, Columbus, OH 43210 (United States); Wang, Zhonghang [Nuclear Engineering Program, Department of Mechanical and Aerospace Engineering, Metallurgical Engineering Department, University of Utah, Salt Lake City, UT 84112 (United States); Nuclear Engineering Program, Department of Mechanical and Aerospace Engineering, National Engineering Laboratory for Hydrometallurgical Cleaner Production Technology, Institute of Process Engineering, Chinese Academy of Sciences, Beijing 100190 (China); Lahti, Erik [Nuclear Engineering Program, Department of Mechanical and Aerospace Engineering, The Ohio State University, 201 W 19th Avenue, Columbus, OH 43210 (United States); Simpson, Michael [Nuclear Engineering Program, Department of Mechanical and Aerospace Engineering, Metallurgical Engineering Department, University of Utah, Salt Lake City, UT 84112 (United States); Zhang, Jinsuo, E-mail: zhang.3558@osu.edu [Nuclear Engineering Program, Department of Mechanical and Aerospace Engineering, The Ohio State University, 201 W 19th Avenue, Columbus, OH 43210 (United States)

    2016-07-15

    Understanding the electrochemical properties of rare earth elements is important for developing efficient techniques for separating rare earth elements from actinides recovered during the electrodeposition process. In this study the cyclic voltammetry for lanthanum in molten LiClKCl eutectic was recorded at 773 K for different scan rates and different bulk concentrations. A model accounting for mass transport, kinetics and adsorption was applied to analyze the experimental data via performing a nonlinear least squares fit. The results of the simulation are compared against the results of a conventional analysis of the cyclic voltammograms and against the existing literature. At the scan rates used, the reduction/oxidation process is quasi-reversible. The values of diffusivities derived from simulation were larger than the ones derived commonly using equations for diffusion-limited processes. However, those equations were derived based on an assumption of reversibility. This simulation-based approach may provide a more accurate option for analyzing systems that do not exhibit reversibility.

  11. Estimation of key physical properties for LaCl_3 in molten eutectic LiCl–KCl by fitting cyclic voltammetry data to a BET-based electrode reaction kinetics model

    International Nuclear Information System (INIS)

    Samin, Adib; Wang, Zhonghang; Lahti, Erik; Simpson, Michael; Zhang, Jinsuo

    2016-01-01

    Understanding the electrochemical properties of rare earth elements is important for developing efficient techniques for separating rare earth elements from actinides recovered during the electrodeposition process. In this study the cyclic voltammetry for lanthanum in molten LiClKCl eutectic was recorded at 773 K for different scan rates and different bulk concentrations. A model accounting for mass transport, kinetics and adsorption was applied to analyze the experimental data via performing a nonlinear least squares fit. The results of the simulation are compared against the results of a conventional analysis of the cyclic voltammograms and against the existing literature. At the scan rates used, the reduction/oxidation process is quasi-reversible. The values of diffusivities derived from simulation were larger than the ones derived commonly using equations for diffusion-limited processes. However, those equations were derived based on an assumption of reversibility. This simulation-based approach may provide a more accurate option for analyzing systems that do not exhibit reversibility.

  12. Produtividade e valor nutritivo da Brachiaria brizantha cv. Marandu em um sistema silvipastoril Productivity and nutritional value of Brachiaria brizantha cv. Marandu in a silvopastoral system

    Directory of Open Access Journals (Sweden)

    L.F. Sousa

    2007-08-01

    Full Text Available O experimento foi realizado em sistema silvipastoril (Ssp localizado no bioma de Cerrado, no município de Lagoa Santa, Minas Gerais, no ano agrícola de 2004-2005. Avaliou-se a influência do Ssp composto pela arbórea bolsa-de-pastor (Zeyheria tuberculosa sobre os parâmetros produção, atributos morfogênicos, composição bromatológica e valor nutritivo da gramínea Brachiaria brizantha cv. Marandu, e os efeitos sobre as condições microclimáticas. O delineamento experimental foi em blocos ao acaso, com cinco blocos (épocas de corte, dois tratamentos (T1 - B. brizantha cv. Marandu sombreada com a Z. tuberculosa e T2 - B. brizantha cv. Marandu, a pleno sol e três repetições (parcelas. O sombreamento proporcionado pela Z. tuberculosa, apesar de reduzir a produção de matéria seca (MS da gramínea, favoreceu o aumento do teor de proteina bruta (PB e não alterou a produção de PB/ha e nem afetou a concentração de FDN. Os teores de FDA foram mais altos que os encontrados a pleno sol, o que provavelmente resultou em menor degradabilidade in vitro da MS e da matéria orgânica, não alterando a degradabilidade efetiva.The experiment was carried out in a Silvopastoral system (Sps located in Brazilian Savannah, Lagoa Santa county, Minas Gerais State, during the agricultural year of 2004-2005. It was studied the influence of Sps formed by "Bolsa de Pastor" (Zeyheria tuberculosa on the production, morphogenic attributes, bromatological composition and nutritional value of the graminaceous Brachiaria brizantha cv. Marandu as well as on the microclimatic aspects. The Sps was established in 1982, in a red-yellow latossol by the natural regeneration process. The experiment was based on a randomized block design, with 5 blocks (cutting times, 2 treatments (T1 - B. brizantha cv. Marandu shaded by Z. tuberculosa and T2 - B. brizantha cv. Marandu at open sky and three repetitions (plots. Although the DM production of the graminaceous in the Sps

  13. FORMULASI STRATEGI PENINGKATAN PRODUKSI DOMBA CV MITRA TANI FARM, CIAMPEA, BOGOR

    Directory of Open Access Journals (Sweden)

    Amalia Sholehana

    2014-04-01

    Full Text Available ABSTRACTThis research was conducted to formulate to increase the sheep production at CV Mitra Tani Farm (CV MT Farm, Ciampea, Bogor. The research was conducted using descriptive analysis by analyzing the problem experienced by CV. MitraTani Farm. Primary data and secondary data were gathered at this research. The research was also conducted using several analytical methods such as value chain mapping, internal factor evaluation (IFE and external factor evaluation (EFE matrix, SWOT and quantitative strategic planning matrix (QSPM. Based on the value chain analysis, the current production of sheep at CV MT farm is highly depending on the supply from its partners and internal farmers. According to the IFE and EFE results, the differences of each weighted values were respectively 2,120 and 0,686 so the position of the company in the SWOT matrix was situated at Quadrant I. Therefore the company needs to use a growth strategy. The QSPM sequenced the strategy priority as follow (1 increasing the number of lambs, (2 developing the management, (3 strengthening the capital and ownership, (4 improving the quality through technology. The result of the gross profit margin calculation, if the sheep‘s selling is increased up to 1000 sheep per month then the possible annual profit that can be earned by CV MT farm is 40,34% of the total production.Keywords: MT Farm, sheep production, strategies, SWOT, QSPM, gross profit marginABSTRAKPenelitian ini dilakukan untuk memformulasikan strategi peningkatan produksi domba di CV Mitra Tani Farm (CV MT Farm, Ciampea, Bogor. Pendekatan penelitian yang diterapkan adalah analisis deskriptif yang dilakukan dengan mempelajari permasalahan dari objek yang diteliti. Data yang dikumpulkan dalam penelitian ini adalah data primer dan data sekunder. Penelitian dilakukan menggunakan alat analisis berupa pemetaan rantai nilai,  matriks IFE (Internal Factor Evaluation dan EFE (External Factor Evaluation, SWOT, dan QSPM (Quantitative

  14. SnO2/CNT nanocomposite supercapacitors fabricated using scanning atmospheric-pressure plasma jets

    Science.gov (United States)

    Xu, Chang-Han; Chiu, Yi-Fan; Yeh, Po-Wei; Chen, Jian-Zhang

    2016-08-01

    SnO2/CNT electrodes for supercapacitors are fabricated by first screen-printing pastes containing SnO2 nanoparticles and CNTs on carbon cloth, following which nitrogen atmospheric pressure plasma jet (APPJ) sintering is performed at various APPJ scan rates. The APPJ scan rates change the time intervals for which the reactive plasma species and the heat of the nitrogen APPJs influence the designated sintering spot on the carbon cloth, resulting in APPJ-sintered SnO2/CNT nanocomposites with different properties. The water contact angle decreases with the APPJ scan rate. The improved wettability can facilitate the penetration of the electrolyte into the nanopores of the SnO2/CNT nanocomposites, thereby improving the charge storage and specific capacitance of the supercapacitors. Among the three tested APPJ scan rates, 1.5, 3, and 6 mm s-1, the SnO2/CNT supercapacitor sintered by APPJ under the lowest APPJ scan rate of 1.5 mm s-1 shows the best specific capacitance of ˜90 F g-1 as evaluated by cyclic voltammetry under a potential scan rate of 2 mV s-1. A high APPJ scan rate may result in low degree of materials activation and sintering, leading to poorer performance of SnO2/CNT supercapacitors. The results suggest the feasibility of an APPJ roll-to-roll process for the fabrication of SnO2/CNT nanocomposite supercapacitors.

  15. CERES BiDirectional Scans (BDS) data in HDF (CER_BDS_TRMM-PFM_Edition1)

    Science.gov (United States)

    Wielicki, Bruce A. (Principal Investigator)

    Each BiDirectional Scans (BDS) data product contains twenty-four hours of Level-1b data for each CERES scanner instrument mounted on each spacecraft. The BDS includes samples taken in normal and short Earth scan elevation profiles in both fixed and rotating azimuth scan modes (including space, internal calibration, and solar calibration views). The BDS contains Level-0 raw (unconverted) science and instrument data as well as the geolocated converted science and instrument data. The BDS contains additional data not found in the Level-0 input file, including converted satellite position and velocity data, celestial data, converted digital status data, and parameters used in the radiance count conversion equations. The following CERES BDS data sets are currently available: CER_BDS_TRMM-PFM_Edition1 CER_BDS_Terra-FM1_Edition1 CER_BDS_Terra-FM2_Edition1 CER_BDS_Terra-FM1_Edition2 CER_BDS_Terra-FM2_Edition2 CER_BDS_Aqua-FM3_Edition1 CER_BDS_Aqua-FM4_Edition1 CER_BDS_Aqua-FM3_Edition2 CER_BDS_Aqua-FM4_Edition2 CER_BDS_Aqua-FM3_Edition1-CV CER_BDS_Aqua-FM4_Edition1-CV CER_BDS_Terra-FM1_Edition1-CV CER_BDS_Terra-FM2_Edition1-CV. [Location=GLOBAL] [Temporal_Coverage: Start_Date=1997-12-27; Stop_Date=2000-12-31] [Spatial_Coverage: Southernmost_Latitude=-90; Northernmost_Latitude=90; Westernmost_Longitude=-180; Easternmost_Longitude=180] [Data_Resolution: Temporal_Resolution=1 day; Temporal_Resolution_Range=Daily - < Weekly].

  16. Determination of Ascorbic Acid Content of Some Fruit Juices and Wine by Voltammetry Performed at Pt and Carbon Paste Electrodes

    Directory of Open Access Journals (Sweden)

    Aurel Pisoschi

    2011-02-01

    Full Text Available A method was developed for assessing ascorbic acid concentration in fruit juices and wine by differential pulse voltammetry. The oxidation peak for ascorbic acid occurs at about 530 mV (versus SCE on a Pt strip working electrode and at about 470 mV on a carbon paste working electrode. The influence of the operational parameters like the pulse amplitude and the pulse period on the analytical signal was investigated. The obtained calibration graph shows a linear dependence between the peak height and ascorbic acid concentration within the range 0.31-20 mM with a Pt working electrode, and within the range 0.07-20 mM with a carbon paste working electrode. The equation of the calibration graph was y = 21.839x + 35.726, r2 = 0.9940, when a Pt strip electrode was used (where y represents the value of the current intensity measured for the peak height, expressed as µA and x the analyte concentration, as mM. R.S.D. = 2.09%, n = 10, Cascorbic acid = 2.5 mM. The equation of the calibration graph was y = 3.4429x + 5.7334, r2 = 0.9971, when a carbon paste electrode was used (where y represents the value of intensity measured for the peak height, expressed as µA and x the analyte concentration, as mM. R.S.D. = 2.35%, n = 10, Cascorbic acid = 2.5 mM. The developed method was applied to ascorbic acid assessment in fruit juices and wine. The ascorbic acid content determined ranged between 6.83 mg/100 mL juice for soft drinks (Fanta Madness and 54.74 mg/100 mL for citrus (lemon juices obtained by squeezing fruit. Different ascorbic acid concentrations (from standard solutions were added to the analysed samples, the degree of recovery being comprised between 94.74 and 104.97%. The results of ascorbic acid assessment by differential pulse voltammetry were compared with those obtained by cyclic voltammetry. The results obtained by the two methods were in good agreement.

  17. Analytical solutions of the planar cyclic voltammetry process for two soluble species with equal diffusivities and fast electron transfer using the method of eigenfunction expansions

    Energy Technology Data Exchange (ETDEWEB)

    Samin, Adib; Lahti, Erik; Zhang, Jinsuo, E-mail: zhang.3558@osu.edu [Nuclear Engineering Program, Department of Mechanical and Aerospace Engineering, The Ohio State University, 201 W 19" t" h Avenue, Columbus, Ohio 43210 (United States)

    2015-08-15

    Cyclic voltammetry is a powerful tool that is used for characterizing electrochemical processes. Models of cyclic voltammetry take into account the mass transport of species and the kinetics at the electrode surface. Analytical solutions of these models are not well-known due to the complexity of the boundary conditions. In this study we present closed form analytical solutions of the planar voltammetry model for two soluble species with fast electron transfer and equal diffusivities using the eigenfunction expansion method. Our solution methodology does not incorporate Laplace transforms and yields good agreement with the numerical solution. This solution method can be extended to cases that are more general and may be useful for benchmarking purposes.

  18. Analytical solutions of the planar cyclic voltammetry process for two soluble species with equal diffusivities and fast electron transfer using the method of eigenfunction expansions

    International Nuclear Information System (INIS)

    th Avenue, Columbus, Ohio 43210 (United States))" data-affiliation=" (Nuclear Engineering Program, Department of Mechanical and Aerospace Engineering, The Ohio State University, 201 W 19th Avenue, Columbus, Ohio 43210 (United States))" >Samin, Adib; th Avenue, Columbus, Ohio 43210 (United States))" data-affiliation=" (Nuclear Engineering Program, Department of Mechanical and Aerospace Engineering, The Ohio State University, 201 W 19th Avenue, Columbus, Ohio 43210 (United States))" >Lahti, Erik; th Avenue, Columbus, Ohio 43210 (United States))" data-affiliation=" (Nuclear Engineering Program, Department of Mechanical and Aerospace Engineering, The Ohio State University, 201 W 19th Avenue, Columbus, Ohio 43210 (United States))" >Zhang, Jinsuo

    2015-01-01

    Cyclic voltammetry is a powerful tool that is used for characterizing electrochemical processes. Models of cyclic voltammetry take into account the mass transport of species and the kinetics at the electrode surface. Analytical solutions of these models are not well-known due to the complexity of the boundary conditions. In this study we present closed form analytical solutions of the planar voltammetry model for two soluble species with fast electron transfer and equal diffusivities using the eigenfunction expansion method. Our solution methodology does not incorporate Laplace transforms and yields good agreement with the numerical solution. This solution method can be extended to cases that are more general and may be useful for benchmarking purposes

  19. 3CV+2: modelo de calidad para la construcción de la vivienda 3CV+2: quality model for dwelling construction

    Directory of Open Access Journals (Sweden)

    Salvador García Rodríguez

    2008-08-01

    Full Text Available Este artículo presenta el modelo y los resultados que, desde Junio de 2005, se han alcanzado en el desarrollo del Programa Nacional de Certificación de los Procesos Constructivos de la Vivienda en base al Modelo 3cv+2. El programa se ha desarrollado con base a un convenio entre el Tecnológico de Monterrey y la Cámara Nacional de la Industria de Desarrollo y Promoción de Vivienda. Actualmente se encuentran voluntariamente en el programa 52 empresas inmobiliarias de diferentes estados de la República Mexicana. El modelo de calidad 3cv+2 es una metodología que busca establecer en los niveles operativos de la construcción criterios que permitan reducir la variabilidad del proceso de construcción, y además permita de manera sistemática, y en un proceso de mejora continua, evaluar el desempeño de calidad en proyectos de construcción de vivienda. El modelo 3cv+2 define en su nombre el alcance del mismo, 3 criterios de calidad para la vivienda (insumos, proceso y producto, apoyado por 2 auditorías (+2, la auditoría interna de la propia empresa, mas la auditoría externa hecha por el Tecnológico de Monterrey. El modelo 3cv+2 busca garantizar que los insumos utilizados en la construcción de las viviendas sean de calidad superior, y que los procesos de ejecución posean características de calidad, productividad, eficiencia, racionalización, y estandarización; de tal manera que insumos y productos sean de alto valor agregado, y garanticen la calidad especificada en las etapas parciales y en la vivienda terminada.This paper presents the model and the results that have been achieved during the development of the National Quality Certification Program based on the model 3cv +2 from June 2005. This program has been developed based on an agreement between the Monterrey Tech and the National Chamber of Housing Industry. Nowadays, the program has 52 voluntary real estate companies from different states of Mexico. The 3cv+2 quality model is a

  20. Automatic Ultrasound Scanning

    DEFF Research Database (Denmark)

    Moshavegh, Ramin

    on the user adjustments on the scanner interface to optimize the scan settings. This explains the huge interest in the subject of this PhD project entitled “AUTOMATIC ULTRASOUND SCANNING”. The key goals of the project have been to develop automated techniques to minimize the unnecessary settings...... on the scanners, and to improve the computer-aided diagnosis (CAD) in ultrasound by introducing new quantitative measures. Thus, four major issues concerning automation of the medical ultrasound are addressed in this PhD project. They touch upon gain adjustments in ultrasound, automatic synthetic aperture image...

  1. Radiographic scanning agent

    International Nuclear Information System (INIS)

    Bevan, J.A.

    1983-01-01

    This invention relates to radiodiagnostic agents and more particularly to a composition and method for preparing a highly effective technetium-99m-based bone scanning agent. One deficiency of x-ray examination is the inability of that technique to detect skeletal metastases in their incipient stages. It has been discovered that the methanehydroxydiphosphonate bone mineral-seeking agent is unique in that it provides the dual benefits of sharp radiographic imaging and excellent lesion detection when used with technetium-99m. This agent can also be used with technetium-99m for detecting soft tissue calcification in the manner of the inorganic phosphate radiodiagnostic agents

  2. Spinal CT scan, 1

    International Nuclear Information System (INIS)

    Nakagawa, Hiroshi

    1982-01-01

    Methods of CT of the cervical and thoracic spines were explained, and normal CT pictures of them were described. Spinal CT was evaluated in comparison with other methods in various spinal diseases. Plain CT revealed stenosis due to spondylosis or ossification of posterior longitudinal ligament and hernia of intervertebral disc. CT took an important role in the diagnosis of spinal cord tumors with calcification and destruction of the bone. CT scan in combination with other methods was also useful for the diagnosis of spinal injuries, congenital anomalies and infections. (Ueda, J.)

  3. Scanning Color Laser Microscope

    Science.gov (United States)

    Awamura, D.; Ode, T.; Yonezawa, M.

    1988-01-01

    A confocal color laser microscope which utilizes a three color laser light source (Red: He-Ne, Green: Ar, Blue: Ar) has been developed and is finding useful applications in the semiconductor field. The color laser microscope, when compared to a conventional microscope, offers superior color separation, higher resolution, and sharper contrast. Recently some new functions including a Focus Scan Memory, a Surface Profile Measurement System, a Critical Dimension Measurement system (CD) and an Optical Beam Induced Current Function (OBIC) have been developed for the color laser microscope. This paper will discuss these new features.

  4. Scanning apparatus and method

    International Nuclear Information System (INIS)

    Brunnett, C.J.

    1980-01-01

    A novel method is described for processing the analogue signals from the photomultiplier tubes in a tomographic X-ray scanner. The system produces a series of pulses whose instantaneous frequency depends on the detected intensity of the X-radiation. A timer unit is used to determine the segment scan intervals and also to deduce the average radiation intensity detected during this interval. The overall system is claimed to possess the advantageous properties of low time delay, wide bandwidth and relative low cost. (U.K.)

  5. Studies of frequency dependent C-V characteristics of neutron irradiated p+-n silicon detectors

    International Nuclear Information System (INIS)

    Li, Zheng; Kraner, H.W.

    1990-10-01

    Frequency-dependent capacitance-voltage fluence (C-V) characteristics of neutron irradiated high resistivity silicon p + -n detectors have been observed up to a fluence of 8.0 x 10 12 n/cm 2 . It has been found that frequency dependence of the deviation of the C-V characteristic (from its normal V -1/2 dependence), is strongly dependent on the ratio of the defect density and the effective doping density N t /N' d . As the defect density approaches the effective dopant density, or N t /N' d → 1, the junction capacitance eventually assumes the value of the detector geometry capacitance at high frequencies (f ≤ 10 5 Hz), independent of voltage. A two-trap-level model using the concept of quasi-fermi levels has been developed, which predicts both the effects of C-V frequency dependence and dopant compensation observed in this study

  6. Immobilization of enzymatic extracts of Portulaca oleracea cv. roots for oxidizing aqueous bisphenol A.

    Science.gov (United States)

    Matsushima, Kazuki; Kaneda, Hirokazu; Harada, Kazuo; Matsuura, Hideyuki; Hirata, Kazumasa

    2015-05-01

    Water pollution from the release of industrial wastewater is a serious problem for almost every industry. Enzymes from portulaca, Portulaca oleracea cv., have been investigated for their ability to degrade bisphenol A (BPA), one of the well-known estrogenic pollutants. Enzymatic crude extracts from P. oleracea cv. roots were immobilized on aminopropyl-modified glass beads. They maintained BPA metabolic activity over a broad range of pH values and temperatures. The immobilized enzyme was reusable with more than 50 % of its initial activity retained after 12 batch reactions and no loss of activity after storage for 1 month at -30 °C. Thus, the immobilization of extracts from P. oleracea cv. roots is a useful method for removing BPA from industrial wastewater.

  7. Light equation in eclipsing binary CV Boo: third body candidate in elliptical orbit

    Science.gov (United States)

    Bogomazov, A. I.; Kozyreva, V. S.; Satovskii, B. L.; Krushevska, V. N.; Kuznyetsova, Y. G.; Ehgamberdiev, S. A.; Karimov, R. G.; Khalikova, A. V.; Ibrahimov, M. A.; Irsmambetova, T. R.; Tutukov, A. V.

    2016-12-01

    A short period eclipsing binary star CV Boo is tested for the possible existence of additional bodies in the system with a help of the light equation method. We use data on the moments of minima from the literature as well as from our observations during 2014 May-July. A variation of the CV Boo's orbital period is found with a period of {≈}75 d. This variation can be explained by the influence of a third star with a mass of {≈}0.4 M_{⊙} in an eccentric orbit with e≈0.9. A possibility that the orbital period changes on long time scales is discussed. The suggested tertiary companion is near the chaotic zone around the central binary, so CV Boo represents an interesting example to test its dynamical evolution. A list of 14 minima moments of the binary obtained from our observations is presented.

  8. Segmentation of kidney using C-V model and anatomy priors

    Science.gov (United States)

    Lu, Jinghua; Chen, Jie; Zhang, Juan; Yang, Wenjia

    2007-12-01

    This paper presents an approach for kidney segmentation on abdominal CT images as the first step of a virtual reality surgery system. Segmentation for medical images is often challenging because of the objects' complicated anatomical structures, various gray levels, and unclear edges. A coarse to fine approach has been applied in the kidney segmentation using Chan-Vese model (C-V model) and anatomy prior knowledge. In pre-processing stage, the candidate kidney regions are located. Then C-V model formulated by level set method is applied in these smaller ROI, which can reduce the calculation complexity to a certain extent. At last, after some mathematical morphology procedures, the specified kidney structures have been extracted interactively with prior knowledge. The satisfying results on abdominal CT series show that the proposed approach keeps all the advantages of C-V model and overcome its disadvantages.

  9. Voltammetry of Vitamin B12 on a thin self-assembled monolayer modified electrode

    International Nuclear Information System (INIS)

    Yang Nianjun; Wan Qijin; Wang, Xiaoxia

    2005-01-01

    Vitamin B 12 showed three reduction waves at a thin self-assembled monolayer of mercaptoacetic acid modified gold electrode at 0.21, 0.16, -0.41 V in a 0.01 mol l -1 HCl solution at a scan rate of 100 mV s -1 . The overall electrode reaction followed an ECE mechanism, leading to a total two-electron exchange. The predominant Co(III) form was reduced directly at 0.21 V by a one-electron transfer accomplished by CN - cleavage into the cyanocob(II)alamin. The latter species then equilibrated with the base-off B 12r , which was immediately reduced into B 12s at 0.16 V. The wave at -0.41 V might be a catalytic hydrogen wave. The cathodic peak currents at 0.21 V were controlled by the diffusion of Vitamin B 12 . On the base of its diffusion behavior, the semi-derivate voltammetric method for the detection of Vitamin B 12 was presented. The semi-derivate voltammetric peak current of the wave at 0.21 V was linear with the content of Vitamin B 12 in the range of 4.0 x 10 -9 to 4.0 x 10 -5 mol l -1 . The detection limit was 1.0 x 10 -9 mol l -1 . The proposed method was applied successfully to determine the content of Vitamin B 12 in pharmaceutical preparations

  10. Isotopic coherence of refractory inclusions from CV and CK meteorites: Evidence from multiple isotope systems

    Science.gov (United States)

    Shollenberger, Quinn R.; Borg, Lars E.; Render, Jan; Ebert, Samuel; Bischoff, Addi; Russell, Sara S.; Brennecka, Gregory A.

    2018-05-01

    Calcium-aluminum-rich inclusions (CAIs) are the oldest dated materials in the Solar System and numerous previous studies have revealed nucleosynthetic anomalies relative to terrestrial rock standards in many isotopic systems. However, most of the isotopic data from CAIs has been limited to the Allende meteorite and a handful of other CV3 chondrites. To better constrain the isotopic composition of the CAI-forming region, we report the first Sr, Mo, Ba, Nd, and Sm isotopic compositions of two CAIs hosted in the CK3 desert meteorites NWA 4964 and NWA 6254 along with two CAIs from the CV3 desert meteorites NWA 6619 and NWA 6991. After consideration of neutron capture processes and the effects of hot-desert weathering, the Sr, Mo, Ba, Nd, and Sm stable isotopic compositions of the samples show clearly resolvable nucleosynthetic anomalies that are in agreement with previous results from Allende and other CV meteorites. The extent of neutron capture, as manifested by shifts in the observed 149Sm-150Sm isotopic composition of the CAIs is used to estimate the neutron fluence experienced by some of these samples and ranges from 8.40 × 1013 to 2.11 × 1015 n/cm2. Overall, regardless of CAI type or host meteorite, CAIs from CV and CK chondrites have similar nucleosynthetic anomalies within analytical uncertainty. We suggest the region that CV and CK CAIs formed was largely uniform with respect to Sr, Mo, Ba, Nd, and Sm isotopes when CAIs condensed and that CAIs hosted in CV and CK meteorites are derived from the same isotopic reservoir.

  11. Khatyrka, a new CV3 find from the Koryak Mountains, Eastern Russia

    Science.gov (United States)

    MacPherson, Glenn J.; Andronicos, Christopher L.; Bindi, Luca; Distler, Vadim V.; Eddy, Michael P.; Eiler, John M.; Guan, Yunbin; Hollister, Lincoln S.; Kostin, Alexander; Kryachko, Valery; Steinhardt, William M.; Yudovskaya, Marina; Steinhardt, Paul J.

    2013-08-01

    A new meteorite find, named Khatyrka, was recovered from eastern Siberia as a result of a search for naturally occurring quasicrystals. The meteorite occurs as clastic grains within postglacial clay-rich layers along the banks of a small stream in the Koryak Mountains, Chukotka Autonomous Okrug of far eastern Russia. Some of the grains are clearly chondritic and contain Type IA porphyritic olivine chondrules enclosed in matrices that have the characteristic platy olivine texture, matrix olivine composition, and mineralogy (olivine, pentlandite, nickel-rich iron-nickel metal, nepheline, and calcic pyroxene [diopside-hedenbergite solid solution]) of oxidized-subgroup CV3 chondrites. A few grains are fine-grained spinel-rich calcium-aluminum-rich inclusions with mineral oxygen isotopic compositions again typical of such objects in CV3 chondrites. The chondritic and CAI grains contain small fragments of metallic copper-aluminum-iron alloys that include the quasicrystalline phase icosahedrite. One grain is an achondritic intergrowth of Cu-Al metal alloys and forsteritic olivine ± diopsidic pyroxene, both of which have meteoritic (CV3-like) oxygen isotopic compositions. Finally, some grains consist almost entirely of metallic alloys of aluminum + copper ± iron. The Cu-Al-Fe metal alloys and the alloy-bearing achondrite clast are interpreted to be an accretionary component of what otherwise is a fairly normal CV3 (oxidized) chondrite. This association of CV3 chondritic grains with metallic copper-aluminum alloys makes Khatyrka a unique meteorite, perhaps best described as a complex CV3 (ox) breccia.

  12. Influence of anode material on the electrochemical oxidation of 2-naphthol Part 1. Cyclic voltammetry and potential step experiments

    Energy Technology Data Exchange (ETDEWEB)

    Panizza, M.; Cerisola, G

    2003-10-15

    The anodic oxidation of 2-naphthol has been studied by cyclic voltammetry and chronoamperometry, using a range of electrode materials such as Ti-Ru-Sn ternary oxide, lead dioxide and boron-doped diamond (BDD) anodes. The results show that polymeric films, which cause electrode fouling, are formed during oxidation in the potential region of supporting electrolyte stability. IR spectroscopy verified the formation of this organic film. While the Ti-Ru-Sn ternary oxide surface cannot be reactivated, PbO{sub 2} and BDD can be restored to their initial activity by simple anodic treatment in the potential region of electrolyte decomposition. In fact, during the polarization in this region, complex oxidation reactions leading to the complete incineration of polymeric materials can take place on these electrodes due to electrogenerated hydroxyl radicals. Moreover, it was found that BDD deactivation was less pronounced and its reactivation was faster than that of the other electrodes.

  13. Influence of anode material on the electrochemical oxidation of 2-naphthol Part 1. Cyclic voltammetry and potential step experiments

    International Nuclear Information System (INIS)

    Panizza, M.; Cerisola, G.

    2003-01-01

    The anodic oxidation of 2-naphthol has been studied by cyclic voltammetry and chronoamperometry, using a range of electrode materials such as Ti-Ru-Sn ternary oxide, lead dioxide and boron-doped diamond (BDD) anodes. The results show that polymeric films, which cause electrode fouling, are formed during oxidation in the potential region of supporting electrolyte stability. IR spectroscopy verified the formation of this organic film. While the Ti-Ru-Sn ternary oxide surface cannot be reactivated, PbO 2 and BDD can be restored to their initial activity by simple anodic treatment in the potential region of electrolyte decomposition. In fact, during the polarization in this region, complex oxidation reactions leading to the complete incineration of polymeric materials can take place on these electrodes due to electrogenerated hydroxyl radicals. Moreover, it was found that BDD deactivation was less pronounced and its reactivation was faster than that of the other electrodes

  14. Study of antioxidant properties of a water-soluble Vitamin E derivative-tocopherol monoglucoside (TMG) by differential pulse voltammetry.

    Science.gov (United States)

    Korotkova, E I; Avramchik, O A; Kagiya, T V; Karbainov, Y A; Tcherdyntseva, N V

    2004-06-17

    Study of antioxidant properties of tocopherol monoglucoside (TMG), a water-soluble Vitamin E derivative, by differential pulse voltammetry has been carried out in this work. The pH influence on the antioxidant properties of TMG has been also investigated. It was observed that the antioxidant activity of TMG is greater at 6.90TMG and reactive oxygen species have been considered. Antioxidant activity of some standard antioxidants including Vitamin E was given for comparison. The results indicate that the TMG is an effective antioxidant in neutral solutions. The oxidation potential for TMG at pH 7.31 has been found (E=0.55+/-0.03V versus Ag|AgCl|KCl(sat) electrode). Finally the use of TMG for protection against oxidative stress has been recommended.

  15. Mineralogy and Petrography of MIL 090001, a Highly Altered CV Chondrite from the Reduced Sub-Group

    Science.gov (United States)

    Keller, Lindsay P.

    2011-01-01

    MIL 090001 is a large (greater than 6 kg) CV chondrite from the reduced subgroup (CV(sub red)) that was recovered during the 2009-2010 ANSMET field season [1]. The CV(sub red) subgroup meteorites retain primitive characteristics and have escaped the Na and Fe meta-somatism that affected the oxidized (CV(sub ox)) subgroups. MIL 090001 is, however, reported to be altered [1], and thus a major objective of this study is to characterize its mineralogy and petrography and the extent of the alteration.

  16. NEW SCANNING DEVICE FOR SCANNING TUNNELING MICROSCOPE APPLICATIONS

    NARCIS (Netherlands)

    SAWATZKY, GA; Koops, Karl Richard

    A small, single piezo XYZ translator has been developed. The device has been used as a scanner for a scanning tunneling microscope and has been tested successfully in air and in UHV. Its simple design results in a rigid and compact scanning unit which permits high scanning rates.

  17. Ultrafast scanning tunneling microscopy

    Energy Technology Data Exchange (ETDEWEB)

    Botkin, D.A. [California Univ., Berkeley, CA (United States). Dept. of Physics]|[Lawrence Berkeley Lab., CA (United States)

    1995-09-01

    I have developed an ultrafast scanning tunneling microscope (USTM) based on uniting stroboscopic methods of ultrafast optics and scanned probe microscopy to obtain nanometer spatial resolution and sub-picosecond temporal resolution. USTM increases the achievable time resolution of a STM by more than 6 orders of magnitude; this should enable exploration of mesoscopic and nanometer size systems on time scales corresponding to the period or decay of fundamental excitations. USTM consists of a photoconductive switch with subpicosecond response time in series with the tip of a STM. An optical pulse from a modelocked laser activates the switch to create a gate for the tunneling current, while a second laser pulse on the sample initiates a dynamic process which affects the tunneling current. By sending a large sequence of identical pulse pairs and measuring the average tunnel current as a function of the relative time delay between the pulses in each pair, one can map the time evolution of the surface process. USTM was used to measure the broadband response of the STM`s atomic size tunnel barrier in frequencies from tens to hundreds of GHz. The USTM signal amplitude decays linearly with the tunnel junction conductance, so the spatial resolution of the time-resolved signal is comparable to that of a conventional STM. Geometrical capacitance of the junction does not appear to play an important role in the measurement, but a capacitive effect intimately related to tunneling contributes to the measured signals and may limit the ultimate resolution of the USTM.

  18. Detoxification of microcystin-LR in water by Portulaca oleracea cv.

    Science.gov (United States)

    Isobe, Takatoshi; Okuhata, Hiroshi; Miyasaka, Hitoshi; Jeon, Bong-Seok; Park, Ho-Dong

    2014-03-01

    Microcystin-LR (0.02 μg/ml) in the hydroculture medium of Portulaca oleracea cv., became below the detection level (<0.0001 μg/ml) by HPLC analysis after 7 days. The toxicity of microcystin estimated with protein phosphatase inhibition assay, however, remained at 37% of the initial level, indicating that microcystin-LR was transformed by P. oleracea cv. into unknown compound(s) of lower toxicity. Copyright © 2013 The Society for Biotechnology, Japan. Published by Elsevier B.V. All rights reserved.

  19. Probing Electrode Heterogeneity Using Fourier-Transformed Alternating Current Voltammetry: Application to a Dual-Electrode Configuration.

    Science.gov (United States)

    Tan, Sze-Yin; Unwin, Patrick R; Macpherson, Julie V; Zhang, Jie; Bond, Alan M

    2017-03-07

    Quantitative studies of electron transfer processes at electrode/electrolyte interfaces, originally developed for homogeneous liquid mercury or metallic electrodes, are difficult to adapt to the spatially heterogeneous nanostructured electrode materials that are now commonly used in modern electrochemistry. In this study, the impact of surface heterogeneity on Fourier-transformed alternating current voltammetry (FTACV) has been investigated theoretically under the simplest possible conditions where no overlap of diffusion layers occurs and where numerical simulations based on a 1D diffusion model are sufficient to describe the mass transport problem. Experimental data that meet these requirements can be obtained with the aqueous [Ru(NH 3 ) 6 ] 3+/2+ redox process at a dual-electrode system comprised of electrically coupled but well-separated glassy carbon (GC) and boron-doped diamond (BDD) electrodes. Simulated and experimental FTACV data obtained with this electrode configuration, and where distinctly different heterogeneous charge transfer rate constants (k 0 values) apply at the individual GC and BDD electrode surfaces, are in excellent agreement. Principally, because of the far greater dependence of the AC current magnitude on k 0 , it is straightforward with the FTACV method to resolve electrochemical heterogeneities that are ∼1-2 orders of magnitude apart, as applies in the [Ru(NH 3 ) 6 ] 3+/2+ dual-electrode configuration experiments, without prior knowledge of the individual kinetic parameters (k 0 1 and k 0 2 ) or the electrode size ratio (θ 1 :θ 2 ). In direct current voltammetry, a difference in k 0 of >3 orders of magnitude is required to make this distinction.

  20. Simultaneous determination of lead, cadmium and zinc in Metro Manila air particulates by anodic stripping voltammetry

    International Nuclear Information System (INIS)

    Castaneda, Soledad S.

    1999-02-01

    Air particulate samples were collected from two monitoring stations in Metro Manila using a 'Gent' type dichotomous sampler for pollutant source apportionment studies. Samples were collected in two fractions: a fine fraction with aerodynamic diameter, d p p 3 : HCL: HF, 4: 1: 1) for at least 20 minutes with subsequent heating at lower power settings for a total of 20 minutes more, effectively decomposed the sample with complete recovery of the elements. The digests were evaporated to near dryness to eliminate the troublesome effect of HF and HNO 3 and to decrease acidity of the electrolytic solution to pH ≥ 2. At pH 2, the addition of at least 0.01 M KCl was needed to improve sensitivity. The formation of Zn-Cu intermetallic compounds which interfered in the accurate quantitation of zinc was eliminated by addition of gallium as a 'third' element. The amount of gallium needed varied from sample to sample and was affected by the pH of the solution. The DPASV parameters found to be optimum for the analysis of the air particulate samples are as follows: pulse amplitude, 50 mV; scan rate, 10 mV/sec; E dep , - 1.30 V; t dep , 2 min; and RDE rotation rate, 1500 rpm. Detection limits of 0.2 ppb for zinc, 0.6 ppb for lead, and 0.05 ppb for cadmium in the sample matrix were obtained. The standard addition method was found to be reliable for the quantitative determination of the analytes in the sample. All R 2 values obtained were > 0.9900 at 95% confidence level. Validation of the established analytical methodology by analyzing certified reference standards and performing parallel analysis by GF-AAS and flame AAS showed acceptable accuracy of the DPASV measurements. (Author)

  1. Ultrastructural changes and the distribution of arabinogalactan proteins during somatic embryogenesis of banana (Musa spp. AAA cv. 'Yueyoukang 1').

    Science.gov (United States)

    Pan, Xiao; Yang, Xiao; Lin, Guimei; Zou, Ru; Chen, Houbin; Samaj, Jozef; Xu, Chunxiang

    2011-08-01

    A better understanding of somatic embryogenesis in banana (Musa spp.) may provide a practical way to improve regeneration of banana plants. In this study, we applied scanning electron microscopy (SEM) and transmission electron microscopy (TEM) to visualize the ultrastructural changes during somatic embryogenesis of banana (Musa AAA cv. 'Yueyoukang 1'). We also used histological and immunohistochemical techniques with 16 monoclonal antibodies to study the spatial distribution and cellular/subcellular localization of different arabinogalactan protein (AGP) components of the cell wall during somatic embryogenesis. Histological study with periodic acid-Schiff staining documented diverse embryogenic stages from embryogenic cells (ECs) to the late embryos. SEM revealed a mesh-like structure on the surface of proembryos which represented an early structural marker of somatic embryogenesis. TEM showed that ECs were rich in juvenile mitochondria, endoplasmic reticulum and Golgi stacks. Cells in proembryos and early globular embryos resembled ECs, but they were more vacuolated, showed more regular nuclei and slightly more developed organelles. Immunocytochemical study revealed that the signal of most AGP epitopes was stronger in starch-rich cells when compared with typical ECs. The main AGP component in the extracellular matrix surface network of banana proembryos was the MAC204 epitope. Later, AGP immunolabelling patterns varied with the developmental stages of the embryos. These results about developmental regulation of AGP epitopes along with developmental changes in the ultrastructure of cells are providing new insights into the somatic embryogenesis of banana. Copyright © Physiologia Plantarum 2011.

  2. Scanning device for a spectrometer

    International Nuclear Information System (INIS)

    Ignat'ev, V.M.

    1982-01-01

    The invention belongs to scanning devices and is intended for spectrum scanning in spectral devices. The purpose of the invention is broadening of spectral scanning range. The device construction ensures the spectrum scanning range determined from revolution fractions to several revolutions of the monochromator drum head, any number of the drum head revolutions determined by integral number with addition of the drum revolution fractions with high degree of accuracy being possible

  3. Factors influencing bone scan quality

    International Nuclear Information System (INIS)

    Adams, F.G.; Shirley, A.W.

    1983-01-01

    A reliable subjective method of assessing bone scan quality is described. A large number of variables which theoretically could influence scan quality were submitted to regression and factor analysis. Obesity, age, sex and abnormality of scan were found to be significant but weak variables. (orig.)

  4. CT scans in encephalitis

    International Nuclear Information System (INIS)

    Imanishi, Masami; Morimoto, Tetsuya; Iida, Noriyuki; Hisanaga, Manabu; Kinugawa, Kazuhiko

    1980-01-01

    Generally, CT scans reveal a decrease in the volume of the ventricular system, sylvian fissures and cortical sulci in the acute stage of encephalitis, and softening of the cerebral lobes with dilatation of the lateral ventricles and subarachnoidian dilated spaces in the chronic stage. We encountered three cases of encephalitis: mumps (case 1), herpes simplex (case 2), and syphilis (case 3). In case 1, brain edema was seen in the acute stage and brain atrophy in the chronic stage. In case 2, necrosis of the temporal pole, which is pathognomonic in herpes simplex encephalitis, was recognized. And in case 3, multiple lesions whose CT appearance was enhanced by contrast materials were found scattered over the whole brain. These lesions were diagnosed as inflammatory granuloma by histological examination. (author)

  5. Scanning device for scintigraphy

    International Nuclear Information System (INIS)

    Casale, R.

    1975-01-01

    A device is described for the scintigraphic scanning according to a horizontal plane, comprising: (a) A support provided with two guides horizontally and longitudinally located, one of which is located in the upper part of the support, while the second guide is located in the lower part of the support; (b) A carriage, movable with respect to the support along the two guides, provided in its upper part, projecting above the support, with rolling means suitable to support and to cause to slide along its axis a support rod for the first detector, horizontally and transversely located, said carriage being further provided in its lower part with a recess with possible rolling means suitable to support and to cause to slide along its axis a second support rod for the second detector, said second rod being located parallel to the first rod and below it; (c) One or two support rods for the detectors, the first of said rods being supported above the support in a sliding way along its axis, by the rolling means located in the upper part of the carriage, and the second rod if present is supported slidingly along its axis by the possible rolling means contained in the suitable recess which is provided in the lower part of the carriage, and (d) A vertical shaft supported by said carriage on which is mounted a toothed wheel for each rod, each toothed wheel engaging a positive drive belt or the like, which is connected to each said rod so that rotation of the shaft determines the simultaneous displacement of the two rods along their axes; and single motor means for driving said shaft during a scanning operation. (U.S.)

  6. Scanning the periphery.

    Science.gov (United States)

    Day, George S; Schoemaker, Paul J H

    2005-11-01

    Companies often face new rivals, technologies, regulations, and other environmental changes that seem to come out of left field. How can they see these changes sooner and capitalize on them? Such changes often begin as weak signals on what the authors call the periphery, or the blurry zone at the edge of an organization's vision. As with human peripheral vision, these signals are difficult to see and interpret but can be vital to success or survival. Unfortunately, most companies lack a systematic method for determining where on the periphery they should be looking, how to interpret the weak signals they see, and how to allocate limited scanning resources. This article provides such a method-a question-based framework for helping companies scan the periphery more efficiently and effectively. The framework divides questions into three categories: learning from the past (What have been our past blind spots? What instructive analogies do other industries offer? Who in the industry is skilled at picking up weak signals and acting on them?); evaluating the present (What important signals are we rationalizing away? What are our mavericks, outliers, complainers, and defectors telling us? What are our peripheral customers and competitors really thinking?); and envisioning the future (What future surprises could really hurt or help us? What emerging technologies could change the game? Is there an unthinkable scenario that might disrupt our business?). Answering these questions is a good first step toward anticipating problems or opportunities that may appear on the business horizon. The article concludes with a self-test that companies can use to assess their need and capability for peripheral vision.

  7. Agrobacterium-mediated transformation of Easter lily (Lilium longiflorum cv. Nellie White)

    Science.gov (United States)

    Conditions were optimized for transient transformation of Lilium longiflorum cv. Nellie White using Agrobacterium tumefaciens. Bulb scale and basal meristem explants were inoculated with A. tumefaciens strain AGL1 containing the binary vector pCAMBIA 2301 which has the uidA gene that codes for ß-gl...

  8. Possibility of Recombination Gain Increase in CV Ions at 4.0 nm Via Coherence

    Science.gov (United States)

    Luo, Y.; Morozov, A.; Gordon, D.; Sprangle, P.; Svidzinsky, A.; Xia, H.; Scully, M.; Suckewer, S.

    This paper is about the recent experimental results on amplification of the CV line in the "water window" at 4.03 nm from resonance transition to the ground level of He-like ions in recombination scheme. The indication of the amplification of the CV line has been observed when an elongated narrow plasma channel was created, where high intensity 100 fs beams, optimal for creating CV ions in high density plasma, was propagated up to 0.5-0.6 mm. Without channeling the effective plasma length was much shorter and there was no indication of amplification.The large interest in gain generation in He-like ions in the transition to ground state is due to the possibility of applying a recently developed theory of Lasing Without Inversion (LWI) in XUV and X-ray regions to largely increase the gain for such transitions. The presented results of the indication of CV line amplifications are being discussed from the point of view of using LWI as a superradiance gain increase, hence to construct a very compact soft X-ray laser in the "water window".The last part of the paper is related to the application of the ultra-intensive fs plasma laser, which is currently in the process of development by using stimulated Raman backscattering (SRBS) to create a plasma amplifier and compressor, as the pump for compact laser operating in the "water window" and also at shorter wavelengths.

  9. RADISH CV. MOKHOVSKIY IS A SOURCE OF MS- AND MF-LINES AT BREEDING FOR HETEROSIS

    Directory of Open Access Journals (Sweden)

    M. I. Fedorova

    2015-01-01

    Full Text Available Based on hybrid and inbreed population of radish cv. Mokhovskiy using CMS-ogura nine lines with 100% of male sterility and fertile maintainers were selected. Using the multiplex PCR, the presence of cytoplasm of Ogura type in ms-lines and its absence in mf-lines were confirmed.

  10. Limited geographic distribution of the novel cyclovirus CyCV-VN

    NARCIS (Netherlands)

    Le, Van Tan; de Jong, Menno D.; Nguyen, Van Kinh; Nguyen, Vu Trung; Taylor, Walter; Wertheim, Heiman F. L.; van der Ende, Arie; van der Hoek, Lia; Canuti, Marta; Crusat, Martin; Sona, Soeng; Nguyen, Hanh Uyen; Giri, Abhishek; Nguyen, Thi Thuy Chinh Bkrong; Ho, Dang Trung Nghia; Farrar, Jeremy; Bryant, Juliet E.; Tran, Tinh Hien; Nguyen, Van Vinh Chau; van Doorn, H. Rogier

    2014-01-01

    A novel cyclovirus, CyCV-VN, was recently identified in cerebrospinal fluid (CSF) from patients with central nervous system (CNS) infections in central and southern Vietnam. To explore the geographic distribution of this novel virus, more than 600 CSF specimens from patients with suspected CNS

  11. Automatic tracking of red blood cells in micro channels using OpenCV

    Science.gov (United States)

    Rodrigues, Vânia; Rodrigues, Pedro J.; Pereira, Ana I.; Lima, Rui

    2013-10-01

    The present study aims to developan automatic method able to track red blood cells (RBCs) trajectories flowing through a microchannel using the Open Source Computer Vision (OpenCV). The developed method is based on optical flux calculation assisted by the maximization of the template-matching product. The experimental results show a good functional performance of this method.

  12. Cherry Picking Robot Vision Recognition System Based on OpenCV

    Directory of Open Access Journals (Sweden)

    Zhang Qi Rong

    2016-01-01

    Full Text Available Through OpenCV function, the cherry in a natural environment image after image preprocessing, color recognition, threshold segmentation, morphological filtering, edge detection, circle Hough transform, you can draw the cherry’s center and circular contour, to carry out the purpose of the machine picking. The system is simple and effective.

  13. Production of calibration sources and/or radioactive tracers with the cyclotron CV-28

    International Nuclear Information System (INIS)

    Osso Junior, Joao Alberto

    1995-01-01

    The present stage of production of calibration sources and radioactive tracers with the Cyclotron CV-28 is described. Among the methods already developed special attention is given to the production of 57 Co, 109 Cd and 111 In. (author). 3 refs

  14. Lipid abnormalities in streptozotocin-diabetes: Amelioration by Morus indica L. cv Suguna leaves

    OpenAIRE

    Andallu, B.; Vinay Kumar, A. V.; Varadacharyulu, N. Ch.

    2009-01-01

    AIM: To observe the influence of mulberry (Morus indica L. cv Suguna) leaves on lipid abnormalities in STZ-diabetic rats. MATERIALS AND METHODS: Treatment with dried mulberry leaf powder for a period of 8 weeks in hyperglycemic and hyperlipidemic STZ-diabetic rats. RESULTS: Mulberry leaves regulated fasting blood glucose, ameliorated the abnormalities in lipid profile as indicated by significant (P

  15. Connected Vehicle Pilot Deployment Program, Comprehensive Installation Plan - WYDOT CV Pilot

    Science.gov (United States)

    2018-02-16

    The Wyoming Department of Transportation's (WYDOT) Connected Vehicle (CV) Pilot Deployment Program is intended to develop a suite of applications that utilize vehicle-to-infrastructure (V2I) and vehicle-to-vehicle (V2V) communication technology to re...

  16. NALISIS PENGAKUAN PENDAPATAN BERDASARKAN PSAK NOMOR 23 PADA CV TILZAK KABUPATEN PINRANG

    Directory of Open Access Journals (Sweden)

    ILHAM ARIFIN

    2017-05-01

    This research was conducted at CV. Tilzak Pinrang which is a business as a cog in the business of selling. Based on research that has been done, it is not all revenue recognition in accordance with IAS 23 is not dibuatkannya marked revenue balance sheet and income statement, so that the impact to the company's earnings were only included proceeds earned in one year.

  17. STRATEGI SEGMENTASI PASAR TERHADAP VOLUME PENJUALAN BUSANA MUSLIM PADA CV RABBANI ASYSA MAKASSAR

    OpenAIRE

    KARASE, HASNAWATI

    2014-01-01

    2014 Hasnawati Karase Haris Maupa Mukhtar Penelitian ini bertujuan untuk menganalisis strategi segmentasi pasar terhadap volume penjualan busana muslim pada CV Rabbani Asysa Makassar. Data penelitian ini diperoleh dari kuesioner (primer) mengenai segmentasi pasar Rabbani Makassar dengan mengambil sampel sebanyak 75 responden. Temuan penelitian ini menunjukkan bahwa variabel strategi segmentasi pasar yang terdiri dari segmentasi geografis, segmentasi demografis, segm...

  18. In vitro multiplication of banana (Musa sp.) cv. Grand Naine | Ahmed ...

    African Journals Online (AJOL)

    A micropropagation method is described for banana (Musa Spp.) Cv. Grand Naine. Suckers were surface sterilized with HgCl2 (0.1%) for 6 min which gave minimum contamination with maximum culture establishment. Of various treatment combinations, Murashige and Skoog (MS) medium + BAP 4.00 mg/l with IAA 2.00 ...

  19. PlantCV v2: Image analysis software for high-throughput plant phenotyping

    Directory of Open Access Journals (Sweden)

    Malia A. Gehan

    2017-12-01

    Full Text Available Systems for collecting image data in conjunction with computer vision techniques are a powerful tool for increasing the temporal resolution at which plant phenotypes can be measured non-destructively. Computational tools that are flexible and extendable are needed to address the diversity of plant phenotyping problems. We previously described the Plant Computer Vision (PlantCV software package, which is an image processing toolkit for plant phenotyping analysis. The goal of the PlantCV project is to develop a set of modular, reusable, and repurposable tools for plant image analysis that are open-source and community-developed. Here we present the details and rationale for major developments in the second major release of PlantCV. In addition to overall improvements in the organization of the PlantCV project, new functionality includes a set of new image processing and normalization tools, support for analyzing images that include multiple plants, leaf segmentation, landmark identification tools for morphometrics, and modules for machine learning.

  20. The influence of virus diseases on grape polyphenols of cv. 'Refosk'

    International Nuclear Information System (INIS)

    Tomazic, I.; Vrhovsek, U.; Korosec-Koruza, Z.

    2003-01-01

    External stimuli such as microbial infections, ultraviolet radiation, and chemical stressors can modulate the synthesis of polyphenols in the plants. Cv. 'Refosk' was used to show the influence of the GLRaV-1 and rugose wood (RW) on the polyphenols in grape. The infection shifted polyphenols from seeds to grape skins but had no impact on anthocyanins

  1. Endogenous auxin regulates the sensitivity of Dendrobium (cv. Miss Teen) flower pedicel abscission to ethylene

    NARCIS (Netherlands)

    Rungruchkanont, K.; Ketsa, S.; Chatchawankanphanich, O.; Doorn, van W.G.

    2007-01-01

    Dendrobium flower buds and flowers have an abscission zone at the base of the pedicel (flower stalk). Ethylene treatment of cv. Miss Teen inflorescences induced high rates of abscission in flower buds but did not affect abscission once the flowers had opened. It is not known if auxin is a regulator

  2. THE USE OF COMPUTER VISION ALGORITHMS FOR AUTOMATIC ORIENTATION OF TERRESTRIAL LASER SCANNING DATA

    Directory of Open Access Journals (Sweden)

    J. S. Markiewicz

    2016-06-01

    Full Text Available The paper presents analysis of the orientation of terrestrial laser scanning (TLS data. In the proposed data processing methodology, point clouds are considered as panoramic images enriched by the depth map. Computer vision (CV algorithms are used for orientation, which are applied for testing the correctness of the detection of tie points and time of computations, and for assessing difficulties in their implementation. The BRISK, FASRT, MSER, SIFT, SURF, ASIFT and CenSurE algorithms are used to search for key-points. The source data are point clouds acquired using a Z+F 5006h terrestrial laser scanner on the ruins of Iłża Castle, Poland. Algorithms allowing combination of the photogrammetric and CV approaches are also presented.

  3. The Use of Computer Vision Algorithms for Automatic Orientation of Terrestrial Laser Scanning Data

    Science.gov (United States)

    Markiewicz, Jakub Stefan

    2016-06-01

    The paper presents analysis of the orientation of terrestrial laser scanning (TLS) data. In the proposed data processing methodology, point clouds are considered as panoramic images enriched by the depth map. Computer vision (CV) algorithms are used for orientation, which are applied for testing the correctness of the detection of tie points and time of computations, and for assessing difficulties in their implementation. The BRISK, FASRT, MSER, SIFT, SURF, ASIFT and CenSurE algorithms are used to search for key-points. The source data are point clouds acquired using a Z+F 5006h terrestrial laser scanner on the ruins of Iłża Castle, Poland. Algorithms allowing combination of the photogrammetric and CV approaches are also presented.

  4. Simulating Linear Sweep Voltammetry from First-Principles: Application to Electrochemical Oxidation of Water on Pt(111) and Pt3Ni(111)

    DEFF Research Database (Denmark)

    Viswanathan, Venkatasubramanian; Hansen, Heine Anton; Rossmeisl, Jan

    2012-01-01

    Cyclic voltammetry is a fundamental experimental method for characterizing adsorbates on electrochemical surfaces. We present a model for the electrochemical solid–liquid interface, and we simulate the linear sweep voltammogram of the electrochemical oxidation of H2O on Pt(111) and Pt3Ni(111...

  5. International comparison of Cd content in a quality control material of Navajuelas (Tagelus dombeii) determined by anodic stripping voltammetry, atomic absorption spectrometry and neutron activation analysis

    International Nuclear Information System (INIS)

    Queirolo, F.; Forschungszentrum Juelich GmbH; Universidad de Extremadura, Badajoz; Ostapczuk, P.; Valenta, P.; Stegen, S.; Universidad de Extremadura, Badajoz; Marin, C.; Vinagre, F.; Sanchez, A.

    1991-01-01

    The determination of Cd was performed by neutron activation analysis (NAA), atomic absorption spectrometry (AAS) with flame or in the electrothermal mode and anodic stripping voltammetry in the differential pulse mode (DPASV) and the square wave mode (SWASV). (orig./EF)

  6. Electrochemical Performances of Diamond Like Carbon Films for Pb(II) Detection in Tap Water Using Differential Pulse Anodic Stripping Voltammetry Technique

    Czech Academy of Sciences Publication Activity Database

    Sbartai, A.; Namour, F.; Barbier, F.; Krejčí, J.; Kučerová, R.; Krejčí, T.; Neděla, Vilém; Sobota, Jaroslav; Jaffrezic-Renault, N.

    2013-01-01

    Roč. 11, č. 8 (2013), s. 1524-1529 ISSN 1546-198X Institutional support: RVO:68081731 Keywords : Diamond Like Carbon DLC * Lead Detection * Differential Pulse Anodic Stripping * Voltammetry * Tap Water Subject RIV: JA - Electronics ; Optoelectronics, Electrical Engineering Impact factor: 0.558, year: 2013

  7. Modification of Poly- and Oligosaccharides with Os(VI) pyridine. Voltammetry of the Os(VI) Adducts Obtained by Ligand Exchange

    Czech Academy of Sciences Publication Activity Database

    Trefulka, Mojmír; Paleček, Emil

    2013-01-01

    Roč. 25, č. 8 (2013), s. 1813-1817 ISSN 1040-0397 R&D Projects: GA ČR(CZ) GAP301/11/2055 Institutional research plan: CEZ:AV0Z50040702 Institutional support: RVO:68081707 Keywords : OS(VI)-MODIFIED POLYSACCHARIDES * STRIPPING VOLTAMMETRY * TRANS-ESTERIFICATION Subject RIV: BO - Biophysics Impact factor: 2.502, year: 2013

  8. Modeling the butterfly: the voltammetry of ((sqrt(3)xsqrt(3))R30 and p(2x2) overlayers of (111) electrodes

    NARCIS (Netherlands)

    Koper, M.T.M.; Lukkien, J.J.

    2000-01-01

    The voltammetry of the formation of (v3×v3)R30° and p(2×2) overlayers on (111) electrodes is modeled by analytical and Monte Carlo techniques. Both ordered structures are formed by second-order order–disorder phase transitions that lead to sharply-peaked ‘butterfly’ features in the voltammogram. The

  9. ANALISIS SEWA MENYEWA PARALEL PADA PERUSAHAAN RENT CAR CV. HARKAT DALAM PERSPEKTIF EKONOMI ISLAM

    Directory of Open Access Journals (Sweden)

    Samsuardi Samsuardi

    2013-12-01

    Full Text Available This study aims at determining the parallel process of car rental agreement between Harkat Rent Car Company and the owner of the car, and between the company and its customers in an Islamic economics perspective. This study also aims to analyze the risk coverage of the leased car. The data for this study was gathered through interviews, observation and documentation studies. The collected data was then analyzed using descriptive analysis method. Results showed that the process of car leasing begin when customer rented a car from CV. Harkat which was owned by its partner. The company provided a shared price for car owners according to a mutual agreement and applied only for a certain period. Furthermore, the partner has to allocate 20 percent of the income for the company. In addition, the company also required the partner to cover for maintenance costs, insurance, equipment, and spare parts. In the context of Islamic economics, the practice of leasing parallel conducted by the company was not fully Shariah compliance due to practice a lease above a lease and using two contracts in one transaction. =========================================== Penelitian ini bertujuan untuk mengetahui perjanjian sewa menyewa mobil secara paralel antara Perusahaan Rent Car CV. Harkat dengan pemilik mobil dan dengan konsumennya dalam perspektif ekonomi Islam. Penelitian ini juga bertujuan untuk menanganalisis pertanggungan resiko terhadap mobil yang dijadikan objek sewa menyewa tersebut sewa menyewa mobil di Perusahaan Rent Car CV. Data untuk penelitian ini bersumber dari wawancara, obesrvasi dan studi dokumentasi. Metode yang digunakan dalam penelitian ini adalah deskriptif analisis. Hasil penelitian menunjukkan bahwa CV. Harkat menyewakan mobil milik mitra kerjanya (pemilik mobil kepada pelanggan yang membutuhkan sewa mobil untuk keperluannya. Pemilik usaha memberikan harga kongsi kepada pemilik mobil sesuai dengan kesepakatan bersama dan untuk jangka waktu

  10. CERES ERBE-like Instantaneous TOA Estimates (ES-8) in HDF (CER_ES8_Aqua-FM4_Edition1-CV)

    Science.gov (United States)

    Wielicki, Bruce A. (Principal Investigator)

    The ES-8 archival data product contains a 24-hour, single-satellite, instantaneous view of scanner fluxes at the top-of-atmosphere (TOA) reduced from spacecraft altitude unfiltered radiances using Earth Radiation Budget Experiment (ERBE) scanner Inversion algorithms and the ERBE shortwave (SW) and longwave (LW) Angular Distribution Models (ADMs). The ES-8 also includes the total (TOT), SW, LW, and window (WN) channel radiometric data; SW, LW, and WN unfiltered radiance values; and the ERBE scene identification for each measurement. These data are organized according to the CERES 3.3-second scan into 6.6-second records. As long as there is one valid scanner measurement within a record, the ES-8 record will be generated. The following CERES ES8 data sets are currently available: CER_ES8_TRMM-PFM_Edition1 CER_ES8_TRMM-PFM_Edition2 CER_ES8_TRMM-PFM_Transient-Ops2 CER_ES8_Terra-FM1_Edition1 CER_ES8_Terra-FM2_Edition1 CER_ES8_Terra-FM1_Edition2 CER_ES8_Terra-FM2_Edition2 CER_ES8_Aqua-FM3_Edition1 CER_ES8_Aqua-FM4_Edition1 CER_ES8_Aqua-FM3_Edition2 CER_ES8_Aqua-FM4_Edition2 CER_ES8_Aqua-FM3_Edition1-CV CER_ES8_Aqua-FM4_Edition1-CV CER_ES8_Terra-FM1_Edition1-CV CER_ES8_Terra-FM1_Edition1-CV. [Location=GLOBAL] [Temporal_Coverage: Start_Date=1997-12-27; Stop_Date=2005-03-29] [Spatial_Coverage: Southernmost_Latitude=-90; Northernmost_Latitude=90; Westernmost_Longitude=-180; Easternmost_Longitude=180] [Data_Resolution: Temporal_Resolution=1 day; Temporal_Resolution_Range=Daily - < Weekly].

  11. CERES ERBE-like Instantaneous TOA Estimates (ES-8) in HDF (CER_ES8_Terra-FM1_Edition1-CV)

    Science.gov (United States)

    Wielicki, Bruce A. (Principal Investigator)

    The ES-8 archival data product contains a 24-hour, single-satellite, instantaneous view of scanner fluxes at the top-of-atmosphere (TOA) reduced from spacecraft altitude unfiltered radiances using Earth Radiation Budget Experiment (ERBE) scanner Inversion algorithms and the ERBE shortwave (SW) and longwave (LW) Angular Distribution Models (ADMs). The ES-8 also includes the total (TOT), SW, LW, and window (WN) channel radiometric data; SW, LW, and WN unfiltered radiance values; and the ERBE scene identification for each measurement. These data are organized according to the CERES 3.3-second scan into 6.6-second records. As long as there is one valid scanner measurement within a record, the ES-8 record will be generated. The following CERES ES8 data sets are currently available: CER_ES8_TRMM-PFM_Edition1 CER_ES8_TRMM-PFM_Edition2 CER_ES8_TRMM-PFM_Transient-Ops2 CER_ES8_Terra-FM1_Edition1 CER_ES8_Terra-FM2_Edition1 CER_ES8_Terra-FM1_Edition2 CER_ES8_Terra-FM2_Edition2 CER_ES8_Aqua-FM3_Edition1 CER_ES8_Aqua-FM4_Edition1 CER_ES8_Aqua-FM3_Edition2 CER_ES8_Aqua-FM4_Edition2 CER_ES8_Aqua-FM3_Edition1-CV CER_ES8_Aqua-FM4_Edition1-CV CER_ES8_Terra-FM1_Edition1-CV CER_ES8_Terra-FM1_Edition1-CV. [Location=GLOBAL] [Temporal_Coverage: Start_Date=1997-12-27; Stop_Date=2006-09-30] [Spatial_Coverage: Southernmost_Latitude=-90; Northernmost_Latitude=90; Westernmost_Longitude=-180; Easternmost_Longitude=180] [Data_Resolution: Temporal_Resolution=1 day; Temporal_Resolution_Range=Daily - < Weekly].

  12. TENCompetence Learning Design Toolkit, Runtime component, ccsi_v3_2_10c_v1_4

    NARCIS (Netherlands)

    Sharples, Paul; Popat, Kris; Llobet, Lau; Santos, Patricia; Hernández-Leo, Davinia; Miao, Yongwu; Griffiths, David; Beauvoir, Phillip

    2010-01-01

    Sharples, P., Popat, K., Llobet, L., Santos, P., Hernandez-Leo, D., Miao, Y., Griffiths, D. & Beauvoir, P. (2009) TENCompetence Learning Design Toolkit, Runtime component, ccsi_v3_2_10c_v1_4 This release is composed of three files corresponding to CopperCore Service Integration (CCSI) v3.2-10cv1.4,

  13. ANALISIS KEBUTUHAN TENAGA KERJA RESERVASI TERHADAP PERENCANAAN PENGEMBANGAN SUMBER DAYA MANUSIA PADA CV. CAN TOUR & TRAVEL

    Directory of Open Access Journals (Sweden)

    Maya Christina

    2017-01-01

    Full Text Available Employment remains the fundamental probel faced by many countries including Indonesia. One of the efforts the Government of Indonesia in extending employment opportunities is to develop the tourism sector. Bali is one of the potential tourist destinastions and it needs to be marketed. Cooperation between the Travel Bureau with the provider of the accommodation or hotel is one of the ways the potential market and the most instrumental in the development of the company, namely human resources required or called by labor. CV. CAN Tour and Travel is one of the tourist industry in Bali trip with a number of guest handling that quite a lot. This research aims to know the availability of labor needs resevartion in order CV. CAN Tour and Travel development and also to find out how the workforce qualification is required. Determination technique using the key informant that was labor reservation CV. CAN Tour and Travel, while the base of the informant was CV. CAN Tour and Travel Manager. Data analysis technique used is the analysis of workload and workforce needs analysis. The research results obtained indicate that shortage of time working as many as 210 minutes. So the manpower needed by CV. CAN Tour and Travel is two people with the fact that there is only 1 nowaday. It can be seen from the burden of the work done in a day’s work and the workforce absences. So labor needs on the Reservation Department is supposed to be 3 people, with 2 staff 1 reservations and ticketing staff. It was necessary increase manpower in the Labour Departmen’s Reservation in the reservation and also training to develop the ability to work.

  14. The Application of Restriction Landmark Genome Scanning Method for Surveillance of Non-Mendelian Inheritance in F1 Hybrids

    Directory of Open Access Journals (Sweden)

    Tomoko Takamiya

    2009-01-01

    Full Text Available We analyzed inheritance of DNA methylation in reciprocal F1 hybrids (subsp. japonica cv. Nipponbare × subsp. indica cv. Kasalath of rice (Oryza sativa L. using restriction landmark genome scanning (RLGS, and detected differing RLGS spots between the parents and reciprocal F1 hybrids. MspI/HpaII restriction sites in the DNA from these different spots were suspected to be heterozygously methylated in the Nipponbare parent. These spots segregated in F1 plants, but did not segregate in selfed progeny of Nipponbare, showing non-Mendelian inheritance of the methylation status. As a result of RT-PCR and sequencing, a specific allele of the gene nearest to the methylated sites was expressed in reciprocal F1 plants, showing evidence of biased allelic expression. These results show the applicability of RLGS for scanning of non-Mendelian inheritance of DNA methylation and biased allelic expression.

  15. GPR scan assessment

    Directory of Open Access Journals (Sweden)

    Abbas M. Abbas

    2015-06-01

    Full Text Available Mekaad Radwan monument is situated in the neighborhood of Bab Zuweila in the historical Cairo, Egypt. It was constructed at the middle XVII century (1635 AD. The building has a rectangle shape plan (13 × 6 m with the longitudinal sides approximately WNW-ESE. It comprises three storages namely; the ground floor; the opened floor (RADWAN Bench and the living floor with a total elevation of 15 m above the street level. The building suffers from severe deterioration phenomena with patterns of damage which have occurred over time. These deterioration and damages could be attributed to foundation problems, subsoil water and also to the earthquake that affected the entire Greater Cairo area in October 1992. Ground Penetrating Radar (GPR scan was accomplished against the walls of the opened floor (RADWAN Bench to evaluate the hazard impact on the walls textures and integrity. The results showed an anomalous feature through the southern wall of RADWAN Bench. A mathematical model has been simulated to confirm the obtained anomaly and the model response exhibited a good matching with the outlined anomaly.

  16. Radionuclide brain scanning

    International Nuclear Information System (INIS)

    Abdel-Dayem, H.

    1992-01-01

    At one stage of medical imaging development, radionuclide brain scanning was the only technique available for imaging of the brain. Advent of CT and MRI pushed it to the background. It regained some of the grounds lost to ''allied advances'' with the introduction of brain perfusion radiopharmaceuticals. Positron emission tomography is a promising functional imaging modality that at present will remain as a research tool in special centres in developed countries. However, clinically useful developments will gradually percolate from PET to SPECT. The non-nuclear imaging methods are totally instrument dependent; they are somewhat like escalators, which can go that far and no further. Nuclear imaging has an unlimited scope for advance because of the new developments in radiopharmaceuticals. As the introduction of a radiopharmaceutical is less costly than buying new instruments, the recent advances in nuclear imaging are gradually perfusing through the developing countries also. Therefore, it is essential to follow very closely PET developments because what is research today might become routine tomorrow

  17. LANL Robotic Vessel Scanning

    Energy Technology Data Exchange (ETDEWEB)

    Webber, Nels W. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2015-11-25

    Los Alamos National Laboratory in J-1 DARHT Operations Group uses 6ft spherical vessels to contain hazardous materials produced in a hydrodynamic experiment. These contaminated vessels must be analyzed by means of a worker entering the vessel to locate, measure, and document every penetration mark on the vessel. If the worker can be replaced by a highly automated robotic system with a high precision scanner, it will eliminate the risks to the worker and provide management with an accurate 3D model of the vessel presenting the existing damage with the flexibility to manipulate the model for better and more in-depth assessment.The project was successful in meeting the primary goal of installing an automated system which scanned a 6ft vessel with an elapsed time of 45 minutes. This robotic system reduces the total time for the original scope of work by 75 minutes and results in excellent data accumulation and transmission to the 3D model imaging program.

  18. Gastrointestinal scanning agent

    International Nuclear Information System (INIS)

    Francis, M.D.

    1980-01-01

    An easily prepared radiolabeled gastrointestinal scanning agent is described. Technetium-99m has ideal characteristics for imaging the upper and lower GI tract and determining stomach emptying and intestinal transit time when used with an insoluble particulate material. For example, crystalline and amorphous calcium phosphate particles can be effectively labeled in a one-step process using sup(99m)TcO 4 and SnCl 2 . These labeled particles have insignificant mass and when administered orally pass through the GI tract unchanged, without affecting the handling and density of the intestinal contents. Visualization of the esophageal entry into the stomach, the greater and lesser curvatures of the stomach, ejection into the duodenum, and rates of passage through the upper and lower GI tract are obtained. The slurry of sup(99m)TC particulate can be given rectally by enema. Good images of the cecum and the ascending, transverse, and descending colon are obtained. Mucosal folds and the splenic and hepatic flexures are visualized. The resilience of the large intestine is also readily visualized by pneumocolonographic techniques. (author)

  19. Radionuclide brain scanning

    Energy Technology Data Exchange (ETDEWEB)

    Abdel-Dayem, H

    1993-12-31

    At one stage of medical imaging development, radionuclide brain scanning was the only technique available for imaging of the brain. Advent of CT and MRI pushed it to the background. It regained some of the grounds lost to ``allied advances`` with the introduction of brain perfusion radiopharmaceuticals. Positron emission tomography is a promising functional imaging modality that at present will remain as a research tool in special centres in developed countries. However, clinically useful developments will gradually percolate from PET to SPECT. The non-nuclear imaging methods are totally instrument dependent; they are somewhat like escalators, which can go that far and no further. Nuclear imaging has an unlimited scope for advance because of the new developments in radiopharmaceuticals. As the introduction of a radiopharmaceutical is less costly than buying new instruments, the recent advances in nuclear imaging are gradually perfusing through the developing countries also. Therefore, it is essential to follow very closely PET developments because what is research today might become routine tomorrow

  20. Comportamento agronômico inicial da cv. Chimarrita enxertada em cinco porta-enxertos de pessegueiro Agronomical behavior of cv. Chimarrita on five rootstocks of peach trees

    Directory of Open Access Journals (Sweden)

    Moacir da Silva Rocha

    2007-01-01

    Full Text Available O trabalho teve por objetivo avaliar a resposta agronômica da cv. Chimarrita enxertada em cinco porta-enxertos, nas condições edafoclimáticas da região de Pelotas-RS, no período de 2003 a 2005. Durante o período de execução do experimento, foram avaliados o diâmetro do tronco do porta-enxerto e da cultivar-copa, comprimento médio dos ramos principais, volume de copa, massa fresca e massa seca do material vegetal retirado nas podas verde e de inverno, índice de intensidade de poda, massa média dos frutos, produção por planta, eficiência produtiva, produção por hectare, sólidos solúveis totais, firmeza da polpa, diâmetro e coloração dos frutos. O porta-enxerto 'Capdeboscq' induziu o maior crescimento vegetativo na cv. Chimarrita durante os três anos de avaliação, seguido do porta-enxerto 'Okinawa'. Este, por sua vez, induziu o maior rendimento produtivo (1,65 t ha-1. A cv. Capdeboscq proporcionou a obtenção de frutos com maior massa. Os porta-enxertos 'GF 305' e 'Aldrighi' induziram menor desenvolvimento vegetativo e a mais baixa produtividade (0,52 t.ha-1 .The objective for this study was to evaluate the agronomical behavior of cv. Chimarrita on five rootstocks of peach trees in Pelotas- RS from 2003 to 2005. The variables evaluated were: trunk diameters of the rootstock and of the scion; length of the annual terminal growth; volume of the canopy; fresh and dry weight of the material taken by the summer and winter pruning; pruning intensity index; fruit weight; fruit production per tree; production efficiency; productivity per hectare; total soluble solids; pulp firmness; and fruit diameter and color. It was observed that the trees from: rootstock 'Capdeboscq' promoted higher vegetative growth and larger fruits, followed by the ones from the rootstock 'Okinawa' which promoted the highest yield (1, 65 t.ha-1; the rootstock 'GF 305' and 'Aldrighi' had the lowest vegetative development and yield (0, 52 t.ha-1.

  1. Hyperchromatic laser scanning cytometry

    Science.gov (United States)

    Tárnok, Attila; Mittag, Anja

    2007-02-01

    In the emerging fields of high-content and high-throughput single cell analysis for Systems Biology and Cytomics multi- and polychromatic analysis of biological specimens has become increasingly important. Combining different technologies and staining methods polychromatic analysis (i.e. using 8 or more fluorescent colors at a time) can be pushed forward to measure anything stainable in a cell, an approach termed hyperchromatic cytometry. For cytometric cell analysis microscope based Slide Based Cytometry (SBC) technologies are ideal as, unlike flow cytometry, they are non-consumptive, i.e. the analyzed sample is fixed on the slide. Based on the feature of relocation identical cells can be subsequently reanalyzed. In this manner data on the single cell level after manipulation steps can be collected. In this overview various components for hyperchromatic cytometry are demonstrated for a SBC instrument, the Laser Scanning Cytometer (Compucyte Corp., Cambridge, MA): 1) polychromatic cytometry, 2) iterative restaining (using the same fluorochrome for restaining and subsequent reanalysis), 3) differential photobleaching (differentiating fluorochromes by their different photostability), 4) photoactivation (activating fluorescent nanoparticles or photocaged dyes), and 5) photodestruction (destruction of FRET dyes). With the intelligent combination of several of these techniques hyperchromatic cytometry allows to quantify and analyze virtually all components of relevance on the identical cell. The combination of high-throughput and high-content SBC analysis with high-resolution confocal imaging allows clear verification of phenotypically distinct subpopulations of cells with structural information. The information gained per specimen is only limited by the number of available antibodies and by sterical hindrance.

  2. Direct evidence of ionic fluxes across ion-selective membranes: a scanning electrochemical microscopic and potentiometric study.

    Science.gov (United States)

    Gyurcsányi, R E; Pergel, E; Nagy, R; Kapui, I; Lan, B T; Tóth, K; Bitter, I; Lindner, E

    2001-05-01

    Scanning electrochemical microscopy (SECM) supplemented with potentiometric measurements was used to follow the time-dependent buildup of a steady-state diffusion layer at the aqueous-phase boundary of lead ion-selective electrodes (ISEs). Differential pulse voltammetry is adapted to SECM for probing the local concentration profiles at the sample side of solvent polymeric membranes. Major factors affecting the membrane transport-related surface concentrations were identified from SECM data and the potentiometric transients obtained under different experimental conditions (inner filling solution composition, membrane thickness, surface pretreatment). The amperometrically determined surface concentrations correlated well with the lower detection limits of the lead ion-selective electrodes.

  3. Gallium scans in myasthenia gravis

    International Nuclear Information System (INIS)

    Swick, H.M.; Preston, D.F.; McQuillen, M.P.

    1976-01-01

    A study was conducted to determine whether 67 Ga scans could be used for the detection of thymomas and to investigate the activity of the thymus gland in patients with myasthenia gravis. Scans of the anterior mediastinum proved to be a reliable way to detect thymomas. The scans were positive in eight patients including three with myasthenia gravis and histologically proved thymomas, three others with severe myasthenia gravis and thymic tumors, and two with histologically proved thymomas not associated with myasthenia. Activity on 67 Ga scans was not directly related to the increased activity of the thymus gland that is presumed to be associated with myasthenia gravis

  4. Gallium scans in myasthenia gravis

    Energy Technology Data Exchange (ETDEWEB)

    Swick, H.M. (Univ. of Kentucky, Lexington); Preston, D.F.; McQuillen, M.P.

    1976-01-01

    A study was conducted to determine whether /sup 67/Ga scans could be used for the detection of thymomas and to investigate the activity of the thymus gland in patients with myasthenia gravis. Scans of the anterior mediastinum proved to be a reliable way to detect thymomas. The scans were positive in eight patients including three with myasthenia gravis and histologically proved thymomas, three others with severe myasthenia gravis and thymic tumors, and two with histologically proved thymomas not associated with myasthenia. Activity on /sup 67/Ga scans was not directly related to the increased activity of the thymus gland that is presumed to be associated with myasthenia gravis. (HLW)

  5. Fox grape cv. Bordô (Vitis labrusca L. and grapevine cv. Chardonnay (Vitis vinifera L. cultivated in vitro under different carbohydrates, amino acids and 6-Benzylaminopurine levels

    Directory of Open Access Journals (Sweden)

    Dayse Cristina de Carvalho

    2013-04-01

    Full Text Available The aim of this work was to study the influence of sucrose and glucose, amino acids and BAP (6-Benzylaminopurine levels on in vitro shoot regeneration of fox grape cv. Bordô and grapevine cv. Chardonnay. The nodal segments from micropropagated material were used as explants and half-strength MS medium as the basal medium. Sucrose and glucose at 15, 30 and 45 g.L-1 were tested as a carbon source and the supplementation of adenine, asparagine, alanine, glycine, cysteine, glutamine, arginine was tested at 40 g.L-1. The BAP levels (1 and 5 μM in solid and double-phase media were evaluated and compared with a control medium without BAP. Bordô had best in vitro growth than Chardonnay. Sucrose was a better carbohydrate source than glucose for both the cultivars. Bordô and Chardonnay had different amino acid preferences for some parameters. In conclusion, for in vitro shoot regeneration from the nodal segments, culture on solid medium with 5 μM BAP, 15 g.L-1 sucrose for Bordô and 45 g.L-1 sucrose for Chardonnay showed better results. Similarly, the supplementation of 40 g.L-1 arginine for Bordô and 40 g.L-1 arginine or glycine for Chardonnay showed better results.

  6. Effect of mechanical damage and wound healing on the viscoelastic properties of stems of flax cultivars (Linum usitatissimum L. cv. Eden and cv. Drakkar).

    Science.gov (United States)

    Paul-Victor, Cloé; Dalle Vacche, Sara; Sordo, Federica; Fink, Siegfried; Speck, Thomas; Michaud, Véronique; Speck, Olga

    2017-01-01

    As plant fibres are increasingly used in technical textiles and their composites, underlying principles of wound healing in living plant fibres are relevant to product quality, and provide inspiration for biomimetic healing in synthetic materials. In this work, two Linum usitatissimum cultivars differing in their stem mechanical properties, cv. Eden (stems resistant to lodging) and cv. Drakkar (with more flexible stems), were grown without wound or with stems previously wounded with a cut parallel or transversal to the stem. To investigate wound healing efficiency, growth traits, stem biomechanics with Dynamic Mechanical Analysis and anatomy were analysed after 25-day recovery. Longitudinal incisions formed open wounds while transversal incisions generated stem growth restoring the whole cross-section but not the original stem organisation. In the case of transversal wound healing, all the bast fibre bundles in the perturbed area became lignified and pulled apart by parenchyma cells growth. Both Linum cultivars showed a healing efficiency from 79% to 95% with higher scores for transversal healing. Morphological and anatomical modifications of Linum were related to mechanical properties and healing ability. Alongside with an increased understanding of wound healing in plants, our results highlight their possible impact on textile quality and fibre yield.

  7. Effect of inoculation and nitrogen top-dressing on yields and fodder value of winter pea cv. Maksimirski ozimi in triticale cv. Clercal mixture

    Directory of Open Access Journals (Sweden)

    Darko Uher

    2006-07-01

    Full Text Available Two year field trials (1999-2001 were aimed to determine the inoculation seed winter pea and nitrogen top-dressing effect on number and active nodules of pea root and also on the green mass and dry matter yield of winter pea cv. Maksimirski ozimi and triticale cv. Clercal mixture. Immediately before sowing the inoculation of pea seeds was done by the indigenous variety of Rhizobium leguminosarum bv. viciae which belongs to the collection of Department of Microbiology at the Faculty of Agriculture University of Zagreb. The highest total nodule number on pea root (134 was determined on the inoculated variant as well as active nodule (120. Average mixture green mass yields were ranging from 20.9 t ha-1 (control up to 30.1 t ha-1 (inoculation + nitrogen top-dressing. Total dry matter yields were ranging from 3.71 t ha-1 (control up to 5.36 t ha-1 (nitrogen top-dressing. Pea crude protein yields in 2001 were ranging from 500 kg ha-1 (nitrogen top-dressing up to 642 kg ha-1 (inoculation and for triticale, those values were from 322 kg ha-1 (control up to 498 kg ha-1 (nitrogen top-dressing. Total mixture crude proteins yields were from 845 kg ha-1 (control up to 998 kg ha-1 (nitrogen top-dressing.

  8. Effect of inoculation and nitrogen top-dressing on yields and fodder value of winter pea cv. Maksimirski ozimi in wheat cv. Sana mixture

    Directory of Open Access Journals (Sweden)

    Darko Uher

    2007-06-01

    Full Text Available Two year field trials (1999 - 2001 were performed to determine theinoculation seed winter pea and nitrogen top-dressing effect on number and active nodules of pea root and also on the green mass and dry matter yield of winter pea cv. Maksimirski ozimi and wheat cv. Sana mixture. Immediately before sowing the inoculation of pea seeds was accomplished by the indigenous variety of Rhizobium leguminosarum bv. viciae which belongs to the collection of Department of Microbiology at the Faculty of Agriculture University of Zagreb. The highest total nodule number on pea root (159 was determined on the inoculated variant as well as active nodule 144. Average mixture green mass yield were ranging from 24,65 t ha-1 (control up to 35,50 t ha-1 (inoculation. Total dry matter yields were ranging from 3,93 t ha-1 (control up to 5,66 t ha-1 (inoculation. Yields crude proteins pea in 2001 were ranging from 692 kg ha-1 (control up to 1058 kg ha-1 (inoculation and for wheat, those values ranged from 199 kg ha-1 (control up to 454 kg ha-1 (nitrogen top-dressing. Total crude proteins mixture yields were in range from 891 kg ha-1 (control up to 1360 kg ha-1 (inoculation.

  9. Avaliação da Brachiaria brizantha cv. marandu em sistemas silvipastoris Evaluation of Brachiaria brizantha cv. marandu in silvopastoral systems

    Directory of Open Access Journals (Sweden)

    G.R. Moreira

    2009-06-01

    Full Text Available Avaliou-se a degradabilidade in situ da matéria seca (MS da Brachiaria brizantha cv. marandu colhida em dois sistemas silvipastoris compostos pelas arbóreas, ipê felpudo (Zeyheria tuberculosa e aroeira (Myracrodruon urundeuva, localizados no bioma Cerrado, município de Lagoa Santa, MG. O período de coleta da forragem foi de dezembro de 2004 a abril de 2005. O delineamento utilizado foi em blocos ao acaso, segundo esquema de parcelas subdivididas, sendo as parcelas os tratamentos e as sub-parcelas os tempos de degradação. O sombreamento com as arbóreas não influenciou a degradabilidade in situ da matéria seca da forrageira.In situ degradability of dry matter of Brachiaria brizantha cv. marandu harvested in two silvopastoral systems was evaluated. One system was composed by Zeyheria tuberculosa tree and the other by Myracrodruon urundeuva, both located at Brazilian Savannah, Lagoa Santa, MG. A completely ramdomized block experimental design in a splitplot arrangement was used. The treatments were allocated in the plots and the times in the splitplot. No effect of shade was observed for in situ dry matter degradability.

  10. Thermal stability of oils added with avocado (Persea americana cv. Hass) or olive (Olea europaea cv. Arbequina) leaf extracts during the French potatoes frying.

    Science.gov (United States)

    Jiménez, Paula; García, Paula; Bustamante, Andrés; Barriga, Andrés; Robert, Paz

    2017-04-15

    Effect of the addition of avocado (Persea americana cv. Hass) or olive (Olea europaea cv. Arbequina) hydroalcoholic leaf extracts (AHE and OHE, respectively) on thermal stability of canola oil (CO) and high oleic sunflower oil (HOSO) during French potatoes frying at 180°C was studied. The extracts were characterized by the total phenolic content, phenol chromatographic profiles and antioxidant activity. B-type trimer procyanidins were the major phenolic compounds identified in AHE. OHE showed higher phenol content, antioxidant activity regarding AHE. CO+OHE and HOSO+OHE decreased the formation of polar compounds and showed an anti-polymeric effect with respect to oils without extracts, whereas AHE extract showed a prooxidant effect on HOSO. Therefore, OHE showed an antioxidant effect on HOSO and CO under the studied conditions. In addition, all systems (CO+AHE, HOSO+AHE, CO+OHE and HOSO+OHE) increased the retention of tocopherols. These results demonstrate the potential utility of OHE as natural antioxidant for oils. Copyright © 2016 Elsevier Ltd. All rights reserved.

  11. Reevaluation of Performance of Electric Double-layer Capacitors from Constant-current Charge/Discharge and Cyclic Voltammetry.

    Science.gov (United States)

    Allagui, Anis; Freeborn, Todd J; Elwakil, Ahmed S; Maundy, Brent J

    2016-12-09

    The electric characteristics of electric-double layer capacitors (EDLCs) are determined by their capacitance which is usually measured in the time domain from constant-current charging/discharging and cyclic voltammetry tests, and from the frequency domain using nonlinear least-squares fitting of spectral impedance. The time-voltage and current-voltage profiles from the first two techniques are commonly treated by assuming ideal R s C behavior in spite of the nonlinear response of the device, which in turn provides inaccurate values for its characteristic metrics [corrected]. In this paper we revisit the calculation of capacitance, power and energy of EDLCs from the time domain constant-current step response and linear voltage waveform, under the assumption that the device behaves as an equivalent fractional-order circuit consisting of a resistance R s in series with a constant phase element (CPE(Q, α), with Q being a pseudocapacitance and α a dispersion coefficient). In particular, we show with the derived (R s , Q, α)-based expressions, that the corresponding nonlinear effects in voltage-time and current-voltage can be encompassed through nonlinear terms function of the coefficient α, which is not possible with the classical R s C model. We validate our formulae with the experimental measurements of different EDLCs.

  12. Simultaneous determination of paracetamol and ibuprofen in pharmaceutical samples by differential pulse voltammetry using a boron-doped diamond electrode

    Energy Technology Data Exchange (ETDEWEB)

    Lima, Amanda B.; Guimaraes, Carlos F.R.C.; Verly, Rodrigo M.; Silva, Leonardo M. da [Universidade Federal dos Vales do Jequitinhonha e Mucuri (UFVJM), Diamantina, MG (Brazil). Departamento de Quimica; Torres, Livia M.F.C.; Carvalho, Junior, Alvaro D.; Santos, Wallans T. P. dos, E-mail: wallanst@ufvjm.edu.br [Universidade Federal dos Vales do Jequitinhonha e Mucuri (UFVJM), Diamantina, MG (Brazil). Departamento de Farmacia

    2014-03-15

    This work presents a simple, fast and low-cost methodology for the simultaneous determination of paracetamol (PC) and ibuprofen (IB) in pharmaceutical formulations by differential pulse voltammetry using a boron-doped diamond (BDD) electrode. A well-defined oxidation peak was observed using the BDD electrode for each analyte (0.85 V for PC and 1.72 V for IB (vs. Ag/AgCl)) in 0.1 mol L{sup -1} H{sub 2}SO{sub 4} solution containing 10% (v/v) of ethanol. Calibration curves for the simultaneous determination of PC and IB showed a linear response for both drugs in a concentration range of 20 to 400 μmol L{sup -1} (r{sup 2} = 0.999), with a detection limit of 7.1 μmol L{sup -1} for PC and 3.8 μmol L{sup -1} for IB. The addition-recovery studies in samples were about 100% and the results were validated by chromatographic methods. (author)

  13. Low-level determination of silicon in steels by anodic stripping voltammetry on a hanging mercury drop electrode.

    Science.gov (United States)

    Rahier, A H; Lunardi, S; Nicolle, F; George, S M

    2010-10-15

    The sensitive differential pulse anodic stripping voltammetry (DPASV) proposed originally by Ishiyama et al. (2001) has been revised and improved to allow the accurate measurement of silicon on a hanging mercury drop electrode (HMDE) instead of a glassy carbon electrode. We assessed the rate of formation of the partially reduced β-silicododecamolybdate and found that metallic mercury promotes the reaction in the presence of a large concentration of Fe(3+). The scope of the method has been broadened by carrying out the measurements in the presence of a constant amount of Fe(3+). The limit of detection (LOD) of the method described in the present paper is 100 μg Sig(-1) of steel, with a relative precision ranging from 5% to 12%. It can be further enhanced to 700 ng Sig(-1) of steel provided the weight of the sample, the dilution factors, the duration of the electrolysis and the ballast of iron are adequately revised. The tolerance to several interfering species has been examined, especially regarding Al(3+), Cr(3+) and Cr VI species. The method was validated using four low-alloy ferritic steels certified by the National Institute of Standards and Technology (NIST). Its application to nickel base alloys as well as to less complicated matrixes is straightforward. It has also been successfully applied to the determination of free silicon into silicon carbide nano-powder. Copyright © 2010 Elsevier B.V. All rights reserved.

  14. Fast and sensitive metronidazole determination by means of voltammetry on renewable amalgam silver based electrode without the preconcentration step

    Directory of Open Access Journals (Sweden)

    Piech Robert

    2017-01-01

    Full Text Available Application of cyclic renewable amalgam silver-based electrode (Hg(AgFE for sensitive metronidazole detection by the differential pulse voltammetry (DPV is described. The unique properties of the Hg(AgFE such as the relative large surface area and its fast and very simple renewal were fully utilized for sensitive measurements. Compared with the classical hanging mercury drop electrode (HMDE, the renewable Hg(AgFE significantly increases the reduction peak current of metronidazole because of its large surface area. The effects of various factors for the metronidazole determination such as: pulse height and width, step potential, surface area of the working electrode, and basic electrolyte composition are optimized. The obtained calibration graph is linear from 0.1 (17 μg L-1 to 2 μM (342 μg L-1 with correlation coefficient 0.999. For the Hg(AgFE with the surface area of 10.1 mm2 the limit of detection (LOD is 20 nM (3.4 μg L-1. The repeatability of the method at a concentration of the analyte of 0.5 μM (5.6 μg L−1, expressed as relative standard deviation (RSD is 2.1 % (n = 7. The proposed method was successfully applied and confirmed by studying recovery of metronidazole from spiked samples.

  15. Metal ion analysis in contaminated water samples using anodic stripping voltammetry and a nanocrystalline diamond thin-film electrode

    International Nuclear Information System (INIS)

    Sonthalia, Prerna; McGaw, Elizabeth; Show, Yoshiyuki; Swain, Greg M.

    2004-01-01

    Boron-doped nanocrystalline diamond thin-film electrodes were employed for the detection and quantification of Ag (I), Cu (II), Pb (II), Cd (II), and Zn (II) in several contaminated water samples using anodic stripping voltammetric (ASV). Diamond is an alternate electrode that possesses many of the same attributes as Hg and, therefore, appears to be a viable material for this electroanalytical measurement. The nanocrystalline form has been found to perform slightly better than the more conventional microcrystalline form of diamond in this application. Differential pulse voltammetry (DPASV) was used to detect these metal ions in lake water, well water, tap water, wastewater treatment sludge, and soil. The electrochemical results were compared with data from inductively coupled plasma mass spectrometric (ICP-MS) and or atomic absorption spectrometric (AAS) measurements of the same samples. Diamond is shown to function well in this electroanalytical application, providing a wide linear dynamic range, a low limit of quantitation, excellent response precision, and good response accuracy. For the analysis of Pb (II), bare diamond provided a response nearly identical to that obtained with a Hg-coated glassy carbon electrode

  16. Voltammetric determination of Zn(II in Zn-Fe alloy electroplating baths using square-wave voltammetry

    Directory of Open Access Journals (Sweden)

    Favaron Regiane

    2001-01-01

    Full Text Available A routine analytical method for zinc (II determination in Zn-Fe alloy galvanic baths was developed employing square-wave voltammetry with the static mercury drop electrode (SMDE as working electrode. Real alloy bath samples were analyzed by the standard addition method and recovery tests were undertaken. The supporting electrolytes used in the analyses were 1.0 mol L-1 NH3 / 0.2 mol L-1 NH4Cl or 0.1 mol L-1 citric acid (pH=3, presenting peak potentials for zinc (II, respectively, at -1.30 V and -0.99 V vs. Ag|AgCl (saturated KCl. The proposed voltammetric method showed a linear response range at 25 °C between 1.0 x 10-5 and 2.2 x 10-4 mol L-1 for zinc (II, in both electrolytes studied. The interference levels for some metals, such as Cu (II, Pb (II, Cr (III and Mn (II, which could prejudice Zn-Fe alloy deposition, were evaluated. These ions did not present significant degrees of interference in the zinc (II determination. The zinc (II recovery tests for the proposed method exhibited a good agreement with the reference method, showing relative errors lower than 3.0%.

  17. Substituent Inductive Effects on the Electrochemical Oxidation of Flavonoids Studied by Square Wave Voltammetry and Ab Initio Calculations.

    Science.gov (United States)

    Arroyo-Currás, Netzahualcóyotl; Rosas-García, Víctor M; Videa, Marcelo

    2016-10-27

    Flavonoids are natural products commonly found in the human diet that show antioxidant, anti-inflammatory and anti-hepatotoxic activities. These nutraceutical properties may relate to the electrochemical activity of flavonoids. To increase the understanding of structure-electrochemical activity relations and the inductive effects that OH substituents have on the redox potential of flavonoids, we carried out square-wave voltammetry experiments and ab initio calculations of eight flavonoids selected following a systematic variation in the number of hydroxyl substituents and their location on the flavan backbone: three flavonols, three anthocyanidins, one anthocyanin and the flavonoid backbone flavone. We compared the effect that the number of -OH groups in the ring B of flavan has on the oxidation potential of the flavonoids considered, finding linear correlations for both flavonols and anthocyanidins ( R 2 = 0.98 ). We analyzed the effects that position and number of -OH substituents have on electron density distributions via ab initio quantum chemical calculations. We present direct correlations between structural features and oxidation potentials that provide a deeper insight into the redox chemistry of these molecules.

  18. Solid-state voltammetry-based electrochemical immunosensor for Escherichia coli using graphene oxide-Ag nanoparticle composites as labels.

    Science.gov (United States)

    Jiang, Xiaochun; Chen, Kun; Wang, Jing; Shao, Kang; Fu, Tao; Shao, Feng; Lu, Donglian; Liang, Jiangong; Foda, M Frahat; Han, Heyou

    2013-06-21

    A new electrochemical immunosensor based on solid-state voltammetry was fabricated for the detection of Escherichia coli (E. coli) by using graphene oxide-Ag nanoparticle composites (P-GO-Ag) as labels. To construct the platform, Au nanoparticles (AuNPs) were first self-assembled on an Au electrode surface through cysteamine and served as an effective matrix for antibody (Ab) attachment. Under a sandwich-type immunoassay format, the analyte and the probe (P-GO-Ag-Ab) were successively captured onto the immunosensor. Finally, the bonded AgNPs were detected through a solid-state redox process in 0.2 M of KCl solution. Combining the advantages of the high-loading capability of graphene oxide with promoted electron-transfer rate of AuNPs, this immunosensor produced a 26.92-fold signal enhancement compared with the unamplified protocol. Under the optimal conditions, the immunosensor exhibited a wide linear dependence on the logarithm of the concentration of E. coli ranging from 50 to 1.0 × 10(6) cfu mL(-1) with a detection limit of 10 cfu mL(-1). Moreover, as a practical application, the proposed immunosensor was used to monitor E. coli in lake water with satisfactory results.

  19. Determination of mercury in ambient water samples by anodic stripping voltammetry on screen-printed gold electrodes.

    Science.gov (United States)

    Bernalte, E; Marín Sánchez, C; Pinilla Gil, E

    2011-03-09

    The applicability of commercial screen-printed gold electrodes (SPGEs) for the determination of Hg(II) in ambient water samples by square wave anodic stripping voltammetry has been demonstrated. Electrode conditioning procedures, chemical and instrumental variables have been optimized to develop a reliable method capable of measuring dissolved mercury in the low ng mL(-1) range (detection limit 1.1 ng mL(-1)), useful for pollution monitoring or screening purposes. The proposed method was tested with the NIST 1641d Mercury in Water Standard Reference Material (recoveries 90.0-110%) and the NCS ZC 76303 Mercury in Water Certified Reference Material (recoveries 82.5-90.6%). Waste water samples from industrial origin and fortified rain water samples were assayed for mercury by the proposed method and by a reference ICP-MS method, with good agreement. Screen printing technology thus opens a useful way for the construction of reliable electrochemical sensors for decentralized or even field Hg(II) testing. Copyright © 2011 Elsevier B.V. All rights reserved.

  20. Stripping voltammetry glassy carbon on the study of Cd and Pb heavy metals pollution using anadara antiquata linn bioindicator

    International Nuclear Information System (INIS)

    Iswani, G.S.; Hidayat, F.; Zulkarnaen, A.

    1996-01-01

    The presence of cadmium and lead in sea water and shell fish (anadara antiquata linn) bioindicator in Gresik waters by glassy carbon stripping voltammetry was studied at menu 2 parameters as follows: time and potential plating-1000V and 90 second, sweep rate: 375 mV/second, strip time 2 second, electrolyte: aquatrides, pH = 0.4 (for shell fish) and -1000 V and 120 second, 999 mV/se con, 2 second, chloracetic, pH = 5.0. It was found that the mean of Cd and Pb contents in sea water at pH = 7.0, salinity = 28-29 ppm, oxygen content = 7.1-8.1 and temperature = 27-30 o C which was monitoring at location 1.2 and location 3.4 were 0.01 and 0.17 ppm, 1.44 and 1.35 ppm respectively. Furthermore the mean of Cd and Pb contents in shell fish at location 1.2 and 3.4 (snail range and shell fish dry weight were reported) were 5.94 and 3.05 ppm, 0,03 and 0,03 ppm. The t-tes for Cd and Pb contents in sea waters and shell fish at location 1,2 compared with location 3.4 were significant and no significant. The accuracy of the method was tested with SRM coppepoda MA-A-1-A-a and W-4. (author)